Actual source code: matrix.c

  1: /*
  2:    This is where the abstract matrix operations are defined
  3:    Portions of this code are under:
  4:    Copyright (c) 2022 Advanced Micro Devices, Inc. All rights reserved.
  5: */

  7: #include <petsc/private/matimpl.h>
  8: #include <petsc/private/isimpl.h>
  9: #include <petsc/private/vecimpl.h>

 11: /* Logging support */
 12: PetscClassId MAT_CLASSID;
 13: PetscClassId MAT_COLORING_CLASSID;
 14: PetscClassId MAT_FDCOLORING_CLASSID;
 15: PetscClassId MAT_TRANSPOSECOLORING_CLASSID;

 17: PetscLogEvent MAT_Mult, MAT_MultAdd, MAT_MultTranspose;
 18: PetscLogEvent MAT_ADot, MAT_ANorm;
 19: PetscLogEvent MAT_MultTransposeAdd, MAT_Solve, MAT_Solves, MAT_SolveAdd, MAT_SolveTranspose, MAT_MatSolve, MAT_MatTrSolve;
 20: PetscLogEvent MAT_SolveTransposeAdd, MAT_SOR, MAT_ForwardSolve, MAT_BackwardSolve, MAT_LUFactor, MAT_LUFactorSymbolic;
 21: PetscLogEvent MAT_LUFactorNumeric, MAT_CholeskyFactor, MAT_CholeskyFactorSymbolic, MAT_CholeskyFactorNumeric, MAT_ILUFactor;
 22: PetscLogEvent MAT_ILUFactorSymbolic, MAT_ICCFactorSymbolic, MAT_Copy, MAT_Convert, MAT_Scale, MAT_AssemblyBegin;
 23: PetscLogEvent MAT_QRFactorNumeric, MAT_QRFactorSymbolic, MAT_QRFactor;
 24: PetscLogEvent MAT_AssemblyEnd, MAT_SetValues, MAT_GetValues, MAT_GetRow, MAT_GetRowIJ, MAT_CreateSubMats, MAT_GetOrdering, MAT_RedundantMat, MAT_GetSeqNonzeroStructure;
 25: PetscLogEvent MAT_IncreaseOverlap, MAT_Partitioning, MAT_PartitioningND, MAT_Coarsen, MAT_ZeroEntries, MAT_Load, MAT_View, MAT_AXPY, MAT_FDColoringCreate;
 26: PetscLogEvent MAT_FDColoringSetUp, MAT_FDColoringApply, MAT_Transpose, MAT_FDColoringFunction, MAT_CreateSubMat;
 27: PetscLogEvent MAT_TransposeColoringCreate;
 28: PetscLogEvent MAT_MatMult, MAT_MatMultSymbolic, MAT_MatMultNumeric;
 29: PetscLogEvent MAT_PtAP, MAT_PtAPSymbolic, MAT_PtAPNumeric, MAT_RARt, MAT_RARtSymbolic, MAT_RARtNumeric;
 30: PetscLogEvent MAT_MatTransposeMult, MAT_MatTransposeMultSymbolic, MAT_MatTransposeMultNumeric;
 31: PetscLogEvent MAT_TransposeMatMult, MAT_TransposeMatMultSymbolic, MAT_TransposeMatMultNumeric;
 32: PetscLogEvent MAT_MatMatMult, MAT_MatMatMultSymbolic, MAT_MatMatMultNumeric;
 33: PetscLogEvent MAT_MultHermitianTranspose, MAT_MultHermitianTransposeAdd;
 34: PetscLogEvent MAT_Getsymtransreduced, MAT_GetBrowsOfAcols;
 35: PetscLogEvent MAT_GetBrowsOfAocols, MAT_Getlocalmat, MAT_Getlocalmatcondensed, MAT_Seqstompi, MAT_Seqstompinum, MAT_Seqstompisym;
 36: PetscLogEvent MAT_GetMultiProcBlock;
 37: PetscLogEvent MAT_CUSPARSECopyToGPU, MAT_CUSPARSECopyFromGPU, MAT_CUSPARSEGenerateTranspose, MAT_CUSPARSESolveAnalysis;
 38: PetscLogEvent MAT_HIPSPARSECopyToGPU, MAT_HIPSPARSECopyFromGPU, MAT_HIPSPARSEGenerateTranspose, MAT_HIPSPARSESolveAnalysis;
 39: PetscLogEvent MAT_PreallCOO, MAT_SetVCOO;
 40: PetscLogEvent MAT_CreateGraph;
 41: PetscLogEvent MAT_SetValuesBatch;
 42: PetscLogEvent MAT_ViennaCLCopyToGPU;
 43: PetscLogEvent MAT_CUDACopyToGPU, MAT_HIPCopyToGPU;
 44: PetscLogEvent MAT_DenseCopyToGPU, MAT_DenseCopyFromGPU;
 45: PetscLogEvent MAT_Merge, MAT_Residual, MAT_SetRandom;
 46: PetscLogEvent MAT_FactorFactS, MAT_FactorInvS;
 47: PetscLogEvent MATCOLORING_Apply, MATCOLORING_Comm, MATCOLORING_Local, MATCOLORING_ISCreate, MATCOLORING_SetUp, MATCOLORING_Weights;
 48: PetscLogEvent MAT_H2Opus_Build, MAT_H2Opus_Compress, MAT_H2Opus_Orthog, MAT_H2Opus_LR;

 50: const char *const MatFactorTypes[] = {"NONE", "LU", "CHOLESKY", "ILU", "ICC", "ILUDT", "QR", "MatFactorType", "MAT_FACTOR_", NULL};

 52: /*@
 53:   MatSetRandom - Sets all components of a matrix to random numbers.

 55:   Logically Collective

 57:   Input Parameters:
 58: + x    - the matrix
 59: - rctx - the `PetscRandom` object, formed by `PetscRandomCreate()`, or `NULL` and
 60:           it will create one internally.

 62:   Example:
 63: .vb
 64:      PetscRandomCreate(PETSC_COMM_WORLD,&rctx);
 65:      MatSetRandom(x,rctx);
 66:      PetscRandomDestroy(rctx);
 67: .ve

 69:   Level: intermediate

 71:   Notes:
 72:   For sparse matrices that have been preallocated but not been assembled, it randomly selects appropriate locations,

 74:   for sparse matrices that already have nonzero locations, it fills the locations with random numbers.

 76:   It generates an error if used on unassembled sparse matrices that have not been preallocated.

 78: .seealso: [](ch_matrices), `Mat`, `PetscRandom`, `PetscRandomCreate()`, `MatZeroEntries()`, `MatSetValues()`, `PetscRandomDestroy()`
 79: @*/
 80: PetscErrorCode MatSetRandom(Mat x, PetscRandom rctx)
 81: {
 82:   PetscRandom randObj = NULL;

 84:   PetscFunctionBegin;
 88:   MatCheckPreallocated(x, 1);

 90:   if (!rctx) {
 91:     MPI_Comm comm;
 92:     PetscCall(PetscObjectGetComm((PetscObject)x, &comm));
 93:     PetscCall(PetscRandomCreate(comm, &randObj));
 94:     PetscCall(PetscRandomSetType(randObj, x->defaultrandtype));
 95:     PetscCall(PetscRandomSetFromOptions(randObj));
 96:     rctx = randObj;
 97:   }
 98:   PetscCall(PetscLogEventBegin(MAT_SetRandom, x, rctx, 0, 0));
 99:   PetscUseTypeMethod(x, setrandom, rctx);
100:   PetscCall(PetscLogEventEnd(MAT_SetRandom, x, rctx, 0, 0));

102:   PetscCall(MatAssemblyBegin(x, MAT_FINAL_ASSEMBLY));
103:   PetscCall(MatAssemblyEnd(x, MAT_FINAL_ASSEMBLY));
104:   PetscCall(PetscRandomDestroy(&randObj));
105:   PetscFunctionReturn(PETSC_SUCCESS);
106: }

108: /*@
109:   MatCopyHashToXAIJ - copy hash table entries into an XAIJ matrix type

111:   Logically Collective

113:   Input Parameter:
114: . A - A matrix in unassembled, hash table form

116:   Output Parameter:
117: . B - The XAIJ matrix. This can either be `A` or some matrix of equivalent size, e.g. obtained from `A` via `MatDuplicate()`

119:   Example:
120: .vb
121:      PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &B));
122:      PetscCall(MatCopyHashToXAIJ(A, B));
123: .ve

125:   Level: advanced

127:   Notes:
128:   If `B` is `A`, then the hash table data structure will be destroyed. `B` is assembled

130: .seealso: [](ch_matrices), `Mat`, `MAT_USE_HASH_TABLE`
131: @*/
132: PetscErrorCode MatCopyHashToXAIJ(Mat A, Mat B)
133: {
134:   PetscFunctionBegin;
136:   PetscUseTypeMethod(A, copyhashtoxaij, B);
137:   PetscFunctionReturn(PETSC_SUCCESS);
138: }

140: /*@
141:   MatFactorGetErrorZeroPivot - returns the pivot value that was determined to be zero and the row it occurred in

143:   Logically Collective

145:   Input Parameter:
146: . mat - the factored matrix

148:   Output Parameters:
149: + pivot - the pivot value computed
150: - row   - the row that the zero pivot occurred. This row value must be interpreted carefully due to row reorderings and which processes
151:          the share the matrix

153:   Level: advanced

155:   Notes:
156:   This routine does not work for factorizations done with external packages.

158:   This routine should only be called if `MatGetFactorError()` returns a value of `MAT_FACTOR_NUMERIC_ZEROPIVOT`

160:   This can also be called on non-factored matrices that come from, for example, matrices used in SOR.

162: .seealso: [](ch_matrices), `Mat`, `MatZeroEntries()`, `MatFactor()`, `MatGetFactor()`,
163: `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatFactorClearError()`,
164: `MAT_FACTOR_NUMERIC_ZEROPIVOT`
165: @*/
166: PetscErrorCode MatFactorGetErrorZeroPivot(Mat mat, PetscReal *pivot, PetscInt *row)
167: {
168:   PetscFunctionBegin;
170:   PetscAssertPointer(pivot, 2);
171:   PetscAssertPointer(row, 3);
172:   *pivot = mat->factorerror_zeropivot_value;
173:   *row   = mat->factorerror_zeropivot_row;
174:   PetscFunctionReturn(PETSC_SUCCESS);
175: }

177: /*@
178:   MatFactorGetError - gets the error code from a factorization

180:   Logically Collective

182:   Input Parameter:
183: . mat - the factored matrix

185:   Output Parameter:
186: . err - the error code

188:   Level: advanced

190:   Note:
191:   This can also be called on non-factored matrices that come from, for example, matrices used in SOR.

193: .seealso: [](ch_matrices), `Mat`, `MatZeroEntries()`, `MatFactor()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`,
194:           `MatFactorClearError()`, `MatFactorGetErrorZeroPivot()`, `MatFactorError`
195: @*/
196: PetscErrorCode MatFactorGetError(Mat mat, MatFactorError *err)
197: {
198:   PetscFunctionBegin;
200:   PetscAssertPointer(err, 2);
201:   *err = mat->factorerrortype;
202:   PetscFunctionReturn(PETSC_SUCCESS);
203: }

205: /*@
206:   MatFactorClearError - clears the error code in a factorization

208:   Logically Collective

210:   Input Parameter:
211: . mat - the factored matrix

213:   Level: developer

215:   Note:
216:   This can also be called on non-factored matrices that come from, for example, matrices used in SOR.

218: .seealso: [](ch_matrices), `Mat`, `MatZeroEntries()`, `MatFactor()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatFactorGetError()`, `MatFactorGetErrorZeroPivot()`,
219:           `MatGetErrorCode()`, `MatFactorError`
220: @*/
221: PetscErrorCode MatFactorClearError(Mat mat)
222: {
223:   PetscFunctionBegin;
225:   mat->factorerrortype             = MAT_FACTOR_NOERROR;
226:   mat->factorerror_zeropivot_value = 0.0;
227:   mat->factorerror_zeropivot_row   = 0;
228:   PetscFunctionReturn(PETSC_SUCCESS);
229: }

231: PetscErrorCode MatFindNonzeroRowsOrCols_Basic(Mat mat, PetscBool cols, PetscReal tol, IS *nonzero)
232: {
233:   Vec                r, l;
234:   const PetscScalar *al;
235:   PetscInt           i, nz, gnz, N, n, st;

237:   PetscFunctionBegin;
238:   PetscCall(MatCreateVecs(mat, &r, &l));
239:   if (!cols) { /* nonzero rows */
240:     PetscCall(MatGetOwnershipRange(mat, &st, NULL));
241:     PetscCall(MatGetSize(mat, &N, NULL));
242:     PetscCall(MatGetLocalSize(mat, &n, NULL));
243:     PetscCall(VecSet(l, 0.0));
244:     PetscCall(VecSetRandom(r, NULL));
245:     PetscCall(MatMult(mat, r, l));
246:     PetscCall(VecGetArrayRead(l, &al));
247:   } else { /* nonzero columns */
248:     PetscCall(MatGetOwnershipRangeColumn(mat, &st, NULL));
249:     PetscCall(MatGetSize(mat, NULL, &N));
250:     PetscCall(MatGetLocalSize(mat, NULL, &n));
251:     PetscCall(VecSet(r, 0.0));
252:     PetscCall(VecSetRandom(l, NULL));
253:     PetscCall(MatMultTranspose(mat, l, r));
254:     PetscCall(VecGetArrayRead(r, &al));
255:   }
256:   if (tol <= 0.0) {
257:     for (i = 0, nz = 0; i < n; i++)
258:       if (al[i] != 0.0) nz++;
259:   } else {
260:     for (i = 0, nz = 0; i < n; i++)
261:       if (PetscAbsScalar(al[i]) > tol) nz++;
262:   }
263:   PetscCallMPI(MPIU_Allreduce(&nz, &gnz, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)mat)));
264:   if (gnz != N) {
265:     PetscInt *nzr;
266:     PetscCall(PetscMalloc1(nz, &nzr));
267:     if (nz) {
268:       if (tol < 0) {
269:         for (i = 0, nz = 0; i < n; i++)
270:           if (al[i] != 0.0) nzr[nz++] = i + st;
271:       } else {
272:         for (i = 0, nz = 0; i < n; i++)
273:           if (PetscAbsScalar(al[i]) > tol) nzr[nz++] = i + st;
274:       }
275:     }
276:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)mat), nz, nzr, PETSC_OWN_POINTER, nonzero));
277:   } else *nonzero = NULL;
278:   if (!cols) { /* nonzero rows */
279:     PetscCall(VecRestoreArrayRead(l, &al));
280:   } else {
281:     PetscCall(VecRestoreArrayRead(r, &al));
282:   }
283:   PetscCall(VecDestroy(&l));
284:   PetscCall(VecDestroy(&r));
285:   PetscFunctionReturn(PETSC_SUCCESS);
286: }

288: /*@
289:   MatFindNonzeroRows - Locate all rows that are not completely zero in the matrix

291:   Input Parameter:
292: . mat - the matrix

294:   Output Parameter:
295: . keptrows - the rows that are not completely zero

297:   Level: intermediate

299:   Note:
300:   `keptrows` is set to `NULL` if all rows are nonzero.

302:   Developer Note:
303:   If `keptrows` is not `NULL`, it must be sorted.

305: .seealso: [](ch_matrices), `Mat`, `MatFindZeroRows()`
306:  @*/
307: PetscErrorCode MatFindNonzeroRows(Mat mat, IS *keptrows)
308: {
309:   PetscFunctionBegin;
312:   PetscAssertPointer(keptrows, 2);
313:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
314:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
315:   if (mat->ops->findnonzerorows) PetscUseTypeMethod(mat, findnonzerorows, keptrows);
316:   else PetscCall(MatFindNonzeroRowsOrCols_Basic(mat, PETSC_FALSE, 0.0, keptrows));
317:   if (keptrows && *keptrows) PetscCall(ISSetInfo(*keptrows, IS_SORTED, IS_GLOBAL, PETSC_FALSE, PETSC_TRUE));
318:   PetscFunctionReturn(PETSC_SUCCESS);
319: }

321: /*@
322:   MatFindZeroRows - Locate all rows that are completely zero in the matrix

324:   Input Parameter:
325: . mat - the matrix

327:   Output Parameter:
328: . zerorows - the rows that are completely zero

330:   Level: intermediate

332:   Note:
333:   `zerorows` is set to `NULL` if no rows are zero.

335: .seealso: [](ch_matrices), `Mat`, `MatFindNonzeroRows()`
336:  @*/
337: PetscErrorCode MatFindZeroRows(Mat mat, IS *zerorows)
338: {
339:   IS       keptrows;
340:   PetscInt m, n;

342:   PetscFunctionBegin;
345:   PetscAssertPointer(zerorows, 2);
346:   PetscCall(MatFindNonzeroRows(mat, &keptrows));
347:   /* MatFindNonzeroRows sets keptrows to NULL if there are no zero rows.
348:      In keeping with this convention, we set zerorows to NULL if there are no zero
349:      rows. */
350:   if (keptrows == NULL) {
351:     *zerorows = NULL;
352:   } else {
353:     PetscCall(MatGetOwnershipRange(mat, &m, &n));
354:     PetscCall(ISComplement(keptrows, m, n, zerorows));
355:     PetscCall(ISDestroy(&keptrows));
356:   }
357:   PetscFunctionReturn(PETSC_SUCCESS);
358: }

360: /*@
361:   MatGetDiagonalBlock - Returns the part of the matrix associated with the on-process coupling

363:   Not Collective

365:   Input Parameter:
366: . A - the matrix

368:   Output Parameter:
369: . a - the diagonal part (which is a SEQUENTIAL matrix)

371:   Level: advanced

373:   Notes:
374:   See `MatCreateAIJ()` for more information on the "diagonal part" of the matrix.

376:   Use caution, as the reference count on the returned matrix is not incremented and it is used as part of `A`'s normal operation.

378: .seealso: [](ch_matrices), `Mat`, `MatCreateAIJ()`, `MATAIJ`, `MATBAIJ`, `MATSBAIJ`
379: @*/
380: PetscErrorCode MatGetDiagonalBlock(Mat A, Mat *a)
381: {
382:   PetscFunctionBegin;
385:   PetscAssertPointer(a, 2);
386:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
387:   if (A->ops->getdiagonalblock) PetscUseTypeMethod(A, getdiagonalblock, a);
388:   else {
389:     PetscMPIInt size;

391:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)A), &size));
392:     PetscCheck(size == 1, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Not for parallel matrix type %s", ((PetscObject)A)->type_name);
393:     *a = A;
394:   }
395:   PetscFunctionReturn(PETSC_SUCCESS);
396: }

398: /*@
399:   MatGetTrace - Gets the trace of a matrix. The sum of the diagonal entries.

401:   Collective

403:   Input Parameter:
404: . mat - the matrix

406:   Output Parameter:
407: . trace - the sum of the diagonal entries

409:   Level: advanced

411: .seealso: [](ch_matrices), `Mat`
412: @*/
413: PetscErrorCode MatGetTrace(Mat mat, PetscScalar *trace)
414: {
415:   Vec diag;

417:   PetscFunctionBegin;
419:   PetscAssertPointer(trace, 2);
420:   PetscCall(MatCreateVecs(mat, &diag, NULL));
421:   PetscCall(MatGetDiagonal(mat, diag));
422:   PetscCall(VecSum(diag, trace));
423:   PetscCall(VecDestroy(&diag));
424:   PetscFunctionReturn(PETSC_SUCCESS);
425: }

427: /*@
428:   MatRealPart - Zeros out the imaginary part of the matrix

430:   Logically Collective

432:   Input Parameter:
433: . mat - the matrix

435:   Level: advanced

437: .seealso: [](ch_matrices), `Mat`, `MatImaginaryPart()`
438: @*/
439: PetscErrorCode MatRealPart(Mat mat)
440: {
441:   PetscFunctionBegin;
444:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
445:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
446:   MatCheckPreallocated(mat, 1);
447:   PetscUseTypeMethod(mat, realpart);
448:   PetscFunctionReturn(PETSC_SUCCESS);
449: }

451: /*@C
452:   MatGetGhosts - Get the global indices of all ghost nodes defined by the sparse matrix

454:   Collective

456:   Input Parameter:
457: . mat - the matrix

459:   Output Parameters:
460: + nghosts - number of ghosts (for `MATBAIJ` and `MATSBAIJ` matrices there is one ghost for each matrix block)
461: - ghosts  - the global indices of the ghost points

463:   Level: advanced

465:   Note:
466:   `nghosts` and `ghosts` are suitable to pass into `VecCreateGhost()` or `VecCreateGhostBlock()`

468: .seealso: [](ch_matrices), `Mat`, `VecCreateGhost()`, `VecCreateGhostBlock()`
469: @*/
470: PetscErrorCode MatGetGhosts(Mat mat, PetscInt *nghosts, const PetscInt *ghosts[])
471: {
472:   PetscFunctionBegin;
475:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
476:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
477:   if (mat->ops->getghosts) PetscUseTypeMethod(mat, getghosts, nghosts, ghosts);
478:   else {
479:     if (nghosts) *nghosts = 0;
480:     if (ghosts) *ghosts = NULL;
481:   }
482:   PetscFunctionReturn(PETSC_SUCCESS);
483: }

485: /*@
486:   MatImaginaryPart - Moves the imaginary part of the matrix to the real part and zeros the imaginary part

488:   Logically Collective

490:   Input Parameter:
491: . mat - the matrix

493:   Level: advanced

495: .seealso: [](ch_matrices), `Mat`, `MatRealPart()`
496: @*/
497: PetscErrorCode MatImaginaryPart(Mat mat)
498: {
499:   PetscFunctionBegin;
502:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
503:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
504:   MatCheckPreallocated(mat, 1);
505:   PetscUseTypeMethod(mat, imaginarypart);
506:   PetscFunctionReturn(PETSC_SUCCESS);
507: }

509: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
510: /*@C
511:   MatGetRow - Gets a row of a matrix.  You MUST call `MatRestoreRow()`
512:   for each row that you get to ensure that your application does
513:   not bleed memory.

515:   Not Collective

517:   Input Parameters:
518: + mat - the matrix
519: - row - the row to get

521:   Output Parameters:
522: + ncols - if not `NULL`, the number of nonzeros in `row`
523: . cols  - if not `NULL`, the column numbers
524: - vals  - if not `NULL`, the numerical values

526:   Level: advanced

528:   Notes:
529:   This routine is provided for people who need to have direct access
530:   to the structure of a matrix.  We hope that we provide enough
531:   high-level matrix routines that few users will need it.

533:   `MatGetRow()` always returns 0-based column indices, regardless of
534:   whether the internal representation is 0-based (default) or 1-based.

536:   For better efficiency, set `cols` and/or `vals` to `NULL` if you do
537:   not wish to extract these quantities.

539:   The user can only examine the values extracted with `MatGetRow()`;
540:   the values CANNOT be altered.  To change the matrix entries, one
541:   must use `MatSetValues()`.

543:   You can only have one call to `MatGetRow()` outstanding for a particular
544:   matrix at a time, per processor. `MatGetRow()` can only obtain rows
545:   associated with the given processor, it cannot get rows from the
546:   other processors; for that we suggest using `MatCreateSubMatrices()`, then
547:   `MatGetRow()` on the submatrix. The row index passed to `MatGetRow()`
548:   is in the global number of rows.

550:   Use `MatGetRowIJ()` and `MatRestoreRowIJ()` to access all the local indices of the sparse matrix.

552:   Use `MatSeqAIJGetArray()` and similar functions to access the numerical values for certain matrix types directly.

554:   Fortran Note:
555: .vb
556:   PetscInt, pointer :: cols(:)
557:   PetscScalar, pointer :: vals(:)
558: .ve

560: .seealso: [](ch_matrices), `Mat`, `MatRestoreRow()`, `MatSetValues()`, `MatGetValues()`, `MatCreateSubMatrices()`, `MatGetDiagonal()`, `MatGetRowIJ()`, `MatRestoreRowIJ()`
561: @*/
562: PetscErrorCode MatGetRow(Mat mat, PetscInt row, PetscInt *ncols, const PetscInt *cols[], const PetscScalar *vals[])
563: {
564:   PetscInt incols;

566:   PetscFunctionBegin;
569:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
570:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
571:   MatCheckPreallocated(mat, 1);
572:   PetscCheck(row >= mat->rmap->rstart && row < mat->rmap->rend, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Only for local rows, %" PetscInt_FMT " not in [%" PetscInt_FMT ",%" PetscInt_FMT ")", row, mat->rmap->rstart, mat->rmap->rend);
573:   PetscCall(PetscLogEventBegin(MAT_GetRow, mat, 0, 0, 0));
574:   PetscUseTypeMethod(mat, getrow, row, &incols, (PetscInt **)cols, (PetscScalar **)vals);
575:   if (ncols) *ncols = incols;
576:   PetscCall(PetscLogEventEnd(MAT_GetRow, mat, 0, 0, 0));
577:   PetscFunctionReturn(PETSC_SUCCESS);
578: }

580: /*@
581:   MatConjugate - replaces the matrix values with their complex conjugates

583:   Logically Collective

585:   Input Parameter:
586: . mat - the matrix

588:   Level: advanced

590: .seealso: [](ch_matrices), `Mat`, `MatRealPart()`, `MatImaginaryPart()`, `VecConjugate()`, `MatTranspose()`
591: @*/
592: PetscErrorCode MatConjugate(Mat mat)
593: {
594:   PetscFunctionBegin;
596:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
597:   if (PetscDefined(USE_COMPLEX) && !(mat->symmetric == PETSC_BOOL3_TRUE && mat->hermitian == PETSC_BOOL3_TRUE)) {
598:     PetscUseTypeMethod(mat, conjugate);
599:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
600:   }
601:   PetscFunctionReturn(PETSC_SUCCESS);
602: }

604: /*@C
605:   MatRestoreRow - Frees any temporary space allocated by `MatGetRow()`.

607:   Not Collective

609:   Input Parameters:
610: + mat   - the matrix
611: . row   - the row to get
612: . ncols - the number of nonzeros
613: . cols  - the columns of the nonzeros
614: - vals  - if nonzero the column values

616:   Level: advanced

618:   Notes:
619:   This routine should be called after you have finished examining the entries.

621:   This routine zeros out `ncols`, `cols`, and `vals`. This is to prevent accidental
622:   us of the array after it has been restored. If you pass `NULL`, it will
623:   not zero the pointers.  Use of `cols` or `vals` after `MatRestoreRow()` is invalid.

625:   Fortran Note:
626: .vb
627:   PetscInt, pointer :: cols(:)
628:   PetscScalar, pointer :: vals(:)
629: .ve

631: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`
632: @*/
633: PetscErrorCode MatRestoreRow(Mat mat, PetscInt row, PetscInt *ncols, const PetscInt *cols[], const PetscScalar *vals[])
634: {
635:   PetscFunctionBegin;
637:   if (ncols) PetscAssertPointer(ncols, 3);
638:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
639:   PetscTryTypeMethod(mat, restorerow, row, ncols, (PetscInt **)cols, (PetscScalar **)vals);
640:   if (ncols) *ncols = 0;
641:   if (cols) *cols = NULL;
642:   if (vals) *vals = NULL;
643:   PetscFunctionReturn(PETSC_SUCCESS);
644: }

646: /*@
647:   MatGetRowUpperTriangular - Sets a flag to enable calls to `MatGetRow()` for matrix in `MATSBAIJ` format.
648:   You should call `MatRestoreRowUpperTriangular()` after calling` MatGetRow()` and `MatRestoreRow()` to disable the flag.

650:   Not Collective

652:   Input Parameter:
653: . mat - the matrix

655:   Level: advanced

657:   Note:
658:   The flag is to ensure that users are aware that `MatGetRow()` only provides the upper triangular part of the row for the matrices in `MATSBAIJ` format.

660: .seealso: [](ch_matrices), `Mat`, `MATSBAIJ`, `MatRestoreRowUpperTriangular()`
661: @*/
662: PetscErrorCode MatGetRowUpperTriangular(Mat mat)
663: {
664:   PetscFunctionBegin;
667:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
668:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
669:   MatCheckPreallocated(mat, 1);
670:   PetscTryTypeMethod(mat, getrowuppertriangular);
671:   PetscFunctionReturn(PETSC_SUCCESS);
672: }

674: /*@
675:   MatRestoreRowUpperTriangular - Disable calls to `MatGetRow()` for matrix in `MATSBAIJ` format.

677:   Not Collective

679:   Input Parameter:
680: . mat - the matrix

682:   Level: advanced

684:   Note:
685:   This routine should be called after you have finished calls to `MatGetRow()` and `MatRestoreRow()`.

687: .seealso: [](ch_matrices), `Mat`, `MATSBAIJ`, `MatGetRowUpperTriangular()`
688: @*/
689: PetscErrorCode MatRestoreRowUpperTriangular(Mat mat)
690: {
691:   PetscFunctionBegin;
694:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
695:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
696:   MatCheckPreallocated(mat, 1);
697:   PetscTryTypeMethod(mat, restorerowuppertriangular);
698:   PetscFunctionReturn(PETSC_SUCCESS);
699: }

701: /*@
702:   MatSetOptionsPrefix - Sets the prefix used for searching for all
703:   `Mat` options in the database.

705:   Logically Collective

707:   Input Parameters:
708: + A      - the matrix
709: - prefix - the prefix to prepend to all option names

711:   Level: advanced

713:   Notes:
714:   A hyphen (-) must NOT be given at the beginning of the prefix name.
715:   The first character of all runtime options is AUTOMATICALLY the hyphen.

717:   This is NOT used for options for the factorization of the matrix. Normally the
718:   prefix is automatically passed in from the PC calling the factorization. To set
719:   it directly use  `MatSetOptionsPrefixFactor()`

721: .seealso: [](ch_matrices), `Mat`, `MatSetFromOptions()`, `MatSetOptionsPrefixFactor()`
722: @*/
723: PetscErrorCode MatSetOptionsPrefix(Mat A, const char prefix[])
724: {
725:   PetscFunctionBegin;
727:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)A, prefix));
728:   PetscTryMethod(A, "MatSetOptionsPrefix_C", (Mat, const char[]), (A, prefix));
729:   PetscFunctionReturn(PETSC_SUCCESS);
730: }

732: /*@
733:   MatSetOptionsPrefixFactor - Sets the prefix used for searching for all matrix factor options in the database for
734:   for matrices created with `MatGetFactor()`

736:   Logically Collective

738:   Input Parameters:
739: + A      - the matrix
740: - prefix - the prefix to prepend to all option names for the factored matrix

742:   Level: developer

744:   Notes:
745:   A hyphen (-) must NOT be given at the beginning of the prefix name.
746:   The first character of all runtime options is AUTOMATICALLY the hyphen.

748:   Normally the prefix is automatically passed in from the `PC` calling the factorization. To set
749:   it directly when not using `KSP`/`PC` use  `MatSetOptionsPrefixFactor()`

751: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSetFromOptions()`, `MatSetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`
752: @*/
753: PetscErrorCode MatSetOptionsPrefixFactor(Mat A, const char prefix[])
754: {
755:   PetscFunctionBegin;
757:   if (prefix) {
758:     PetscAssertPointer(prefix, 2);
759:     PetscCheck(prefix[0] != '-', PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Options prefix should not begin with a hyphen");
760:     if (prefix != A->factorprefix) {
761:       PetscCall(PetscFree(A->factorprefix));
762:       PetscCall(PetscStrallocpy(prefix, &A->factorprefix));
763:     }
764:   } else PetscCall(PetscFree(A->factorprefix));
765:   PetscFunctionReturn(PETSC_SUCCESS);
766: }

768: /*@
769:   MatAppendOptionsPrefixFactor - Appends to the prefix used for searching for all matrix factor options in the database for
770:   for matrices created with `MatGetFactor()`

772:   Logically Collective

774:   Input Parameters:
775: + A      - the matrix
776: - prefix - the prefix to prepend to all option names for the factored matrix

778:   Level: developer

780:   Notes:
781:   A hyphen (-) must NOT be given at the beginning of the prefix name.
782:   The first character of all runtime options is AUTOMATICALLY the hyphen.

784:   Normally the prefix is automatically passed in from the `PC` calling the factorization. To set
785:   it directly when not using `KSP`/`PC` use  `MatAppendOptionsPrefixFactor()`

787: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `PetscOptionsCreate()`, `PetscOptionsDestroy()`, `PetscObjectSetOptionsPrefix()`, `PetscObjectPrependOptionsPrefix()`,
788:           `PetscObjectGetOptionsPrefix()`, `TSAppendOptionsPrefix()`, `SNESAppendOptionsPrefix()`, `KSPAppendOptionsPrefix()`, `MatSetOptionsPrefixFactor()`,
789:           `MatSetOptionsPrefix()`
790: @*/
791: PetscErrorCode MatAppendOptionsPrefixFactor(Mat A, const char prefix[])
792: {
793:   size_t len1, len2, new_len;

795:   PetscFunctionBegin;
797:   if (!prefix) PetscFunctionReturn(PETSC_SUCCESS);
798:   if (!A->factorprefix) {
799:     PetscCall(MatSetOptionsPrefixFactor(A, prefix));
800:     PetscFunctionReturn(PETSC_SUCCESS);
801:   }
802:   PetscCheck(prefix[0] != '-', PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Options prefix should not begin with a hyphen");

804:   PetscCall(PetscStrlen(A->factorprefix, &len1));
805:   PetscCall(PetscStrlen(prefix, &len2));
806:   new_len = len1 + len2 + 1;
807:   PetscCall(PetscRealloc(new_len * sizeof(*A->factorprefix), &A->factorprefix));
808:   PetscCall(PetscStrncpy(A->factorprefix + len1, prefix, len2 + 1));
809:   PetscFunctionReturn(PETSC_SUCCESS);
810: }

812: /*@
813:   MatAppendOptionsPrefix - Appends to the prefix used for searching for all
814:   matrix options in the database.

816:   Logically Collective

818:   Input Parameters:
819: + A      - the matrix
820: - prefix - the prefix to prepend to all option names

822:   Level: advanced

824:   Note:
825:   A hyphen (-) must NOT be given at the beginning of the prefix name.
826:   The first character of all runtime options is AUTOMATICALLY the hyphen.

828: .seealso: [](ch_matrices), `Mat`, `MatGetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`, `MatSetOptionsPrefix()`
829: @*/
830: PetscErrorCode MatAppendOptionsPrefix(Mat A, const char prefix[])
831: {
832:   PetscFunctionBegin;
834:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)A, prefix));
835:   PetscTryMethod(A, "MatAppendOptionsPrefix_C", (Mat, const char[]), (A, prefix));
836:   PetscFunctionReturn(PETSC_SUCCESS);
837: }

839: /*@
840:   MatGetOptionsPrefix - Gets the prefix used for searching for all
841:   matrix options in the database.

843:   Not Collective

845:   Input Parameter:
846: . A - the matrix

848:   Output Parameter:
849: . prefix - pointer to the prefix string used

851:   Level: advanced

853: .seealso: [](ch_matrices), `Mat`, `MatAppendOptionsPrefix()`, `MatSetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`, `MatSetOptionsPrefixFactor()`
854: @*/
855: PetscErrorCode MatGetOptionsPrefix(Mat A, const char *prefix[])
856: {
857:   PetscFunctionBegin;
859:   PetscAssertPointer(prefix, 2);
860:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)A, prefix));
861:   PetscFunctionReturn(PETSC_SUCCESS);
862: }

864: /*@
865:   MatGetState - Gets the state of a `Mat`. Same value as returned by `PetscObjectStateGet()`

867:   Not Collective

869:   Input Parameter:
870: . A - the matrix

872:   Output Parameter:
873: . state - the object state

875:   Level: advanced

877:   Note:
878:   Object state is an integer which gets increased every time
879:   the object is changed. By saving and later querying the object state
880:   one can determine whether information about the object is still current.

882:   See `MatGetNonzeroState()` to determine if the nonzero structure of the matrix has changed.

884: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PetscObjectStateGet()`, `MatGetNonzeroState()`
885: @*/
886: PetscErrorCode MatGetState(Mat A, PetscObjectState *state)
887: {
888:   PetscFunctionBegin;
890:   PetscAssertPointer(state, 2);
891:   PetscCall(PetscObjectStateGet((PetscObject)A, state));
892:   PetscFunctionReturn(PETSC_SUCCESS);
893: }

895: /*@
896:   MatResetPreallocation - Reset matrix to use the original preallocation values provided by the user, for example with `MatXAIJSetPreallocation()`

898:   Collective

900:   Input Parameter:
901: . A - the matrix

903:   Level: beginner

905:   Notes:
906:   After calling `MatAssemblyBegin()` and `MatAssemblyEnd()` with `MAT_FINAL_ASSEMBLY` the matrix data structures represent the nonzeros assigned to the
907:   matrix. If that space is less than the preallocated space that extra preallocated space is no longer available to take on new values. `MatResetPreallocation()`
908:   makes all of the preallocation space available

910:   Current values in the matrix are lost in this call

912:   Currently only supported for  `MATAIJ` matrices.

914: .seealso: [](ch_matrices), `Mat`, `MatSeqAIJSetPreallocation()`, `MatMPIAIJSetPreallocation()`, `MatXAIJSetPreallocation()`
915: @*/
916: PetscErrorCode MatResetPreallocation(Mat A)
917: {
918:   PetscFunctionBegin;
921:   PetscUseMethod(A, "MatResetPreallocation_C", (Mat), (A));
922:   PetscFunctionReturn(PETSC_SUCCESS);
923: }

925: /*@
926:   MatResetHash - Reset the matrix so that it will use a hash table for the next round of `MatSetValues()` and `MatAssemblyBegin()`/`MatAssemblyEnd()`.

928:   Collective

930:   Input Parameter:
931: . A - the matrix

933:   Level: intermediate

935:   Notes:
936:   The matrix will again delete the hash table data structures after following calls to `MatAssemblyBegin()`/`MatAssemblyEnd()` with `MAT_FINAL_ASSEMBLY`.

938:   Currently only supported for `MATAIJ` matrices.

940: .seealso: [](ch_matrices), `Mat`, `MatResetPreallocation()`
941: @*/
942: PetscErrorCode MatResetHash(Mat A)
943: {
944:   PetscFunctionBegin;
947:   PetscCheck(A->insertmode == NOT_SET_VALUES, PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot reset to hash state after setting some values but not yet calling MatAssemblyBegin()/MatAssemblyEnd()");
948:   if (A->num_ass == 0) PetscFunctionReturn(PETSC_SUCCESS);
949:   PetscUseMethod(A, "MatResetHash_C", (Mat), (A));
950:   /* These flags are used to determine whether certain setups occur */
951:   A->was_assembled = PETSC_FALSE;
952:   A->assembled     = PETSC_FALSE;
953:   /* Log that the state of this object has changed; this will help guarantee that preconditioners get re-setup */
954:   PetscCall(PetscObjectStateIncrease((PetscObject)A));
955:   PetscFunctionReturn(PETSC_SUCCESS);
956: }

958: /*@
959:   MatSetUp - Sets up the internal matrix data structures for later use by the matrix

961:   Collective

963:   Input Parameter:
964: . A - the matrix

966:   Level: advanced

968:   Notes:
969:   If the user has not set preallocation for this matrix then an efficient algorithm will be used for the first round of
970:   setting values in the matrix.

972:   This routine is called internally by other `Mat` functions when needed so rarely needs to be called by users

974: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatCreate()`, `MatDestroy()`, `MatXAIJSetPreallocation()`
975: @*/
976: PetscErrorCode MatSetUp(Mat A)
977: {
978:   PetscFunctionBegin;
980:   if (!((PetscObject)A)->type_name) {
981:     PetscMPIInt size;

983:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)A), &size));
984:     PetscCall(MatSetType(A, size == 1 ? MATSEQAIJ : MATMPIAIJ));
985:   }
986:   if (!A->preallocated) PetscTryTypeMethod(A, setup);
987:   PetscCall(PetscLayoutSetUp(A->rmap));
988:   PetscCall(PetscLayoutSetUp(A->cmap));
989:   A->preallocated = PETSC_TRUE;
990:   PetscFunctionReturn(PETSC_SUCCESS);
991: }

993: #if defined(PETSC_HAVE_SAWS)
994: #include <petscviewersaws.h>
995: #endif

997: /*
998:    If threadsafety is on extraneous matrices may be printed

1000:    This flag cannot be stored in the matrix because the original matrix in MatView() may assemble a new matrix which is passed into MatViewFromOptions()
1001: */
1002: #if !defined(PETSC_HAVE_THREADSAFETY)
1003: static PetscInt insidematview = 0;
1004: #endif

1006: /*@
1007:   MatViewFromOptions - View properties of the matrix based on options set in the options database

1009:   Collective

1011:   Input Parameters:
1012: + A    - the matrix
1013: . obj  - optional additional object that provides the options prefix to use
1014: - name - command line option

1016:   Options Database Key:
1017: . -mat_view [viewertype]:... - the viewer and its options

1019:   Level: intermediate

1021:   Note:
1022: .vb
1023:     If no value is provided ascii:stdout is used
1024:        ascii[:[filename][:[format][:append]]]    defaults to stdout - format can be one of ascii_info, ascii_info_detail, or ascii_matlab,
1025:                                                   for example ascii::ascii_info prints just the information about the object not all details
1026:                                                   unless :append is given filename opens in write mode, overwriting what was already there
1027:        binary[:[filename][:[format][:append]]]   defaults to the file binaryoutput
1028:        draw[:drawtype[:filename]]                for example, draw:tikz, draw:tikz:figure.tex  or draw:x
1029:        socket[:port]                             defaults to the standard output port
1030:        saws[:communicatorname]                    publishes object to the Scientific Application Webserver (SAWs)
1031: .ve

1033: .seealso: [](ch_matrices), `Mat`, `MatView()`, `PetscObjectViewFromOptions()`, `MatCreate()`
1034: @*/
1035: PetscErrorCode MatViewFromOptions(Mat A, PetscObject obj, const char name[])
1036: {
1037:   PetscFunctionBegin;
1039: #if !defined(PETSC_HAVE_THREADSAFETY)
1040:   if (insidematview) PetscFunctionReturn(PETSC_SUCCESS);
1041: #endif
1042:   PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
1043:   PetscFunctionReturn(PETSC_SUCCESS);
1044: }

1046: /*@
1047:   MatView - display information about a matrix in a variety ways

1049:   Collective on viewer

1051:   Input Parameters:
1052: + mat    - the matrix
1053: - viewer - visualization context

1055:   Options Database Keys:
1056: + -mat_view ::ascii_info         - Prints info on matrix at conclusion of `MatAssemblyEnd()`
1057: . -mat_view ::ascii_info_detail  - Prints more detailed info
1058: . -mat_view                      - Prints matrix in ASCII format
1059: . -mat_view ::ascii_matlab       - Prints matrix in MATLAB format
1060: . -mat_view draw                 - PetscDraws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
1061: . -display name                  - Sets display name (default is host)
1062: . -draw_pause sec                - Sets number of seconds to pause after display
1063: . -mat_view socket               - Sends matrix to socket, can be accessed from MATLAB (see Users-Manual: ch_matlab for details)
1064: . -viewer_socket_machine machine - -
1065: . -viewer_socket_port port       - -
1066: . -mat_view binary               - save matrix to file in binary format
1067: - -viewer_binary_filename name   - -

1069:   Level: beginner

1071:   Notes:
1072:   The available visualization contexts include
1073: +    `PETSC_VIEWER_STDOUT_SELF`   - for sequential matrices
1074: .    `PETSC_VIEWER_STDOUT_WORLD`  - for parallel matrices created on `PETSC_COMM_WORLD`
1075: .    `PETSC_VIEWER_STDOUT_`(comm) - for matrices created on MPI communicator comm
1076: -     `PETSC_VIEWER_DRAW_WORLD`   - graphical display of nonzero structure

1078:   The user can open alternative visualization contexts with
1079: +    `PetscViewerASCIIOpen()`  - Outputs matrix to a specified file
1080: .    `PetscViewerBinaryOpen()` - Outputs matrix in binary to a  specified file; corresponding input uses `MatLoad()`
1081: .    `PetscViewerDrawOpen()`   - Outputs nonzero matrix nonzero structure to an X window display
1082: -    `PetscViewerSocketOpen()` - Outputs matrix to Socket viewer, `PETSCVIEWERSOCKET`. Only the `MATSEQDENSE` and `MATAIJ` types support this viewer.

1084:   The user can call `PetscViewerPushFormat()` to specify the output
1085:   format of ASCII printed objects (when using `PETSC_VIEWER_STDOUT_SELF`,
1086:   `PETSC_VIEWER_STDOUT_WORLD` and `PetscViewerASCIIOpen()`).  Available formats include
1087: +    `PETSC_VIEWER_DEFAULT`           - default, prints matrix contents
1088: .    `PETSC_VIEWER_ASCII_MATLAB`      - prints matrix contents in MATLAB format
1089: .    `PETSC_VIEWER_ASCII_DENSE`       - prints entire matrix including zeros
1090: .    `PETSC_VIEWER_ASCII_COMMON`      - prints matrix contents, using a sparse  format common among all matrix types
1091: .    `PETSC_VIEWER_ASCII_IMPL`        - prints matrix contents, using an implementation-specific format (which is in many cases the same as the default)
1092: .    `PETSC_VIEWER_ASCII_INFO`        - prints basic information about the matrix size and structure (not the matrix entries)
1093: -    `PETSC_VIEWER_ASCII_INFO_DETAIL` - prints more detailed information about the matrix nonzero structure (still not vector or matrix entries)

1095:   The ASCII viewers are only recommended for small matrices on at most a moderate number of processes,
1096:   the program will seemingly hang and take hours for larger matrices, for larger matrices one should use the binary format.

1098:   In the debugger you can do "call MatView(mat,0)" to display the matrix. (The same holds for any PETSc object viewer).

1100:   See the manual page for `MatLoad()` for the exact format of the binary file when the binary
1101:   viewer is used.

1103:   See share/petsc/matlab/PetscBinaryRead.m for a MATLAB code that can read in the binary file when the binary
1104:   viewer is used and lib/petsc/bin/PetscBinaryIO.py for loading them into Python.

1106:   One can use '-mat_view draw -draw_pause -1' to pause the graphical display of matrix nonzero structure,
1107:   and then use the following mouse functions.
1108: .vb
1109:   left mouse: zoom in
1110:   middle mouse: zoom out
1111:   right mouse: continue with the simulation
1112: .ve

1114: .seealso: [](ch_matrices), `Mat`, `PetscViewerPushFormat()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewer`,
1115:           `PetscViewerSocketOpen()`, `PetscViewerBinaryOpen()`, `MatLoad()`, `MatViewFromOptions()`
1116: @*/
1117: PetscErrorCode MatView(Mat mat, PetscViewer viewer)
1118: {
1119:   PetscInt          rows, cols, rbs, cbs;
1120:   PetscBool         isascii, isstring, issaws;
1121:   PetscViewerFormat format;
1122:   PetscMPIInt       size;

1124:   PetscFunctionBegin;
1127:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)mat), &viewer));

1130:   PetscCall(PetscViewerGetFormat(viewer, &format));
1131:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)viewer), &size));
1132:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);

1134: #if !defined(PETSC_HAVE_THREADSAFETY)
1135:   insidematview++;
1136: #endif
1137:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
1138:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
1139:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
1140:   PetscCheck((isascii && (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL)) || !mat->factortype, PetscObjectComm((PetscObject)viewer), PETSC_ERR_ARG_WRONGSTATE, "No viewers for factored matrix except ASCII, info, or info_detail");

1142:   PetscCall(PetscLogEventBegin(MAT_View, mat, viewer, 0, 0));
1143:   if (isascii) {
1144:     if (!mat->preallocated) {
1145:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been preallocated yet\n"));
1146: #if !defined(PETSC_HAVE_THREADSAFETY)
1147:       insidematview--;
1148: #endif
1149:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1150:       PetscFunctionReturn(PETSC_SUCCESS);
1151:     }
1152:     if (!mat->assembled) {
1153:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been assembled yet\n"));
1154: #if !defined(PETSC_HAVE_THREADSAFETY)
1155:       insidematview--;
1156: #endif
1157:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1158:       PetscFunctionReturn(PETSC_SUCCESS);
1159:     }
1160:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)mat, viewer));
1161:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1162:       MatNullSpace nullsp, transnullsp;

1164:       PetscCall(PetscViewerASCIIPushTab(viewer));
1165:       PetscCall(MatGetSize(mat, &rows, &cols));
1166:       PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
1167:       if (rbs != 1 || cbs != 1) {
1168:         if (rbs != cbs) PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT ", rbs=%" PetscInt_FMT ", cbs=%" PetscInt_FMT "%s\n", rows, cols, rbs, cbs, mat->bsizes ? " variable blocks set" : ""));
1169:         else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT ", bs=%" PetscInt_FMT "%s\n", rows, cols, rbs, mat->bsizes ? " variable blocks set" : ""));
1170:       } else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", rows, cols));
1171:       if (mat->factortype) {
1172:         MatSolverType solver;
1173:         PetscCall(MatFactorGetSolverType(mat, &solver));
1174:         PetscCall(PetscViewerASCIIPrintf(viewer, "package used to perform factorization: %s\n", solver));
1175:       }
1176:       if (mat->ops->getinfo) {
1177:         PetscBool is_constant_or_diagonal;

1179:         // Don't print nonzero information for constant or diagonal matrices, it just adds noise to the output
1180:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &is_constant_or_diagonal, MATCONSTANTDIAGONAL, MATDIAGONAL, ""));
1181:         if (!is_constant_or_diagonal) {
1182:           MatInfo info;

1184:           PetscCall(MatGetInfo(mat, MAT_GLOBAL_SUM, &info));
1185:           PetscCall(PetscViewerASCIIPrintf(viewer, "total: nonzeros=%.f, allocated nonzeros=%.f\n", info.nz_used, info.nz_allocated));
1186:           if (!mat->factortype) PetscCall(PetscViewerASCIIPrintf(viewer, "total number of mallocs used during MatSetValues calls=%" PetscInt_FMT "\n", (PetscInt)info.mallocs));
1187:         }
1188:       }
1189:       PetscCall(MatGetNullSpace(mat, &nullsp));
1190:       PetscCall(MatGetTransposeNullSpace(mat, &transnullsp));
1191:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached null space\n"));
1192:       if (transnullsp && transnullsp != nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached transposed null space\n"));
1193:       PetscCall(MatGetNearNullSpace(mat, &nullsp));
1194:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached near null space\n"));
1195:       PetscCall(PetscViewerASCIIPushTab(viewer));
1196:       PetscCall(MatProductView(mat, viewer));
1197:       PetscCall(PetscViewerASCIIPopTab(viewer));
1198:       if (mat->bsizes && format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1199:         IS tmp;

1201:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)viewer), mat->nblocks, mat->bsizes, PETSC_USE_POINTER, &tmp));
1202:         PetscCall(PetscObjectSetName((PetscObject)tmp, "Block Sizes"));
1203:         PetscCall(PetscViewerASCIIPushTab(viewer));
1204:         PetscCall(ISView(tmp, viewer));
1205:         PetscCall(PetscViewerASCIIPopTab(viewer));
1206:         PetscCall(ISDestroy(&tmp));
1207:       }
1208:     }
1209:   } else if (issaws) {
1210: #if defined(PETSC_HAVE_SAWS)
1211:     PetscMPIInt rank;

1213:     PetscCall(PetscObjectName((PetscObject)mat));
1214:     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
1215:     if (!((PetscObject)mat)->amsmem && rank == 0) PetscCall(PetscObjectViewSAWs((PetscObject)mat, viewer));
1216: #endif
1217:   } else if (isstring) {
1218:     const char *type;
1219:     PetscCall(MatGetType(mat, &type));
1220:     PetscCall(PetscViewerStringSPrintf(viewer, " MatType: %-7.7s", type));
1221:     PetscTryTypeMethod(mat, view, viewer);
1222:   }
1223:   if ((format == PETSC_VIEWER_NATIVE || format == PETSC_VIEWER_LOAD_BALANCE) && mat->ops->viewnative) {
1224:     PetscCall(PetscViewerASCIIPushTab(viewer));
1225:     PetscUseTypeMethod(mat, viewnative, viewer);
1226:     PetscCall(PetscViewerASCIIPopTab(viewer));
1227:   } else if (mat->ops->view) {
1228:     PetscCall(PetscViewerASCIIPushTab(viewer));
1229:     PetscUseTypeMethod(mat, view, viewer);
1230:     PetscCall(PetscViewerASCIIPopTab(viewer));
1231:   }
1232:   if (isascii) {
1233:     PetscCall(PetscViewerGetFormat(viewer, &format));
1234:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerASCIIPopTab(viewer));
1235:   }
1236:   PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1237: #if !defined(PETSC_HAVE_THREADSAFETY)
1238:   insidematview--;
1239: #endif
1240:   PetscFunctionReturn(PETSC_SUCCESS);
1241: }

1243: #if defined(PETSC_USE_DEBUG)
1244: #include <../src/sys/totalview/tv_data_display.h>
1245: PETSC_UNUSED static int TV_display_type(const struct _p_Mat *mat)
1246: {
1247:   TV_add_row("Local rows", "int", &mat->rmap->n);
1248:   TV_add_row("Local columns", "int", &mat->cmap->n);
1249:   TV_add_row("Global rows", "int", &mat->rmap->N);
1250:   TV_add_row("Global columns", "int", &mat->cmap->N);
1251:   TV_add_row("Typename", TV_ascii_string_type, ((PetscObject)mat)->type_name);
1252:   return TV_format_OK;
1253: }
1254: #endif

1256: /*@
1257:   MatLoad - Loads a matrix that has been stored in binary/HDF5 format
1258:   with `MatView()`.  The matrix format is determined from the options database.
1259:   Generates a parallel MPI matrix if the communicator has more than one
1260:   processor.  The default matrix type is `MATAIJ`.

1262:   Collective

1264:   Input Parameters:
1265: + mat    - the newly loaded matrix, this needs to have been created with `MatCreate()`
1266:             or some related function before a call to `MatLoad()`
1267: - viewer - `PETSCVIEWERBINARY`/`PETSCVIEWERHDF5` file viewer

1269:   Options Database Key:
1270: . -matload_block_size bs - set block size

1272:   Level: beginner

1274:   Notes:
1275:   If the `Mat` type has not yet been given then `MATAIJ` is used, call `MatSetFromOptions()` on the
1276:   `Mat` before calling this routine if you wish to set it from the options database.

1278:   `MatLoad()` automatically loads into the options database any options
1279:   given in the file filename.info where filename is the name of the file
1280:   that was passed to the `PetscViewerBinaryOpen()`. The options in the info
1281:   file will be ignored if you use the -viewer_binary_skip_info option.

1283:   If the type or size of mat is not set before a call to `MatLoad()`, PETSc
1284:   sets the default matrix type AIJ and sets the local and global sizes.
1285:   If type and/or size is already set, then the same are used.

