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: . -name [viewertype][:...] - option name and values. See `PetscObjectViewFromOptions()` for the possible arguments

1019:   Level: intermediate

1021: .seealso: [](ch_matrices), `Mat`, `MatView()`, `PetscObjectViewFromOptions()`, `MatCreate()`
1022: @*/
1023: PetscErrorCode MatViewFromOptions(Mat A, PetscObject obj, const char name[])
1024: {
1025:   PetscFunctionBegin;
1027: #if !defined(PETSC_HAVE_THREADSAFETY)
1028:   if (insidematview) PetscFunctionReturn(PETSC_SUCCESS);
1029: #endif
1030:   PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
1031:   PetscFunctionReturn(PETSC_SUCCESS);
1032: }

1034: /*@
1035:   MatView - display information about a matrix in a variety ways

1037:   Collective on viewer

1039:   Input Parameters:
1040: + mat    - the matrix
1041: - viewer - visualization context

1043:   Options Database Keys:
1044: + -mat_view ::ascii_info         - Prints info on matrix at conclusion of `MatAssemblyEnd()`
1045: . -mat_view ::ascii_info_detail  - Prints more detailed info
1046: . -mat_view                      - Prints matrix in ASCII format
1047: . -mat_view ::ascii_matlab       - Prints matrix in MATLAB format
1048: . -mat_view draw                 - PetscDraws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
1049: . -display name                  - Sets display name (default is host)
1050: . -draw_pause sec                - Sets number of seconds to pause after display
1051: . -mat_view socket               - Sends matrix to socket, can be accessed from MATLAB (see Users-Manual: ch_matlab for details)
1052: . -viewer_socket_machine machine - -
1053: . -viewer_socket_port port       - -
1054: . -mat_view binary               - save matrix to file in binary format
1055: - -viewer_binary_filename name   - -

1057:   Level: beginner

1059:   Notes:
1060:   The available visualization contexts include
1061: +    `PETSC_VIEWER_STDOUT_SELF`   - for sequential matrices
1062: .    `PETSC_VIEWER_STDOUT_WORLD`  - for parallel matrices created on `PETSC_COMM_WORLD`
1063: .    `PETSC_VIEWER_STDOUT_`(comm) - for matrices created on MPI communicator comm
1064: -     `PETSC_VIEWER_DRAW_WORLD`   - graphical display of nonzero structure

1066:   The user can open alternative visualization contexts with
1067: +    `PetscViewerASCIIOpen()`  - Outputs matrix to a specified file
1068: .    `PetscViewerBinaryOpen()` - Outputs matrix in binary to a  specified file; corresponding input uses `MatLoad()`
1069: .    `PetscViewerDrawOpen()`   - Outputs nonzero matrix nonzero structure to an X window display
1070: -    `PetscViewerSocketOpen()` - Outputs matrix to Socket viewer, `PETSCVIEWERSOCKET`. Only the `MATSEQDENSE` and `MATAIJ` types support this viewer.

1072:   The user can call `PetscViewerPushFormat()` to specify the output
1073:   format of ASCII printed objects (when using `PETSC_VIEWER_STDOUT_SELF`,
1074:   `PETSC_VIEWER_STDOUT_WORLD` and `PetscViewerASCIIOpen()`).  Available formats include
1075: +    `PETSC_VIEWER_DEFAULT`           - default, prints matrix contents
1076: .    `PETSC_VIEWER_ASCII_MATLAB`      - prints matrix contents in MATLAB format
1077: .    `PETSC_VIEWER_ASCII_DENSE`       - prints entire matrix including zeros
1078: .    `PETSC_VIEWER_ASCII_COMMON`      - prints matrix contents, using a sparse  format common among all matrix types
1079: .    `PETSC_VIEWER_ASCII_IMPL`        - prints matrix contents, using an implementation-specific format (which is in many cases the same as the default)
1080: .    `PETSC_VIEWER_ASCII_INFO`        - prints basic information about the matrix size and structure (not the matrix entries)
1081: -    `PETSC_VIEWER_ASCII_INFO_DETAIL` - prints more detailed information about the matrix nonzero structure (still not vector or matrix entries)

1083:   The ASCII viewers are only recommended for small matrices on at most a moderate number of processes,
1084:   the program will seemingly hang and take hours for larger matrices, for larger matrices one should use the binary format.

1086:   In the debugger you can do "call MatView(mat,0)" to display the matrix. (The same holds for any PETSc object viewer).

1088:   See the manual page for `MatLoad()` for the exact format of the binary file when the binary
1089:   viewer is used.

1091:   See share/petsc/matlab/PetscBinaryRead.m for a MATLAB code that can read in the binary file when the binary
1092:   viewer is used and lib/petsc/bin/PetscBinaryIO.py for loading them into Python.

1094:   One can use `-mat_view draw -draw_pause -1` to pause the graphical display of matrix nonzero structure,
1095:   and then use the following mouse functions.
1096: .vb
1097:   left mouse: zoom in
1098:   middle mouse: zoom out
1099:   right mouse: continue with the simulation
1100: .ve

1102: .seealso: [](ch_matrices), `Mat`, `PetscViewerPushFormat()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewer`,
1103:           `PetscViewerSocketOpen()`, `PetscViewerBinaryOpen()`, `MatLoad()`, `MatViewFromOptions()`
1104: @*/
1105: PetscErrorCode MatView(Mat mat, PetscViewer viewer)
1106: {
1107:   PetscInt          rows, cols, rbs, cbs;
1108:   PetscBool         isascii, isstring, issaws;
1109:   PetscViewerFormat format;
1110:   PetscMPIInt       size;

1112:   PetscFunctionBegin;
1115:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)mat), &viewer));

1118:   PetscCall(PetscViewerGetFormat(viewer, &format));
1119:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)viewer), &size));
1120:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);

1122: #if !defined(PETSC_HAVE_THREADSAFETY)
1123:   insidematview++;
1124: #endif
1125:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
1126:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
1127:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
1128:   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");

1130:   PetscCall(PetscLogEventBegin(MAT_View, mat, viewer, 0, 0));
1131:   if (isascii) {
1132:     if (!mat->preallocated) {
1133:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been preallocated yet\n"));
1134: #if !defined(PETSC_HAVE_THREADSAFETY)
1135:       insidematview--;
1136: #endif
1137:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1138:       PetscFunctionReturn(PETSC_SUCCESS);
1139:     }
1140:     if (!mat->assembled) {
1141:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been assembled yet\n"));
1142: #if !defined(PETSC_HAVE_THREADSAFETY)
1143:       insidematview--;
1144: #endif
1145:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1146:       PetscFunctionReturn(PETSC_SUCCESS);
1147:     }
1148:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)mat, viewer));
1149:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1150:       MatNullSpace nullsp, transnullsp;

1152:       PetscCall(PetscViewerASCIIPushTab(viewer));
1153:       PetscCall(MatGetSize(mat, &rows, &cols));
1154:       PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
1155:       if (rbs != 1 || cbs != 1) {
1156:         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" : ""));
1157:         else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT ", bs=%" PetscInt_FMT "%s\n", rows, cols, rbs, mat->bsizes ? " variable blocks set" : ""));
1158:       } else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", rows, cols));
1159:       if (mat->factortype) {
1160:         MatSolverType solver;
1161:         PetscCall(MatFactorGetSolverType(mat, &solver));
1162:         PetscCall(PetscViewerASCIIPrintf(viewer, "package used to perform factorization: %s\n", solver));
1163:       }
1164:       if (mat->ops->getinfo) {
1165:         PetscBool is_constant_or_diagonal;

1167:         // Don't print nonzero information for constant or diagonal matrices, it just adds noise to the output
1168:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &is_constant_or_diagonal, MATCONSTANTDIAGONAL, MATDIAGONAL, ""));
1169:         if (!is_constant_or_diagonal) {
1170:           MatInfo info;

1172:           PetscCall(MatGetInfo(mat, MAT_GLOBAL_SUM, &info));
1173:           PetscCall(PetscViewerASCIIPrintf(viewer, "total: nonzeros=%.f, allocated nonzeros=%.f\n", info.nz_used, info.nz_allocated));
1174:           if (!mat->factortype) PetscCall(PetscViewerASCIIPrintf(viewer, "total number of mallocs used during MatSetValues calls=%" PetscInt_FMT "\n", (PetscInt)info.mallocs));
1175:         }
1176:       }
1177:       PetscCall(MatGetNullSpace(mat, &nullsp));
1178:       PetscCall(MatGetTransposeNullSpace(mat, &transnullsp));
1179:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached null space\n"));
1180:       if (transnullsp && transnullsp != nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached transposed null space\n"));
1181:       PetscCall(MatGetNearNullSpace(mat, &nullsp));
1182:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached near null space\n"));
1183:       PetscCall(PetscViewerASCIIPushTab(viewer));
1184:       PetscCall(MatProductView(mat, viewer));
1185:       PetscCall(PetscViewerASCIIPopTab(viewer));
1186:       if (mat->bsizes && format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1187:         IS tmp;

1189:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)viewer), mat->nblocks, mat->bsizes, PETSC_USE_POINTER, &tmp));
1190:         PetscCall(PetscObjectSetName((PetscObject)tmp, "Block Sizes"));
1191:         PetscCall(PetscViewerASCIIPushTab(viewer));
1192:         PetscCall(ISView(tmp, viewer));
1193:         PetscCall(PetscViewerASCIIPopTab(viewer));
1194:         PetscCall(ISDestroy(&tmp));
1195:       }
1196:     }
1197:   } else if (issaws) {
1198: #if defined(PETSC_HAVE_SAWS)
1199:     PetscMPIInt rank;

1201:     PetscCall(PetscObjectName((PetscObject)mat));
1202:     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
1203:     if (!((PetscObject)mat)->amsmem && rank == 0) PetscCall(PetscObjectViewSAWs((PetscObject)mat, viewer));
1204: #endif
1205:   } else if (isstring) {
1206:     const char *type;
1207:     PetscCall(MatGetType(mat, &type));
1208:     PetscCall(PetscViewerStringSPrintf(viewer, " MatType: %-7.7s", type));
1209:     PetscTryTypeMethod(mat, view, viewer);
1210:   }
1211:   if ((format == PETSC_VIEWER_NATIVE || format == PETSC_VIEWER_LOAD_BALANCE) && mat->ops->viewnative) {
1212:     PetscCall(PetscViewerASCIIPushTab(viewer));
1213:     PetscUseTypeMethod(mat, viewnative, viewer);
1214:     PetscCall(PetscViewerASCIIPopTab(viewer));
1215:   } else if (mat->ops->view) {
1216:     PetscCall(PetscViewerASCIIPushTab(viewer));
1217:     PetscUseTypeMethod(mat, view, viewer);
1218:     PetscCall(PetscViewerASCIIPopTab(viewer));
1219:   }
1220:   if (isascii) {
1221:     PetscCall(PetscViewerGetFormat(viewer, &format));
1222:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerASCIIPopTab(viewer));
1223:   }
1224:   PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1225: #if !defined(PETSC_HAVE_THREADSAFETY)
1226:   insidematview--;
1227: #endif
1228:   PetscFunctionReturn(PETSC_SUCCESS);
1229: }

1231: #if defined(PETSC_USE_DEBUG)
1232: #include <../src/sys/totalview/tv_data_display.h>
1233: PETSC_UNUSED static int TV_display_type(const struct _p_Mat *mat)
1234: {
1235:   TV_add_row("Local rows", "int", &mat->rmap->n);
1236:   TV_add_row("Local columns", "int", &mat->cmap->n);
1237:   TV_add_row("Global rows", "int", &mat->rmap->N);
1238:   TV_add_row("Global columns", "int", &mat->cmap->N);
1239:   TV_add_row("Typename", TV_ascii_string_type, ((PetscObject)mat)->type_name);
1240:   return TV_format_OK;
1241: }
1242: #endif

1244: /*@
1245:   MatLoad - Loads a matrix that has been stored in binary/HDF5 format
1246:   with `MatView()`.  The matrix format is determined from the options database.
1247:   Generates a parallel MPI matrix if the communicator has more than one
1248:   processor.  The default matrix type is `MATAIJ`.

1250:   Collective

1252:   Input Parameters:
1253: + mat    - the newly loaded matrix, this needs to have been created with `MatCreate()`
1254:             or some related function before a call to `MatLoad()`
1255: - viewer - `PETSCVIEWERBINARY`/`PETSCVIEWERHDF5` file viewer

1257:   Options Database Key:
1258: . -matload_block_size bs - set block size

1260:   Level: beginner

1262:   Notes:
1263:   If the `Mat` type has not yet been given then `MATAIJ` is used, call `MatSetFromOptions()` on the
1264:   `Mat` before calling this routine if you wish to set it from the options database.

1266:   `MatLoad()` automatically loads into the options database any options
1267:   given in the file filename.info where filename is the name of the file
1268:   that was passed to the `PetscViewerBinaryOpen()`. The options in the info
1269:   file will be ignored if you use the -viewer_binary_skip_info option.

1271:   If the type or size of mat is not set before a call to `MatLoad()`, PETSc
1272:   sets the default matrix type AIJ and sets the local and global sizes.
1273:   If type and/or size is already set, then the same are used.

1275:   In parallel, each processor can load a subset of rows (or the
1276:   entire matrix).  This routine is especially useful when a large
1277:   matrix is stored on disk and only part of it is desired on each
1278:   processor.  For example, a parallel solver may access only some of
1279:   the rows from each processor.  The algorithm used here reads
1280:   relatively small blocks of data rather than reading the entire
1281:   matrix and then subsetting it.

1283:   Viewer's `PetscViewerType` must be either `PETSCVIEWERBINARY` or `PETSCVIEWERHDF5`.
1284:   Such viewer can be created using `PetscViewerBinaryOpen()` or `PetscViewerHDF5Open()`,
1285:   or the sequence like
1286: .vb
1287:     `PetscViewer` v;
1288:     `PetscViewerCreate`(`PETSC_COMM_WORLD`,&v);
1289:     `PetscViewerSetType`(v,`PETSCVIEWERBINARY`);
1290:     `PetscViewerSetFromOptions`(v);
1291:     `PetscViewerFileSetMode`(v,`FILE_MODE_READ`);
1292:     `PetscViewerFileSetName`(v,"datafile");
1293: .ve
1294:   The optional `PetscViewerSetFromOptions()` call allows overriding `PetscViewerSetType()` using the option
1295: .vb
1296:   -viewer_type {binary, hdf5}
1297: .ve

1299:   See the example src/ksp/ksp/tutorials/ex27.c with the first approach,
1300:   and src/mat/tutorials/ex10.c with the second approach.

1302:   In case of `PETSCVIEWERBINARY`, a native PETSc binary format is used. Each of the blocks
1303:   is read onto MPI rank 0 and then shipped to its destination MPI rank, one after another.
1304:   Multiple objects, both matrices and vectors, can be stored within the same file.
1305:   Their `PetscObject` name is ignored; they are loaded in the order of their storage.

1307:   Most users should not need to know the details of the binary storage
1308:   format, since `MatLoad()` and `MatView()` completely hide these details.
1309:   But for anyone who is interested, the standard binary matrix storage
1310:   format is

1312: .vb
1313:     PetscInt    MAT_FILE_CLASSID
1314:     PetscInt    number of rows
1315:     PetscInt    number of columns
1316:     PetscInt    total number of nonzeros
1317:     PetscInt    *number nonzeros in each row
1318:     PetscInt    *column indices of all nonzeros (starting index is zero)
1319:     PetscScalar *values of all nonzeros
1320: .ve
1321:   If PETSc was not configured with `--with-64-bit-indices` then only `MATMPIAIJ` matrices with more than `PETSC_INT_MAX` non-zeros can be
1322:   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
1323:   case will not fit in a (32-bit) `PetscInt` the value `PETSC_INT_MAX` is used for the header entry `total number of nonzeros`.

1325:   PETSc automatically does the byte swapping for
1326:   machines that store the bytes reversed. Thus if you write your own binary
1327:   read/write routines you have to swap the bytes; see `PetscBinaryRead()`
1328:   and `PetscBinaryWrite()` to see how this may be done.

1330:   In case of `PETSCVIEWERHDF5`, a parallel HDF5 reader is used.
1331:   Each processor's chunk is loaded independently by its owning MPI process.
1332:   Multiple objects, both matrices and vectors, can be stored within the same file.
1333:   They are looked up by their PetscObject name.

1335:   As the MATLAB MAT-File Version 7.3 format is also a HDF5 flavor, we decided to use
1336:   by default the same structure and naming of the AIJ arrays and column count
1337:   within the HDF5 file. This means that a MAT file saved with -v7.3 flag, e.g.
1338: .vb
1339:   save example.mat A b -v7.3
1340: .ve
1341:   can be directly read by this routine (see Reference 1 for details).

1343:   Depending on your MATLAB version, this format might be a default,
1344:   otherwise you can set it as default in Preferences.

1346:   Unless -nocompression flag is used to save the file in MATLAB,
1347:   PETSc must be configured with ZLIB package.

1349:   See also examples src/mat/tutorials/ex10.c and src/ksp/ksp/tutorials/ex27.c

1351:   This reader currently supports only real `MATSEQAIJ`, `MATMPIAIJ`, `MATSEQDENSE` and `MATMPIDENSE` matrices for `PETSCVIEWERHDF5`

1353:   Corresponding `MatView()` is not yet implemented.

1355:   The loaded matrix is actually a transpose of the original one in MATLAB,
1356:   unless you push `PETSC_VIEWER_HDF5_MAT` format (see examples above).
1357:   With this format, matrix is automatically transposed by PETSc,
1358:   unless the matrix is marked as SPD or symmetric
1359:   (see `MatSetOption()`, `MAT_SPD`, `MAT_SYMMETRIC`).

1361:   See MATLAB Documentation on `save()`, <https://www.mathworks.com/help/matlab/ref/save.html#btox10b-1-version>

1363: .seealso: [](ch_matrices), `Mat`, `PetscViewerBinaryOpen()`, `PetscViewerSetType()`, `MatView()`, `VecLoad()`
1364:  @*/
1365: PetscErrorCode MatLoad(Mat mat, PetscViewer viewer)
1366: {
1367:   PetscBool flg;

1369:   PetscFunctionBegin;

1373:   if (!((PetscObject)mat)->type_name) PetscCall(MatSetType(mat, MATAIJ));

1375:   flg = PETSC_FALSE;
1376:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_symmetric", &flg, NULL));
1377:   if (flg) {
1378:     PetscCall(MatSetOption(mat, MAT_SYMMETRIC, PETSC_TRUE));
1379:     PetscCall(MatSetOption(mat, MAT_SYMMETRY_ETERNAL, PETSC_TRUE));
1380:   }
1381:   flg = PETSC_FALSE;
1382:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_spd", &flg, NULL));
1383:   if (flg) PetscCall(MatSetOption(mat, MAT_SPD, PETSC_TRUE));

1385:   PetscCall(PetscLogEventBegin(MAT_Load, mat, viewer, 0, 0));
1386:   PetscUseTypeMethod(mat, load, viewer);
1387:   PetscCall(PetscLogEventEnd(MAT_Load, mat, viewer, 0, 0));
1388:   PetscFunctionReturn(PETSC_SUCCESS);
1389: }

1391: static PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1392: {
1393:   Mat_Redundant *redund = *redundant;

1395:   PetscFunctionBegin;
1396:   if (redund) {
1397:     if (redund->matseq) { /* via MatCreateSubMatrices()  */
1398:       PetscCall(ISDestroy(&redund->isrow));
1399:       PetscCall(ISDestroy(&redund->iscol));
1400:       PetscCall(MatDestroySubMatrices(1, &redund->matseq));
1401:     } else {
1402:       PetscCall(PetscFree2(redund->send_rank, redund->recv_rank));
1403:       PetscCall(PetscFree(redund->sbuf_j));
1404:       PetscCall(PetscFree(redund->sbuf_a));
1405:       for (PetscInt i = 0; i < redund->nrecvs; i++) {
1406:         PetscCall(PetscFree(redund->rbuf_j[i]));
1407:         PetscCall(PetscFree(redund->rbuf_a[i]));
1408:       }
1409:       PetscCall(PetscFree4(redund->sbuf_nz, redund->rbuf_nz, redund->rbuf_j, redund->rbuf_a));
1410:     }

1412:     PetscCall(PetscCommDestroy(&redund->subcomm));
1413:     PetscCall(PetscFree(redund));
1414:   }
1415:   PetscFunctionReturn(PETSC_SUCCESS);
1416: }

1418: /*@
1419:   MatDestroy - Frees space taken by a matrix.

1421:   Collective

1423:   Input Parameter:
1424: . A - the matrix

1426:   Level: beginner

1428:   Developer Note:
1429:   Some special arrays of matrices are not destroyed in this routine but instead by the routines called by
1430:   `MatDestroySubMatrices()`. Thus one must be sure that any changes here must also be made in those routines.
1431:   `MatHeaderMerge()` and `MatHeaderReplace()` also manipulate the data in the `Mat` object and likely need changes
1432:   if changes are needed here.

1434: .seealso: [](ch_matrices), `Mat`, `MatCreate()`
1435: @*/
1436: PetscErrorCode MatDestroy(Mat *A)
1437: {
1438:   PetscFunctionBegin;
1439:   if (!*A) PetscFunctionReturn(PETSC_SUCCESS);
1441:   if (--((PetscObject)*A)->refct > 0) {
1442:     *A = NULL;
1443:     PetscFunctionReturn(PETSC_SUCCESS);
1444:   }

1446:   /* if memory was published with SAWs then destroy it */
1447:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*A));
1448:   PetscTryTypeMethod(*A, destroy);

1450:   PetscCall(PetscFree((*A)->factorprefix));
1451:   PetscCall(PetscFree((*A)->defaultvectype));
1452:   PetscCall(PetscFree((*A)->defaultrandtype));
1453:   PetscCall(PetscFree((*A)->bsizes));
1454:   PetscCall(PetscFree((*A)->solvertype));
1455:   for (PetscInt i = 0; i < MAT_FACTOR_NUM_TYPES; i++) PetscCall(PetscFree((*A)->preferredordering[i]));
1456:   if ((*A)->redundant && (*A)->redundant->matseq[0] == *A) (*A)->redundant->matseq[0] = NULL;
1457:   PetscCall(MatDestroy_Redundant(&(*A)->redundant));
1458:   PetscCall(MatProductClear(*A));
1459:   PetscCall(MatNullSpaceDestroy(&(*A)->nullsp));
1460:   PetscCall(MatNullSpaceDestroy(&(*A)->transnullsp));
1461:   PetscCall(MatNullSpaceDestroy(&(*A)->nearnullsp));
1462:   PetscCall(MatDestroy(&(*A)->schur));
1463:   PetscCall(VecDestroy(&(*A)->dot_vec));
1464:   PetscCall(PetscLayoutDestroy(&(*A)->rmap));
1465:   PetscCall(PetscLayoutDestroy(&(*A)->cmap));
1466:   PetscCall(PetscHeaderDestroy(A));
1467:   PetscFunctionReturn(PETSC_SUCCESS);
1468: }

1470: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1471: /*@
1472:   MatSetValues - Inserts or adds a block of values into a matrix.
1473:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1474:   MUST be called after all calls to `MatSetValues()` have been completed.

1476:   Not Collective

1478:   Input Parameters:
1479: + mat  - the matrix
1480: . m    - the number of rows
1481: . idxm - the global indices of the rows
1482: . n    - the number of columns
1483: . idxn - the global indices of the columns
1484: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1485:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1486: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1488:   Level: beginner

1490:   Notes:
1491:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1492:   options cannot be mixed without intervening calls to the assembly
1493:   routines.

1495:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1496:   as well as in C.

1498:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1499:   simply ignored. This allows easily inserting element stiffness matrices
1500:   with homogeneous Dirichlet boundary conditions that you don't want represented
1501:   in the matrix.

1503:   Efficiency Alert:
1504:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1505:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1507:   Fortran Notes:
1508:   If any of `idxm`, `idxn`, and `v` are scalars pass them using, for example,
1509: .vb
1510:   call MatSetValues(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
1511: .ve

1513:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1515:   Developer Note:
1516:   This is labeled with C so does not automatically generate Fortran stubs and interfaces
1517:   because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.

1519: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1520:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1521: @*/
1522: PetscErrorCode MatSetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
1523: {
1524:   PetscFunctionBeginHot;
1527:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1528:   PetscAssertPointer(idxm, 3);
1529:   PetscAssertPointer(idxn, 5);
1530:   MatCheckPreallocated(mat, 1);

1532:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
1533:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");

1535:   if (PetscDefined(USE_DEBUG)) {
1536:     PetscInt i, j;

1538:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1539:     if (v) {
1540:       for (i = 0; i < m; i++) {
1541:         for (j = 0; j < n; j++) {
1542:           if (mat->erroriffailure && PetscIsInfOrNanScalar(v[i * n + j]))
1543: #if defined(PETSC_USE_COMPLEX)
1544:             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]);
1545: #else
1546:             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]);
1547: #endif
1548:         }
1549:       }
1550:     }
1551:     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);
1552:     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);
1553:   }

1555:   if (mat->assembled) {
1556:     mat->was_assembled = PETSC_TRUE;
1557:     mat->assembled     = PETSC_FALSE;
1558:   }
1559:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1560:   PetscUseTypeMethod(mat, setvalues, m, idxm, n, idxn, v, addv);
1561:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1562:   PetscFunctionReturn(PETSC_SUCCESS);
1563: }

1565: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1566: /*@
1567:   MatSetValuesIS - Inserts or adds a block of values into a matrix using an `IS` to indicate the rows and columns
1568:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1569:   MUST be called after all calls to `MatSetValues()` have been completed.

1571:   Not Collective

1573:   Input Parameters:
1574: + mat  - the matrix
1575: . ism  - the rows to provide
1576: . isn  - the columns to provide
1577: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1578:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1579: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1581:   Level: beginner

1583:   Notes:
1584:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1586:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1587:   options cannot be mixed without intervening calls to the assembly
1588:   routines.

1590:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1591:   as well as in C.

1593:   Negative indices may be passed in `ism` and `isn`, these rows and columns are
1594:   simply ignored. This allows easily inserting element stiffness matrices
1595:   with homogeneous Dirichlet boundary conditions that you don't want represented
1596:   in the matrix.

1598:   Fortran Note:
1599:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1601:   Efficiency Alert:
1602:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1603:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1605:   This is currently not optimized for any particular `ISType`

1607: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatSetValues()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1608:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1609: @*/
1610: PetscErrorCode MatSetValuesIS(Mat mat, IS ism, IS isn, const PetscScalar v[], InsertMode addv)
1611: {
1612:   PetscInt        m, n;
1613:   const PetscInt *rows, *cols;

1615:   PetscFunctionBeginHot;
1617:   PetscCall(ISGetIndices(ism, &rows));
1618:   PetscCall(ISGetIndices(isn, &cols));
1619:   PetscCall(ISGetLocalSize(ism, &m));
1620:   PetscCall(ISGetLocalSize(isn, &n));
1621:   PetscCall(MatSetValues(mat, m, rows, n, cols, v, addv));
1622:   PetscCall(ISRestoreIndices(ism, &rows));
1623:   PetscCall(ISRestoreIndices(isn, &cols));
1624:   PetscFunctionReturn(PETSC_SUCCESS);
1625: }

1627: /*@
1628:   MatSetValuesRowLocal - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1629:   values into a matrix

1631:   Not Collective

1633:   Input Parameters:
1634: + mat - the matrix
1635: . row - the (block) row to set
1636: - 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.
1637:         See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1639:   Level: intermediate

1641:   Notes:
1642:   The values, `v`, are column-oriented (for the block version) and sorted

1644:   All the nonzero values in `row` must be provided

1646:   The matrix must have previously had its column indices set, likely by having been assembled.

1648:   `row` must belong to this MPI process

1650:   Fortran Note:
1651:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1653: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1654:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetValuesRow()`, `MatSetLocalToGlobalMapping()`
1655: @*/
1656: PetscErrorCode MatSetValuesRowLocal(Mat mat, PetscInt row, const PetscScalar v[])
1657: {
1658:   PetscInt globalrow;

1660:   PetscFunctionBegin;
1663:   PetscAssertPointer(v, 3);
1664:   PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, 1, &row, &globalrow));
1665:   PetscCall(MatSetValuesRow(mat, globalrow, v));
1666:   PetscFunctionReturn(PETSC_SUCCESS);
1667: }

1669: /*@
1670:   MatSetValuesRow - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1671:   values into a matrix

1673:   Not Collective

1675:   Input Parameters:
1676: + mat - the matrix
1677: . row - the (block) row to set
1678: - 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

1680:   Level: advanced

1682:   Notes:
1683:   The values, `v`, are column-oriented for the block version.

1685:   All the nonzeros in `row` must be provided

1687:   THE MATRIX MUST HAVE PREVIOUSLY HAD ITS COLUMN INDICES SET. IT IS RARE THAT THIS ROUTINE IS USED, usually `MatSetValues()` is used.

1689:   `row` must belong to this process

1691: .seealso: [](ch_matrices), `Mat`, `MatSetValues()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1692:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1693: @*/
1694: PetscErrorCode MatSetValuesRow(Mat mat, PetscInt row, const PetscScalar v[])
1695: {
1696:   PetscFunctionBeginHot;
1699:   MatCheckPreallocated(mat, 1);
1700:   PetscAssertPointer(v, 3);
1701:   PetscCheck(mat->insertmode != ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add and insert values");
1702:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1703:   mat->insertmode = INSERT_VALUES;

1705:   if (mat->assembled) {
1706:     mat->was_assembled = PETSC_TRUE;
1707:     mat->assembled     = PETSC_FALSE;
1708:   }
1709:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1710:   PetscUseTypeMethod(mat, setvaluesrow, row, v);
1711:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1712:   PetscFunctionReturn(PETSC_SUCCESS);
1713: }

1715: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1716: /*@
1717:   MatSetValuesStencil - Inserts or adds a block of values into a matrix.
1718:   Using structured grid indexing

1720:   Not Collective

1722:   Input Parameters:
1723: + mat  - the matrix
1724: . m    - number of rows being entered
1725: . idxm - grid coordinates (and component number when dof > 1) for matrix rows being entered
1726: . n    - number of columns being entered
1727: . idxn - grid coordinates (and component number when dof > 1) for matrix columns being entered
1728: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1729:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1730: - addv - either `ADD_VALUES` to add to existing entries at that location or `INSERT_VALUES` to replace existing entries with new values

1732:   Level: beginner

1734:   Notes:
1735:   By default the values, `v`, are row-oriented.  See `MatSetOption()` for other options.

1737:   Calls to `MatSetValuesStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1738:   options cannot be mixed without intervening calls to the assembly
1739:   routines.

1741:   The grid coordinates are across the entire grid, not just the local portion

1743:   `MatSetValuesStencil()` uses 0-based row and column numbers in Fortran
1744:   as well as in C.

1746:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1748:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1749:   or call `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1751:   The columns and rows in the stencil passed in MUST be contained within the
1752:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1753:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1754:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1755:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1757:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
1758:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
1759:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
1760:   `DM_BOUNDARY_PERIODIC` boundary type.

1762:   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
1763:   a single value per point) you can skip filling those indices.

1765:   Inspired by the structured grid interface to the HYPRE package
1766:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1768:   Fortran Note:
1769:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1771:   Efficiency Alert:
1772:   The routine `MatSetValuesBlockedStencil()` may offer much better efficiency
1773:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1775: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1776:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`
1777: @*/
1778: PetscErrorCode MatSetValuesStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1779: {
1780:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1781:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1782:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1784:   PetscFunctionBegin;
1785:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1788:   PetscAssertPointer(idxm, 3);
1789:   PetscAssertPointer(idxn, 5);

1791:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1792:     jdxm = buf;
1793:     jdxn = buf + m;
1794:   } else {
1795:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1796:     jdxm = bufm;
1797:     jdxn = bufn;
1798:   }
1799:   for (i = 0; i < m; i++) {
1800:     for (j = 0; j < 3 - sdim; j++) dxm++;
1801:     tmp = *dxm++ - starts[0];
1802:     for (j = 0; j < dim - 1; j++) {
1803:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1804:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1805:     }
1806:     if (mat->stencil.noc) dxm++;
1807:     jdxm[i] = tmp;
1808:   }
1809:   for (i = 0; i < n; i++) {
1810:     for (j = 0; j < 3 - sdim; j++) dxn++;
1811:     tmp = *dxn++ - starts[0];
1812:     for (j = 0; j < dim - 1; j++) {
1813:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1814:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1815:     }
1816:     if (mat->stencil.noc) dxn++;
1817:     jdxn[i] = tmp;
1818:   }
1819:   PetscCall(MatSetValuesLocal(mat, m, jdxm, n, jdxn, v, addv));
1820:   PetscCall(PetscFree2(bufm, bufn));
1821:   PetscFunctionReturn(PETSC_SUCCESS);
1822: }

1824: /*@
1825:   MatSetValuesBlockedStencil - Inserts or adds a block of values into a matrix.
1826:   Using structured grid indexing

1828:   Not Collective

1830:   Input Parameters:
1831: + mat  - the matrix
1832: . m    - number of rows being entered
1833: . idxm - grid coordinates for matrix rows being entered
1834: . n    - number of columns being entered
1835: . idxn - grid coordinates for matrix columns being entered
1836: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1837:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1838: - addv - either `ADD_VALUES` to add to existing entries or `INSERT_VALUES` to replace existing entries with new values

1840:   Level: beginner

1842:   Notes:
1843:   By default the values, `v`, are row-oriented and unsorted.
1844:   See `MatSetOption()` for other options.

1846:   Calls to `MatSetValuesBlockedStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1847:   options cannot be mixed without intervening calls to the assembly
1848:   routines.

1850:   The grid coordinates are across the entire grid, not just the local portion

1852:   `MatSetValuesBlockedStencil()` uses 0-based row and column numbers in Fortran
1853:   as well as in C.

1855:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1857:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1858:   or call `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1860:   The columns and rows in the stencil passed in MUST be contained within the
1861:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1862:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1863:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1864:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1866:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1867:   simply ignored. This allows easily inserting element stiffness matrices
1868:   with homogeneous Dirichlet boundary conditions that you don't want represented
1869:   in the matrix.

1871:   Inspired by the structured grid interface to the HYPRE package
1872:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1874:   Fortran Notes:
1875:   `idxm` and `idxn` should be declared as
1876: .vb
1877:     MatStencil idxm(4,m),idxn(4,n)
1878: .ve
1879:   and the values inserted using
1880: .vb
1881:     idxm(MatStencil_i,1) = i
1882:     idxm(MatStencil_j,1) = j
1883:     idxm(MatStencil_k,1) = k
1884:    etc
1885: .ve

1887:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1889: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1890:           `MatSetValues()`, `MatSetValuesStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`,
1891:           `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`
1892: @*/
1893: PetscErrorCode MatSetValuesBlockedStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1894: {
1895:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1896:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1897:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1899:   PetscFunctionBegin;
1900:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1903:   PetscAssertPointer(idxm, 3);
1904:   PetscAssertPointer(idxn, 5);
1905:   PetscAssertPointer(v, 6);

1907:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1908:     jdxm = buf;
1909:     jdxn = buf + m;
1910:   } else {
1911:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1912:     jdxm = bufm;
1913:     jdxn = bufn;
1914:   }
1915:   for (i = 0; i < m; i++) {
1916:     for (j = 0; j < 3 - sdim; j++) dxm++;
1917:     tmp = *dxm++ - starts[0];
1918:     for (j = 0; j < sdim - 1; j++) {
1919:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1920:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1921:     }
1922:     dxm++;
1923:     jdxm[i] = tmp;
1924:   }
1925:   for (i = 0; i < n; i++) {
1926:     for (j = 0; j < 3 - sdim; j++) dxn++;
1927:     tmp = *dxn++ - starts[0];
1928:     for (j = 0; j < sdim - 1; j++) {
1929:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1930:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1931:     }
1932:     dxn++;
1933:     jdxn[i] = tmp;
1934:   }
1935:   PetscCall(MatSetValuesBlockedLocal(mat, m, jdxm, n, jdxn, v, addv));
1936:   PetscCall(PetscFree2(bufm, bufn));
1937:   PetscFunctionReturn(PETSC_SUCCESS);
1938: }

1940: /*@
1941:   MatSetStencil - Sets the grid information for setting values into a matrix via
1942:   `MatSetValuesStencil()`

1944:   Not Collective

1946:   Input Parameters:
1947: + mat    - the matrix
1948: . dim    - dimension of the grid 1, 2, or 3
1949: . dims   - number of grid points in x, y, and z direction, including ghost points on your processor
1950: . starts - starting point of ghost nodes on your processor in x, y, and z direction
1951: - dof    - number of degrees of freedom per node

1953:   Level: beginner

1955:   Notes:
1956:   Inspired by the structured grid interface to the HYPRE package
1957:   (www.llnl.gov/CASC/hyper)

1959:   For matrices generated with `DMCreateMatrix()` this routine is automatically called and so not needed by the
1960:   user.

1962: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1963:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetValuesStencil()`
1964: @*/
1965: PetscErrorCode MatSetStencil(Mat mat, PetscInt dim, const PetscInt dims[], const PetscInt starts[], PetscInt dof)
1966: {
1967:   PetscFunctionBegin;
1969:   PetscAssertPointer(dims, 3);
1970:   PetscAssertPointer(starts, 4);

1972:   mat->stencil.dim = dim + (dof > 1);
1973:   for (PetscInt i = 0; i < dim; i++) {
1974:     mat->stencil.dims[i]   = dims[dim - i - 1]; /* copy the values in backwards */
1975:     mat->stencil.starts[i] = starts[dim - i - 1];
1976:   }
1977:   mat->stencil.dims[dim]   = dof;
1978:   mat->stencil.starts[dim] = 0;
1979:   mat->stencil.noc         = (PetscBool)(dof == 1);
1980:   PetscFunctionReturn(PETSC_SUCCESS);
1981: }

1983: /*@
1984:   MatSetValuesBlocked - Inserts or adds a block of values into a matrix.

1986:   Not Collective

1988:   Input Parameters:
1989: + mat  - the matrix
1990: . m    - the number of block rows
1991: . idxm - the global block indices
1992: . n    - the number of block columns
1993: . idxn - the global block indices
1994: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1995:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1996: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` replaces existing entries with new values

1998:   Level: intermediate

2000:   Notes:
2001:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call
2002:   MatXXXXSetPreallocation() or `MatSetUp()` before using this routine.

2004:   The `m` and `n` count the NUMBER of blocks in the row direction and column direction,
2005:   NOT the total number of rows/columns; for example, if the block size is 2 and
2006:   you are passing in values for rows 2,3,4,5  then `m` would be 2 (not 4).
2007:   The values in `idxm` would be 1 2; that is the first index for each block divided by
2008:   the block size.

2010:   You must call `MatSetBlockSize()` when constructing this matrix (before
2011:   preallocating it).

2013:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2015:   Calls to `MatSetValuesBlocked()` with the `INSERT_VALUES` and `ADD_VALUES`
2016:   options cannot be mixed without intervening calls to the assembly
2017:   routines.

2019:   `MatSetValuesBlocked()` uses 0-based row and column numbers in Fortran
2020:   as well as in C.

2022:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
2023:   simply ignored. This allows easily inserting element stiffness matrices
2024:   with homogeneous Dirichlet boundary conditions that you don't want represented
2025:   in the matrix.

2027:   Each time an entry is set within a sparse matrix via `MatSetValues()`,
2028:   internal searching must be done to determine where to place the
2029:   data in the matrix storage space.  By instead inserting blocks of
2030:   entries via `MatSetValuesBlocked()`, the overhead of matrix assembly is
2031:   reduced.

2033:   Example:
2034: .vb
2035:    Suppose m=n=2 and block size(bs) = 2 The array is

2037:    1  2  | 3  4
2038:    5  6  | 7  8
2039:    - - - | - - -
2040:    9  10 | 11 12
2041:    13 14 | 15 16

2043:    v[] should be passed in like
2044:    v[] = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

2046:   If you are not using row-oriented storage of v (that is you called MatSetOption(mat,MAT_ROW_ORIENTED,PETSC_FALSE)) then
2047:    v[] = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16]
2048: .ve

2050:   Fortran Notes:
2051:   If any of `idmx`, `idxn`, and `v` are scalars pass them using, for example,
2052: .vb
2053:   call MatSetValuesBlocked(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
2054: .ve

2056:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2058: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesBlockedLocal()`
2059: @*/
2060: PetscErrorCode MatSetValuesBlocked(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
2061: {
2062:   PetscFunctionBeginHot;
2065:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2066:   PetscAssertPointer(idxm, 3);
2067:   PetscAssertPointer(idxn, 5);
2068:   MatCheckPreallocated(mat, 1);
2069:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2070:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2071:   if (PetscDefined(USE_DEBUG)) {
2072:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2073:     PetscCheck(mat->ops->setvaluesblocked || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2074:   }
2075:   if (PetscDefined(USE_DEBUG)) {
2076:     PetscInt rbs, cbs, M, N, i;
2077:     PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
2078:     PetscCall(MatGetSize(mat, &M, &N));
2079:     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);
2080:     for (i = 0; i < n; i++)
2081:       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);
2082:   }
2083:   if (mat->assembled) {
2084:     mat->was_assembled = PETSC_TRUE;
2085:     mat->assembled     = PETSC_FALSE;
2086:   }
2087:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2088:   if (mat->ops->setvaluesblocked) PetscUseTypeMethod(mat, setvaluesblocked, m, idxm, n, idxn, v, addv);
2089:   else {
2090:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *iidxm, *iidxn;
2091:     PetscInt i, j, bs, cbs;

2093:     PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
2094:     if ((m * bs + n * cbs) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2095:       iidxm = buf;
2096:       iidxn = buf + m * bs;
2097:     } else {
2098:       PetscCall(PetscMalloc2(m * bs, &bufr, n * cbs, &bufc));
2099:       iidxm = bufr;
2100:       iidxn = bufc;
2101:     }
2102:     for (i = 0; i < m; i++) {
2103:       for (j = 0; j < bs; j++) iidxm[i * bs + j] = bs * idxm[i] + j;
2104:     }
2105:     if (m != n || bs != cbs || idxm != idxn) {
2106:       for (i = 0; i < n; i++) {
2107:         for (j = 0; j < cbs; j++) iidxn[i * cbs + j] = cbs * idxn[i] + j;
2108:       }
2109:     } else iidxn = iidxm;
2110:     PetscCall(MatSetValues(mat, m * bs, iidxm, n * cbs, iidxn, v, addv));
2111:     PetscCall(PetscFree2(bufr, bufc));
2112:   }
2113:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2114:   PetscFunctionReturn(PETSC_SUCCESS);
2115: }

2117: /*@
2118:   MatGetValues - Gets a block of local values from a matrix.

2120:   Not Collective; can only return values that are owned by the give process

2122:   Input Parameters:
2123: + mat  - the matrix
2124: . v    - a logically two-dimensional array for storing the values
2125: . m    - the number of rows
2126: . idxm - the  global indices of the rows
2127: . n    - the number of columns
2128: - idxn - the global indices of the columns

2130:   Level: advanced

2132:   Notes:
2133:   The user must allocate space (m*n `PetscScalar`s) for the values, `v`.
2134:   The values, `v`, are then returned in a row-oriented format,
2135:   analogous to that used by default in `MatSetValues()`.

2137:   `MatGetValues()` uses 0-based row and column numbers in
2138:   Fortran as well as in C.

2140:   `MatGetValues()` requires that the matrix has been assembled
2141:   with `MatAssemblyBegin()`/`MatAssemblyEnd()`.  Thus, calls to
2142:   `MatSetValues()` and `MatGetValues()` CANNOT be made in succession
2143:   without intermediate matrix assembly.

2145:   Negative row or column indices will be ignored and those locations in `v` will be
2146:   left unchanged.

2148:   For the standard row-based matrix formats, `idxm` can only contain rows owned by the requesting MPI process.
2149:   That is, rows with global index greater than or equal to rstart and less than rend where rstart and rend are obtainable
2150:   from `MatGetOwnershipRange`(mat,&rstart,&rend).

2152: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatSetValues()`, `MatGetOwnershipRange()`, `MatGetValuesLocal()`, `MatGetValue()`
2153: @*/
2154: PetscErrorCode MatGetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], PetscScalar v[])
2155: {
2156:   PetscFunctionBegin;
2159:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS);
2160:   PetscAssertPointer(idxm, 3);
2161:   PetscAssertPointer(idxn, 5);
2162:   PetscAssertPointer(v, 6);
2163:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2164:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2165:   MatCheckPreallocated(mat, 1);

2167:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2168:   PetscUseTypeMethod(mat, getvalues, m, idxm, n, idxn, v);
2169:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2170:   PetscFunctionReturn(PETSC_SUCCESS);
2171: }

2173: /*@
2174:   MatGetValuesLocal - retrieves values from certain locations in a matrix using the local numbering of the indices
2175:   defined previously by `MatSetLocalToGlobalMapping()`

2177:   Not Collective

2179:   Input Parameters:
2180: + mat  - the matrix
2181: . nrow - number of rows
2182: . irow - the row local indices
2183: . ncol - number of columns
2184: - icol - the column local indices

2186:   Output Parameter:
2187: . y - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2188:       See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2190:   Level: advanced

2192:   Notes:
2193:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine.

2195:   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,
2196:   are greater than or equal to rstart and less than rend where rstart and rend are obtainable from `MatGetOwnershipRange`(mat,&rstart,&rend). One can
2197:   determine if the resulting global row associated with the local row r is owned by the requesting MPI process by applying the `ISLocalToGlobalMapping` set
2198:   with `MatSetLocalToGlobalMapping()`.

2200: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2201:           `MatSetValuesLocal()`, `MatGetValues()`
2202: @*/
2203: PetscErrorCode MatGetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], PetscScalar y[])
2204: {
2205:   PetscFunctionBeginHot;
2208:   MatCheckPreallocated(mat, 1);
2209:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to retrieve */
2210:   PetscAssertPointer(irow, 3);
2211:   PetscAssertPointer(icol, 5);
2212:   if (PetscDefined(USE_DEBUG)) {
2213:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2214:     PetscCheck(mat->ops->getvalueslocal || mat->ops->getvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2215:   }
2216:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2217:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2218:   if (mat->ops->getvalueslocal) PetscUseTypeMethod(mat, getvalueslocal, nrow, irow, ncol, icol, y);
2219:   else {
2220:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *irowm, *icolm;
2221:     if ((nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2222:       irowm = buf;
2223:       icolm = buf + nrow;
2224:     } else {
2225:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2226:       irowm = bufr;
2227:       icolm = bufc;
2228:     }
2229:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global row mapping (See MatSetLocalToGlobalMapping()).");
2230:     PetscCheck(mat->cmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global column mapping (See MatSetLocalToGlobalMapping()).");
2231:     PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, irowm));
2232:     PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, icolm));
2233:     PetscCall(MatGetValues(mat, nrow, irowm, ncol, icolm, y));
2234:     PetscCall(PetscFree2(bufr, bufc));
2235:   }
2236:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2237:   PetscFunctionReturn(PETSC_SUCCESS);
2238: }

2240: /*@
2241:   MatSetValuesBatch - Adds (`ADD_VALUES`) many blocks of values into a matrix at once. The blocks must all be square and
2242:   the same size. Currently, this can only be called once and creates the given matrix.

