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

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

 51: /*@
 52:   MatSetRandom - Sets all components of a matrix to random numbers.

 54:   Logically Collective

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

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

 68:   Level: intermediate

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

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

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

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

 83:   PetscFunctionBegin;
 87:   MatCheckPreallocated(x, 1);

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

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

107: /*@
108:   MatCopyHashToXAIJ - copy hash table entries into an XAIJ matrix type

110:   Logically Collective

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

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

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

124:   Level: advanced

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

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

139: /*@
140:   MatFactorGetErrorZeroPivot - returns the pivot value that was determined to be zero and the row it occurred in

142:   Logically Collective

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

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

152:   Level: advanced

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

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

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

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

176: /*@
177:   MatFactorGetError - gets the error code from a factorization

179:   Logically Collective

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

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

187:   Level: advanced

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

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

204: /*@
205:   MatFactorClearError - clears the error code in a factorization

207:   Logically Collective

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

212:   Level: developer

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

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

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

236:   PetscFunctionBegin;
237:   PetscCall(MatCreateVecs(mat, &r, &l));
238:   if (!cols) { /* nonzero rows */
239:     PetscCall(MatGetOwnershipRange(mat, &st, NULL));
240:     PetscCall(MatGetSize(mat, &N, NULL));
241:     PetscCall(MatGetLocalSize(mat, &n, NULL));
242:     PetscCall(VecSet(l, 0.0));
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: /*@
509:   MatMissingDiagonal - Determine if sparse matrix is missing a diagonal entry (or block entry for `MATBAIJ` and `MATSBAIJ` matrices) in the nonzero structure

511:   Not Collective

513:   Input Parameter:
514: . mat - the matrix

516:   Output Parameters:
517: + missing - is any diagonal entry missing
518: - dd      - first diagonal entry that is missing (optional) on this process

520:   Level: advanced

522:   Note:
523:   This does not return diagonal entries that are in the nonzero structure but happen to have a zero numerical value

525: .seealso: [](ch_matrices), `Mat`
526: @*/
527: PetscErrorCode MatMissingDiagonal(Mat mat, PetscBool *missing, PetscInt *dd)
528: {
529:   PetscFunctionBegin;
532:   PetscAssertPointer(missing, 2);
533:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix %s", ((PetscObject)mat)->type_name);
534:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
535:   PetscUseTypeMethod(mat, missingdiagonal, missing, dd);
536:   PetscFunctionReturn(PETSC_SUCCESS);
537: }

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

545:   Not Collective

547:   Input Parameters:
548: + mat - the matrix
549: - row - the row to get

551:   Output Parameters:
552: + ncols - if not `NULL`, the number of nonzeros in `row`
553: . cols  - if not `NULL`, the column numbers
554: - vals  - if not `NULL`, the numerical values

556:   Level: advanced

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

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

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

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

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

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

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

584:   Fortran Note:
585: .vb
586:   PetscInt, pointer :: cols(:)
587:   PetscScalar, pointer :: vals(:)
588: .ve

590: .seealso: [](ch_matrices), `Mat`, `MatRestoreRow()`, `MatSetValues()`, `MatGetValues()`, `MatCreateSubMatrices()`, `MatGetDiagonal()`, `MatGetRowIJ()`, `MatRestoreRowIJ()`
591: @*/
592: PetscErrorCode MatGetRow(Mat mat, PetscInt row, PetscInt *ncols, const PetscInt *cols[], const PetscScalar *vals[])
593: {
594:   PetscInt incols;

596:   PetscFunctionBegin;
599:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
600:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
601:   MatCheckPreallocated(mat, 1);
602:   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);
603:   PetscCall(PetscLogEventBegin(MAT_GetRow, mat, 0, 0, 0));
604:   PetscUseTypeMethod(mat, getrow, row, &incols, (PetscInt **)cols, (PetscScalar **)vals);
605:   if (ncols) *ncols = incols;
606:   PetscCall(PetscLogEventEnd(MAT_GetRow, mat, 0, 0, 0));
607:   PetscFunctionReturn(PETSC_SUCCESS);
608: }

610: /*@
611:   MatConjugate - replaces the matrix values with their complex conjugates

613:   Logically Collective

615:   Input Parameter:
616: . mat - the matrix

618:   Level: advanced

620: .seealso: [](ch_matrices), `Mat`, `MatRealPart()`, `MatImaginaryPart()`, `VecConjugate()`, `MatTranspose()`
621: @*/
622: PetscErrorCode MatConjugate(Mat mat)
623: {
624:   PetscFunctionBegin;
626:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
627:   if (PetscDefined(USE_COMPLEX) && mat->hermitian != PETSC_BOOL3_TRUE) {
628:     PetscUseTypeMethod(mat, conjugate);
629:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
630:   }
631:   PetscFunctionReturn(PETSC_SUCCESS);
632: }

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

637:   Not Collective

639:   Input Parameters:
640: + mat   - the matrix
641: . row   - the row to get
642: . ncols - the number of nonzeros
643: . cols  - the columns of the nonzeros
644: - vals  - if nonzero the column values

646:   Level: advanced

648:   Notes:
649:   This routine should be called after you have finished examining the entries.

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

655:   Fortran Note:
656: .vb
657:   PetscInt, pointer :: cols(:)
658:   PetscScalar, pointer :: vals(:)
659: .ve

661: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`
662: @*/
663: PetscErrorCode MatRestoreRow(Mat mat, PetscInt row, PetscInt *ncols, const PetscInt *cols[], const PetscScalar *vals[])
664: {
665:   PetscFunctionBegin;
667:   if (ncols) PetscAssertPointer(ncols, 3);
668:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
669:   PetscTryTypeMethod(mat, restorerow, row, ncols, (PetscInt **)cols, (PetscScalar **)vals);
670:   if (ncols) *ncols = 0;
671:   if (cols) *cols = NULL;
672:   if (vals) *vals = NULL;
673:   PetscFunctionReturn(PETSC_SUCCESS);
674: }

676: /*@
677:   MatGetRowUpperTriangular - Sets a flag to enable calls to `MatGetRow()` for matrix in `MATSBAIJ` format.
678:   You should call `MatRestoreRowUpperTriangular()` after calling` MatGetRow()` and `MatRestoreRow()` to disable the flag.

680:   Not Collective

682:   Input Parameter:
683: . mat - the matrix

685:   Level: advanced

687:   Note:
688:   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.

