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

287: /*@
288:   MatFindNonzeroRows - Locate all rows that are not completely zero in the matrix

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

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

296:   Level: intermediate

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

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

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

320: /*@
321:   MatFindZeroRows - Locate all rows that are completely zero in the matrix

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

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

329:   Level: intermediate

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

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

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

359: /*@
360:   MatGetDiagonalBlock - Returns the part of the matrix associated with the on-process coupling

362:   Not Collective

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

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

370:   Level: advanced

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

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

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

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

397: /*@
398:   MatGetTrace - Gets the trace of a matrix. The sum of the diagonal entries.

400:   Collective

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

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

408:   Level: advanced

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

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

426: /*@
427:   MatRealPart - Zeros out the imaginary part of the matrix

429:   Logically Collective

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

434:   Level: advanced

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

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

453:   Collective

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

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

462:   Level: advanced

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

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

484: /*@
485:   MatImaginaryPart - Moves the imaginary part of the matrix to the real part and zeros the imaginary part

487:   Logically Collective

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

492:   Level: advanced

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

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

514:   Not Collective

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

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

525:   Level: advanced

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

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

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

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

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

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

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

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

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

565:   PetscFunctionBegin;
568:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
569:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
570:   MatCheckPreallocated(mat, 1);
571:   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);
572:   PetscCall(PetscLogEventBegin(MAT_GetRow, mat, 0, 0, 0));
573:   PetscUseTypeMethod(mat, getrow, row, &incols, (PetscInt **)cols, (PetscScalar **)vals);
574:   if (ncols) *ncols = incols;
575:   PetscCall(PetscLogEventEnd(MAT_GetRow, mat, 0, 0, 0));
576:   PetscFunctionReturn(PETSC_SUCCESS);
577: }

579: /*@
580:   MatConjugate - replaces the matrix values with their complex conjugates

582:   Logically Collective

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

587:   Level: advanced

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

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

606:   Not Collective

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

615:   Level: advanced

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

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

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

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

645: /*@
646:   MatGetRowUpperTriangular - Sets a flag to enable calls to `MatGetRow()` for matrix in `MATSBAIJ` format.
647:   You should call `MatRestoreRowUpperTriangular()` after calling` MatGetRow()` and `MatRestoreRow()` to disable the flag.

649:   Not Collective

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

654:   Level: advanced

656:   Note:
657:   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.

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

673: /*@
674:   MatRestoreRowUpperTriangular - Disable calls to `MatGetRow()` for matrix in `MATSBAIJ` format.

676:   Not Collective

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

681:   Level: advanced

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

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

700: /*@
701:   MatSetOptionsPrefix - Sets the prefix used for searching for all
702:   `Mat` options in the database.

704:   Logically Collective

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

710:   Level: advanced

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

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

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

731: /*@
732:   MatSetOptionsPrefixFactor - Sets the prefix used for searching for all matrix factor options in the database for
733:   for matrices created with `MatGetFactor()`

735:   Logically Collective

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

741:   Level: developer

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

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

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

767: /*@
768:   MatAppendOptionsPrefixFactor - Appends to the prefix used for searching for all matrix factor options in the database for
769:   for matrices created with `MatGetFactor()`

771:   Logically Collective

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

777:   Level: developer

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

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

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

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

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

811: /*@
812:   MatAppendOptionsPrefix - Appends to the prefix used for searching for all
813:   matrix options in the database.

815:   Logically Collective

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

821:   Level: advanced

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

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

838: /*@
839:   MatGetOptionsPrefix - Gets the prefix used for searching for all
840:   matrix options in the database.

842:   Not Collective

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

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

850:   Level: advanced

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

863: /*@
864:   MatGetState - Gets the state of a `Mat`. Same value as returned by `PetscObjectStateGet()`

866:   Not Collective

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

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

874:   Level: advanced

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

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

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

894: /*@
895:   MatResetPreallocation - Reset matrix to use the original preallocation values provided by the user, for example with `MatXAIJSetPreallocation()`

897:   Collective

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

902:   Level: beginner

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

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

911:   Currently only supported for  `MATAIJ` matrices.

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

924: /*@
925:   MatResetHash - Reset the matrix so that it will use a hash table for the next round of `MatSetValues()` and `MatAssemblyBegin()`/`MatAssemblyEnd()`.

927:   Collective

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

932:   Level: intermediate

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

937:   Currently only supported for `MATAIJ` matrices.

939: .seealso: [](ch_matrices), `Mat`, `MatResetPreallocation()`
940: @*/
941: PetscErrorCode MatResetHash(Mat A)
942: {
943:   PetscFunctionBegin;
946:   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()");
947:   if (A->num_ass == 0) PetscFunctionReturn(PETSC_SUCCESS);
948:   PetscUseMethod(A, "MatResetHash_C", (Mat), (A));
949:   /* These flags are used to determine whether certain setups occur */
950:   A->was_assembled = PETSC_FALSE;
951:   A->assembled     = PETSC_FALSE;
952:   /* Log that the state of this object has changed; this will help guarantee that preconditioners get re-setup */
953:   PetscCall(PetscObjectStateIncrease((PetscObject)A));
954:   PetscFunctionReturn(PETSC_SUCCESS);
955: }

957: /*@
958:   MatSetUp - Sets up the internal matrix data structures for later use by the matrix

960:   Collective

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

965:   Level: advanced

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

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

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

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

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

996: /*
997:    If threadsafety is on extraneous matrices may be printed

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

1005: /*@
1006:   MatViewFromOptions - View properties of the matrix based on options set in the options database

1008:   Collective

1010:   Input Parameters:
1011: + A    - the matrix
1012: . obj  - optional additional object that provides the options prefix to use
1013: - name - command line option

1015:   Options Database Key:
1016: . -name [viewertype][:...] - option name and values. See `PetscObjectViewFromOptions()` for the possible arguments

1018:   Level: intermediate

1020: .seealso: [](ch_matrices), `Mat`, `MatView()`, `PetscObjectViewFromOptions()`, `MatCreate()`
1021: @*/
1022: PetscErrorCode MatViewFromOptions(Mat A, PetscObject obj, const char name[])
1023: {
1024:   PetscFunctionBegin;
1026: #if !defined(PETSC_HAVE_THREADSAFETY)
1027:   if (insidematview) PetscFunctionReturn(PETSC_SUCCESS);
1028: #endif
1029:   PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
1030:   PetscFunctionReturn(PETSC_SUCCESS);
1031: }

1033: /*@
1034:   MatView - display information about a matrix in a variety ways

1036:   Collective on viewer

1038:   Input Parameters:
1039: + mat    - the matrix
1040: - viewer - visualization context

1042:   Options Database Keys:
1043: + -mat_view ::ascii_info         - Prints info on matrix at conclusion of `MatAssemblyEnd()`
1044: . -mat_view ::ascii_info_detail  - Prints more detailed info
1045: . -mat_view                      - Prints matrix in ASCII format
1046: . -mat_view ::ascii_matlab       - Prints matrix in MATLAB format
1047: . -mat_view draw                 - PetscDraws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
1048: . -display name                  - Sets display name (default is host)
1049: . -draw_pause sec                - Sets number of seconds to pause after display
1050: . -mat_view socket               - Sends matrix to socket, can be accessed from MATLAB (see Users-Manual: ch_matlab for details)
1051: . -viewer_socket_machine machine - -
1052: . -viewer_socket_port port       - -
1053: . -mat_view binary               - save matrix to file in binary format
1054: - -viewer_binary_filename name   - -

1056:   Level: beginner

1058:   Notes:
1059:   The available visualization contexts include
1060: +    `PETSC_VIEWER_STDOUT_SELF`   - for sequential matrices
1061: .    `PETSC_VIEWER_STDOUT_WORLD`  - for parallel matrices created on `PETSC_COMM_WORLD`
1062: .    `PETSC_VIEWER_STDOUT_`(comm) - for matrices created on MPI communicator comm
1063: -     `PETSC_VIEWER_DRAW_WORLD`   - graphical display of nonzero structure

1065:   The user can open alternative visualization contexts with
1066: +    `PetscViewerASCIIOpen()`  - Outputs matrix to a specified file
1067: .    `PetscViewerBinaryOpen()` - Outputs matrix in binary to a  specified file; corresponding input uses `MatLoad()`
1068: .    `PetscViewerDrawOpen()`   - Outputs nonzero matrix nonzero structure to an X window display
1069: -    `PetscViewerSocketOpen()` - Outputs matrix to Socket viewer, `PETSCVIEWERSOCKET`. Only the `MATSEQDENSE` and `MATAIJ` types support this viewer.

1071:   The user can call `PetscViewerPushFormat()` to specify the output
1072:   format of ASCII printed objects (when using `PETSC_VIEWER_STDOUT_SELF`,
1073:   `PETSC_VIEWER_STDOUT_WORLD` and `PetscViewerASCIIOpen()`).  Available formats include
1074: +    `PETSC_VIEWER_DEFAULT`           - default, prints matrix contents
1075: .    `PETSC_VIEWER_ASCII_MATLAB`      - prints matrix contents in MATLAB format
1076: .    `PETSC_VIEWER_ASCII_DENSE`       - prints entire matrix including zeros
1077: .    `PETSC_VIEWER_ASCII_COMMON`      - prints matrix contents, using a sparse  format common among all matrix types
1078: .    `PETSC_VIEWER_ASCII_IMPL`        - prints matrix contents, using an implementation-specific format (which is in many cases the same as the default)
1079: .    `PETSC_VIEWER_ASCII_INFO`        - prints basic information about the matrix size and structure (not the matrix entries)
1080: -    `PETSC_VIEWER_ASCII_INFO_DETAIL` - prints more detailed information about the matrix nonzero structure (still not vector or matrix entries)

1082:   The ASCII viewers are only recommended for small matrices on at most a moderate number of processes,
1083:   the program will seemingly hang and take hours for larger matrices, for larger matrices one should use the binary format.

1085:   In the debugger you can do "call MatView(mat,0)" to display the matrix. (The same holds for any PETSc object viewer).

1087:   See the manual page for `MatLoad()` for the exact format of the binary file when the binary
1088:   viewer is used.

1090:   See share/petsc/matlab/PetscBinaryRead.m for a MATLAB code that can read in the binary file when the binary
1091:   viewer is used and lib/petsc/bin/PetscBinaryIO.py for loading them into Python.

1093:   One can use '-mat_view draw -draw_pause -1' to pause the graphical display of matrix nonzero structure,
1094:   and then use the following mouse functions.
1095: .vb
1096:   left mouse: zoom in
1097:   middle mouse: zoom out
1098:   right mouse: continue with the simulation
1099: .ve

1101: .seealso: [](ch_matrices), `Mat`, `PetscViewerPushFormat()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewer`,
1102:           `PetscViewerSocketOpen()`, `PetscViewerBinaryOpen()`, `MatLoad()`, `MatViewFromOptions()`
1103: @*/
1104: PetscErrorCode MatView(Mat mat, PetscViewer viewer)
1105: {
1106:   PetscInt          rows, cols, rbs, cbs;
1107:   PetscBool         isascii, isstring, issaws;
1108:   PetscViewerFormat format;
1109:   PetscMPIInt       size;

1111:   PetscFunctionBegin;
1114:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)mat), &viewer));

1117:   PetscCall(PetscViewerGetFormat(viewer, &format));
1118:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)viewer), &size));
1119:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);

1121: #if !defined(PETSC_HAVE_THREADSAFETY)
1122:   insidematview++;
1123: #endif
1124:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
1125:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
1126:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
1127:   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");

1129:   PetscCall(PetscLogEventBegin(MAT_View, mat, viewer, 0, 0));
1130:   if (isascii) {
1131:     if (!mat->preallocated) {
1132:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been preallocated yet\n"));
1133: #if !defined(PETSC_HAVE_THREADSAFETY)
1134:       insidematview--;
1135: #endif
1136:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1137:       PetscFunctionReturn(PETSC_SUCCESS);
1138:     }
1139:     if (!mat->assembled) {
1140:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been assembled yet\n"));
1141: #if !defined(PETSC_HAVE_THREADSAFETY)
1142:       insidematview--;
1143: #endif
1144:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1145:       PetscFunctionReturn(PETSC_SUCCESS);
1146:     }
1147:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)mat, viewer));
1148:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1149:       MatNullSpace nullsp, transnullsp;

1151:       PetscCall(PetscViewerASCIIPushTab(viewer));
1152:       PetscCall(MatGetSize(mat, &rows, &cols));
1153:       PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
1154:       if (rbs != 1 || cbs != 1) {
1155:         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" : ""));
1156:         else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT ", bs=%" PetscInt_FMT "%s\n", rows, cols, rbs, mat->bsizes ? " variable blocks set" : ""));
1157:       } else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", rows, cols));
1158:       if (mat->factortype) {
1159:         MatSolverType solver;
1160:         PetscCall(MatFactorGetSolverType(mat, &solver));
1161:         PetscCall(PetscViewerASCIIPrintf(viewer, "package used to perform factorization: %s\n", solver));
1162:       }
1163:       if (mat->ops->getinfo) {
1164:         PetscBool is_constant_or_diagonal;

1166:         // Don't print nonzero information for constant or diagonal matrices, it just adds noise to the output
1167:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &is_constant_or_diagonal, MATCONSTANTDIAGONAL, MATDIAGONAL, ""));
1168:         if (!is_constant_or_diagonal) {
1169:           MatInfo info;

1171:           PetscCall(MatGetInfo(mat, MAT_GLOBAL_SUM, &info));
1172:           PetscCall(PetscViewerASCIIPrintf(viewer, "total: nonzeros=%.f, allocated nonzeros=%.f\n", info.nz_used, info.nz_allocated));
1173:           if (!mat->factortype) PetscCall(PetscViewerASCIIPrintf(viewer, "total number of mallocs used during MatSetValues calls=%" PetscInt_FMT "\n", (PetscInt)info.mallocs));
1174:         }
1175:       }
1176:       PetscCall(MatGetNullSpace(mat, &nullsp));
1177:       PetscCall(MatGetTransposeNullSpace(mat, &transnullsp));
1178:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached null space\n"));
1179:       if (transnullsp && transnullsp != nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached transposed null space\n"));
1180:       PetscCall(MatGetNearNullSpace(mat, &nullsp));
1181:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached near null space\n"));
1182:       PetscCall(PetscViewerASCIIPushTab(viewer));
1183:       PetscCall(MatProductView(mat, viewer));
1184:       PetscCall(PetscViewerASCIIPopTab(viewer));
1185:       if (mat->bsizes && format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1186:         IS tmp;

1188:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)viewer), mat->nblocks, mat->bsizes, PETSC_USE_POINTER, &tmp));
1189:         PetscCall(PetscObjectSetName((PetscObject)tmp, "Block Sizes"));
1190:         PetscCall(PetscViewerASCIIPushTab(viewer));
1191:         PetscCall(ISView(tmp, viewer));
1192:         PetscCall(PetscViewerASCIIPopTab(viewer));
1193:         PetscCall(ISDestroy(&tmp));
1194:       }
1195:     }
1196:   } else if (issaws) {
1197: #if defined(PETSC_HAVE_SAWS)
1198:     PetscMPIInt rank;

1200:     PetscCall(PetscObjectName((PetscObject)mat));
1201:     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
1202:     if (!((PetscObject)mat)->amsmem && rank == 0) PetscCall(PetscObjectViewSAWs((PetscObject)mat, viewer));
1203: #endif
1204:   } else if (isstring) {
1205:     const char *type;
1206:     PetscCall(MatGetType(mat, &type));
1207:     PetscCall(PetscViewerStringSPrintf(viewer, " MatType: %-7.7s", type));
1208:     PetscTryTypeMethod(mat, view, viewer);
1209:   }
1210:   if ((format == PETSC_VIEWER_NATIVE || format == PETSC_VIEWER_LOAD_BALANCE) && mat->ops->viewnative) {
1211:     PetscCall(PetscViewerASCIIPushTab(viewer));
1212:     PetscUseTypeMethod(mat, viewnative, viewer);
1213:     PetscCall(PetscViewerASCIIPopTab(viewer));
1214:   } else if (mat->ops->view) {
1215:     PetscCall(PetscViewerASCIIPushTab(viewer));
1216:     PetscUseTypeMethod(mat, view, viewer);
1217:     PetscCall(PetscViewerASCIIPopTab(viewer));
1218:   }
1219:   if (isascii) {
1220:     PetscCall(PetscViewerGetFormat(viewer, &format));
1221:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerASCIIPopTab(viewer));
1222:   }
1223:   PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1224: #if !defined(PETSC_HAVE_THREADSAFETY)
1225:   insidematview--;
1226: #endif
1227:   PetscFunctionReturn(PETSC_SUCCESS);
1228: }

1230: #if defined(PETSC_USE_DEBUG)
1231: #include <../src/sys/totalview/tv_data_display.h>
1232: PETSC_UNUSED static int TV_display_type(const struct _p_Mat *mat)
1233: {
1234:   TV_add_row("Local rows", "int", &mat->rmap->n);
1235:   TV_add_row("Local columns", "int", &mat->cmap->n);
1236:   TV_add_row("Global rows", "int", &mat->rmap->N);
1237:   TV_add_row("Global columns", "int", &mat->cmap->N);
1238:   TV_add_row("Typename", TV_ascii_string_type, ((PetscObject)mat)->type_name);
1239:   return TV_format_OK;
1240: }
1241: #endif

1243: /*@
1244:   MatLoad - Loads a matrix that has been stored in binary/HDF5 format
1245:   with `MatView()`.  The matrix format is determined from the options database.
1246:   Generates a parallel MPI matrix if the communicator has more than one
1247:   processor.  The default matrix type is `MATAIJ`.

1249:   Collective

1251:   Input Parameters:
1252: + mat    - the newly loaded matrix, this needs to have been created with `MatCreate()`
1253:             or some related function before a call to `MatLoad()`
1254: - viewer - `PETSCVIEWERBINARY`/`PETSCVIEWERHDF5` file viewer

1256:   Options Database Key:
1257: . -matload_block_size bs - set block size

1259:   Level: beginner

1261:   Notes:
1262:   If the `Mat` type has not yet been given then `MATAIJ` is used, call `MatSetFromOptions()` on the
1263:   `Mat` before calling this routine if you wish to set it from the options database.

1265:   `MatLoad()` automatically loads into the options database any options
1266:   given in the file filename.info where filename is the name of the file
1267:   that was passed to the `PetscViewerBinaryOpen()`. The options in the info
1268:   file will be ignored if you use the -viewer_binary_skip_info option.

1270:   If the type or size of mat is not set before a call to `MatLoad()`, PETSc
1271:   sets the default matrix type AIJ and sets the local and global sizes.
1272:   If type and/or size is already set, then the same are used.

1274:   In parallel, each processor can load a subset of rows (or the
1275:   entire matrix).  This routine is especially useful when a large
1276:   matrix is stored on disk and only part of it is desired on each
1277:   processor.  For example, a parallel solver may access only some of
1278:   the rows from each processor.  The algorithm used here reads
1279:   relatively small blocks of data rather than reading the entire
1280:   matrix and then subsetting it.

1282:   Viewer's `PetscViewerType` must be either `PETSCVIEWERBINARY` or `PETSCVIEWERHDF5`.
1283:   Such viewer can be created using `PetscViewerBinaryOpen()` or `PetscViewerHDF5Open()`,
1284:   or the sequence like
1285: .vb
1286:     `PetscViewer` v;
1287:     `PetscViewerCreate`(`PETSC_COMM_WORLD`,&v);
1288:     `PetscViewerSetType`(v,`PETSCVIEWERBINARY`);
1289:     `PetscViewerSetFromOptions`(v);
1290:     `PetscViewerFileSetMode`(v,`FILE_MODE_READ`);
1291:     `PetscViewerFileSetName`(v,"datafile");
1292: .ve
1293:   The optional `PetscViewerSetFromOptions()` call allows overriding `PetscViewerSetType()` using the option
1294: .vb
1295:   -viewer_type {binary, hdf5}
1296: .ve

1298:   See the example src/ksp/ksp/tutorials/ex27.c with the first approach,
1299:   and src/mat/tutorials/ex10.c with the second approach.

1301:   In case of `PETSCVIEWERBINARY`, a native PETSc binary format is used. Each of the blocks
1302:   is read onto MPI rank 0 and then shipped to its destination MPI rank, one after another.
1303:   Multiple objects, both matrices and vectors, can be stored within the same file.
1304:   Their `PetscObject` name is ignored; they are loaded in the order of their storage.

1306:   Most users should not need to know the details of the binary storage
1307:   format, since `MatLoad()` and `MatView()` completely hide these details.
1308:   But for anyone who is interested, the standard binary matrix storage
1309:   format is

1311: .vb
1312:     PetscInt    MAT_FILE_CLASSID
1313:     PetscInt    number of rows
1314:     PetscInt    number of columns
1315:     PetscInt    total number of nonzeros
1316:     PetscInt    *number nonzeros in each row
1317:     PetscInt    *column indices of all nonzeros (starting index is zero)
1318:     PetscScalar *values of all nonzeros
1319: .ve
1320:   If PETSc was not configured with `--with-64-bit-indices` then only `MATMPIAIJ` matrices with more than `PETSC_INT_MAX` non-zeros can be
1321:   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
1322:   case will not fit in a (32-bit) `PetscInt` the value `PETSC_INT_MAX` is used for the header entry `total number of nonzeros`.

1324:   PETSc automatically does the byte swapping for
1325:   machines that store the bytes reversed. Thus if you write your own binary
1326:   read/write routines you have to swap the bytes; see `PetscBinaryRead()`
1327:   and `PetscBinaryWrite()` to see how this may be done.

1329:   In case of `PETSCVIEWERHDF5`, a parallel HDF5 reader is used.
1330:   Each processor's chunk is loaded independently by its owning MPI process.
1331:   Multiple objects, both matrices and vectors, can be stored within the same file.
1332:   They are looked up by their PetscObject name.

1334:   As the MATLAB MAT-File Version 7.3 format is also a HDF5 flavor, we decided to use
1335:   by default the same structure and naming of the AIJ arrays and column count
1336:   within the HDF5 file. This means that a MAT file saved with -v7.3 flag, e.g.
1337: .vb
1338:   save example.mat A b -v7.3
1339: .ve
1340:   can be directly read by this routine (see Reference 1 for details).

1342:   Depending on your MATLAB version, this format might be a default,
1343:   otherwise you can set it as default in Preferences.

1345:   Unless -nocompression flag is used to save the file in MATLAB,
1346:   PETSc must be configured with ZLIB package.

1348:   See also examples src/mat/tutorials/ex10.c and src/ksp/ksp/tutorials/ex27.c

1350:   This reader currently supports only real `MATSEQAIJ`, `MATMPIAIJ`, `MATSEQDENSE` and `MATMPIDENSE` matrices for `PETSCVIEWERHDF5`

1352:   Corresponding `MatView()` is not yet implemented.

1354:   The loaded matrix is actually a transpose of the original one in MATLAB,
1355:   unless you push `PETSC_VIEWER_HDF5_MAT` format (see examples above).
1356:   With this format, matrix is automatically transposed by PETSc,
1357:   unless the matrix is marked as SPD or symmetric
1358:   (see `MatSetOption()`, `MAT_SPD`, `MAT_SYMMETRIC`).

1360:   See MATLAB Documentation on `save()`, <https://www.mathworks.com/help/matlab/ref/save.html#btox10b-1-version>

1362: .seealso: [](ch_matrices), `Mat`, `PetscViewerBinaryOpen()`, `PetscViewerSetType()`, `MatView()`, `VecLoad()`
1363:  @*/
1364: PetscErrorCode MatLoad(Mat mat, PetscViewer viewer)
1365: {
1366:   PetscBool flg;

1368:   PetscFunctionBegin;

1372:   if (!((PetscObject)mat)->type_name) PetscCall(MatSetType(mat, MATAIJ));

1374:   flg = PETSC_FALSE;
1375:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_symmetric", &flg, NULL));
1376:   if (flg) {
1377:     PetscCall(MatSetOption(mat, MAT_SYMMETRIC, PETSC_TRUE));
1378:     PetscCall(MatSetOption(mat, MAT_SYMMETRY_ETERNAL, PETSC_TRUE));
1379:   }
1380:   flg = PETSC_FALSE;
1381:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_spd", &flg, NULL));
1382:   if (flg) PetscCall(MatSetOption(mat, MAT_SPD, PETSC_TRUE));

1384:   PetscCall(PetscLogEventBegin(MAT_Load, mat, viewer, 0, 0));
1385:   PetscUseTypeMethod(mat, load, viewer);
1386:   PetscCall(PetscLogEventEnd(MAT_Load, mat, viewer, 0, 0));
1387:   PetscFunctionReturn(PETSC_SUCCESS);
1388: }

1390: static PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1391: {
1392:   Mat_Redundant *redund = *redundant;

1394:   PetscFunctionBegin;
1395:   if (redund) {
1396:     if (redund->matseq) { /* via MatCreateSubMatrices()  */
1397:       PetscCall(ISDestroy(&redund->isrow));
1398:       PetscCall(ISDestroy(&redund->iscol));
1399:       PetscCall(MatDestroySubMatrices(1, &redund->matseq));
1400:     } else {
1401:       PetscCall(PetscFree2(redund->send_rank, redund->recv_rank));
1402:       PetscCall(PetscFree(redund->sbuf_j));
1403:       PetscCall(PetscFree(redund->sbuf_a));
1404:       for (PetscInt i = 0; i < redund->nrecvs; i++) {
1405:         PetscCall(PetscFree(redund->rbuf_j[i]));
1406:         PetscCall(PetscFree(redund->rbuf_a[i]));
1407:       }
1408:       PetscCall(PetscFree4(redund->sbuf_nz, redund->rbuf_nz, redund->rbuf_j, redund->rbuf_a));
1409:     }

1411:     PetscCall(PetscCommDestroy(&redund->subcomm));
1412:     PetscCall(PetscFree(redund));
1413:   }
1414:   PetscFunctionReturn(PETSC_SUCCESS);
1415: }

1417: /*@
1418:   MatDestroy - Frees space taken by a matrix.

1420:   Collective

1422:   Input Parameter:
1423: . A - the matrix

1425:   Level: beginner

1427:   Developer Note:
1428:   Some special arrays of matrices are not destroyed in this routine but instead by the routines called by
1429:   `MatDestroySubMatrices()`. Thus one must be sure that any changes here must also be made in those routines.
1430:   `MatHeaderMerge()` and `MatHeaderReplace()` also manipulate the data in the `Mat` object and likely need changes
1431:   if changes are needed here.

1433: .seealso: [](ch_matrices), `Mat`, `MatCreate()`
1434: @*/
1435: PetscErrorCode MatDestroy(Mat *A)
1436: {
1437:   PetscFunctionBegin;
1438:   if (!*A) PetscFunctionReturn(PETSC_SUCCESS);
1440:   if (--((PetscObject)*A)->refct > 0) {
1441:     *A = NULL;
1442:     PetscFunctionReturn(PETSC_SUCCESS);
1443:   }

1445:   /* if memory was published with SAWs then destroy it */
1446:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*A));
1447:   PetscTryTypeMethod(*A, destroy);

1449:   PetscCall(PetscFree((*A)->factorprefix));
1450:   PetscCall(PetscFree((*A)->defaultvectype));
1451:   PetscCall(PetscFree((*A)->defaultrandtype));
1452:   PetscCall(PetscFree((*A)->bsizes));
1453:   PetscCall(PetscFree((*A)->solvertype));
1454:   for (PetscInt i = 0; i < MAT_FACTOR_NUM_TYPES; i++) PetscCall(PetscFree((*A)->preferredordering[i]));
1455:   if ((*A)->redundant && (*A)->redundant->matseq[0] == *A) (*A)->redundant->matseq[0] = NULL;
1456:   PetscCall(MatDestroy_Redundant(&(*A)->redundant));
1457:   PetscCall(MatProductClear(*A));
1458:   PetscCall(MatNullSpaceDestroy(&(*A)->nullsp));
1459:   PetscCall(MatNullSpaceDestroy(&(*A)->transnullsp));
1460:   PetscCall(MatNullSpaceDestroy(&(*A)->nearnullsp));
1461:   PetscCall(MatDestroy(&(*A)->schur));
1462:   PetscCall(VecDestroy(&(*A)->dot_vec));
1463:   PetscCall(PetscLayoutDestroy(&(*A)->rmap));
1464:   PetscCall(PetscLayoutDestroy(&(*A)->cmap));
1465:   PetscCall(PetscHeaderDestroy(A));
1466:   PetscFunctionReturn(PETSC_SUCCESS);
1467: }

1469: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1470: /*@
1471:   MatSetValues - Inserts or adds a block of values into a matrix.
1472:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1473:   MUST be called after all calls to `MatSetValues()` have been completed.

1475:   Not Collective

1477:   Input Parameters:
1478: + mat  - the matrix
1479: . m    - the number of rows
1480: . idxm - the global indices of the rows
1481: . n    - the number of columns
1482: . idxn - the global indices of the columns
1483: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1484:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1485: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1487:   Level: beginner

1489:   Notes:
1490:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1491:   options cannot be mixed without intervening calls to the assembly
1492:   routines.

1494:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1495:   as well as in C.

1497:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1498:   simply ignored. This allows easily inserting element stiffness matrices
1499:   with homogeneous Dirichlet boundary conditions that you don't want represented
1500:   in the matrix.

1502:   Efficiency Alert:
1503:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1504:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1506:   Fortran Notes:
1507:   If any of `idxm`, `idxn`, and `v` are scalars pass them using, for example,
1508: .vb
1509:   call MatSetValues(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
1510: .ve

1512:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1514:   Developer Note:
1515:   This is labeled with C so does not automatically generate Fortran stubs and interfaces
1516:   because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.

1518: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1519:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1520: @*/
1521: PetscErrorCode MatSetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
1522: {
1523:   PetscFunctionBeginHot;
1526:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1527:   PetscAssertPointer(idxm, 3);
1528:   PetscAssertPointer(idxn, 5);
1529:   MatCheckPreallocated(mat, 1);

1531:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
1532:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");

1534:   if (PetscDefined(USE_DEBUG)) {
1535:     PetscInt i, j;

1537:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1538:     if (v) {
1539:       for (i = 0; i < m; i++) {
1540:         for (j = 0; j < n; j++) {
1541:           if (mat->erroriffailure && PetscIsInfOrNanScalar(v[i * n + j]))
1542: #if defined(PETSC_USE_COMPLEX)
1543:             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]);
1544: #else
1545:             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]);
1546: #endif
1547:         }
1548:       }
1549:     }
1550:     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);
1551:     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);
1552:   }

1554:   if (mat->assembled) {
1555:     mat->was_assembled = PETSC_TRUE;
1556:     mat->assembled     = PETSC_FALSE;
1557:   }
1558:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1559:   PetscUseTypeMethod(mat, setvalues, m, idxm, n, idxn, v, addv);
1560:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1561:   PetscFunctionReturn(PETSC_SUCCESS);
1562: }

1564: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1565: /*@
1566:   MatSetValuesIS - Inserts or adds a block of values into a matrix using an `IS` to indicate the rows and columns
1567:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1568:   MUST be called after all calls to `MatSetValues()` have been completed.

1570:   Not Collective

1572:   Input Parameters:
1573: + mat  - the matrix
1574: . ism  - the rows to provide
1575: . isn  - the columns to provide
1576: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1577:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1578: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1580:   Level: beginner

1582:   Notes:
1583:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1585:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1586:   options cannot be mixed without intervening calls to the assembly
1587:   routines.

1589:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1590:   as well as in C.

1592:   Negative indices may be passed in `ism` and `isn`, these rows and columns are
1593:   simply ignored. This allows easily inserting element stiffness matrices
1594:   with homogeneous Dirichlet boundary conditions that you don't want represented
1595:   in the matrix.

1597:   Fortran Note:
1598:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1600:   Efficiency Alert:
1601:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1602:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1604:   This is currently not optimized for any particular `ISType`

1606: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatSetValues()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1607:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1608: @*/
1609: PetscErrorCode MatSetValuesIS(Mat mat, IS ism, IS isn, const PetscScalar v[], InsertMode addv)
1610: {
1611:   PetscInt        m, n;
1612:   const PetscInt *rows, *cols;

1614:   PetscFunctionBeginHot;
1616:   PetscCall(ISGetIndices(ism, &rows));
1617:   PetscCall(ISGetIndices(isn, &cols));
1618:   PetscCall(ISGetLocalSize(ism, &m));
1619:   PetscCall(ISGetLocalSize(isn, &n));
1620:   PetscCall(MatSetValues(mat, m, rows, n, cols, v, addv));
1621:   PetscCall(ISRestoreIndices(ism, &rows));
1622:   PetscCall(ISRestoreIndices(isn, &cols));
1623:   PetscFunctionReturn(PETSC_SUCCESS);
1624: }

1626: /*@
1627:   MatSetValuesRowLocal - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1628:   values into a matrix

1630:   Not Collective

1632:   Input Parameters:
1633: + mat - the matrix
1634: . row - the (block) row to set
1635: - 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.
1636:         See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1638:   Level: intermediate

1640:   Notes:
1641:   The values, `v`, are column-oriented (for the block version) and sorted

1643:   All the nonzero values in `row` must be provided

1645:   The matrix must have previously had its column indices set, likely by having been assembled.

1647:   `row` must belong to this MPI process

1649:   Fortran Note:
1650:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1652: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1653:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetValuesRow()`, `MatSetLocalToGlobalMapping()`
1654: @*/
1655: PetscErrorCode MatSetValuesRowLocal(Mat mat, PetscInt row, const PetscScalar v[])
1656: {
1657:   PetscInt globalrow;

1659:   PetscFunctionBegin;
1662:   PetscAssertPointer(v, 3);
1663:   PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, 1, &row, &globalrow));
1664:   PetscCall(MatSetValuesRow(mat, globalrow, v));
1665:   PetscFunctionReturn(PETSC_SUCCESS);
1666: }

1668: /*@
1669:   MatSetValuesRow - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1670:   values into a matrix

1672:   Not Collective

1674:   Input Parameters:
1675: + mat - the matrix
1676: . row - the (block) row to set
1677: - 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

1679:   Level: advanced

1681:   Notes:
1682:   The values, `v`, are column-oriented for the block version.

1684:   All the nonzeros in `row` must be provided

1686:   THE MATRIX MUST HAVE PREVIOUSLY HAD ITS COLUMN INDICES SET. IT IS RARE THAT THIS ROUTINE IS USED, usually `MatSetValues()` is used.

1688:   `row` must belong to this process

1690: .seealso: [](ch_matrices), `Mat`, `MatSetValues()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1691:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1692: @*/
1693: PetscErrorCode MatSetValuesRow(Mat mat, PetscInt row, const PetscScalar v[])
1694: {
1695:   PetscFunctionBeginHot;
1698:   MatCheckPreallocated(mat, 1);
1699:   PetscAssertPointer(v, 3);
1700:   PetscCheck(mat->insertmode != ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add and insert values");
1701:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1702:   mat->insertmode = INSERT_VALUES;

1704:   if (mat->assembled) {
1705:     mat->was_assembled = PETSC_TRUE;
1706:     mat->assembled     = PETSC_FALSE;
1707:   }
1708:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1709:   PetscUseTypeMethod(mat, setvaluesrow, row, v);
1710:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1711:   PetscFunctionReturn(PETSC_SUCCESS);
1712: }

1714: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1715: /*@
1716:   MatSetValuesStencil - Inserts or adds a block of values into a matrix.
1717:   Using structured grid indexing

1719:   Not Collective

1721:   Input Parameters:
1722: + mat  - the matrix
1723: . m    - number of rows being entered
1724: . idxm - grid coordinates (and component number when dof > 1) for matrix rows being entered
1725: . n    - number of columns being entered
1726: . idxn - grid coordinates (and component number when dof > 1) for matrix columns being entered
1727: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1728:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1729: - addv - either `ADD_VALUES` to add to existing entries at that location or `INSERT_VALUES` to replace existing entries with new values

1731:   Level: beginner

1733:   Notes:
1734:   By default the values, `v`, are row-oriented.  See `MatSetOption()` for other options.

1736:   Calls to `MatSetValuesStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1737:   options cannot be mixed without intervening calls to the assembly
1738:   routines.

1740:   The grid coordinates are across the entire grid, not just the local portion

1742:   `MatSetValuesStencil()` uses 0-based row and column numbers in Fortran
1743:   as well as in C.

1745:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1747:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1748:   or call `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1750:   The columns and rows in the stencil passed in MUST be contained within the
1751:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1752:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1753:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1754:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1756:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
1757:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
1758:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
1759:   `DM_BOUNDARY_PERIODIC` boundary type.

1761:   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
1762:   a single value per point) you can skip filling those indices.

1764:   Inspired by the structured grid interface to the HYPRE package
1765:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1767:   Fortran Note:
1768:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1770:   Efficiency Alert:
1771:   The routine `MatSetValuesBlockedStencil()` may offer much better efficiency
1772:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1774: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1775:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`
1776: @*/
1777: PetscErrorCode MatSetValuesStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1778: {
1779:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1780:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1781:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1783:   PetscFunctionBegin;
1784:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1787:   PetscAssertPointer(idxm, 3);
1788:   PetscAssertPointer(idxn, 5);

1790:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1791:     jdxm = buf;
1792:     jdxn = buf + m;
1793:   } else {
1794:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1795:     jdxm = bufm;
1796:     jdxn = bufn;
1797:   }
1798:   for (i = 0; i < m; i++) {
1799:     for (j = 0; j < 3 - sdim; j++) dxm++;
1800:     tmp = *dxm++ - starts[0];
1801:     for (j = 0; j < dim - 1; j++) {
1802:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1803:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1804:     }
1805:     if (mat->stencil.noc) dxm++;
1806:     jdxm[i] = tmp;
1807:   }
1808:   for (i = 0; i < n; i++) {
1809:     for (j = 0; j < 3 - sdim; j++) dxn++;
1810:     tmp = *dxn++ - starts[0];
1811:     for (j = 0; j < dim - 1; j++) {
1812:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1813:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1814:     }
1815:     if (mat->stencil.noc) dxn++;
1816:     jdxn[i] = tmp;
1817:   }
1818:   PetscCall(MatSetValuesLocal(mat, m, jdxm, n, jdxn, v, addv));
1819:   PetscCall(PetscFree2(bufm, bufn));
1820:   PetscFunctionReturn(PETSC_SUCCESS);
1821: }

1823: /*@
1824:   MatSetValuesBlockedStencil - Inserts or adds a block of values into a matrix.
1825:   Using structured grid indexing

1827:   Not Collective

1829:   Input Parameters:
1830: + mat  - the matrix
1831: . m    - number of rows being entered
1832: . idxm - grid coordinates for matrix rows being entered
1833: . n    - number of columns being entered
1834: . idxn - grid coordinates for matrix columns being entered
1835: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1836:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1837: - addv - either `ADD_VALUES` to add to existing entries or `INSERT_VALUES` to replace existing entries with new values

1839:   Level: beginner

1841:   Notes:
1842:   By default the values, `v`, are row-oriented and unsorted.
1843:   See `MatSetOption()` for other options.

1845:   Calls to `MatSetValuesBlockedStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1846:   options cannot be mixed without intervening calls to the assembly
1847:   routines.

1849:   The grid coordinates are across the entire grid, not just the local portion

1851:   `MatSetValuesBlockedStencil()` uses 0-based row and column numbers in Fortran
1852:   as well as in C.

1854:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1856:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1857:   or call `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1859:   The columns and rows in the stencil passed in MUST be contained within the
1860:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1861:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1862:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1863:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1865:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1866:   simply ignored. This allows easily inserting element stiffness matrices
1867:   with homogeneous Dirichlet boundary conditions that you don't want represented
1868:   in the matrix.

1870:   Inspired by the structured grid interface to the HYPRE package
1871:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1873:   Fortran Notes:
1874:   `idxm` and `idxn` should be declared as
1875: .vb
1876:     MatStencil idxm(4,m),idxn(4,n)
1877: .ve
1878:   and the values inserted using
1879: .vb
1880:     idxm(MatStencil_i,1) = i
1881:     idxm(MatStencil_j,1) = j
1882:     idxm(MatStencil_k,1) = k
1883:    etc
1884: .ve

1886:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1888: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1889:           `MatSetValues()`, `MatSetValuesStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`,
1890:           `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`
1891: @*/
1892: PetscErrorCode MatSetValuesBlockedStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1893: {
1894:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1895:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1896:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1898:   PetscFunctionBegin;
1899:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1902:   PetscAssertPointer(idxm, 3);
1903:   PetscAssertPointer(idxn, 5);
1904:   PetscAssertPointer(v, 6);

1906:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1907:     jdxm = buf;
1908:     jdxn = buf + m;
1909:   } else {
1910:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1911:     jdxm = bufm;
1912:     jdxn = bufn;
1913:   }
1914:   for (i = 0; i < m; i++) {
1915:     for (j = 0; j < 3 - sdim; j++) dxm++;
1916:     tmp = *dxm++ - starts[0];
1917:     for (j = 0; j < sdim - 1; j++) {
1918:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1919:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1920:     }
1921:     dxm++;
1922:     jdxm[i] = tmp;
1923:   }
1924:   for (i = 0; i < n; i++) {
1925:     for (j = 0; j < 3 - sdim; j++) dxn++;
1926:     tmp = *dxn++ - starts[0];
1927:     for (j = 0; j < sdim - 1; j++) {
1928:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1929:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1930:     }
1931:     dxn++;
1932:     jdxn[i] = tmp;
1933:   }
1934:   PetscCall(MatSetValuesBlockedLocal(mat, m, jdxm, n, jdxn, v, addv));
1935:   PetscCall(PetscFree2(bufm, bufn));
1936:   PetscFunctionReturn(PETSC_SUCCESS);
1937: }

1939: /*@
1940:   MatSetStencil - Sets the grid information for setting values into a matrix via
1941:   `MatSetValuesStencil()`

1943:   Not Collective

1945:   Input Parameters:
1946: + mat    - the matrix
1947: . dim    - dimension of the grid 1, 2, or 3
1948: . dims   - number of grid points in x, y, and z direction, including ghost points on your processor
1949: . starts - starting point of ghost nodes on your processor in x, y, and z direction
1950: - dof    - number of degrees of freedom per node

1952:   Level: beginner

1954:   Notes:
1955:   Inspired by the structured grid interface to the HYPRE package
1956:   (www.llnl.gov/CASC/hyper)

1958:   For matrices generated with `DMCreateMatrix()` this routine is automatically called and so not needed by the
1959:   user.

1961: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1962:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetValuesStencil()`
1963: @*/
1964: PetscErrorCode MatSetStencil(Mat mat, PetscInt dim, const PetscInt dims[], const PetscInt starts[], PetscInt dof)
1965: {
1966:   PetscFunctionBegin;
1968:   PetscAssertPointer(dims, 3);
1969:   PetscAssertPointer(starts, 4);

1971:   mat->stencil.dim = dim + (dof > 1);
1972:   for (PetscInt i = 0; i < dim; i++) {
1973:     mat->stencil.dims[i]   = dims[dim - i - 1]; /* copy the values in backwards */
1974:     mat->stencil.starts[i] = starts[dim - i - 1];
1975:   }
1976:   mat->stencil.dims[dim]   = dof;
1977:   mat->stencil.starts[dim] = 0;
1978:   mat->stencil.noc         = (PetscBool)(dof == 1);
1979:   PetscFunctionReturn(PETSC_SUCCESS);
1980: }

1982: /*@
1983:   MatSetValuesBlocked - Inserts or adds a block of values into a matrix.

1985:   Not Collective

1987:   Input Parameters:
1988: + mat  - the matrix
1989: . m    - the number of block rows
1990: . idxm - the global block indices
1991: . n    - the number of block columns
1992: . idxn - the global block indices
1993: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1994:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1995: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` replaces existing entries with new values

1997:   Level: intermediate

1999:   Notes:
2000:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call
2001:   MatXXXXSetPreallocation() or `MatSetUp()` before using this routine.

2003:   The `m` and `n` count the NUMBER of blocks in the row direction and column direction,
2004:   NOT the total number of rows/columns; for example, if the block size is 2 and
2005:   you are passing in values for rows 2,3,4,5  then `m` would be 2 (not 4).
2006:   The values in `idxm` would be 1 2; that is the first index for each block divided by
2007:   the block size.

2009:   You must call `MatSetBlockSize()` when constructing this matrix (before
2010:   preallocating it).

2012:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2014:   Calls to `MatSetValuesBlocked()` with the `INSERT_VALUES` and `ADD_VALUES`
2015:   options cannot be mixed without intervening calls to the assembly
2016:   routines.

2018:   `MatSetValuesBlocked()` uses 0-based row and column numbers in Fortran
2019:   as well as in C.

2021:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
2022:   simply ignored. This allows easily inserting element stiffness matrices
2023:   with homogeneous Dirichlet boundary conditions that you don't want represented
2024:   in the matrix.

2026:   Each time an entry is set within a sparse matrix via `MatSetValues()`,
2027:   internal searching must be done to determine where to place the
2028:   data in the matrix storage space.  By instead inserting blocks of
2029:   entries via `MatSetValuesBlocked()`, the overhead of matrix assembly is
2030:   reduced.

2032:   Example:
2033: .vb
2034:    Suppose m=n=2 and block size(bs) = 2 The array is

2036:    1  2  | 3  4
2037:    5  6  | 7  8
2038:    - - - | - - -
2039:    9  10 | 11 12
2040:    13 14 | 15 16

2042:    v[] should be passed in like
2043:    v[] = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

2045:   If you are not using row-oriented storage of v (that is you called MatSetOption(mat,MAT_ROW_ORIENTED,PETSC_FALSE)) then
2046:    v[] = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16]
2047: .ve

2049:   Fortran Notes:
2050:   If any of `idmx`, `idxn`, and `v` are scalars pass them using, for example,
2051: .vb
2052:   call MatSetValuesBlocked(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
2053: .ve

2055:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2057: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesBlockedLocal()`
2058: @*/
2059: PetscErrorCode MatSetValuesBlocked(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
2060: {
2061:   PetscFunctionBeginHot;
2064:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2065:   PetscAssertPointer(idxm, 3);
2066:   PetscAssertPointer(idxn, 5);
2067:   MatCheckPreallocated(mat, 1);
2068:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2069:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2070:   if (PetscDefined(USE_DEBUG)) {
2071:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2072:     PetscCheck(mat->ops->setvaluesblocked || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2073:   }
2074:   if (PetscDefined(USE_DEBUG)) {
2075:     PetscInt rbs, cbs, M, N, i;
2076:     PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
2077:     PetscCall(MatGetSize(mat, &M, &N));
2078:     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);
2079:     for (i = 0; i < n; i++)
2080:       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);
2081:   }
2082:   if (mat->assembled) {
2083:     mat->was_assembled = PETSC_TRUE;
2084:     mat->assembled     = PETSC_FALSE;
2085:   }
2086:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2087:   if (mat->ops->setvaluesblocked) PetscUseTypeMethod(mat, setvaluesblocked, m, idxm, n, idxn, v, addv);
2088:   else {
2089:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *iidxm, *iidxn;
2090:     PetscInt i, j, bs, cbs;

2092:     PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
2093:     if ((m * bs + n * cbs) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2094:       iidxm = buf;
2095:       iidxn = buf + m * bs;
2096:     } else {
2097:       PetscCall(PetscMalloc2(m * bs, &bufr, n * cbs, &bufc));
2098:       iidxm = bufr;
2099:       iidxn = bufc;
2100:     }
2101:     for (i = 0; i < m; i++) {
2102:       for (j = 0; j < bs; j++) iidxm[i * bs + j] = bs * idxm[i] + j;
2103:     }
2104:     if (m != n || bs != cbs || idxm != idxn) {
2105:       for (i = 0; i < n; i++) {
2106:         for (j = 0; j < cbs; j++) iidxn[i * cbs + j] = cbs * idxn[i] + j;
2107:       }
2108:     } else iidxn = iidxm;
2109:     PetscCall(MatSetValues(mat, m * bs, iidxm, n * cbs, iidxn, v, addv));
2110:     PetscCall(PetscFree2(bufr, bufc));
2111:   }
2112:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2113:   PetscFunctionReturn(PETSC_SUCCESS);
2114: }

2116: /*@
2117:   MatGetValues - Gets a block of local values from a matrix.