2244:   Not Collective

2246:   Input Parameters:
2247: + mat  - the matrix
2248: . nb   - the number of blocks
2249: . bs   - the number of rows (and columns) in each block
2250: . rows - a concatenation of the rows for each block
2251: - v    - a concatenation of logically two-dimensional arrays of values

2253:   Level: advanced

2255:   Notes:
2256:   `MatSetPreallocationCOO()` and `MatSetValuesCOO()` may be a better way to provide the values

2258:   In the future, we will extend this routine to handle rectangular blocks, and to allow multiple calls for a given matrix.

2260: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
2261:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
2262: @*/
2263: PetscErrorCode MatSetValuesBatch(Mat mat, PetscInt nb, PetscInt bs, PetscInt rows[], const PetscScalar v[])
2264: {
2265:   PetscFunctionBegin;
2268:   PetscAssertPointer(rows, 4);
2269:   PetscAssertPointer(v, 5);
2270:   PetscAssert(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

2272:   PetscCall(PetscLogEventBegin(MAT_SetValuesBatch, mat, 0, 0, 0));
2273:   if (mat->ops->setvaluesbatch) PetscUseTypeMethod(mat, setvaluesbatch, nb, bs, rows, v);
2274:   else {
2275:     for (PetscInt b = 0; b < nb; ++b) PetscCall(MatSetValues(mat, bs, &rows[b * bs], bs, &rows[b * bs], &v[b * bs * bs], ADD_VALUES));
2276:   }
2277:   PetscCall(PetscLogEventEnd(MAT_SetValuesBatch, mat, 0, 0, 0));
2278:   PetscFunctionReturn(PETSC_SUCCESS);
2279: }

2281: /*@
2282:   MatSetLocalToGlobalMapping - Sets a local-to-global numbering for use by
2283:   the routine `MatSetValuesLocal()` to allow users to insert matrix entries
2284:   using a local (per-processor) numbering.

2286:   Not Collective

2288:   Input Parameters:
2289: + x        - the matrix
2290: . rmapping - row mapping created with `ISLocalToGlobalMappingCreate()` or `ISLocalToGlobalMappingCreateIS()`
2291: - cmapping - column mapping

2293:   Level: intermediate

2295:   Note:
2296:   If the matrix is obtained with `DMCreateMatrix()` then this may already have been called on the matrix

2298: .seealso: [](ch_matrices), `Mat`, `DM`, `DMCreateMatrix()`, `MatGetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesLocal()`, `MatGetValuesLocal()`
2299: @*/
2300: PetscErrorCode MatSetLocalToGlobalMapping(Mat x, ISLocalToGlobalMapping rmapping, ISLocalToGlobalMapping cmapping)
2301: {
2302:   PetscFunctionBegin;
2307:   if (x->ops->setlocaltoglobalmapping) PetscUseTypeMethod(x, setlocaltoglobalmapping, rmapping, cmapping);
2308:   else {
2309:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->rmap, rmapping));
2310:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->cmap, cmapping));
2311:   }
2312:   PetscFunctionReturn(PETSC_SUCCESS);
2313: }

2315: /*@
2316:   MatGetLocalToGlobalMapping - Gets the local-to-global numbering set by `MatSetLocalToGlobalMapping()`

2318:   Not Collective

2320:   Input Parameter:
2321: . A - the matrix

2323:   Output Parameters:
2324: + rmapping - row mapping
2325: - cmapping - column mapping

2327:   Level: advanced

2329: .seealso: [](ch_matrices), `Mat`, `MatSetLocalToGlobalMapping()`, `MatSetValuesLocal()`
2330: @*/
2331: PetscErrorCode MatGetLocalToGlobalMapping(Mat A, ISLocalToGlobalMapping *rmapping, ISLocalToGlobalMapping *cmapping)
2332: {
2333:   PetscFunctionBegin;
2336:   if (rmapping) {
2337:     PetscAssertPointer(rmapping, 2);
2338:     *rmapping = A->rmap->mapping;
2339:   }
2340:   if (cmapping) {
2341:     PetscAssertPointer(cmapping, 3);
2342:     *cmapping = A->cmap->mapping;
2343:   }
2344:   PetscFunctionReturn(PETSC_SUCCESS);
2345: }

2347: /*@
2348:   MatSetLayouts - Sets the `PetscLayout` objects for rows and columns of a matrix

2350:   Logically Collective

2352:   Input Parameters:
2353: + A    - the matrix
2354: . rmap - row layout
2355: - cmap - column layout

2357:   Level: advanced

2359:   Note:
2360:   The `PetscLayout` objects are usually created automatically for the matrix so this routine rarely needs to be called.

2362: .seealso: [](ch_matrices), `Mat`, `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatGetLayouts()`
2363: @*/
2364: PetscErrorCode MatSetLayouts(Mat A, PetscLayout rmap, PetscLayout cmap)
2365: {
2366:   PetscFunctionBegin;
2368:   PetscCall(PetscLayoutReference(rmap, &A->rmap));
2369:   PetscCall(PetscLayoutReference(cmap, &A->cmap));
2370:   PetscFunctionReturn(PETSC_SUCCESS);
2371: }

2373: /*@
2374:   MatGetLayouts - Gets the `PetscLayout` objects for rows and columns

2376:   Not Collective

2378:   Input Parameter:
2379: . A - the matrix

2381:   Output Parameters:
2382: + rmap - row layout
2383: - cmap - column layout

2385:   Level: advanced

2387: .seealso: [](ch_matrices), `Mat`, [Matrix Layouts](sec_matlayout), `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatSetLayouts()`
2388: @*/
2389: PetscErrorCode MatGetLayouts(Mat A, PetscLayout *rmap, PetscLayout *cmap)
2390: {
2391:   PetscFunctionBegin;
2394:   if (rmap) {
2395:     PetscAssertPointer(rmap, 2);
2396:     *rmap = A->rmap;
2397:   }
2398:   if (cmap) {
2399:     PetscAssertPointer(cmap, 3);
2400:     *cmap = A->cmap;
2401:   }
2402:   PetscFunctionReturn(PETSC_SUCCESS);
2403: }

2405: /*@
2406:   MatSetValuesLocal - Inserts or adds values into certain locations of a matrix,
2407:   using a local numbering of the rows and columns.

2409:   Not Collective

2411:   Input Parameters:
2412: + mat  - the matrix
2413: . nrow - number of rows
2414: . irow - the row local indices
2415: . ncol - number of columns
2416: . icol - the column local indices
2417: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2418:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2419: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2421:   Level: intermediate

2423:   Notes:
2424:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine

2426:   Calls to `MatSetValuesLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2427:   options cannot be mixed without intervening calls to the assembly
2428:   routines.

2430:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2431:   MUST be called after all calls to `MatSetValuesLocal()` have been completed.

2433:   Fortran Notes:
2434:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2435: .vb
2436:   call MatSetValuesLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2437: .ve

2439:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2441: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2442:           `MatGetValuesLocal()`
2443: @*/
2444: PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2445: {
2446:   PetscFunctionBeginHot;
2449:   MatCheckPreallocated(mat, 1);
2450:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2451:   PetscAssertPointer(irow, 3);
2452:   PetscAssertPointer(icol, 5);
2453:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2454:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2455:   if (PetscDefined(USE_DEBUG)) {
2456:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2457:     PetscCheck(mat->ops->setvalueslocal || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2458:   }

2460:   if (mat->assembled) {
2461:     mat->was_assembled = PETSC_TRUE;
2462:     mat->assembled     = PETSC_FALSE;
2463:   }
2464:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2465:   if (mat->ops->setvalueslocal) PetscUseTypeMethod(mat, setvalueslocal, nrow, irow, ncol, icol, y, addv);
2466:   else {
2467:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2468:     const PetscInt *irowm, *icolm;

2470:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2471:       bufr  = buf;
2472:       bufc  = buf + nrow;
2473:       irowm = bufr;
2474:       icolm = bufc;
2475:     } else {
2476:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2477:       irowm = bufr;
2478:       icolm = bufc;
2479:     }
2480:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, bufr));
2481:     else irowm = irow;
2482:     if (mat->cmap->mapping) {
2483:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, bufc));
2484:       else icolm = irowm;
2485:     } else icolm = icol;
2486:     PetscCall(MatSetValues(mat, nrow, irowm, ncol, icolm, y, addv));
2487:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2488:   }
2489:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2490:   PetscFunctionReturn(PETSC_SUCCESS);
2491: }

2493: /*@
2494:   MatSetValuesBlockedLocal - Inserts or adds values into certain locations of a matrix,
2495:   using a local ordering of the nodes a block at a time.

2497:   Not Collective

2499:   Input Parameters:
2500: + mat  - the matrix
2501: . nrow - number of rows
2502: . irow - the row local indices
2503: . ncol - number of columns
2504: . icol - the column local indices
2505: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2506:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2507: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2509:   Level: intermediate

2511:   Notes:
2512:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetBlockSize()` and `MatSetLocalToGlobalMapping()`
2513:   before using this routineBefore calling `MatSetValuesLocal()`, the user must first set the

2515:   Calls to `MatSetValuesBlockedLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2516:   options cannot be mixed without intervening calls to the assembly
2517:   routines.

2519:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2520:   MUST be called after all calls to `MatSetValuesBlockedLocal()` have been completed.

2522:   Fortran Notes:
2523:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2524: .vb
2525:   call MatSetValuesBlockedLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2526: .ve

2528:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2530: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`,
2531:           `MatSetValuesLocal()`, `MatSetValuesBlocked()`
2532: @*/
2533: PetscErrorCode MatSetValuesBlockedLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2534: {
2535:   PetscFunctionBeginHot;
2538:   MatCheckPreallocated(mat, 1);
2539:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2540:   PetscAssertPointer(irow, 3);
2541:   PetscAssertPointer(icol, 5);
2542:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2543:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2544:   if (PetscDefined(USE_DEBUG)) {
2545:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2546:     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);
2547:   }

2549:   if (mat->assembled) {
2550:     mat->was_assembled = PETSC_TRUE;
2551:     mat->assembled     = PETSC_FALSE;
2552:   }
2553:   if (PetscUnlikelyDebug(mat->rmap->mapping)) { /* Condition on the mapping existing, because MatSetValuesBlockedLocal_IS does not require it to be set. */
2554:     PetscInt irbs, rbs;
2555:     PetscCall(MatGetBlockSizes(mat, &rbs, NULL));
2556:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->rmap->mapping, &irbs));
2557:     PetscCheck(rbs == irbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different row block sizes! mat %" PetscInt_FMT ", row l2g map %" PetscInt_FMT, rbs, irbs);
2558:   }
2559:   if (PetscUnlikelyDebug(mat->cmap->mapping)) {
2560:     PetscInt icbs, cbs;
2561:     PetscCall(MatGetBlockSizes(mat, NULL, &cbs));
2562:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->cmap->mapping, &icbs));
2563:     PetscCheck(cbs == icbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different col block sizes! mat %" PetscInt_FMT ", col l2g map %" PetscInt_FMT, cbs, icbs);
2564:   }
2565:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2566:   if (mat->ops->setvaluesblockedlocal) PetscUseTypeMethod(mat, setvaluesblockedlocal, nrow, irow, ncol, icol, y, addv);
2567:   else {
2568:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2569:     const PetscInt *irowm, *icolm;

2571:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= ((PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf))) {
2572:       bufr  = buf;
2573:       bufc  = buf + nrow;
2574:       irowm = bufr;
2575:       icolm = bufc;
2576:     } else {
2577:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2578:       irowm = bufr;
2579:       icolm = bufc;
2580:     }
2581:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->rmap->mapping, nrow, irow, bufr));
2582:     else irowm = irow;
2583:     if (mat->cmap->mapping) {
2584:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->cmap->mapping, ncol, icol, bufc));
2585:       else icolm = irowm;
2586:     } else icolm = icol;
2587:     PetscCall(MatSetValuesBlocked(mat, nrow, irowm, ncol, icolm, y, addv));
2588:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2589:   }
2590:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2591:   PetscFunctionReturn(PETSC_SUCCESS);
2592: }

2594: /*@
2595:   MatMultDiagonalBlock - Computes the matrix-vector product, $y = Dx$. Where `D` is defined by the inode or block structure of the diagonal

2597:   Collective

2599:   Input Parameters:
2600: + mat - the matrix
2601: - x   - the vector to be multiplied

2603:   Output Parameter:
2604: . y - the result

2606:   Level: developer

2608:   Note:
2609:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2610:   call `MatMultDiagonalBlock`(A,y,y).

2612: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2613: @*/
2614: PetscErrorCode MatMultDiagonalBlock(Mat mat, Vec x, Vec y)
2615: {
2616:   PetscFunctionBegin;

2622:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2623:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2624:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2625:   MatCheckPreallocated(mat, 1);

2627:   PetscUseTypeMethod(mat, multdiagonalblock, x, y);
2628:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2629:   PetscFunctionReturn(PETSC_SUCCESS);
2630: }

2632: /*@
2633:   MatMult - Computes the matrix-vector product, $y = Ax$.

2635:   Neighbor-wise Collective

2637:   Input Parameters:
2638: + mat - the matrix
2639: - x   - the vector to be multiplied

2641:   Output Parameter:
2642: . y - the result

2644:   Level: beginner

2646:   Note:
2647:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2648:   call `MatMult`(A,y,y).

2650: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2651: @*/
2652: PetscErrorCode MatMult(Mat mat, Vec x, Vec y)
2653: {
2654:   PetscFunctionBegin;
2658:   VecCheckAssembled(x);
2660:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2661:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2662:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2663:   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);
2664:   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);
2665:   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);
2666:   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);
2667:   PetscCall(VecSetErrorIfLocked(y, 3));
2668:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2669:   MatCheckPreallocated(mat, 1);

2671:   PetscCall(VecLockReadPush(x));
2672:   PetscCall(PetscLogEventBegin(MAT_Mult, mat, x, y, 0));
2673:   PetscUseTypeMethod(mat, mult, x, y);
2674:   PetscCall(PetscLogEventEnd(MAT_Mult, mat, x, y, 0));
2675:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2676:   PetscCall(VecLockReadPop(x));
2677:   PetscFunctionReturn(PETSC_SUCCESS);
2678: }

2680: /*@
2681:   MatMultTranspose - Computes matrix transpose times a vector $y = A^T * x$.

2683:   Neighbor-wise Collective

2685:   Input Parameters:
2686: + mat - the matrix
2687: - x   - the vector to be multiplied

2689:   Output Parameter:
2690: . y - the result

2692:   Level: beginner

2694:   Notes:
2695:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2696:   call `MatMultTranspose`(A,y,y).

2698:   For complex numbers this does NOT compute the Hermitian (complex conjugate) transpose multiple,
2699:   use `MatMultHermitianTranspose()`

2701: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatMultHermitianTranspose()`, `MatTranspose()`
2702: @*/
2703: PetscErrorCode MatMultTranspose(Mat mat, Vec x, Vec y)
2704: {
2705:   PetscErrorCode (*op)(Mat, Vec, Vec) = NULL;

2707:   PetscFunctionBegin;
2711:   VecCheckAssembled(x);

2714:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2715:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2716:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2717:   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);
2718:   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);
2719:   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);
2720:   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);
2721:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2722:   MatCheckPreallocated(mat, 1);

2724:   if (!mat->ops->multtranspose) {
2725:     if (mat->symmetric == PETSC_BOOL3_TRUE && mat->ops->mult) op = mat->ops->mult;
2726:     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);
2727:   } else op = mat->ops->multtranspose;
2728:   PetscCall(PetscLogEventBegin(MAT_MultTranspose, mat, x, y, 0));
2729:   PetscCall(VecLockReadPush(x));
2730:   PetscCall((*op)(mat, x, y));
2731:   PetscCall(VecLockReadPop(x));
2732:   PetscCall(PetscLogEventEnd(MAT_MultTranspose, mat, x, y, 0));
2733:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2734:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2735:   PetscFunctionReturn(PETSC_SUCCESS);
2736: }

2738: /*@
2739:   MatMultHermitianTranspose - Computes matrix Hermitian-transpose times a vector $y = A^H * x$.

2741:   Neighbor-wise Collective

2743:   Input Parameters:
2744: + mat - the matrix
2745: - x   - the vector to be multiplied

2747:   Output Parameter:
2748: . y - the result

2750:   Level: beginner

2752:   Notes:
2753:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2754:   call `MatMultHermitianTranspose`(A,y,y).

2756:   Also called the conjugate transpose, complex conjugate transpose, or adjoint.

2758:   For real numbers `MatMultTranspose()` and `MatMultHermitianTranspose()` are identical.

2760: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultHermitianTransposeAdd()`, `MatMultTranspose()`
2761: @*/
2762: PetscErrorCode MatMultHermitianTranspose(Mat mat, Vec x, Vec y)
2763: {
2764:   PetscFunctionBegin;

2770:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2771:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2772:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2773:   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);
2774:   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);
2775:   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);
2776:   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);
2777:   MatCheckPreallocated(mat, 1);

2779:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTranspose, mat, x, y, 0));
2780: #if defined(PETSC_USE_COMPLEX)
2781:   if (mat->ops->multhermitiantranspose || (mat->hermitian == PETSC_BOOL3_TRUE && mat->ops->mult)) {
2782:     PetscCall(VecLockReadPush(x));
2783:     if (mat->ops->multhermitiantranspose) PetscUseTypeMethod(mat, multhermitiantranspose, x, y);
2784:     else PetscUseTypeMethod(mat, mult, x, y);
2785:     PetscCall(VecLockReadPop(x));
2786:   } else {
2787:     Vec w;
2788:     PetscCall(VecDuplicate(x, &w));
2789:     PetscCall(VecCopy(x, w));
2790:     PetscCall(VecConjugate(w));
2791:     PetscCall(MatMultTranspose(mat, w, y));
2792:     PetscCall(VecDestroy(&w));
2793:     PetscCall(VecConjugate(y));
2794:   }
2795:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2796: #else
2797:   PetscCall(MatMultTranspose(mat, x, y));
2798: #endif
2799:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTranspose, mat, x, y, 0));
2800:   PetscFunctionReturn(PETSC_SUCCESS);
2801: }

2803: /*@
2804:   MatMultAdd -  Computes $v3 = v2 + A * v1$.

2806:   Neighbor-wise Collective

2808:   Input Parameters:
2809: + mat - the matrix
2810: . v1  - the vector to be multiplied by `mat`
2811: - v2  - the vector to be added to the result

2813:   Output Parameter:
2814: . v3 - the result

2816:   Level: beginner

2818:   Note:
2819:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2820:   call `MatMultAdd`(A,v1,v2,v1).

2822: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMult()`, `MatMultTransposeAdd()`
2823: @*/
2824: PetscErrorCode MatMultAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2825: {
2826:   PetscFunctionBegin;

2833:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2834:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2835:   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);
2836:   /* 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);
2837:      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); */
2838:   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);
2839:   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);
2840:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2841:   MatCheckPreallocated(mat, 1);

2843:   PetscCall(PetscLogEventBegin(MAT_MultAdd, mat, v1, v2, v3));
2844:   PetscCall(VecLockReadPush(v1));
2845:   PetscUseTypeMethod(mat, multadd, v1, v2, v3);
2846:   PetscCall(VecLockReadPop(v1));
2847:   PetscCall(PetscLogEventEnd(MAT_MultAdd, mat, v1, v2, v3));
2848:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2849:   PetscFunctionReturn(PETSC_SUCCESS);
2850: }

2852: /*@
2853:   MatMultTransposeAdd - Computes $v3 = v2 + A^T * v1$.

2855:   Neighbor-wise Collective

2857:   Input Parameters:
2858: + mat - the matrix
2859: . v1  - the vector to be multiplied by the transpose of the matrix
2860: - v2  - the vector to be added to the result

2862:   Output Parameter:
2863: . v3 - the result

2865:   Level: beginner

2867:   Note:
2868:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2869:   call `MatMultTransposeAdd`(A,v1,v2,v1).

2871: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2872: @*/
2873: PetscErrorCode MatMultTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2874: {
2875:   PetscErrorCode (*op)(Mat, Vec, Vec, Vec) = (!mat->ops->multtransposeadd && mat->symmetric) ? mat->ops->multadd : mat->ops->multtransposeadd;

2877:   PetscFunctionBegin;

2884:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2885:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2886:   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);
2887:   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);
2888:   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);
2889:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2890:   PetscCheck(op, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2891:   MatCheckPreallocated(mat, 1);

2893:   PetscCall(PetscLogEventBegin(MAT_MultTransposeAdd, mat, v1, v2, v3));
2894:   PetscCall(VecLockReadPush(v1));
2895:   PetscCall((*op)(mat, v1, v2, v3));
2896:   PetscCall(VecLockReadPop(v1));
2897:   PetscCall(PetscLogEventEnd(MAT_MultTransposeAdd, mat, v1, v2, v3));
2898:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2899:   PetscFunctionReturn(PETSC_SUCCESS);
2900: }

2902: /*@
2903:   MatMultHermitianTransposeAdd - Computes $v3 = v2 + A^H * v1$.

2905:   Neighbor-wise Collective

2907:   Input Parameters:
2908: + mat - the matrix
2909: . v1  - the vector to be multiplied by the Hermitian transpose
2910: - v2  - the vector to be added to the result

2912:   Output Parameter:
2913: . v3 - the result

2915:   Level: beginner

2917:   Note:
2918:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2919:   call `MatMultHermitianTransposeAdd`(A,v1,v2,v1).

2921: .seealso: [](ch_matrices), `Mat`, `MatMultHermitianTranspose()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2922: @*/
2923: PetscErrorCode MatMultHermitianTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2924: {
2925:   PetscFunctionBegin;

2932:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2933:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2934:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2935:   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);
2936:   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);
2937:   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);
2938:   MatCheckPreallocated(mat, 1);

2940:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2941:   PetscCall(VecLockReadPush(v1));
2942:   if (mat->ops->multhermitiantransposeadd) PetscUseTypeMethod(mat, multhermitiantransposeadd, v1, v2, v3);
2943:   else {
2944:     Vec w, z;
2945:     PetscCall(VecDuplicate(v1, &w));
2946:     PetscCall(VecCopy(v1, w));
2947:     PetscCall(VecConjugate(w));
2948:     PetscCall(VecDuplicate(v3, &z));
2949:     PetscCall(MatMultTranspose(mat, w, z));
2950:     PetscCall(VecDestroy(&w));
2951:     PetscCall(VecConjugate(z));
2952:     if (v2 != v3) PetscCall(VecWAXPY(v3, 1.0, v2, z));
2953:     else PetscCall(VecAXPY(v3, 1.0, z));
2954:     PetscCall(VecDestroy(&z));
2955:   }
2956:   PetscCall(VecLockReadPop(v1));
2957:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2958:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2959:   PetscFunctionReturn(PETSC_SUCCESS);
2960: }

2962: PetscErrorCode MatADot_Default(Mat mat, Vec x, Vec y, PetscScalar *val)
2963: {
2964:   PetscFunctionBegin;
2965:   if (!mat->dot_vec) PetscCall(MatCreateVecs(mat, &mat->dot_vec, NULL));
2966:   PetscCall(MatMult(mat, x, mat->dot_vec));
2967:   PetscCall(VecDot(mat->dot_vec, y, val));
2968:   PetscFunctionReturn(PETSC_SUCCESS);
2969: }

2971: PetscErrorCode MatANorm_Default(Mat mat, Vec x, PetscReal *val)
2972: {
2973:   PetscScalar sval;

2975:   PetscFunctionBegin;
2976:   PetscCall(MatADot_Default(mat, x, x, &sval));
2977:   PetscCheck(PetscRealPart(sval) >= 0.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix argument is not positive definite");
2978:   PetscCheck(PetscAbsReal(PetscImaginaryPart(sval)) < 100 * PETSC_MACHINE_EPSILON, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix argument is not Hermitian");
2979:   *val = PetscSqrtReal(PetscRealPart(sval));
2980:   PetscFunctionReturn(PETSC_SUCCESS);
2981: }

2983: /*@
2984:   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)
2985:   positive definite.

2987:   Collective

2989:   Input Parameters:
2990: + mat - matrix used to define the inner product
2991: . x   - first vector
2992: - y   - second vector

2994:   Output Parameter:
2995: . val - the dot product with respect to `A`

2997:   Level: intermediate

2999:   Note:
3000:   For complex vectors, `MatADot()` computes
3001: $$
3002:   val = (x,y)_A = y^H A x,
3003: $$
3004:   where $y^H$ denotes the conjugate transpose of `y`. Note that this corresponds to the "mathematicians" complex
3005:   inner product where the SECOND argument gets the complex conjugate.

3007: .seealso: [](ch_matrices), `Mat`, `MatANorm()`, `VecDot()`, `VecNorm()`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`
3008: @*/
3009: PetscErrorCode MatADot(Mat mat, Vec x, Vec y, PetscScalar *val)
3010: {
3011:   PetscFunctionBegin;
3015:   VecCheckAssembled(x);
3017:   VecCheckAssembled(y);
3020:   PetscAssertPointer(val, 4);
3021:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3022:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3023:   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);
3024:   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);
3025:   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);
3026:   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);
3027:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
3028:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_TRUE));
3029:   MatCheckPreallocated(mat, 1);

3031:   PetscCall(VecLockReadPush(x));
3032:   PetscCall(VecLockReadPush(y));
3033:   PetscCall(PetscLogEventBegin(MAT_ADot, mat, x, y, 0));
3034:   PetscUseTypeMethod(mat, adot, x, y, val);
3035:   PetscCall(PetscLogEventEnd(MAT_ADot, mat, x, y, 0));
3036:   PetscCall(VecLockReadPop(y));
3037:   PetscCall(VecLockReadPop(x));
3038:   PetscFunctionReturn(PETSC_SUCCESS);
3039: }

3041: /*@
3042:   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)
3043:   positive definite.

3045:   Collective

3047:   Input Parameters:
3048: + mat - matrix used to define norm
3049: - x   - the vector to compute the norm of

3051:   Output Parameter:
3052: . val - the norm with respect to `A`

3054:   Level: intermediate

3056:   Note:
3057:   For complex vectors, `MatANorm()` computes
3058: $$
3059:   val = (x,x)_A^{1/2} = (x^H A x)^{1/2},
3060: $$
3061:   where $x^H$ denotes the conjugate transpose of `x`.

3063: .seealso: [](ch_matrices), `Mat`, `MatADot()`, `VecDot()`, `VecNorm()`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`
3064: @*/
3065: PetscErrorCode MatANorm(Mat mat, Vec x, PetscReal *val)
3066: {
3067:   PetscFunctionBegin;
3071:   VecCheckAssembled(x);
3073:   PetscAssertPointer(val, 3);
3074:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3075:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3076:   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);
3077:   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);
3078:   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);
3079:   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);
3080:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
3081:   MatCheckPreallocated(mat, 1);

3083:   PetscCall(VecLockReadPush(x));
3084:   PetscCall(PetscLogEventBegin(MAT_ANorm, mat, x, 0, 0));
3085:   PetscUseTypeMethod(mat, anorm, x, val);
3086:   PetscCall(PetscLogEventEnd(MAT_ANorm, mat, x, 0, 0));
3087:   PetscCall(VecLockReadPop(x));
3088:   PetscFunctionReturn(PETSC_SUCCESS);
3089: }

3091: /*@
3092:   MatGetFactorType - gets the type of factorization a matrix is

3094:   Not Collective

3096:   Input Parameter:
3097: . mat - the matrix

3099:   Output Parameter:
3100: . 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`

3102:   Level: intermediate

3104: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatSetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3105:           `MAT_FACTOR_ICC`, `MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3106: @*/
3107: PetscErrorCode MatGetFactorType(Mat mat, MatFactorType *t)
3108: {
3109:   PetscFunctionBegin;
3112:   PetscAssertPointer(t, 2);
3113:   *t = mat->factortype;
3114:   PetscFunctionReturn(PETSC_SUCCESS);
3115: }

3117: /*@
3118:   MatSetFactorType - sets the type of factorization a matrix is

3120:   Logically Collective

3122:   Input Parameters:
3123: + mat - the matrix
3124: - 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`

3126:   Level: intermediate

3128: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatGetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3129:           `MAT_FACTOR_ICC`, `MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3130: @*/
3131: PetscErrorCode MatSetFactorType(Mat mat, MatFactorType t)
3132: {
3133:   PetscFunctionBegin;
3136:   mat->factortype = t;
3137:   PetscFunctionReturn(PETSC_SUCCESS);
3138: }

3140: /*@
3141:   MatGetInfo - Returns information about matrix storage (number of
3142:   nonzeros, memory, etc.).

3144:   Collective if `MAT_GLOBAL_MAX` or `MAT_GLOBAL_SUM` is used as the flag

3146:   Input Parameters:
3147: + mat  - the matrix
3148: - 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)

3150:   Output Parameter:
3151: . info - matrix information context

3153:   Options Database Key:
3154: . -mat_view ::ascii_info - print matrix info to `PETSC_STDOUT`

3156:   Level: intermediate

3158:   Notes:
3159:   The `MatInfo` context contains a variety of matrix data, including
3160:   number of nonzeros allocated and used, number of mallocs during
3161:   matrix assembly, etc.  Additional information for factored matrices
3162:   is provided (such as the fill ratio, number of mallocs during
3163:   factorization, etc.).

3165:   Example:
3166:   See the file ${PETSC_DIR}/include/petscmat.h for a complete list of
3167:   data within the `MatInfo` context.  For example,
3168: .vb
3169:       MatInfo info;
3170:       Mat     A;
3171:       double  mal, nz_a, nz_u;

3173:       MatGetInfo(A, MAT_LOCAL, &info);
3174:       mal  = info.mallocs;
3175:       nz_a = info.nz_allocated;
3176: .ve

3178: .seealso: [](ch_matrices), `Mat`, `MatInfo`, `MatStashGetInfo()`
3179: @*/
3180: PetscErrorCode MatGetInfo(Mat mat, MatInfoType flag, MatInfo *info)
3181: {
3182:   PetscFunctionBegin;
3185:   PetscAssertPointer(info, 3);
3186:   MatCheckPreallocated(mat, 1);
3187:   PetscUseTypeMethod(mat, getinfo, flag, info);
3188:   PetscFunctionReturn(PETSC_SUCCESS);
3189: }

3191: /*
3192:    This is used by external packages where it is not easy to get the info from the actual
3193:    matrix factorization.
3194: */
3195: PetscErrorCode MatGetInfo_External(Mat A, MatInfoType flag, MatInfo *info)
3196: {
3197:   PetscFunctionBegin;
3198:   PetscCall(PetscMemzero(info, sizeof(MatInfo)));
3199:   PetscFunctionReturn(PETSC_SUCCESS);
3200: }

3202: /*@
3203:   MatLUFactor - Performs in-place LU factorization of matrix.

3205:   Collective

3207:   Input Parameters:
3208: + mat  - the matrix
3209: . row  - row permutation
3210: . col  - column permutation
3211: - info - options for factorization, includes
3212: .vb
3213:           fill - expected fill as ratio of original fill.
3214:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3215:                    Run with the option -info to determine an optimal value to use
3216: .ve

3218:   Level: developer

3220:   Notes:
3221:   Most users should employ the `KSP` interface for linear solvers
3222:   instead of working directly with matrix algebra routines such as this.
3223:   See, e.g., `KSPCreate()`.

3225:   This changes the state of the matrix to a factored matrix; it cannot be used
3226:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3228:   This is really in-place only for dense matrices, the preferred approach is to use `MatGetFactor()`, `MatLUFactorSymbolic()`, and `MatLUFactorNumeric()`
3229:   when not using `KSP`.

3231:   Fortran Note:
3232:   A valid (non-null) `info` argument must be provided

3234: .seealso: [](ch_matrices), [Matrix Factorization](sec_matfactor), `Mat`, `MatFactorType`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
3235:           `MatGetOrdering()`, `MatSetUnfactored()`, `MatFactorInfo`, `MatGetFactor()`
3236: @*/
3237: PetscErrorCode MatLUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3238: {
3239:   MatFactorInfo tinfo;

3241:   PetscFunctionBegin;
3245:   if (info) PetscAssertPointer(info, 4);
3247:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3248:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3249:   MatCheckPreallocated(mat, 1);
3250:   if (!info) {
3251:     PetscCall(MatFactorInfoInitialize(&tinfo));
3252:     info = &tinfo;
3253:   }

3255:   PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, row, col, 0));
3256:   PetscUseTypeMethod(mat, lufactor, row, col, info);
3257:   PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, row, col, 0));
3258:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3259:   PetscFunctionReturn(PETSC_SUCCESS);
3260: }

3262: /*@
3263:   MatILUFactor - Performs in-place ILU factorization of matrix.

3265:   Collective

3267:   Input Parameters:
3268: + mat  - the matrix
3269: . row  - row permutation
3270: . col  - column permutation
3271: - info - structure containing
3272: .vb
3273:       levels - number of levels of fill.
3274:       expected fill - as ratio of original fill.
3275:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
3276:                 missing diagonal entries)
3277: .ve

3279:   Level: developer

3281:   Notes:
3282:   Most users should employ the `KSP` interface for linear solvers
3283:   instead of working directly with matrix algebra routines such as this.
3284:   See, e.g., `KSPCreate()`.

3286:   Probably really in-place only when level of fill is zero, otherwise allocates
3287:   new space to store factored matrix and deletes previous memory. The preferred approach is to use `MatGetFactor()`, `MatILUFactorSymbolic()`, and `MatLUFactorNumeric()`
3288:   when not using `KSP`.

3290:   Fortran Note:
3291:   A valid (non-null) `info` argument must be provided

3293: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatILUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
3294: @*/
3295: PetscErrorCode MatILUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3296: {
3297:   PetscFunctionBegin;
3301:   PetscAssertPointer(info, 4);
3303:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
3304:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3305:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3306:   MatCheckPreallocated(mat, 1);

3308:   PetscCall(PetscLogEventBegin(MAT_ILUFactor, mat, row, col, 0));
3309:   PetscUseTypeMethod(mat, ilufactor, row, col, info);
3310:   PetscCall(PetscLogEventEnd(MAT_ILUFactor, mat, row, col, 0));
3311:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3312:   PetscFunctionReturn(PETSC_SUCCESS);
3313: }

3315: /*@
3316:   MatLUFactorSymbolic - Performs symbolic LU factorization of matrix.
3317:   Call this routine before calling `MatLUFactorNumeric()` and after `MatGetFactor()`.

3319:   Collective

3321:   Input Parameters:
3322: + fact - the factor matrix obtained with `MatGetFactor()`
3323: . mat  - the matrix
3324: . row  - the row permutation
3325: . col  - the column permutation
3326: - info - options for factorization, includes
3327: .vb
3328:           fill - expected fill as ratio of original fill. Run with the option -info to determine an optimal value to use
3329:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3330: .ve

3332:   Level: developer

3334:   Notes:
3335:   See [Matrix Factorization](sec_matfactor) for additional information about factorizations

3337:   Most users should employ the simplified `KSP` interface for linear solvers
3338:   instead of working directly with matrix algebra routines such as this.
3339:   See, e.g., `KSPCreate()`.

3341:   Fortran Note:
3342:   A valid (non-null) `info` argument must be provided

3344: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`, `MatFactorInfoInitialize()`
3345: @*/
3346: PetscErrorCode MatLUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
3347: {
3348:   MatFactorInfo tinfo;

3350:   PetscFunctionBegin;
3355:   if (info) PetscAssertPointer(info, 5);
3358:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3359:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3360:   MatCheckPreallocated(mat, 2);
3361:   if (!info) {
3362:     PetscCall(MatFactorInfoInitialize(&tinfo));
3363:     info = &tinfo;
3364:   }

3366:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorSymbolic, mat, row, col, 0));
3367:   PetscUseTypeMethod(fact, lufactorsymbolic, mat, row, col, info);
3368:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorSymbolic, mat, row, col, 0));
3369:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3370:   PetscFunctionReturn(PETSC_SUCCESS);
3371: }

3373: /*@
3374:   MatLUFactorNumeric - Performs numeric LU factorization of a matrix.
3375:   Call this routine after first calling `MatLUFactorSymbolic()` and `MatGetFactor()`.

3377:   Collective

3379:   Input Parameters:
3380: + fact - the factor matrix obtained with `MatGetFactor()`
3381: . mat  - the matrix
3382: - info - options for factorization

3384:   Level: developer

3386:   Notes:
3387:   See `MatLUFactor()` for in-place factorization.  See
3388:   `MatCholeskyFactorNumeric()` for the symmetric, positive definite case.

3390:   Most users should employ the `KSP` interface for linear solvers
3391:   instead of working directly with matrix algebra routines such as this.
3392:   See, e.g., `KSPCreate()`.

3394:   Fortran Note:
3395:   A valid (non-null) `info` argument must be provided

3397: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactorSymbolic()`, `MatLUFactor()`, `MatCholeskyFactor()`
3398: @*/
3399: PetscErrorCode MatLUFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3400: {
3401:   MatFactorInfo tinfo;

3403:   PetscFunctionBegin;
3408:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3409:   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,
3410:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3412:   MatCheckPreallocated(mat, 2);
3413:   if (!info) {
3414:     PetscCall(MatFactorInfoInitialize(&tinfo));
3415:     info = &tinfo;
3416:   }

3418:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorNumeric, mat, fact, 0, 0));
3419:   else PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, fact, 0, 0));
3420:   PetscUseTypeMethod(fact, lufactornumeric, mat, info);
3421:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorNumeric, mat, fact, 0, 0));
3422:   else PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, fact, 0, 0));
3423:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3424:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3425:   PetscFunctionReturn(PETSC_SUCCESS);
3426: }

3428: /*@
3429:   MatCholeskyFactor - Performs in-place Cholesky factorization of a
3430:   symmetric matrix.

3432:   Collective

3434:   Input Parameters:
3435: + mat  - the matrix
3436: . perm - row and column permutations
3437: - info - expected fill as ratio of original fill

3439:   Level: developer

3441:   Notes:
3442:   See `MatLUFactor()` for the nonsymmetric case.  See also `MatGetFactor()`,
3443:   `MatCholeskyFactorSymbolic()`, and `MatCholeskyFactorNumeric()`.

3445:   Most users should employ the `KSP` interface for linear solvers
3446:   instead of working directly with matrix algebra routines such as this.
3447:   See, e.g., `KSPCreate()`.

3449:   Fortran Note:
3450:   A valid (non-null) `info` argument must be provided

3452: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactorNumeric()`,
3453:           `MatGetOrdering()`
3454: @*/
3455: PetscErrorCode MatCholeskyFactor(Mat mat, IS perm, const MatFactorInfo *info)
3456: {
3457:   MatFactorInfo tinfo;

3459:   PetscFunctionBegin;
3462:   if (info) PetscAssertPointer(info, 3);
3464:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3465:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3466:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3467:   MatCheckPreallocated(mat, 1);
3468:   if (!info) {
3469:     PetscCall(MatFactorInfoInitialize(&tinfo));
3470:     info = &tinfo;
3471:   }

3473:   PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, perm, 0, 0));
3474:   PetscUseTypeMethod(mat, choleskyfactor, perm, info);
3475:   PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, perm, 0, 0));
3476:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3477:   PetscFunctionReturn(PETSC_SUCCESS);
3478: }

3480: /*@
3481:   MatCholeskyFactorSymbolic - Performs symbolic Cholesky factorization
3482:   of a symmetric matrix.

3484:   Collective

3486:   Input Parameters:
3487: + fact - the factor matrix obtained with `MatGetFactor()`
3488: . mat  - the matrix
3489: . perm - row and column permutations
3490: - info - options for factorization, includes
3491: .vb
3492:           fill - expected fill as ratio of original fill.
3493:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3494:                    Run with the option -info to determine an optimal value to use
3495: .ve

3497:   Level: developer

3499:   Notes:
3500:   See `MatLUFactorSymbolic()` for the nonsymmetric case.  See also
3501:   `MatCholeskyFactor()` and `MatCholeskyFactorNumeric()`.

3503:   Most users should employ the `KSP` interface for linear solvers
3504:   instead of working directly with matrix algebra routines such as this.
3505:   See, e.g., `KSPCreate()`.

3507:   Fortran Note:
3508:   A valid (non-null) `info` argument must be provided

3510: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactor()`, `MatCholeskyFactorNumeric()`,
3511:           `MatGetOrdering()`
3512: @*/
3513: PetscErrorCode MatCholeskyFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
3514: {
3515:   MatFactorInfo tinfo;

3517:   PetscFunctionBegin;
3521:   if (info) PetscAssertPointer(info, 4);
3524:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3525:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3526:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3527:   MatCheckPreallocated(mat, 2);
3528:   if (!info) {
3529:     PetscCall(MatFactorInfoInitialize(&tinfo));
3530:     info = &tinfo;
3531:   }

3533:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3534:   PetscUseTypeMethod(fact, choleskyfactorsymbolic, mat, perm, info);
3535:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3536:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3537:   PetscFunctionReturn(PETSC_SUCCESS);
3538: }

3540: /*@
3541:   MatCholeskyFactorNumeric - Performs numeric Cholesky factorization
3542:   of a symmetric matrix. Call this routine after first calling `MatGetFactor()` and
3543:   `MatCholeskyFactorSymbolic()`.

3545:   Collective

3547:   Input Parameters:
3548: + fact - the factor matrix obtained with `MatGetFactor()`, where the factored values are stored
3549: . mat  - the initial matrix that is to be factored
3550: - info - options for factorization

3552:   Level: developer

3554:   Note:
3555:   Most users should employ the `KSP` interface for linear solvers
3556:   instead of working directly with matrix algebra routines such as this.
3557:   See, e.g., `KSPCreate()`.

3559:   Fortran Note:
3560:   A valid (non-null) `info` argument must be provided

3562: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactor()`, `MatLUFactorNumeric()`
3563: @*/
3564: PetscErrorCode MatCholeskyFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3565: {
3566:   MatFactorInfo tinfo;

3568:   PetscFunctionBegin;
3573:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3574:   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,
3575:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);
3576:   MatCheckPreallocated(mat, 2);
3577:   if (!info) {
3578:     PetscCall(MatFactorInfoInitialize(&tinfo));
3579:     info = &tinfo;
3580:   }

3582:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3583:   else PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, fact, 0, 0));
3584:   PetscUseTypeMethod(fact, choleskyfactornumeric, mat, info);
3585:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3586:   else PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, fact, 0, 0));
3587:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3588:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3589:   PetscFunctionReturn(PETSC_SUCCESS);
3590: }

3592: /*@
3593:   MatQRFactor - Performs in-place QR factorization of matrix.

3595:   Collective

3597:   Input Parameters:
3598: + mat  - the matrix
3599: . col  - column permutation
3600: - info - options for factorization, includes
3601: .vb
3602:           fill - expected fill as ratio of original fill.
3603:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3604:                    Run with the option -info to determine an optimal value to use
3605: .ve

3607:   Level: developer

3609:   Notes:
3610:   Most users should employ the `KSP` interface for linear solvers
3611:   instead of working directly with matrix algebra routines such as this.
3612:   See, e.g., `KSPCreate()`.

3614:   This changes the state of the matrix to a factored matrix; it cannot be used
3615:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3617:   Fortran Note:
3618:   A valid (non-null) `info` argument must be provided

3620: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactorSymbolic()`, `MatQRFactorNumeric()`, `MatLUFactor()`,
3621:           `MatSetUnfactored()`
3622: @*/
3623: PetscErrorCode MatQRFactor(Mat mat, IS col, const MatFactorInfo *info)
3624: {
3625:   PetscFunctionBegin;
3628:   if (info) PetscAssertPointer(info, 3);
3630:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3631:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3632:   MatCheckPreallocated(mat, 1);
3633:   PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, col, 0, 0));
3634:   PetscUseMethod(mat, "MatQRFactor_C", (Mat, IS, const MatFactorInfo *), (mat, col, info));
3635:   PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, col, 0, 0));
3636:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3637:   PetscFunctionReturn(PETSC_SUCCESS);
3638: }

3640: /*@
3641:   MatQRFactorSymbolic - Performs symbolic QR factorization of matrix.
3642:   Call this routine after `MatGetFactor()` but before calling `MatQRFactorNumeric()`.

3644:   Collective

3646:   Input Parameters:
3647: + fact - the factor matrix obtained with `MatGetFactor()`
3648: . mat  - the matrix
3649: . col  - column permutation
3650: - info - options for factorization, includes
3651: .vb
3652:           fill - expected fill as ratio of original fill.
3653:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3654:                    Run with the option -info to determine an optimal value to use
3655: .ve

3657:   Level: developer

3659:   Note:
3660:   Most users should employ the `KSP` interface for linear solvers
3661:   instead of working directly with matrix algebra routines such as this.
3662:   See, e.g., `KSPCreate()`.

3664:   Fortran Note:
3665:   A valid (non-null) `info` argument must be provided

3667: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatQRFactor()`, `MatQRFactorNumeric()`, `MatLUFactor()`, `MatFactorInfoInitialize()`
3668: @*/
3669: PetscErrorCode MatQRFactorSymbolic(Mat fact, Mat mat, IS col, const MatFactorInfo *info)
3670: {
3671:   MatFactorInfo tinfo;

3673:   PetscFunctionBegin;
3677:   if (info) PetscAssertPointer(info, 4);
3680:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3681:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3682:   MatCheckPreallocated(mat, 2);
3683:   if (!info) {
3684:     PetscCall(MatFactorInfoInitialize(&tinfo));
3685:     info = &tinfo;
3686:   }

3688:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorSymbolic, fact, mat, col, 0));
3689:   PetscUseMethod(fact, "MatQRFactorSymbolic_C", (Mat, Mat, IS, const MatFactorInfo *), (fact, mat, col, info));
3690:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorSymbolic, fact, mat, col, 0));
3691:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3692:   PetscFunctionReturn(PETSC_SUCCESS);
3693: }

3695: /*@
3696:   MatQRFactorNumeric - Performs numeric QR factorization of a matrix.
3697:   Call this routine after first calling `MatGetFactor()`, and `MatQRFactorSymbolic()`.

3699:   Collective

3701:   Input Parameters:
3702: + fact - the factor matrix obtained with `MatGetFactor()`
3703: . mat  - the matrix
3704: - info - options for factorization

3706:   Level: developer

3708:   Notes:
3709:   See `MatQRFactor()` for in-place factorization.

3711:   Most users should employ the `KSP` interface for linear solvers
3712:   instead of working directly with matrix algebra routines such as this.
3713:   See, e.g., `KSPCreate()`.

3715:   Fortran Note:
3716:   A valid (non-null) `info` argument must be provided

3718: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactor()`, `MatQRFactorSymbolic()`, `MatLUFactor()`
3719: @*/
3720: PetscErrorCode MatQRFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3721: {
3722:   MatFactorInfo tinfo;

3724:   PetscFunctionBegin;
3729:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3730:   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,
3731:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3733:   MatCheckPreallocated(mat, 2);
3734:   if (!info) {
3735:     PetscCall(MatFactorInfoInitialize(&tinfo));
3736:     info = &tinfo;
3737:   }

3739:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorNumeric, mat, fact, 0, 0));
3740:   else PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, fact, 0, 0));
3741:   PetscUseMethod(fact, "MatQRFactorNumeric_C", (Mat, Mat, const MatFactorInfo *), (fact, mat, info));
3742:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorNumeric, mat, fact, 0, 0));
3743:   else PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, fact, 0, 0));
3744:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3745:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3746:   PetscFunctionReturn(PETSC_SUCCESS);
3747: }

3749: /*@
3750:   MatSolve - Solves $A x = b$, given a factored matrix.