690: .seealso: [](ch_matrices), `Mat`, `MATSBAIJ`, `MatRestoreRowUpperTriangular()`
691: @*/
692: PetscErrorCode MatGetRowUpperTriangular(Mat mat)
693: {
694:   PetscFunctionBegin;
697:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
698:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
699:   MatCheckPreallocated(mat, 1);
700:   PetscTryTypeMethod(mat, getrowuppertriangular);
701:   PetscFunctionReturn(PETSC_SUCCESS);
702: }

704: /*@
705:   MatRestoreRowUpperTriangular - Disable calls to `MatGetRow()` for matrix in `MATSBAIJ` format.

707:   Not Collective

709:   Input Parameter:
710: . mat - the matrix

712:   Level: advanced

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

717: .seealso: [](ch_matrices), `Mat`, `MATSBAIJ`, `MatGetRowUpperTriangular()`
718: @*/
719: PetscErrorCode MatRestoreRowUpperTriangular(Mat mat)
720: {
721:   PetscFunctionBegin;
724:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
725:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
726:   MatCheckPreallocated(mat, 1);
727:   PetscTryTypeMethod(mat, restorerowuppertriangular);
728:   PetscFunctionReturn(PETSC_SUCCESS);
729: }

731: /*@
732:   MatSetOptionsPrefix - Sets the prefix used for searching for all
733:   `Mat` options in the database.

735:   Logically Collective

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

741:   Level: advanced

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

751: .seealso: [](ch_matrices), `Mat`, `MatSetFromOptions()`, `MatSetOptionsPrefixFactor()`
752: @*/
753: PetscErrorCode MatSetOptionsPrefix(Mat A, const char prefix[])
754: {
755:   PetscFunctionBegin;
757:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)A, prefix));
758:   PetscTryMethod(A, "MatSetOptionsPrefix_C", (Mat, const char[]), (A, prefix));
759:   PetscFunctionReturn(PETSC_SUCCESS);
760: }

762: /*@
763:   MatSetOptionsPrefixFactor - Sets the prefix used for searching for all matrix factor options in the database for
764:   for matrices created with `MatGetFactor()`

766:   Logically Collective

768:   Input Parameters:
769: + A      - the matrix
770: - prefix - the prefix to prepend to all option names for the factored matrix

772:   Level: developer

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

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

781: .seealso: [](ch_matrices), `Mat`,   [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSetFromOptions()`, `MatSetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`
782: @*/
783: PetscErrorCode MatSetOptionsPrefixFactor(Mat A, const char prefix[])
784: {
785:   PetscFunctionBegin;
787:   if (prefix) {
788:     PetscAssertPointer(prefix, 2);
789:     PetscCheck(prefix[0] != '-', PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Options prefix should not begin with a hyphen");
790:     if (prefix != A->factorprefix) {
791:       PetscCall(PetscFree(A->factorprefix));
792:       PetscCall(PetscStrallocpy(prefix, &A->factorprefix));
793:     }
794:   } else PetscCall(PetscFree(A->factorprefix));
795:   PetscFunctionReturn(PETSC_SUCCESS);
796: }

798: /*@
799:   MatAppendOptionsPrefixFactor - Appends to the prefix used for searching for all matrix factor options in the database for
800:   for matrices created with `MatGetFactor()`

802:   Logically Collective

804:   Input Parameters:
805: + A      - the matrix
806: - prefix - the prefix to prepend to all option names for the factored matrix

808:   Level: developer

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

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

817: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `PetscOptionsCreate()`, `PetscOptionsDestroy()`, `PetscObjectSetOptionsPrefix()`, `PetscObjectPrependOptionsPrefix()`,
818:           `PetscObjectGetOptionsPrefix()`, `TSAppendOptionsPrefix()`, `SNESAppendOptionsPrefix()`, `KSPAppendOptionsPrefix()`, `MatSetOptionsPrefixFactor()`,
819:           `MatSetOptionsPrefix()`
820: @*/
821: PetscErrorCode MatAppendOptionsPrefixFactor(Mat A, const char prefix[])
822: {
823:   size_t len1, len2, new_len;

825:   PetscFunctionBegin;
827:   if (!prefix) PetscFunctionReturn(PETSC_SUCCESS);
828:   if (!A->factorprefix) {
829:     PetscCall(MatSetOptionsPrefixFactor(A, prefix));
830:     PetscFunctionReturn(PETSC_SUCCESS);
831:   }
832:   PetscCheck(prefix[0] != '-', PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Options prefix should not begin with a hyphen");

834:   PetscCall(PetscStrlen(A->factorprefix, &len1));
835:   PetscCall(PetscStrlen(prefix, &len2));
836:   new_len = len1 + len2 + 1;
837:   PetscCall(PetscRealloc(new_len * sizeof(*A->factorprefix), &A->factorprefix));
838:   PetscCall(PetscStrncpy(A->factorprefix + len1, prefix, len2 + 1));
839:   PetscFunctionReturn(PETSC_SUCCESS);
840: }

842: /*@
843:   MatAppendOptionsPrefix - Appends to the prefix used for searching for all
844:   matrix options in the database.

846:   Logically Collective

848:   Input Parameters:
849: + A      - the matrix
850: - prefix - the prefix to prepend to all option names

852:   Level: advanced

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

858: .seealso: [](ch_matrices), `Mat`, `MatGetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`, `MatSetOptionsPrefix()`
859: @*/
860: PetscErrorCode MatAppendOptionsPrefix(Mat A, const char prefix[])
861: {
862:   PetscFunctionBegin;
864:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)A, prefix));
865:   PetscTryMethod(A, "MatAppendOptionsPrefix_C", (Mat, const char[]), (A, prefix));
866:   PetscFunctionReturn(PETSC_SUCCESS);
867: }

869: /*@
870:   MatGetOptionsPrefix - Gets the prefix used for searching for all
871:   matrix options in the database.

873:   Not Collective

875:   Input Parameter:
876: . A - the matrix

878:   Output Parameter:
879: . prefix - pointer to the prefix string used

881:   Level: advanced

883: .seealso: [](ch_matrices), `Mat`, `MatAppendOptionsPrefix()`, `MatSetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`, `MatSetOptionsPrefixFactor()`
884: @*/
885: PetscErrorCode MatGetOptionsPrefix(Mat A, const char *prefix[])
886: {
887:   PetscFunctionBegin;
889:   PetscAssertPointer(prefix, 2);
890:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)A, prefix));
891:   PetscFunctionReturn(PETSC_SUCCESS);
892: }

894: /*@
895:   MatGetState - Gets the state of a `Mat`. Same value as returned by `PetscObjectStateGet()`

897:   Not Collective

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

902:   Output Parameter:
903: . state - the object state

905:   Level: advanced

907:   Note:
908:   Object state is an integer which gets increased every time
909:   the object is changed. By saving and later querying the object state
910:   one can determine whether information about the object is still current.