1287:   In parallel, each processor can load a subset of rows (or the
1288:   entire matrix).  This routine is especially useful when a large
1289:   matrix is stored on disk and only part of it is desired on each
1290:   processor.  For example, a parallel solver may access only some of
1291:   the rows from each processor.  The algorithm used here reads
1292:   relatively small blocks of data rather than reading the entire
1293:   matrix and then subsetting it.

1295:   Viewer's `PetscViewerType` must be either `PETSCVIEWERBINARY` or `PETSCVIEWERHDF5`.
1296:   Such viewer can be created using `PetscViewerBinaryOpen()` or `PetscViewerHDF5Open()`,
1297:   or the sequence like
1298: .vb
1299:     `PetscViewer` v;
1300:     `PetscViewerCreate`(`PETSC_COMM_WORLD`,&v);
1301:     `PetscViewerSetType`(v,`PETSCVIEWERBINARY`);
1302:     `PetscViewerSetFromOptions`(v);
1303:     `PetscViewerFileSetMode`(v,`FILE_MODE_READ`);
1304:     `PetscViewerFileSetName`(v,"datafile");
1305: .ve
1306:   The optional `PetscViewerSetFromOptions()` call allows overriding `PetscViewerSetType()` using the option
1307: .vb
1308:   -viewer_type {binary, hdf5}
1309: .ve

1311:   See the example src/ksp/ksp/tutorials/ex27.c with the first approach,
1312:   and src/mat/tutorials/ex10.c with the second approach.

1314:   In case of `PETSCVIEWERBINARY`, a native PETSc binary format is used. Each of the blocks
1315:   is read onto MPI rank 0 and then shipped to its destination MPI rank, one after another.
1316:   Multiple objects, both matrices and vectors, can be stored within the same file.
1317:   Their `PetscObject` name is ignored; they are loaded in the order of their storage.

1319:   Most users should not need to know the details of the binary storage
1320:   format, since `MatLoad()` and `MatView()` completely hide these details.
1321:   But for anyone who is interested, the standard binary matrix storage
1322:   format is

1324: .vb
1325:     PetscInt    MAT_FILE_CLASSID
1326:     PetscInt    number of rows
1327:     PetscInt    number of columns
1328:     PetscInt    total number of nonzeros
1329:     PetscInt    *number nonzeros in each row
1330:     PetscInt    *column indices of all nonzeros (starting index is zero)
1331:     PetscScalar *values of all nonzeros
1332: .ve
1333:   If PETSc was not configured with `--with-64-bit-indices` then only `MATMPIAIJ` matrices with more than `PETSC_INT_MAX` non-zeros can be
1334:   stored or loaded (each MPI process part of the matrix must have less than `PETSC_INT_MAX` nonzeros). Since the total nonzero count in this
1335:   case will not fit in a (32-bit) `PetscInt` the value `PETSC_INT_MAX` is used for the header entry `total number of nonzeros`.

1337:   PETSc automatically does the byte swapping for
1338:   machines that store the bytes reversed. Thus if you write your own binary
1339:   read/write routines you have to swap the bytes; see `PetscBinaryRead()`
1340:   and `PetscBinaryWrite()` to see how this may be done.

1342:   In case of `PETSCVIEWERHDF5`, a parallel HDF5 reader is used.
1343:   Each processor's chunk is loaded independently by its owning MPI process.
1344:   Multiple objects, both matrices and vectors, can be stored within the same file.
1345:   They are looked up by their PetscObject name.

1347:   As the MATLAB MAT-File Version 7.3 format is also a HDF5 flavor, we decided to use
1348:   by default the same structure and naming of the AIJ arrays and column count
1349:   within the HDF5 file. This means that a MAT file saved with -v7.3 flag, e.g.
1350: .vb
1351:   save example.mat A b -v7.3
1352: .ve
1353:   can be directly read by this routine (see Reference 1 for details).

1355:   Depending on your MATLAB version, this format might be a default,
1356:   otherwise you can set it as default in Preferences.

1358:   Unless -nocompression flag is used to save the file in MATLAB,
1359:   PETSc must be configured with ZLIB package.

1361:   See also examples src/mat/tutorials/ex10.c and src/ksp/ksp/tutorials/ex27.c

1363:   This reader currently supports only real `MATSEQAIJ`, `MATMPIAIJ`, `MATSEQDENSE` and `MATMPIDENSE` matrices for `PETSCVIEWERHDF5`

1365:   Corresponding `MatView()` is not yet implemented.

1367:   The loaded matrix is actually a transpose of the original one in MATLAB,
1368:   unless you push `PETSC_VIEWER_HDF5_MAT` format (see examples above).
1369:   With this format, matrix is automatically transposed by PETSc,
1370:   unless the matrix is marked as SPD or symmetric
1371:   (see `MatSetOption()`, `MAT_SPD`, `MAT_SYMMETRIC`).

1373:   See MATLAB Documentation on `save()`, <https://www.mathworks.com/help/matlab/ref/save.html#btox10b-1-version>

1375: .seealso: [](ch_matrices), `Mat`, `PetscViewerBinaryOpen()`, `PetscViewerSetType()`, `MatView()`, `VecLoad()`
1376:  @*/
1377: PetscErrorCode MatLoad(Mat mat, PetscViewer viewer)
1378: {
1379:   PetscBool flg;

1381:   PetscFunctionBegin;

1385:   if (!((PetscObject)mat)->type_name) PetscCall(MatSetType(mat, MATAIJ));

1387:   flg = PETSC_FALSE;
1388:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_symmetric", &flg, NULL));
1389:   if (flg) {
1390:     PetscCall(MatSetOption(mat, MAT_SYMMETRIC, PETSC_TRUE));
1391:     PetscCall(MatSetOption(mat, MAT_SYMMETRY_ETERNAL, PETSC_TRUE));
1392:   }
1393:   flg = PETSC_FALSE;
1394:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_spd", &flg, NULL));
1395:   if (flg) PetscCall(MatSetOption(mat, MAT_SPD, PETSC_TRUE));

1397:   PetscCall(PetscLogEventBegin(MAT_Load, mat, viewer, 0, 0));
1398:   PetscUseTypeMethod(mat, load, viewer);
1399:   PetscCall(PetscLogEventEnd(MAT_Load, mat, viewer, 0, 0));
1400:   PetscFunctionReturn(PETSC_SUCCESS);
1401: }

1403: static PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1404: {
1405:   Mat_Redundant *redund = *redundant;

1407:   PetscFunctionBegin;
1408:   if (redund) {
1409:     if (redund->matseq) { /* via MatCreateSubMatrices()  */
1410:       PetscCall(ISDestroy(&redund->isrow));
1411:       PetscCall(ISDestroy(&redund->iscol));
1412:       PetscCall(MatDestroySubMatrices(1, &redund->matseq));
1413:     } else {
1414:       PetscCall(PetscFree2(redund->send_rank, redund->recv_rank));
1415:       PetscCall(PetscFree(redund->sbuf_j));
1416:       PetscCall(PetscFree(redund->sbuf_a));
1417:       for (PetscInt i = 0; i < redund->nrecvs; i++) {
1418:         PetscCall(PetscFree(redund->rbuf_j[i]));
1419:         PetscCall(PetscFree(redund->rbuf_a[i]));
1420:       }
1421:       PetscCall(PetscFree4(redund->sbuf_nz, redund->rbuf_nz, redund->rbuf_j, redund->rbuf_a));
1422:     }

1424:     PetscCall(PetscCommDestroy(&redund->subcomm));
1425:     PetscCall(PetscFree(redund));
1426:   }
1427:   PetscFunctionReturn(PETSC_SUCCESS);
1428: }

1430: /*@
1431:   MatDestroy - Frees space taken by a matrix.

1433:   Collective

1435:   Input Parameter:
1436: . A - the matrix

1438:   Level: beginner

1440:   Developer Note:
1441:   Some special arrays of matrices are not destroyed in this routine but instead by the routines called by
1442:   `MatDestroySubMatrices()`. Thus one must be sure that any changes here must also be made in those routines.
1443:   `MatHeaderMerge()` and `MatHeaderReplace()` also manipulate the data in the `Mat` object and likely need changes
1444:   if changes are needed here.

1446: .seealso: [](ch_matrices), `Mat`, `MatCreate()`
1447: @*/
1448: PetscErrorCode MatDestroy(Mat *A)
1449: {
1450:   PetscFunctionBegin;
1451:   if (!*A) PetscFunctionReturn(PETSC_SUCCESS);
1453:   if (--((PetscObject)*A)->refct > 0) {
1454:     *A = NULL;
1455:     PetscFunctionReturn(PETSC_SUCCESS);
1456:   }

1458:   /* if memory was published with SAWs then destroy it */
1459:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*A));
1460:   PetscTryTypeMethod(*A, destroy);

1462:   PetscCall(PetscFree((*A)->factorprefix));
1463:   PetscCall(PetscFree((*A)->defaultvectype));
1464:   PetscCall(PetscFree((*A)->defaultrandtype));
1465:   PetscCall(PetscFree((*A)->bsizes));
1466:   PetscCall(PetscFree((*A)->solvertype));
1467:   for (PetscInt i = 0; i < MAT_FACTOR_NUM_TYPES; i++) PetscCall(PetscFree((*A)->preferredordering[i]));
1468:   if ((*A)->redundant && (*A)->redundant->matseq[0] == *A) (*A)->redundant->matseq[0] = NULL;
1469:   PetscCall(MatDestroy_Redundant(&(*A)->redundant));
1470:   PetscCall(MatProductClear(*A));
1471:   PetscCall(MatNullSpaceDestroy(&(*A)->nullsp));
1472:   PetscCall(MatNullSpaceDestroy(&(*A)->transnullsp));
1473:   PetscCall(MatNullSpaceDestroy(&(*A)->nearnullsp));
1474:   PetscCall(MatDestroy(&(*A)->schur));
1475:   PetscCall(VecDestroy(&(*A)->dot_vec));
1476:   PetscCall(PetscLayoutDestroy(&(*A)->rmap));
1477:   PetscCall(PetscLayoutDestroy(&(*A)->cmap));
1478:   PetscCall(PetscHeaderDestroy(A));
1479:   PetscFunctionReturn(PETSC_SUCCESS);
1480: }

1482: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1483: /*@
1484:   MatSetValues - Inserts or adds a block of values into a matrix.
1485:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1486:   MUST be called after all calls to `MatSetValues()` have been completed.

1488:   Not Collective

1490:   Input Parameters:
1491: + mat  - the matrix
1492: . m    - the number of rows
1493: . idxm - the global indices of the rows
1494: . n    - the number of columns
1495: . idxn - the global indices of the columns
1496: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1497:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1498: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1500:   Level: beginner

1502:   Notes:
1503:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1504:   options cannot be mixed without intervening calls to the assembly
1505:   routines.

1507:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1508:   as well as in C.

1510:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1511:   simply ignored. This allows easily inserting element stiffness matrices
1512:   with homogeneous Dirichlet boundary conditions that you don't want represented
1513:   in the matrix.

1515:   Efficiency Alert:
1516:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1517:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1519:   Fortran Notes:
1520:   If any of `idxm`, `idxn`, and `v` are scalars pass them using, for example,
1521: .vb
1522:   call MatSetValues(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
1523: .ve

1525:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1527:   Developer Note:
1528:   This is labeled with C so does not automatically generate Fortran stubs and interfaces
1529:   because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.

1531: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1532:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1533: @*/
1534: PetscErrorCode MatSetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
1535: {
1536:   PetscFunctionBeginHot;
1539:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1540:   PetscAssertPointer(idxm, 3);
1541:   PetscAssertPointer(idxn, 5);
1542:   MatCheckPreallocated(mat, 1);

1544:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
1545:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");

1547:   if (PetscDefined(USE_DEBUG)) {
1548:     PetscInt i, j;

1550:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1551:     if (v) {
1552:       for (i = 0; i < m; i++) {
1553:         for (j = 0; j < n; j++) {
1554:           if (mat->erroriffailure && PetscIsInfOrNanScalar(v[i * n + j]))
1555: #if defined(PETSC_USE_COMPLEX)
1556:             SETERRQ(PETSC_COMM_SELF, PETSC_ERR_FP, "Inserting %g+i%g at matrix entry (%" PetscInt_FMT ",%" PetscInt_FMT ")", (double)PetscRealPart(v[i * n + j]), (double)PetscImaginaryPart(v[i * n + j]), idxm[i], idxn[j]);
1557: #else
1558:             SETERRQ(PETSC_COMM_SELF, PETSC_ERR_FP, "Inserting %g at matrix entry (%" PetscInt_FMT ",%" PetscInt_FMT ")", (double)v[i * n + j], idxm[i], idxn[j]);
1559: #endif
1560:         }
1561:       }
1562:     }
1563:     for (i = 0; i < m; i++) PetscCheck(idxm[i] < mat->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cannot insert in row %" PetscInt_FMT ", maximum is %" PetscInt_FMT, idxm[i], mat->rmap->N - 1);
1564:     for (i = 0; i < n; i++) PetscCheck(idxn[i] < mat->cmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cannot insert in column %" PetscInt_FMT ", maximum is %" PetscInt_FMT, idxn[i], mat->cmap->N - 1);
1565:   }

1567:   if (mat->assembled) {
1568:     mat->was_assembled = PETSC_TRUE;
1569:     mat->assembled     = PETSC_FALSE;
1570:   }
1571:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1572:   PetscUseTypeMethod(mat, setvalues, m, idxm, n, idxn, v, addv);
1573:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1574:   PetscFunctionReturn(PETSC_SUCCESS);
1575: }

1577: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1578: /*@
1579:   MatSetValuesIS - Inserts or adds a block of values into a matrix using an `IS` to indicate the rows and columns
1580:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1581:   MUST be called after all calls to `MatSetValues()` have been completed.

1583:   Not Collective

1585:   Input Parameters:
1586: + mat  - the matrix
1587: . ism  - the rows to provide
1588: . isn  - the columns to provide
1589: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1590:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1591: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1593:   Level: beginner

1595:   Notes:
1596:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1598:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1599:   options cannot be mixed without intervening calls to the assembly
1600:   routines.

1602:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1603:   as well as in C.

1605:   Negative indices may be passed in `ism` and `isn`, these rows and columns are
1606:   simply ignored. This allows easily inserting element stiffness matrices
1607:   with homogeneous Dirichlet boundary conditions that you don't want represented
1608:   in the matrix.

1610:   Fortran Note:
1611:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1613:   Efficiency Alert:
1614:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1615:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1617:   This is currently not optimized for any particular `ISType`

1619: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatSetValues()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1620:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1621: @*/
1622: PetscErrorCode MatSetValuesIS(Mat mat, IS ism, IS isn, const PetscScalar v[], InsertMode addv)
1623: {
1624:   PetscInt        m, n;
1625:   const PetscInt *rows, *cols;

1627:   PetscFunctionBeginHot;
1629:   PetscCall(ISGetIndices(ism, &rows));
1630:   PetscCall(ISGetIndices(isn, &cols));
1631:   PetscCall(ISGetLocalSize(ism, &m));
1632:   PetscCall(ISGetLocalSize(isn, &n));
1633:   PetscCall(MatSetValues(mat, m, rows, n, cols, v, addv));
1634:   PetscCall(ISRestoreIndices(ism, &rows));
1635:   PetscCall(ISRestoreIndices(isn, &cols));
1636:   PetscFunctionReturn(PETSC_SUCCESS);
1637: }

1639: /*@
1640:   MatSetValuesRowLocal - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1641:   values into a matrix

1643:   Not Collective

1645:   Input Parameters:
1646: + mat - the matrix
1647: . row - the (block) row to set
1648: - v   - a one-dimensional array that contains the values. For `MATBAIJ` they are implicitly stored as a two-dimensional array, by default in row-major order.
1649:         See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1651:   Level: intermediate

1653:   Notes:
1654:   The values, `v`, are column-oriented (for the block version) and sorted

1656:   All the nonzero values in `row` must be provided

1658:   The matrix must have previously had its column indices set, likely by having been assembled.

1660:   `row` must belong to this MPI process

1662:   Fortran Note:
1663:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1665: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1666:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetValuesRow()`, `MatSetLocalToGlobalMapping()`
1667: @*/
1668: PetscErrorCode MatSetValuesRowLocal(Mat mat, PetscInt row, const PetscScalar v[])
1669: {
1670:   PetscInt globalrow;

1672:   PetscFunctionBegin;
1675:   PetscAssertPointer(v, 3);
1676:   PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, 1, &row, &globalrow));
1677:   PetscCall(MatSetValuesRow(mat, globalrow, v));
1678:   PetscFunctionReturn(PETSC_SUCCESS);
1679: }

1681: /*@
1682:   MatSetValuesRow - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1683:   values into a matrix

1685:   Not Collective

1687:   Input Parameters:
1688: + mat - the matrix
1689: . row - the (block) row to set
1690: - v   - a logically two-dimensional (column major) array of values for  block matrices with blocksize larger than one, otherwise a one dimensional array of values

1692:   Level: advanced

1694:   Notes:
1695:   The values, `v`, are column-oriented for the block version.

1697:   All the nonzeros in `row` must be provided

1699:   THE MATRIX MUST HAVE PREVIOUSLY HAD ITS COLUMN INDICES SET. IT IS RARE THAT THIS ROUTINE IS USED, usually `MatSetValues()` is used.

1701:   `row` must belong to this process

1703: .seealso: [](ch_matrices), `Mat`, `MatSetValues()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1704:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1705: @*/
1706: PetscErrorCode MatSetValuesRow(Mat mat, PetscInt row, const PetscScalar v[])
1707: {
1708:   PetscFunctionBeginHot;
1711:   MatCheckPreallocated(mat, 1);
1712:   PetscAssertPointer(v, 3);
1713:   PetscCheck(mat->insertmode != ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add and insert values");
1714:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1715:   mat->insertmode = INSERT_VALUES;

1717:   if (mat->assembled) {
1718:     mat->was_assembled = PETSC_TRUE;
1719:     mat->assembled     = PETSC_FALSE;
1720:   }
1721:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1722:   PetscUseTypeMethod(mat, setvaluesrow, row, v);
1723:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1724:   PetscFunctionReturn(PETSC_SUCCESS);
1725: }

1727: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1728: /*@
1729:   MatSetValuesStencil - Inserts or adds a block of values into a matrix.
1730:   Using structured grid indexing

1732:   Not Collective

1734:   Input Parameters:
1735: + mat  - the matrix
1736: . m    - number of rows being entered
1737: . idxm - grid coordinates (and component number when dof > 1) for matrix rows being entered
1738: . n    - number of columns being entered
1739: . idxn - grid coordinates (and component number when dof > 1) for matrix columns being entered
1740: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1741:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1742: - addv - either `ADD_VALUES` to add to existing entries at that location or `INSERT_VALUES` to replace existing entries with new values

1744:   Level: beginner

1746:   Notes:
1747:   By default the values, `v`, are row-oriented.  See `MatSetOption()` for other options.

1749:   Calls to `MatSetValuesStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1750:   options cannot be mixed without intervening calls to the assembly
1751:   routines.

1753:   The grid coordinates are across the entire grid, not just the local portion

1755:   `MatSetValuesStencil()` uses 0-based row and column numbers in Fortran
1756:   as well as in C.

1758:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1760:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1761:   or call `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1763:   The columns and rows in the stencil passed in MUST be contained within the
1764:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1765:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1766:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1767:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1769:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
1770:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
1771:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
1772:   `DM_BOUNDARY_PERIODIC` boundary type.

1774:   For indices that don't mean anything for your case (like the k index when working in 2d) or the c index when you have
1775:   a single value per point) you can skip filling those indices.

1777:   Inspired by the structured grid interface to the HYPRE package
1778:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1780:   Fortran Note:
1781:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1783:   Efficiency Alert:
1784:   The routine `MatSetValuesBlockedStencil()` may offer much better efficiency
1785:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1787: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1788:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`
1789: @*/
1790: PetscErrorCode MatSetValuesStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1791: {
1792:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1793:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1794:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1796:   PetscFunctionBegin;
1797:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1800:   PetscAssertPointer(idxm, 3);
1801:   PetscAssertPointer(idxn, 5);

1803:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1804:     jdxm = buf;
1805:     jdxn = buf + m;
1806:   } else {
1807:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1808:     jdxm = bufm;
1809:     jdxn = bufn;
1810:   }
1811:   for (i = 0; i < m; i++) {
1812:     for (j = 0; j < 3 - sdim; j++) dxm++;
1813:     tmp = *dxm++ - starts[0];
1814:     for (j = 0; j < dim - 1; j++) {
1815:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1816:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1817:     }
1818:     if (mat->stencil.noc) dxm++;
1819:     jdxm[i] = tmp;
1820:   }
1821:   for (i = 0; i < n; i++) {
1822:     for (j = 0; j < 3 - sdim; j++) dxn++;
1823:     tmp = *dxn++ - starts[0];
1824:     for (j = 0; j < dim - 1; j++) {
1825:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1826:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1827:     }
1828:     if (mat->stencil.noc) dxn++;
1829:     jdxn[i] = tmp;
1830:   }
1831:   PetscCall(MatSetValuesLocal(mat, m, jdxm, n, jdxn, v, addv));
1832:   PetscCall(PetscFree2(bufm, bufn));
1833:   PetscFunctionReturn(PETSC_SUCCESS);
1834: }

1836: /*@
1837:   MatSetValuesBlockedStencil - Inserts or adds a block of values into a matrix.
1838:   Using structured grid indexing

1840:   Not Collective

1842:   Input Parameters:
1843: + mat  - the matrix
1844: . m    - number of rows being entered
1845: . idxm - grid coordinates for matrix rows being entered
1846: . n    - number of columns being entered
1847: . idxn - grid coordinates for matrix columns being entered
1848: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1849:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1850: - addv - either `ADD_VALUES` to add to existing entries or `INSERT_VALUES` to replace existing entries with new values

1852:   Level: beginner

1854:   Notes:
1855:   By default the values, `v`, are row-oriented and unsorted.
1856:   See `MatSetOption()` for other options.

1858:   Calls to `MatSetValuesBlockedStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1859:   options cannot be mixed without intervening calls to the assembly
1860:   routines.

1862:   The grid coordinates are across the entire grid, not just the local portion

1864:   `MatSetValuesBlockedStencil()` uses 0-based row and column numbers in Fortran
1865:   as well as in C.

1867:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1869:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1870:   or call `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1872:   The columns and rows in the stencil passed in MUST be contained within the
1873:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1874:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1875:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1876:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1878:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1879:   simply ignored. This allows easily inserting element stiffness matrices
1880:   with homogeneous Dirichlet boundary conditions that you don't want represented
1881:   in the matrix.

1883:   Inspired by the structured grid interface to the HYPRE package
1884:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1886:   Fortran Notes:
1887:   `idxm` and `idxn` should be declared as
1888: .vb
1889:     MatStencil idxm(4,m),idxn(4,n)
1890: .ve
1891:   and the values inserted using
1892: .vb
1893:     idxm(MatStencil_i,1) = i
1894:     idxm(MatStencil_j,1) = j
1895:     idxm(MatStencil_k,1) = k
1896:    etc
1897: .ve

1899:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1901: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1902:           `MatSetValues()`, `MatSetValuesStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`,
1903:           `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`
1904: @*/
1905: PetscErrorCode MatSetValuesBlockedStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1906: {
1907:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1908:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1909:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1911:   PetscFunctionBegin;
1912:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1915:   PetscAssertPointer(idxm, 3);
1916:   PetscAssertPointer(idxn, 5);
1917:   PetscAssertPointer(v, 6);

1919:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1920:     jdxm = buf;
1921:     jdxn = buf + m;
1922:   } else {
1923:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1924:     jdxm = bufm;
1925:     jdxn = bufn;
1926:   }
1927:   for (i = 0; i < m; i++) {
1928:     for (j = 0; j < 3 - sdim; j++) dxm++;
1929:     tmp = *dxm++ - starts[0];
1930:     for (j = 0; j < sdim - 1; j++) {
1931:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1932:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1933:     }
1934:     dxm++;
1935:     jdxm[i] = tmp;
1936:   }
1937:   for (i = 0; i < n; i++) {
1938:     for (j = 0; j < 3 - sdim; j++) dxn++;
1939:     tmp = *dxn++ - starts[0];
1940:     for (j = 0; j < sdim - 1; j++) {
1941:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1942:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1943:     }
1944:     dxn++;
1945:     jdxn[i] = tmp;
1946:   }
1947:   PetscCall(MatSetValuesBlockedLocal(mat, m, jdxm, n, jdxn, v, addv));
1948:   PetscCall(PetscFree2(bufm, bufn));
1949:   PetscFunctionReturn(PETSC_SUCCESS);
1950: }

1952: /*@
1953:   MatSetStencil - Sets the grid information for setting values into a matrix via
1954:   `MatSetValuesStencil()`

1956:   Not Collective

1958:   Input Parameters:
1959: + mat    - the matrix
1960: . dim    - dimension of the grid 1, 2, or 3
1961: . dims   - number of grid points in x, y, and z direction, including ghost points on your processor
1962: . starts - starting point of ghost nodes on your processor in x, y, and z direction
1963: - dof    - number of degrees of freedom per node

1965:   Level: beginner

1967:   Notes:
1968:   Inspired by the structured grid interface to the HYPRE package
1969:   (www.llnl.gov/CASC/hyper)

1971:   For matrices generated with `DMCreateMatrix()` this routine is automatically called and so not needed by the
1972:   user.

1974: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1975:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetValuesStencil()`
1976: @*/
1977: PetscErrorCode MatSetStencil(Mat mat, PetscInt dim, const PetscInt dims[], const PetscInt starts[], PetscInt dof)
1978: {
1979:   PetscFunctionBegin;
1981:   PetscAssertPointer(dims, 3);
1982:   PetscAssertPointer(starts, 4);

1984:   mat->stencil.dim = dim + (dof > 1);
1985:   for (PetscInt i = 0; i < dim; i++) {
1986:     mat->stencil.dims[i]   = dims[dim - i - 1]; /* copy the values in backwards */
1987:     mat->stencil.starts[i] = starts[dim - i - 1];
1988:   }
1989:   mat->stencil.dims[dim]   = dof;
1990:   mat->stencil.starts[dim] = 0;
1991:   mat->stencil.noc         = (PetscBool)(dof == 1);
1992:   PetscFunctionReturn(PETSC_SUCCESS);
1993: }

1995: /*@
1996:   MatSetValuesBlocked - Inserts or adds a block of values into a matrix.

1998:   Not Collective

2000:   Input Parameters:
2001: + mat  - the matrix
2002: . m    - the number of block rows
2003: . idxm - the global block indices
2004: . n    - the number of block columns
2005: . idxn - the global block indices
2006: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2007:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2008: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` replaces existing entries with new values

2010:   Level: intermediate

2012:   Notes:
2013:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call
2014:   MatXXXXSetPreallocation() or `MatSetUp()` before using this routine.

2016:   The `m` and `n` count the NUMBER of blocks in the row direction and column direction,
2017:   NOT the total number of rows/columns; for example, if the block size is 2 and
2018:   you are passing in values for rows 2,3,4,5  then `m` would be 2 (not 4).
2019:   The values in `idxm` would be 1 2; that is the first index for each block divided by
2020:   the block size.

2022:   You must call `MatSetBlockSize()` when constructing this matrix (before
2023:   preallocating it).

2025:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2027:   Calls to `MatSetValuesBlocked()` with the `INSERT_VALUES` and `ADD_VALUES`
2028:   options cannot be mixed without intervening calls to the assembly
2029:   routines.

2031:   `MatSetValuesBlocked()` uses 0-based row and column numbers in Fortran
2032:   as well as in C.

2034:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
2035:   simply ignored. This allows easily inserting element stiffness matrices
2036:   with homogeneous Dirichlet boundary conditions that you don't want represented
2037:   in the matrix.

2039:   Each time an entry is set within a sparse matrix via `MatSetValues()`,
2040:   internal searching must be done to determine where to place the
2041:   data in the matrix storage space.  By instead inserting blocks of
2042:   entries via `MatSetValuesBlocked()`, the overhead of matrix assembly is
2043:   reduced.

2045:   Example:
2046: .vb
2047:    Suppose m=n=2 and block size(bs) = 2 The array is

2049:    1  2  | 3  4
2050:    5  6  | 7  8
2051:    - - - | - - -
2052:    9  10 | 11 12
2053:    13 14 | 15 16

2055:    v[] should be passed in like
2056:    v[] = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

2058:   If you are not using row-oriented storage of v (that is you called MatSetOption(mat,MAT_ROW_ORIENTED,PETSC_FALSE)) then
2059:    v[] = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16]
2060: .ve

2062:   Fortran Notes:
2063:   If any of `idmx`, `idxn`, and `v` are scalars pass them using, for example,
2064: .vb
2065:   call MatSetValuesBlocked(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
2066: .ve

2068:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2070: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesBlockedLocal()`
2071: @*/
2072: PetscErrorCode MatSetValuesBlocked(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
2073: {
2074:   PetscFunctionBeginHot;
2077:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2078:   PetscAssertPointer(idxm, 3);
2079:   PetscAssertPointer(idxn, 5);
2080:   MatCheckPreallocated(mat, 1);
2081:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2082:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2083:   if (PetscDefined(USE_DEBUG)) {
2084:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2085:     PetscCheck(mat->ops->setvaluesblocked || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2086:   }
2087:   if (PetscDefined(USE_DEBUG)) {
2088:     PetscInt rbs, cbs, M, N, i;
2089:     PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
2090:     PetscCall(MatGetSize(mat, &M, &N));
2091:     for (i = 0; i < m; i++) PetscCheck(idxm[i] * rbs < M, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row block %" PetscInt_FMT " contains an index %" PetscInt_FMT "*%" PetscInt_FMT " greater than row length %" PetscInt_FMT, i, idxm[i], rbs, M);
2092:     for (i = 0; i < n; i++)
2093:       PetscCheck(idxn[i] * cbs < N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column block %" PetscInt_FMT " contains an index %" PetscInt_FMT "*%" PetscInt_FMT " greater than column length %" PetscInt_FMT, i, idxn[i], cbs, N);
2094:   }
2095:   if (mat->assembled) {
2096:     mat->was_assembled = PETSC_TRUE;
2097:     mat->assembled     = PETSC_FALSE;
2098:   }
2099:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2100:   if (mat->ops->setvaluesblocked) PetscUseTypeMethod(mat, setvaluesblocked, m, idxm, n, idxn, v, addv);
2101:   else {
2102:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *iidxm, *iidxn;
2103:     PetscInt i, j, bs, cbs;

2105:     PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
2106:     if ((m * bs + n * cbs) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2107:       iidxm = buf;
2108:       iidxn = buf + m * bs;
2109:     } else {
2110:       PetscCall(PetscMalloc2(m * bs, &bufr, n * cbs, &bufc));
2111:       iidxm = bufr;
2112:       iidxn = bufc;
2113:     }
2114:     for (i = 0; i < m; i++) {
2115:       for (j = 0; j < bs; j++) iidxm[i * bs + j] = bs * idxm[i] + j;
2116:     }
2117:     if (m != n || bs != cbs || idxm != idxn) {
2118:       for (i = 0; i < n; i++) {
2119:         for (j = 0; j < cbs; j++) iidxn[i * cbs + j] = cbs * idxn[i] + j;
2120:       }
2121:     } else iidxn = iidxm;
2122:     PetscCall(MatSetValues(mat, m * bs, iidxm, n * cbs, iidxn, v, addv));
2123:     PetscCall(PetscFree2(bufr, bufc));
2124:   }
2125:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2126:   PetscFunctionReturn(PETSC_SUCCESS);
2127: }

2129: /*@
2130:   MatGetValues - Gets a block of local values from a matrix.

2132:   Not Collective; can only return values that are owned by the give process

2134:   Input Parameters:
2135: + mat  - the matrix
2136: . v    - a logically two-dimensional array for storing the values
2137: . m    - the number of rows
2138: . idxm - the  global indices of the rows
2139: . n    - the number of columns
2140: - idxn - the global indices of the columns

2142:   Level: advanced

2144:   Notes:
2145:   The user must allocate space (m*n `PetscScalar`s) for the values, `v`.
2146:   The values, `v`, are then returned in a row-oriented format,
2147:   analogous to that used by default in `MatSetValues()`.

2149:   `MatGetValues()` uses 0-based row and column numbers in
2150:   Fortran as well as in C.

2152:   `MatGetValues()` requires that the matrix has been assembled
2153:   with `MatAssemblyBegin()`/`MatAssemblyEnd()`.  Thus, calls to
2154:   `MatSetValues()` and `MatGetValues()` CANNOT be made in succession
2155:   without intermediate matrix assembly.

2157:   Negative row or column indices will be ignored and those locations in `v` will be
2158:   left unchanged.

2160:   For the standard row-based matrix formats, `idxm` can only contain rows owned by the requesting MPI process.
2161:   That is, rows with global index greater than or equal to rstart and less than rend where rstart and rend are obtainable
2162:   from `MatGetOwnershipRange`(mat,&rstart,&rend).

2164: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatSetValues()`, `MatGetOwnershipRange()`, `MatGetValuesLocal()`, `MatGetValue()`
2165: @*/
2166: PetscErrorCode MatGetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], PetscScalar v[])
2167: {
2168:   PetscFunctionBegin;
2171:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS);
2172:   PetscAssertPointer(idxm, 3);
2173:   PetscAssertPointer(idxn, 5);
2174:   PetscAssertPointer(v, 6);
2175:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2176:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2177:   MatCheckPreallocated(mat, 1);

2179:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2180:   PetscUseTypeMethod(mat, getvalues, m, idxm, n, idxn, v);
2181:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2182:   PetscFunctionReturn(PETSC_SUCCESS);
2183: }

2185: /*@
2186:   MatGetValuesLocal - retrieves values from certain locations in a matrix using the local numbering of the indices
2187:   defined previously by `MatSetLocalToGlobalMapping()`

2189:   Not Collective

2191:   Input Parameters:
2192: + mat  - the matrix
2193: . nrow - number of rows
2194: . irow - the row local indices
2195: . ncol - number of columns
2196: - icol - the column local indices

2198:   Output Parameter:
2199: . y - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2200:       See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2202:   Level: advanced

2204:   Notes:
2205:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine.

2207:   This routine can only return values that are owned by the requesting MPI process. That is, for standard matrix formats, rows that, in the global numbering,
2208:   are greater than or equal to rstart and less than rend where rstart and rend are obtainable from `MatGetOwnershipRange`(mat,&rstart,&rend). One can
2209:   determine if the resulting global row associated with the local row r is owned by the requesting MPI process by applying the `ISLocalToGlobalMapping` set
2210:   with `MatSetLocalToGlobalMapping()`.

2212: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2213:           `MatSetValuesLocal()`, `MatGetValues()`
2214: @*/
2215: PetscErrorCode MatGetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], PetscScalar y[])
2216: {
2217:   PetscFunctionBeginHot;
2220:   MatCheckPreallocated(mat, 1);
2221:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to retrieve */
2222:   PetscAssertPointer(irow, 3);
2223:   PetscAssertPointer(icol, 5);
2224:   if (PetscDefined(USE_DEBUG)) {
2225:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2226:     PetscCheck(mat->ops->getvalueslocal || mat->ops->getvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2227:   }
2228:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2229:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2230:   if (mat->ops->getvalueslocal) PetscUseTypeMethod(mat, getvalueslocal, nrow, irow, ncol, icol, y);
2231:   else {
2232:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *irowm, *icolm;
2233:     if ((nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2234:       irowm = buf;
2235:       icolm = buf + nrow;
2236:     } else {
2237:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2238:       irowm = bufr;
2239:       icolm = bufc;
2240:     }
2241:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global row mapping (See MatSetLocalToGlobalMapping()).");
2242:     PetscCheck(mat->cmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global column mapping (See MatSetLocalToGlobalMapping()).");
2243:     PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, irowm));
2244:     PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, icolm));
2245:     PetscCall(MatGetValues(mat, nrow, irowm, ncol, icolm, y));
2246:     PetscCall(PetscFree2(bufr, bufc));
2247:   }
2248:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2249:   PetscFunctionReturn(PETSC_SUCCESS);
2250: }

2252: /*@
2253:   MatSetValuesBatch - Adds (`ADD_VALUES`) many blocks of values into a matrix at once. The blocks must all be square and
2254:   the same size. Currently, this can only be called once and creates the given matrix.

2256:   Not Collective

2258:   Input Parameters:
2259: + mat  - the matrix
2260: . nb   - the number of blocks
2261: . bs   - the number of rows (and columns) in each block
2262: . rows - a concatenation of the rows for each block
2263: - v    - a concatenation of logically two-dimensional arrays of values

2265:   Level: advanced

2267:   Notes:
2268:   `MatSetPreallocationCOO()` and `MatSetValuesCOO()` may be a better way to provide the values

2270:   In the future, we will extend this routine to handle rectangular blocks, and to allow multiple calls for a given matrix.

2272: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
2273:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
2274: @*/
2275: PetscErrorCode MatSetValuesBatch(Mat mat, PetscInt nb, PetscInt bs, PetscInt rows[], const PetscScalar v[])
2276: {
2277:   PetscFunctionBegin;
2280:   PetscAssertPointer(rows, 4);
2281:   PetscAssertPointer(v, 5);
2282:   PetscAssert(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

2284:   PetscCall(PetscLogEventBegin(MAT_SetValuesBatch, mat, 0, 0, 0));
2285:   for (PetscInt b = 0; b < nb; ++b) PetscCall(MatSetValues(mat, bs, &rows[b * bs], bs, &rows[b * bs], &v[b * bs * bs], ADD_VALUES));
2286:   PetscCall(PetscLogEventEnd(MAT_SetValuesBatch, mat, 0, 0, 0));
2287:   PetscFunctionReturn(PETSC_SUCCESS);
2288: }

2290: /*@
2291:   MatSetLocalToGlobalMapping - Sets a local-to-global numbering for use by
2292:   the routine `MatSetValuesLocal()` to allow users to insert matrix entries
2293:   using a local (per-processor) numbering.

2295:   Not Collective

2297:   Input Parameters:
2298: + x        - the matrix
2299: . rmapping - row mapping created with `ISLocalToGlobalMappingCreate()` or `ISLocalToGlobalMappingCreateIS()`
2300: - cmapping - column mapping

2302:   Level: intermediate

2304:   Note:
2305:   If the matrix is obtained with `DMCreateMatrix()` then this may already have been called on the matrix

2307: .seealso: [](ch_matrices), `Mat`, `DM`, `DMCreateMatrix()`, `MatGetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesLocal()`, `MatGetValuesLocal()`
2308: @*/
2309: PetscErrorCode MatSetLocalToGlobalMapping(Mat x, ISLocalToGlobalMapping rmapping, ISLocalToGlobalMapping cmapping)
2310: {
2311:   PetscFunctionBegin;
2316:   if (x->ops->setlocaltoglobalmapping) PetscUseTypeMethod(x, setlocaltoglobalmapping, rmapping, cmapping);
2317:   else {
2318:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->rmap, rmapping));
2319:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->cmap, cmapping));
2320:   }
2321:   PetscFunctionReturn(PETSC_SUCCESS);
2322: }

2324: /*@
2325:   MatGetLocalToGlobalMapping - Gets the local-to-global numbering set by `MatSetLocalToGlobalMapping()`

2327:   Not Collective

2329:   Input Parameter:
2330: . A - the matrix

2332:   Output Parameters:
2333: + rmapping - row mapping
2334: - cmapping - column mapping

2336:   Level: advanced

2338: .seealso: [](ch_matrices), `Mat`, `MatSetLocalToGlobalMapping()`, `MatSetValuesLocal()`
2339: @*/
2340: PetscErrorCode MatGetLocalToGlobalMapping(Mat A, ISLocalToGlobalMapping *rmapping, ISLocalToGlobalMapping *cmapping)
2341: {
2342:   PetscFunctionBegin;
2345:   if (rmapping) {
2346:     PetscAssertPointer(rmapping, 2);
2347:     *rmapping = A->rmap->mapping;
2348:   }
2349:   if (cmapping) {
2350:     PetscAssertPointer(cmapping, 3);
2351:     *cmapping = A->cmap->mapping;
2352:   }
2353:   PetscFunctionReturn(PETSC_SUCCESS);
2354: }

2356: /*@
2357:   MatSetLayouts - Sets the `PetscLayout` objects for rows and columns of a matrix

2359:   Logically Collective

2361:   Input Parameters:
2362: + A    - the matrix
2363: . rmap - row layout
2364: - cmap - column layout

2366:   Level: advanced

2368:   Note:
2369:   The `PetscLayout` objects are usually created automatically for the matrix so this routine rarely needs to be called.

2371: .seealso: [](ch_matrices), `Mat`, `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatGetLayouts()`
2372: @*/
2373: PetscErrorCode MatSetLayouts(Mat A, PetscLayout rmap, PetscLayout cmap)
2374: {
2375:   PetscFunctionBegin;
2377:   PetscCall(PetscLayoutReference(rmap, &A->rmap));
2378:   PetscCall(PetscLayoutReference(cmap, &A->cmap));
2379:   PetscFunctionReturn(PETSC_SUCCESS);
2380: }

2382: /*@
2383:   MatGetLayouts - Gets the `PetscLayout` objects for rows and columns

2385:   Not Collective

2387:   Input Parameter:
2388: . A - the matrix

2390:   Output Parameters:
2391: + rmap - row layout
2392: - cmap - column layout

2394:   Level: advanced

2396: .seealso: [](ch_matrices), `Mat`, [Matrix Layouts](sec_matlayout), `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatSetLayouts()`
2397: @*/
2398: PetscErrorCode MatGetLayouts(Mat A, PetscLayout *rmap, PetscLayout *cmap)
2399: {
2400:   PetscFunctionBegin;
2403:   if (rmap) {
2404:     PetscAssertPointer(rmap, 2);
2405:     *rmap = A->rmap;
2406:   }
2407:   if (cmap) {
2408:     PetscAssertPointer(cmap, 3);
2409:     *cmap = A->cmap;
2410:   }
2411:   PetscFunctionReturn(PETSC_SUCCESS);
2412: }

2414: /*@
2415:   MatSetValuesLocal - Inserts or adds values into certain locations of a matrix,
2416:   using a local numbering of the rows and columns.

2418:   Not Collective

2420:   Input Parameters:
2421: + mat  - the matrix
2422: . nrow - number of rows
2423: . irow - the row local indices
2424: . ncol - number of columns
2425: . icol - the column local indices
2426: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2427:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2428: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2430:   Level: intermediate

2432:   Notes:
2433:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine

2435:   Calls to `MatSetValuesLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2436:   options cannot be mixed without intervening calls to the assembly
2437:   routines.

2439:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2440:   MUST be called after all calls to `MatSetValuesLocal()` have been completed.

2442:   Fortran Notes:
2443:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2444: .vb
2445:   call MatSetValuesLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2446: .ve

2448:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2450: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2451:           `MatGetValuesLocal()`
2452: @*/
2453: PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2454: {
2455:   PetscFunctionBeginHot;
2458:   MatCheckPreallocated(mat, 1);
2459:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2460:   PetscAssertPointer(irow, 3);
2461:   PetscAssertPointer(icol, 5);
2462:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2463:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2464:   if (PetscDefined(USE_DEBUG)) {
2465:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2466:     PetscCheck(mat->ops->setvalueslocal || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2467:   }

2469:   if (mat->assembled) {
2470:     mat->was_assembled = PETSC_TRUE;
2471:     mat->assembled     = PETSC_FALSE;
2472:   }
2473:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2474:   if (mat->ops->setvalueslocal) PetscUseTypeMethod(mat, setvalueslocal, nrow, irow, ncol, icol, y, addv);
2475:   else {
2476:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2477:     const PetscInt *irowm, *icolm;

2479:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2480:       bufr  = buf;
2481:       bufc  = buf + nrow;
2482:       irowm = bufr;
2483:       icolm = bufc;
2484:     } else {
2485:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2486:       irowm = bufr;
2487:       icolm = bufc;
2488:     }
2489:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, bufr));
2490:     else irowm = irow;
2491:     if (mat->cmap->mapping) {
2492:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, bufc));
2493:       else icolm = irowm;
2494:     } else icolm = icol;
2495:     PetscCall(MatSetValues(mat, nrow, irowm, ncol, icolm, y, addv));
2496:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2497:   }
2498:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2499:   PetscFunctionReturn(PETSC_SUCCESS);
2500: }

2502: /*@
2503:   MatSetValuesBlockedLocal - Inserts or adds values into certain locations of a matrix,
2504:   using a local ordering of the nodes a block at a time.

2506:   Not Collective

2508:   Input Parameters:
2509: + mat  - the matrix
2510: . nrow - number of rows
2511: . irow - the row local indices
2512: . ncol - number of columns
2513: . icol - the column local indices
2514: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2515:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2516: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2518:   Level: intermediate

2520:   Notes:
2521:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetBlockSize()` and `MatSetLocalToGlobalMapping()`
2522:   before using this routineBefore calling `MatSetValuesLocal()`, the user must first set the

2524:   Calls to `MatSetValuesBlockedLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2525:   options cannot be mixed without intervening calls to the assembly
2526:   routines.

2528:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2529:   MUST be called after all calls to `MatSetValuesBlockedLocal()` have been completed.

2531:   Fortran Notes:
2532:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2533: .vb
2534:   call MatSetValuesBlockedLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2535: .ve

2537:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2539: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`,
2540:           `MatSetValuesLocal()`, `MatSetValuesBlocked()`
2541: @*/
2542: PetscErrorCode MatSetValuesBlockedLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2543: {
2544:   PetscFunctionBeginHot;
2547:   MatCheckPreallocated(mat, 1);
2548:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2549:   PetscAssertPointer(irow, 3);
2550:   PetscAssertPointer(icol, 5);
2551:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2552:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2553:   if (PetscDefined(USE_DEBUG)) {
2554:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2555:     PetscCheck(mat->ops->setvaluesblockedlocal || mat->ops->setvaluesblocked || mat->ops->setvalueslocal || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2556:   }

2558:   if (mat->assembled) {
2559:     mat->was_assembled = PETSC_TRUE;
2560:     mat->assembled     = PETSC_FALSE;
2561:   }
2562:   if (PetscUnlikelyDebug(mat->rmap->mapping)) { /* Condition on the mapping existing, because MatSetValuesBlockedLocal_IS does not require it to be set. */
2563:     PetscInt irbs, rbs;
2564:     PetscCall(MatGetBlockSizes(mat, &rbs, NULL));
2565:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->rmap->mapping, &irbs));
2566:     PetscCheck(rbs == irbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different row block sizes! mat %" PetscInt_FMT ", row l2g map %" PetscInt_FMT, rbs, irbs);
2567:   }
2568:   if (PetscUnlikelyDebug(mat->cmap->mapping)) {
2569:     PetscInt icbs, cbs;
2570:     PetscCall(MatGetBlockSizes(mat, NULL, &cbs));
2571:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->cmap->mapping, &icbs));
2572:     PetscCheck(cbs == icbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different col block sizes! mat %" PetscInt_FMT ", col l2g map %" PetscInt_FMT, cbs, icbs);
2573:   }
2574:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2575:   if (mat->ops->setvaluesblockedlocal) PetscUseTypeMethod(mat, setvaluesblockedlocal, nrow, irow, ncol, icol, y, addv);
2576:   else {
2577:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2578:     const PetscInt *irowm, *icolm;

2580:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= ((PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf))) {
2581:       bufr  = buf;
2582:       bufc  = buf + nrow;
2583:       irowm = bufr;
2584:       icolm = bufc;
2585:     } else {
2586:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2587:       irowm = bufr;
2588:       icolm = bufc;
2589:     }
2590:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->rmap->mapping, nrow, irow, bufr));
2591:     else irowm = irow;
2592:     if (mat->cmap->mapping) {
2593:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->cmap->mapping, ncol, icol, bufc));
2594:       else icolm = irowm;
2595:     } else icolm = icol;
2596:     PetscCall(MatSetValuesBlocked(mat, nrow, irowm, ncol, icolm, y, addv));
2597:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2598:   }
2599:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2600:   PetscFunctionReturn(PETSC_SUCCESS);
2601: }

2603: /*@
2604:   MatMultDiagonalBlock - Computes the matrix-vector product, $y = Dx$. Where `D` is defined by the inode or block structure of the diagonal

2606:   Collective

2608:   Input Parameters:
2609: + mat - the matrix
2610: - x   - the vector to be multiplied

2612:   Output Parameter:
2613: . y - the result

2615:   Level: developer

2617:   Note:
2618:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2619:   call `MatMultDiagonalBlock`(A,y,y).

2621: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2622: @*/
2623: PetscErrorCode MatMultDiagonalBlock(Mat mat, Vec x, Vec y)
2624: {
2625:   PetscFunctionBegin;

2631:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2632:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2633:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2634:   MatCheckPreallocated(mat, 1);

2636:   PetscUseTypeMethod(mat, multdiagonalblock, x, y);
2637:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2638:   PetscFunctionReturn(PETSC_SUCCESS);
2639: }

2641: /*@
2642:   MatMult - Computes the matrix-vector product, $y = Ax$.

2644:   Neighbor-wise Collective

2646:   Input Parameters:
2647: + mat - the matrix
2648: - x   - the vector to be multiplied

2650:   Output Parameter:
2651: . y - the result

2653:   Level: beginner

2655:   Note:
2656:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2657:   call `MatMult`(A,y,y).

2659: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2660: @*/
2661: PetscErrorCode MatMult(Mat mat, Vec x, Vec y)
2662: {
2663:   PetscFunctionBegin;
2667:   VecCheckAssembled(x);
2669:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2670:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2671:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2672:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
2673:   PetscCheck(mat->rmap->N == y->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, y->map->N);
2674:   PetscCheck(mat->cmap->n == x->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->n, x->map->n);
2675:   PetscCheck(mat->rmap->n == y->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, y->map->n);
2676:   PetscCall(VecSetErrorIfLocked(y, 3));
2677:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2678:   MatCheckPreallocated(mat, 1);

2680:   PetscCall(VecLockReadPush(x));
2681:   PetscCall(PetscLogEventBegin(MAT_Mult, mat, x, y, 0));
2682:   PetscUseTypeMethod(mat, mult, x, y);
2683:   PetscCall(PetscLogEventEnd(MAT_Mult, mat, x, y, 0));
2684:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2685:   PetscCall(VecLockReadPop(x));
2686:   PetscFunctionReturn(PETSC_SUCCESS);
2687: }

2689: /*@
2690:   MatMultTranspose - Computes matrix transpose times a vector $y = A^T * x$.

2692:   Neighbor-wise Collective

2694:   Input Parameters:
2695: + mat - the matrix
2696: - x   - the vector to be multiplied

2698:   Output Parameter:
2699: . y - the result

2701:   Level: beginner

2703:   Notes:
2704:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2705:   call `MatMultTranspose`(A,y,y).

2707:   For complex numbers this does NOT compute the Hermitian (complex conjugate) transpose multiple,
2708:   use `MatMultHermitianTranspose()`

2710: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatMultHermitianTranspose()`, `MatTranspose()`
2711: @*/
2712: PetscErrorCode MatMultTranspose(Mat mat, Vec x, Vec y)
2713: {
2714:   PetscErrorCode (*op)(Mat, Vec, Vec) = NULL;

2716:   PetscFunctionBegin;
2720:   VecCheckAssembled(x);

2723:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2724:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2725:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2726:   PetscCheck(mat->cmap->N == y->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, y->map->N);
2727:   PetscCheck(mat->rmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, x->map->N);
2728:   PetscCheck(mat->cmap->n == y->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->n, y->map->n);
2729:   PetscCheck(mat->rmap->n == x->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, x->map->n);
2730:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2731:   MatCheckPreallocated(mat, 1);

2733:   if (!mat->ops->multtranspose) {
2734:     if (mat->symmetric == PETSC_BOOL3_TRUE && mat->ops->mult) op = mat->ops->mult;
2735:     PetscCheck(op, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Matrix type %s does not have a multiply transpose defined or is symmetric and does not have a multiply defined", ((PetscObject)mat)->type_name);
2736:   } else op = mat->ops->multtranspose;
2737:   PetscCall(PetscLogEventBegin(MAT_MultTranspose, mat, x, y, 0));
2738:   PetscCall(VecLockReadPush(x));
2739:   PetscCall((*op)(mat, x, y));
2740:   PetscCall(VecLockReadPop(x));
2741:   PetscCall(PetscLogEventEnd(MAT_MultTranspose, mat, x, y, 0));
2742:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2743:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2744:   PetscFunctionReturn(PETSC_SUCCESS);
2745: }

2747: /*@
2748:   MatMultHermitianTranspose - Computes matrix Hermitian-transpose times a vector $y = A^H * x$.

2750:   Neighbor-wise Collective

2752:   Input Parameters:
2753: + mat - the matrix
2754: - x   - the vector to be multiplied

2756:   Output Parameter:
2757: . y - the result

2759:   Level: beginner

2761:   Notes:
2762:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2763:   call `MatMultHermitianTranspose`(A,y,y).

2765:   Also called the conjugate transpose, complex conjugate transpose, or adjoint.

2767:   For real numbers `MatMultTranspose()` and `MatMultHermitianTranspose()` are identical.

2769: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultHermitianTransposeAdd()`, `MatMultTranspose()`
2770: @*/
2771: PetscErrorCode MatMultHermitianTranspose(Mat mat, Vec x, Vec y)
2772: {
2773:   PetscFunctionBegin;

2779:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2780:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2781:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2782:   PetscCheck(mat->cmap->N == y->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, y->map->N);
2783:   PetscCheck(mat->rmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, x->map->N);
2784:   PetscCheck(mat->cmap->n == y->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->n, y->map->n);
2785:   PetscCheck(mat->rmap->n == x->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, x->map->n);
2786:   MatCheckPreallocated(mat, 1);

2788:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTranspose, mat, x, y, 0));
2789: #if defined(PETSC_USE_COMPLEX)
2790:   if (mat->ops->multhermitiantranspose || (mat->hermitian == PETSC_BOOL3_TRUE && mat->ops->mult)) {
2791:     PetscCall(VecLockReadPush(x));
2792:     if (mat->ops->multhermitiantranspose) PetscUseTypeMethod(mat, multhermitiantranspose, x, y);
2793:     else PetscUseTypeMethod(mat, mult, x, y);
2794:     PetscCall(VecLockReadPop(x));
2795:   } else {
2796:     Vec w;
2797:     PetscCall(VecDuplicate(x, &w));
2798:     PetscCall(VecCopy(x, w));
2799:     PetscCall(VecConjugate(w));
2800:     PetscCall(MatMultTranspose(mat, w, y));
2801:     PetscCall(VecDestroy(&w));
2802:     PetscCall(VecConjugate(y));
2803:   }
2804:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2805: #else
2806:   PetscCall(MatMultTranspose(mat, x, y));
2807: #endif
2808:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTranspose, mat, x, y, 0));
2809:   PetscFunctionReturn(PETSC_SUCCESS);
2810: }

2812: /*@
2813:   MatMultAdd -  Computes $v3 = v2 + A * v1$.