3752:   Neighbor-wise Collective

3754:   Input Parameters:
3755: + mat - the factored matrix
3756: - b   - the right-hand-side vector

3758:   Output Parameter:
3759: . x - the result vector

3761:   Level: developer

3763:   Notes:
3764:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3765:   call `MatSolve`(A,x,x).

3767:   Most users should employ the `KSP` interface for linear solvers
3768:   instead of working directly with matrix algebra routines such as this.
3769:   See, e.g., `KSPCreate()`.

3771: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
3772: @*/
3773: PetscErrorCode MatSolve(Mat mat, Vec b, Vec x)
3774: {
3775:   PetscFunctionBegin;
3780:   PetscCheckSameComm(mat, 1, b, 2);
3781:   PetscCheckSameComm(mat, 1, x, 3);
3782:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3783:   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);
3784:   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);
3785:   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);
3786:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3787:   MatCheckPreallocated(mat, 1);

3789:   PetscCall(PetscLogEventBegin(MAT_Solve, mat, b, x, 0));
3790:   PetscCall(VecFlag(x, mat->factorerrortype));
3791:   if (mat->factorerrortype) PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
3792:   else PetscUseTypeMethod(mat, solve, b, x);
3793:   PetscCall(PetscLogEventEnd(MAT_Solve, mat, b, x, 0));
3794:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3795:   PetscFunctionReturn(PETSC_SUCCESS);
3796: }

3798: static PetscErrorCode MatMatSolve_Basic(Mat A, Mat B, Mat X, PetscBool trans)
3799: {
3800:   Vec      b, x;
3801:   PetscInt N, i;
3802:   PetscErrorCode (*f)(Mat, Vec, Vec);
3803:   PetscBool Abound, Bneedconv = PETSC_FALSE, Xneedconv = PETSC_FALSE;

3805:   PetscFunctionBegin;
3806:   if (A->factorerrortype) {
3807:     PetscCall(PetscInfo(A, "MatFactorError %d\n", A->factorerrortype));
3808:     PetscCall(MatSetInf(X));
3809:     PetscFunctionReturn(PETSC_SUCCESS);
3810:   }
3811:   f = (!trans || (!A->ops->solvetranspose && A->symmetric)) ? A->ops->solve : A->ops->solvetranspose;
3812:   PetscCheck(f, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)A)->type_name);
3813:   PetscCall(MatBoundToCPU(A, &Abound));
3814:   if (!Abound) {
3815:     PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &Bneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3816:     PetscCall(PetscObjectTypeCompareAny((PetscObject)X, &Xneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3817:   }
3818: #if PetscDefined(HAVE_CUDA)
3819:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSECUDA, MAT_INPLACE_MATRIX, &B));
3820:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSECUDA, MAT_INPLACE_MATRIX, &X));
3821: #elif PetscDefined(HAVE_HIP)
3822:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSEHIP, MAT_INPLACE_MATRIX, &B));
3823:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSEHIP, MAT_INPLACE_MATRIX, &X));
3824: #endif
3825:   PetscCall(MatGetSize(B, NULL, &N));
3826:   for (i = 0; i < N; i++) {
3827:     PetscCall(MatDenseGetColumnVecRead(B, i, &b));
3828:     PetscCall(MatDenseGetColumnVecWrite(X, i, &x));
3829:     PetscCall((*f)(A, b, x));
3830:     PetscCall(MatDenseRestoreColumnVecWrite(X, i, &x));
3831:     PetscCall(MatDenseRestoreColumnVecRead(B, i, &b));
3832:   }
3833:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSE, MAT_INPLACE_MATRIX, &B));
3834:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSE, MAT_INPLACE_MATRIX, &X));
3835:   PetscFunctionReturn(PETSC_SUCCESS);
3836: }

3838: /*@
3839:   MatMatSolve - Solves $A X = B$, given a factored matrix.

3841:   Neighbor-wise Collective

3843:   Input Parameters:
3844: + A - the factored matrix
3845: - B - the right-hand-side matrix `MATDENSE` (or sparse `MATAIJ`-- when using MUMPS)

3847:   Output Parameter:
3848: . X - the result matrix (dense matrix)

3850:   Level: developer

3852:   Note:
3853:   If `B` is a `MATDENSE` matrix then one can call `MatMatSolve`(A,B,B) except with `MATSOLVERMKL_CPARDISO`;
3854:   otherwise, `B` and `X` cannot be the same.

3856: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3857: @*/
3858: PetscErrorCode MatMatSolve(Mat A, Mat B, Mat X)
3859: {
3860:   PetscFunctionBegin;
3865:   PetscCheckSameComm(A, 1, B, 2);
3866:   PetscCheckSameComm(A, 1, X, 3);
3867:   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);
3868:   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);
3869:   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");
3870:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3871:   MatCheckPreallocated(A, 1);

3873:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3874:   if (!A->ops->matsolve) {
3875:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolve\n", ((PetscObject)A)->type_name));
3876:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_FALSE));
3877:   } else PetscUseTypeMethod(A, matsolve, B, X);
3878:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3879:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3880:   PetscFunctionReturn(PETSC_SUCCESS);
3881: }

3883: /*@
3884:   MatMatSolveTranspose - Solves $A^T X = B $, given a factored matrix.

3886:   Neighbor-wise Collective

3888:   Input Parameters:
3889: + A - the factored matrix
3890: - B - the right-hand-side matrix  (`MATDENSE` matrix)

3892:   Output Parameter:
3893: . X - the result matrix (dense matrix)

3895:   Level: developer

3897:   Note:
3898:   The matrices `B` and `X` cannot be the same.  I.e., one cannot
3899:   call `MatMatSolveTranspose`(A,X,X).

3901: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolveTranspose()`, `MatMatSolve()`, `MatLUFactor()`, `MatCholeskyFactor()`
3902: @*/
3903: PetscErrorCode MatMatSolveTranspose(Mat A, Mat B, Mat X)
3904: {
3905:   PetscFunctionBegin;
3910:   PetscCheckSameComm(A, 1, B, 2);
3911:   PetscCheckSameComm(A, 1, X, 3);
3912:   PetscCheck(X != B, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3913:   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);
3914:   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);
3915:   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);
3916:   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");
3917:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3918:   MatCheckPreallocated(A, 1);

3920:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3921:   if (!A->ops->matsolvetranspose) {
3922:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolveTranspose\n", ((PetscObject)A)->type_name));
3923:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_TRUE));
3924:   } else PetscUseTypeMethod(A, matsolvetranspose, B, X);
3925:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3926:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3927:   PetscFunctionReturn(PETSC_SUCCESS);
3928: }

3930: /*@
3931:   MatMatTransposeSolve - Solves $A X = B^T$, given a factored matrix.

3933:   Neighbor-wise Collective

3935:   Input Parameters:
3936: + A  - the factored matrix
3937: - Bt - the transpose of right-hand-side matrix as a `MATDENSE`

3939:   Output Parameter:
3940: . X - the result matrix (dense matrix)

3942:   Level: developer

3944:   Note:
3945:   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
3946:   format on the host processor and call `MatMatTransposeSolve()` to implement MUMPS' `MatMatSolve()`.

3948: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatMatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3949: @*/
3950: PetscErrorCode MatMatTransposeSolve(Mat A, Mat Bt, Mat X)
3951: {
3952:   PetscFunctionBegin;
3957:   PetscCheckSameComm(A, 1, Bt, 2);
3958:   PetscCheckSameComm(A, 1, X, 3);

3960:   PetscCheck(X != Bt, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3961:   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);
3962:   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);
3963:   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");
3964:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3965:   PetscCheck(A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
3966:   MatCheckPreallocated(A, 1);

3968:   PetscCall(PetscLogEventBegin(MAT_MatTrSolve, A, Bt, X, 0));
3969:   PetscUseTypeMethod(A, mattransposesolve, Bt, X);
3970:   PetscCall(PetscLogEventEnd(MAT_MatTrSolve, A, Bt, X, 0));
3971:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3972:   PetscFunctionReturn(PETSC_SUCCESS);
3973: }

3975: /*@
3976:   MatForwardSolve - Solves $ L x = b $, given a factored matrix, $A = LU $, or
3977:   $U^T*D^(1/2) x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3979:   Neighbor-wise Collective

3981:   Input Parameters:
3982: + mat - the factored matrix
3983: - b   - the right-hand-side vector

3985:   Output Parameter:
3986: . x - the result vector

3988:   Level: developer

3990:   Notes:
3991:   `MatSolve()` should be used for most applications, as it performs
3992:   a forward solve followed by a backward solve.

3994:   The vectors `b` and `x` cannot be the same,  i.e., one cannot
3995:   call `MatForwardSolve`(A,x,x).

3997:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
3998:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
3999:   `MatForwardSolve()` solves $U^T*D y = b$, and
4000:   `MatBackwardSolve()` solves $U x = y$.
4001:   Thus they do not provide a symmetric preconditioner.

4003: .seealso: [](ch_matrices), `Mat`, `MatBackwardSolve()`, `MatGetFactor()`, `MatSolve()`
4004: @*/
4005: PetscErrorCode MatForwardSolve(Mat mat, Vec b, Vec x)
4006: {
4007:   PetscFunctionBegin;
4012:   PetscCheckSameComm(mat, 1, b, 2);
4013:   PetscCheckSameComm(mat, 1, x, 3);
4014:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4015:   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);
4016:   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);
4017:   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);
4018:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4019:   MatCheckPreallocated(mat, 1);

4021:   PetscCall(PetscLogEventBegin(MAT_ForwardSolve, mat, b, x, 0));
4022:   PetscUseTypeMethod(mat, forwardsolve, b, x);
4023:   PetscCall(PetscLogEventEnd(MAT_ForwardSolve, mat, b, x, 0));
4024:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4025:   PetscFunctionReturn(PETSC_SUCCESS);
4026: }

4028: /*@
4029:   MatBackwardSolve - Solves $U x = b$, given a factored matrix, $A = LU$.
4030:   $D^(1/2) U x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

4032:   Neighbor-wise Collective

4034:   Input Parameters:
4035: + mat - the factored matrix
4036: - b   - the right-hand-side vector

4038:   Output Parameter:
4039: . x - the result vector

4041:   Level: developer

4043:   Notes:
4044:   `MatSolve()` should be used for most applications, as it performs
4045:   a forward solve followed by a backward solve.

4047:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4048:   call `MatBackwardSolve`(A,x,x).

4050:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
4051:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
4052:   `MatForwardSolve()` solves $U^T*D y = b$, and
4053:   `MatBackwardSolve()` solves $U x = y$.
4054:   Thus they do not provide a symmetric preconditioner.

4056: .seealso: [](ch_matrices), `Mat`, `MatForwardSolve()`, `MatGetFactor()`, `MatSolve()`
4057: @*/
4058: PetscErrorCode MatBackwardSolve(Mat mat, Vec b, Vec x)
4059: {
4060:   PetscFunctionBegin;
4065:   PetscCheckSameComm(mat, 1, b, 2);
4066:   PetscCheckSameComm(mat, 1, x, 3);
4067:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4068:   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);
4069:   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);
4070:   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);
4071:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4072:   MatCheckPreallocated(mat, 1);

4074:   PetscCall(PetscLogEventBegin(MAT_BackwardSolve, mat, b, x, 0));
4075:   PetscUseTypeMethod(mat, backwardsolve, b, x);
4076:   PetscCall(PetscLogEventEnd(MAT_BackwardSolve, mat, b, x, 0));
4077:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4078:   PetscFunctionReturn(PETSC_SUCCESS);
4079: }

4081: /*@
4082:   MatSolveAdd - Computes $x = y + A^{-1}*b$, given a factored matrix.

4084:   Neighbor-wise Collective

4086:   Input Parameters:
4087: + mat - the factored matrix
4088: . b   - the right-hand-side vector
4089: - y   - the vector to be added to

4091:   Output Parameter:
4092: . x - the result vector

4094:   Level: developer

4096:   Note:
4097:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4098:   call `MatSolveAdd`(A,x,y,x).

4100: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolve()`, `MatGetFactor()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
4101: @*/
4102: PetscErrorCode MatSolveAdd(Mat mat, Vec b, Vec y, Vec x)
4103: {
4104:   PetscScalar one = 1.0;
4105:   Vec         tmp;

4107:   PetscFunctionBegin;
4113:   PetscCheckSameComm(mat, 1, b, 2);
4114:   PetscCheckSameComm(mat, 1, y, 3);
4115:   PetscCheckSameComm(mat, 1, x, 4);
4116:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4117:   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);
4118:   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);
4119:   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);
4120:   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);
4121:   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);
4122:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4123:   MatCheckPreallocated(mat, 1);

4125:   PetscCall(PetscLogEventBegin(MAT_SolveAdd, mat, b, x, y));
4126:   PetscCall(VecFlag(x, mat->factorerrortype));
4127:   if (mat->factorerrortype) {
4128:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4129:   } else if (mat->ops->solveadd) {
4130:     PetscUseTypeMethod(mat, solveadd, b, y, x);
4131:   } else {
4132:     /* do the solve then the add manually */
4133:     if (x != y) {
4134:       PetscCall(MatSolve(mat, b, x));
4135:       PetscCall(VecAXPY(x, one, y));
4136:     } else {
4137:       PetscCall(VecDuplicate(x, &tmp));
4138:       PetscCall(VecCopy(x, tmp));
4139:       PetscCall(MatSolve(mat, b, x));
4140:       PetscCall(VecAXPY(x, one, tmp));
4141:       PetscCall(VecDestroy(&tmp));
4142:     }
4143:   }
4144:   PetscCall(PetscLogEventEnd(MAT_SolveAdd, mat, b, x, y));
4145:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4146:   PetscFunctionReturn(PETSC_SUCCESS);
4147: }

4149: /*@
4150:   MatSolveTranspose - Solves $A^T x = b$, given a factored matrix.

4152:   Neighbor-wise Collective

4154:   Input Parameters:
4155: + mat - the factored matrix
4156: - b   - the right-hand-side vector

4158:   Output Parameter:
4159: . x - the result vector

4161:   Level: developer

4163:   Notes:
4164:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4165:   call `MatSolveTranspose`(A,x,x).

4167:   Most users should employ the `KSP` interface for linear solvers
4168:   instead of working directly with matrix algebra routines such as this.
4169:   See, e.g., `KSPCreate()`.

4171: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `KSP`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTransposeAdd()`
4172: @*/
4173: PetscErrorCode MatSolveTranspose(Mat mat, Vec b, Vec x)
4174: {
4175:   PetscErrorCode (*f)(Mat, Vec, Vec) = (!mat->ops->solvetranspose && mat->symmetric) ? mat->ops->solve : mat->ops->solvetranspose;

4177:   PetscFunctionBegin;
4182:   PetscCheckSameComm(mat, 1, b, 2);
4183:   PetscCheckSameComm(mat, 1, x, 3);
4184:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4185:   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);
4186:   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);
4187:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4188:   MatCheckPreallocated(mat, 1);
4189:   PetscCall(PetscLogEventBegin(MAT_SolveTranspose, mat, b, x, 0));
4190:   PetscCall(VecFlag(x, mat->factorerrortype));
4191:   if (mat->factorerrortype) {
4192:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4193:   } else {
4194:     PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Matrix type %s", ((PetscObject)mat)->type_name);
4195:     PetscCall((*f)(mat, b, x));
4196:   }
4197:   PetscCall(PetscLogEventEnd(MAT_SolveTranspose, mat, b, x, 0));
4198:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4199:   PetscFunctionReturn(PETSC_SUCCESS);
4200: }

4202: /*@
4203:   MatSolveTransposeAdd - Computes $x = y + A^{-T} b$
4204:   factored matrix.

4206:   Neighbor-wise Collective

4208:   Input Parameters:
4209: + mat - the factored matrix
4210: . b   - the right-hand-side vector
4211: - y   - the vector to be added to

4213:   Output Parameter:
4214: . x - the result vector

4216:   Level: developer

4218:   Note:
4219:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4220:   call `MatSolveTransposeAdd`(A,x,y,x).

4222: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTranspose()`
4223: @*/
4224: PetscErrorCode MatSolveTransposeAdd(Mat mat, Vec b, Vec y, Vec x)
4225: {
4226:   PetscScalar one = 1.0;
4227:   Vec         tmp;
4228:   PetscErrorCode (*f)(Mat, Vec, Vec, Vec) = (!mat->ops->solvetransposeadd && mat->symmetric) ? mat->ops->solveadd : mat->ops->solvetransposeadd;

4230:   PetscFunctionBegin;
4236:   PetscCheckSameComm(mat, 1, b, 2);
4237:   PetscCheckSameComm(mat, 1, y, 3);
4238:   PetscCheckSameComm(mat, 1, x, 4);
4239:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4240:   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);
4241:   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);
4242:   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);
4243:   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);
4244:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4245:   MatCheckPreallocated(mat, 1);

4247:   PetscCall(PetscLogEventBegin(MAT_SolveTransposeAdd, mat, b, x, y));
4248:   PetscCall(VecFlag(x, mat->factorerrortype));
4249:   if (mat->factorerrortype) {
4250:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4251:   } else if (f) {
4252:     PetscCall((*f)(mat, b, y, x));
4253:   } else {
4254:     /* do the solve then the add manually */
4255:     if (x != y) {
4256:       PetscCall(MatSolveTranspose(mat, b, x));
4257:       PetscCall(VecAXPY(x, one, y));
4258:     } else {
4259:       PetscCall(VecDuplicate(x, &tmp));
4260:       PetscCall(VecCopy(x, tmp));
4261:       PetscCall(MatSolveTranspose(mat, b, x));
4262:       PetscCall(VecAXPY(x, one, tmp));
4263:       PetscCall(VecDestroy(&tmp));
4264:     }
4265:   }
4266:   PetscCall(PetscLogEventEnd(MAT_SolveTransposeAdd, mat, b, x, y));
4267:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4268:   PetscFunctionReturn(PETSC_SUCCESS);
4269: }

4271: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
4272: /*@
4273:   MatSOR - Computes relaxation (SOR, Gauss-Seidel) sweeps.

4275:   Neighbor-wise Collective

4277:   Input Parameters:
4278: + mat   - the matrix
4279: . b     - the right-hand side
4280: . omega - the relaxation factor
4281: . flag  - flag indicating the type of SOR (see below)
4282: . shift - diagonal shift
4283: . its   - the number of iterations
4284: - lits  - the number of local iterations

4286:   Output Parameter:
4287: . x - the solution (can contain an initial guess, use option `SOR_ZERO_INITIAL_GUESS` to indicate no guess)

4289:   SOR Flags:
4290: +     `SOR_FORWARD_SWEEP` - forward SOR
4291: .     `SOR_BACKWARD_SWEEP` - backward SOR
4292: .     `SOR_SYMMETRIC_SWEEP` - SSOR (symmetric SOR)
4293: .     `SOR_LOCAL_FORWARD_SWEEP` - local forward SOR
4294: .     `SOR_LOCAL_BACKWARD_SWEEP` - local forward SOR
4295: .     `SOR_LOCAL_SYMMETRIC_SWEEP` - local SSOR
4296: .     `SOR_EISENSTAT` - SOR with Eisenstat trick
4297: .     `SOR_APPLY_UPPER`, `SOR_APPLY_LOWER` - applies upper/lower triangular part of matrix to vector (with `omega`)
4298: -     `SOR_ZERO_INITIAL_GUESS` - zero initial guess

4300:   Level: developer

4302:   Notes:
4303:   `SOR_LOCAL_FORWARD_SWEEP`, `SOR_LOCAL_BACKWARD_SWEEP`, and
4304:   `SOR_LOCAL_SYMMETRIC_SWEEP` perform separate independent smoothings
4305:   on each processor.

4307:   Application programmers will not generally use `MatSOR()` directly,
4308:   but instead will employ `PCSOR` or `PCEISENSTAT`

4310:   For `MATBAIJ`, `MATSBAIJ`, and `MATAIJ` matrices with inodes, this does a block SOR smoothing, otherwise it does a pointwise smoothing.
4311:   For `MATAIJ` matrices with inodes, the block sizes are determined by the inode sizes, not the block size set with `MatSetBlockSize()`

4313:   Vectors `x` and `b` CANNOT be the same

4315:   The flags are implemented as bitwise inclusive or operations.
4316:   For example, use (`SOR_ZERO_INITIAL_GUESS` | `SOR_SYMMETRIC_SWEEP`)
4317:   to specify a zero initial guess for SSOR.

4319:   Developer Note:
4320:   We should add block SOR support for `MATAIJ` matrices with block size set to greater than one and no inodes

4322: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `KSP`, `PC`, `MatGetFactor()`
4323: @*/
4324: PetscErrorCode MatSOR(Mat mat, Vec b, PetscReal omega, MatSORType flag, PetscReal shift, PetscInt its, PetscInt lits, Vec x)
4325: {
4326:   PetscFunctionBegin;
4331:   PetscCheckSameComm(mat, 1, b, 2);
4332:   PetscCheckSameComm(mat, 1, x, 8);
4333:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4334:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4335:   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);
4336:   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);
4337:   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);
4338:   PetscCheck(its > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires global its %" PetscInt_FMT " positive", its);
4339:   PetscCheck(lits > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires local its %" PetscInt_FMT " positive", lits);
4340:   PetscCheck(b != x, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "b and x vector cannot be the same");

4342:   MatCheckPreallocated(mat, 1);
4343:   PetscCall(PetscLogEventBegin(MAT_SOR, mat, b, x, 0));
4344:   PetscUseTypeMethod(mat, sor, b, omega, flag, shift, its, lits, x);
4345:   PetscCall(PetscLogEventEnd(MAT_SOR, mat, b, x, 0));
4346:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4347:   PetscFunctionReturn(PETSC_SUCCESS);
4348: }

4350: /*
4351:       Default matrix copy routine.
4352: */
4353: PetscErrorCode MatCopy_Basic(Mat A, Mat B, MatStructure str)
4354: {
4355:   PetscInt           i, rstart = 0, rend = 0, nz;
4356:   const PetscInt    *cwork;
4357:   const PetscScalar *vwork;

4359:   PetscFunctionBegin;
4360:   if (B->assembled) PetscCall(MatZeroEntries(B));
4361:   if (str == SAME_NONZERO_PATTERN) {
4362:     PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
4363:     for (i = rstart; i < rend; i++) {
4364:       PetscCall(MatGetRow(A, i, &nz, &cwork, &vwork));
4365:       PetscCall(MatSetValues(B, 1, &i, nz, cwork, vwork, INSERT_VALUES));
4366:       PetscCall(MatRestoreRow(A, i, &nz, &cwork, &vwork));
4367:     }
4368:   } else {
4369:     PetscCall(MatAYPX(B, 0.0, A, str));
4370:   }
4371:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4372:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4373:   PetscFunctionReturn(PETSC_SUCCESS);
4374: }

4376: /*@
4377:   MatCopy - Copies a matrix to another matrix.

4379:   Collective

4381:   Input Parameters:
4382: + A   - the matrix
4383: - str - `SAME_NONZERO_PATTERN` or `DIFFERENT_NONZERO_PATTERN`

4385:   Output Parameter:
4386: . B - where the copy is put

4388:   Level: intermediate

4390:   Notes:
4391:   If you use `SAME_NONZERO_PATTERN`, then the two matrices must have the same nonzero pattern or the routine will crash.

4393:   `MatCopy()` copies the matrix entries of a matrix to another existing
4394:   matrix (after first zeroing the second matrix).  A related routine is
4395:   `MatConvert()`, which first creates a new matrix and then copies the data.

4397: .seealso: [](ch_matrices), `Mat`, `MatConvert()`, `MatDuplicate()`
4398: @*/
4399: PetscErrorCode MatCopy(Mat A, Mat B, MatStructure str)
4400: {
4401:   PetscInt i;

4403:   PetscFunctionBegin;
4408:   PetscCheckSameComm(A, 1, B, 2);
4409:   MatCheckPreallocated(B, 2);
4410:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4411:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4412:   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,
4413:              A->cmap->N, B->cmap->N);
4414:   MatCheckPreallocated(A, 1);
4415:   if (A == B) PetscFunctionReturn(PETSC_SUCCESS);

4417:   PetscCall(PetscLogEventBegin(MAT_Copy, A, B, 0, 0));
4418:   if (A->ops->copy) PetscUseTypeMethod(A, copy, B, str);
4419:   else PetscCall(MatCopy_Basic(A, B, str));

4421:   B->stencil.dim = A->stencil.dim;
4422:   B->stencil.noc = A->stencil.noc;
4423:   for (i = 0; i <= A->stencil.dim + (A->stencil.noc ? 0 : -1); i++) {
4424:     B->stencil.dims[i]   = A->stencil.dims[i];
4425:     B->stencil.starts[i] = A->stencil.starts[i];
4426:   }

4428:   PetscCall(PetscLogEventEnd(MAT_Copy, A, B, 0, 0));
4429:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
4430:   PetscFunctionReturn(PETSC_SUCCESS);
4431: }

4433: /*@
4434:   MatConvert - Converts a matrix to another matrix, either of the same
4435:   or different type.

4437:   Collective

4439:   Input Parameters:
4440: + mat     - the matrix
4441: . newtype - new matrix type.  Use `MATSAME` to create a new matrix of the
4442:             same type as the original matrix.
4443: - reuse   - denotes if the destination matrix is to be created or reused.
4444:             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
4445:             `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).

4447:   Output Parameter:
4448: . M - pointer to place new matrix

4450:   Level: intermediate

4452:   Notes:
4453:   `MatConvert()` first creates a new matrix and then copies the data from
4454:   the first matrix.  A related routine is `MatCopy()`, which copies the matrix
4455:   entries of one matrix to another already existing matrix context.

4457:   Cannot be used to convert a sequential matrix to parallel or parallel to sequential,
4458:   the MPI communicator of the generated matrix is always the same as the communicator
4459:   of the input matrix.

4461: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatDuplicate()`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
4462: @*/
4463: PetscErrorCode MatConvert(Mat mat, MatType newtype, MatReuse reuse, Mat *M)
4464: {
4465:   PetscBool  sametype, issame, flg;
4466:   PetscBool3 issymmetric, ishermitian, isspd;
4467:   char       convname[256], mtype[256];
4468:   Mat        B;

4470:   PetscFunctionBegin;
4473:   PetscAssertPointer(M, 4);
4474:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4475:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4476:   MatCheckPreallocated(mat, 1);

4478:   PetscCall(PetscOptionsGetString(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matconvert_type", mtype, sizeof(mtype), &flg));
4479:   if (flg) newtype = mtype;

4481:   PetscCall(PetscObjectTypeCompare((PetscObject)mat, newtype, &sametype));
4482:   PetscCall(PetscStrcmp(newtype, "same", &issame));
4483:   PetscCheck(!(reuse == MAT_INPLACE_MATRIX) || !(mat != *M), PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires same input and output matrix");
4484:   if (reuse == MAT_REUSE_MATRIX) {
4486:     PetscCheck(mat != *M, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_REUSE_MATRIX means reuse matrix in final argument, perhaps you mean MAT_INPLACE_MATRIX");
4487:   }

4489:   if ((reuse == MAT_INPLACE_MATRIX) && (issame || sametype)) {
4490:     PetscCall(PetscInfo(mat, "Early return for inplace %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4491:     PetscFunctionReturn(PETSC_SUCCESS);
4492:   }

4494:   /* Cache Mat options because some converters use MatHeaderReplace() */
4495:   issymmetric = mat->symmetric;
4496:   ishermitian = mat->hermitian;
4497:   isspd       = mat->spd;

4499:   if ((sametype || issame) && (reuse == MAT_INITIAL_MATRIX) && mat->ops->duplicate) {
4500:     PetscCall(PetscInfo(mat, "Calling duplicate for initial matrix %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4501:     PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4502:   } else {
4503:     PetscErrorCode (*conv)(Mat, MatType, MatReuse, Mat *) = NULL;
4504:     const char *prefix[3]                                 = {"seq", "mpi", ""};
4505:     PetscInt    i;
4506:     /*
4507:        Order of precedence:
4508:        0) See if newtype is a superclass of the current matrix.
4509:        1) See if a specialized converter is known to the current matrix.
4510:        2) See if a specialized converter is known to the desired matrix class.
4511:        3) See if a good general converter is registered for the desired class
4512:           (as of 6/27/03 only MATMPIADJ falls into this category).
4513:        4) See if a good general converter is known for the current matrix.
4514:        5) Use a really basic converter.
4515:     */

4517:     /* 0) See if newtype is a superclass of the current matrix.
4518:           i.e mat is mpiaij and newtype is aij */
4519:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4520:       PetscCall(PetscStrncpy(convname, prefix[i], sizeof(convname)));
4521:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4522:       PetscCall(PetscStrcmp(convname, ((PetscObject)mat)->type_name, &flg));
4523:       PetscCall(PetscInfo(mat, "Check superclass %s %s -> %d\n", convname, ((PetscObject)mat)->type_name, flg));
4524:       if (flg) {
4525:         if (reuse == MAT_INPLACE_MATRIX) {
4526:           PetscCall(PetscInfo(mat, "Early return\n"));
4527:           PetscFunctionReturn(PETSC_SUCCESS);
4528:         } else if (reuse == MAT_INITIAL_MATRIX && mat->ops->duplicate) {
4529:           PetscCall(PetscInfo(mat, "Calling MatDuplicate\n"));
4530:           PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4531:           PetscFunctionReturn(PETSC_SUCCESS);
4532:         } else if (reuse == MAT_REUSE_MATRIX && mat->ops->copy) {
4533:           PetscCall(PetscInfo(mat, "Calling MatCopy\n"));
4534:           PetscCall(MatCopy(mat, *M, SAME_NONZERO_PATTERN));
4535:           PetscFunctionReturn(PETSC_SUCCESS);
4536:         }
4537:       }
4538:     }
4539:     /* 1) See if a specialized converter is known to the current matrix and the desired class */
4540:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4541:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4542:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4543:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4544:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4545:       PetscCall(PetscStrlcat(convname, issame ? ((PetscObject)mat)->type_name : newtype, sizeof(convname)));
4546:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4547:       PetscCall(PetscObjectQueryFunction((PetscObject)mat, convname, &conv));
4548:       PetscCall(PetscInfo(mat, "Check specialized (1) %s (%s) -> %d\n", convname, ((PetscObject)mat)->type_name, !!conv));
4549:       if (conv) goto foundconv;
4550:     }

4552:     /* 2)  See if a specialized converter is known to the desired matrix class. */
4553:     PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &B));
4554:     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
4555:     PetscCall(MatSetType(B, newtype));
4556:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4557:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4558:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4559:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4560:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4561:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4562:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4563:       PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
4564:       PetscCall(PetscInfo(mat, "Check specialized (2) %s (%s) -> %d\n", convname, ((PetscObject)B)->type_name, !!conv));
4565:       if (conv) {
4566:         PetscCall(MatDestroy(&B));
4567:         goto foundconv;
4568:       }
4569:     }

4571:     /* 3) See if a good general converter is registered for the desired class */
4572:     conv = B->ops->convertfrom;
4573:     PetscCall(PetscInfo(mat, "Check convertfrom (%s) -> %d\n", ((PetscObject)B)->type_name, !!conv));
4574:     PetscCall(MatDestroy(&B));
4575:     if (conv) goto foundconv;

4577:     /* 4) See if a good general converter is known for the current matrix */
4578:     if (mat->ops->convert) conv = mat->ops->convert;
4579:     PetscCall(PetscInfo(mat, "Check general convert (%s) -> %d\n", ((PetscObject)mat)->type_name, !!conv));
4580:     if (conv) goto foundconv;

4582:     /* 5) Use a really basic converter. */
4583:     PetscCall(PetscInfo(mat, "Using MatConvert_Basic\n"));
4584:     conv = MatConvert_Basic;

4586:   foundconv:
4587:     PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4588:     PetscCall((*conv)(mat, newtype, reuse, M));
4589:     if (mat->rmap->mapping && mat->cmap->mapping && !(*M)->rmap->mapping && !(*M)->cmap->mapping) {
4590:       /* the block sizes must be same if the mappings are copied over */
4591:       (*M)->rmap->bs = mat->rmap->bs;
4592:       (*M)->cmap->bs = mat->cmap->bs;
4593:       PetscCall(PetscObjectReference((PetscObject)mat->rmap->mapping));
4594:       PetscCall(PetscObjectReference((PetscObject)mat->cmap->mapping));
4595:       (*M)->rmap->mapping = mat->rmap->mapping;
4596:       (*M)->cmap->mapping = mat->cmap->mapping;
4597:     }
4598:     (*M)->stencil.dim = mat->stencil.dim;
4599:     (*M)->stencil.noc = mat->stencil.noc;
4600:     for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4601:       (*M)->stencil.dims[i]   = mat->stencil.dims[i];
4602:       (*M)->stencil.starts[i] = mat->stencil.starts[i];
4603:     }
4604:     PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4605:   }
4606:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));

4608:   /* Reset Mat options */
4609:   if (issymmetric != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PetscBool3ToBool(issymmetric)));
4610:   if (ishermitian != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PetscBool3ToBool(ishermitian)));
4611:   if (isspd != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_SPD, PetscBool3ToBool(isspd)));
4612:   PetscFunctionReturn(PETSC_SUCCESS);
4613: }

4615: /*@
4616:   MatFactorGetSolverType - Returns name of the package providing the factorization routines

4618:   Not Collective

4620:   Input Parameter:
4621: . mat - the matrix, must be a factored matrix

4623:   Output Parameter:
4624: . type - the string name of the package (do not free this string)

4626:   Level: intermediate

4628: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolverType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`
4629: @*/
4630: PetscErrorCode MatFactorGetSolverType(Mat mat, MatSolverType *type)
4631: {
4632:   PetscErrorCode (*conv)(Mat, MatSolverType *);

4634:   PetscFunctionBegin;
4637:   PetscAssertPointer(type, 2);
4638:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
4639:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorGetSolverType_C", &conv));
4640:   if (conv) PetscCall((*conv)(mat, type));
4641:   else *type = MATSOLVERPETSC;
4642:   PetscFunctionReturn(PETSC_SUCCESS);
4643: }

4645: typedef struct _MatSolverTypeForSpecifcType *MatSolverTypeForSpecifcType;
4646: struct _MatSolverTypeForSpecifcType {
4647:   MatType mtype;
4648:   /* no entry for MAT_FACTOR_NONE */
4649:   PetscErrorCode (*createfactor[MAT_FACTOR_NUM_TYPES - 1])(Mat, MatFactorType, Mat *);
4650:   MatSolverTypeForSpecifcType next;
4651: };

4653: typedef struct _MatSolverTypeHolder *MatSolverTypeHolder;
4654: struct _MatSolverTypeHolder {
4655:   char                       *name;
4656:   MatSolverTypeForSpecifcType handlers;
4657:   MatSolverTypeHolder         next;
4658: };

4660: static MatSolverTypeHolder MatSolverTypeHolders = NULL;

4662: /*@C
4663:   MatSolverTypeRegister - Registers a `MatSolverType` that works for a particular matrix type

4665:   Logically Collective, No Fortran Support

4667:   Input Parameters:
4668: + package      - name of the package, for example `petsc` or `superlu`
4669: . mtype        - the matrix type that works with this package
4670: . ftype        - the type of factorization supported by the package
4671: - createfactor - routine that will create the factored matrix ready to be used

4673:   Level: developer

4675: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorGetSolverType()`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`,
4676:   `MatGetFactor()`
4677: @*/
4678: PetscErrorCode MatSolverTypeRegister(MatSolverType package, MatType mtype, MatFactorType ftype, PetscErrorCode (*createfactor)(Mat, MatFactorType, Mat *))
4679: {
4680:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev = NULL;
4681:   PetscBool                   flg;
4682:   MatSolverTypeForSpecifcType inext, iprev = NULL;

4684:   PetscFunctionBegin;
4685:   PetscCall(MatInitializePackage());
4686:   if (!next) {
4687:     PetscCall(PetscNew(&MatSolverTypeHolders));
4688:     PetscCall(PetscStrallocpy(package, &MatSolverTypeHolders->name));
4689:     PetscCall(PetscNew(&MatSolverTypeHolders->handlers));
4690:     PetscCall(PetscStrallocpy(mtype, (char **)&MatSolverTypeHolders->handlers->mtype));
4691:     MatSolverTypeHolders->handlers->createfactor[(int)ftype - 1] = createfactor;
4692:     PetscFunctionReturn(PETSC_SUCCESS);
4693:   }
4694:   while (next) {
4695:     PetscCall(PetscStrcasecmp(package, next->name, &flg));
4696:     if (flg) {
4697:       PetscCheck(next->handlers, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatSolverTypeHolder is missing handlers");
4698:       inext = next->handlers;
4699:       while (inext) {
4700:         PetscCall(PetscStrcasecmp(mtype, inext->mtype, &flg));
4701:         if (flg) {
4702:           inext->createfactor[(int)ftype - 1] = createfactor;
4703:           PetscFunctionReturn(PETSC_SUCCESS);
4704:         }
4705:         iprev = inext;
4706:         inext = inext->next;
4707:       }
4708:       PetscCall(PetscNew(&iprev->next));
4709:       PetscCall(PetscStrallocpy(mtype, (char **)&iprev->next->mtype));
4710:       iprev->next->createfactor[(int)ftype - 1] = createfactor;
4711:       PetscFunctionReturn(PETSC_SUCCESS);
4712:     }
4713:     prev = next;
4714:     next = next->next;
4715:   }
4716:   PetscCall(PetscNew(&prev->next));
4717:   PetscCall(PetscStrallocpy(package, &prev->next->name));
4718:   PetscCall(PetscNew(&prev->next->handlers));
4719:   PetscCall(PetscStrallocpy(mtype, (char **)&prev->next->handlers->mtype));
4720:   prev->next->handlers->createfactor[(int)ftype - 1] = createfactor;
4721:   PetscFunctionReturn(PETSC_SUCCESS);
4722: }

4724: /*@C
4725:   MatSolverTypeGet - Gets the function that creates the factor matrix if it exist

4727:   Input Parameters:
4728: + 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
4729: . ftype - the type of factorization supported by the type
4730: - mtype - the matrix type that works with this type

4732:   Output Parameters:
4733: + foundtype    - `PETSC_TRUE` if the type was registered
4734: . foundmtype   - `PETSC_TRUE` if the type supports the requested mtype
4735: - createfactor - routine that will create the factored matrix ready to be used or `NULL` if not found

4737:   Calling sequence of `createfactor`:
4738: + A     - the matrix providing the factor matrix
4739: . ftype - the `MatFactorType` of the factor requested
4740: - B     - the new factor matrix that responds to MatXXFactorSymbolic,Numeric() functions, such as `MatLUFactorSymbolic()`

4742:   Level: developer

4744:   Note:
4745:   When `type` is `NULL` the available functions are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4746:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4747:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4749: .seealso: [](ch_matrices), `Mat`, `MatFactorType`, `MatType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatSolverTypeRegister()`, `MatGetFactor()`,
4750:           `MatInitializePackage()`
4751: @*/
4752: PetscErrorCode MatSolverTypeGet(MatSolverType type, MatType mtype, MatFactorType ftype, PetscBool *foundtype, PetscBool *foundmtype, PetscErrorCode (**createfactor)(Mat A, MatFactorType ftype, Mat *B))
4753: {
4754:   MatSolverTypeHolder         next = MatSolverTypeHolders;
4755:   PetscBool                   flg;
4756:   MatSolverTypeForSpecifcType inext;

4758:   PetscFunctionBegin;
4759:   if (foundtype) *foundtype = PETSC_FALSE;
4760:   if (foundmtype) *foundmtype = PETSC_FALSE;
4761:   if (createfactor) *createfactor = NULL;

4763:   if (type) {
4764:     while (next) {
4765:       PetscCall(PetscStrcasecmp(type, next->name, &flg));
4766:       if (flg) {
4767:         if (foundtype) *foundtype = PETSC_TRUE;
4768:         inext = next->handlers;
4769:         while (inext) {
4770:           PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4771:           if (flg) {
4772:             if (foundmtype) *foundmtype = PETSC_TRUE;
4773:             if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4774:             PetscFunctionReturn(PETSC_SUCCESS);
4775:           }
4776:           inext = inext->next;
4777:         }
4778:       }
4779:       next = next->next;
4780:     }
4781:   } else {
4782:     while (next) {
4783:       inext = next->handlers;
4784:       while (inext) {
4785:         PetscCall(PetscStrcmp(mtype, inext->mtype, &flg));
4786:         if (flg && inext->createfactor[(int)ftype - 1]) {
4787:           if (foundtype) *foundtype = PETSC_TRUE;
4788:           if (foundmtype) *foundmtype = PETSC_TRUE;
4789:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4790:           PetscFunctionReturn(PETSC_SUCCESS);
4791:         }
4792:         inext = inext->next;
4793:       }
4794:       next = next->next;
4795:     }
4796:     /* try with base classes inext->mtype */
4797:     next = MatSolverTypeHolders;
4798:     while (next) {
4799:       inext = next->handlers;
4800:       while (inext) {
4801:         PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4802:         if (flg && inext->createfactor[(int)ftype - 1]) {
4803:           if (foundtype) *foundtype = PETSC_TRUE;
4804:           if (foundmtype) *foundmtype = PETSC_TRUE;
4805:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4806:           PetscFunctionReturn(PETSC_SUCCESS);
4807:         }
4808:         inext = inext->next;
4809:       }
4810:       next = next->next;
4811:     }
4812:   }
4813:   PetscFunctionReturn(PETSC_SUCCESS);
4814: }

4816: PetscErrorCode MatSolverTypeDestroy(void)
4817: {
4818:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev;
4819:   MatSolverTypeForSpecifcType inext, iprev;

4821:   PetscFunctionBegin;
4822:   while (next) {
4823:     PetscCall(PetscFree(next->name));
4824:     inext = next->handlers;
4825:     while (inext) {
4826:       PetscCall(PetscFree(inext->mtype));
4827:       iprev = inext;
4828:       inext = inext->next;
4829:       PetscCall(PetscFree(iprev));
4830:     }
4831:     prev = next;
4832:     next = next->next;
4833:     PetscCall(PetscFree(prev));
4834:   }
4835:   MatSolverTypeHolders = NULL;
4836:   PetscFunctionReturn(PETSC_SUCCESS);
4837: }

4839: /*@
4840:   MatFactorGetCanUseOrdering - Indicates if the factorization can use the ordering provided in `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`

4842:   Logically Collective

4844:   Input Parameter:
4845: . mat - the matrix

4847:   Output Parameter:
4848: . flg - `PETSC_TRUE` if uses the ordering

4850:   Level: developer

4852:   Note:
4853:   Most internal PETSc factorizations use the ordering passed to the factorization routine but external
4854:   packages do not, thus we want to skip generating the ordering when it is not needed or used.

4856: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4857: @*/
4858: PetscErrorCode MatFactorGetCanUseOrdering(Mat mat, PetscBool *flg)
4859: {
4860:   PetscFunctionBegin;
4861:   *flg = mat->canuseordering;
4862:   PetscFunctionReturn(PETSC_SUCCESS);
4863: }

4865: /*@
4866:   MatFactorGetPreferredOrdering - The preferred ordering for a particular matrix factor object

4868:   Logically Collective

4870:   Input Parameters:
4871: + mat   - the matrix obtained with `MatGetFactor()`
4872: - ftype - the factorization type to be used

4874:   Output Parameter:
4875: . otype - the preferred ordering type

4877:   Level: developer

4879: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatOrderingType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4880: @*/
4881: PetscErrorCode MatFactorGetPreferredOrdering(Mat mat, MatFactorType ftype, MatOrderingType *otype)
4882: {
4883:   PetscFunctionBegin;
4884:   *otype = mat->preferredordering[ftype];
4885:   PetscCheck(*otype, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatFactor did not have a preferred ordering");
4886:   PetscFunctionReturn(PETSC_SUCCESS);
4887: }

4889: /*@
4890:   MatGetFactor - Returns a matrix suitable to calls to routines such as `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatILUFactorSymbolic()`,
4891:   `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, and `MatCholeskyFactorNumeric()`

4893:   Collective

4895:   Input Parameters:
4896: + mat   - the matrix
4897: . 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
4898:           the other criteria is returned
4899: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4901:   Output Parameter:
4902: . f - the factor matrix used with MatXXFactorSymbolic,Numeric() calls. Can be `NULL` in some cases, see notes below.

4904:   Options Database Keys:
4905: + -pc_factor_mat_solver_type type            - choose the type at run time. When using `KSP` solvers
4906: . -pc_factor_mat_factor_on_host (true|false) - do matrix factorization on host (with device matrices). Default is doing it on device
4907: - -pc_factor_mat_solve_on_host (true|false)  - do matrix solve on host (with device matrices). Default is doing it on device

4909:   Level: intermediate

4911:   Notes:
4912:   Some of the packages, such as MUMPS, have options for controlling the factorization, these are in the form `-prefix_mat_packagename_packageoption`
4913:   (for example, `-mat_mumps_icntl_6 1`)  where `prefix` is normally set automatically from the calling `KSP`/`PC`. If `MatGetFactor()` is called directly,
4914:   without using a `PC`, one can set the prefix by
4915:   calling `MatSetOptionsPrefixFactor()` on the originating matrix or  `MatSetOptionsPrefix()` on the resulting factor matrix.

4917:   Some PETSc matrix formats have alternative solvers available that are provided by alternative packages
4918:   such as PaStiX, SuperLU_DIST, MUMPS etc. PETSc must have been configured to use the external solver,
4919:   using the corresponding `./configure` option such as `--download-package` or `--with-package-dir`.

4921:   When `type` is `NULL` the available results are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4922:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4923:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4925:   The return matrix can be `NULL` if the requested factorization is not available, since some combinations of matrix types and factorization
4926:   types registered with `MatSolverTypeRegister()` cannot be fully tested if not at runtime.

4928:   Developer Note:
4929:   This should actually be called `MatCreateFactor()` since it creates a new factor object

4931:   The `MatGetFactor()` implementations should not be accessing the PETSc options database or making other decisions about solver options,
4932:   that should be delayed until the later operations. This is to ensure the correct options prefix has been set in the factor matrix.

4934: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `KSP`, `MatSolverType`, `MatFactorType`, `MatCopy()`, `MatDuplicate()`,
4935:           `MatGetFactorAvailable()`, `MatFactorGetCanUseOrdering()`, `MatSolverTypeRegister()`, `MatSolverTypeGet()`,
4936:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatInitializePackage()`,
4937:           `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatILUFactorSymbolic()`,
4938:           `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactorNumeric()`
4939: @*/
4940: PetscErrorCode MatGetFactor(Mat mat, MatSolverType type, MatFactorType ftype, Mat *f)
4941: {
4942:   PetscBool foundtype, foundmtype, shell, hasop = PETSC_FALSE;
4943:   PetscErrorCode (*conv)(Mat, MatFactorType, Mat *);

4945:   PetscFunctionBegin;

4949:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4950:   MatCheckPreallocated(mat, 1);

4952:   PetscCall(MatIsShell(mat, &shell));
4953:   if (shell) PetscCall(MatHasOperation(mat, MATOP_GET_FACTOR, &hasop));
4954:   if (hasop) {
4955:     PetscUseTypeMethod(mat, getfactor, type, ftype, f);
4956:     PetscFunctionReturn(PETSC_SUCCESS);
4957:   }

4959:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, &foundtype, &foundmtype, &conv));
4960:   if (!foundtype) {
4961:     if (type) {
4962:       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],
4963:               ((PetscObject)mat)->type_name, type);
4964:     } else {
4965:       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);
4966:     }
4967:   }
4968:   PetscCheck(foundmtype, PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "MatSolverType %s does not support matrix type %s", type, ((PetscObject)mat)->type_name);
4969:   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);

4971:   PetscCall((*conv)(mat, ftype, f));
4972:   if (mat->factorprefix) PetscCall(MatSetOptionsPrefix(*f, mat->factorprefix));
4973:   PetscFunctionReturn(PETSC_SUCCESS);
4974: }

4976: /*@
4977:   MatGetFactorAvailable - Returns a flag if matrix supports particular type and factor type

4979:   Not Collective

4981:   Input Parameters:
4982: + mat   - the matrix
4983: . type  - name of solver type, for example, `superlu`, `petsc` (to use PETSc's default)
4984: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4986:   Output Parameter:
4987: . flg - PETSC_TRUE if the factorization is available

4989:   Level: intermediate

4991:   Notes:
4992:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
4993:   such as pastix, superlu, mumps etc.