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

914: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PetscObjectStateGet()`, `MatGetNonzeroState()`
915: @*/
916: PetscErrorCode MatGetState(Mat A, PetscObjectState *state)
917: {
918:   PetscFunctionBegin;
920:   PetscAssertPointer(state, 2);
921:   PetscCall(PetscObjectStateGet((PetscObject)A, state));
922:   PetscFunctionReturn(PETSC_SUCCESS);
923: }

925: /*@
926:   MatResetPreallocation - Reset matrix to use the original preallocation values provided by the user, for example with `MatXAIJSetPreallocation()`

928:   Collective

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

933:   Level: beginner

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

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

942:   Currently only supported for  `MATAIJ` matrices.

944: .seealso: [](ch_matrices), `Mat`, `MatSeqAIJSetPreallocation()`, `MatMPIAIJSetPreallocation()`, `MatXAIJSetPreallocation()`
945: @*/
946: PetscErrorCode MatResetPreallocation(Mat A)
947: {
948:   PetscFunctionBegin;
951:   PetscUseMethod(A, "MatResetPreallocation_C", (Mat), (A));
952:   PetscFunctionReturn(PETSC_SUCCESS);
953: }

955: /*@
956:   MatResetHash - Reset the matrix so that it will use a hash table for the next round of `MatSetValues()` and `MatAssemblyBegin()`/`MatAssemblyEnd()`.

958:   Collective

960:   Input Parameter:
961: . A - the matrix

963:   Level: intermediate

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

968:   Currently only supported for `MATAIJ` matrices.

970: .seealso: [](ch_matrices), `Mat`, `MatResetPreallocation()`
971: @*/
972: PetscErrorCode MatResetHash(Mat A)
973: {
974:   PetscFunctionBegin;
977:   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()");
978:   if (A->num_ass == 0) PetscFunctionReturn(PETSC_SUCCESS);
979:   PetscUseMethod(A, "MatResetHash_C", (Mat), (A));
980:   /* These flags are used to determine whether certain setups occur */
981:   A->was_assembled = PETSC_FALSE;
982:   A->assembled     = PETSC_FALSE;
983:   /* Log that the state of this object has changed; this will help guarantee that preconditioners get re-setup */
984:   PetscCall(PetscObjectStateIncrease((PetscObject)A));
985:   PetscFunctionReturn(PETSC_SUCCESS);
986: }

988: /*@
989:   MatSetUp - Sets up the internal matrix data structures for later use by the matrix

991:   Collective

993:   Input Parameter:
994: . A - the matrix

996:   Level: advanced

998:   Notes:
999:   If the user has not set preallocation for this matrix then an efficient algorithm will be used for the first round of
1000:   setting values in the matrix.

1002:   This routine is called internally by other `Mat` functions when needed so rarely needs to be called by users

1004: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatCreate()`, `MatDestroy()`, `MatXAIJSetPreallocation()`
1005: @*/
1006: PetscErrorCode MatSetUp(Mat A)
1007: {
1008:   PetscFunctionBegin;
1010:   if (!((PetscObject)A)->type_name) {
1011:     PetscMPIInt size;

1013:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)A), &size));
1014:     PetscCall(MatSetType(A, size == 1 ? MATSEQAIJ : MATMPIAIJ));
1015:   }
1016:   if (!A->preallocated) PetscTryTypeMethod(A, setup);
1017:   PetscCall(PetscLayoutSetUp(A->rmap));
1018:   PetscCall(PetscLayoutSetUp(A->cmap));
1019:   A->preallocated = PETSC_TRUE;
1020:   PetscFunctionReturn(PETSC_SUCCESS);
1021: }

1023: #if defined(PETSC_HAVE_SAWS)
1024: #include <petscviewersaws.h>
1025: #endif

1027: /*
1028:    If threadsafety is on extraneous matrices may be printed

1030:    This flag cannot be stored in the matrix because the original matrix in MatView() may assemble a new matrix which is passed into MatViewFromOptions()
1031: */
1032: #if !defined(PETSC_HAVE_THREADSAFETY)
1033: static PetscInt insidematview = 0;
1034: #endif

1036: /*@
1037:   MatViewFromOptions - View properties of the matrix based on options set in the options database

1039:   Collective

1041:   Input Parameters:
1042: + A    - the matrix
1043: . obj  - optional additional object that provides the options prefix to use
1044: - name - command line option

1046:   Options Database Key:
1047: . -mat_view [viewertype]:... - the viewer and its options

1049:   Level: intermediate

1051:   Note:
1052: .vb
1053:     If no value is provided ascii:stdout is used
1054:        ascii[:[filename][:[format][:append]]]    defaults to stdout - format can be one of ascii_info, ascii_info_detail, or ascii_matlab,
1055:                                                   for example ascii::ascii_info prints just the information about the object not all details
1056:                                                   unless :append is given filename opens in write mode, overwriting what was already there
1057:        binary[:[filename][:[format][:append]]]   defaults to the file binaryoutput
1058:        draw[:drawtype[:filename]]                for example, draw:tikz, draw:tikz:figure.tex  or draw:x
1059:        socket[:port]                             defaults to the standard output port
1060:        saws[:communicatorname]                    publishes object to the Scientific Application Webserver (SAWs)
1061: .ve

1063: .seealso: [](ch_matrices), `Mat`, `MatView()`, `PetscObjectViewFromOptions()`, `MatCreate()`
1064: @*/
1065: PetscErrorCode MatViewFromOptions(Mat A, PetscObject obj, const char name[])
1066: {
1067:   PetscFunctionBegin;
1069: #if !defined(PETSC_HAVE_THREADSAFETY)
1070:   if (insidematview) PetscFunctionReturn(PETSC_SUCCESS);
1071: #endif
1072:   PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
1073:   PetscFunctionReturn(PETSC_SUCCESS);
1074: }

1076: /*@
1077:   MatView - display information about a matrix in a variety ways

1079:   Collective on viewer

1081:   Input Parameters:
1082: + mat    - the matrix
1083: - viewer - visualization context