2119:   Not Collective; can only return values that are owned by the give process

2121:   Input Parameters:
2122: + mat  - the matrix
2123: . v    - a logically two-dimensional array for storing the values
2124: . m    - the number of rows
2125: . idxm - the  global indices of the rows
2126: . n    - the number of columns
2127: - idxn - the global indices of the columns

2129:   Level: advanced

2131:   Notes:
2132:   The user must allocate space (m*n `PetscScalar`s) for the values, `v`.
2133:   The values, `v`, are then returned in a row-oriented format,
2134:   analogous to that used by default in `MatSetValues()`.

2136:   `MatGetValues()` uses 0-based row and column numbers in
2137:   Fortran as well as in C.

2139:   `MatGetValues()` requires that the matrix has been assembled
2140:   with `MatAssemblyBegin()`/`MatAssemblyEnd()`.  Thus, calls to
2141:   `MatSetValues()` and `MatGetValues()` CANNOT be made in succession
2142:   without intermediate matrix assembly.

2144:   Negative row or column indices will be ignored and those locations in `v` will be
2145:   left unchanged.

2147:   For the standard row-based matrix formats, `idxm` can only contain rows owned by the requesting MPI process.
2148:   That is, rows with global index greater than or equal to rstart and less than rend where rstart and rend are obtainable
2149:   from `MatGetOwnershipRange`(mat,&rstart,&rend).

2151: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatSetValues()`, `MatGetOwnershipRange()`, `MatGetValuesLocal()`, `MatGetValue()`
2152: @*/
2153: PetscErrorCode MatGetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], PetscScalar v[])
2154: {
2155:   PetscFunctionBegin;
2158:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS);
2159:   PetscAssertPointer(idxm, 3);
2160:   PetscAssertPointer(idxn, 5);
2161:   PetscAssertPointer(v, 6);
2162:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2163:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2164:   MatCheckPreallocated(mat, 1);

2166:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2167:   PetscUseTypeMethod(mat, getvalues, m, idxm, n, idxn, v);
2168:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2169:   PetscFunctionReturn(PETSC_SUCCESS);
2170: }

2172: /*@
2173:   MatGetValuesLocal - retrieves values from certain locations in a matrix using the local numbering of the indices
2174:   defined previously by `MatSetLocalToGlobalMapping()`

2176:   Not Collective

2178:   Input Parameters:
2179: + mat  - the matrix
2180: . nrow - number of rows
2181: . irow - the row local indices
2182: . ncol - number of columns
2183: - icol - the column local indices

2185:   Output Parameter:
2186: . y - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2187:       See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2189:   Level: advanced

2191:   Notes:
2192:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine.

2194:   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,
2195:   are greater than or equal to rstart and less than rend where rstart and rend are obtainable from `MatGetOwnershipRange`(mat,&rstart,&rend). One can
2196:   determine if the resulting global row associated with the local row r is owned by the requesting MPI process by applying the `ISLocalToGlobalMapping` set
2197:   with `MatSetLocalToGlobalMapping()`.

2199: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2200:           `MatSetValuesLocal()`, `MatGetValues()`
2201: @*/
2202: PetscErrorCode MatGetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], PetscScalar y[])
2203: {
2204:   PetscFunctionBeginHot;
2207:   MatCheckPreallocated(mat, 1);
2208:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to retrieve */
2209:   PetscAssertPointer(irow, 3);
2210:   PetscAssertPointer(icol, 5);
2211:   if (PetscDefined(USE_DEBUG)) {
2212:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2213:     PetscCheck(mat->ops->getvalueslocal || mat->ops->getvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2214:   }
2215:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2216:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2217:   if (mat->ops->getvalueslocal) PetscUseTypeMethod(mat, getvalueslocal, nrow, irow, ncol, icol, y);
2218:   else {
2219:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *irowm, *icolm;
2220:     if ((nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2221:       irowm = buf;
2222:       icolm = buf + nrow;
2223:     } else {
2224:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2225:       irowm = bufr;
2226:       icolm = bufc;
2227:     }
2228:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global row mapping (See MatSetLocalToGlobalMapping()).");
2229:     PetscCheck(mat->cmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global column mapping (See MatSetLocalToGlobalMapping()).");
2230:     PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, irowm));
2231:     PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, icolm));
2232:     PetscCall(MatGetValues(mat, nrow, irowm, ncol, icolm, y));
2233:     PetscCall(PetscFree2(bufr, bufc));
2234:   }
2235:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2236:   PetscFunctionReturn(PETSC_SUCCESS);
2237: }

2239: /*@
2240:   MatSetValuesBatch - Adds (`ADD_VALUES`) many blocks of values into a matrix at once. The blocks must all be square and
2241:   the same size. Currently, this can only be called once and creates the given matrix.

2243:   Not Collective

2245:   Input Parameters:
2246: + mat  - the matrix
2247: . nb   - the number of blocks
2248: . bs   - the number of rows (and columns) in each block
2249: . rows - a concatenation of the rows for each block
2250: - v    - a concatenation of logically two-dimensional arrays of values

2252:   Level: advanced

2254:   Notes:
2255:   `MatSetPreallocationCOO()` and `MatSetValuesCOO()` may be a better way to provide the values

2257:   In the future, we will extend this routine to handle rectangular blocks, and to allow multiple calls for a given matrix.

2259: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
2260:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
2261: @*/
2262: PetscErrorCode MatSetValuesBatch(Mat mat, PetscInt nb, PetscInt bs, PetscInt rows[], const PetscScalar v[])
2263: {
2264:   PetscFunctionBegin;
2267:   PetscAssertPointer(rows, 4);
2268:   PetscAssertPointer(v, 5);
2269:   PetscAssert(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

2271:   PetscCall(PetscLogEventBegin(MAT_SetValuesBatch, mat, 0, 0, 0));
2272:   for (PetscInt b = 0; b < nb; ++b) PetscCall(MatSetValues(mat, bs, &rows[b * bs], bs, &rows[b * bs], &v[b * bs * bs], ADD_VALUES));
2273:   PetscCall(PetscLogEventEnd(MAT_SetValuesBatch, mat, 0, 0, 0));
2274:   PetscFunctionReturn(PETSC_SUCCESS);
2275: }

2277: /*@
2278:   MatSetLocalToGlobalMapping - Sets a local-to-global numbering for use by
2279:   the routine `MatSetValuesLocal()` to allow users to insert matrix entries
2280:   using a local (per-processor) numbering.

2282:   Not Collective

2284:   Input Parameters:
2285: + x        - the matrix
2286: . rmapping - row mapping created with `ISLocalToGlobalMappingCreate()` or `ISLocalToGlobalMappingCreateIS()`
2287: - cmapping - column mapping

2289:   Level: intermediate

2291:   Note:
2292:   If the matrix is obtained with `DMCreateMatrix()` then this may already have been called on the matrix

2294: .seealso: [](ch_matrices), `Mat`, `DM`, `DMCreateMatrix()`, `MatGetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesLocal()`, `MatGetValuesLocal()`
2295: @*/
2296: PetscErrorCode MatSetLocalToGlobalMapping(Mat x, ISLocalToGlobalMapping rmapping, ISLocalToGlobalMapping cmapping)
2297: {
2298:   PetscFunctionBegin;
2303:   if (x->ops->setlocaltoglobalmapping) PetscUseTypeMethod(x, setlocaltoglobalmapping, rmapping, cmapping);
2304:   else {
2305:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->rmap, rmapping));
2306:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->cmap, cmapping));
2307:   }
2308:   PetscFunctionReturn(PETSC_SUCCESS);
2309: }

2311: /*@
2312:   MatGetLocalToGlobalMapping - Gets the local-to-global numbering set by `MatSetLocalToGlobalMapping()`

2314:   Not Collective

2316:   Input Parameter:
2317: . A - the matrix

2319:   Output Parameters:
2320: + rmapping - row mapping
2321: - cmapping - column mapping

2323:   Level: advanced

2325: .seealso: [](ch_matrices), `Mat`, `MatSetLocalToGlobalMapping()`, `MatSetValuesLocal()`
2326: @*/
2327: PetscErrorCode MatGetLocalToGlobalMapping(Mat A, ISLocalToGlobalMapping *rmapping, ISLocalToGlobalMapping *cmapping)
2328: {
2329:   PetscFunctionBegin;
2332:   if (rmapping) {
2333:     PetscAssertPointer(rmapping, 2);
2334:     *rmapping = A->rmap->mapping;
2335:   }
2336:   if (cmapping) {
2337:     PetscAssertPointer(cmapping, 3);
2338:     *cmapping = A->cmap->mapping;
2339:   }
2340:   PetscFunctionReturn(PETSC_SUCCESS);
2341: }

2343: /*@
2344:   MatSetLayouts - Sets the `PetscLayout` objects for rows and columns of a matrix

2346:   Logically Collective

2348:   Input Parameters:
2349: + A    - the matrix
2350: . rmap - row layout
2351: - cmap - column layout

2353:   Level: advanced

2355:   Note:
2356:   The `PetscLayout` objects are usually created automatically for the matrix so this routine rarely needs to be called.

2358: .seealso: [](ch_matrices), `Mat`, `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatGetLayouts()`
2359: @*/
2360: PetscErrorCode MatSetLayouts(Mat A, PetscLayout rmap, PetscLayout cmap)
2361: {
2362:   PetscFunctionBegin;
2364:   PetscCall(PetscLayoutReference(rmap, &A->rmap));
2365:   PetscCall(PetscLayoutReference(cmap, &A->cmap));
2366:   PetscFunctionReturn(PETSC_SUCCESS);
2367: }

2369: /*@
2370:   MatGetLayouts - Gets the `PetscLayout` objects for rows and columns

2372:   Not Collective

2374:   Input Parameter:
2375: . A - the matrix

2377:   Output Parameters:
2378: + rmap - row layout
2379: - cmap - column layout

2381:   Level: advanced

2383: .seealso: [](ch_matrices), `Mat`, [Matrix Layouts](sec_matlayout), `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatSetLayouts()`
2384: @*/
2385: PetscErrorCode MatGetLayouts(Mat A, PetscLayout *rmap, PetscLayout *cmap)
2386: {
2387:   PetscFunctionBegin;
2390:   if (rmap) {
2391:     PetscAssertPointer(rmap, 2);
2392:     *rmap = A->rmap;
2393:   }
2394:   if (cmap) {
2395:     PetscAssertPointer(cmap, 3);
2396:     *cmap = A->cmap;
2397:   }
2398:   PetscFunctionReturn(PETSC_SUCCESS);
2399: }

2401: /*@
2402:   MatSetValuesLocal - Inserts or adds values into certain locations of a matrix,
2403:   using a local numbering of the rows and columns.

2405:   Not Collective

2407:   Input Parameters:
2408: + mat  - the matrix
2409: . nrow - number of rows
2410: . irow - the row local indices
2411: . ncol - number of columns
2412: . icol - the column local indices
2413: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2414:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2415: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2417:   Level: intermediate

2419:   Notes:
2420:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine

2422:   Calls to `MatSetValuesLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2423:   options cannot be mixed without intervening calls to the assembly
2424:   routines.

2426:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2427:   MUST be called after all calls to `MatSetValuesLocal()` have been completed.

2429:   Fortran Notes:
2430:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2431: .vb
2432:   call MatSetValuesLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2433: .ve

2435:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2437: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2438:           `MatGetValuesLocal()`
2439: @*/
2440: PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2441: {
2442:   PetscFunctionBeginHot;
2445:   MatCheckPreallocated(mat, 1);
2446:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2447:   PetscAssertPointer(irow, 3);
2448:   PetscAssertPointer(icol, 5);
2449:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2450:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2451:   if (PetscDefined(USE_DEBUG)) {
2452:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2453:     PetscCheck(mat->ops->setvalueslocal || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2454:   }

2456:   if (mat->assembled) {
2457:     mat->was_assembled = PETSC_TRUE;
2458:     mat->assembled     = PETSC_FALSE;
2459:   }
2460:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2461:   if (mat->ops->setvalueslocal) PetscUseTypeMethod(mat, setvalueslocal, nrow, irow, ncol, icol, y, addv);
2462:   else {
2463:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2464:     const PetscInt *irowm, *icolm;

2466:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2467:       bufr  = buf;
2468:       bufc  = buf + nrow;
2469:       irowm = bufr;
2470:       icolm = bufc;
2471:     } else {
2472:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2473:       irowm = bufr;
2474:       icolm = bufc;
2475:     }
2476:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, bufr));
2477:     else irowm = irow;
2478:     if (mat->cmap->mapping) {
2479:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, bufc));
2480:       else icolm = irowm;
2481:     } else icolm = icol;
2482:     PetscCall(MatSetValues(mat, nrow, irowm, ncol, icolm, y, addv));
2483:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2484:   }
2485:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2486:   PetscFunctionReturn(PETSC_SUCCESS);
2487: }

2489: /*@
2490:   MatSetValuesBlockedLocal - Inserts or adds values into certain locations of a matrix,
2491:   using a local ordering of the nodes a block at a time.

2493:   Not Collective

2495:   Input Parameters:
2496: + mat  - the matrix
2497: . nrow - number of rows
2498: . irow - the row local indices
2499: . ncol - number of columns
2500: . icol - the column local indices
2501: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2502:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2503: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2505:   Level: intermediate

2507:   Notes:
2508:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetBlockSize()` and `MatSetLocalToGlobalMapping()`
2509:   before using this routineBefore calling `MatSetValuesLocal()`, the user must first set the

2511:   Calls to `MatSetValuesBlockedLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2512:   options cannot be mixed without intervening calls to the assembly
2513:   routines.

2515:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2516:   MUST be called after all calls to `MatSetValuesBlockedLocal()` have been completed.

2518:   Fortran Notes:
2519:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2520: .vb
2521:   call MatSetValuesBlockedLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2522: .ve

2524:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2526: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`,
2527:           `MatSetValuesLocal()`, `MatSetValuesBlocked()`
2528: @*/
2529: PetscErrorCode MatSetValuesBlockedLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2530: {
2531:   PetscFunctionBeginHot;
2534:   MatCheckPreallocated(mat, 1);
2535:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2536:   PetscAssertPointer(irow, 3);
2537:   PetscAssertPointer(icol, 5);
2538:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2539:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2540:   if (PetscDefined(USE_DEBUG)) {
2541:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2542:     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);
2543:   }

2545:   if (mat->assembled) {
2546:     mat->was_assembled = PETSC_TRUE;
2547:     mat->assembled     = PETSC_FALSE;
2548:   }
2549:   if (PetscUnlikelyDebug(mat->rmap->mapping)) { /* Condition on the mapping existing, because MatSetValuesBlockedLocal_IS does not require it to be set. */
2550:     PetscInt irbs, rbs;
2551:     PetscCall(MatGetBlockSizes(mat, &rbs, NULL));
2552:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->rmap->mapping, &irbs));
2553:     PetscCheck(rbs == irbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different row block sizes! mat %" PetscInt_FMT ", row l2g map %" PetscInt_FMT, rbs, irbs);
2554:   }
2555:   if (PetscUnlikelyDebug(mat->cmap->mapping)) {
2556:     PetscInt icbs, cbs;
2557:     PetscCall(MatGetBlockSizes(mat, NULL, &cbs));
2558:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->cmap->mapping, &icbs));
2559:     PetscCheck(cbs == icbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different col block sizes! mat %" PetscInt_FMT ", col l2g map %" PetscInt_FMT, cbs, icbs);
2560:   }
2561:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2562:   if (mat->ops->setvaluesblockedlocal) PetscUseTypeMethod(mat, setvaluesblockedlocal, nrow, irow, ncol, icol, y, addv);
2563:   else {
2564:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2565:     const PetscInt *irowm, *icolm;

2567:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= ((PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf))) {
2568:       bufr  = buf;
2569:       bufc  = buf + nrow;
2570:       irowm = bufr;
2571:       icolm = bufc;
2572:     } else {
2573:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2574:       irowm = bufr;
2575:       icolm = bufc;
2576:     }
2577:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->rmap->mapping, nrow, irow, bufr));
2578:     else irowm = irow;
2579:     if (mat->cmap->mapping) {
2580:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->cmap->mapping, ncol, icol, bufc));
2581:       else icolm = irowm;
2582:     } else icolm = icol;
2583:     PetscCall(MatSetValuesBlocked(mat, nrow, irowm, ncol, icolm, y, addv));
2584:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2585:   }
2586:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2587:   PetscFunctionReturn(PETSC_SUCCESS);
2588: }

2590: /*@
2591:   MatMultDiagonalBlock - Computes the matrix-vector product, $y = Dx$. Where `D` is defined by the inode or block structure of the diagonal

2593:   Collective

2595:   Input Parameters:
2596: + mat - the matrix
2597: - x   - the vector to be multiplied

2599:   Output Parameter:
2600: . y - the result

2602:   Level: developer

2604:   Note:
2605:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2606:   call `MatMultDiagonalBlock`(A,y,y).

2608: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2609: @*/
2610: PetscErrorCode MatMultDiagonalBlock(Mat mat, Vec x, Vec y)
2611: {
2612:   PetscFunctionBegin;

2618:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2619:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2620:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2621:   MatCheckPreallocated(mat, 1);

2623:   PetscUseTypeMethod(mat, multdiagonalblock, x, y);
2624:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2625:   PetscFunctionReturn(PETSC_SUCCESS);
2626: }

2628: /*@
2629:   MatMult - Computes the matrix-vector product, $y = Ax$.

2631:   Neighbor-wise Collective

2633:   Input Parameters:
2634: + mat - the matrix
2635: - x   - the vector to be multiplied

2637:   Output Parameter:
2638: . y - the result

2640:   Level: beginner

2642:   Note:
2643:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2644:   call `MatMult`(A,y,y).

2646: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2647: @*/
2648: PetscErrorCode MatMult(Mat mat, Vec x, Vec y)
2649: {
2650:   PetscFunctionBegin;
2654:   VecCheckAssembled(x);
2656:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2657:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2658:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2659:   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);
2660:   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);
2661:   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);
2662:   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);
2663:   PetscCall(VecSetErrorIfLocked(y, 3));
2664:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2665:   MatCheckPreallocated(mat, 1);

2667:   PetscCall(VecLockReadPush(x));
2668:   PetscCall(PetscLogEventBegin(MAT_Mult, mat, x, y, 0));
2669:   PetscUseTypeMethod(mat, mult, x, y);
2670:   PetscCall(PetscLogEventEnd(MAT_Mult, mat, x, y, 0));
2671:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2672:   PetscCall(VecLockReadPop(x));
2673:   PetscFunctionReturn(PETSC_SUCCESS);
2674: }

2676: /*@
2677:   MatMultTranspose - Computes matrix transpose times a vector $y = A^T * x$.

2679:   Neighbor-wise Collective

2681:   Input Parameters:
2682: + mat - the matrix
2683: - x   - the vector to be multiplied

2685:   Output Parameter:
2686: . y - the result

2688:   Level: beginner

2690:   Notes:
2691:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2692:   call `MatMultTranspose`(A,y,y).

2694:   For complex numbers this does NOT compute the Hermitian (complex conjugate) transpose multiple,
2695:   use `MatMultHermitianTranspose()`

2697: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatMultHermitianTranspose()`, `MatTranspose()`
2698: @*/
2699: PetscErrorCode MatMultTranspose(Mat mat, Vec x, Vec y)
2700: {
2701:   PetscErrorCode (*op)(Mat, Vec, Vec) = NULL;

2703:   PetscFunctionBegin;
2707:   VecCheckAssembled(x);

2710:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2711:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2712:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2713:   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);
2714:   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);
2715:   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);
2716:   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);
2717:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2718:   MatCheckPreallocated(mat, 1);

2720:   if (!mat->ops->multtranspose) {
2721:     if (mat->symmetric == PETSC_BOOL3_TRUE && mat->ops->mult) op = mat->ops->mult;
2722:     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);
2723:   } else op = mat->ops->multtranspose;
2724:   PetscCall(PetscLogEventBegin(MAT_MultTranspose, mat, x, y, 0));
2725:   PetscCall(VecLockReadPush(x));
2726:   PetscCall((*op)(mat, x, y));
2727:   PetscCall(VecLockReadPop(x));
2728:   PetscCall(PetscLogEventEnd(MAT_MultTranspose, mat, x, y, 0));
2729:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2730:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2731:   PetscFunctionReturn(PETSC_SUCCESS);
2732: }

2734: /*@
2735:   MatMultHermitianTranspose - Computes matrix Hermitian-transpose times a vector $y = A^H * x$.

2737:   Neighbor-wise Collective

2739:   Input Parameters:
2740: + mat - the matrix
2741: - x   - the vector to be multiplied

2743:   Output Parameter:
2744: . y - the result

2746:   Level: beginner

2748:   Notes:
2749:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2750:   call `MatMultHermitianTranspose`(A,y,y).

2752:   Also called the conjugate transpose, complex conjugate transpose, or adjoint.

2754:   For real numbers `MatMultTranspose()` and `MatMultHermitianTranspose()` are identical.

2756: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultHermitianTransposeAdd()`, `MatMultTranspose()`
2757: @*/
2758: PetscErrorCode MatMultHermitianTranspose(Mat mat, Vec x, Vec y)
2759: {
2760:   PetscFunctionBegin;

2766:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2767:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2768:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2769:   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);
2770:   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);
2771:   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);
2772:   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);
2773:   MatCheckPreallocated(mat, 1);

2775:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTranspose, mat, x, y, 0));
2776: #if defined(PETSC_USE_COMPLEX)
2777:   if (mat->ops->multhermitiantranspose || (mat->hermitian == PETSC_BOOL3_TRUE && mat->ops->mult)) {
2778:     PetscCall(VecLockReadPush(x));
2779:     if (mat->ops->multhermitiantranspose) PetscUseTypeMethod(mat, multhermitiantranspose, x, y);
2780:     else PetscUseTypeMethod(mat, mult, x, y);
2781:     PetscCall(VecLockReadPop(x));
2782:   } else {
2783:     Vec w;
2784:     PetscCall(VecDuplicate(x, &w));
2785:     PetscCall(VecCopy(x, w));
2786:     PetscCall(VecConjugate(w));
2787:     PetscCall(MatMultTranspose(mat, w, y));
2788:     PetscCall(VecDestroy(&w));
2789:     PetscCall(VecConjugate(y));
2790:   }
2791:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2792: #else
2793:   PetscCall(MatMultTranspose(mat, x, y));
2794: #endif
2795:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTranspose, mat, x, y, 0));
2796:   PetscFunctionReturn(PETSC_SUCCESS);
2797: }

2799: /*@
2800:   MatMultAdd -  Computes $v3 = v2 + A * v1$.

2802:   Neighbor-wise Collective

2804:   Input Parameters:
2805: + mat - the matrix
2806: . v1  - the vector to be multiplied by `mat`
2807: - v2  - the vector to be added to the result

2809:   Output Parameter:
2810: . v3 - the result

2812:   Level: beginner

2814:   Note:
2815:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2816:   call `MatMultAdd`(A,v1,v2,v1).

2818: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMult()`, `MatMultTransposeAdd()`
2819: @*/
2820: PetscErrorCode MatMultAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2821: {
2822:   PetscFunctionBegin;

2829:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2830:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2831:   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);
2832:   /* 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);
2833:      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); */
2834:   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);
2835:   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);
2836:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2837:   MatCheckPreallocated(mat, 1);

2839:   PetscCall(PetscLogEventBegin(MAT_MultAdd, mat, v1, v2, v3));
2840:   PetscCall(VecLockReadPush(v1));
2841:   PetscUseTypeMethod(mat, multadd, v1, v2, v3);
2842:   PetscCall(VecLockReadPop(v1));
2843:   PetscCall(PetscLogEventEnd(MAT_MultAdd, mat, v1, v2, v3));
2844:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2845:   PetscFunctionReturn(PETSC_SUCCESS);
2846: }

2848: /*@
2849:   MatMultTransposeAdd - Computes $v3 = v2 + A^T * v1$.

2851:   Neighbor-wise Collective

2853:   Input Parameters:
2854: + mat - the matrix
2855: . v1  - the vector to be multiplied by the transpose of the matrix
2856: - v2  - the vector to be added to the result

2858:   Output Parameter:
2859: . v3 - the result

2861:   Level: beginner

2863:   Note:
2864:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2865:   call `MatMultTransposeAdd`(A,v1,v2,v1).

2867: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2868: @*/
2869: PetscErrorCode MatMultTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2870: {
2871:   PetscErrorCode (*op)(Mat, Vec, Vec, Vec) = (!mat->ops->multtransposeadd && mat->symmetric) ? mat->ops->multadd : mat->ops->multtransposeadd;

2873:   PetscFunctionBegin;

2880:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2881:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2882:   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);
2883:   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);
2884:   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);
2885:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2886:   PetscCheck(op, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2887:   MatCheckPreallocated(mat, 1);

2889:   PetscCall(PetscLogEventBegin(MAT_MultTransposeAdd, mat, v1, v2, v3));
2890:   PetscCall(VecLockReadPush(v1));
2891:   PetscCall((*op)(mat, v1, v2, v3));
2892:   PetscCall(VecLockReadPop(v1));
2893:   PetscCall(PetscLogEventEnd(MAT_MultTransposeAdd, mat, v1, v2, v3));
2894:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2895:   PetscFunctionReturn(PETSC_SUCCESS);
2896: }

2898: /*@
2899:   MatMultHermitianTransposeAdd - Computes $v3 = v2 + A^H * v1$.

2901:   Neighbor-wise Collective

2903:   Input Parameters:
2904: + mat - the matrix
2905: . v1  - the vector to be multiplied by the Hermitian transpose
2906: - v2  - the vector to be added to the result

2908:   Output Parameter:
2909: . v3 - the result

2911:   Level: beginner

2913:   Note:
2914:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2915:   call `MatMultHermitianTransposeAdd`(A,v1,v2,v1).

2917: .seealso: [](ch_matrices), `Mat`, `MatMultHermitianTranspose()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2918: @*/
2919: PetscErrorCode MatMultHermitianTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2920: {
2921:   PetscFunctionBegin;

2928:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2929:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2930:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2931:   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);
2932:   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);
2933:   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);
2934:   MatCheckPreallocated(mat, 1);

2936:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2937:   PetscCall(VecLockReadPush(v1));
2938:   if (mat->ops->multhermitiantransposeadd) PetscUseTypeMethod(mat, multhermitiantransposeadd, v1, v2, v3);
2939:   else {
2940:     Vec w, z;
2941:     PetscCall(VecDuplicate(v1, &w));
2942:     PetscCall(VecCopy(v1, w));
2943:     PetscCall(VecConjugate(w));
2944:     PetscCall(VecDuplicate(v3, &z));
2945:     PetscCall(MatMultTranspose(mat, w, z));
2946:     PetscCall(VecDestroy(&w));
2947:     PetscCall(VecConjugate(z));
2948:     if (v2 != v3) PetscCall(VecWAXPY(v3, 1.0, v2, z));
2949:     else PetscCall(VecAXPY(v3, 1.0, z));
2950:     PetscCall(VecDestroy(&z));
2951:   }
2952:   PetscCall(VecLockReadPop(v1));
2953:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2954:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2955:   PetscFunctionReturn(PETSC_SUCCESS);
2956: }

2958: PetscErrorCode MatADot_Default(Mat mat, Vec x, Vec y, PetscScalar *val)
2959: {
2960:   PetscFunctionBegin;
2961:   if (!mat->dot_vec) PetscCall(MatCreateVecs(mat, &mat->dot_vec, NULL));
2962:   PetscCall(MatMult(mat, x, mat->dot_vec));
2963:   PetscCall(VecDot(mat->dot_vec, y, val));
2964:   PetscFunctionReturn(PETSC_SUCCESS);
2965: }

2967: PetscErrorCode MatANorm_Default(Mat mat, Vec x, PetscReal *val)
2968: {
2969:   PetscScalar sval;

2971:   PetscFunctionBegin;
2972:   PetscCall(MatADot_Default(mat, x, x, &sval));
2973:   PetscCheck(PetscRealPart(sval) >= 0.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix argument is not positive definite");
2974:   PetscCheck(PetscAbsReal(PetscImaginaryPart(sval)) < 100 * PETSC_MACHINE_EPSILON, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix argument is not Hermitian");
2975:   *val = PetscSqrtReal(PetscRealPart(sval));
2976:   PetscFunctionReturn(PETSC_SUCCESS);
2977: }

2979: /*@
2980:   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)
2981:   positive definite.

2983:   Collective

2985:   Input Parameters:
2986: + mat - matrix used to define the inner product
2987: . x   - first vector
2988: - y   - second vector

2990:   Output Parameter:
2991: . val - the dot product with respect to `A`

2993:   Level: intermediate

2995:   Note:
2996:   For complex vectors, `MatADot()` computes
2997: $$
2998:   val = (x,y)_A = y^H A x,
2999: $$
3000:   where $y^H$ denotes the conjugate transpose of `y`. Note that this corresponds to the "mathematicians" complex
3001:   inner product where the SECOND argument gets the complex conjugate.

3003: .seealso: [](ch_matrices), `Mat`, `MatANorm()`, `VecDot()`, `VecNorm()`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`
3004: @*/
3005: PetscErrorCode MatADot(Mat mat, Vec x, Vec y, PetscScalar *val)
3006: {
3007:   PetscFunctionBegin;
3011:   VecCheckAssembled(x);
3013:   VecCheckAssembled(y);
3016:   PetscAssertPointer(val, 4);
3017:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3018:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3019:   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);
3020:   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);
3021:   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);
3022:   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);
3023:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
3024:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_TRUE));
3025:   MatCheckPreallocated(mat, 1);

3027:   PetscCall(VecLockReadPush(x));
3028:   PetscCall(VecLockReadPush(y));
3029:   PetscCall(PetscLogEventBegin(MAT_ADot, mat, x, y, 0));
3030:   PetscUseTypeMethod(mat, adot, x, y, val);
3031:   PetscCall(PetscLogEventEnd(MAT_ADot, mat, x, y, 0));
3032:   PetscCall(VecLockReadPop(y));
3033:   PetscCall(VecLockReadPop(x));
3034:   PetscFunctionReturn(PETSC_SUCCESS);
3035: }

3037: /*@
3038:   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)
3039:   positive definite.

3041:   Collective

3043:   Input Parameters:
3044: + mat - matrix used to define norm
3045: - x   - the vector to compute the norm of

3047:   Output Parameter:
3048: . val - the norm with respect to `A`

3050:   Level: intermediate

3052:   Note:
3053:   For complex vectors, `MatANorm()` computes
3054: $$
3055:   val = (x,x)_A^{1/2} = (x^H A x)^{1/2},
3056: $$
3057:   where $x^H$ denotes the conjugate transpose of `x`.

3059: .seealso: [](ch_matrices), `Mat`, `MatADot()`, `VecDot()`, `VecNorm()`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`
3060: @*/
3061: PetscErrorCode MatANorm(Mat mat, Vec x, PetscReal *val)
3062: {
3063:   PetscFunctionBegin;
3067:   VecCheckAssembled(x);
3069:   PetscAssertPointer(val, 3);
3070:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3071:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3072:   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);
3073:   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);
3074:   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);
3075:   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);
3076:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
3077:   MatCheckPreallocated(mat, 1);

3079:   PetscCall(VecLockReadPush(x));
3080:   PetscCall(PetscLogEventBegin(MAT_ANorm, mat, x, 0, 0));
3081:   PetscUseTypeMethod(mat, anorm, x, val);
3082:   PetscCall(PetscLogEventEnd(MAT_ANorm, mat, x, 0, 0));
3083:   PetscCall(VecLockReadPop(x));
3084:   PetscFunctionReturn(PETSC_SUCCESS);
3085: }

3087: /*@
3088:   MatGetFactorType - gets the type of factorization a matrix is

3090:   Not Collective

3092:   Input Parameter:
3093: . mat - the matrix

3095:   Output Parameter:
3096: . 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`

3098:   Level: intermediate

3100: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatSetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3101:           `MAT_FACTOR_ICC`, `MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3102: @*/
3103: PetscErrorCode MatGetFactorType(Mat mat, MatFactorType *t)
3104: {
3105:   PetscFunctionBegin;
3108:   PetscAssertPointer(t, 2);
3109:   *t = mat->factortype;
3110:   PetscFunctionReturn(PETSC_SUCCESS);
3111: }

3113: /*@
3114:   MatSetFactorType - sets the type of factorization a matrix is

3116:   Logically Collective

3118:   Input Parameters:
3119: + mat - the matrix
3120: - 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`

3122:   Level: intermediate

3124: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatGetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3125:           `MAT_FACTOR_ICC`, `MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3126: @*/
3127: PetscErrorCode MatSetFactorType(Mat mat, MatFactorType t)
3128: {
3129:   PetscFunctionBegin;
3132:   mat->factortype = t;
3133:   PetscFunctionReturn(PETSC_SUCCESS);
3134: }

3136: /*@
3137:   MatGetInfo - Returns information about matrix storage (number of
3138:   nonzeros, memory, etc.).

3140:   Collective if `MAT_GLOBAL_MAX` or `MAT_GLOBAL_SUM` is used as the flag

3142:   Input Parameters:
3143: + mat  - the matrix
3144: - 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)

3146:   Output Parameter:
3147: . info - matrix information context

3149:   Options Database Key:
3150: . -mat_view ::ascii_info - print matrix info to `PETSC_STDOUT`

3152:   Level: intermediate

3154:   Notes:
3155:   The `MatInfo` context contains a variety of matrix data, including
3156:   number of nonzeros allocated and used, number of mallocs during
3157:   matrix assembly, etc.  Additional information for factored matrices
3158:   is provided (such as the fill ratio, number of mallocs during
3159:   factorization, etc.).

3161:   Example:
3162:   See the file ${PETSC_DIR}/include/petscmat.h for a complete list of
3163:   data within the `MatInfo` context.  For example,
3164: .vb
3165:       MatInfo info;
3166:       Mat     A;
3167:       double  mal, nz_a, nz_u;

3169:       MatGetInfo(A, MAT_LOCAL, &info);
3170:       mal  = info.mallocs;
3171:       nz_a = info.nz_allocated;
3172: .ve

3174: .seealso: [](ch_matrices), `Mat`, `MatInfo`, `MatStashGetInfo()`
3175: @*/
3176: PetscErrorCode MatGetInfo(Mat mat, MatInfoType flag, MatInfo *info)
3177: {
3178:   PetscFunctionBegin;
3181:   PetscAssertPointer(info, 3);
3182:   MatCheckPreallocated(mat, 1);
3183:   PetscUseTypeMethod(mat, getinfo, flag, info);
3184:   PetscFunctionReturn(PETSC_SUCCESS);
3185: }

3187: /*
3188:    This is used by external packages where it is not easy to get the info from the actual
3189:    matrix factorization.
3190: */
3191: PetscErrorCode MatGetInfo_External(Mat A, MatInfoType flag, MatInfo *info)
3192: {
3193:   PetscFunctionBegin;
3194:   PetscCall(PetscMemzero(info, sizeof(MatInfo)));
3195:   PetscFunctionReturn(PETSC_SUCCESS);
3196: }

3198: /*@
3199:   MatLUFactor - Performs in-place LU factorization of matrix.

3201:   Collective

3203:   Input Parameters:
3204: + mat  - the matrix
3205: . row  - row permutation
3206: . col  - column permutation
3207: - info - options for factorization, includes
3208: .vb
3209:           fill - expected fill as ratio of original fill.
3210:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3211:                    Run with the option -info to determine an optimal value to use
3212: .ve

3214:   Level: developer

3216:   Notes:
3217:   Most users should employ the `KSP` interface for linear solvers
3218:   instead of working directly with matrix algebra routines such as this.
3219:   See, e.g., `KSPCreate()`.

3221:   This changes the state of the matrix to a factored matrix; it cannot be used
3222:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3224:   This is really in-place only for dense matrices, the preferred approach is to use `MatGetFactor()`, `MatLUFactorSymbolic()`, and `MatLUFactorNumeric()`
3225:   when not using `KSP`.

3227:   Fortran Note:
3228:   A valid (non-null) `info` argument must be provided

3230: .seealso: [](ch_matrices), [Matrix Factorization](sec_matfactor), `Mat`, `MatFactorType`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
3231:           `MatGetOrdering()`, `MatSetUnfactored()`, `MatFactorInfo`, `MatGetFactor()`
3232: @*/
3233: PetscErrorCode MatLUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3234: {
3235:   MatFactorInfo tinfo;

3237:   PetscFunctionBegin;
3241:   if (info) PetscAssertPointer(info, 4);
3243:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3244:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3245:   MatCheckPreallocated(mat, 1);
3246:   if (!info) {
3247:     PetscCall(MatFactorInfoInitialize(&tinfo));
3248:     info = &tinfo;
3249:   }

3251:   PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, row, col, 0));
3252:   PetscUseTypeMethod(mat, lufactor, row, col, info);
3253:   PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, row, col, 0));
3254:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3255:   PetscFunctionReturn(PETSC_SUCCESS);
3256: }

3258: /*@
3259:   MatILUFactor - Performs in-place ILU factorization of matrix.

3261:   Collective

3263:   Input Parameters:
3264: + mat  - the matrix
3265: . row  - row permutation
3266: . col  - column permutation
3267: - info - structure containing
3268: .vb
3269:       levels - number of levels of fill.
3270:       expected fill - as ratio of original fill.
3271:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
3272:                 missing diagonal entries)
3273: .ve

3275:   Level: developer

3277:   Notes:
3278:   Most users should employ the `KSP` interface for linear solvers
3279:   instead of working directly with matrix algebra routines such as this.
3280:   See, e.g., `KSPCreate()`.

3282:   Probably really in-place only when level of fill is zero, otherwise allocates
3283:   new space to store factored matrix and deletes previous memory. The preferred approach is to use `MatGetFactor()`, `MatILUFactorSymbolic()`, and `MatILUFactorNumeric()`
3284:   when not using `KSP`.

3286:   Fortran Note:
3287:   A valid (non-null) `info` argument must be provided

3289: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatILUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
3290: @*/
3291: PetscErrorCode MatILUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3292: {
3293:   PetscFunctionBegin;
3297:   PetscAssertPointer(info, 4);
3299:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
3300:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3301:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3302:   MatCheckPreallocated(mat, 1);

3304:   PetscCall(PetscLogEventBegin(MAT_ILUFactor, mat, row, col, 0));
3305:   PetscUseTypeMethod(mat, ilufactor, row, col, info);
3306:   PetscCall(PetscLogEventEnd(MAT_ILUFactor, mat, row, col, 0));
3307:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3308:   PetscFunctionReturn(PETSC_SUCCESS);
3309: }

3311: /*@
3312:   MatLUFactorSymbolic - Performs symbolic LU factorization of matrix.
3313:   Call this routine before calling `MatLUFactorNumeric()` and after `MatGetFactor()`.

3315:   Collective

3317:   Input Parameters:
3318: + fact - the factor matrix obtained with `MatGetFactor()`
3319: . mat  - the matrix
3320: . row  - the row permutation
3321: . col  - the column permutation
3322: - info - options for factorization, includes
3323: .vb
3324:           fill - expected fill as ratio of original fill. Run with the option -info to determine an optimal value to use
3325:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3326: .ve

3328:   Level: developer

3330:   Notes:
3331:   See [Matrix Factorization](sec_matfactor) for additional information about factorizations

3333:   Most users should employ the simplified `KSP` interface for linear solvers
3334:   instead of working directly with matrix algebra routines such as this.
3335:   See, e.g., `KSPCreate()`.

3337:   Fortran Note:
3338:   A valid (non-null) `info` argument must be provided

3340: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`, `MatFactorInfoInitialize()`
3341: @*/
3342: PetscErrorCode MatLUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
3343: {
3344:   MatFactorInfo tinfo;

3346:   PetscFunctionBegin;
3351:   if (info) PetscAssertPointer(info, 5);
3354:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3355:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3356:   MatCheckPreallocated(mat, 2);
3357:   if (!info) {
3358:     PetscCall(MatFactorInfoInitialize(&tinfo));
3359:     info = &tinfo;
3360:   }

3362:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorSymbolic, mat, row, col, 0));
3363:   PetscUseTypeMethod(fact, lufactorsymbolic, mat, row, col, info);
3364:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorSymbolic, mat, row, col, 0));
3365:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3366:   PetscFunctionReturn(PETSC_SUCCESS);
3367: }

3369: /*@
3370:   MatLUFactorNumeric - Performs numeric LU factorization of a matrix.
3371:   Call this routine after first calling `MatLUFactorSymbolic()` and `MatGetFactor()`.

3373:   Collective

3375:   Input Parameters:
3376: + fact - the factor matrix obtained with `MatGetFactor()`
3377: . mat  - the matrix
3378: - info - options for factorization

3380:   Level: developer

3382:   Notes:
3383:   See `MatLUFactor()` for in-place factorization.  See
3384:   `MatCholeskyFactorNumeric()` for the symmetric, positive definite case.

3386:   Most users should employ the `KSP` interface for linear solvers
3387:   instead of working directly with matrix algebra routines such as this.
3388:   See, e.g., `KSPCreate()`.

3390:   Fortran Note:
3391:   A valid (non-null) `info` argument must be provided

3393: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactorSymbolic()`, `MatLUFactor()`, `MatCholeskyFactor()`
3394: @*/
3395: PetscErrorCode MatLUFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3396: {
3397:   MatFactorInfo tinfo;

3399:   PetscFunctionBegin;
3404:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3405:   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,
3406:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3408:   MatCheckPreallocated(mat, 2);
3409:   if (!info) {
3410:     PetscCall(MatFactorInfoInitialize(&tinfo));
3411:     info = &tinfo;
3412:   }

3414:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorNumeric, mat, fact, 0, 0));
3415:   else PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, fact, 0, 0));
3416:   PetscUseTypeMethod(fact, lufactornumeric, mat, info);
3417:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorNumeric, mat, fact, 0, 0));
3418:   else PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, fact, 0, 0));
3419:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3420:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3421:   PetscFunctionReturn(PETSC_SUCCESS);
3422: }

3424: /*@
3425:   MatCholeskyFactor - Performs in-place Cholesky factorization of a
3426:   symmetric matrix.

3428:   Collective

3430:   Input Parameters:
3431: + mat  - the matrix
3432: . perm - row and column permutations
3433: - info - expected fill as ratio of original fill

3435:   Level: developer

3437:   Notes:
3438:   See `MatLUFactor()` for the nonsymmetric case.  See also `MatGetFactor()`,
3439:   `MatCholeskyFactorSymbolic()`, and `MatCholeskyFactorNumeric()`.

3441:   Most users should employ the `KSP` interface for linear solvers
3442:   instead of working directly with matrix algebra routines such as this.
3443:   See, e.g., `KSPCreate()`.

3445:   Fortran Note:
3446:   A valid (non-null) `info` argument must be provided

3448: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactorNumeric()`,
3449:           `MatGetOrdering()`
3450: @*/
3451: PetscErrorCode MatCholeskyFactor(Mat mat, IS perm, const MatFactorInfo *info)
3452: {
3453:   MatFactorInfo tinfo;

3455:   PetscFunctionBegin;
3458:   if (info) PetscAssertPointer(info, 3);
3460:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3461:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3462:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3463:   MatCheckPreallocated(mat, 1);
3464:   if (!info) {
3465:     PetscCall(MatFactorInfoInitialize(&tinfo));
3466:     info = &tinfo;
3467:   }

3469:   PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, perm, 0, 0));
3470:   PetscUseTypeMethod(mat, choleskyfactor, perm, info);
3471:   PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, perm, 0, 0));
3472:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3473:   PetscFunctionReturn(PETSC_SUCCESS);
3474: }

3476: /*@
3477:   MatCholeskyFactorSymbolic - Performs symbolic Cholesky factorization
3478:   of a symmetric matrix.

3480:   Collective

3482:   Input Parameters:
3483: + fact - the factor matrix obtained with `MatGetFactor()`
3484: . mat  - the matrix
3485: . perm - row and column permutations
3486: - info - options for factorization, includes
3487: .vb
3488:           fill - expected fill as ratio of original fill.
3489:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3490:                    Run with the option -info to determine an optimal value to use
3491: .ve

3493:   Level: developer

3495:   Notes:
3496:   See `MatLUFactorSymbolic()` for the nonsymmetric case.  See also
3497:   `MatCholeskyFactor()` and `MatCholeskyFactorNumeric()`.

3499:   Most users should employ the `KSP` interface for linear solvers
3500:   instead of working directly with matrix algebra routines such as this.
3501:   See, e.g., `KSPCreate()`.

3503:   Fortran Note:
3504:   A valid (non-null) `info` argument must be provided

3506: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactor()`, `MatCholeskyFactorNumeric()`,
3507:           `MatGetOrdering()`
3508: @*/
3509: PetscErrorCode MatCholeskyFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
3510: {
3511:   MatFactorInfo tinfo;

3513:   PetscFunctionBegin;
3517:   if (info) PetscAssertPointer(info, 4);
3520:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3521:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3522:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3523:   MatCheckPreallocated(mat, 2);
3524:   if (!info) {
3525:     PetscCall(MatFactorInfoInitialize(&tinfo));
3526:     info = &tinfo;
3527:   }

3529:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3530:   PetscUseTypeMethod(fact, choleskyfactorsymbolic, mat, perm, info);
3531:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3532:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3533:   PetscFunctionReturn(PETSC_SUCCESS);
3534: }

3536: /*@
3537:   MatCholeskyFactorNumeric - Performs numeric Cholesky factorization
3538:   of a symmetric matrix. Call this routine after first calling `MatGetFactor()` and
3539:   `MatCholeskyFactorSymbolic()`.

3541:   Collective

3543:   Input Parameters:
3544: + fact - the factor matrix obtained with `MatGetFactor()`, where the factored values are stored
3545: . mat  - the initial matrix that is to be factored
3546: - info - options for factorization

3548:   Level: developer

3550:   Note:
3551:   Most users should employ the `KSP` interface for linear solvers
3552:   instead of working directly with matrix algebra routines such as this.
3553:   See, e.g., `KSPCreate()`.

3555:   Fortran Note:
3556:   A valid (non-null) `info` argument must be provided

3558: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactor()`, `MatLUFactorNumeric()`
3559: @*/
3560: PetscErrorCode MatCholeskyFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3561: {
3562:   MatFactorInfo tinfo;

3564:   PetscFunctionBegin;
3569:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3570:   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,
3571:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);
3572:   MatCheckPreallocated(mat, 2);
3573:   if (!info) {
3574:     PetscCall(MatFactorInfoInitialize(&tinfo));
3575:     info = &tinfo;
3576:   }

3578:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3579:   else PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, fact, 0, 0));
3580:   PetscUseTypeMethod(fact, choleskyfactornumeric, mat, info);
3581:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3582:   else PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, fact, 0, 0));
3583:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3584:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3585:   PetscFunctionReturn(PETSC_SUCCESS);
3586: }

3588: /*@
3589:   MatQRFactor - Performs in-place QR factorization of matrix.

3591:   Collective

3593:   Input Parameters:
3594: + mat  - the matrix
3595: . col  - column permutation
3596: - info - options for factorization, includes
3597: .vb
3598:           fill - expected fill as ratio of original fill.
3599:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3600:                    Run with the option -info to determine an optimal value to use
3601: .ve

3603:   Level: developer

3605:   Notes:
3606:   Most users should employ the `KSP` interface for linear solvers
3607:   instead of working directly with matrix algebra routines such as this.
3608:   See, e.g., `KSPCreate()`.