4995:   PETSc must have been ./configure to use the external solver, using the option --download-package

4997:   Developer Note:
4998:   This should actually be called `MatCreateFactorAvailable()` since `MatGetFactor()` creates a new factor object

5000: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolverType`, `MatFactorType`, `MatGetFactor()`, `MatCopy()`, `MatDuplicate()`, `MatSolverTypeRegister()`,
5001:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatSolverTypeGet()`
5002: @*/
5003: PetscErrorCode MatGetFactorAvailable(Mat mat, MatSolverType type, MatFactorType ftype, PetscBool *flg)
5004: {
5005:   PetscErrorCode (*gconv)(Mat, MatFactorType, Mat *);

5007:   PetscFunctionBegin;
5009:   PetscAssertPointer(flg, 4);

5011:   *flg = PETSC_FALSE;
5012:   if (!((PetscObject)mat)->type_name) PetscFunctionReturn(PETSC_SUCCESS);

5014:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5015:   MatCheckPreallocated(mat, 1);

5017:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, NULL, NULL, &gconv));
5018:   *flg = gconv ? PETSC_TRUE : PETSC_FALSE;
5019:   PetscFunctionReturn(PETSC_SUCCESS);
5020: }

5022: /*@
5023:   MatDuplicate - Duplicates a matrix including the non-zero structure.

5025:   Collective

5027:   Input Parameters:
5028: + mat - the matrix
5029: - op  - One of `MAT_DO_NOT_COPY_VALUES`, `MAT_COPY_VALUES`, or `MAT_SHARE_NONZERO_PATTERN`.
5030:         See the manual page for `MatDuplicateOption()` for an explanation of these options.

5032:   Output Parameter:
5033: . M - pointer to place new matrix

5035:   Level: intermediate

5037:   Notes:
5038:   You cannot change the nonzero pattern for the parent or child matrix later if you use `MAT_SHARE_NONZERO_PATTERN`.

5040:   If `op` is not `MAT_COPY_VALUES` the numerical values in the new matrix are zeroed.

5042:   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.

5044:   When original mat is a product of matrix operation, e.g., an output of `MatMatMult()` or `MatCreateSubMatrix()`, only the matrix data structure of `mat`
5045:   is duplicated and the internal data structures created for the reuse of previous matrix operations are not duplicated.
5046:   User should not use `MatDuplicate()` to create new matrix `M` if `M` is intended to be reused as the product of matrix operation.

5048: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatConvert()`, `MatDuplicateOption`
5049: @*/
5050: PetscErrorCode MatDuplicate(Mat mat, MatDuplicateOption op, Mat *M)
5051: {
5052:   Mat               B;
5053:   VecType           vtype;
5054:   PetscInt          i;
5055:   PetscObject       dm, container_h, container_d;
5056:   PetscErrorCodeFn *viewf;

5058:   PetscFunctionBegin;
5061:   PetscAssertPointer(M, 3);
5062:   PetscCheck(op != MAT_COPY_VALUES || mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MAT_COPY_VALUES not allowed for unassembled matrix");
5063:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5064:   MatCheckPreallocated(mat, 1);

5066:   PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
5067:   PetscUseTypeMethod(mat, duplicate, op, M);
5068:   PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
5069:   B = *M;

5071:   PetscCall(MatGetOperation(mat, MATOP_VIEW, &viewf));
5072:   if (viewf) PetscCall(MatSetOperation(B, MATOP_VIEW, viewf));
5073:   PetscCall(MatGetVecType(mat, &vtype));
5074:   PetscCall(MatSetVecType(B, vtype));

5076:   B->stencil.dim = mat->stencil.dim;
5077:   B->stencil.noc = mat->stencil.noc;
5078:   for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
5079:     B->stencil.dims[i]   = mat->stencil.dims[i];
5080:     B->stencil.starts[i] = mat->stencil.starts[i];
5081:   }

5083:   B->nooffproczerorows = mat->nooffproczerorows;
5084:   B->nooffprocentries  = mat->nooffprocentries;

5086:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_dm", &dm));
5087:   if (dm) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_dm", dm));
5088:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Host", &container_h));
5089:   if (container_h) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Host", container_h));
5090:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Device", &container_d));
5091:   if (container_d) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Device", container_d));
5092:   if (op == MAT_COPY_VALUES) PetscCall(MatPropagateSymmetryOptions(mat, B));
5093:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
5094:   PetscFunctionReturn(PETSC_SUCCESS);
5095: }

5097: /*@
5098:   MatGetDiagonal - Gets the diagonal of a matrix as a `Vec`

5100:   Logically Collective

5102:   Input Parameter:
5103: . mat - the matrix

5105:   Output Parameter:
5106: . v - the diagonal of the matrix

5108:   Level: intermediate

5110:   Note:
5111:   If `mat` has local sizes `n` x `m`, this routine fills the first `ndiag = min(n, m)` entries
5112:   of `v` with the diagonal values. Thus `v` must have local size of at least `ndiag`. If `v`
5113:   is larger than `ndiag`, the values of the remaining entries are unspecified.

5115:   Currently only correct in parallel for square matrices.

5117: .seealso: [](ch_matrices), `Mat`, `Vec`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`
5118: @*/
5119: PetscErrorCode MatGetDiagonal(Mat mat, Vec v)
5120: {
5121:   PetscFunctionBegin;
5125:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5126:   MatCheckPreallocated(mat, 1);
5127:   if (PetscDefined(USE_DEBUG)) {
5128:     PetscInt nv, row, col, ndiag;

5130:     PetscCall(VecGetLocalSize(v, &nv));
5131:     PetscCall(MatGetLocalSize(mat, &row, &col));
5132:     ndiag = PetscMin(row, col);
5133:     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);
5134:   }

5136:   PetscUseTypeMethod(mat, getdiagonal, v);
5137:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5138:   PetscFunctionReturn(PETSC_SUCCESS);
5139: }

5141: /*@
5142:   MatGetRowMin - Gets the minimum value (of the real part) of each
5143:   row of the matrix

5145:   Logically Collective

5147:   Input Parameter:
5148: . mat - the matrix

5150:   Output Parameters:
5151: + v   - the vector for storing the maximums
5152: - idx - the indices of the column found for each row (optional, pass `NULL` if not needed)

5154:   Level: intermediate

5156:   Note:
5157:   The result of this call are the same as if one converted the matrix to dense format
5158:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5160:   This code is only implemented for a couple of matrix formats.

5162: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`,
5163:           `MatGetRowMax()`
5164: @*/
5165: PetscErrorCode MatGetRowMin(Mat mat, Vec v, PetscInt idx[])
5166: {
5167:   PetscFunctionBegin;
5171:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5173:   if (!mat->cmap->N) {
5174:     PetscCall(VecSet(v, PETSC_MAX_REAL));
5175:     if (idx) {
5176:       PetscInt i, m = mat->rmap->n;
5177:       for (i = 0; i < m; i++) idx[i] = -1;
5178:     }
5179:   } else {
5180:     MatCheckPreallocated(mat, 1);
5181:   }
5182:   PetscUseTypeMethod(mat, getrowmin, v, idx);
5183:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5184:   PetscFunctionReturn(PETSC_SUCCESS);
5185: }

5187: /*@
5188:   MatGetRowMinAbs - Gets the minimum value (in absolute value) of each
5189:   row of the matrix

5191:   Logically Collective

5193:   Input Parameter:
5194: . mat - the matrix

5196:   Output Parameters:
5197: + v   - the vector for storing the minimums
5198: - idx - the indices of the column found for each row (or `NULL` if not needed)

5200:   Level: intermediate

5202:   Notes:
5203:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5204:   row is 0 (the first column).

5206:   This code is only implemented for a couple of matrix formats.

5208: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`
5209: @*/
5210: PetscErrorCode MatGetRowMinAbs(Mat mat, Vec v, PetscInt idx[])
5211: {
5212:   PetscFunctionBegin;
5216:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5217:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

5219:   if (!mat->cmap->N) {
5220:     PetscCall(VecSet(v, 0.0));
5221:     if (idx) {
5222:       PetscInt i, m = mat->rmap->n;
5223:       for (i = 0; i < m; i++) idx[i] = -1;
5224:     }
5225:   } else {
5226:     MatCheckPreallocated(mat, 1);
5227:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5228:     PetscUseTypeMethod(mat, getrowminabs, v, idx);
5229:   }
5230:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5231:   PetscFunctionReturn(PETSC_SUCCESS);
5232: }

5234: /*@
5235:   MatGetRowMax - Gets the maximum value (of the real part) of each
5236:   row of the matrix

5238:   Logically Collective

5240:   Input Parameter:
5241: . mat - the matrix

5243:   Output Parameters:
5244: + v   - the vector for storing the maximums
5245: - idx - the indices of the column found for each row (optional, otherwise pass `NULL`)

5247:   Level: intermediate

5249:   Notes:
5250:   The result of this call are the same as if one converted the matrix to dense format
5251:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5253:   This code is only implemented for a couple of matrix formats.

5255: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5256: @*/
5257: PetscErrorCode MatGetRowMax(Mat mat, Vec v, PetscInt idx[])
5258: {
5259:   PetscFunctionBegin;
5263:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5265:   if (!mat->cmap->N) {
5266:     PetscCall(VecSet(v, PETSC_MIN_REAL));
5267:     if (idx) {
5268:       PetscInt i, m = mat->rmap->n;
5269:       for (i = 0; i < m; i++) idx[i] = -1;
5270:     }
5271:   } else {
5272:     MatCheckPreallocated(mat, 1);
5273:     PetscUseTypeMethod(mat, getrowmax, v, idx);
5274:   }
5275:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5276:   PetscFunctionReturn(PETSC_SUCCESS);
5277: }

5279: /*@
5280:   MatGetRowMaxAbs - Gets the maximum value (in absolute value) of each
5281:   row of the matrix

5283:   Logically Collective

5285:   Input Parameter:
5286: . mat - the matrix

5288:   Output Parameters:
5289: + v   - the vector for storing the maximums
5290: - idx - the indices of the column found for each row (or `NULL` if not needed)

5292:   Level: intermediate

5294:   Notes:
5295:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5296:   row is 0 (the first column).

5298:   This code is only implemented for a couple of matrix formats.

5300: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowSum()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5301: @*/
5302: PetscErrorCode MatGetRowMaxAbs(Mat mat, Vec v, PetscInt idx[])
5303: {
5304:   PetscFunctionBegin;
5308:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5310:   if (!mat->cmap->N) {
5311:     PetscCall(VecSet(v, 0.0));
5312:     if (idx) {
5313:       PetscInt i, m = mat->rmap->n;
5314:       for (i = 0; i < m; i++) idx[i] = -1;
5315:     }
5316:   } else {
5317:     MatCheckPreallocated(mat, 1);
5318:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5319:     PetscUseTypeMethod(mat, getrowmaxabs, v, idx);
5320:   }
5321:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5322:   PetscFunctionReturn(PETSC_SUCCESS);
5323: }

5325: /*@
5326:   MatGetRowSumAbs - Gets the sum value (in absolute value) of each row of the matrix

5328:   Logically Collective

5330:   Input Parameter:
5331: . mat - the matrix

5333:   Output Parameter:
5334: . v - the vector for storing the sum

5336:   Level: intermediate

5338:   This code is only implemented for a couple of matrix formats.

5340: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5341: @*/
5342: PetscErrorCode MatGetRowSumAbs(Mat mat, Vec v)
5343: {
5344:   PetscFunctionBegin;
5348:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5350:   if (!mat->cmap->N) PetscCall(VecSet(v, 0.0));
5351:   else {
5352:     MatCheckPreallocated(mat, 1);
5353:     PetscUseTypeMethod(mat, getrowsumabs, v);
5354:   }
5355:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5356:   PetscFunctionReturn(PETSC_SUCCESS);
5357: }

5359: /*@
5360:   MatGetRowSum - Gets the sum of each row of the matrix

5362:   Logically or Neighborhood Collective

5364:   Input Parameter:
5365: . mat - the matrix

5367:   Output Parameter:
5368: . v - the vector for storing the sum of rows

5370:   Level: intermediate

5372:   Note:
5373:   This code is slow since it is not currently specialized for different formats

5375: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`, `MatGetRowSumAbs()`
5376: @*/
5377: PetscErrorCode MatGetRowSum(Mat mat, Vec v)
5378: {
5379:   Vec ones;

5381:   PetscFunctionBegin;
5385:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5386:   MatCheckPreallocated(mat, 1);
5387:   PetscCall(MatCreateVecs(mat, &ones, NULL));
5388:   PetscCall(VecSet(ones, 1.));
5389:   PetscCall(MatMult(mat, ones, v));
5390:   PetscCall(VecDestroy(&ones));
5391:   PetscFunctionReturn(PETSC_SUCCESS);
5392: }

5394: /*@
5395:   MatTransposeSetPrecursor - Set the matrix from which the second matrix will receive numerical transpose data with a call to `MatTranspose`(A,`MAT_REUSE_MATRIX`,&B)
5396:   when B was not obtained with `MatTranspose`(A,`MAT_INITIAL_MATRIX`,&B)

5398:   Collective

5400:   Input Parameter:
5401: . mat - the matrix to provide the transpose

5403:   Output Parameter:
5404: . 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

5406:   Level: advanced

5408:   Note:
5409:   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
5410:   routine allows bypassing that call.

5412: .seealso: [](ch_matrices), `Mat`, `MatTransposeSymbolic()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5413: @*/
5414: PetscErrorCode MatTransposeSetPrecursor(Mat mat, Mat B)
5415: {
5416:   MatParentState *rb = NULL;

5418:   PetscFunctionBegin;
5419:   PetscCall(PetscNew(&rb));
5420:   rb->id    = ((PetscObject)mat)->id;
5421:   rb->state = 0;
5422:   PetscCall(MatGetNonzeroState(mat, &rb->nonzerostate));
5423:   PetscCall(PetscObjectContainerCompose((PetscObject)B, "MatTransposeParent", rb, PetscCtxDestroyDefault));
5424:   PetscFunctionReturn(PETSC_SUCCESS);
5425: }

5427: static PetscErrorCode MatTranspose_Private(Mat mat, MatReuse reuse, Mat *B, PetscBool conjugate)
5428: {
5429:   PetscContainer  rB                        = NULL;
5430:   MatParentState *rb                        = NULL;
5431:   PetscErrorCode (*f)(Mat, MatReuse, Mat *) = NULL;

5433:   PetscFunctionBegin;
5436:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5437:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5438:   PetscCheck(reuse != MAT_INPLACE_MATRIX || mat == *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires last matrix to match first");
5439:   PetscCheck(reuse != MAT_REUSE_MATRIX || mat != *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Perhaps you mean MAT_INPLACE_MATRIX");
5440:   MatCheckPreallocated(mat, 1);
5441:   if (reuse == MAT_REUSE_MATRIX) {
5442:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5443:     PetscCheck(rB, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose(). Suggest MatTransposeSetPrecursor().");
5444:     PetscCall(PetscContainerGetPointer(rB, &rb));
5445:     PetscCheck(rb->id == ((PetscObject)mat)->id, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5446:     if (rb->state == ((PetscObject)mat)->state) PetscFunctionReturn(PETSC_SUCCESS);
5447:   }

5449:   if (conjugate) {
5450:     f = mat->ops->hermitiantranspose;
5451:     if (f) PetscCall((*f)(mat, reuse, B));
5452:   }
5453:   if (!f && !(reuse == MAT_INPLACE_MATRIX && mat->hermitian == PETSC_BOOL3_TRUE && conjugate)) {
5454:     PetscCall(PetscLogEventBegin(MAT_Transpose, mat, 0, 0, 0));
5455:     if (reuse != MAT_INPLACE_MATRIX || mat->symmetric != PETSC_BOOL3_TRUE) {
5456:       PetscUseTypeMethod(mat, transpose, reuse, B);
5457:       PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5458:     }
5459:     PetscCall(PetscLogEventEnd(MAT_Transpose, mat, 0, 0, 0));
5460:     if (conjugate) PetscCall(MatConjugate(*B));
5461:   }

5463:   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatTransposeSetPrecursor(mat, *B));
5464:   if (reuse != MAT_INPLACE_MATRIX) {
5465:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5466:     PetscCall(PetscContainerGetPointer(rB, &rb));
5467:     rb->state        = ((PetscObject)mat)->state;
5468:     rb->nonzerostate = mat->nonzerostate;
5469:   }
5470:   PetscFunctionReturn(PETSC_SUCCESS);
5471: }

5473: /*@
5474:   MatTranspose - Computes the transpose of a matrix, either in-place or out-of-place.

5476:   Collective

5478:   Input Parameters:
5479: + mat   - the matrix to transpose
5480: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5482:   Output Parameter:
5483: . B - the transpose of the matrix

5485:   Level: intermediate

5487:   Notes:
5488:   If you use `MAT_INPLACE_MATRIX` then you must pass in `&mat` for `B`

5490:   `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
5491:   transpose, call `MatTransposeSetPrecursor(mat, B)` before calling this routine.

5493:   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.

5495:   Consider using `MatCreateTranspose()` instead if you only need a matrix that behaves like the transpose but don't need the storage to be changed.
5496:   For example, the result of `MatCreateTranspose()` will compute the transpose of the given matrix times a vector for matrix-vector products computed with `MatMult()`.

5498:   If `mat` is unchanged from the last call this function returns immediately without recomputing the result

5500:   If you only need the symbolic transpose of a matrix, and not the numerical values, use `MatTransposeSymbolic()`

5502: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`,
5503:           `MatTransposeSymbolic()`, `MatCreateTranspose()`
5504: @*/
5505: PetscErrorCode MatTranspose(Mat mat, MatReuse reuse, Mat *B)
5506: {
5507:   PetscFunctionBegin;
5508:   PetscCall(MatTranspose_Private(mat, reuse, B, PETSC_FALSE));
5509:   PetscFunctionReturn(PETSC_SUCCESS);
5510: }

5512: /*@
5513:   MatTransposeSymbolic - Computes the symbolic part of the transpose of a matrix.

5515:   Collective

5517:   Input Parameter:
5518: . A - the matrix to transpose

5520:   Output Parameter:
5521: . 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
5522:       numerical portion.

5524:   Level: intermediate

5526:   Note:
5527:   This is not supported for many matrix types, use `MatTranspose()` in those cases

5529: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5530: @*/
5531: PetscErrorCode MatTransposeSymbolic(Mat A, Mat *B)
5532: {
5533:   PetscFunctionBegin;
5536:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5537:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5538:   PetscCall(PetscLogEventBegin(MAT_Transpose, A, 0, 0, 0));
5539:   PetscUseTypeMethod(A, transposesymbolic, B);
5540:   PetscCall(PetscLogEventEnd(MAT_Transpose, A, 0, 0, 0));

5542:   PetscCall(MatTransposeSetPrecursor(A, *B));
5543:   PetscFunctionReturn(PETSC_SUCCESS);
5544: }

5546: PetscErrorCode MatTransposeCheckNonzeroState_Private(Mat A, Mat B)
5547: {
5548:   PetscContainer  rB;
5549:   MatParentState *rb;

5551:   PetscFunctionBegin;
5554:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5555:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5556:   PetscCall(PetscObjectQuery((PetscObject)B, "MatTransposeParent", (PetscObject *)&rB));
5557:   PetscCheck(rB, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose()");
5558:   PetscCall(PetscContainerGetPointer(rB, &rb));
5559:   PetscCheck(rb->id == ((PetscObject)A)->id, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5560:   PetscCheck(rb->nonzerostate == A->nonzerostate, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Reuse matrix has changed nonzero structure");
5561:   PetscFunctionReturn(PETSC_SUCCESS);
5562: }

5564: /*@
5565:   MatIsTranspose - Test whether a matrix is another one's transpose,
5566:   or its own, in which case it tests symmetry.

5568:   Collective

5570:   Input Parameters:
5571: + A   - the matrix to test
5572: . B   - the matrix to test against, this can equal the first parameter
5573: - tol - tolerance, differences between entries smaller than this are counted as zero

5575:   Output Parameter:
5576: . flg - the result

5578:   Level: intermediate

5580:   Notes:
5581:   The sequential algorithm has a running time of the order of the number of nonzeros; the parallel
5582:   test involves parallel copies of the block off-diagonal parts of the matrix.

5584: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`
5585: @*/
5586: PetscErrorCode MatIsTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5587: {
5588:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5590:   PetscFunctionBegin;
5593:   PetscAssertPointer(flg, 4);
5594:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsTranspose_C", &f));
5595:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsTranspose_C", &g));
5596:   *flg = PETSC_FALSE;
5597:   if (f && g) {
5598:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for symmetry test");
5599:     PetscCall((*f)(A, B, tol, flg));
5600:   } else {
5601:     MatType mattype;

5603:     PetscCall(MatGetType(f ? B : A, &mattype));
5604:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for transpose", mattype);
5605:   }
5606:   PetscFunctionReturn(PETSC_SUCCESS);
5607: }

5609: /*@
5610:   MatHermitianTranspose - Computes an in-place or out-of-place Hermitian transpose of a matrix in complex conjugate.

5612:   Collective

5614:   Input Parameters:
5615: + mat   - the matrix to transpose and complex conjugate
5616: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5618:   Output Parameter:
5619: . B - the Hermitian transpose

5621:   Level: intermediate

5623: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`
5624: @*/
5625: PetscErrorCode MatHermitianTranspose(Mat mat, MatReuse reuse, Mat *B)
5626: {
5627:   PetscFunctionBegin;
5628:   PetscCall(MatTranspose_Private(mat, reuse, B, PETSC_TRUE));
5629:   PetscFunctionReturn(PETSC_SUCCESS);
5630: }

5632: /*@
5633:   MatIsHermitianTranspose - Test whether a matrix is another one's Hermitian transpose,

5635:   Collective

5637:   Input Parameters:
5638: + A   - the matrix to test
5639: . B   - the matrix to test against, this can equal the first parameter
5640: - tol - tolerance, differences between entries smaller than this are counted as zero

5642:   Output Parameter:
5643: . flg - the result

5645:   Level: intermediate

5647:   Notes:
5648:   Only available for `MATAIJ` matrices.

5650:   The sequential algorithm
5651:   has a running time of the order of the number of nonzeros; the parallel
5652:   test involves parallel copies of the block off-diagonal parts of the matrix.

5654: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsTranspose()`
5655: @*/
5656: PetscErrorCode MatIsHermitianTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5657: {
5658:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5660:   PetscFunctionBegin;
5663:   PetscAssertPointer(flg, 4);
5664:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsHermitianTranspose_C", &f));
5665:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsHermitianTranspose_C", &g));
5666:   if (f && g) {
5667:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for Hermitian test");
5668:     PetscCall((*f)(A, B, tol, flg));
5669:   } else {
5670:     MatType mattype;

5672:     PetscCall(MatGetType(f ? B : A, &mattype));
5673:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for Hermitian transpose", mattype);
5674:   }
5675:   PetscFunctionReturn(PETSC_SUCCESS);
5676: }

5678: /*@
5679:   MatPermute - Creates a new matrix with rows and columns permuted from the
5680:   original.

5682:   Collective

5684:   Input Parameters:
5685: + mat - the matrix to permute
5686: . row - row permutation, each processor supplies only the permutation for its rows
5687: - col - column permutation, each processor supplies only the permutation for its columns

5689:   Output Parameter:
5690: . B - the permuted matrix

5692:   Level: advanced

5694:   Note:
5695:   The index sets map from row/col of permuted matrix to row/col of original matrix.
5696:   The index sets should be on the same communicator as mat and have the same local sizes.

5698:   Developer Note:
5699:   If you want to implement `MatPermute()` for a matrix type, and your approach doesn't
5700:   exploit the fact that row and col are permutations, consider implementing the
5701:   more general `MatCreateSubMatrix()` instead.

5703: .seealso: [](ch_matrices), `Mat`, `MatGetOrdering()`, `ISAllGather()`, `MatCreateSubMatrix()`
5704: @*/
5705: PetscErrorCode MatPermute(Mat mat, IS row, IS col, Mat *B)
5706: {
5707:   PetscFunctionBegin;
5712:   PetscAssertPointer(B, 4);
5713:   PetscCheckSameComm(mat, 1, row, 2);
5714:   if (row != col) PetscCheckSameComm(row, 2, col, 3);
5715:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5716:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5717:   PetscCheck(mat->ops->permute || mat->ops->createsubmatrix, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatPermute not available for Mat type %s", ((PetscObject)mat)->type_name);
5718:   MatCheckPreallocated(mat, 1);

5720:   if (mat->ops->permute) {
5721:     PetscUseTypeMethod(mat, permute, row, col, B);
5722:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5723:   } else {
5724:     PetscCall(MatCreateSubMatrix(mat, row, col, MAT_INITIAL_MATRIX, B));
5725:   }
5726:   PetscFunctionReturn(PETSC_SUCCESS);
5727: }

5729: /*@
5730:   MatEqual - Compares two matrices.

5732:   Collective

5734:   Input Parameters:
5735: + A - the first matrix
5736: - B - the second matrix

5738:   Output Parameter:
5739: . flg - `PETSC_TRUE` if the matrices are equal; `PETSC_FALSE` otherwise.

5741:   Level: intermediate

5743:   Note:
5744:   If either of the matrix is "matrix-free", meaning the matrix entries are not stored explicitly then equality is determined by comparing
5745:   the results of several matrix-vector product using randomly created vectors, see `MatMultEqual()`.

5747: .seealso: [](ch_matrices), `Mat`, `MatMultEqual()`
5748: @*/
5749: PetscErrorCode MatEqual(Mat A, Mat B, PetscBool *flg)
5750: {
5751:   PetscFunctionBegin;
5756:   PetscAssertPointer(flg, 3);
5757:   PetscCheckSameComm(A, 1, B, 2);
5758:   MatCheckPreallocated(A, 1);
5759:   MatCheckPreallocated(B, 2);
5760:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5761:   PetscCheck(B->assembled, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5762:   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,
5763:              B->cmap->N);
5764:   if (A->ops->equal && A->ops->equal == B->ops->equal) PetscUseTypeMethod(A, equal, B, flg);
5765:   else PetscCall(MatMultEqual(A, B, 10, flg));
5766:   PetscFunctionReturn(PETSC_SUCCESS);
5767: }

5769: /*@
5770:   MatDiagonalScale - Scales a matrix on the left and right by diagonal
5771:   matrices that are stored as vectors.  Either of the two scaling
5772:   matrices can be `NULL`.

5774:   Collective

5776:   Input Parameters:
5777: + mat - the matrix to be scaled
5778: . l   - the left scaling vector (or `NULL`)
5779: - r   - the right scaling vector (or `NULL`)

5781:   Level: intermediate

5783:   Note:
5784:   `MatDiagonalScale()` computes $A = LAR$, where
5785:   L = a diagonal matrix (stored as a vector), R = a diagonal matrix (stored as a vector)
5786:   The L scales the rows of the matrix, the R scales the columns of the matrix.

5788: .seealso: [](ch_matrices), `Mat`, `MatScale()`, `MatShift()`, `MatDiagonalSet()`
5789: @*/
5790: PetscErrorCode MatDiagonalScale(Mat mat, Vec l, Vec r)
5791: {
5792:   PetscBool flg = PETSC_FALSE;

5794:   PetscFunctionBegin;
5797:   if (l) {
5799:     PetscCheckSameComm(mat, 1, l, 2);
5800:   }
5801:   if (r) {
5803:     PetscCheckSameComm(mat, 1, r, 3);
5804:   }
5805:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5806:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5807:   MatCheckPreallocated(mat, 1);
5808:   if (!l && !r) PetscFunctionReturn(PETSC_SUCCESS);

5810:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5811:   PetscUseTypeMethod(mat, diagonalscale, l, r);
5812:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5813:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5814:   if (l != r && (PetscBool3ToBool(mat->symmetric) || PetscBool3ToBool(mat->hermitian))) {
5815:     if (!PetscDefined(USE_COMPLEX) || PetscBool3ToBool(mat->symmetric)) {
5816:       if (l && r) PetscCall(VecEqual(l, r, &flg));
5817:       if (!flg) {
5818:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
5819:         PetscCheck(!flg, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "For symmetric format, left and right scaling vectors must be the same");
5820:         mat->symmetric = mat->spd = PETSC_BOOL3_FALSE;
5821:         if (!PetscDefined(USE_COMPLEX)) mat->hermitian = PETSC_BOOL3_FALSE;
5822:         else mat->hermitian = PETSC_BOOL3_UNKNOWN;
5823:       }
5824:     }
5825:     if (PetscDefined(USE_COMPLEX) && PetscBool3ToBool(mat->hermitian)) {
5826:       flg = PETSC_FALSE;
5827:       if (l && r) {
5828:         Vec conjugate;

5830:         PetscCall(VecDuplicate(l, &conjugate));
5831:         PetscCall(VecCopy(l, conjugate));
5832:         PetscCall(VecConjugate(conjugate));
5833:         PetscCall(VecEqual(conjugate, r, &flg));
5834:         PetscCall(VecDestroy(&conjugate));
5835:       }
5836:       if (!flg) {
5837:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
5838:         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");
5839:         mat->hermitian = PETSC_BOOL3_FALSE;
5840:         mat->symmetric = mat->spd = PETSC_BOOL3_UNKNOWN;
5841:       }
5842:     }
5843:   }
5844:   PetscFunctionReturn(PETSC_SUCCESS);
5845: }

5847: /*@
5848:   MatScale - Scales all elements of a matrix by a given number.

5850:   Logically Collective

5852:   Input Parameters:
5853: + mat - the matrix to be scaled
5854: - a   - the scaling value

5856:   Level: intermediate

5858: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
5859: @*/
5860: PetscErrorCode MatScale(Mat mat, PetscScalar a)
5861: {
5862:   PetscFunctionBegin;
5865:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5866:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5868:   MatCheckPreallocated(mat, 1);

5870:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5871:   if (a != (PetscScalar)1.0) {
5872:     PetscUseTypeMethod(mat, scale, a);
5873:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5874:   }
5875:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5876:   PetscFunctionReturn(PETSC_SUCCESS);
5877: }

5879: /*@
5880:   MatNorm - Calculates various norms of a matrix.

5882:   Collective

5884:   Input Parameters:
5885: + mat  - the matrix
5886: - type - the type of norm, `NORM_1`, `NORM_FROBENIUS`, `NORM_INFINITY`

5888:   Output Parameter:
5889: . nrm - the resulting norm

5891:   Level: intermediate

5893: .seealso: [](ch_matrices), `Mat`
5894: @*/
5895: PetscErrorCode MatNorm(Mat mat, NormType type, PetscReal *nrm)
5896: {
5897:   PetscFunctionBegin;
5900:   PetscAssertPointer(nrm, 3);

5902:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5903:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5904:   MatCheckPreallocated(mat, 1);

5906:   PetscUseTypeMethod(mat, norm, type, nrm);
5907:   PetscFunctionReturn(PETSC_SUCCESS);
5908: }

5910: /*
5911:      This variable is used to prevent counting of MatAssemblyBegin() that
5912:    are called from within a MatAssemblyEnd().
5913: */
5914: static PetscInt MatAssemblyEnd_InUse = 0;
5915: /*@
5916:   MatAssemblyBegin - Begins assembling the matrix.  This routine should
5917:   be called after completing all calls to `MatSetValues()`.

5919:   Collective

5921:   Input Parameters:
5922: + mat  - the matrix
5923: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5925:   Level: beginner

5927:   Notes:
5928:   `MatSetValues()` generally caches the values that belong to other MPI processes.  The matrix is ready to
5929:   use only after `MatAssemblyBegin()` and `MatAssemblyEnd()` have been called.

5931:   Use `MAT_FLUSH_ASSEMBLY` when switching between `ADD_VALUES` and `INSERT_VALUES`
5932:   in `MatSetValues()`; use `MAT_FINAL_ASSEMBLY` for the final assembly before
5933:   using the matrix.

5935:   ALL processes that share a matrix MUST call `MatAssemblyBegin()` and `MatAssemblyEnd()` the SAME NUMBER of times, and each time with the
5936:   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
5937:   a global collective operation requiring all processes that share the matrix.

5939:   Space for preallocated nonzeros that is not filled by a call to `MatSetValues()` or a related routine are compressed
5940:   out by assembly. If you intend to use that extra space on a subsequent assembly, be sure to insert explicit zeros
5941:   before `MAT_FINAL_ASSEMBLY` so the space is not compressed out.

5943: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssembled()`
5944: @*/
5945: PetscErrorCode MatAssemblyBegin(Mat mat, MatAssemblyType type)
5946: {
5947:   PetscFunctionBegin;
5950:   MatCheckPreallocated(mat, 1);
5951:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix. Did you forget to call MatSetUnfactored()?");
5952:   if (mat->assembled) {
5953:     mat->was_assembled = PETSC_TRUE;
5954:     mat->assembled     = PETSC_FALSE;
5955:   }

5957:   if (!MatAssemblyEnd_InUse) {
5958:     PetscCall(PetscLogEventBegin(MAT_AssemblyBegin, mat, 0, 0, 0));
5959:     PetscTryTypeMethod(mat, assemblybegin, type);
5960:     PetscCall(PetscLogEventEnd(MAT_AssemblyBegin, mat, 0, 0, 0));
5961:   } else PetscTryTypeMethod(mat, assemblybegin, type);
5962:   PetscFunctionReturn(PETSC_SUCCESS);
5963: }

5965: /*@
5966:   MatAssembled - Indicates if a matrix has been assembled and is ready for
5967:   use; for example, in matrix-vector product.

5969:   Not Collective

5971:   Input Parameter:
5972: . mat - the matrix

5974:   Output Parameter:
5975: . assembled - `PETSC_TRUE` or `PETSC_FALSE`

5977:   Level: advanced

5979: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssemblyBegin()`
5980: @*/
5981: PetscErrorCode MatAssembled(Mat mat, PetscBool *assembled)
5982: {
5983:   PetscFunctionBegin;
5985:   PetscAssertPointer(assembled, 2);
5986:   *assembled = mat->assembled;
5987:   PetscFunctionReturn(PETSC_SUCCESS);
5988: }

5990: /*@
5991:   MatAssemblyEnd - Completes assembling the matrix.  This routine should
5992:   be called after `MatAssemblyBegin()`.

5994:   Collective

5996:   Input Parameters:
5997: + mat  - the matrix
5998: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

6000:   Options Database Key:
6001: . -mat_view [viewertype][:...] - option name and values. See `MatViewFromOptions()`/`PetscObjectViewFromOptions()` for the possible arguments

6003:   Level: beginner

6005: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatSetValues()`, `PetscDrawOpenX()`, `PetscDrawCreate()`, `MatView()`, `MatAssembled()`, `PetscViewerSocketOpen()`,
6006:           `MatViewFromOptions()`, `PetscObjectViewFromOptions()`
6007: @*/
6008: PetscErrorCode MatAssemblyEnd(Mat mat, MatAssemblyType type)
6009: {
6010:   static PetscInt inassm = 0;
6011:   PetscBool       flg    = PETSC_FALSE;

6013:   PetscFunctionBegin;

6017:   inassm++;
6018:   MatAssemblyEnd_InUse++;
6019:   if (MatAssemblyEnd_InUse == 1) { /* Do the logging only the first time through */
6020:     PetscCall(PetscLogEventBegin(MAT_AssemblyEnd, mat, 0, 0, 0));
6021:     PetscTryTypeMethod(mat, assemblyend, type);
6022:     PetscCall(PetscLogEventEnd(MAT_AssemblyEnd, mat, 0, 0, 0));
6023:   } else PetscTryTypeMethod(mat, assemblyend, type);

6025:   /* Flush assembly is not a true assembly */
6026:   if (type != MAT_FLUSH_ASSEMBLY) {
6027:     if (mat->num_ass) {
6028:       if (!mat->symmetry_eternal) {
6029:         mat->symmetric = PETSC_BOOL3_UNKNOWN;
6030:         mat->hermitian = PETSC_BOOL3_UNKNOWN;
6031:       }
6032:       if (!mat->structural_symmetry_eternal && mat->ass_nonzerostate != mat->nonzerostate) mat->structurally_symmetric = PETSC_BOOL3_UNKNOWN;
6033:       if (!mat->spd_eternal) mat->spd = PETSC_BOOL3_UNKNOWN;
6034:     }
6035:     mat->num_ass++;
6036:     mat->assembled        = PETSC_TRUE;
6037:     mat->ass_nonzerostate = mat->nonzerostate;
6038:   }

6040:   mat->insertmode = NOT_SET_VALUES;
6041:   MatAssemblyEnd_InUse--;
6042:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6043:   if (inassm == 1 && type != MAT_FLUSH_ASSEMBLY) {
6044:     PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));

6046:     if (mat->checksymmetryonassembly) {
6047:       PetscCall(MatIsSymmetric(mat, mat->checksymmetrytol, &flg));
6048:       if (flg) {
6049:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
6050:       } else {
6051:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is not symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
6052:       }
6053:     }
6054:     if (mat->nullsp && mat->checknullspaceonassembly) PetscCall(MatNullSpaceTest(mat->nullsp, mat, NULL));
6055:   }
6056:   inassm--;
6057:   PetscFunctionReturn(PETSC_SUCCESS);
6058: }

6060: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
6061: /*@
6062:   MatSetOption - Sets a parameter option for a matrix. Some options
6063:   may be specific to certain storage formats.  Some options
6064:   determine how values will be inserted (or added). Sorted,
6065:   row-oriented input will generally assemble the fastest. The default
6066:   is row-oriented.

6068:   Logically Collective for certain operations, such as `MAT_SPD`, not collective for `MAT_ROW_ORIENTED`, see `MatOption`

6070:   Input Parameters:
6071: + mat - the matrix
6072: . op  - the option, one of those listed below (and possibly others),
6073: - flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6075:   Options Describing Matrix Structure:
6076: + `MAT_SPD`                         - symmetric positive definite
6077: . `MAT_SYMMETRIC`                   - symmetric in terms of both structure and value
6078: . `MAT_HERMITIAN`                   - transpose is the complex conjugation
6079: . `MAT_STRUCTURALLY_SYMMETRIC`      - symmetric nonzero structure
6080: . `MAT_SYMMETRY_ETERNAL`            - indicates the symmetry (or Hermitian structure) or its absence will persist through any changes to the matrix
6081: . `MAT_STRUCTURAL_SYMMETRY_ETERNAL` - indicates the structural symmetry or its absence will persist through any changes to the matrix
6082: . `MAT_SPD_ETERNAL`                 - indicates the value of `MAT_SPD` (true or false) will persist through any changes to the matrix

6084:    These are not really options of the matrix, they are knowledge about the structure of the matrix that users may provide so that they
6085:    do not need to be computed (usually at a high cost)

6087:    Options For Use with `MatSetValues()`:
6088:    Insert a logically dense subblock, which can be
6089: . `MAT_ROW_ORIENTED`                - row-oriented (default)

6091:    These options reflect the data you pass in with `MatSetValues()`; it has
6092:    nothing to do with how the data is stored internally in the matrix
6093:    data structure.

6095:    When (re)assembling a matrix, we can restrict the input for
6096:    efficiency/debugging purposes.  These options include
6097: . `MAT_NEW_NONZERO_LOCATIONS`       - additional insertions will be allowed if they generate a new nonzero (slow)
6098: . `MAT_FORCE_DIAGONAL_ENTRIES`      - forces diagonal entries to be allocated
6099: . `MAT_IGNORE_OFF_PROC_ENTRIES`     - drops off-processor entries
6100: . `MAT_NEW_NONZERO_LOCATION_ERR`    - generates an error for new matrix entry
6101: . `MAT_USE_HASH_TABLE`              - uses a hash table to speed up matrix assembly
6102: . `MAT_NO_OFF_PROC_ENTRIES`         - you know each process will only set values for its own rows, will generate an error if
6103:         any process sets values for another process. This avoids all reductions in the MatAssembly routines and thus improves
6104:         performance for very large process counts.
6105: - `MAT_SUBSET_OFF_PROC_ENTRIES`     - you know that the first assembly after setting this flag will set a superset
6106:         of the off-process entries required for all subsequent assemblies. This avoids a rendezvous step in the MatAssembly
6107:         functions, instead sending only neighbor messages.

6109:   Level: intermediate

6111:   Notes:
6112:   Except for `MAT_UNUSED_NONZERO_LOCATION_ERR` and  `MAT_ROW_ORIENTED` all processes that share the matrix must pass the same value in flg!

6114:   Some options are relevant only for particular matrix types and
6115:   are thus ignored by others.  Other options are not supported by
6116:   certain matrix types and will generate an error message if set.

6118:   If using Fortran to compute a matrix, one may need to
6119:   use the column-oriented option (or convert to the row-oriented
6120:   format).

6122:   `MAT_NEW_NONZERO_LOCATIONS` set to `PETSC_FALSE` indicates that any add or insertion
6123:   that would generate a new entry in the nonzero structure is instead
6124:   ignored.  Thus, if memory has not already been allocated for this particular
6125:   data, then the insertion is ignored. For dense matrices, in which
6126:   the entire array is allocated, no entries are ever ignored.
6127:   Set after the first `MatAssemblyEnd()`. If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6129:   `MAT_NEW_NONZERO_LOCATION_ERR` set to PETSC_TRUE indicates that any add or insertion
6130:   that would generate a new entry in the nonzero structure instead produces
6131:   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

6133:   `MAT_NEW_NONZERO_ALLOCATION_ERR` set to `PETSC_TRUE` indicates that any add or insertion
6134:   that would generate a new entry that has not been preallocated will
6135:   instead produce an error. (Currently supported for `MATAIJ` and `MATBAIJ` formats
6136:   only.) This is a useful flag when debugging matrix memory preallocation.
6137:   If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6139:   `MAT_IGNORE_OFF_PROC_ENTRIES` set to `PETSC_TRUE` indicates entries destined for
6140:   other processors should be dropped, rather than stashed.
6141:   This is useful if you know that the "owning" processor is also
6142:   always generating the correct matrix entries, so that PETSc need
6143:   not transfer duplicate entries generated on another processor.

6145:   `MAT_USE_HASH_TABLE` indicates that a hash table be used to improve the
6146:   searches during matrix assembly. When this flag is set, the hash table
6147:   is created during the first matrix assembly. This hash table is
6148:   used the next time through, during `MatSetValues()`/`MatSetValuesBlocked()`
6149:   to improve the searching of indices. `MAT_NEW_NONZERO_LOCATIONS` flag
6150:   should be used with `MAT_USE_HASH_TABLE` flag. This option is currently
6151:   supported by `MATMPIBAIJ` format only.

6153:   `MAT_KEEP_NONZERO_PATTERN` indicates when `MatZeroRows()` is called the zeroed entries
6154:   are kept in the nonzero structure. This flag is not used for `MatZeroRowsColumns()`

6156:   `MAT_IGNORE_ZERO_ENTRIES` - for `MATAIJ` and `MATIS` matrices this will stop zero values from creating
6157:   a zero location in the matrix

6159:   `MAT_USE_INODES` - indicates using inode version of the code - works with `MATAIJ` matrix types

6161:   `MAT_NO_OFF_PROC_ZERO_ROWS` - you know each process will only zero its own rows. This avoids all reductions in the
6162:   zero row routines and thus improves performance for very large process counts.

6164:   `MAT_IGNORE_LOWER_TRIANGULAR` - For `MATSBAIJ` matrices will ignore any insertions you make in the lower triangular
6165:   part of the matrix (since they should match the upper triangular part).

6167:   `MAT_SORTED_FULL` - each process provides exactly its local rows; all column indices for a given row are passed in a
6168:   single call to `MatSetValues()`, preallocation is perfect, row-oriented, `INSERT_VALUES` is used. Common
6169:   with finite difference schemes with non-periodic boundary conditions.

6171:   Developer Note:
6172:   `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, and `MAT_SPD_ETERNAL` are used by `MatAssemblyEnd()` and in other
6173:   places where otherwise the value of `MAT_SYMMETRIC`, `MAT_STRUCTURALLY_SYMMETRIC` or `MAT_SPD` would need to be changed back
6174:   to `PETSC_BOOL3_UNKNOWN` because the matrix values had changed so the code cannot be certain that the related property had
6175:   not changed.

6177: .seealso: [](ch_matrices), `MatOption`, `Mat`, `MatGetOption()`
6178: @*/
6179: PetscErrorCode MatSetOption(Mat mat, MatOption op, PetscBool flg)
6180: {
6181:   PetscFunctionBegin;
6183:   if (op > 0) {
6186:   }

6188:   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);

6190:   switch (op) {
6191:   case MAT_FORCE_DIAGONAL_ENTRIES:
6192:     mat->force_diagonals = flg;
6193:     PetscFunctionReturn(PETSC_SUCCESS);
6194:   case MAT_NO_OFF_PROC_ENTRIES:
6195:     mat->nooffprocentries = flg;
6196:     PetscFunctionReturn(PETSC_SUCCESS);
6197:   case MAT_SUBSET_OFF_PROC_ENTRIES:
6198:     mat->assembly_subset = flg;
6199:     if (!mat->assembly_subset) { /* See the same logic in VecAssembly wrt VEC_SUBSET_OFF_PROC_ENTRIES */
6200: #if !defined(PETSC_HAVE_MPIUNI)
6201:       PetscCall(MatStashScatterDestroy_BTS(&mat->stash));
6202: #endif
6203:       mat->stash.first_assembly_done = PETSC_FALSE;
6204:     }
6205:     PetscFunctionReturn(PETSC_SUCCESS);
6206:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6207:     mat->nooffproczerorows = flg;
6208:     PetscFunctionReturn(PETSC_SUCCESS);
6209:   case MAT_SPD:
6210:     if (flg) {
6211:       mat->spd                    = PETSC_BOOL3_TRUE;
6212:       mat->symmetric              = PETSC_BOOL3_TRUE;
6213:       mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6214: #if !defined(PETSC_USE_COMPLEX)
6215:       mat->hermitian = PETSC_BOOL3_TRUE;
6216: #endif
6217:     } else {
6218:       mat->spd = PETSC_BOOL3_FALSE;
6219:     }
6220:     break;
6221:   case MAT_SYMMETRIC:
6222:     mat->symmetric = PetscBoolToBool3(flg);
6223:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6224: #if !defined(PETSC_USE_COMPLEX)
6225:     mat->hermitian = PetscBoolToBool3(flg);
6226: #endif
6227:     break;
6228:   case MAT_HERMITIAN:
6229:     mat->hermitian = PetscBoolToBool3(flg);
6230:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6231: #if !defined(PETSC_USE_COMPLEX)
6232:     mat->symmetric = PetscBoolToBool3(flg);
6233: #endif
6234:     break;
6235:   case MAT_STRUCTURALLY_SYMMETRIC:
6236:     mat->structurally_symmetric = PetscBoolToBool3(flg);
6237:     break;
6238:   case MAT_SYMMETRY_ETERNAL:
6239:     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");
6240:     mat->symmetry_eternal = flg;
6241:     if (flg) mat->structural_symmetry_eternal = PETSC_TRUE;
6242:     break;
6243:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6244:     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");
6245:     mat->structural_symmetry_eternal = flg;
6246:     break;
6247:   case MAT_SPD_ETERNAL:
6248:     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");
6249:     mat->spd_eternal = flg;
6250:     if (flg) {
6251:       mat->structural_symmetry_eternal = PETSC_TRUE;
6252:       mat->symmetry_eternal            = PETSC_TRUE;
6253:     }
6254:     break;
6255:   case MAT_STRUCTURE_ONLY:
6256:     mat->structure_only = flg;
6257:     break;
6258:   case MAT_SORTED_FULL:
6259:     mat->sortedfull = flg;
6260:     break;
6261:   default:
6262:     break;
6263:   }
6264:   PetscTryTypeMethod(mat, setoption, op, flg);
6265:   PetscFunctionReturn(PETSC_SUCCESS);
6266: }

6268: /*@
6269:   MatGetOption - Gets a parameter option that has been set for a matrix.