1085:   Options Database Keys:
1086: + -mat_view ::ascii_info           - Prints info on matrix at conclusion of `MatAssemblyEnd()`
1087: . -mat_view ::ascii_info_detail    - Prints more detailed info
1088: . -mat_view                        - Prints matrix in ASCII format
1089: . -mat_view ::ascii_matlab         - Prints matrix in MATLAB format
1090: . -mat_view draw                   - PetscDraws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
1091: . -display <name>                  - Sets display name (default is host)
1092: . -draw_pause <sec>                - Sets number of seconds to pause after display
1093: . -mat_view socket                 - Sends matrix to socket, can be accessed from MATLAB (see Users-Manual: ch_matlab for details)
1094: . -viewer_socket_machine <machine> - -
1095: . -viewer_socket_port <port>       - -
1096: . -mat_view binary                 - save matrix to file in binary format
1097: - -viewer_binary_filename <name>   - -

1099:   Level: beginner

1101:   Notes:
1102:   The available visualization contexts include
1103: +    `PETSC_VIEWER_STDOUT_SELF`   - for sequential matrices
1104: .    `PETSC_VIEWER_STDOUT_WORLD`  - for parallel matrices created on `PETSC_COMM_WORLD`
1105: .    `PETSC_VIEWER_STDOUT_`(comm) - for matrices created on MPI communicator comm
1106: -     `PETSC_VIEWER_DRAW_WORLD`   - graphical display of nonzero structure

1108:   The user can open alternative visualization contexts with
1109: +    `PetscViewerASCIIOpen()`  - Outputs matrix to a specified file
1110: .    `PetscViewerBinaryOpen()` - Outputs matrix in binary to a  specified file; corresponding input uses `MatLoad()`
1111: .    `PetscViewerDrawOpen()`   - Outputs nonzero matrix nonzero structure to an X window display
1112: -    `PetscViewerSocketOpen()` - Outputs matrix to Socket viewer, `PETSCVIEWERSOCKET`. Only the `MATSEQDENSE` and `MATAIJ` types support this viewer.

1114:   The user can call `PetscViewerPushFormat()` to specify the output
1115:   format of ASCII printed objects (when using `PETSC_VIEWER_STDOUT_SELF`,
1116:   `PETSC_VIEWER_STDOUT_WORLD` and `PetscViewerASCIIOpen()`).  Available formats include
1117: +    `PETSC_VIEWER_DEFAULT`           - default, prints matrix contents
1118: .    `PETSC_VIEWER_ASCII_MATLAB`      - prints matrix contents in MATLAB format
1119: .    `PETSC_VIEWER_ASCII_DENSE`       - prints entire matrix including zeros
1120: .    `PETSC_VIEWER_ASCII_COMMON`      - prints matrix contents, using a sparse  format common among all matrix types
1121: .    `PETSC_VIEWER_ASCII_IMPL`        - prints matrix contents, using an implementation-specific format (which is in many cases the same as the default)
1122: .    `PETSC_VIEWER_ASCII_INFO`        - prints basic information about the matrix size and structure (not the matrix entries)
1123: -    `PETSC_VIEWER_ASCII_INFO_DETAIL` - prints more detailed information about the matrix nonzero structure (still not vector or matrix entries)

1125:   The ASCII viewers are only recommended for small matrices on at most a moderate number of processes,
1126:   the program will seemingly hang and take hours for larger matrices, for larger matrices one should use the binary format.

1128:   In the debugger you can do "call MatView(mat,0)" to display the matrix. (The same holds for any PETSc object viewer).

1130:   See the manual page for `MatLoad()` for the exact format of the binary file when the binary
1131:   viewer is used.

1133:   See share/petsc/matlab/PetscBinaryRead.m for a MATLAB code that can read in the binary file when the binary
1134:   viewer is used and lib/petsc/bin/PetscBinaryIO.py for loading them into Python.

1136:   One can use '-mat_view draw -draw_pause -1' to pause the graphical display of matrix nonzero structure,
1137:   and then use the following mouse functions.
1138: .vb
1139:   left mouse: zoom in
1140:   middle mouse: zoom out
1141:   right mouse: continue with the simulation
1142: .ve

1144: .seealso: [](ch_matrices), `Mat`, `PetscViewerPushFormat()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewer`,
1145:           `PetscViewerSocketOpen()`, `PetscViewerBinaryOpen()`, `MatLoad()`, `MatViewFromOptions()`
1146: @*/
1147: PetscErrorCode MatView(Mat mat, PetscViewer viewer)
1148: {
1149:   PetscInt          rows, cols, rbs, cbs;
1150:   PetscBool         isascii, isstring, issaws;
1151:   PetscViewerFormat format;
1152:   PetscMPIInt       size;

1154:   PetscFunctionBegin;
1157:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)mat), &viewer));

1160:   PetscCall(PetscViewerGetFormat(viewer, &format));
1161:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)viewer), &size));
1162:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);

1164: #if !defined(PETSC_HAVE_THREADSAFETY)
1165:   insidematview++;
1166: #endif
1167:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
1168:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
1169:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
1170:   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");

1172:   PetscCall(PetscLogEventBegin(MAT_View, mat, viewer, 0, 0));
1173:   if (isascii) {
1174:     if (!mat->preallocated) {
1175:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been preallocated yet\n"));
1176: #if !defined(PETSC_HAVE_THREADSAFETY)
1177:       insidematview--;
1178: #endif
1179:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1180:       PetscFunctionReturn(PETSC_SUCCESS);
1181:     }
1182:     if (!mat->assembled) {
1183:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been assembled yet\n"));
1184: #if !defined(PETSC_HAVE_THREADSAFETY)
1185:       insidematview--;
1186: #endif
1187:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1188:       PetscFunctionReturn(PETSC_SUCCESS);
1189:     }
1190:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)mat, viewer));
1191:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1192:       MatNullSpace nullsp, transnullsp;

1194:       PetscCall(PetscViewerASCIIPushTab(viewer));
1195:       PetscCall(MatGetSize(mat, &rows, &cols));
1196:       PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
1197:       if (rbs != 1 || cbs != 1) {
1198:         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" : ""));
1199:         else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT ", bs=%" PetscInt_FMT "%s\n", rows, cols, rbs, mat->bsizes ? " variable blocks set" : ""));
1200:       } else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", rows, cols));
1201:       if (mat->factortype) {
1202:         MatSolverType solver;
1203:         PetscCall(MatFactorGetSolverType(mat, &solver));
1204:         PetscCall(PetscViewerASCIIPrintf(viewer, "package used to perform factorization: %s\n", solver));
1205:       }
1206:       if (mat->ops->getinfo) {
1207:         PetscBool is_constant_or_diagonal;

1209:         // Don't print nonzero information for constant or diagonal matrices, it just adds noise to the output
1210:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &is_constant_or_diagonal, MATCONSTANTDIAGONAL, MATDIAGONAL, ""));
1211:         if (!is_constant_or_diagonal) {
1212:           MatInfo info;