3610:   This changes the state of the matrix to a factored matrix; it cannot be used
3611:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3613:   Fortran Note:
3614:   A valid (non-null) `info` argument must be provided

3616: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactorSymbolic()`, `MatQRFactorNumeric()`, `MatLUFactor()`,
3617:           `MatSetUnfactored()`
3618: @*/
3619: PetscErrorCode MatQRFactor(Mat mat, IS col, const MatFactorInfo *info)
3620: {
3621:   PetscFunctionBegin;
3624:   if (info) PetscAssertPointer(info, 3);
3626:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3627:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3628:   MatCheckPreallocated(mat, 1);
3629:   PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, col, 0, 0));
3630:   PetscUseMethod(mat, "MatQRFactor_C", (Mat, IS, const MatFactorInfo *), (mat, col, info));
3631:   PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, col, 0, 0));
3632:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3633:   PetscFunctionReturn(PETSC_SUCCESS);
3634: }

3636: /*@
3637:   MatQRFactorSymbolic - Performs symbolic QR factorization of matrix.
3638:   Call this routine after `MatGetFactor()` but before calling `MatQRFactorNumeric()`.

3640:   Collective

3642:   Input Parameters:
3643: + fact - the factor matrix obtained with `MatGetFactor()`
3644: . mat  - the matrix
3645: . col  - column permutation
3646: - info - options for factorization, includes
3647: .vb
3648:           fill - expected fill as ratio of original fill.
3649:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3650:                    Run with the option -info to determine an optimal value to use
3651: .ve

3653:   Level: developer

3655:   Note:
3656:   Most users should employ the `KSP` interface for linear solvers
3657:   instead of working directly with matrix algebra routines such as this.
3658:   See, e.g., `KSPCreate()`.

3660:   Fortran Note:
3661:   A valid (non-null) `info` argument must be provided

3663: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatQRFactor()`, `MatQRFactorNumeric()`, `MatLUFactor()`, `MatFactorInfoInitialize()`
3664: @*/
3665: PetscErrorCode MatQRFactorSymbolic(Mat fact, Mat mat, IS col, const MatFactorInfo *info)
3666: {
3667:   MatFactorInfo tinfo;

3669:   PetscFunctionBegin;
3673:   if (info) PetscAssertPointer(info, 4);
3676:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3677:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3678:   MatCheckPreallocated(mat, 2);
3679:   if (!info) {
3680:     PetscCall(MatFactorInfoInitialize(&tinfo));
3681:     info = &tinfo;
3682:   }

3684:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorSymbolic, fact, mat, col, 0));
3685:   PetscUseMethod(fact, "MatQRFactorSymbolic_C", (Mat, Mat, IS, const MatFactorInfo *), (fact, mat, col, info));
3686:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorSymbolic, fact, mat, col, 0));
3687:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3688:   PetscFunctionReturn(PETSC_SUCCESS);
3689: }

3691: /*@
3692:   MatQRFactorNumeric - Performs numeric QR factorization of a matrix.
3693:   Call this routine after first calling `MatGetFactor()`, and `MatQRFactorSymbolic()`.

3695:   Collective

3697:   Input Parameters:
3698: + fact - the factor matrix obtained with `MatGetFactor()`
3699: . mat  - the matrix
3700: - info - options for factorization

3702:   Level: developer

3704:   Notes:
3705:   See `MatQRFactor()` for in-place factorization.

3707:   Most users should employ the `KSP` interface for linear solvers
3708:   instead of working directly with matrix algebra routines such as this.
3709:   See, e.g., `KSPCreate()`.

3711:   Fortran Note:
3712:   A valid (non-null) `info` argument must be provided

3714: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactor()`, `MatQRFactorSymbolic()`, `MatLUFactor()`
3715: @*/
3716: PetscErrorCode MatQRFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3717: {
3718:   MatFactorInfo tinfo;

3720:   PetscFunctionBegin;
3725:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3726:   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,
3727:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3729:   MatCheckPreallocated(mat, 2);
3730:   if (!info) {
3731:     PetscCall(MatFactorInfoInitialize(&tinfo));
3732:     info = &tinfo;
3733:   }

3735:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorNumeric, mat, fact, 0, 0));
3736:   else PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, fact, 0, 0));
3737:   PetscUseMethod(fact, "MatQRFactorNumeric_C", (Mat, Mat, const MatFactorInfo *), (fact, mat, info));
3738:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorNumeric, mat, fact, 0, 0));
3739:   else PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, fact, 0, 0));
3740:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3741:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3742:   PetscFunctionReturn(PETSC_SUCCESS);
3743: }

3745: /*@
3746:   MatSolve - Solves $A x = b$, given a factored matrix.

3748:   Neighbor-wise Collective

3750:   Input Parameters:
3751: + mat - the factored matrix
3752: - b   - the right-hand-side vector

3754:   Output Parameter:
3755: . x - the result vector

3757:   Level: developer

3759:   Notes:
3760:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3761:   call `MatSolve`(A,x,x).

3763:   Most users should employ the `KSP` interface for linear solvers
3764:   instead of working directly with matrix algebra routines such as this.
3765:   See, e.g., `KSPCreate()`.

3767: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
3768: @*/
3769: PetscErrorCode MatSolve(Mat mat, Vec b, Vec x)
3770: {
3771:   PetscFunctionBegin;
3776:   PetscCheckSameComm(mat, 1, b, 2);
3777:   PetscCheckSameComm(mat, 1, x, 3);
3778:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3779:   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);
3780:   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);
3781:   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);
3782:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3783:   MatCheckPreallocated(mat, 1);

3785:   PetscCall(PetscLogEventBegin(MAT_Solve, mat, b, x, 0));
3786:   PetscCall(VecFlag(x, mat->factorerrortype));
3787:   if (mat->factorerrortype) PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
3788:   else PetscUseTypeMethod(mat, solve, b, x);
3789:   PetscCall(PetscLogEventEnd(MAT_Solve, mat, b, x, 0));
3790:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3791:   PetscFunctionReturn(PETSC_SUCCESS);
3792: }

3794: static PetscErrorCode MatMatSolve_Basic(Mat A, Mat B, Mat X, PetscBool trans)
3795: {
3796:   Vec      b, x;
3797:   PetscInt N;
3798:   PetscErrorCode (*f)(Mat, Vec, Vec);
3799:   PetscBool Abound, Bneedconv = PETSC_FALSE, Xneedconv = PETSC_FALSE;

3801:   PetscFunctionBegin;
3802:   if (A->factorerrortype) {
3803:     PetscCall(PetscInfo(A, "MatFactorError %d\n", A->factorerrortype));
3804:     PetscCall(MatSetInf(X));
3805:     PetscFunctionReturn(PETSC_SUCCESS);
3806:   }
3807:   f = (!trans || (!A->ops->solvetranspose && A->symmetric)) ? A->ops->solve : A->ops->solvetranspose;
3808:   PetscCheck(f, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)A)->type_name);
3809:   PetscCall(MatBoundToCPU(A, &Abound));
3810:   if (!Abound) {
3811:     PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &Bneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3812:     PetscCall(PetscObjectTypeCompareAny((PetscObject)X, &Xneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3813:   }
3814: #if PetscDefined(HAVE_CUDA)
3815:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSECUDA, MAT_INPLACE_MATRIX, &B));
3816:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSECUDA, MAT_INPLACE_MATRIX, &X));
3817: #elif PetscDefined(HAVE_HIP)
3818:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSEHIP, MAT_INPLACE_MATRIX, &B));
3819:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSEHIP, MAT_INPLACE_MATRIX, &X));
3820: #endif
3821:   PetscCall(MatGetSize(B, NULL, &N));
3822:   for (PetscInt i = 0; i < N; i++) {
3823:     PetscCall(MatDenseGetColumnVecRead(B, i, &b));
3824:     PetscCall(MatDenseGetColumnVecWrite(X, i, &x));
3825:     PetscCall((*f)(A, b, x));
3826:     PetscCall(MatDenseRestoreColumnVecWrite(X, i, &x));
3827:     PetscCall(MatDenseRestoreColumnVecRead(B, i, &b));
3828:   }
3829:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSE, MAT_INPLACE_MATRIX, &B));
3830:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSE, MAT_INPLACE_MATRIX, &X));
3831:   PetscFunctionReturn(PETSC_SUCCESS);
3832: }

3834: /*@
3835:   MatMatSolve - Solves $A X = B$, given a factored matrix.

3837:   Neighbor-wise Collective

3839:   Input Parameters:
3840: + A - the factored matrix
3841: - B - the right-hand-side matrix `MATDENSE` (or sparse `MATAIJ`-- when using MUMPS)

3843:   Output Parameter:
3844: . X - the result matrix (dense matrix)

3846:   Level: developer

3848:   Note:
3849:   If `B` is a `MATDENSE` matrix then one can call `MatMatSolve`(A,B,B) except with `MATSOLVERMKL_CPARDISO`;
3850:   otherwise, `B` and `X` cannot be the same.

3852: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3853: @*/
3854: PetscErrorCode MatMatSolve(Mat A, Mat B, Mat X)
3855: {
3856:   PetscFunctionBegin;
3861:   PetscCheckSameComm(A, 1, B, 2);
3862:   PetscCheckSameComm(A, 1, X, 3);
3863:   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);
3864:   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);
3865:   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");
3866:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3867:   MatCheckPreallocated(A, 1);

3869:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3870:   if (!A->ops->matsolve) {
3871:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolve\n", ((PetscObject)A)->type_name));
3872:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_FALSE));
3873:   } else PetscUseTypeMethod(A, matsolve, B, X);
3874:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3875:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3876:   PetscFunctionReturn(PETSC_SUCCESS);
3877: }

3879: /*@
3880:   MatMatSolveTranspose - Solves $A^T X = B $, given a factored matrix.

3882:   Neighbor-wise Collective

3884:   Input Parameters:
3885: + A - the factored matrix
3886: - B - the right-hand-side matrix  (`MATDENSE` matrix)

3888:   Output Parameter:
3889: . X - the result matrix (dense matrix)

3891:   Level: developer

3893:   Note:
3894:   The matrices `B` and `X` cannot be the same.  I.e., one cannot
3895:   call `MatMatSolveTranspose`(A,X,X).

3897: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolveTranspose()`, `MatMatSolve()`, `MatLUFactor()`, `MatCholeskyFactor()`
3898: @*/
3899: PetscErrorCode MatMatSolveTranspose(Mat A, Mat B, Mat X)
3900: {
3901:   PetscFunctionBegin;
3906:   PetscCheckSameComm(A, 1, B, 2);
3907:   PetscCheckSameComm(A, 1, X, 3);
3908:   PetscCheck(X != B, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3909:   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);
3910:   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);
3911:   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);
3912:   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");
3913:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3914:   MatCheckPreallocated(A, 1);

3916:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3917:   if (!A->ops->matsolvetranspose) {
3918:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolveTranspose\n", ((PetscObject)A)->type_name));
3919:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_TRUE));
3920:   } else PetscUseTypeMethod(A, matsolvetranspose, B, X);
3921:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3922:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3923:   PetscFunctionReturn(PETSC_SUCCESS);
3924: }

3926: /*@
3927:   MatMatTransposeSolve - Solves $A X = B^T$, given a factored matrix.

3929:   Neighbor-wise Collective

3931:   Input Parameters:
3932: + A  - the factored matrix
3933: - Bt - the transpose of right-hand-side matrix as a `MATDENSE`

3935:   Output Parameter:
3936: . X - the result matrix (dense matrix)

3938:   Level: developer

3940:   Note:
3941:   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
3942:   format on the host processor and call `MatMatTransposeSolve()` to implement MUMPS' `MatMatSolve()`.

3944: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatMatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3945: @*/
3946: PetscErrorCode MatMatTransposeSolve(Mat A, Mat Bt, Mat X)
3947: {
3948:   PetscFunctionBegin;
3953:   PetscCheckSameComm(A, 1, Bt, 2);
3954:   PetscCheckSameComm(A, 1, X, 3);

3956:   PetscCheck(X != Bt, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3957:   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);
3958:   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);
3959:   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");
3960:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3961:   PetscCheck(A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
3962:   MatCheckPreallocated(A, 1);

3964:   PetscCall(PetscLogEventBegin(MAT_MatTrSolve, A, Bt, X, 0));
3965:   PetscUseTypeMethod(A, mattransposesolve, Bt, X);
3966:   PetscCall(PetscLogEventEnd(MAT_MatTrSolve, A, Bt, X, 0));
3967:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3968:   PetscFunctionReturn(PETSC_SUCCESS);
3969: }

3971: /*@
3972:   MatForwardSolve - Solves $ L x = b $, given a factored matrix, $A = LU $, or
3973:   $U^T*D^(1/2) x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3975:   Neighbor-wise Collective

3977:   Input Parameters:
3978: + mat - the factored matrix
3979: - b   - the right-hand-side vector

3981:   Output Parameter:
3982: . x - the result vector

3984:   Level: developer

3986:   Notes:
3987:   `MatSolve()` should be used for most applications, as it performs
3988:   a forward solve followed by a backward solve.

3990:   The vectors `b` and `x` cannot be the same,  i.e., one cannot
3991:   call `MatForwardSolve`(A,x,x).

3993:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
3994:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
3995:   `MatForwardSolve()` solves $U^T*D y = b$, and
3996:   `MatBackwardSolve()` solves $U x = y$.
3997:   Thus they do not provide a symmetric preconditioner.

3999: .seealso: [](ch_matrices), `Mat`, `MatBackwardSolve()`, `MatGetFactor()`, `MatSolve()`
4000: @*/
4001: PetscErrorCode MatForwardSolve(Mat mat, Vec b, Vec x)
4002: {
4003:   PetscFunctionBegin;
4008:   PetscCheckSameComm(mat, 1, b, 2);
4009:   PetscCheckSameComm(mat, 1, x, 3);
4010:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4011:   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);
4012:   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);
4013:   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);
4014:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4015:   MatCheckPreallocated(mat, 1);

4017:   PetscCall(PetscLogEventBegin(MAT_ForwardSolve, mat, b, x, 0));
4018:   PetscUseTypeMethod(mat, forwardsolve, b, x);
4019:   PetscCall(PetscLogEventEnd(MAT_ForwardSolve, mat, b, x, 0));
4020:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4021:   PetscFunctionReturn(PETSC_SUCCESS);
4022: }

4024: /*@
4025:   MatBackwardSolve - Solves $U x = b$, given a factored matrix, $A = LU$.
4026:   $D^(1/2) U x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

4028:   Neighbor-wise Collective

4030:   Input Parameters:
4031: + mat - the factored matrix
4032: - b   - the right-hand-side vector

4034:   Output Parameter:
4035: . x - the result vector

4037:   Level: developer

4039:   Notes:
4040:   `MatSolve()` should be used for most applications, as it performs
4041:   a forward solve followed by a backward solve.

4043:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4044:   call `MatBackwardSolve`(A,x,x).

4046:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
4047:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
4048:   `MatForwardSolve()` solves $U^T*D y = b$, and
4049:   `MatBackwardSolve()` solves $U x = y$.
4050:   Thus they do not provide a symmetric preconditioner.

4052: .seealso: [](ch_matrices), `Mat`, `MatForwardSolve()`, `MatGetFactor()`, `MatSolve()`
4053: @*/
4054: PetscErrorCode MatBackwardSolve(Mat mat, Vec b, Vec x)
4055: {
4056:   PetscFunctionBegin;
4061:   PetscCheckSameComm(mat, 1, b, 2);
4062:   PetscCheckSameComm(mat, 1, x, 3);
4063:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4064:   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);
4065:   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);
4066:   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);
4067:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4068:   MatCheckPreallocated(mat, 1);

4070:   PetscCall(PetscLogEventBegin(MAT_BackwardSolve, mat, b, x, 0));
4071:   PetscUseTypeMethod(mat, backwardsolve, b, x);
4072:   PetscCall(PetscLogEventEnd(MAT_BackwardSolve, mat, b, x, 0));
4073:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4074:   PetscFunctionReturn(PETSC_SUCCESS);
4075: }

4077: /*@
4078:   MatSolveAdd - Computes $x = y + A^{-1}*b$, given a factored matrix.

4080:   Neighbor-wise Collective

4082:   Input Parameters:
4083: + mat - the factored matrix
4084: . b   - the right-hand-side vector
4085: - y   - the vector to be added to

4087:   Output Parameter:
4088: . x - the result vector

4090:   Level: developer

4092:   Note:
4093:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4094:   call `MatSolveAdd`(A,x,y,x).

4096: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolve()`, `MatGetFactor()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
4097: @*/
4098: PetscErrorCode MatSolveAdd(Mat mat, Vec b, Vec y, Vec x)
4099: {
4100:   PetscScalar one = 1.0;
4101:   Vec         tmp;

4103:   PetscFunctionBegin;
4109:   PetscCheckSameComm(mat, 1, b, 2);
4110:   PetscCheckSameComm(mat, 1, y, 3);
4111:   PetscCheckSameComm(mat, 1, x, 4);
4112:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4113:   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);
4114:   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);
4115:   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);
4116:   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);
4117:   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);
4118:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4119:   MatCheckPreallocated(mat, 1);

4121:   PetscCall(PetscLogEventBegin(MAT_SolveAdd, mat, b, x, y));
4122:   PetscCall(VecFlag(x, mat->factorerrortype));
4123:   if (mat->factorerrortype) {
4124:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4125:   } else if (mat->ops->solveadd) {
4126:     PetscUseTypeMethod(mat, solveadd, b, y, x);
4127:   } else {
4128:     /* do the solve then the add manually */
4129:     if (x != y) {
4130:       PetscCall(MatSolve(mat, b, x));
4131:       PetscCall(VecAXPY(x, one, y));
4132:     } else {
4133:       PetscCall(VecDuplicate(x, &tmp));
4134:       PetscCall(VecCopy(x, tmp));
4135:       PetscCall(MatSolve(mat, b, x));
4136:       PetscCall(VecAXPY(x, one, tmp));
4137:       PetscCall(VecDestroy(&tmp));
4138:     }
4139:   }
4140:   PetscCall(PetscLogEventEnd(MAT_SolveAdd, mat, b, x, y));
4141:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4142:   PetscFunctionReturn(PETSC_SUCCESS);
4143: }

4145: /*@
4146:   MatSolveTranspose - Solves $A^T x = b$, given a factored matrix.

4148:   Neighbor-wise Collective

4150:   Input Parameters:
4151: + mat - the factored matrix
4152: - b   - the right-hand-side vector

4154:   Output Parameter:
4155: . x - the result vector

4157:   Level: developer

4159:   Notes:
4160:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4161:   call `MatSolveTranspose`(A,x,x).

4163:   Most users should employ the `KSP` interface for linear solvers
4164:   instead of working directly with matrix algebra routines such as this.
4165:   See, e.g., `KSPCreate()`.

4167: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `KSP`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTransposeAdd()`
4168: @*/
4169: PetscErrorCode MatSolveTranspose(Mat mat, Vec b, Vec x)
4170: {
4171:   PetscErrorCode (*f)(Mat, Vec, Vec) = (!mat->ops->solvetranspose && mat->symmetric) ? mat->ops->solve : mat->ops->solvetranspose;

4173:   PetscFunctionBegin;
4178:   PetscCheckSameComm(mat, 1, b, 2);
4179:   PetscCheckSameComm(mat, 1, x, 3);
4180:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4181:   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);
4182:   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);
4183:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4184:   MatCheckPreallocated(mat, 1);
4185:   PetscCall(PetscLogEventBegin(MAT_SolveTranspose, mat, b, x, 0));
4186:   PetscCall(VecFlag(x, mat->factorerrortype));
4187:   if (mat->factorerrortype) {
4188:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4189:   } else {
4190:     PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Matrix type %s", ((PetscObject)mat)->type_name);
4191:     PetscCall((*f)(mat, b, x));
4192:   }
4193:   PetscCall(PetscLogEventEnd(MAT_SolveTranspose, mat, b, x, 0));
4194:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4195:   PetscFunctionReturn(PETSC_SUCCESS);
4196: }

4198: /*@
4199:   MatSolveTransposeAdd - Computes $x = y + A^{-T} b$
4200:   factored matrix.

4202:   Neighbor-wise Collective

4204:   Input Parameters:
4205: + mat - the factored matrix
4206: . b   - the right-hand-side vector
4207: - y   - the vector to be added to

4209:   Output Parameter:
4210: . x - the result vector

4212:   Level: developer

4214:   Note:
4215:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4216:   call `MatSolveTransposeAdd`(A,x,y,x).

4218: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTranspose()`
4219: @*/
4220: PetscErrorCode MatSolveTransposeAdd(Mat mat, Vec b, Vec y, Vec x)
4221: {
4222:   PetscScalar one = 1.0;
4223:   Vec         tmp;
4224:   PetscErrorCode (*f)(Mat, Vec, Vec, Vec) = (!mat->ops->solvetransposeadd && mat->symmetric) ? mat->ops->solveadd : mat->ops->solvetransposeadd;

4226:   PetscFunctionBegin;
4232:   PetscCheckSameComm(mat, 1, b, 2);
4233:   PetscCheckSameComm(mat, 1, y, 3);
4234:   PetscCheckSameComm(mat, 1, x, 4);
4235:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4236:   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);
4237:   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);
4238:   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);
4239:   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);
4240:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4241:   MatCheckPreallocated(mat, 1);

4243:   PetscCall(PetscLogEventBegin(MAT_SolveTransposeAdd, mat, b, x, y));
4244:   PetscCall(VecFlag(x, mat->factorerrortype));
4245:   if (mat->factorerrortype) {
4246:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4247:   } else if (f) {
4248:     PetscCall((*f)(mat, b, y, x));
4249:   } else {
4250:     /* do the solve then the add manually */
4251:     if (x != y) {
4252:       PetscCall(MatSolveTranspose(mat, b, x));
4253:       PetscCall(VecAXPY(x, one, y));
4254:     } else {
4255:       PetscCall(VecDuplicate(x, &tmp));
4256:       PetscCall(VecCopy(x, tmp));
4257:       PetscCall(MatSolveTranspose(mat, b, x));
4258:       PetscCall(VecAXPY(x, one, tmp));
4259:       PetscCall(VecDestroy(&tmp));
4260:     }
4261:   }
4262:   PetscCall(PetscLogEventEnd(MAT_SolveTransposeAdd, mat, b, x, y));
4263:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4264:   PetscFunctionReturn(PETSC_SUCCESS);
4265: }

4267: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
4268: /*@
4269:   MatSOR - Computes relaxation (SOR, Gauss-Seidel) sweeps.

4271:   Neighbor-wise Collective

4273:   Input Parameters:
4274: + mat   - the matrix
4275: . b     - the right-hand side
4276: . omega - the relaxation factor
4277: . flag  - flag indicating the type of SOR (see below)
4278: . shift - diagonal shift
4279: . its   - the number of iterations
4280: - lits  - the number of local iterations

4282:   Output Parameter:
4283: . x - the solution (can contain an initial guess, use option `SOR_ZERO_INITIAL_GUESS` to indicate no guess)

4285:   SOR Flags:
4286: +     `SOR_FORWARD_SWEEP` - forward SOR
4287: .     `SOR_BACKWARD_SWEEP` - backward SOR
4288: .     `SOR_SYMMETRIC_SWEEP` - SSOR (symmetric SOR)
4289: .     `SOR_LOCAL_FORWARD_SWEEP` - local forward SOR
4290: .     `SOR_LOCAL_BACKWARD_SWEEP` - local forward SOR
4291: .     `SOR_LOCAL_SYMMETRIC_SWEEP` - local SSOR
4292: .     `SOR_EISENSTAT` - SOR with Eisenstat trick
4293: .     `SOR_APPLY_UPPER`, `SOR_APPLY_LOWER` - applies upper/lower triangular part of matrix to vector (with `omega`)
4294: -     `SOR_ZERO_INITIAL_GUESS` - zero initial guess

4296:   Level: developer

4298:   Notes:
4299:   `SOR_LOCAL_FORWARD_SWEEP`, `SOR_LOCAL_BACKWARD_SWEEP`, and
4300:   `SOR_LOCAL_SYMMETRIC_SWEEP` perform separate independent smoothings
4301:   on each processor.

4303:   Application programmers will not generally use `MatSOR()` directly,
4304:   but instead will employ `PCSOR` or `PCEISENSTAT`

4306:   For `MATBAIJ`, `MATSBAIJ`, and `MATAIJ` matrices with inodes, this does a block SOR smoothing, otherwise it does a pointwise smoothing.
4307:   For `MATAIJ` matrices with inodes, the block sizes are determined by the inode sizes, not the block size set with `MatSetBlockSize()`

4309:   Vectors `x` and `b` CANNOT be the same

4311:   The flags are implemented as bitwise inclusive or operations.
4312:   For example, use (`SOR_ZERO_INITIAL_GUESS` | `SOR_SYMMETRIC_SWEEP`)
4313:   to specify a zero initial guess for SSOR.

4315:   Developer Note:
4316:   We should add block SOR support for `MATAIJ` matrices with block size set to greater than one and no inodes

4318: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `KSP`, `PC`, `MatGetFactor()`
4319: @*/
4320: PetscErrorCode MatSOR(Mat mat, Vec b, PetscReal omega, MatSORType flag, PetscReal shift, PetscInt its, PetscInt lits, Vec x)
4321: {
4322:   PetscFunctionBegin;
4327:   PetscCheckSameComm(mat, 1, b, 2);
4328:   PetscCheckSameComm(mat, 1, x, 8);
4329:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4330:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4331:   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);
4332:   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);
4333:   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);
4334:   PetscCheck(its > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires global its %" PetscInt_FMT " positive", its);
4335:   PetscCheck(lits > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires local its %" PetscInt_FMT " positive", lits);
4336:   PetscCheck(b != x, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "b and x vector cannot be the same");

4338:   MatCheckPreallocated(mat, 1);
4339:   PetscCall(PetscLogEventBegin(MAT_SOR, mat, b, x, 0));
4340:   PetscUseTypeMethod(mat, sor, b, omega, flag, shift, its, lits, x);
4341:   PetscCall(PetscLogEventEnd(MAT_SOR, mat, b, x, 0));
4342:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4343:   PetscFunctionReturn(PETSC_SUCCESS);
4344: }

4346: /*
4347:       Default matrix copy routine.
4348: */
4349: PetscErrorCode MatCopy_Basic(Mat A, Mat B, MatStructure str)
4350: {
4351:   PetscInt           i, rstart = 0, rend = 0, nz;
4352:   const PetscInt    *cwork;
4353:   const PetscScalar *vwork;

4355:   PetscFunctionBegin;
4356:   if (B->assembled) PetscCall(MatZeroEntries(B));
4357:   if (str == SAME_NONZERO_PATTERN) {
4358:     PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
4359:     for (i = rstart; i < rend; i++) {
4360:       PetscCall(MatGetRow(A, i, &nz, &cwork, &vwork));
4361:       PetscCall(MatSetValues(B, 1, &i, nz, cwork, vwork, INSERT_VALUES));
4362:       PetscCall(MatRestoreRow(A, i, &nz, &cwork, &vwork));
4363:     }
4364:   } else {
4365:     PetscCall(MatAYPX(B, 0.0, A, str));
4366:   }
4367:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4368:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4369:   PetscFunctionReturn(PETSC_SUCCESS);
4370: }

4372: /*@
4373:   MatCopy - Copies a matrix to another matrix.

4375:   Collective

4377:   Input Parameters:
4378: + A   - the matrix
4379: - str - `SAME_NONZERO_PATTERN` or `DIFFERENT_NONZERO_PATTERN`

4381:   Output Parameter:
4382: . B - where the copy is put

4384:   Level: intermediate

4386:   Notes:
4387:   If you use `SAME_NONZERO_PATTERN`, then the two matrices must have the same nonzero pattern or the routine will crash.

4389:   `MatCopy()` copies the matrix entries of a matrix to another existing
4390:   matrix (after first zeroing the second matrix).  A related routine is
4391:   `MatConvert()`, which first creates a new matrix and then copies the data.

4393: .seealso: [](ch_matrices), `Mat`, `MatConvert()`, `MatDuplicate()`
4394: @*/
4395: PetscErrorCode MatCopy(Mat A, Mat B, MatStructure str)
4396: {
4397:   PetscInt i;

4399:   PetscFunctionBegin;
4404:   PetscCheckSameComm(A, 1, B, 2);
4405:   MatCheckPreallocated(B, 2);
4406:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4407:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4408:   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,
4409:              A->cmap->N, B->cmap->N);
4410:   MatCheckPreallocated(A, 1);
4411:   if (A == B) PetscFunctionReturn(PETSC_SUCCESS);

4413:   PetscCall(PetscLogEventBegin(MAT_Copy, A, B, 0, 0));
4414:   if (A->ops->copy) PetscUseTypeMethod(A, copy, B, str);
4415:   else PetscCall(MatCopy_Basic(A, B, str));

4417:   B->stencil.dim = A->stencil.dim;
4418:   B->stencil.noc = A->stencil.noc;
4419:   for (i = 0; i <= A->stencil.dim + (A->stencil.noc ? 0 : -1); i++) {
4420:     B->stencil.dims[i]   = A->stencil.dims[i];
4421:     B->stencil.starts[i] = A->stencil.starts[i];
4422:   }

4424:   PetscCall(PetscLogEventEnd(MAT_Copy, A, B, 0, 0));
4425:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
4426:   PetscFunctionReturn(PETSC_SUCCESS);
4427: }

4429: /*@
4430:   MatConvert - Converts a matrix to another matrix, either of the same
4431:   or different type.

4433:   Collective

4435:   Input Parameters:
4436: + mat     - the matrix
4437: . newtype - new matrix type.  Use `MATSAME` to create a new matrix of the
4438:             same type as the original matrix.
4439: - reuse   - denotes if the destination matrix is to be created or reused.
4440:             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
4441:             `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).

4443:   Output Parameter:
4444: . M - pointer to place new matrix

4446:   Level: intermediate

4448:   Notes:
4449:   `MatConvert()` first creates a new matrix and then copies the data from
4450:   the first matrix.  A related routine is `MatCopy()`, which copies the matrix
4451:   entries of one matrix to another already existing matrix context.

4453:   Cannot be used to convert a sequential matrix to parallel or parallel to sequential,
4454:   the MPI communicator of the generated matrix is always the same as the communicator
4455:   of the input matrix.

4457: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatDuplicate()`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
4458: @*/
4459: PetscErrorCode MatConvert(Mat mat, MatType newtype, MatReuse reuse, Mat *M)
4460: {
4461:   PetscBool  sametype, issame, flg;
4462:   PetscBool3 issymmetric, ishermitian, isspd;
4463:   char       convname[256], mtype[256];
4464:   Mat        B;

4466:   PetscFunctionBegin;
4469:   PetscAssertPointer(M, 4);
4470:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4471:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4472:   MatCheckPreallocated(mat, 1);

4474:   PetscCall(PetscOptionsGetString(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matconvert_type", mtype, sizeof(mtype), &flg));
4475:   if (flg) newtype = mtype;

4477:   PetscCall(PetscObjectTypeCompare((PetscObject)mat, newtype, &sametype));
4478:   PetscCall(PetscStrcmp(newtype, "same", &issame));
4479:   PetscCheck(!(reuse == MAT_INPLACE_MATRIX) || !(mat != *M), PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires same input and output matrix");
4480:   if (reuse == MAT_REUSE_MATRIX) {
4482:     PetscCheck(mat != *M, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_REUSE_MATRIX means reuse matrix in final argument, perhaps you mean MAT_INPLACE_MATRIX");
4483:   }

4485:   if ((reuse == MAT_INPLACE_MATRIX) && (issame || sametype)) {
4486:     PetscCall(PetscInfo(mat, "Early return for inplace %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4487:     PetscFunctionReturn(PETSC_SUCCESS);
4488:   }

4490:   /* Cache Mat options because some converters use MatHeaderReplace() */
4491:   issymmetric = mat->symmetric;
4492:   ishermitian = mat->hermitian;
4493:   isspd       = mat->spd;

4495:   if ((sametype || issame) && (reuse == MAT_INITIAL_MATRIX) && mat->ops->duplicate) {
4496:     PetscCall(PetscInfo(mat, "Calling duplicate for initial matrix %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4497:     PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4498:   } else {
4499:     PetscErrorCode (*conv)(Mat, MatType, MatReuse, Mat *) = NULL;
4500:     const char *prefix[3]                                 = {"seq", "mpi", ""};
4501:     PetscInt    i;
4502:     /*
4503:        Order of precedence:
4504:        0) See if newtype is a superclass of the current matrix.
4505:        1) See if a specialized converter is known to the current matrix.
4506:        2) See if a specialized converter is known to the desired matrix class.
4507:        3) See if a good general converter is registered for the desired class
4508:           (as of 6/27/03 only MATMPIADJ falls into this category).
4509:        4) See if a good general converter is known for the current matrix.
4510:        5) Use a really basic converter.
4511:     */

4513:     /* 0) See if newtype is a superclass of the current matrix.
4514:           i.e mat is mpiaij and newtype is aij */
4515:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4516:       PetscCall(PetscStrncpy(convname, prefix[i], sizeof(convname)));
4517:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4518:       PetscCall(PetscStrcmp(convname, ((PetscObject)mat)->type_name, &flg));
4519:       PetscCall(PetscInfo(mat, "Check superclass %s %s -> %d\n", convname, ((PetscObject)mat)->type_name, flg));
4520:       if (flg) {
4521:         if (reuse == MAT_INPLACE_MATRIX) {
4522:           PetscCall(PetscInfo(mat, "Early return\n"));
4523:           PetscFunctionReturn(PETSC_SUCCESS);
4524:         } else if (reuse == MAT_INITIAL_MATRIX && mat->ops->duplicate) {
4525:           PetscCall(PetscInfo(mat, "Calling MatDuplicate\n"));
4526:           PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4527:           PetscFunctionReturn(PETSC_SUCCESS);
4528:         } else if (reuse == MAT_REUSE_MATRIX && mat->ops->copy) {
4529:           PetscCall(PetscInfo(mat, "Calling MatCopy\n"));
4530:           PetscCall(MatCopy(mat, *M, SAME_NONZERO_PATTERN));
4531:           PetscFunctionReturn(PETSC_SUCCESS);
4532:         }
4533:       }
4534:     }
4535:     /* 1) See if a specialized converter is known to the current matrix and the desired class */
4536:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4537:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4538:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4539:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4540:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4541:       PetscCall(PetscStrlcat(convname, issame ? ((PetscObject)mat)->type_name : newtype, sizeof(convname)));
4542:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4543:       PetscCall(PetscObjectQueryFunction((PetscObject)mat, convname, &conv));
4544:       PetscCall(PetscInfo(mat, "Check specialized (1) %s (%s) -> %d\n", convname, ((PetscObject)mat)->type_name, !!conv));
4545:       if (conv) goto foundconv;
4546:     }

4548:     /* 2)  See if a specialized converter is known to the desired matrix class. */
4549:     PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &B));
4550:     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
4551:     PetscCall(MatSetType(B, newtype));
4552:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4553:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4554:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4555:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4556:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4557:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4558:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4559:       PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
4560:       PetscCall(PetscInfo(mat, "Check specialized (2) %s (%s) -> %d\n", convname, ((PetscObject)B)->type_name, !!conv));
4561:       if (conv) {
4562:         PetscCall(MatDestroy(&B));
4563:         goto foundconv;
4564:       }
4565:     }

4567:     /* 3) See if a good general converter is registered for the desired class */
4568:     conv = B->ops->convertfrom;
4569:     PetscCall(PetscInfo(mat, "Check convertfrom (%s) -> %d\n", ((PetscObject)B)->type_name, !!conv));
4570:     PetscCall(MatDestroy(&B));
4571:     if (conv) goto foundconv;

4573:     /* 4) See if a good general converter is known for the current matrix */
4574:     if (mat->ops->convert) conv = mat->ops->convert;
4575:     PetscCall(PetscInfo(mat, "Check general convert (%s) -> %d\n", ((PetscObject)mat)->type_name, !!conv));
4576:     if (conv) goto foundconv;

4578:     /* 5) Use a really basic converter. */
4579:     PetscCall(PetscInfo(mat, "Using MatConvert_Basic\n"));
4580:     conv = MatConvert_Basic;

4582:   foundconv:
4583:     PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4584:     PetscCall((*conv)(mat, newtype, reuse, M));
4585:     if (mat->rmap->mapping && mat->cmap->mapping && !(*M)->rmap->mapping && !(*M)->cmap->mapping) {
4586:       /* the block sizes must be same if the mappings are copied over */
4587:       (*M)->rmap->bs = mat->rmap->bs;
4588:       (*M)->cmap->bs = mat->cmap->bs;
4589:       PetscCall(PetscObjectReference((PetscObject)mat->rmap->mapping));
4590:       PetscCall(PetscObjectReference((PetscObject)mat->cmap->mapping));
4591:       (*M)->rmap->mapping = mat->rmap->mapping;
4592:       (*M)->cmap->mapping = mat->cmap->mapping;
4593:     }
4594:     (*M)->stencil.dim = mat->stencil.dim;
4595:     (*M)->stencil.noc = mat->stencil.noc;
4596:     for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4597:       (*M)->stencil.dims[i]   = mat->stencil.dims[i];
4598:       (*M)->stencil.starts[i] = mat->stencil.starts[i];
4599:     }
4600:     PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4601:   }
4602:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));

4604:   /* Reset Mat options */
4605:   if (issymmetric != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PetscBool3ToBool(issymmetric)));
4606:   if (ishermitian != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PetscBool3ToBool(ishermitian)));
4607:   if (isspd != PETSC_BOOL3_UNKNOWN) PetscCall(MatSetOption(*M, MAT_SPD, PetscBool3ToBool(isspd)));
4608:   PetscFunctionReturn(PETSC_SUCCESS);
4609: }

4611: /*@
4612:   MatFactorGetSolverType - Returns name of the package providing the factorization routines

4614:   Not Collective

4616:   Input Parameter:
4617: . mat - the matrix, must be a factored matrix

4619:   Output Parameter:
4620: . type - the string name of the package (do not free this string)

4622:   Level: intermediate

4624: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolverType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`
4625: @*/
4626: PetscErrorCode MatFactorGetSolverType(Mat mat, MatSolverType *type)
4627: {
4628:   PetscErrorCode (*conv)(Mat, MatSolverType *);

4630:   PetscFunctionBegin;
4633:   PetscAssertPointer(type, 2);
4634:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
4635:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorGetSolverType_C", &conv));
4636:   if (conv) PetscCall((*conv)(mat, type));
4637:   else *type = MATSOLVERPETSC;
4638:   PetscFunctionReturn(PETSC_SUCCESS);
4639: }

4641: typedef struct _MatSolverTypeForSpecifcType *MatSolverTypeForSpecifcType;
4642: struct _MatSolverTypeForSpecifcType {
4643:   MatType mtype;
4644:   /* no entry for MAT_FACTOR_NONE */
4645:   PetscErrorCode (*createfactor[MAT_FACTOR_NUM_TYPES - 1])(Mat, MatFactorType, Mat *);
4646:   MatSolverTypeForSpecifcType next;
4647: };

4649: typedef struct _MatSolverTypeHolder *MatSolverTypeHolder;
4650: struct _MatSolverTypeHolder {
4651:   char                       *name;
4652:   MatSolverTypeForSpecifcType handlers;
4653:   MatSolverTypeHolder         next;
4654: };

4656: static MatSolverTypeHolder MatSolverTypeHolders = NULL;

4658: /*@C
4659:   MatSolverTypeRegister - Registers a `MatSolverType` that works for a particular matrix type

4661:   Logically Collective, No Fortran Support

4663:   Input Parameters:
4664: + package      - name of the package, for example `petsc` or `superlu`
4665: . mtype        - the matrix type that works with this package
4666: . ftype        - the type of factorization supported by the package
4667: - createfactor - routine that will create the factored matrix ready to be used

4669:   Level: developer

4671: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorGetSolverType()`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`,
4672:   `MatGetFactor()`
4673: @*/
4674: PetscErrorCode MatSolverTypeRegister(MatSolverType package, MatType mtype, MatFactorType ftype, PetscErrorCode (*createfactor)(Mat, MatFactorType, Mat *))
4675: {
4676:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev = NULL;
4677:   PetscBool                   flg;
4678:   MatSolverTypeForSpecifcType inext, iprev = NULL;

4680:   PetscFunctionBegin;
4681:   PetscCall(MatInitializePackage());
4682:   if (!next) {
4683:     PetscCall(PetscNew(&MatSolverTypeHolders));
4684:     PetscCall(PetscStrallocpy(package, &MatSolverTypeHolders->name));
4685:     PetscCall(PetscNew(&MatSolverTypeHolders->handlers));
4686:     PetscCall(PetscStrallocpy(mtype, (char **)&MatSolverTypeHolders->handlers->mtype));
4687:     MatSolverTypeHolders->handlers->createfactor[(int)ftype - 1] = createfactor;
4688:     PetscFunctionReturn(PETSC_SUCCESS);
4689:   }
4690:   while (next) {
4691:     PetscCall(PetscStrcasecmp(package, next->name, &flg));
4692:     if (flg) {
4693:       PetscCheck(next->handlers, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatSolverTypeHolder is missing handlers");
4694:       inext = next->handlers;
4695:       while (inext) {
4696:         PetscCall(PetscStrcasecmp(mtype, inext->mtype, &flg));
4697:         if (flg) {
4698:           inext->createfactor[(int)ftype - 1] = createfactor;
4699:           PetscFunctionReturn(PETSC_SUCCESS);
4700:         }
4701:         iprev = inext;
4702:         inext = inext->next;
4703:       }
4704:       PetscCall(PetscNew(&iprev->next));
4705:       PetscCall(PetscStrallocpy(mtype, (char **)&iprev->next->mtype));
4706:       iprev->next->createfactor[(int)ftype - 1] = createfactor;
4707:       PetscFunctionReturn(PETSC_SUCCESS);
4708:     }
4709:     prev = next;
4710:     next = next->next;
4711:   }
4712:   PetscCall(PetscNew(&prev->next));
4713:   PetscCall(PetscStrallocpy(package, &prev->next->name));
4714:   PetscCall(PetscNew(&prev->next->handlers));
4715:   PetscCall(PetscStrallocpy(mtype, (char **)&prev->next->handlers->mtype));
4716:   prev->next->handlers->createfactor[(int)ftype - 1] = createfactor;
4717:   PetscFunctionReturn(PETSC_SUCCESS);
4718: }

4720: /*@C
4721:   MatSolverTypeGet - Gets the function that creates the factor matrix if it exist

4723:   Input Parameters:
4724: + 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
4725: . ftype - the type of factorization supported by the type
4726: - mtype - the matrix type that works with this type

4728:   Output Parameters:
4729: + foundtype    - `PETSC_TRUE` if the type was registered
4730: . foundmtype   - `PETSC_TRUE` if the type supports the requested mtype
4731: - createfactor - routine that will create the factored matrix ready to be used or `NULL` if not found

4733:   Calling sequence of `createfactor`:
4734: + A     - the matrix providing the factor matrix
4735: . ftype - the `MatFactorType` of the factor requested
4736: - B     - the new factor matrix that responds to MatXXFactorSymbolic,Numeric() functions, such as `MatLUFactorSymbolic()`

4738:   Level: developer

4740:   Note:
4741:   When `type` is `NULL` the available functions are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4742:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4743:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4745: .seealso: [](ch_matrices), `Mat`, `MatFactorType`, `MatType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatSolverTypeRegister()`, `MatGetFactor()`,
4746:           `MatInitializePackage()`
4747: @*/
4748: PetscErrorCode MatSolverTypeGet(MatSolverType type, MatType mtype, MatFactorType ftype, PetscBool *foundtype, PetscBool *foundmtype, PetscErrorCode (**createfactor)(Mat A, MatFactorType ftype, Mat *B))
4749: {
4750:   MatSolverTypeHolder         next = MatSolverTypeHolders;
4751:   PetscBool                   flg;
4752:   MatSolverTypeForSpecifcType inext;

4754:   PetscFunctionBegin;
4755:   if (foundtype) *foundtype = PETSC_FALSE;
4756:   if (foundmtype) *foundmtype = PETSC_FALSE;
4757:   if (createfactor) *createfactor = NULL;

4759:   if (type) {
4760:     while (next) {
4761:       PetscCall(PetscStrcasecmp(type, next->name, &flg));
4762:       if (flg) {
4763:         if (foundtype) *foundtype = PETSC_TRUE;
4764:         inext = next->handlers;
4765:         while (inext) {
4766:           PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4767:           if (flg) {
4768:             if (foundmtype) *foundmtype = PETSC_TRUE;
4769:             if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4770:             PetscFunctionReturn(PETSC_SUCCESS);
4771:           }
4772:           inext = inext->next;
4773:         }
4774:       }
4775:       next = next->next;
4776:     }
4777:   } else {
4778:     while (next) {
4779:       inext = next->handlers;
4780:       while (inext) {
4781:         PetscCall(PetscStrcmp(mtype, inext->mtype, &flg));
4782:         if (flg && inext->createfactor[(int)ftype - 1]) {
4783:           if (foundtype) *foundtype = PETSC_TRUE;
4784:           if (foundmtype) *foundmtype = PETSC_TRUE;
4785:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4786:           PetscFunctionReturn(PETSC_SUCCESS);
4787:         }
4788:         inext = inext->next;
4789:       }
4790:       next = next->next;
4791:     }
4792:     /* try with base classes inext->mtype */
4793:     next = MatSolverTypeHolders;
4794:     while (next) {
4795:       inext = next->handlers;
4796:       while (inext) {
4797:         PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4798:         if (flg && inext->createfactor[(int)ftype - 1]) {
4799:           if (foundtype) *foundtype = PETSC_TRUE;
4800:           if (foundmtype) *foundmtype = PETSC_TRUE;
4801:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4802:           PetscFunctionReturn(PETSC_SUCCESS);
4803:         }
4804:         inext = inext->next;
4805:       }
4806:       next = next->next;
4807:     }
4808:   }
4809:   PetscFunctionReturn(PETSC_SUCCESS);
4810: }

4812: PetscErrorCode MatSolverTypeDestroy(void)
4813: {
4814:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev;
4815:   MatSolverTypeForSpecifcType inext, iprev;

4817:   PetscFunctionBegin;
4818:   while (next) {
4819:     PetscCall(PetscFree(next->name));
4820:     inext = next->handlers;
4821:     while (inext) {
4822:       PetscCall(PetscFree(inext->mtype));
4823:       iprev = inext;
4824:       inext = inext->next;
4825:       PetscCall(PetscFree(iprev));
4826:     }
4827:     prev = next;
4828:     next = next->next;
4829:     PetscCall(PetscFree(prev));
4830:   }
4831:   MatSolverTypeHolders = NULL;
4832:   PetscFunctionReturn(PETSC_SUCCESS);
4833: }

4835: /*@
4836:   MatFactorGetCanUseOrdering - Indicates if the factorization can use the ordering provided in `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`

4838:   Logically Collective

4840:   Input Parameter:
4841: . mat - the matrix

4843:   Output Parameter:
4844: . flg - `PETSC_TRUE` if uses the ordering

4846:   Level: developer

4848:   Note:
4849:   Most internal PETSc factorizations use the ordering passed to the factorization routine but external
4850:   packages do not, thus we want to skip generating the ordering when it is not needed or used.

4852: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4853: @*/
4854: PetscErrorCode MatFactorGetCanUseOrdering(Mat mat, PetscBool *flg)
4855: {
4856:   PetscFunctionBegin;
4857:   *flg = mat->canuseordering;
4858:   PetscFunctionReturn(PETSC_SUCCESS);
4859: }

4861: /*@
4862:   MatFactorGetPreferredOrdering - The preferred ordering for a particular matrix factor object

4864:   Logically Collective

4866:   Input Parameters:
4867: + mat   - the matrix obtained with `MatGetFactor()`
4868: - ftype - the factorization type to be used

4870:   Output Parameter:
4871: . otype - the preferred ordering type

4873:   Level: developer

4875: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatOrderingType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4876: @*/
4877: PetscErrorCode MatFactorGetPreferredOrdering(Mat mat, MatFactorType ftype, MatOrderingType *otype)
4878: {
4879:   PetscFunctionBegin;
4880:   *otype = mat->preferredordering[ftype];
4881:   PetscCheck(*otype, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatFactor did not have a preferred ordering");
4882:   PetscFunctionReturn(PETSC_SUCCESS);
4883: }

4885: /*@
4886:   MatGetFactor - Returns a matrix suitable to calls to routines such as `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatILUFactorSymbolic()`,
4887:   `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactorNumeric()`, `MatILUFactorNumeric()`, and
4888:   `MatICCFactorNumeric()`

4890:   Collective

4892:   Input Parameters:
4893: + mat   - the matrix
4894: . 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
4895:           the other criteria is returned
4896: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4898:   Output Parameter:
4899: . f - the factor matrix used with MatXXFactorSymbolic,Numeric() calls. Can be `NULL` in some cases, see notes below.