6271:   Logically Collective

6273:   Input Parameters:
6274: + mat - the matrix
6275: - op  - the option, this only responds to certain options, check the code for which ones

6277:   Output Parameter:
6278: . flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6280:   Level: intermediate

6282:   Notes:
6283:   Can only be called after `MatSetSizes()` and `MatSetType()` have been set.

6285:   Certain option values may be unknown, for those use the routines `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, or
6286:   `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`

6288: .seealso: [](ch_matrices), `Mat`, `MatOption`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`,
6289:     `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
6290: @*/
6291: PetscErrorCode MatGetOption(Mat mat, MatOption op, PetscBool *flg)
6292: {
6293:   PetscFunctionBegin;

6297:   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);
6298:   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()");

6300:   switch (op) {
6301:   case MAT_NO_OFF_PROC_ENTRIES:
6302:     *flg = mat->nooffprocentries;
6303:     break;
6304:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6305:     *flg = mat->nooffproczerorows;
6306:     break;
6307:   case MAT_SYMMETRIC:
6308:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSymmetric() or MatIsSymmetricKnown()");
6309:     break;
6310:   case MAT_HERMITIAN:
6311:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsHermitian() or MatIsHermitianKnown()");
6312:     break;
6313:   case MAT_STRUCTURALLY_SYMMETRIC:
6314:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsStructurallySymmetric() or MatIsStructurallySymmetricKnown()");
6315:     break;
6316:   case MAT_SPD:
6317:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSPDKnown()");
6318:     break;
6319:   case MAT_SYMMETRY_ETERNAL:
6320:     *flg = mat->symmetry_eternal;
6321:     break;
6322:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6323:     *flg = mat->symmetry_eternal;
6324:     break;
6325:   default:
6326:     break;
6327:   }
6328:   PetscFunctionReturn(PETSC_SUCCESS);
6329: }

6331: /*@
6332:   MatZeroEntries - Zeros all entries of a matrix.  For sparse matrices
6333:   this routine retains the old nonzero structure.

6335:   Logically Collective

6337:   Input Parameter:
6338: . mat - the matrix

6340:   Level: intermediate

6342:   Note:
6343:   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.
6344:   See the Performance chapter of the users manual for information on preallocating matrices.

6346: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`
6347: @*/
6348: PetscErrorCode MatZeroEntries(Mat mat)
6349: {
6350:   PetscFunctionBegin;
6353:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6354:   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");
6355:   MatCheckPreallocated(mat, 1);

6357:   PetscCall(PetscLogEventBegin(MAT_ZeroEntries, mat, 0, 0, 0));
6358:   PetscUseTypeMethod(mat, zeroentries);
6359:   PetscCall(PetscLogEventEnd(MAT_ZeroEntries, mat, 0, 0, 0));
6360:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6361:   PetscFunctionReturn(PETSC_SUCCESS);
6362: }

6364: /*@
6365:   MatZeroRowsColumns - Zeros all entries (except possibly the main diagonal)
6366:   of a set of rows and columns of a matrix.

6368:   Collective

6370:   Input Parameters:
6371: + mat     - the matrix
6372: . numRows - the number of rows/columns to zero
6373: . rows    - the global row indices
6374: . diag    - value put in the diagonal of the eliminated rows
6375: . x       - optional vector of the solution for zeroed rows (other entries in vector are not used), these must be set before this call
6376: - b       - optional vector of the right-hand side, that will be adjusted by provided solution entries

6378:   Level: intermediate

6380:   Notes:
6381:   This routine, along with `MatZeroRows()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6383:   For each zeroed row, the value of the corresponding `b` is set to diag times the value of the corresponding `x`.
6384:   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

6386:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6387:   Krylov method to take advantage of the known solution on the zeroed rows.

6389:   For the parallel case, all processes that share the matrix (i.e.,
6390:   those in the communicator used for matrix creation) MUST call this
6391:   routine, regardless of whether any rows being zeroed are owned by
6392:   them.

6394:   Unlike `MatZeroRows()`, this ignores the `MAT_KEEP_NONZERO_PATTERN` option value set with `MatSetOption()`, it merely zeros those entries in the matrix, but never
6395:   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
6396:   missing.

6398:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6399:   list only rows local to itself).

6401:   The option `MAT_NO_OFF_PROC_ZERO_ROWS` does not apply to this routine.

6403: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRows()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6404:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6405: @*/
6406: PetscErrorCode MatZeroRowsColumns(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6407: {
6408:   PetscFunctionBegin;
6411:   if (numRows) PetscAssertPointer(rows, 3);
6412:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6413:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6414:   MatCheckPreallocated(mat, 1);

6416:   PetscUseTypeMethod(mat, zerorowscolumns, numRows, rows, diag, x, b);
6417:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6418:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6419:   PetscFunctionReturn(PETSC_SUCCESS);
6420: }

6422: /*@
6423:   MatZeroRowsColumnsIS - Zeros all entries (except possibly the main diagonal)
6424:   of a set of rows and columns of a matrix.

6426:   Collective

6428:   Input Parameters:
6429: + mat  - the matrix
6430: . is   - the rows to zero
6431: . diag - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6432: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6433: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6435:   Level: intermediate

6437:   Note:
6438:   See `MatZeroRowsColumns()` for details on how this routine operates.

6440: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6441:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRows()`, `MatZeroRowsColumnsStencil()`
6442: @*/
6443: PetscErrorCode MatZeroRowsColumnsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6444: {
6445:   PetscInt        numRows;
6446:   const PetscInt *rows;

6448:   PetscFunctionBegin;
6453:   PetscCall(ISGetLocalSize(is, &numRows));
6454:   PetscCall(ISGetIndices(is, &rows));
6455:   PetscCall(MatZeroRowsColumns(mat, numRows, rows, diag, x, b));
6456:   PetscCall(ISRestoreIndices(is, &rows));
6457:   PetscFunctionReturn(PETSC_SUCCESS);
6458: }

6460: /*@
6461:   MatZeroRows - Zeros all entries (except possibly the main diagonal)
6462:   of a set of rows of a matrix.

6464:   Collective

6466:   Input Parameters:
6467: + mat     - the matrix
6468: . numRows - the number of rows to zero
6469: . rows    - the global row indices
6470: . diag    - value put in the diagonal of the zeroed rows
6471: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used), these must be set before this call
6472: - b       - optional vector of right-hand side, that will be adjusted by provided solution entries

6474:   Level: intermediate

6476:   Notes:
6477:   This routine, along with `MatZeroRowsColumns()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6479:   For each zeroed row, the value of the corresponding `b` is set to `diag` times the value of the corresponding `x`.

6481:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6482:   Krylov method to take advantage of the known solution on the zeroed rows.

6484:   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)
6485:   from the matrix.

6487:   Unlike `MatZeroRowsColumns()` for the `MATAIJ` and `MATBAIJ` matrix formats this removes the old nonzero structure, from the eliminated rows of the matrix
6488:   but does not release memory.  Because of this removal matrix-vector products with the adjusted matrix will be a bit faster. For the dense
6489:   formats this does not alter the nonzero structure.

6491:   If the option `MatSetOption`(mat,`MAT_KEEP_NONZERO_PATTERN`,`PETSC_TRUE`) the nonzero structure
6492:   of the matrix is not changed the values are
6493:   merely zeroed.

6495:   The user can set a value in the diagonal entry (or for the `MATAIJ` format
6496:   formats can optionally remove the main diagonal entry from the
6497:   nonzero structure as well, by passing 0.0 as the final argument).

6499:   For the parallel case, all processes that share the matrix (i.e.,
6500:   those in the communicator used for matrix creation) MUST call this
6501:   routine, regardless of whether any rows being zeroed are owned by
6502:   them.

6504:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6505:   list only rows local to itself).

6507:   You can call `MatSetOption`(mat,`MAT_NO_OFF_PROC_ZERO_ROWS`,`PETSC_TRUE`) if each process indicates only rows it
6508:   owns that are to be zeroed. This saves a global synchronization in the implementation.

6510: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6511:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `PCREDISTRIBUTE`, `MAT_KEEP_NONZERO_PATTERN`
6512: @*/
6513: PetscErrorCode MatZeroRows(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6514: {
6515:   PetscFunctionBegin;
6518:   if (numRows) PetscAssertPointer(rows, 3);
6519:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6520:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6521:   MatCheckPreallocated(mat, 1);

6523:   PetscUseTypeMethod(mat, zerorows, numRows, rows, diag, x, b);
6524:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6525:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6526:   PetscFunctionReturn(PETSC_SUCCESS);
6527: }

6529: /*@
6530:   MatZeroRowsIS - Zeros all entries (except possibly the main diagonal)
6531:   of a set of rows of a matrix indicated by an `IS`

6533:   Collective

6535:   Input Parameters:
6536: + mat  - the matrix
6537: . is   - index set, `IS`, of rows to remove (if `NULL` then no row is removed)
6538: . diag - value put in all diagonals of eliminated rows
6539: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6540: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6542:   Level: intermediate

6544:   Note:
6545:   See `MatZeroRows()` for details on how this routine operates.

6547: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6548:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `IS`
6549: @*/
6550: PetscErrorCode MatZeroRowsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6551: {
6552:   PetscInt        numRows = 0;
6553:   const PetscInt *rows    = NULL;

6555:   PetscFunctionBegin;
6558:   if (is) {
6560:     PetscCall(ISGetLocalSize(is, &numRows));
6561:     PetscCall(ISGetIndices(is, &rows));
6562:   }
6563:   PetscCall(MatZeroRows(mat, numRows, rows, diag, x, b));
6564:   if (is) PetscCall(ISRestoreIndices(is, &rows));
6565:   PetscFunctionReturn(PETSC_SUCCESS);
6566: }

6568: /*@
6569:   MatZeroRowsStencil - Zeros all entries (except possibly the main diagonal)
6570:   of a set of rows of a matrix indicated by a `MatStencil`. These rows must be local to the process.

6572:   Collective

6574:   Input Parameters:
6575: + mat     - the matrix
6576: . numRows - the number of rows to remove
6577: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows indicated by an array of `MatStencil`
6578: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6579: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6580: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6582:   Level: intermediate

6584:   Notes:
6585:   See `MatZeroRows()` for details on how this routine operates.

6587:   The grid coordinates are across the entire grid, not just the local portion

6589:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6590:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6591:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6592:   `DM_BOUNDARY_PERIODIC` boundary type.

6594:   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
6595:   a single value per point) you can skip filling those indices.

6597:   Fortran Note:
6598:   `idxm` and `idxn` should be declared as
6599: .vb
6600:     MatStencil idxm(4, m)
6601: .ve
6602:   and the values inserted using
6603: .vb
6604:     idxm(MatStencil_i, 1) = i
6605:     idxm(MatStencil_j, 1) = j
6606:     idxm(MatStencil_k, 1) = k
6607:     idxm(MatStencil_c, 1) = c
6608:    etc
6609: .ve

6611: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRows()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6612:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6613: @*/
6614: PetscErrorCode MatZeroRowsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6615: {
6616:   PetscInt  dim    = mat->stencil.dim;
6617:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6618:   PetscInt *dims   = mat->stencil.dims + 1;
6619:   PetscInt *starts = mat->stencil.starts;
6620:   PetscInt *dxm    = (PetscInt *)rows;
6621:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6623:   PetscFunctionBegin;
6626:   if (numRows) PetscAssertPointer(rows, 3);

6628:   PetscCall(PetscMalloc1(numRows, &jdxm));
6629:   for (i = 0; i < numRows; ++i) {
6630:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6631:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6632:     /* Local index in X dir */
6633:     tmp = *dxm++ - starts[0];
6634:     /* Loop over remaining dimensions */
6635:     for (j = 0; j < dim - 1; ++j) {
6636:       /* If nonlocal, set index to be negative */
6637:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6638:       /* Update local index */
6639:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6640:     }
6641:     /* Skip component slot if necessary */
6642:     if (mat->stencil.noc) dxm++;
6643:     /* Local row number */
6644:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6645:   }
6646:   PetscCall(MatZeroRowsLocal(mat, numNewRows, jdxm, diag, x, b));
6647:   PetscCall(PetscFree(jdxm));
6648:   PetscFunctionReturn(PETSC_SUCCESS);
6649: }

6651: /*@
6652:   MatZeroRowsColumnsStencil - Zeros all row and column entries (except possibly the main diagonal)
6653:   of a set of rows and columns of a matrix.

6655:   Collective

6657:   Input Parameters:
6658: + mat     - the matrix
6659: . numRows - the number of rows/columns to remove
6660: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows
6661: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6662: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6663: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6665:   Level: intermediate

6667:   Notes:
6668:   See `MatZeroRowsColumns()` for details on how this routine operates.

6670:   The grid coordinates are across the entire grid, not just the local portion

6672:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6673:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6674:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6675:   `DM_BOUNDARY_PERIODIC` boundary type.

6677:   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
6678:   a single value per point) you can skip filling those indices.

6680:   Fortran Note:
6681:   `idxm` and `idxn` should be declared as
6682: .vb
6683:     MatStencil idxm(4, m)
6684: .ve
6685:   and the values inserted using
6686: .vb
6687:     idxm(MatStencil_i, 1) = i
6688:     idxm(MatStencil_j, 1) = j
6689:     idxm(MatStencil_k, 1) = k
6690:     idxm(MatStencil_c, 1) = c
6691:     etc
6692: .ve

6694: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6695:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRows()`
6696: @*/
6697: PetscErrorCode MatZeroRowsColumnsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6698: {
6699:   PetscInt  dim    = mat->stencil.dim;
6700:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6701:   PetscInt *dims   = mat->stencil.dims + 1;
6702:   PetscInt *starts = mat->stencil.starts;
6703:   PetscInt *dxm    = (PetscInt *)rows;
6704:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6706:   PetscFunctionBegin;
6709:   if (numRows) PetscAssertPointer(rows, 3);

6711:   PetscCall(PetscMalloc1(numRows, &jdxm));
6712:   for (i = 0; i < numRows; ++i) {
6713:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6714:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6715:     /* Local index in X dir */
6716:     tmp = *dxm++ - starts[0];
6717:     /* Loop over remaining dimensions */
6718:     for (j = 0; j < dim - 1; ++j) {
6719:       /* If nonlocal, set index to be negative */
6720:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6721:       /* Update local index */
6722:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6723:     }
6724:     /* Skip component slot if necessary */
6725:     if (mat->stencil.noc) dxm++;
6726:     /* Local row number */
6727:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6728:   }
6729:   PetscCall(MatZeroRowsColumnsLocal(mat, numNewRows, jdxm, diag, x, b));
6730:   PetscCall(PetscFree(jdxm));
6731:   PetscFunctionReturn(PETSC_SUCCESS);
6732: }

6734: /*@
6735:   MatZeroRowsLocal - Zeros all entries (except possibly the main diagonal)
6736:   of a set of rows of a matrix; using local numbering of rows.

6738:   Collective

6740:   Input Parameters:
6741: + mat     - the matrix
6742: . numRows - the number of rows to remove
6743: . rows    - the local row indices
6744: . diag    - value put in all diagonals of eliminated rows
6745: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6746: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6748:   Level: intermediate

6750:   Notes:
6751:   Before calling `MatZeroRowsLocal()`, the user must first set the
6752:   local-to-global mapping by calling MatSetLocalToGlobalMapping(), this is often already set for matrices obtained with `DMCreateMatrix()`.

6754:   See `MatZeroRows()` for details on how this routine operates.

6756: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRows()`, `MatSetOption()`,
6757:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6758: @*/
6759: PetscErrorCode MatZeroRowsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6760: {
6761:   PetscFunctionBegin;
6764:   if (numRows) PetscAssertPointer(rows, 3);
6765:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6766:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6767:   MatCheckPreallocated(mat, 1);

6769:   if (mat->ops->zerorowslocal) {
6770:     PetscUseTypeMethod(mat, zerorowslocal, numRows, rows, diag, x, b);
6771:   } else {
6772:     IS        is, newis;
6773:     PetscInt *newRows, nl = 0;

6775:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6776:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6777:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6778:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6779:     for (PetscInt i = 0; i < numRows; i++)
6780:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6781:     PetscUseTypeMethod(mat, zerorows, nl, newRows, diag, x, b);
6782:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6783:     PetscCall(ISDestroy(&newis));
6784:     PetscCall(ISDestroy(&is));
6785:   }
6786:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6787:   PetscFunctionReturn(PETSC_SUCCESS);
6788: }

6790: /*@
6791:   MatZeroRowsLocalIS - Zeros all entries (except possibly the main diagonal)
6792:   of a set of rows of a matrix; using local numbering of rows.

6794:   Collective

6796:   Input Parameters:
6797: + mat  - the matrix
6798: . is   - index set of rows to remove
6799: . diag - value put in all diagonals of eliminated rows
6800: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6801: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6803:   Level: intermediate

6805:   Notes:
6806:   Before calling `MatZeroRowsLocalIS()`, the user must first set the
6807:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6809:   See `MatZeroRows()` for details on how this routine operates.

6811: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRows()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6812:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6813: @*/
6814: PetscErrorCode MatZeroRowsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6815: {
6816:   PetscInt        numRows;
6817:   const PetscInt *rows;

6819:   PetscFunctionBegin;
6823:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6824:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6825:   MatCheckPreallocated(mat, 1);

6827:   PetscCall(ISGetLocalSize(is, &numRows));
6828:   PetscCall(ISGetIndices(is, &rows));
6829:   PetscCall(MatZeroRowsLocal(mat, numRows, rows, diag, x, b));
6830:   PetscCall(ISRestoreIndices(is, &rows));
6831:   PetscFunctionReturn(PETSC_SUCCESS);
6832: }

6834: /*@
6835:   MatZeroRowsColumnsLocal - Zeros all entries (except possibly the main diagonal)
6836:   of a set of rows and columns of a matrix; using local numbering of rows.

6838:   Collective

6840:   Input Parameters:
6841: + mat     - the matrix
6842: . numRows - the number of rows to remove
6843: . rows    - the global row indices
6844: . diag    - value put in all diagonals of eliminated rows
6845: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6846: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6848:   Level: intermediate

6850:   Notes:
6851:   Before calling `MatZeroRowsColumnsLocal()`, the user must first set the
6852:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6854:   See `MatZeroRowsColumns()` for details on how this routine operates.

6856: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6857:           `MatZeroRows()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6858: @*/
6859: PetscErrorCode MatZeroRowsColumnsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6860: {
6861:   PetscFunctionBegin;
6864:   if (numRows) PetscAssertPointer(rows, 3);
6865:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6866:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6867:   MatCheckPreallocated(mat, 1);

6869:   if (mat->ops->zerorowscolumnslocal) {
6870:     PetscUseTypeMethod(mat, zerorowscolumnslocal, numRows, rows, diag, x, b);
6871:   } else {
6872:     IS        is, newis;
6873:     PetscInt *newRows, nl = 0;

6875:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6876:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6877:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6878:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6879:     for (PetscInt i = 0; i < numRows; i++)
6880:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6881:     PetscUseTypeMethod(mat, zerorowscolumns, nl, newRows, diag, x, b);
6882:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6883:     PetscCall(ISDestroy(&newis));
6884:     PetscCall(ISDestroy(&is));
6885:   }
6886:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6887:   PetscFunctionReturn(PETSC_SUCCESS);
6888: }

6890: /*@
6891:   MatZeroRowsColumnsLocalIS - Zeros all entries (except possibly the main diagonal)
6892:   of a set of rows and columns of a matrix; using local numbering of rows.

6894:   Collective

6896:   Input Parameters:
6897: + mat  - the matrix
6898: . is   - index set of rows to remove
6899: . diag - value put in all diagonals of eliminated rows
6900: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6901: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6903:   Level: intermediate

6905:   Notes:
6906:   Before calling `MatZeroRowsColumnsLocalIS()`, the user must first set the
6907:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6909:   See `MatZeroRowsColumns()` for details on how this routine operates.

6911: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6912:           `MatZeroRowsColumnsLocal()`, `MatZeroRows()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6913: @*/
6914: PetscErrorCode MatZeroRowsColumnsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6915: {
6916:   PetscInt        numRows;
6917:   const PetscInt *rows;

6919:   PetscFunctionBegin;
6923:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6924:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6925:   MatCheckPreallocated(mat, 1);

6927:   PetscCall(ISGetLocalSize(is, &numRows));
6928:   PetscCall(ISGetIndices(is, &rows));
6929:   PetscCall(MatZeroRowsColumnsLocal(mat, numRows, rows, diag, x, b));
6930:   PetscCall(ISRestoreIndices(is, &rows));
6931:   PetscFunctionReturn(PETSC_SUCCESS);
6932: }

6934: /*@
6935:   MatGetSize - Returns the numbers of rows and columns in a matrix.

6937:   Not Collective

6939:   Input Parameter:
6940: . mat - the matrix

6942:   Output Parameters:
6943: + m - the number of global rows
6944: - n - the number of global columns

6946:   Level: beginner

6948:   Note:
6949:   Both output parameters can be `NULL` on input.

6951: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetLocalSize()`
6952: @*/
6953: PetscErrorCode MatGetSize(Mat mat, PetscInt *m, PetscInt *n)
6954: {
6955:   PetscFunctionBegin;
6957:   if (m) *m = mat->rmap->N;
6958:   if (n) *n = mat->cmap->N;
6959:   PetscFunctionReturn(PETSC_SUCCESS);
6960: }

6962: /*@
6963:   MatGetLocalSize - For most matrix formats, excluding `MATELEMENTAL` and `MATSCALAPACK`, Returns the number of local rows and local columns
6964:   of a matrix. For all matrices this is the local size of the left and right vectors as returned by `MatCreateVecs()`.

6966:   Not Collective

6968:   Input Parameter:
6969: . mat - the matrix

6971:   Output Parameters:
6972: + m - the number of local rows, use `NULL` to not obtain this value
6973: - n - the number of local columns, use `NULL` to not obtain this value

6975:   Level: beginner

6977: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetSize()`
6978: @*/
6979: PetscErrorCode MatGetLocalSize(Mat mat, PetscInt *m, PetscInt *n)
6980: {
6981:   PetscFunctionBegin;
6983:   if (m) PetscAssertPointer(m, 2);
6984:   if (n) PetscAssertPointer(n, 3);
6985:   if (m) *m = mat->rmap->n;
6986:   if (n) *n = mat->cmap->n;
6987:   PetscFunctionReturn(PETSC_SUCCESS);
6988: }

6990: /*@
6991:   MatGetOwnershipRangeColumn - Returns the range of matrix columns associated with rows of a
6992:   vector one multiplies this matrix by that are owned by this processor.

6994:   Not Collective, unless matrix has not been allocated, then collective

6996:   Input Parameter:
6997: . mat - the matrix

6999:   Output Parameters:
7000: + m - the global index of the first local column, use `NULL` to not obtain this value
7001: - n - one more than the global index of the last local column, use `NULL` to not obtain this value

7003:   Level: developer

7005:   Notes:
7006:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7008:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7009:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7011:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7012:   the local values in the matrix.

7014:   Returns the columns of the "diagonal block" for most sparse matrix formats. See [Matrix
7015:   Layouts](sec_matlayout) for details on matrix layouts.

7017: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
7018:           `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
7019: @*/
7020: PetscErrorCode MatGetOwnershipRangeColumn(Mat mat, PetscInt *m, PetscInt *n)
7021: {
7022:   PetscFunctionBegin;
7025:   if (m) PetscAssertPointer(m, 2);
7026:   if (n) PetscAssertPointer(n, 3);
7027:   MatCheckPreallocated(mat, 1);
7028:   if (m) *m = mat->cmap->rstart;
7029:   if (n) *n = mat->cmap->rend;
7030:   PetscFunctionReturn(PETSC_SUCCESS);
7031: }

7033: /*@
7034:   MatGetOwnershipRange - For matrices that own values by row, excludes `MATELEMENTAL` and `MATSCALAPACK`, returns the range of matrix rows owned by
7035:   this MPI process.

7037:   Not Collective

7039:   Input Parameter:
7040: . mat - the matrix

7042:   Output Parameters:
7043: + m - the global index of the first local row, use `NULL` to not obtain this value
7044: - n - one more than the global index of the last local row, use `NULL` to not obtain this value

7046:   Level: beginner

7048:   Notes:
7049:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7051:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7052:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7054:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7055:   the local values in the matrix.

7057:   The high argument is one more than the last element stored locally.

7059:   For all matrices  it returns the range of matrix rows associated with rows of a vector that
7060:   would contain the result of a matrix vector product with this matrix. See [Matrix
7061:   Layouts](sec_matlayout) for details on matrix layouts.

7063: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscSplitOwnership()`,
7064:           `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
7065: @*/
7066: PetscErrorCode MatGetOwnershipRange(Mat mat, PetscInt *m, PetscInt *n)
7067: {
7068:   PetscFunctionBegin;
7071:   if (m) PetscAssertPointer(m, 2);
7072:   if (n) PetscAssertPointer(n, 3);
7073:   MatCheckPreallocated(mat, 1);
7074:   if (m) *m = mat->rmap->rstart;
7075:   if (n) *n = mat->rmap->rend;
7076:   PetscFunctionReturn(PETSC_SUCCESS);
7077: }

7079: /*@C
7080:   MatGetOwnershipRanges - For matrices that own values by row, excludes `MATELEMENTAL` and
7081:   `MATSCALAPACK`, returns the range of matrix rows owned by each process.

7083:   Not Collective, unless matrix has not been allocated

7085:   Input Parameter:
7086: . mat - the matrix

7088:   Output Parameter:
7089: . ranges - start of each processors portion plus one more than the total length at the end, of length `size` + 1
7090:            where `size` is the number of MPI processes used by `mat`

7092:   Level: beginner

7094:   Notes:
7095:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7097:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7098:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7100:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7101:   the local values in the matrix.

7103:   For all matrices  it returns the ranges of matrix rows associated with rows of a vector that
7104:   would contain the result of a matrix vector product with this matrix. See [Matrix
7105:   Layouts](sec_matlayout) for details on matrix layouts.

7107: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
7108:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `MatSetSizes()`, `MatCreateAIJ()`,
7109:           `DMDAGetGhostCorners()`, `DM`
7110: @*/
7111: PetscErrorCode MatGetOwnershipRanges(Mat mat, const PetscInt *ranges[])
7112: {
7113:   PetscFunctionBegin;
7116:   MatCheckPreallocated(mat, 1);
7117:   PetscCall(PetscLayoutGetRanges(mat->rmap, ranges));
7118:   PetscFunctionReturn(PETSC_SUCCESS);
7119: }

7121: /*@C
7122:   MatGetOwnershipRangesColumn - Returns the ranges of matrix columns associated with rows of a
7123:   vector one multiplies this vector by that are owned by each processor.

7125:   Not Collective, unless matrix has not been allocated

7127:   Input Parameter:
7128: . mat - the matrix

7130:   Output Parameter:
7131: . ranges - start of each processors portion plus one more than the total length at the end

7133:   Level: beginner

7135:   Notes:
7136:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7138:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7139:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7141:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7142:   the local values in the matrix.

7144:   Returns the columns of the "diagonal blocks", for most sparse matrix formats. See [Matrix
7145:   Layouts](sec_matlayout) for details on matrix layouts.

7147: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRanges()`,
7148:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`,
7149:           `DMDAGetGhostCorners()`, `DM`
7150: @*/
7151: PetscErrorCode MatGetOwnershipRangesColumn(Mat mat, const PetscInt *ranges[])
7152: {
7153:   PetscFunctionBegin;
7156:   MatCheckPreallocated(mat, 1);
7157:   PetscCall(PetscLayoutGetRanges(mat->cmap, ranges));
7158:   PetscFunctionReturn(PETSC_SUCCESS);
7159: }

7161: /*@
7162:   MatGetOwnershipIS - Get row and column ownership of a matrices' values as index sets.

7164:   Not Collective

7166:   Input Parameter:
7167: . A - matrix

7169:   Output Parameters:
7170: + rows - rows in which this process owns elements, , use `NULL` to not obtain this value
7171: - cols - columns in which this process owns elements, use `NULL` to not obtain this value

7173:   Level: intermediate

7175:   Note:
7176:   You should call `ISDestroy()` on the returned `IS`

7178:   For most matrices, excluding `MATELEMENTAL` and `MATSCALAPACK`, this corresponds to values
7179:   returned by `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`. For `MATELEMENTAL` and
7180:   `MATSCALAPACK` the ownership is more complicated. See [Matrix Layouts](sec_matlayout) for
7181:   details on matrix layouts.

7183: .seealso: [](ch_matrices), `IS`, `Mat`, `MatGetOwnershipRanges()`, `MatSetValues()`, `MATELEMENTAL`, `MATSCALAPACK`
7184: @*/
7185: PetscErrorCode MatGetOwnershipIS(Mat A, IS *rows, IS *cols)
7186: {
7187:   PetscErrorCode (*f)(Mat, IS *, IS *);

7189:   PetscFunctionBegin;
7192:   MatCheckPreallocated(A, 1);
7193:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatGetOwnershipIS_C", &f));
7194:   if (f) {
7195:     PetscCall((*f)(A, rows, cols));
7196:   } else { /* Create a standard row-based partition, each process is responsible for ALL columns in their row block */
7197:     if (rows) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->rmap->n, A->rmap->rstart, 1, rows));
7198:     if (cols) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->cmap->N, 0, 1, cols));
7199:   }
7200:   PetscFunctionReturn(PETSC_SUCCESS);
7201: }

7203: /*@
7204:   MatILUFactorSymbolic - Performs symbolic ILU factorization of a matrix obtained with `MatGetFactor()`
7205:   Uses levels of fill only, not drop tolerance. Use `MatLUFactorNumeric()`
7206:   to complete the factorization.

7208:   Collective

7210:   Input Parameters:
7211: + fact - the factorized matrix obtained with `MatGetFactor()`
7212: . mat  - the matrix
7213: . row  - row permutation
7214: . col  - column permutation
7215: - info - structure containing
7216: .vb
7217:       levels - number of levels of fill.
7218:       expected fill - as ratio of original fill.
7219:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
7220:                 missing diagonal entries)
7221: .ve

7223:   Level: developer

7225:   Notes:
7226:   See [Matrix Factorization](sec_matfactor) for additional information.

7228:   Most users should employ the `KSP` interface for linear solvers
7229:   instead of working directly with matrix algebra routines such as this.
7230:   See, e.g., `KSPCreate()`.

7232:   Uses the definition of level of fill as in Y. Saad, {cite}`saad2003`

7234:   Fortran Note:
7235:   A valid (non-null) `info` argument must be provided

7237: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
7238:           `MatGetOrdering()`, `MatFactorInfo`
7239: @*/
7240: PetscErrorCode MatILUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
7241: {
7242:   PetscFunctionBegin;
7247:   PetscAssertPointer(info, 5);
7248:   PetscAssertPointer(fact, 1);
7249:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels of fill negative %" PetscInt_FMT, (PetscInt)info->levels);
7250:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7251:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7252:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7253:   MatCheckPreallocated(mat, 2);

7255:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ILUFactorSymbolic, mat, row, col, 0));
7256:   PetscUseTypeMethod(fact, ilufactorsymbolic, mat, row, col, info);
7257:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ILUFactorSymbolic, mat, row, col, 0));
7258:   PetscFunctionReturn(PETSC_SUCCESS);
7259: }

7261: /*@
7262:   MatICCFactorSymbolic - Performs symbolic incomplete
7263:   Cholesky factorization for a symmetric matrix.  Use
7264:   `MatCholeskyFactorNumeric()` to complete the factorization.

7266:   Collective

7268:   Input Parameters:
7269: + fact - the factorized matrix obtained with `MatGetFactor()`
7270: . mat  - the matrix to be factored
7271: . perm - row and column permutation
7272: - info - structure containing
7273: .vb
7274:       levels - number of levels of fill.
7275:       expected fill - as ratio of original fill.
7276: .ve

7278:   Level: developer

7280:   Notes:
7281:   Most users should employ the `KSP` interface for linear solvers
7282:   instead of working directly with matrix algebra routines such as this.
7283:   See, e.g., `KSPCreate()`.

7285:   This uses the definition of level of fill as in Y. Saad {cite}`saad2003`

7287:   Fortran Note:
7288:   A valid (non-null) `info` argument must be provided

7290: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
7291: @*/
7292: PetscErrorCode MatICCFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
7293: {
7294:   PetscFunctionBegin;
7298:   PetscAssertPointer(info, 4);
7299:   PetscAssertPointer(fact, 1);
7300:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7301:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels negative %" PetscInt_FMT, (PetscInt)info->levels);
7302:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7303:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7304:   MatCheckPreallocated(mat, 2);

7306:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7307:   PetscUseTypeMethod(fact, iccfactorsymbolic, mat, perm, info);
7308:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7309:   PetscFunctionReturn(PETSC_SUCCESS);
7310: }

7312: /*@C
7313:   MatCreateSubMatrices - Extracts several submatrices from a matrix. If submat
7314:   points to an array of valid matrices, they may be reused to store the new
7315:   submatrices.

7317:   Collective

7319:   Input Parameters:
7320: + mat   - the matrix
7321: . n     - the number of submatrixes to be extracted (on this processor, may be zero)
7322: . irow  - index set of rows to extract
7323: . icol  - index set of columns to extract
7324: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7326:   Output Parameter:
7327: . submat - the array of submatrices

7329:   Level: advanced

7331:   Notes:
7332:   `MatCreateSubMatrices()` can extract ONLY sequential submatrices
7333:   (from both sequential and parallel matrices). Use `MatCreateSubMatrix()`
7334:   to extract a parallel submatrix.

7336:   Some matrix types place restrictions on the row and column
7337:   indices, such as that they be sorted or that they be equal to each other.

7339:   The index sets may not have duplicate entries.

7341:   When extracting submatrices from a parallel matrix, each processor can
7342:   form a different submatrix by setting the rows and columns of its
7343:   individual index sets according to the local submatrix desired.

7345:   When finished using the submatrices, the user should destroy
7346:   them with `MatDestroySubMatrices()`.

7348:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
7349:   original matrix has not changed from that last call to `MatCreateSubMatrices()`.

7351:   This routine creates the matrices in submat; you should NOT create them before
7352:   calling it. It also allocates the array of matrix pointers submat.

7354:   For `MATBAIJ` matrices the index sets must respect the block structure, that is if they
7355:   request one row/column in a block, they must request all rows/columns that are in
7356:   that block. For example, if the block size is 2 you cannot request just row 0 and
7357:   column 0.

7359:   Fortran Note:
7360: .vb
7361:   Mat, pointer :: submat(:)
7362: .ve

7364: .seealso: [](ch_matrices), `Mat`, `MatDestroySubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7365: @*/
7366: PetscErrorCode MatCreateSubMatrices(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7367: {
7368:   PetscInt  i;
7369:   PetscBool eq;

7371:   PetscFunctionBegin;
7374:   if (n) {
7375:     PetscAssertPointer(irow, 3);
7377:     PetscAssertPointer(icol, 4);
7379:   }
7380:   PetscAssertPointer(submat, 6);
7381:   if (n && scall == MAT_REUSE_MATRIX) {
7382:     PetscAssertPointer(*submat, 6);
7384:   }
7385:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7386:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7387:   MatCheckPreallocated(mat, 1);
7388:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7389:   PetscUseTypeMethod(mat, createsubmatrices, n, irow, icol, scall, submat);
7390:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7391:   for (i = 0; i < n; i++) {
7392:     (*submat)[i]->factortype = MAT_FACTOR_NONE; /* in case in place factorization was previously done on submatrix */
7393:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7394:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7395: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
7396:     if (mat->boundtocpu && mat->bindingpropagates) {
7397:       PetscCall(MatBindToCPU((*submat)[i], PETSC_TRUE));
7398:       PetscCall(MatSetBindingPropagates((*submat)[i], PETSC_TRUE));
7399:     }
7400: #endif
7401:   }
7402:   PetscFunctionReturn(PETSC_SUCCESS);
7403: }

7405: /*@C
7406:   MatCreateSubMatricesMPI - Extracts MPI submatrices across a sub communicator of `mat` (by pairs of `IS` that may live on subcomms).

7408:   Collective

7410:   Input Parameters:
7411: + mat   - the matrix
7412: . n     - the number of submatrixes to be extracted
7413: . irow  - index set of rows to extract
7414: . icol  - index set of columns to extract
7415: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7417:   Output Parameter:
7418: . submat - the array of submatrices

7420:   Level: advanced

7422:   Note:
7423:   This is used by `PCGASM`

7425: .seealso: [](ch_matrices), `Mat`, `PCGASM`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7426: @*/
7427: PetscErrorCode MatCreateSubMatricesMPI(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7428: {
7429:   PetscInt  i;
7430:   PetscBool eq;

7432:   PetscFunctionBegin;
7435:   if (n) {
7436:     PetscAssertPointer(irow, 3);
7438:     PetscAssertPointer(icol, 4);
7440:   }
7441:   PetscAssertPointer(submat, 6);
7442:   if (n && scall == MAT_REUSE_MATRIX) {
7443:     PetscAssertPointer(*submat, 6);
7445:   }
7446:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7447:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7448:   MatCheckPreallocated(mat, 1);

7450:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7451:   PetscUseTypeMethod(mat, createsubmatricesmpi, n, irow, icol, scall, submat);
7452:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7453:   for (i = 0; i < n; i++) {
7454:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7455:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7456:   }
7457:   PetscFunctionReturn(PETSC_SUCCESS);
7458: }

7460: /*@C
7461:   MatDestroyMatrices - Destroys an array of matrices

7463:   Collective

7465:   Input Parameters:
7466: + n   - the number of local matrices
7467: - mat - the matrices (this is a pointer to the array of matrices)

7469:   Level: advanced

7471:   Notes:
7472:   Frees not only the matrices, but also the array that contains the matrices

7474:   For matrices obtained with  `MatCreateSubMatrices()` use `MatDestroySubMatrices()`

7476: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroySubMatrices()`
7477: @*/
7478: PetscErrorCode MatDestroyMatrices(PetscInt n, Mat *mat[])
7479: {
7480:   PetscInt i;

7482:   PetscFunctionBegin;
7483:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7484:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7485:   PetscAssertPointer(mat, 2);

7487:   for (i = 0; i < n; i++) PetscCall(MatDestroy(&(*mat)[i]));

7489:   /* memory is allocated even if n = 0 */
7490:   PetscCall(PetscFree(*mat));
7491:   PetscFunctionReturn(PETSC_SUCCESS);
7492: }

7494: /*@C
7495:   MatDestroySubMatrices - Destroys a set of matrices obtained with `MatCreateSubMatrices()`.

7497:   Collective

7499:   Input Parameters:
7500: + n   - the number of local matrices
7501: - mat - the matrices (this is a pointer to the array of matrices, to match the calling sequence of `MatCreateSubMatrices()`)

7503:   Level: advanced

7505:   Note:
7506:   Frees not only the matrices, but also the array that contains the matrices

7508: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7509: @*/
7510: PetscErrorCode MatDestroySubMatrices(PetscInt n, Mat *mat[])
7511: {
7512:   Mat mat0;

7514:   PetscFunctionBegin;
7515:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7516:   /* mat[] is an array of length n+1, see MatCreateSubMatrices_xxx() */
7517:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7518:   PetscAssertPointer(mat, 2);

7520:   mat0 = (*mat)[0];
7521:   if (mat0 && mat0->ops->destroysubmatrices) {
7522:     PetscCall((*mat0->ops->destroysubmatrices)(n, mat));
7523:   } else {
7524:     PetscCall(MatDestroyMatrices(n, mat));
7525:   }
7526:   PetscFunctionReturn(PETSC_SUCCESS);
7527: }

7529: /*@
7530:   MatGetSeqNonzeroStructure - Extracts the nonzero structure from a matrix and stores it, in its entirety, on each process

7532:   Collective

7534:   Input Parameter:
7535: . mat - the matrix

7537:   Output Parameter:
7538: . matstruct - the sequential matrix with the nonzero structure of `mat`

7540:   Level: developer

7542: .seealso: [](ch_matrices), `Mat`, `MatDestroySeqNonzeroStructure()`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7543: @*/
7544: PetscErrorCode MatGetSeqNonzeroStructure(Mat mat, Mat *matstruct)
7545: {
7546:   PetscFunctionBegin;
7548:   PetscAssertPointer(matstruct, 2);

7551:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7552:   MatCheckPreallocated(mat, 1);

7554:   PetscCall(PetscLogEventBegin(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7555:   PetscUseTypeMethod(mat, getseqnonzerostructure, matstruct);
7556:   PetscCall(PetscLogEventEnd(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7557:   PetscFunctionReturn(PETSC_SUCCESS);
7558: }

7560: /*@C
7561:   MatDestroySeqNonzeroStructure - Destroys matrix obtained with `MatGetSeqNonzeroStructure()`.

7563:   Collective

7565:   Input Parameter:
7566: . mat - the matrix

7568:   Level: advanced

7570:   Note:
7571:   This is not needed, one can just call `MatDestroy()`

7573: .seealso: [](ch_matrices), `Mat`, `MatGetSeqNonzeroStructure()`
7574: @*/
7575: PetscErrorCode MatDestroySeqNonzeroStructure(Mat *mat)
7576: {
7577:   PetscFunctionBegin;
7578:   PetscAssertPointer(mat, 1);
7579:   PetscCall(MatDestroy(mat));
7580:   PetscFunctionReturn(PETSC_SUCCESS);
7581: }

7583: /*@
7584:   MatIncreaseOverlap - Given a set of submatrices indicated by index sets,
7585:   replaces the index sets by larger ones that represent submatrices with
7586:   additional overlap.

7588:   Collective

7590:   Input Parameters:
7591: + mat - the matrix
7592: . n   - the number of index sets
7593: . is  - the array of index sets (these index sets will changed during the call)
7594: - ov  - the additional overlap requested

7596:   Options Database Key:
7597: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7599:   Level: developer

7601:   Note:
7602:   The computed overlap preserves the matrix block sizes when the blocks are square.
7603:   That is: if a matrix nonzero for a given block would increase the overlap all columns associated with
7604:   that block are included in the overlap regardless of whether each specific column would increase the overlap.

7606: .seealso: [](ch_matrices), `Mat`, `PCASM`, `MatSetBlockSize()`, `MatIncreaseOverlapSplit()`, `MatCreateSubMatrices()`
7607: @*/
7608: PetscErrorCode MatIncreaseOverlap(Mat mat, PetscInt n, IS is[], PetscInt ov)
7609: {
7610:   PetscInt i, bs, cbs;

7612:   PetscFunctionBegin;
7616:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7617:   if (n) {
7618:     PetscAssertPointer(is, 3);
7620:   }
7621:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7622:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7623:   MatCheckPreallocated(mat, 1);

7625:   if (!ov || !n) PetscFunctionReturn(PETSC_SUCCESS);
7626:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7627:   PetscUseTypeMethod(mat, increaseoverlap, n, is, ov);
7628:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7629:   PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
7630:   if (bs == cbs) {
7631:     for (i = 0; i < n; i++) PetscCall(ISSetBlockSize(is[i], bs));
7632:   }
7633:   PetscFunctionReturn(PETSC_SUCCESS);
7634: }

7636: PetscErrorCode MatIncreaseOverlapSplit_Single(Mat, IS *, PetscInt);

7638: /*@
7639:   MatIncreaseOverlapSplit - Given a set of submatrices indicated by index sets across
7640:   a sub communicator, replaces the index sets by larger ones that represent submatrices with
7641:   additional overlap.

7643:   Collective

7645:   Input Parameters:
7646: + mat - the matrix
7647: . n   - the number of index sets
7648: . is  - the array of index sets (these index sets will changed during the call)
7649: - ov  - the additional overlap requested

7651:   `   Options Database Key:
7652: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7654:   Level: developer

7656: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatIncreaseOverlap()`
7657: @*/
7658: PetscErrorCode MatIncreaseOverlapSplit(Mat mat, PetscInt n, IS is[], PetscInt ov)
7659: {
7660:   PetscInt i;

7662:   PetscFunctionBegin;
7665:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7666:   if (n) {
7667:     PetscAssertPointer(is, 3);
7669:   }
7670:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7671:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7672:   MatCheckPreallocated(mat, 1);
7673:   if (!ov) PetscFunctionReturn(PETSC_SUCCESS);
7674:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7675:   for (i = 0; i < n; i++) PetscCall(MatIncreaseOverlapSplit_Single(mat, &is[i], ov));
7676:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7677:   PetscFunctionReturn(PETSC_SUCCESS);
7678: }

7680: /*@
7681:   MatGetBlockSize - Returns the matrix block size.

7683:   Not Collective

7685:   Input Parameter:
7686: . mat - the matrix

7688:   Output Parameter:
7689: . bs - block size

7691:   Level: intermediate

7693:   Notes:
7694:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.

7696:   If the block size has not been set yet this routine returns 1.

7698: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSizes()`
7699: @*/
7700: PetscErrorCode MatGetBlockSize(Mat mat, PetscInt *bs)
7701: {
7702:   PetscFunctionBegin;
7704:   PetscAssertPointer(bs, 2);
7705:   *bs = mat->rmap->bs;
7706:   PetscFunctionReturn(PETSC_SUCCESS);
7707: }

7709: /*@
7710:   MatGetBlockSizes - Returns the matrix block row and column sizes.

7712:   Not Collective

7714:   Input Parameter:
7715: . mat - the matrix

7717:   Output Parameters:
7718: + rbs - row block size
7719: - cbs - column block size

7721:   Level: intermediate

7723:   Notes:
7724:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.
7725:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.

7727:   If a block size has not been set yet this routine returns 1.

7729: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatSetBlockSizes()`
7730: @*/
7731: PetscErrorCode MatGetBlockSizes(Mat mat, PetscInt *rbs, PetscInt *cbs)
7732: {
7733:   PetscFunctionBegin;
7735:   if (rbs) PetscAssertPointer(rbs, 2);
7736:   if (cbs) PetscAssertPointer(cbs, 3);
7737:   if (rbs) *rbs = mat->rmap->bs;
7738:   if (cbs) *cbs = mat->cmap->bs;
7739:   PetscFunctionReturn(PETSC_SUCCESS);
7740: }

7742: /*@
7743:   MatSetBlockSize - Sets the matrix block size.