1214:           PetscCall(MatGetInfo(mat, MAT_GLOBAL_SUM, &info));
1215:           PetscCall(PetscViewerASCIIPrintf(viewer, "total: nonzeros=%.f, allocated nonzeros=%.f\n", info.nz_used, info.nz_allocated));
1216:           if (!mat->factortype) PetscCall(PetscViewerASCIIPrintf(viewer, "total number of mallocs used during MatSetValues calls=%" PetscInt_FMT "\n", (PetscInt)info.mallocs));
1217:         }
1218:       }
1219:       PetscCall(MatGetNullSpace(mat, &nullsp));
1220:       PetscCall(MatGetTransposeNullSpace(mat, &transnullsp));
1221:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached null space\n"));
1222:       if (transnullsp && transnullsp != nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached transposed null space\n"));
1223:       PetscCall(MatGetNearNullSpace(mat, &nullsp));
1224:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached near null space\n"));
1225:       PetscCall(PetscViewerASCIIPushTab(viewer));
1226:       PetscCall(MatProductView(mat, viewer));
1227:       PetscCall(PetscViewerASCIIPopTab(viewer));
1228:       if (mat->bsizes && format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1229:         IS tmp;

1231:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)viewer), mat->nblocks, mat->bsizes, PETSC_USE_POINTER, &tmp));
1232:         PetscCall(PetscObjectSetName((PetscObject)tmp, "Block Sizes"));
1233:         PetscCall(PetscViewerASCIIPushTab(viewer));
1234:         PetscCall(ISView(tmp, viewer));
1235:         PetscCall(PetscViewerASCIIPopTab(viewer));
1236:         PetscCall(ISDestroy(&tmp));
1237:       }
1238:     }
1239:   } else if (issaws) {
1240: #if defined(PETSC_HAVE_SAWS)
1241:     PetscMPIInt rank;

1243:     PetscCall(PetscObjectName((PetscObject)mat));
1244:     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
1245:     if (!((PetscObject)mat)->amsmem && rank == 0) PetscCall(PetscObjectViewSAWs((PetscObject)mat, viewer));
1246: #endif
1247:   } else if (isstring) {
1248:     const char *type;
1249:     PetscCall(MatGetType(mat, &type));
1250:     PetscCall(PetscViewerStringSPrintf(viewer, " MatType: %-7.7s", type));
1251:     PetscTryTypeMethod(mat, view, viewer);
1252:   }
1253:   if ((format == PETSC_VIEWER_NATIVE || format == PETSC_VIEWER_LOAD_BALANCE) && mat->ops->viewnative) {
1254:     PetscCall(PetscViewerASCIIPushTab(viewer));
1255:     PetscUseTypeMethod(mat, viewnative, viewer);
1256:     PetscCall(PetscViewerASCIIPopTab(viewer));
1257:   } else if (mat->ops->view) {
1258:     PetscCall(PetscViewerASCIIPushTab(viewer));
1259:     PetscUseTypeMethod(mat, view, viewer);
1260:     PetscCall(PetscViewerASCIIPopTab(viewer));
1261:   }
1262:   if (isascii) {
1263:     PetscCall(PetscViewerGetFormat(viewer, &format));
1264:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerASCIIPopTab(viewer));
1265:   }
1266:   PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1267: #if !defined(PETSC_HAVE_THREADSAFETY)
1268:   insidematview--;
1269: #endif
1270:   PetscFunctionReturn(PETSC_SUCCESS);
1271: }

1273: #if defined(PETSC_USE_DEBUG)
1274: #include <../src/sys/totalview/tv_data_display.h>
1275: PETSC_UNUSED static int TV_display_type(const struct _p_Mat *mat)
1276: {
1277:   TV_add_row("Local rows", "int", &mat->rmap->n);
1278:   TV_add_row("Local columns", "int", &mat->cmap->n);
1279:   TV_add_row("Global rows", "int", &mat->rmap->N);
1280:   TV_add_row("Global columns", "int", &mat->cmap->N);
1281:   TV_add_row("Typename", TV_ascii_string_type, ((PetscObject)mat)->type_name);
1282:   return TV_format_OK;
1283: }
1284: #endif

1286: /*@
1287:   MatLoad - Loads a matrix that has been stored in binary/HDF5 format
1288:   with `MatView()`.  The matrix format is determined from the options database.
1289:   Generates a parallel MPI matrix if the communicator has more than one
1290:   processor.  The default matrix type is `MATAIJ`.

1292:   Collective

1294:   Input Parameters:
1295: + mat    - the newly loaded matrix, this needs to have been created with `MatCreate()`
1296:             or some related function before a call to `MatLoad()`
1297: - viewer - `PETSCVIEWERBINARY`/`PETSCVIEWERHDF5` file viewer

1299:   Options Database Key:
1300: . -matload_block_size <bs> - set block size

1302:   Level: beginner

1304:   Notes:
1305:   If the `Mat` type has not yet been given then `MATAIJ` is used, call `MatSetFromOptions()` on the
1306:   `Mat` before calling this routine if you wish to set it from the options database.

1308:   `MatLoad()` automatically loads into the options database any options
1309:   given in the file filename.info where filename is the name of the file
1310:   that was passed to the `PetscViewerBinaryOpen()`. The options in the info
1311:   file will be ignored if you use the -viewer_binary_skip_info option.

1313:   If the type or size of mat is not set before a call to `MatLoad()`, PETSc
1314:   sets the default matrix type AIJ and sets the local and global sizes.
1315:   If type and/or size is already set, then the same are used.

1317:   In parallel, each processor can load a subset of rows (or the
1318:   entire matrix).  This routine is especially useful when a large
1319:   matrix is stored on disk and only part of it is desired on each
1320:   processor.  For example, a parallel solver may access only some of
1321:   the rows from each processor.  The algorithm used here reads
1322:   relatively small blocks of data rather than reading the entire
1323:   matrix and then subsetting it.

1325:   Viewer's `PetscViewerType` must be either `PETSCVIEWERBINARY` or `PETSCVIEWERHDF5`.
1326:   Such viewer can be created using `PetscViewerBinaryOpen()` or `PetscViewerHDF5Open()`,
1327:   or the sequence like
1328: .vb
1329:     `PetscViewer` v;
1330:     `PetscViewerCreate`(`PETSC_COMM_WORLD`,&v);
1331:     `PetscViewerSetType`(v,`PETSCVIEWERBINARY`);
1332:     `PetscViewerSetFromOptions`(v);
1333:     `PetscViewerFileSetMode`(v,`FILE_MODE_READ`);
1334:     `PetscViewerFileSetName`(v,"datafile");
1335: .ve
1336:   The optional `PetscViewerSetFromOptions()` call allows overriding `PetscViewerSetType()` using the option
1337: .vb
1338:   -viewer_type {binary, hdf5}
1339: .ve

1341:   See the example src/ksp/ksp/tutorials/ex27.c with the first approach,
1342:   and src/mat/tutorials/ex10.c with the second approach.