4901:   Options Database Keys:
4902: + -pc_factor_mat_solver_type type            - choose the type at run time. When using `KSP` solvers
4903: . -pc_factor_mat_factor_on_host (true|false) - do matrix factorization on host (with device matrices). Default is doing it on device
4904: - -pc_factor_mat_solve_on_host (true|false)  - do matrix solve on host (with device matrices). Default is doing it on device

4906:   Level: intermediate

4908:   Notes:
4909:   Some of the packages, such as MUMPS, have options for controlling the factorization, these are in the form `-prefix_mat_packagename_packageoption`
4910:   (for example, `-mat_mumps_icntl_6 1`)  where `prefix` is normally set automatically from the calling `KSP`/`PC`. If `MatGetFactor()` is called directly,
4911:   without using a `PC`, one can set the prefix by
4912:   calling `MatSetOptionsPrefixFactor()` on the originating matrix or  `MatSetOptionsPrefix()` on the resulting factor matrix.

4914:   Some PETSc matrix formats have alternative solvers available that are provided by alternative packages
4915:   such as PaStiX, SuperLU_DIST, MUMPS etc. PETSc must have been configured to use the external solver,
4916:   using the corresponding `./configure` option such as `--download-package` or `--with-package-dir`.

4918:   When `type` is `NULL` the available results are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4919:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4920:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4922:   The return matrix can be `NULL` if the requested factorization is not available, since some combinations of matrix types and factorization
4923:   types registered with `MatSolverTypeRegister()` cannot be fully tested if not at runtime.

4925:   Developer Note:
4926:   This should actually be called `MatCreateFactor()` since it creates a new factor object

4928:   The `MatGetFactor()` implementations should not be accessing the PETSc options database or making other decisions about solver options,
4929:   that should be delayed until the later operations. This is to ensure the correct options prefix has been set in the factor matrix.

4931: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `KSP`, `MatSolverType`, `MatFactorType`, `MatCopy()`, `MatDuplicate()`,
4932:           `MatGetFactorAvailable()`, `MatFactorGetCanUseOrdering()`, `MatSolverTypeRegister()`, `MatSolverTypeGet()`,
4933:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatInitializePackage()`,
4934:           `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`, `MatILUFactorSymbolic()`,
4935:           `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactorNumeric()`, `MatILUFactorNumeric()`,
4936:           `MatICCFactorNumeric()`
4937: @*/
4938: PetscErrorCode MatGetFactor(Mat mat, MatSolverType type, MatFactorType ftype, Mat *f)
4939: {
4940:   PetscBool foundtype, foundmtype, shell, hasop = PETSC_FALSE;
4941:   PetscErrorCode (*conv)(Mat, MatFactorType, Mat *);

4943:   PetscFunctionBegin;

4947:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4948:   MatCheckPreallocated(mat, 1);

4950:   PetscCall(MatIsShell(mat, &shell));
4951:   if (shell) PetscCall(MatHasOperation(mat, MATOP_GET_FACTOR, &hasop));
4952:   if (hasop) {
4953:     PetscUseTypeMethod(mat, getfactor, type, ftype, f);
4954:     PetscFunctionReturn(PETSC_SUCCESS);
4955:   }

4957:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, &foundtype, &foundmtype, &conv));
4958:   if (!foundtype) {
4959:     if (type) {
4960:       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],
4961:               ((PetscObject)mat)->type_name, type);
4962:     } else {
4963:       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);
4964:     }
4965:   }
4966:   PetscCheck(foundmtype, PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "MatSolverType %s does not support matrix type %s", type, ((PetscObject)mat)->type_name);
4967:   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);

4969:   PetscCall((*conv)(mat, ftype, f));
4970:   if (mat->factorprefix) PetscCall(MatSetOptionsPrefix(*f, mat->factorprefix));
4971:   PetscFunctionReturn(PETSC_SUCCESS);
4972: }

4974: /*@
4975:   MatGetFactorAvailable - Returns a flag if matrix supports particular type and factor type

4977:   Not Collective

4979:   Input Parameters:
4980: + mat   - the matrix
4981: . type  - name of solver type, for example, `superlu`, `petsc` (to use PETSc's default)
4982: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4984:   Output Parameter:
4985: . flg - PETSC_TRUE if the factorization is available

4987:   Level: intermediate

4989:   Notes:
4990:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
4991:   such as pastix, superlu, mumps etc.

4993:   PETSc must have been ./configure to use the external solver, using the option --download-package

4995:   Developer Note:
4996:   This should actually be called `MatCreateFactorAvailable()` since `MatGetFactor()` creates a new factor object

4998: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolverType`, `MatFactorType`, `MatGetFactor()`, `MatCopy()`, `MatDuplicate()`, `MatSolverTypeRegister()`,
4999:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatSolverTypeGet()`
5000: @*/
5001: PetscErrorCode MatGetFactorAvailable(Mat mat, MatSolverType type, MatFactorType ftype, PetscBool *flg)
5002: {
5003:   PetscErrorCode (*gconv)(Mat, MatFactorType, Mat *);

5005:   PetscFunctionBegin;
5007:   PetscAssertPointer(flg, 4);

5009:   *flg = PETSC_FALSE;
5010:   if (!((PetscObject)mat)->type_name) PetscFunctionReturn(PETSC_SUCCESS);

5012:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5013:   MatCheckPreallocated(mat, 1);

5015:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, NULL, NULL, &gconv));
5016:   *flg = gconv ? PETSC_TRUE : PETSC_FALSE;
5017:   PetscFunctionReturn(PETSC_SUCCESS);
5018: }

5020: /*@
5021:   MatDuplicate - Duplicates a matrix including the non-zero structure.

5023:   Collective

5025:   Input Parameters:
5026: + mat - the matrix
5027: - op  - One of `MAT_DO_NOT_COPY_VALUES`, `MAT_COPY_VALUES`, or `MAT_SHARE_NONZERO_PATTERN`.
5028:         See the manual page for `MatDuplicateOption()` for an explanation of these options.

5030:   Output Parameter:
5031: . M - pointer to place new matrix

5033:   Level: intermediate

5035:   Notes:
5036:   You cannot change the nonzero pattern for the parent or child matrix later if you use `MAT_SHARE_NONZERO_PATTERN`.

5038:   If `op` is not `MAT_COPY_VALUES` the numerical values in the new matrix are zeroed.

5040:   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.

5042:   When original mat is a product of matrix operation, e.g., an output of `MatMatMult()` or `MatCreateSubMatrix()`, only the matrix data structure of `mat`
5043:   is duplicated and the internal data structures created for the reuse of previous matrix operations are not duplicated.
5044:   User should not use `MatDuplicate()` to create new matrix `M` if `M` is intended to be reused as the product of matrix operation.

5046: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatConvert()`, `MatDuplicateOption`
5047: @*/
5048: PetscErrorCode MatDuplicate(Mat mat, MatDuplicateOption op, Mat *M)
5049: {
5050:   Mat               B;
5051:   VecType           vtype;
5052:   PetscInt          i;
5053:   PetscObject       dm, container_h, container_d;
5054:   PetscErrorCodeFn *viewf;

5056:   PetscFunctionBegin;
5059:   PetscAssertPointer(M, 3);
5060:   PetscCheck(op != MAT_COPY_VALUES || mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MAT_COPY_VALUES not allowed for unassembled matrix");
5061:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5062:   MatCheckPreallocated(mat, 1);

5064:   PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
5065:   PetscUseTypeMethod(mat, duplicate, op, M);
5066:   PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
5067:   B = *M;

5069:   PetscCall(MatGetOperation(mat, MATOP_VIEW, &viewf));
5070:   if (viewf) PetscCall(MatSetOperation(B, MATOP_VIEW, viewf));
5071:   PetscCall(MatGetVecType(mat, &vtype));
5072:   PetscCall(MatSetVecType(B, vtype));

5074:   B->stencil.dim = mat->stencil.dim;
5075:   B->stencil.noc = mat->stencil.noc;
5076:   for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
5077:     B->stencil.dims[i]   = mat->stencil.dims[i];
5078:     B->stencil.starts[i] = mat->stencil.starts[i];
5079:   }

5081:   B->nooffproczerorows = mat->nooffproczerorows;
5082:   B->nooffprocentries  = mat->nooffprocentries;

5084:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_dm", &dm));
5085:   if (dm) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_dm", dm));
5086:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Host", &container_h));
5087:   if (container_h) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Host", container_h));
5088:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Device", &container_d));
5089:   if (container_d) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Device", container_d));
5090:   if (op == MAT_COPY_VALUES) PetscCall(MatPropagateSymmetryOptions(mat, B));
5091:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
5092:   PetscFunctionReturn(PETSC_SUCCESS);
5093: }

5095: /*@
5096:   MatGetDiagonal - Gets the diagonal of a matrix as a `Vec`

5098:   Logically Collective

5100:   Input Parameter:
5101: . mat - the matrix

5103:   Output Parameter:
5104: . v - the diagonal of the matrix

5106:   Level: intermediate

5108:   Note:
5109:   If `mat` has local sizes `n` x `m`, this routine fills the first `ndiag = min(n, m)` entries
5110:   of `v` with the diagonal values. Thus `v` must have local size of at least `ndiag`. If `v`
5111:   is larger than `ndiag`, the values of the remaining entries are unspecified.

5113:   Currently only correct in parallel for square matrices.

5115: .seealso: [](ch_matrices), `Mat`, `Vec`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`
5116: @*/
5117: PetscErrorCode MatGetDiagonal(Mat mat, Vec v)
5118: {
5119:   PetscFunctionBegin;
5123:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5124:   MatCheckPreallocated(mat, 1);
5125:   if (PetscDefined(USE_DEBUG)) {
5126:     PetscInt nv, row, col, ndiag;

5128:     PetscCall(VecGetLocalSize(v, &nv));
5129:     PetscCall(MatGetLocalSize(mat, &row, &col));
5130:     ndiag = PetscMin(row, col);
5131:     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);
5132:   }

5134:   PetscUseTypeMethod(mat, getdiagonal, v);
5135:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5136:   PetscFunctionReturn(PETSC_SUCCESS);
5137: }

5139: /*@
5140:   MatGetRowMin - Gets the minimum value (of the real part) of each
5141:   row of the matrix

5143:   Logically Collective

5145:   Input Parameter:
5146: . mat - the matrix

5148:   Output Parameters:
5149: + v   - the vector for storing the maximums
5150: - idx - the indices of the column found for each row (optional, pass `NULL` if not needed)

5152:   Level: intermediate

5154:   Note:
5155:   The result of this call are the same as if one converted the matrix to dense format
5156:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5158:   This code is only implemented for a couple of matrix formats.

5160: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`,
5161:           `MatGetRowMax()`
5162: @*/
5163: PetscErrorCode MatGetRowMin(Mat mat, Vec v, PetscInt idx[])
5164: {
5165:   PetscFunctionBegin;
5169:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5171:   if (!mat->cmap->N) {
5172:     PetscCall(VecSet(v, PETSC_MAX_REAL));
5173:     if (idx) {
5174:       PetscInt i, m = mat->rmap->n;
5175:       for (i = 0; i < m; i++) idx[i] = -1;
5176:     }
5177:   } else {
5178:     MatCheckPreallocated(mat, 1);
5179:   }
5180:   PetscUseTypeMethod(mat, getrowmin, v, idx);
5181:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5182:   PetscFunctionReturn(PETSC_SUCCESS);
5183: }

5185: /*@
5186:   MatGetRowMinAbs - Gets the minimum value (in absolute value) of each
5187:   row of the matrix

5189:   Logically Collective

5191:   Input Parameter:
5192: . mat - the matrix

5194:   Output Parameters:
5195: + v   - the vector for storing the minimums
5196: - idx - the indices of the column found for each row (or `NULL` if not needed)

5198:   Level: intermediate

5200:   Notes:
5201:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5202:   row is 0 (the first column).

5204:   This code is only implemented for a couple of matrix formats.

5206: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`
5207: @*/
5208: PetscErrorCode MatGetRowMinAbs(Mat mat, Vec v, PetscInt idx[])
5209: {
5210:   PetscFunctionBegin;
5214:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5215:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

5217:   if (!mat->cmap->N) {
5218:     PetscCall(VecSet(v, 0.0));
5219:     if (idx) {
5220:       PetscInt i, m = mat->rmap->n;
5221:       for (i = 0; i < m; i++) idx[i] = -1;
5222:     }
5223:   } else {
5224:     MatCheckPreallocated(mat, 1);
5225:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5226:     PetscUseTypeMethod(mat, getrowminabs, v, idx);
5227:   }
5228:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5229:   PetscFunctionReturn(PETSC_SUCCESS);
5230: }

5232: /*@
5233:   MatGetRowMax - Gets the maximum value (of the real part) of each
5234:   row of the matrix

5236:   Logically Collective

5238:   Input Parameter:
5239: . mat - the matrix

5241:   Output Parameters:
5242: + v   - the vector for storing the maximums
5243: - idx - the indices of the column found for each row (optional, otherwise pass `NULL`)

5245:   Level: intermediate

5247:   Notes:
5248:   The result of this call are the same as if one converted the matrix to dense format
5249:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5251:   This code is only implemented for a couple of matrix formats.

5253: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5254: @*/
5255: PetscErrorCode MatGetRowMax(Mat mat, Vec v, PetscInt idx[])
5256: {
5257:   PetscFunctionBegin;
5261:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5263:   if (!mat->cmap->N) {
5264:     PetscCall(VecSet(v, PETSC_MIN_REAL));
5265:     if (idx) {
5266:       PetscInt i, m = mat->rmap->n;
5267:       for (i = 0; i < m; i++) idx[i] = -1;
5268:     }
5269:   } else {
5270:     MatCheckPreallocated(mat, 1);
5271:     PetscUseTypeMethod(mat, getrowmax, v, idx);
5272:   }
5273:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5274:   PetscFunctionReturn(PETSC_SUCCESS);
5275: }

5277: /*@
5278:   MatGetRowMaxAbs - Gets the maximum value (in absolute value) of each
5279:   row of the matrix

5281:   Logically Collective

5283:   Input Parameter:
5284: . mat - the matrix

5286:   Output Parameters:
5287: + v   - the vector for storing the maximums
5288: - idx - the indices of the column found for each row (or `NULL` if not needed)

5290:   Level: intermediate

5292:   Notes:
5293:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5294:   row is 0 (the first column).

5296:   This code is only implemented for a couple of matrix formats.

5298: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowSum()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5299: @*/
5300: PetscErrorCode MatGetRowMaxAbs(Mat mat, Vec v, PetscInt idx[])
5301: {
5302:   PetscFunctionBegin;
5306:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5308:   if (!mat->cmap->N) {
5309:     PetscCall(VecSet(v, 0.0));
5310:     if (idx) {
5311:       PetscInt i, m = mat->rmap->n;
5312:       for (i = 0; i < m; i++) idx[i] = -1;
5313:     }
5314:   } else {
5315:     MatCheckPreallocated(mat, 1);
5316:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5317:     PetscUseTypeMethod(mat, getrowmaxabs, v, idx);
5318:   }
5319:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5320:   PetscFunctionReturn(PETSC_SUCCESS);
5321: }

5323: /*@
5324:   MatGetRowSumAbs - Gets the sum value (in absolute value) of each row of the matrix

5326:   Logically Collective

5328:   Input Parameter:
5329: . mat - the matrix

5331:   Output Parameter:
5332: . v - the vector for storing the sum

5334:   Level: intermediate

5336:   This code is only implemented for a couple of matrix formats.

5338: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5339: @*/
5340: PetscErrorCode MatGetRowSumAbs(Mat mat, Vec v)
5341: {
5342:   PetscFunctionBegin;
5346:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5348:   if (!mat->cmap->N) PetscCall(VecSet(v, 0.0));
5349:   else {
5350:     MatCheckPreallocated(mat, 1);
5351:     PetscUseTypeMethod(mat, getrowsumabs, v);
5352:   }
5353:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5354:   PetscFunctionReturn(PETSC_SUCCESS);
5355: }

5357: /*@
5358:   MatGetRowSum - Gets the sum of each row of the matrix

5360:   Logically or Neighborhood Collective

5362:   Input Parameter:
5363: . mat - the matrix

5365:   Output Parameter:
5366: . v - the vector for storing the sum of rows

5368:   Level: intermediate

5370:   Note:
5371:   This code is slow since it is not currently specialized for different formats

5373: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`, `MatGetRowSumAbs()`
5374: @*/
5375: PetscErrorCode MatGetRowSum(Mat mat, Vec v)
5376: {
5377:   Vec ones;

5379:   PetscFunctionBegin;
5383:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5384:   MatCheckPreallocated(mat, 1);
5385:   PetscCall(MatCreateVecs(mat, &ones, NULL));
5386:   PetscCall(VecSet(ones, 1.));
5387:   PetscCall(MatMult(mat, ones, v));
5388:   PetscCall(VecDestroy(&ones));
5389:   PetscFunctionReturn(PETSC_SUCCESS);
5390: }

5392: /*@
5393:   MatTransposeSetPrecursor - Set the matrix from which the second matrix will receive numerical transpose data with a call to `MatTranspose`(A,`MAT_REUSE_MATRIX`,&B)
5394:   when B was not obtained with `MatTranspose`(A,`MAT_INITIAL_MATRIX`,&B)

5396:   Collective

5398:   Input Parameter:
5399: . mat - the matrix to provide the transpose

5401:   Output Parameter:
5402: . 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

5404:   Level: advanced

5406:   Note:
5407:   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
5408:   routine allows bypassing that call.

5410: .seealso: [](ch_matrices), `Mat`, `MatTransposeSymbolic()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5411: @*/
5412: PetscErrorCode MatTransposeSetPrecursor(Mat mat, Mat B)
5413: {
5414:   MatParentState *rb = NULL;

5416:   PetscFunctionBegin;
5417:   PetscCall(PetscNew(&rb));
5418:   rb->id    = ((PetscObject)mat)->id;
5419:   rb->state = 0;
5420:   PetscCall(MatGetNonzeroState(mat, &rb->nonzerostate));
5421:   PetscCall(PetscObjectContainerCompose((PetscObject)B, "MatTransposeParent", rb, PetscCtxDestroyDefault));
5422:   PetscFunctionReturn(PETSC_SUCCESS);
5423: }

5425: static PetscErrorCode MatTranspose_Private(Mat mat, MatReuse reuse, Mat *B, PetscBool conjugate)
5426: {
5427:   PetscContainer  rB                        = NULL;
5428:   MatParentState *rb                        = NULL;
5429:   PetscErrorCode (*f)(Mat, MatReuse, Mat *) = NULL;

5431:   PetscFunctionBegin;
5434:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5435:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5436:   PetscCheck(reuse != MAT_INPLACE_MATRIX || mat == *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires last matrix to match first");
5437:   PetscCheck(reuse != MAT_REUSE_MATRIX || mat != *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Perhaps you mean MAT_INPLACE_MATRIX");
5438:   MatCheckPreallocated(mat, 1);
5439:   if (reuse == MAT_REUSE_MATRIX) {
5440:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5441:     PetscCheck(rB, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose(). Suggest MatTransposeSetPrecursor().");
5442:     PetscCall(PetscContainerGetPointer(rB, &rb));
5443:     PetscCheck(rb->id == ((PetscObject)mat)->id, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5444:     if (rb->state == ((PetscObject)mat)->state) PetscFunctionReturn(PETSC_SUCCESS);
5445:   }

5447:   if (conjugate) {
5448:     f = mat->ops->hermitiantranspose;
5449:     if (f) PetscCall((*f)(mat, reuse, B));
5450:   }
5451:   if (!f && !(reuse == MAT_INPLACE_MATRIX && mat->hermitian == PETSC_BOOL3_TRUE && conjugate)) {
5452:     PetscCall(PetscLogEventBegin(MAT_Transpose, mat, 0, 0, 0));
5453:     if (reuse != MAT_INPLACE_MATRIX || mat->symmetric != PETSC_BOOL3_TRUE) {
5454:       PetscUseTypeMethod(mat, transpose, reuse, B);
5455:       PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5456:     }
5457:     PetscCall(PetscLogEventEnd(MAT_Transpose, mat, 0, 0, 0));
5458:     if (conjugate) PetscCall(MatConjugate(*B));
5459:   }

5461:   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatTransposeSetPrecursor(mat, *B));
5462:   if (reuse != MAT_INPLACE_MATRIX) {
5463:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5464:     PetscCall(PetscContainerGetPointer(rB, &rb));
5465:     rb->state        = ((PetscObject)mat)->state;
5466:     rb->nonzerostate = mat->nonzerostate;
5467:   }
5468:   PetscFunctionReturn(PETSC_SUCCESS);
5469: }

5471: /*@
5472:   MatTranspose - Computes the transpose of a matrix, either in-place or out-of-place.

5474:   Collective

5476:   Input Parameters:
5477: + mat   - the matrix to transpose
5478: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5480:   Output Parameter:
5481: . B - the transpose of the matrix

5483:   Level: intermediate

5485:   Notes:
5486:   If you use `MAT_INPLACE_MATRIX` then you must pass in `&mat` for `B`

5488:   `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
5489:   transpose, call `MatTransposeSetPrecursor(mat, B)` before calling this routine.

5491:   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.

5493:   Consider using `MatCreateTranspose()` instead if you only need a matrix that behaves like the transpose but don't need the storage to be changed.
5494:   For example, the result of `MatCreateTranspose()` will compute the transpose of the given matrix times a vector for matrix-vector products computed with `MatMult()`.

5496:   If `mat` is unchanged from the last call this function returns immediately without recomputing the result

5498:   If you only need the symbolic transpose of a matrix, and not the numerical values, use `MatTransposeSymbolic()`

5500: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`,
5501:           `MatTransposeSymbolic()`, `MatCreateTranspose()`
5502: @*/
5503: PetscErrorCode MatTranspose(Mat mat, MatReuse reuse, Mat *B)
5504: {
5505:   PetscFunctionBegin;
5506:   PetscCall(MatTranspose_Private(mat, reuse, B, PETSC_FALSE));
5507:   PetscFunctionReturn(PETSC_SUCCESS);
5508: }

5510: /*@
5511:   MatTransposeSymbolic - Computes the symbolic part of the transpose of a matrix.

5513:   Collective

5515:   Input Parameter:
5516: . A - the matrix to transpose

5518:   Output Parameter:
5519: . 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
5520:       numerical portion.

5522:   Level: intermediate

5524:   Note:
5525:   This is not supported for many matrix types, use `MatTranspose()` in those cases

5527: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5528: @*/
5529: PetscErrorCode MatTransposeSymbolic(Mat A, Mat *B)
5530: {
5531:   PetscFunctionBegin;
5534:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5535:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5536:   PetscCall(PetscLogEventBegin(MAT_Transpose, A, 0, 0, 0));
5537:   PetscUseTypeMethod(A, transposesymbolic, B);
5538:   PetscCall(PetscLogEventEnd(MAT_Transpose, A, 0, 0, 0));

5540:   PetscCall(MatTransposeSetPrecursor(A, *B));
5541:   PetscFunctionReturn(PETSC_SUCCESS);
5542: }

5544: PetscErrorCode MatTransposeCheckNonzeroState_Private(Mat A, Mat B)
5545: {
5546:   PetscContainer  rB;
5547:   MatParentState *rb;

5549:   PetscFunctionBegin;
5552:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5553:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5554:   PetscCall(PetscObjectQuery((PetscObject)B, "MatTransposeParent", (PetscObject *)&rB));
5555:   PetscCheck(rB, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose()");
5556:   PetscCall(PetscContainerGetPointer(rB, &rb));
5557:   PetscCheck(rb->id == ((PetscObject)A)->id, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5558:   PetscCheck(rb->nonzerostate == A->nonzerostate, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Reuse matrix has changed nonzero structure");
5559:   PetscFunctionReturn(PETSC_SUCCESS);
5560: }

5562: /*@
5563:   MatIsTranspose - Test whether a matrix is another one's transpose,
5564:   or its own, in which case it tests symmetry.

5566:   Collective

5568:   Input Parameters:
5569: + A   - the matrix to test
5570: . B   - the matrix to test against, this can equal the first parameter
5571: - tol - tolerance, differences between entries smaller than this are counted as zero

5573:   Output Parameter:
5574: . flg - the result

5576:   Level: intermediate

5578:   Notes:
5579:   The sequential algorithm has a running time of the order of the number of nonzeros; the parallel
5580:   test involves parallel copies of the block off-diagonal parts of the matrix.

5582: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`
5583: @*/
5584: PetscErrorCode MatIsTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5585: {
5586:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5588:   PetscFunctionBegin;
5591:   PetscAssertPointer(flg, 4);
5592:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsTranspose_C", &f));
5593:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsTranspose_C", &g));
5594:   *flg = PETSC_FALSE;
5595:   if (f && g) {
5596:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for symmetry test");
5597:     PetscCall((*f)(A, B, tol, flg));
5598:   } else {
5599:     MatType mattype;

5601:     PetscCall(MatGetType(f ? B : A, &mattype));
5602:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for transpose", mattype);
5603:   }
5604:   PetscFunctionReturn(PETSC_SUCCESS);
5605: }

5607: /*@
5608:   MatHermitianTranspose - Computes an in-place or out-of-place Hermitian transpose of a matrix in complex conjugate.

5610:   Collective

5612:   Input Parameters:
5613: + mat   - the matrix to transpose and complex conjugate
5614: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5616:   Output Parameter:
5617: . B - the Hermitian transpose

5619:   Level: intermediate

5621: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`
5622: @*/
5623: PetscErrorCode MatHermitianTranspose(Mat mat, MatReuse reuse, Mat *B)
5624: {
5625:   PetscFunctionBegin;
5626:   PetscCall(MatTranspose_Private(mat, reuse, B, PETSC_TRUE));
5627:   PetscFunctionReturn(PETSC_SUCCESS);
5628: }

5630: /*@
5631:   MatIsHermitianTranspose - Test whether a matrix is another one's Hermitian transpose,

5633:   Collective

5635:   Input Parameters:
5636: + A   - the matrix to test
5637: . B   - the matrix to test against, this can equal the first parameter
5638: - tol - tolerance, differences between entries smaller than this are counted as zero

5640:   Output Parameter:
5641: . flg - the result

5643:   Level: intermediate

5645:   Notes:
5646:   Only available for `MATAIJ` matrices.

5648:   The sequential algorithm
5649:   has a running time of the order of the number of nonzeros; the parallel
5650:   test involves parallel copies of the block off-diagonal parts of the matrix.

5652: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsTranspose()`
5653: @*/
5654: PetscErrorCode MatIsHermitianTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5655: {
5656:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5658:   PetscFunctionBegin;
5661:   PetscAssertPointer(flg, 4);
5662:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsHermitianTranspose_C", &f));
5663:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsHermitianTranspose_C", &g));
5664:   if (f && g) {
5665:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for Hermitian test");
5666:     PetscCall((*f)(A, B, tol, flg));
5667:   } else {
5668:     MatType mattype;

5670:     PetscCall(MatGetType(f ? B : A, &mattype));
5671:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for Hermitian transpose", mattype);
5672:   }
5673:   PetscFunctionReturn(PETSC_SUCCESS);
5674: }

5676: /*@
5677:   MatPermute - Creates a new matrix with rows and columns permuted from the
5678:   original.

5680:   Collective

5682:   Input Parameters:
5683: + mat - the matrix to permute
5684: . row - row permutation, each processor supplies only the permutation for its rows
5685: - col - column permutation, each processor supplies only the permutation for its columns

5687:   Output Parameter:
5688: . B - the permuted matrix

5690:   Level: advanced

5692:   Note:
5693:   The index sets map from row/col of permuted matrix to row/col of original matrix.
5694:   The index sets should be on the same communicator as mat and have the same local sizes.

5696:   Developer Note:
5697:   If you want to implement `MatPermute()` for a matrix type, and your approach doesn't
5698:   exploit the fact that row and col are permutations, consider implementing the
5699:   more general `MatCreateSubMatrix()` instead.

5701: .seealso: [](ch_matrices), `Mat`, `MatGetOrdering()`, `ISAllGather()`, `MatCreateSubMatrix()`
5702: @*/
5703: PetscErrorCode MatPermute(Mat mat, IS row, IS col, Mat *B)
5704: {
5705:   PetscFunctionBegin;
5710:   PetscAssertPointer(B, 4);
5711:   PetscCheckSameComm(mat, 1, row, 2);
5712:   if (row != col) PetscCheckSameComm(row, 2, col, 3);
5713:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5714:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5715:   PetscCheck(mat->ops->permute || mat->ops->createsubmatrix, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatPermute not available for Mat type %s", ((PetscObject)mat)->type_name);
5716:   MatCheckPreallocated(mat, 1);

5718:   if (mat->ops->permute) {
5719:     PetscUseTypeMethod(mat, permute, row, col, B);
5720:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5721:   } else {
5722:     PetscCall(MatCreateSubMatrix(mat, row, col, MAT_INITIAL_MATRIX, B));
5723:   }
5724:   PetscFunctionReturn(PETSC_SUCCESS);
5725: }

5727: /*@
5728:   MatEqual - Compares two matrices.

5730:   Collective

5732:   Input Parameters:
5733: + A - the first matrix
5734: - B - the second matrix

5736:   Output Parameter:
5737: . flg - `PETSC_TRUE` if the matrices are equal; `PETSC_FALSE` otherwise.

5739:   Level: intermediate

5741:   Note:
5742:   If either of the matrix is "matrix-free", meaning the matrix entries are not stored explicitly then equality is determined by comparing
5743:   the results of several matrix-vector product using randomly created vectors, see `MatMultEqual()`.

5745: .seealso: [](ch_matrices), `Mat`, `MatMultEqual()`
5746: @*/
5747: PetscErrorCode MatEqual(Mat A, Mat B, PetscBool *flg)
5748: {
5749:   PetscFunctionBegin;
5754:   PetscAssertPointer(flg, 3);
5755:   PetscCheckSameComm(A, 1, B, 2);
5756:   MatCheckPreallocated(A, 1);
5757:   MatCheckPreallocated(B, 2);
5758:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5759:   PetscCheck(B->assembled, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5760:   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,
5761:              B->cmap->N);
5762:   if (A->ops->equal && A->ops->equal == B->ops->equal) PetscUseTypeMethod(A, equal, B, flg);
5763:   else PetscCall(MatMultEqual(A, B, 10, flg));
5764:   PetscFunctionReturn(PETSC_SUCCESS);
5765: }

5767: /*@
5768:   MatDiagonalScale - Scales a matrix on the left and right by diagonal
5769:   matrices that are stored as vectors.  Either of the two scaling
5770:   matrices can be `NULL`.

5772:   Collective

5774:   Input Parameters:
5775: + mat - the matrix to be scaled
5776: . l   - the left scaling vector (or `NULL`)
5777: - r   - the right scaling vector (or `NULL`)

5779:   Level: intermediate

5781:   Note:
5782:   `MatDiagonalScale()` computes $A = LAR$, where
5783:   L = a diagonal matrix (stored as a vector), R = a diagonal matrix (stored as a vector)
5784:   The L scales the rows of the matrix, the R scales the columns of the matrix.

5786: .seealso: [](ch_matrices), `Mat`, `MatScale()`, `MatShift()`, `MatDiagonalSet()`
5787: @*/
5788: PetscErrorCode MatDiagonalScale(Mat mat, Vec l, Vec r)
5789: {
5790:   PetscBool flg = PETSC_FALSE;

5792:   PetscFunctionBegin;
5795:   if (l) {
5797:     PetscCheckSameComm(mat, 1, l, 2);
5798:   }
5799:   if (r) {
5801:     PetscCheckSameComm(mat, 1, r, 3);
5802:   }
5803:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5804:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5805:   MatCheckPreallocated(mat, 1);
5806:   if (!l && !r) PetscFunctionReturn(PETSC_SUCCESS);

5808:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5809:   PetscUseTypeMethod(mat, diagonalscale, l, r);
5810:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5811:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5812:   if (l != r && (PetscBool3ToBool(mat->symmetric) || PetscBool3ToBool(mat->hermitian))) {
5813:     if (!PetscDefined(USE_COMPLEX) || PetscBool3ToBool(mat->symmetric)) {
5814:       if (l && r) PetscCall(VecEqual(l, r, &flg));
5815:       if (!flg) {
5816:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
5817:         PetscCheck(!flg, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "For symmetric format, left and right scaling vectors must be the same");
5818:         mat->symmetric = mat->spd = PETSC_BOOL3_FALSE;
5819:         if (!PetscDefined(USE_COMPLEX)) mat->hermitian = PETSC_BOOL3_FALSE;
5820:         else mat->hermitian = PETSC_BOOL3_UNKNOWN;
5821:       }
5822:     }
5823:     if (PetscDefined(USE_COMPLEX) && PetscBool3ToBool(mat->hermitian)) {
5824:       flg = PETSC_FALSE;
5825:       if (l && r) {
5826:         Vec conjugate;

5828:         PetscCall(VecDuplicate(l, &conjugate));
5829:         PetscCall(VecCopy(l, conjugate));
5830:         PetscCall(VecConjugate(conjugate));
5831:         PetscCall(VecEqual(conjugate, r, &flg));
5832:         PetscCall(VecDestroy(&conjugate));
5833:       }
5834:       if (!flg) {
5835:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
5836:         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");
5837:         mat->hermitian = PETSC_BOOL3_FALSE;
5838:         mat->symmetric = mat->spd = PETSC_BOOL3_UNKNOWN;
5839:       }
5840:     }
5841:   }
5842:   PetscFunctionReturn(PETSC_SUCCESS);
5843: }

5845: /*@
5846:   MatScale - Scales all elements of a matrix by a given number.

5848:   Logically Collective

5850:   Input Parameters:
5851: + mat - the matrix to be scaled
5852: - a   - the scaling value

5854:   Level: intermediate

5856: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
5857: @*/
5858: PetscErrorCode MatScale(Mat mat, PetscScalar a)
5859: {
5860:   PetscFunctionBegin;
5863:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5864:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5866:   MatCheckPreallocated(mat, 1);

5868:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5869:   if (a != (PetscScalar)1.0) {
5870:     PetscUseTypeMethod(mat, scale, a);
5871:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5872:   }
5873:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5874:   PetscFunctionReturn(PETSC_SUCCESS);
5875: }

5877: /*@
5878:   MatNorm - Calculates various norms of a matrix.

5880:   Collective

5882:   Input Parameters:
5883: + mat  - the matrix
5884: - type - the type of norm, `NORM_1`, `NORM_FROBENIUS`, `NORM_INFINITY`

5886:   Output Parameter:
5887: . nrm - the resulting norm

5889:   Level: intermediate

5891: .seealso: [](ch_matrices), `Mat`
5892: @*/
5893: PetscErrorCode MatNorm(Mat mat, NormType type, PetscReal *nrm)
5894: {
5895:   PetscFunctionBegin;
5898:   PetscAssertPointer(nrm, 3);

5900:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5901:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5902:   MatCheckPreallocated(mat, 1);

5904:   PetscUseTypeMethod(mat, norm, type, nrm);
5905:   PetscFunctionReturn(PETSC_SUCCESS);
5906: }

5908: /*
5909:      This variable is used to prevent counting of MatAssemblyBegin() that
5910:    are called from within a MatAssemblyEnd().
5911: */
5912: static PetscInt MatAssemblyEnd_InUse = 0;
5913: /*@
5914:   MatAssemblyBegin - Begins assembling the matrix.  This routine should
5915:   be called after completing all calls to `MatSetValues()`.

5917:   Collective

5919:   Input Parameters:
5920: + mat  - the matrix
5921: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5923:   Level: beginner

5925:   Notes:
5926:   `MatSetValues()` generally caches the values that belong to other MPI processes.  The matrix is ready to
5927:   use only after `MatAssemblyBegin()` and `MatAssemblyEnd()` have been called.

5929:   Use `MAT_FLUSH_ASSEMBLY` when switching between `ADD_VALUES` and `INSERT_VALUES`
5930:   in `MatSetValues()`; use `MAT_FINAL_ASSEMBLY` for the final assembly before
5931:   using the matrix.

5933:   ALL processes that share a matrix MUST call `MatAssemblyBegin()` and `MatAssemblyEnd()` the SAME NUMBER of times, and each time with the
5934:   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
5935:   a global collective operation requiring all processes that share the matrix.

5937:   Space for preallocated nonzeros that is not filled by a call to `MatSetValues()` or a related routine are compressed
5938:   out by assembly. If you intend to use that extra space on a subsequent assembly, be sure to insert explicit zeros
5939:   before `MAT_FINAL_ASSEMBLY` so the space is not compressed out.

5941: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssembled()`
5942: @*/
5943: PetscErrorCode MatAssemblyBegin(Mat mat, MatAssemblyType type)
5944: {
5945:   PetscFunctionBegin;
5948:   MatCheckPreallocated(mat, 1);
5949:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix. Did you forget to call MatSetUnfactored()?");
5950:   if (mat->assembled) {
5951:     mat->was_assembled = PETSC_TRUE;
5952:     mat->assembled     = PETSC_FALSE;
5953:   }

5955:   if (!MatAssemblyEnd_InUse) {
5956:     PetscCall(PetscLogEventBegin(MAT_AssemblyBegin, mat, 0, 0, 0));
5957:     PetscTryTypeMethod(mat, assemblybegin, type);
5958:     PetscCall(PetscLogEventEnd(MAT_AssemblyBegin, mat, 0, 0, 0));
5959:   } else PetscTryTypeMethod(mat, assemblybegin, type);
5960:   PetscFunctionReturn(PETSC_SUCCESS);
5961: }

5963: /*@
5964:   MatAssembled - Indicates if a matrix has been assembled and is ready for
5965:   use; for example, in matrix-vector product.

5967:   Not Collective

5969:   Input Parameter:
5970: . mat - the matrix

5972:   Output Parameter:
5973: . assembled - `PETSC_TRUE` or `PETSC_FALSE`

5975:   Level: advanced

5977: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssemblyBegin()`
5978: @*/
5979: PetscErrorCode MatAssembled(Mat mat, PetscBool *assembled)
5980: {
5981:   PetscFunctionBegin;
5983:   PetscAssertPointer(assembled, 2);
5984:   *assembled = mat->assembled;
5985:   PetscFunctionReturn(PETSC_SUCCESS);
5986: }

5988: /*@
5989:   MatAssemblyEnd - Completes assembling the matrix.  This routine should
5990:   be called after `MatAssemblyBegin()`.

5992:   Collective

5994:   Input Parameters:
5995: + mat  - the matrix
5996: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5998:   Options Database Key:
5999: . -mat_view [viewertype][:...] - option name and values. See `MatViewFromOptions()`/`PetscObjectViewFromOptions()` for the possible arguments

6001:   Level: beginner

6003: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatSetValues()`, `PetscDrawOpenX()`, `PetscDrawCreate()`, `MatView()`, `MatAssembled()`, `PetscViewerSocketOpen()`,
6004:           `MatViewFromOptions()`, `PetscObjectViewFromOptions()`
6005: @*/
6006: PetscErrorCode MatAssemblyEnd(Mat mat, MatAssemblyType type)
6007: {
6008:   static PetscInt inassm = 0;
6009:   PetscBool       flg    = PETSC_FALSE;

6011:   PetscFunctionBegin;

6015:   inassm++;
6016:   MatAssemblyEnd_InUse++;
6017:   if (MatAssemblyEnd_InUse == 1) { /* Do the logging only the first time through */
6018:     PetscCall(PetscLogEventBegin(MAT_AssemblyEnd, mat, 0, 0, 0));
6019:     PetscTryTypeMethod(mat, assemblyend, type);
6020:     PetscCall(PetscLogEventEnd(MAT_AssemblyEnd, mat, 0, 0, 0));
6021:   } else PetscTryTypeMethod(mat, assemblyend, type);

6023:   /* Flush assembly is not a true assembly */
6024:   if (type != MAT_FLUSH_ASSEMBLY) {
6025:     if (mat->num_ass) {
6026:       if (!mat->symmetry_eternal) {
6027:         mat->symmetric = PETSC_BOOL3_UNKNOWN;
6028:         mat->hermitian = PETSC_BOOL3_UNKNOWN;
6029:       }
6030:       if (!mat->structural_symmetry_eternal && mat->ass_nonzerostate != mat->nonzerostate) mat->structurally_symmetric = PETSC_BOOL3_UNKNOWN;
6031:       if (!mat->spd_eternal) mat->spd = PETSC_BOOL3_UNKNOWN;
6032:     }
6033:     mat->num_ass++;
6034:     mat->assembled        = PETSC_TRUE;
6035:     mat->ass_nonzerostate = mat->nonzerostate;
6036:   }

6038:   mat->insertmode = NOT_SET_VALUES;
6039:   MatAssemblyEnd_InUse--;
6040:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6041:   if (inassm == 1 && type != MAT_FLUSH_ASSEMBLY) {
6042:     PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));

6044:     if (mat->checksymmetryonassembly) {
6045:       PetscCall(MatIsSymmetric(mat, mat->checksymmetrytol, &flg));
6046:       if (flg) {
6047:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
6048:       } else {
6049:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is not symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
6050:       }
6051:     }
6052:     if (mat->nullsp && mat->checknullspaceonassembly) PetscCall(MatNullSpaceTest(mat->nullsp, mat, NULL));
6053:   }
6054:   inassm--;
6055:   PetscFunctionReturn(PETSC_SUCCESS);
6056: }

6058: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
6059: /*@
6060:   MatSetOption - Sets a parameter option for a matrix. Some options
6061:   may be specific to certain storage formats.  Some options
6062:   determine how values will be inserted (or added). Sorted,
6063:   row-oriented input will generally assemble the fastest. The default
6064:   is row-oriented.

6066:   Logically Collective for certain operations, such as `MAT_SPD`, not collective for `MAT_ROW_ORIENTED`, see `MatOption`

6068:   Input Parameters:
6069: + mat - the matrix
6070: . op  - the option, one of those listed below (and possibly others),
6071: - flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6073:   Options Describing Matrix Structure:
6074: + `MAT_SPD`                         - symmetric positive definite
6075: . `MAT_SYMMETRIC`                   - symmetric in terms of both structure and value
6076: . `MAT_HERMITIAN`                   - transpose is the complex conjugation
6077: . `MAT_STRUCTURALLY_SYMMETRIC`      - symmetric nonzero structure
6078: . `MAT_SYMMETRY_ETERNAL`            - indicates the symmetry (or Hermitian structure) or its absence will persist through any changes to the matrix
6079: . `MAT_STRUCTURAL_SYMMETRY_ETERNAL` - indicates the structural symmetry or its absence will persist through any changes to the matrix
6080: . `MAT_SPD_ETERNAL`                 - indicates the value of `MAT_SPD` (true or false) will persist through any changes to the matrix

6082:    These are not really options of the matrix, they are knowledge about the structure of the matrix that users may provide so that they
6083:    do not need to be computed (usually at a high cost)

6085:    Options For Use with `MatSetValues()`:
6086:    Insert a logically dense subblock, which can be
6087: . `MAT_ROW_ORIENTED`                - row-oriented (default)

6089:    These options reflect the data you pass in with `MatSetValues()`; it has
6090:    nothing to do with how the data is stored internally in the matrix
6091:    data structure.

6093:    When (re)assembling a matrix, we can restrict the input for
6094:    efficiency/debugging purposes.  These options include
6095: . `MAT_NEW_NONZERO_LOCATIONS`       - additional insertions will be allowed if they generate a new nonzero (slow)
6096: . `MAT_FORCE_DIAGONAL_ENTRIES`      - forces diagonal entries to be allocated
6097: . `MAT_IGNORE_OFF_PROC_ENTRIES`     - drops off-processor entries
6098: . `MAT_NEW_NONZERO_LOCATION_ERR`    - generates an error for new matrix entry
6099: . `MAT_USE_HASH_TABLE`              - uses a hash table to speed up matrix assembly
6100: . `MAT_NO_OFF_PROC_ENTRIES`         - you know each process will only set values for its own rows, will generate an error if
6101:         any process sets values for another process. This avoids all reductions in the MatAssembly routines and thus improves
6102:         performance for very large process counts.
6103: - `MAT_SUBSET_OFF_PROC_ENTRIES`     - you know that the first assembly after setting this flag will set a superset
6104:         of the off-process entries required for all subsequent assemblies. This avoids a rendezvous step in the MatAssembly
6105:         functions, instead sending only neighbor messages.

6107:   Level: intermediate

6109:   Notes:
6110:   Except for `MAT_UNUSED_NONZERO_LOCATION_ERR` and  `MAT_ROW_ORIENTED` all processes that share the matrix must pass the same value in flg!

6112:   Some options are relevant only for particular matrix types and
6113:   are thus ignored by others.  Other options are not supported by
6114:   certain matrix types and will generate an error message if set.

6116:   If using Fortran to compute a matrix, one may need to
6117:   use the column-oriented option (or convert to the row-oriented
6118:   format).

6120:   `MAT_NEW_NONZERO_LOCATIONS` set to `PETSC_FALSE` indicates that any add or insertion
6121:   that would generate a new entry in the nonzero structure is instead
6122:   ignored.  Thus, if memory has not already been allocated for this particular
6123:   data, then the insertion is ignored. For dense matrices, in which
6124:   the entire array is allocated, no entries are ever ignored.
6125:   Set after the first `MatAssemblyEnd()`. If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6127:   `MAT_NEW_NONZERO_LOCATION_ERR` set to PETSC_TRUE indicates that any add or insertion
6128:   that would generate a new entry in the nonzero structure instead produces
6129:   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

6131:   `MAT_NEW_NONZERO_ALLOCATION_ERR` set to `PETSC_TRUE` indicates that any add or insertion
6132:   that would generate a new entry that has not been preallocated will
6133:   instead produce an error. (Currently supported for `MATAIJ` and `MATBAIJ` formats
6134:   only.) This is a useful flag when debugging matrix memory preallocation.
6135:   If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6137:   `MAT_IGNORE_OFF_PROC_ENTRIES` set to `PETSC_TRUE` indicates entries destined for
6138:   other processors should be dropped, rather than stashed.
6139:   This is useful if you know that the "owning" processor is also
6140:   always generating the correct matrix entries, so that PETSc need
6141:   not transfer duplicate entries generated on another processor.

6143:   `MAT_USE_HASH_TABLE` indicates that a hash table be used to improve the
6144:   searches during matrix assembly. When this flag is set, the hash table
6145:   is created during the first matrix assembly. This hash table is
6146:   used the next time through, during `MatSetValues()`/`MatSetValuesBlocked()`
6147:   to improve the searching of indices. `MAT_NEW_NONZERO_LOCATIONS` flag
6148:   should be used with `MAT_USE_HASH_TABLE` flag. This option is currently
6149:   supported by `MATMPIBAIJ` format only.

6151:   `MAT_KEEP_NONZERO_PATTERN` indicates when `MatZeroRows()` is called the zeroed entries
6152:   are kept in the nonzero structure. This flag is not used for `MatZeroRowsColumns()`

6154:   `MAT_IGNORE_ZERO_ENTRIES` - for `MATAIJ` and `MATIS` matrices this will stop zero values from creating
6155:   a zero location in the matrix

6157:   `MAT_USE_INODES` - indicates using inode version of the code - works with `MATAIJ` matrix types

6159:   `MAT_NO_OFF_PROC_ZERO_ROWS` - you know each process will only zero its own rows. This avoids all reductions in the
6160:   zero row routines and thus improves performance for very large process counts.

6162:   `MAT_IGNORE_LOWER_TRIANGULAR` - For `MATSBAIJ` matrices will ignore any insertions you make in the lower triangular
6163:   part of the matrix (since they should match the upper triangular part).

6165:   `MAT_SORTED_FULL` - each process provides exactly its local rows; all column indices for a given row are passed in a
6166:   single call to `MatSetValues()`, preallocation is perfect, row-oriented, `INSERT_VALUES` is used. Common
6167:   with finite difference schemes with non-periodic boundary conditions.