2815:   Neighbor-wise Collective

2817:   Input Parameters:
2818: + mat - the matrix
2819: . v1  - the vector to be multiplied by `mat`
2820: - v2  - the vector to be added to the result

2822:   Output Parameter:
2823: . v3 - the result

2825:   Level: beginner

2827:   Note:
2828:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2829:   call `MatMultAdd`(A,v1,v2,v1).

2831: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMult()`, `MatMultTransposeAdd()`
2832: @*/
2833: PetscErrorCode MatMultAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2834: {
2835:   PetscFunctionBegin;

2842:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2843:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2844:   PetscCheck(mat->cmap->N == v1->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v1: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, v1->map->N);
2845:   /* PetscCheck(mat->rmap->N == v2->map->N,PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Mat mat,Vec v2: global dim %" PetscInt_FMT " %" PetscInt_FMT,mat->rmap->N,v2->map->N);
2846:      PetscCheck(mat->rmap->N == v3->map->N,PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Mat mat,Vec v3: global dim %" PetscInt_FMT " %" PetscInt_FMT,mat->rmap->N,v3->map->N); */
2847:   PetscCheck(mat->rmap->n == v3->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec v3: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, v3->map->n);
2848:   PetscCheck(mat->rmap->n == v2->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec v2: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, v2->map->n);
2849:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2850:   MatCheckPreallocated(mat, 1);

2852:   PetscCall(PetscLogEventBegin(MAT_MultAdd, mat, v1, v2, v3));
2853:   PetscCall(VecLockReadPush(v1));
2854:   PetscUseTypeMethod(mat, multadd, v1, v2, v3);
2855:   PetscCall(VecLockReadPop(v1));
2856:   PetscCall(PetscLogEventEnd(MAT_MultAdd, mat, v1, v2, v3));
2857:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2858:   PetscFunctionReturn(PETSC_SUCCESS);
2859: }

2861: /*@
2862:   MatMultTransposeAdd - Computes $v3 = v2 + A^T * v1$.

2864:   Neighbor-wise Collective

2866:   Input Parameters:
2867: + mat - the matrix
2868: . v1  - the vector to be multiplied by the transpose of the matrix
2869: - v2  - the vector to be added to the result

2871:   Output Parameter:
2872: . v3 - the result

2874:   Level: beginner

2876:   Note:
2877:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2878:   call `MatMultTransposeAdd`(A,v1,v2,v1).

2880: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2881: @*/
2882: PetscErrorCode MatMultTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2883: {
2884:   PetscErrorCode (*op)(Mat, Vec, Vec, Vec) = (!mat->ops->multtransposeadd && mat->symmetric) ? mat->ops->multadd : mat->ops->multtransposeadd;

2886:   PetscFunctionBegin;

2893:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2894:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2895:   PetscCheck(mat->rmap->N == v1->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v1: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, v1->map->N);
2896:   PetscCheck(mat->cmap->N == v2->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v2: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, v2->map->N);
2897:   PetscCheck(mat->cmap->N == v3->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v3: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, v3->map->N);
2898:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2899:   PetscCheck(op, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2900:   MatCheckPreallocated(mat, 1);

2902:   PetscCall(PetscLogEventBegin(MAT_MultTransposeAdd, mat, v1, v2, v3));
2903:   PetscCall(VecLockReadPush(v1));
2904:   PetscCall((*op)(mat, v1, v2, v3));
2905:   PetscCall(VecLockReadPop(v1));
2906:   PetscCall(PetscLogEventEnd(MAT_MultTransposeAdd, mat, v1, v2, v3));
2907:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2908:   PetscFunctionReturn(PETSC_SUCCESS);
2909: }

2911: /*@
2912:   MatMultHermitianTransposeAdd - Computes $v3 = v2 + A^H * v1$.

2914:   Neighbor-wise Collective

2916:   Input Parameters:
2917: + mat - the matrix
2918: . v1  - the vector to be multiplied by the Hermitian transpose
2919: - v2  - the vector to be added to the result

2921:   Output Parameter:
2922: . v3 - the result

2924:   Level: beginner

2926:   Note:
2927:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2928:   call `MatMultHermitianTransposeAdd`(A,v1,v2,v1).

2930: .seealso: [](ch_matrices), `Mat`, `MatMultHermitianTranspose()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2931: @*/
2932: PetscErrorCode MatMultHermitianTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2933: {
2934:   PetscFunctionBegin;

2941:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2942:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2943:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2944:   PetscCheck(mat->rmap->N == v1->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v1: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, v1->map->N);
2945:   PetscCheck(mat->cmap->N == v2->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v2: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, v2->map->N);
2946:   PetscCheck(mat->cmap->N == v3->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec v3: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, v3->map->N);
2947:   MatCheckPreallocated(mat, 1);

2949:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2950:   PetscCall(VecLockReadPush(v1));
2951:   if (mat->ops->multhermitiantransposeadd) PetscUseTypeMethod(mat, multhermitiantransposeadd, v1, v2, v3);
2952:   else {
2953:     Vec w, z;
2954:     PetscCall(VecDuplicate(v1, &w));
2955:     PetscCall(VecCopy(v1, w));
2956:     PetscCall(VecConjugate(w));
2957:     PetscCall(VecDuplicate(v3, &z));
2958:     PetscCall(MatMultTranspose(mat, w, z));
2959:     PetscCall(VecDestroy(&w));
2960:     PetscCall(VecConjugate(z));
2961:     if (v2 != v3) PetscCall(VecWAXPY(v3, 1.0, v2, z));
2962:     else PetscCall(VecAXPY(v3, 1.0, z));
2963:     PetscCall(VecDestroy(&z));
2964:   }
2965:   PetscCall(VecLockReadPop(v1));
2966:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2967:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2968:   PetscFunctionReturn(PETSC_SUCCESS);
2969: }

2971: PetscErrorCode MatADot_Default(Mat mat, Vec x, Vec y, PetscScalar *val)
2972: {
2973:   PetscFunctionBegin;
2974:   if (!mat->dot_vec) PetscCall(MatCreateVecs(mat, &mat->dot_vec, NULL));
2975:   PetscCall(MatMult(mat, x, mat->dot_vec));
2976:   PetscCall(VecDot(mat->dot_vec, y, val));
2977:   PetscFunctionReturn(PETSC_SUCCESS);
2978: }

2980: PetscErrorCode MatANorm_Default(Mat mat, Vec x, PetscReal *val)
2981: {
2982:   PetscScalar sval;

2984:   PetscFunctionBegin;
2985:   PetscCall(MatADot_Default(mat, x, x, &sval));
2986:   PetscCheck(PetscRealPart(sval) >= 0.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix argument is not positive definite");
2987:   PetscCheck(PetscAbsReal(PetscImaginaryPart(sval)) < 100 * PETSC_MACHINE_EPSILON, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix argument is not Hermitian");
2988:   *val = PetscSqrtReal(PetscRealPart(sval));
2989:   PetscFunctionReturn(PETSC_SUCCESS);
2990: }

2992: /*@
2993:   MatADot - Computes the inner product with respect to a matrix, i.e., $(x, y)_A = y^H A x$ where $A$ is symmetric (Hermitian when using complex)
2994:   positive definite.

2996:   Collective

2998:   Input Parameters:
2999: + mat - matrix used to define the inner product
3000: . x   - first vector
3001: - y   - second vector

3003:   Output Parameter:
3004: . val - the dot product with respect to `A`

3006:   Level: intermediate

3008:   Note:
3009:   For complex vectors, `MatADot()` computes
3010: $$
3011:   val = (x,y)_A = y^H A x,
3012: $$
3013:   where $y^H$ denotes the conjugate transpose of `y`. Note that this corresponds to the "mathematicians" complex
3014:   inner product where the SECOND argument gets the complex conjugate.

3016: .seealso: [](ch_matrices), `Mat`, `MatANorm()`, `VecDot()`, `VecNorm()`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`
3017: @*/
3018: PetscErrorCode MatADot(Mat mat, Vec x, Vec y, PetscScalar *val)
3019: {
3020:   PetscFunctionBegin;
3024:   VecCheckAssembled(x);
3026:   VecCheckAssembled(y);
3029:   PetscAssertPointer(val, 4);
3030:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3031:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3032:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
3033:   PetscCheck(mat->rmap->N == y->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, y->map->N);
3034:   PetscCheck(mat->cmap->n == x->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->n, x->map->n);
3035:   PetscCheck(mat->rmap->n == y->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, y->map->n);
3036:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
3037:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_TRUE));
3038:   MatCheckPreallocated(mat, 1);

3040:   PetscCall(VecLockReadPush(x));
3041:   PetscCall(VecLockReadPush(y));
3042:   PetscCall(PetscLogEventBegin(MAT_ADot, mat, x, y, 0));
3043:   PetscUseTypeMethod(mat, adot, x, y, val);
3044:   PetscCall(PetscLogEventEnd(MAT_ADot, mat, x, y, 0));
3045:   PetscCall(VecLockReadPop(y));
3046:   PetscCall(VecLockReadPop(x));
3047:   PetscFunctionReturn(PETSC_SUCCESS);
3048: }

3050: /*@
3051:   MatANorm - Computes the norm with respect to a matrix, i.e., $(x, x)_A^{1/2} = (x^H A x)^{1/2}$ where $A$ is symmetric (Hermitian when using complex)
3052:   positive definite.

3054:   Collective

3056:   Input Parameters:
3057: + mat - matrix used to define norm
3058: - x   - the vector to compute the norm of

3060:   Output Parameter:
3061: . val - the norm with respect to `A`

3063:   Level: intermediate

3065:   Note:
3066:   For complex vectors, `MatANorm()` computes
3067: $$
3068:   val = (x,x)_A^{1/2} = (x^H A x)^{1/2},
3069: $$
3070:   where $x^H$ denotes the conjugate transpose of `x`.

3072: .seealso: [](ch_matrices), `Mat`, `MatADot()`, `VecDot()`, `VecNorm()`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`
3073: @*/
3074: PetscErrorCode MatANorm(Mat mat, Vec x, PetscReal *val)
3075: {
3076:   PetscFunctionBegin;
3080:   VecCheckAssembled(x);
3082:   PetscAssertPointer(val, 3);
3083:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3084:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3085:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
3086:   PetscCheck(mat->rmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, x->map->N);
3087:   PetscCheck(mat->cmap->n == x->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->n, x->map->n);
3088:   PetscCheck(mat->rmap->n == x->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, x->map->n);
3089:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
3090:   MatCheckPreallocated(mat, 1);

3092:   PetscCall(VecLockReadPush(x));
3093:   PetscCall(PetscLogEventBegin(MAT_ANorm, mat, x, 0, 0));
3094:   PetscUseTypeMethod(mat, anorm, x, val);
3095:   PetscCall(PetscLogEventEnd(MAT_ANorm, mat, x, 0, 0));
3096:   PetscCall(VecLockReadPop(x));
3097:   PetscFunctionReturn(PETSC_SUCCESS);
3098: }

3100: /*@
3101:   MatGetFactorType - gets the type of factorization a matrix is

3103:   Not Collective

3105:   Input Parameter:
3106: . mat - the matrix

3108:   Output Parameter:
3109: . t - the type, one of `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`, `MAT_FACTOR_ICC,MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`

3111:   Level: intermediate

3113: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatSetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3114:           `MAT_FACTOR_ICC`, `MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3115: @*/
3116: PetscErrorCode MatGetFactorType(Mat mat, MatFactorType *t)
3117: {
3118:   PetscFunctionBegin;
3121:   PetscAssertPointer(t, 2);
3122:   *t = mat->factortype;
3123:   PetscFunctionReturn(PETSC_SUCCESS);
3124: }

3126: /*@
3127:   MatSetFactorType - sets the type of factorization a matrix is

3129:   Logically Collective

3131:   Input Parameters:
3132: + mat - the matrix
3133: - t   - the type, one of `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`, `MAT_FACTOR_ICC,MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`

3135:   Level: intermediate

3137: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatGetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3138:           `MAT_FACTOR_ICC`, `MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3139: @*/
3140: PetscErrorCode MatSetFactorType(Mat mat, MatFactorType t)
3141: {
3142:   PetscFunctionBegin;
3145:   mat->factortype = t;
3146:   PetscFunctionReturn(PETSC_SUCCESS);
3147: }

3149: /*@
3150:   MatGetInfo - Returns information about matrix storage (number of
3151:   nonzeros, memory, etc.).

3153:   Collective if `MAT_GLOBAL_MAX` or `MAT_GLOBAL_SUM` is used as the flag

3155:   Input Parameters:
3156: + mat  - the matrix
3157: - flag - flag indicating the type of parameters to be returned (`MAT_LOCAL` - local matrix, `MAT_GLOBAL_MAX` - maximum over all processors, `MAT_GLOBAL_SUM` - sum over all processors)

3159:   Output Parameter:
3160: . info - matrix information context

3162:   Options Database Key:
3163: . -mat_view ::ascii_info - print matrix info to `PETSC_STDOUT`

3165:   Level: intermediate

3167:   Notes:
3168:   The `MatInfo` context contains a variety of matrix data, including
3169:   number of nonzeros allocated and used, number of mallocs during
3170:   matrix assembly, etc.  Additional information for factored matrices
3171:   is provided (such as the fill ratio, number of mallocs during
3172:   factorization, etc.).

3174:   Example:
3175:   See the file ${PETSC_DIR}/include/petscmat.h for a complete list of
3176:   data within the `MatInfo` context.  For example,
3177: .vb
3178:       MatInfo info;
3179:       Mat     A;
3180:       double  mal, nz_a, nz_u;

3182:       MatGetInfo(A, MAT_LOCAL, &info);
3183:       mal  = info.mallocs;
3184:       nz_a = info.nz_allocated;
3185: .ve

3187: .seealso: [](ch_matrices), `Mat`, `MatInfo`, `MatStashGetInfo()`
3188: @*/
3189: PetscErrorCode MatGetInfo(Mat mat, MatInfoType flag, MatInfo *info)
3190: {
3191:   PetscFunctionBegin;
3194:   PetscAssertPointer(info, 3);
3195:   MatCheckPreallocated(mat, 1);
3196:   PetscUseTypeMethod(mat, getinfo, flag, info);
3197:   PetscFunctionReturn(PETSC_SUCCESS);
3198: }

3200: /*
3201:    This is used by external packages where it is not easy to get the info from the actual
3202:    matrix factorization.
3203: */
3204: PetscErrorCode MatGetInfo_External(Mat A, MatInfoType flag, MatInfo *info)
3205: {
3206:   PetscFunctionBegin;
3207:   PetscCall(PetscMemzero(info, sizeof(MatInfo)));
3208:   PetscFunctionReturn(PETSC_SUCCESS);
3209: }

3211: /*@
3212:   MatLUFactor - Performs in-place LU factorization of matrix.

3214:   Collective

3216:   Input Parameters:
3217: + mat  - the matrix
3218: . row  - row permutation
3219: . col  - column permutation
3220: - info - options for factorization, includes
3221: .vb
3222:           fill - expected fill as ratio of original fill.
3223:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3224:                    Run with the option -info to determine an optimal value to use
3225: .ve

3227:   Level: developer

3229:   Notes:
3230:   Most users should employ the `KSP` interface for linear solvers
3231:   instead of working directly with matrix algebra routines such as this.
3232:   See, e.g., `KSPCreate()`.

3234:   This changes the state of the matrix to a factored matrix; it cannot be used
3235:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3237:   This is really in-place only for dense matrices, the preferred approach is to use `MatGetFactor()`, `MatLUFactorSymbolic()`, and `MatLUFactorNumeric()`
3238:   when not using `KSP`.

3240:   Fortran Note:
3241:   A valid (non-null) `info` argument must be provided

3243: .seealso: [](ch_matrices), [Matrix Factorization](sec_matfactor), `Mat`, `MatFactorType`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
3244:           `MatGetOrdering()`, `MatSetUnfactored()`, `MatFactorInfo`, `MatGetFactor()`
3245: @*/
3246: PetscErrorCode MatLUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3247: {
3248:   MatFactorInfo tinfo;

3250:   PetscFunctionBegin;
3254:   if (info) PetscAssertPointer(info, 4);
3256:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3257:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3258:   MatCheckPreallocated(mat, 1);
3259:   if (!info) {
3260:     PetscCall(MatFactorInfoInitialize(&tinfo));
3261:     info = &tinfo;
3262:   }

3264:   PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, row, col, 0));
3265:   PetscUseTypeMethod(mat, lufactor, row, col, info);
3266:   PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, row, col, 0));
3267:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3268:   PetscFunctionReturn(PETSC_SUCCESS);
3269: }

3271: /*@
3272:   MatILUFactor - Performs in-place ILU factorization of matrix.

3274:   Collective

3276:   Input Parameters:
3277: + mat  - the matrix
3278: . row  - row permutation
3279: . col  - column permutation
3280: - info - structure containing
3281: .vb
3282:       levels - number of levels of fill.
3283:       expected fill - as ratio of original fill.
3284:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
3285:                 missing diagonal entries)
3286: .ve

3288:   Level: developer

3290:   Notes:
3291:   Most users should employ the `KSP` interface for linear solvers
3292:   instead of working directly with matrix algebra routines such as this.
3293:   See, e.g., `KSPCreate()`.

3295:   Probably really in-place only when level of fill is zero, otherwise allocates
3296:   new space to store factored matrix and deletes previous memory. The preferred approach is to use `MatGetFactor()`, `MatILUFactorSymbolic()`, and `MatILUFactorNumeric()`
3297:   when not using `KSP`.

3299:   Fortran Note:
3300:   A valid (non-null) `info` argument must be provided

3302: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatILUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
3303: @*/
3304: PetscErrorCode MatILUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3305: {
3306:   PetscFunctionBegin;
3310:   PetscAssertPointer(info, 4);
3312:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
3313:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3314:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3315:   MatCheckPreallocated(mat, 1);

3317:   PetscCall(PetscLogEventBegin(MAT_ILUFactor, mat, row, col, 0));
3318:   PetscUseTypeMethod(mat, ilufactor, row, col, info);
3319:   PetscCall(PetscLogEventEnd(MAT_ILUFactor, mat, row, col, 0));
3320:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3321:   PetscFunctionReturn(PETSC_SUCCESS);
3322: }

3324: /*@
3325:   MatLUFactorSymbolic - Performs symbolic LU factorization of matrix.
3326:   Call this routine before calling `MatLUFactorNumeric()` and after `MatGetFactor()`.

3328:   Collective

3330:   Input Parameters:
3331: + fact - the factor matrix obtained with `MatGetFactor()`
3332: . mat  - the matrix
3333: . row  - the row permutation
3334: . col  - the column permutation
3335: - info - options for factorization, includes
3336: .vb
3337:           fill - expected fill as ratio of original fill. Run with the option -info to determine an optimal value to use
3338:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3339: .ve

3341:   Level: developer

3343:   Notes:
3344:   See [Matrix Factorization](sec_matfactor) for additional information about factorizations

3346:   Most users should employ the simplified `KSP` interface for linear solvers
3347:   instead of working directly with matrix algebra routines such as this.
3348:   See, e.g., `KSPCreate()`.

3350:   Fortran Note:
3351:   A valid (non-null) `info` argument must be provided

3353: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`, `MatFactorInfoInitialize()`
3354: @*/
3355: PetscErrorCode MatLUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
3356: {
3357:   MatFactorInfo tinfo;

3359:   PetscFunctionBegin;
3364:   if (info) PetscAssertPointer(info, 5);
3367:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3368:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3369:   MatCheckPreallocated(mat, 2);
3370:   if (!info) {
3371:     PetscCall(MatFactorInfoInitialize(&tinfo));
3372:     info = &tinfo;
3373:   }

3375:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorSymbolic, mat, row, col, 0));
3376:   PetscUseTypeMethod(fact, lufactorsymbolic, mat, row, col, info);
3377:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorSymbolic, mat, row, col, 0));
3378:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3379:   PetscFunctionReturn(PETSC_SUCCESS);
3380: }

3382: /*@
3383:   MatLUFactorNumeric - Performs numeric LU factorization of a matrix.
3384:   Call this routine after first calling `MatLUFactorSymbolic()` and `MatGetFactor()`.

3386:   Collective

3388:   Input Parameters:
3389: + fact - the factor matrix obtained with `MatGetFactor()`
3390: . mat  - the matrix
3391: - info - options for factorization

3393:   Level: developer

3395:   Notes:
3396:   See `MatLUFactor()` for in-place factorization.  See
3397:   `MatCholeskyFactorNumeric()` for the symmetric, positive definite case.

3399:   Most users should employ the `KSP` interface for linear solvers
3400:   instead of working directly with matrix algebra routines such as this.
3401:   See, e.g., `KSPCreate()`.

3403:   Fortran Note:
3404:   A valid (non-null) `info` argument must be provided

3406: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactorSymbolic()`, `MatLUFactor()`, `MatCholeskyFactor()`
3407: @*/
3408: PetscErrorCode MatLUFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3409: {
3410:   MatFactorInfo tinfo;

3412:   PetscFunctionBegin;
3417:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3418:   PetscCheck(mat->rmap->N == (fact)->rmap->N && mat->cmap->N == (fact)->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Mat fact: global dimensions are different %" PetscInt_FMT " should = %" PetscInt_FMT " %" PetscInt_FMT " should = %" PetscInt_FMT,
3419:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3421:   MatCheckPreallocated(mat, 2);
3422:   if (!info) {
3423:     PetscCall(MatFactorInfoInitialize(&tinfo));
3424:     info = &tinfo;
3425:   }

3427:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorNumeric, mat, fact, 0, 0));
3428:   else PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, fact, 0, 0));
3429:   PetscUseTypeMethod(fact, lufactornumeric, mat, info);
3430:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorNumeric, mat, fact, 0, 0));
3431:   else PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, fact, 0, 0));
3432:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3433:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3434:   PetscFunctionReturn(PETSC_SUCCESS);
3435: }

3437: /*@
3438:   MatCholeskyFactor - Performs in-place Cholesky factorization of a
3439:   symmetric matrix.

3441:   Collective

3443:   Input Parameters:
3444: + mat  - the matrix
3445: . perm - row and column permutations
3446: - info - expected fill as ratio of original fill

3448:   Level: developer

3450:   Notes:
3451:   See `MatLUFactor()` for the nonsymmetric case.  See also `MatGetFactor()`,
3452:   `MatCholeskyFactorSymbolic()`, and `MatCholeskyFactorNumeric()`.

3454:   Most users should employ the `KSP` interface for linear solvers
3455:   instead of working directly with matrix algebra routines such as this.
3456:   See, e.g., `KSPCreate()`.

3458:   Fortran Note:
3459:   A valid (non-null) `info` argument must be provided

3461: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactorNumeric()`,
3462:           `MatGetOrdering()`
3463: @*/
3464: PetscErrorCode MatCholeskyFactor(Mat mat, IS perm, const MatFactorInfo *info)
3465: {
3466:   MatFactorInfo tinfo;

3468:   PetscFunctionBegin;
3471:   if (info) PetscAssertPointer(info, 3);
3473:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3474:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3475:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3476:   MatCheckPreallocated(mat, 1);
3477:   if (!info) {
3478:     PetscCall(MatFactorInfoInitialize(&tinfo));
3479:     info = &tinfo;
3480:   }

3482:   PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, perm, 0, 0));
3483:   PetscUseTypeMethod(mat, choleskyfactor, perm, info);
3484:   PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, perm, 0, 0));
3485:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3486:   PetscFunctionReturn(PETSC_SUCCESS);
3487: }

3489: /*@
3490:   MatCholeskyFactorSymbolic - Performs symbolic Cholesky factorization
3491:   of a symmetric matrix.

3493:   Collective

3495:   Input Parameters:
3496: + fact - the factor matrix obtained with `MatGetFactor()`
3497: . mat  - the matrix
3498: . perm - row and column permutations
3499: - info - options for factorization, includes
3500: .vb
3501:           fill - expected fill as ratio of original fill.
3502:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3503:                    Run with the option -info to determine an optimal value to use
3504: .ve

3506:   Level: developer

3508:   Notes:
3509:   See `MatLUFactorSymbolic()` for the nonsymmetric case.  See also
3510:   `MatCholeskyFactor()` and `MatCholeskyFactorNumeric()`.

3512:   Most users should employ the `KSP` interface for linear solvers
3513:   instead of working directly with matrix algebra routines such as this.
3514:   See, e.g., `KSPCreate()`.

3516:   Fortran Note:
3517:   A valid (non-null) `info` argument must be provided

3519: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactor()`, `MatCholeskyFactorNumeric()`,
3520:           `MatGetOrdering()`
3521: @*/
3522: PetscErrorCode MatCholeskyFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
3523: {
3524:   MatFactorInfo tinfo;

3526:   PetscFunctionBegin;
3530:   if (info) PetscAssertPointer(info, 4);
3533:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3534:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3535:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3536:   MatCheckPreallocated(mat, 2);
3537:   if (!info) {
3538:     PetscCall(MatFactorInfoInitialize(&tinfo));
3539:     info = &tinfo;
3540:   }

3542:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3543:   PetscUseTypeMethod(fact, choleskyfactorsymbolic, mat, perm, info);
3544:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3545:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3546:   PetscFunctionReturn(PETSC_SUCCESS);
3547: }

3549: /*@
3550:   MatCholeskyFactorNumeric - Performs numeric Cholesky factorization
3551:   of a symmetric matrix. Call this routine after first calling `MatGetFactor()` and
3552:   `MatCholeskyFactorSymbolic()`.

3554:   Collective

3556:   Input Parameters:
3557: + fact - the factor matrix obtained with `MatGetFactor()`, where the factored values are stored
3558: . mat  - the initial matrix that is to be factored
3559: - info - options for factorization

3561:   Level: developer

3563:   Note:
3564:   Most users should employ the `KSP` interface for linear solvers
3565:   instead of working directly with matrix algebra routines such as this.
3566:   See, e.g., `KSPCreate()`.

3568:   Fortran Note:
3569:   A valid (non-null) `info` argument must be provided

3571: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactor()`, `MatLUFactorNumeric()`
3572: @*/
3573: PetscErrorCode MatCholeskyFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3574: {
3575:   MatFactorInfo tinfo;

3577:   PetscFunctionBegin;
3582:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3583:   PetscCheck(mat->rmap->N == (fact)->rmap->N && mat->cmap->N == (fact)->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Mat fact: global dim %" PetscInt_FMT " should = %" PetscInt_FMT " %" PetscInt_FMT " should = %" PetscInt_FMT,
3584:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);
3585:   MatCheckPreallocated(mat, 2);
3586:   if (!info) {
3587:     PetscCall(MatFactorInfoInitialize(&tinfo));
3588:     info = &tinfo;
3589:   }

3591:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3592:   else PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, fact, 0, 0));
3593:   PetscUseTypeMethod(fact, choleskyfactornumeric, mat, info);
3594:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3595:   else PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, fact, 0, 0));
3596:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3597:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3598:   PetscFunctionReturn(PETSC_SUCCESS);
3599: }

3601: /*@
3602:   MatQRFactor - Performs in-place QR factorization of matrix.

3604:   Collective

3606:   Input Parameters:
3607: + mat  - the matrix
3608: . col  - column permutation
3609: - info - options for factorization, includes
3610: .vb
3611:           fill - expected fill as ratio of original fill.
3612:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3613:                    Run with the option -info to determine an optimal value to use
3614: .ve

3616:   Level: developer

3618:   Notes:
3619:   Most users should employ the `KSP` interface for linear solvers
3620:   instead of working directly with matrix algebra routines such as this.
3621:   See, e.g., `KSPCreate()`.

3623:   This changes the state of the matrix to a factored matrix; it cannot be used
3624:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3626:   Fortran Note:
3627:   A valid (non-null) `info` argument must be provided

3629: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactorSymbolic()`, `MatQRFactorNumeric()`, `MatLUFactor()`,
3630:           `MatSetUnfactored()`
3631: @*/
3632: PetscErrorCode MatQRFactor(Mat mat, IS col, const MatFactorInfo *info)
3633: {
3634:   PetscFunctionBegin;
3637:   if (info) PetscAssertPointer(info, 3);
3639:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3640:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3641:   MatCheckPreallocated(mat, 1);
3642:   PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, col, 0, 0));
3643:   PetscUseMethod(mat, "MatQRFactor_C", (Mat, IS, const MatFactorInfo *), (mat, col, info));
3644:   PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, col, 0, 0));
3645:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3646:   PetscFunctionReturn(PETSC_SUCCESS);
3647: }

3649: /*@
3650:   MatQRFactorSymbolic - Performs symbolic QR factorization of matrix.
3651:   Call this routine after `MatGetFactor()` but before calling `MatQRFactorNumeric()`.

3653:   Collective

3655:   Input Parameters:
3656: + fact - the factor matrix obtained with `MatGetFactor()`
3657: . mat  - the matrix
3658: . col  - column permutation
3659: - info - options for factorization, includes
3660: .vb
3661:           fill - expected fill as ratio of original fill.
3662:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3663:                    Run with the option -info to determine an optimal value to use
3664: .ve

3666:   Level: developer

3668:   Note:
3669:   Most users should employ the `KSP` interface for linear solvers
3670:   instead of working directly with matrix algebra routines such as this.
3671:   See, e.g., `KSPCreate()`.

3673:   Fortran Note:
3674:   A valid (non-null) `info` argument must be provided

3676: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatQRFactor()`, `MatQRFactorNumeric()`, `MatLUFactor()`, `MatFactorInfoInitialize()`
3677: @*/
3678: PetscErrorCode MatQRFactorSymbolic(Mat fact, Mat mat, IS col, const MatFactorInfo *info)
3679: {
3680:   MatFactorInfo tinfo;

3682:   PetscFunctionBegin;
3686:   if (info) PetscAssertPointer(info, 4);
3689:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3690:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3691:   MatCheckPreallocated(mat, 2);
3692:   if (!info) {
3693:     PetscCall(MatFactorInfoInitialize(&tinfo));
3694:     info = &tinfo;
3695:   }

3697:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorSymbolic, fact, mat, col, 0));
3698:   PetscUseMethod(fact, "MatQRFactorSymbolic_C", (Mat, Mat, IS, const MatFactorInfo *), (fact, mat, col, info));
3699:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorSymbolic, fact, mat, col, 0));
3700:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3701:   PetscFunctionReturn(PETSC_SUCCESS);
3702: }

3704: /*@
3705:   MatQRFactorNumeric - Performs numeric QR factorization of a matrix.
3706:   Call this routine after first calling `MatGetFactor()`, and `MatQRFactorSymbolic()`.

3708:   Collective

3710:   Input Parameters:
3711: + fact - the factor matrix obtained with `MatGetFactor()`
3712: . mat  - the matrix
3713: - info - options for factorization

3715:   Level: developer

3717:   Notes:
3718:   See `MatQRFactor()` for in-place factorization.

3720:   Most users should employ the `KSP` interface for linear solvers
3721:   instead of working directly with matrix algebra routines such as this.
3722:   See, e.g., `KSPCreate()`.

3724:   Fortran Note:
3725:   A valid (non-null) `info` argument must be provided

3727: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactor()`, `MatQRFactorSymbolic()`, `MatLUFactor()`
3728: @*/
3729: PetscErrorCode MatQRFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3730: {
3731:   MatFactorInfo tinfo;

3733:   PetscFunctionBegin;
3738:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3739:   PetscCheck(mat->rmap->N == fact->rmap->N && mat->cmap->N == fact->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Mat fact: global dimensions are different %" PetscInt_FMT " should = %" PetscInt_FMT " %" PetscInt_FMT " should = %" PetscInt_FMT,
3740:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3742:   MatCheckPreallocated(mat, 2);
3743:   if (!info) {
3744:     PetscCall(MatFactorInfoInitialize(&tinfo));
3745:     info = &tinfo;
3746:   }

3748:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorNumeric, mat, fact, 0, 0));
3749:   else PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, fact, 0, 0));
3750:   PetscUseMethod(fact, "MatQRFactorNumeric_C", (Mat, Mat, const MatFactorInfo *), (fact, mat, info));
3751:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorNumeric, mat, fact, 0, 0));
3752:   else PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, fact, 0, 0));
3753:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3754:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3755:   PetscFunctionReturn(PETSC_SUCCESS);
3756: }

3758: /*@
3759:   MatSolve - Solves $A x = b$, given a factored matrix.

3761:   Neighbor-wise Collective

3763:   Input Parameters:
3764: + mat - the factored matrix
3765: - b   - the right-hand-side vector

3767:   Output Parameter:
3768: . x - the result vector

3770:   Level: developer

3772:   Notes:
3773:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3774:   call `MatSolve`(A,x,x).

3776:   Most users should employ the `KSP` interface for linear solvers
3777:   instead of working directly with matrix algebra routines such as this.
3778:   See, e.g., `KSPCreate()`.

3780: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
3781: @*/
3782: PetscErrorCode MatSolve(Mat mat, Vec b, Vec x)
3783: {
3784:   PetscFunctionBegin;
3789:   PetscCheckSameComm(mat, 1, b, 2);
3790:   PetscCheckSameComm(mat, 1, x, 3);
3791:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3792:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
3793:   PetscCheck(mat->rmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, b->map->N);
3794:   PetscCheck(mat->rmap->n == b->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, b->map->n);
3795:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3796:   MatCheckPreallocated(mat, 1);

3798:   PetscCall(PetscLogEventBegin(MAT_Solve, mat, b, x, 0));
3799:   PetscCall(VecFlag(x, mat->factorerrortype));
3800:   if (mat->factorerrortype) PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
3801:   else PetscUseTypeMethod(mat, solve, b, x);
3802:   PetscCall(PetscLogEventEnd(MAT_Solve, mat, b, x, 0));
3803:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3804:   PetscFunctionReturn(PETSC_SUCCESS);
3805: }

3807: static PetscErrorCode MatMatSolve_Basic(Mat A, Mat B, Mat X, PetscBool trans)
3808: {
3809:   Vec      b, x;
3810:   PetscInt N, i;
3811:   PetscErrorCode (*f)(Mat, Vec, Vec);
3812:   PetscBool Abound, Bneedconv = PETSC_FALSE, Xneedconv = PETSC_FALSE;

3814:   PetscFunctionBegin;
3815:   if (A->factorerrortype) {
3816:     PetscCall(PetscInfo(A, "MatFactorError %d\n", A->factorerrortype));
3817:     PetscCall(MatSetInf(X));
3818:     PetscFunctionReturn(PETSC_SUCCESS);
3819:   }
3820:   f = (!trans || (!A->ops->solvetranspose && A->symmetric)) ? A->ops->solve : A->ops->solvetranspose;
3821:   PetscCheck(f, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)A)->type_name);
3822:   PetscCall(MatBoundToCPU(A, &Abound));
3823:   if (!Abound) {
3824:     PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &Bneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3825:     PetscCall(PetscObjectTypeCompareAny((PetscObject)X, &Xneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3826:   }
3827: #if PetscDefined(HAVE_CUDA)
3828:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSECUDA, MAT_INPLACE_MATRIX, &B));
3829:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSECUDA, MAT_INPLACE_MATRIX, &X));
3830: #elif PetscDefined(HAVE_HIP)
3831:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSEHIP, MAT_INPLACE_MATRIX, &B));
3832:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSEHIP, MAT_INPLACE_MATRIX, &X));
3833: #endif
3834:   PetscCall(MatGetSize(B, NULL, &N));
3835:   for (i = 0; i < N; i++) {
3836:     PetscCall(MatDenseGetColumnVecRead(B, i, &b));
3837:     PetscCall(MatDenseGetColumnVecWrite(X, i, &x));
3838:     PetscCall((*f)(A, b, x));
3839:     PetscCall(MatDenseRestoreColumnVecWrite(X, i, &x));
3840:     PetscCall(MatDenseRestoreColumnVecRead(B, i, &b));
3841:   }
3842:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSE, MAT_INPLACE_MATRIX, &B));
3843:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSE, MAT_INPLACE_MATRIX, &X));
3844:   PetscFunctionReturn(PETSC_SUCCESS);
3845: }

3847: /*@
3848:   MatMatSolve - Solves $A X = B$, given a factored matrix.

3850:   Neighbor-wise Collective

3852:   Input Parameters:
3853: + A - the factored matrix
3854: - B - the right-hand-side matrix `MATDENSE` (or sparse `MATAIJ`-- when using MUMPS)

3856:   Output Parameter:
3857: . X - the result matrix (dense matrix)

3859:   Level: developer

3861:   Note:
3862:   If `B` is a `MATDENSE` matrix then one can call `MatMatSolve`(A,B,B) except with `MATSOLVERMKL_CPARDISO`;
3863:   otherwise, `B` and `X` cannot be the same.

3865: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3866: @*/
3867: PetscErrorCode MatMatSolve(Mat A, Mat B, Mat X)
3868: {
3869:   PetscFunctionBegin;
3874:   PetscCheckSameComm(A, 1, B, 2);
3875:   PetscCheckSameComm(A, 1, X, 3);
3876:   PetscCheck(A->cmap->N == X->rmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat X: global dim %" PetscInt_FMT " %" PetscInt_FMT, A->cmap->N, X->rmap->N);
3877:   PetscCheck(A->rmap->N == B->rmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat B: global dim %" PetscInt_FMT " %" PetscInt_FMT, A->rmap->N, B->rmap->N);
3878:   PetscCheck(X->cmap->N == B->cmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Solution matrix must have same number of columns as rhs matrix");
3879:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3880:   MatCheckPreallocated(A, 1);

3882:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3883:   if (!A->ops->matsolve) {
3884:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolve\n", ((PetscObject)A)->type_name));
3885:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_FALSE));
3886:   } else PetscUseTypeMethod(A, matsolve, B, X);
3887:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3888:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3889:   PetscFunctionReturn(PETSC_SUCCESS);
3890: }

3892: /*@
3893:   MatMatSolveTranspose - Solves $A^T X = B $, given a factored matrix.

3895:   Neighbor-wise Collective

3897:   Input Parameters:
3898: + A - the factored matrix
3899: - B - the right-hand-side matrix  (`MATDENSE` matrix)

3901:   Output Parameter:
3902: . X - the result matrix (dense matrix)

3904:   Level: developer

3906:   Note:
3907:   The matrices `B` and `X` cannot be the same.  I.e., one cannot
3908:   call `MatMatSolveTranspose`(A,X,X).

3910: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolveTranspose()`, `MatMatSolve()`, `MatLUFactor()`, `MatCholeskyFactor()`
3911: @*/
3912: PetscErrorCode MatMatSolveTranspose(Mat A, Mat B, Mat X)
3913: {
3914:   PetscFunctionBegin;
3919:   PetscCheckSameComm(A, 1, B, 2);
3920:   PetscCheckSameComm(A, 1, X, 3);
3921:   PetscCheck(X != B, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3922:   PetscCheck(A->cmap->N == X->rmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat X: global dim %" PetscInt_FMT " %" PetscInt_FMT, A->cmap->N, X->rmap->N);
3923:   PetscCheck(A->rmap->N == B->rmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat B: global dim %" PetscInt_FMT " %" PetscInt_FMT, A->rmap->N, B->rmap->N);
3924:   PetscCheck(A->rmap->n == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat A,Mat B: local dim %" PetscInt_FMT " %" PetscInt_FMT, A->rmap->n, B->rmap->n);
3925:   PetscCheck(X->cmap->N >= B->cmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Solution matrix must have same number of columns as rhs matrix");
3926:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3927:   MatCheckPreallocated(A, 1);

3929:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3930:   if (!A->ops->matsolvetranspose) {
3931:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolveTranspose\n", ((PetscObject)A)->type_name));
3932:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_TRUE));
3933:   } else PetscUseTypeMethod(A, matsolvetranspose, B, X);
3934:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3935:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3936:   PetscFunctionReturn(PETSC_SUCCESS);
3937: }

3939: /*@
3940:   MatMatTransposeSolve - Solves $A X = B^T$, given a factored matrix.

3942:   Neighbor-wise Collective

3944:   Input Parameters:
3945: + A  - the factored matrix
3946: - Bt - the transpose of right-hand-side matrix as a `MATDENSE`

3948:   Output Parameter:
3949: . X - the result matrix (dense matrix)

3951:   Level: developer

3953:   Note:
3954:   For MUMPS, it only supports centralized sparse compressed column format on the host processor for right-hand side matrix. User must create `Bt` in sparse compressed row
3955:   format on the host processor and call `MatMatTransposeSolve()` to implement MUMPS' `MatMatSolve()`.

3957: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatMatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3958: @*/
3959: PetscErrorCode MatMatTransposeSolve(Mat A, Mat Bt, Mat X)
3960: {
3961:   PetscFunctionBegin;
3966:   PetscCheckSameComm(A, 1, Bt, 2);
3967:   PetscCheckSameComm(A, 1, X, 3);

3969:   PetscCheck(X != Bt, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3970:   PetscCheck(A->cmap->N == X->rmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat X: global dim %" PetscInt_FMT " %" PetscInt_FMT, A->cmap->N, X->rmap->N);
3971:   PetscCheck(A->rmap->N == Bt->cmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat Bt: global dim %" PetscInt_FMT " %" PetscInt_FMT, A->rmap->N, Bt->cmap->N);
3972:   PetscCheck(X->cmap->N >= Bt->rmap->N, PetscObjectComm((PetscObject)X), PETSC_ERR_ARG_SIZ, "Solution matrix must have same number of columns as row number of the rhs matrix");
3973:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3974:   PetscCheck(A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
3975:   MatCheckPreallocated(A, 1);

3977:   PetscCall(PetscLogEventBegin(MAT_MatTrSolve, A, Bt, X, 0));
3978:   PetscUseTypeMethod(A, mattransposesolve, Bt, X);
3979:   PetscCall(PetscLogEventEnd(MAT_MatTrSolve, A, Bt, X, 0));
3980:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3981:   PetscFunctionReturn(PETSC_SUCCESS);
3982: }

3984: /*@
3985:   MatForwardSolve - Solves $ L x = b $, given a factored matrix, $A = LU $, or
3986:   $U^T*D^(1/2) x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3988:   Neighbor-wise Collective

3990:   Input Parameters:
3991: + mat - the factored matrix
3992: - b   - the right-hand-side vector

3994:   Output Parameter:
3995: . x - the result vector

3997:   Level: developer

3999:   Notes:
4000:   `MatSolve()` should be used for most applications, as it performs
4001:   a forward solve followed by a backward solve.

4003:   The vectors `b` and `x` cannot be the same,  i.e., one cannot
4004:   call `MatForwardSolve`(A,x,x).

4006:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
4007:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
4008:   `MatForwardSolve()` solves $U^T*D y = b$, and
4009:   `MatBackwardSolve()` solves $U x = y$.
4010:   Thus they do not provide a symmetric preconditioner.

4012: .seealso: [](ch_matrices), `Mat`, `MatBackwardSolve()`, `MatGetFactor()`, `MatSolve()`
4013: @*/
4014: PetscErrorCode MatForwardSolve(Mat mat, Vec b, Vec x)
4015: {
4016:   PetscFunctionBegin;
4021:   PetscCheckSameComm(mat, 1, b, 2);
4022:   PetscCheckSameComm(mat, 1, x, 3);
4023:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4024:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
4025:   PetscCheck(mat->rmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, b->map->N);
4026:   PetscCheck(mat->rmap->n == b->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, b->map->n);
4027:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4028:   MatCheckPreallocated(mat, 1);

4030:   PetscCall(PetscLogEventBegin(MAT_ForwardSolve, mat, b, x, 0));
4031:   PetscUseTypeMethod(mat, forwardsolve, b, x);
4032:   PetscCall(PetscLogEventEnd(MAT_ForwardSolve, mat, b, x, 0));
4033:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4034:   PetscFunctionReturn(PETSC_SUCCESS);
4035: }

4037: /*@
4038:   MatBackwardSolve - Solves $U x = b$, given a factored matrix, $A = LU$.
4039:   $D^(1/2) U x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

4041:   Neighbor-wise Collective

4043:   Input Parameters:
4044: + mat - the factored matrix
4045: - b   - the right-hand-side vector

4047:   Output Parameter:
4048: . x - the result vector

4050:   Level: developer

4052:   Notes:
4053:   `MatSolve()` should be used for most applications, as it performs
4054:   a forward solve followed by a backward solve.

4056:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4057:   call `MatBackwardSolve`(A,x,x).

4059:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
4060:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
4061:   `MatForwardSolve()` solves $U^T*D y = b$, and
4062:   `MatBackwardSolve()` solves $U x = y$.
4063:   Thus they do not provide a symmetric preconditioner.

4065: .seealso: [](ch_matrices), `Mat`, `MatForwardSolve()`, `MatGetFactor()`, `MatSolve()`
4066: @*/
4067: PetscErrorCode MatBackwardSolve(Mat mat, Vec b, Vec x)
4068: {
4069:   PetscFunctionBegin;
4074:   PetscCheckSameComm(mat, 1, b, 2);
4075:   PetscCheckSameComm(mat, 1, x, 3);
4076:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4077:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
4078:   PetscCheck(mat->rmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, b->map->N);
4079:   PetscCheck(mat->rmap->n == b->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, b->map->n);
4080:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4081:   MatCheckPreallocated(mat, 1);

4083:   PetscCall(PetscLogEventBegin(MAT_BackwardSolve, mat, b, x, 0));
4084:   PetscUseTypeMethod(mat, backwardsolve, b, x);
4085:   PetscCall(PetscLogEventEnd(MAT_BackwardSolve, mat, b, x, 0));
4086:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4087:   PetscFunctionReturn(PETSC_SUCCESS);
4088: }

4090: /*@
4091:   MatSolveAdd - Computes $x = y + A^{-1}*b$, given a factored matrix.

4093:   Neighbor-wise Collective

4095:   Input Parameters:
4096: + mat - the factored matrix
4097: . b   - the right-hand-side vector
4098: - y   - the vector to be added to

4100:   Output Parameter:
4101: . x - the result vector

4103:   Level: developer

4105:   Note:
4106:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4107:   call `MatSolveAdd`(A,x,y,x).

4109: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolve()`, `MatGetFactor()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
4110: @*/
4111: PetscErrorCode MatSolveAdd(Mat mat, Vec b, Vec y, Vec x)
4112: {
4113:   PetscScalar one = 1.0;
4114:   Vec         tmp;

4116:   PetscFunctionBegin;
4122:   PetscCheckSameComm(mat, 1, b, 2);
4123:   PetscCheckSameComm(mat, 1, y, 3);
4124:   PetscCheckSameComm(mat, 1, x, 4);
4125:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4126:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
4127:   PetscCheck(mat->rmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, b->map->N);
4128:   PetscCheck(mat->rmap->N == y->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, y->map->N);
4129:   PetscCheck(mat->rmap->n == b->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, b->map->n);
4130:   PetscCheck(x->map->n == y->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Vec x,Vec y: local dim %" PetscInt_FMT " %" PetscInt_FMT, x->map->n, y->map->n);
4131:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4132:   MatCheckPreallocated(mat, 1);

4134:   PetscCall(PetscLogEventBegin(MAT_SolveAdd, mat, b, x, y));
4135:   PetscCall(VecFlag(x, mat->factorerrortype));
4136:   if (mat->factorerrortype) {
4137:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4138:   } else if (mat->ops->solveadd) {
4139:     PetscUseTypeMethod(mat, solveadd, b, y, x);
4140:   } else {
4141:     /* do the solve then the add manually */
4142:     if (x != y) {
4143:       PetscCall(MatSolve(mat, b, x));
4144:       PetscCall(VecAXPY(x, one, y));
4145:     } else {
4146:       PetscCall(VecDuplicate(x, &tmp));
4147:       PetscCall(VecCopy(x, tmp));
4148:       PetscCall(MatSolve(mat, b, x));
4149:       PetscCall(VecAXPY(x, one, tmp));
4150:       PetscCall(VecDestroy(&tmp));
4151:     }
4152:   }
4153:   PetscCall(PetscLogEventEnd(MAT_SolveAdd, mat, b, x, y));
4154:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4155:   PetscFunctionReturn(PETSC_SUCCESS);
4156: }

4158: /*@
4159:   MatSolveTranspose - Solves $A^T x = b$, given a factored matrix.

4161:   Neighbor-wise Collective

4163:   Input Parameters:
4164: + mat - the factored matrix
4165: - b   - the right-hand-side vector

4167:   Output Parameter:
4168: . x - the result vector

4170:   Level: developer

4172:   Notes:
4173:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4174:   call `MatSolveTranspose`(A,x,x).

4176:   Most users should employ the `KSP` interface for linear solvers
4177:   instead of working directly with matrix algebra routines such as this.
4178:   See, e.g., `KSPCreate()`.

4180: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `KSP`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTransposeAdd()`
4181: @*/
4182: PetscErrorCode MatSolveTranspose(Mat mat, Vec b, Vec x)
4183: {
4184:   PetscErrorCode (*f)(Mat, Vec, Vec) = (!mat->ops->solvetranspose && mat->symmetric) ? mat->ops->solve : mat->ops->solvetranspose;

4186:   PetscFunctionBegin;
4191:   PetscCheckSameComm(mat, 1, b, 2);
4192:   PetscCheckSameComm(mat, 1, x, 3);
4193:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4194:   PetscCheck(mat->rmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, x->map->N);
4195:   PetscCheck(mat->cmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, b->map->N);
4196:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4197:   MatCheckPreallocated(mat, 1);
4198:   PetscCall(PetscLogEventBegin(MAT_SolveTranspose, mat, b, x, 0));
4199:   PetscCall(VecFlag(x, mat->factorerrortype));
4200:   if (mat->factorerrortype) {
4201:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4202:   } else {
4203:     PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Matrix type %s", ((PetscObject)mat)->type_name);
4204:     PetscCall((*f)(mat, b, x));
4205:   }
4206:   PetscCall(PetscLogEventEnd(MAT_SolveTranspose, mat, b, x, 0));
4207:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4208:   PetscFunctionReturn(PETSC_SUCCESS);
4209: }

4211: /*@
4212:   MatSolveTransposeAdd - Computes $x = y + A^{-T} b$
4213:   factored matrix.

4215:   Neighbor-wise Collective

4217:   Input Parameters:
4218: + mat - the factored matrix
4219: . b   - the right-hand-side vector
4220: - y   - the vector to be added to

4222:   Output Parameter:
4223: . x - the result vector

4225:   Level: developer

4227:   Note:
4228:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4229:   call `MatSolveTransposeAdd`(A,x,y,x).

4231: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTranspose()`
4232: @*/
4233: PetscErrorCode MatSolveTransposeAdd(Mat mat, Vec b, Vec y, Vec x)
4234: {
4235:   PetscScalar one = 1.0;
4236:   Vec         tmp;
4237:   PetscErrorCode (*f)(Mat, Vec, Vec, Vec) = (!mat->ops->solvetransposeadd && mat->symmetric) ? mat->ops->solveadd : mat->ops->solvetransposeadd;

4239:   PetscFunctionBegin;
4245:   PetscCheckSameComm(mat, 1, b, 2);
4246:   PetscCheckSameComm(mat, 1, y, 3);
4247:   PetscCheckSameComm(mat, 1, x, 4);
4248:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4249:   PetscCheck(mat->rmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, x->map->N);
4250:   PetscCheck(mat->cmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, b->map->N);
4251:   PetscCheck(mat->cmap->N == y->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec y: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, y->map->N);
4252:   PetscCheck(x->map->n == y->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Vec x,Vec y: local dim %" PetscInt_FMT " %" PetscInt_FMT, x->map->n, y->map->n);
4253:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4254:   MatCheckPreallocated(mat, 1);

4256:   PetscCall(PetscLogEventBegin(MAT_SolveTransposeAdd, mat, b, x, y));
4257:   PetscCall(VecFlag(x, mat->factorerrortype));
4258:   if (mat->factorerrortype) {
4259:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4260:   } else if (f) {
4261:     PetscCall((*f)(mat, b, y, x));
4262:   } else {
4263:     /* do the solve then the add manually */
4264:     if (x != y) {
4265:       PetscCall(MatSolveTranspose(mat, b, x));
4266:       PetscCall(VecAXPY(x, one, y));
4267:     } else {
4268:       PetscCall(VecDuplicate(x, &tmp));
4269:       PetscCall(VecCopy(x, tmp));
4270:       PetscCall(MatSolveTranspose(mat, b, x));
4271:       PetscCall(VecAXPY(x, one, tmp));
4272:       PetscCall(VecDestroy(&tmp));
4273:     }
4274:   }
4275:   PetscCall(PetscLogEventEnd(MAT_SolveTransposeAdd, mat, b, x, y));
4276:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4277:   PetscFunctionReturn(PETSC_SUCCESS);
4278: }

4280: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
4281: /*@
4282:   MatSOR - Computes relaxation (SOR, Gauss-Seidel) sweeps.

4284:   Neighbor-wise Collective

4286:   Input Parameters:
4287: + mat   - the matrix
4288: . b     - the right-hand side
4289: . omega - the relaxation factor
4290: . flag  - flag indicating the type of SOR (see below)
4291: . shift - diagonal shift
4292: . its   - the number of iterations
4293: - lits  - the number of local iterations

4295:   Output Parameter:
4296: . x - the solution (can contain an initial guess, use option `SOR_ZERO_INITIAL_GUESS` to indicate no guess)

4298:   SOR Flags:
4299: +     `SOR_FORWARD_SWEEP` - forward SOR
4300: .     `SOR_BACKWARD_SWEEP` - backward SOR
4301: .     `SOR_SYMMETRIC_SWEEP` - SSOR (symmetric SOR)
4302: .     `SOR_LOCAL_FORWARD_SWEEP` - local forward SOR
4303: .     `SOR_LOCAL_BACKWARD_SWEEP` - local forward SOR
4304: .     `SOR_LOCAL_SYMMETRIC_SWEEP` - local SSOR
4305: .     `SOR_EISENSTAT` - SOR with Eisenstat trick
4306: .     `SOR_APPLY_UPPER`, `SOR_APPLY_LOWER` - applies upper/lower triangular part of matrix to vector (with `omega`)
4307: -     `SOR_ZERO_INITIAL_GUESS` - zero initial guess

4309:   Level: developer

4311:   Notes:
4312:   `SOR_LOCAL_FORWARD_SWEEP`, `SOR_LOCAL_BACKWARD_SWEEP`, and
4313:   `SOR_LOCAL_SYMMETRIC_SWEEP` perform separate independent smoothings
4314:   on each processor.

4316:   Application programmers will not generally use `MatSOR()` directly,
4317:   but instead will employ `PCSOR` or `PCEISENSTAT`

4319:   For `MATBAIJ`, `MATSBAIJ`, and `MATAIJ` matrices with inodes, this does a block SOR smoothing, otherwise it does a pointwise smoothing.
4320:   For `MATAIJ` matrices with inodes, the block sizes are determined by the inode sizes, not the block size set with `MatSetBlockSize()`

4322:   Vectors `x` and `b` CANNOT be the same

4324:   The flags are implemented as bitwise inclusive or operations.
4325:   For example, use (`SOR_ZERO_INITIAL_GUESS` | `SOR_SYMMETRIC_SWEEP`)
4326:   to specify a zero initial guess for SSOR.