1344:   In case of `PETSCVIEWERBINARY`, a native PETSc binary format is used. Each of the blocks
1345:   is read onto MPI rank 0 and then shipped to its destination MPI rank, one after another.
1346:   Multiple objects, both matrices and vectors, can be stored within the same file.
1347:   Their `PetscObject` name is ignored; they are loaded in the order of their storage.

1349:   Most users should not need to know the details of the binary storage
1350:   format, since `MatLoad()` and `MatView()` completely hide these details.
1351:   But for anyone who is interested, the standard binary matrix storage
1352:   format is

1354: .vb
1355:     PetscInt    MAT_FILE_CLASSID
1356:     PetscInt    number of rows
1357:     PetscInt    number of columns
1358:     PetscInt    total number of nonzeros
1359:     PetscInt    *number nonzeros in each row
1360:     PetscInt    *column indices of all nonzeros (starting index is zero)
1361:     PetscScalar *values of all nonzeros
1362: .ve
1363:   If PETSc was not configured with `--with-64-bit-indices` then only `MATMPIAIJ` matrices with more than `PETSC_INT_MAX` non-zeros can be
1364:   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
1365:   case will not fit in a (32-bit) `PetscInt` the value `PETSC_INT_MAX` is used for the header entry `total number of nonzeros`.

1367:   PETSc automatically does the byte swapping for
1368:   machines that store the bytes reversed. Thus if you write your own binary
1369:   read/write routines you have to swap the bytes; see `PetscBinaryRead()`
1370:   and `PetscBinaryWrite()` to see how this may be done.

1372:   In case of `PETSCVIEWERHDF5`, a parallel HDF5 reader is used.
1373:   Each processor's chunk is loaded independently by its owning MPI process.
1374:   Multiple objects, both matrices and vectors, can be stored within the same file.
1375:   They are looked up by their PetscObject name.

1377:   As the MATLAB MAT-File Version 7.3 format is also a HDF5 flavor, we decided to use
1378:   by default the same structure and naming of the AIJ arrays and column count
1379:   within the HDF5 file. This means that a MAT file saved with -v7.3 flag, e.g.
1380: .vb
1381:   save example.mat A b -v7.3
1382: .ve
1383:   can be directly read by this routine (see Reference 1 for details).

1385:   Depending on your MATLAB version, this format might be a default,
1386:   otherwise you can set it as default in Preferences.

1388:   Unless -nocompression flag is used to save the file in MATLAB,
1389:   PETSc must be configured with ZLIB package.

1391:   See also examples src/mat/tutorials/ex10.c and src/ksp/ksp/tutorials/ex27.c

1393:   This reader currently supports only real `MATSEQAIJ`, `MATMPIAIJ`, `MATSEQDENSE` and `MATMPIDENSE` matrices for `PETSCVIEWERHDF5`

1395:   Corresponding `MatView()` is not yet implemented.

1397:   The loaded matrix is actually a transpose of the original one in MATLAB,
1398:   unless you push `PETSC_VIEWER_HDF5_MAT` format (see examples above).
1399:   With this format, matrix is automatically transposed by PETSc,
1400:   unless the matrix is marked as SPD or symmetric
1401:   (see `MatSetOption()`, `MAT_SPD`, `MAT_SYMMETRIC`).

1403:   See MATLAB Documentation on `save()`, <https://www.mathworks.com/help/matlab/ref/save.html#btox10b-1-version>

1405: .seealso: [](ch_matrices), `Mat`, `PetscViewerBinaryOpen()`, `PetscViewerSetType()`, `MatView()`, `VecLoad()`
1406:  @*/
1407: PetscErrorCode MatLoad(Mat mat, PetscViewer viewer)
1408: {
1409:   PetscBool flg;

1411:   PetscFunctionBegin;

1415:   if (!((PetscObject)mat)->type_name) PetscCall(MatSetType(mat, MATAIJ));

1417:   flg = PETSC_FALSE;
1418:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_symmetric", &flg, NULL));
1419:   if (flg) {
1420:     PetscCall(MatSetOption(mat, MAT_SYMMETRIC, PETSC_TRUE));
1421:     PetscCall(MatSetOption(mat, MAT_SYMMETRY_ETERNAL, PETSC_TRUE));
1422:   }
1423:   flg = PETSC_FALSE;
1424:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_spd", &flg, NULL));
1425:   if (flg) PetscCall(MatSetOption(mat, MAT_SPD, PETSC_TRUE));

1427:   PetscCall(PetscLogEventBegin(MAT_Load, mat, viewer, 0, 0));
1428:   PetscUseTypeMethod(mat, load, viewer);
1429:   PetscCall(PetscLogEventEnd(MAT_Load, mat, viewer, 0, 0));
1430:   PetscFunctionReturn(PETSC_SUCCESS);
1431: }

1433: static PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1434: {
1435:   Mat_Redundant *redund = *redundant;

1437:   PetscFunctionBegin;
1438:   if (redund) {
1439:     if (redund->matseq) { /* via MatCreateSubMatrices()  */
1440:       PetscCall(ISDestroy(&redund->isrow));
1441:       PetscCall(ISDestroy(&redund->iscol));
1442:       PetscCall(MatDestroySubMatrices(1, &redund->matseq));
1443:     } else {
1444:       PetscCall(PetscFree2(redund->send_rank, redund->recv_rank));
1445:       PetscCall(PetscFree(redund->sbuf_j));
1446:       PetscCall(PetscFree(redund->sbuf_a));
1447:       for (PetscInt i = 0; i < redund->nrecvs; i++) {
1448:         PetscCall(PetscFree(redund->rbuf_j[i]));
1449:         PetscCall(PetscFree(redund->rbuf_a[i]));
1450:       }
1451:       PetscCall(PetscFree4(redund->sbuf_nz, redund->rbuf_nz, redund->rbuf_j, redund->rbuf_a));
1452:     }

1454:     if (redund->subcomm) PetscCall(PetscCommDestroy(&redund->subcomm));
1455:     PetscCall(PetscFree(redund));
1456:   }
1457:   PetscFunctionReturn(PETSC_SUCCESS);
1458: }

1460: /*@
1461:   MatDestroy - Frees space taken by a matrix.