6169:   Developer Note:
6170:   `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, and `MAT_SPD_ETERNAL` are used by `MatAssemblyEnd()` and in other
6171:   places where otherwise the value of `MAT_SYMMETRIC`, `MAT_STRUCTURALLY_SYMMETRIC` or `MAT_SPD` would need to be changed back
6172:   to `PETSC_BOOL3_UNKNOWN` because the matrix values had changed so the code cannot be certain that the related property had
6173:   not changed.

6175: .seealso: [](ch_matrices), `MatOption`, `Mat`, `MatGetOption()`
6176: @*/
6177: PetscErrorCode MatSetOption(Mat mat, MatOption op, PetscBool flg)
6178: {
6179:   PetscFunctionBegin;
6181:   if (op > 0) {
6184:   }

6186:   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);

6188:   switch (op) {
6189:   case MAT_FORCE_DIAGONAL_ENTRIES:
6190:     mat->force_diagonals = flg;
6191:     PetscFunctionReturn(PETSC_SUCCESS);
6192:   case MAT_NO_OFF_PROC_ENTRIES:
6193:     mat->nooffprocentries = flg;
6194:     PetscFunctionReturn(PETSC_SUCCESS);
6195:   case MAT_SUBSET_OFF_PROC_ENTRIES:
6196:     mat->assembly_subset = flg;
6197:     if (!mat->assembly_subset) { /* See the same logic in VecAssembly wrt VEC_SUBSET_OFF_PROC_ENTRIES */
6198: #if !defined(PETSC_HAVE_MPIUNI)
6199:       PetscCall(MatStashScatterDestroy_BTS(&mat->stash));
6200: #endif
6201:       mat->stash.first_assembly_done = PETSC_FALSE;
6202:     }
6203:     PetscFunctionReturn(PETSC_SUCCESS);
6204:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6205:     mat->nooffproczerorows = flg;
6206:     PetscFunctionReturn(PETSC_SUCCESS);
6207:   case MAT_SPD:
6208:     if (flg) {
6209:       mat->spd                    = PETSC_BOOL3_TRUE;
6210:       mat->symmetric              = PETSC_BOOL3_TRUE;
6211:       mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6212: #if !defined(PETSC_USE_COMPLEX)
6213:       mat->hermitian = PETSC_BOOL3_TRUE;
6214: #endif
6215:     } else {
6216:       mat->spd = PETSC_BOOL3_FALSE;
6217:     }
6218:     break;
6219:   case MAT_SYMMETRIC:
6220:     mat->symmetric = PetscBoolToBool3(flg);
6221:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6222: #if !defined(PETSC_USE_COMPLEX)
6223:     mat->hermitian = PetscBoolToBool3(flg);
6224: #endif
6225:     break;
6226:   case MAT_HERMITIAN:
6227:     mat->hermitian = PetscBoolToBool3(flg);
6228:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6229: #if !defined(PETSC_USE_COMPLEX)
6230:     mat->symmetric = PetscBoolToBool3(flg);
6231: #endif
6232:     break;
6233:   case MAT_STRUCTURALLY_SYMMETRIC:
6234:     mat->structurally_symmetric = PetscBoolToBool3(flg);
6235:     break;
6236:   case MAT_SYMMETRY_ETERNAL:
6237:     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");
6238:     mat->symmetry_eternal = flg;
6239:     if (flg) mat->structural_symmetry_eternal = PETSC_TRUE;
6240:     break;
6241:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6242:     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");
6243:     mat->structural_symmetry_eternal = flg;
6244:     break;
6245:   case MAT_SPD_ETERNAL:
6246:     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");
6247:     mat->spd_eternal = flg;
6248:     if (flg) {
6249:       mat->structural_symmetry_eternal = PETSC_TRUE;
6250:       mat->symmetry_eternal            = PETSC_TRUE;
6251:     }
6252:     break;
6253:   case MAT_STRUCTURE_ONLY:
6254:     mat->structure_only = flg;
6255:     break;
6256:   case MAT_SORTED_FULL:
6257:     mat->sortedfull = flg;
6258:     break;
6259:   default:
6260:     break;
6261:   }
6262:   PetscTryTypeMethod(mat, setoption, op, flg);
6263:   PetscFunctionReturn(PETSC_SUCCESS);
6264: }

6266: /*@
6267:   MatGetOption - Gets a parameter option that has been set for a matrix.

6269:   Logically Collective

6271:   Input Parameters:
6272: + mat - the matrix
6273: - op  - the option, this only responds to certain options, check the code for which ones

6275:   Output Parameter:
6276: . flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6278:   Level: intermediate

6280:   Notes:
6281:   Can only be called after `MatSetSizes()` and `MatSetType()` have been set.

6283:   Certain option values may be unknown, for those use the routines `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, or
6284:   `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`

6286: .seealso: [](ch_matrices), `Mat`, `MatOption`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`,
6287:     `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
6288: @*/
6289: PetscErrorCode MatGetOption(Mat mat, MatOption op, PetscBool *flg)
6290: {
6291:   PetscFunctionBegin;

6295:   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);
6296:   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()");

6298:   switch (op) {
6299:   case MAT_NO_OFF_PROC_ENTRIES:
6300:     *flg = mat->nooffprocentries;
6301:     break;
6302:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6303:     *flg = mat->nooffproczerorows;
6304:     break;
6305:   case MAT_SYMMETRIC:
6306:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSymmetric() or MatIsSymmetricKnown()");
6307:     break;
6308:   case MAT_HERMITIAN:
6309:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsHermitian() or MatIsHermitianKnown()");
6310:     break;
6311:   case MAT_STRUCTURALLY_SYMMETRIC:
6312:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsStructurallySymmetric() or MatIsStructurallySymmetricKnown()");
6313:     break;
6314:   case MAT_SPD:
6315:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSPDKnown()");
6316:     break;
6317:   case MAT_SYMMETRY_ETERNAL:
6318:     *flg = mat->symmetry_eternal;
6319:     break;
6320:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6321:     *flg = mat->symmetry_eternal;
6322:     break;
6323:   default:
6324:     break;
6325:   }
6326:   PetscFunctionReturn(PETSC_SUCCESS);
6327: }

6329: /*@
6330:   MatZeroEntries - Zeros all entries of a matrix.  For sparse matrices
6331:   this routine retains the old nonzero structure.

6333:   Logically Collective

6335:   Input Parameter:
6336: . mat - the matrix

6338:   Level: intermediate

6340:   Note:
6341:   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.
6342:   See the Performance chapter of the users manual for information on preallocating matrices.

6344: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`
6345: @*/
6346: PetscErrorCode MatZeroEntries(Mat mat)
6347: {
6348:   PetscFunctionBegin;
6351:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6352:   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");
6353:   MatCheckPreallocated(mat, 1);

6355:   PetscCall(PetscLogEventBegin(MAT_ZeroEntries, mat, 0, 0, 0));
6356:   PetscUseTypeMethod(mat, zeroentries);
6357:   PetscCall(PetscLogEventEnd(MAT_ZeroEntries, mat, 0, 0, 0));
6358:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6359:   PetscFunctionReturn(PETSC_SUCCESS);
6360: }

6362: /*@
6363:   MatZeroRowsColumns - Zeros all entries (except possibly the main diagonal)
6364:   of a set of rows and columns of a matrix.

6366:   Collective

6368:   Input Parameters:
6369: + mat     - the matrix
6370: . numRows - the number of rows/columns to zero
6371: . rows    - the global row indices
6372: . diag    - value put in the diagonal of the eliminated rows
6373: . x       - optional vector of the solution for zeroed rows (other entries in vector are not used), these must be set before this call
6374: - b       - optional vector of the right-hand side, that will be adjusted by provided solution entries

6376:   Level: intermediate

6378:   Notes:
6379:   This routine, along with `MatZeroRows()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6381:   For each zeroed row, the value of the corresponding `b` is set to diag times the value of the corresponding `x`.
6382:   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

6384:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6385:   Krylov method to take advantage of the known solution on the zeroed rows.

6387:   For the parallel case, all processes that share the matrix (i.e.,
6388:   those in the communicator used for matrix creation) MUST call this
6389:   routine, regardless of whether any rows being zeroed are owned by
6390:   them.

6392:   Unlike `MatZeroRows()`, this ignores the `MAT_KEEP_NONZERO_PATTERN` option value set with `MatSetOption()`, it merely zeros those entries in the matrix, but never
6393:   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
6394:   missing.

6396:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6397:   list only rows local to itself).

6399:   The option `MAT_NO_OFF_PROC_ZERO_ROWS` does not apply to this routine.

6401: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRows()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6402:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6403: @*/
6404: PetscErrorCode MatZeroRowsColumns(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6405: {
6406:   PetscFunctionBegin;
6409:   if (numRows) PetscAssertPointer(rows, 3);
6410:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6411:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6412:   MatCheckPreallocated(mat, 1);

6414:   PetscUseTypeMethod(mat, zerorowscolumns, numRows, rows, diag, x, b);
6415:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6416:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6417:   PetscFunctionReturn(PETSC_SUCCESS);
6418: }

6420: /*@
6421:   MatZeroRowsColumnsIS - Zeros all entries (except possibly the main diagonal)
6422:   of a set of rows and columns of a matrix.

6424:   Collective

6426:   Input Parameters:
6427: + mat  - the matrix
6428: . is   - the rows to zero
6429: . diag - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6430: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6431: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6433:   Level: intermediate

6435:   Note:
6436:   See `MatZeroRowsColumns()` for details on how this routine operates.

6438: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6439:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRows()`, `MatZeroRowsColumnsStencil()`
6440: @*/
6441: PetscErrorCode MatZeroRowsColumnsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6442: {
6443:   PetscInt        numRows;
6444:   const PetscInt *rows;

6446:   PetscFunctionBegin;
6451:   PetscCall(ISGetLocalSize(is, &numRows));
6452:   PetscCall(ISGetIndices(is, &rows));
6453:   PetscCall(MatZeroRowsColumns(mat, numRows, rows, diag, x, b));
6454:   PetscCall(ISRestoreIndices(is, &rows));
6455:   PetscFunctionReturn(PETSC_SUCCESS);
6456: }

6458: /*@
6459:   MatZeroRows - Zeros all entries (except possibly the main diagonal)
6460:   of a set of rows of a matrix.

6462:   Collective

6464:   Input Parameters:
6465: + mat     - the matrix
6466: . numRows - the number of rows to zero
6467: . rows    - the global row indices
6468: . diag    - value put in the diagonal of the zeroed rows
6469: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used), these must be set before this call
6470: - b       - optional vector of right-hand side, that will be adjusted by provided solution entries

6472:   Level: intermediate

6474:   Notes:
6475:   This routine, along with `MatZeroRowsColumns()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6477:   For each zeroed row, the value of the corresponding `b` is set to `diag` times the value of the corresponding `x`.

6479:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6480:   Krylov method to take advantage of the known solution on the zeroed rows.

6482:   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)
6483:   from the matrix.

6485:   Unlike `MatZeroRowsColumns()` for the `MATAIJ` and `MATBAIJ` matrix formats this removes the old nonzero structure, from the eliminated rows of the matrix
6486:   but does not release memory.  Because of this removal matrix-vector products with the adjusted matrix will be a bit faster. For the dense
6487:   formats this does not alter the nonzero structure.

6489:   If the option `MatSetOption`(mat,`MAT_KEEP_NONZERO_PATTERN`,`PETSC_TRUE`) the nonzero structure
6490:   of the matrix is not changed the values are
6491:   merely zeroed.

6493:   The user can set a value in the diagonal entry (or for the `MATAIJ` format
6494:   formats can optionally remove the main diagonal entry from the
6495:   nonzero structure as well, by passing 0.0 as the final argument).

6497:   For the parallel case, all processes that share the matrix (i.e.,
6498:   those in the communicator used for matrix creation) MUST call this
6499:   routine, regardless of whether any rows being zeroed are owned by
6500:   them.

6502:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6503:   list only rows local to itself).

6505:   You can call `MatSetOption`(mat,`MAT_NO_OFF_PROC_ZERO_ROWS`,`PETSC_TRUE`) if each process indicates only rows it
6506:   owns that are to be zeroed. This saves a global synchronization in the implementation.

6508: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6509:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `PCREDISTRIBUTE`, `MAT_KEEP_NONZERO_PATTERN`
6510: @*/
6511: PetscErrorCode MatZeroRows(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6512: {
6513:   PetscFunctionBegin;
6516:   if (numRows) PetscAssertPointer(rows, 3);
6517:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6518:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6519:   MatCheckPreallocated(mat, 1);

6521:   PetscUseTypeMethod(mat, zerorows, numRows, rows, diag, x, b);
6522:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6523:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6524:   PetscFunctionReturn(PETSC_SUCCESS);
6525: }

6527: /*@
6528:   MatZeroRowsIS - Zeros all entries (except possibly the main diagonal)
6529:   of a set of rows of a matrix indicated by an `IS`

6531:   Collective

6533:   Input Parameters:
6534: + mat  - the matrix
6535: . is   - index set, `IS`, of rows to remove (if `NULL` then no row is removed)
6536: . diag - value put in all diagonals of eliminated rows
6537: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6538: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6540:   Level: intermediate

6542:   Note:
6543:   See `MatZeroRows()` for details on how this routine operates.

6545: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6546:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `IS`
6547: @*/
6548: PetscErrorCode MatZeroRowsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6549: {
6550:   PetscInt        numRows = 0;
6551:   const PetscInt *rows    = NULL;

6553:   PetscFunctionBegin;
6556:   if (is) {
6558:     PetscCall(ISGetLocalSize(is, &numRows));
6559:     PetscCall(ISGetIndices(is, &rows));
6560:   }
6561:   PetscCall(MatZeroRows(mat, numRows, rows, diag, x, b));
6562:   if (is) PetscCall(ISRestoreIndices(is, &rows));
6563:   PetscFunctionReturn(PETSC_SUCCESS);
6564: }

6566: /*@
6567:   MatZeroRowsStencil - Zeros all entries (except possibly the main diagonal)
6568:   of a set of rows of a matrix indicated by a `MatStencil`. These rows must be local to the process.

6570:   Collective

6572:   Input Parameters:
6573: + mat     - the matrix
6574: . numRows - the number of rows to remove
6575: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows indicated by an array of `MatStencil`
6576: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6577: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6578: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6580:   Level: intermediate

6582:   Notes:
6583:   See `MatZeroRows()` for details on how this routine operates.

6585:   The grid coordinates are across the entire grid, not just the local portion

6587:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6588:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6589:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6590:   `DM_BOUNDARY_PERIODIC` boundary type.

6592:   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
6593:   a single value per point) you can skip filling those indices.

6595:   Fortran Note:
6596:   `idxm` and `idxn` should be declared as
6597: .vb
6598:     MatStencil idxm(4, m)
6599: .ve
6600:   and the values inserted using
6601: .vb
6602:     idxm(MatStencil_i, 1) = i
6603:     idxm(MatStencil_j, 1) = j
6604:     idxm(MatStencil_k, 1) = k
6605:     idxm(MatStencil_c, 1) = c
6606:    etc
6607: .ve

6609: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRows()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6610:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6611: @*/
6612: PetscErrorCode MatZeroRowsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6613: {
6614:   PetscInt  dim    = mat->stencil.dim;
6615:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6616:   PetscInt *dims   = mat->stencil.dims + 1;
6617:   PetscInt *starts = mat->stencil.starts;
6618:   PetscInt *dxm    = (PetscInt *)rows;
6619:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6621:   PetscFunctionBegin;
6624:   if (numRows) PetscAssertPointer(rows, 3);

6626:   PetscCall(PetscMalloc1(numRows, &jdxm));
6627:   for (i = 0; i < numRows; ++i) {
6628:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6629:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6630:     /* Local index in X dir */
6631:     tmp = *dxm++ - starts[0];
6632:     /* Loop over remaining dimensions */
6633:     for (j = 0; j < dim - 1; ++j) {
6634:       /* If nonlocal, set index to be negative */
6635:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6636:       /* Update local index */
6637:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6638:     }
6639:     /* Skip component slot if necessary */
6640:     if (mat->stencil.noc) dxm++;
6641:     /* Local row number */
6642:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6643:   }
6644:   PetscCall(MatZeroRowsLocal(mat, numNewRows, jdxm, diag, x, b));
6645:   PetscCall(PetscFree(jdxm));
6646:   PetscFunctionReturn(PETSC_SUCCESS);
6647: }

6649: /*@
6650:   MatZeroRowsColumnsStencil - Zeros all row and column entries (except possibly the main diagonal)
6651:   of a set of rows and columns of a matrix.

6653:   Collective

6655:   Input Parameters:
6656: + mat     - the matrix
6657: . numRows - the number of rows/columns to remove
6658: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows
6659: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6660: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6661: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6663:   Level: intermediate

6665:   Notes:
6666:   See `MatZeroRowsColumns()` for details on how this routine operates.

6668:   The grid coordinates are across the entire grid, not just the local portion

6670:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6671:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6672:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6673:   `DM_BOUNDARY_PERIODIC` boundary type.

6675:   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
6676:   a single value per point) you can skip filling those indices.

6678:   Fortran Note:
6679:   `idxm` and `idxn` should be declared as
6680: .vb
6681:     MatStencil idxm(4, m)
6682: .ve
6683:   and the values inserted using
6684: .vb
6685:     idxm(MatStencil_i, 1) = i
6686:     idxm(MatStencil_j, 1) = j
6687:     idxm(MatStencil_k, 1) = k
6688:     idxm(MatStencil_c, 1) = c
6689:     etc
6690: .ve

6692: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6693:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRows()`
6694: @*/
6695: PetscErrorCode MatZeroRowsColumnsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6696: {
6697:   PetscInt  dim    = mat->stencil.dim;
6698:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6699:   PetscInt *dims   = mat->stencil.dims + 1;
6700:   PetscInt *starts = mat->stencil.starts;
6701:   PetscInt *dxm    = (PetscInt *)rows;
6702:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6704:   PetscFunctionBegin;
6707:   if (numRows) PetscAssertPointer(rows, 3);

6709:   PetscCall(PetscMalloc1(numRows, &jdxm));
6710:   for (i = 0; i < numRows; ++i) {
6711:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6712:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6713:     /* Local index in X dir */
6714:     tmp = *dxm++ - starts[0];
6715:     /* Loop over remaining dimensions */
6716:     for (j = 0; j < dim - 1; ++j) {
6717:       /* If nonlocal, set index to be negative */
6718:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6719:       /* Update local index */
6720:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6721:     }
6722:     /* Skip component slot if necessary */
6723:     if (mat->stencil.noc) dxm++;
6724:     /* Local row number */
6725:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6726:   }
6727:   PetscCall(MatZeroRowsColumnsLocal(mat, numNewRows, jdxm, diag, x, b));
6728:   PetscCall(PetscFree(jdxm));
6729:   PetscFunctionReturn(PETSC_SUCCESS);
6730: }

6732: /*@
6733:   MatZeroRowsLocal - Zeros all entries (except possibly the main diagonal)
6734:   of a set of rows of a matrix; using local numbering of rows.

6736:   Collective

6738:   Input Parameters:
6739: + mat     - the matrix
6740: . numRows - the number of rows to remove
6741: . rows    - the local row indices
6742: . diag    - value put in all diagonals of eliminated rows
6743: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6744: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6746:   Level: intermediate

6748:   Notes:
6749:   Before calling `MatZeroRowsLocal()`, the user must first set the
6750:   local-to-global mapping by calling MatSetLocalToGlobalMapping(), this is often already set for matrices obtained with `DMCreateMatrix()`.

6752:   See `MatZeroRows()` for details on how this routine operates.

6754: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRows()`, `MatSetOption()`,
6755:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6756: @*/
6757: PetscErrorCode MatZeroRowsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6758: {
6759:   PetscFunctionBegin;
6762:   if (numRows) PetscAssertPointer(rows, 3);
6763:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6764:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6765:   MatCheckPreallocated(mat, 1);

6767:   if (mat->ops->zerorowslocal) {
6768:     PetscUseTypeMethod(mat, zerorowslocal, numRows, rows, diag, x, b);
6769:   } else {
6770:     IS        is, newis;
6771:     PetscInt *newRows, nl = 0;

6773:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6774:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6775:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6776:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6777:     for (PetscInt i = 0; i < numRows; i++)
6778:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6779:     PetscUseTypeMethod(mat, zerorows, nl, newRows, diag, x, b);
6780:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6781:     PetscCall(ISDestroy(&newis));
6782:     PetscCall(ISDestroy(&is));
6783:   }
6784:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6785:   PetscFunctionReturn(PETSC_SUCCESS);
6786: }

6788: /*@
6789:   MatZeroRowsLocalIS - Zeros all entries (except possibly the main diagonal)
6790:   of a set of rows of a matrix; using local numbering of rows.

6792:   Collective

6794:   Input Parameters:
6795: + mat  - the matrix
6796: . is   - index set of rows to remove
6797: . diag - value put in all diagonals of eliminated rows
6798: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6799: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6801:   Level: intermediate

6803:   Notes:
6804:   Before calling `MatZeroRowsLocalIS()`, the user must first set the
6805:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6807:   See `MatZeroRows()` for details on how this routine operates.

6809: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRows()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6810:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6811: @*/
6812: PetscErrorCode MatZeroRowsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6813: {
6814:   PetscInt        numRows;
6815:   const PetscInt *rows;

6817:   PetscFunctionBegin;
6821:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6822:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6823:   MatCheckPreallocated(mat, 1);

6825:   PetscCall(ISGetLocalSize(is, &numRows));
6826:   PetscCall(ISGetIndices(is, &rows));
6827:   PetscCall(MatZeroRowsLocal(mat, numRows, rows, diag, x, b));
6828:   PetscCall(ISRestoreIndices(is, &rows));
6829:   PetscFunctionReturn(PETSC_SUCCESS);
6830: }

6832: /*@
6833:   MatZeroRowsColumnsLocal - Zeros all entries (except possibly the main diagonal)
6834:   of a set of rows and columns of a matrix; using local numbering of rows.

6836:   Collective

6838:   Input Parameters:
6839: + mat     - the matrix
6840: . numRows - the number of rows to remove
6841: . rows    - the global row indices
6842: . diag    - value put in all diagonals of eliminated rows
6843: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6844: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6846:   Level: intermediate

6848:   Notes:
6849:   Before calling `MatZeroRowsColumnsLocal()`, the user must first set the
6850:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6852:   See `MatZeroRowsColumns()` for details on how this routine operates.

6854: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6855:           `MatZeroRows()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6856: @*/
6857: PetscErrorCode MatZeroRowsColumnsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6858: {
6859:   PetscFunctionBegin;
6862:   if (numRows) PetscAssertPointer(rows, 3);
6863:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6864:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6865:   MatCheckPreallocated(mat, 1);

6867:   if (mat->ops->zerorowscolumnslocal) {
6868:     PetscUseTypeMethod(mat, zerorowscolumnslocal, numRows, rows, diag, x, b);
6869:   } else {
6870:     IS        is, newis;
6871:     PetscInt *newRows, nl = 0;

6873:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6874:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6875:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6876:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6877:     for (PetscInt i = 0; i < numRows; i++)
6878:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6879:     PetscUseTypeMethod(mat, zerorowscolumns, nl, newRows, diag, x, b);
6880:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6881:     PetscCall(ISDestroy(&newis));
6882:     PetscCall(ISDestroy(&is));
6883:   }
6884:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6885:   PetscFunctionReturn(PETSC_SUCCESS);
6886: }

6888: /*@
6889:   MatZeroRowsColumnsLocalIS - Zeros all entries (except possibly the main diagonal)
6890:   of a set of rows and columns of a matrix; using local numbering of rows.

6892:   Collective

6894:   Input Parameters:
6895: + mat  - the matrix
6896: . is   - index set of rows to remove
6897: . diag - value put in all diagonals of eliminated rows
6898: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6899: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6901:   Level: intermediate

6903:   Notes:
6904:   Before calling `MatZeroRowsColumnsLocalIS()`, the user must first set the
6905:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6907:   See `MatZeroRowsColumns()` for details on how this routine operates.

6909: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6910:           `MatZeroRowsColumnsLocal()`, `MatZeroRows()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6911: @*/
6912: PetscErrorCode MatZeroRowsColumnsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6913: {
6914:   PetscInt        numRows;
6915:   const PetscInt *rows;

6917:   PetscFunctionBegin;
6921:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6922:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6923:   MatCheckPreallocated(mat, 1);

6925:   PetscCall(ISGetLocalSize(is, &numRows));
6926:   PetscCall(ISGetIndices(is, &rows));
6927:   PetscCall(MatZeroRowsColumnsLocal(mat, numRows, rows, diag, x, b));
6928:   PetscCall(ISRestoreIndices(is, &rows));
6929:   PetscFunctionReturn(PETSC_SUCCESS);
6930: }

6932: /*@
6933:   MatGetSize - Returns the numbers of rows and columns in a matrix.

6935:   Not Collective

6937:   Input Parameter:
6938: . mat - the matrix

6940:   Output Parameters:
6941: + m - the number of global rows
6942: - n - the number of global columns

6944:   Level: beginner

6946:   Note:
6947:   Both output parameters can be `NULL` on input.

6949: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetLocalSize()`
6950: @*/
6951: PetscErrorCode MatGetSize(Mat mat, PetscInt *m, PetscInt *n)
6952: {
6953:   PetscFunctionBegin;
6955:   if (m) *m = mat->rmap->N;
6956:   if (n) *n = mat->cmap->N;
6957:   PetscFunctionReturn(PETSC_SUCCESS);
6958: }

6960: /*@
6961:   MatGetLocalSize - For most matrix formats, excluding `MATELEMENTAL` and `MATSCALAPACK`, Returns the number of local rows and local columns
6962:   of a matrix. For all matrices this is the local size of the left and right vectors as returned by `MatCreateVecs()`.

6964:   Not Collective

6966:   Input Parameter:
6967: . mat - the matrix

6969:   Output Parameters:
6970: + m - the number of local rows, use `NULL` to not obtain this value
6971: - n - the number of local columns, use `NULL` to not obtain this value

6973:   Level: beginner

6975: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetSize()`
6976: @*/
6977: PetscErrorCode MatGetLocalSize(Mat mat, PetscInt *m, PetscInt *n)
6978: {
6979:   PetscFunctionBegin;
6981:   if (m) PetscAssertPointer(m, 2);
6982:   if (n) PetscAssertPointer(n, 3);
6983:   if (m) *m = mat->rmap->n;
6984:   if (n) *n = mat->cmap->n;
6985:   PetscFunctionReturn(PETSC_SUCCESS);
6986: }

6988: /*@
6989:   MatGetOwnershipRangeColumn - Returns the range of matrix columns associated with rows of a
6990:   vector one multiplies this matrix by that are owned by this processor.

6992:   Not Collective, unless matrix has not been allocated, then collective

6994:   Input Parameter:
6995: . mat - the matrix

6997:   Output Parameters:
6998: + m - the global index of the first local column, use `NULL` to not obtain this value
6999: - n - one more than the global index of the last local column, use `NULL` to not obtain this value

7001:   Level: developer

7003:   Notes:
7004:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7006:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7007:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7009:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7010:   the local values in the matrix.

7012:   Returns the columns of the "diagonal block" for most sparse matrix formats. See [Matrix
7013:   Layouts](sec_matlayout) for details on matrix layouts.

7015: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
7016:           `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
7017: @*/
7018: PetscErrorCode MatGetOwnershipRangeColumn(Mat mat, PetscInt *m, PetscInt *n)
7019: {
7020:   PetscFunctionBegin;
7023:   if (m) PetscAssertPointer(m, 2);
7024:   if (n) PetscAssertPointer(n, 3);
7025:   MatCheckPreallocated(mat, 1);
7026:   if (m) *m = mat->cmap->rstart;
7027:   if (n) *n = mat->cmap->rend;
7028:   PetscFunctionReturn(PETSC_SUCCESS);
7029: }

7031: /*@
7032:   MatGetOwnershipRange - For matrices that own values by row, excludes `MATELEMENTAL` and `MATSCALAPACK`, returns the range of matrix rows owned by
7033:   this MPI process.

7035:   Not Collective

7037:   Input Parameter:
7038: . mat - the matrix

7040:   Output Parameters:
7041: + m - the global index of the first local row, use `NULL` to not obtain this value
7042: - n - one more than the global index of the last local row, use `NULL` to not obtain this value

7044:   Level: beginner

7046:   Notes:
7047:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7049:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7050:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7052:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7053:   the local values in the matrix.

7055:   The high argument is one more than the last element stored locally.

7057:   For all matrices  it returns the range of matrix rows associated with rows of a vector that
7058:   would contain the result of a matrix vector product with this matrix. See [Matrix
7059:   Layouts](sec_matlayout) for details on matrix layouts.

7061: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscSplitOwnership()`,
7062:           `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
7063: @*/
7064: PetscErrorCode MatGetOwnershipRange(Mat mat, PetscInt *m, PetscInt *n)
7065: {
7066:   PetscFunctionBegin;
7069:   if (m) PetscAssertPointer(m, 2);
7070:   if (n) PetscAssertPointer(n, 3);
7071:   MatCheckPreallocated(mat, 1);
7072:   if (m) *m = mat->rmap->rstart;
7073:   if (n) *n = mat->rmap->rend;
7074:   PetscFunctionReturn(PETSC_SUCCESS);
7075: }

7077: /*@C
7078:   MatGetOwnershipRanges - For matrices that own values by row, excludes `MATELEMENTAL` and
7079:   `MATSCALAPACK`, returns the range of matrix rows owned by each process.

7081:   Not Collective, unless matrix has not been allocated

7083:   Input Parameter:
7084: . mat - the matrix

7086:   Output Parameter:
7087: . ranges - start of each processors portion plus one more than the total length at the end, of length `size` + 1
7088:            where `size` is the number of MPI processes used by `mat`

7090:   Level: beginner

7092:   Notes:
7093:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7095:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7096:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7098:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7099:   the local values in the matrix.

7101:   For all matrices  it returns the ranges of matrix rows associated with rows of a vector that
7102:   would contain the result of a matrix vector product with this matrix. See [Matrix
7103:   Layouts](sec_matlayout) for details on matrix layouts.

7105: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
7106:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `MatSetSizes()`, `MatCreateAIJ()`,
7107:           `DMDAGetGhostCorners()`, `DM`
7108: @*/
7109: PetscErrorCode MatGetOwnershipRanges(Mat mat, const PetscInt *ranges[])
7110: {
7111:   PetscFunctionBegin;
7114:   MatCheckPreallocated(mat, 1);
7115:   PetscCall(PetscLayoutGetRanges(mat->rmap, ranges));
7116:   PetscFunctionReturn(PETSC_SUCCESS);
7117: }

7119: /*@C
7120:   MatGetOwnershipRangesColumn - Returns the ranges of matrix columns associated with rows of a
7121:   vector one multiplies this vector by that are owned by each processor.

7123:   Not Collective, unless matrix has not been allocated

7125:   Input Parameter:
7126: . mat - the matrix

7128:   Output Parameter:
7129: . ranges - start of each processors portion plus one more than the total length at the end

7131:   Level: beginner

7133:   Notes:
7134:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7136:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7137:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7139:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7140:   the local values in the matrix.

7142:   Returns the columns of the "diagonal blocks", for most sparse matrix formats. See [Matrix
7143:   Layouts](sec_matlayout) for details on matrix layouts.

7145: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRanges()`,
7146:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`,
7147:           `DMDAGetGhostCorners()`, `DM`
7148: @*/
7149: PetscErrorCode MatGetOwnershipRangesColumn(Mat mat, const PetscInt *ranges[])
7150: {
7151:   PetscFunctionBegin;
7154:   MatCheckPreallocated(mat, 1);
7155:   PetscCall(PetscLayoutGetRanges(mat->cmap, ranges));
7156:   PetscFunctionReturn(PETSC_SUCCESS);
7157: }

7159: /*@
7160:   MatGetOwnershipIS - Get row and column ownership of a matrices' values as index sets.

7162:   Not Collective

7164:   Input Parameter:
7165: . A - matrix

7167:   Output Parameters:
7168: + rows - rows in which this process owns elements, , use `NULL` to not obtain this value
7169: - cols - columns in which this process owns elements, use `NULL` to not obtain this value

7171:   Level: intermediate

7173:   Note:
7174:   You should call `ISDestroy()` on the returned `IS`

7176:   For most matrices, excluding `MATELEMENTAL` and `MATSCALAPACK`, this corresponds to values
7177:   returned by `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`. For `MATELEMENTAL` and
7178:   `MATSCALAPACK` the ownership is more complicated. See [Matrix Layouts](sec_matlayout) for
7179:   details on matrix layouts.

7181: .seealso: [](ch_matrices), `IS`, `Mat`, `MatGetOwnershipRanges()`, `MatSetValues()`, `MATELEMENTAL`, `MATSCALAPACK`
7182: @*/
7183: PetscErrorCode MatGetOwnershipIS(Mat A, IS *rows, IS *cols)
7184: {
7185:   PetscErrorCode (*f)(Mat, IS *, IS *);

7187:   PetscFunctionBegin;
7190:   MatCheckPreallocated(A, 1);
7191:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatGetOwnershipIS_C", &f));
7192:   if (f) {
7193:     PetscCall((*f)(A, rows, cols));
7194:   } else { /* Create a standard row-based partition, each process is responsible for ALL columns in their row block */
7195:     if (rows) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->rmap->n, A->rmap->rstart, 1, rows));
7196:     if (cols) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->cmap->N, 0, 1, cols));
7197:   }
7198:   PetscFunctionReturn(PETSC_SUCCESS);
7199: }

7201: /*@
7202:   MatILUFactorSymbolic - Performs symbolic ILU factorization of a matrix obtained with `MatGetFactor()`
7203:   Uses levels of fill only, not drop tolerance. Use `MatLUFactorNumeric()`
7204:   to complete the factorization.

7206:   Collective

7208:   Input Parameters:
7209: + fact - the factorized matrix obtained with `MatGetFactor()`
7210: . mat  - the matrix
7211: . row  - row permutation
7212: . col  - column permutation
7213: - info - structure containing
7214: .vb
7215:       levels - number of levels of fill.
7216:       expected fill - as ratio of original fill.
7217:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
7218:                 missing diagonal entries)
7219: .ve

7221:   Level: developer

7223:   Notes:
7224:   See [Matrix Factorization](sec_matfactor) for additional information.

7226:   Most users should employ the `KSP` interface for linear solvers
7227:   instead of working directly with matrix algebra routines such as this.
7228:   See, e.g., `KSPCreate()`.

7230:   Uses the definition of level of fill as in Y. Saad, {cite}`saad2003`

7232:   Fortran Note:
7233:   A valid (non-null) `info` argument must be provided

7235: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
7236:           `MatGetOrdering()`, `MatFactorInfo`
7237: @*/
7238: PetscErrorCode MatILUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
7239: {
7240:   PetscFunctionBegin;
7245:   PetscAssertPointer(info, 5);
7246:   PetscAssertPointer(fact, 1);
7247:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels of fill negative %" PetscInt_FMT, (PetscInt)info->levels);
7248:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7249:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7250:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7251:   MatCheckPreallocated(mat, 2);

7253:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ILUFactorSymbolic, mat, row, col, 0));
7254:   PetscUseTypeMethod(fact, ilufactorsymbolic, mat, row, col, info);
7255:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ILUFactorSymbolic, mat, row, col, 0));
7256:   PetscFunctionReturn(PETSC_SUCCESS);
7257: }

7259: /*@
7260:   MatICCFactorSymbolic - Performs symbolic incomplete
7261:   Cholesky factorization for a symmetric matrix.  Use
7262:   `MatCholeskyFactorNumeric()` to complete the factorization.

7264:   Collective

7266:   Input Parameters:
7267: + fact - the factorized matrix obtained with `MatGetFactor()`
7268: . mat  - the matrix to be factored
7269: . perm - row and column permutation
7270: - info - structure containing
7271: .vb
7272:       levels - number of levels of fill.
7273:       expected fill - as ratio of original fill.
7274: .ve

7276:   Level: developer

7278:   Notes:
7279:   Most users should employ the `KSP` interface for linear solvers
7280:   instead of working directly with matrix algebra routines such as this.
7281:   See, e.g., `KSPCreate()`.

7283:   This uses the definition of level of fill as in Y. Saad {cite}`saad2003`

7285:   Fortran Note:
7286:   A valid (non-null) `info` argument must be provided

7288: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
7289: @*/
7290: PetscErrorCode MatICCFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
7291: {
7292:   PetscFunctionBegin;
7296:   PetscAssertPointer(info, 4);
7297:   PetscAssertPointer(fact, 1);
7298:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7299:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels negative %" PetscInt_FMT, (PetscInt)info->levels);
7300:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7301:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7302:   MatCheckPreallocated(mat, 2);

7304:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7305:   PetscUseTypeMethod(fact, iccfactorsymbolic, mat, perm, info);
7306:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7307:   PetscFunctionReturn(PETSC_SUCCESS);
7308: }

7310: /*@C
7311:   MatCreateSubMatrices - Extracts several submatrices from a matrix. If submat
7312:   points to an array of valid matrices, they may be reused to store the new
7313:   submatrices.

7315:   Collective

7317:   Input Parameters:
7318: + mat   - the matrix
7319: . n     - the number of submatrixes to be extracted (on this processor, may be zero)
7320: . irow  - index set of rows to extract
7321: . icol  - index set of columns to extract
7322: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7324:   Output Parameter:
7325: . submat - the array of submatrices

7327:   Level: advanced

7329:   Notes:
7330:   `MatCreateSubMatrices()` can extract ONLY sequential submatrices
7331:   (from both sequential and parallel matrices). Use `MatCreateSubMatrix()`
7332:   to extract a parallel submatrix.

7334:   Some matrix types place restrictions on the row and column
7335:   indices, such as that they be sorted or that they be equal to each other.

7337:   The index sets may not have duplicate entries.

7339:   When extracting submatrices from a parallel matrix, each processor can
7340:   form a different submatrix by setting the rows and columns of its
7341:   individual index sets according to the local submatrix desired.

7343:   When finished using the submatrices, the user should destroy
7344:   them with `MatDestroySubMatrices()`.

7346:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
7347:   original matrix has not changed from that last call to `MatCreateSubMatrices()`.

7349:   This routine creates the matrices in submat; you should NOT create them before
7350:   calling it. It also allocates the array of matrix pointers submat.

7352:   For `MATBAIJ` matrices the index sets must respect the block structure, that is if they
7353:   request one row/column in a block, they must request all rows/columns that are in
7354:   that block. For example, if the block size is 2 you cannot request just row 0 and
7355:   column 0.

7357:   Fortran Note:
7358: .vb
7359:   Mat, pointer :: submat(:)
7360: .ve

7362: .seealso: [](ch_matrices), `Mat`, `MatDestroySubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7363: @*/
7364: PetscErrorCode MatCreateSubMatrices(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7365: {
7366:   PetscInt  i;
7367:   PetscBool eq;

7369:   PetscFunctionBegin;
7372:   if (n) {
7373:     PetscAssertPointer(irow, 3);
7375:     PetscAssertPointer(icol, 4);
7377:   }
7378:   PetscAssertPointer(submat, 6);
7379:   if (n && scall == MAT_REUSE_MATRIX) {
7380:     PetscAssertPointer(*submat, 6);
7382:   }
7383:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7384:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7385:   MatCheckPreallocated(mat, 1);
7386:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7387:   PetscUseTypeMethod(mat, createsubmatrices, n, irow, icol, scall, submat);
7388:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7389:   for (i = 0; i < n; i++) {
7390:     (*submat)[i]->factortype = MAT_FACTOR_NONE; /* in case in place factorization was previously done on submatrix */
7391:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7392:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7393: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
7394:     if (mat->boundtocpu && mat->bindingpropagates) {
7395:       PetscCall(MatBindToCPU((*submat)[i], PETSC_TRUE));
7396:       PetscCall(MatSetBindingPropagates((*submat)[i], PETSC_TRUE));
7397:     }
7398: #endif
7399:   }
7400:   PetscFunctionReturn(PETSC_SUCCESS);
7401: }

7403: /*@C
7404:   MatCreateSubMatricesMPI - Extracts MPI submatrices across a sub communicator of `mat` (by pairs of `IS` that may live on subcomms).

7406:   Collective

7408:   Input Parameters:
7409: + mat   - the matrix
7410: . n     - the number of submatrixes to be extracted
7411: . irow  - index set of rows to extract
7412: . icol  - index set of columns to extract
7413: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7415:   Output Parameter:
7416: . submat - the array of submatrices

7418:   Level: advanced

7420:   Note:
7421:   This is used by `PCGASM`

7423: .seealso: [](ch_matrices), `Mat`, `PCGASM`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7424: @*/
7425: PetscErrorCode MatCreateSubMatricesMPI(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7426: {
7427:   PetscInt  i;
7428:   PetscBool eq;

7430:   PetscFunctionBegin;
7433:   if (n) {
7434:     PetscAssertPointer(irow, 3);
7436:     PetscAssertPointer(icol, 4);
7438:   }
7439:   PetscAssertPointer(submat, 6);
7440:   if (n && scall == MAT_REUSE_MATRIX) {
7441:     PetscAssertPointer(*submat, 6);
7443:   }
7444:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7445:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7446:   MatCheckPreallocated(mat, 1);

7448:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7449:   PetscUseTypeMethod(mat, createsubmatricesmpi, n, irow, icol, scall, submat);
7450:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7451:   for (i = 0; i < n; i++) {
7452:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7453:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7454:   }
7455:   PetscFunctionReturn(PETSC_SUCCESS);
7456: }

7458: /*@C
7459:   MatDestroyMatrices - Destroys an array of matrices

7461:   Collective

7463:   Input Parameters:
7464: + n   - the number of local matrices
7465: - mat - the matrices (this is a pointer to the array of matrices)

7467:   Level: advanced

7469:   Notes:
7470:   Frees not only the matrices, but also the array that contains the matrices

7472:   For matrices obtained with  `MatCreateSubMatrices()` use `MatDestroySubMatrices()`

7474: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroySubMatrices()`
7475: @*/
7476: PetscErrorCode MatDestroyMatrices(PetscInt n, Mat *mat[])
7477: {
7478:   PetscInt i;

7480:   PetscFunctionBegin;
7481:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7482:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7483:   PetscAssertPointer(mat, 2);

7485:   for (i = 0; i < n; i++) PetscCall(MatDestroy(&(*mat)[i]));

7487:   /* memory is allocated even if n = 0 */
7488:   PetscCall(PetscFree(*mat));
7489:   PetscFunctionReturn(PETSC_SUCCESS);
7490: }

7492: /*@C
7493:   MatDestroySubMatrices - Destroys a set of matrices obtained with `MatCreateSubMatrices()`.

7495:   Collective

7497:   Input Parameters:
7498: + n   - the number of local matrices
7499: - mat - the matrices (this is a pointer to the array of matrices, to match the calling sequence of `MatCreateSubMatrices()`)

7501:   Level: advanced

7503:   Note:
7504:   Frees not only the matrices, but also the array that contains the matrices

7506: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7507: @*/
7508: PetscErrorCode MatDestroySubMatrices(PetscInt n, Mat *mat[])
7509: {
7510:   Mat mat0;

7512:   PetscFunctionBegin;
7513:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7514:   /* mat[] is an array of length n+1, see MatCreateSubMatrices_xxx() */
7515:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7516:   PetscAssertPointer(mat, 2);

7518:   mat0 = (*mat)[0];
7519:   if (mat0 && mat0->ops->destroysubmatrices) {
7520:     PetscCall((*mat0->ops->destroysubmatrices)(n, mat));
7521:   } else {
7522:     PetscCall(MatDestroyMatrices(n, mat));
7523:   }
7524:   PetscFunctionReturn(PETSC_SUCCESS);
7525: }

7527: /*@
7528:   MatGetSeqNonzeroStructure - Extracts the nonzero structure from a matrix and stores it, in its entirety, on each process

7530:   Collective

7532:   Input Parameter:
7533: . mat - the matrix

7535:   Output Parameter:
7536: . matstruct - the sequential matrix with the nonzero structure of `mat`

7538:   Level: developer

7540: .seealso: [](ch_matrices), `Mat`, `MatDestroySeqNonzeroStructure()`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7541: @*/
7542: PetscErrorCode MatGetSeqNonzeroStructure(Mat mat, Mat *matstruct)
7543: {
7544:   PetscFunctionBegin;
7546:   PetscAssertPointer(matstruct, 2);

7549:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7550:   MatCheckPreallocated(mat, 1);

7552:   PetscCall(PetscLogEventBegin(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7553:   PetscUseTypeMethod(mat, getseqnonzerostructure, matstruct);
7554:   PetscCall(PetscLogEventEnd(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7555:   PetscFunctionReturn(PETSC_SUCCESS);
7556: }

7558: /*@C
7559:   MatDestroySeqNonzeroStructure - Destroys matrix obtained with `MatGetSeqNonzeroStructure()`.

7561:   Collective

7563:   Input Parameter:
7564: . mat - the matrix

7566:   Level: advanced

7568:   Note:
7569:   This is not needed, one can just call `MatDestroy()`

7571: .seealso: [](ch_matrices), `Mat`, `MatGetSeqNonzeroStructure()`
7572: @*/
7573: PetscErrorCode MatDestroySeqNonzeroStructure(Mat *mat)
7574: {
7575:   PetscFunctionBegin;
7576:   PetscAssertPointer(mat, 1);
7577:   PetscCall(MatDestroy(mat));
7578:   PetscFunctionReturn(PETSC_SUCCESS);
7579: }

7581: /*@
7582:   MatIncreaseOverlap - Given a set of submatrices indicated by index sets,
7583:   replaces the index sets by larger ones that represent submatrices with
7584:   additional overlap.

7586:   Collective

7588:   Input Parameters:
7589: + mat - the matrix
7590: . n   - the number of index sets
7591: . is  - the array of index sets (these index sets will changed during the call)
7592: - ov  - the additional overlap requested

7594:   Options Database Key:
7595: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7597:   Level: developer

7599:   Note:
7600:   The computed overlap preserves the matrix block sizes when the blocks are square.
7601:   That is: if a matrix nonzero for a given block would increase the overlap all columns associated with
7602:   that block are included in the overlap regardless of whether each specific column would increase the overlap.

7604: .seealso: [](ch_matrices), `Mat`, `PCASM`, `MatSetBlockSize()`, `MatIncreaseOverlapSplit()`, `MatCreateSubMatrices()`
7605: @*/
7606: PetscErrorCode MatIncreaseOverlap(Mat mat, PetscInt n, IS is[], PetscInt ov)
7607: {
7608:   PetscInt i, bs, cbs;

7610:   PetscFunctionBegin;
7614:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7615:   if (n) {
7616:     PetscAssertPointer(is, 3);
7618:   }
7619:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7620:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7621:   MatCheckPreallocated(mat, 1);

7623:   if (!ov || !n) PetscFunctionReturn(PETSC_SUCCESS);
7624:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7625:   PetscUseTypeMethod(mat, increaseoverlap, n, is, ov);
7626:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7627:   PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
7628:   if (bs == cbs) {
7629:     for (i = 0; i < n; i++) PetscCall(ISSetBlockSize(is[i], bs));
7630:   }
7631:   PetscFunctionReturn(PETSC_SUCCESS);
7632: }

7634: PetscErrorCode MatIncreaseOverlapSplit_Single(Mat, IS *, PetscInt);

7636: /*@
7637:   MatIncreaseOverlapSplit - Given a set of submatrices indicated by index sets across
7638:   a sub communicator, replaces the index sets by larger ones that represent submatrices with
7639:   additional overlap.