4328:   Developer Note:
4329:   We should add block SOR support for `MATAIJ` matrices with block size set to greater than one and no inodes

4331: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `KSP`, `PC`, `MatGetFactor()`
4332: @*/
4333: PetscErrorCode MatSOR(Mat mat, Vec b, PetscReal omega, MatSORType flag, PetscReal shift, PetscInt its, PetscInt lits, Vec x)
4334: {
4335:   PetscFunctionBegin;
4340:   PetscCheckSameComm(mat, 1, b, 2);
4341:   PetscCheckSameComm(mat, 1, x, 8);
4342:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4343:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4344:   PetscCheck(mat->cmap->N == x->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec x: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->cmap->N, x->map->N);
4345:   PetscCheck(mat->rmap->N == b->map->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: global dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->N, b->map->N);
4346:   PetscCheck(mat->rmap->n == b->map->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Mat mat,Vec b: local dim %" PetscInt_FMT " %" PetscInt_FMT, mat->rmap->n, b->map->n);
4347:   PetscCheck(its > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires global its %" PetscInt_FMT " positive", its);
4348:   PetscCheck(lits > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires local its %" PetscInt_FMT " positive", lits);
4349:   PetscCheck(b != x, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "b and x vector cannot be the same");

4351:   MatCheckPreallocated(mat, 1);
4352:   PetscCall(PetscLogEventBegin(MAT_SOR, mat, b, x, 0));
4353:   PetscUseTypeMethod(mat, sor, b, omega, flag, shift, its, lits, x);
4354:   PetscCall(PetscLogEventEnd(MAT_SOR, mat, b, x, 0));
4355:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4356:   PetscFunctionReturn(PETSC_SUCCESS);
4357: }

4359: /*
4360:       Default matrix copy routine.
4361: */
4362: PetscErrorCode MatCopy_Basic(Mat A, Mat B, MatStructure str)
4363: {
4364:   PetscInt           i, rstart = 0, rend = 0, nz;
4365:   const PetscInt    *cwork;
4366:   const PetscScalar *vwork;

4368:   PetscFunctionBegin;
4369:   if (B->assembled) PetscCall(MatZeroEntries(B));
4370:   if (str == SAME_NONZERO_PATTERN) {
4371:     PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
4372:     for (i = rstart; i < rend; i++) {
4373:       PetscCall(MatGetRow(A, i, &nz, &cwork, &vwork));
4374:       PetscCall(MatSetValues(B, 1, &i, nz, cwork, vwork, INSERT_VALUES));
4375:       PetscCall(MatRestoreRow(A, i, &nz, &cwork, &vwork));
4376:     }
4377:   } else {
4378:     PetscCall(MatAYPX(B, 0.0, A, str));
4379:   }
4380:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4381:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4382:   PetscFunctionReturn(PETSC_SUCCESS);
4383: }

4385: /*@
4386:   MatCopy - Copies a matrix to another matrix.

4388:   Collective

4390:   Input Parameters:
4391: + A   - the matrix
4392: - str - `SAME_NONZERO_PATTERN` or `DIFFERENT_NONZERO_PATTERN`

4394:   Output Parameter:
4395: . B - where the copy is put

4397:   Level: intermediate

4399:   Notes:
4400:   If you use `SAME_NONZERO_PATTERN`, then the two matrices must have the same nonzero pattern or the routine will crash.

4402:   `MatCopy()` copies the matrix entries of a matrix to another existing
4403:   matrix (after first zeroing the second matrix).  A related routine is
4404:   `MatConvert()`, which first creates a new matrix and then copies the data.

4406: .seealso: [](ch_matrices), `Mat`, `MatConvert()`, `MatDuplicate()`
4407: @*/
4408: PetscErrorCode MatCopy(Mat A, Mat B, MatStructure str)
4409: {
4410:   PetscInt i;

4412:   PetscFunctionBegin;
4417:   PetscCheckSameComm(A, 1, B, 2);
4418:   MatCheckPreallocated(B, 2);
4419:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4420:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4421:   PetscCheck(A->rmap->N == B->rmap->N && A->cmap->N == B->cmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat B: global dim (%" PetscInt_FMT ",%" PetscInt_FMT ") (%" PetscInt_FMT ",%" PetscInt_FMT ")", A->rmap->N, B->rmap->N,
4422:              A->cmap->N, B->cmap->N);
4423:   MatCheckPreallocated(A, 1);
4424:   if (A == B) PetscFunctionReturn(PETSC_SUCCESS);

4426:   PetscCall(PetscLogEventBegin(MAT_Copy, A, B, 0, 0));
4427:   if (A->ops->copy) PetscUseTypeMethod(A, copy, B, str);
4428:   else PetscCall(MatCopy_Basic(A, B, str));

4430:   B->stencil.dim = A->stencil.dim;
4431:   B->stencil.noc = A->stencil.noc;
4432:   for (i = 0; i <= A->stencil.dim + (A->stencil.noc ? 0 : -1); i++) {
4433:     B->stencil.dims[i]   = A->stencil.dims[i];
4434:     B->stencil.starts[i] = A->stencil.starts[i];
4435:   }

4437:   PetscCall(PetscLogEventEnd(MAT_Copy, A, B, 0, 0));
4438:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
4439:   PetscFunctionReturn(PETSC_SUCCESS);
4440: }

4442: /*@
4443:   MatConvert - Converts a matrix to another matrix, either of the same
4444:   or different type.

4446:   Collective

4448:   Input Parameters:
4449: + mat     - the matrix
4450: . newtype - new matrix type.  Use `MATSAME` to create a new matrix of the
4451:             same type as the original matrix.
4452: - reuse   - denotes if the destination matrix is to be created or reused.
4453:             Use `MAT_INPLACE_MATRIX` for inplace conversion (that is when you want the input `Mat` to be changed to contain the matrix in the new format), otherwise use
4454:             `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX` (can only be used after the first call was made with `MAT_INITIAL_MATRIX`, causes the matrix space in M to be reused).

4456:   Output Parameter:
4457: . M - pointer to place new matrix

4459:   Level: intermediate

4461:   Notes:
4462:   `MatConvert()` first creates a new matrix and then copies the data from
4463:   the first matrix.  A related routine is `MatCopy()`, which copies the matrix
4464:   entries of one matrix to another already existing matrix context.

4466:   Cannot be used to convert a sequential matrix to parallel or parallel to sequential,
4467:   the MPI communicator of the generated matrix is always the same as the communicator
4468:   of the input matrix.

4470: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatDuplicate()`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
4471: @*/
4472: PetscErrorCode MatConvert(Mat mat, MatType newtype, MatReuse reuse, Mat *M)
4473: {
4474:   PetscBool  sametype, issame, flg;
4475:   PetscBool3 issymmetric, ishermitian, isspd;
4476:   char       convname[256], mtype[256];
4477:   Mat        B;

4479:   PetscFunctionBegin;
4482:   PetscAssertPointer(M, 4);
4483:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4484:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4485:   MatCheckPreallocated(mat, 1);

4487:   PetscCall(PetscOptionsGetString(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matconvert_type", mtype, sizeof(mtype), &flg));
4488:   if (flg) newtype = mtype;

4490:   PetscCall(PetscObjectTypeCompare((PetscObject)mat, newtype, &sametype));
4491:   PetscCall(PetscStrcmp(newtype, "same", &issame));
4492:   PetscCheck(!(reuse == MAT_INPLACE_MATRIX) || !(mat != *M), PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires same input and output matrix");
4493:   if (reuse == MAT_REUSE_MATRIX) {
4495:     PetscCheck(mat != *M, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_REUSE_MATRIX means reuse matrix in final argument, perhaps you mean MAT_INPLACE_MATRIX");
4496:   }

4498:   if ((reuse == MAT_INPLACE_MATRIX) && (issame || sametype)) {
4499:     PetscCall(PetscInfo(mat, "Early return for inplace %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4500:     PetscFunctionReturn(PETSC_SUCCESS);
4501:   }

4503:   /* Cache Mat options because some converters use MatHeaderReplace() */
4504:   issymmetric = mat->symmetric;
4505:   ishermitian = mat->hermitian;
4506:   isspd       = mat->spd;

4508:   if ((sametype || issame) && (reuse == MAT_INITIAL_MATRIX) && mat->ops->duplicate) {
4509:     PetscCall(PetscInfo(mat, "Calling duplicate for initial matrix %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4510:     PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4511:   } else {
4512:     PetscErrorCode (*conv)(Mat, MatType, MatReuse, Mat *) = NULL;
4513:     const char *prefix[3]                                 = {"seq", "mpi", ""};
4514:     PetscInt    i;
4515:     /*
4516:        Order of precedence:
4517:        0) See if newtype is a superclass of the current matrix.
4518:        1) See if a specialized converter is known to the current matrix.
4519:        2) See if a specialized converter is known to the desired matrix class.
4520:        3) See if a good general converter is registered for the desired class
4521:           (as of 6/27/03 only MATMPIADJ falls into this category).
4522:        4) See if a good general converter is known for the current matrix.
4523:        5) Use a really basic converter.
4524:     */

4526:     /* 0) See if newtype is a superclass of the current matrix.
4527:           i.e mat is mpiaij and newtype is aij */
4528:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4529:       PetscCall(PetscStrncpy(convname, prefix[i], sizeof(convname)));
4530:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4531:       PetscCall(PetscStrcmp(convname, ((PetscObject)mat)->type_name, &flg));
4532:       PetscCall(PetscInfo(mat, "Check superclass %s %s -> %d\n", convname, ((PetscObject)mat)->type_name, flg));
4533:       if (flg) {
4534:         if (reuse == MAT_INPLACE_MATRIX) {
4535:           PetscCall(PetscInfo(mat, "Early return\n"));
4536:           PetscFunctionReturn(PETSC_SUCCESS);
4537:         } else if (reuse == MAT_INITIAL_MATRIX && mat->ops->duplicate) {
4538:           PetscCall(PetscInfo(mat, "Calling MatDuplicate\n"));
4539:           PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4540:           PetscFunctionReturn(PETSC_SUCCESS);
4541:         } else if (reuse == MAT_REUSE_MATRIX && mat->ops->copy) {
4542:           PetscCall(PetscInfo(mat, "Calling MatCopy\n"));
4543:           PetscCall(MatCopy(mat, *M, SAME_NONZERO_PATTERN));
4544:           PetscFunctionReturn(PETSC_SUCCESS);
4545:         }
4546:       }
4547:     }
4548:     /* 1) See if a specialized converter is known to the current matrix and the desired class */
4549:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4550:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4551:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4552:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4553:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4554:       PetscCall(PetscStrlcat(convname, issame ? ((PetscObject)mat)->type_name : newtype, sizeof(convname)));
4555:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4556:       PetscCall(PetscObjectQueryFunction((PetscObject)mat, convname, &conv));
4557:       PetscCall(PetscInfo(mat, "Check specialized (1) %s (%s) -> %d\n", convname, ((PetscObject)mat)->type_name, !!conv));
4558:       if (conv) goto foundconv;
4559:     }

4561:     /* 2)  See if a specialized converter is known to the desired matrix class. */
4562:     PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &B));
4563:     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
4564:     PetscCall(MatSetType(B, newtype));
4565:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4566:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4567:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4568:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4569:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4570:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4571:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4572:       PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
4573:       PetscCall(PetscInfo(mat, "Check specialized (2) %s (%s) -> %d\n", convname, ((PetscObject)B)->type_name, !!conv));
4574:       if (conv) {
4575:         PetscCall(MatDestroy(&B));
4576:         goto foundconv;
4577:       }
4578:     }

4580:     /* 3) See if a good general converter is registered for the desired class */
4581:     conv = B->ops->convertfrom;
4582:     PetscCall(PetscInfo(mat, "Check convertfrom (%s) -> %d\n", ((PetscObject)B)->type_name, !!conv));
4583:     PetscCall(MatDestroy(&B));
4584:     if (conv) goto foundconv;

4586:     /* 4) See if a good general converter is known for the current matrix */
4587:     if (mat->ops->convert) conv = mat->ops->convert;
4588:     PetscCall(PetscInfo(mat, "Check general convert (%s) -> %d\n", ((PetscObject)mat)->type_name, !!conv));
4589:     if (conv) goto foundconv;

4591:     /* 5) Use a really basic converter. */
4592:     PetscCall(PetscInfo(mat, "Using MatConvert_Basic\n"));
4593:     conv = MatConvert_Basic;

4595:   foundconv:
4596:     PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4597:     PetscCall((*conv)(mat, newtype, reuse, M));
4598:     if (mat->rmap->mapping && mat->cmap->mapping && !(*M)->rmap->mapping && !(*M)->cmap->mapping) {
4599:       /* the block sizes must be same if the mappings are copied over */
4600:       (*M)->rmap->bs = mat->rmap->bs;
4601:       (*M)->cmap->bs = mat->cmap->bs;
4602:       PetscCall(PetscObjectReference((PetscObject)mat->rmap->mapping));
4603:       PetscCall(PetscObjectReference((PetscObject)mat->cmap->mapping));
4604:       (*M)->rmap->mapping = mat->rmap->mapping;
4605:       (*M)->cmap->mapping = mat->cmap->mapping;
4606:     }
4607:     (*M)->stencil.dim = mat->stencil.dim;
4608:     (*M)->stencil.noc = mat->stencil.noc;
4609:     for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4610:       (*M)->stencil.dims[i]   = mat->stencil.dims[i];
4611:       (*M)->stencil.starts[i] = mat->stencil.starts[i];
4612:     }
4613:     PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4614:   }
4615:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));

4617:   /* Reset Mat options */
4618:   if (issymmetric != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PetscBool3ToBool(issymmetric)));
4619:   if (ishermitian != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PetscBool3ToBool(ishermitian)));
4620:   if (isspd != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_SPD, PetscBool3ToBool(isspd)));
4621:   PetscFunctionReturn(PETSC_SUCCESS);
4622: }

4624: /*@
4625:   MatFactorGetSolverType - Returns name of the package providing the factorization routines

4627:   Not Collective

4629:   Input Parameter:
4630: . mat - the matrix, must be a factored matrix

4632:   Output Parameter:
4633: . type - the string name of the package (do not free this string)

4635:   Level: intermediate

4637: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolverType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`
4638: @*/
4639: PetscErrorCode MatFactorGetSolverType(Mat mat, MatSolverType *type)
4640: {
4641:   PetscErrorCode (*conv)(Mat, MatSolverType *);

4643:   PetscFunctionBegin;
4646:   PetscAssertPointer(type, 2);
4647:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
4648:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorGetSolverType_C", &conv));
4649:   if (conv) PetscCall((*conv)(mat, type));
4650:   else *type = MATSOLVERPETSC;
4651:   PetscFunctionReturn(PETSC_SUCCESS);
4652: }

4654: typedef struct _MatSolverTypeForSpecifcType *MatSolverTypeForSpecifcType;
4655: struct _MatSolverTypeForSpecifcType {
4656:   MatType mtype;
4657:   /* no entry for MAT_FACTOR_NONE */
4658:   PetscErrorCode (*createfactor[MAT_FACTOR_NUM_TYPES - 1])(Mat, MatFactorType, Mat *);
4659:   MatSolverTypeForSpecifcType next;
4660: };

4662: typedef struct _MatSolverTypeHolder *MatSolverTypeHolder;
4663: struct _MatSolverTypeHolder {
4664:   char                       *name;
4665:   MatSolverTypeForSpecifcType handlers;
4666:   MatSolverTypeHolder         next;
4667: };

4669: static MatSolverTypeHolder MatSolverTypeHolders = NULL;

4671: /*@C
4672:   MatSolverTypeRegister - Registers a `MatSolverType` that works for a particular matrix type

4674:   Logically Collective, No Fortran Support

4676:   Input Parameters:
4677: + package      - name of the package, for example `petsc` or `superlu`
4678: . mtype        - the matrix type that works with this package
4679: . ftype        - the type of factorization supported by the package
4680: - createfactor - routine that will create the factored matrix ready to be used

4682:   Level: developer

4684: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorGetSolverType()`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`,
4685:   `MatGetFactor()`
4686: @*/
4687: PetscErrorCode MatSolverTypeRegister(MatSolverType package, MatType mtype, MatFactorType ftype, PetscErrorCode (*createfactor)(Mat, MatFactorType, Mat *))
4688: {
4689:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev = NULL;
4690:   PetscBool                   flg;
4691:   MatSolverTypeForSpecifcType inext, iprev = NULL;

4693:   PetscFunctionBegin;
4694:   PetscCall(MatInitializePackage());
4695:   if (!next) {
4696:     PetscCall(PetscNew(&MatSolverTypeHolders));
4697:     PetscCall(PetscStrallocpy(package, &MatSolverTypeHolders->name));
4698:     PetscCall(PetscNew(&MatSolverTypeHolders->handlers));
4699:     PetscCall(PetscStrallocpy(mtype, (char **)&MatSolverTypeHolders->handlers->mtype));
4700:     MatSolverTypeHolders->handlers->createfactor[(int)ftype - 1] = createfactor;
4701:     PetscFunctionReturn(PETSC_SUCCESS);
4702:   }
4703:   while (next) {
4704:     PetscCall(PetscStrcasecmp(package, next->name, &flg));
4705:     if (flg) {
4706:       PetscCheck(next->handlers, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatSolverTypeHolder is missing handlers");
4707:       inext = next->handlers;
4708:       while (inext) {
4709:         PetscCall(PetscStrcasecmp(mtype, inext->mtype, &flg));
4710:         if (flg) {
4711:           inext->createfactor[(int)ftype - 1] = createfactor;
4712:           PetscFunctionReturn(PETSC_SUCCESS);
4713:         }
4714:         iprev = inext;
4715:         inext = inext->next;
4716:       }
4717:       PetscCall(PetscNew(&iprev->next));
4718:       PetscCall(PetscStrallocpy(mtype, (char **)&iprev->next->mtype));
4719:       iprev->next->createfactor[(int)ftype - 1] = createfactor;
4720:       PetscFunctionReturn(PETSC_SUCCESS);
4721:     }
4722:     prev = next;
4723:     next = next->next;
4724:   }
4725:   PetscCall(PetscNew(&prev->next));
4726:   PetscCall(PetscStrallocpy(package, &prev->next->name));
4727:   PetscCall(PetscNew(&prev->next->handlers));
4728:   PetscCall(PetscStrallocpy(mtype, (char **)&prev->next->handlers->mtype));
4729:   prev->next->handlers->createfactor[(int)ftype - 1] = createfactor;
4730:   PetscFunctionReturn(PETSC_SUCCESS);
4731: }

4733: /*@C
4734:   MatSolverTypeGet - Gets the function that creates the factor matrix if it exist

4736:   Input Parameters:
4737: + type  - name of the package, for example `petsc` or `superlu`, if this is 'NULL', then the first result that satisfies the other criteria is returned
4738: . ftype - the type of factorization supported by the type
4739: - mtype - the matrix type that works with this type

4741:   Output Parameters:
4742: + foundtype    - `PETSC_TRUE` if the type was registered
4743: . foundmtype   - `PETSC_TRUE` if the type supports the requested mtype
4744: - createfactor - routine that will create the factored matrix ready to be used or `NULL` if not found

4746:   Calling sequence of `createfactor`:
4747: + A     - the matrix providing the factor matrix
4748: . ftype - the `MatFactorType` of the factor requested
4749: - B     - the new factor matrix that responds to MatXXFactorSymbolic,Numeric() functions, such as `MatLUFactorSymbolic()`

4751:   Level: developer

4753:   Note:
4754:   When `type` is `NULL` the available functions are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4755:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4756:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4758: .seealso: [](ch_matrices), `Mat`, `MatFactorType`, `MatType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatSolverTypeRegister()`, `MatGetFactor()`,
4759:           `MatInitializePackage()`
4760: @*/
4761: PetscErrorCode MatSolverTypeGet(MatSolverType type, MatType mtype, MatFactorType ftype, PetscBool *foundtype, PetscBool *foundmtype, PetscErrorCode (**createfactor)(Mat A, MatFactorType ftype, Mat *B))
4762: {
4763:   MatSolverTypeHolder         next = MatSolverTypeHolders;
4764:   PetscBool                   flg;
4765:   MatSolverTypeForSpecifcType inext;

4767:   PetscFunctionBegin;
4768:   if (foundtype) *foundtype = PETSC_FALSE;
4769:   if (foundmtype) *foundmtype = PETSC_FALSE;
4770:   if (createfactor) *createfactor = NULL;

4772:   if (type) {
4773:     while (next) {
4774:       PetscCall(PetscStrcasecmp(type, next->name, &flg));
4775:       if (flg) {
4776:         if (foundtype) *foundtype = PETSC_TRUE;
4777:         inext = next->handlers;
4778:         while (inext) {
4779:           PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4780:           if (flg) {
4781:             if (foundmtype) *foundmtype = PETSC_TRUE;
4782:             if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4783:             PetscFunctionReturn(PETSC_SUCCESS);
4784:           }
4785:           inext = inext->next;
4786:         }
4787:       }
4788:       next = next->next;
4789:     }
4790:   } else {
4791:     while (next) {
4792:       inext = next->handlers;
4793:       while (inext) {
4794:         PetscCall(PetscStrcmp(mtype, inext->mtype, &flg));
4795:         if (flg && inext->createfactor[(int)ftype - 1]) {
4796:           if (foundtype) *foundtype = PETSC_TRUE;
4797:           if (foundmtype) *foundmtype = PETSC_TRUE;
4798:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4799:           PetscFunctionReturn(PETSC_SUCCESS);
4800:         }
4801:         inext = inext->next;
4802:       }
4803:       next = next->next;
4804:     }
4805:     /* try with base classes inext->mtype */
4806:     next = MatSolverTypeHolders;
4807:     while (next) {
4808:       inext = next->handlers;
4809:       while (inext) {
4810:         PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4811:         if (flg && inext->createfactor[(int)ftype - 1]) {
4812:           if (foundtype) *foundtype = PETSC_TRUE;
4813:           if (foundmtype) *foundmtype = PETSC_TRUE;
4814:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4815:           PetscFunctionReturn(PETSC_SUCCESS);
4816:         }
4817:         inext = inext->next;
4818:       }
4819:       next = next->next;
4820:     }
4821:   }
4822:   PetscFunctionReturn(PETSC_SUCCESS);
4823: }

4825: PetscErrorCode MatSolverTypeDestroy(void)
4826: {
4827:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev;
4828:   MatSolverTypeForSpecifcType inext, iprev;

4830:   PetscFunctionBegin;
4831:   while (next) {
4832:     PetscCall(PetscFree(next->name));
4833:     inext = next->handlers;
4834:     while (inext) {
4835:       PetscCall(PetscFree(inext->mtype));
4836:       iprev = inext;
4837:       inext = inext->next;
4838:       PetscCall(PetscFree(iprev));
4839:     }
4840:     prev = next;
4841:     next = next->next;
4842:     PetscCall(PetscFree(prev));
4843:   }
4844:   MatSolverTypeHolders = NULL;
4845:   PetscFunctionReturn(PETSC_SUCCESS);
4846: }

4848: /*@
4849:   MatFactorGetCanUseOrdering - Indicates if the factorization can use the ordering provided in `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`

4851:   Logically Collective

4853:   Input Parameter:
4854: . mat - the matrix

4856:   Output Parameter:
4857: . flg - `PETSC_TRUE` if uses the ordering

4859:   Level: developer

4861:   Note:
4862:   Most internal PETSc factorizations use the ordering passed to the factorization routine but external
4863:   packages do not, thus we want to skip generating the ordering when it is not needed or used.

4865: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4866: @*/
4867: PetscErrorCode MatFactorGetCanUseOrdering(Mat mat, PetscBool *flg)
4868: {
4869:   PetscFunctionBegin;
4870:   *flg = mat->canuseordering;
4871:   PetscFunctionReturn(PETSC_SUCCESS);
4872: }

4874: /*@
4875:   MatFactorGetPreferredOrdering - The preferred ordering for a particular matrix factor object

4877:   Logically Collective

4879:   Input Parameters:
4880: + mat   - the matrix obtained with `MatGetFactor()`
4881: - ftype - the factorization type to be used

4883:   Output Parameter:
4884: . otype - the preferred ordering type

4886:   Level: developer

4888: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatOrderingType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4889: @*/
4890: PetscErrorCode MatFactorGetPreferredOrdering(Mat mat, MatFactorType ftype, MatOrderingType *otype)
4891: {
4892:   PetscFunctionBegin;
4893:   *otype = mat->preferredordering[ftype];
4894:   PetscCheck(*otype, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatFactor did not have a preferred ordering");
4895:   PetscFunctionReturn(PETSC_SUCCESS);
4896: }

4898: /*@
4899:   MatGetFactor - Returns a matrix suitable to calls to routines such as `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatILUFactorSymbolic()`,
4900:   `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactorNumeric()`, `MatILUFactorNumeric()`, and
4901:   `MatICCFactorNumeric()`

4903:   Collective

4905:   Input Parameters:
4906: + mat   - the matrix
4907: . type  - name of solver type, for example, `superlu_dist`, `petsc` (to use PETSc's solver if it is available), if this is 'NULL', then the first result that satisfies
4908:           the other criteria is returned
4909: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4911:   Output Parameter:
4912: . f - the factor matrix used with MatXXFactorSymbolic,Numeric() calls. Can be `NULL` in some cases, see notes below.

4914:   Options Database Keys:
4915: + -pc_factor_mat_solver_type type            - choose the type at run time. When using `KSP` solvers
4916: . -pc_factor_mat_factor_on_host (true|false) - do matrix factorization on host (with device matrices). Default is doing it on device
4917: - -pc_factor_mat_solve_on_host (true|false)  - do matrix solve on host (with device matrices). Default is doing it on device

4919:   Level: intermediate

4921:   Notes:
4922:   Some of the packages, such as MUMPS, have options for controlling the factorization, these are in the form `-prefix_mat_packagename_packageoption`
4923:   (for example, `-mat_mumps_icntl_6 1`)  where `prefix` is normally set automatically from the calling `KSP`/`PC`. If `MatGetFactor()` is called directly,
4924:   without using a `PC`, one can set the prefix by
4925:   calling `MatSetOptionsPrefixFactor()` on the originating matrix or  `MatSetOptionsPrefix()` on the resulting factor matrix.

4927:   Some PETSc matrix formats have alternative solvers available that are provided by alternative packages
4928:   such as PaStiX, SuperLU_DIST, MUMPS etc. PETSc must have been configured to use the external solver,
4929:   using the corresponding `./configure` option such as `--download-package` or `--with-package-dir`.

4931:   When `type` is `NULL` the available results are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4932:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4933:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4935:   The return matrix can be `NULL` if the requested factorization is not available, since some combinations of matrix types and factorization
4936:   types registered with `MatSolverTypeRegister()` cannot be fully tested if not at runtime.

4938:   Developer Note:
4939:   This should actually be called `MatCreateFactor()` since it creates a new factor object

4941:   The `MatGetFactor()` implementations should not be accessing the PETSc options database or making other decisions about solver options,
4942:   that should be delayed until the later operations. This is to ensure the correct options prefix has been set in the factor matrix.

4944: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `KSP`, `MatSolverType`, `MatFactorType`, `MatCopy()`, `MatDuplicate()`,
4945:           `MatGetFactorAvailable()`, `MatFactorGetCanUseOrdering()`, `MatSolverTypeRegister()`, `MatSolverTypeGet()`,
4946:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatInitializePackage()`,
4947:           `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatILUFactorSymbolic()`,
4948:           `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactorNumeric()`, `MatILUFactorNumeric()`,
4949:           `MatICCFactorNumeric()`
4950: @*/
4951: PetscErrorCode MatGetFactor(Mat mat, MatSolverType type, MatFactorType ftype, Mat *f)
4952: {
4953:   PetscBool foundtype, foundmtype, shell, hasop = PETSC_FALSE;
4954:   PetscErrorCode (*conv)(Mat, MatFactorType, Mat *);

4956:   PetscFunctionBegin;

4960:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4961:   MatCheckPreallocated(mat, 1);

4963:   PetscCall(MatIsShell(mat, &shell));
4964:   if (shell) PetscCall(MatHasOperation(mat, MATOP_GET_FACTOR, &hasop));
4965:   if (hasop) {
4966:     PetscUseTypeMethod(mat, getfactor, type, ftype, f);
4967:     PetscFunctionReturn(PETSC_SUCCESS);
4968:   }

4970:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, &foundtype, &foundmtype, &conv));
4971:   if (!foundtype) {
4972:     if (type) {
4973:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "Could not locate solver type %s for factorization type %s and matrix type %s. Perhaps you must ./configure with --download-%s", type, MatFactorTypes[ftype],
4974:               ((PetscObject)mat)->type_name, type);
4975:     } else {
4976:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "Could not locate a solver type for factorization type %s and matrix type %s.", MatFactorTypes[ftype], ((PetscObject)mat)->type_name);
4977:     }
4978:   }
4979:   PetscCheck(foundmtype, PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "MatSolverType %s does not support matrix type %s", type, ((PetscObject)mat)->type_name);
4980:   PetscCheck(conv, PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "MatSolverType %s does not support factorization type %s for matrix type %s", type, MatFactorTypes[ftype], ((PetscObject)mat)->type_name);

4982:   PetscCall((*conv)(mat, ftype, f));
4983:   if (mat->factorprefix) PetscCall(MatSetOptionsPrefix(*f, mat->factorprefix));
4984:   PetscFunctionReturn(PETSC_SUCCESS);
4985: }

4987: /*@
4988:   MatGetFactorAvailable - Returns a flag if matrix supports particular type and factor type

4990:   Not Collective

4992:   Input Parameters:
4993: + mat   - the matrix
4994: . type  - name of solver type, for example, `superlu`, `petsc` (to use PETSc's default)
4995: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4997:   Output Parameter:
4998: . flg - PETSC_TRUE if the factorization is available

5000:   Level: intermediate

5002:   Notes:
5003:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
5004:   such as pastix, superlu, mumps etc.

5006:   PETSc must have been ./configure to use the external solver, using the option --download-package

5008:   Developer Note:
5009:   This should actually be called `MatCreateFactorAvailable()` since `MatGetFactor()` creates a new factor object

5011: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolverType`, `MatFactorType`, `MatGetFactor()`, `MatCopy()`, `MatDuplicate()`, `MatSolverTypeRegister()`,
5012:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatSolverTypeGet()`
5013: @*/
5014: PetscErrorCode MatGetFactorAvailable(Mat mat, MatSolverType type, MatFactorType ftype, PetscBool *flg)
5015: {
5016:   PetscErrorCode (*gconv)(Mat, MatFactorType, Mat *);

5018:   PetscFunctionBegin;
5020:   PetscAssertPointer(flg, 4);

5022:   *flg = PETSC_FALSE;
5023:   if (!((PetscObject)mat)->type_name) PetscFunctionReturn(PETSC_SUCCESS);

5025:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5026:   MatCheckPreallocated(mat, 1);

5028:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, NULL, NULL, &gconv));
5029:   *flg = gconv ? PETSC_TRUE : PETSC_FALSE;
5030:   PetscFunctionReturn(PETSC_SUCCESS);
5031: }

5033: /*@
5034:   MatDuplicate - Duplicates a matrix including the non-zero structure.

5036:   Collective

5038:   Input Parameters:
5039: + mat - the matrix
5040: - op  - One of `MAT_DO_NOT_COPY_VALUES`, `MAT_COPY_VALUES`, or `MAT_SHARE_NONZERO_PATTERN`.
5041:         See the manual page for `MatDuplicateOption()` for an explanation of these options.

5043:   Output Parameter:
5044: . M - pointer to place new matrix

5046:   Level: intermediate

5048:   Notes:
5049:   You cannot change the nonzero pattern for the parent or child matrix later if you use `MAT_SHARE_NONZERO_PATTERN`.

5051:   If `op` is not `MAT_COPY_VALUES` the numerical values in the new matrix are zeroed.

5053:   May be called with an unassembled input `Mat` if `MAT_DO_NOT_COPY_VALUES` is used, in which case the output `Mat` is unassembled as well.

5055:   When original mat is a product of matrix operation, e.g., an output of `MatMatMult()` or `MatCreateSubMatrix()`, only the matrix data structure of `mat`
5056:   is duplicated and the internal data structures created for the reuse of previous matrix operations are not duplicated.
5057:   User should not use `MatDuplicate()` to create new matrix `M` if `M` is intended to be reused as the product of matrix operation.

5059: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatConvert()`, `MatDuplicateOption`
5060: @*/
5061: PetscErrorCode MatDuplicate(Mat mat, MatDuplicateOption op, Mat *M)
5062: {
5063:   Mat               B;
5064:   VecType           vtype;
5065:   PetscInt          i;
5066:   PetscObject       dm, container_h, container_d;
5067:   PetscErrorCodeFn *viewf;

5069:   PetscFunctionBegin;
5072:   PetscAssertPointer(M, 3);
5073:   PetscCheck(op != MAT_COPY_VALUES || mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MAT_COPY_VALUES not allowed for unassembled matrix");
5074:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5075:   MatCheckPreallocated(mat, 1);

5077:   PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
5078:   PetscUseTypeMethod(mat, duplicate, op, M);
5079:   PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
5080:   B = *M;

5082:   PetscCall(MatGetOperation(mat, MATOP_VIEW, &viewf));
5083:   if (viewf) PetscCall(MatSetOperation(B, MATOP_VIEW, viewf));
5084:   PetscCall(MatGetVecType(mat, &vtype));
5085:   PetscCall(MatSetVecType(B, vtype));

5087:   B->stencil.dim = mat->stencil.dim;
5088:   B->stencil.noc = mat->stencil.noc;
5089:   for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
5090:     B->stencil.dims[i]   = mat->stencil.dims[i];
5091:     B->stencil.starts[i] = mat->stencil.starts[i];
5092:   }

5094:   B->nooffproczerorows = mat->nooffproczerorows;
5095:   B->nooffprocentries  = mat->nooffprocentries;

5097:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_dm", &dm));
5098:   if (dm) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_dm", dm));
5099:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Host", &container_h));
5100:   if (container_h) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Host", container_h));
5101:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Device", &container_d));
5102:   if (container_d) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Device", container_d));
5103:   if (op == MAT_COPY_VALUES) PetscCall(MatPropagateSymmetryOptions(mat, B));
5104:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
5105:   PetscFunctionReturn(PETSC_SUCCESS);
5106: }

5108: /*@
5109:   MatGetDiagonal - Gets the diagonal of a matrix as a `Vec`

5111:   Logically Collective

5113:   Input Parameter:
5114: . mat - the matrix

5116:   Output Parameter:
5117: . v - the diagonal of the matrix

5119:   Level: intermediate

5121:   Note:
5122:   If `mat` has local sizes `n` x `m`, this routine fills the first `ndiag = min(n, m)` entries
5123:   of `v` with the diagonal values. Thus `v` must have local size of at least `ndiag`. If `v`
5124:   is larger than `ndiag`, the values of the remaining entries are unspecified.

5126:   Currently only correct in parallel for square matrices.

5128: .seealso: [](ch_matrices), `Mat`, `Vec`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`
5129: @*/
5130: PetscErrorCode MatGetDiagonal(Mat mat, Vec v)
5131: {
5132:   PetscFunctionBegin;
5136:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5137:   MatCheckPreallocated(mat, 1);
5138:   if (PetscDefined(USE_DEBUG)) {
5139:     PetscInt nv, row, col, ndiag;

5141:     PetscCall(VecGetLocalSize(v, &nv));
5142:     PetscCall(MatGetLocalSize(mat, &row, &col));
5143:     ndiag = PetscMin(row, col);
5144:     PetscCheck(nv >= ndiag, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming Mat and Vec. Vec local size %" PetscInt_FMT " < Mat local diagonal length %" PetscInt_FMT, nv, ndiag);
5145:   }

5147:   PetscUseTypeMethod(mat, getdiagonal, v);
5148:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5149:   PetscFunctionReturn(PETSC_SUCCESS);
5150: }

5152: /*@
5153:   MatGetRowMin - Gets the minimum value (of the real part) of each
5154:   row of the matrix

5156:   Logically Collective

5158:   Input Parameter:
5159: . mat - the matrix

5161:   Output Parameters:
5162: + v   - the vector for storing the maximums
5163: - idx - the indices of the column found for each row (optional, pass `NULL` if not needed)

5165:   Level: intermediate

5167:   Note:
5168:   The result of this call are the same as if one converted the matrix to dense format
5169:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5171:   This code is only implemented for a couple of matrix formats.

5173: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`,
5174:           `MatGetRowMax()`
5175: @*/
5176: PetscErrorCode MatGetRowMin(Mat mat, Vec v, PetscInt idx[])
5177: {
5178:   PetscFunctionBegin;
5182:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5184:   if (!mat->cmap->N) {
5185:     PetscCall(VecSet(v, PETSC_MAX_REAL));
5186:     if (idx) {
5187:       PetscInt i, m = mat->rmap->n;
5188:       for (i = 0; i < m; i++) idx[i] = -1;
5189:     }
5190:   } else {
5191:     MatCheckPreallocated(mat, 1);
5192:   }
5193:   PetscUseTypeMethod(mat, getrowmin, v, idx);
5194:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5195:   PetscFunctionReturn(PETSC_SUCCESS);
5196: }

5198: /*@
5199:   MatGetRowMinAbs - Gets the minimum value (in absolute value) of each
5200:   row of the matrix

5202:   Logically Collective

5204:   Input Parameter:
5205: . mat - the matrix

5207:   Output Parameters:
5208: + v   - the vector for storing the minimums
5209: - idx - the indices of the column found for each row (or `NULL` if not needed)

5211:   Level: intermediate

5213:   Notes:
5214:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5215:   row is 0 (the first column).

5217:   This code is only implemented for a couple of matrix formats.

5219: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`
5220: @*/
5221: PetscErrorCode MatGetRowMinAbs(Mat mat, Vec v, PetscInt idx[])
5222: {
5223:   PetscFunctionBegin;
5227:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5228:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

5230:   if (!mat->cmap->N) {
5231:     PetscCall(VecSet(v, 0.0));
5232:     if (idx) {
5233:       PetscInt i, m = mat->rmap->n;
5234:       for (i = 0; i < m; i++) idx[i] = -1;
5235:     }
5236:   } else {
5237:     MatCheckPreallocated(mat, 1);
5238:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5239:     PetscUseTypeMethod(mat, getrowminabs, v, idx);
5240:   }
5241:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5242:   PetscFunctionReturn(PETSC_SUCCESS);
5243: }

5245: /*@
5246:   MatGetRowMax - Gets the maximum value (of the real part) of each
5247:   row of the matrix

5249:   Logically Collective

5251:   Input Parameter:
5252: . mat - the matrix

5254:   Output Parameters:
5255: + v   - the vector for storing the maximums
5256: - idx - the indices of the column found for each row (optional, otherwise pass `NULL`)

5258:   Level: intermediate

5260:   Notes:
5261:   The result of this call are the same as if one converted the matrix to dense format
5262:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5264:   This code is only implemented for a couple of matrix formats.

5266: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5267: @*/
5268: PetscErrorCode MatGetRowMax(Mat mat, Vec v, PetscInt idx[])
5269: {
5270:   PetscFunctionBegin;
5274:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5276:   if (!mat->cmap->N) {
5277:     PetscCall(VecSet(v, PETSC_MIN_REAL));
5278:     if (idx) {
5279:       PetscInt i, m = mat->rmap->n;
5280:       for (i = 0; i < m; i++) idx[i] = -1;
5281:     }
5282:   } else {
5283:     MatCheckPreallocated(mat, 1);
5284:     PetscUseTypeMethod(mat, getrowmax, v, idx);
5285:   }
5286:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5287:   PetscFunctionReturn(PETSC_SUCCESS);
5288: }

5290: /*@
5291:   MatGetRowMaxAbs - Gets the maximum value (in absolute value) of each
5292:   row of the matrix

5294:   Logically Collective

5296:   Input Parameter:
5297: . mat - the matrix

5299:   Output Parameters:
5300: + v   - the vector for storing the maximums
5301: - idx - the indices of the column found for each row (or `NULL` if not needed)

5303:   Level: intermediate

5305:   Notes:
5306:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5307:   row is 0 (the first column).

5309:   This code is only implemented for a couple of matrix formats.

5311: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowSum()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5312: @*/
5313: PetscErrorCode MatGetRowMaxAbs(Mat mat, Vec v, PetscInt idx[])
5314: {
5315:   PetscFunctionBegin;
5319:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5321:   if (!mat->cmap->N) {
5322:     PetscCall(VecSet(v, 0.0));
5323:     if (idx) {
5324:       PetscInt i, m = mat->rmap->n;
5325:       for (i = 0; i < m; i++) idx[i] = -1;
5326:     }
5327:   } else {
5328:     MatCheckPreallocated(mat, 1);
5329:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5330:     PetscUseTypeMethod(mat, getrowmaxabs, v, idx);
5331:   }
5332:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5333:   PetscFunctionReturn(PETSC_SUCCESS);
5334: }

5336: /*@
5337:   MatGetRowSumAbs - Gets the sum value (in absolute value) of each row of the matrix

5339:   Logically Collective

5341:   Input Parameter:
5342: . mat - the matrix

5344:   Output Parameter:
5345: . v - the vector for storing the sum

5347:   Level: intermediate

5349:   This code is only implemented for a couple of matrix formats.

5351: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5352: @*/
5353: PetscErrorCode MatGetRowSumAbs(Mat mat, Vec v)
5354: {
5355:   PetscFunctionBegin;
5359:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5361:   if (!mat->cmap->N) PetscCall(VecSet(v, 0.0));
5362:   else {
5363:     MatCheckPreallocated(mat, 1);
5364:     PetscUseTypeMethod(mat, getrowsumabs, v);
5365:   }
5366:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5367:   PetscFunctionReturn(PETSC_SUCCESS);
5368: }

5370: /*@
5371:   MatGetRowSum - Gets the sum of each row of the matrix

5373:   Logically or Neighborhood Collective

5375:   Input Parameter:
5376: . mat - the matrix

5378:   Output Parameter:
5379: . v - the vector for storing the sum of rows

5381:   Level: intermediate

5383:   Note:
5384:   This code is slow since it is not currently specialized for different formats

5386: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`, `MatGetRowSumAbs()`
5387: @*/
5388: PetscErrorCode MatGetRowSum(Mat mat, Vec v)
5389: {
5390:   Vec ones;

5392:   PetscFunctionBegin;
5396:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5397:   MatCheckPreallocated(mat, 1);
5398:   PetscCall(MatCreateVecs(mat, &ones, NULL));
5399:   PetscCall(VecSet(ones, 1.));
5400:   PetscCall(MatMult(mat, ones, v));
5401:   PetscCall(VecDestroy(&ones));
5402:   PetscFunctionReturn(PETSC_SUCCESS);
5403: }

5405: /*@
5406:   MatTransposeSetPrecursor - Set the matrix from which the second matrix will receive numerical transpose data with a call to `MatTranspose`(A,`MAT_REUSE_MATRIX`,&B)
5407:   when B was not obtained with `MatTranspose`(A,`MAT_INITIAL_MATRIX`,&B)

5409:   Collective

5411:   Input Parameter:
5412: . mat - the matrix to provide the transpose

5414:   Output Parameter:
5415: . B - the matrix to contain the transpose; it MUST have the nonzero structure of the transpose of A or the code will crash or generate incorrect results

5417:   Level: advanced

5419:   Note:
5420:   Normally the use of `MatTranspose`(A, `MAT_REUSE_MATRIX`, &B) requires that `B` was obtained with a call to `MatTranspose`(A, `MAT_INITIAL_MATRIX`, &B). This
5421:   routine allows bypassing that call.

5423: .seealso: [](ch_matrices), `Mat`, `MatTransposeSymbolic()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5424: @*/
5425: PetscErrorCode MatTransposeSetPrecursor(Mat mat, Mat B)
5426: {
5427:   MatParentState *rb = NULL;

5429:   PetscFunctionBegin;
5430:   PetscCall(PetscNew(&rb));
5431:   rb->id    = ((PetscObject)mat)->id;
5432:   rb->state = 0;
5433:   PetscCall(MatGetNonzeroState(mat, &rb->nonzerostate));
5434:   PetscCall(PetscObjectContainerCompose((PetscObject)B, "MatTransposeParent", rb, PetscCtxDestroyDefault));
5435:   PetscFunctionReturn(PETSC_SUCCESS);
5436: }

5438: static PetscErrorCode MatTranspose_Private(Mat mat, MatReuse reuse, Mat *B, PetscBool conjugate)
5439: {
5440:   PetscContainer  rB                        = NULL;
5441:   MatParentState *rb                        = NULL;
5442:   PetscErrorCode (*f)(Mat, MatReuse, Mat *) = NULL;

5444:   PetscFunctionBegin;
5447:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5448:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5449:   PetscCheck(reuse != MAT_INPLACE_MATRIX || mat == *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires last matrix to match first");
5450:   PetscCheck(reuse != MAT_REUSE_MATRIX || mat != *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Perhaps you mean MAT_INPLACE_MATRIX");
5451:   MatCheckPreallocated(mat, 1);
5452:   if (reuse == MAT_REUSE_MATRIX) {
5453:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5454:     PetscCheck(rB, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose(). Suggest MatTransposeSetPrecursor().");
5455:     PetscCall(PetscContainerGetPointer(rB, &rb));
5456:     PetscCheck(rb->id == ((PetscObject)mat)->id, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5457:     if (rb->state == ((PetscObject)mat)->state) PetscFunctionReturn(PETSC_SUCCESS);
5458:   }

5460:   if (conjugate) {
5461:     f = mat->ops->hermitiantranspose;
5462:     if (f) PetscCall((*f)(mat, reuse, B));
5463:   }
5464:   if (!f && !(reuse == MAT_INPLACE_MATRIX && mat->hermitian == PETSC_BOOL3_TRUE && conjugate)) {
5465:     PetscCall(PetscLogEventBegin(MAT_Transpose, mat, 0, 0, 0));
5466:     if (reuse != MAT_INPLACE_MATRIX || mat->symmetric != PETSC_BOOL3_TRUE) {
5467:       PetscUseTypeMethod(mat, transpose, reuse, B);
5468:       PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5469:     }
5470:     PetscCall(PetscLogEventEnd(MAT_Transpose, mat, 0, 0, 0));
5471:     if (conjugate) PetscCall(MatConjugate(*B));
5472:   }

5474:   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatTransposeSetPrecursor(mat, *B));
5475:   if (reuse != MAT_INPLACE_MATRIX) {
5476:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5477:     PetscCall(PetscContainerGetPointer(rB, &rb));
5478:     rb->state        = ((PetscObject)mat)->state;
5479:     rb->nonzerostate = mat->nonzerostate;
5480:   }
5481:   PetscFunctionReturn(PETSC_SUCCESS);
5482: }

5484: /*@
5485:   MatTranspose - Computes the transpose of a matrix, either in-place or out-of-place.

5487:   Collective

5489:   Input Parameters:
5490: + mat   - the matrix to transpose
5491: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5493:   Output Parameter:
5494: . B - the transpose of the matrix

5496:   Level: intermediate

5498:   Notes:
5499:   If you use `MAT_INPLACE_MATRIX` then you must pass in `&mat` for `B`

5501:   `MAT_REUSE_MATRIX` uses the `B` matrix obtained from a previous call to this function with `MAT_INITIAL_MATRIX` to store the transpose. If you already have a matrix to contain the
5502:   transpose, call `MatTransposeSetPrecursor(mat, B)` before calling this routine.

5504:   If the nonzero structure of `mat` changed from the previous call to this function with the same matrices an error will be generated for some matrix types.

5506:   Consider using `MatCreateTranspose()` instead if you only need a matrix that behaves like the transpose but don't need the storage to be changed.
5507:   For example, the result of `MatCreateTranspose()` will compute the transpose of the given matrix times a vector for matrix-vector products computed with `MatMult()`.

5509:   If `mat` is unchanged from the last call this function returns immediately without recomputing the result

5511:   If you only need the symbolic transpose of a matrix, and not the numerical values, use `MatTransposeSymbolic()`

5513: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`,
5514:           `MatTransposeSymbolic()`, `MatCreateTranspose()`
5515: @*/
5516: PetscErrorCode MatTranspose(Mat mat, MatReuse reuse, Mat *B)
5517: {
5518:   PetscFunctionBegin;
5519:   PetscCall(MatTranspose_Private(mat, reuse, B, PETSC_FALSE));
5520:   PetscFunctionReturn(PETSC_SUCCESS);
5521: }

5523: /*@
5524:   MatTransposeSymbolic - Computes the symbolic part of the transpose of a matrix.

5526:   Collective

5528:   Input Parameter:
5529: . A - the matrix to transpose

5531:   Output Parameter:
5532: . B - the transpose. This is a complete matrix but the numerical portion is invalid. One can call `MatTranspose`(A,`MAT_REUSE_MATRIX`,&B) to compute the
5533:       numerical portion.

5535:   Level: intermediate

5537:   Note:
5538:   This is not supported for many matrix types, use `MatTranspose()` in those cases

5540: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5541: @*/
5542: PetscErrorCode MatTransposeSymbolic(Mat A, Mat *B)
5543: {
5544:   PetscFunctionBegin;
5547:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5548:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5549:   PetscCall(PetscLogEventBegin(MAT_Transpose, A, 0, 0, 0));
5550:   PetscUseTypeMethod(A, transposesymbolic, B);
5551:   PetscCall(PetscLogEventEnd(MAT_Transpose, A, 0, 0, 0));

5553:   PetscCall(MatTransposeSetPrecursor(A, *B));
5554:   PetscFunctionReturn(PETSC_SUCCESS);
5555: }

5557: PetscErrorCode MatTransposeCheckNonzeroState_Private(Mat A, Mat B)
5558: {
5559:   PetscContainer  rB;
5560:   MatParentState *rb;

5562:   PetscFunctionBegin;
5565:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5566:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5567:   PetscCall(PetscObjectQuery((PetscObject)B, "MatTransposeParent", (PetscObject *)&rB));
5568:   PetscCheck(rB, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose()");
5569:   PetscCall(PetscContainerGetPointer(rB, &rb));
5570:   PetscCheck(rb->id == ((PetscObject)A)->id, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5571:   PetscCheck(rb->nonzerostate == A->nonzerostate, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Reuse matrix has changed nonzero structure");
5572:   PetscFunctionReturn(PETSC_SUCCESS);
5573: }

5575: /*@
5576:   MatIsTranspose - Test whether a matrix is another one's transpose,
5577:   or its own, in which case it tests symmetry.

5579:   Collective

5581:   Input Parameters:
5582: + A   - the matrix to test
5583: . B   - the matrix to test against, this can equal the first parameter
5584: - tol - tolerance, differences between entries smaller than this are counted as zero

5586:   Output Parameter:
5587: . flg - the result

5589:   Level: intermediate

5591:   Notes:
5592:   The sequential algorithm has a running time of the order of the number of nonzeros; the parallel
5593:   test involves parallel copies of the block off-diagonal parts of the matrix.

5595: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`
5596: @*/
5597: PetscErrorCode MatIsTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5598: {
5599:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5601:   PetscFunctionBegin;
5604:   PetscAssertPointer(flg, 4);
5605:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsTranspose_C", &f));
5606:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsTranspose_C", &g));
5607:   *flg = PETSC_FALSE;
5608:   if (f && g) {
5609:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for symmetry test");
5610:     PetscCall((*f)(A, B, tol, flg));
5611:   } else {
5612:     MatType mattype;

5614:     PetscCall(MatGetType(f ? B : A, &mattype));
5615:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for transpose", mattype);
5616:   }
5617:   PetscFunctionReturn(PETSC_SUCCESS);
5618: }

5620: /*@
5621:   MatHermitianTranspose - Computes an in-place or out-of-place Hermitian transpose of a matrix in complex conjugate.

5623:   Collective

5625:   Input Parameters:
5626: + mat   - the matrix to transpose and complex conjugate
5627: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5629:   Output Parameter:
5630: . B - the Hermitian transpose

5632:   Level: intermediate

5634: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`
5635: @*/
5636: PetscErrorCode MatHermitianTranspose(Mat mat, MatReuse reuse, Mat *B)
5637: {
5638:   PetscFunctionBegin;
5639:   PetscCall(MatTranspose_Private(mat, reuse, B, PETSC_TRUE));
5640:   PetscFunctionReturn(PETSC_SUCCESS);
5641: }

5643: /*@
5644:   MatIsHermitianTranspose - Test whether a matrix is another one's Hermitian transpose,

5646:   Collective

5648:   Input Parameters:
5649: + A   - the matrix to test
5650: . B   - the matrix to test against, this can equal the first parameter
5651: - tol - tolerance, differences between entries smaller than this are counted as zero

5653:   Output Parameter:
5654: . flg - the result

5656:   Level: intermediate

5658:   Notes:
5659:   Only available for `MATAIJ` matrices.

5661:   The sequential algorithm
5662:   has a running time of the order of the number of nonzeros; the parallel
5663:   test involves parallel copies of the block off-diagonal parts of the matrix.

5665: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsTranspose()`
5666: @*/
5667: PetscErrorCode MatIsHermitianTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5668: {
5669:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5671:   PetscFunctionBegin;
5674:   PetscAssertPointer(flg, 4);
5675:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsHermitianTranspose_C", &f));
5676:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsHermitianTranspose_C", &g));
5677:   if (f && g) {
5678:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for Hermitian test");
5679:     PetscCall((*f)(A, B, tol, flg));
5680:   } else {
5681:     MatType mattype;

5683:     PetscCall(MatGetType(f ? B : A, &mattype));
5684:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for Hermitian transpose", mattype);
5685:   }
5686:   PetscFunctionReturn(PETSC_SUCCESS);
5687: }

5689: /*@
5690:   MatPermute - Creates a new matrix with rows and columns permuted from the
5691:   original.

5693:   Collective

5695:   Input Parameters:
5696: + mat - the matrix to permute
5697: . row - row permutation, each processor supplies only the permutation for its rows
5698: - col - column permutation, each processor supplies only the permutation for its columns

5700:   Output Parameter:
5701: . B - the permuted matrix

5703:   Level: advanced

5705:   Note:
5706:   The index sets map from row/col of permuted matrix to row/col of original matrix.
5707:   The index sets should be on the same communicator as mat and have the same local sizes.

5709:   Developer Note:
5710:   If you want to implement `MatPermute()` for a matrix type, and your approach doesn't
5711:   exploit the fact that row and col are permutations, consider implementing the
5712:   more general `MatCreateSubMatrix()` instead.