7745:   Logically Collective

7747:   Input Parameters:
7748: + mat - the matrix
7749: - bs  - block size

7751:   Level: intermediate

7753:   Notes:
7754:   Block row formats are `MATBAIJ` and `MATSBAIJ` formats ALWAYS have square block storage in the matrix.
7755:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

7757:   For `MATAIJ` matrix format, this function can be called at a later stage, provided that the specified block size
7758:   is compatible with the matrix local sizes.

7760: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MATAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`
7761: @*/
7762: PetscErrorCode MatSetBlockSize(Mat mat, PetscInt bs)
7763: {
7764:   PetscFunctionBegin;
7767:   PetscCall(MatSetBlockSizes(mat, bs, bs));
7768:   PetscFunctionReturn(PETSC_SUCCESS);
7769: }

7771: typedef struct {
7772:   PetscInt         n;
7773:   IS              *is;
7774:   Mat             *mat;
7775:   PetscObjectState nonzerostate;
7776:   Mat              C;
7777: } EnvelopeData;

7779: static PetscErrorCode EnvelopeDataDestroy(PetscCtxRt ptr)
7780: {
7781:   EnvelopeData *edata = *(EnvelopeData **)ptr;

7783:   PetscFunctionBegin;
7784:   for (PetscInt i = 0; i < edata->n; i++) PetscCall(ISDestroy(&edata->is[i]));
7785:   PetscCall(PetscFree(edata->is));
7786:   PetscCall(PetscFree(edata));
7787:   PetscFunctionReturn(PETSC_SUCCESS);
7788: }

7790: /*@
7791:   MatComputeVariableBlockEnvelope - Given a matrix whose nonzeros are in blocks along the diagonal this computes and stores
7792:   the sizes of these blocks in the matrix. An individual block may lie over several processes.

7794:   Collective

7796:   Input Parameter:
7797: . mat - the matrix

7799:   Level: intermediate

7801:   Notes:
7802:   There can be zeros within the blocks

7804:   The blocks can overlap between processes, including laying on more than two processes

7806: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatSetVariableBlockSizes()`
7807: @*/
7808: PetscErrorCode MatComputeVariableBlockEnvelope(Mat mat)
7809: {
7810:   PetscInt           n, *sizes, *starts, i = 0, env = 0, tbs = 0, lblocks = 0, rstart, II, ln = 0, cnt = 0, cstart, cend;
7811:   PetscInt          *diag, *odiag, sc;
7812:   VecScatter         scatter;
7813:   PetscScalar       *seqv;
7814:   const PetscScalar *parv;
7815:   const PetscInt    *ia, *ja;
7816:   PetscBool          set, flag, done;
7817:   Mat                AA = mat, A;
7818:   MPI_Comm           comm;
7819:   PetscMPIInt        rank, size, tag;
7820:   MPI_Status         status;
7821:   PetscContainer     container;
7822:   EnvelopeData      *edata;
7823:   Vec                seq, par;
7824:   IS                 isglobal;

7826:   PetscFunctionBegin;
7828:   PetscCall(MatIsSymmetricKnown(mat, &set, &flag));
7829:   if (!set || !flag) {
7830:     /* TODO: only needs nonzero structure of transpose */
7831:     PetscCall(MatTranspose(mat, MAT_INITIAL_MATRIX, &AA));
7832:     PetscCall(MatAXPY(AA, 1.0, mat, DIFFERENT_NONZERO_PATTERN));
7833:   }
7834:   PetscCall(MatAIJGetLocalMat(AA, &A));
7835:   PetscCall(MatGetRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7836:   PetscCheck(done, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unable to get IJ structure from matrix");

7838:   PetscCall(MatGetLocalSize(mat, &n, NULL));
7839:   PetscCall(PetscObjectGetNewTag((PetscObject)mat, &tag));
7840:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
7841:   PetscCallMPI(MPI_Comm_size(comm, &size));
7842:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

7844:   PetscCall(PetscMalloc2(n, &sizes, n, &starts));

7846:   if (rank > 0) {
7847:     PetscCallMPI(MPI_Recv(&env, 1, MPIU_INT, rank - 1, tag, comm, &status));
7848:     PetscCallMPI(MPI_Recv(&tbs, 1, MPIU_INT, rank - 1, tag, comm, &status));
7849:   }
7850:   PetscCall(MatGetOwnershipRange(mat, &rstart, NULL));
7851:   for (i = 0; i < n; i++) {
7852:     env = PetscMax(env, ja[ia[i + 1] - 1]);
7853:     II  = rstart + i;
7854:     if (env == II) {
7855:       starts[lblocks]  = tbs;
7856:       sizes[lblocks++] = 1 + II - tbs;
7857:       tbs              = 1 + II;
7858:     }
7859:   }
7860:   if (rank < size - 1) {
7861:     PetscCallMPI(MPI_Send(&env, 1, MPIU_INT, rank + 1, tag, comm));
7862:     PetscCallMPI(MPI_Send(&tbs, 1, MPIU_INT, rank + 1, tag, comm));
7863:   }

7865:   PetscCall(MatRestoreRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7866:   if (!set || !flag) PetscCall(MatDestroy(&AA));
7867:   PetscCall(MatDestroy(&A));

7869:   PetscCall(PetscNew(&edata));
7870:   PetscCall(MatGetNonzeroState(mat, &edata->nonzerostate));
7871:   edata->n = lblocks;
7872:   /* create IS needed for extracting blocks from the original matrix */
7873:   PetscCall(PetscMalloc1(lblocks, &edata->is));
7874:   for (PetscInt i = 0; i < lblocks; i++) PetscCall(ISCreateStride(PETSC_COMM_SELF, sizes[i], starts[i], 1, &edata->is[i]));

7876:   /* Create the resulting inverse matrix nonzero structure with preallocation information */
7877:   PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &edata->C));
7878:   PetscCall(MatSetSizes(edata->C, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
7879:   PetscCall(MatSetBlockSizesFromMats(edata->C, mat, mat));
7880:   PetscCall(MatSetType(edata->C, MATAIJ));

7882:   /* Communicate the start and end of each row, from each block to the correct rank */
7883:   /* TODO: Use PetscSF instead of VecScatter */
7884:   for (PetscInt i = 0; i < lblocks; i++) ln += sizes[i];
7885:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, 2 * ln, &seq));
7886:   PetscCall(VecGetArrayWrite(seq, &seqv));
7887:   for (PetscInt i = 0; i < lblocks; i++) {
7888:     for (PetscInt j = 0; j < sizes[i]; j++) {
7889:       seqv[cnt]     = starts[i];
7890:       seqv[cnt + 1] = starts[i] + sizes[i];
7891:       cnt += 2;
7892:     }
7893:   }
7894:   PetscCall(VecRestoreArrayWrite(seq, &seqv));
7895:   PetscCallMPI(MPI_Scan(&cnt, &sc, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)mat)));
7896:   sc -= cnt;
7897:   PetscCall(VecCreateMPI(PetscObjectComm((PetscObject)mat), 2 * mat->rmap->n, 2 * mat->rmap->N, &par));
7898:   PetscCall(ISCreateStride(PETSC_COMM_SELF, cnt, sc, 1, &isglobal));
7899:   PetscCall(VecScatterCreate(seq, NULL, par, isglobal, &scatter));
7900:   PetscCall(ISDestroy(&isglobal));
7901:   PetscCall(VecScatterBegin(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7902:   PetscCall(VecScatterEnd(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7903:   PetscCall(VecScatterDestroy(&scatter));
7904:   PetscCall(VecDestroy(&seq));
7905:   PetscCall(MatGetOwnershipRangeColumn(mat, &cstart, &cend));
7906:   PetscCall(PetscMalloc2(mat->rmap->n, &diag, mat->rmap->n, &odiag));
7907:   PetscCall(VecGetArrayRead(par, &parv));
7908:   cnt = 0;
7909:   PetscCall(MatGetSize(mat, NULL, &n));
7910:   for (PetscInt i = 0; i < mat->rmap->n; i++) {
7911:     PetscInt start, end, d = 0, od = 0;

7913:     start = (PetscInt)PetscRealPart(parv[cnt]);
7914:     end   = (PetscInt)PetscRealPart(parv[cnt + 1]);
7915:     cnt += 2;

7917:     if (start < cstart) {
7918:       od += cstart - start + n - cend;
7919:       d += cend - cstart;
7920:     } else if (start < cend) {
7921:       od += n - cend;
7922:       d += cend - start;
7923:     } else od += n - start;
7924:     if (end <= cstart) {
7925:       od -= cstart - end + n - cend;
7926:       d -= cend - cstart;
7927:     } else if (end < cend) {
7928:       od -= n - cend;
7929:       d -= cend - end;
7930:     } else od -= n - end;

7932:     odiag[i] = od;
7933:     diag[i]  = d;
7934:   }
7935:   PetscCall(VecRestoreArrayRead(par, &parv));
7936:   PetscCall(VecDestroy(&par));
7937:   PetscCall(MatXAIJSetPreallocation(edata->C, mat->rmap->bs, diag, odiag, NULL, NULL));
7938:   PetscCall(PetscFree2(diag, odiag));
7939:   PetscCall(PetscFree2(sizes, starts));

7941:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
7942:   PetscCall(PetscContainerSetPointer(container, edata));
7943:   PetscCall(PetscContainerSetCtxDestroy(container, EnvelopeDataDestroy));
7944:   PetscCall(PetscObjectCompose((PetscObject)mat, "EnvelopeData", (PetscObject)container));
7945:   PetscCall(PetscObjectDereference((PetscObject)container));
7946:   PetscFunctionReturn(PETSC_SUCCESS);
7947: }

7949: /*@
7950:   MatInvertVariableBlockEnvelope - set matrix C to be the inverted block diagonal of matrix A

7952:   Collective

7954:   Input Parameters:
7955: + A     - the matrix
7956: - reuse - indicates if the `C` matrix was obtained from a previous call to this routine

7958:   Output Parameter:
7959: . C - matrix with inverted block diagonal of `A`

7961:   Level: advanced

7963:   Note:
7964:   For efficiency the matrix `A` should have all the nonzero entries clustered in smallish blocks along the diagonal.

7966: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatComputeBlockDiagonal()`
7967: @*/
7968: PetscErrorCode MatInvertVariableBlockEnvelope(Mat A, MatReuse reuse, Mat *C)
7969: {
7970:   PetscContainer   container;
7971:   EnvelopeData    *edata;
7972:   PetscObjectState nonzerostate;

7974:   PetscFunctionBegin;
7975:   PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7976:   if (!container) {
7977:     PetscCall(MatComputeVariableBlockEnvelope(A));
7978:     PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7979:   }
7980:   PetscCall(PetscContainerGetPointer(container, &edata));
7981:   PetscCall(MatGetNonzeroState(A, &nonzerostate));
7982:   PetscCheck(nonzerostate <= edata->nonzerostate, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Cannot handle changes to matrix nonzero structure");
7983:   PetscCheck(reuse != MAT_REUSE_MATRIX || *C == edata->C, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "C matrix must be the same as previously output");

7985:   PetscCall(MatCreateSubMatrices(A, edata->n, edata->is, edata->is, MAT_INITIAL_MATRIX, &edata->mat));
7986:   *C = edata->C;

7988:   for (PetscInt i = 0; i < edata->n; i++) {
7989:     Mat          D;
7990:     PetscScalar *dvalues;

7992:     PetscCall(MatConvert(edata->mat[i], MATSEQDENSE, MAT_INITIAL_MATRIX, &D));
7993:     PetscCall(MatSetOption(*C, MAT_ROW_ORIENTED, PETSC_FALSE));
7994:     PetscCall(MatSeqDenseInvert(D));
7995:     PetscCall(MatDenseGetArray(D, &dvalues));
7996:     PetscCall(MatSetValuesIS(*C, edata->is[i], edata->is[i], dvalues, INSERT_VALUES));
7997:     PetscCall(MatDestroy(&D));
7998:   }
7999:   PetscCall(MatDestroySubMatrices(edata->n, &edata->mat));
8000:   PetscCall(MatAssemblyBegin(*C, MAT_FINAL_ASSEMBLY));
8001:   PetscCall(MatAssemblyEnd(*C, MAT_FINAL_ASSEMBLY));
8002:   PetscFunctionReturn(PETSC_SUCCESS);
8003: }

8005: /*@
8006:   MatSetVariableBlockSizes - Sets diagonal point-blocks of the matrix that need not be of the same size

8008:   Not Collective

8010:   Input Parameters:
8011: + mat     - the matrix
8012: . nblocks - the number of blocks on this process, each block can only exist on a single process
8013: - bsizes  - the block sizes

8015:   Level: intermediate

8017:   Notes:
8018:   Currently used by `PCVPBJACOBI` for `MATAIJ` matrices

8020:   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.

8022: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatGetVariableBlockSizes()`,
8023:           `MatComputeVariableBlockEnvelope()`, `PCVPBJACOBI`
8024: @*/
8025: PetscErrorCode MatSetVariableBlockSizes(Mat mat, PetscInt nblocks, const PetscInt bsizes[])
8026: {
8027:   PetscInt ncnt = 0, nlocal;

8029:   PetscFunctionBegin;
8031:   PetscCall(MatGetLocalSize(mat, &nlocal, NULL));
8032:   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);
8033:   for (PetscInt i = 0; i < nblocks; i++) ncnt += bsizes[i];
8034:   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);
8035:   PetscCall(PetscFree(mat->bsizes));
8036:   mat->nblocks = nblocks;
8037:   PetscCall(PetscMalloc1(nblocks, &mat->bsizes));
8038:   PetscCall(PetscArraycpy(mat->bsizes, bsizes, nblocks));
8039:   PetscFunctionReturn(PETSC_SUCCESS);
8040: }

8042: /*@C
8043:   MatGetVariableBlockSizes - Gets a diagonal blocks of the matrix that need not be of the same size

8045:   Not Collective; No Fortran Support

8047:   Input Parameter:
8048: . mat - the matrix

8050:   Output Parameters:
8051: + nblocks - the number of blocks on this process
8052: - bsizes  - the block sizes

8054:   Level: intermediate

8056: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
8057: @*/
8058: PetscErrorCode MatGetVariableBlockSizes(Mat mat, PetscInt *nblocks, const PetscInt *bsizes[])
8059: {
8060:   PetscFunctionBegin;
8062:   if (nblocks) *nblocks = mat->nblocks;
8063:   if (bsizes) *bsizes = mat->bsizes;
8064:   PetscFunctionReturn(PETSC_SUCCESS);
8065: }

8067: /*@
8068:   MatSelectVariableBlockSizes - When creating a submatrix, pass on the variable block sizes

8070:   Not Collective

8072:   Input Parameter:
8073: + subA  - the submatrix
8074: . A     - the original matrix
8075: - isrow - The `IS` of selected rows for the submatrix, must be sorted

8077:   Level: developer

8079:   Notes:
8080:   If the index set is not sorted or contains off-process entries, this function will do nothing.

8082: .seealso: [](ch_matrices), `Mat`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
8083: @*/
8084: PetscErrorCode MatSelectVariableBlockSizes(Mat subA, Mat A, IS isrow)
8085: {
8086:   const PetscInt *rows;
8087:   PetscInt        n, rStart, rEnd, Nb = 0;
8088:   PetscBool       flg = A->bsizes ? PETSC_TRUE : PETSC_FALSE;

8090:   PetscFunctionBegin;
8091:   // The code for block size extraction does not support an unsorted IS
8092:   if (flg) PetscCall(ISSorted(isrow, &flg));
8093:   // We don't support originally off-diagonal blocks
8094:   if (flg) {
8095:     PetscCall(MatGetOwnershipRange(A, &rStart, &rEnd));
8096:     PetscCall(ISGetLocalSize(isrow, &n));
8097:     PetscCall(ISGetIndices(isrow, &rows));
8098:     for (PetscInt i = 0; i < n && flg; ++i) {
8099:       if (rows[i] < rStart || rows[i] >= rEnd) flg = PETSC_FALSE;
8100:     }
8101:     PetscCall(ISRestoreIndices(isrow, &rows));
8102:   }
8103:   // quiet return if we can't extract block size
8104:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &flg, 1, MPI_C_BOOL, MPI_LAND, PetscObjectComm((PetscObject)subA)));
8105:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

8107:   // extract block sizes
8108:   PetscCall(ISGetIndices(isrow, &rows));
8109:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8110:     PetscBool occupied = PETSC_FALSE;

8112:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8113:       const PetscInt row = gr + br;

8115:       if (i == n) break;
8116:       if (rows[i] == row) {
8117:         occupied = PETSC_TRUE;
8118:         ++i;
8119:       }
8120:       while (i < n && rows[i] < row) ++i;
8121:     }
8122:     gr += A->bsizes[b];
8123:     if (occupied) ++Nb;
8124:   }
8125:   subA->nblocks = Nb;
8126:   PetscCall(PetscFree(subA->bsizes));
8127:   PetscCall(PetscMalloc1(subA->nblocks, &subA->bsizes));
8128:   PetscInt sb = 0;
8129:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8130:     if (sb < subA->nblocks) subA->bsizes[sb] = 0;
8131:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8132:       const PetscInt row = gr + br;

8134:       if (i == n) break;
8135:       if (rows[i] == row) {
8136:         ++subA->bsizes[sb];
8137:         ++i;
8138:       }
8139:       while (i < n && rows[i] < row) ++i;
8140:     }
8141:     gr += A->bsizes[b];
8142:     if (sb < subA->nblocks && subA->bsizes[sb]) ++sb;
8143:   }
8144:   PetscCheck(sb == subA->nblocks, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of blocks %" PetscInt_FMT " != %" PetscInt_FMT, sb, subA->nblocks);
8145:   PetscInt nlocal, ncnt = 0;
8146:   PetscCall(MatGetLocalSize(subA, &nlocal, NULL));
8147:   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);
8148:   for (PetscInt i = 0; i < subA->nblocks; i++) ncnt += subA->bsizes[i];
8149:   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);
8150:   PetscCall(ISRestoreIndices(isrow, &rows));
8151:   PetscFunctionReturn(PETSC_SUCCESS);
8152: }

8154: /*@
8155:   MatSetBlockSizes - Sets the matrix block row and column sizes.

8157:   Logically Collective

8159:   Input Parameters:
8160: + mat - the matrix
8161: . rbs - row block size
8162: - cbs - column block size

8164:   Level: intermediate

8166:   Notes:
8167:   Block row formats are `MATBAIJ` and  `MATSBAIJ`. These formats ALWAYS have square block storage in the matrix.
8168:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.
8169:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

8171:   For `MATAIJ` matrix this function can be called at a later stage, provided that the specified block sizes
8172:   are compatible with the matrix local sizes.

8174:   The row and column block size determine the blocksize of the "row" and "column" vectors returned by `MatCreateVecs()`.

8176: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatGetBlockSizes()`
8177: @*/
8178: PetscErrorCode MatSetBlockSizes(Mat mat, PetscInt rbs, PetscInt cbs)
8179: {
8180:   PetscFunctionBegin;
8184:   PetscTryTypeMethod(mat, setblocksizes, rbs, cbs);
8185:   if (mat->rmap->refcnt) {
8186:     ISLocalToGlobalMapping l2g  = NULL;
8187:     PetscLayout            nmap = NULL;

8189:     PetscCall(PetscLayoutDuplicate(mat->rmap, &nmap));
8190:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->rmap->mapping, &l2g));
8191:     PetscCall(PetscLayoutDestroy(&mat->rmap));
8192:     mat->rmap          = nmap;
8193:     mat->rmap->mapping = l2g;
8194:   }
8195:   if (mat->cmap->refcnt) {
8196:     ISLocalToGlobalMapping l2g  = NULL;
8197:     PetscLayout            nmap = NULL;

8199:     PetscCall(PetscLayoutDuplicate(mat->cmap, &nmap));
8200:     if (mat->cmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->cmap->mapping, &l2g));
8201:     PetscCall(PetscLayoutDestroy(&mat->cmap));
8202:     mat->cmap          = nmap;
8203:     mat->cmap->mapping = l2g;
8204:   }
8205:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, rbs));
8206:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, cbs));
8207:   PetscFunctionReturn(PETSC_SUCCESS);
8208: }

8210: /*@
8211:   MatSetBlockSizesFromMats - Sets the matrix block row and column sizes to match a pair of matrices

8213:   Logically Collective

8215:   Input Parameters:
8216: + mat     - the matrix
8217: . fromRow - matrix from which to copy row block size
8218: - fromCol - matrix from which to copy column block size (can be same as `fromRow`)

8220:   Level: developer

8222: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`
8223: @*/
8224: PetscErrorCode MatSetBlockSizesFromMats(Mat mat, Mat fromRow, Mat fromCol)
8225: {
8226:   PetscFunctionBegin;
8230:   PetscTryTypeMethod(mat, setblocksizes, fromRow->rmap->bs, fromCol->cmap->bs);
8231:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, fromRow->rmap->bs));
8232:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, fromCol->cmap->bs));
8233:   PetscFunctionReturn(PETSC_SUCCESS);
8234: }

8236: /*@
8237:   MatResidual - Default routine to calculate the residual r = b - Ax

8239:   Collective

8241:   Input Parameters:
8242: + mat - the matrix
8243: . b   - the right-hand-side
8244: - x   - the approximate solution

8246:   Output Parameter:
8247: . r - location to store the residual

8249:   Level: developer

8251: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `PCMGSetResidual()`
8252: @*/
8253: PetscErrorCode MatResidual(Mat mat, Vec b, Vec x, Vec r)
8254: {
8255:   PetscFunctionBegin;
8261:   MatCheckPreallocated(mat, 1);
8262:   PetscCall(PetscLogEventBegin(MAT_Residual, mat, 0, 0, 0));
8263:   if (!mat->ops->residual) {
8264:     PetscCall(MatMult(mat, x, r));
8265:     PetscCall(VecAYPX(r, -1.0, b));
8266:   } else {
8267:     PetscUseTypeMethod(mat, residual, b, x, r);
8268:   }
8269:   PetscCall(PetscLogEventEnd(MAT_Residual, mat, 0, 0, 0));
8270:   PetscFunctionReturn(PETSC_SUCCESS);
8271: }

8273: /*@C
8274:   MatGetRowIJ - Returns the compressed row storage i and j indices for the local rows of a sparse matrix

8276:   Collective

8278:   Input Parameters:
8279: + mat             - the matrix
8280: . shift           - 0 or 1 indicating we want the indices starting at 0 or 1
8281: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8282: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE`  indicating if the nonzero structure of the
8283:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8284:                  always used.

8286:   Output Parameters:
8287: + n    - number of local rows in the (possibly compressed) matrix, use `NULL` if not needed
8288: . 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
8289: . ja   - the column indices, use `NULL` if not needed
8290: - done - indicates if the routine actually worked and returned appropriate ia[] and ja[] arrays; callers
8291:            are responsible for handling the case when done == `PETSC_FALSE` and ia and ja are not set

8293:   Level: developer

8295:   Notes:
8296:   You CANNOT change any of the ia[] or ja[] values.

8298:   Use `MatRestoreRowIJ()` when you are finished accessing the ia[] and ja[] values.

8300:   Fortran Notes:
8301:   Use
8302: .vb
8303:     PetscInt, pointer :: ia(:),ja(:)
8304:     call MatGetRowIJ(mat,shift,symmetric,inodecompressed,n,ia,ja,done,ierr)
8305:     ! Access the ith and jth entries via ia(i) and ja(j)
8306: .ve

8308: .seealso: [](ch_matrices), `Mat`, `MATAIJ`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`, `MatSeqAIJGetArray()`
8309: @*/
8310: PetscErrorCode MatGetRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8311: {
8312:   PetscFunctionBegin;
8315:   if (n) PetscAssertPointer(n, 5);
8316:   if (ia) PetscAssertPointer(ia, 6);
8317:   if (ja) PetscAssertPointer(ja, 7);
8318:   if (done) PetscAssertPointer(done, 8);
8319:   MatCheckPreallocated(mat, 1);
8320:   if (!mat->ops->getrowij && done) *done = PETSC_FALSE;
8321:   else {
8322:     if (done) *done = PETSC_TRUE;
8323:     PetscCall(PetscLogEventBegin(MAT_GetRowIJ, mat, 0, 0, 0));
8324:     PetscUseTypeMethod(mat, getrowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8325:     PetscCall(PetscLogEventEnd(MAT_GetRowIJ, mat, 0, 0, 0));
8326:   }
8327:   PetscFunctionReturn(PETSC_SUCCESS);
8328: }

8330: /*@C
8331:   MatGetColumnIJ - Returns the compressed column storage i and j indices for sequential matrices.

8333:   Collective

8335:   Input Parameters:
8336: + mat             - the matrix
8337: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8338: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be
8339:                 symmetrized
8340: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8341:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8342:                  always used.

8344:   Output Parameters:
8345: + n    - number of columns in the (possibly compressed) matrix
8346: . ia   - the column pointers; that is ia[0] = 0, ia[col] = i[col-1] + number of elements in that col of the matrix
8347: . ja   - the row indices
8348: - done - `PETSC_TRUE` or `PETSC_FALSE`, indicating whether the values have been returned

8350:   Level: developer

8352: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8353: @*/
8354: PetscErrorCode MatGetColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8355: {
8356:   PetscFunctionBegin;
8359:   PetscAssertPointer(n, 5);
8360:   if (ia) PetscAssertPointer(ia, 6);
8361:   if (ja) PetscAssertPointer(ja, 7);
8362:   PetscAssertPointer(done, 8);
8363:   MatCheckPreallocated(mat, 1);
8364:   if (!mat->ops->getcolumnij) *done = PETSC_FALSE;
8365:   else {
8366:     *done = PETSC_TRUE;
8367:     PetscUseTypeMethod(mat, getcolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8368:   }
8369:   PetscFunctionReturn(PETSC_SUCCESS);
8370: }

8372: /*@C
8373:   MatRestoreRowIJ - Call after you are completed with the ia,ja indices obtained with `MatGetRowIJ()`.

8375:   Collective

8377:   Input Parameters:
8378: + mat             - the matrix
8379: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8380: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8381: . inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8382:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8383:                     always used.
8384: . n               - size of (possibly compressed) matrix
8385: . ia              - the row pointers
8386: - ja              - the column indices

8388:   Output Parameter:
8389: . done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8391:   Level: developer

8393:   Note:
8394:   This routine zeros out `n`, `ia`, and `ja`. This is to prevent accidental
8395:   us of the array after it has been restored. If you pass `NULL`, it will
8396:   not zero the pointers.  Use of ia or ja after `MatRestoreRowIJ()` is invalid.

8398: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8399: @*/
8400: PetscErrorCode MatRestoreRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8401: {
8402:   PetscFunctionBegin;
8405:   if (ia) PetscAssertPointer(ia, 6);
8406:   if (ja) PetscAssertPointer(ja, 7);
8407:   if (done) PetscAssertPointer(done, 8);
8408:   MatCheckPreallocated(mat, 1);

8410:   if (!mat->ops->restorerowij && done) *done = PETSC_FALSE;
8411:   else {
8412:     if (done) *done = PETSC_TRUE;
8413:     PetscUseTypeMethod(mat, restorerowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8414:     if (n) *n = 0;
8415:     if (ia) *ia = NULL;
8416:     if (ja) *ja = NULL;
8417:   }
8418:   PetscFunctionReturn(PETSC_SUCCESS);
8419: }

8421: /*@C
8422:   MatRestoreColumnIJ - Call after you are completed with the ia,ja indices obtained with `MatGetColumnIJ()`.

8424:   Collective

8426:   Input Parameters:
8427: + mat             - the matrix
8428: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8429: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8430: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8431:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8432:                     always used.

8434:   Output Parameters:
8435: + n    - size of (possibly compressed) matrix
8436: . ia   - the column pointers
8437: . ja   - the row indices
8438: - done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8440:   Level: developer

8442: .seealso: [](ch_matrices), `Mat`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`
8443: @*/
8444: PetscErrorCode MatRestoreColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8445: {
8446:   PetscFunctionBegin;
8449:   if (ia) PetscAssertPointer(ia, 6);
8450:   if (ja) PetscAssertPointer(ja, 7);
8451:   PetscAssertPointer(done, 8);
8452:   MatCheckPreallocated(mat, 1);

8454:   if (!mat->ops->restorecolumnij) *done = PETSC_FALSE;
8455:   else {
8456:     *done = PETSC_TRUE;
8457:     PetscUseTypeMethod(mat, restorecolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8458:     if (n) *n = 0;
8459:     if (ia) *ia = NULL;
8460:     if (ja) *ja = NULL;
8461:   }
8462:   PetscFunctionReturn(PETSC_SUCCESS);
8463: }

8465: /*@
8466:   MatColoringPatch - Used inside matrix coloring routines that use `MatGetRowIJ()` and/or
8467:   `MatGetColumnIJ()`.

8469:   Collective

8471:   Input Parameters:
8472: + mat        - the matrix
8473: . ncolors    - maximum color value
8474: . n          - number of entries in colorarray
8475: - colorarray - array indicating color for each column

8477:   Output Parameter:
8478: . iscoloring - coloring generated using colorarray information

8480:   Level: developer

8482: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatGetColumnIJ()`
8483: @*/
8484: PetscErrorCode MatColoringPatch(Mat mat, PetscInt ncolors, PetscInt n, ISColoringValue colorarray[], ISColoring *iscoloring)
8485: {
8486:   PetscFunctionBegin;
8489:   PetscAssertPointer(colorarray, 4);
8490:   PetscAssertPointer(iscoloring, 5);
8491:   MatCheckPreallocated(mat, 1);

8493:   if (!mat->ops->coloringpatch) {
8494:     PetscCall(ISColoringCreate(PetscObjectComm((PetscObject)mat), ncolors, n, colorarray, PETSC_OWN_POINTER, iscoloring));
8495:   } else {
8496:     PetscUseTypeMethod(mat, coloringpatch, ncolors, n, colorarray, iscoloring);
8497:   }
8498:   PetscFunctionReturn(PETSC_SUCCESS);
8499: }

8501: /*@
8502:   MatSetUnfactored - Resets a factored matrix to be treated as unfactored.

8504:   Logically Collective

8506:   Input Parameter:
8507: . mat - the factored matrix to be reset

8509:   Level: developer

8511:   Notes:
8512:   This routine should be used only with factored matrices formed by in-place
8513:   factorization via ILU(0) (or by in-place LU factorization for the `MATSEQDENSE`
8514:   format).  This option can save memory, for example, when solving nonlinear
8515:   systems with a matrix-free Newton-Krylov method and a matrix-based, in-place
8516:   ILU(0) preconditioner.

8518:   One can specify in-place ILU(0) factorization by calling
8519: .vb
8520:      PCType(pc,PCILU);
8521:      PCFactorSeUseInPlace(pc);
8522: .ve
8523:   or by using the options -pc_type ilu -pc_factor_in_place

8525:   In-place factorization ILU(0) can also be used as a local
8526:   solver for the blocks within the block Jacobi or additive Schwarz
8527:   methods (runtime option: -sub_pc_factor_in_place).  See Users-Manual: ch_pc
8528:   for details on setting local solver options.

8530:   Most users should employ the `KSP` interface for linear solvers
8531:   instead of working directly with matrix algebra routines such as this.
8532:   See, e.g., `KSPCreate()`.

8534: .seealso: [](ch_matrices), `Mat`, `PCFactorSetUseInPlace()`, `PCFactorGetUseInPlace()`
8535: @*/
8536: PetscErrorCode MatSetUnfactored(Mat mat)
8537: {
8538:   PetscFunctionBegin;
8541:   MatCheckPreallocated(mat, 1);
8542:   mat->factortype = MAT_FACTOR_NONE;
8543:   if (!mat->ops->setunfactored) PetscFunctionReturn(PETSC_SUCCESS);
8544:   PetscUseTypeMethod(mat, setunfactored);
8545:   PetscFunctionReturn(PETSC_SUCCESS);
8546: }

8548: /*@
8549:   MatCreateSubMatrix - Gets a single submatrix on the same number of processors
8550:   as the original matrix.

8552:   Collective

8554:   Input Parameters:
8555: + mat   - the original matrix
8556: . isrow - parallel `IS` containing the rows this processor should obtain
8557: . 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.
8558: - cll   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

8560:   Output Parameter:
8561: . newmat - the new submatrix, of the same type as the original matrix

8563:   Level: advanced

8565:   Notes:
8566:   The submatrix will be able to be multiplied with vectors using the same layout as `iscol`.

8568:   Some matrix types place restrictions on the row and column indices, such
8569:   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;
8570:   for example, if the block size is 3 one cannot select the 0 and 2 rows without selecting the 1 row.

8572:   The index sets may not have duplicate entries.

8574:   The first time this is called you should use a cll of `MAT_INITIAL_MATRIX`,
8575:   the `MatCreateSubMatrix()` routine will create the newmat for you. Any additional calls
8576:   to this routine with a mat of the same nonzero structure and with a call of `MAT_REUSE_MATRIX`
8577:   will reuse the matrix generated the first time.  You should call `MatDestroy()` on `newmat` when
8578:   you are finished using it.

8580:   The communicator of the newly obtained matrix is ALWAYS the same as the communicator of
8581:   the input matrix.

8583:   If `iscol` is `NULL` then all columns are obtained (not supported in Fortran).

8585:   If `isrow` and `iscol` have a nontrivial block-size, then the resulting matrix has this block-size as well. This feature
8586:   is used by `PCFIELDSPLIT` to allow easy nesting of its use.

8588:   Example usage:
8589:   Consider the following 8x8 matrix with 34 non-zero values, that is
8590:   assembled across 3 processors. Let's assume that proc0 owns 3 rows,
8591:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
8592:   as follows
8593: .vb
8594:             1  2  0  |  0  3  0  |  0  4
8595:     Proc0   0  5  6  |  7  0  0  |  8  0
8596:             9  0 10  | 11  0  0  | 12  0
8597:     -------------------------------------
8598:            13  0 14  | 15 16 17  |  0  0
8599:     Proc1   0 18  0  | 19 20 21  |  0  0
8600:             0  0  0  | 22 23  0  | 24  0
8601:     -------------------------------------
8602:     Proc2  25 26 27  |  0  0 28  | 29  0
8603:            30  0  0  | 31 32 33  |  0 34
8604: .ve

8606:   Suppose `isrow` = [0 1 | 4 | 6 7] and `iscol` = [1 2 | 3 4 5 | 6].  The resulting submatrix is

8608: .vb
8609:             2  0  |  0  3  0  |  0
8610:     Proc0   5  6  |  7  0  0  |  8
8611:     -------------------------------
8612:     Proc1  18  0  | 19 20 21  |  0
8613:     -------------------------------
8614:     Proc2  26 27  |  0  0 28  | 29
8615:             0  0  | 31 32 33  |  0
8616: .ve

8618: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatCreateSubMatricesMPI()`, `MatCreateSubMatrixVirtual()`, `MatSubMatrixVirtualUpdate()`
8619: @*/
8620: PetscErrorCode MatCreateSubMatrix(Mat mat, IS isrow, IS iscol, MatReuse cll, Mat *newmat)
8621: {
8622:   PetscMPIInt size;
8623:   Mat        *local;
8624:   IS          iscoltmp;
8625:   PetscBool   flg;

8627:   PetscFunctionBegin;
8631:   PetscAssertPointer(newmat, 5);
8634:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
8635:   PetscCheck(cll != MAT_IGNORE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_IGNORE_MATRIX");
8636:   PetscCheck(cll != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_INPLACE_MATRIX");

8638:   MatCheckPreallocated(mat, 1);
8639:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));

8641:   if (!iscol || isrow == iscol) {
8642:     PetscBool   stride;
8643:     PetscMPIInt grabentirematrix = 0, grab;
8644:     PetscCall(PetscObjectTypeCompare((PetscObject)isrow, ISSTRIDE, &stride));
8645:     if (stride) {
8646:       PetscInt first, step, n, rstart, rend;
8647:       PetscCall(ISStrideGetInfo(isrow, &first, &step));
8648:       if (step == 1) {
8649:         PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
8650:         if (rstart == first) {
8651:           PetscCall(ISGetLocalSize(isrow, &n));
8652:           if (n == rend - rstart) grabentirematrix = 1;
8653:         }
8654:       }
8655:     }
8656:     PetscCallMPI(MPIU_Allreduce(&grabentirematrix, &grab, 1, MPI_INT, MPI_MIN, PetscObjectComm((PetscObject)mat)));
8657:     if (grab) {
8658:       PetscCall(PetscInfo(mat, "Getting entire matrix as submatrix\n"));
8659:       if (cll == MAT_INITIAL_MATRIX) {
8660:         *newmat = mat;
8661:         PetscCall(PetscObjectReference((PetscObject)mat));
8662:       }
8663:       PetscFunctionReturn(PETSC_SUCCESS);
8664:     }
8665:   }

8667:   if (!iscol) {
8668:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), mat->cmap->n, mat->cmap->rstart, 1, &iscoltmp));
8669:   } else {
8670:     iscoltmp = iscol;
8671:   }

8673:   /* if original matrix is on just one processor then use submatrix generated */
8674:   if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1 && cll == MAT_REUSE_MATRIX) {
8675:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_REUSE_MATRIX, &newmat));
8676:     goto setproperties;
8677:   } else if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1) {
8678:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_INITIAL_MATRIX, &local));
8679:     *newmat = *local;
8680:     PetscCall(PetscFree(local));
8681:     goto setproperties;
8682:   } else if (!mat->ops->createsubmatrix) {
8683:     /* Create a new matrix type that implements the operation using the full matrix */
8684:     PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8685:     switch (cll) {
8686:     case MAT_INITIAL_MATRIX:
8687:       PetscCall(MatCreateSubMatrixVirtual(mat, isrow, iscoltmp, newmat));
8688:       break;
8689:     case MAT_REUSE_MATRIX:
8690:       PetscCall(MatSubMatrixVirtualUpdate(*newmat, mat, isrow, iscoltmp));
8691:       break;
8692:     default:
8693:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Invalid MatReuse, must be either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX");
8694:     }
8695:     PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));
8696:     goto setproperties;
8697:   }

8699:   PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8700:   PetscUseTypeMethod(mat, createsubmatrix, isrow, iscoltmp, cll, newmat);
8701:   PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));

8703: setproperties:
8704:   if ((*newmat)->symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->structurally_symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->spd == PETSC_BOOL3_UNKNOWN && (*newmat)->hermitian == PETSC_BOOL3_UNKNOWN) {
8705:     PetscCall(ISEqualUnsorted(isrow, iscoltmp, &flg));
8706:     if (flg) PetscCall(MatPropagateSymmetryOptions(mat, *newmat));
8707:   }
8708:   if (!iscol) PetscCall(ISDestroy(&iscoltmp));
8709:   if (*newmat && cll == MAT_INITIAL_MATRIX) PetscCall(PetscObjectStateIncrease((PetscObject)*newmat));
8710:   if (!iscol || isrow == iscol) PetscCall(MatSelectVariableBlockSizes(*newmat, mat, isrow));
8711:   PetscFunctionReturn(PETSC_SUCCESS);
8712: }

8714: /*@
8715:   MatPropagateSymmetryOptions - Propagates symmetry options set on a matrix to another matrix

8717:   Not Collective

8719:   Input Parameters:
8720: + A - the matrix we wish to propagate options from
8721: - B - the matrix we wish to propagate options to

8723:   Level: beginner

8725:   Note:
8726:   Propagates the options associated to `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_HERMITIAN`, `MAT_SPD`, `MAT_SYMMETRIC`, and `MAT_STRUCTURAL_SYMMETRY_ETERNAL`

8728: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatIsSymmetricKnown()`, `MatIsSPDKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
8729: @*/
8730: PetscErrorCode MatPropagateSymmetryOptions(Mat A, Mat B)
8731: {
8732:   PetscFunctionBegin;
8735:   B->symmetry_eternal            = A->symmetry_eternal;
8736:   B->structural_symmetry_eternal = A->structural_symmetry_eternal;
8737:   B->symmetric                   = A->symmetric;
8738:   B->structurally_symmetric      = A->structurally_symmetric;
8739:   B->spd                         = A->spd;
8740:   B->hermitian                   = A->hermitian;
8741:   PetscFunctionReturn(PETSC_SUCCESS);
8742: }

8744: /*@
8745:   MatStashSetInitialSize - sets the sizes of the matrix stash, that is
8746:   used during the assembly process to store values that belong to
8747:   other processors.

8749:   Not Collective

8751:   Input Parameters:
8752: + mat   - the matrix
8753: . size  - the initial size of the stash.
8754: - bsize - the initial size of the block-stash(if used).

8756:   Options Database Keys:
8757: + -matstash_initial_size size or size0,size1,...,sizep-1            - set initial size
8758: - -matstash_block_initial_size bsize  or bsize0,bsize1,...,bsizep-1 - set initial block size

8760:   Level: intermediate

8762:   Notes:
8763:   The block-stash is used for values set with `MatSetValuesBlocked()` while
8764:   the stash is used for values set with `MatSetValues()`

8766:   Run with the option -info and look for output of the form
8767:   MatAssemblyBegin_MPIXXX:Stash has MM entries, uses nn mallocs.
8768:   to determine the appropriate value, MM, to use for size and
8769:   MatAssemblyBegin_MPIXXX:Block-Stash has BMM entries, uses nn mallocs.
8770:   to determine the value, BMM to use for bsize

8772: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashGetInfo()`
8773: @*/
8774: PetscErrorCode MatStashSetInitialSize(Mat mat, PetscInt size, PetscInt bsize)
8775: {
8776:   PetscFunctionBegin;
8779:   PetscCall(MatStashSetInitialSize_Private(&mat->stash, size));
8780:   PetscCall(MatStashSetInitialSize_Private(&mat->bstash, bsize));
8781:   PetscFunctionReturn(PETSC_SUCCESS);
8782: }

8784: /*@
8785:   MatInterpolateAdd - $w = y + A*x$ or $A^T*x$ depending on the shape of
8786:   the matrix

8788:   Neighbor-wise Collective

8790:   Input Parameters:
8791: + A - the matrix
8792: . x - the vector to be multiplied by the interpolation operator
8793: - y - the vector to be added to the result

8795:   Output Parameter:
8796: . w - the resulting vector

8798:   Level: intermediate

8800:   Notes:
8801:   `w` may be the same vector as `y`.

8803:   This allows one to use either the restriction or interpolation (its transpose)
8804:   matrix to do the interpolation

8806: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8807: @*/
8808: PetscErrorCode MatInterpolateAdd(Mat A, Vec x, Vec y, Vec w)
8809: {
8810:   PetscInt M, N, Ny;

8812:   PetscFunctionBegin;
8817:   PetscCall(MatGetSize(A, &M, &N));
8818:   PetscCall(VecGetSize(y, &Ny));
8819:   if (M == Ny) PetscCall(MatMultAdd(A, x, y, w));
8820:   else PetscCall(MatMultTransposeAdd(A, x, y, w));
8821:   PetscFunctionReturn(PETSC_SUCCESS);
8822: }

8824: /*@
8825:   MatInterpolate - $y = A*x$ or $A^T*x$ depending on the shape of
8826:   the matrix

8828:   Neighbor-wise Collective

8830:   Input Parameters:
8831: + A - the matrix
8832: - x - the vector to be interpolated

8834:   Output Parameter:
8835: . y - the resulting vector

8837:   Level: intermediate

8839:   Note:
8840:   This allows one to use either the restriction or interpolation (its transpose)
8841:   matrix to do the interpolation

8843: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8844: @*/
8845: PetscErrorCode MatInterpolate(Mat A, Vec x, Vec y)
8846: {
8847:   PetscInt M, N, Ny;

8849:   PetscFunctionBegin;
8853:   PetscCall(MatGetSize(A, &M, &N));
8854:   PetscCall(VecGetSize(y, &Ny));
8855:   if (M == Ny) PetscCall(MatMult(A, x, y));
8856:   else PetscCall(MatMultTranspose(A, x, y));
8857:   PetscFunctionReturn(PETSC_SUCCESS);
8858: }

8860: /*@
8861:   MatRestrict - $y = A*x$ or $A^T*x$

8863:   Neighbor-wise Collective

8865:   Input Parameters:
8866: + A - the matrix
8867: - x - the vector to be restricted

8869:   Output Parameter:
8870: . y - the resulting vector

8872:   Level: intermediate

8874:   Note:
8875:   This allows one to use either the restriction or interpolation (its transpose)
8876:   matrix to do the restriction

8878: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatInterpolate()`, `PCMG`
8879: @*/
8880: PetscErrorCode MatRestrict(Mat A, Vec x, Vec y)
8881: {
8882:   PetscInt M, N, Nx;

8884:   PetscFunctionBegin;
8888:   PetscCall(MatGetSize(A, &M, &N));
8889:   PetscCall(VecGetSize(x, &Nx));
8890:   if (M == Nx) PetscCall(MatMultTranspose(A, x, y));
8891:   else PetscCall(MatMult(A, x, y));
8892:   PetscFunctionReturn(PETSC_SUCCESS);
8893: }

8895: /*@
8896:   MatMatInterpolateAdd - $Y = W + A*X$ or $W + A^T*X$ depending on the shape of `A`

8898:   Neighbor-wise Collective

8900:   Input Parameters:
8901: + A - the matrix
8902: . x - the input dense matrix to be multiplied
8903: - w - the input dense matrix to be added to the result

8905:   Output Parameter:
8906: . y - the output dense matrix

8908:   Level: intermediate

8910:   Note:
8911:   This allows one to use either the restriction or interpolation (its transpose)
8912:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8913:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8915: .seealso: [](ch_matrices), `Mat`, `MatInterpolateAdd()`, `MatMatInterpolate()`, `MatMatRestrict()`, `PCMG`
8916: @*/
8917: PetscErrorCode MatMatInterpolateAdd(Mat A, Mat x, Mat w, Mat *y)
8918: {
8919:   PetscInt  M, N, Mx, Nx, Mo, My = 0, Ny = 0;
8920:   PetscBool trans = PETSC_TRUE;
8921:   MatReuse  reuse = MAT_INITIAL_MATRIX;

8923:   PetscFunctionBegin;
8929:   PetscCall(MatGetSize(A, &M, &N));
8930:   PetscCall(MatGetSize(x, &Mx, &Nx));
8931:   if (N == Mx) trans = PETSC_FALSE;
8932:   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);
8933:   Mo = trans ? N : M;
8934:   if (*y) {
8935:     PetscCall(MatGetSize(*y, &My, &Ny));
8936:     if (Mo == My && Nx == Ny) reuse = MAT_REUSE_MATRIX;
8937:     else {
8938:       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);
8939:       PetscCall(MatDestroy(y));
8940:     }
8941:   }

8943:   if (w && *y == w) { /* this is to minimize changes in PCMG */
8944:     PetscBool flg;

8946:     PetscCall(PetscObjectQuery((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject *)&w));
8947:     if (w) {
8948:       PetscInt My, Ny, Mw, Nw;

8950:       PetscCall(PetscObjectTypeCompare((PetscObject)*y, ((PetscObject)w)->type_name, &flg));
8951:       PetscCall(MatGetSize(*y, &My, &Ny));
8952:       PetscCall(MatGetSize(w, &Mw, &Nw));
8953:       if (!flg || My != Mw || Ny != Nw) w = NULL;
8954:     }
8955:     if (!w) {
8956:       PetscCall(MatDuplicate(*y, MAT_COPY_VALUES, &w));
8957:       PetscCall(PetscObjectCompose((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject)w));
8958:       PetscCall(PetscObjectDereference((PetscObject)w));
8959:     } else PetscCall(MatCopy(*y, w, UNKNOWN_NONZERO_PATTERN));
8960:   }
8961:   if (!trans) PetscCall(MatMatMult(A, x, reuse, PETSC_DETERMINE, y));
8962:   else PetscCall(MatTransposeMatMult(A, x, reuse, PETSC_DETERMINE, y));
8963:   if (w) PetscCall(MatAXPY(*y, 1.0, w, UNKNOWN_NONZERO_PATTERN));
8964:   PetscFunctionReturn(PETSC_SUCCESS);
8965: }

8967: /*@
8968:   MatMatInterpolate - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8970:   Neighbor-wise Collective

8972:   Input Parameters:
8973: + A - the matrix
8974: - x - the input dense matrix

8976:   Output Parameter:
8977: . y - the output dense matrix

8979:   Level: intermediate

8981:   Note:
8982:   This allows one to use either the restriction or interpolation (its transpose)
8983:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8984:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8986: .seealso: [](ch_matrices), `Mat`, `MatInterpolate()`, `MatRestrict()`, `MatMatRestrict()`, `PCMG`
8987: @*/
8988: PetscErrorCode MatMatInterpolate(Mat A, Mat x, Mat *y)
8989: {
8990:   PetscFunctionBegin;
8991:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
8992:   PetscFunctionReturn(PETSC_SUCCESS);
8993: }

8995: /*@
8996:   MatMatRestrict - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8998:   Neighbor-wise Collective

9000:   Input Parameters:
9001: + A - the matrix
9002: - x - the input dense matrix

9004:   Output Parameter:
9005: . y - the output dense matrix

9007:   Level: intermediate

9009:   Note:
9010:   This allows one to use either the restriction or interpolation (its transpose)
9011:   matrix to do the restriction. `y` matrix can be reused if already created with the proper sizes,
9012:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

9014: .seealso: [](ch_matrices), `Mat`, `MatRestrict()`, `MatInterpolate()`, `MatMatInterpolate()`, `PCMG`
9015: @*/
9016: PetscErrorCode MatMatRestrict(Mat A, Mat x, Mat *y)
9017: {
9018:   PetscFunctionBegin;
9019:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
9020:   PetscFunctionReturn(PETSC_SUCCESS);
9021: }

9023: /*@
9024:   MatGetNullSpace - retrieves the null space of a matrix.