7641:   Collective

7643:   Input Parameters:
7644: + mat - the matrix
7645: . n   - the number of index sets
7646: . is  - the array of index sets (these index sets will changed during the call)
7647: - ov  - the additional overlap requested

7649:   `   Options Database Key:
7650: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7652:   Level: developer

7654: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatIncreaseOverlap()`
7655: @*/
7656: PetscErrorCode MatIncreaseOverlapSplit(Mat mat, PetscInt n, IS is[], PetscInt ov)
7657: {
7658:   PetscInt i;

7660:   PetscFunctionBegin;
7663:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7664:   if (n) {
7665:     PetscAssertPointer(is, 3);
7667:   }
7668:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7669:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7670:   MatCheckPreallocated(mat, 1);
7671:   if (!ov) PetscFunctionReturn(PETSC_SUCCESS);
7672:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7673:   for (i = 0; i < n; i++) PetscCall(MatIncreaseOverlapSplit_Single(mat, &is[i], ov));
7674:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7675:   PetscFunctionReturn(PETSC_SUCCESS);
7676: }

7678: /*@
7679:   MatGetBlockSize - Returns the matrix block size.

7681:   Not Collective

7683:   Input Parameter:
7684: . mat - the matrix

7686:   Output Parameter:
7687: . bs - block size

7689:   Level: intermediate

7691:   Notes:
7692:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.

7694:   If the block size has not been set yet this routine returns 1.

7696: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSizes()`
7697: @*/
7698: PetscErrorCode MatGetBlockSize(Mat mat, PetscInt *bs)
7699: {
7700:   PetscFunctionBegin;
7702:   PetscAssertPointer(bs, 2);
7703:   *bs = mat->rmap->bs;
7704:   PetscFunctionReturn(PETSC_SUCCESS);
7705: }

7707: /*@
7708:   MatGetBlockSizes - Returns the matrix block row and column sizes.

7710:   Not Collective

7712:   Input Parameter:
7713: . mat - the matrix

7715:   Output Parameters:
7716: + rbs - row block size
7717: - cbs - column block size

7719:   Level: intermediate

7721:   Notes:
7722:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.
7723:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.

7725:   If a block size has not been set yet this routine returns 1.

7727: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatSetBlockSizes()`
7728: @*/
7729: PetscErrorCode MatGetBlockSizes(Mat mat, PetscInt *rbs, PetscInt *cbs)
7730: {
7731:   PetscFunctionBegin;
7733:   if (rbs) PetscAssertPointer(rbs, 2);
7734:   if (cbs) PetscAssertPointer(cbs, 3);
7735:   if (rbs) *rbs = mat->rmap->bs;
7736:   if (cbs) *cbs = mat->cmap->bs;
7737:   PetscFunctionReturn(PETSC_SUCCESS);
7738: }

7740: /*@
7741:   MatSetBlockSize - Sets the matrix block size.

7743:   Logically Collective

7745:   Input Parameters:
7746: + mat - the matrix
7747: - bs  - block size

7749:   Level: intermediate

7751:   Notes:
7752:   Block row formats are `MATBAIJ` and `MATSBAIJ` formats ALWAYS have square block storage in the matrix.
7753:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

7755:   For `MATAIJ` matrix format, this function can be called at a later stage, provided that the specified block size
7756:   is compatible with the matrix local sizes.

7758: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MATAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`
7759: @*/
7760: PetscErrorCode MatSetBlockSize(Mat mat, PetscInt bs)
7761: {
7762:   PetscFunctionBegin;
7765:   PetscCall(MatSetBlockSizes(mat, bs, bs));
7766:   PetscFunctionReturn(PETSC_SUCCESS);
7767: }

7769: typedef struct {
7770:   PetscInt         n;
7771:   IS              *is;
7772:   Mat             *mat;
7773:   PetscObjectState nonzerostate;
7774:   Mat              C;
7775: } EnvelopeData;

7777: static PetscErrorCode EnvelopeDataDestroy(PetscCtxRt ptr)
7778: {
7779:   EnvelopeData *edata = *(EnvelopeData **)ptr;

7781:   PetscFunctionBegin;
7782:   for (PetscInt i = 0; i < edata->n; i++) PetscCall(ISDestroy(&edata->is[i]));
7783:   PetscCall(PetscFree(edata->is));
7784:   PetscCall(PetscFree(edata));
7785:   PetscFunctionReturn(PETSC_SUCCESS);
7786: }

7788: /*@
7789:   MatComputeVariableBlockEnvelope - Given a matrix whose nonzeros are in blocks along the diagonal this computes and stores
7790:   the sizes of these blocks in the matrix. An individual block may lie over several processes.

7792:   Collective

7794:   Input Parameter:
7795: . mat - the matrix

7797:   Level: intermediate

7799:   Notes:
7800:   There can be zeros within the blocks

7802:   The blocks can overlap between processes, including laying on more than two processes

7804: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatSetVariableBlockSizes()`
7805: @*/
7806: PetscErrorCode MatComputeVariableBlockEnvelope(Mat mat)
7807: {
7808:   PetscInt           n, *sizes, *starts, i = 0, env = 0, tbs = 0, lblocks = 0, rstart, II, ln = 0, cnt = 0, cstart, cend;
7809:   PetscInt          *diag, *odiag, sc;
7810:   VecScatter         scatter;
7811:   PetscScalar       *seqv;
7812:   const PetscScalar *parv;
7813:   const PetscInt    *ia, *ja;
7814:   PetscBool          set, flag, done;
7815:   Mat                AA = mat, A;
7816:   MPI_Comm           comm;
7817:   PetscMPIInt        rank, size, tag;
7818:   MPI_Status         status;
7819:   PetscContainer     container;
7820:   EnvelopeData      *edata;
7821:   Vec                seq, par;
7822:   IS                 isglobal;

7824:   PetscFunctionBegin;
7826:   PetscCall(MatIsSymmetricKnown(mat, &set, &flag));
7827:   if (!set || !flag) {
7828:     /* TODO: only needs nonzero structure of transpose */
7829:     PetscCall(MatTranspose(mat, MAT_INITIAL_MATRIX, &AA));
7830:     PetscCall(MatAXPY(AA, 1.0, mat, DIFFERENT_NONZERO_PATTERN));
7831:   }
7832:   PetscCall(MatAIJGetLocalMat(AA, &A));
7833:   PetscCall(MatGetRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7834:   PetscCheck(done, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unable to get IJ structure from matrix");

7836:   PetscCall(MatGetLocalSize(mat, &n, NULL));
7837:   PetscCall(PetscObjectGetNewTag((PetscObject)mat, &tag));
7838:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
7839:   PetscCallMPI(MPI_Comm_size(comm, &size));
7840:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

7842:   PetscCall(PetscMalloc2(n, &sizes, n, &starts));

7844:   if (rank > 0) {
7845:     PetscCallMPI(MPI_Recv(&env, 1, MPIU_INT, rank - 1, tag, comm, &status));
7846:     PetscCallMPI(MPI_Recv(&tbs, 1, MPIU_INT, rank - 1, tag, comm, &status));
7847:   }
7848:   PetscCall(MatGetOwnershipRange(mat, &rstart, NULL));
7849:   for (i = 0; i < n; i++) {
7850:     env = PetscMax(env, ja[ia[i + 1] - 1]);
7851:     II  = rstart + i;
7852:     if (env == II) {
7853:       starts[lblocks]  = tbs;
7854:       sizes[lblocks++] = 1 + II - tbs;
7855:       tbs              = 1 + II;
7856:     }
7857:   }
7858:   if (rank < size - 1) {
7859:     PetscCallMPI(MPI_Send(&env, 1, MPIU_INT, rank + 1, tag, comm));
7860:     PetscCallMPI(MPI_Send(&tbs, 1, MPIU_INT, rank + 1, tag, comm));
7861:   }

7863:   PetscCall(MatRestoreRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7864:   if (!set || !flag) PetscCall(MatDestroy(&AA));
7865:   PetscCall(MatDestroy(&A));

7867:   PetscCall(PetscNew(&edata));
7868:   PetscCall(MatGetNonzeroState(mat, &edata->nonzerostate));
7869:   edata->n = lblocks;
7870:   /* create IS needed for extracting blocks from the original matrix */
7871:   PetscCall(PetscMalloc1(lblocks, &edata->is));
7872:   for (PetscInt i = 0; i < lblocks; i++) PetscCall(ISCreateStride(PETSC_COMM_SELF, sizes[i], starts[i], 1, &edata->is[i]));

7874:   /* Create the resulting inverse matrix nonzero structure with preallocation information */
7875:   PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &edata->C));
7876:   PetscCall(MatSetSizes(edata->C, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
7877:   PetscCall(MatSetBlockSizesFromMats(edata->C, mat, mat));
7878:   PetscCall(MatSetType(edata->C, MATAIJ));

7880:   /* Communicate the start and end of each row, from each block to the correct rank */
7881:   /* TODO: Use PetscSF instead of VecScatter */
7882:   for (PetscInt i = 0; i < lblocks; i++) ln += sizes[i];
7883:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, 2 * ln, &seq));
7884:   PetscCall(VecGetArrayWrite(seq, &seqv));
7885:   for (PetscInt i = 0; i < lblocks; i++) {
7886:     for (PetscInt j = 0; j < sizes[i]; j++) {
7887:       seqv[cnt]     = starts[i];
7888:       seqv[cnt + 1] = starts[i] + sizes[i];
7889:       cnt += 2;
7890:     }
7891:   }
7892:   PetscCall(VecRestoreArrayWrite(seq, &seqv));
7893:   PetscCallMPI(MPI_Scan(&cnt, &sc, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)mat)));
7894:   sc -= cnt;
7895:   PetscCall(VecCreateMPI(PetscObjectComm((PetscObject)mat), 2 * mat->rmap->n, 2 * mat->rmap->N, &par));
7896:   PetscCall(ISCreateStride(PETSC_COMM_SELF, cnt, sc, 1, &isglobal));
7897:   PetscCall(VecScatterCreate(seq, NULL, par, isglobal, &scatter));
7898:   PetscCall(ISDestroy(&isglobal));
7899:   PetscCall(VecScatterBegin(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7900:   PetscCall(VecScatterEnd(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7901:   PetscCall(VecScatterDestroy(&scatter));
7902:   PetscCall(VecDestroy(&seq));
7903:   PetscCall(MatGetOwnershipRangeColumn(mat, &cstart, &cend));
7904:   PetscCall(PetscMalloc2(mat->rmap->n, &diag, mat->rmap->n, &odiag));
7905:   PetscCall(VecGetArrayRead(par, &parv));
7906:   cnt = 0;
7907:   PetscCall(MatGetSize(mat, NULL, &n));
7908:   for (PetscInt i = 0; i < mat->rmap->n; i++) {
7909:     PetscInt start, end, d = 0, od = 0;

7911:     start = (PetscInt)PetscRealPart(parv[cnt]);
7912:     end   = (PetscInt)PetscRealPart(parv[cnt + 1]);
7913:     cnt += 2;

7915:     if (start < cstart) {
7916:       od += cstart - start + n - cend;
7917:       d += cend - cstart;
7918:     } else if (start < cend) {
7919:       od += n - cend;
7920:       d += cend - start;
7921:     } else od += n - start;
7922:     if (end <= cstart) {
7923:       od -= cstart - end + n - cend;
7924:       d -= cend - cstart;
7925:     } else if (end < cend) {
7926:       od -= n - cend;
7927:       d -= cend - end;
7928:     } else od -= n - end;

7930:     odiag[i] = od;
7931:     diag[i]  = d;
7932:   }
7933:   PetscCall(VecRestoreArrayRead(par, &parv));
7934:   PetscCall(VecDestroy(&par));
7935:   PetscCall(MatXAIJSetPreallocation(edata->C, mat->rmap->bs, diag, odiag, NULL, NULL));
7936:   PetscCall(PetscFree2(diag, odiag));
7937:   PetscCall(PetscFree2(sizes, starts));

7939:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
7940:   PetscCall(PetscContainerSetPointer(container, edata));
7941:   PetscCall(PetscContainerSetCtxDestroy(container, EnvelopeDataDestroy));
7942:   PetscCall(PetscObjectCompose((PetscObject)mat, "EnvelopeData", (PetscObject)container));
7943:   PetscCall(PetscObjectDereference((PetscObject)container));
7944:   PetscFunctionReturn(PETSC_SUCCESS);
7945: }

7947: /*@
7948:   MatInvertVariableBlockEnvelope - set matrix C to be the inverted block diagonal of matrix A

7950:   Collective

7952:   Input Parameters:
7953: + A     - the matrix
7954: - reuse - indicates if the `C` matrix was obtained from a previous call to this routine

7956:   Output Parameter:
7957: . C - matrix with inverted block diagonal of `A`

7959:   Level: advanced

7961:   Note:
7962:   For efficiency the matrix `A` should have all the nonzero entries clustered in smallish blocks along the diagonal.

7964: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatComputeBlockDiagonal()`
7965: @*/
7966: PetscErrorCode MatInvertVariableBlockEnvelope(Mat A, MatReuse reuse, Mat *C)
7967: {
7968:   PetscContainer   container;
7969:   EnvelopeData    *edata;
7970:   PetscObjectState nonzerostate;

7972:   PetscFunctionBegin;
7973:   PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7974:   if (!container) {
7975:     PetscCall(MatComputeVariableBlockEnvelope(A));
7976:     PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7977:   }
7978:   PetscCall(PetscContainerGetPointer(container, &edata));
7979:   PetscCall(MatGetNonzeroState(A, &nonzerostate));
7980:   PetscCheck(nonzerostate <= edata->nonzerostate, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Cannot handle changes to matrix nonzero structure");
7981:   PetscCheck(reuse != MAT_REUSE_MATRIX || *C == edata->C, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "C matrix must be the same as previously output");

7983:   PetscCall(MatCreateSubMatrices(A, edata->n, edata->is, edata->is, MAT_INITIAL_MATRIX, &edata->mat));
7984:   *C = edata->C;

7986:   for (PetscInt i = 0; i < edata->n; i++) {
7987:     Mat          D;
7988:     PetscScalar *dvalues;

7990:     PetscCall(MatConvert(edata->mat[i], MATSEQDENSE, MAT_INITIAL_MATRIX, &D));
7991:     PetscCall(MatSetOption(*C, MAT_ROW_ORIENTED, PETSC_FALSE));
7992:     PetscCall(MatSeqDenseInvert(D));
7993:     PetscCall(MatDenseGetArray(D, &dvalues));
7994:     PetscCall(MatSetValuesIS(*C, edata->is[i], edata->is[i], dvalues, INSERT_VALUES));
7995:     PetscCall(MatDestroy(&D));
7996:   }
7997:   PetscCall(MatDestroySubMatrices(edata->n, &edata->mat));
7998:   PetscCall(MatAssemblyBegin(*C, MAT_FINAL_ASSEMBLY));
7999:   PetscCall(MatAssemblyEnd(*C, MAT_FINAL_ASSEMBLY));
8000:   PetscFunctionReturn(PETSC_SUCCESS);
8001: }

8003: /*@
8004:   MatSetVariableBlockSizes - Sets diagonal point-blocks of the matrix that need not be of the same size

8006:   Not Collective

8008:   Input Parameters:
8009: + mat     - the matrix
8010: . nblocks - the number of blocks on this process, each block can only exist on a single process
8011: - bsizes  - the block sizes

8013:   Level: intermediate

8015:   Notes:
8016:   Currently used by `PCVPBJACOBI` for `MATAIJ` matrices

8018:   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.

8020: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatGetVariableBlockSizes()`,
8021:           `MatComputeVariableBlockEnvelope()`, `PCVPBJACOBI`
8022: @*/
8023: PetscErrorCode MatSetVariableBlockSizes(Mat mat, PetscInt nblocks, const PetscInt bsizes[])
8024: {
8025:   PetscInt ncnt = 0, nlocal;

8027:   PetscFunctionBegin;
8029:   PetscCall(MatGetLocalSize(mat, &nlocal, NULL));
8030:   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);
8031:   for (PetscInt i = 0; i < nblocks; i++) ncnt += bsizes[i];
8032:   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);
8033:   PetscCall(PetscFree(mat->bsizes));
8034:   mat->nblocks = nblocks;
8035:   PetscCall(PetscMalloc1(nblocks, &mat->bsizes));
8036:   PetscCall(PetscArraycpy(mat->bsizes, bsizes, nblocks));
8037:   PetscFunctionReturn(PETSC_SUCCESS);
8038: }

8040: /*@C
8041:   MatGetVariableBlockSizes - Gets a diagonal blocks of the matrix that need not be of the same size

8043:   Not Collective; No Fortran Support

8045:   Input Parameter:
8046: . mat - the matrix

8048:   Output Parameters:
8049: + nblocks - the number of blocks on this process
8050: - bsizes  - the block sizes

8052:   Level: intermediate

8054: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
8055: @*/
8056: PetscErrorCode MatGetVariableBlockSizes(Mat mat, PetscInt *nblocks, const PetscInt *bsizes[])
8057: {
8058:   PetscFunctionBegin;
8060:   if (nblocks) *nblocks = mat->nblocks;
8061:   if (bsizes) *bsizes = mat->bsizes;
8062:   PetscFunctionReturn(PETSC_SUCCESS);
8063: }

8065: /*@
8066:   MatSelectVariableBlockSizes - When creating a submatrix, pass on the variable block sizes

8068:   Not Collective

8070:   Input Parameter:
8071: + subA  - the submatrix
8072: . A     - the original matrix
8073: - isrow - The `IS` of selected rows for the submatrix, must be sorted

8075:   Level: developer

8077:   Notes:
8078:   If the index set is not sorted or contains off-process entries, this function will do nothing.

8080: .seealso: [](ch_matrices), `Mat`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
8081: @*/
8082: PetscErrorCode MatSelectVariableBlockSizes(Mat subA, Mat A, IS isrow)
8083: {
8084:   const PetscInt *rows;
8085:   PetscInt        n, rStart, rEnd, Nb = 0;
8086:   PetscBool       flg = A->bsizes ? PETSC_TRUE : PETSC_FALSE;

8088:   PetscFunctionBegin;
8089:   // The code for block size extraction does not support an unsorted IS
8090:   if (flg) PetscCall(ISSorted(isrow, &flg));
8091:   // We don't support originally off-diagonal blocks
8092:   if (flg) {
8093:     PetscCall(MatGetOwnershipRange(A, &rStart, &rEnd));
8094:     PetscCall(ISGetLocalSize(isrow, &n));
8095:     PetscCall(ISGetIndices(isrow, &rows));
8096:     for (PetscInt i = 0; i < n && flg; ++i) {
8097:       if (rows[i] < rStart || rows[i] >= rEnd) flg = PETSC_FALSE;
8098:     }
8099:     PetscCall(ISRestoreIndices(isrow, &rows));
8100:   }
8101:   // quiet return if we can't extract block size
8102:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &flg, 1, MPI_C_BOOL, MPI_LAND, PetscObjectComm((PetscObject)subA)));
8103:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

8105:   // extract block sizes
8106:   PetscCall(ISGetIndices(isrow, &rows));
8107:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8108:     PetscBool occupied = PETSC_FALSE;

8110:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8111:       const PetscInt row = gr + br;

8113:       if (i == n) break;
8114:       if (rows[i] == row) {
8115:         occupied = PETSC_TRUE;
8116:         ++i;
8117:       }
8118:       while (i < n && rows[i] < row) ++i;
8119:     }
8120:     gr += A->bsizes[b];
8121:     if (occupied) ++Nb;
8122:   }
8123:   subA->nblocks = Nb;
8124:   PetscCall(PetscFree(subA->bsizes));
8125:   PetscCall(PetscMalloc1(subA->nblocks, &subA->bsizes));
8126:   PetscInt sb = 0;
8127:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8128:     if (sb < subA->nblocks) subA->bsizes[sb] = 0;
8129:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8130:       const PetscInt row = gr + br;

8132:       if (i == n) break;
8133:       if (rows[i] == row) {
8134:         ++subA->bsizes[sb];
8135:         ++i;
8136:       }
8137:       while (i < n && rows[i] < row) ++i;
8138:     }
8139:     gr += A->bsizes[b];
8140:     if (sb < subA->nblocks && subA->bsizes[sb]) ++sb;
8141:   }
8142:   PetscCheck(sb == subA->nblocks, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of blocks %" PetscInt_FMT " != %" PetscInt_FMT, sb, subA->nblocks);
8143:   PetscInt nlocal, ncnt = 0;
8144:   PetscCall(MatGetLocalSize(subA, &nlocal, NULL));
8145:   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);
8146:   for (PetscInt i = 0; i < subA->nblocks; i++) ncnt += subA->bsizes[i];
8147:   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);
8148:   PetscCall(ISRestoreIndices(isrow, &rows));
8149:   PetscFunctionReturn(PETSC_SUCCESS);
8150: }

8152: /*@
8153:   MatSetBlockSizes - Sets the matrix block row and column sizes.

8155:   Logically Collective

8157:   Input Parameters:
8158: + mat - the matrix
8159: . rbs - row block size
8160: - cbs - column block size

8162:   Level: intermediate

8164:   Notes:
8165:   Block row formats are `MATBAIJ` and  `MATSBAIJ`. These formats ALWAYS have square block storage in the matrix.
8166:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.
8167:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

8169:   For `MATAIJ` matrix this function can be called at a later stage, provided that the specified block sizes
8170:   are compatible with the matrix local sizes.

8172:   The row and column block size determine the blocksize of the "row" and "column" vectors returned by `MatCreateVecs()`.

8174: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatGetBlockSizes()`
8175: @*/
8176: PetscErrorCode MatSetBlockSizes(Mat mat, PetscInt rbs, PetscInt cbs)
8177: {
8178:   PetscFunctionBegin;
8182:   PetscTryTypeMethod(mat, setblocksizes, rbs, cbs);
8183:   if (mat->rmap->refcnt) {
8184:     ISLocalToGlobalMapping l2g  = NULL;
8185:     PetscLayout            nmap = NULL;

8187:     PetscCall(PetscLayoutDuplicate(mat->rmap, &nmap));
8188:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->rmap->mapping, &l2g));
8189:     PetscCall(PetscLayoutDestroy(&mat->rmap));
8190:     mat->rmap          = nmap;
8191:     mat->rmap->mapping = l2g;
8192:   }
8193:   if (mat->cmap->refcnt) {
8194:     ISLocalToGlobalMapping l2g  = NULL;
8195:     PetscLayout            nmap = NULL;

8197:     PetscCall(PetscLayoutDuplicate(mat->cmap, &nmap));
8198:     if (mat->cmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->cmap->mapping, &l2g));
8199:     PetscCall(PetscLayoutDestroy(&mat->cmap));
8200:     mat->cmap          = nmap;
8201:     mat->cmap->mapping = l2g;
8202:   }
8203:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, rbs));
8204:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, cbs));
8205:   PetscFunctionReturn(PETSC_SUCCESS);
8206: }

8208: /*@
8209:   MatSetBlockSizesFromMats - Sets the matrix block row and column sizes to match a pair of matrices

8211:   Logically Collective

8213:   Input Parameters:
8214: + mat     - the matrix
8215: . fromRow - matrix from which to copy row block size
8216: - fromCol - matrix from which to copy column block size (can be same as `fromRow`)

8218:   Level: developer

8220: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`
8221: @*/
8222: PetscErrorCode MatSetBlockSizesFromMats(Mat mat, Mat fromRow, Mat fromCol)
8223: {
8224:   PetscFunctionBegin;
8228:   PetscTryTypeMethod(mat, setblocksizes, fromRow->rmap->bs, fromCol->cmap->bs);
8229:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, fromRow->rmap->bs));
8230:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, fromCol->cmap->bs));
8231:   PetscFunctionReturn(PETSC_SUCCESS);
8232: }

8234: /*@
8235:   MatResidual - Default routine to calculate the residual r = b - Ax

8237:   Collective

8239:   Input Parameters:
8240: + mat - the matrix
8241: . b   - the right-hand-side
8242: - x   - the approximate solution

8244:   Output Parameter:
8245: . r - location to store the residual

8247:   Level: developer

8249: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `PCMGSetResidual()`
8250: @*/
8251: PetscErrorCode MatResidual(Mat mat, Vec b, Vec x, Vec r)
8252: {
8253:   PetscFunctionBegin;
8259:   MatCheckPreallocated(mat, 1);
8260:   PetscCall(PetscLogEventBegin(MAT_Residual, mat, 0, 0, 0));
8261:   if (!mat->ops->residual) {
8262:     PetscCall(MatMult(mat, x, r));
8263:     PetscCall(VecAYPX(r, -1.0, b));
8264:   } else {
8265:     PetscUseTypeMethod(mat, residual, b, x, r);
8266:   }
8267:   PetscCall(PetscLogEventEnd(MAT_Residual, mat, 0, 0, 0));
8268:   PetscFunctionReturn(PETSC_SUCCESS);
8269: }

8271: /*@C
8272:   MatGetRowIJ - Returns the compressed row storage i and j indices for the local rows of a sparse matrix

8274:   Collective

8276:   Input Parameters:
8277: + mat             - the matrix
8278: . shift           - 0 or 1 indicating we want the indices starting at 0 or 1
8279: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8280: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE`  indicating if the nonzero structure of the
8281:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8282:                  always used.

8284:   Output Parameters:
8285: + n    - number of local rows in the (possibly compressed) matrix, use `NULL` if not needed
8286: . 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
8287: . ja   - the column indices, use `NULL` if not needed
8288: - done - indicates if the routine actually worked and returned appropriate ia[] and ja[] arrays; callers
8289:            are responsible for handling the case when done == `PETSC_FALSE` and ia and ja are not set

8291:   Level: developer

8293:   Notes:
8294:   You CANNOT change any of the ia[] or ja[] values.

8296:   Use `MatRestoreRowIJ()` when you are finished accessing the ia[] and ja[] values.

8298:   Fortran Notes:
8299:   Use
8300: .vb
8301:     PetscInt, pointer :: ia(:),ja(:)
8302:     call MatGetRowIJ(mat,shift,symmetric,inodecompressed,n,ia,ja,done,ierr)
8303:     ! Access the ith and jth entries via ia(i) and ja(j)
8304: .ve

8306: .seealso: [](ch_matrices), `Mat`, `MATAIJ`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`, `MatSeqAIJGetArray()`
8307: @*/
8308: PetscErrorCode MatGetRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8309: {
8310:   PetscFunctionBegin;
8313:   if (n) PetscAssertPointer(n, 5);
8314:   if (ia) PetscAssertPointer(ia, 6);
8315:   if (ja) PetscAssertPointer(ja, 7);
8316:   if (done) PetscAssertPointer(done, 8);
8317:   MatCheckPreallocated(mat, 1);
8318:   if (!mat->ops->getrowij && done) *done = PETSC_FALSE;
8319:   else {
8320:     if (done) *done = PETSC_TRUE;
8321:     PetscCall(PetscLogEventBegin(MAT_GetRowIJ, mat, 0, 0, 0));
8322:     PetscUseTypeMethod(mat, getrowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8323:     PetscCall(PetscLogEventEnd(MAT_GetRowIJ, mat, 0, 0, 0));
8324:   }
8325:   PetscFunctionReturn(PETSC_SUCCESS);
8326: }

8328: /*@C
8329:   MatGetColumnIJ - Returns the compressed column storage i and j indices for sequential matrices.

8331:   Collective

8333:   Input Parameters:
8334: + mat             - the matrix
8335: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8336: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be
8337:                 symmetrized
8338: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8339:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8340:                  always used.

8342:   Output Parameters:
8343: + n    - number of columns in the (possibly compressed) matrix
8344: . ia   - the column pointers; that is ia[0] = 0, ia[col] = i[col-1] + number of elements in that col of the matrix
8345: . ja   - the row indices
8346: - done - `PETSC_TRUE` or `PETSC_FALSE`, indicating whether the values have been returned

8348:   Level: developer

8350: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8351: @*/
8352: PetscErrorCode MatGetColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8353: {
8354:   PetscFunctionBegin;
8357:   PetscAssertPointer(n, 5);
8358:   if (ia) PetscAssertPointer(ia, 6);
8359:   if (ja) PetscAssertPointer(ja, 7);
8360:   PetscAssertPointer(done, 8);
8361:   MatCheckPreallocated(mat, 1);
8362:   if (!mat->ops->getcolumnij) *done = PETSC_FALSE;
8363:   else {
8364:     *done = PETSC_TRUE;
8365:     PetscUseTypeMethod(mat, getcolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8366:   }
8367:   PetscFunctionReturn(PETSC_SUCCESS);
8368: }

8370: /*@C
8371:   MatRestoreRowIJ - Call after you are completed with the ia,ja indices obtained with `MatGetRowIJ()`.

8373:   Collective

8375:   Input Parameters:
8376: + mat             - the matrix
8377: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8378: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8379: . inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8380:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8381:                     always used.
8382: . n               - size of (possibly compressed) matrix
8383: . ia              - the row pointers
8384: - ja              - the column indices

8386:   Output Parameter:
8387: . done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8389:   Level: developer

8391:   Note:
8392:   This routine zeros out `n`, `ia`, and `ja`. This is to prevent accidental
8393:   us of the array after it has been restored. If you pass `NULL`, it will
8394:   not zero the pointers.  Use of ia or ja after `MatRestoreRowIJ()` is invalid.

8396: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8397: @*/
8398: PetscErrorCode MatRestoreRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8399: {
8400:   PetscFunctionBegin;
8403:   if (ia) PetscAssertPointer(ia, 6);
8404:   if (ja) PetscAssertPointer(ja, 7);
8405:   if (done) PetscAssertPointer(done, 8);
8406:   MatCheckPreallocated(mat, 1);

8408:   if (!mat->ops->restorerowij && done) *done = PETSC_FALSE;
8409:   else {
8410:     if (done) *done = PETSC_TRUE;
8411:     PetscUseTypeMethod(mat, restorerowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8412:     if (n) *n = 0;
8413:     if (ia) *ia = NULL;
8414:     if (ja) *ja = NULL;
8415:   }
8416:   PetscFunctionReturn(PETSC_SUCCESS);
8417: }

8419: /*@C
8420:   MatRestoreColumnIJ - Call after you are completed with the ia,ja indices obtained with `MatGetColumnIJ()`.

8422:   Collective

8424:   Input Parameters:
8425: + mat             - the matrix
8426: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8427: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8428: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8429:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8430:                     always used.

8432:   Output Parameters:
8433: + n    - size of (possibly compressed) matrix
8434: . ia   - the column pointers
8435: . ja   - the row indices
8436: - done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8438:   Level: developer

8440: .seealso: [](ch_matrices), `Mat`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`
8441: @*/
8442: PetscErrorCode MatRestoreColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8443: {
8444:   PetscFunctionBegin;
8447:   if (ia) PetscAssertPointer(ia, 6);
8448:   if (ja) PetscAssertPointer(ja, 7);
8449:   PetscAssertPointer(done, 8);
8450:   MatCheckPreallocated(mat, 1);

8452:   if (!mat->ops->restorecolumnij) *done = PETSC_FALSE;
8453:   else {
8454:     *done = PETSC_TRUE;
8455:     PetscUseTypeMethod(mat, restorecolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8456:     if (n) *n = 0;
8457:     if (ia) *ia = NULL;
8458:     if (ja) *ja = NULL;
8459:   }
8460:   PetscFunctionReturn(PETSC_SUCCESS);
8461: }

8463: /*@
8464:   MatColoringPatch - Used inside matrix coloring routines that use `MatGetRowIJ()` and/or
8465:   `MatGetColumnIJ()`.

8467:   Collective

8469:   Input Parameters:
8470: + mat        - the matrix
8471: . ncolors    - maximum color value
8472: . n          - number of entries in colorarray
8473: - colorarray - array indicating color for each column

8475:   Output Parameter:
8476: . iscoloring - coloring generated using colorarray information

8478:   Level: developer

8480: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatGetColumnIJ()`
8481: @*/
8482: PetscErrorCode MatColoringPatch(Mat mat, PetscInt ncolors, PetscInt n, ISColoringValue colorarray[], ISColoring *iscoloring)
8483: {
8484:   PetscFunctionBegin;
8487:   PetscAssertPointer(colorarray, 4);
8488:   PetscAssertPointer(iscoloring, 5);
8489:   MatCheckPreallocated(mat, 1);

8491:   if (!mat->ops->coloringpatch) {
8492:     PetscCall(ISColoringCreate(PetscObjectComm((PetscObject)mat), ncolors, n, colorarray, PETSC_OWN_POINTER, iscoloring));
8493:   } else {
8494:     PetscUseTypeMethod(mat, coloringpatch, ncolors, n, colorarray, iscoloring);
8495:   }
8496:   PetscFunctionReturn(PETSC_SUCCESS);
8497: }

8499: /*@
8500:   MatSetUnfactored - Resets a factored matrix to be treated as unfactored.

8502:   Logically Collective

8504:   Input Parameter:
8505: . mat - the factored matrix to be reset

8507:   Level: developer

8509:   Notes:
8510:   This routine should be used only with factored matrices formed by in-place
8511:   factorization via ILU(0) (or by in-place LU factorization for the `MATSEQDENSE`
8512:   format).  This option can save memory, for example, when solving nonlinear
8513:   systems with a matrix-free Newton-Krylov method and a matrix-based, in-place
8514:   ILU(0) preconditioner.

8516:   One can specify in-place ILU(0) factorization by calling
8517: .vb
8518:      PCType(pc,PCILU);
8519:      PCFactorSeUseInPlace(pc);
8520: .ve
8521:   or by using the options -pc_type ilu -pc_factor_in_place

8523:   In-place factorization ILU(0) can also be used as a local
8524:   solver for the blocks within the block Jacobi or additive Schwarz
8525:   methods (runtime option: -sub_pc_factor_in_place).  See Users-Manual: ch_pc
8526:   for details on setting local solver options.

8528:   Most users should employ the `KSP` interface for linear solvers
8529:   instead of working directly with matrix algebra routines such as this.
8530:   See, e.g., `KSPCreate()`.

8532: .seealso: [](ch_matrices), `Mat`, `PCFactorSetUseInPlace()`, `PCFactorGetUseInPlace()`
8533: @*/
8534: PetscErrorCode MatSetUnfactored(Mat mat)
8535: {
8536:   PetscFunctionBegin;
8539:   MatCheckPreallocated(mat, 1);
8540:   mat->factortype = MAT_FACTOR_NONE;
8541:   if (!mat->ops->setunfactored) PetscFunctionReturn(PETSC_SUCCESS);
8542:   PetscUseTypeMethod(mat, setunfactored);
8543:   PetscFunctionReturn(PETSC_SUCCESS);
8544: }

8546: /*@
8547:   MatCreateSubMatrix - Gets a single submatrix on the same number of processors
8548:   as the original matrix.

8550:   Collective

8552:   Input Parameters:
8553: + mat   - the original matrix
8554: . isrow - parallel `IS` containing the rows this processor should obtain
8555: . 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.
8556: - cll   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

8558:   Output Parameter:
8559: . newmat - the new submatrix, of the same type as the original matrix

8561:   Level: advanced

8563:   Notes:
8564:   The submatrix will be able to be multiplied with vectors using the same layout as `iscol`.

8566:   Some matrix types place restrictions on the row and column indices, such
8567:   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;
8568:   for example, if the block size is 3 one cannot select the 0 and 2 rows without selecting the 1 row.

8570:   The index sets may not have duplicate entries.

8572:   The first time this is called you should use a cll of `MAT_INITIAL_MATRIX`,
8573:   the `MatCreateSubMatrix()` routine will create the newmat for you. Any additional calls
8574:   to this routine with a mat of the same nonzero structure and with a call of `MAT_REUSE_MATRIX`
8575:   will reuse the matrix generated the first time.  You should call `MatDestroy()` on `newmat` when
8576:   you are finished using it.

8578:   The communicator of the newly obtained matrix is ALWAYS the same as the communicator of
8579:   the input matrix.

8581:   If `iscol` is `NULL` then all columns are obtained (not supported in Fortran).

8583:   If `isrow` and `iscol` have a nontrivial block-size, then the resulting matrix has this block-size as well. This feature
8584:   is used by `PCFIELDSPLIT` to allow easy nesting of its use.

8586:   Example usage:
8587:   Consider the following 8x8 matrix with 34 non-zero values, that is
8588:   assembled across 3 processors. Let's assume that proc0 owns 3 rows,
8589:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
8590:   as follows
8591: .vb
8592:             1  2  0  |  0  3  0  |  0  4
8593:     Proc0   0  5  6  |  7  0  0  |  8  0
8594:             9  0 10  | 11  0  0  | 12  0
8595:     -------------------------------------
8596:            13  0 14  | 15 16 17  |  0  0
8597:     Proc1   0 18  0  | 19 20 21  |  0  0
8598:             0  0  0  | 22 23  0  | 24  0
8599:     -------------------------------------
8600:     Proc2  25 26 27  |  0  0 28  | 29  0
8601:            30  0  0  | 31 32 33  |  0 34
8602: .ve

8604:   Suppose `isrow` = [0 1 | 4 | 6 7] and `iscol` = [1 2 | 3 4 5 | 6].  The resulting submatrix is

8606: .vb
8607:             2  0  |  0  3  0  |  0
8608:     Proc0   5  6  |  7  0  0  |  8
8609:     -------------------------------
8610:     Proc1  18  0  | 19 20 21  |  0
8611:     -------------------------------
8612:     Proc2  26 27  |  0  0 28  | 29
8613:             0  0  | 31 32 33  |  0
8614: .ve

8616: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatCreateSubMatricesMPI()`, `MatCreateSubMatrixVirtual()`, `MatSubMatrixVirtualUpdate()`
8617: @*/
8618: PetscErrorCode MatCreateSubMatrix(Mat mat, IS isrow, IS iscol, MatReuse cll, Mat *newmat)
8619: {
8620:   PetscMPIInt size;
8621:   Mat        *local;
8622:   IS          iscoltmp;
8623:   PetscBool   flg;

8625:   PetscFunctionBegin;
8629:   PetscAssertPointer(newmat, 5);
8632:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
8633:   PetscCheck(cll != MAT_IGNORE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_IGNORE_MATRIX");
8634:   PetscCheck(cll != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_INPLACE_MATRIX");

8636:   MatCheckPreallocated(mat, 1);
8637:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));

8639:   if (!iscol || isrow == iscol) {
8640:     PetscBool   stride;
8641:     PetscMPIInt grabentirematrix = 0, grab;
8642:     PetscCall(PetscObjectTypeCompare((PetscObject)isrow, ISSTRIDE, &stride));
8643:     if (stride) {
8644:       PetscInt first, step, n, rstart, rend;
8645:       PetscCall(ISStrideGetInfo(isrow, &first, &step));
8646:       if (step == 1) {
8647:         PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
8648:         if (rstart == first) {
8649:           PetscCall(ISGetLocalSize(isrow, &n));
8650:           if (n == rend - rstart) grabentirematrix = 1;
8651:         }
8652:       }
8653:     }
8654:     PetscCallMPI(MPIU_Allreduce(&grabentirematrix, &grab, 1, MPI_INT, MPI_MIN, PetscObjectComm((PetscObject)mat)));
8655:     if (grab) {
8656:       PetscCall(PetscInfo(mat, "Getting entire matrix as submatrix\n"));
8657:       if (cll == MAT_INITIAL_MATRIX) {
8658:         *newmat = mat;
8659:         PetscCall(PetscObjectReference((PetscObject)mat));
8660:       }
8661:       PetscFunctionReturn(PETSC_SUCCESS);
8662:     }
8663:   }

8665:   if (!iscol) {
8666:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), mat->cmap->n, mat->cmap->rstart, 1, &iscoltmp));
8667:   } else {
8668:     iscoltmp = iscol;
8669:   }

8671:   /* if original matrix is on just one processor then use submatrix generated */
8672:   if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1 && cll == MAT_REUSE_MATRIX) {
8673:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_REUSE_MATRIX, &newmat));
8674:     goto setproperties;
8675:   } else if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1) {
8676:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_INITIAL_MATRIX, &local));
8677:     *newmat = *local;
8678:     PetscCall(PetscFree(local));
8679:     goto setproperties;
8680:   } else if (!mat->ops->createsubmatrix) {
8681:     /* Create a new matrix type that implements the operation using the full matrix */
8682:     PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8683:     switch (cll) {
8684:     case MAT_INITIAL_MATRIX:
8685:       PetscCall(MatCreateSubMatrixVirtual(mat, isrow, iscoltmp, newmat));
8686:       break;
8687:     case MAT_REUSE_MATRIX:
8688:       PetscCall(MatSubMatrixVirtualUpdate(*newmat, mat, isrow, iscoltmp));
8689:       break;
8690:     default:
8691:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Invalid MatReuse, must be either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX");
8692:     }
8693:     PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));
8694:     goto setproperties;
8695:   }

8697:   PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8698:   PetscUseTypeMethod(mat, createsubmatrix, isrow, iscoltmp, cll, newmat);
8699:   PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));

8701: setproperties:
8702:   if ((*newmat)->symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->structurally_symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->spd == PETSC_BOOL3_UNKNOWN && (*newmat)->hermitian == PETSC_BOOL3_UNKNOWN) {
8703:     PetscCall(ISEqualUnsorted(isrow, iscoltmp, &flg));
8704:     if (flg) PetscCall(MatPropagateSymmetryOptions(mat, *newmat));
8705:   }
8706:   if (!iscol) PetscCall(ISDestroy(&iscoltmp));
8707:   if (*newmat && cll == MAT_INITIAL_MATRIX) PetscCall(PetscObjectStateIncrease((PetscObject)*newmat));
8708:   if (!iscol || isrow == iscol) PetscCall(MatSelectVariableBlockSizes(*newmat, mat, isrow));
8709:   PetscFunctionReturn(PETSC_SUCCESS);
8710: }

8712: /*@
8713:   MatPropagateSymmetryOptions - Propagates symmetry options set on a matrix to another matrix

8715:   Not Collective

8717:   Input Parameters:
8718: + A - the matrix we wish to propagate options from
8719: - B - the matrix we wish to propagate options to

8721:   Level: beginner

8723:   Note:
8724:   Propagates the options associated to `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_HERMITIAN`, `MAT_SPD`, `MAT_SYMMETRIC`, and `MAT_STRUCTURAL_SYMMETRY_ETERNAL`

8726: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatIsSymmetricKnown()`, `MatIsSPDKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
8727: @*/
8728: PetscErrorCode MatPropagateSymmetryOptions(Mat A, Mat B)
8729: {
8730:   PetscFunctionBegin;
8733:   B->symmetry_eternal            = A->symmetry_eternal;
8734:   B->structural_symmetry_eternal = A->structural_symmetry_eternal;
8735:   B->symmetric                   = A->symmetric;
8736:   B->structurally_symmetric      = A->structurally_symmetric;
8737:   B->spd                         = A->spd;
8738:   B->hermitian                   = A->hermitian;
8739:   PetscFunctionReturn(PETSC_SUCCESS);
8740: }

8742: /*@
8743:   MatStashSetInitialSize - sets the sizes of the matrix stash, that is
8744:   used during the assembly process to store values that belong to
8745:   other processors.

8747:   Not Collective

8749:   Input Parameters:
8750: + mat   - the matrix
8751: . size  - the initial size of the stash.
8752: - bsize - the initial size of the block-stash(if used).

8754:   Options Database Keys:
8755: + -matstash_initial_size size or size0,size1,...,sizep-1            - set initial size
8756: - -matstash_block_initial_size bsize  or bsize0,bsize1,...,bsizep-1 - set initial block size

8758:   Level: intermediate

8760:   Notes:
8761:   The block-stash is used for values set with `MatSetValuesBlocked()` while
8762:   the stash is used for values set with `MatSetValues()`

8764:   Run with the option -info and look for output of the form
8765:   MatAssemblyBegin_MPIXXX:Stash has MM entries, uses nn mallocs.
8766:   to determine the appropriate value, MM, to use for size and
8767:   MatAssemblyBegin_MPIXXX:Block-Stash has BMM entries, uses nn mallocs.
8768:   to determine the value, BMM to use for bsize

8770: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashGetInfo()`
8771: @*/
8772: PetscErrorCode MatStashSetInitialSize(Mat mat, PetscInt size, PetscInt bsize)
8773: {
8774:   PetscFunctionBegin;
8777:   PetscCall(MatStashSetInitialSize_Private(&mat->stash, size));
8778:   PetscCall(MatStashSetInitialSize_Private(&mat->bstash, bsize));
8779:   PetscFunctionReturn(PETSC_SUCCESS);
8780: }

8782: /*@
8783:   MatInterpolateAdd - $w = y + A*x$ or $A^T*x$ depending on the shape of
8784:   the matrix

8786:   Neighbor-wise Collective

8788:   Input Parameters:
8789: + A - the matrix
8790: . x - the vector to be multiplied by the interpolation operator
8791: - y - the vector to be added to the result

8793:   Output Parameter:
8794: . w - the resulting vector

8796:   Level: intermediate

8798:   Notes:
8799:   `w` may be the same vector as `y`.