1463:   Collective

1465:   Input Parameter:
1466: . A - the matrix

1468:   Level: beginner

1470:   Developer Note:
1471:   Some special arrays of matrices are not destroyed in this routine but instead by the routines called by
1472:   `MatDestroySubMatrices()`. Thus one must be sure that any changes here must also be made in those routines.
1473:   `MatHeaderMerge()` and `MatHeaderReplace()` also manipulate the data in the `Mat` object and likely need changes
1474:   if changes are needed here.

1476: .seealso: [](ch_matrices), `Mat`, `MatCreate()`
1477: @*/
1478: PetscErrorCode MatDestroy(Mat *A)
1479: {
1480:   PetscFunctionBegin;
1481:   if (!*A) PetscFunctionReturn(PETSC_SUCCESS);
1483:   if (--((PetscObject)*A)->refct > 0) {
1484:     *A = NULL;
1485:     PetscFunctionReturn(PETSC_SUCCESS);
1486:   }

1488:   /* if memory was published with SAWs then destroy it */
1489:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*A));
1490:   PetscTryTypeMethod(*A, destroy);

1492:   PetscCall(PetscFree((*A)->factorprefix));
1493:   PetscCall(PetscFree((*A)->defaultvectype));
1494:   PetscCall(PetscFree((*A)->defaultrandtype));
1495:   PetscCall(PetscFree((*A)->bsizes));
1496:   PetscCall(PetscFree((*A)->solvertype));
1497:   for (PetscInt i = 0; i < MAT_FACTOR_NUM_TYPES; i++) PetscCall(PetscFree((*A)->preferredordering[i]));
1498:   if ((*A)->redundant && (*A)->redundant->matseq[0] == *A) (*A)->redundant->matseq[0] = NULL;
1499:   PetscCall(MatDestroy_Redundant(&(*A)->redundant));
1500:   PetscCall(MatProductClear(*A));
1501:   PetscCall(MatNullSpaceDestroy(&(*A)->nullsp));
1502:   PetscCall(MatNullSpaceDestroy(&(*A)->transnullsp));
1503:   PetscCall(MatNullSpaceDestroy(&(*A)->nearnullsp));
1504:   PetscCall(MatDestroy(&(*A)->schur));
1505:   PetscCall(PetscLayoutDestroy(&(*A)->rmap));
1506:   PetscCall(PetscLayoutDestroy(&(*A)->cmap));
1507:   PetscCall(PetscHeaderDestroy(A));
1508:   PetscFunctionReturn(PETSC_SUCCESS);
1509: }

1511: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1512: /*@
1513:   MatSetValues - Inserts or adds a block of values into a matrix.
1514:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1515:   MUST be called after all calls to `MatSetValues()` have been completed.

1517:   Not Collective

1519:   Input Parameters:
1520: + mat  - the matrix
1521: . m    - the number of rows
1522: . idxm - the global indices of the rows
1523: . n    - the number of columns
1524: . idxn - the global indices of the columns
1525: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1526:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1527: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1529:   Level: beginner

1531:   Notes:
1532:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1533:   options cannot be mixed without intervening calls to the assembly
1534:   routines.

1536:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1537:   as well as in C.

1539:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1540:   simply ignored. This allows easily inserting element stiffness matrices
1541:   with homogeneous Dirichlet boundary conditions that you don't want represented
1542:   in the matrix.

1544:   Efficiency Alert:
1545:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1546:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1548:   Fortran Notes:
1549:   If any of `idxm`, `idxn`, and `v` are scalars pass them using, for example,
1550: .vb
1551:   call MatSetValues(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
1552: .ve

1554:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1556:   Developer Note:
1557:   This is labeled with C so does not automatically generate Fortran stubs and interfaces
1558:   because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.

1560: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1561:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1562: @*/
1563: PetscErrorCode MatSetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
1564: {
1565:   PetscFunctionBeginHot;
1568:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1569:   PetscAssertPointer(idxm, 3);
1570:   PetscAssertPointer(idxn, 5);
1571:   MatCheckPreallocated(mat, 1);

1573:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
1574:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");

1576:   if (PetscDefined(USE_DEBUG)) {
1577:     PetscInt i, j;

1579:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1580:     if (v) {
1581:       for (i = 0; i < m; i++) {
1582:         for (j = 0; j < n; j++) {
1583:           if (mat->erroriffailure && PetscIsInfOrNanScalar(v[i * n + j]))
1584: #if defined(PETSC_USE_COMPLEX)
1585:             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]);
1586: #else
1587:             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]);
1588: #endif
1589:         }
1590:       }
1591:     }
1592:     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);
1593:     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);
1594:   }

1596:   if (mat->assembled) {
1597:     mat->was_assembled = PETSC_TRUE;
1598:     mat->assembled     = PETSC_FALSE;
1599:   }
1600:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1601:   PetscUseTypeMethod(mat, setvalues, m, idxm, n, idxn, v, addv);
1602:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1603:   PetscFunctionReturn(PETSC_SUCCESS);
1604: }

1606: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1607: /*@
1608:   MatSetValuesIS - Inserts or adds a block of values into a matrix using an `IS` to indicate the rows and columns
1609:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1610:   MUST be called after all calls to `MatSetValues()` have been completed.

1612:   Not Collective

1614:   Input Parameters:
1615: + mat  - the matrix
1616: . ism  - the rows to provide
1617: . isn  - the columns to provide
1618: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1619:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1620: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1622:   Level: beginner

1624:   Notes:
1625:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1627:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1628:   options cannot be mixed without intervening calls to the assembly
1629:   routines.

1631:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1632:   as well as in C.

1634:   Negative indices may be passed in `ism` and `isn`, these rows and columns are
1635:   simply ignored. This allows easily inserting element stiffness matrices
1636:   with homogeneous Dirichlet boundary conditions that you don't want represented
1637:   in the matrix.