5714: .seealso: [](ch_matrices), `Mat`, `MatGetOrdering()`, `ISAllGather()`, `MatCreateSubMatrix()`
5715: @*/
5716: PetscErrorCode MatPermute(Mat mat, IS row, IS col, Mat *B)
5717: {
5718:   PetscFunctionBegin;
5723:   PetscAssertPointer(B, 4);
5724:   PetscCheckSameComm(mat, 1, row, 2);
5725:   if (row != col) PetscCheckSameComm(row, 2, col, 3);
5726:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5727:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5728:   PetscCheck(mat->ops->permute || mat->ops->createsubmatrix, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatPermute not available for Mat type %s", ((PetscObject)mat)->type_name);
5729:   MatCheckPreallocated(mat, 1);

5731:   if (mat->ops->permute) {
5732:     PetscUseTypeMethod(mat, permute, row, col, B);
5733:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5734:   } else {
5735:     PetscCall(MatCreateSubMatrix(mat, row, col, MAT_INITIAL_MATRIX, B));
5736:   }
5737:   PetscFunctionReturn(PETSC_SUCCESS);
5738: }

5740: /*@
5741:   MatEqual - Compares two matrices.

5743:   Collective

5745:   Input Parameters:
5746: + A - the first matrix
5747: - B - the second matrix

5749:   Output Parameter:
5750: . flg - `PETSC_TRUE` if the matrices are equal; `PETSC_FALSE` otherwise.

5752:   Level: intermediate

5754:   Note:
5755:   If either of the matrix is "matrix-free", meaning the matrix entries are not stored explicitly then equality is determined by comparing
5756:   the results of several matrix-vector product using randomly created vectors, see `MatMultEqual()`.

5758: .seealso: [](ch_matrices), `Mat`, `MatMultEqual()`
5759: @*/
5760: PetscErrorCode MatEqual(Mat A, Mat B, PetscBool *flg)
5761: {
5762:   PetscFunctionBegin;
5767:   PetscAssertPointer(flg, 3);
5768:   PetscCheckSameComm(A, 1, B, 2);
5769:   MatCheckPreallocated(A, 1);
5770:   MatCheckPreallocated(B, 2);
5771:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5772:   PetscCheck(B->assembled, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5773:   PetscCheck(A->rmap->N == B->rmap->N && A->cmap->N == B->cmap->N, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Mat A,Mat B: global dim %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT, A->rmap->N, B->rmap->N, A->cmap->N,
5774:              B->cmap->N);
5775:   if (A->ops->equal && A->ops->equal == B->ops->equal) PetscUseTypeMethod(A, equal, B, flg);
5776:   else PetscCall(MatMultEqual(A, B, 10, flg));
5777:   PetscFunctionReturn(PETSC_SUCCESS);
5778: }

5780: /*@
5781:   MatDiagonalScale - Scales a matrix on the left and right by diagonal
5782:   matrices that are stored as vectors.  Either of the two scaling
5783:   matrices can be `NULL`.

5785:   Collective

5787:   Input Parameters:
5788: + mat - the matrix to be scaled
5789: . l   - the left scaling vector (or `NULL`)
5790: - r   - the right scaling vector (or `NULL`)

5792:   Level: intermediate

5794:   Note:
5795:   `MatDiagonalScale()` computes $A = LAR$, where
5796:   L = a diagonal matrix (stored as a vector), R = a diagonal matrix (stored as a vector)
5797:   The L scales the rows of the matrix, the R scales the columns of the matrix.

5799: .seealso: [](ch_matrices), `Mat`, `MatScale()`, `MatShift()`, `MatDiagonalSet()`
5800: @*/
5801: PetscErrorCode MatDiagonalScale(Mat mat, Vec l, Vec r)
5802: {
5803:   PetscBool flg = PETSC_FALSE;

5805:   PetscFunctionBegin;
5808:   if (l) {
5810:     PetscCheckSameComm(mat, 1, l, 2);
5811:   }
5812:   if (r) {
5814:     PetscCheckSameComm(mat, 1, r, 3);
5815:   }
5816:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5817:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5818:   MatCheckPreallocated(mat, 1);
5819:   if (!l && !r) PetscFunctionReturn(PETSC_SUCCESS);

5821:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5822:   PetscUseTypeMethod(mat, diagonalscale, l, r);
5823:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5824:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5825:   if (l != r && (PetscBool3ToBool(mat->symmetric) || PetscBool3ToBool(mat->hermitian))) {
5826:     if (!PetscDefined(USE_COMPLEX) || PetscBool3ToBool(mat->symmetric)) {
5827:       if (l && r) PetscCall(VecEqual(l, r, &flg));
5828:       if (!flg) {
5829:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
5830:         PetscCheck(!flg, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "For symmetric format, left and right scaling vectors must be the same");
5831:         mat->symmetric = mat->spd = PETSC_BOOL3_FALSE;
5832:         if (!PetscDefined(USE_COMPLEX)) mat->hermitian = PETSC_BOOL3_FALSE;
5833:         else mat->hermitian = PETSC_BOOL3_UNKNOWN;
5834:       }
5835:     }
5836:     if (PetscDefined(USE_COMPLEX) && PetscBool3ToBool(mat->hermitian)) {
5837:       flg = PETSC_FALSE;
5838:       if (l && r) {
5839:         Vec conjugate;

5841:         PetscCall(VecDuplicate(l, &conjugate));
5842:         PetscCall(VecCopy(l, conjugate));
5843:         PetscCall(VecConjugate(conjugate));
5844:         PetscCall(VecEqual(conjugate, r, &flg));
5845:         PetscCall(VecDestroy(&conjugate));
5846:       }
5847:       if (!flg) {
5848:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
5849:         PetscCheck(!flg, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "For symmetric format and Hermitian matrix, left and right scaling vectors must be conjugate one of the other");
5850:         mat->hermitian = PETSC_BOOL3_FALSE;
5851:         mat->symmetric = mat->spd = PETSC_BOOL3_UNKNOWN;
5852:       }
5853:     }
5854:   }
5855:   PetscFunctionReturn(PETSC_SUCCESS);
5856: }

5858: /*@
5859:   MatScale - Scales all elements of a matrix by a given number.

5861:   Logically Collective

5863:   Input Parameters:
5864: + mat - the matrix to be scaled
5865: - a   - the scaling value

5867:   Level: intermediate

5869: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
5870: @*/
5871: PetscErrorCode MatScale(Mat mat, PetscScalar a)
5872: {
5873:   PetscFunctionBegin;
5876:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5877:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5879:   MatCheckPreallocated(mat, 1);

5881:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5882:   if (a != (PetscScalar)1.0) {
5883:     PetscUseTypeMethod(mat, scale, a);
5884:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5885:   }
5886:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5887:   PetscFunctionReturn(PETSC_SUCCESS);
5888: }

5890: /*@
5891:   MatNorm - Calculates various norms of a matrix.

5893:   Collective

5895:   Input Parameters:
5896: + mat  - the matrix
5897: - type - the type of norm, `NORM_1`, `NORM_FROBENIUS`, `NORM_INFINITY`

5899:   Output Parameter:
5900: . nrm - the resulting norm

5902:   Level: intermediate

5904: .seealso: [](ch_matrices), `Mat`
5905: @*/
5906: PetscErrorCode MatNorm(Mat mat, NormType type, PetscReal *nrm)
5907: {
5908:   PetscFunctionBegin;
5911:   PetscAssertPointer(nrm, 3);

5913:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5914:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5915:   MatCheckPreallocated(mat, 1);

5917:   PetscUseTypeMethod(mat, norm, type, nrm);
5918:   PetscFunctionReturn(PETSC_SUCCESS);
5919: }

5921: /*
5922:      This variable is used to prevent counting of MatAssemblyBegin() that
5923:    are called from within a MatAssemblyEnd().
5924: */
5925: static PetscInt MatAssemblyEnd_InUse = 0;
5926: /*@
5927:   MatAssemblyBegin - Begins assembling the matrix.  This routine should
5928:   be called after completing all calls to `MatSetValues()`.

5930:   Collective

5932:   Input Parameters:
5933: + mat  - the matrix
5934: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5936:   Level: beginner

5938:   Notes:
5939:   `MatSetValues()` generally caches the values that belong to other MPI processes.  The matrix is ready to
5940:   use only after `MatAssemblyBegin()` and `MatAssemblyEnd()` have been called.

5942:   Use `MAT_FLUSH_ASSEMBLY` when switching between `ADD_VALUES` and `INSERT_VALUES`
5943:   in `MatSetValues()`; use `MAT_FINAL_ASSEMBLY` for the final assembly before
5944:   using the matrix.

5946:   ALL processes that share a matrix MUST call `MatAssemblyBegin()` and `MatAssemblyEnd()` the SAME NUMBER of times, and each time with the
5947:   same flag of `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY` for all processes. Thus you CANNOT locally change from `ADD_VALUES` to `INSERT_VALUES`, that is
5948:   a global collective operation requiring all processes that share the matrix.

5950:   Space for preallocated nonzeros that is not filled by a call to `MatSetValues()` or a related routine are compressed
5951:   out by assembly. If you intend to use that extra space on a subsequent assembly, be sure to insert explicit zeros
5952:   before `MAT_FINAL_ASSEMBLY` so the space is not compressed out.

5954: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssembled()`
5955: @*/
5956: PetscErrorCode MatAssemblyBegin(Mat mat, MatAssemblyType type)
5957: {
5958:   PetscFunctionBegin;
5961:   MatCheckPreallocated(mat, 1);
5962:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix. Did you forget to call MatSetUnfactored()?");
5963:   if (mat->assembled) {
5964:     mat->was_assembled = PETSC_TRUE;
5965:     mat->assembled     = PETSC_FALSE;
5966:   }

5968:   if (!MatAssemblyEnd_InUse) {
5969:     PetscCall(PetscLogEventBegin(MAT_AssemblyBegin, mat, 0, 0, 0));
5970:     PetscTryTypeMethod(mat, assemblybegin, type);
5971:     PetscCall(PetscLogEventEnd(MAT_AssemblyBegin, mat, 0, 0, 0));
5972:   } else PetscTryTypeMethod(mat, assemblybegin, type);
5973:   PetscFunctionReturn(PETSC_SUCCESS);
5974: }

5976: /*@
5977:   MatAssembled - Indicates if a matrix has been assembled and is ready for
5978:   use; for example, in matrix-vector product.

5980:   Not Collective

5982:   Input Parameter:
5983: . mat - the matrix

5985:   Output Parameter:
5986: . assembled - `PETSC_TRUE` or `PETSC_FALSE`

5988:   Level: advanced

5990: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssemblyBegin()`
5991: @*/
5992: PetscErrorCode MatAssembled(Mat mat, PetscBool *assembled)
5993: {
5994:   PetscFunctionBegin;
5996:   PetscAssertPointer(assembled, 2);
5997:   *assembled = mat->assembled;
5998:   PetscFunctionReturn(PETSC_SUCCESS);
5999: }

6001: /*@
6002:   MatAssemblyEnd - Completes assembling the matrix.  This routine should
6003:   be called after `MatAssemblyBegin()`.

6005:   Collective

6007:   Input Parameters:
6008: + mat  - the matrix
6009: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

6011:   Options Database Keys:
6012: + -mat_view ::ascii_info             - Prints info on matrix at conclusion of `MatAssemblyEnd()`
6013: . -mat_view ::ascii_info_detail      - Prints more detailed info
6014: . -mat_view                          - Prints matrix in ASCII format
6015: . -mat_view ::ascii_matlab           - Prints matrix in MATLAB format
6016: . -mat_view draw                     - draws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
6017: . -display name                      - Sets display name (default is host)
6018: . -draw_pause sec                    - Sets number of seconds to pause after display
6019: . -mat_view socket                   - Sends matrix to socket, can be accessed from MATLAB (See [Using MATLAB with PETSc](ch_matlab))
6020: . -viewer_socket_machine machine     - Machine to use for socket
6021: . -viewer_socket_port port           - Port number to use for socket
6022: - -mat_view binary:filename[:append] - Save matrix to file in binary format

6024:   Level: beginner

6026: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatSetValues()`, `PetscDrawOpenX()`, `PetscDrawCreate()`, `MatView()`, `MatAssembled()`, `PetscViewerSocketOpen()`
6027: @*/
6028: PetscErrorCode MatAssemblyEnd(Mat mat, MatAssemblyType type)
6029: {
6030:   static PetscInt inassm = 0;
6031:   PetscBool       flg    = PETSC_FALSE;

6033:   PetscFunctionBegin;

6037:   inassm++;
6038:   MatAssemblyEnd_InUse++;
6039:   if (MatAssemblyEnd_InUse == 1) { /* Do the logging only the first time through */
6040:     PetscCall(PetscLogEventBegin(MAT_AssemblyEnd, mat, 0, 0, 0));
6041:     PetscTryTypeMethod(mat, assemblyend, type);
6042:     PetscCall(PetscLogEventEnd(MAT_AssemblyEnd, mat, 0, 0, 0));
6043:   } else PetscTryTypeMethod(mat, assemblyend, type);

6045:   /* Flush assembly is not a true assembly */
6046:   if (type != MAT_FLUSH_ASSEMBLY) {
6047:     if (mat->num_ass) {
6048:       if (!mat->symmetry_eternal) {
6049:         mat->symmetric = PETSC_BOOL3_UNKNOWN;
6050:         mat->hermitian = PETSC_BOOL3_UNKNOWN;
6051:       }
6052:       if (!mat->structural_symmetry_eternal && mat->ass_nonzerostate != mat->nonzerostate) mat->structurally_symmetric = PETSC_BOOL3_UNKNOWN;
6053:       if (!mat->spd_eternal) mat->spd = PETSC_BOOL3_UNKNOWN;
6054:     }
6055:     mat->num_ass++;
6056:     mat->assembled        = PETSC_TRUE;
6057:     mat->ass_nonzerostate = mat->nonzerostate;
6058:   }

6060:   mat->insertmode = NOT_SET_VALUES;
6061:   MatAssemblyEnd_InUse--;
6062:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6063:   if (inassm == 1 && type != MAT_FLUSH_ASSEMBLY) {
6064:     PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));

6066:     if (mat->checksymmetryonassembly) {
6067:       PetscCall(MatIsSymmetric(mat, mat->checksymmetrytol, &flg));
6068:       if (flg) {
6069:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
6070:       } else {
6071:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is not symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
6072:       }
6073:     }
6074:     if (mat->nullsp && mat->checknullspaceonassembly) PetscCall(MatNullSpaceTest(mat->nullsp, mat, NULL));
6075:   }
6076:   inassm--;
6077:   PetscFunctionReturn(PETSC_SUCCESS);
6078: }

6080: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
6081: /*@
6082:   MatSetOption - Sets a parameter option for a matrix. Some options
6083:   may be specific to certain storage formats.  Some options
6084:   determine how values will be inserted (or added). Sorted,
6085:   row-oriented input will generally assemble the fastest. The default
6086:   is row-oriented.

6088:   Logically Collective for certain operations, such as `MAT_SPD`, not collective for `MAT_ROW_ORIENTED`, see `MatOption`

6090:   Input Parameters:
6091: + mat - the matrix
6092: . op  - the option, one of those listed below (and possibly others),
6093: - flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6095:   Options Describing Matrix Structure:
6096: + `MAT_SPD`                         - symmetric positive definite
6097: . `MAT_SYMMETRIC`                   - symmetric in terms of both structure and value
6098: . `MAT_HERMITIAN`                   - transpose is the complex conjugation
6099: . `MAT_STRUCTURALLY_SYMMETRIC`      - symmetric nonzero structure
6100: . `MAT_SYMMETRY_ETERNAL`            - indicates the symmetry (or Hermitian structure) or its absence will persist through any changes to the matrix
6101: . `MAT_STRUCTURAL_SYMMETRY_ETERNAL` - indicates the structural symmetry or its absence will persist through any changes to the matrix
6102: . `MAT_SPD_ETERNAL`                 - indicates the value of `MAT_SPD` (true or false) will persist through any changes to the matrix

6104:    These are not really options of the matrix, they are knowledge about the structure of the matrix that users may provide so that they
6105:    do not need to be computed (usually at a high cost)

6107:    Options For Use with `MatSetValues()`:
6108:    Insert a logically dense subblock, which can be
6109: . `MAT_ROW_ORIENTED`                - row-oriented (default)

6111:    These options reflect the data you pass in with `MatSetValues()`; it has
6112:    nothing to do with how the data is stored internally in the matrix
6113:    data structure.

6115:    When (re)assembling a matrix, we can restrict the input for
6116:    efficiency/debugging purposes.  These options include
6117: . `MAT_NEW_NONZERO_LOCATIONS`       - additional insertions will be allowed if they generate a new nonzero (slow)
6118: . `MAT_FORCE_DIAGONAL_ENTRIES`      - forces diagonal entries to be allocated
6119: . `MAT_IGNORE_OFF_PROC_ENTRIES`     - drops off-processor entries
6120: . `MAT_NEW_NONZERO_LOCATION_ERR`    - generates an error for new matrix entry
6121: . `MAT_USE_HASH_TABLE`              - uses a hash table to speed up matrix assembly
6122: . `MAT_NO_OFF_PROC_ENTRIES`         - you know each process will only set values for its own rows, will generate an error if
6123:         any process sets values for another process. This avoids all reductions in the MatAssembly routines and thus improves
6124:         performance for very large process counts.
6125: - `MAT_SUBSET_OFF_PROC_ENTRIES`     - you know that the first assembly after setting this flag will set a superset
6126:         of the off-process entries required for all subsequent assemblies. This avoids a rendezvous step in the MatAssembly
6127:         functions, instead sending only neighbor messages.

6129:   Level: intermediate

6131:   Notes:
6132:   Except for `MAT_UNUSED_NONZERO_LOCATION_ERR` and  `MAT_ROW_ORIENTED` all processes that share the matrix must pass the same value in flg!

6134:   Some options are relevant only for particular matrix types and
6135:   are thus ignored by others.  Other options are not supported by
6136:   certain matrix types and will generate an error message if set.

6138:   If using Fortran to compute a matrix, one may need to
6139:   use the column-oriented option (or convert to the row-oriented
6140:   format).

6142:   `MAT_NEW_NONZERO_LOCATIONS` set to `PETSC_FALSE` indicates that any add or insertion
6143:   that would generate a new entry in the nonzero structure is instead
6144:   ignored.  Thus, if memory has not already been allocated for this particular
6145:   data, then the insertion is ignored. For dense matrices, in which
6146:   the entire array is allocated, no entries are ever ignored.
6147:   Set after the first `MatAssemblyEnd()`. If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6149:   `MAT_NEW_NONZERO_LOCATION_ERR` set to PETSC_TRUE indicates that any add or insertion
6150:   that would generate a new entry in the nonzero structure instead produces
6151:   an error. (Currently supported for `MATAIJ` and `MATBAIJ` formats only.) If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6153:   `MAT_NEW_NONZERO_ALLOCATION_ERR` set to `PETSC_TRUE` indicates that any add or insertion
6154:   that would generate a new entry that has not been preallocated will
6155:   instead produce an error. (Currently supported for `MATAIJ` and `MATBAIJ` formats
6156:   only.) This is a useful flag when debugging matrix memory preallocation.
6157:   If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6159:   `MAT_IGNORE_OFF_PROC_ENTRIES` set to `PETSC_TRUE` indicates entries destined for
6160:   other processors should be dropped, rather than stashed.
6161:   This is useful if you know that the "owning" processor is also
6162:   always generating the correct matrix entries, so that PETSc need
6163:   not transfer duplicate entries generated on another processor.

6165:   `MAT_USE_HASH_TABLE` indicates that a hash table be used to improve the
6166:   searches during matrix assembly. When this flag is set, the hash table
6167:   is created during the first matrix assembly. This hash table is
6168:   used the next time through, during `MatSetValues()`/`MatSetValuesBlocked()`
6169:   to improve the searching of indices. `MAT_NEW_NONZERO_LOCATIONS` flag
6170:   should be used with `MAT_USE_HASH_TABLE` flag. This option is currently
6171:   supported by `MATMPIBAIJ` format only.

6173:   `MAT_KEEP_NONZERO_PATTERN` indicates when `MatZeroRows()` is called the zeroed entries
6174:   are kept in the nonzero structure. This flag is not used for `MatZeroRowsColumns()`

6176:   `MAT_IGNORE_ZERO_ENTRIES` - for `MATAIJ` and `MATIS` matrices this will stop zero values from creating
6177:   a zero location in the matrix

6179:   `MAT_USE_INODES` - indicates using inode version of the code - works with `MATAIJ` matrix types

6181:   `MAT_NO_OFF_PROC_ZERO_ROWS` - you know each process will only zero its own rows. This avoids all reductions in the
6182:   zero row routines and thus improves performance for very large process counts.

6184:   `MAT_IGNORE_LOWER_TRIANGULAR` - For `MATSBAIJ` matrices will ignore any insertions you make in the lower triangular
6185:   part of the matrix (since they should match the upper triangular part).

6187:   `MAT_SORTED_FULL` - each process provides exactly its local rows; all column indices for a given row are passed in a
6188:   single call to `MatSetValues()`, preallocation is perfect, row-oriented, `INSERT_VALUES` is used. Common
6189:   with finite difference schemes with non-periodic boundary conditions.

6191:   Developer Note:
6192:   `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, and `MAT_SPD_ETERNAL` are used by `MatAssemblyEnd()` and in other
6193:   places where otherwise the value of `MAT_SYMMETRIC`, `MAT_STRUCTURALLY_SYMMETRIC` or `MAT_SPD` would need to be changed back
6194:   to `PETSC_BOOL3_UNKNOWN` because the matrix values had changed so the code cannot be certain that the related property had
6195:   not changed.

6197: .seealso: [](ch_matrices), `MatOption`, `Mat`, `MatGetOption()`
6198: @*/
6199: PetscErrorCode MatSetOption(Mat mat, MatOption op, PetscBool flg)
6200: {
6201:   PetscFunctionBegin;
6203:   if (op > 0) {
6206:   }

6208:   PetscCheck(((int)op) > MAT_OPTION_MIN && ((int)op) < MAT_OPTION_MAX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Options %d is out of range", (int)op);

6210:   switch (op) {
6211:   case MAT_FORCE_DIAGONAL_ENTRIES:
6212:     mat->force_diagonals = flg;
6213:     PetscFunctionReturn(PETSC_SUCCESS);
6214:   case MAT_NO_OFF_PROC_ENTRIES:
6215:     mat->nooffprocentries = flg;
6216:     PetscFunctionReturn(PETSC_SUCCESS);
6217:   case MAT_SUBSET_OFF_PROC_ENTRIES:
6218:     mat->assembly_subset = flg;
6219:     if (!mat->assembly_subset) { /* See the same logic in VecAssembly wrt VEC_SUBSET_OFF_PROC_ENTRIES */
6220: #if !defined(PETSC_HAVE_MPIUNI)
6221:       PetscCall(MatStashScatterDestroy_BTS(&mat->stash));
6222: #endif
6223:       mat->stash.first_assembly_done = PETSC_FALSE;
6224:     }
6225:     PetscFunctionReturn(PETSC_SUCCESS);
6226:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6227:     mat->nooffproczerorows = flg;
6228:     PetscFunctionReturn(PETSC_SUCCESS);
6229:   case MAT_SPD:
6230:     if (flg) {
6231:       mat->spd                    = PETSC_BOOL3_TRUE;
6232:       mat->symmetric              = PETSC_BOOL3_TRUE;
6233:       mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6234: #if !defined(PETSC_USE_COMPLEX)
6235:       mat->hermitian = PETSC_BOOL3_TRUE;
6236: #endif
6237:     } else {
6238:       mat->spd = PETSC_BOOL3_FALSE;
6239:     }
6240:     break;
6241:   case MAT_SYMMETRIC:
6242:     mat->symmetric = PetscBoolToBool3(flg);
6243:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6244: #if !defined(PETSC_USE_COMPLEX)
6245:     mat->hermitian = PetscBoolToBool3(flg);
6246: #endif
6247:     break;
6248:   case MAT_HERMITIAN:
6249:     mat->hermitian = PetscBoolToBool3(flg);
6250:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6251: #if !defined(PETSC_USE_COMPLEX)
6252:     mat->symmetric = PetscBoolToBool3(flg);
6253: #endif
6254:     break;
6255:   case MAT_STRUCTURALLY_SYMMETRIC:
6256:     mat->structurally_symmetric = PetscBoolToBool3(flg);
6257:     break;
6258:   case MAT_SYMMETRY_ETERNAL:
6259:     PetscCheck(mat->symmetric != PETSC_BOOL3_UNKNOWN, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot set MAT_SYMMETRY_ETERNAL without first setting MAT_SYMMETRIC to true or false");
6260:     mat->symmetry_eternal = flg;
6261:     if (flg) mat->structural_symmetry_eternal = PETSC_TRUE;
6262:     break;
6263:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6264:     PetscCheck(mat->structurally_symmetric != PETSC_BOOL3_UNKNOWN, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot set MAT_STRUCTURAL_SYMMETRY_ETERNAL without first setting MAT_STRUCTURALLY_SYMMETRIC to true or false");
6265:     mat->structural_symmetry_eternal = flg;
6266:     break;
6267:   case MAT_SPD_ETERNAL:
6268:     PetscCheck(mat->spd != PETSC_BOOL3_UNKNOWN, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot set MAT_SPD_ETERNAL without first setting MAT_SPD to true or false");
6269:     mat->spd_eternal = flg;
6270:     if (flg) {
6271:       mat->structural_symmetry_eternal = PETSC_TRUE;
6272:       mat->symmetry_eternal            = PETSC_TRUE;
6273:     }
6274:     break;
6275:   case MAT_STRUCTURE_ONLY:
6276:     mat->structure_only = flg;
6277:     break;
6278:   case MAT_SORTED_FULL:
6279:     mat->sortedfull = flg;
6280:     break;
6281:   default:
6282:     break;
6283:   }
6284:   PetscTryTypeMethod(mat, setoption, op, flg);
6285:   PetscFunctionReturn(PETSC_SUCCESS);
6286: }

6288: /*@
6289:   MatGetOption - Gets a parameter option that has been set for a matrix.

6291:   Logically Collective

6293:   Input Parameters:
6294: + mat - the matrix
6295: - op  - the option, this only responds to certain options, check the code for which ones

6297:   Output Parameter:
6298: . flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6300:   Level: intermediate

6302:   Notes:
6303:   Can only be called after `MatSetSizes()` and `MatSetType()` have been set.

6305:   Certain option values may be unknown, for those use the routines `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, or
6306:   `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`

6308: .seealso: [](ch_matrices), `Mat`, `MatOption`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`,
6309:     `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
6310: @*/
6311: PetscErrorCode MatGetOption(Mat mat, MatOption op, PetscBool *flg)
6312: {
6313:   PetscFunctionBegin;

6317:   PetscCheck(((int)op) > MAT_OPTION_MIN && ((int)op) < MAT_OPTION_MAX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Options %d is out of range", (int)op);
6318:   PetscCheck(((PetscObject)mat)->type_name, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_TYPENOTSET, "Cannot get options until type and size have been set, see MatSetType() and MatSetSizes()");

6320:   switch (op) {
6321:   case MAT_NO_OFF_PROC_ENTRIES:
6322:     *flg = mat->nooffprocentries;
6323:     break;
6324:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6325:     *flg = mat->nooffproczerorows;
6326:     break;
6327:   case MAT_SYMMETRIC:
6328:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSymmetric() or MatIsSymmetricKnown()");
6329:     break;
6330:   case MAT_HERMITIAN:
6331:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsHermitian() or MatIsHermitianKnown()");
6332:     break;
6333:   case MAT_STRUCTURALLY_SYMMETRIC:
6334:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsStructurallySymmetric() or MatIsStructurallySymmetricKnown()");
6335:     break;
6336:   case MAT_SPD:
6337:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSPDKnown()");
6338:     break;
6339:   case MAT_SYMMETRY_ETERNAL:
6340:     *flg = mat->symmetry_eternal;
6341:     break;
6342:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6343:     *flg = mat->symmetry_eternal;
6344:     break;
6345:   default:
6346:     break;
6347:   }
6348:   PetscFunctionReturn(PETSC_SUCCESS);
6349: }

6351: /*@
6352:   MatZeroEntries - Zeros all entries of a matrix.  For sparse matrices
6353:   this routine retains the old nonzero structure.

6355:   Logically Collective

6357:   Input Parameter:
6358: . mat - the matrix

6360:   Level: intermediate

6362:   Note:
6363:   If the matrix was not preallocated then a default, likely poor preallocation will be set in the matrix, so this should be called after the preallocation phase.
6364:   See the Performance chapter of the users manual for information on preallocating matrices.

6366: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`
6367: @*/
6368: PetscErrorCode MatZeroEntries(Mat mat)
6369: {
6370:   PetscFunctionBegin;
6373:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6374:   PetscCheck(mat->insertmode == NOT_SET_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for matrices where you have set values but not yet assembled");
6375:   MatCheckPreallocated(mat, 1);

6377:   PetscCall(PetscLogEventBegin(MAT_ZeroEntries, mat, 0, 0, 0));
6378:   PetscUseTypeMethod(mat, zeroentries);
6379:   PetscCall(PetscLogEventEnd(MAT_ZeroEntries, mat, 0, 0, 0));
6380:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6381:   PetscFunctionReturn(PETSC_SUCCESS);
6382: }

6384: /*@
6385:   MatZeroRowsColumns - Zeros all entries (except possibly the main diagonal)
6386:   of a set of rows and columns of a matrix.

6388:   Collective

6390:   Input Parameters:
6391: + mat     - the matrix
6392: . numRows - the number of rows/columns to zero
6393: . rows    - the global row indices
6394: . diag    - value put in the diagonal of the eliminated rows
6395: . x       - optional vector of the solution for zeroed rows (other entries in vector are not used), these must be set before this call
6396: - b       - optional vector of the right-hand side, that will be adjusted by provided solution entries

6398:   Level: intermediate

6400:   Notes:
6401:   This routine, along with `MatZeroRows()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6403:   For each zeroed row, the value of the corresponding `b` is set to diag times the value of the corresponding `x`.
6404:   The other entries of `b` will be adjusted by the known values of `x` times the corresponding matrix entries in the columns that are being eliminated

6406:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6407:   Krylov method to take advantage of the known solution on the zeroed rows.

6409:   For the parallel case, all processes that share the matrix (i.e.,
6410:   those in the communicator used for matrix creation) MUST call this
6411:   routine, regardless of whether any rows being zeroed are owned by
6412:   them.

6414:   Unlike `MatZeroRows()`, this ignores the `MAT_KEEP_NONZERO_PATTERN` option value set with `MatSetOption()`, it merely zeros those entries in the matrix, but never
6415:   removes them from the nonzero pattern. The nonzero pattern of the matrix can still change if a nonzero needs to be inserted on a diagonal entry that was previously
6416:   missing.

6418:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6419:   list only rows local to itself).

6421:   The option `MAT_NO_OFF_PROC_ZERO_ROWS` does not apply to this routine.

6423: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRows()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6424:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6425: @*/
6426: PetscErrorCode MatZeroRowsColumns(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6427: {
6428:   PetscFunctionBegin;
6431:   if (numRows) PetscAssertPointer(rows, 3);
6432:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6433:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6434:   MatCheckPreallocated(mat, 1);

6436:   PetscUseTypeMethod(mat, zerorowscolumns, numRows, rows, diag, x, b);
6437:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6438:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6439:   PetscFunctionReturn(PETSC_SUCCESS);
6440: }

6442: /*@
6443:   MatZeroRowsColumnsIS - Zeros all entries (except possibly the main diagonal)
6444:   of a set of rows and columns of a matrix.

6446:   Collective

6448:   Input Parameters:
6449: + mat  - the matrix
6450: . is   - the rows to zero
6451: . diag - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6452: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6453: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6455:   Level: intermediate

6457:   Note:
6458:   See `MatZeroRowsColumns()` for details on how this routine operates.

6460: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6461:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRows()`, `MatZeroRowsColumnsStencil()`
6462: @*/
6463: PetscErrorCode MatZeroRowsColumnsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6464: {
6465:   PetscInt        numRows;
6466:   const PetscInt *rows;

6468:   PetscFunctionBegin;
6473:   PetscCall(ISGetLocalSize(is, &numRows));
6474:   PetscCall(ISGetIndices(is, &rows));
6475:   PetscCall(MatZeroRowsColumns(mat, numRows, rows, diag, x, b));
6476:   PetscCall(ISRestoreIndices(is, &rows));
6477:   PetscFunctionReturn(PETSC_SUCCESS);
6478: }

6480: /*@
6481:   MatZeroRows - Zeros all entries (except possibly the main diagonal)
6482:   of a set of rows of a matrix.

6484:   Collective

6486:   Input Parameters:
6487: + mat     - the matrix
6488: . numRows - the number of rows to zero
6489: . rows    - the global row indices
6490: . diag    - value put in the diagonal of the zeroed rows
6491: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used), these must be set before this call
6492: - b       - optional vector of right-hand side, that will be adjusted by provided solution entries

6494:   Level: intermediate

6496:   Notes:
6497:   This routine, along with `MatZeroRowsColumns()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6499:   For each zeroed row, the value of the corresponding `b` is set to `diag` times the value of the corresponding `x`.

6501:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6502:   Krylov method to take advantage of the known solution on the zeroed rows.

6504:   May be followed by using a `PC` of type `PCREDISTRIBUTE` to solve the reduced problem (`PCDISTRIBUTE` completely eliminates the zeroed rows and their corresponding columns)
6505:   from the matrix.

6507:   Unlike `MatZeroRowsColumns()` for the `MATAIJ` and `MATBAIJ` matrix formats this removes the old nonzero structure, from the eliminated rows of the matrix
6508:   but does not release memory.  Because of this removal matrix-vector products with the adjusted matrix will be a bit faster. For the dense
6509:   formats this does not alter the nonzero structure.

6511:   If the option `MatSetOption`(mat,`MAT_KEEP_NONZERO_PATTERN`,`PETSC_TRUE`) the nonzero structure
6512:   of the matrix is not changed the values are
6513:   merely zeroed.

6515:   The user can set a value in the diagonal entry (or for the `MATAIJ` format
6516:   formats can optionally remove the main diagonal entry from the
6517:   nonzero structure as well, by passing 0.0 as the final argument).

6519:   For the parallel case, all processes that share the matrix (i.e.,
6520:   those in the communicator used for matrix creation) MUST call this
6521:   routine, regardless of whether any rows being zeroed are owned by
6522:   them.

6524:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6525:   list only rows local to itself).

6527:   You can call `MatSetOption`(mat,`MAT_NO_OFF_PROC_ZERO_ROWS`,`PETSC_TRUE`) if each process indicates only rows it
6528:   owns that are to be zeroed. This saves a global synchronization in the implementation.

6530: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6531:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `PCREDISTRIBUTE`, `MAT_KEEP_NONZERO_PATTERN`
6532: @*/
6533: PetscErrorCode MatZeroRows(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6534: {
6535:   PetscFunctionBegin;
6538:   if (numRows) PetscAssertPointer(rows, 3);
6539:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6540:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6541:   MatCheckPreallocated(mat, 1);

6543:   PetscUseTypeMethod(mat, zerorows, numRows, rows, diag, x, b);
6544:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6545:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6546:   PetscFunctionReturn(PETSC_SUCCESS);
6547: }

6549: /*@
6550:   MatZeroRowsIS - Zeros all entries (except possibly the main diagonal)
6551:   of a set of rows of a matrix indicated by an `IS`

6553:   Collective

6555:   Input Parameters:
6556: + mat  - the matrix
6557: . is   - index set, `IS`, of rows to remove (if `NULL` then no row is removed)
6558: . diag - value put in all diagonals of eliminated rows
6559: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6560: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6562:   Level: intermediate

6564:   Note:
6565:   See `MatZeroRows()` for details on how this routine operates.

6567: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6568:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `IS`
6569: @*/
6570: PetscErrorCode MatZeroRowsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6571: {
6572:   PetscInt        numRows = 0;
6573:   const PetscInt *rows    = NULL;

6575:   PetscFunctionBegin;
6578:   if (is) {
6580:     PetscCall(ISGetLocalSize(is, &numRows));
6581:     PetscCall(ISGetIndices(is, &rows));
6582:   }
6583:   PetscCall(MatZeroRows(mat, numRows, rows, diag, x, b));
6584:   if (is) PetscCall(ISRestoreIndices(is, &rows));
6585:   PetscFunctionReturn(PETSC_SUCCESS);
6586: }

6588: /*@
6589:   MatZeroRowsStencil - Zeros all entries (except possibly the main diagonal)
6590:   of a set of rows of a matrix indicated by a `MatStencil`. These rows must be local to the process.

6592:   Collective

6594:   Input Parameters:
6595: + mat     - the matrix
6596: . numRows - the number of rows to remove
6597: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows indicated by an array of `MatStencil`
6598: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6599: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6600: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6602:   Level: intermediate

6604:   Notes:
6605:   See `MatZeroRows()` for details on how this routine operates.

6607:   The grid coordinates are across the entire grid, not just the local portion

6609:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6610:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6611:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6612:   `DM_BOUNDARY_PERIODIC` boundary type.

6614:   For indices that don't mean anything for your case (like the `k` index when working in 2d) or the `c` index when you have
6615:   a single value per point) you can skip filling those indices.

6617:   Fortran Note:
6618:   `idxm` and `idxn` should be declared as
6619: .vb
6620:     MatStencil idxm(4, m)
6621: .ve
6622:   and the values inserted using
6623: .vb
6624:     idxm(MatStencil_i, 1) = i
6625:     idxm(MatStencil_j, 1) = j
6626:     idxm(MatStencil_k, 1) = k
6627:     idxm(MatStencil_c, 1) = c
6628:    etc
6629: .ve

6631: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRows()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6632:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6633: @*/
6634: PetscErrorCode MatZeroRowsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6635: {
6636:   PetscInt  dim    = mat->stencil.dim;
6637:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6638:   PetscInt *dims   = mat->stencil.dims + 1;
6639:   PetscInt *starts = mat->stencil.starts;
6640:   PetscInt *dxm    = (PetscInt *)rows;
6641:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6643:   PetscFunctionBegin;
6646:   if (numRows) PetscAssertPointer(rows, 3);

6648:   PetscCall(PetscMalloc1(numRows, &jdxm));
6649:   for (i = 0; i < numRows; ++i) {
6650:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6651:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6652:     /* Local index in X dir */
6653:     tmp = *dxm++ - starts[0];
6654:     /* Loop over remaining dimensions */
6655:     for (j = 0; j < dim - 1; ++j) {
6656:       /* If nonlocal, set index to be negative */
6657:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6658:       /* Update local index */
6659:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6660:     }
6661:     /* Skip component slot if necessary */
6662:     if (mat->stencil.noc) dxm++;
6663:     /* Local row number */
6664:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6665:   }
6666:   PetscCall(MatZeroRowsLocal(mat, numNewRows, jdxm, diag, x, b));
6667:   PetscCall(PetscFree(jdxm));
6668:   PetscFunctionReturn(PETSC_SUCCESS);
6669: }

6671: /*@
6672:   MatZeroRowsColumnsStencil - Zeros all row and column entries (except possibly the main diagonal)
6673:   of a set of rows and columns of a matrix.

6675:   Collective

6677:   Input Parameters:
6678: + mat     - the matrix
6679: . numRows - the number of rows/columns to remove
6680: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows
6681: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6682: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6683: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6685:   Level: intermediate

6687:   Notes:
6688:   See `MatZeroRowsColumns()` for details on how this routine operates.

6690:   The grid coordinates are across the entire grid, not just the local portion

6692:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6693:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6694:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6695:   `DM_BOUNDARY_PERIODIC` boundary type.

6697:   For indices that don't mean anything for your case (like the `k` index when working in 2d) or the `c` index when you have
6698:   a single value per point) you can skip filling those indices.

6700:   Fortran Note:
6701:   `idxm` and `idxn` should be declared as
6702: .vb
6703:     MatStencil idxm(4, m)
6704: .ve
6705:   and the values inserted using
6706: .vb
6707:     idxm(MatStencil_i, 1) = i
6708:     idxm(MatStencil_j, 1) = j
6709:     idxm(MatStencil_k, 1) = k
6710:     idxm(MatStencil_c, 1) = c
6711:     etc
6712: .ve

6714: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6715:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRows()`
6716: @*/
6717: PetscErrorCode MatZeroRowsColumnsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6718: {
6719:   PetscInt  dim    = mat->stencil.dim;
6720:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6721:   PetscInt *dims   = mat->stencil.dims + 1;
6722:   PetscInt *starts = mat->stencil.starts;
6723:   PetscInt *dxm    = (PetscInt *)rows;
6724:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6726:   PetscFunctionBegin;
6729:   if (numRows) PetscAssertPointer(rows, 3);

6731:   PetscCall(PetscMalloc1(numRows, &jdxm));
6732:   for (i = 0; i < numRows; ++i) {
6733:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6734:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6735:     /* Local index in X dir */
6736:     tmp = *dxm++ - starts[0];
6737:     /* Loop over remaining dimensions */
6738:     for (j = 0; j < dim - 1; ++j) {
6739:       /* If nonlocal, set index to be negative */
6740:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6741:       /* Update local index */
6742:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6743:     }
6744:     /* Skip component slot if necessary */
6745:     if (mat->stencil.noc) dxm++;
6746:     /* Local row number */
6747:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6748:   }
6749:   PetscCall(MatZeroRowsColumnsLocal(mat, numNewRows, jdxm, diag, x, b));
6750:   PetscCall(PetscFree(jdxm));
6751:   PetscFunctionReturn(PETSC_SUCCESS);
6752: }

6754: /*@
6755:   MatZeroRowsLocal - Zeros all entries (except possibly the main diagonal)
6756:   of a set of rows of a matrix; using local numbering of rows.

6758:   Collective

6760:   Input Parameters:
6761: + mat     - the matrix
6762: . numRows - the number of rows to remove
6763: . rows    - the local row indices
6764: . diag    - value put in all diagonals of eliminated rows
6765: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6766: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6768:   Level: intermediate

6770:   Notes:
6771:   Before calling `MatZeroRowsLocal()`, the user must first set the
6772:   local-to-global mapping by calling MatSetLocalToGlobalMapping(), this is often already set for matrices obtained with `DMCreateMatrix()`.

6774:   See `MatZeroRows()` for details on how this routine operates.

6776: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRows()`, `MatSetOption()`,
6777:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6778: @*/
6779: PetscErrorCode MatZeroRowsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6780: {
6781:   PetscFunctionBegin;
6784:   if (numRows) PetscAssertPointer(rows, 3);
6785:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6786:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6787:   MatCheckPreallocated(mat, 1);

6789:   if (mat->ops->zerorowslocal) {
6790:     PetscUseTypeMethod(mat, zerorowslocal, numRows, rows, diag, x, b);
6791:   } else {
6792:     IS        is, newis;
6793:     PetscInt *newRows, nl = 0;

6795:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6796:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6797:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6798:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6799:     for (PetscInt i = 0; i < numRows; i++)
6800:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6801:     PetscUseTypeMethod(mat, zerorows, nl, newRows, diag, x, b);
6802:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6803:     PetscCall(ISDestroy(&newis));
6804:     PetscCall(ISDestroy(&is));
6805:   }
6806:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6807:   PetscFunctionReturn(PETSC_SUCCESS);
6808: }

6810: /*@
6811:   MatZeroRowsLocalIS - Zeros all entries (except possibly the main diagonal)
6812:   of a set of rows of a matrix; using local numbering of rows.

6814:   Collective

6816:   Input Parameters:
6817: + mat  - the matrix
6818: . is   - index set of rows to remove
6819: . diag - value put in all diagonals of eliminated rows
6820: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6821: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6823:   Level: intermediate

6825:   Notes:
6826:   Before calling `MatZeroRowsLocalIS()`, the user must first set the
6827:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6829:   See `MatZeroRows()` for details on how this routine operates.

6831: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRows()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6832:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6833: @*/
6834: PetscErrorCode MatZeroRowsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6835: {
6836:   PetscInt        numRows;
6837:   const PetscInt *rows;

6839:   PetscFunctionBegin;
6843:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6844:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6845:   MatCheckPreallocated(mat, 1);

6847:   PetscCall(ISGetLocalSize(is, &numRows));
6848:   PetscCall(ISGetIndices(is, &rows));
6849:   PetscCall(MatZeroRowsLocal(mat, numRows, rows, diag, x, b));
6850:   PetscCall(ISRestoreIndices(is, &rows));
6851:   PetscFunctionReturn(PETSC_SUCCESS);
6852: }

6854: /*@
6855:   MatZeroRowsColumnsLocal - Zeros all entries (except possibly the main diagonal)
6856:   of a set of rows and columns of a matrix; using local numbering of rows.

6858:   Collective

6860:   Input Parameters:
6861: + mat     - the matrix
6862: . numRows - the number of rows to remove
6863: . rows    - the global row indices
6864: . diag    - value put in all diagonals of eliminated rows
6865: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6866: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6868:   Level: intermediate

6870:   Notes:
6871:   Before calling `MatZeroRowsColumnsLocal()`, the user must first set the
6872:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6874:   See `MatZeroRowsColumns()` for details on how this routine operates.

6876: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6877:           `MatZeroRows()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6878: @*/
6879: PetscErrorCode MatZeroRowsColumnsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6880: {
6881:   PetscFunctionBegin;
6884:   if (numRows) PetscAssertPointer(rows, 3);
6885:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6886:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6887:   MatCheckPreallocated(mat, 1);

6889:   if (mat->ops->zerorowscolumnslocal) {
6890:     PetscUseTypeMethod(mat, zerorowscolumnslocal, numRows, rows, diag, x, b);
6891:   } else {
6892:     IS        is, newis;
6893:     PetscInt *newRows, nl = 0;

6895:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6896:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6897:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6898:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6899:     for (PetscInt i = 0; i < numRows; i++)
6900:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6901:     PetscUseTypeMethod(mat, zerorowscolumns, nl, newRows, diag, x, b);
6902:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6903:     PetscCall(ISDestroy(&newis));
6904:     PetscCall(ISDestroy(&is));
6905:   }
6906:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6907:   PetscFunctionReturn(PETSC_SUCCESS);
6908: }

6910: /*@
6911:   MatZeroRowsColumnsLocalIS - Zeros all entries (except possibly the main diagonal)
6912:   of a set of rows and columns of a matrix; using local numbering of rows.

6914:   Collective

6916:   Input Parameters:
6917: + mat  - the matrix
6918: . is   - index set of rows to remove
6919: . diag - value put in all diagonals of eliminated rows
6920: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6921: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6923:   Level: intermediate

6925:   Notes:
6926:   Before calling `MatZeroRowsColumnsLocalIS()`, the user must first set the
6927:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6929:   See `MatZeroRowsColumns()` for details on how this routine operates.

6931: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6932:           `MatZeroRowsColumnsLocal()`, `MatZeroRows()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6933: @*/
6934: PetscErrorCode MatZeroRowsColumnsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6935: {
6936:   PetscInt        numRows;
6937:   const PetscInt *rows;

6939:   PetscFunctionBegin;
6943:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6944:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6945:   MatCheckPreallocated(mat, 1);

6947:   PetscCall(ISGetLocalSize(is, &numRows));
6948:   PetscCall(ISGetIndices(is, &rows));
6949:   PetscCall(MatZeroRowsColumnsLocal(mat, numRows, rows, diag, x, b));
6950:   PetscCall(ISRestoreIndices(is, &rows));
6951:   PetscFunctionReturn(PETSC_SUCCESS);
6952: }

6954: /*@
6955:   MatGetSize - Returns the numbers of rows and columns in a matrix.

6957:   Not Collective

6959:   Input Parameter:
6960: . mat - the matrix

6962:   Output Parameters:
6963: + m - the number of global rows
6964: - n - the number of global columns

6966:   Level: beginner

6968:   Note:
6969:   Both output parameters can be `NULL` on input.

6971: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetLocalSize()`
6972: @*/
6973: PetscErrorCode MatGetSize(Mat mat, PetscInt *m, PetscInt *n)
6974: {
6975:   PetscFunctionBegin;
6977:   if (m) *m = mat->rmap->N;
6978:   if (n) *n = mat->cmap->N;
6979:   PetscFunctionReturn(PETSC_SUCCESS);
6980: }

6982: /*@
6983:   MatGetLocalSize - For most matrix formats, excluding `MATELEMENTAL` and `MATSCALAPACK`, Returns the number of local rows and local columns
6984:   of a matrix. For all matrices this is the local size of the left and right vectors as returned by `MatCreateVecs()`.

6986:   Not Collective

6988:   Input Parameter:
6989: . mat - the matrix

6991:   Output Parameters:
6992: + m - the number of local rows, use `NULL` to not obtain this value
6993: - n - the number of local columns, use `NULL` to not obtain this value

6995:   Level: beginner

6997: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetSize()`
6998: @*/
6999: PetscErrorCode MatGetLocalSize(Mat mat, PetscInt *m, PetscInt *n)
7000: {
7001:   PetscFunctionBegin;
7003:   if (m) PetscAssertPointer(m, 2);
7004:   if (n) PetscAssertPointer(n, 3);
7005:   if (m) *m = mat->rmap->n;
7006:   if (n) *n = mat->cmap->n;
7007:   PetscFunctionReturn(PETSC_SUCCESS);
7008: }

7010: /*@
7011:   MatGetOwnershipRangeColumn - Returns the range of matrix columns associated with rows of a
7012:   vector one multiplies this matrix by that are owned by this processor.

7014:   Not Collective, unless matrix has not been allocated, then collective

7016:   Input Parameter:
7017: . mat - the matrix

7019:   Output Parameters:
7020: + m - the global index of the first local column, use `NULL` to not obtain this value
7021: - n - one more than the global index of the last local column, use `NULL` to not obtain this value

7023:   Level: developer

7025:   Notes:
7026:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7028:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7029:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7031:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7032:   the local values in the matrix.

7034:   Returns the columns of the "diagonal block" for most sparse matrix formats. See [Matrix
7035:   Layouts](sec_matlayout) for details on matrix layouts.

7037: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
7038:           `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
7039: @*/
7040: PetscErrorCode MatGetOwnershipRangeColumn(Mat mat, PetscInt *m, PetscInt *n)
7041: {
7042:   PetscFunctionBegin;
7045:   if (m) PetscAssertPointer(m, 2);
7046:   if (n) PetscAssertPointer(n, 3);
7047:   MatCheckPreallocated(mat, 1);
7048:   if (m) *m = mat->cmap->rstart;
7049:   if (n) *n = mat->cmap->rend;
7050:   PetscFunctionReturn(PETSC_SUCCESS);
7051: }

7053: /*@
7054:   MatGetOwnershipRange - For matrices that own values by row, excludes `MATELEMENTAL` and `MATSCALAPACK`, returns the range of matrix rows owned by
7055:   this MPI process.

7057:   Not Collective

7059:   Input Parameter:
7060: . mat - the matrix

7062:   Output Parameters:
7063: + m - the global index of the first local row, use `NULL` to not obtain this value
7064: - n - one more than the global index of the last local row, use `NULL` to not obtain this value

7066:   Level: beginner

7068:   Notes:
7069:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7071:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7072:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7074:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7075:   the local values in the matrix.

7077:   The high argument is one more than the last element stored locally.

7079:   For all matrices  it returns the range of matrix rows associated with rows of a vector that
7080:   would contain the result of a matrix vector product with this matrix. See [Matrix
7081:   Layouts](sec_matlayout) for details on matrix layouts.

7083: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscSplitOwnership()`,
7084:           `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
7085: @*/
7086: PetscErrorCode MatGetOwnershipRange(Mat mat, PetscInt *m, PetscInt *n)
7087: {
7088:   PetscFunctionBegin;
7091:   if (m) PetscAssertPointer(m, 2);
7092:   if (n) PetscAssertPointer(n, 3);
7093:   MatCheckPreallocated(mat, 1);
7094:   if (m) *m = mat->rmap->rstart;
7095:   if (n) *n = mat->rmap->rend;
7096:   PetscFunctionReturn(PETSC_SUCCESS);
7097: }

7099: /*@C
7100:   MatGetOwnershipRanges - For matrices that own values by row, excludes `MATELEMENTAL` and
7101:   `MATSCALAPACK`, returns the range of matrix rows owned by each process.

7103:   Not Collective, unless matrix has not been allocated

7105:   Input Parameter:
7106: . mat - the matrix

7108:   Output Parameter:
7109: . ranges - start of each processors portion plus one more than the total length at the end, of length `size` + 1
7110:            where `size` is the number of MPI processes used by `mat`

7112:   Level: beginner

7114:   Notes:
7115:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7117:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7118:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7120:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7121:   the local values in the matrix.

7123:   For all matrices  it returns the ranges of matrix rows associated with rows of a vector that
7124:   would contain the result of a matrix vector product with this matrix. See [Matrix
7125:   Layouts](sec_matlayout) for details on matrix layouts.

7127: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
7128:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `MatSetSizes()`, `MatCreateAIJ()`,
7129:           `DMDAGetGhostCorners()`, `DM`
7130: @*/
7131: PetscErrorCode MatGetOwnershipRanges(Mat mat, const PetscInt *ranges[])
7132: {
7133:   PetscFunctionBegin;
7136:   MatCheckPreallocated(mat, 1);
7137:   PetscCall(PetscLayoutGetRanges(mat->rmap, ranges));
7138:   PetscFunctionReturn(PETSC_SUCCESS);
7139: }

7141: /*@C
7142:   MatGetOwnershipRangesColumn - Returns the ranges of matrix columns associated with rows of a
7143:   vector one multiplies this vector by that are owned by each processor.

7145:   Not Collective, unless matrix has not been allocated

7147:   Input Parameter:
7148: . mat - the matrix

7150:   Output Parameter:
7151: . ranges - start of each processors portion plus one more than the total length at the end

7153:   Level: beginner

7155:   Notes:
7156:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7158:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7159:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7161:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7162:   the local values in the matrix.

7164:   Returns the columns of the "diagonal blocks", for most sparse matrix formats. See [Matrix
7165:   Layouts](sec_matlayout) for details on matrix layouts.

7167: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRanges()`,
7168:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`,
7169:           `DMDAGetGhostCorners()`, `DM`
7170: @*/
7171: PetscErrorCode MatGetOwnershipRangesColumn(Mat mat, const PetscInt *ranges[])
7172: {
7173:   PetscFunctionBegin;
7176:   MatCheckPreallocated(mat, 1);
7177:   PetscCall(PetscLayoutGetRanges(mat->cmap, ranges));
7178:   PetscFunctionReturn(PETSC_SUCCESS);
7179: }

7181: /*@
7182:   MatGetOwnershipIS - Get row and column ownership of a matrices' values as index sets.

7184:   Not Collective

7186:   Input Parameter:
7187: . A - matrix

7189:   Output Parameters:
7190: + rows - rows in which this process owns elements, , use `NULL` to not obtain this value
7191: - cols - columns in which this process owns elements, use `NULL` to not obtain this value

7193:   Level: intermediate

7195:   Note:
7196:   You should call `ISDestroy()` on the returned `IS`

7198:   For most matrices, excluding `MATELEMENTAL` and `MATSCALAPACK`, this corresponds to values
7199:   returned by `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`. For `MATELEMENTAL` and
7200:   `MATSCALAPACK` the ownership is more complicated. See [Matrix Layouts](sec_matlayout) for
7201:   details on matrix layouts.