8801:   This allows one to use either the restriction or interpolation (its transpose)
8802:   matrix to do the interpolation

8804: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8805: @*/
8806: PetscErrorCode MatInterpolateAdd(Mat A, Vec x, Vec y, Vec w)
8807: {
8808:   PetscInt M, N, Ny;

8810:   PetscFunctionBegin;
8815:   PetscCall(MatGetSize(A, &M, &N));
8816:   PetscCall(VecGetSize(y, &Ny));
8817:   if (M == Ny) PetscCall(MatMultAdd(A, x, y, w));
8818:   else PetscCall(MatMultTransposeAdd(A, x, y, w));
8819:   PetscFunctionReturn(PETSC_SUCCESS);
8820: }

8822: /*@
8823:   MatInterpolate - $y = A*x$ or $A^T*x$ depending on the shape of
8824:   the matrix

8826:   Neighbor-wise Collective

8828:   Input Parameters:
8829: + A - the matrix
8830: - x - the vector to be interpolated

8832:   Output Parameter:
8833: . y - the resulting vector

8835:   Level: intermediate

8837:   Note:
8838:   This allows one to use either the restriction or interpolation (its transpose)
8839:   matrix to do the interpolation

8841: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8842: @*/
8843: PetscErrorCode MatInterpolate(Mat A, Vec x, Vec y)
8844: {
8845:   PetscInt M, N, Ny;

8847:   PetscFunctionBegin;
8851:   PetscCall(MatGetSize(A, &M, &N));
8852:   PetscCall(VecGetSize(y, &Ny));
8853:   if (M == Ny) PetscCall(MatMult(A, x, y));
8854:   else PetscCall(MatMultTranspose(A, x, y));
8855:   PetscFunctionReturn(PETSC_SUCCESS);
8856: }

8858: /*@
8859:   MatRestrict - $y = A*x$ or $A^T*x$

8861:   Neighbor-wise Collective

8863:   Input Parameters:
8864: + A - the matrix
8865: - x - the vector to be restricted

8867:   Output Parameter:
8868: . y - the resulting vector

8870:   Level: intermediate

8872:   Note:
8873:   This allows one to use either the restriction or interpolation (its transpose)
8874:   matrix to do the restriction

8876: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatInterpolate()`, `PCMG`
8877: @*/
8878: PetscErrorCode MatRestrict(Mat A, Vec x, Vec y)
8879: {
8880:   PetscInt M, N, Nx;

8882:   PetscFunctionBegin;
8886:   PetscCall(MatGetSize(A, &M, &N));
8887:   PetscCall(VecGetSize(x, &Nx));
8888:   if (M == Nx) PetscCall(MatMultTranspose(A, x, y));
8889:   else PetscCall(MatMult(A, x, y));
8890:   PetscFunctionReturn(PETSC_SUCCESS);
8891: }

8893: /*@
8894:   MatMatInterpolateAdd - $Y = W + A*X$ or $W + A^T*X$ depending on the shape of `A`

8896:   Neighbor-wise Collective

8898:   Input Parameters:
8899: + A - the matrix
8900: . x - the input dense matrix to be multiplied
8901: - w - the input dense matrix to be added to the result

8903:   Output Parameter:
8904: . y - the output dense matrix

8906:   Level: intermediate

8908:   Note:
8909:   This allows one to use either the restriction or interpolation (its transpose)
8910:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8911:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8913: .seealso: [](ch_matrices), `Mat`, `MatInterpolateAdd()`, `MatMatInterpolate()`, `MatMatRestrict()`, `PCMG`
8914: @*/
8915: PetscErrorCode MatMatInterpolateAdd(Mat A, Mat x, Mat w, Mat *y)
8916: {
8917:   PetscInt  M, N, Mx, Nx, Mo, My = 0, Ny = 0;
8918:   PetscBool trans = PETSC_TRUE;
8919:   MatReuse  reuse = MAT_INITIAL_MATRIX;

8921:   PetscFunctionBegin;
8927:   PetscCall(MatGetSize(A, &M, &N));
8928:   PetscCall(MatGetSize(x, &Mx, &Nx));
8929:   if (N == Mx) trans = PETSC_FALSE;
8930:   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);
8931:   Mo = trans ? N : M;
8932:   if (*y) {
8933:     PetscCall(MatGetSize(*y, &My, &Ny));
8934:     if (Mo == My && Nx == Ny) reuse = MAT_REUSE_MATRIX;
8935:     else {
8936:       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);
8937:       PetscCall(MatDestroy(y));
8938:     }
8939:   }

8941:   if (w && *y == w) { /* this is to minimize changes in PCMG */
8942:     PetscBool flg;

8944:     PetscCall(PetscObjectQuery((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject *)&w));
8945:     if (w) {
8946:       PetscInt My, Ny, Mw, Nw;

8948:       PetscCall(PetscObjectTypeCompare((PetscObject)*y, ((PetscObject)w)->type_name, &flg));
8949:       PetscCall(MatGetSize(*y, &My, &Ny));
8950:       PetscCall(MatGetSize(w, &Mw, &Nw));
8951:       if (!flg || My != Mw || Ny != Nw) w = NULL;
8952:     }
8953:     if (!w) {
8954:       PetscCall(MatDuplicate(*y, MAT_COPY_VALUES, &w));
8955:       PetscCall(PetscObjectCompose((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject)w));
8956:       PetscCall(PetscObjectDereference((PetscObject)w));
8957:     } else PetscCall(MatCopy(*y, w, UNKNOWN_NONZERO_PATTERN));
8958:   }
8959:   if (!trans) PetscCall(MatMatMult(A, x, reuse, PETSC_DETERMINE, y));
8960:   else PetscCall(MatTransposeMatMult(A, x, reuse, PETSC_DETERMINE, y));
8961:   if (w) PetscCall(MatAXPY(*y, 1.0, w, UNKNOWN_NONZERO_PATTERN));
8962:   PetscFunctionReturn(PETSC_SUCCESS);
8963: }

8965: /*@
8966:   MatMatInterpolate - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8968:   Neighbor-wise Collective

8970:   Input Parameters:
8971: + A - the matrix
8972: - x - the input dense matrix

8974:   Output Parameter:
8975: . y - the output dense matrix

8977:   Level: intermediate

8979:   Note:
8980:   This allows one to use either the restriction or interpolation (its transpose)
8981:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8982:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8984: .seealso: [](ch_matrices), `Mat`, `MatInterpolate()`, `MatRestrict()`, `MatMatRestrict()`, `PCMG`
8985: @*/
8986: PetscErrorCode MatMatInterpolate(Mat A, Mat x, Mat *y)
8987: {
8988:   PetscFunctionBegin;
8989:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
8990:   PetscFunctionReturn(PETSC_SUCCESS);
8991: }

8993: /*@
8994:   MatMatRestrict - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8996:   Neighbor-wise Collective

8998:   Input Parameters:
8999: + A - the matrix
9000: - x - the input dense matrix

9002:   Output Parameter:
9003: . y - the output dense matrix

9005:   Level: intermediate

9007:   Note:
9008:   This allows one to use either the restriction or interpolation (its transpose)
9009:   matrix to do the restriction. `y` matrix can be reused if already created with the proper sizes,
9010:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

9012: .seealso: [](ch_matrices), `Mat`, `MatRestrict()`, `MatInterpolate()`, `MatMatInterpolate()`, `PCMG`
9013: @*/
9014: PetscErrorCode MatMatRestrict(Mat A, Mat x, Mat *y)
9015: {
9016:   PetscFunctionBegin;
9017:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
9018:   PetscFunctionReturn(PETSC_SUCCESS);
9019: }

9021: /*@
9022:   MatGetNullSpace - retrieves the null space of a matrix.

9024:   Logically Collective

9026:   Input Parameters:
9027: + mat    - the matrix
9028: - nullsp - the null space object

9030:   Level: developer

9032: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetNullSpace()`, `MatNullSpace`
9033: @*/
9034: PetscErrorCode MatGetNullSpace(Mat mat, MatNullSpace *nullsp)
9035: {
9036:   PetscFunctionBegin;
9038:   PetscAssertPointer(nullsp, 2);
9039:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->nullsp) ? mat->transnullsp : mat->nullsp;
9040:   PetscFunctionReturn(PETSC_SUCCESS);
9041: }

9043: /*@C
9044:   MatGetNullSpaces - gets the null spaces, transpose null spaces, and near null spaces from an array of matrices

9046:   Logically Collective

9048:   Input Parameters:
9049: + n   - the number of matrices
9050: - mat - the array of matrices

9052:   Output Parameters:
9053: . nullsp - an array of null spaces, `NULL` for each matrix that does not have a null space, length 3 * `n`

9055:   Level: developer

9057:   Note:
9058:   Call `MatRestoreNullspaces()` to provide these to another array of matrices

9060: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
9061:           `MatNullSpaceRemove()`, `MatRestoreNullSpaces()`
9062: @*/
9063: PetscErrorCode MatGetNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
9064: {
9065:   PetscFunctionBegin;
9066:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
9067:   PetscAssertPointer(mat, 2);
9068:   PetscAssertPointer(nullsp, 3);

9070:   PetscCall(PetscCalloc1(3 * n, nullsp));
9071:   for (PetscInt i = 0; i < n; i++) {
9073:     (*nullsp)[i] = mat[i]->nullsp;
9074:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[i]));
9075:     (*nullsp)[n + i] = mat[i]->nearnullsp;
9076:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[n + i]));
9077:     (*nullsp)[2 * n + i] = mat[i]->transnullsp;
9078:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[2 * n + i]));
9079:   }
9080:   PetscFunctionReturn(PETSC_SUCCESS);
9081: }

9083: /*@C
9084:   MatRestoreNullSpaces - sets the null spaces, transpose null spaces, and near null spaces obtained with `MatGetNullSpaces()` for an array of matrices

9086:   Logically Collective

9088:   Input Parameters:
9089: + n      - the number of matrices
9090: . mat    - the array of matrices
9091: - nullsp - an array of null spaces

9093:   Level: developer

9095:   Note:
9096:   Call `MatGetNullSpaces()` to create `nullsp`

9098: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
9099:           `MatNullSpaceRemove()`, `MatGetNullSpaces()`
9100: @*/
9101: PetscErrorCode MatRestoreNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
9102: {
9103:   PetscFunctionBegin;
9104:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
9105:   PetscAssertPointer(mat, 2);
9106:   PetscAssertPointer(nullsp, 3);
9107:   PetscAssertPointer(*nullsp, 3);

9109:   for (PetscInt i = 0; i < n; i++) {
9111:     PetscCall(MatSetNullSpace(mat[i], (*nullsp)[i]));
9112:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[i]));
9113:     PetscCall(MatSetNearNullSpace(mat[i], (*nullsp)[n + i]));
9114:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[n + i]));
9115:     PetscCall(MatSetTransposeNullSpace(mat[i], (*nullsp)[2 * n + i]));
9116:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[2 * n + i]));
9117:   }
9118:   PetscCall(PetscFree(*nullsp));
9119:   PetscFunctionReturn(PETSC_SUCCESS);
9120: }

9122: /*@
9123:   MatSetNullSpace - attaches a null space to a matrix.

9125:   Logically Collective

9127:   Input Parameters:
9128: + mat    - the matrix
9129: - nullsp - the null space object

9131:   Level: advanced

9133:   Notes:
9134:   This null space is used by the `KSP` linear solvers to solve singular systems.

9136:   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`

9138:   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
9139:   to zero but the linear system will still be solved in a least squares sense.

9141:   The fundamental theorem of linear algebra (Gilbert Strang, Introduction to Applied Mathematics, page 72) states that
9142:   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 $A^T$, $R(A^T)$.
9143:   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
9144:   $n(A^T))$ 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
9145:   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 $n(A^T)$.
9146:   This  $\hat{b}$ can be obtained by calling `MatNullSpaceRemove()` with the null space of the transpose of the matrix.

9148:   If the matrix is known to be symmetric because it is an `MATSBAIJ` matrix or one has called
9149:   `MatSetOption`(mat,`MAT_SYMMETRIC` or possibly `MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`); this
9150:   routine also automatically calls `MatSetTransposeNullSpace()`.

9152:   The user should call `MatNullSpaceDestroy()`.

9154: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`,
9155:           `KSPSetPCSide()`
9156: @*/
9157: PetscErrorCode MatSetNullSpace(Mat mat, MatNullSpace nullsp)
9158: {
9159:   PetscFunctionBegin;
9162:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9163:   PetscCall(MatNullSpaceDestroy(&mat->nullsp));
9164:   mat->nullsp = nullsp;
9165:   if (mat->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetTransposeNullSpace(mat, nullsp));
9166:   PetscFunctionReturn(PETSC_SUCCESS);
9167: }

9169: /*@
9170:   MatGetTransposeNullSpace - retrieves the null space of the transpose of a matrix.

9172:   Logically Collective

9174:   Input Parameters:
9175: + mat    - the matrix
9176: - nullsp - the null space object

9178:   Level: developer

9180: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetTransposeNullSpace()`, `MatSetNullSpace()`, `MatGetNullSpace()`
9181: @*/
9182: PetscErrorCode MatGetTransposeNullSpace(Mat mat, MatNullSpace *nullsp)
9183: {
9184:   PetscFunctionBegin;
9187:   PetscAssertPointer(nullsp, 2);
9188:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->transnullsp) ? mat->nullsp : mat->transnullsp;
9189:   PetscFunctionReturn(PETSC_SUCCESS);
9190: }

9192: /*@
9193:   MatSetTransposeNullSpace - attaches the null space of a transpose of a matrix to the matrix

9195:   Logically Collective

9197:   Input Parameters:
9198: + mat    - the matrix
9199: - nullsp - the null space object

9201:   Level: advanced

9203:   Notes:
9204:   This allows solving singular linear systems defined by the transpose of the matrix using `KSP` solvers with left preconditioning.

9206:   See `MatSetNullSpace()`

9208: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`, `KSPSetPCSide()`
9209: @*/
9210: PetscErrorCode MatSetTransposeNullSpace(Mat mat, MatNullSpace nullsp)
9211: {
9212:   PetscFunctionBegin;
9215:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9216:   PetscCall(MatNullSpaceDestroy(&mat->transnullsp));
9217:   mat->transnullsp = nullsp;
9218:   PetscFunctionReturn(PETSC_SUCCESS);
9219: }

9221: /*@
9222:   MatSetNearNullSpace - attaches a null space to a matrix, which is often the null space (rigid body modes) of the operator without boundary conditions
9223:   This null space will be used to provide near null space vectors to a multigrid preconditioner built from this matrix.

9225:   Logically Collective

9227:   Input Parameters:
9228: + mat    - the matrix
9229: - nullsp - the null space object

9231:   Level: advanced

9233:   Notes:
9234:   Overwrites any previous near null space that may have been attached

9236:   You can remove the null space by calling this routine with an `nullsp` of `NULL`

9238: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNullSpace()`, `MatNullSpaceCreateRigidBody()`, `MatGetNearNullSpace()`
9239: @*/
9240: PetscErrorCode MatSetNearNullSpace(Mat mat, MatNullSpace nullsp)
9241: {
9242:   PetscFunctionBegin;
9246:   MatCheckPreallocated(mat, 1);
9247:   PetscCall(PetscObjectReference((PetscObject)nullsp));
9248:   PetscCall(MatNullSpaceDestroy(&mat->nearnullsp));
9249:   mat->nearnullsp = nullsp;
9250:   PetscFunctionReturn(PETSC_SUCCESS);
9251: }

9253: /*@
9254:   MatGetNearNullSpace - Get null space attached with `MatSetNearNullSpace()`

9256:   Not Collective

9258:   Input Parameter:
9259: . mat - the matrix

9261:   Output Parameter:
9262: . nullsp - the null space object, `NULL` if not set

9264:   Level: advanced

9266: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatNullSpaceCreate()`
9267: @*/
9268: PetscErrorCode MatGetNearNullSpace(Mat mat, MatNullSpace *nullsp)
9269: {
9270:   PetscFunctionBegin;
9273:   PetscAssertPointer(nullsp, 2);
9274:   MatCheckPreallocated(mat, 1);
9275:   *nullsp = mat->nearnullsp;
9276:   PetscFunctionReturn(PETSC_SUCCESS);
9277: }

9279: /*@
9280:   MatICCFactor - Performs in-place incomplete Cholesky factorization of matrix.

9282:   Collective

9284:   Input Parameters:
9285: + mat  - the matrix
9286: . row  - row/column permutation
9287: - info - information on desired factorization process

9289:   Level: developer

9291:   Notes:
9292:   Probably really in-place only when level of fill is zero, otherwise allocates
9293:   new space to store factored matrix and deletes previous memory.

9295:   Most users should employ the `KSP` interface for linear solvers
9296:   instead of working directly with matrix algebra routines such as this.
9297:   See, e.g., `KSPCreate()`.

9299:   Fortran Note:
9300:   A valid (non-null) `info` argument must be provided

9302: .seealso: [](ch_matrices), `Mat`, `MatFactorInfo`, `MatGetFactor()`, `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
9303: @*/
9304: PetscErrorCode MatICCFactor(Mat mat, IS row, const MatFactorInfo *info)
9305: {
9306:   PetscFunctionBegin;
9310:   PetscAssertPointer(info, 3);
9311:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
9312:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
9313:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
9314:   MatCheckPreallocated(mat, 1);
9315:   PetscUseTypeMethod(mat, iccfactor, row, info);
9316:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9317:   PetscFunctionReturn(PETSC_SUCCESS);
9318: }

9320: /*@
9321:   MatDiagonalScaleLocal - Scales columns of a matrix given the scaling values including the
9322:   ghosted ones.

9324:   Not Collective

9326:   Input Parameters:
9327: + mat  - the matrix
9328: - diag - the diagonal values, including ghost ones

9330:   Level: developer

9332:   Notes:
9333:   Works only for `MATMPIAIJ` and `MATMPIBAIJ` matrices

9335:   This allows one to avoid during communication to perform the scaling that must be done with `MatDiagonalScale()`

9337: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
9338: @*/
9339: PetscErrorCode MatDiagonalScaleLocal(Mat mat, Vec diag)
9340: {
9341:   PetscMPIInt size;

9343:   PetscFunctionBegin;

9348:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must be already assembled");
9349:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
9350:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
9351:   if (size == 1) {
9352:     PetscInt n, m;
9353:     PetscCall(VecGetSize(diag, &n));
9354:     PetscCall(MatGetSize(mat, NULL, &m));
9355:     PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supported for sequential matrices when no ghost points/periodic conditions");
9356:     PetscCall(MatDiagonalScale(mat, NULL, diag));
9357:   } else PetscUseMethod(mat, "MatDiagonalScaleLocal_C", (Mat, Vec), (mat, diag));
9358:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
9359:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9360:   PetscFunctionReturn(PETSC_SUCCESS);
9361: }

9363: /*@
9364:   MatGetInertia - Gets the inertia from a factored matrix

9366:   Collective

9368:   Input Parameter:
9369: . mat - the matrix

9371:   Output Parameters:
9372: + nneg  - number of negative eigenvalues
9373: . nzero - number of zero eigenvalues
9374: - npos  - number of positive eigenvalues

9376:   Level: advanced

9378:   Note:
9379:   Matrix must have been factored by `MatCholeskyFactor()`

9381: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactor()`
9382: @*/
9383: PetscErrorCode MatGetInertia(Mat mat, PetscInt *nneg, PetscInt *nzero, PetscInt *npos)
9384: {
9385:   PetscFunctionBegin;
9388:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9389:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Numeric factor mat is not assembled");
9390:   PetscUseTypeMethod(mat, getinertia, nneg, nzero, npos);
9391:   PetscFunctionReturn(PETSC_SUCCESS);
9392: }

9394: /*@C
9395:   MatSolves - Solves $A x = b$, given a factored matrix, for a collection of vectors

9397:   Neighbor-wise Collective

9399:   Input Parameters:
9400: + mat - the factored matrix obtained with `MatGetFactor()`
9401: - b   - the right-hand-side vectors

9403:   Output Parameter:
9404: . x - the result vectors

9406:   Level: developer

9408:   Note:
9409:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
9410:   call `MatSolves`(A,x,x).

9412: .seealso: [](ch_matrices), `Mat`, `Vecs`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`, `MatSolve()`
9413: @*/
9414: PetscErrorCode MatSolves(Mat mat, Vecs b, Vecs x)
9415: {
9416:   PetscFunctionBegin;
9419:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
9420:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9421:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);

9423:   MatCheckPreallocated(mat, 1);
9424:   PetscCall(PetscLogEventBegin(MAT_Solves, mat, 0, 0, 0));
9425:   PetscUseTypeMethod(mat, solves, b, x);
9426:   PetscCall(PetscLogEventEnd(MAT_Solves, mat, 0, 0, 0));
9427:   PetscFunctionReturn(PETSC_SUCCESS);
9428: }

9430: /*@
9431:   MatIsSymmetric - Test whether a matrix is symmetric

9433:   Collective

9435:   Input Parameters:
9436: + A   - the matrix to test
9437: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact transpose)

9439:   Output Parameter:
9440: . flg - the result

9442:   Level: intermediate

9444:   Notes:
9445:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9447:   If the matrix does not yet know if it is symmetric or not this can be an expensive operation, also available `MatIsSymmetricKnown()`

9449:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9450:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9452: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetricKnown()`,
9453:           `MAT_SYMMETRIC`, `MAT_SYMMETRY_ETERNAL`
9454: @*/
9455: PetscErrorCode MatIsSymmetric(Mat A, PetscReal tol, PetscBool *flg)
9456: {
9457:   PetscFunctionBegin;
9459:   PetscAssertPointer(flg, 3);
9460:   if (A->symmetric != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->symmetric);
9461:   else {
9462:     if (A->ops->issymmetric) PetscUseTypeMethod(A, issymmetric, tol, flg);
9463:     else PetscCall(MatIsTranspose(A, A, tol, flg));
9464:     if (!tol) PetscCall(MatSetOption(A, MAT_SYMMETRIC, *flg));
9465:   }
9466:   PetscFunctionReturn(PETSC_SUCCESS);
9467: }

9469: /*@
9470:   MatIsHermitian - Test whether a matrix is Hermitian

9472:   Collective

9474:   Input Parameters:
9475: + A   - the matrix to test
9476: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact Hermitian)

9478:   Output Parameter:
9479: . flg - the result

9481:   Level: intermediate

9483:   Notes:
9484:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9486:   If the matrix does not yet know if it is Hermitian or not this can be an expensive operation, also available `MatIsHermitianKnown()`

9488:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9489:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMEMTRY_ETERNAL`,`PETSC_TRUE`)

9491: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetric()`, `MatSetOption()`,
9492:           `MatIsSymmetricKnown()`, `MatIsSymmetric()`, `MAT_HERMITIAN`, `MAT_SYMMETRY_ETERNAL`
9493: @*/
9494: PetscErrorCode MatIsHermitian(Mat A, PetscReal tol, PetscBool *flg)
9495: {
9496:   PetscFunctionBegin;
9498:   PetscAssertPointer(flg, 3);
9499:   if (A->hermitian != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->hermitian);
9500:   else {
9501:     if (A->ops->ishermitian) PetscUseTypeMethod(A, ishermitian, tol, flg);
9502:     else PetscCall(MatIsHermitianTranspose(A, A, tol, flg));
9503:     if (!tol) PetscCall(MatSetOption(A, MAT_HERMITIAN, *flg));
9504:   }
9505:   PetscFunctionReturn(PETSC_SUCCESS);
9506: }

9508: /*@
9509:   MatIsSymmetricKnown - Checks if a matrix knows if it is symmetric or not and its symmetric state

9511:   Not Collective

9513:   Input Parameter:
9514: . A - the matrix to check

9516:   Output Parameters:
9517: + set - `PETSC_TRUE` if the matrix knows its symmetry state (this tells you if the next flag is valid)
9518: - flg - the result (only valid if set is `PETSC_TRUE`)

9520:   Level: advanced

9522:   Notes:
9523:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsSymmetric()`
9524:   if you want it explicitly checked

9526:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9527:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9529: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9530: @*/
9531: PetscErrorCode MatIsSymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9532: {
9533:   PetscFunctionBegin;
9535:   PetscAssertPointer(set, 2);
9536:   PetscAssertPointer(flg, 3);
9537:   if (A->symmetric != PETSC_BOOL3_UNKNOWN) {
9538:     *set = PETSC_TRUE;
9539:     *flg = PetscBool3ToBool(A->symmetric);
9540:   } else *set = PETSC_FALSE;
9541:   PetscFunctionReturn(PETSC_SUCCESS);
9542: }

9544: /*@
9545:   MatIsSPDKnown - Checks if a matrix knows if it is symmetric positive definite or not and its symmetric positive definite state

9547:   Not Collective

9549:   Input Parameter:
9550: . A - the matrix to check

9552:   Output Parameters:
9553: + set - `PETSC_TRUE` if the matrix knows its symmetric positive definite state (this tells you if the next flag is valid)
9554: - flg - the result (only valid if set is `PETSC_TRUE`)

9556:   Level: advanced

9558:   Notes:
9559:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`).

9561:   One can declare that a matrix is SPD with `MatSetOption`(mat,`MAT_SPD`,`PETSC_TRUE`) and if it is known to remain SPD
9562:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SPD_ETERNAL`,`PETSC_TRUE`)

9564: .seealso: [](ch_matrices), `Mat`, `MAT_SPD_ETERNAL`, `MAT_SPD`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9565: @*/
9566: PetscErrorCode MatIsSPDKnown(Mat A, PetscBool *set, PetscBool *flg)
9567: {
9568:   PetscFunctionBegin;
9570:   PetscAssertPointer(set, 2);
9571:   PetscAssertPointer(flg, 3);
9572:   if (A->spd != PETSC_BOOL3_UNKNOWN) {
9573:     *set = PETSC_TRUE;
9574:     *flg = PetscBool3ToBool(A->spd);
9575:   } else *set = PETSC_FALSE;
9576:   PetscFunctionReturn(PETSC_SUCCESS);
9577: }

9579: /*@
9580:   MatIsHermitianKnown - Checks if a matrix knows if it is Hermitian or not and its Hermitian state

9582:   Not Collective

9584:   Input Parameter:
9585: . A - the matrix to check

9587:   Output Parameters:
9588: + set - `PETSC_TRUE` if the matrix knows its Hermitian state (this tells you if the next flag is valid)
9589: - flg - the result (only valid if set is `PETSC_TRUE`)

9591:   Level: advanced

9593:   Notes:
9594:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsHermitian()`
9595:   if you want it explicitly checked

9597:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9598:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9600: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MAT_HERMITIAN`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`
9601: @*/
9602: PetscErrorCode MatIsHermitianKnown(Mat A, PetscBool *set, PetscBool *flg)
9603: {
9604:   PetscFunctionBegin;
9606:   PetscAssertPointer(set, 2);
9607:   PetscAssertPointer(flg, 3);
9608:   if (A->hermitian != PETSC_BOOL3_UNKNOWN) {
9609:     *set = PETSC_TRUE;
9610:     *flg = PetscBool3ToBool(A->hermitian);
9611:   } else *set = PETSC_FALSE;
9612:   PetscFunctionReturn(PETSC_SUCCESS);
9613: }

9615: /*@
9616:   MatIsStructurallySymmetric - Test whether a matrix is structurally symmetric

9618:   Collective

9620:   Input Parameter:
9621: . A - the matrix to test

9623:   Output Parameter:
9624: . flg - the result

9626:   Level: intermediate

9628:   Notes:
9629:   If the matrix does yet know it is structurally symmetric this can be an expensive operation, also available `MatIsStructurallySymmetricKnown()`

9631:   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
9632:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9634: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsSymmetric()`, `MatSetOption()`, `MatIsStructurallySymmetricKnown()`
9635: @*/
9636: PetscErrorCode MatIsStructurallySymmetric(Mat A, PetscBool *flg)
9637: {
9638:   PetscFunctionBegin;
9640:   PetscAssertPointer(flg, 2);
9641:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) *flg = PetscBool3ToBool(A->structurally_symmetric);
9642:   else {
9643:     PetscUseTypeMethod(A, isstructurallysymmetric, flg);
9644:     PetscCall(MatSetOption(A, MAT_STRUCTURALLY_SYMMETRIC, *flg));
9645:   }
9646:   PetscFunctionReturn(PETSC_SUCCESS);
9647: }

9649: /*@
9650:   MatIsStructurallySymmetricKnown - Checks if a matrix knows if it is structurally symmetric or not and its structurally symmetric state

9652:   Not Collective

9654:   Input Parameter:
9655: . A - the matrix to check

9657:   Output Parameters:
9658: + set - PETSC_TRUE if the matrix knows its structurally symmetric state (this tells you if the next flag is valid)
9659: - flg - the result (only valid if set is PETSC_TRUE)

9661:   Level: advanced

9663:   Notes:
9664:   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
9665:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9667:   Use `MatIsStructurallySymmetric()` to explicitly check if a matrix is structurally symmetric (this is an expensive operation)

9669: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9670: @*/
9671: PetscErrorCode MatIsStructurallySymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9672: {
9673:   PetscFunctionBegin;
9675:   PetscAssertPointer(set, 2);
9676:   PetscAssertPointer(flg, 3);
9677:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9678:     *set = PETSC_TRUE;
9679:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9680:   } else *set = PETSC_FALSE;
9681:   PetscFunctionReturn(PETSC_SUCCESS);
9682: }

9684: /*@
9685:   MatStashGetInfo - Gets how many values are currently in the matrix stash, i.e. need
9686:   to be communicated to other processors during the `MatAssemblyBegin()`/`MatAssemblyEnd()` process

9688:   Not Collective

9690:   Input Parameter:
9691: . mat - the matrix

9693:   Output Parameters:
9694: + nstash    - the size of the stash
9695: . reallocs  - the number of additional mallocs incurred.
9696: . bnstash   - the size of the block stash
9697: - breallocs - the number of additional mallocs incurred.in the block stash

9699:   Level: advanced

9701: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashSetInitialSize()`
9702: @*/
9703: PetscErrorCode MatStashGetInfo(Mat mat, PetscInt *nstash, PetscInt *reallocs, PetscInt *bnstash, PetscInt *breallocs)
9704: {
9705:   PetscFunctionBegin;
9706:   PetscCall(MatStashGetInfo_Private(&mat->stash, nstash, reallocs));
9707:   PetscCall(MatStashGetInfo_Private(&mat->bstash, bnstash, breallocs));
9708:   PetscFunctionReturn(PETSC_SUCCESS);
9709: }

9711: /*@
9712:   MatCreateVecs - Get vector(s) compatible with the matrix, i.e. with the same
9713:   parallel layout, `PetscLayout` for rows and columns

9715:   Collective

9717:   Input Parameter:
9718: . mat - the matrix

9720:   Output Parameters:
9721: + right - (optional) vector that the matrix can be multiplied against
9722: - left  - (optional) vector that the matrix vector product can be stored in

9724:   Options Database Key:
9725: . -mat_vec_type type - set the `VecType` of the created vectors during `MatSetFromOptions()`

9727:   Level: advanced

9729:   Notes:
9730:   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()`.

9732:   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`.

9734:   These are new vectors which are not owned by the `mat`, they should be destroyed with `VecDestroy()` when no longer needed.

9736: .seealso: [](ch_matrices), `Mat`, `Vec`, `VecCreate()`, `VecDestroy()`, `DMCreateGlobalVector()`, `MatSetVecType()`
9737: @*/
9738: PetscErrorCode MatCreateVecs(Mat mat, Vec *right, Vec *left)
9739: {
9740:   PetscFunctionBegin;
9743:   if (mat->ops->getvecs) {
9744:     PetscUseTypeMethod(mat, getvecs, right, left);
9745:   } else {
9746:     if (right) {
9747:       PetscCheck(mat->cmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for columns not yet setup");
9748:       PetscCall(VecCreateWithLayout_Private(mat->cmap, right));
9749:       PetscCall(VecSetType(*right, mat->defaultvectype));
9750: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9751:       if (mat->boundtocpu && mat->bindingpropagates) {
9752:         PetscCall(VecSetBindingPropagates(*right, PETSC_TRUE));
9753:         PetscCall(VecBindToCPU(*right, PETSC_TRUE));
9754:       }
9755: #endif
9756:     }
9757:     if (left) {
9758:       PetscCheck(mat->rmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for rows not yet setup");
9759:       PetscCall(VecCreateWithLayout_Private(mat->rmap, left));
9760:       PetscCall(VecSetType(*left, mat->defaultvectype));
9761: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9762:       if (mat->boundtocpu && mat->bindingpropagates) {
9763:         PetscCall(VecSetBindingPropagates(*left, PETSC_TRUE));
9764:         PetscCall(VecBindToCPU(*left, PETSC_TRUE));
9765:       }
9766: #endif
9767:     }
9768:   }
9769:   PetscFunctionReturn(PETSC_SUCCESS);
9770: }

9772: /*@
9773:   MatFactorInfoInitialize - Initializes a `MatFactorInfo` data structure
9774:   with default values.

9776:   Not Collective

9778:   Input Parameter:
9779: . info - the `MatFactorInfo` data structure

9781:   Level: developer

9783:   Notes:
9784:   The solvers are generally used through the `KSP` and `PC` objects, for example
9785:   `PCLU`, `PCILU`, `PCCHOLESKY`, `PCICC`

9787:   Once the data structure is initialized one may change certain entries as desired for the particular factorization to be performed

9789: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorInfo`
9790: @*/
9791: PetscErrorCode MatFactorInfoInitialize(MatFactorInfo *info)
9792: {
9793:   PetscFunctionBegin;
9794:   PetscCall(PetscMemzero(info, sizeof(MatFactorInfo)));
9795:   PetscFunctionReturn(PETSC_SUCCESS);
9796: }

9798: /*@
9799:   MatFactorSetSchurIS - Set indices corresponding to the Schur complement you wish to have computed

9801:   Collective

9803:   Input Parameters:
9804: + mat - the factored matrix
9805: - is  - the index set defining the Schur indices (0-based)

9807:   Level: advanced

9809:   Notes:
9810:   Call `MatFactorSolveSchurComplement()` or `MatFactorSolveSchurComplementTranspose()` after this call to solve a Schur complement system.

9812:   You can call `MatFactorGetSchurComplement()` or `MatFactorCreateSchurComplement()` after this call.

9814:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9816: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorGetSchurComplement()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSolveSchurComplement()`,
9817:           `MatFactorSolveSchurComplementTranspose()`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9818: @*/
9819: PetscErrorCode MatFactorSetSchurIS(Mat mat, IS is)
9820: {
9821:   PetscErrorCode (*f)(Mat, IS);

9823:   PetscFunctionBegin;
9828:   PetscCheckSameComm(mat, 1, is, 2);
9829:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
9830:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorSetSchurIS_C", &f));
9831:   PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "The selected MatSolverType does not support Schur complement computation. You should use MATSOLVERMUMPS or MATSOLVERMKL_PARDISO");
9832:   PetscCall(MatDestroy(&mat->schur));
9833:   PetscCall((*f)(mat, is));
9834:   PetscCheck(mat->schur, PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "Schur complement has not been created");
9835:   PetscFunctionReturn(PETSC_SUCCESS);
9836: }

9838: /*@
9839:   MatFactorCreateSchurComplement - Create a Schur complement matrix object using Schur data computed during the factorization step

9841:   Logically Collective

9843:   Input Parameters:
9844: + F      - the factored matrix obtained by calling `MatGetFactor()`
9845: . S      - location where to return the Schur complement, can be `NULL`
9846: - status - the status of the Schur complement matrix, can be `NULL`

9848:   Level: advanced

9850:   Notes:
9851:   You must call `MatFactorSetSchurIS()` before calling this routine.

9853:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9855:   The routine provides a copy of the Schur matrix stored within the solver data structures.
9856:   The caller must destroy the object when it is no longer needed.
9857:   If `MatFactorInvertSchurComplement()` has been called, the routine gets back the inverse.

9859:   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)

9861:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9863:   Developer Note:
9864:   The reason this routine exists is because the representation of the Schur complement within the factor matrix may be different than a standard PETSc
9865:   matrix representation and we normally do not want to use the time or memory to make a copy as a regular PETSc matrix.

9867: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorSchurStatus`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9868: @*/
9869: PetscErrorCode MatFactorCreateSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9870: {
9871:   PetscFunctionBegin;
9873:   if (S) PetscAssertPointer(S, 2);
9874:   if (status) PetscAssertPointer(status, 3);
9875:   if (S) {
9876:     PetscErrorCode (*f)(Mat, Mat *);

9878:     PetscCall(PetscObjectQueryFunction((PetscObject)F, "MatFactorCreateSchurComplement_C", &f));
9879:     if (f) PetscCall((*f)(F, S));
9880:     else PetscCall(MatDuplicate(F->schur, MAT_COPY_VALUES, S));
9881:   }
9882:   if (status) *status = F->schur_status;
9883:   PetscFunctionReturn(PETSC_SUCCESS);
9884: }

9886: /*@
9887:   MatFactorGetSchurComplement - Gets access to a Schur complement matrix using the current Schur data within a factored matrix

9889:   Logically Collective

9891:   Input Parameters:
9892: + F      - the factored matrix obtained by calling `MatGetFactor()`
9893: . S      - location where to return the Schur complement, can be `NULL`
9894: - status - the status of the Schur complement matrix, can be `NULL`

9896:   Level: advanced

9898:   Notes:
9899:   You must call `MatFactorSetSchurIS()` before calling this routine.

9901:   Schur complement mode is currently implemented for sequential matrices with factor type of `MATSOLVERMUMPS`

9903:   The routine returns a the Schur Complement stored within the data structures of the solver.

9905:   If `MatFactorInvertSchurComplement()` has previously been called, the returned matrix is actually the inverse of the Schur complement.

9907:   The returned matrix should not be destroyed; the caller should call `MatFactorRestoreSchurComplement()` when the object is no longer needed.

9909:   Use `MatFactorCreateSchurComplement()` to create a copy of the Schur complement matrix that is within a factored matrix

9911:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9913: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9914: @*/
9915: PetscErrorCode MatFactorGetSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9916: {
9917:   PetscFunctionBegin;
9919:   if (S) {
9920:     PetscAssertPointer(S, 2);
9921:     *S = F->schur;
9922:   }
9923:   if (status) {
9924:     PetscAssertPointer(status, 3);
9925:     *status = F->schur_status;
9926:   }
9927:   PetscFunctionReturn(PETSC_SUCCESS);
9928: }

9930: static PetscErrorCode MatFactorUpdateSchurStatus_Private(Mat F)
9931: {
9932:   Mat S = F->schur;

9934:   PetscFunctionBegin;
9935:   switch (F->schur_status) {
9936:   case MAT_FACTOR_SCHUR_UNFACTORED: // fall-through
9937:   case MAT_FACTOR_SCHUR_INVERTED:
9938:     if (S) {
9939:       S->ops->solve             = NULL;
9940:       S->ops->matsolve          = NULL;
9941:       S->ops->solvetranspose    = NULL;
9942:       S->ops->matsolvetranspose = NULL;
9943:       S->ops->solveadd          = NULL;
9944:       S->ops->solvetransposeadd = NULL;
9945:       S->factortype             = MAT_FACTOR_NONE;
9946:       PetscCall(PetscFree(S->solvertype));
9947:     }
9948:   case MAT_FACTOR_SCHUR_FACTORED: // fall-through
9949:     break;
9950:   default:
9951:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9952:   }
9953:   PetscFunctionReturn(PETSC_SUCCESS);
9954: }

9956: /*@
9957:   MatFactorRestoreSchurComplement - Restore the Schur complement matrix object obtained from a call to `MatFactorGetSchurComplement()`

9959:   Logically Collective

9961:   Input Parameters:
9962: + F      - the factored matrix obtained by calling `MatGetFactor()`
9963: . S      - location where the Schur complement is stored
9964: - status - the status of the Schur complement matrix (see `MatFactorSchurStatus`)

9966:   Level: advanced

9968: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9969: @*/
9970: PetscErrorCode MatFactorRestoreSchurComplement(Mat F, Mat *S, MatFactorSchurStatus status)
9971: {
9972:   PetscFunctionBegin;
9974:   if (S) {
9976:     *S = NULL;
9977:   }
9978:   F->schur_status = status;
9979:   PetscCall(MatFactorUpdateSchurStatus_Private(F));
9980:   PetscFunctionReturn(PETSC_SUCCESS);
9981: }

9983: /*@
9984:   MatFactorSolveSchurComplementTranspose - Solve the transpose of the Schur complement system computed during the factorization step

9986:   Logically Collective

9988:   Input Parameters:
9989: + F   - the factored matrix obtained by calling `MatGetFactor()`
9990: . rhs - location where the right-hand side of the Schur complement system is stored
9991: - sol - location where the solution of the Schur complement system has to be returned

9993:   Level: advanced

9995:   Notes:
9996:   The sizes of the vectors should match the size of the Schur complement

9998:   Must be called after `MatFactorSetSchurIS()`

10000: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplement()`
10001: @*/
10002: PetscErrorCode MatFactorSolveSchurComplementTranspose(Mat F, Vec rhs, Vec sol)
10003: {
10004:   PetscFunctionBegin;
10011:   PetscCheckSameComm(F, 1, rhs, 2);
10012:   PetscCheckSameComm(F, 1, sol, 3);
10013:   PetscCall(MatFactorFactorizeSchurComplement(F));
10014:   switch (F->schur_status) {
10015:   case MAT_FACTOR_SCHUR_FACTORED:
10016:     PetscCall(MatSolveTranspose(F->schur, rhs, sol));
10017:     break;
10018:   case MAT_FACTOR_SCHUR_INVERTED:
10019:     PetscCall(MatMultTranspose(F->schur, rhs, sol));
10020:     break;
10021:   default:
10022:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
10023:   }
10024:   PetscFunctionReturn(PETSC_SUCCESS);
10025: }

10027: /*@
10028:   MatFactorSolveSchurComplement - Solve the Schur complement system computed during the factorization step

10030:   Logically Collective

10032:   Input Parameters:
10033: + F   - the factored matrix obtained by calling `MatGetFactor()`
10034: . rhs - location where the right-hand side of the Schur complement system is stored
10035: - sol - location where the solution of the Schur complement system has to be returned

10037:   Level: advanced

10039:   Notes:
10040:   The sizes of the vectors should match the size of the Schur complement

10042:   Must be called after `MatFactorSetSchurIS()`

10044: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplementTranspose()`
10045: @*/
10046: PetscErrorCode MatFactorSolveSchurComplement(Mat F, Vec rhs, Vec sol)
10047: {
10048:   PetscFunctionBegin;
10055:   PetscCheckSameComm(F, 1, rhs, 2);
10056:   PetscCheckSameComm(F, 1, sol, 3);
10057:   PetscCall(MatFactorFactorizeSchurComplement(F));
10058:   switch (F->schur_status) {
10059:   case MAT_FACTOR_SCHUR_FACTORED:
10060:     PetscCall(MatSolve(F->schur, rhs, sol));
10061:     break;
10062:   case MAT_FACTOR_SCHUR_INVERTED:
10063:     PetscCall(MatMult(F->schur, rhs, sol));
10064:     break;
10065:   default:
10066:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
10067:   }
10068:   PetscFunctionReturn(PETSC_SUCCESS);
10069: }

10071: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseInvertFactors_Private(Mat);
10072: #if PetscDefined(HAVE_CUDA)
10073: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseCUDAInvertFactors_Internal(Mat);
10074: #endif

10076: /* Schur status updated in the interface */
10077: static PetscErrorCode MatFactorInvertSchurComplement_Private(Mat F)
10078: {
10079:   Mat S = F->schur;

10081:   PetscFunctionBegin;
10082:   if (S) {
10083:     PetscMPIInt size;
10084:     PetscBool   isdense, isdensecuda;

10086:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)S), &size));
10087:     PetscCheck(size <= 1, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not yet implemented");
10088:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSE, &isdense));
10089:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSECUDA, &isdensecuda));
10090:     PetscCheck(isdense || isdensecuda, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not implemented for type %s", ((PetscObject)S)->type_name);
10091:     PetscCall(PetscLogEventBegin(MAT_FactorInvS, F, 0, 0, 0));
10092:     if (isdense) {
10093:       PetscCall(MatSeqDenseInvertFactors_Private(S));
10094:     } else if (isdensecuda) {
10095: #if defined(PETSC_HAVE_CUDA)
10096:       PetscCall(MatSeqDenseCUDAInvertFactors_Internal(S));
10097: #endif
10098:     }
10099:     // HIP??????????????
10100:     PetscCall(PetscLogEventEnd(MAT_FactorInvS, F, 0, 0, 0));
10101:   }
10102:   PetscFunctionReturn(PETSC_SUCCESS);
10103: }

10105: /*@
10106:   MatFactorInvertSchurComplement - Invert the Schur complement matrix computed during the factorization step

10108:   Logically Collective

10110:   Input Parameter:
10111: . F - the factored matrix obtained by calling `MatGetFactor()`

10113:   Level: advanced

10115:   Notes:
10116:   Must be called after `MatFactorSetSchurIS()`.

10118:   Call `MatFactorGetSchurComplement()` or  `MatFactorCreateSchurComplement()` AFTER this call to actually compute the inverse and get access to it.

10120: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorCreateSchurComplement()`
10121: @*/
10122: PetscErrorCode MatFactorInvertSchurComplement(Mat F)
10123: {
10124:   PetscFunctionBegin;
10127:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED) PetscFunctionReturn(PETSC_SUCCESS);
10128:   PetscCall(MatFactorFactorizeSchurComplement(F));
10129:   PetscCall(MatFactorInvertSchurComplement_Private(F));
10130:   F->schur_status = MAT_FACTOR_SCHUR_INVERTED;
10131:   PetscFunctionReturn(PETSC_SUCCESS);
10132: }

10134: /*@
10135:   MatFactorFactorizeSchurComplement - Factorize the Schur complement matrix computed during the factorization step

10137:   Logically Collective

10139:   Input Parameter:
10140: . F - the factored matrix obtained by calling `MatGetFactor()`

10142:   Level: advanced

10144:   Note:
10145:   Must be called after `MatFactorSetSchurIS()`

10147: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorInvertSchurComplement()`
10148: @*/
10149: PetscErrorCode MatFactorFactorizeSchurComplement(Mat F)
10150: {
10151:   MatFactorInfo info;

10153:   PetscFunctionBegin;
10156:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED || F->schur_status == MAT_FACTOR_SCHUR_FACTORED) PetscFunctionReturn(PETSC_SUCCESS);
10157:   PetscCall(PetscLogEventBegin(MAT_FactorFactS, F, 0, 0, 0));
10158:   PetscCall(PetscMemzero(&info, sizeof(MatFactorInfo)));
10159:   if (F->factortype == MAT_FACTOR_CHOLESKY) { /* LDL^t regarded as Cholesky */
10160:     PetscCall(MatCholeskyFactor(F->schur, NULL, &info));
10161:   } else {
10162:     PetscCall(MatLUFactor(F->schur, NULL, NULL, &info));
10163:   }
10164:   PetscCall(PetscLogEventEnd(MAT_FactorFactS, F, 0, 0, 0));
10165:   F->schur_status = MAT_FACTOR_SCHUR_FACTORED;
10166:   PetscFunctionReturn(PETSC_SUCCESS);
10167: }

10169: /*@
10170:   MatPtAP - Creates the matrix product $C = P^T * A * P$

10172:   Neighbor-wise Collective

10174:   Input Parameters:
10175: + A     - the matrix
10176: . P     - the projection matrix
10177: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10178: - 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
10179:           if the result is a dense matrix this is irrelevant

10181:   Output Parameter:
10182: . C - the product matrix

10184:   Level: intermediate

10186:   Notes:
10187:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10189:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_PtAP`
10190:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10192:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10194:   Developer Note:
10195:   For matrix types without special implementation the function fallbacks to `MatMatMult()` followed by `MatTransposeMatMult()`.

10197: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatRARt()`
10198: @*/
10199: PetscErrorCode MatPtAP(Mat A, Mat P, MatReuse scall, PetscReal fill, Mat *C)
10200: {
10201:   PetscFunctionBegin;
10202:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10203:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10205:   if (scall == MAT_INITIAL_MATRIX) {
10206:     PetscCall(MatProductCreate(A, P, NULL, C));
10207:     PetscCall(MatProductSetType(*C, MATPRODUCT_PtAP));
10208:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10209:     PetscCall(MatProductSetFill(*C, fill));

10211:     (*C)->product->api_user = PETSC_TRUE;
10212:     PetscCall(MatProductSetFromOptions(*C));
10213:     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);
10214:     PetscCall(MatProductSymbolic(*C));
10215:   } else { /* scall == MAT_REUSE_MATRIX */
10216:     PetscCall(MatProductReplaceMats(A, P, NULL, *C));
10217:   }

10219:   PetscCall(MatProductNumeric(*C));
10220:   if (A->symmetric == PETSC_BOOL3_TRUE) {
10221:     PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10222:     (*C)->spd = A->spd;
10223:   }
10224:   PetscFunctionReturn(PETSC_SUCCESS);
10225: }

10227: /*@
10228:   MatRARt - Creates the matrix product $C = R * A * R^T$

10230:   Neighbor-wise Collective

10232:   Input Parameters:
10233: + A     - the matrix
10234: . R     - the projection matrix
10235: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10236: - fill  - expected fill as ratio of nnz(C)/nnz(A), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10237:           if the result is a dense matrix this is irrelevant

10239:   Output Parameter:
10240: . C - the product matrix

10242:   Level: intermediate

10244:   Notes:
10245:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10247:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_RARt`
10248:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10250:   This routine is currently only implemented for pairs of `MATAIJ` matrices and classes
10251:   which inherit from `MATAIJ`. Due to PETSc sparse matrix block row distribution among processes,
10252:   the parallel `MatRARt()` is implemented computing the explicit transpose of `R`, which can be very expensive.
10253:   We recommend using `MatPtAP()` when possible.

10255:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10257: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatPtAP()`
10258: @*/
10259: PetscErrorCode MatRARt(Mat A, Mat R, MatReuse scall, PetscReal fill, Mat *C)
10260: {
10261:   PetscFunctionBegin;
10262:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10263:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10265:   if (scall == MAT_INITIAL_MATRIX) {
10266:     PetscCall(MatProductCreate(A, R, NULL, C));
10267:     PetscCall(MatProductSetType(*C, MATPRODUCT_RARt));
10268:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10269:     PetscCall(MatProductSetFill(*C, fill));

10271:     (*C)->product->api_user = PETSC_TRUE;
10272:     PetscCall(MatProductSetFromOptions(*C));
10273:     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);
10274:     PetscCall(MatProductSymbolic(*C));
10275:   } else { /* scall == MAT_REUSE_MATRIX */
10276:     PetscCall(MatProductReplaceMats(A, R, NULL, *C));
10277:   }

10279:   PetscCall(MatProductNumeric(*C));
10280:   if (A->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10281:   PetscFunctionReturn(PETSC_SUCCESS);
10282: }

10284: static PetscErrorCode MatProduct_Private(Mat A, Mat B, MatReuse scall, PetscReal fill, MatProductType ptype, Mat *C)
10285: {
10286:   PetscBool flg = PETSC_TRUE;

10288:   PetscFunctionBegin;
10289:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX product not supported");
10290:   if (scall == MAT_INITIAL_MATRIX) {
10291:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_INITIAL_MATRIX and product type %s\n", MatProductTypes[ptype]));
10292:     PetscCall(MatProductCreate(A, B, NULL, C));
10293:     PetscCall(MatProductSetAlgorithm(*C, MATPRODUCTALGORITHMDEFAULT));
10294:     PetscCall(MatProductSetFill(*C, fill));
10295:   } else { /* scall == MAT_REUSE_MATRIX */
10296:     Mat_Product *product = (*C)->product;

10298:     PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)*C, &flg, MATSEQDENSE, MATMPIDENSE, ""));
10299:     if (flg && product && product->type != ptype) {
10300:       PetscCall(MatProductClear(*C));
10301:       product = NULL;
10302:     }
10303:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_REUSE_MATRIX %s product present and product type %s\n", product ? "with" : "without", MatProductTypes[ptype]));
10304:     if (!product) { /* user provide the dense matrix *C without calling MatProductCreate() or reusing it from previous calls */
10305:       PetscCheck(flg, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "Call MatProductCreate() first");
10306:       PetscCall(MatProductCreate_Private(A, B, NULL, *C));
10307:       product        = (*C)->product;
10308:       product->fill  = fill;
10309:       product->clear = PETSC_TRUE;
10310:     } else { /* user may change input matrices A or B when MAT_REUSE_MATRIX */
10311:       flg = PETSC_FALSE;
10312:       PetscCall(MatProductReplaceMats(A, B, NULL, *C));
10313:     }
10314:   }
10315:   if (flg) {
10316:     (*C)->product->api_user = PETSC_TRUE;
10317:     PetscCall(MatProductSetType(*C, ptype));
10318:     PetscCall(MatProductSetFromOptions(*C));
10319:     PetscCall(MatProductSymbolic(*C));
10320:   }
10321:   PetscCall(MatProductNumeric(*C));
10322:   PetscFunctionReturn(PETSC_SUCCESS);
10323: }

10325: /*@
10326:   MatMatMult - Performs matrix-matrix multiplication $ C=A*B $.