9026:   Logically Collective

9028:   Input Parameters:
9029: + mat    - the matrix
9030: - nullsp - the null space object

9032:   Level: developer

9034: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetNullSpace()`, `MatNullSpace`
9035: @*/
9036: PetscErrorCode MatGetNullSpace(Mat mat, MatNullSpace *nullsp)
9037: {
9038:   PetscFunctionBegin;
9040:   PetscAssertPointer(nullsp, 2);
9041:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->nullsp) ? mat->transnullsp : mat->nullsp;
9042:   PetscFunctionReturn(PETSC_SUCCESS);
9043: }

9045: /*@C
9046:   MatGetNullSpaces - gets the null spaces, transpose null spaces, and near null spaces from an array of matrices

9048:   Logically Collective

9050:   Input Parameters:
9051: + n   - the number of matrices
9052: - mat - the array of matrices

9054:   Output Parameters:
9055: . nullsp - an array of null spaces, `NULL` for each matrix that does not have a null space, length 3 * `n`

9057:   Level: developer

9059:   Note:
9060:   Call `MatRestoreNullspaces()` to provide these to another array of matrices

9062: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
9063:           `MatNullSpaceRemove()`, `MatRestoreNullSpaces()`
9064: @*/
9065: PetscErrorCode MatGetNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
9066: {
9067:   PetscFunctionBegin;
9068:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
9069:   PetscAssertPointer(mat, 2);
9070:   PetscAssertPointer(nullsp, 3);

9072:   PetscCall(PetscCalloc1(3 * n, nullsp));
9073:   for (PetscInt i = 0; i < n; i++) {
9075:     (*nullsp)[i] = mat[i]->nullsp;
9076:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[i]));
9077:     (*nullsp)[n + i] = mat[i]->nearnullsp;
9078:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[n + i]));
9079:     (*nullsp)[2 * n + i] = mat[i]->transnullsp;
9080:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[2 * n + i]));
9081:   }
9082:   PetscFunctionReturn(PETSC_SUCCESS);
9083: }

9085: /*@C
9086:   MatRestoreNullSpaces - sets the null spaces, transpose null spaces, and near null spaces obtained with `MatGetNullSpaces()` for an array of matrices

9088:   Logically Collective

9090:   Input Parameters:
9091: + n      - the number of matrices
9092: . mat    - the array of matrices
9093: - nullsp - an array of null spaces

9095:   Level: developer

9097:   Note:
9098:   Call `MatGetNullSpaces()` to create `nullsp`

9100: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
9101:           `MatNullSpaceRemove()`, `MatGetNullSpaces()`
9102: @*/
9103: PetscErrorCode MatRestoreNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
9104: {
9105:   PetscFunctionBegin;
9106:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
9107:   PetscAssertPointer(mat, 2);
9108:   PetscAssertPointer(nullsp, 3);
9109:   PetscAssertPointer(*nullsp, 3);

9111:   for (PetscInt i = 0; i < n; i++) {
9113:     PetscCall(MatSetNullSpace(mat[i], (*nullsp)[i]));
9114:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[i]));
9115:     PetscCall(MatSetNearNullSpace(mat[i], (*nullsp)[n + i]));
9116:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[n + i]));
9117:     PetscCall(MatSetTransposeNullSpace(mat[i], (*nullsp)[2 * n + i]));
9118:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[2 * n + i]));
9119:   }
9120:   PetscCall(PetscFree(*nullsp));
9121:   PetscFunctionReturn(PETSC_SUCCESS);
9122: }

9124: /*@
9125:   MatSetNullSpace - attaches a null space to a matrix.

9127:   Logically Collective

9129:   Input Parameters:
9130: + mat    - the matrix
9131: - nullsp - the null space object

9133:   Level: advanced

9135:   Notes:
9136:   This null space is used by the `KSP` linear solvers to solve singular systems.

9138:   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`

9140:   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
9141:   to zero but the linear system will still be solved in a least squares sense.

9143:   The fundamental theorem of linear algebra (Gilbert Strang, Introduction to Applied Mathematics, page 72) states that
9144:   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 $A^T$, $R(A^T)$.
9145:   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
9146:   $n(A^T))$ 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
9147:   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 $n(A^T)$.
9148:   This  $\hat{b}$ can be obtained by calling `MatNullSpaceRemove()` with the null space of the transpose of the matrix.

9150:   If the matrix is known to be symmetric because it is an `MATSBAIJ` matrix or one has called
9151:   `MatSetOption`(mat,`MAT_SYMMETRIC` or possibly `MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`); this
9152:   routine also automatically calls `MatSetTransposeNullSpace()`.

9154:   The user should call `MatNullSpaceDestroy()`.

9156: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`,
9157:           `KSPSetPCSide()`
9158: @*/
9159: PetscErrorCode MatSetNullSpace(Mat mat, MatNullSpace nullsp)
9160: {
9161:   PetscFunctionBegin;
9164:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9165:   PetscCall(MatNullSpaceDestroy(&mat->nullsp));
9166:   mat->nullsp = nullsp;
9167:   if (mat->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetTransposeNullSpace(mat, nullsp));
9168:   PetscFunctionReturn(PETSC_SUCCESS);
9169: }

9171: /*@
9172:   MatGetTransposeNullSpace - retrieves the null space of the transpose of a matrix.

9174:   Logically Collective

9176:   Input Parameters:
9177: + mat    - the matrix
9178: - nullsp - the null space object

9180:   Level: developer

9182: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetTransposeNullSpace()`, `MatSetNullSpace()`, `MatGetNullSpace()`
9183: @*/
9184: PetscErrorCode MatGetTransposeNullSpace(Mat mat, MatNullSpace *nullsp)
9185: {
9186:   PetscFunctionBegin;
9189:   PetscAssertPointer(nullsp, 2);
9190:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->transnullsp) ? mat->nullsp : mat->transnullsp;
9191:   PetscFunctionReturn(PETSC_SUCCESS);
9192: }

9194: /*@
9195:   MatSetTransposeNullSpace - attaches the null space of a transpose of a matrix to the matrix

9197:   Logically Collective

9199:   Input Parameters:
9200: + mat    - the matrix
9201: - nullsp - the null space object

9203:   Level: advanced

9205:   Notes:
9206:   This allows solving singular linear systems defined by the transpose of the matrix using `KSP` solvers with left preconditioning.

9208:   See `MatSetNullSpace()`

9210: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`, `KSPSetPCSide()`
9211: @*/
9212: PetscErrorCode MatSetTransposeNullSpace(Mat mat, MatNullSpace nullsp)
9213: {
9214:   PetscFunctionBegin;
9217:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9218:   PetscCall(MatNullSpaceDestroy(&mat->transnullsp));
9219:   mat->transnullsp = nullsp;
9220:   PetscFunctionReturn(PETSC_SUCCESS);
9221: }

9223: /*@
9224:   MatSetNearNullSpace - attaches a null space to a matrix, which is often the null space (rigid body modes) of the operator without boundary conditions
9225:   This null space will be used to provide near null space vectors to a multigrid preconditioner built from this matrix.

9227:   Logically Collective

9229:   Input Parameters:
9230: + mat    - the matrix
9231: - nullsp - the null space object

9233:   Level: advanced

9235:   Notes:
9236:   Overwrites any previous near null space that may have been attached

9238:   You can remove the null space by calling this routine with an `nullsp` of `NULL`

9240: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNullSpace()`, `MatNullSpaceCreateRigidBody()`, `MatGetNearNullSpace()`
9241: @*/
9242: PetscErrorCode MatSetNearNullSpace(Mat mat, MatNullSpace nullsp)
9243: {
9244:   PetscFunctionBegin;
9248:   MatCheckPreallocated(mat, 1);
9249:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9250:   PetscCall(MatNullSpaceDestroy(&mat->nearnullsp));
9251:   mat->nearnullsp = nullsp;
9252:   PetscFunctionReturn(PETSC_SUCCESS);
9253: }

9255: /*@
9256:   MatGetNearNullSpace - Get null space attached with `MatSetNearNullSpace()`

9258:   Not Collective

9260:   Input Parameter:
9261: . mat - the matrix

9263:   Output Parameter:
9264: . nullsp - the null space object, `NULL` if not set

9266:   Level: advanced

9268: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatNullSpaceCreate()`
9269: @*/
9270: PetscErrorCode MatGetNearNullSpace(Mat mat, MatNullSpace *nullsp)
9271: {
9272:   PetscFunctionBegin;
9275:   PetscAssertPointer(nullsp, 2);
9276:   MatCheckPreallocated(mat, 1);
9277:   *nullsp = mat->nearnullsp;
9278:   PetscFunctionReturn(PETSC_SUCCESS);
9279: }

9281: /*@
9282:   MatICCFactor - Performs in-place incomplete Cholesky factorization of matrix.

9284:   Collective

9286:   Input Parameters:
9287: + mat  - the matrix
9288: . row  - row/column permutation
9289: - info - information on desired factorization process

9291:   Level: developer

9293:   Notes:
9294:   Probably really in-place only when level of fill is zero, otherwise allocates
9295:   new space to store factored matrix and deletes previous memory.

9297:   Most users should employ the `KSP` interface for linear solvers
9298:   instead of working directly with matrix algebra routines such as this.
9299:   See, e.g., `KSPCreate()`.

9301:   Fortran Note:
9302:   A valid (non-null) `info` argument must be provided

9304: .seealso: [](ch_matrices), `Mat`, `MatFactorInfo`, `MatGetFactor()`, `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
9305: @*/
9306: PetscErrorCode MatICCFactor(Mat mat, IS row, const MatFactorInfo *info)
9307: {
9308:   PetscFunctionBegin;
9312:   PetscAssertPointer(info, 3);
9313:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
9314:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
9315:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
9316:   MatCheckPreallocated(mat, 1);
9317:   PetscUseTypeMethod(mat, iccfactor, row, info);
9318:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9319:   PetscFunctionReturn(PETSC_SUCCESS);
9320: }

9322: /*@
9323:   MatDiagonalScaleLocal - Scales columns of a matrix given the scaling values including the
9324:   ghosted ones.

9326:   Not Collective

9328:   Input Parameters:
9329: + mat  - the matrix
9330: - diag - the diagonal values, including ghost ones

9332:   Level: developer

9334:   Notes:
9335:   Works only for `MATMPIAIJ` and `MATMPIBAIJ` matrices

9337:   This allows one to avoid during communication to perform the scaling that must be done with `MatDiagonalScale()`

9339: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
9340: @*/
9341: PetscErrorCode MatDiagonalScaleLocal(Mat mat, Vec diag)
9342: {
9343:   PetscMPIInt size;

9345:   PetscFunctionBegin;

9350:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must be already assembled");
9351:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
9352:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
9353:   if (size == 1) {
9354:     PetscInt n, m;
9355:     PetscCall(VecGetSize(diag, &n));
9356:     PetscCall(MatGetSize(mat, NULL, &m));
9357:     PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supported for sequential matrices when no ghost points/periodic conditions");
9358:     PetscCall(MatDiagonalScale(mat, NULL, diag));
9359:   } else PetscUseMethod(mat, "MatDiagonalScaleLocal_C", (Mat, Vec), (mat, diag));
9360:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
9361:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9362:   PetscFunctionReturn(PETSC_SUCCESS);
9363: }

9365: /*@
9366:   MatGetInertia - Gets the inertia from a factored matrix

9368:   Collective

9370:   Input Parameter:
9371: . mat - the matrix

9373:   Output Parameters:
9374: + nneg  - number of negative eigenvalues
9375: . nzero - number of zero eigenvalues
9376: - npos  - number of positive eigenvalues

9378:   Level: advanced

9380:   Note:
9381:   Matrix must have been factored by `MatCholeskyFactor()`

9383: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactor()`
9384: @*/
9385: PetscErrorCode MatGetInertia(Mat mat, PetscInt *nneg, PetscInt *nzero, PetscInt *npos)
9386: {
9387:   PetscFunctionBegin;
9390:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9391:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Numeric factor mat is not assembled");
9392:   PetscUseTypeMethod(mat, getinertia, nneg, nzero, npos);
9393:   PetscFunctionReturn(PETSC_SUCCESS);
9394: }

9396: /*@C
9397:   MatSolves - Solves $A x = b$, given a factored matrix, for a collection of vectors

9399:   Neighbor-wise Collective

9401:   Input Parameters:
9402: + mat - the factored matrix obtained with `MatGetFactor()`
9403: - b   - the right-hand-side vectors

9405:   Output Parameter:
9406: . x - the result vectors

9408:   Level: developer

9410:   Note:
9411:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
9412:   call `MatSolves`(A,x,x).

9414: .seealso: [](ch_matrices), `Mat`, `Vecs`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`, `MatSolve()`
9415: @*/
9416: PetscErrorCode MatSolves(Mat mat, Vecs b, Vecs x)
9417: {
9418:   PetscFunctionBegin;
9421:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
9422:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9423:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);

9425:   MatCheckPreallocated(mat, 1);
9426:   PetscCall(PetscLogEventBegin(MAT_Solves, mat, 0, 0, 0));
9427:   PetscUseTypeMethod(mat, solves, b, x);
9428:   PetscCall(PetscLogEventEnd(MAT_Solves, mat, 0, 0, 0));
9429:   PetscFunctionReturn(PETSC_SUCCESS);
9430: }

9432: /*@
9433:   MatIsSymmetric - Test whether a matrix is symmetric

9435:   Collective

9437:   Input Parameters:
9438: + A   - the matrix to test
9439: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact transpose)

9441:   Output Parameter:
9442: . flg - the result

9444:   Level: intermediate

9446:   Notes:
9447:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9449:   If the matrix does not yet know if it is symmetric or not this can be an expensive operation, also available `MatIsSymmetricKnown()`

9451:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9452:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9454: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetricKnown()`,
9455:           `MAT_SYMMETRIC`, `MAT_SYMMETRY_ETERNAL`
9456: @*/
9457: PetscErrorCode MatIsSymmetric(Mat A, PetscReal tol, PetscBool *flg)
9458: {
9459:   PetscFunctionBegin;
9461:   PetscAssertPointer(flg, 3);
9462:   if (A->symmetric != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->symmetric);
9463:   else {
9464:     if (A->ops->issymmetric) PetscUseTypeMethod(A, issymmetric, tol, flg);
9465:     else PetscCall(MatIsTranspose(A, A, tol, flg));
9466:     if (!tol) PetscCall(MatSetOption(A, MAT_SYMMETRIC, *flg));
9467:   }
9468:   PetscFunctionReturn(PETSC_SUCCESS);
9469: }

9471: /*@
9472:   MatIsHermitian - Test whether a matrix is Hermitian

9474:   Collective

9476:   Input Parameters:
9477: + A   - the matrix to test
9478: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact Hermitian)

9480:   Output Parameter:
9481: . flg - the result

9483:   Level: intermediate

9485:   Notes:
9486:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9488:   If the matrix does not yet know if it is Hermitian or not this can be an expensive operation, also available `MatIsHermitianKnown()`

9490:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9491:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMEMTRY_ETERNAL`,`PETSC_TRUE`)

9493: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetric()`, `MatSetOption()`,
9494:           `MatIsSymmetricKnown()`, `MatIsSymmetric()`, `MAT_HERMITIAN`, `MAT_SYMMETRY_ETERNAL`
9495: @*/
9496: PetscErrorCode MatIsHermitian(Mat A, PetscReal tol, PetscBool *flg)
9497: {
9498:   PetscFunctionBegin;
9500:   PetscAssertPointer(flg, 3);
9501:   if (A->hermitian != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->hermitian);
9502:   else {
9503:     if (A->ops->ishermitian) PetscUseTypeMethod(A, ishermitian, tol, flg);
9504:     else PetscCall(MatIsHermitianTranspose(A, A, tol, flg));
9505:     if (!tol) PetscCall(MatSetOption(A, MAT_HERMITIAN, *flg));
9506:   }
9507:   PetscFunctionReturn(PETSC_SUCCESS);
9508: }

9510: /*@
9511:   MatIsSymmetricKnown - Checks if a matrix knows if it is symmetric or not and its symmetric state

9513:   Not Collective

9515:   Input Parameter:
9516: . A - the matrix to check

9518:   Output Parameters:
9519: + set - `PETSC_TRUE` if the matrix knows its symmetry state (this tells you if the next flag is valid)
9520: - flg - the result (only valid if set is `PETSC_TRUE`)

9522:   Level: advanced

9524:   Notes:
9525:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsSymmetric()`
9526:   if you want it explicitly checked

9528:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9529:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9531: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9532: @*/
9533: PetscErrorCode MatIsSymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9534: {
9535:   PetscFunctionBegin;
9537:   PetscAssertPointer(set, 2);
9538:   PetscAssertPointer(flg, 3);
9539:   if (A->symmetric != PETSC_BOOL3_UNKNOWN) {
9540:     *set = PETSC_TRUE;
9541:     *flg = PetscBool3ToBool(A->symmetric);
9542:   } else *set = PETSC_FALSE;
9543:   PetscFunctionReturn(PETSC_SUCCESS);
9544: }

9546: /*@
9547:   MatIsSPDKnown - Checks if a matrix knows if it is symmetric positive definite or not and its symmetric positive definite state

9549:   Not Collective

9551:   Input Parameter:
9552: . A - the matrix to check

9554:   Output Parameters:
9555: + set - `PETSC_TRUE` if the matrix knows its symmetric positive definite state (this tells you if the next flag is valid)
9556: - flg - the result (only valid if set is `PETSC_TRUE`)

9558:   Level: advanced

9560:   Notes:
9561:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`).

9563:   One can declare that a matrix is SPD with `MatSetOption`(mat,`MAT_SPD`,`PETSC_TRUE`) and if it is known to remain SPD
9564:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SPD_ETERNAL`,`PETSC_TRUE`)

9566: .seealso: [](ch_matrices), `Mat`, `MAT_SPD_ETERNAL`, `MAT_SPD`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9567: @*/
9568: PetscErrorCode MatIsSPDKnown(Mat A, PetscBool *set, PetscBool *flg)
9569: {
9570:   PetscFunctionBegin;
9572:   PetscAssertPointer(set, 2);
9573:   PetscAssertPointer(flg, 3);
9574:   if (A->spd != PETSC_BOOL3_UNKNOWN) {
9575:     *set = PETSC_TRUE;
9576:     *flg = PetscBool3ToBool(A->spd);
9577:   } else *set = PETSC_FALSE;
9578:   PetscFunctionReturn(PETSC_SUCCESS);
9579: }

9581: /*@
9582:   MatIsHermitianKnown - Checks if a matrix knows if it is Hermitian or not and its Hermitian state

9584:   Not Collective

9586:   Input Parameter:
9587: . A - the matrix to check

9589:   Output Parameters:
9590: + set - `PETSC_TRUE` if the matrix knows its Hermitian state (this tells you if the next flag is valid)
9591: - flg - the result (only valid if set is `PETSC_TRUE`)

9593:   Level: advanced

9595:   Notes:
9596:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsHermitian()`
9597:   if you want it explicitly checked

9599:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9600:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9602: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MAT_HERMITIAN`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`
9603: @*/
9604: PetscErrorCode MatIsHermitianKnown(Mat A, PetscBool *set, PetscBool *flg)
9605: {
9606:   PetscFunctionBegin;
9608:   PetscAssertPointer(set, 2);
9609:   PetscAssertPointer(flg, 3);
9610:   if (A->hermitian != PETSC_BOOL3_UNKNOWN) {
9611:     *set = PETSC_TRUE;
9612:     *flg = PetscBool3ToBool(A->hermitian);
9613:   } else *set = PETSC_FALSE;
9614:   PetscFunctionReturn(PETSC_SUCCESS);
9615: }

9617: /*@
9618:   MatIsStructurallySymmetric - Test whether a matrix is structurally symmetric

9620:   Collective

9622:   Input Parameter:
9623: . A - the matrix to test

9625:   Output Parameter:
9626: . flg - the result

9628:   Level: intermediate

9630:   Notes:
9631:   If the matrix does yet know it is structurally symmetric this can be an expensive operation, also available `MatIsStructurallySymmetricKnown()`

9633:   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
9634:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9636: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsSymmetric()`, `MatSetOption()`, `MatIsStructurallySymmetricKnown()`
9637: @*/
9638: PetscErrorCode MatIsStructurallySymmetric(Mat A, PetscBool *flg)
9639: {
9640:   PetscFunctionBegin;
9642:   PetscAssertPointer(flg, 2);
9643:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) *flg = PetscBool3ToBool(A->structurally_symmetric);
9644:   else {
9645:     PetscUseTypeMethod(A, isstructurallysymmetric, flg);
9646:     PetscCall(MatSetOption(A, MAT_STRUCTURALLY_SYMMETRIC, *flg));
9647:   }
9648:   PetscFunctionReturn(PETSC_SUCCESS);
9649: }

9651: /*@
9652:   MatIsStructurallySymmetricKnown - Checks if a matrix knows if it is structurally symmetric or not and its structurally symmetric state

9654:   Not Collective

9656:   Input Parameter:
9657: . A - the matrix to check

9659:   Output Parameters:
9660: + set - PETSC_TRUE if the matrix knows its structurally symmetric state (this tells you if the next flag is valid)
9661: - flg - the result (only valid if set is PETSC_TRUE)

9663:   Level: advanced

9665:   Notes:
9666:   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
9667:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9669:   Use `MatIsStructurallySymmetric()` to explicitly check if a matrix is structurally symmetric (this is an expensive operation)

9671: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9672: @*/
9673: PetscErrorCode MatIsStructurallySymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9674: {
9675:   PetscFunctionBegin;
9677:   PetscAssertPointer(set, 2);
9678:   PetscAssertPointer(flg, 3);
9679:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9680:     *set = PETSC_TRUE;
9681:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9682:   } else *set = PETSC_FALSE;
9683:   PetscFunctionReturn(PETSC_SUCCESS);
9684: }

9686: /*@
9687:   MatStashGetInfo - Gets how many values are currently in the matrix stash, i.e. need
9688:   to be communicated to other processors during the `MatAssemblyBegin()`/`MatAssemblyEnd()` process

9690:   Not Collective

9692:   Input Parameter:
9693: . mat - the matrix

9695:   Output Parameters:
9696: + nstash    - the size of the stash
9697: . reallocs  - the number of additional mallocs incurred.
9698: . bnstash   - the size of the block stash
9699: - breallocs - the number of additional mallocs incurred.in the block stash

9701:   Level: advanced

9703: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashSetInitialSize()`
9704: @*/
9705: PetscErrorCode MatStashGetInfo(Mat mat, PetscInt *nstash, PetscInt *reallocs, PetscInt *bnstash, PetscInt *breallocs)
9706: {
9707:   PetscFunctionBegin;
9708:   PetscCall(MatStashGetInfo_Private(&mat->stash, nstash, reallocs));
9709:   PetscCall(MatStashGetInfo_Private(&mat->bstash, bnstash, breallocs));
9710:   PetscFunctionReturn(PETSC_SUCCESS);
9711: }

9713: /*@
9714:   MatCreateVecs - Get vector(s) compatible with the matrix, i.e. with the same
9715:   parallel layout, `PetscLayout` for rows and columns

9717:   Collective

9719:   Input Parameter:
9720: . mat - the matrix

9722:   Output Parameters:
9723: + right - (optional) vector that the matrix can be multiplied against
9724: - left  - (optional) vector that the matrix vector product can be stored in

9726:   Options Database Key:
9727: . -mat_vec_type type - set the `VecType` of the created vectors during `MatSetFromOptions()`

9729:   Level: advanced

9731:   Notes:
9732:   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()`.

9734:   The `VecType` of the created vectors is determined by the `MatType` of `mat`. This can be overridden by using `MatSetVecType()` or the option `-mat_vec_type`.

9736:   These are new vectors which are not owned by the `mat`, they should be destroyed with `VecDestroy()` when no longer needed.

9738:   PETSc `Vec` always have all zero entries when created with `MatCreateVecs()` until routines such as `VecSet()` or `VecSetValues()`
9739:   are used to change the values. There is no reason to call `VecZeroEntries()` after creation.

9741: .seealso: [](ch_matrices), `Mat`, `Vec`, `VecCreate()`, `VecDestroy()`, `DMCreateGlobalVector()`, `MatSetVecType()`
9742: @*/
9743: PetscErrorCode MatCreateVecs(Mat mat, Vec *right, Vec *left)
9744: {
9745:   PetscFunctionBegin;
9748:   if (mat->ops->getvecs) {
9749:     PetscUseTypeMethod(mat, getvecs, right, left);
9750:   } else {
9751:     if (right) {
9752:       PetscCheck(mat->cmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for columns not yet setup");
9753:       PetscCall(VecCreateWithLayout_Private(mat->cmap, right));
9754:       PetscCall(VecSetType(*right, mat->defaultvectype));
9755: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9756:       if (mat->boundtocpu && mat->bindingpropagates) {
9757:         PetscCall(VecSetBindingPropagates(*right, PETSC_TRUE));
9758:         PetscCall(VecBindToCPU(*right, PETSC_TRUE));
9759:       }
9760: #endif
9761:     }
9762:     if (left) {
9763:       PetscCheck(mat->rmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for rows not yet setup");
9764:       PetscCall(VecCreateWithLayout_Private(mat->rmap, left));
9765:       PetscCall(VecSetType(*left, mat->defaultvectype));
9766: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9767:       if (mat->boundtocpu && mat->bindingpropagates) {
9768:         PetscCall(VecSetBindingPropagates(*left, PETSC_TRUE));
9769:         PetscCall(VecBindToCPU(*left, PETSC_TRUE));
9770:       }
9771: #endif
9772:     }
9773:   }
9774:   PetscFunctionReturn(PETSC_SUCCESS);
9775: }

9777: /*@
9778:   MatFactorInfoInitialize - Initializes a `MatFactorInfo` data structure
9779:   with default values.

9781:   Not Collective

9783:   Input Parameter:
9784: . info - the `MatFactorInfo` data structure

9786:   Level: developer

9788:   Notes:
9789:   The solvers are generally used through the `KSP` and `PC` objects, for example
9790:   `PCLU`, `PCILU`, `PCCHOLESKY`, `PCICC`

9792:   Once the data structure is initialized one may change certain entries as desired for the particular factorization to be performed

9794: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorInfo`
9795: @*/
9796: PetscErrorCode MatFactorInfoInitialize(MatFactorInfo *info)
9797: {
9798:   PetscFunctionBegin;
9799:   PetscCall(PetscMemzero(info, sizeof(MatFactorInfo)));
9800:   PetscFunctionReturn(PETSC_SUCCESS);
9801: }

9803: /*@
9804:   MatFactorSetSchurIS - Set indices corresponding to the Schur complement you wish to have computed

9806:   Collective

9808:   Input Parameters:
9809: + mat - the factored matrix
9810: - is  - the index set defining the Schur indices (0-based)

9812:   Level: advanced

9814:   Notes:
9815:   Call `MatFactorSolveSchurComplement()` or `MatFactorSolveSchurComplementTranspose()` after this call to solve a Schur complement system.

9817:   You can call `MatFactorGetSchurComplement()` or `MatFactorCreateSchurComplement()` after this call.

9819:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9821: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorGetSchurComplement()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSolveSchurComplement()`,
9822:           `MatFactorSolveSchurComplementTranspose()`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9823: @*/
9824: PetscErrorCode MatFactorSetSchurIS(Mat mat, IS is)
9825: {
9826:   PetscErrorCode (*f)(Mat, IS);

9828:   PetscFunctionBegin;
9833:   PetscCheckSameComm(mat, 1, is, 2);
9834:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
9835:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorSetSchurIS_C", &f));
9836:   PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "The selected MatSolverType does not support Schur complement computation. You should use MATSOLVERMUMPS or MATSOLVERMKL_PARDISO");
9837:   PetscCall(MatDestroy(&mat->schur));
9838:   PetscCall((*f)(mat, is));
9839:   PetscCheck(mat->schur, PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "Schur complement has not been created");
9840:   PetscFunctionReturn(PETSC_SUCCESS);
9841: }

9843: /*@
9844:   MatFactorCreateSchurComplement - Create a Schur complement matrix object using Schur data computed during the factorization step

9846:   Logically Collective

9848:   Input Parameters:
9849: + F      - the factored matrix obtained by calling `MatGetFactor()`
9850: . S      - location where to return the Schur complement, can be `NULL`
9851: - status - the status of the Schur complement matrix, can be `NULL`

9853:   Level: advanced

9855:   Notes:
9856:   You must call `MatFactorSetSchurIS()` before calling this routine.

9858:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9860:   The routine provides a copy of the Schur matrix stored within the solver data structures.
9861:   The caller must destroy the object when it is no longer needed.
9862:   If `MatFactorInvertSchurComplement()` has been called, the routine gets back the inverse.

9864:   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)

9866:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9868:   Developer Note:
9869:   The reason this routine exists is because the representation of the Schur complement within the factor matrix may be different than a standard PETSc
9870:   matrix representation and we normally do not want to use the time or memory to make a copy as a regular PETSc matrix.

9872: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorSchurStatus`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9873: @*/
9874: PetscErrorCode MatFactorCreateSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9875: {
9876:   PetscFunctionBegin;
9878:   if (S) PetscAssertPointer(S, 2);
9879:   if (status) PetscAssertPointer(status, 3);
9880:   if (S) {
9881:     PetscErrorCode (*f)(Mat, Mat *);

9883:     PetscCall(PetscObjectQueryFunction((PetscObject)F, "MatFactorCreateSchurComplement_C", &f));
9884:     if (f) PetscCall((*f)(F, S));
9885:     else PetscCall(MatDuplicate(F->schur, MAT_COPY_VALUES, S));
9886:   }
9887:   if (status) *status = F->schur_status;
9888:   PetscFunctionReturn(PETSC_SUCCESS);
9889: }

9891: /*@
9892:   MatFactorGetSchurComplement - Gets access to a Schur complement matrix using the current Schur data within a factored matrix

9894:   Logically Collective

9896:   Input Parameters:
9897: + F      - the factored matrix obtained by calling `MatGetFactor()`
9898: . S      - location where to return the Schur complement, can be `NULL`
9899: - status - the status of the Schur complement matrix, can be `NULL`

9901:   Level: advanced

9903:   Notes:
9904:   You must call `MatFactorSetSchurIS()` before calling this routine.

9906:   Schur complement mode is currently implemented for sequential matrices with factor type of `MATSOLVERMUMPS`

9908:   The routine returns a the Schur Complement stored within the data structures of the solver.

9910:   If `MatFactorInvertSchurComplement()` has previously been called, the returned matrix is actually the inverse of the Schur complement.

9912:   The returned matrix should not be destroyed; the caller should call `MatFactorRestoreSchurComplement()` when the object is no longer needed.

9914:   Use `MatFactorCreateSchurComplement()` to create a copy of the Schur complement matrix that is within a factored matrix

9916:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9918: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9919: @*/
9920: PetscErrorCode MatFactorGetSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9921: {
9922:   PetscFunctionBegin;
9924:   if (S) {
9925:     PetscAssertPointer(S, 2);
9926:     *S = F->schur;
9927:   }
9928:   if (status) {
9929:     PetscAssertPointer(status, 3);
9930:     *status = F->schur_status;
9931:   }
9932:   PetscFunctionReturn(PETSC_SUCCESS);
9933: }

9935: static PetscErrorCode MatFactorUpdateSchurStatus_Private(Mat F)
9936: {
9937:   Mat S = F->schur;

9939:   PetscFunctionBegin;
9940:   switch (F->schur_status) {
9941:   case MAT_FACTOR_SCHUR_UNFACTORED: // fall-through
9942:   case MAT_FACTOR_SCHUR_INVERTED:
9943:     if (S) {
9944:       S->ops->solve             = NULL;
9945:       S->ops->matsolve          = NULL;
9946:       S->ops->solvetranspose    = NULL;
9947:       S->ops->matsolvetranspose = NULL;
9948:       S->ops->solveadd          = NULL;
9949:       S->ops->solvetransposeadd = NULL;
9950:       S->factortype             = MAT_FACTOR_NONE;
9951:       PetscCall(PetscFree(S->solvertype));
9952:     }
9953:   case MAT_FACTOR_SCHUR_FACTORED: // fall-through
9954:     break;
9955:   default:
9956:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9957:   }
9958:   PetscFunctionReturn(PETSC_SUCCESS);
9959: }

9961: /*@
9962:   MatFactorRestoreSchurComplement - Restore the Schur complement matrix object obtained from a call to `MatFactorGetSchurComplement()`

9964:   Logically Collective

9966:   Input Parameters:
9967: + F      - the factored matrix obtained by calling `MatGetFactor()`
9968: . S      - location where the Schur complement is stored
9969: - status - the status of the Schur complement matrix (see `MatFactorSchurStatus`)

9971:   Level: advanced

9973: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9974: @*/
9975: PetscErrorCode MatFactorRestoreSchurComplement(Mat F, Mat *S, MatFactorSchurStatus status)
9976: {
9977:   PetscFunctionBegin;
9979:   if (S) {
9981:     *S = NULL;
9982:   }
9983:   F->schur_status = status;
9984:   PetscCall(MatFactorUpdateSchurStatus_Private(F));
9985:   PetscFunctionReturn(PETSC_SUCCESS);
9986: }

9988: /*@
9989:   MatFactorSolveSchurComplementTranspose - Solve the transpose of the Schur complement system computed during the factorization step

9991:   Logically Collective

9993:   Input Parameters:
9994: + F   - the factored matrix obtained by calling `MatGetFactor()`
9995: . rhs - location where the right-hand side of the Schur complement system is stored
9996: - sol - location where the solution of the Schur complement system has to be returned

9998:   Level: advanced

10000:   Notes:
10001:   The sizes of the vectors should match the size of the Schur complement

10003:   Must be called after `MatFactorSetSchurIS()`

10005: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplement()`
10006: @*/
10007: PetscErrorCode MatFactorSolveSchurComplementTranspose(Mat F, Vec rhs, Vec sol)
10008: {
10009:   PetscFunctionBegin;
10016:   PetscCheckSameComm(F, 1, rhs, 2);
10017:   PetscCheckSameComm(F, 1, sol, 3);
10018:   PetscCall(MatFactorFactorizeSchurComplement(F));
10019:   switch (F->schur_status) {
10020:   case MAT_FACTOR_SCHUR_FACTORED:
10021:     PetscCall(MatSolveTranspose(F->schur, rhs, sol));
10022:     break;
10023:   case MAT_FACTOR_SCHUR_INVERTED:
10024:     PetscCall(MatMultTranspose(F->schur, rhs, sol));
10025:     break;
10026:   default:
10027:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
10028:   }
10029:   PetscFunctionReturn(PETSC_SUCCESS);
10030: }

10032: /*@
10033:   MatFactorSolveSchurComplement - Solve the Schur complement system computed during the factorization step

10035:   Logically Collective

10037:   Input Parameters:
10038: + F   - the factored matrix obtained by calling `MatGetFactor()`
10039: . rhs - location where the right-hand side of the Schur complement system is stored
10040: - sol - location where the solution of the Schur complement system has to be returned

10042:   Level: advanced

10044:   Notes:
10045:   The sizes of the vectors should match the size of the Schur complement

10047:   Must be called after `MatFactorSetSchurIS()`

10049: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplementTranspose()`
10050: @*/
10051: PetscErrorCode MatFactorSolveSchurComplement(Mat F, Vec rhs, Vec sol)
10052: {
10053:   PetscFunctionBegin;
10060:   PetscCheckSameComm(F, 1, rhs, 2);
10061:   PetscCheckSameComm(F, 1, sol, 3);
10062:   PetscCall(MatFactorFactorizeSchurComplement(F));
10063:   switch (F->schur_status) {
10064:   case MAT_FACTOR_SCHUR_FACTORED:
10065:     PetscCall(MatSolve(F->schur, rhs, sol));
10066:     break;
10067:   case MAT_FACTOR_SCHUR_INVERTED:
10068:     PetscCall(MatMult(F->schur, rhs, sol));
10069:     break;
10070:   default:
10071:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
10072:   }
10073:   PetscFunctionReturn(PETSC_SUCCESS);
10074: }

10076: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseInvertFactors_Private(Mat);
10077: #if PetscDefined(HAVE_CUDA)
10078: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseCUDAInvertFactors_Internal(Mat);
10079: #endif

10081: /* Schur status updated in the interface */
10082: static PetscErrorCode MatFactorInvertSchurComplement_Private(Mat F)
10083: {
10084:   Mat S = F->schur;

10086:   PetscFunctionBegin;
10087:   if (S) {
10088:     PetscMPIInt size;
10089:     PetscBool   isdense, isdensecuda;

10091:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)S), &size));
10092:     PetscCheck(size <= 1, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not yet implemented");
10093:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSE, &isdense));
10094:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSECUDA, &isdensecuda));
10095:     PetscCheck(isdense || isdensecuda, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not implemented for type %s", ((PetscObject)S)->type_name);
10096:     PetscCall(PetscLogEventBegin(MAT_FactorInvS, F, 0, 0, 0));
10097:     if (isdense) {
10098:       PetscCall(MatSeqDenseInvertFactors_Private(S));
10099:     } else if (isdensecuda) {
10100: #if defined(PETSC_HAVE_CUDA)
10101:       PetscCall(MatSeqDenseCUDAInvertFactors_Internal(S));
10102: #endif
10103:     }
10104:     // HIP??????????????
10105:     PetscCall(PetscLogEventEnd(MAT_FactorInvS, F, 0, 0, 0));
10106:   }
10107:   PetscFunctionReturn(PETSC_SUCCESS);
10108: }

10110: /*@
10111:   MatFactorInvertSchurComplement - Invert the Schur complement matrix computed during the factorization step

10113:   Logically Collective

10115:   Input Parameter:
10116: . F - the factored matrix obtained by calling `MatGetFactor()`

10118:   Level: advanced

10120:   Notes:
10121:   Must be called after `MatFactorSetSchurIS()`.

10123:   Call `MatFactorGetSchurComplement()` or  `MatFactorCreateSchurComplement()` AFTER this call to actually compute the inverse and get access to it.

10125: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorCreateSchurComplement()`
10126: @*/
10127: PetscErrorCode MatFactorInvertSchurComplement(Mat F)
10128: {
10129:   PetscFunctionBegin;
10132:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED) PetscFunctionReturn(PETSC_SUCCESS);
10133:   PetscCall(MatFactorFactorizeSchurComplement(F));
10134:   PetscCall(MatFactorInvertSchurComplement_Private(F));
10135:   F->schur_status = MAT_FACTOR_SCHUR_INVERTED;
10136:   PetscFunctionReturn(PETSC_SUCCESS);
10137: }

10139: /*@
10140:   MatFactorFactorizeSchurComplement - Factorize the Schur complement matrix computed during the factorization step

10142:   Logically Collective

10144:   Input Parameter:
10145: . F - the factored matrix obtained by calling `MatGetFactor()`

10147:   Level: advanced

10149:   Note:
10150:   Must be called after `MatFactorSetSchurIS()`

10152: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorInvertSchurComplement()`
10153: @*/
10154: PetscErrorCode MatFactorFactorizeSchurComplement(Mat F)
10155: {
10156:   MatFactorInfo info;

10158:   PetscFunctionBegin;
10161:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED || F->schur_status == MAT_FACTOR_SCHUR_FACTORED) PetscFunctionReturn(PETSC_SUCCESS);
10162:   PetscCall(PetscLogEventBegin(MAT_FactorFactS, F, 0, 0, 0));
10163:   PetscCall(PetscMemzero(&info, sizeof(MatFactorInfo)));
10164:   if (F->factortype == MAT_FACTOR_CHOLESKY) { /* LDL^t regarded as Cholesky */
10165:     PetscCall(MatCholeskyFactor(F->schur, NULL, &info));
10166:   } else {
10167:     PetscCall(MatLUFactor(F->schur, NULL, NULL, &info));
10168:   }
10169:   PetscCall(PetscLogEventEnd(MAT_FactorFactS, F, 0, 0, 0));
10170:   F->schur_status = MAT_FACTOR_SCHUR_FACTORED;
10171:   PetscFunctionReturn(PETSC_SUCCESS);
10172: }

10174: /*@
10175:   MatPtAP - Creates the matrix product $C = P^T * A * P$

10177:   Neighbor-wise Collective

10179:   Input Parameters:
10180: + A     - the matrix
10181: . P     - the projection matrix
10182: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10183: - 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
10184:           if the result is a dense matrix this is irrelevant

10186:   Output Parameter:
10187: . C - the product matrix

10189:   Level: intermediate

10191:   Notes:
10192:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10194:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_PtAP`
10195:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10197:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10199:   Developer Note:
10200:   For matrix types without special implementation the function fallbacks to `MatMatMult()` followed by `MatTransposeMatMult()`.

10202: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatRARt()`
10203: @*/
10204: PetscErrorCode MatPtAP(Mat A, Mat P, MatReuse scall, PetscReal fill, Mat *C)
10205: {
10206:   PetscFunctionBegin;
10207:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10208:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10210:   if (scall == MAT_INITIAL_MATRIX) {
10211:     PetscCall(MatProductCreate(A, P, NULL, C));
10212:     PetscCall(MatProductSetType(*C, MATPRODUCT_PtAP));
10213:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10214:     PetscCall(MatProductSetFill(*C, fill));

10216:     (*C)->product->api_user = PETSC_TRUE;
10217:     PetscCall(MatProductSetFromOptions(*C));
10218:     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);
10219:     PetscCall(MatProductSymbolic(*C));
10220:   } else { /* scall == MAT_REUSE_MATRIX */
10221:     PetscCall(MatProductReplaceMats(A, P, NULL, *C));
10222:   }

10224:   PetscCall(MatProductNumeric(*C));
10225:   if (A->symmetric == PETSC_BOOL3_TRUE) {
10226:     PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10227:     (*C)->spd = A->spd;
10228:   }
10229:   PetscFunctionReturn(PETSC_SUCCESS);
10230: }

10232: /*@
10233:   MatRARt - Creates the matrix product $C = R * A * R^T$

10235:   Neighbor-wise Collective

10237:   Input Parameters:
10238: + A     - the matrix
10239: . R     - the projection matrix
10240: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10241: - fill  - expected fill as ratio of nnz(C)/nnz(A), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10242:           if the result is a dense matrix this is irrelevant

10244:   Output Parameter:
10245: . C - the product matrix

10247:   Level: intermediate

10249:   Notes:
10250:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10252:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_RARt`
10253:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10255:   This routine is currently only implemented for pairs of `MATAIJ` matrices and classes
10256:   which inherit from `MATAIJ`. Due to PETSc sparse matrix block row distribution among processes,
10257:   the parallel `MatRARt()` is implemented computing the explicit transpose of `R`, which can be very expensive.
10258:   We recommend using `MatPtAP()` when possible.

10260:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10262: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatPtAP()`
10263: @*/
10264: PetscErrorCode MatRARt(Mat A, Mat R, MatReuse scall, PetscReal fill, Mat *C)
10265: {
10266:   PetscFunctionBegin;
10267:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10268:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10270:   if (scall == MAT_INITIAL_MATRIX) {
10271:     PetscCall(MatProductCreate(A, R, NULL, C));
10272:     PetscCall(MatProductSetType(*C, MATPRODUCT_RARt));
10273:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10274:     PetscCall(MatProductSetFill(*C, fill));

10276:     (*C)->product->api_user = PETSC_TRUE;
10277:     PetscCall(MatProductSetFromOptions(*C));
10278:     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);
10279:     PetscCall(MatProductSymbolic(*C));
10280:   } else { /* scall == MAT_REUSE_MATRIX */
10281:     PetscCall(MatProductReplaceMats(A, R, NULL, *C));
10282:   }

10284:   PetscCall(MatProductNumeric(*C));
10285:   if (A->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10286:   PetscFunctionReturn(PETSC_SUCCESS);
10287: }

10289: static PetscErrorCode MatProduct_Private(Mat A, Mat B, MatReuse scall, PetscReal fill, MatProductType ptype, Mat *C)
10290: {
10291:   PetscBool flg = PETSC_TRUE;

10293:   PetscFunctionBegin;
10294:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX product not supported");
10295:   if (scall == MAT_INITIAL_MATRIX) {
10296:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_INITIAL_MATRIX and product type %s\n", MatProductTypes[ptype]));
10297:     PetscCall(MatProductCreate(A, B, NULL, C));
10298:     PetscCall(MatProductSetAlgorithm(*C, MATPRODUCTALGORITHMDEFAULT));
10299:     PetscCall(MatProductSetFill(*C, fill));
10300:   } else { /* scall == MAT_REUSE_MATRIX */
10301:     Mat_Product *product = (*C)->product;

10303:     PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)*C, &flg, MATSEQDENSE, MATMPIDENSE, ""));
10304:     if (flg && product && product->type != ptype) {
10305:       PetscCall(MatProductClear(*C));
10306:       product = NULL;
10307:     }
10308:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_REUSE_MATRIX %s product present and product type %s\n", product ? "with" : "without", MatProductTypes[ptype]));
10309:     if (!product) { /* user provide the dense matrix *C without calling MatProductCreate() or reusing it from previous calls */
10310:       PetscCheck(flg, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "Call MatProductCreate() first");
10311:       PetscCall(MatProductCreate_Private(A, B, NULL, *C));
10312:       product        = (*C)->product;
10313:       product->fill  = fill;
10314:       product->clear = PETSC_TRUE;
10315:     } else { /* user may change input matrices A or B when MAT_REUSE_MATRIX */
10316:       flg = PETSC_FALSE;
10317:       PetscCall(MatProductReplaceMats(A, B, NULL, *C));
10318:     }
10319:   }
10320:   if (flg) {
10321:     (*C)->product->api_user = PETSC_TRUE;
10322:     PetscCall(MatProductSetType(*C, ptype));
10323:     PetscCall(MatProductSetFromOptions(*C));
10324:     PetscCall(MatProductSymbolic(*C));
10325:   }
10326:   PetscCall(MatProductNumeric(*C));
10327:   PetscFunctionReturn(PETSC_SUCCESS);
10328: }

10330: /*@
10331:   MatMatMult - Performs matrix-matrix multiplication $ C=A*B $.