7203: .seealso: [](ch_matrices), `IS`, `Mat`, `MatGetOwnershipRanges()`, `MatSetValues()`, `MATELEMENTAL`, `MATSCALAPACK`
7204: @*/
7205: PetscErrorCode MatGetOwnershipIS(Mat A, IS *rows, IS *cols)
7206: {
7207:   PetscErrorCode (*f)(Mat, IS *, IS *);

7209:   PetscFunctionBegin;
7212:   MatCheckPreallocated(A, 1);
7213:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatGetOwnershipIS_C", &f));
7214:   if (f) {
7215:     PetscCall((*f)(A, rows, cols));
7216:   } else { /* Create a standard row-based partition, each process is responsible for ALL columns in their row block */
7217:     if (rows) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->rmap->n, A->rmap->rstart, 1, rows));
7218:     if (cols) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->cmap->N, 0, 1, cols));
7219:   }
7220:   PetscFunctionReturn(PETSC_SUCCESS);
7221: }

7223: /*@
7224:   MatILUFactorSymbolic - Performs symbolic ILU factorization of a matrix obtained with `MatGetFactor()`
7225:   Uses levels of fill only, not drop tolerance. Use `MatLUFactorNumeric()`
7226:   to complete the factorization.

7228:   Collective

7230:   Input Parameters:
7231: + fact - the factorized matrix obtained with `MatGetFactor()`
7232: . mat  - the matrix
7233: . row  - row permutation
7234: . col  - column permutation
7235: - info - structure containing
7236: .vb
7237:       levels - number of levels of fill.
7238:       expected fill - as ratio of original fill.
7239:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
7240:                 missing diagonal entries)
7241: .ve

7243:   Level: developer

7245:   Notes:
7246:   See [Matrix Factorization](sec_matfactor) for additional information.

7248:   Most users should employ the `KSP` interface for linear solvers
7249:   instead of working directly with matrix algebra routines such as this.
7250:   See, e.g., `KSPCreate()`.

7252:   Uses the definition of level of fill as in Y. Saad, {cite}`saad2003`

7254:   Fortran Note:
7255:   A valid (non-null) `info` argument must be provided

7257: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
7258:           `MatGetOrdering()`, `MatFactorInfo`
7259: @*/
7260: PetscErrorCode MatILUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
7261: {
7262:   PetscFunctionBegin;
7267:   PetscAssertPointer(info, 5);
7268:   PetscAssertPointer(fact, 1);
7269:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels of fill negative %" PetscInt_FMT, (PetscInt)info->levels);
7270:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7271:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7272:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7273:   MatCheckPreallocated(mat, 2);

7275:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ILUFactorSymbolic, mat, row, col, 0));
7276:   PetscUseTypeMethod(fact, ilufactorsymbolic, mat, row, col, info);
7277:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ILUFactorSymbolic, mat, row, col, 0));
7278:   PetscFunctionReturn(PETSC_SUCCESS);
7279: }

7281: /*@
7282:   MatICCFactorSymbolic - Performs symbolic incomplete
7283:   Cholesky factorization for a symmetric matrix.  Use
7284:   `MatCholeskyFactorNumeric()` to complete the factorization.

7286:   Collective

7288:   Input Parameters:
7289: + fact - the factorized matrix obtained with `MatGetFactor()`
7290: . mat  - the matrix to be factored
7291: . perm - row and column permutation
7292: - info - structure containing
7293: .vb
7294:       levels - number of levels of fill.
7295:       expected fill - as ratio of original fill.
7296: .ve

7298:   Level: developer

7300:   Notes:
7301:   Most users should employ the `KSP` interface for linear solvers
7302:   instead of working directly with matrix algebra routines such as this.
7303:   See, e.g., `KSPCreate()`.

7305:   This uses the definition of level of fill as in Y. Saad {cite}`saad2003`

7307:   Fortran Note:
7308:   A valid (non-null) `info` argument must be provided

7310: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
7311: @*/
7312: PetscErrorCode MatICCFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
7313: {
7314:   PetscFunctionBegin;
7318:   PetscAssertPointer(info, 4);
7319:   PetscAssertPointer(fact, 1);
7320:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7321:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels negative %" PetscInt_FMT, (PetscInt)info->levels);
7322:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7323:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7324:   MatCheckPreallocated(mat, 2);

7326:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7327:   PetscUseTypeMethod(fact, iccfactorsymbolic, mat, perm, info);
7328:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7329:   PetscFunctionReturn(PETSC_SUCCESS);
7330: }

7332: /*@C
7333:   MatCreateSubMatrices - Extracts several submatrices from a matrix. If submat
7334:   points to an array of valid matrices, they may be reused to store the new
7335:   submatrices.

7337:   Collective

7339:   Input Parameters:
7340: + mat   - the matrix
7341: . n     - the number of submatrixes to be extracted (on this processor, may be zero)
7342: . irow  - index set of rows to extract
7343: . icol  - index set of columns to extract
7344: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7346:   Output Parameter:
7347: . submat - the array of submatrices

7349:   Level: advanced

7351:   Notes:
7352:   `MatCreateSubMatrices()` can extract ONLY sequential submatrices
7353:   (from both sequential and parallel matrices). Use `MatCreateSubMatrix()`
7354:   to extract a parallel submatrix.

7356:   Some matrix types place restrictions on the row and column
7357:   indices, such as that they be sorted or that they be equal to each other.

7359:   The index sets may not have duplicate entries.

7361:   When extracting submatrices from a parallel matrix, each processor can
7362:   form a different submatrix by setting the rows and columns of its
7363:   individual index sets according to the local submatrix desired.

7365:   When finished using the submatrices, the user should destroy
7366:   them with `MatDestroySubMatrices()`.

7368:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
7369:   original matrix has not changed from that last call to `MatCreateSubMatrices()`.

7371:   This routine creates the matrices in submat; you should NOT create them before
7372:   calling it. It also allocates the array of matrix pointers submat.

7374:   For `MATBAIJ` matrices the index sets must respect the block structure, that is if they
7375:   request one row/column in a block, they must request all rows/columns that are in
7376:   that block. For example, if the block size is 2 you cannot request just row 0 and
7377:   column 0.

7379:   Fortran Note:
7380: .vb
7381:   Mat, pointer :: submat(:)
7382: .ve

7384: .seealso: [](ch_matrices), `Mat`, `MatDestroySubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7385: @*/
7386: PetscErrorCode MatCreateSubMatrices(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7387: {
7388:   PetscInt  i;
7389:   PetscBool eq;

7391:   PetscFunctionBegin;
7394:   if (n) {
7395:     PetscAssertPointer(irow, 3);
7397:     PetscAssertPointer(icol, 4);
7399:   }
7400:   PetscAssertPointer(submat, 6);
7401:   if (n && scall == MAT_REUSE_MATRIX) {
7402:     PetscAssertPointer(*submat, 6);
7404:   }
7405:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7406:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7407:   MatCheckPreallocated(mat, 1);
7408:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7409:   PetscUseTypeMethod(mat, createsubmatrices, n, irow, icol, scall, submat);
7410:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7411:   for (i = 0; i < n; i++) {
7412:     (*submat)[i]->factortype = MAT_FACTOR_NONE; /* in case in place factorization was previously done on submatrix */
7413:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7414:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7415: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
7416:     if (mat->boundtocpu && mat->bindingpropagates) {
7417:       PetscCall(MatBindToCPU((*submat)[i], PETSC_TRUE));
7418:       PetscCall(MatSetBindingPropagates((*submat)[i], PETSC_TRUE));
7419:     }
7420: #endif
7421:   }
7422:   PetscFunctionReturn(PETSC_SUCCESS);
7423: }

7425: /*@C
7426:   MatCreateSubMatricesMPI - Extracts MPI submatrices across a sub communicator of `mat` (by pairs of `IS` that may live on subcomms).

7428:   Collective

7430:   Input Parameters:
7431: + mat   - the matrix
7432: . n     - the number of submatrixes to be extracted
7433: . irow  - index set of rows to extract
7434: . icol  - index set of columns to extract
7435: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7437:   Output Parameter:
7438: . submat - the array of submatrices

7440:   Level: advanced

7442:   Note:
7443:   This is used by `PCGASM`

7445: .seealso: [](ch_matrices), `Mat`, `PCGASM`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7446: @*/
7447: PetscErrorCode MatCreateSubMatricesMPI(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7448: {
7449:   PetscInt  i;
7450:   PetscBool eq;

7452:   PetscFunctionBegin;
7455:   if (n) {
7456:     PetscAssertPointer(irow, 3);
7458:     PetscAssertPointer(icol, 4);
7460:   }
7461:   PetscAssertPointer(submat, 6);
7462:   if (n && scall == MAT_REUSE_MATRIX) {
7463:     PetscAssertPointer(*submat, 6);
7465:   }
7466:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7467:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7468:   MatCheckPreallocated(mat, 1);

7470:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7471:   PetscUseTypeMethod(mat, createsubmatricesmpi, n, irow, icol, scall, submat);
7472:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7473:   for (i = 0; i < n; i++) {
7474:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7475:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7476:   }
7477:   PetscFunctionReturn(PETSC_SUCCESS);
7478: }

7480: /*@C
7481:   MatDestroyMatrices - Destroys an array of matrices

7483:   Collective

7485:   Input Parameters:
7486: + n   - the number of local matrices
7487: - mat - the matrices (this is a pointer to the array of matrices)

7489:   Level: advanced

7491:   Notes:
7492:   Frees not only the matrices, but also the array that contains the matrices

7494:   For matrices obtained with  `MatCreateSubMatrices()` use `MatDestroySubMatrices()`

7496: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroySubMatrices()`
7497: @*/
7498: PetscErrorCode MatDestroyMatrices(PetscInt n, Mat *mat[])
7499: {
7500:   PetscInt i;

7502:   PetscFunctionBegin;
7503:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7504:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7505:   PetscAssertPointer(mat, 2);

7507:   for (i = 0; i < n; i++) PetscCall(MatDestroy(&(*mat)[i]));

7509:   /* memory is allocated even if n = 0 */
7510:   PetscCall(PetscFree(*mat));
7511:   PetscFunctionReturn(PETSC_SUCCESS);
7512: }

7514: /*@C
7515:   MatDestroySubMatrices - Destroys a set of matrices obtained with `MatCreateSubMatrices()`.

7517:   Collective

7519:   Input Parameters:
7520: + n   - the number of local matrices
7521: - mat - the matrices (this is a pointer to the array of matrices, to match the calling sequence of `MatCreateSubMatrices()`)

7523:   Level: advanced

7525:   Note:
7526:   Frees not only the matrices, but also the array that contains the matrices

7528: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7529: @*/
7530: PetscErrorCode MatDestroySubMatrices(PetscInt n, Mat *mat[])
7531: {
7532:   Mat mat0;

7534:   PetscFunctionBegin;
7535:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7536:   /* mat[] is an array of length n+1, see MatCreateSubMatrices_xxx() */
7537:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7538:   PetscAssertPointer(mat, 2);

7540:   mat0 = (*mat)[0];
7541:   if (mat0 && mat0->ops->destroysubmatrices) {
7542:     PetscCall((*mat0->ops->destroysubmatrices)(n, mat));
7543:   } else {
7544:     PetscCall(MatDestroyMatrices(n, mat));
7545:   }
7546:   PetscFunctionReturn(PETSC_SUCCESS);
7547: }

7549: /*@
7550:   MatGetSeqNonzeroStructure - Extracts the nonzero structure from a matrix and stores it, in its entirety, on each process

7552:   Collective

7554:   Input Parameter:
7555: . mat - the matrix

7557:   Output Parameter:
7558: . matstruct - the sequential matrix with the nonzero structure of `mat`

7560:   Level: developer

7562: .seealso: [](ch_matrices), `Mat`, `MatDestroySeqNonzeroStructure()`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7563: @*/
7564: PetscErrorCode MatGetSeqNonzeroStructure(Mat mat, Mat *matstruct)
7565: {
7566:   PetscFunctionBegin;
7568:   PetscAssertPointer(matstruct, 2);

7571:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7572:   MatCheckPreallocated(mat, 1);

7574:   PetscCall(PetscLogEventBegin(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7575:   PetscUseTypeMethod(mat, getseqnonzerostructure, matstruct);
7576:   PetscCall(PetscLogEventEnd(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7577:   PetscFunctionReturn(PETSC_SUCCESS);
7578: }

7580: /*@C
7581:   MatDestroySeqNonzeroStructure - Destroys matrix obtained with `MatGetSeqNonzeroStructure()`.

7583:   Collective

7585:   Input Parameter:
7586: . mat - the matrix

7588:   Level: advanced

7590:   Note:
7591:   This is not needed, one can just call `MatDestroy()`

7593: .seealso: [](ch_matrices), `Mat`, `MatGetSeqNonzeroStructure()`
7594: @*/
7595: PetscErrorCode MatDestroySeqNonzeroStructure(Mat *mat)
7596: {
7597:   PetscFunctionBegin;
7598:   PetscAssertPointer(mat, 1);
7599:   PetscCall(MatDestroy(mat));
7600:   PetscFunctionReturn(PETSC_SUCCESS);
7601: }

7603: /*@
7604:   MatIncreaseOverlap - Given a set of submatrices indicated by index sets,
7605:   replaces the index sets by larger ones that represent submatrices with
7606:   additional overlap.

7608:   Collective

7610:   Input Parameters:
7611: + mat - the matrix
7612: . n   - the number of index sets
7613: . is  - the array of index sets (these index sets will changed during the call)
7614: - ov  - the additional overlap requested

7616:   Options Database Key:
7617: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7619:   Level: developer

7621:   Note:
7622:   The computed overlap preserves the matrix block sizes when the blocks are square.
7623:   That is: if a matrix nonzero for a given block would increase the overlap all columns associated with
7624:   that block are included in the overlap regardless of whether each specific column would increase the overlap.

7626: .seealso: [](ch_matrices), `Mat`, `PCASM`, `MatSetBlockSize()`, `MatIncreaseOverlapSplit()`, `MatCreateSubMatrices()`
7627: @*/
7628: PetscErrorCode MatIncreaseOverlap(Mat mat, PetscInt n, IS is[], PetscInt ov)
7629: {
7630:   PetscInt i, bs, cbs;

7632:   PetscFunctionBegin;
7636:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7637:   if (n) {
7638:     PetscAssertPointer(is, 3);
7640:   }
7641:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7642:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7643:   MatCheckPreallocated(mat, 1);

7645:   if (!ov || !n) PetscFunctionReturn(PETSC_SUCCESS);
7646:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7647:   PetscUseTypeMethod(mat, increaseoverlap, n, is, ov);
7648:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7649:   PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
7650:   if (bs == cbs) {
7651:     for (i = 0; i < n; i++) PetscCall(ISSetBlockSize(is[i], bs));
7652:   }
7653:   PetscFunctionReturn(PETSC_SUCCESS);
7654: }

7656: PetscErrorCode MatIncreaseOverlapSplit_Single(Mat, IS *, PetscInt);

7658: /*@
7659:   MatIncreaseOverlapSplit - Given a set of submatrices indicated by index sets across
7660:   a sub communicator, replaces the index sets by larger ones that represent submatrices with
7661:   additional overlap.

7663:   Collective

7665:   Input Parameters:
7666: + mat - the matrix
7667: . n   - the number of index sets
7668: . is  - the array of index sets (these index sets will changed during the call)
7669: - ov  - the additional overlap requested

7671:   `   Options Database Key:
7672: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7674:   Level: developer

7676: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatIncreaseOverlap()`
7677: @*/
7678: PetscErrorCode MatIncreaseOverlapSplit(Mat mat, PetscInt n, IS is[], PetscInt ov)
7679: {
7680:   PetscInt i;

7682:   PetscFunctionBegin;
7685:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7686:   if (n) {
7687:     PetscAssertPointer(is, 3);
7689:   }
7690:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7691:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7692:   MatCheckPreallocated(mat, 1);
7693:   if (!ov) PetscFunctionReturn(PETSC_SUCCESS);
7694:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7695:   for (i = 0; i < n; i++) PetscCall(MatIncreaseOverlapSplit_Single(mat, &is[i], ov));
7696:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7697:   PetscFunctionReturn(PETSC_SUCCESS);
7698: }

7700: /*@
7701:   MatGetBlockSize - Returns the matrix block size.

7703:   Not Collective

7705:   Input Parameter:
7706: . mat - the matrix

7708:   Output Parameter:
7709: . bs - block size

7711:   Level: intermediate

7713:   Notes:
7714:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.

7716:   If the block size has not been set yet this routine returns 1.

7718: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSizes()`
7719: @*/
7720: PetscErrorCode MatGetBlockSize(Mat mat, PetscInt *bs)
7721: {
7722:   PetscFunctionBegin;
7724:   PetscAssertPointer(bs, 2);
7725:   *bs = mat->rmap->bs;
7726:   PetscFunctionReturn(PETSC_SUCCESS);
7727: }

7729: /*@
7730:   MatGetBlockSizes - Returns the matrix block row and column sizes.

7732:   Not Collective

7734:   Input Parameter:
7735: . mat - the matrix

7737:   Output Parameters:
7738: + rbs - row block size
7739: - cbs - column block size

7741:   Level: intermediate

7743:   Notes:
7744:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.
7745:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.

7747:   If a block size has not been set yet this routine returns 1.

7749: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatSetBlockSizes()`
7750: @*/
7751: PetscErrorCode MatGetBlockSizes(Mat mat, PetscInt *rbs, PetscInt *cbs)
7752: {
7753:   PetscFunctionBegin;
7755:   if (rbs) PetscAssertPointer(rbs, 2);
7756:   if (cbs) PetscAssertPointer(cbs, 3);
7757:   if (rbs) *rbs = mat->rmap->bs;
7758:   if (cbs) *cbs = mat->cmap->bs;
7759:   PetscFunctionReturn(PETSC_SUCCESS);
7760: }

7762: /*@
7763:   MatSetBlockSize - Sets the matrix block size.

7765:   Logically Collective

7767:   Input Parameters:
7768: + mat - the matrix
7769: - bs  - block size

7771:   Level: intermediate

7773:   Notes:
7774:   Block row formats are `MATBAIJ` and `MATSBAIJ` formats ALWAYS have square block storage in the matrix.
7775:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

7777:   For `MATAIJ` matrix format, this function can be called at a later stage, provided that the specified block size
7778:   is compatible with the matrix local sizes.

7780: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MATAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`
7781: @*/
7782: PetscErrorCode MatSetBlockSize(Mat mat, PetscInt bs)
7783: {
7784:   PetscFunctionBegin;
7787:   PetscCall(MatSetBlockSizes(mat, bs, bs));
7788:   PetscFunctionReturn(PETSC_SUCCESS);
7789: }

7791: typedef struct {
7792:   PetscInt         n;
7793:   IS              *is;
7794:   Mat             *mat;
7795:   PetscObjectState nonzerostate;
7796:   Mat              C;
7797: } EnvelopeData;

7799: static PetscErrorCode EnvelopeDataDestroy(PetscCtxRt ptr)
7800: {
7801:   EnvelopeData *edata = *(EnvelopeData **)ptr;

7803:   PetscFunctionBegin;
7804:   for (PetscInt i = 0; i < edata->n; i++) PetscCall(ISDestroy(&edata->is[i]));
7805:   PetscCall(PetscFree(edata->is));
7806:   PetscCall(PetscFree(edata));
7807:   PetscFunctionReturn(PETSC_SUCCESS);
7808: }

7810: /*@
7811:   MatComputeVariableBlockEnvelope - Given a matrix whose nonzeros are in blocks along the diagonal this computes and stores
7812:   the sizes of these blocks in the matrix. An individual block may lie over several processes.

7814:   Collective

7816:   Input Parameter:
7817: . mat - the matrix

7819:   Level: intermediate

7821:   Notes:
7822:   There can be zeros within the blocks

7824:   The blocks can overlap between processes, including laying on more than two processes

7826: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatSetVariableBlockSizes()`
7827: @*/
7828: PetscErrorCode MatComputeVariableBlockEnvelope(Mat mat)
7829: {
7830:   PetscInt           n, *sizes, *starts, i = 0, env = 0, tbs = 0, lblocks = 0, rstart, II, ln = 0, cnt = 0, cstart, cend;
7831:   PetscInt          *diag, *odiag, sc;
7832:   VecScatter         scatter;
7833:   PetscScalar       *seqv;
7834:   const PetscScalar *parv;
7835:   const PetscInt    *ia, *ja;
7836:   PetscBool          set, flag, done;
7837:   Mat                AA = mat, A;
7838:   MPI_Comm           comm;
7839:   PetscMPIInt        rank, size, tag;
7840:   MPI_Status         status;
7841:   PetscContainer     container;
7842:   EnvelopeData      *edata;
7843:   Vec                seq, par;
7844:   IS                 isglobal;

7846:   PetscFunctionBegin;
7848:   PetscCall(MatIsSymmetricKnown(mat, &set, &flag));
7849:   if (!set || !flag) {
7850:     /* TODO: only needs nonzero structure of transpose */
7851:     PetscCall(MatTranspose(mat, MAT_INITIAL_MATRIX, &AA));
7852:     PetscCall(MatAXPY(AA, 1.0, mat, DIFFERENT_NONZERO_PATTERN));
7853:   }
7854:   PetscCall(MatAIJGetLocalMat(AA, &A));
7855:   PetscCall(MatGetRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7856:   PetscCheck(done, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unable to get IJ structure from matrix");

7858:   PetscCall(MatGetLocalSize(mat, &n, NULL));
7859:   PetscCall(PetscObjectGetNewTag((PetscObject)mat, &tag));
7860:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
7861:   PetscCallMPI(MPI_Comm_size(comm, &size));
7862:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

7864:   PetscCall(PetscMalloc2(n, &sizes, n, &starts));

7866:   if (rank > 0) {
7867:     PetscCallMPI(MPI_Recv(&env, 1, MPIU_INT, rank - 1, tag, comm, &status));
7868:     PetscCallMPI(MPI_Recv(&tbs, 1, MPIU_INT, rank - 1, tag, comm, &status));
7869:   }
7870:   PetscCall(MatGetOwnershipRange(mat, &rstart, NULL));
7871:   for (i = 0; i < n; i++) {
7872:     env = PetscMax(env, ja[ia[i + 1] - 1]);
7873:     II  = rstart + i;
7874:     if (env == II) {
7875:       starts[lblocks]  = tbs;
7876:       sizes[lblocks++] = 1 + II - tbs;
7877:       tbs              = 1 + II;
7878:     }
7879:   }
7880:   if (rank < size - 1) {
7881:     PetscCallMPI(MPI_Send(&env, 1, MPIU_INT, rank + 1, tag, comm));
7882:     PetscCallMPI(MPI_Send(&tbs, 1, MPIU_INT, rank + 1, tag, comm));
7883:   }

7885:   PetscCall(MatRestoreRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7886:   if (!set || !flag) PetscCall(MatDestroy(&AA));
7887:   PetscCall(MatDestroy(&A));

7889:   PetscCall(PetscNew(&edata));
7890:   PetscCall(MatGetNonzeroState(mat, &edata->nonzerostate));
7891:   edata->n = lblocks;
7892:   /* create IS needed for extracting blocks from the original matrix */
7893:   PetscCall(PetscMalloc1(lblocks, &edata->is));
7894:   for (PetscInt i = 0; i < lblocks; i++) PetscCall(ISCreateStride(PETSC_COMM_SELF, sizes[i], starts[i], 1, &edata->is[i]));

7896:   /* Create the resulting inverse matrix nonzero structure with preallocation information */
7897:   PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &edata->C));
7898:   PetscCall(MatSetSizes(edata->C, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
7899:   PetscCall(MatSetBlockSizesFromMats(edata->C, mat, mat));
7900:   PetscCall(MatSetType(edata->C, MATAIJ));

7902:   /* Communicate the start and end of each row, from each block to the correct rank */
7903:   /* TODO: Use PetscSF instead of VecScatter */
7904:   for (PetscInt i = 0; i < lblocks; i++) ln += sizes[i];
7905:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, 2 * ln, &seq));
7906:   PetscCall(VecGetArrayWrite(seq, &seqv));
7907:   for (PetscInt i = 0; i < lblocks; i++) {
7908:     for (PetscInt j = 0; j < sizes[i]; j++) {
7909:       seqv[cnt]     = starts[i];
7910:       seqv[cnt + 1] = starts[i] + sizes[i];
7911:       cnt += 2;
7912:     }
7913:   }
7914:   PetscCall(VecRestoreArrayWrite(seq, &seqv));
7915:   PetscCallMPI(MPI_Scan(&cnt, &sc, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)mat)));
7916:   sc -= cnt;
7917:   PetscCall(VecCreateMPI(PetscObjectComm((PetscObject)mat), 2 * mat->rmap->n, 2 * mat->rmap->N, &par));
7918:   PetscCall(ISCreateStride(PETSC_COMM_SELF, cnt, sc, 1, &isglobal));
7919:   PetscCall(VecScatterCreate(seq, NULL, par, isglobal, &scatter));
7920:   PetscCall(ISDestroy(&isglobal));
7921:   PetscCall(VecScatterBegin(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7922:   PetscCall(VecScatterEnd(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7923:   PetscCall(VecScatterDestroy(&scatter));
7924:   PetscCall(VecDestroy(&seq));
7925:   PetscCall(MatGetOwnershipRangeColumn(mat, &cstart, &cend));
7926:   PetscCall(PetscMalloc2(mat->rmap->n, &diag, mat->rmap->n, &odiag));
7927:   PetscCall(VecGetArrayRead(par, &parv));
7928:   cnt = 0;
7929:   PetscCall(MatGetSize(mat, NULL, &n));
7930:   for (PetscInt i = 0; i < mat->rmap->n; i++) {
7931:     PetscInt start, end, d = 0, od = 0;

7933:     start = (PetscInt)PetscRealPart(parv[cnt]);
7934:     end   = (PetscInt)PetscRealPart(parv[cnt + 1]);
7935:     cnt += 2;

7937:     if (start < cstart) {
7938:       od += cstart - start + n - cend;
7939:       d += cend - cstart;
7940:     } else if (start < cend) {
7941:       od += n - cend;
7942:       d += cend - start;
7943:     } else od += n - start;
7944:     if (end <= cstart) {
7945:       od -= cstart - end + n - cend;
7946:       d -= cend - cstart;
7947:     } else if (end < cend) {
7948:       od -= n - cend;
7949:       d -= cend - end;
7950:     } else od -= n - end;

7952:     odiag[i] = od;
7953:     diag[i]  = d;
7954:   }
7955:   PetscCall(VecRestoreArrayRead(par, &parv));
7956:   PetscCall(VecDestroy(&par));
7957:   PetscCall(MatXAIJSetPreallocation(edata->C, mat->rmap->bs, diag, odiag, NULL, NULL));
7958:   PetscCall(PetscFree2(diag, odiag));
7959:   PetscCall(PetscFree2(sizes, starts));

7961:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
7962:   PetscCall(PetscContainerSetPointer(container, edata));
7963:   PetscCall(PetscContainerSetCtxDestroy(container, EnvelopeDataDestroy));
7964:   PetscCall(PetscObjectCompose((PetscObject)mat, "EnvelopeData", (PetscObject)container));
7965:   PetscCall(PetscObjectDereference((PetscObject)container));
7966:   PetscFunctionReturn(PETSC_SUCCESS);
7967: }

7969: /*@
7970:   MatInvertVariableBlockEnvelope - set matrix C to be the inverted block diagonal of matrix A

7972:   Collective

7974:   Input Parameters:
7975: + A     - the matrix
7976: - reuse - indicates if the `C` matrix was obtained from a previous call to this routine

7978:   Output Parameter:
7979: . C - matrix with inverted block diagonal of `A`

7981:   Level: advanced

7983:   Note:
7984:   For efficiency the matrix `A` should have all the nonzero entries clustered in smallish blocks along the diagonal.

7986: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatComputeBlockDiagonal()`
7987: @*/
7988: PetscErrorCode MatInvertVariableBlockEnvelope(Mat A, MatReuse reuse, Mat *C)
7989: {
7990:   PetscContainer   container;
7991:   EnvelopeData    *edata;
7992:   PetscObjectState nonzerostate;

7994:   PetscFunctionBegin;
7995:   PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7996:   if (!container) {
7997:     PetscCall(MatComputeVariableBlockEnvelope(A));
7998:     PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7999:   }
8000:   PetscCall(PetscContainerGetPointer(container, &edata));
8001:   PetscCall(MatGetNonzeroState(A, &nonzerostate));
8002:   PetscCheck(nonzerostate <= edata->nonzerostate, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Cannot handle changes to matrix nonzero structure");
8003:   PetscCheck(reuse != MAT_REUSE_MATRIX || *C == edata->C, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "C matrix must be the same as previously output");

8005:   PetscCall(MatCreateSubMatrices(A, edata->n, edata->is, edata->is, MAT_INITIAL_MATRIX, &edata->mat));
8006:   *C = edata->C;

8008:   for (PetscInt i = 0; i < edata->n; i++) {
8009:     Mat          D;
8010:     PetscScalar *dvalues;

8012:     PetscCall(MatConvert(edata->mat[i], MATSEQDENSE, MAT_INITIAL_MATRIX, &D));
8013:     PetscCall(MatSetOption(*C, MAT_ROW_ORIENTED, PETSC_FALSE));
8014:     PetscCall(MatSeqDenseInvert(D));
8015:     PetscCall(MatDenseGetArray(D, &dvalues));
8016:     PetscCall(MatSetValuesIS(*C, edata->is[i], edata->is[i], dvalues, INSERT_VALUES));
8017:     PetscCall(MatDestroy(&D));
8018:   }
8019:   PetscCall(MatDestroySubMatrices(edata->n, &edata->mat));
8020:   PetscCall(MatAssemblyBegin(*C, MAT_FINAL_ASSEMBLY));
8021:   PetscCall(MatAssemblyEnd(*C, MAT_FINAL_ASSEMBLY));
8022:   PetscFunctionReturn(PETSC_SUCCESS);
8023: }

8025: /*@
8026:   MatSetVariableBlockSizes - Sets diagonal point-blocks of the matrix that need not be of the same size

8028:   Not Collective

8030:   Input Parameters:
8031: + mat     - the matrix
8032: . nblocks - the number of blocks on this process, each block can only exist on a single process
8033: - bsizes  - the block sizes

8035:   Level: intermediate

8037:   Notes:
8038:   Currently used by `PCVPBJACOBI` for `MATAIJ` matrices

8040:   Each variable point-block set of degrees of freedom must live on a single MPI process. That is a point block cannot straddle two MPI processes.

8042: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatGetVariableBlockSizes()`,
8043:           `MatComputeVariableBlockEnvelope()`, `PCVPBJACOBI`
8044: @*/
8045: PetscErrorCode MatSetVariableBlockSizes(Mat mat, PetscInt nblocks, const PetscInt bsizes[])
8046: {
8047:   PetscInt ncnt = 0, nlocal;

8049:   PetscFunctionBegin;
8051:   PetscCall(MatGetLocalSize(mat, &nlocal, NULL));
8052:   PetscCheck(nblocks >= 0 && nblocks <= nlocal, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Number of local blocks %" PetscInt_FMT " is not in [0, %" PetscInt_FMT "]", nblocks, nlocal);
8053:   for (PetscInt i = 0; i < nblocks; i++) ncnt += bsizes[i];
8054:   PetscCheck(ncnt == nlocal, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Sum of local block sizes %" PetscInt_FMT " does not equal local size of matrix %" PetscInt_FMT, ncnt, nlocal);
8055:   PetscCall(PetscFree(mat->bsizes));
8056:   mat->nblocks = nblocks;
8057:   PetscCall(PetscMalloc1(nblocks, &mat->bsizes));
8058:   PetscCall(PetscArraycpy(mat->bsizes, bsizes, nblocks));
8059:   PetscFunctionReturn(PETSC_SUCCESS);
8060: }

8062: /*@C
8063:   MatGetVariableBlockSizes - Gets a diagonal blocks of the matrix that need not be of the same size

8065:   Not Collective; No Fortran Support

8067:   Input Parameter:
8068: . mat - the matrix

8070:   Output Parameters:
8071: + nblocks - the number of blocks on this process
8072: - bsizes  - the block sizes

8074:   Level: intermediate

8076: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
8077: @*/
8078: PetscErrorCode MatGetVariableBlockSizes(Mat mat, PetscInt *nblocks, const PetscInt *bsizes[])
8079: {
8080:   PetscFunctionBegin;
8082:   if (nblocks) *nblocks = mat->nblocks;
8083:   if (bsizes) *bsizes = mat->bsizes;
8084:   PetscFunctionReturn(PETSC_SUCCESS);
8085: }

8087: /*@
8088:   MatSelectVariableBlockSizes - When creating a submatrix, pass on the variable block sizes

8090:   Not Collective

8092:   Input Parameter:
8093: + subA  - the submatrix
8094: . A     - the original matrix
8095: - isrow - The `IS` of selected rows for the submatrix, must be sorted

8097:   Level: developer

8099:   Notes:
8100:   If the index set is not sorted or contains off-process entries, this function will do nothing.

8102: .seealso: [](ch_matrices), `Mat`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
8103: @*/
8104: PetscErrorCode MatSelectVariableBlockSizes(Mat subA, Mat A, IS isrow)
8105: {
8106:   const PetscInt *rows;
8107:   PetscInt        n, rStart, rEnd, Nb = 0;
8108:   PetscBool       flg = A->bsizes ? PETSC_TRUE : PETSC_FALSE;

8110:   PetscFunctionBegin;
8111:   // The code for block size extraction does not support an unsorted IS
8112:   if (flg) PetscCall(ISSorted(isrow, &flg));
8113:   // We don't support originally off-diagonal blocks
8114:   if (flg) {
8115:     PetscCall(MatGetOwnershipRange(A, &rStart, &rEnd));
8116:     PetscCall(ISGetLocalSize(isrow, &n));
8117:     PetscCall(ISGetIndices(isrow, &rows));
8118:     for (PetscInt i = 0; i < n && flg; ++i) {
8119:       if (rows[i] < rStart || rows[i] >= rEnd) flg = PETSC_FALSE;
8120:     }
8121:     PetscCall(ISRestoreIndices(isrow, &rows));
8122:   }
8123:   // quiet return if we can't extract block size
8124:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &flg, 1, MPI_C_BOOL, MPI_LAND, PetscObjectComm((PetscObject)subA)));
8125:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

8127:   // extract block sizes
8128:   PetscCall(ISGetIndices(isrow, &rows));
8129:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8130:     PetscBool occupied = PETSC_FALSE;

8132:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8133:       const PetscInt row = gr + br;

8135:       if (i == n) break;
8136:       if (rows[i] == row) {
8137:         occupied = PETSC_TRUE;
8138:         ++i;
8139:       }
8140:       while (i < n && rows[i] < row) ++i;
8141:     }
8142:     gr += A->bsizes[b];
8143:     if (occupied) ++Nb;
8144:   }
8145:   subA->nblocks = Nb;
8146:   PetscCall(PetscFree(subA->bsizes));
8147:   PetscCall(PetscMalloc1(subA->nblocks, &subA->bsizes));
8148:   PetscInt sb = 0;
8149:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8150:     if (sb < subA->nblocks) subA->bsizes[sb] = 0;
8151:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8152:       const PetscInt row = gr + br;

8154:       if (i == n) break;
8155:       if (rows[i] == row) {
8156:         ++subA->bsizes[sb];
8157:         ++i;
8158:       }
8159:       while (i < n && rows[i] < row) ++i;
8160:     }
8161:     gr += A->bsizes[b];
8162:     if (sb < subA->nblocks && subA->bsizes[sb]) ++sb;
8163:   }
8164:   PetscCheck(sb == subA->nblocks, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of blocks %" PetscInt_FMT " != %" PetscInt_FMT, sb, subA->nblocks);
8165:   PetscInt nlocal, ncnt = 0;
8166:   PetscCall(MatGetLocalSize(subA, &nlocal, NULL));
8167:   PetscCheck(subA->nblocks >= 0 && subA->nblocks <= nlocal, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Number of local blocks %" PetscInt_FMT " is not in [0, %" PetscInt_FMT "]", subA->nblocks, nlocal);
8168:   for (PetscInt i = 0; i < subA->nblocks; i++) ncnt += subA->bsizes[i];
8169:   PetscCheck(ncnt == nlocal, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Sum of local block sizes %" PetscInt_FMT " does not equal local size of matrix %" PetscInt_FMT, ncnt, nlocal);
8170:   PetscCall(ISRestoreIndices(isrow, &rows));
8171:   PetscFunctionReturn(PETSC_SUCCESS);
8172: }

8174: /*@
8175:   MatSetBlockSizes - Sets the matrix block row and column sizes.

8177:   Logically Collective

8179:   Input Parameters:
8180: + mat - the matrix
8181: . rbs - row block size
8182: - cbs - column block size

8184:   Level: intermediate

8186:   Notes:
8187:   Block row formats are `MATBAIJ` and  `MATSBAIJ`. These formats ALWAYS have square block storage in the matrix.
8188:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.
8189:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

8191:   For `MATAIJ` matrix this function can be called at a later stage, provided that the specified block sizes
8192:   are compatible with the matrix local sizes.

8194:   The row and column block size determine the blocksize of the "row" and "column" vectors returned by `MatCreateVecs()`.

8196: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatGetBlockSizes()`
8197: @*/
8198: PetscErrorCode MatSetBlockSizes(Mat mat, PetscInt rbs, PetscInt cbs)
8199: {
8200:   PetscFunctionBegin;
8204:   PetscTryTypeMethod(mat, setblocksizes, rbs, cbs);
8205:   if (mat->rmap->refcnt) {
8206:     ISLocalToGlobalMapping l2g  = NULL;
8207:     PetscLayout            nmap = NULL;

8209:     PetscCall(PetscLayoutDuplicate(mat->rmap, &nmap));
8210:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->rmap->mapping, &l2g));
8211:     PetscCall(PetscLayoutDestroy(&mat->rmap));
8212:     mat->rmap          = nmap;
8213:     mat->rmap->mapping = l2g;
8214:   }
8215:   if (mat->cmap->refcnt) {
8216:     ISLocalToGlobalMapping l2g  = NULL;
8217:     PetscLayout            nmap = NULL;

8219:     PetscCall(PetscLayoutDuplicate(mat->cmap, &nmap));
8220:     if (mat->cmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->cmap->mapping, &l2g));
8221:     PetscCall(PetscLayoutDestroy(&mat->cmap));
8222:     mat->cmap          = nmap;
8223:     mat->cmap->mapping = l2g;
8224:   }
8225:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, rbs));
8226:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, cbs));
8227:   PetscFunctionReturn(PETSC_SUCCESS);
8228: }

8230: /*@
8231:   MatSetBlockSizesFromMats - Sets the matrix block row and column sizes to match a pair of matrices

8233:   Logically Collective

8235:   Input Parameters:
8236: + mat     - the matrix
8237: . fromRow - matrix from which to copy row block size
8238: - fromCol - matrix from which to copy column block size (can be same as `fromRow`)

8240:   Level: developer

8242: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`
8243: @*/
8244: PetscErrorCode MatSetBlockSizesFromMats(Mat mat, Mat fromRow, Mat fromCol)
8245: {
8246:   PetscFunctionBegin;
8250:   PetscTryTypeMethod(mat, setblocksizes, fromRow->rmap->bs, fromCol->cmap->bs);
8251:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, fromRow->rmap->bs));
8252:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, fromCol->cmap->bs));
8253:   PetscFunctionReturn(PETSC_SUCCESS);
8254: }

8256: /*@
8257:   MatResidual - Default routine to calculate the residual r = b - Ax

8259:   Collective

8261:   Input Parameters:
8262: + mat - the matrix
8263: . b   - the right-hand-side
8264: - x   - the approximate solution

8266:   Output Parameter:
8267: . r - location to store the residual

8269:   Level: developer

8271: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `PCMGSetResidual()`
8272: @*/
8273: PetscErrorCode MatResidual(Mat mat, Vec b, Vec x, Vec r)
8274: {
8275:   PetscFunctionBegin;
8281:   MatCheckPreallocated(mat, 1);
8282:   PetscCall(PetscLogEventBegin(MAT_Residual, mat, 0, 0, 0));
8283:   if (!mat->ops->residual) {
8284:     PetscCall(MatMult(mat, x, r));
8285:     PetscCall(VecAYPX(r, -1.0, b));
8286:   } else {
8287:     PetscUseTypeMethod(mat, residual, b, x, r);
8288:   }
8289:   PetscCall(PetscLogEventEnd(MAT_Residual, mat, 0, 0, 0));
8290:   PetscFunctionReturn(PETSC_SUCCESS);
8291: }

8293: /*@C
8294:   MatGetRowIJ - Returns the compressed row storage i and j indices for the local rows of a sparse matrix

8296:   Collective

8298:   Input Parameters:
8299: + mat             - the matrix
8300: . shift           - 0 or 1 indicating we want the indices starting at 0 or 1
8301: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8302: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE`  indicating if the nonzero structure of the
8303:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8304:                  always used.

8306:   Output Parameters:
8307: + n    - number of local rows in the (possibly compressed) matrix, use `NULL` if not needed
8308: . ia   - the row pointers; that is ia[0] = 0, ia[row] = ia[row-1] + number of elements in that row of the matrix, use `NULL` if not needed
8309: . ja   - the column indices, use `NULL` if not needed
8310: - done - indicates if the routine actually worked and returned appropriate ia[] and ja[] arrays; callers
8311:            are responsible for handling the case when done == `PETSC_FALSE` and ia and ja are not set

8313:   Level: developer

8315:   Notes:
8316:   You CANNOT change any of the ia[] or ja[] values.

8318:   Use `MatRestoreRowIJ()` when you are finished accessing the ia[] and ja[] values.

8320:   Fortran Notes:
8321:   Use
8322: .vb
8323:     PetscInt, pointer :: ia(:),ja(:)
8324:     call MatGetRowIJ(mat,shift,symmetric,inodecompressed,n,ia,ja,done,ierr)
8325:     ! Access the ith and jth entries via ia(i) and ja(j)
8326: .ve

8328: .seealso: [](ch_matrices), `Mat`, `MATAIJ`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`, `MatSeqAIJGetArray()`
8329: @*/
8330: PetscErrorCode MatGetRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8331: {
8332:   PetscFunctionBegin;
8335:   if (n) PetscAssertPointer(n, 5);
8336:   if (ia) PetscAssertPointer(ia, 6);
8337:   if (ja) PetscAssertPointer(ja, 7);
8338:   if (done) PetscAssertPointer(done, 8);
8339:   MatCheckPreallocated(mat, 1);
8340:   if (!mat->ops->getrowij && done) *done = PETSC_FALSE;
8341:   else {
8342:     if (done) *done = PETSC_TRUE;
8343:     PetscCall(PetscLogEventBegin(MAT_GetRowIJ, mat, 0, 0, 0));
8344:     PetscUseTypeMethod(mat, getrowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8345:     PetscCall(PetscLogEventEnd(MAT_GetRowIJ, mat, 0, 0, 0));
8346:   }
8347:   PetscFunctionReturn(PETSC_SUCCESS);
8348: }

8350: /*@C
8351:   MatGetColumnIJ - Returns the compressed column storage i and j indices for sequential matrices.

8353:   Collective

8355:   Input Parameters:
8356: + mat             - the matrix
8357: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8358: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be
8359:                 symmetrized
8360: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8361:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8362:                  always used.

8364:   Output Parameters:
8365: + n    - number of columns in the (possibly compressed) matrix
8366: . ia   - the column pointers; that is ia[0] = 0, ia[col] = i[col-1] + number of elements in that col of the matrix
8367: . ja   - the row indices
8368: - done - `PETSC_TRUE` or `PETSC_FALSE`, indicating whether the values have been returned

8370:   Level: developer

8372: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8373: @*/
8374: PetscErrorCode MatGetColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8375: {
8376:   PetscFunctionBegin;
8379:   PetscAssertPointer(n, 5);
8380:   if (ia) PetscAssertPointer(ia, 6);
8381:   if (ja) PetscAssertPointer(ja, 7);
8382:   PetscAssertPointer(done, 8);
8383:   MatCheckPreallocated(mat, 1);
8384:   if (!mat->ops->getcolumnij) *done = PETSC_FALSE;
8385:   else {
8386:     *done = PETSC_TRUE;
8387:     PetscUseTypeMethod(mat, getcolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8388:   }
8389:   PetscFunctionReturn(PETSC_SUCCESS);
8390: }

8392: /*@C
8393:   MatRestoreRowIJ - Call after you are completed with the ia,ja indices obtained with `MatGetRowIJ()`.

8395:   Collective

8397:   Input Parameters:
8398: + mat             - the matrix
8399: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8400: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8401: . inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8402:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8403:                     always used.
8404: . n               - size of (possibly compressed) matrix
8405: . ia              - the row pointers
8406: - ja              - the column indices

8408:   Output Parameter:
8409: . done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8411:   Level: developer

8413:   Note:
8414:   This routine zeros out `n`, `ia`, and `ja`. This is to prevent accidental
8415:   us of the array after it has been restored. If you pass `NULL`, it will
8416:   not zero the pointers.  Use of ia or ja after `MatRestoreRowIJ()` is invalid.

8418: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8419: @*/
8420: PetscErrorCode MatRestoreRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8421: {
8422:   PetscFunctionBegin;
8425:   if (ia) PetscAssertPointer(ia, 6);
8426:   if (ja) PetscAssertPointer(ja, 7);
8427:   if (done) PetscAssertPointer(done, 8);
8428:   MatCheckPreallocated(mat, 1);

8430:   if (!mat->ops->restorerowij && done) *done = PETSC_FALSE;
8431:   else {
8432:     if (done) *done = PETSC_TRUE;
8433:     PetscUseTypeMethod(mat, restorerowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8434:     if (n) *n = 0;
8435:     if (ia) *ia = NULL;
8436:     if (ja) *ja = NULL;
8437:   }
8438:   PetscFunctionReturn(PETSC_SUCCESS);
8439: }

8441: /*@C
8442:   MatRestoreColumnIJ - Call after you are completed with the ia,ja indices obtained with `MatGetColumnIJ()`.

8444:   Collective

8446:   Input Parameters:
8447: + mat             - the matrix
8448: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8449: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8450: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8451:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8452:                     always used.

8454:   Output Parameters:
8455: + n    - size of (possibly compressed) matrix
8456: . ia   - the column pointers
8457: . ja   - the row indices
8458: - done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8460:   Level: developer

8462: .seealso: [](ch_matrices), `Mat`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`
8463: @*/
8464: PetscErrorCode MatRestoreColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8465: {
8466:   PetscFunctionBegin;
8469:   if (ia) PetscAssertPointer(ia, 6);
8470:   if (ja) PetscAssertPointer(ja, 7);
8471:   PetscAssertPointer(done, 8);
8472:   MatCheckPreallocated(mat, 1);

8474:   if (!mat->ops->restorecolumnij) *done = PETSC_FALSE;
8475:   else {
8476:     *done = PETSC_TRUE;
8477:     PetscUseTypeMethod(mat, restorecolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8478:     if (n) *n = 0;
8479:     if (ia) *ia = NULL;
8480:     if (ja) *ja = NULL;
8481:   }
8482:   PetscFunctionReturn(PETSC_SUCCESS);
8483: }

8485: /*@
8486:   MatColoringPatch - Used inside matrix coloring routines that use `MatGetRowIJ()` and/or
8487:   `MatGetColumnIJ()`.

8489:   Collective

8491:   Input Parameters:
8492: + mat        - the matrix
8493: . ncolors    - maximum color value
8494: . n          - number of entries in colorarray
8495: - colorarray - array indicating color for each column

8497:   Output Parameter:
8498: . iscoloring - coloring generated using colorarray information

8500:   Level: developer

8502: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatGetColumnIJ()`
8503: @*/
8504: PetscErrorCode MatColoringPatch(Mat mat, PetscInt ncolors, PetscInt n, ISColoringValue colorarray[], ISColoring *iscoloring)
8505: {
8506:   PetscFunctionBegin;
8509:   PetscAssertPointer(colorarray, 4);
8510:   PetscAssertPointer(iscoloring, 5);
8511:   MatCheckPreallocated(mat, 1);

8513:   if (!mat->ops->coloringpatch) {
8514:     PetscCall(ISColoringCreate(PetscObjectComm((PetscObject)mat), ncolors, n, colorarray, PETSC_OWN_POINTER, iscoloring));
8515:   } else {
8516:     PetscUseTypeMethod(mat, coloringpatch, ncolors, n, colorarray, iscoloring);
8517:   }
8518:   PetscFunctionReturn(PETSC_SUCCESS);
8519: }

8521: /*@
8522:   MatSetUnfactored - Resets a factored matrix to be treated as unfactored.

8524:   Logically Collective

8526:   Input Parameter:
8527: . mat - the factored matrix to be reset

8529:   Level: developer

8531:   Notes:
8532:   This routine should be used only with factored matrices formed by in-place
8533:   factorization via ILU(0) (or by in-place LU factorization for the `MATSEQDENSE`
8534:   format).  This option can save memory, for example, when solving nonlinear
8535:   systems with a matrix-free Newton-Krylov method and a matrix-based, in-place
8536:   ILU(0) preconditioner.

8538:   One can specify in-place ILU(0) factorization by calling
8539: .vb
8540:      PCType(pc,PCILU);
8541:      PCFactorSeUseInPlace(pc);
8542: .ve
8543:   or by using the options -pc_type ilu -pc_factor_in_place

8545:   In-place factorization ILU(0) can also be used as a local
8546:   solver for the blocks within the block Jacobi or additive Schwarz
8547:   methods (runtime option: -sub_pc_factor_in_place).  See Users-Manual: ch_pc
8548:   for details on setting local solver options.

8550:   Most users should employ the `KSP` interface for linear solvers
8551:   instead of working directly with matrix algebra routines such as this.
8552:   See, e.g., `KSPCreate()`.

8554: .seealso: [](ch_matrices), `Mat`, `PCFactorSetUseInPlace()`, `PCFactorGetUseInPlace()`
8555: @*/
8556: PetscErrorCode MatSetUnfactored(Mat mat)
8557: {
8558:   PetscFunctionBegin;
8561:   MatCheckPreallocated(mat, 1);
8562:   mat->factortype = MAT_FACTOR_NONE;
8563:   if (!mat->ops->setunfactored) PetscFunctionReturn(PETSC_SUCCESS);
8564:   PetscUseTypeMethod(mat, setunfactored);
8565:   PetscFunctionReturn(PETSC_SUCCESS);
8566: }

8568: /*@
8569:   MatCreateSubMatrix - Gets a single submatrix on the same number of processors
8570:   as the original matrix.

8572:   Collective

8574:   Input Parameters:
8575: + mat   - the original matrix
8576: . isrow - parallel `IS` containing the rows this processor should obtain
8577: . iscol - parallel `IS` containing all columns you wish to keep. Each process should list the columns that will be in IT's "diagonal part" in the new matrix.
8578: - cll   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

8580:   Output Parameter:
8581: . newmat - the new submatrix, of the same type as the original matrix

8583:   Level: advanced

8585:   Notes:
8586:   The submatrix will be able to be multiplied with vectors using the same layout as `iscol`.

8588:   Some matrix types place restrictions on the row and column indices, such
8589:   as that they be sorted or that they be equal to each other. For `MATBAIJ` and `MATSBAIJ` matrices the indices must include all rows/columns of a block;
8590:   for example, if the block size is 3 one cannot select the 0 and 2 rows without selecting the 1 row.

8592:   The index sets may not have duplicate entries.

8594:   The first time this is called you should use a cll of `MAT_INITIAL_MATRIX`,
8595:   the `MatCreateSubMatrix()` routine will create the newmat for you. Any additional calls
8596:   to this routine with a mat of the same nonzero structure and with a call of `MAT_REUSE_MATRIX`
8597:   will reuse the matrix generated the first time.  You should call `MatDestroy()` on `newmat` when
8598:   you are finished using it.

8600:   The communicator of the newly obtained matrix is ALWAYS the same as the communicator of
8601:   the input matrix.

8603:   If `iscol` is `NULL` then all columns are obtained (not supported in Fortran).

8605:   If `isrow` and `iscol` have a nontrivial block-size, then the resulting matrix has this block-size as well. This feature
8606:   is used by `PCFIELDSPLIT` to allow easy nesting of its use.