10328:   Neighbor-wise Collective

10330:   Input Parameters:
10331: + A     - the left matrix
10332: . B     - the right matrix
10333: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10334: - 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
10335:           if the result is a dense matrix this is irrelevant

10337:   Output Parameter:
10338: . C - the product matrix

10340:   Notes:
10341:   Unless scall is `MAT_REUSE_MATRIX` C will be created.

10343:   `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
10344:   call to this function with `MAT_INITIAL_MATRIX`.

10346:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value actually needed.

10348:   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`,
10349:   rather than first having `MatMatMult()` create it for you. You can NEVER do this if the matrix `C` is sparse.

10351:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10353:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AB`
10354:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10356:   Example of Usage:
10357: .vb
10358:      MatProductCreate(A,B,NULL,&C);
10359:      MatProductSetType(C,MATPRODUCT_AB);
10360:      MatProductSymbolic(C);
10361:      MatProductNumeric(C); // compute C=A * B
10362:      MatProductReplaceMats(A1,B1,NULL,C); // compute C=A1 * B1
10363:      MatProductNumeric(C);
10364:      MatProductReplaceMats(A2,NULL,NULL,C); // compute C=A2 * B1
10365:      MatProductNumeric(C);
10366: .ve

10368:   Level: intermediate

10370: .seealso: [](ch_matrices), `Mat`, `MatProductType`, `MATPRODUCT_AB`, `MatTransposeMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`, `MatProductCreate()`, `MatProductSymbolic()`, `MatProductReplaceMats()`, `MatProductNumeric()`
10371: @*/
10372: PetscErrorCode MatMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10373: {
10374:   PetscFunctionBegin;
10375:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AB, C));
10376:   PetscFunctionReturn(PETSC_SUCCESS);
10377: }

10379: /*@
10380:   MatMatTransposeMult - Performs matrix-matrix multiplication $C = A*B^T$.

10382:   Neighbor-wise Collective

10384:   Input Parameters:
10385: + A     - the left matrix
10386: . B     - the right matrix
10387: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10388: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10390:   Output Parameter:
10391: . C - the product matrix

10393:   Options Database Key:
10394: . -matmattransmult_mpidense_mpidense_via {allgatherv,cyclic} - Choose between algorithms for `MATMPIDENSE` matrices: the
10395:               first redundantly copies the transposed `B` matrix on each process and requires O(log P) communication complexity;
10396:               the second never stores more than one portion of the `B` matrix at a time but requires O(P) communication complexity.

10398:   Level: intermediate

10400:   Notes:
10401:   C will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10403:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call

10405:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10406:   actually needed.

10408:   This routine is currently only implemented for pairs of `MATSEQAIJ` matrices, for the `MATSEQDENSE` class,
10409:   and for pairs of `MATMPIDENSE` matrices.

10411:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABt`
10412:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10414:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10416: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABt`, `MatMatMult()`, `MatTransposeMatMult()`, `MatPtAP()`, `MatProductAlgorithm`, `MatProductType`
10417: @*/
10418: PetscErrorCode MatMatTransposeMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10419: {
10420:   PetscFunctionBegin;
10421:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_ABt, C));
10422:   if (A == B) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10423:   PetscFunctionReturn(PETSC_SUCCESS);
10424: }

10426: /*@
10427:   MatTransposeMatMult - Performs matrix-matrix multiplication $C = A^T*B$.

10429:   Neighbor-wise Collective

10431:   Input Parameters:
10432: + A     - the left matrix
10433: . B     - the right matrix
10434: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10435: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10437:   Output Parameter:
10438: . C - the product matrix

10440:   Level: intermediate

10442:   Notes:
10443:   `C` will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10445:   `MAT_REUSE_MATRIX` can only be used if `A` and `B` have the same nonzero pattern as in the previous call.

10447:   This is a convenience routine that wraps the use of `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AtB`
10448:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10450:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10451:   actually needed.

10453:   This routine is currently implemented for pairs of `MATAIJ` matrices and pairs of `MATSEQDENSE` matrices and classes
10454:   which inherit from `MATSEQAIJ`.  `C` will be of the same type as the input matrices.

10456:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10458: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_AtB`, `MatMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`
10459: @*/
10460: PetscErrorCode MatTransposeMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10461: {
10462:   PetscFunctionBegin;
10463:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AtB, C));
10464:   PetscFunctionReturn(PETSC_SUCCESS);
10465: }

10467: /*@
10468:   MatMatMatMult - Performs matrix-matrix-matrix multiplication D=A*B*C.

10470:   Neighbor-wise Collective

10472:   Input Parameters:
10473: + A     - the left matrix
10474: . B     - the middle matrix
10475: . C     - the right matrix
10476: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10477: - 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
10478:           if the result is a dense matrix this is irrelevant

10480:   Output Parameter:
10481: . D - the product matrix

10483:   Level: intermediate

10485:   Notes:
10486:   Unless `scall` is `MAT_REUSE_MATRIX` `D` will be created.

10488:   `MAT_REUSE_MATRIX` can only be used if the matrices `A`, `B`, and `C` have the same nonzero pattern as in the previous call

10490:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABC`
10491:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10493:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value
10494:   actually needed.

10496:   If you have many matrices with the same non-zero structure to multiply, you
10497:   should use `MAT_REUSE_MATRIX` in all calls but the first

10499:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10501: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABC`, `MatMatMult`, `MatPtAP()`, `MatMatTransposeMult()`, `MatTransposeMatMult()`
10502: @*/
10503: PetscErrorCode MatMatMatMult(Mat A, Mat B, Mat C, MatReuse scall, PetscReal fill, Mat *D)
10504: {
10505:   PetscFunctionBegin;
10506:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*D, 6);
10507:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10509:   if (scall == MAT_INITIAL_MATRIX) {
10510:     PetscCall(MatProductCreate(A, B, C, D));
10511:     PetscCall(MatProductSetType(*D, MATPRODUCT_ABC));
10512:     PetscCall(MatProductSetAlgorithm(*D, "default"));
10513:     PetscCall(MatProductSetFill(*D, fill));

10515:     (*D)->product->api_user = PETSC_TRUE;
10516:     PetscCall(MatProductSetFromOptions(*D));
10517:     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,
10518:                ((PetscObject)C)->type_name);
10519:     PetscCall(MatProductSymbolic(*D));
10520:   } else { /* user may change input matrices when REUSE */
10521:     PetscCall(MatProductReplaceMats(A, B, C, *D));
10522:   }
10523:   PetscCall(MatProductNumeric(*D));
10524:   PetscFunctionReturn(PETSC_SUCCESS);
10525: }

10527: /*@
10528:   MatCreateRedundantMatrix - Create redundant matrices and put them into processors of subcommunicators.

10530:   Collective

10532:   Input Parameters:
10533: + mat      - the matrix
10534: . nsubcomm - the number of subcommunicators (= number of redundant parallel or sequential matrices)
10535: . subcomm  - MPI communicator split from the communicator where mat resides in (or `MPI_COMM_NULL` if nsubcomm is used)
10536: - reuse    - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10538:   Output Parameter:
10539: . matredundant - redundant matrix

10541:   Level: advanced

10543:   Notes:
10544:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
10545:   original matrix has not changed from that last call to `MatCreateRedundantMatrix()`.

10547:   This routine creates the duplicated matrices in the subcommunicators; you should NOT create them before
10548:   calling it.

10550:   `PetscSubcommCreate()` can be used to manage the creation of the subcomm but need not be.

10552: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `PetscSubcommCreate()`, `PetscSubcomm`
10553: @*/
10554: PetscErrorCode MatCreateRedundantMatrix(Mat mat, PetscInt nsubcomm, MPI_Comm subcomm, MatReuse reuse, Mat *matredundant)
10555: {
10556:   MPI_Comm       comm;
10557:   PetscMPIInt    size;
10558:   PetscInt       mloc_sub, nloc_sub, rstart, rend, M = mat->rmap->N, N = mat->cmap->N, bs = mat->rmap->bs;
10559:   Mat_Redundant *redund     = NULL;
10560:   PetscSubcomm   psubcomm   = NULL;
10561:   MPI_Comm       subcomm_in = subcomm;
10562:   Mat           *matseq;
10563:   IS             isrow, iscol;
10564:   PetscBool      newsubcomm = PETSC_FALSE;

10566:   PetscFunctionBegin;
10568:   if (nsubcomm && reuse == MAT_REUSE_MATRIX) {
10569:     PetscAssertPointer(*matredundant, 5);
10571:   }

10573:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
10574:   if (size == 1 || nsubcomm == 1) {
10575:     if (reuse == MAT_INITIAL_MATRIX) {
10576:       PetscCall(MatDuplicate(mat, MAT_COPY_VALUES, matredundant));
10577:     } else {
10578:       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");
10579:       PetscCall(MatCopy(mat, *matredundant, SAME_NONZERO_PATTERN));
10580:     }
10581:     PetscFunctionReturn(PETSC_SUCCESS);
10582:   }

10584:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10585:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10586:   MatCheckPreallocated(mat, 1);

10588:   PetscCall(PetscLogEventBegin(MAT_RedundantMat, mat, 0, 0, 0));
10589:   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
10590:     /* create psubcomm, then get subcomm */
10591:     PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10592:     PetscCallMPI(MPI_Comm_size(comm, &size));
10593:     PetscCheck(nsubcomm >= 1 && nsubcomm <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "nsubcomm must between 1 and %d", size);

10595:     PetscCall(PetscSubcommCreate(comm, &psubcomm));
10596:     PetscCall(PetscSubcommSetNumber(psubcomm, nsubcomm));
10597:     PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_CONTIGUOUS));
10598:     PetscCall(PetscSubcommSetFromOptions(psubcomm));
10599:     PetscCall(PetscCommDuplicate(PetscSubcommChild(psubcomm), &subcomm, NULL));
10600:     newsubcomm = PETSC_TRUE;
10601:     PetscCall(PetscSubcommDestroy(&psubcomm));
10602:   }

10604:   /* get isrow, iscol and a local sequential matrix matseq[0] */
10605:   if (reuse == MAT_INITIAL_MATRIX) {
10606:     mloc_sub = PETSC_DECIDE;
10607:     nloc_sub = PETSC_DECIDE;
10608:     if (bs < 1) {
10609:       PetscCall(PetscSplitOwnership(subcomm, &mloc_sub, &M));
10610:       PetscCall(PetscSplitOwnership(subcomm, &nloc_sub, &N));
10611:     } else {
10612:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &mloc_sub, &M));
10613:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &nloc_sub, &N));
10614:     }
10615:     PetscCallMPI(MPI_Scan(&mloc_sub, &rend, 1, MPIU_INT, MPI_SUM, subcomm));
10616:     rstart = rend - mloc_sub;
10617:     PetscCall(ISCreateStride(PETSC_COMM_SELF, mloc_sub, rstart, 1, &isrow));
10618:     PetscCall(ISCreateStride(PETSC_COMM_SELF, N, 0, 1, &iscol));
10619:     PetscCall(ISSetIdentity(iscol));
10620:   } else { /* reuse == MAT_REUSE_MATRIX */
10621:     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");
10622:     /* retrieve subcomm */
10623:     PetscCall(PetscObjectGetComm((PetscObject)*matredundant, &subcomm));
10624:     redund = (*matredundant)->redundant;
10625:     isrow  = redund->isrow;
10626:     iscol  = redund->iscol;
10627:     matseq = redund->matseq;
10628:   }
10629:   PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscol, reuse, &matseq));

10631:   /* get matredundant over subcomm */
10632:   if (reuse == MAT_INITIAL_MATRIX) {
10633:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], nloc_sub, reuse, matredundant));

10635:     /* create a supporting struct and attach it to C for reuse */
10636:     PetscCall(PetscNew(&redund));
10637:     (*matredundant)->redundant = redund;
10638:     redund->isrow              = isrow;
10639:     redund->iscol              = iscol;
10640:     redund->matseq             = matseq;
10641:     if (newsubcomm) {
10642:       redund->subcomm = subcomm;
10643:     } else {
10644:       redund->subcomm = MPI_COMM_NULL;
10645:     }
10646:   } else {
10647:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], PETSC_DECIDE, reuse, matredundant));
10648:   }
10649: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
10650:   if (matseq[0]->boundtocpu && matseq[0]->bindingpropagates) {
10651:     PetscCall(MatBindToCPU(*matredundant, PETSC_TRUE));
10652:     PetscCall(MatSetBindingPropagates(*matredundant, PETSC_TRUE));
10653:   }
10654: #endif
10655:   PetscCall(PetscLogEventEnd(MAT_RedundantMat, mat, 0, 0, 0));
10656:   PetscFunctionReturn(PETSC_SUCCESS);
10657: }

10659: /*@C
10660:   MatGetMultiProcBlock - Create multiple 'parallel submatrices' from
10661:   a given `Mat`. Each submatrix can span multiple procs.

10663:   Collective

10665:   Input Parameters:
10666: + mat     - the matrix
10667: . subComm - the sub communicator obtained as if by `MPI_Comm_split(PetscObjectComm((PetscObject)mat))`
10668: - scall   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10670:   Output Parameter:
10671: . subMat - parallel sub-matrices each spanning a given `subcomm`

10673:   Level: advanced

10675:   Notes:
10676:   The submatrix partition across processors is dictated by `subComm` a
10677:   communicator obtained by `MPI_comm_split()` or via `PetscSubcommCreate()`. The `subComm`
10678:   is not restricted to be grouped with consecutive original MPI processes.

10680:   Due the `MPI_Comm_split()` usage, the parallel layout of the submatrices
10681:   map directly to the layout of the original matrix [wrt the local
10682:   row,col partitioning]. So the original 'DiagonalMat' naturally maps
10683:   into the 'DiagonalMat' of the `subMat`, hence it is used directly from
10684:   the `subMat`. However the offDiagMat looses some columns - and this is
10685:   reconstructed with `MatSetValues()`

10687:   This is used by `PCBJACOBI` when a single block spans multiple MPI processes.

10689: .seealso: [](ch_matrices), `Mat`, `MatCreateRedundantMatrix()`, `MatCreateSubMatrices()`, `PCBJACOBI`
10690: @*/
10691: PetscErrorCode MatGetMultiProcBlock(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
10692: {
10693:   PetscMPIInt commsize, subCommSize;

10695:   PetscFunctionBegin;
10696:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &commsize));
10697:   PetscCallMPI(MPI_Comm_size(subComm, &subCommSize));
10698:   PetscCheck(subCommSize <= commsize, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "CommSize %d < SubCommZize %d", commsize, subCommSize);

10700:   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");
10701:   PetscCall(PetscLogEventBegin(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10702:   PetscUseTypeMethod(mat, getmultiprocblock, subComm, scall, subMat);
10703:   PetscCall(PetscLogEventEnd(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10704:   PetscFunctionReturn(PETSC_SUCCESS);
10705: }

10707: /*@
10708:   MatGetLocalSubMatrix - Gets a reference to a submatrix specified in local numbering

10710:   Not Collective

10712:   Input Parameters:
10713: + mat   - matrix to extract local submatrix from
10714: . isrow - local row indices for submatrix
10715: - iscol - local column indices for submatrix

10717:   Output Parameter:
10718: . submat - the submatrix

10720:   Level: intermediate

10722:   Notes:
10723:   `submat` should be disposed of with `MatRestoreLocalSubMatrix()`.

10725:   Depending on the format of `mat`, the returned `submat` may not implement `MatMult()`.  Its communicator may be
10726:   the same as `mat`, it may be `PETSC_COMM_SELF`, or some other sub-communictor of `mat`'s.

10728:   `submat` always implements `MatSetValuesLocal()`.  If `isrow` and `iscol` have the same block size, then
10729:   `MatSetValuesBlockedLocal()` will also be implemented.

10731:   `mat` must have had a `ISLocalToGlobalMapping` provided to it with `MatSetLocalToGlobalMapping()`.
10732:   Matrices obtained with `DMCreateMatrix()` generally already have the local to global mapping provided.

10734: .seealso: [](ch_matrices), `Mat`, `MatRestoreLocalSubMatrix()`, `MatCreateLocalRef()`, `MatSetLocalToGlobalMapping()`
10735: @*/
10736: PetscErrorCode MatGetLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10737: {
10738:   PetscFunctionBegin;
10742:   PetscCheckSameComm(isrow, 2, iscol, 3);
10743:   PetscAssertPointer(submat, 4);
10744:   PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must have local to global mapping provided before this call");

10746:   if (mat->ops->getlocalsubmatrix) {
10747:     PetscUseTypeMethod(mat, getlocalsubmatrix, isrow, iscol, submat);
10748:   } else {
10749:     PetscCall(MatCreateLocalRef(mat, isrow, iscol, submat));
10750:   }
10751:   (*submat)->assembled = mat->assembled;
10752:   PetscFunctionReturn(PETSC_SUCCESS);
10753: }

10755: /*@
10756:   MatRestoreLocalSubMatrix - Restores a reference to a submatrix specified in local numbering obtained with `MatGetLocalSubMatrix()`

10758:   Not Collective

10760:   Input Parameters:
10761: + mat    - matrix to extract local submatrix from
10762: . isrow  - local row indices for submatrix
10763: . iscol  - local column indices for submatrix
10764: - submat - the submatrix

10766:   Level: intermediate

10768: .seealso: [](ch_matrices), `Mat`, `MatGetLocalSubMatrix()`
10769: @*/
10770: PetscErrorCode MatRestoreLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10771: {
10772:   PetscFunctionBegin;
10776:   PetscCheckSameComm(isrow, 2, iscol, 3);
10777:   PetscAssertPointer(submat, 4);

10780:   if (mat->ops->restorelocalsubmatrix) {
10781:     PetscUseTypeMethod(mat, restorelocalsubmatrix, isrow, iscol, submat);
10782:   } else {
10783:     PetscCall(MatDestroy(submat));
10784:   }
10785:   *submat = NULL;
10786:   PetscFunctionReturn(PETSC_SUCCESS);
10787: }

10789: /*@
10790:   MatFindZeroDiagonals - Finds all the rows of a matrix that have zero or no diagonal entry in the matrix

10792:   Collective

10794:   Input Parameter:
10795: . mat - the matrix

10797:   Output Parameter:
10798: . is - if any rows have zero diagonals this contains the list of them

10800:   Level: developer

10802: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10803: @*/
10804: PetscErrorCode MatFindZeroDiagonals(Mat mat, IS *is)
10805: {
10806:   PetscFunctionBegin;
10809:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10810:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10812:   if (!mat->ops->findzerodiagonals) {
10813:     Vec                diag;
10814:     const PetscScalar *a;
10815:     PetscInt          *rows;
10816:     PetscInt           rStart, rEnd, r, nrow = 0;

10818:     PetscCall(MatCreateVecs(mat, &diag, NULL));
10819:     PetscCall(MatGetDiagonal(mat, diag));
10820:     PetscCall(MatGetOwnershipRange(mat, &rStart, &rEnd));
10821:     PetscCall(VecGetArrayRead(diag, &a));
10822:     for (r = 0; r < rEnd - rStart; ++r)
10823:       if (a[r] == 0.0) ++nrow;
10824:     PetscCall(PetscMalloc1(nrow, &rows));
10825:     nrow = 0;
10826:     for (r = 0; r < rEnd - rStart; ++r)
10827:       if (a[r] == 0.0) rows[nrow++] = r + rStart;
10828:     PetscCall(VecRestoreArrayRead(diag, &a));
10829:     PetscCall(VecDestroy(&diag));
10830:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)mat), nrow, rows, PETSC_OWN_POINTER, is));
10831:   } else {
10832:     PetscUseTypeMethod(mat, findzerodiagonals, is);
10833:   }
10834:   PetscFunctionReturn(PETSC_SUCCESS);
10835: }

10837: /*@
10838:   MatFindOffBlockDiagonalEntries - Finds all the rows of a matrix that have entries outside of the main diagonal block (defined by the matrix block size)

10840:   Collective

10842:   Input Parameter:
10843: . mat - the matrix

10845:   Output Parameter:
10846: . is - contains the list of rows with off block diagonal entries

10848:   Level: developer

10850: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10851: @*/
10852: PetscErrorCode MatFindOffBlockDiagonalEntries(Mat mat, IS *is)
10853: {
10854:   PetscFunctionBegin;
10857:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10858:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10860:   PetscUseTypeMethod(mat, findoffblockdiagonalentries, is);
10861:   PetscFunctionReturn(PETSC_SUCCESS);
10862: }

10864: /*@C
10865:   MatInvertBlockDiagonal - Inverts the block diagonal entries.

10867:   Collective; No Fortran Support

10869:   Input Parameter:
10870: . mat - the matrix

10872:   Output Parameter:
10873: . values - the block inverses in column major order (FORTRAN-like)

10875:   Level: advanced

10877:   Notes:
10878:   The size of the blocks is determined by the block size of the matrix.

10880:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10882:   The blocks all have the same size, use `MatInvertVariableBlockDiagonal()` for variable block size

10884: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatInvertBlockDiagonalMat()`
10885: @*/
10886: PetscErrorCode MatInvertBlockDiagonal(Mat mat, const PetscScalar *values[])
10887: {
10888:   PetscFunctionBegin;
10890:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10891:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10892:   PetscUseTypeMethod(mat, invertblockdiagonal, values);
10893:   PetscFunctionReturn(PETSC_SUCCESS);
10894: }

10896: /*@
10897:   MatInvertVariableBlockDiagonal - Inverts the point block diagonal entries.

10899:   Collective; No Fortran Support

10901:   Input Parameters:
10902: + mat     - the matrix
10903: . nblocks - the number of blocks on the process, set with `MatSetVariableBlockSizes()`
10904: - bsizes  - the size of each block on the process, set with `MatSetVariableBlockSizes()`

10906:   Output Parameter:
10907: . values - the block inverses in column major order (FORTRAN-like)

10909:   Level: advanced

10911:   Notes:
10912:   Use `MatInvertBlockDiagonal()` if all blocks have the same size

10914:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10916: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatSetVariableBlockSizes()`, `MatInvertVariableBlockEnvelope()`
10917: @*/
10918: PetscErrorCode MatInvertVariableBlockDiagonal(Mat mat, PetscInt nblocks, const PetscInt bsizes[], PetscScalar values[])
10919: {
10920:   PetscFunctionBegin;
10922:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10923:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10924:   PetscUseTypeMethod(mat, invertvariableblockdiagonal, nblocks, bsizes, values);
10925:   PetscFunctionReturn(PETSC_SUCCESS);
10926: }

10928: /*@
10929:   MatInvertBlockDiagonalMat - set the values of matrix C to be the inverted block diagonal of matrix A

10931:   Collective

10933:   Input Parameters:
10934: + A - the matrix
10935: - C - matrix with inverted block diagonal of `A`.  This matrix should be created and may have its type set.

10937:   Level: advanced

10939:   Note:
10940:   The blocksize of the matrix is used to determine the blocks on the diagonal of `C`

10942: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`
10943: @*/
10944: PetscErrorCode MatInvertBlockDiagonalMat(Mat A, Mat C)
10945: {
10946:   const PetscScalar *vals;
10947:   PetscInt          *dnnz;
10948:   PetscInt           m, rstart, rend, bs, i, j;

10950:   PetscFunctionBegin;
10951:   PetscCall(MatInvertBlockDiagonal(A, &vals));
10952:   PetscCall(MatGetBlockSize(A, &bs));
10953:   PetscCall(MatGetLocalSize(A, &m, NULL));
10954:   PetscCall(MatSetLayouts(C, A->rmap, A->cmap));
10955:   PetscCall(MatSetBlockSizes(C, A->rmap->bs, A->cmap->bs));
10956:   PetscCall(PetscMalloc1(m / bs, &dnnz));
10957:   for (j = 0; j < m / bs; j++) dnnz[j] = 1;
10958:   PetscCall(MatXAIJSetPreallocation(C, bs, dnnz, NULL, NULL, NULL));
10959:   PetscCall(PetscFree(dnnz));
10960:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
10961:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_FALSE));
10962:   for (i = rstart / bs; i < rend / bs; i++) PetscCall(MatSetValuesBlocked(C, 1, &i, 1, &i, &vals[(i - rstart / bs) * bs * bs], INSERT_VALUES));
10963:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
10964:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
10965:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
10966:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_FALSE));
10967:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_TRUE));
10968:   PetscFunctionReturn(PETSC_SUCCESS);
10969: }

10971: /*@
10972:   MatTransposeColoringDestroy - Destroys a coloring context for matrix product $C = A*B^T$ that was created
10973:   via `MatTransposeColoringCreate()`.

10975:   Collective

10977:   Input Parameter:
10978: . c - coloring context

10980:   Level: intermediate

10982: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`
10983: @*/
10984: PetscErrorCode MatTransposeColoringDestroy(MatTransposeColoring *c)
10985: {
10986:   MatTransposeColoring matcolor = *c;

10988:   PetscFunctionBegin;
10989:   if (!matcolor) PetscFunctionReturn(PETSC_SUCCESS);
10990:   if (--((PetscObject)matcolor)->refct > 0) {
10991:     matcolor = NULL;
10992:     PetscFunctionReturn(PETSC_SUCCESS);
10993:   }

10995:   PetscCall(PetscFree3(matcolor->ncolumns, matcolor->nrows, matcolor->colorforrow));
10996:   PetscCall(PetscFree(matcolor->rows));
10997:   PetscCall(PetscFree(matcolor->den2sp));
10998:   PetscCall(PetscFree(matcolor->colorforcol));
10999:   PetscCall(PetscFree(matcolor->columns));
11000:   if (matcolor->brows > 0) PetscCall(PetscFree(matcolor->lstart));
11001:   PetscCall(PetscHeaderDestroy(c));
11002:   PetscFunctionReturn(PETSC_SUCCESS);
11003: }

11005: /*@
11006:   MatTransColoringApplySpToDen - Given a symbolic matrix product $C = A*B^T$ for which
11007:   a `MatTransposeColoring` context has been created, computes a dense $B^T$ by applying
11008:   `MatTransposeColoring` to sparse `B`.

11010:   Collective

11012:   Input Parameters:
11013: + coloring - coloring context created with `MatTransposeColoringCreate()`
11014: - B        - sparse matrix

11016:   Output Parameter:
11017: . Btdense - dense matrix $B^T$

11019:   Level: developer

11021:   Note:
11022:   These are used internally for some implementations of `MatRARt()`

11024: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplyDenToSp()`
11025: @*/
11026: PetscErrorCode MatTransColoringApplySpToDen(MatTransposeColoring coloring, Mat B, Mat Btdense)
11027: {
11028:   PetscFunctionBegin;

11033:   PetscCall((*B->ops->transcoloringapplysptoden)(coloring, B, Btdense));
11034:   PetscFunctionReturn(PETSC_SUCCESS);
11035: }

11037: /*@
11038:   MatTransColoringApplyDenToSp - Given a symbolic matrix product $C_{sp} = A*B^T$ for which
11039:   a `MatTransposeColoring` context has been created and a dense matrix $C_{den} = A*B^T_{dense}$
11040:   in which `B^T_{dens}` is obtained from `MatTransColoringApplySpToDen()`, recover sparse matrix
11041:   $C_{sp}$ from $C_{den}$.

11043:   Collective

11045:   Input Parameters:
11046: + matcoloring - coloring context created with `MatTransposeColoringCreate()`
11047: - Cden        - matrix product of a sparse matrix and a dense matrix Btdense

11049:   Output Parameter:
11050: . Csp - sparse matrix

11052:   Level: developer

11054:   Note:
11055:   These are used internally for some implementations of `MatRARt()`

11057: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`
11058: @*/
11059: PetscErrorCode MatTransColoringApplyDenToSp(MatTransposeColoring matcoloring, Mat Cden, Mat Csp)
11060: {
11061:   PetscFunctionBegin;

11066:   PetscCall((*Csp->ops->transcoloringapplydentosp)(matcoloring, Cden, Csp));
11067:   PetscCall(MatAssemblyBegin(Csp, MAT_FINAL_ASSEMBLY));
11068:   PetscCall(MatAssemblyEnd(Csp, MAT_FINAL_ASSEMBLY));
11069:   PetscFunctionReturn(PETSC_SUCCESS);
11070: }

11072: /*@
11073:   MatTransposeColoringCreate - Creates a matrix coloring context for the matrix product $C = A*B^T$.

11075:   Collective

11077:   Input Parameters:
11078: + mat        - the matrix product C
11079: - iscoloring - the coloring of the matrix; usually obtained with `MatColoringCreate()` or `DMCreateColoring()`

11081:   Output Parameter:
11082: . color - the new coloring context

11084:   Level: intermediate

11086: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`,
11087:           `MatTransColoringApplyDenToSp()`
11088: @*/
11089: PetscErrorCode MatTransposeColoringCreate(Mat mat, ISColoring iscoloring, MatTransposeColoring *color)
11090: {
11091:   MatTransposeColoring c;
11092:   MPI_Comm             comm;

11094:   PetscFunctionBegin;
11095:   PetscAssertPointer(color, 3);

11097:   PetscCall(PetscLogEventBegin(MAT_TransposeColoringCreate, mat, 0, 0, 0));
11098:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
11099:   PetscCall(PetscHeaderCreate(c, MAT_TRANSPOSECOLORING_CLASSID, "MatTransposeColoring", "Matrix product C=A*B^T via coloring", "Mat", comm, MatTransposeColoringDestroy, NULL));
11100:   c->ctype = iscoloring->ctype;
11101:   PetscUseTypeMethod(mat, transposecoloringcreate, iscoloring, c);
11102:   *color = c;
11103:   PetscCall(PetscLogEventEnd(MAT_TransposeColoringCreate, mat, 0, 0, 0));
11104:   PetscFunctionReturn(PETSC_SUCCESS);
11105: }

11107: /*@
11108:   MatGetNonzeroState - Returns a 64-bit integer representing the current state of nonzeros in the matrix. If the
11109:   matrix has had new nonzero locations added to (or removed from) the matrix since the previous call, the value will be larger.

11111:   Not Collective

11113:   Input Parameter:
11114: . mat - the matrix

11116:   Output Parameter:
11117: . state - the current state

11119:   Level: intermediate

11121:   Notes:
11122:   You can only compare states from two different calls to the SAME matrix, you cannot compare calls between
11123:   different matrices

11125:   Use `PetscObjectStateGet()` to check for changes to the numerical values in a matrix

11127:   Use the result of `PetscObjectGetId()` to compare if a previously checked matrix is the same as the current matrix, do not compare object pointers.

11129: .seealso: [](ch_matrices), `Mat`, `PetscObjectStateGet()`, `PetscObjectGetId()`
11130: @*/
11131: PetscErrorCode MatGetNonzeroState(Mat mat, PetscObjectState *state)
11132: {
11133:   PetscFunctionBegin;
11135:   *state = mat->nonzerostate;
11136:   PetscFunctionReturn(PETSC_SUCCESS);
11137: }

11139: /*@
11140:   MatCreateMPIMatConcatenateSeqMat - Creates a single large PETSc matrix by concatenating sequential
11141:   matrices from each processor

11143:   Collective

11145:   Input Parameters:
11146: + comm   - the communicators the parallel matrix will live on
11147: . seqmat - the input sequential matrices
11148: . n      - number of local columns (or `PETSC_DECIDE`)
11149: - reuse  - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

11151:   Output Parameter:
11152: . mpimat - the parallel matrix generated

11154:   Level: developer

11156:   Note:
11157:   The number of columns of the matrix in EACH processor MUST be the same.

11159: .seealso: [](ch_matrices), `Mat`
11160: @*/
11161: PetscErrorCode MatCreateMPIMatConcatenateSeqMat(MPI_Comm comm, Mat seqmat, PetscInt n, MatReuse reuse, Mat *mpimat)
11162: {
11163:   PetscMPIInt size;

11165:   PetscFunctionBegin;
11166:   PetscCallMPI(MPI_Comm_size(comm, &size));
11167:   if (size == 1) {
11168:     if (reuse == MAT_INITIAL_MATRIX) {
11169:       PetscCall(MatDuplicate(seqmat, MAT_COPY_VALUES, mpimat));
11170:     } else {
11171:       PetscCall(MatCopy(seqmat, *mpimat, SAME_NONZERO_PATTERN));
11172:     }
11173:     PetscFunctionReturn(PETSC_SUCCESS);
11174:   }

11176:   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");

11178:   PetscCall(PetscLogEventBegin(MAT_Merge, seqmat, 0, 0, 0));
11179:   PetscCall((*seqmat->ops->creatempimatconcatenateseqmat)(comm, seqmat, n, reuse, mpimat));
11180:   PetscCall(PetscLogEventEnd(MAT_Merge, seqmat, 0, 0, 0));
11181:   PetscFunctionReturn(PETSC_SUCCESS);
11182: }

11184: /*@
11185:   MatSubdomainsCreateCoalesce - Creates index subdomains by coalescing adjacent MPI processes' ownership ranges.

11187:   Collective

11189:   Input Parameters:
11190: + A - the matrix to create subdomains from
11191: - N - requested number of subdomains

11193:   Output Parameters:
11194: + n   - number of subdomains resulting on this MPI process
11195: - iss - `IS` list with indices of subdomains on this MPI process

11197:   Level: advanced

11199:   Note:
11200:   The number of subdomains must be smaller than the communicator size

11202: .seealso: [](ch_matrices), `Mat`, `IS`
11203: @*/
11204: PetscErrorCode MatSubdomainsCreateCoalesce(Mat A, PetscInt N, PetscInt *n, IS *iss[])
11205: {
11206:   MPI_Comm    comm, subcomm;
11207:   PetscMPIInt size, rank, color;
11208:   PetscInt    rstart, rend, k;

11210:   PetscFunctionBegin;
11211:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
11212:   PetscCallMPI(MPI_Comm_size(comm, &size));
11213:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
11214:   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);
11215:   *n    = 1;
11216:   k     = size / N + (size % N > 0); /* There are up to k ranks to a color */
11217:   color = rank / k;
11218:   PetscCallMPI(MPI_Comm_split(comm, color, rank, &subcomm));
11219:   PetscCall(PetscMalloc1(1, iss));
11220:   PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
11221:   PetscCall(ISCreateStride(subcomm, rend - rstart, rstart, 1, iss[0]));
11222:   PetscCallMPI(MPI_Comm_free(&subcomm));
11223:   PetscFunctionReturn(PETSC_SUCCESS);
11224: }

11226: /*@
11227:   MatGalerkin - Constructs the coarse grid problem matrix via Galerkin projection.

11229:   If the interpolation and restriction operators are the same, uses `MatPtAP()`.
11230:   If they are not the same, uses `MatMatMatMult()`.

11232:   Once the coarse grid problem is constructed, correct for interpolation operators
11233:   that are not of full rank, which can legitimately happen in the case of non-nested
11234:   geometric multigrid.

11236:   Input Parameters:
11237: + restrct     - restriction operator
11238: . dA          - fine grid matrix
11239: . interpolate - interpolation operator
11240: . reuse       - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
11241: - fill        - expected fill, use `PETSC_DETERMINE` or `PETSC_DETERMINE` if you do not have a good estimate

11243:   Output Parameter:
11244: . A - the Galerkin coarse matrix

11246:   Options Database Key:
11247: . -pc_mg_galerkin (both|pmat|mat|none) - for what matrices the Galerkin process should be used

11249:   Level: developer

11251:   Note:
11252:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

11254: .seealso: [](ch_matrices), `Mat`, `MatPtAP()`, `MatMatMatMult()`
11255: @*/
11256: PetscErrorCode MatGalerkin(Mat restrct, Mat dA, Mat interpolate, MatReuse reuse, PetscReal fill, Mat *A)
11257: {
11258:   IS  zerorows;
11259:   Vec diag;

11261:   PetscFunctionBegin;
11262:   PetscCheck(reuse != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");
11263:   /* Construct the coarse grid matrix */
11264:   if (interpolate == restrct) {
11265:     PetscCall(MatPtAP(dA, interpolate, reuse, fill, A));
11266:   } else {
11267:     PetscCall(MatMatMatMult(restrct, dA, interpolate, reuse, fill, A));
11268:   }

11270:   /* If the interpolation matrix is not of full rank, A will have zero rows.
11271:      This can legitimately happen in the case of non-nested geometric multigrid.
11272:      In that event, we set the rows of the matrix to the rows of the identity,
11273:      ignoring the equations (as the RHS will also be zero). */

11275:   PetscCall(MatFindZeroRows(*A, &zerorows));

11277:   if (zerorows != NULL) { /* if there are any zero rows */
11278:     PetscCall(MatCreateVecs(*A, &diag, NULL));
11279:     PetscCall(MatGetDiagonal(*A, diag));
11280:     PetscCall(VecISSet(diag, zerorows, 1.0));
11281:     PetscCall(MatDiagonalSet(*A, diag, INSERT_VALUES));
11282:     PetscCall(VecDestroy(&diag));
11283:     PetscCall(ISDestroy(&zerorows));
11284:   }
11285:   PetscFunctionReturn(PETSC_SUCCESS);
11286: }

11288: /*@C
11289:   MatSetOperation - Allows user to set a matrix operation for any matrix type

11291:   Logically Collective

11293:   Input Parameters:
11294: + mat - the matrix
11295: . op  - the name of the operation
11296: - f   - the function that provides the operation

11298:   Level: developer

11300:   Example Usage:
11301: .vb
11302:   extern PetscErrorCode usermult(Mat, Vec, Vec);

11304:   PetscCall(MatCreateXXX(comm, ..., &A));
11305:   PetscCall(MatSetOperation(A, MATOP_MULT, (PetscErrorCodeFn *)usermult));
11306: .ve

11308:   Notes:
11309:   See the file `include/petscmat.h` for a complete list of matrix
11310:   operations, which all have the form MATOP_<OPERATION>, where
11311:   <OPERATION> is the name (in all capital letters) of the
11312:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11314:   All user-provided functions (except for `MATOP_DESTROY`) should have the same calling
11315:   sequence as the usual matrix interface routines, since they
11316:   are intended to be accessed via the usual matrix interface
11317:   routines, e.g.,
11318: .vb
11319:   MatMult(Mat, Vec, Vec) -> usermult(Mat, Vec, Vec)
11320: .ve

11322:   In particular each function MUST return `PETSC_SUCCESS` on success and
11323:   nonzero on failure.

11325:   This routine is distinct from `MatShellSetOperation()` in that it can be called on any matrix type.

11327: .seealso: [](ch_matrices), `Mat`, `MatGetOperation()`, `MatCreateShell()`, `MatShellSetContext()`, `MatShellSetOperation()`
11328: @*/
11329: PetscErrorCode MatSetOperation(Mat mat, MatOperation op, PetscErrorCodeFn *f)
11330: {
11331:   PetscFunctionBegin;
11333:   if (op == MATOP_VIEW && !mat->ops->viewnative && f != (PetscErrorCodeFn *)mat->ops->view) mat->ops->viewnative = mat->ops->view;
11334:   (((PetscErrorCodeFn **)mat->ops)[op]) = f;
11335:   PetscFunctionReturn(PETSC_SUCCESS);
11336: }

11338: /*@C
11339:   MatGetOperation - Gets a matrix operation for any matrix type.

11341:   Not Collective

11343:   Input Parameters:
11344: + mat - the matrix
11345: - op  - the name of the operation

11347:   Output Parameter:
11348: . f - the function that provides the operation

11350:   Level: developer

11352:   Example Usage:
11353: .vb
11354:   PetscErrorCode (*usermult)(Mat, Vec, Vec);

11356:   MatGetOperation(A, MATOP_MULT, (PetscErrorCodeFn **)&usermult);
11357: .ve

11359:   Notes:
11360:   See the file `include/petscmat.h` for a complete list of matrix
11361:   operations, which all have the form MATOP_<OPERATION>, where
11362:   <OPERATION> is the name (in all capital letters) of the
11363:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11365:   This routine is distinct from `MatShellGetOperation()` in that it can be called on any matrix type.

11367: .seealso: [](ch_matrices), `Mat`, `MatSetOperation()`, `MatCreateShell()`, `MatShellGetContext()`, `MatShellGetOperation()`
11368: @*/
11369: PetscErrorCode MatGetOperation(Mat mat, MatOperation op, PetscErrorCodeFn **f)
11370: {
11371:   PetscFunctionBegin;
11373:   *f = (((PetscErrorCodeFn **)mat->ops)[op]);
11374:   PetscFunctionReturn(PETSC_SUCCESS);
11375: }

11377: /*@
11378:   MatHasOperation - Determines whether the given matrix supports the particular operation.

11380:   Not Collective

11382:   Input Parameters:
11383: + mat - the matrix
11384: - op  - the operation, for example, `MATOP_GET_DIAGONAL`

11386:   Output Parameter:
11387: . has - either `PETSC_TRUE` or `PETSC_FALSE`

11389:   Level: advanced

11391:   Note:
11392:   See `MatSetOperation()` for additional discussion on naming convention and usage of `op`.

11394: .seealso: [](ch_matrices), `Mat`, `MatCreateShell()`, `MatGetOperation()`, `MatSetOperation()`
11395: @*/
11396: PetscErrorCode MatHasOperation(Mat mat, MatOperation op, PetscBool *has)
11397: {
11398:   PetscFunctionBegin;
11400:   PetscAssertPointer(has, 3);
11401:   if (mat->ops->hasoperation) {
11402:     PetscUseTypeMethod(mat, hasoperation, op, has);
11403:   } else {
11404:     if (((void **)mat->ops)[op]) *has = PETSC_TRUE;
11405:     else {
11406:       *has = PETSC_FALSE;
11407:       if (op == MATOP_CREATE_SUBMATRIX) {
11408:         PetscMPIInt size;

11410:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
11411:         if (size == 1) PetscCall(MatHasOperation(mat, MATOP_CREATE_SUBMATRICES, has));
11412:       }
11413:     }
11414:   }
11415:   PetscFunctionReturn(PETSC_SUCCESS);
11416: }

11418: /*@
11419:   MatHasCongruentLayouts - Determines whether the rows and columns layouts of the matrix are congruent

11421:   Collective

11423:   Input Parameter:
11424: . mat - the matrix

11426:   Output Parameter:
11427: . cong - either `PETSC_TRUE` or `PETSC_FALSE`

11429:   Level: beginner

11431: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatSetSizes()`, `PetscLayout`
11432: @*/
11433: PetscErrorCode MatHasCongruentLayouts(Mat mat, PetscBool *cong)
11434: {
11435:   PetscFunctionBegin;
11438:   PetscAssertPointer(cong, 2);
11439:   if (!mat->rmap || !mat->cmap) {
11440:     *cong = mat->rmap == mat->cmap ? PETSC_TRUE : PETSC_FALSE;
11441:     PetscFunctionReturn(PETSC_SUCCESS);
11442:   }
11443:   if (mat->congruentlayouts == PETSC_DECIDE) { /* first time we compare rows and cols layouts */
11444:     PetscCall(PetscLayoutSetUp(mat->rmap));
11445:     PetscCall(PetscLayoutSetUp(mat->cmap));
11446:     PetscCall(PetscLayoutCompare(mat->rmap, mat->cmap, cong));
11447:     if (*cong) mat->congruentlayouts = 1;
11448:     else mat->congruentlayouts = 0;
11449:   } else *cong = mat->congruentlayouts ? PETSC_TRUE : PETSC_FALSE;
11450:   PetscFunctionReturn(PETSC_SUCCESS);
11451: }

11453: PetscErrorCode MatSetInf(Mat A)
11454: {
11455:   PetscFunctionBegin;
11456:   PetscUseTypeMethod(A, setinf);
11457:   PetscFunctionReturn(PETSC_SUCCESS);
11458: }

11460: /*@
11461:   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
11462:   and possibly removes small values from the graph structure.

11464:   Collective

11466:   Input Parameters:
11467: + A       - the matrix
11468: . sym     - `PETSC_TRUE` indicates that the graph should be symmetrized
11469: . scale   - `PETSC_TRUE` indicates that the graph edge weights should be symmetrically scaled with the diagonal entry
11470: . filter  - filter value - < 0: does nothing; == 0: removes only 0.0 entries; otherwise: removes entries with abs(entries) <= value
11471: . num_idx - size of 'index' array
11472: - index   - array of block indices to use for graph strength of connection weight

11474:   Output Parameter:
11475: . graph - the resulting graph

11477:   Level: advanced

11479: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PCGAMG`
11480: @*/
11481: PetscErrorCode MatCreateGraph(Mat A, PetscBool sym, PetscBool scale, PetscReal filter, PetscInt num_idx, PetscInt index[], Mat *graph)
11482: {
11483:   PetscFunctionBegin;
11487:   PetscAssertPointer(graph, 7);
11488:   PetscCall(PetscLogEventBegin(MAT_CreateGraph, A, 0, 0, 0));
11489:   PetscUseTypeMethod(A, creategraph, sym, scale, filter, num_idx, index, graph);
11490:   PetscCall(PetscLogEventEnd(MAT_CreateGraph, A, 0, 0, 0));
11491:   PetscFunctionReturn(PETSC_SUCCESS);
11492: }

11494: /*@
11495:   MatEliminateZeros - eliminate the nondiagonal zero entries in place from the nonzero structure of a sparse `Mat` in place,
11496:   meaning the same memory is used for the matrix, and no new memory is allocated.

11498:   Collective

11500:   Input Parameters:
11501: + A    - the matrix
11502: - 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

11504:   Level: intermediate

11506:   Developer Note:
11507:   The entries in the sparse matrix data structure are shifted to fill in the unneeded locations in the data. Thus the end
11508:   of the arrays in the data structure are unneeded.

11510: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateGraph()`, `MatFilter()`
11511: @*/
11512: PetscErrorCode MatEliminateZeros(Mat A, PetscBool keep)
11513: {
11514:   PetscFunctionBegin;
11516:   PetscUseTypeMethod(A, eliminatezeros, keep);
11517:   PetscFunctionReturn(PETSC_SUCCESS);
11518: }

11520: /*@C
11521:   MatGetCurrentMemType - Get the memory location of the matrix

11523:   Not Collective, but the result will be the same on all MPI processes

11525:   Input Parameter:
11526: . A - the matrix whose memory type we are checking

11528:   Output Parameter:
11529: . m - the memory type

11531:   Level: intermediate

11533: .seealso: [](ch_matrices), `Mat`, `MatBoundToCPU()`, `PetscMemType`
11534: @*/
11535: PetscErrorCode MatGetCurrentMemType(Mat A, PetscMemType *m)
11536: {
11537:   PetscFunctionBegin;
11539:   PetscAssertPointer(m, 2);
11540:   if (A->ops->getcurrentmemtype) PetscUseTypeMethod(A, getcurrentmemtype, m);
11541:   else *m = PETSC_MEMTYPE_HOST;
11542:   PetscFunctionReturn(PETSC_SUCCESS);
11543: }