10333:   Neighbor-wise Collective

10335:   Input Parameters:
10336: + A     - the left matrix
10337: . B     - the right matrix
10338: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10339: - 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
10340:           if the result is a dense matrix this is irrelevant

10342:   Output Parameter:
10343: . C - the product matrix

10345:   Notes:
10346:   Unless scall is `MAT_REUSE_MATRIX` C will be created.

10348:   `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
10349:   call to this function with `MAT_INITIAL_MATRIX`.

10351:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value actually needed.

10353:   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`,
10354:   rather than first having `MatMatMult()` create it for you. You can NEVER do this if the matrix `C` is sparse.

10356:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10358:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AB`
10359:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10361:   Example of Usage:
10362: .vb
10363:      MatProductCreate(A,B,NULL,&C);
10364:      MatProductSetType(C,MATPRODUCT_AB);
10365:      MatProductSymbolic(C);
10366:      MatProductNumeric(C); // compute C=A * B
10367:      MatProductReplaceMats(A1,B1,NULL,C); // compute C=A1 * B1
10368:      MatProductNumeric(C);
10369:      MatProductReplaceMats(A2,NULL,NULL,C); // compute C=A2 * B1
10370:      MatProductNumeric(C);
10371: .ve

10373:   Level: intermediate

10375: .seealso: [](ch_matrices), `Mat`, `MatProductType`, `MATPRODUCT_AB`, `MatTransposeMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`, `MatProductCreate()`, `MatProductSymbolic()`, `MatProductReplaceMats()`, `MatProductNumeric()`
10376: @*/
10377: PetscErrorCode MatMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10378: {
10379:   PetscFunctionBegin;
10380:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AB, C));
10381:   PetscFunctionReturn(PETSC_SUCCESS);
10382: }

10384: /*@
10385:   MatMatTransposeMult - Performs matrix-matrix multiplication $C = A*B^T$.

10387:   Neighbor-wise Collective

10389:   Input Parameters:
10390: + A     - the left matrix
10391: . B     - the right matrix
10392: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10393: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10395:   Output Parameter:
10396: . C - the product matrix

10398:   Options Database Key:
10399: . -matmattransmult_mpidense_mpidense_via {allgatherv,cyclic} - Choose between algorithms for `MATMPIDENSE` matrices: the
10400:               first redundantly copies the transposed `B` matrix on each process and requires O(log P) communication complexity;
10401:               the second never stores more than one portion of the `B` matrix at a time but requires O(P) communication complexity.

10403:   Level: intermediate

10405:   Notes:
10406:   C will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10408:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call

10410:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10411:   actually needed.

10413:   This routine is currently only implemented for pairs of `MATSEQAIJ` matrices, for the `MATSEQDENSE` class,
10414:   and for pairs of `MATMPIDENSE` matrices.

10416:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABt`
10417:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10419:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10421: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABt`, `MatMatMult()`, `MatTransposeMatMult()`, `MatPtAP()`, `MatProductAlgorithm`, `MatProductType`
10422: @*/
10423: PetscErrorCode MatMatTransposeMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10424: {
10425:   PetscFunctionBegin;
10426:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_ABt, C));
10427:   if (A == B) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10428:   PetscFunctionReturn(PETSC_SUCCESS);
10429: }

10431: /*@
10432:   MatTransposeMatMult - Performs matrix-matrix multiplication $C = A^T*B$.

10434:   Neighbor-wise Collective

10436:   Input Parameters:
10437: + A     - the left matrix
10438: . B     - the right matrix
10439: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10440: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10442:   Output Parameter:
10443: . C - the product matrix

10445:   Level: intermediate

10447:   Notes:
10448:   `C` will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10450:   `MAT_REUSE_MATRIX` can only be used if `A` and `B` have the same nonzero pattern as in the previous call.

10452:   This is a convenience routine that wraps the use of `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AtB`
10453:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10455:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10456:   actually needed.

10458:   This routine is currently implemented for pairs of `MATAIJ` matrices and pairs of `MATSEQDENSE` matrices and classes
10459:   which inherit from `MATSEQAIJ`.  `C` will be of the same type as the input matrices.

10461:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10463: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_AtB`, `MatMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`
10464: @*/
10465: PetscErrorCode MatTransposeMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10466: {
10467:   PetscFunctionBegin;
10468:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AtB, C));
10469:   PetscFunctionReturn(PETSC_SUCCESS);
10470: }

10472: /*@
10473:   MatMatMatMult - Performs matrix-matrix-matrix multiplication D=A*B*C.

10475:   Neighbor-wise Collective

10477:   Input Parameters:
10478: + A     - the left matrix
10479: . B     - the middle matrix
10480: . C     - the right matrix
10481: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10482: - 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
10483:           if the result is a dense matrix this is irrelevant

10485:   Output Parameter:
10486: . D - the product matrix

10488:   Level: intermediate

10490:   Notes:
10491:   Unless `scall` is `MAT_REUSE_MATRIX` `D` will be created.

10493:   `MAT_REUSE_MATRIX` can only be used if the matrices `A`, `B`, and `C` have the same nonzero pattern as in the previous call

10495:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABC`
10496:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10498:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value
10499:   actually needed.

10501:   If you have many matrices with the same non-zero structure to multiply, you
10502:   should use `MAT_REUSE_MATRIX` in all calls but the first

10504:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10506: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABC`, `MatMatMult`, `MatPtAP()`, `MatMatTransposeMult()`, `MatTransposeMatMult()`
10507: @*/
10508: PetscErrorCode MatMatMatMult(Mat A, Mat B, Mat C, MatReuse scall, PetscReal fill, Mat *D)
10509: {
10510:   PetscFunctionBegin;
10511:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*D, 6);
10512:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10514:   if (scall == MAT_INITIAL_MATRIX) {
10515:     PetscCall(MatProductCreate(A, B, C, D));
10516:     PetscCall(MatProductSetType(*D, MATPRODUCT_ABC));
10517:     PetscCall(MatProductSetAlgorithm(*D, "default"));
10518:     PetscCall(MatProductSetFill(*D, fill));

10520:     (*D)->product->api_user = PETSC_TRUE;
10521:     PetscCall(MatProductSetFromOptions(*D));
10522:     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,
10523:                ((PetscObject)C)->type_name);
10524:     PetscCall(MatProductSymbolic(*D));
10525:   } else { /* user may change input matrices when REUSE */
10526:     PetscCall(MatProductReplaceMats(A, B, C, *D));
10527:   }
10528:   PetscCall(MatProductNumeric(*D));
10529:   PetscFunctionReturn(PETSC_SUCCESS);
10530: }

10532: /*@
10533:   MatCreateRedundantMatrix - Create redundant matrices and put them into processors of subcommunicators.

10535:   Collective

10537:   Input Parameters:
10538: + mat      - the matrix
10539: . nsubcomm - the number of subcommunicators (= number of redundant parallel or sequential matrices)
10540: . subcomm  - MPI communicator split from the communicator where mat resides in (or `MPI_COMM_NULL` if nsubcomm is used)
10541: - reuse    - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10543:   Output Parameter:
10544: . matredundant - redundant matrix

10546:   Level: advanced

10548:   Notes:
10549:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
10550:   original matrix has not changed from that last call to `MatCreateRedundantMatrix()`.

10552:   This routine creates the duplicated matrices in the subcommunicators; you should NOT create them before
10553:   calling it.

10555:   `PetscSubcommCreate()` can be used to manage the creation of the subcomm but need not be.

10557: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `PetscSubcommCreate()`, `PetscSubcomm`
10558: @*/
10559: PetscErrorCode MatCreateRedundantMatrix(Mat mat, PetscInt nsubcomm, MPI_Comm subcomm, MatReuse reuse, Mat *matredundant)
10560: {
10561:   MPI_Comm       comm;
10562:   PetscMPIInt    size;
10563:   PetscInt       mloc_sub, nloc_sub, rstart, rend, M = mat->rmap->N, N = mat->cmap->N, bs = mat->rmap->bs;
10564:   Mat_Redundant *redund     = NULL;
10565:   PetscSubcomm   psubcomm   = NULL;
10566:   MPI_Comm       subcomm_in = subcomm;
10567:   Mat           *matseq;
10568:   IS             isrow, iscol;
10569:   PetscBool      newsubcomm = PETSC_FALSE;

10571:   PetscFunctionBegin;
10573:   if (nsubcomm && reuse == MAT_REUSE_MATRIX) {
10574:     PetscAssertPointer(*matredundant, 5);
10576:   }

10578:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
10579:   if (size == 1 || nsubcomm == 1) {
10580:     if (reuse == MAT_INITIAL_MATRIX) {
10581:       PetscCall(MatDuplicate(mat, MAT_COPY_VALUES, matredundant));
10582:     } else {
10583:       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");
10584:       PetscCall(MatCopy(mat, *matredundant, SAME_NONZERO_PATTERN));
10585:     }
10586:     PetscFunctionReturn(PETSC_SUCCESS);
10587:   }

10589:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10590:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10591:   MatCheckPreallocated(mat, 1);

10593:   PetscCall(PetscLogEventBegin(MAT_RedundantMat, mat, 0, 0, 0));
10594:   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
10595:     /* create psubcomm, then get subcomm */
10596:     PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10597:     PetscCallMPI(MPI_Comm_size(comm, &size));
10598:     PetscCheck(nsubcomm >= 1 && nsubcomm <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "nsubcomm must between 1 and %d", size);

10600:     PetscCall(PetscSubcommCreate(comm, &psubcomm));
10601:     PetscCall(PetscSubcommSetNumber(psubcomm, nsubcomm));
10602:     PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_CONTIGUOUS));
10603:     PetscCall(PetscSubcommSetFromOptions(psubcomm));
10604:     PetscCall(PetscCommDuplicate(PetscSubcommChild(psubcomm), &subcomm, NULL));
10605:     newsubcomm = PETSC_TRUE;
10606:     PetscCall(PetscSubcommDestroy(&psubcomm));
10607:   }

10609:   /* get isrow, iscol and a local sequential matrix matseq[0] */
10610:   if (reuse == MAT_INITIAL_MATRIX) {
10611:     mloc_sub = PETSC_DECIDE;
10612:     nloc_sub = PETSC_DECIDE;
10613:     if (bs < 1) {
10614:       PetscCall(PetscSplitOwnership(subcomm, &mloc_sub, &M));
10615:       PetscCall(PetscSplitOwnership(subcomm, &nloc_sub, &N));
10616:     } else {
10617:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &mloc_sub, &M));
10618:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &nloc_sub, &N));
10619:     }
10620:     PetscCallMPI(MPI_Scan(&mloc_sub, &rend, 1, MPIU_INT, MPI_SUM, subcomm));
10621:     rstart = rend - mloc_sub;
10622:     PetscCall(ISCreateStride(PETSC_COMM_SELF, mloc_sub, rstart, 1, &isrow));
10623:     PetscCall(ISCreateStride(PETSC_COMM_SELF, N, 0, 1, &iscol));
10624:     PetscCall(ISSetIdentity(iscol));
10625:   } else { /* reuse == MAT_REUSE_MATRIX */
10626:     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");
10627:     /* retrieve subcomm */
10628:     PetscCall(PetscObjectGetComm((PetscObject)*matredundant, &subcomm));
10629:     redund = (*matredundant)->redundant;
10630:     isrow  = redund->isrow;
10631:     iscol  = redund->iscol;
10632:     matseq = redund->matseq;
10633:   }
10634:   PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscol, reuse, &matseq));

10636:   /* get matredundant over subcomm */
10637:   if (reuse == MAT_INITIAL_MATRIX) {
10638:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], nloc_sub, reuse, matredundant));

10640:     /* create a supporting struct and attach it to C for reuse */
10641:     PetscCall(PetscNew(&redund));
10642:     (*matredundant)->redundant = redund;
10643:     redund->isrow              = isrow;
10644:     redund->iscol              = iscol;
10645:     redund->matseq             = matseq;
10646:     if (newsubcomm) {
10647:       redund->subcomm = subcomm;
10648:     } else {
10649:       redund->subcomm = MPI_COMM_NULL;
10650:     }
10651:   } else {
10652:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], PETSC_DECIDE, reuse, matredundant));
10653:   }
10654: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
10655:   if (matseq[0]->boundtocpu && matseq[0]->bindingpropagates) {
10656:     PetscCall(MatBindToCPU(*matredundant, PETSC_TRUE));
10657:     PetscCall(MatSetBindingPropagates(*matredundant, PETSC_TRUE));
10658:   }
10659: #endif
10660:   PetscCall(PetscLogEventEnd(MAT_RedundantMat, mat, 0, 0, 0));
10661:   PetscFunctionReturn(PETSC_SUCCESS);
10662: }

10664: /*@C
10665:   MatGetMultiProcBlock - Create multiple 'parallel submatrices' from
10666:   a given `Mat`. Each submatrix can span multiple procs.

10668:   Collective

10670:   Input Parameters:
10671: + mat     - the matrix
10672: . subComm - the sub communicator obtained as if by `MPI_Comm_split(PetscObjectComm((PetscObject)mat))`
10673: - scall   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10675:   Output Parameter:
10676: . subMat - parallel sub-matrices each spanning a given `subcomm`

10678:   Level: advanced

10680:   Notes:
10681:   The submatrix partition across processors is dictated by `subComm` a
10682:   communicator obtained by `MPI_comm_split()` or via `PetscSubcommCreate()`. The `subComm`
10683:   is not restricted to be grouped with consecutive original MPI processes.

10685:   Due the `MPI_Comm_split()` usage, the parallel layout of the submatrices
10686:   map directly to the layout of the original matrix [wrt the local
10687:   row,col partitioning]. So the original 'DiagonalMat' naturally maps
10688:   into the 'DiagonalMat' of the `subMat`, hence it is used directly from
10689:   the `subMat`. However the offDiagMat looses some columns - and this is
10690:   reconstructed with `MatSetValues()`

10692:   This is used by `PCBJACOBI` when a single block spans multiple MPI processes.

10694: .seealso: [](ch_matrices), `Mat`, `MatCreateRedundantMatrix()`, `MatCreateSubMatrices()`, `PCBJACOBI`
10695: @*/
10696: PetscErrorCode MatGetMultiProcBlock(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
10697: {
10698:   PetscMPIInt commsize, subCommSize;

10700:   PetscFunctionBegin;
10701:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &commsize));
10702:   PetscCallMPI(MPI_Comm_size(subComm, &subCommSize));
10703:   PetscCheck(subCommSize <= commsize, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "CommSize %d < SubCommZize %d", commsize, subCommSize);

10705:   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");
10706:   PetscCall(PetscLogEventBegin(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10707:   PetscUseTypeMethod(mat, getmultiprocblock, subComm, scall, subMat);
10708:   PetscCall(PetscLogEventEnd(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10709:   PetscFunctionReturn(PETSC_SUCCESS);
10710: }

10712: /*@
10713:   MatGetLocalSubMatrix - Gets a reference to a submatrix specified in local numbering

10715:   Not Collective

10717:   Input Parameters:
10718: + mat   - matrix to extract local submatrix from
10719: . isrow - local row indices for submatrix
10720: - iscol - local column indices for submatrix

10722:   Output Parameter:
10723: . submat - the submatrix

10725:   Level: intermediate

10727:   Notes:
10728:   `submat` should be disposed of with `MatRestoreLocalSubMatrix()`.

10730:   Depending on the format of `mat`, the returned `submat` may not implement `MatMult()`.  Its communicator may be
10731:   the same as `mat`, it may be `PETSC_COMM_SELF`, or some other sub-communictor of `mat`'s.

10733:   `submat` always implements `MatSetValuesLocal()`.  If `isrow` and `iscol` have the same block size, then
10734:   `MatSetValuesBlockedLocal()` will also be implemented.

10736:   `mat` must have had a `ISLocalToGlobalMapping` provided to it with `MatSetLocalToGlobalMapping()`.
10737:   Matrices obtained with `DMCreateMatrix()` generally already have the local to global mapping provided.

10739: .seealso: [](ch_matrices), `Mat`, `MatRestoreLocalSubMatrix()`, `MatCreateLocalRef()`, `MatSetLocalToGlobalMapping()`
10740: @*/
10741: PetscErrorCode MatGetLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10742: {
10743:   PetscFunctionBegin;
10747:   PetscCheckSameComm(isrow, 2, iscol, 3);
10748:   PetscAssertPointer(submat, 4);
10749:   PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must have local to global mapping provided before this call");

10751:   if (mat->ops->getlocalsubmatrix) {
10752:     PetscUseTypeMethod(mat, getlocalsubmatrix, isrow, iscol, submat);
10753:   } else {
10754:     PetscCall(MatCreateLocalRef(mat, isrow, iscol, submat));
10755:   }
10756:   (*submat)->assembled = mat->assembled;
10757:   PetscFunctionReturn(PETSC_SUCCESS);
10758: }

10760: /*@
10761:   MatRestoreLocalSubMatrix - Restores a reference to a submatrix specified in local numbering obtained with `MatGetLocalSubMatrix()`

10763:   Not Collective

10765:   Input Parameters:
10766: + mat    - matrix to extract local submatrix from
10767: . isrow  - local row indices for submatrix
10768: . iscol  - local column indices for submatrix
10769: - submat - the submatrix

10771:   Level: intermediate

10773: .seealso: [](ch_matrices), `Mat`, `MatGetLocalSubMatrix()`
10774: @*/
10775: PetscErrorCode MatRestoreLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10776: {
10777:   PetscFunctionBegin;
10781:   PetscCheckSameComm(isrow, 2, iscol, 3);
10782:   PetscAssertPointer(submat, 4);

10785:   if (mat->ops->restorelocalsubmatrix) {
10786:     PetscUseTypeMethod(mat, restorelocalsubmatrix, isrow, iscol, submat);
10787:   } else {
10788:     PetscCall(MatDestroy(submat));
10789:   }
10790:   *submat = NULL;
10791:   PetscFunctionReturn(PETSC_SUCCESS);
10792: }

10794: /*@
10795:   MatFindZeroDiagonals - Finds all the rows of a matrix that have zero or no diagonal entry in the matrix

10797:   Collective

10799:   Input Parameter:
10800: . mat - the matrix

10802:   Output Parameter:
10803: . is - if any rows have zero diagonals this contains the list of them

10805:   Level: developer

10807: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10808: @*/
10809: PetscErrorCode MatFindZeroDiagonals(Mat mat, IS *is)
10810: {
10811:   PetscFunctionBegin;
10814:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10815:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10817:   if (!mat->ops->findzerodiagonals) {
10818:     Vec                diag;
10819:     const PetscScalar *a;
10820:     PetscInt          *rows;
10821:     PetscInt           rStart, rEnd, r, nrow = 0;

10823:     PetscCall(MatCreateVecs(mat, &diag, NULL));
10824:     PetscCall(MatGetDiagonal(mat, diag));
10825:     PetscCall(MatGetOwnershipRange(mat, &rStart, &rEnd));
10826:     PetscCall(VecGetArrayRead(diag, &a));
10827:     for (r = 0; r < rEnd - rStart; ++r)
10828:       if (a[r] == 0.0) ++nrow;
10829:     PetscCall(PetscMalloc1(nrow, &rows));
10830:     nrow = 0;
10831:     for (r = 0; r < rEnd - rStart; ++r)
10832:       if (a[r] == 0.0) rows[nrow++] = r + rStart;
10833:     PetscCall(VecRestoreArrayRead(diag, &a));
10834:     PetscCall(VecDestroy(&diag));
10835:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)mat), nrow, rows, PETSC_OWN_POINTER, is));
10836:   } else {
10837:     PetscUseTypeMethod(mat, findzerodiagonals, is);
10838:   }
10839:   PetscFunctionReturn(PETSC_SUCCESS);
10840: }

10842: /*@
10843:   MatFindOffBlockDiagonalEntries - Finds all the rows of a matrix that have entries outside of the main diagonal block (defined by the matrix block size)

10845:   Collective

10847:   Input Parameter:
10848: . mat - the matrix

10850:   Output Parameter:
10851: . is - contains the list of rows with off block diagonal entries

10853:   Level: developer

10855: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10856: @*/
10857: PetscErrorCode MatFindOffBlockDiagonalEntries(Mat mat, IS *is)
10858: {
10859:   PetscFunctionBegin;
10862:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10863:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10865:   PetscUseTypeMethod(mat, findoffblockdiagonalentries, is);
10866:   PetscFunctionReturn(PETSC_SUCCESS);
10867: }

10869: /*@C
10870:   MatInvertBlockDiagonal - Inverts the block diagonal entries.

10872:   Collective; No Fortran Support

10874:   Input Parameter:
10875: . mat - the matrix

10877:   Output Parameter:
10878: . values - the block inverses in column major order (FORTRAN-like)

10880:   Level: advanced

10882:   Notes:
10883:   The size of the blocks is determined by the block size of the matrix.

10885:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10887:   The blocks all have the same size, use `MatInvertVariableBlockDiagonal()` for variable block size

10889: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatInvertBlockDiagonalMat()`
10890: @*/
10891: PetscErrorCode MatInvertBlockDiagonal(Mat mat, const PetscScalar *values[])
10892: {
10893:   PetscFunctionBegin;
10895:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10896:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10897:   PetscUseTypeMethod(mat, invertblockdiagonal, values);
10898:   PetscFunctionReturn(PETSC_SUCCESS);
10899: }

10901: /*@
10902:   MatInvertVariableBlockDiagonal - Inverts the point block diagonal entries.

10904:   Collective; No Fortran Support

10906:   Input Parameters:
10907: + mat     - the matrix
10908: . nblocks - the number of blocks on the process, set with `MatSetVariableBlockSizes()`
10909: - bsizes  - the size of each block on the process, set with `MatSetVariableBlockSizes()`

10911:   Output Parameter:
10912: . values - the block inverses in column major order (FORTRAN-like)

10914:   Level: advanced

10916:   Notes:
10917:   Use `MatInvertBlockDiagonal()` if all blocks have the same size

10919:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10921: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatSetVariableBlockSizes()`, `MatInvertVariableBlockEnvelope()`
10922: @*/
10923: PetscErrorCode MatInvertVariableBlockDiagonal(Mat mat, PetscInt nblocks, const PetscInt bsizes[], PetscScalar values[])
10924: {
10925:   PetscFunctionBegin;
10927:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10928:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10929:   PetscUseTypeMethod(mat, invertvariableblockdiagonal, nblocks, bsizes, values);
10930:   PetscFunctionReturn(PETSC_SUCCESS);
10931: }

10933: /*@
10934:   MatInvertBlockDiagonalMat - set the values of matrix C to be the inverted block diagonal of matrix A

10936:   Collective

10938:   Input Parameters:
10939: + A - the matrix
10940: - C - matrix with inverted block diagonal of `A`.  This matrix should be created and may have its type set.

10942:   Level: advanced

10944:   Note:
10945:   The blocksize of the matrix is used to determine the blocks on the diagonal of `C`

10947: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`
10948: @*/
10949: PetscErrorCode MatInvertBlockDiagonalMat(Mat A, Mat C)
10950: {
10951:   const PetscScalar *vals;
10952:   PetscInt          *dnnz;
10953:   PetscInt           m, rstart, rend, bs, i, j;

10955:   PetscFunctionBegin;
10956:   PetscCall(MatInvertBlockDiagonal(A, &vals));
10957:   PetscCall(MatGetBlockSize(A, &bs));
10958:   PetscCall(MatGetLocalSize(A, &m, NULL));
10959:   PetscCall(MatSetLayouts(C, A->rmap, A->cmap));
10960:   PetscCall(MatSetBlockSizes(C, A->rmap->bs, A->cmap->bs));
10961:   PetscCall(PetscMalloc1(m / bs, &dnnz));
10962:   for (j = 0; j < m / bs; j++) dnnz[j] = 1;
10963:   PetscCall(MatXAIJSetPreallocation(C, bs, dnnz, NULL, NULL, NULL));
10964:   PetscCall(PetscFree(dnnz));
10965:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
10966:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_FALSE));
10967:   for (i = rstart / bs; i < rend / bs; i++) PetscCall(MatSetValuesBlocked(C, 1, &i, 1, &i, &vals[(i - rstart / bs) * bs * bs], INSERT_VALUES));
10968:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
10969:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
10970:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
10971:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_FALSE));
10972:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_TRUE));
10973:   PetscFunctionReturn(PETSC_SUCCESS);
10974: }

10976: /*@
10977:   MatTransposeColoringDestroy - Destroys a coloring context for matrix product $C = A*B^T$ that was created
10978:   via `MatTransposeColoringCreate()`.

10980:   Collective

10982:   Input Parameter:
10983: . c - coloring context

10985:   Level: intermediate

10987: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`
10988: @*/
10989: PetscErrorCode MatTransposeColoringDestroy(MatTransposeColoring *c)
10990: {
10991:   MatTransposeColoring matcolor = *c;

10993:   PetscFunctionBegin;
10994:   if (!matcolor) PetscFunctionReturn(PETSC_SUCCESS);
10995:   if (--((PetscObject)matcolor)->refct > 0) {
10996:     matcolor = NULL;
10997:     PetscFunctionReturn(PETSC_SUCCESS);
10998:   }

11000:   PetscCall(PetscFree3(matcolor->ncolumns, matcolor->nrows, matcolor->colorforrow));
11001:   PetscCall(PetscFree(matcolor->rows));
11002:   PetscCall(PetscFree(matcolor->den2sp));
11003:   PetscCall(PetscFree(matcolor->colorforcol));
11004:   PetscCall(PetscFree(matcolor->columns));
11005:   if (matcolor->brows > 0) PetscCall(PetscFree(matcolor->lstart));
11006:   PetscCall(PetscHeaderDestroy(c));
11007:   PetscFunctionReturn(PETSC_SUCCESS);
11008: }

11010: /*@
11011:   MatTransColoringApplySpToDen - Given a symbolic matrix product $C = A*B^T$ for which
11012:   a `MatTransposeColoring` context has been created, computes a dense $B^T$ by applying
11013:   `MatTransposeColoring` to sparse `B`.

11015:   Collective

11017:   Input Parameters:
11018: + coloring - coloring context created with `MatTransposeColoringCreate()`
11019: - B        - sparse matrix

11021:   Output Parameter:
11022: . Btdense - dense matrix $B^T$

11024:   Level: developer

11026:   Note:
11027:   These are used internally for some implementations of `MatRARt()`

11029: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplyDenToSp()`
11030: @*/
11031: PetscErrorCode MatTransColoringApplySpToDen(MatTransposeColoring coloring, Mat B, Mat Btdense)
11032: {
11033:   PetscFunctionBegin;

11038:   PetscCall((*B->ops->transcoloringapplysptoden)(coloring, B, Btdense));
11039:   PetscFunctionReturn(PETSC_SUCCESS);
11040: }

11042: /*@
11043:   MatTransColoringApplyDenToSp - Given a symbolic matrix product $C_{sp} = A*B^T$ for which
11044:   a `MatTransposeColoring` context has been created and a dense matrix $C_{den} = A*B^T_{dense}$
11045:   in which `B^T_{dens}` is obtained from `MatTransColoringApplySpToDen()`, recover sparse matrix
11046:   $C_{sp}$ from $C_{den}$.

11048:   Collective

11050:   Input Parameters:
11051: + matcoloring - coloring context created with `MatTransposeColoringCreate()`
11052: - Cden        - matrix product of a sparse matrix and a dense matrix Btdense

11054:   Output Parameter:
11055: . Csp - sparse matrix

11057:   Level: developer

11059:   Note:
11060:   These are used internally for some implementations of `MatRARt()`

11062: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`
11063: @*/
11064: PetscErrorCode MatTransColoringApplyDenToSp(MatTransposeColoring matcoloring, Mat Cden, Mat Csp)
11065: {
11066:   PetscFunctionBegin;

11071:   PetscCall((*Csp->ops->transcoloringapplydentosp)(matcoloring, Cden, Csp));
11072:   PetscCall(MatAssemblyBegin(Csp, MAT_FINAL_ASSEMBLY));
11073:   PetscCall(MatAssemblyEnd(Csp, MAT_FINAL_ASSEMBLY));
11074:   PetscFunctionReturn(PETSC_SUCCESS);
11075: }

11077: /*@
11078:   MatTransposeColoringCreate - Creates a matrix coloring context for the matrix product $C = A*B^T$.

11080:   Collective

11082:   Input Parameters:
11083: + mat        - the matrix product C
11084: - iscoloring - the coloring of the matrix; usually obtained with `MatColoringCreate()` or `DMCreateColoring()`

11086:   Output Parameter:
11087: . color - the new coloring context

11089:   Level: intermediate

11091: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`,
11092:           `MatTransColoringApplyDenToSp()`
11093: @*/
11094: PetscErrorCode MatTransposeColoringCreate(Mat mat, ISColoring iscoloring, MatTransposeColoring *color)
11095: {
11096:   MatTransposeColoring c;
11097:   MPI_Comm             comm;

11099:   PetscFunctionBegin;
11100:   PetscAssertPointer(color, 3);

11102:   PetscCall(PetscLogEventBegin(MAT_TransposeColoringCreate, mat, 0, 0, 0));
11103:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
11104:   PetscCall(PetscHeaderCreate(c, MAT_TRANSPOSECOLORING_CLASSID, "MatTransposeColoring", "Matrix product C=A*B^T via coloring", "Mat", comm, MatTransposeColoringDestroy, NULL));
11105:   c->ctype = iscoloring->ctype;
11106:   PetscUseTypeMethod(mat, transposecoloringcreate, iscoloring, c);
11107:   *color = c;
11108:   PetscCall(PetscLogEventEnd(MAT_TransposeColoringCreate, mat, 0, 0, 0));
11109:   PetscFunctionReturn(PETSC_SUCCESS);
11110: }

11112: /*@
11113:   MatGetNonzeroState - Returns a 64-bit integer representing the current state of nonzeros in the matrix. If the
11114:   matrix has had new nonzero locations added to (or removed from) the matrix since the previous call, the value will be larger.

11116:   Not Collective

11118:   Input Parameter:
11119: . mat - the matrix

11121:   Output Parameter:
11122: . state - the current state

11124:   Level: intermediate

11126:   Notes:
11127:   You can only compare states from two different calls to the SAME matrix, you cannot compare calls between
11128:   different matrices

11130:   Use `PetscObjectStateGet()` to check for changes to the numerical values in a matrix

11132:   Use the result of `PetscObjectGetId()` to compare if a previously checked matrix is the same as the current matrix, do not compare object pointers.

11134: .seealso: [](ch_matrices), `Mat`, `PetscObjectStateGet()`, `PetscObjectGetId()`
11135: @*/
11136: PetscErrorCode MatGetNonzeroState(Mat mat, PetscObjectState *state)
11137: {
11138:   PetscFunctionBegin;
11140:   *state = mat->nonzerostate;
11141:   PetscFunctionReturn(PETSC_SUCCESS);
11142: }

11144: /*@
11145:   MatCreateMPIMatConcatenateSeqMat - Creates a single large PETSc matrix by concatenating sequential
11146:   matrices from each processor

11148:   Collective

11150:   Input Parameters:
11151: + comm   - the communicators the parallel matrix will live on
11152: . seqmat - the input sequential matrices
11153: . n      - number of local columns (or `PETSC_DECIDE`)
11154: - reuse  - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

11156:   Output Parameter:
11157: . mpimat - the parallel matrix generated

11159:   Level: developer

11161:   Note:
11162:   The number of columns of the matrix in EACH processor MUST be the same.

11164: .seealso: [](ch_matrices), `Mat`
11165: @*/
11166: PetscErrorCode MatCreateMPIMatConcatenateSeqMat(MPI_Comm comm, Mat seqmat, PetscInt n, MatReuse reuse, Mat *mpimat)
11167: {
11168:   PetscMPIInt size;

11170:   PetscFunctionBegin;
11171:   PetscCallMPI(MPI_Comm_size(comm, &size));
11172:   if (size == 1) {
11173:     if (reuse == MAT_INITIAL_MATRIX) {
11174:       PetscCall(MatDuplicate(seqmat, MAT_COPY_VALUES, mpimat));
11175:     } else {
11176:       PetscCall(MatCopy(seqmat, *mpimat, SAME_NONZERO_PATTERN));
11177:     }
11178:     PetscFunctionReturn(PETSC_SUCCESS);
11179:   }

11181:   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");

11183:   PetscCall(PetscLogEventBegin(MAT_Merge, seqmat, 0, 0, 0));
11184:   PetscCall((*seqmat->ops->creatempimatconcatenateseqmat)(comm, seqmat, n, reuse, mpimat));
11185:   PetscCall(PetscLogEventEnd(MAT_Merge, seqmat, 0, 0, 0));
11186:   PetscFunctionReturn(PETSC_SUCCESS);
11187: }

11189: /*@
11190:   MatSubdomainsCreateCoalesce - Creates index subdomains by coalescing adjacent MPI processes' ownership ranges.

11192:   Collective

11194:   Input Parameters:
11195: + A - the matrix to create subdomains from
11196: - N - requested number of subdomains

11198:   Output Parameters:
11199: + n   - number of subdomains resulting on this MPI process
11200: - iss - `IS` list with indices of subdomains on this MPI process

11202:   Level: advanced

11204:   Note:
11205:   The number of subdomains must be smaller than the communicator size

11207: .seealso: [](ch_matrices), `Mat`, `IS`
11208: @*/
11209: PetscErrorCode MatSubdomainsCreateCoalesce(Mat A, PetscInt N, PetscInt *n, IS *iss[])
11210: {
11211:   MPI_Comm    comm, subcomm;
11212:   PetscMPIInt size, rank, color;
11213:   PetscInt    rstart, rend, k;

11215:   PetscFunctionBegin;
11216:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
11217:   PetscCallMPI(MPI_Comm_size(comm, &size));
11218:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
11219:   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);
11220:   *n    = 1;
11221:   k     = size / N + (size % N > 0); /* There are up to k ranks to a color */
11222:   color = rank / k;
11223:   PetscCallMPI(MPI_Comm_split(comm, color, rank, &subcomm));
11224:   PetscCall(PetscMalloc1(1, iss));
11225:   PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
11226:   PetscCall(ISCreateStride(subcomm, rend - rstart, rstart, 1, iss[0]));
11227:   PetscCallMPI(MPI_Comm_free(&subcomm));
11228:   PetscFunctionReturn(PETSC_SUCCESS);
11229: }

11231: /*@
11232:   MatGalerkin - Constructs the coarse grid problem matrix via Galerkin projection.

11234:   If the interpolation and restriction operators are the same, uses `MatPtAP()`.
11235:   If they are not the same, uses `MatMatMatMult()`.

11237:   Once the coarse grid problem is constructed, correct for interpolation operators
11238:   that are not of full rank, which can legitimately happen in the case of non-nested
11239:   geometric multigrid.

11241:   Input Parameters:
11242: + restrct     - restriction operator
11243: . dA          - fine grid matrix
11244: . interpolate - interpolation operator
11245: . reuse       - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
11246: - fill        - expected fill, use `PETSC_DETERMINE` or `PETSC_DETERMINE` if you do not have a good estimate

11248:   Output Parameter:
11249: . A - the Galerkin coarse matrix

11251:   Options Database Key:
11252: . -pc_mg_galerkin (both|pmat|mat|none) - for what matrices the Galerkin process should be used

11254:   Level: developer

11256:   Note:
11257:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

11259: .seealso: [](ch_matrices), `Mat`, `MatPtAP()`, `MatMatMatMult()`
11260: @*/
11261: PetscErrorCode MatGalerkin(Mat restrct, Mat dA, Mat interpolate, MatReuse reuse, PetscReal fill, Mat *A)
11262: {
11263:   IS  zerorows;
11264:   Vec diag;

11266:   PetscFunctionBegin;
11267:   PetscCheck(reuse != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");
11268:   /* Construct the coarse grid matrix */
11269:   if (interpolate == restrct) {
11270:     PetscCall(MatPtAP(dA, interpolate, reuse, fill, A));
11271:   } else {
11272:     PetscCall(MatMatMatMult(restrct, dA, interpolate, reuse, fill, A));
11273:   }

11275:   /* If the interpolation matrix is not of full rank, A will have zero rows.
11276:      This can legitimately happen in the case of non-nested geometric multigrid.
11277:      In that event, we set the rows of the matrix to the rows of the identity,
11278:      ignoring the equations (as the RHS will also be zero). */

11280:   PetscCall(MatFindZeroRows(*A, &zerorows));

11282:   if (zerorows != NULL) { /* if there are any zero rows */
11283:     PetscCall(MatCreateVecs(*A, &diag, NULL));
11284:     PetscCall(MatGetDiagonal(*A, diag));
11285:     PetscCall(VecISSet(diag, zerorows, 1.0));
11286:     PetscCall(MatDiagonalSet(*A, diag, INSERT_VALUES));
11287:     PetscCall(VecDestroy(&diag));
11288:     PetscCall(ISDestroy(&zerorows));
11289:   }
11290:   PetscFunctionReturn(PETSC_SUCCESS);
11291: }

11293: /*@C
11294:   MatSetOperation - Allows user to set a matrix operation for any matrix type

11296:   Logically Collective

11298:   Input Parameters:
11299: + mat - the matrix
11300: . op  - the name of the operation
11301: - f   - the function that provides the operation

11303:   Level: developer

11305:   Example Usage:
11306: .vb
11307:   extern PetscErrorCode usermult(Mat, Vec, Vec);

11309:   PetscCall(MatCreateXXX(comm, ..., &A));
11310:   PetscCall(MatSetOperation(A, MATOP_MULT, (PetscErrorCodeFn *)usermult));
11311: .ve

11313:   Notes:
11314:   See the file `include/petscmat.h` for a complete list of matrix
11315:   operations, which all have the form MATOP_<OPERATION>, where
11316:   <OPERATION> is the name (in all capital letters) of the
11317:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11319:   All user-provided functions (except for `MATOP_DESTROY`) should have the same calling
11320:   sequence as the usual matrix interface routines, since they
11321:   are intended to be accessed via the usual matrix interface
11322:   routines, e.g.,
11323: .vb
11324:   MatMult(Mat, Vec, Vec) -> usermult(Mat, Vec, Vec)
11325: .ve

11327:   In particular each function MUST return `PETSC_SUCCESS` on success and
11328:   nonzero on failure.

11330:   This routine is distinct from `MatShellSetOperation()` in that it can be called on any matrix type.

11332: .seealso: [](ch_matrices), `Mat`, `MatGetOperation()`, `MatCreateShell()`, `MatShellSetContext()`, `MatShellSetOperation()`
11333: @*/
11334: PetscErrorCode MatSetOperation(Mat mat, MatOperation op, PetscErrorCodeFn *f)
11335: {
11336:   PetscFunctionBegin;
11338:   if (op == MATOP_VIEW && !mat->ops->viewnative && f != (PetscErrorCodeFn *)mat->ops->view) mat->ops->viewnative = mat->ops->view;
11339:   (((PetscErrorCodeFn **)mat->ops)[op]) = f;
11340:   PetscFunctionReturn(PETSC_SUCCESS);
11341: }

11343: /*@C
11344:   MatGetOperation - Gets a matrix operation for any matrix type.

11346:   Not Collective

11348:   Input Parameters:
11349: + mat - the matrix
11350: - op  - the name of the operation

11352:   Output Parameter:
11353: . f - the function that provides the operation

11355:   Level: developer

11357:   Example Usage:
11358: .vb
11359:   PetscErrorCode (*usermult)(Mat, Vec, Vec);

11361:   MatGetOperation(A, MATOP_MULT, (PetscErrorCodeFn **)&usermult);
11362: .ve

11364:   Notes:
11365:   See the file `include/petscmat.h` for a complete list of matrix
11366:   operations, which all have the form MATOP_<OPERATION>, where
11367:   <OPERATION> is the name (in all capital letters) of the
11368:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11370:   This routine is distinct from `MatShellGetOperation()` in that it can be called on any matrix type.

11372: .seealso: [](ch_matrices), `Mat`, `MatSetOperation()`, `MatCreateShell()`, `MatShellGetContext()`, `MatShellGetOperation()`
11373: @*/
11374: PetscErrorCode MatGetOperation(Mat mat, MatOperation op, PetscErrorCodeFn **f)
11375: {
11376:   PetscFunctionBegin;
11378:   *f = (((PetscErrorCodeFn **)mat->ops)[op]);
11379:   PetscFunctionReturn(PETSC_SUCCESS);
11380: }

11382: /*@
11383:   MatHasOperation - Determines whether the given matrix supports the particular operation.

11385:   Not Collective

11387:   Input Parameters:
11388: + mat - the matrix
11389: - op  - the operation, for example, `MATOP_GET_DIAGONAL`

11391:   Output Parameter:
11392: . has - either `PETSC_TRUE` or `PETSC_FALSE`

11394:   Level: advanced

11396:   Note:
11397:   See `MatSetOperation()` for additional discussion on naming convention and usage of `op`.

11399: .seealso: [](ch_matrices), `Mat`, `MatCreateShell()`, `MatGetOperation()`, `MatSetOperation()`
11400: @*/
11401: PetscErrorCode MatHasOperation(Mat mat, MatOperation op, PetscBool *has)
11402: {
11403:   PetscFunctionBegin;
11405:   PetscAssertPointer(has, 3);
11406:   if (mat->ops->hasoperation) {
11407:     PetscUseTypeMethod(mat, hasoperation, op, has);
11408:   } else {
11409:     if (((void **)mat->ops)[op]) *has = PETSC_TRUE;
11410:     else {
11411:       *has = PETSC_FALSE;
11412:       if (op == MATOP_CREATE_SUBMATRIX) {
11413:         PetscMPIInt size;

11415:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
11416:         if (size == 1) PetscCall(MatHasOperation(mat, MATOP_CREATE_SUBMATRICES, has));
11417:       }
11418:     }
11419:   }
11420:   PetscFunctionReturn(PETSC_SUCCESS);
11421: }

11423: /*@
11424:   MatHasCongruentLayouts - Determines whether the rows and columns layouts of the matrix are congruent

11426:   Collective

11428:   Input Parameter:
11429: . mat - the matrix

11431:   Output Parameter:
11432: . cong - either `PETSC_TRUE` or `PETSC_FALSE`

11434:   Level: beginner

11436: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatSetSizes()`, `PetscLayout`
11437: @*/
11438: PetscErrorCode MatHasCongruentLayouts(Mat mat, PetscBool *cong)
11439: {
11440:   PetscFunctionBegin;
11443:   PetscAssertPointer(cong, 2);
11444:   if (!mat->rmap || !mat->cmap) {
11445:     *cong = mat->rmap == mat->cmap ? PETSC_TRUE : PETSC_FALSE;
11446:     PetscFunctionReturn(PETSC_SUCCESS);
11447:   }
11448:   if (mat->congruentlayouts == PETSC_DECIDE) { /* first time we compare rows and cols layouts */
11449:     PetscCall(PetscLayoutSetUp(mat->rmap));
11450:     PetscCall(PetscLayoutSetUp(mat->cmap));
11451:     PetscCall(PetscLayoutCompare(mat->rmap, mat->cmap, cong));
11452:     if (*cong) mat->congruentlayouts = 1;
11453:     else mat->congruentlayouts = 0;
11454:   } else *cong = mat->congruentlayouts ? PETSC_TRUE : PETSC_FALSE;
11455:   PetscFunctionReturn(PETSC_SUCCESS);
11456: }

11458: PetscErrorCode MatSetInf(Mat A)
11459: {
11460:   PetscFunctionBegin;
11461:   PetscUseTypeMethod(A, setinf);
11462:   PetscFunctionReturn(PETSC_SUCCESS);
11463: }

11465: /*@
11466:   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
11467:   and possibly removes small values from the graph structure.

11469:   Collective

11471:   Input Parameters:
11472: + A       - the matrix
11473: . sym     - `PETSC_TRUE` indicates that the graph should be symmetrized
11474: . scale   - `PETSC_TRUE` indicates that the graph edge weights should be symmetrically scaled with the diagonal entry
11475: . filter  - filter value - < 0: does nothing; == 0: removes only 0.0 entries; otherwise: removes entries with abs(entries) <= value
11476: . num_idx - size of `index` array
11477: - index   - array of block indices to use for graph strength of connection weight

11479:   Output Parameter:
11480: . graph - the resulting graph

11482:   Level: advanced

11484: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PCGAMG`
11485: @*/
11486: PetscErrorCode MatCreateGraph(Mat A, PetscBool sym, PetscBool scale, PetscReal filter, PetscInt num_idx, PetscInt index[], Mat *graph)
11487: {
11488:   PetscFunctionBegin;
11492:   PetscAssertPointer(graph, 7);
11493:   PetscCall(PetscLogEventBegin(MAT_CreateGraph, A, 0, 0, 0));
11494:   PetscUseTypeMethod(A, creategraph, sym, scale, filter, num_idx, index, graph);
11495:   PetscCall(PetscLogEventEnd(MAT_CreateGraph, A, 0, 0, 0));
11496:   PetscFunctionReturn(PETSC_SUCCESS);
11497: }

11499: /*@
11500:   MatEliminateZeros - eliminate the nondiagonal zero entries in place from the nonzero structure of a sparse `Mat` in place,
11501:   meaning the same memory is used for the matrix, and no new memory is allocated.

11503:   Collective

11505:   Input Parameters:
11506: + A    - the matrix
11507: - 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

11509:   Level: intermediate

11511:   Developer Note:
11512:   The entries in the sparse matrix data structure are shifted to fill in the unneeded locations in the data. Thus the end
11513:   of the arrays in the data structure are unneeded.

11515: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateGraph()`, `MatFilter()`
11516: @*/
11517: PetscErrorCode MatEliminateZeros(Mat A, PetscBool keep)
11518: {
11519:   PetscFunctionBegin;
11521:   PetscUseTypeMethod(A, eliminatezeros, keep);
11522:   PetscFunctionReturn(PETSC_SUCCESS);
11523: }

11525: /*@C
11526:   MatGetCurrentMemType - Get the memory location of the matrix

11528:   Not Collective, but the result will be the same on all MPI processes

11530:   Input Parameter:
11531: . A - the matrix whose memory type we are checking

11533:   Output Parameter:
11534: . m - the memory type

11536:   Level: intermediate

11538: .seealso: [](ch_matrices), `Mat`, `MatBoundToCPU()`, `PetscMemType`
11539: @*/
11540: PetscErrorCode MatGetCurrentMemType(Mat A, PetscMemType *m)
11541: {
11542:   PetscFunctionBegin;
11544:   PetscAssertPointer(m, 2);
11545:   if (A->ops->getcurrentmemtype) PetscUseTypeMethod(A, getcurrentmemtype, m);
11546:   else *m = PETSC_MEMTYPE_HOST;
11547:   PetscFunctionReturn(PETSC_SUCCESS);
11548: }