8608:   Example usage:
8609:   Consider the following 8x8 matrix with 34 non-zero values, that is
8610:   assembled across 3 processors. Let's assume that proc0 owns 3 rows,
8611:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
8612:   as follows
8613: .vb
8614:             1  2  0  |  0  3  0  |  0  4
8615:     Proc0   0  5  6  |  7  0  0  |  8  0
8616:             9  0 10  | 11  0  0  | 12  0
8617:     -------------------------------------
8618:            13  0 14  | 15 16 17  |  0  0
8619:     Proc1   0 18  0  | 19 20 21  |  0  0
8620:             0  0  0  | 22 23  0  | 24  0
8621:     -------------------------------------
8622:     Proc2  25 26 27  |  0  0 28  | 29  0
8623:            30  0  0  | 31 32 33  |  0 34
8624: .ve

8626:   Suppose `isrow` = [0 1 | 4 | 6 7] and `iscol` = [1 2 | 3 4 5 | 6].  The resulting submatrix is

8628: .vb
8629:             2  0  |  0  3  0  |  0
8630:     Proc0   5  6  |  7  0  0  |  8
8631:     -------------------------------
8632:     Proc1  18  0  | 19 20 21  |  0
8633:     -------------------------------
8634:     Proc2  26 27  |  0  0 28  | 29
8635:             0  0  | 31 32 33  |  0
8636: .ve

8638: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatCreateSubMatricesMPI()`, `MatCreateSubMatrixVirtual()`, `MatSubMatrixVirtualUpdate()`
8639: @*/
8640: PetscErrorCode MatCreateSubMatrix(Mat mat, IS isrow, IS iscol, MatReuse cll, Mat *newmat)
8641: {
8642:   PetscMPIInt size;
8643:   Mat        *local;
8644:   IS          iscoltmp;
8645:   PetscBool   flg;

8647:   PetscFunctionBegin;
8651:   PetscAssertPointer(newmat, 5);
8654:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
8655:   PetscCheck(cll != MAT_IGNORE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_IGNORE_MATRIX");
8656:   PetscCheck(cll != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_INPLACE_MATRIX");

8658:   MatCheckPreallocated(mat, 1);
8659:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));

8661:   if (!iscol || isrow == iscol) {
8662:     PetscBool   stride;
8663:     PetscMPIInt grabentirematrix = 0, grab;
8664:     PetscCall(PetscObjectTypeCompare((PetscObject)isrow, ISSTRIDE, &stride));
8665:     if (stride) {
8666:       PetscInt first, step, n, rstart, rend;
8667:       PetscCall(ISStrideGetInfo(isrow, &first, &step));
8668:       if (step == 1) {
8669:         PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
8670:         if (rstart == first) {
8671:           PetscCall(ISGetLocalSize(isrow, &n));
8672:           if (n == rend - rstart) grabentirematrix = 1;
8673:         }
8674:       }
8675:     }
8676:     PetscCallMPI(MPIU_Allreduce(&grabentirematrix, &grab, 1, MPI_INT, MPI_MIN, PetscObjectComm((PetscObject)mat)));
8677:     if (grab) {
8678:       PetscCall(PetscInfo(mat, "Getting entire matrix as submatrix\n"));
8679:       if (cll == MAT_INITIAL_MATRIX) {
8680:         *newmat = mat;
8681:         PetscCall(PetscObjectReference((PetscObject)mat));
8682:       }
8683:       PetscFunctionReturn(PETSC_SUCCESS);
8684:     }
8685:   }

8687:   if (!iscol) {
8688:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), mat->cmap->n, mat->cmap->rstart, 1, &iscoltmp));
8689:   } else {
8690:     iscoltmp = iscol;
8691:   }

8693:   /* if original matrix is on just one processor then use submatrix generated */
8694:   if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1 && cll == MAT_REUSE_MATRIX) {
8695:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_REUSE_MATRIX, &newmat));
8696:     goto setproperties;
8697:   } else if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1) {
8698:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_INITIAL_MATRIX, &local));
8699:     *newmat = *local;
8700:     PetscCall(PetscFree(local));
8701:     goto setproperties;
8702:   } else if (!mat->ops->createsubmatrix) {
8703:     /* Create a new matrix type that implements the operation using the full matrix */
8704:     PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8705:     switch (cll) {
8706:     case MAT_INITIAL_MATRIX:
8707:       PetscCall(MatCreateSubMatrixVirtual(mat, isrow, iscoltmp, newmat));
8708:       break;
8709:     case MAT_REUSE_MATRIX:
8710:       PetscCall(MatSubMatrixVirtualUpdate(*newmat, mat, isrow, iscoltmp));
8711:       break;
8712:     default:
8713:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Invalid MatReuse, must be either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX");
8714:     }
8715:     PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));
8716:     goto setproperties;
8717:   }

8719:   PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8720:   PetscUseTypeMethod(mat, createsubmatrix, isrow, iscoltmp, cll, newmat);
8721:   PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));

8723: setproperties:
8724:   if ((*newmat)->symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->structurally_symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->spd == PETSC_BOOL3_UNKNOWN && (*newmat)->hermitian == PETSC_BOOL3_UNKNOWN) {
8725:     PetscCall(ISEqualUnsorted(isrow, iscoltmp, &flg));
8726:     if (flg) PetscCall(MatPropagateSymmetryOptions(mat, *newmat));
8727:   }
8728:   if (!iscol) PetscCall(ISDestroy(&iscoltmp));
8729:   if (*newmat && cll == MAT_INITIAL_MATRIX) PetscCall(PetscObjectStateIncrease((PetscObject)*newmat));
8730:   if (!iscol || isrow == iscol) PetscCall(MatSelectVariableBlockSizes(*newmat, mat, isrow));
8731:   PetscFunctionReturn(PETSC_SUCCESS);
8732: }

8734: /*@
8735:   MatPropagateSymmetryOptions - Propagates symmetry options set on a matrix to another matrix

8737:   Not Collective

8739:   Input Parameters:
8740: + A - the matrix we wish to propagate options from
8741: - B - the matrix we wish to propagate options to

8743:   Level: beginner

8745:   Note:
8746:   Propagates the options associated to `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_HERMITIAN`, `MAT_SPD`, `MAT_SYMMETRIC`, and `MAT_STRUCTURAL_SYMMETRY_ETERNAL`

8748: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatIsSymmetricKnown()`, `MatIsSPDKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
8749: @*/
8750: PetscErrorCode MatPropagateSymmetryOptions(Mat A, Mat B)
8751: {
8752:   PetscFunctionBegin;
8755:   B->symmetry_eternal            = A->symmetry_eternal;
8756:   B->structural_symmetry_eternal = A->structural_symmetry_eternal;
8757:   B->symmetric                   = A->symmetric;
8758:   B->structurally_symmetric      = A->structurally_symmetric;
8759:   B->spd                         = A->spd;
8760:   B->hermitian                   = A->hermitian;
8761:   PetscFunctionReturn(PETSC_SUCCESS);
8762: }

8764: /*@
8765:   MatStashSetInitialSize - sets the sizes of the matrix stash, that is
8766:   used during the assembly process to store values that belong to
8767:   other processors.

8769:   Not Collective

8771:   Input Parameters:
8772: + mat   - the matrix
8773: . size  - the initial size of the stash.
8774: - bsize - the initial size of the block-stash(if used).

8776:   Options Database Keys:
8777: + -matstash_initial_size size or size0,size1,...,sizep-1            - set initial size
8778: - -matstash_block_initial_size bsize  or bsize0,bsize1,...,bsizep-1 - set initial block size

8780:   Level: intermediate

8782:   Notes:
8783:   The block-stash is used for values set with `MatSetValuesBlocked()` while
8784:   the stash is used for values set with `MatSetValues()`

8786:   Run with the option -info and look for output of the form
8787:   MatAssemblyBegin_MPIXXX:Stash has MM entries, uses nn mallocs.
8788:   to determine the appropriate value, MM, to use for size and
8789:   MatAssemblyBegin_MPIXXX:Block-Stash has BMM entries, uses nn mallocs.
8790:   to determine the value, BMM to use for bsize

8792: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashGetInfo()`
8793: @*/
8794: PetscErrorCode MatStashSetInitialSize(Mat mat, PetscInt size, PetscInt bsize)
8795: {
8796:   PetscFunctionBegin;
8799:   PetscCall(MatStashSetInitialSize_Private(&mat->stash, size));
8800:   PetscCall(MatStashSetInitialSize_Private(&mat->bstash, bsize));
8801:   PetscFunctionReturn(PETSC_SUCCESS);
8802: }

8804: /*@
8805:   MatInterpolateAdd - $w = y + A*x$ or $A^T*x$ depending on the shape of
8806:   the matrix

8808:   Neighbor-wise Collective

8810:   Input Parameters:
8811: + A - the matrix
8812: . x - the vector to be multiplied by the interpolation operator
8813: - y - the vector to be added to the result

8815:   Output Parameter:
8816: . w - the resulting vector

8818:   Level: intermediate

8820:   Notes:
8821:   `w` may be the same vector as `y`.

8823:   This allows one to use either the restriction or interpolation (its transpose)
8824:   matrix to do the interpolation

8826: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8827: @*/
8828: PetscErrorCode MatInterpolateAdd(Mat A, Vec x, Vec y, Vec w)
8829: {
8830:   PetscInt M, N, Ny;

8832:   PetscFunctionBegin;
8837:   PetscCall(MatGetSize(A, &M, &N));
8838:   PetscCall(VecGetSize(y, &Ny));
8839:   if (M == Ny) PetscCall(MatMultAdd(A, x, y, w));
8840:   else PetscCall(MatMultTransposeAdd(A, x, y, w));
8841:   PetscFunctionReturn(PETSC_SUCCESS);
8842: }

8844: /*@
8845:   MatInterpolate - $y = A*x$ or $A^T*x$ depending on the shape of
8846:   the matrix

8848:   Neighbor-wise Collective

8850:   Input Parameters:
8851: + A - the matrix
8852: - x - the vector to be interpolated

8854:   Output Parameter:
8855: . y - the resulting vector

8857:   Level: intermediate

8859:   Note:
8860:   This allows one to use either the restriction or interpolation (its transpose)
8861:   matrix to do the interpolation

8863: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8864: @*/
8865: PetscErrorCode MatInterpolate(Mat A, Vec x, Vec y)
8866: {
8867:   PetscInt M, N, Ny;

8869:   PetscFunctionBegin;
8873:   PetscCall(MatGetSize(A, &M, &N));
8874:   PetscCall(VecGetSize(y, &Ny));
8875:   if (M == Ny) PetscCall(MatMult(A, x, y));
8876:   else PetscCall(MatMultTranspose(A, x, y));
8877:   PetscFunctionReturn(PETSC_SUCCESS);
8878: }

8880: /*@
8881:   MatRestrict - $y = A*x$ or $A^T*x$

8883:   Neighbor-wise Collective

8885:   Input Parameters:
8886: + A - the matrix
8887: - x - the vector to be restricted

8889:   Output Parameter:
8890: . y - the resulting vector

8892:   Level: intermediate

8894:   Note:
8895:   This allows one to use either the restriction or interpolation (its transpose)
8896:   matrix to do the restriction

8898: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatInterpolate()`, `PCMG`
8899: @*/
8900: PetscErrorCode MatRestrict(Mat A, Vec x, Vec y)
8901: {
8902:   PetscInt M, N, Nx;

8904:   PetscFunctionBegin;
8908:   PetscCall(MatGetSize(A, &M, &N));
8909:   PetscCall(VecGetSize(x, &Nx));
8910:   if (M == Nx) PetscCall(MatMultTranspose(A, x, y));
8911:   else PetscCall(MatMult(A, x, y));
8912:   PetscFunctionReturn(PETSC_SUCCESS);
8913: }

8915: /*@
8916:   MatMatInterpolateAdd - $Y = W + A*X$ or $W + A^T*X$ depending on the shape of `A`

8918:   Neighbor-wise Collective

8920:   Input Parameters:
8921: + A - the matrix
8922: . x - the input dense matrix to be multiplied
8923: - w - the input dense matrix to be added to the result

8925:   Output Parameter:
8926: . y - the output dense matrix

8928:   Level: intermediate

8930:   Note:
8931:   This allows one to use either the restriction or interpolation (its transpose)
8932:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8933:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8935: .seealso: [](ch_matrices), `Mat`, `MatInterpolateAdd()`, `MatMatInterpolate()`, `MatMatRestrict()`, `PCMG`
8936: @*/
8937: PetscErrorCode MatMatInterpolateAdd(Mat A, Mat x, Mat w, Mat *y)
8938: {
8939:   PetscInt  M, N, Mx, Nx, Mo, My = 0, Ny = 0;
8940:   PetscBool trans = PETSC_TRUE;
8941:   MatReuse  reuse = MAT_INITIAL_MATRIX;

8943:   PetscFunctionBegin;
8949:   PetscCall(MatGetSize(A, &M, &N));
8950:   PetscCall(MatGetSize(x, &Mx, &Nx));
8951:   if (N == Mx) trans = PETSC_FALSE;
8952:   else PetscCheck(M == Mx, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Size mismatch: A %" PetscInt_FMT "x%" PetscInt_FMT ", X %" PetscInt_FMT "x%" PetscInt_FMT, M, N, Mx, Nx);
8953:   Mo = trans ? N : M;
8954:   if (*y) {
8955:     PetscCall(MatGetSize(*y, &My, &Ny));
8956:     if (Mo == My && Nx == Ny) reuse = MAT_REUSE_MATRIX;
8957:     else {
8958:       PetscCheck(w || *y != w, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Cannot reuse y and w, size mismatch: A %" PetscInt_FMT "x%" PetscInt_FMT ", X %" PetscInt_FMT "x%" PetscInt_FMT ", Y %" PetscInt_FMT "x%" PetscInt_FMT, M, N, Mx, Nx, My, Ny);
8959:       PetscCall(MatDestroy(y));
8960:     }
8961:   }

8963:   if (w && *y == w) { /* this is to minimize changes in PCMG */
8964:     PetscBool flg;

8966:     PetscCall(PetscObjectQuery((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject *)&w));
8967:     if (w) {
8968:       PetscInt My, Ny, Mw, Nw;

8970:       PetscCall(PetscObjectTypeCompare((PetscObject)*y, ((PetscObject)w)->type_name, &flg));
8971:       PetscCall(MatGetSize(*y, &My, &Ny));
8972:       PetscCall(MatGetSize(w, &Mw, &Nw));
8973:       if (!flg || My != Mw || Ny != Nw) w = NULL;
8974:     }
8975:     if (!w) {
8976:       PetscCall(MatDuplicate(*y, MAT_COPY_VALUES, &w));
8977:       PetscCall(PetscObjectCompose((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject)w));
8978:       PetscCall(PetscObjectDereference((PetscObject)w));
8979:     } else PetscCall(MatCopy(*y, w, UNKNOWN_NONZERO_PATTERN));
8980:   }
8981:   if (!trans) PetscCall(MatMatMult(A, x, reuse, PETSC_DETERMINE, y));
8982:   else PetscCall(MatTransposeMatMult(A, x, reuse, PETSC_DETERMINE, y));
8983:   if (w) PetscCall(MatAXPY(*y, 1.0, w, UNKNOWN_NONZERO_PATTERN));
8984:   PetscFunctionReturn(PETSC_SUCCESS);
8985: }

8987: /*@
8988:   MatMatInterpolate - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8990:   Neighbor-wise Collective

8992:   Input Parameters:
8993: + A - the matrix
8994: - x - the input dense matrix

8996:   Output Parameter:
8997: . y - the output dense matrix

8999:   Level: intermediate

9001:   Note:
9002:   This allows one to use either the restriction or interpolation (its transpose)
9003:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
9004:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

9006: .seealso: [](ch_matrices), `Mat`, `MatInterpolate()`, `MatRestrict()`, `MatMatRestrict()`, `PCMG`
9007: @*/
9008: PetscErrorCode MatMatInterpolate(Mat A, Mat x, Mat *y)
9009: {
9010:   PetscFunctionBegin;
9011:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
9012:   PetscFunctionReturn(PETSC_SUCCESS);
9013: }

9015: /*@
9016:   MatMatRestrict - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

9018:   Neighbor-wise Collective

9020:   Input Parameters:
9021: + A - the matrix
9022: - x - the input dense matrix

9024:   Output Parameter:
9025: . y - the output dense matrix

9027:   Level: intermediate

9029:   Note:
9030:   This allows one to use either the restriction or interpolation (its transpose)
9031:   matrix to do the restriction. `y` matrix can be reused if already created with the proper sizes,
9032:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

9034: .seealso: [](ch_matrices), `Mat`, `MatRestrict()`, `MatInterpolate()`, `MatMatInterpolate()`, `PCMG`
9035: @*/
9036: PetscErrorCode MatMatRestrict(Mat A, Mat x, Mat *y)
9037: {
9038:   PetscFunctionBegin;
9039:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
9040:   PetscFunctionReturn(PETSC_SUCCESS);
9041: }

9043: /*@
9044:   MatGetNullSpace - retrieves the null space of a matrix.

9046:   Logically Collective

9048:   Input Parameters:
9049: + mat    - the matrix
9050: - nullsp - the null space object

9052:   Level: developer

9054: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetNullSpace()`, `MatNullSpace`
9055: @*/
9056: PetscErrorCode MatGetNullSpace(Mat mat, MatNullSpace *nullsp)
9057: {
9058:   PetscFunctionBegin;
9060:   PetscAssertPointer(nullsp, 2);
9061:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->nullsp) ? mat->transnullsp : mat->nullsp;
9062:   PetscFunctionReturn(PETSC_SUCCESS);
9063: }

9065: /*@C
9066:   MatGetNullSpaces - gets the null spaces, transpose null spaces, and near null spaces from an array of matrices

9068:   Logically Collective

9070:   Input Parameters:
9071: + n   - the number of matrices
9072: - mat - the array of matrices

9074:   Output Parameters:
9075: . nullsp - an array of null spaces, `NULL` for each matrix that does not have a null space, length 3 * `n`

9077:   Level: developer

9079:   Note:
9080:   Call `MatRestoreNullspaces()` to provide these to another array of matrices

9082: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
9083:           `MatNullSpaceRemove()`, `MatRestoreNullSpaces()`
9084: @*/
9085: PetscErrorCode MatGetNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
9086: {
9087:   PetscFunctionBegin;
9088:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
9089:   PetscAssertPointer(mat, 2);
9090:   PetscAssertPointer(nullsp, 3);

9092:   PetscCall(PetscCalloc1(3 * n, nullsp));
9093:   for (PetscInt i = 0; i < n; i++) {
9095:     (*nullsp)[i] = mat[i]->nullsp;
9096:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[i]));
9097:     (*nullsp)[n + i] = mat[i]->nearnullsp;
9098:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[n + i]));
9099:     (*nullsp)[2 * n + i] = mat[i]->transnullsp;
9100:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[2 * n + i]));
9101:   }
9102:   PetscFunctionReturn(PETSC_SUCCESS);
9103: }

9105: /*@C
9106:   MatRestoreNullSpaces - sets the null spaces, transpose null spaces, and near null spaces obtained with `MatGetNullSpaces()` for an array of matrices

9108:   Logically Collective

9110:   Input Parameters:
9111: + n      - the number of matrices
9112: . mat    - the array of matrices
9113: - nullsp - an array of null spaces

9115:   Level: developer

9117:   Note:
9118:   Call `MatGetNullSpaces()` to create `nullsp`

9120: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
9121:           `MatNullSpaceRemove()`, `MatGetNullSpaces()`
9122: @*/
9123: PetscErrorCode MatRestoreNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
9124: {
9125:   PetscFunctionBegin;
9126:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
9127:   PetscAssertPointer(mat, 2);
9128:   PetscAssertPointer(nullsp, 3);
9129:   PetscAssertPointer(*nullsp, 3);

9131:   for (PetscInt i = 0; i < n; i++) {
9133:     PetscCall(MatSetNullSpace(mat[i], (*nullsp)[i]));
9134:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[i]));
9135:     PetscCall(MatSetNearNullSpace(mat[i], (*nullsp)[n + i]));
9136:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[n + i]));
9137:     PetscCall(MatSetTransposeNullSpace(mat[i], (*nullsp)[2 * n + i]));
9138:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[2 * n + i]));
9139:   }
9140:   PetscCall(PetscFree(*nullsp));
9141:   PetscFunctionReturn(PETSC_SUCCESS);
9142: }

9144: /*@
9145:   MatSetNullSpace - attaches a null space to a matrix.

9147:   Logically Collective

9149:   Input Parameters:
9150: + mat    - the matrix
9151: - nullsp - the null space object

9153:   Level: advanced

9155:   Notes:
9156:   This null space is used by the `KSP` linear solvers to solve singular systems.

9158:   Overwrites any previous null space that may have been attached. You can remove the null space from the matrix object by calling this routine with an nullsp of `NULL`

9160:   For inconsistent singular systems (linear systems where the right-hand side is not in the range of the operator) the `KSP` residuals will not converge
9161:   to zero but the linear system will still be solved in a least squares sense.

9163:   The fundamental theorem of linear algebra (Gilbert Strang, Introduction to Applied Mathematics, page 72) states that
9164:   the domain of a matrix $A$ (from $R^n$ to $R^m$ ($m$ rows, $n$ columns) $R^n$ = the direct sum of the null space of $A$, $n(A)$, plus the range of $A^T$, $R(A^T)$.
9165:   Similarly $R^m$ = direct sum $n(A^T) + R(A)$.  Hence the linear system $A x = b$ has a solution only if $b$ in $R(A)$ (or correspondingly $b$ is orthogonal to
9166:   $n(A^T))$ and if $x$ is a solution then $x + \alpha n(A)$ is a solution for any $\alpha$. The minimum norm solution is orthogonal to $n(A)$. For problems without a solution
9167:   the solution that minimizes the norm of the residual (the least squares solution) can be obtained by solving $A x = \hat{b}$ where $\hat{b}$ is $b$ orthogonalized to the $n(A^T)$.
9168:   This  $\hat{b}$ can be obtained by calling `MatNullSpaceRemove()` with the null space of the transpose of the matrix.

9170:   If the matrix is known to be symmetric because it is an `MATSBAIJ` matrix or one has called
9171:   `MatSetOption`(mat,`MAT_SYMMETRIC` or possibly `MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`); this
9172:   routine also automatically calls `MatSetTransposeNullSpace()`.

9174:   The user should call `MatNullSpaceDestroy()`.

9176: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`,
9177:           `KSPSetPCSide()`
9178: @*/
9179: PetscErrorCode MatSetNullSpace(Mat mat, MatNullSpace nullsp)
9180: {
9181:   PetscFunctionBegin;
9184:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9185:   PetscCall(MatNullSpaceDestroy(&mat->nullsp));
9186:   mat->nullsp = nullsp;
9187:   if (mat->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetTransposeNullSpace(mat, nullsp));
9188:   PetscFunctionReturn(PETSC_SUCCESS);
9189: }

9191: /*@
9192:   MatGetTransposeNullSpace - retrieves the null space of the transpose of a matrix.

9194:   Logically Collective

9196:   Input Parameters:
9197: + mat    - the matrix
9198: - nullsp - the null space object

9200:   Level: developer

9202: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetTransposeNullSpace()`, `MatSetNullSpace()`, `MatGetNullSpace()`
9203: @*/
9204: PetscErrorCode MatGetTransposeNullSpace(Mat mat, MatNullSpace *nullsp)
9205: {
9206:   PetscFunctionBegin;
9209:   PetscAssertPointer(nullsp, 2);
9210:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->transnullsp) ? mat->nullsp : mat->transnullsp;
9211:   PetscFunctionReturn(PETSC_SUCCESS);
9212: }

9214: /*@
9215:   MatSetTransposeNullSpace - attaches the null space of a transpose of a matrix to the matrix

9217:   Logically Collective

9219:   Input Parameters:
9220: + mat    - the matrix
9221: - nullsp - the null space object

9223:   Level: advanced

9225:   Notes:
9226:   This allows solving singular linear systems defined by the transpose of the matrix using `KSP` solvers with left preconditioning.

9228:   See `MatSetNullSpace()`

9230: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`, `KSPSetPCSide()`
9231: @*/
9232: PetscErrorCode MatSetTransposeNullSpace(Mat mat, MatNullSpace nullsp)
9233: {
9234:   PetscFunctionBegin;
9237:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9238:   PetscCall(MatNullSpaceDestroy(&mat->transnullsp));
9239:   mat->transnullsp = nullsp;
9240:   PetscFunctionReturn(PETSC_SUCCESS);
9241: }

9243: /*@
9244:   MatSetNearNullSpace - attaches a null space to a matrix, which is often the null space (rigid body modes) of the operator without boundary conditions
9245:   This null space will be used to provide near null space vectors to a multigrid preconditioner built from this matrix.

9247:   Logically Collective

9249:   Input Parameters:
9250: + mat    - the matrix
9251: - nullsp - the null space object

9253:   Level: advanced

9255:   Notes:
9256:   Overwrites any previous near null space that may have been attached

9258:   You can remove the null space by calling this routine with an `nullsp` of `NULL`

9260: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNullSpace()`, `MatNullSpaceCreateRigidBody()`, `MatGetNearNullSpace()`
9261: @*/
9262: PetscErrorCode MatSetNearNullSpace(Mat mat, MatNullSpace nullsp)
9263: {
9264:   PetscFunctionBegin;
9268:   MatCheckPreallocated(mat, 1);
9269:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9270:   PetscCall(MatNullSpaceDestroy(&mat->nearnullsp));
9271:   mat->nearnullsp = nullsp;
9272:   PetscFunctionReturn(PETSC_SUCCESS);
9273: }

9275: /*@
9276:   MatGetNearNullSpace - Get null space attached with `MatSetNearNullSpace()`

9278:   Not Collective

9280:   Input Parameter:
9281: . mat - the matrix

9283:   Output Parameter:
9284: . nullsp - the null space object, `NULL` if not set

9286:   Level: advanced

9288: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatNullSpaceCreate()`
9289: @*/
9290: PetscErrorCode MatGetNearNullSpace(Mat mat, MatNullSpace *nullsp)
9291: {
9292:   PetscFunctionBegin;
9295:   PetscAssertPointer(nullsp, 2);
9296:   MatCheckPreallocated(mat, 1);
9297:   *nullsp = mat->nearnullsp;
9298:   PetscFunctionReturn(PETSC_SUCCESS);
9299: }

9301: /*@
9302:   MatICCFactor - Performs in-place incomplete Cholesky factorization of matrix.

9304:   Collective

9306:   Input Parameters:
9307: + mat  - the matrix
9308: . row  - row/column permutation
9309: - info - information on desired factorization process

9311:   Level: developer

9313:   Notes:
9314:   Probably really in-place only when level of fill is zero, otherwise allocates
9315:   new space to store factored matrix and deletes previous memory.

9317:   Most users should employ the `KSP` interface for linear solvers
9318:   instead of working directly with matrix algebra routines such as this.
9319:   See, e.g., `KSPCreate()`.

9321:   Fortran Note:
9322:   A valid (non-null) `info` argument must be provided

9324: .seealso: [](ch_matrices), `Mat`, `MatFactorInfo`, `MatGetFactor()`, `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
9325: @*/
9326: PetscErrorCode MatICCFactor(Mat mat, IS row, const MatFactorInfo *info)
9327: {
9328:   PetscFunctionBegin;
9332:   PetscAssertPointer(info, 3);
9333:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
9334:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
9335:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
9336:   MatCheckPreallocated(mat, 1);
9337:   PetscUseTypeMethod(mat, iccfactor, row, info);
9338:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9339:   PetscFunctionReturn(PETSC_SUCCESS);
9340: }

9342: /*@
9343:   MatDiagonalScaleLocal - Scales columns of a matrix given the scaling values including the
9344:   ghosted ones.

9346:   Not Collective

9348:   Input Parameters:
9349: + mat  - the matrix
9350: - diag - the diagonal values, including ghost ones

9352:   Level: developer

9354:   Notes:
9355:   Works only for `MATMPIAIJ` and `MATMPIBAIJ` matrices

9357:   This allows one to avoid during communication to perform the scaling that must be done with `MatDiagonalScale()`

9359: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
9360: @*/
9361: PetscErrorCode MatDiagonalScaleLocal(Mat mat, Vec diag)
9362: {
9363:   PetscMPIInt size;

9365:   PetscFunctionBegin;

9370:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must be already assembled");
9371:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
9372:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
9373:   if (size == 1) {
9374:     PetscInt n, m;
9375:     PetscCall(VecGetSize(diag, &n));
9376:     PetscCall(MatGetSize(mat, NULL, &m));
9377:     PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supported for sequential matrices when no ghost points/periodic conditions");
9378:     PetscCall(MatDiagonalScale(mat, NULL, diag));
9379:   } else PetscUseMethod(mat, "MatDiagonalScaleLocal_C", (Mat, Vec), (mat, diag));
9380:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
9381:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9382:   PetscFunctionReturn(PETSC_SUCCESS);
9383: }

9385: /*@
9386:   MatGetInertia - Gets the inertia from a factored matrix

9388:   Collective

9390:   Input Parameter:
9391: . mat - the matrix

9393:   Output Parameters:
9394: + nneg  - number of negative eigenvalues
9395: . nzero - number of zero eigenvalues
9396: - npos  - number of positive eigenvalues

9398:   Level: advanced

9400:   Note:
9401:   Matrix must have been factored by `MatCholeskyFactor()`

9403: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactor()`
9404: @*/
9405: PetscErrorCode MatGetInertia(Mat mat, PetscInt *nneg, PetscInt *nzero, PetscInt *npos)
9406: {
9407:   PetscFunctionBegin;
9410:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9411:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Numeric factor mat is not assembled");
9412:   PetscUseTypeMethod(mat, getinertia, nneg, nzero, npos);
9413:   PetscFunctionReturn(PETSC_SUCCESS);
9414: }

9416: /*@C
9417:   MatSolves - Solves $A x = b$, given a factored matrix, for a collection of vectors

9419:   Neighbor-wise Collective

9421:   Input Parameters:
9422: + mat - the factored matrix obtained with `MatGetFactor()`
9423: - b   - the right-hand-side vectors

9425:   Output Parameter:
9426: . x - the result vectors

9428:   Level: developer

9430:   Note:
9431:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
9432:   call `MatSolves`(A,x,x).

9434: .seealso: [](ch_matrices), `Mat`, `Vecs`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`, `MatSolve()`
9435: @*/
9436: PetscErrorCode MatSolves(Mat mat, Vecs b, Vecs x)
9437: {
9438:   PetscFunctionBegin;
9441:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
9442:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9443:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);

9445:   MatCheckPreallocated(mat, 1);
9446:   PetscCall(PetscLogEventBegin(MAT_Solves, mat, 0, 0, 0));
9447:   PetscUseTypeMethod(mat, solves, b, x);
9448:   PetscCall(PetscLogEventEnd(MAT_Solves, mat, 0, 0, 0));
9449:   PetscFunctionReturn(PETSC_SUCCESS);
9450: }

9452: /*@
9453:   MatIsSymmetric - Test whether a matrix is symmetric

9455:   Collective

9457:   Input Parameters:
9458: + A   - the matrix to test
9459: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact transpose)

9461:   Output Parameter:
9462: . flg - the result

9464:   Level: intermediate

9466:   Notes:
9467:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9469:   If the matrix does not yet know if it is symmetric or not this can be an expensive operation, also available `MatIsSymmetricKnown()`

9471:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9472:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9474: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetricKnown()`,
9475:           `MAT_SYMMETRIC`, `MAT_SYMMETRY_ETERNAL`
9476: @*/
9477: PetscErrorCode MatIsSymmetric(Mat A, PetscReal tol, PetscBool *flg)
9478: {
9479:   PetscFunctionBegin;
9481:   PetscAssertPointer(flg, 3);
9482:   if (A->symmetric != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->symmetric);
9483:   else {
9484:     if (A->ops->issymmetric) PetscUseTypeMethod(A, issymmetric, tol, flg);
9485:     else PetscCall(MatIsTranspose(A, A, tol, flg));
9486:     if (!tol) PetscCall(MatSetOption(A, MAT_SYMMETRIC, *flg));
9487:   }
9488:   PetscFunctionReturn(PETSC_SUCCESS);
9489: }

9491: /*@
9492:   MatIsHermitian - Test whether a matrix is Hermitian

9494:   Collective

9496:   Input Parameters:
9497: + A   - the matrix to test
9498: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact Hermitian)

9500:   Output Parameter:
9501: . flg - the result

9503:   Level: intermediate

9505:   Notes:
9506:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9508:   If the matrix does not yet know if it is Hermitian or not this can be an expensive operation, also available `MatIsHermitianKnown()`

9510:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9511:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMEMTRY_ETERNAL`,`PETSC_TRUE`)

9513: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetric()`, `MatSetOption()`,
9514:           `MatIsSymmetricKnown()`, `MatIsSymmetric()`, `MAT_HERMITIAN`, `MAT_SYMMETRY_ETERNAL`
9515: @*/
9516: PetscErrorCode MatIsHermitian(Mat A, PetscReal tol, PetscBool *flg)
9517: {
9518:   PetscFunctionBegin;
9520:   PetscAssertPointer(flg, 3);
9521:   if (A->hermitian != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->hermitian);
9522:   else {
9523:     if (A->ops->ishermitian) PetscUseTypeMethod(A, ishermitian, tol, flg);
9524:     else PetscCall(MatIsHermitianTranspose(A, A, tol, flg));
9525:     if (!tol) PetscCall(MatSetOption(A, MAT_HERMITIAN, *flg));
9526:   }
9527:   PetscFunctionReturn(PETSC_SUCCESS);
9528: }

9530: /*@
9531:   MatIsSymmetricKnown - Checks if a matrix knows if it is symmetric or not and its symmetric state

9533:   Not Collective

9535:   Input Parameter:
9536: . A - the matrix to check

9538:   Output Parameters:
9539: + set - `PETSC_TRUE` if the matrix knows its symmetry state (this tells you if the next flag is valid)
9540: - flg - the result (only valid if set is `PETSC_TRUE`)

9542:   Level: advanced

9544:   Notes:
9545:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsSymmetric()`
9546:   if you want it explicitly checked

9548:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9549:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9551: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9552: @*/
9553: PetscErrorCode MatIsSymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9554: {
9555:   PetscFunctionBegin;
9557:   PetscAssertPointer(set, 2);
9558:   PetscAssertPointer(flg, 3);
9559:   if (A->symmetric != PETSC_BOOL3_UNKNOWN) {
9560:     *set = PETSC_TRUE;
9561:     *flg = PetscBool3ToBool(A->symmetric);
9562:   } else *set = PETSC_FALSE;
9563:   PetscFunctionReturn(PETSC_SUCCESS);
9564: }

9566: /*@
9567:   MatIsSPDKnown - Checks if a matrix knows if it is symmetric positive definite or not and its symmetric positive definite state

9569:   Not Collective

9571:   Input Parameter:
9572: . A - the matrix to check

9574:   Output Parameters:
9575: + set - `PETSC_TRUE` if the matrix knows its symmetric positive definite state (this tells you if the next flag is valid)
9576: - flg - the result (only valid if set is `PETSC_TRUE`)

9578:   Level: advanced

9580:   Notes:
9581:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`).

9583:   One can declare that a matrix is SPD with `MatSetOption`(mat,`MAT_SPD`,`PETSC_TRUE`) and if it is known to remain SPD
9584:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SPD_ETERNAL`,`PETSC_TRUE`)

9586: .seealso: [](ch_matrices), `Mat`, `MAT_SPD_ETERNAL`, `MAT_SPD`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9587: @*/
9588: PetscErrorCode MatIsSPDKnown(Mat A, PetscBool *set, PetscBool *flg)
9589: {
9590:   PetscFunctionBegin;
9592:   PetscAssertPointer(set, 2);
9593:   PetscAssertPointer(flg, 3);
9594:   if (A->spd != PETSC_BOOL3_UNKNOWN) {
9595:     *set = PETSC_TRUE;
9596:     *flg = PetscBool3ToBool(A->spd);
9597:   } else *set = PETSC_FALSE;
9598:   PetscFunctionReturn(PETSC_SUCCESS);
9599: }

9601: /*@
9602:   MatIsHermitianKnown - Checks if a matrix knows if it is Hermitian or not and its Hermitian state

9604:   Not Collective

9606:   Input Parameter:
9607: . A - the matrix to check

9609:   Output Parameters:
9610: + set - `PETSC_TRUE` if the matrix knows its Hermitian state (this tells you if the next flag is valid)
9611: - flg - the result (only valid if set is `PETSC_TRUE`)

9613:   Level: advanced

9615:   Notes:
9616:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsHermitian()`
9617:   if you want it explicitly checked

9619:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9620:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9622: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MAT_HERMITIAN`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`
9623: @*/
9624: PetscErrorCode MatIsHermitianKnown(Mat A, PetscBool *set, PetscBool *flg)
9625: {
9626:   PetscFunctionBegin;
9628:   PetscAssertPointer(set, 2);
9629:   PetscAssertPointer(flg, 3);
9630:   if (A->hermitian != PETSC_BOOL3_UNKNOWN) {
9631:     *set = PETSC_TRUE;
9632:     *flg = PetscBool3ToBool(A->hermitian);
9633:   } else *set = PETSC_FALSE;
9634:   PetscFunctionReturn(PETSC_SUCCESS);
9635: }

9637: /*@
9638:   MatIsStructurallySymmetric - Test whether a matrix is structurally symmetric

9640:   Collective

9642:   Input Parameter:
9643: . A - the matrix to test

9645:   Output Parameter:
9646: . flg - the result

9648:   Level: intermediate

9650:   Notes:
9651:   If the matrix does yet know it is structurally symmetric this can be an expensive operation, also available `MatIsStructurallySymmetricKnown()`

9653:   One can declare that a matrix is structurally symmetric with `MatSetOption`(mat,`MAT_STRUCTURALLY_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain structurally
9654:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9656: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsSymmetric()`, `MatSetOption()`, `MatIsStructurallySymmetricKnown()`
9657: @*/
9658: PetscErrorCode MatIsStructurallySymmetric(Mat A, PetscBool *flg)
9659: {
9660:   PetscFunctionBegin;
9662:   PetscAssertPointer(flg, 2);
9663:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) *flg = PetscBool3ToBool(A->structurally_symmetric);
9664:   else {
9665:     PetscUseTypeMethod(A, isstructurallysymmetric, flg);
9666:     PetscCall(MatSetOption(A, MAT_STRUCTURALLY_SYMMETRIC, *flg));
9667:   }
9668:   PetscFunctionReturn(PETSC_SUCCESS);
9669: }

9671: /*@
9672:   MatIsStructurallySymmetricKnown - Checks if a matrix knows if it is structurally symmetric or not and its structurally symmetric state

9674:   Not Collective

9676:   Input Parameter:
9677: . A - the matrix to check

9679:   Output Parameters:
9680: + set - PETSC_TRUE if the matrix knows its structurally symmetric state (this tells you if the next flag is valid)
9681: - flg - the result (only valid if set is PETSC_TRUE)

9683:   Level: advanced

9685:   Notes:
9686:   One can declare that a matrix is structurally symmetric with `MatSetOption`(mat,`MAT_STRUCTURALLY_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain structurally
9687:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9689:   Use `MatIsStructurallySymmetric()` to explicitly check if a matrix is structurally symmetric (this is an expensive operation)

9691: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9692: @*/
9693: PetscErrorCode MatIsStructurallySymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9694: {
9695:   PetscFunctionBegin;
9697:   PetscAssertPointer(set, 2);
9698:   PetscAssertPointer(flg, 3);
9699:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9700:     *set = PETSC_TRUE;
9701:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9702:   } else *set = PETSC_FALSE;
9703:   PetscFunctionReturn(PETSC_SUCCESS);
9704: }

9706: /*@
9707:   MatStashGetInfo - Gets how many values are currently in the matrix stash, i.e. need
9708:   to be communicated to other processors during the `MatAssemblyBegin()`/`MatAssemblyEnd()` process

9710:   Not Collective

9712:   Input Parameter:
9713: . mat - the matrix

9715:   Output Parameters:
9716: + nstash    - the size of the stash
9717: . reallocs  - the number of additional mallocs incurred.
9718: . bnstash   - the size of the block stash
9719: - breallocs - the number of additional mallocs incurred.in the block stash

9721:   Level: advanced

9723: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashSetInitialSize()`
9724: @*/
9725: PetscErrorCode MatStashGetInfo(Mat mat, PetscInt *nstash, PetscInt *reallocs, PetscInt *bnstash, PetscInt *breallocs)
9726: {
9727:   PetscFunctionBegin;
9728:   PetscCall(MatStashGetInfo_Private(&mat->stash, nstash, reallocs));
9729:   PetscCall(MatStashGetInfo_Private(&mat->bstash, bnstash, breallocs));
9730:   PetscFunctionReturn(PETSC_SUCCESS);
9731: }

9733: /*@
9734:   MatCreateVecs - Get vector(s) compatible with the matrix, i.e. with the same
9735:   parallel layout, `PetscLayout` for rows and columns

9737:   Collective

9739:   Input Parameter:
9740: . mat - the matrix

9742:   Output Parameters:
9743: + right - (optional) vector that the matrix can be multiplied against
9744: - left  - (optional) vector that the matrix vector product can be stored in

9746:   Level: advanced

9748:   Notes:
9749:   The blocksize of the returned vectors is determined by the row and column block sizes set with `MatSetBlockSizes()` or the single blocksize (same for both) set by `MatSetBlockSize()`.

9751:   These are new vectors which are not owned by the mat, they should be destroyed in `VecDestroy()` when no longer needed

9753: .seealso: [](ch_matrices), `Mat`, `Vec`, `VecCreate()`, `VecDestroy()`, `DMCreateGlobalVector()`
9754: @*/
9755: PetscErrorCode MatCreateVecs(Mat mat, Vec *right, Vec *left)
9756: {
9757:   PetscFunctionBegin;
9760:   if (mat->ops->getvecs) {
9761:     PetscUseTypeMethod(mat, getvecs, right, left);
9762:   } else {
9763:     if (right) {
9764:       PetscCheck(mat->cmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for columns not yet setup");
9765:       PetscCall(VecCreateWithLayout_Private(mat->cmap, right));
9766:       PetscCall(VecSetType(*right, mat->defaultvectype));
9767: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9768:       if (mat->boundtocpu && mat->bindingpropagates) {
9769:         PetscCall(VecSetBindingPropagates(*right, PETSC_TRUE));
9770:         PetscCall(VecBindToCPU(*right, PETSC_TRUE));
9771:       }
9772: #endif
9773:     }
9774:     if (left) {
9775:       PetscCheck(mat->rmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for rows not yet setup");
9776:       PetscCall(VecCreateWithLayout_Private(mat->rmap, left));
9777:       PetscCall(VecSetType(*left, mat->defaultvectype));
9778: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9779:       if (mat->boundtocpu && mat->bindingpropagates) {
9780:         PetscCall(VecSetBindingPropagates(*left, PETSC_TRUE));
9781:         PetscCall(VecBindToCPU(*left, PETSC_TRUE));
9782:       }
9783: #endif
9784:     }
9785:   }
9786:   PetscFunctionReturn(PETSC_SUCCESS);
9787: }

9789: /*@
9790:   MatFactorInfoInitialize - Initializes a `MatFactorInfo` data structure
9791:   with default values.

9793:   Not Collective

9795:   Input Parameter:
9796: . info - the `MatFactorInfo` data structure

9798:   Level: developer

9800:   Notes:
9801:   The solvers are generally used through the `KSP` and `PC` objects, for example
9802:   `PCLU`, `PCILU`, `PCCHOLESKY`, `PCICC`

9804:   Once the data structure is initialized one may change certain entries as desired for the particular factorization to be performed

9806: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorInfo`
9807: @*/
9808: PetscErrorCode MatFactorInfoInitialize(MatFactorInfo *info)
9809: {
9810:   PetscFunctionBegin;
9811:   PetscCall(PetscMemzero(info, sizeof(MatFactorInfo)));
9812:   PetscFunctionReturn(PETSC_SUCCESS);
9813: }

9815: /*@
9816:   MatFactorSetSchurIS - Set indices corresponding to the Schur complement you wish to have computed

9818:   Collective

9820:   Input Parameters:
9821: + mat - the factored matrix
9822: - is  - the index set defining the Schur indices (0-based)

9824:   Level: advanced

9826:   Notes:
9827:   Call `MatFactorSolveSchurComplement()` or `MatFactorSolveSchurComplementTranspose()` after this call to solve a Schur complement system.

9829:   You can call `MatFactorGetSchurComplement()` or `MatFactorCreateSchurComplement()` after this call.

9831:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9833: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorGetSchurComplement()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSolveSchurComplement()`,
9834:           `MatFactorSolveSchurComplementTranspose()`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9835: @*/
9836: PetscErrorCode MatFactorSetSchurIS(Mat mat, IS is)
9837: {
9838:   PetscErrorCode (*f)(Mat, IS);

9840:   PetscFunctionBegin;
9845:   PetscCheckSameComm(mat, 1, is, 2);
9846:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
9847:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorSetSchurIS_C", &f));
9848:   PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "The selected MatSolverType does not support Schur complement computation. You should use MATSOLVERMUMPS or MATSOLVERMKL_PARDISO");
9849:   PetscCall(MatDestroy(&mat->schur));
9850:   PetscCall((*f)(mat, is));
9851:   PetscCheck(mat->schur, PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "Schur complement has not been created");
9852:   PetscFunctionReturn(PETSC_SUCCESS);
9853: }

9855: /*@
9856:   MatFactorCreateSchurComplement - Create a Schur complement matrix object using Schur data computed during the factorization step

9858:   Logically Collective

9860:   Input Parameters:
9861: + F      - the factored matrix obtained by calling `MatGetFactor()`
9862: . S      - location where to return the Schur complement, can be `NULL`
9863: - status - the status of the Schur complement matrix, can be `NULL`

9865:   Level: advanced

9867:   Notes:
9868:   You must call `MatFactorSetSchurIS()` before calling this routine.

9870:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9872:   The routine provides a copy of the Schur matrix stored within the solver data structures.
9873:   The caller must destroy the object when it is no longer needed.
9874:   If `MatFactorInvertSchurComplement()` has been called, the routine gets back the inverse.

9876:   Use `MatFactorGetSchurComplement()` to get access to the Schur complement matrix inside the factored matrix instead of making a copy of it (which this function does)

9878:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9880:   Developer Note:
9881:   The reason this routine exists is because the representation of the Schur complement within the factor matrix may be different than a standard PETSc
9882:   matrix representation and we normally do not want to use the time or memory to make a copy as a regular PETSc matrix.

9884: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorSchurStatus`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9885: @*/
9886: PetscErrorCode MatFactorCreateSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9887: {
9888:   PetscFunctionBegin;
9890:   if (S) PetscAssertPointer(S, 2);
9891:   if (status) PetscAssertPointer(status, 3);
9892:   if (S) {
9893:     PetscErrorCode (*f)(Mat, Mat *);

9895:     PetscCall(PetscObjectQueryFunction((PetscObject)F, "MatFactorCreateSchurComplement_C", &f));
9896:     if (f) PetscCall((*f)(F, S));
9897:     else PetscCall(MatDuplicate(F->schur, MAT_COPY_VALUES, S));
9898:   }
9899:   if (status) *status = F->schur_status;
9900:   PetscFunctionReturn(PETSC_SUCCESS);
9901: }

9903: /*@
9904:   MatFactorGetSchurComplement - Gets access to a Schur complement matrix using the current Schur data within a factored matrix

9906:   Logically Collective

9908:   Input Parameters:
9909: + F      - the factored matrix obtained by calling `MatGetFactor()`
9910: . S      - location where to return the Schur complement, can be `NULL`
9911: - status - the status of the Schur complement matrix, can be `NULL`

9913:   Level: advanced

9915:   Notes:
9916:   You must call `MatFactorSetSchurIS()` before calling this routine.

9918:   Schur complement mode is currently implemented for sequential matrices with factor type of `MATSOLVERMUMPS`

9920:   The routine returns a the Schur Complement stored within the data structures of the solver.

9922:   If `MatFactorInvertSchurComplement()` has previously been called, the returned matrix is actually the inverse of the Schur complement.

9924:   The returned matrix should not be destroyed; the caller should call `MatFactorRestoreSchurComplement()` when the object is no longer needed.

9926:   Use `MatFactorCreateSchurComplement()` to create a copy of the Schur complement matrix that is within a factored matrix

9928:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9930: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9931: @*/
9932: PetscErrorCode MatFactorGetSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9933: {
9934:   PetscFunctionBegin;
9936:   if (S) {
9937:     PetscAssertPointer(S, 2);
9938:     *S = F->schur;
9939:   }
9940:   if (status) {
9941:     PetscAssertPointer(status, 3);
9942:     *status = F->schur_status;
9943:   }
9944:   PetscFunctionReturn(PETSC_SUCCESS);
9945: }

9947: static PetscErrorCode MatFactorUpdateSchurStatus_Private(Mat F)
9948: {
9949:   Mat S = F->schur;

9951:   PetscFunctionBegin;
9952:   switch (F->schur_status) {
9953:   case MAT_FACTOR_SCHUR_UNFACTORED: // fall-through
9954:   case MAT_FACTOR_SCHUR_INVERTED:
9955:     if (S) {
9956:       S->ops->solve             = NULL;
9957:       S->ops->matsolve          = NULL;
9958:       S->ops->solvetranspose    = NULL;
9959:       S->ops->matsolvetranspose = NULL;
9960:       S->ops->solveadd          = NULL;
9961:       S->ops->solvetransposeadd = NULL;
9962:       S->factortype             = MAT_FACTOR_NONE;
9963:       PetscCall(PetscFree(S->solvertype));
9964:     }
9965:   case MAT_FACTOR_SCHUR_FACTORED: // fall-through
9966:     break;
9967:   default:
9968:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9969:   }
9970:   PetscFunctionReturn(PETSC_SUCCESS);
9971: }

9973: /*@
9974:   MatFactorRestoreSchurComplement - Restore the Schur complement matrix object obtained from a call to `MatFactorGetSchurComplement()`

9976:   Logically Collective

9978:   Input Parameters:
9979: + F      - the factored matrix obtained by calling `MatGetFactor()`
9980: . S      - location where the Schur complement is stored
9981: - status - the status of the Schur complement matrix (see `MatFactorSchurStatus`)

9983:   Level: advanced

9985: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9986: @*/
9987: PetscErrorCode MatFactorRestoreSchurComplement(Mat F, Mat *S, MatFactorSchurStatus status)
9988: {
9989:   PetscFunctionBegin;
9991:   if (S) {
9993:     *S = NULL;
9994:   }
9995:   F->schur_status = status;
9996:   PetscCall(MatFactorUpdateSchurStatus_Private(F));
9997:   PetscFunctionReturn(PETSC_SUCCESS);
9998: }

10000: /*@
10001:   MatFactorSolveSchurComplementTranspose - Solve the transpose of the Schur complement system computed during the factorization step

10003:   Logically Collective

10005:   Input Parameters:
10006: + F   - the factored matrix obtained by calling `MatGetFactor()`
10007: . rhs - location where the right-hand side of the Schur complement system is stored
10008: - sol - location where the solution of the Schur complement system has to be returned

10010:   Level: advanced

10012:   Notes:
10013:   The sizes of the vectors should match the size of the Schur complement

10015:   Must be called after `MatFactorSetSchurIS()`

10017: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplement()`
10018: @*/
10019: PetscErrorCode MatFactorSolveSchurComplementTranspose(Mat F, Vec rhs, Vec sol)
10020: {
10021:   PetscFunctionBegin;
10028:   PetscCheckSameComm(F, 1, rhs, 2);
10029:   PetscCheckSameComm(F, 1, sol, 3);
10030:   PetscCall(MatFactorFactorizeSchurComplement(F));
10031:   switch (F->schur_status) {
10032:   case MAT_FACTOR_SCHUR_FACTORED:
10033:     PetscCall(MatSolveTranspose(F->schur, rhs, sol));
10034:     break;
10035:   case MAT_FACTOR_SCHUR_INVERTED:
10036:     PetscCall(MatMultTranspose(F->schur, rhs, sol));
10037:     break;
10038:   default:
10039:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
10040:   }
10041:   PetscFunctionReturn(PETSC_SUCCESS);
10042: }

10044: /*@
10045:   MatFactorSolveSchurComplement - Solve the Schur complement system computed during the factorization step

10047:   Logically Collective

10049:   Input Parameters:
10050: + F   - the factored matrix obtained by calling `MatGetFactor()`
10051: . rhs - location where the right-hand side of the Schur complement system is stored
10052: - sol - location where the solution of the Schur complement system has to be returned

10054:   Level: advanced

10056:   Notes:
10057:   The sizes of the vectors should match the size of the Schur complement

10059:   Must be called after `MatFactorSetSchurIS()`

10061: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplementTranspose()`
10062: @*/
10063: PetscErrorCode MatFactorSolveSchurComplement(Mat F, Vec rhs, Vec sol)
10064: {
10065:   PetscFunctionBegin;
10072:   PetscCheckSameComm(F, 1, rhs, 2);
10073:   PetscCheckSameComm(F, 1, sol, 3);
10074:   PetscCall(MatFactorFactorizeSchurComplement(F));
10075:   switch (F->schur_status) {
10076:   case MAT_FACTOR_SCHUR_FACTORED:
10077:     PetscCall(MatSolve(F->schur, rhs, sol));
10078:     break;
10079:   case MAT_FACTOR_SCHUR_INVERTED:
10080:     PetscCall(MatMult(F->schur, rhs, sol));
10081:     break;
10082:   default:
10083:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
10084:   }
10085:   PetscFunctionReturn(PETSC_SUCCESS);
10086: }

10088: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseInvertFactors_Private(Mat);
10089: #if PetscDefined(HAVE_CUDA)
10090: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseCUDAInvertFactors_Internal(Mat);
10091: #endif

10093: /* Schur status updated in the interface */
10094: static PetscErrorCode MatFactorInvertSchurComplement_Private(Mat F)
10095: {
10096:   Mat S = F->schur;

10098:   PetscFunctionBegin;
10099:   if (S) {
10100:     PetscMPIInt size;
10101:     PetscBool   isdense, isdensecuda;

10103:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)S), &size));
10104:     PetscCheck(size <= 1, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not yet implemented");
10105:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSE, &isdense));
10106:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSECUDA, &isdensecuda));
10107:     PetscCheck(isdense || isdensecuda, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not implemented for type %s", ((PetscObject)S)->type_name);
10108:     PetscCall(PetscLogEventBegin(MAT_FactorInvS, F, 0, 0, 0));
10109:     if (isdense) {
10110:       PetscCall(MatSeqDenseInvertFactors_Private(S));
10111:     } else if (isdensecuda) {
10112: #if defined(PETSC_HAVE_CUDA)
10113:       PetscCall(MatSeqDenseCUDAInvertFactors_Internal(S));
10114: #endif
10115:     }
10116:     // HIP??????????????
10117:     PetscCall(PetscLogEventEnd(MAT_FactorInvS, F, 0, 0, 0));
10118:   }
10119:   PetscFunctionReturn(PETSC_SUCCESS);
10120: }

10122: /*@
10123:   MatFactorInvertSchurComplement - Invert the Schur complement matrix computed during the factorization step

10125:   Logically Collective

10127:   Input Parameter:
10128: . F - the factored matrix obtained by calling `MatGetFactor()`

10130:   Level: advanced

10132:   Notes:
10133:   Must be called after `MatFactorSetSchurIS()`.

10135:   Call `MatFactorGetSchurComplement()` or  `MatFactorCreateSchurComplement()` AFTER this call to actually compute the inverse and get access to it.

10137: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorCreateSchurComplement()`
10138: @*/
10139: PetscErrorCode MatFactorInvertSchurComplement(Mat F)
10140: {
10141:   PetscFunctionBegin;
10144:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED) PetscFunctionReturn(PETSC_SUCCESS);
10145:   PetscCall(MatFactorFactorizeSchurComplement(F));
10146:   PetscCall(MatFactorInvertSchurComplement_Private(F));
10147:   F->schur_status = MAT_FACTOR_SCHUR_INVERTED;
10148:   PetscFunctionReturn(PETSC_SUCCESS);
10149: }

10151: /*@
10152:   MatFactorFactorizeSchurComplement - Factorize the Schur complement matrix computed during the factorization step

10154:   Logically Collective

10156:   Input Parameter:
10157: . F - the factored matrix obtained by calling `MatGetFactor()`

10159:   Level: advanced

10161:   Note:
10162:   Must be called after `MatFactorSetSchurIS()`

10164: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorInvertSchurComplement()`
10165: @*/
10166: PetscErrorCode MatFactorFactorizeSchurComplement(Mat F)
10167: {
10168:   MatFactorInfo info;

10170:   PetscFunctionBegin;
10173:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED || F->schur_status == MAT_FACTOR_SCHUR_FACTORED) PetscFunctionReturn(PETSC_SUCCESS);
10174:   PetscCall(PetscLogEventBegin(MAT_FactorFactS, F, 0, 0, 0));
10175:   PetscCall(PetscMemzero(&info, sizeof(MatFactorInfo)));
10176:   if (F->factortype == MAT_FACTOR_CHOLESKY) { /* LDL^t regarded as Cholesky */
10177:     PetscCall(MatCholeskyFactor(F->schur, NULL, &info));
10178:   } else {
10179:     PetscCall(MatLUFactor(F->schur, NULL, NULL, &info));
10180:   }
10181:   PetscCall(PetscLogEventEnd(MAT_FactorFactS, F, 0, 0, 0));
10182:   F->schur_status = MAT_FACTOR_SCHUR_FACTORED;
10183:   PetscFunctionReturn(PETSC_SUCCESS);
10184: }

10186: /*@
10187:   MatPtAP - Creates the matrix product $C = P^T * A * P$

10189:   Neighbor-wise Collective

10191:   Input Parameters:
10192: + A     - the matrix
10193: . P     - the projection matrix
10194: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10195: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(P)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10196:           if the result is a dense matrix this is irrelevant

10198:   Output Parameter:
10199: . C - the product matrix

10201:   Level: intermediate

10203:   Notes:
10204:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10206:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_PtAP`
10207:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10209:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10211:   Developer Note:
10212:   For matrix types without special implementation the function fallbacks to `MatMatMult()` followed by `MatTransposeMatMult()`.

10214: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatRARt()`
10215: @*/
10216: PetscErrorCode MatPtAP(Mat A, Mat P, MatReuse scall, PetscReal fill, Mat *C)
10217: {
10218:   PetscFunctionBegin;
10219:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10220:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10222:   if (scall == MAT_INITIAL_MATRIX) {
10223:     PetscCall(MatProductCreate(A, P, NULL, C));
10224:     PetscCall(MatProductSetType(*C, MATPRODUCT_PtAP));
10225:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10226:     PetscCall(MatProductSetFill(*C, fill));

10228:     (*C)->product->api_user = PETSC_TRUE;
10229:     PetscCall(MatProductSetFromOptions(*C));
10230:     PetscCheck((*C)->ops->productsymbolic, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "MatProduct %s not supported for A %s and P %s", MatProductTypes[MATPRODUCT_PtAP], ((PetscObject)A)->type_name, ((PetscObject)P)->type_name);
10231:     PetscCall(MatProductSymbolic(*C));
10232:   } else { /* scall == MAT_REUSE_MATRIX */
10233:     PetscCall(MatProductReplaceMats(A, P, NULL, *C));
10234:   }

10236:   PetscCall(MatProductNumeric(*C));
10237:   if (A->symmetric == PETSC_BOOL3_TRUE) {
10238:     PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10239:     (*C)->spd = A->spd;
10240:   }
10241:   PetscFunctionReturn(PETSC_SUCCESS);
10242: }

10244: /*@
10245:   MatRARt - Creates the matrix product $C = R * A * R^T$

10247:   Neighbor-wise Collective

10249:   Input Parameters:
10250: + A     - the matrix
10251: . R     - the projection matrix
10252: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10253: - fill  - expected fill as ratio of nnz(C)/nnz(A), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10254:           if the result is a dense matrix this is irrelevant

10256:   Output Parameter:
10257: . C - the product matrix

10259:   Level: intermediate

10261:   Notes:
10262:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10264:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_RARt`
10265:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10267:   This routine is currently only implemented for pairs of `MATAIJ` matrices and classes
10268:   which inherit from `MATAIJ`. Due to PETSc sparse matrix block row distribution among processes,
10269:   the parallel `MatRARt()` is implemented computing the explicit transpose of `R`, which can be very expensive.
10270:   We recommend using `MatPtAP()` when possible.

10272:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10274: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatPtAP()`
10275: @*/
10276: PetscErrorCode MatRARt(Mat A, Mat R, MatReuse scall, PetscReal fill, Mat *C)
10277: {
10278:   PetscFunctionBegin;
10279:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10280:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10282:   if (scall == MAT_INITIAL_MATRIX) {
10283:     PetscCall(MatProductCreate(A, R, NULL, C));
10284:     PetscCall(MatProductSetType(*C, MATPRODUCT_RARt));
10285:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10286:     PetscCall(MatProductSetFill(*C, fill));

10288:     (*C)->product->api_user = PETSC_TRUE;
10289:     PetscCall(MatProductSetFromOptions(*C));
10290:     PetscCheck((*C)->ops->productsymbolic, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "MatProduct %s not supported for A %s and R %s", MatProductTypes[MATPRODUCT_RARt], ((PetscObject)A)->type_name, ((PetscObject)R)->type_name);
10291:     PetscCall(MatProductSymbolic(*C));
10292:   } else { /* scall == MAT_REUSE_MATRIX */
10293:     PetscCall(MatProductReplaceMats(A, R, NULL, *C));
10294:   }

10296:   PetscCall(MatProductNumeric(*C));
10297:   if (A->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10298:   PetscFunctionReturn(PETSC_SUCCESS);
10299: }

10301: static PetscErrorCode MatProduct_Private(Mat A, Mat B, MatReuse scall, PetscReal fill, MatProductType ptype, Mat *C)
10302: {
10303:   PetscBool flg = PETSC_TRUE;

10305:   PetscFunctionBegin;
10306:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX product not supported");
10307:   if (scall == MAT_INITIAL_MATRIX) {
10308:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_INITIAL_MATRIX and product type %s\n", MatProductTypes[ptype]));
10309:     PetscCall(MatProductCreate(A, B, NULL, C));
10310:     PetscCall(MatProductSetAlgorithm(*C, MATPRODUCTALGORITHMDEFAULT));
10311:     PetscCall(MatProductSetFill(*C, fill));
10312:   } else { /* scall == MAT_REUSE_MATRIX */
10313:     Mat_Product *product = (*C)->product;

10315:     PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)*C, &flg, MATSEQDENSE, MATMPIDENSE, ""));
10316:     if (flg && product && product->type != ptype) {
10317:       PetscCall(MatProductClear(*C));
10318:       product = NULL;
10319:     }
10320:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_REUSE_MATRIX %s product present and product type %s\n", product ? "with" : "without", MatProductTypes[ptype]));
10321:     if (!product) { /* user provide the dense matrix *C without calling MatProductCreate() or reusing it from previous calls */
10322:       PetscCheck(flg, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "Call MatProductCreate() first");
10323:       PetscCall(MatProductCreate_Private(A, B, NULL, *C));
10324:       product        = (*C)->product;
10325:       product->fill  = fill;
10326:       product->clear = PETSC_TRUE;
10327:     } else { /* user may change input matrices A or B when MAT_REUSE_MATRIX */
10328:       flg = PETSC_FALSE;
10329:       PetscCall(MatProductReplaceMats(A, B, NULL, *C));
10330:     }
10331:   }
10332:   if (flg) {
10333:     (*C)->product->api_user = PETSC_TRUE;
10334:     PetscCall(MatProductSetType(*C, ptype));
10335:     PetscCall(MatProductSetFromOptions(*C));
10336:     PetscCall(MatProductSymbolic(*C));
10337:   }
10338:   PetscCall(MatProductNumeric(*C));
10339:   PetscFunctionReturn(PETSC_SUCCESS);
10340: }

10342: /*@
10343:   MatMatMult - Performs matrix-matrix multiplication $ C=A*B $.

10345:   Neighbor-wise Collective

10347:   Input Parameters:
10348: + A     - the left matrix
10349: . B     - the right matrix
10350: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10351: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10352:           if the result is a dense matrix this is irrelevant

10354:   Output Parameter:
10355: . C - the product matrix

10357:   Notes:
10358:   Unless scall is `MAT_REUSE_MATRIX` C will be created.

10360:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call and C was obtained from a previous
10361:   call to this function with `MAT_INITIAL_MATRIX`.

10363:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value actually needed.

10365:   In the special case where matrix `B` (and hence `C`) are dense you can create the correctly sized matrix `C` yourself and then call this routine with `MAT_REUSE_MATRIX`,
10366:   rather than first having `MatMatMult()` create it for you. You can NEVER do this if the matrix `C` is sparse.

10368:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10370:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AB`
10371:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10373:   Example of Usage:
10374: .vb
10375:      MatProductCreate(A,B,NULL,&C);
10376:      MatProductSetType(C,MATPRODUCT_AB);
10377:      MatProductSymbolic(C);
10378:      MatProductNumeric(C); // compute C=A * B
10379:      MatProductReplaceMats(A1,B1,NULL,C); // compute C=A1 * B1
10380:      MatProductNumeric(C);
10381:      MatProductReplaceMats(A2,NULL,NULL,C); // compute C=A2 * B1
10382:      MatProductNumeric(C);
10383: .ve

10385:   Level: intermediate

10387: .seealso: [](ch_matrices), `Mat`, `MatProductType`, `MATPRODUCT_AB`, `MatTransposeMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`, `MatProductCreate()`, `MatProductSymbolic()`, `MatProductReplaceMats()`, `MatProductNumeric()`
10388: @*/
10389: PetscErrorCode MatMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10390: {
10391:   PetscFunctionBegin;
10392:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AB, C));
10393:   PetscFunctionReturn(PETSC_SUCCESS);
10394: }

10396: /*@
10397:   MatMatTransposeMult - Performs matrix-matrix multiplication $C = A*B^T$.

10399:   Neighbor-wise Collective

10401:   Input Parameters:
10402: + A     - the left matrix
10403: . B     - the right matrix
10404: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10405: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10407:   Output Parameter:
10408: . C - the product matrix

10410:   Options Database Key:
10411: . -matmattransmult_mpidense_mpidense_via {allgatherv,cyclic} - Choose between algorithms for `MATMPIDENSE` matrices: the
10412:               first redundantly copies the transposed `B` matrix on each process and requires O(log P) communication complexity;
10413:               the second never stores more than one portion of the `B` matrix at a time but requires O(P) communication complexity.

10415:   Level: intermediate

10417:   Notes:
10418:   C will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10420:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call

10422:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10423:   actually needed.

10425:   This routine is currently only implemented for pairs of `MATSEQAIJ` matrices, for the `MATSEQDENSE` class,
10426:   and for pairs of `MATMPIDENSE` matrices.

10428:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABt`
10429:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10431:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10433: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABt`, `MatMatMult()`, `MatTransposeMatMult()`, `MatPtAP()`, `MatProductAlgorithm`, `MatProductType`
10434: @*/
10435: PetscErrorCode MatMatTransposeMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10436: {
10437:   PetscFunctionBegin;
10438:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_ABt, C));
10439:   if (A == B) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10440:   PetscFunctionReturn(PETSC_SUCCESS);
10441: }

10443: /*@
10444:   MatTransposeMatMult - Performs matrix-matrix multiplication $C = A^T*B$.

10446:   Neighbor-wise Collective

10448:   Input Parameters:
10449: + A     - the left matrix
10450: . B     - the right matrix
10451: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10452: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10454:   Output Parameter:
10455: . C - the product matrix

10457:   Level: intermediate

10459:   Notes:
10460:   `C` will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10462:   `MAT_REUSE_MATRIX` can only be used if `A` and `B` have the same nonzero pattern as in the previous call.

10464:   This is a convenience routine that wraps the use of `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AtB`
10465:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10467:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10468:   actually needed.

10470:   This routine is currently implemented for pairs of `MATAIJ` matrices and pairs of `MATSEQDENSE` matrices and classes
10471:   which inherit from `MATSEQAIJ`.  `C` will be of the same type as the input matrices.

10473:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10475: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_AtB`, `MatMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`
10476: @*/
10477: PetscErrorCode MatTransposeMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10478: {
10479:   PetscFunctionBegin;
10480:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AtB, C));
10481:   PetscFunctionReturn(PETSC_SUCCESS);
10482: }

10484: /*@
10485:   MatMatMatMult - Performs matrix-matrix-matrix multiplication D=A*B*C.

10487:   Neighbor-wise Collective

10489:   Input Parameters:
10490: + A     - the left matrix
10491: . B     - the middle matrix
10492: . C     - the right matrix
10493: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10494: - fill  - expected fill as ratio of nnz(D)/(nnz(A) + nnz(B)+nnz(C)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10495:           if the result is a dense matrix this is irrelevant

10497:   Output Parameter:
10498: . D - the product matrix

10500:   Level: intermediate

10502:   Notes:
10503:   Unless `scall` is `MAT_REUSE_MATRIX` `D` will be created.

10505:   `MAT_REUSE_MATRIX` can only be used if the matrices `A`, `B`, and `C` have the same nonzero pattern as in the previous call

10507:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABC`
10508:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10510:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value
10511:   actually needed.

10513:   If you have many matrices with the same non-zero structure to multiply, you
10514:   should use `MAT_REUSE_MATRIX` in all calls but the first

10516:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10518: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABC`, `MatMatMult`, `MatPtAP()`, `MatMatTransposeMult()`, `MatTransposeMatMult()`
10519: @*/
10520: PetscErrorCode MatMatMatMult(Mat A, Mat B, Mat C, MatReuse scall, PetscReal fill, Mat *D)
10521: {
10522:   PetscFunctionBegin;
10523:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*D, 6);
10524:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10526:   if (scall == MAT_INITIAL_MATRIX) {
10527:     PetscCall(MatProductCreate(A, B, C, D));
10528:     PetscCall(MatProductSetType(*D, MATPRODUCT_ABC));
10529:     PetscCall(MatProductSetAlgorithm(*D, "default"));
10530:     PetscCall(MatProductSetFill(*D, fill));

10532:     (*D)->product->api_user = PETSC_TRUE;
10533:     PetscCall(MatProductSetFromOptions(*D));
10534:     PetscCheck((*D)->ops->productsymbolic, PetscObjectComm((PetscObject)*D), PETSC_ERR_SUP, "MatProduct %s not supported for A %s, B %s and C %s", MatProductTypes[MATPRODUCT_ABC], ((PetscObject)A)->type_name, ((PetscObject)B)->type_name,
10535:                ((PetscObject)C)->type_name);
10536:     PetscCall(MatProductSymbolic(*D));
10537:   } else { /* user may change input matrices when REUSE */
10538:     PetscCall(MatProductReplaceMats(A, B, C, *D));
10539:   }
10540:   PetscCall(MatProductNumeric(*D));
10541:   PetscFunctionReturn(PETSC_SUCCESS);
10542: }

10544: /*@
10545:   MatCreateRedundantMatrix - Create redundant matrices and put them into processors of subcommunicators.

10547:   Collective

10549:   Input Parameters:
10550: + mat      - the matrix
10551: . nsubcomm - the number of subcommunicators (= number of redundant parallel or sequential matrices)
10552: . subcomm  - MPI communicator split from the communicator where mat resides in (or `MPI_COMM_NULL` if nsubcomm is used)
10553: - reuse    - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10555:   Output Parameter:
10556: . matredundant - redundant matrix

10558:   Level: advanced

10560:   Notes:
10561:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
10562:   original matrix has not changed from that last call to `MatCreateRedundantMatrix()`.

10564:   This routine creates the duplicated matrices in the subcommunicators; you should NOT create them before
10565:   calling it.

10567:   `PetscSubcommCreate()` can be used to manage the creation of the subcomm but need not be.

10569: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `PetscSubcommCreate()`, `PetscSubcomm`
10570: @*/
10571: PetscErrorCode MatCreateRedundantMatrix(Mat mat, PetscInt nsubcomm, MPI_Comm subcomm, MatReuse reuse, Mat *matredundant)
10572: {
10573:   MPI_Comm       comm;
10574:   PetscMPIInt    size;
10575:   PetscInt       mloc_sub, nloc_sub, rstart, rend, M = mat->rmap->N, N = mat->cmap->N, bs = mat->rmap->bs;
10576:   Mat_Redundant *redund     = NULL;
10577:   PetscSubcomm   psubcomm   = NULL;
10578:   MPI_Comm       subcomm_in = subcomm;
10579:   Mat           *matseq;
10580:   IS             isrow, iscol;
10581:   PetscBool      newsubcomm = PETSC_FALSE;

10583:   PetscFunctionBegin;
10585:   if (nsubcomm && reuse == MAT_REUSE_MATRIX) {
10586:     PetscAssertPointer(*matredundant, 5);
10588:   }

10590:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
10591:   if (size == 1 || nsubcomm == 1) {
10592:     if (reuse == MAT_INITIAL_MATRIX) {
10593:       PetscCall(MatDuplicate(mat, MAT_COPY_VALUES, matredundant));
10594:     } else {
10595:       PetscCheck(*matredundant != mat, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MAT_REUSE_MATRIX means reuse the matrix passed in as the final argument, not the original matrix");
10596:       PetscCall(MatCopy(mat, *matredundant, SAME_NONZERO_PATTERN));
10597:     }
10598:     PetscFunctionReturn(PETSC_SUCCESS);
10599:   }

10601:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10602:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10603:   MatCheckPreallocated(mat, 1);

10605:   PetscCall(PetscLogEventBegin(MAT_RedundantMat, mat, 0, 0, 0));
10606:   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
10607:     /* create psubcomm, then get subcomm */
10608:     PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10609:     PetscCallMPI(MPI_Comm_size(comm, &size));
10610:     PetscCheck(nsubcomm >= 1 && nsubcomm <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "nsubcomm must between 1 and %d", size);

10612:     PetscCall(PetscSubcommCreate(comm, &psubcomm));
10613:     PetscCall(PetscSubcommSetNumber(psubcomm, nsubcomm));
10614:     PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_CONTIGUOUS));
10615:     PetscCall(PetscSubcommSetFromOptions(psubcomm));
10616:     PetscCall(PetscCommDuplicate(PetscSubcommChild(psubcomm), &subcomm, NULL));
10617:     newsubcomm = PETSC_TRUE;
10618:     PetscCall(PetscSubcommDestroy(&psubcomm));
10619:   }

10621:   /* get isrow, iscol and a local sequential matrix matseq[0] */
10622:   if (reuse == MAT_INITIAL_MATRIX) {
10623:     mloc_sub = PETSC_DECIDE;
10624:     nloc_sub = PETSC_DECIDE;
10625:     if (bs < 1) {
10626:       PetscCall(PetscSplitOwnership(subcomm, &mloc_sub, &M));
10627:       PetscCall(PetscSplitOwnership(subcomm, &nloc_sub, &N));
10628:     } else {
10629:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &mloc_sub, &M));
10630:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &nloc_sub, &N));
10631:     }
10632:     PetscCallMPI(MPI_Scan(&mloc_sub, &rend, 1, MPIU_INT, MPI_SUM, subcomm));
10633:     rstart = rend - mloc_sub;
10634:     PetscCall(ISCreateStride(PETSC_COMM_SELF, mloc_sub, rstart, 1, &isrow));
10635:     PetscCall(ISCreateStride(PETSC_COMM_SELF, N, 0, 1, &iscol));
10636:     PetscCall(ISSetIdentity(iscol));
10637:   } else { /* reuse == MAT_REUSE_MATRIX */
10638:     PetscCheck(*matredundant != mat, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MAT_REUSE_MATRIX means reuse the matrix passed in as the final argument, not the original matrix");
10639:     /* retrieve subcomm */
10640:     PetscCall(PetscObjectGetComm((PetscObject)*matredundant, &subcomm));
10641:     redund = (*matredundant)->redundant;
10642:     isrow  = redund->isrow;
10643:     iscol  = redund->iscol;
10644:     matseq = redund->matseq;
10645:   }
10646:   PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscol, reuse, &matseq));

10648:   /* get matredundant over subcomm */
10649:   if (reuse == MAT_INITIAL_MATRIX) {
10650:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], nloc_sub, reuse, matredundant));

10652:     /* create a supporting struct and attach it to C for reuse */
10653:     PetscCall(PetscNew(&redund));
10654:     (*matredundant)->redundant = redund;
10655:     redund->isrow              = isrow;
10656:     redund->iscol              = iscol;
10657:     redund->matseq             = matseq;
10658:     if (newsubcomm) {
10659:       redund->subcomm = subcomm;
10660:     } else {
10661:       redund->subcomm = MPI_COMM_NULL;
10662:     }
10663:   } else {
10664:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], PETSC_DECIDE, reuse, matredundant));
10665:   }
10666: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
10667:   if (matseq[0]->boundtocpu && matseq[0]->bindingpropagates) {
10668:     PetscCall(MatBindToCPU(*matredundant, PETSC_TRUE));
10669:     PetscCall(MatSetBindingPropagates(*matredundant, PETSC_TRUE));
10670:   }
10671: #endif
10672:   PetscCall(PetscLogEventEnd(MAT_RedundantMat, mat, 0, 0, 0));
10673:   PetscFunctionReturn(PETSC_SUCCESS);
10674: }

10676: /*@C
10677:   MatGetMultiProcBlock - Create multiple 'parallel submatrices' from
10678:   a given `Mat`. Each submatrix can span multiple procs.

10680:   Collective

10682:   Input Parameters:
10683: + mat     - the matrix
10684: . subComm - the sub communicator obtained as if by `MPI_Comm_split(PetscObjectComm((PetscObject)mat))`
10685: - scall   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10687:   Output Parameter:
10688: . subMat - parallel sub-matrices each spanning a given `subcomm`

10690:   Level: advanced

10692:   Notes:
10693:   The submatrix partition across processors is dictated by `subComm` a
10694:   communicator obtained by `MPI_comm_split()` or via `PetscSubcommCreate()`. The `subComm`
10695:   is not restricted to be grouped with consecutive original MPI processes.

10697:   Due the `MPI_Comm_split()` usage, the parallel layout of the submatrices
10698:   map directly to the layout of the original matrix [wrt the local
10699:   row,col partitioning]. So the original 'DiagonalMat' naturally maps
10700:   into the 'DiagonalMat' of the `subMat`, hence it is used directly from
10701:   the `subMat`. However the offDiagMat looses some columns - and this is
10702:   reconstructed with `MatSetValues()`

10704:   This is used by `PCBJACOBI` when a single block spans multiple MPI processes.

10706: .seealso: [](ch_matrices), `Mat`, `MatCreateRedundantMatrix()`, `MatCreateSubMatrices()`, `PCBJACOBI`
10707: @*/
10708: PetscErrorCode MatGetMultiProcBlock(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
10709: {
10710:   PetscMPIInt commsize, subCommSize;

10712:   PetscFunctionBegin;
10713:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &commsize));
10714:   PetscCallMPI(MPI_Comm_size(subComm, &subCommSize));
10715:   PetscCheck(subCommSize <= commsize, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "CommSize %d < SubCommZize %d", commsize, subCommSize);

10717:   PetscCheck(scall != MAT_REUSE_MATRIX || *subMat != mat, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MAT_REUSE_MATRIX means reuse the matrix passed in as the final argument, not the original matrix");
10718:   PetscCall(PetscLogEventBegin(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10719:   PetscUseTypeMethod(mat, getmultiprocblock, subComm, scall, subMat);
10720:   PetscCall(PetscLogEventEnd(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10721:   PetscFunctionReturn(PETSC_SUCCESS);
10722: }

10724: /*@
10725:   MatGetLocalSubMatrix - Gets a reference to a submatrix specified in local numbering

10727:   Not Collective

10729:   Input Parameters:
10730: + mat   - matrix to extract local submatrix from
10731: . isrow - local row indices for submatrix
10732: - iscol - local column indices for submatrix

10734:   Output Parameter:
10735: . submat - the submatrix

10737:   Level: intermediate

10739:   Notes:
10740:   `submat` should be disposed of with `MatRestoreLocalSubMatrix()`.

10742:   Depending on the format of `mat`, the returned `submat` may not implement `MatMult()`.  Its communicator may be
10743:   the same as `mat`, it may be `PETSC_COMM_SELF`, or some other sub-communictor of `mat`'s.

10745:   `submat` always implements `MatSetValuesLocal()`.  If `isrow` and `iscol` have the same block size, then
10746:   `MatSetValuesBlockedLocal()` will also be implemented.

10748:   `mat` must have had a `ISLocalToGlobalMapping` provided to it with `MatSetLocalToGlobalMapping()`.
10749:   Matrices obtained with `DMCreateMatrix()` generally already have the local to global mapping provided.

10751: .seealso: [](ch_matrices), `Mat`, `MatRestoreLocalSubMatrix()`, `MatCreateLocalRef()`, `MatSetLocalToGlobalMapping()`
10752: @*/
10753: PetscErrorCode MatGetLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10754: {
10755:   PetscFunctionBegin;
10759:   PetscCheckSameComm(isrow, 2, iscol, 3);
10760:   PetscAssertPointer(submat, 4);
10761:   PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must have local to global mapping provided before this call");

10763:   if (mat->ops->getlocalsubmatrix) {
10764:     PetscUseTypeMethod(mat, getlocalsubmatrix, isrow, iscol, submat);
10765:   } else {
10766:     PetscCall(MatCreateLocalRef(mat, isrow, iscol, submat));
10767:   }
10768:   (*submat)->assembled = mat->assembled;
10769:   PetscFunctionReturn(PETSC_SUCCESS);
10770: }

10772: /*@
10773:   MatRestoreLocalSubMatrix - Restores a reference to a submatrix specified in local numbering obtained with `MatGetLocalSubMatrix()`

10775:   Not Collective

10777:   Input Parameters:
10778: + mat    - matrix to extract local submatrix from
10779: . isrow  - local row indices for submatrix
10780: . iscol  - local column indices for submatrix
10781: - submat - the submatrix

10783:   Level: intermediate

10785: .seealso: [](ch_matrices), `Mat`, `MatGetLocalSubMatrix()`
10786: @*/
10787: PetscErrorCode MatRestoreLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10788: {
10789:   PetscFunctionBegin;
10793:   PetscCheckSameComm(isrow, 2, iscol, 3);
10794:   PetscAssertPointer(submat, 4);

10797:   if (mat->ops->restorelocalsubmatrix) {
10798:     PetscUseTypeMethod(mat, restorelocalsubmatrix, isrow, iscol, submat);
10799:   } else {
10800:     PetscCall(MatDestroy(submat));
10801:   }
10802:   *submat = NULL;
10803:   PetscFunctionReturn(PETSC_SUCCESS);
10804: }

10806: /*@
10807:   MatFindZeroDiagonals - Finds all the rows of a matrix that have zero or no diagonal entry in the matrix

10809:   Collective

10811:   Input Parameter:
10812: . mat - the matrix

10814:   Output Parameter:
10815: . is - if any rows have zero diagonals this contains the list of them

10817:   Level: developer

10819: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10820: @*/
10821: PetscErrorCode MatFindZeroDiagonals(Mat mat, IS *is)
10822: {
10823:   PetscFunctionBegin;
10826:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10827:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10829:   if (!mat->ops->findzerodiagonals) {
10830:     Vec                diag;
10831:     const PetscScalar *a;
10832:     PetscInt          *rows;
10833:     PetscInt           rStart, rEnd, r, nrow = 0;

10835:     PetscCall(MatCreateVecs(mat, &diag, NULL));
10836:     PetscCall(MatGetDiagonal(mat, diag));
10837:     PetscCall(MatGetOwnershipRange(mat, &rStart, &rEnd));
10838:     PetscCall(VecGetArrayRead(diag, &a));
10839:     for (r = 0; r < rEnd - rStart; ++r)
10840:       if (a[r] == 0.0) ++nrow;
10841:     PetscCall(PetscMalloc1(nrow, &rows));
10842:     nrow = 0;
10843:     for (r = 0; r < rEnd - rStart; ++r)
10844:       if (a[r] == 0.0) rows[nrow++] = r + rStart;
10845:     PetscCall(VecRestoreArrayRead(diag, &a));
10846:     PetscCall(VecDestroy(&diag));
10847:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)mat), nrow, rows, PETSC_OWN_POINTER, is));
10848:   } else {
10849:     PetscUseTypeMethod(mat, findzerodiagonals, is);
10850:   }
10851:   PetscFunctionReturn(PETSC_SUCCESS);
10852: }

10854: /*@
10855:   MatFindOffBlockDiagonalEntries - Finds all the rows of a matrix that have entries outside of the main diagonal block (defined by the matrix block size)

10857:   Collective

10859:   Input Parameter:
10860: . mat - the matrix

10862:   Output Parameter:
10863: . is - contains the list of rows with off block diagonal entries

10865:   Level: developer

10867: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10868: @*/
10869: PetscErrorCode MatFindOffBlockDiagonalEntries(Mat mat, IS *is)
10870: {
10871:   PetscFunctionBegin;
10874:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10875:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10877:   PetscUseTypeMethod(mat, findoffblockdiagonalentries, is);
10878:   PetscFunctionReturn(PETSC_SUCCESS);
10879: }

10881: /*@C
10882:   MatInvertBlockDiagonal - Inverts the block diagonal entries.

10884:   Collective; No Fortran Support

10886:   Input Parameter:
10887: . mat - the matrix

10889:   Output Parameter:
10890: . values - the block inverses in column major order (FORTRAN-like)

10892:   Level: advanced

10894:   Notes:
10895:   The size of the blocks is determined by the block size of the matrix.

10897:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10899:   The blocks all have the same size, use `MatInvertVariableBlockDiagonal()` for variable block size

10901: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatInvertBlockDiagonalMat()`
10902: @*/
10903: PetscErrorCode MatInvertBlockDiagonal(Mat mat, const PetscScalar *values[])
10904: {
10905:   PetscFunctionBegin;
10907:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10908:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10909:   PetscUseTypeMethod(mat, invertblockdiagonal, values);
10910:   PetscFunctionReturn(PETSC_SUCCESS);
10911: }

10913: /*@
10914:   MatInvertVariableBlockDiagonal - Inverts the point block diagonal entries.

10916:   Collective; No Fortran Support

10918:   Input Parameters:
10919: + mat     - the matrix
10920: . nblocks - the number of blocks on the process, set with `MatSetVariableBlockSizes()`
10921: - bsizes  - the size of each block on the process, set with `MatSetVariableBlockSizes()`

10923:   Output Parameter:
10924: . values - the block inverses in column major order (FORTRAN-like)

10926:   Level: advanced

10928:   Notes:
10929:   Use `MatInvertBlockDiagonal()` if all blocks have the same size

10931:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10933: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatSetVariableBlockSizes()`, `MatInvertVariableBlockEnvelope()`
10934: @*/
10935: PetscErrorCode MatInvertVariableBlockDiagonal(Mat mat, PetscInt nblocks, const PetscInt bsizes[], PetscScalar values[])
10936: {
10937:   PetscFunctionBegin;
10939:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10940:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10941:   PetscUseTypeMethod(mat, invertvariableblockdiagonal, nblocks, bsizes, values);
10942:   PetscFunctionReturn(PETSC_SUCCESS);
10943: }

10945: /*@
10946:   MatInvertBlockDiagonalMat - set the values of matrix C to be the inverted block diagonal of matrix A

10948:   Collective

10950:   Input Parameters:
10951: + A - the matrix
10952: - C - matrix with inverted block diagonal of `A`.  This matrix should be created and may have its type set.

10954:   Level: advanced

10956:   Note:
10957:   The blocksize of the matrix is used to determine the blocks on the diagonal of `C`

10959: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`
10960: @*/
10961: PetscErrorCode MatInvertBlockDiagonalMat(Mat A, Mat C)
10962: {
10963:   const PetscScalar *vals;
10964:   PetscInt          *dnnz;
10965:   PetscInt           m, rstart, rend, bs, i, j;

10967:   PetscFunctionBegin;
10968:   PetscCall(MatInvertBlockDiagonal(A, &vals));
10969:   PetscCall(MatGetBlockSize(A, &bs));
10970:   PetscCall(MatGetLocalSize(A, &m, NULL));
10971:   PetscCall(MatSetLayouts(C, A->rmap, A->cmap));
10972:   PetscCall(MatSetBlockSizes(C, A->rmap->bs, A->cmap->bs));
10973:   PetscCall(PetscMalloc1(m / bs, &dnnz));
10974:   for (j = 0; j < m / bs; j++) dnnz[j] = 1;
10975:   PetscCall(MatXAIJSetPreallocation(C, bs, dnnz, NULL, NULL, NULL));
10976:   PetscCall(PetscFree(dnnz));
10977:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
10978:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_FALSE));
10979:   for (i = rstart / bs; i < rend / bs; i++) PetscCall(MatSetValuesBlocked(C, 1, &i, 1, &i, &vals[(i - rstart / bs) * bs * bs], INSERT_VALUES));
10980:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
10981:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
10982:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
10983:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_FALSE));
10984:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_TRUE));
10985:   PetscFunctionReturn(PETSC_SUCCESS);
10986: }

10988: /*@
10989:   MatTransposeColoringDestroy - Destroys a coloring context for matrix product $C = A*B^T$ that was created
10990:   via `MatTransposeColoringCreate()`.

10992:   Collective

10994:   Input Parameter:
10995: . c - coloring context

10997:   Level: intermediate

10999: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`
11000: @*/
11001: PetscErrorCode MatTransposeColoringDestroy(MatTransposeColoring *c)
11002: {
11003:   MatTransposeColoring matcolor = *c;

11005:   PetscFunctionBegin;
11006:   if (!matcolor) PetscFunctionReturn(PETSC_SUCCESS);
11007:   if (--((PetscObject)matcolor)->refct > 0) {
11008:     matcolor = NULL;
11009:     PetscFunctionReturn(PETSC_SUCCESS);
11010:   }

11012:   PetscCall(PetscFree3(matcolor->ncolumns, matcolor->nrows, matcolor->colorforrow));
11013:   PetscCall(PetscFree(matcolor->rows));
11014:   PetscCall(PetscFree(matcolor->den2sp));
11015:   PetscCall(PetscFree(matcolor->colorforcol));
11016:   PetscCall(PetscFree(matcolor->columns));
11017:   if (matcolor->brows > 0) PetscCall(PetscFree(matcolor->lstart));
11018:   PetscCall(PetscHeaderDestroy(c));
11019:   PetscFunctionReturn(PETSC_SUCCESS);
11020: }

11022: /*@
11023:   MatTransColoringApplySpToDen - Given a symbolic matrix product $C = A*B^T$ for which
11024:   a `MatTransposeColoring` context has been created, computes a dense $B^T$ by applying
11025:   `MatTransposeColoring` to sparse `B`.

11027:   Collective

11029:   Input Parameters:
11030: + coloring - coloring context created with `MatTransposeColoringCreate()`
11031: - B        - sparse matrix

11033:   Output Parameter:
11034: . Btdense - dense matrix $B^T$

11036:   Level: developer

11038:   Note:
11039:   These are used internally for some implementations of `MatRARt()`

11041: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplyDenToSp()`
11042: @*/
11043: PetscErrorCode MatTransColoringApplySpToDen(MatTransposeColoring coloring, Mat B, Mat Btdense)
11044: {
11045:   PetscFunctionBegin;

11050:   PetscCall((*B->ops->transcoloringapplysptoden)(coloring, B, Btdense));
11051:   PetscFunctionReturn(PETSC_SUCCESS);
11052: }

11054: /*@
11055:   MatTransColoringApplyDenToSp - Given a symbolic matrix product $C_{sp} = A*B^T$ for which
11056:   a `MatTransposeColoring` context has been created and a dense matrix $C_{den} = A*B^T_{dense}$
11057:   in which `B^T_{dens}` is obtained from `MatTransColoringApplySpToDen()`, recover sparse matrix
11058:   $C_{sp}$ from $C_{den}$.

11060:   Collective

11062:   Input Parameters:
11063: + matcoloring - coloring context created with `MatTransposeColoringCreate()`
11064: - Cden        - matrix product of a sparse matrix and a dense matrix Btdense

11066:   Output Parameter:
11067: . Csp - sparse matrix

11069:   Level: developer

11071:   Note:
11072:   These are used internally for some implementations of `MatRARt()`

11074: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`
11075: @*/
11076: PetscErrorCode MatTransColoringApplyDenToSp(MatTransposeColoring matcoloring, Mat Cden, Mat Csp)
11077: {
11078:   PetscFunctionBegin;

11083:   PetscCall((*Csp->ops->transcoloringapplydentosp)(matcoloring, Cden, Csp));
11084:   PetscCall(MatAssemblyBegin(Csp, MAT_FINAL_ASSEMBLY));
11085:   PetscCall(MatAssemblyEnd(Csp, MAT_FINAL_ASSEMBLY));
11086:   PetscFunctionReturn(PETSC_SUCCESS);
11087: }

11089: /*@
11090:   MatTransposeColoringCreate - Creates a matrix coloring context for the matrix product $C = A*B^T$.

11092:   Collective

11094:   Input Parameters:
11095: + mat        - the matrix product C
11096: - iscoloring - the coloring of the matrix; usually obtained with `MatColoringCreate()` or `DMCreateColoring()`

11098:   Output Parameter:
11099: . color - the new coloring context

11101:   Level: intermediate

11103: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`,
11104:           `MatTransColoringApplyDenToSp()`
11105: @*/
11106: PetscErrorCode MatTransposeColoringCreate(Mat mat, ISColoring iscoloring, MatTransposeColoring *color)
11107: {
11108:   MatTransposeColoring c;
11109:   MPI_Comm             comm;

11111:   PetscFunctionBegin;
11112:   PetscAssertPointer(color, 3);

11114:   PetscCall(PetscLogEventBegin(MAT_TransposeColoringCreate, mat, 0, 0, 0));
11115:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
11116:   PetscCall(PetscHeaderCreate(c, MAT_TRANSPOSECOLORING_CLASSID, "MatTransposeColoring", "Matrix product C=A*B^T via coloring", "Mat", comm, MatTransposeColoringDestroy, NULL));
11117:   c->ctype = iscoloring->ctype;
11118:   PetscUseTypeMethod(mat, transposecoloringcreate, iscoloring, c);
11119:   *color = c;
11120:   PetscCall(PetscLogEventEnd(MAT_TransposeColoringCreate, mat, 0, 0, 0));
11121:   PetscFunctionReturn(PETSC_SUCCESS);
11122: }

11124: /*@
11125:   MatGetNonzeroState - Returns a 64-bit integer representing the current state of nonzeros in the matrix. If the
11126:   matrix has had new nonzero locations added to (or removed from) the matrix since the previous call, the value will be larger.

11128:   Not Collective

11130:   Input Parameter:
11131: . mat - the matrix

11133:   Output Parameter:
11134: . state - the current state

11136:   Level: intermediate

11138:   Notes:
11139:   You can only compare states from two different calls to the SAME matrix, you cannot compare calls between
11140:   different matrices

11142:   Use `PetscObjectStateGet()` to check for changes to the numerical values in a matrix

11144:   Use the result of `PetscObjectGetId()` to compare if a previously checked matrix is the same as the current matrix, do not compare object pointers.

11146: .seealso: [](ch_matrices), `Mat`, `PetscObjectStateGet()`, `PetscObjectGetId()`
11147: @*/
11148: PetscErrorCode MatGetNonzeroState(Mat mat, PetscObjectState *state)
11149: {
11150:   PetscFunctionBegin;
11152:   *state = mat->nonzerostate;
11153:   PetscFunctionReturn(PETSC_SUCCESS);
11154: }

11156: /*@
11157:   MatCreateMPIMatConcatenateSeqMat - Creates a single large PETSc matrix by concatenating sequential
11158:   matrices from each processor

11160:   Collective

11162:   Input Parameters:
11163: + comm   - the communicators the parallel matrix will live on
11164: . seqmat - the input sequential matrices
11165: . n      - number of local columns (or `PETSC_DECIDE`)
11166: - reuse  - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

11168:   Output Parameter:
11169: . mpimat - the parallel matrix generated

11171:   Level: developer

11173:   Note:
11174:   The number of columns of the matrix in EACH processor MUST be the same.

11176: .seealso: [](ch_matrices), `Mat`
11177: @*/
11178: PetscErrorCode MatCreateMPIMatConcatenateSeqMat(MPI_Comm comm, Mat seqmat, PetscInt n, MatReuse reuse, Mat *mpimat)
11179: {
11180:   PetscMPIInt size;

11182:   PetscFunctionBegin;
11183:   PetscCallMPI(MPI_Comm_size(comm, &size));
11184:   if (size == 1) {
11185:     if (reuse == MAT_INITIAL_MATRIX) {
11186:       PetscCall(MatDuplicate(seqmat, MAT_COPY_VALUES, mpimat));
11187:     } else {
11188:       PetscCall(MatCopy(seqmat, *mpimat, SAME_NONZERO_PATTERN));
11189:     }
11190:     PetscFunctionReturn(PETSC_SUCCESS);
11191:   }

11193:   PetscCheck(reuse != MAT_REUSE_MATRIX || seqmat != *mpimat, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MAT_REUSE_MATRIX means reuse the matrix passed in as the final argument, not the original matrix");

11195:   PetscCall(PetscLogEventBegin(MAT_Merge, seqmat, 0, 0, 0));
11196:   PetscCall((*seqmat->ops->creatempimatconcatenateseqmat)(comm, seqmat, n, reuse, mpimat));
11197:   PetscCall(PetscLogEventEnd(MAT_Merge, seqmat, 0, 0, 0));
11198:   PetscFunctionReturn(PETSC_SUCCESS);
11199: }

11201: /*@
11202:   MatSubdomainsCreateCoalesce - Creates index subdomains by coalescing adjacent MPI processes' ownership ranges.

11204:   Collective

11206:   Input Parameters:
11207: + A - the matrix to create subdomains from
11208: - N - requested number of subdomains

11210:   Output Parameters:
11211: + n   - number of subdomains resulting on this MPI process
11212: - iss - `IS` list with indices of subdomains on this MPI process

11214:   Level: advanced

11216:   Note:
11217:   The number of subdomains must be smaller than the communicator size

11219: .seealso: [](ch_matrices), `Mat`, `IS`
11220: @*/
11221: PetscErrorCode MatSubdomainsCreateCoalesce(Mat A, PetscInt N, PetscInt *n, IS *iss[])
11222: {
11223:   MPI_Comm    comm, subcomm;
11224:   PetscMPIInt size, rank, color;
11225:   PetscInt    rstart, rend, k;

11227:   PetscFunctionBegin;
11228:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
11229:   PetscCallMPI(MPI_Comm_size(comm, &size));
11230:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
11231:   PetscCheck(N >= 1 && N < size, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "number of subdomains must be > 0 and < %d, got N = %" PetscInt_FMT, size, N);
11232:   *n    = 1;
11233:   k     = size / N + (size % N > 0); /* There are up to k ranks to a color */
11234:   color = rank / k;
11235:   PetscCallMPI(MPI_Comm_split(comm, color, rank, &subcomm));
11236:   PetscCall(PetscMalloc1(1, iss));
11237:   PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
11238:   PetscCall(ISCreateStride(subcomm, rend - rstart, rstart, 1, iss[0]));
11239:   PetscCallMPI(MPI_Comm_free(&subcomm));
11240:   PetscFunctionReturn(PETSC_SUCCESS);
11241: }

11243: /*@
11244:   MatGalerkin - Constructs the coarse grid problem matrix via Galerkin projection.

11246:   If the interpolation and restriction operators are the same, uses `MatPtAP()`.
11247:   If they are not the same, uses `MatMatMatMult()`.

11249:   Once the coarse grid problem is constructed, correct for interpolation operators
11250:   that are not of full rank, which can legitimately happen in the case of non-nested
11251:   geometric multigrid.

11253:   Input Parameters:
11254: + restrct     - restriction operator
11255: . dA          - fine grid matrix
11256: . interpolate - interpolation operator
11257: . reuse       - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
11258: - fill        - expected fill, use `PETSC_DETERMINE` or `PETSC_DETERMINE` if you do not have a good estimate

11260:   Output Parameter:
11261: . A - the Galerkin coarse matrix

11263:   Options Database Key:
11264: . -pc_mg_galerkin (both|pmat|mat|none) - for what matrices the Galerkin process should be used

11266:   Level: developer

11268:   Note:
11269:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

11271: .seealso: [](ch_matrices), `Mat`, `MatPtAP()`, `MatMatMatMult()`
11272: @*/
11273: PetscErrorCode MatGalerkin(Mat restrct, Mat dA, Mat interpolate, MatReuse reuse, PetscReal fill, Mat *A)
11274: {
11275:   IS  zerorows;
11276:   Vec diag;

11278:   PetscFunctionBegin;
11279:   PetscCheck(reuse != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");
11280:   /* Construct the coarse grid matrix */
11281:   if (interpolate == restrct) {
11282:     PetscCall(MatPtAP(dA, interpolate, reuse, fill, A));
11283:   } else {
11284:     PetscCall(MatMatMatMult(restrct, dA, interpolate, reuse, fill, A));
11285:   }

11287:   /* If the interpolation matrix is not of full rank, A will have zero rows.
11288:      This can legitimately happen in the case of non-nested geometric multigrid.
11289:      In that event, we set the rows of the matrix to the rows of the identity,
11290:      ignoring the equations (as the RHS will also be zero). */

11292:   PetscCall(MatFindZeroRows(*A, &zerorows));

11294:   if (zerorows != NULL) { /* if there are any zero rows */
11295:     PetscCall(MatCreateVecs(*A, &diag, NULL));
11296:     PetscCall(MatGetDiagonal(*A, diag));
11297:     PetscCall(VecISSet(diag, zerorows, 1.0));
11298:     PetscCall(MatDiagonalSet(*A, diag, INSERT_VALUES));
11299:     PetscCall(VecDestroy(&diag));
11300:     PetscCall(ISDestroy(&zerorows));
11301:   }
11302:   PetscFunctionReturn(PETSC_SUCCESS);
11303: }

11305: /*@C
11306:   MatSetOperation - Allows user to set a matrix operation for any matrix type

11308:   Logically Collective

11310:   Input Parameters:
11311: + mat - the matrix
11312: . op  - the name of the operation
11313: - f   - the function that provides the operation

11315:   Level: developer

11317:   Example Usage:
11318: .vb
11319:   extern PetscErrorCode usermult(Mat, Vec, Vec);

11321:   PetscCall(MatCreateXXX(comm, ..., &A));
11322:   PetscCall(MatSetOperation(A, MATOP_MULT, (PetscErrorCodeFn *)usermult));
11323: .ve

11325:   Notes:
11326:   See the file `include/petscmat.h` for a complete list of matrix
11327:   operations, which all have the form MATOP_<OPERATION>, where
11328:   <OPERATION> is the name (in all capital letters) of the
11329:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11331:   All user-provided functions (except for `MATOP_DESTROY`) should have the same calling
11332:   sequence as the usual matrix interface routines, since they
11333:   are intended to be accessed via the usual matrix interface
11334:   routines, e.g.,
11335: .vb
11336:   MatMult(Mat, Vec, Vec) -> usermult(Mat, Vec, Vec)
11337: .ve

11339:   In particular each function MUST return `PETSC_SUCCESS` on success and
11340:   nonzero on failure.

11342:   This routine is distinct from `MatShellSetOperation()` in that it can be called on any matrix type.

11344: .seealso: [](ch_matrices), `Mat`, `MatGetOperation()`, `MatCreateShell()`, `MatShellSetContext()`, `MatShellSetOperation()`
11345: @*/
11346: PetscErrorCode MatSetOperation(Mat mat, MatOperation op, PetscErrorCodeFn *f)
11347: {
11348:   PetscFunctionBegin;
11350:   if (op == MATOP_VIEW && !mat->ops->viewnative && f != (PetscErrorCodeFn *)mat->ops->view) mat->ops->viewnative = mat->ops->view;
11351:   (((PetscErrorCodeFn **)mat->ops)[op]) = f;
11352:   PetscFunctionReturn(PETSC_SUCCESS);
11353: }

11355: /*@C
11356:   MatGetOperation - Gets a matrix operation for any matrix type.

11358:   Not Collective

11360:   Input Parameters:
11361: + mat - the matrix
11362: - op  - the name of the operation

11364:   Output Parameter:
11365: . f - the function that provides the operation

11367:   Level: developer

11369:   Example Usage:
11370: .vb
11371:   PetscErrorCode (*usermult)(Mat, Vec, Vec);

11373:   MatGetOperation(A, MATOP_MULT, (PetscErrorCodeFn **)&usermult);
11374: .ve

11376:   Notes:
11377:   See the file `include/petscmat.h` for a complete list of matrix
11378:   operations, which all have the form MATOP_<OPERATION>, where
11379:   <OPERATION> is the name (in all capital letters) of the
11380:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11382:   This routine is distinct from `MatShellGetOperation()` in that it can be called on any matrix type.

11384: .seealso: [](ch_matrices), `Mat`, `MatSetOperation()`, `MatCreateShell()`, `MatShellGetContext()`, `MatShellGetOperation()`
11385: @*/
11386: PetscErrorCode MatGetOperation(Mat mat, MatOperation op, PetscErrorCodeFn **f)
11387: {
11388:   PetscFunctionBegin;
11390:   *f = (((PetscErrorCodeFn **)mat->ops)[op]);
11391:   PetscFunctionReturn(PETSC_SUCCESS);
11392: }

11394: /*@
11395:   MatHasOperation - Determines whether the given matrix supports the particular operation.

11397:   Not Collective

11399:   Input Parameters:
11400: + mat - the matrix
11401: - op  - the operation, for example, `MATOP_GET_DIAGONAL`

11403:   Output Parameter:
11404: . has - either `PETSC_TRUE` or `PETSC_FALSE`

11406:   Level: advanced

11408:   Note:
11409:   See `MatSetOperation()` for additional discussion on naming convention and usage of `op`.

11411: .seealso: [](ch_matrices), `Mat`, `MatCreateShell()`, `MatGetOperation()`, `MatSetOperation()`
11412: @*/
11413: PetscErrorCode MatHasOperation(Mat mat, MatOperation op, PetscBool *has)
11414: {
11415:   PetscFunctionBegin;
11417:   PetscAssertPointer(has, 3);
11418:   if (mat->ops->hasoperation) {
11419:     PetscUseTypeMethod(mat, hasoperation, op, has);
11420:   } else {
11421:     if (((void **)mat->ops)[op]) *has = PETSC_TRUE;
11422:     else {
11423:       *has = PETSC_FALSE;
11424:       if (op == MATOP_CREATE_SUBMATRIX) {
11425:         PetscMPIInt size;

11427:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
11428:         if (size == 1) PetscCall(MatHasOperation(mat, MATOP_CREATE_SUBMATRICES, has));
11429:       }
11430:     }
11431:   }
11432:   PetscFunctionReturn(PETSC_SUCCESS);
11433: }

11435: /*@
11436:   MatHasCongruentLayouts - Determines whether the rows and columns layouts of the matrix are congruent

11438:   Collective

11440:   Input Parameter:
11441: . mat - the matrix

11443:   Output Parameter:
11444: . cong - either `PETSC_TRUE` or `PETSC_FALSE`

11446:   Level: beginner

11448: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatSetSizes()`, `PetscLayout`
11449: @*/
11450: PetscErrorCode MatHasCongruentLayouts(Mat mat, PetscBool *cong)
11451: {
11452:   PetscFunctionBegin;
11455:   PetscAssertPointer(cong, 2);
11456:   if (!mat->rmap || !mat->cmap) {
11457:     *cong = mat->rmap == mat->cmap ? PETSC_TRUE : PETSC_FALSE;
11458:     PetscFunctionReturn(PETSC_SUCCESS);
11459:   }
11460:   if (mat->congruentlayouts == PETSC_DECIDE) { /* first time we compare rows and cols layouts */
11461:     PetscCall(PetscLayoutSetUp(mat->rmap));
11462:     PetscCall(PetscLayoutSetUp(mat->cmap));
11463:     PetscCall(PetscLayoutCompare(mat->rmap, mat->cmap, cong));
11464:     if (*cong) mat->congruentlayouts = 1;
11465:     else mat->congruentlayouts = 0;
11466:   } else *cong = mat->congruentlayouts ? PETSC_TRUE : PETSC_FALSE;
11467:   PetscFunctionReturn(PETSC_SUCCESS);
11468: }

11470: PetscErrorCode MatSetInf(Mat A)
11471: {
11472:   PetscFunctionBegin;
11473:   PetscUseTypeMethod(A, setinf);
11474:   PetscFunctionReturn(PETSC_SUCCESS);
11475: }

11477: /*@
11478:   MatCreateGraph - create a scalar matrix (that is a matrix with one vertex for each block vertex in the original matrix), for use in graph algorithms
11479:   and possibly removes small values from the graph structure.

11481:   Collective

11483:   Input Parameters:
11484: + A       - the matrix
11485: . sym     - `PETSC_TRUE` indicates that the graph should be symmetrized
11486: . scale   - `PETSC_TRUE` indicates that the graph edge weights should be symmetrically scaled with the diagonal entry
11487: . filter  - filter value - < 0: does nothing; == 0: removes only 0.0 entries; otherwise: removes entries with abs(entries) <= value
11488: . num_idx - size of 'index' array
11489: - index   - array of block indices to use for graph strength of connection weight

11491:   Output Parameter:
11492: . graph - the resulting graph

11494:   Level: advanced

11496: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PCGAMG`
11497: @*/
11498: PetscErrorCode MatCreateGraph(Mat A, PetscBool sym, PetscBool scale, PetscReal filter, PetscInt num_idx, PetscInt index[], Mat *graph)
11499: {
11500:   PetscFunctionBegin;
11504:   PetscAssertPointer(graph, 7);
11505:   PetscCall(PetscLogEventBegin(MAT_CreateGraph, A, 0, 0, 0));
11506:   PetscUseTypeMethod(A, creategraph, sym, scale, filter, num_idx, index, graph);
11507:   PetscCall(PetscLogEventEnd(MAT_CreateGraph, A, 0, 0, 0));
11508:   PetscFunctionReturn(PETSC_SUCCESS);
11509: }

11511: /*@
11512:   MatEliminateZeros - eliminate the nondiagonal zero entries in place from the nonzero structure of a sparse `Mat` in place,
11513:   meaning the same memory is used for the matrix, and no new memory is allocated.

11515:   Collective

11517:   Input Parameters:
11518: + A    - the matrix
11519: - keep - if for a given row of `A`, the diagonal coefficient is zero, indicates whether it should be left in the structure or eliminated as well

11521:   Level: intermediate

11523:   Developer Note:
11524:   The entries in the sparse matrix data structure are shifted to fill in the unneeded locations in the data. Thus the end
11525:   of the arrays in the data structure are unneeded.

11527: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateGraph()`, `MatFilter()`
11528: @*/
11529: PetscErrorCode MatEliminateZeros(Mat A, PetscBool keep)
11530: {
11531:   PetscFunctionBegin;
11533:   PetscUseTypeMethod(A, eliminatezeros, keep);
11534:   PetscFunctionReturn(PETSC_SUCCESS);
11535: }

11537: /*@C
11538:   MatGetCurrentMemType - Get the memory location of the matrix

11540:   Not Collective, but the result will be the same on all MPI processes

11542:   Input Parameter:
11543: . A - the matrix whose memory type we are checking

11545:   Output Parameter:
11546: . m - the memory type

11548:   Level: intermediate

11550: .seealso: [](ch_matrices), `Mat`, `MatBoundToCPU()`, `PetscMemType`
11551: @*/
11552: PetscErrorCode MatGetCurrentMemType(Mat A, PetscMemType *m)
11553: {
11554:   PetscFunctionBegin;
11556:   PetscAssertPointer(m, 2);
11557:   if (A->ops->getcurrentmemtype) PetscUseTypeMethod(A, getcurrentmemtype, m);
11558:   else *m = PETSC_MEMTYPE_HOST;
11559:   PetscFunctionReturn(PETSC_SUCCESS);
11560: }