1639:   Fortran Note:
1640:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1642:   Efficiency Alert:
1643:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1644:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1646:   This is currently not optimized for any particular `ISType`

1648: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatSetValues()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1649:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1650: @*/
1651: PetscErrorCode MatSetValuesIS(Mat mat, IS ism, IS isn, const PetscScalar v[], InsertMode addv)
1652: {
1653:   PetscInt        m, n;
1654:   const PetscInt *rows, *cols;

1656:   PetscFunctionBeginHot;
1658:   PetscCall(ISGetIndices(ism, &rows));
1659:   PetscCall(ISGetIndices(isn, &cols));
1660:   PetscCall(ISGetLocalSize(ism, &m));
1661:   PetscCall(ISGetLocalSize(isn, &n));
1662:   PetscCall(MatSetValues(mat, m, rows, n, cols, v, addv));
1663:   PetscCall(ISRestoreIndices(ism, &rows));
1664:   PetscCall(ISRestoreIndices(isn, &cols));
1665:   PetscFunctionReturn(PETSC_SUCCESS);
1666: }

1668: /*@
1669:   MatSetValuesRowLocal - 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 one-dimensional array that contains the values. For `MATBAIJ` they are implicitly stored as a two-dimensional array, by default in row-major order.
1678:         See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1680:   Level: intermediate

1682:   Notes:
1683:   The values, `v`, are column-oriented (for the block version) and sorted

1685:   All the nonzero values in `row` must be provided

1687:   The matrix must have previously had its column indices set, likely by having been assembled.

1689:   `row` must belong to this MPI process

1691:   Fortran Note:
1692:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1694: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1695:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetValuesRow()`, `MatSetLocalToGlobalMapping()`
1696: @*/
1697: PetscErrorCode MatSetValuesRowLocal(Mat mat, PetscInt row, const PetscScalar v[])
1698: {
1699:   PetscInt globalrow;

1701:   PetscFunctionBegin;
1704:   PetscAssertPointer(v, 3);
1705:   PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, 1, &row, &globalrow));
1706:   PetscCall(MatSetValuesRow(mat, globalrow, v));
1707:   PetscFunctionReturn(PETSC_SUCCESS);
1708: }

1710: /*@
1711:   MatSetValuesRow - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1712:   values into a matrix

1714:   Not Collective

1716:   Input Parameters:
1717: + mat - the matrix
1718: . row - the (block) row to set
1719: - 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

1721:   Level: advanced

1723:   Notes:
1724:   The values, `v`, are column-oriented for the block version.

1726:   All the nonzeros in `row` must be provided

1728:   THE MATRIX MUST HAVE PREVIOUSLY HAD ITS COLUMN INDICES SET. IT IS RARE THAT THIS ROUTINE IS USED, usually `MatSetValues()` is used.

1730:   `row` must belong to this process

1732: .seealso: [](ch_matrices), `Mat`, `MatSetValues()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1733:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1734: @*/
1735: PetscErrorCode MatSetValuesRow(Mat mat, PetscInt row, const PetscScalar v[])
1736: {
1737:   PetscFunctionBeginHot;
1740:   MatCheckPreallocated(mat, 1);
1741:   PetscAssertPointer(v, 3);
1742:   PetscCheck(mat->insertmode != ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add and insert values");
1743:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1744:   mat->insertmode = INSERT_VALUES;

1746:   if (mat->assembled) {
1747:     mat->was_assembled = PETSC_TRUE;
1748:     mat->assembled     = PETSC_FALSE;
1749:   }
1750:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1751:   PetscUseTypeMethod(mat, setvaluesrow, row, v);
1752:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1753:   PetscFunctionReturn(PETSC_SUCCESS);
1754: }

1756: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1757: /*@
1758:   MatSetValuesStencil - Inserts or adds a block of values into a matrix.
1759:   Using structured grid indexing

1761:   Not Collective

1763:   Input Parameters:
1764: + mat  - the matrix
1765: . m    - number of rows being entered
1766: . idxm - grid coordinates (and component number when dof > 1) for matrix rows being entered
1767: . n    - number of columns being entered
1768: . idxn - grid coordinates (and component number when dof > 1) for matrix columns being entered
1769: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1770:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1771: - addv - either `ADD_VALUES` to add to existing entries at that location or `INSERT_VALUES` to replace existing entries with new values

1773:   Level: beginner

1775:   Notes:
1776:   By default the values, `v`, are row-oriented.  See `MatSetOption()` for other options.

1778:   Calls to `MatSetValuesStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1779:   options cannot be mixed without intervening calls to the assembly
1780:   routines.

1782:   The grid coordinates are across the entire grid, not just the local portion

1784:   `MatSetValuesStencil()` uses 0-based row and column numbers in Fortran
1785:   as well as in C.

1787:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1789:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1790:   or call `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1792:   The columns and rows in the stencil passed in MUST be contained within the
1793:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1794:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1795:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1796:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1798:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
1799:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
1800:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
1801:   `DM_BOUNDARY_PERIODIC` boundary type.

1803:   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
1804:   a single value per point) you can skip filling those indices.

1806:   Inspired by the structured grid interface to the HYPRE package
1807:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1809:   Fortran Note:
1810:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1812:   Efficiency Alert:
1813:   The routine `MatSetValuesBlockedStencil()` may offer much better efficiency
1814:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1816: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`
1817:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`
1818: @*/
1819: PetscErrorCode MatSetValuesStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1820: {
1821:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1822:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1823:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1825:   PetscFunctionBegin;
1826:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1829:   PetscAssertPointer(idxm, 3);
1830:   PetscAssertPointer(idxn, 5);

1832:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1833:     jdxm = buf;
1834:     jdxn = buf + m;
1835:   } else {
1836:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1837:     jdxm = bufm;
1838:     jdxn = bufn;
1839:   }
1840:   for (i = 0; i < m; i++) {
1841:     for (j = 0; j < 3 - sdim; j++) dxm++;
1842:     tmp = *dxm++ - starts[0];
1843:     for (j = 0; j < dim - 1; j++) {
1844:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1845:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1846:     }
1847:     if (mat->stencil.noc) dxm++;
1848:     jdxm[i] = tmp;
1849:   }
1850:   for (i = 0; i < n; i++) {
1851:     for (j = 0; j < 3 - sdim; j++) dxn++;
1852:     tmp = *dxn++ - starts[0];
1853:     for (j = 0; j < dim - 1; j++) {
1854:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1855:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1856:     }
1857:     if (mat->stencil.noc) dxn++;
1858:     jdxn[i] = tmp;
1859:   }
1860:   PetscCall(MatSetValuesLocal(mat, m, jdxm, n, jdxn, v, addv));
1861:   PetscCall(PetscFree2(bufm, bufn));
1862:   PetscFunctionReturn(PETSC_SUCCESS);
1863: }

1865: /*@
1866:   MatSetValuesBlockedStencil - Inserts or adds a block of values into a matrix.
1867:   Using structured grid indexing

1869:   Not Collective

1871:   Input Parameters:
1872: + mat  - the matrix
1873: . m    - number of rows being entered
1874: . idxm - grid coordinates for matrix rows being entered
1875: . n    - number of columns being entered
1876: . idxn - grid coordinates for matrix columns being entered
1877: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1878:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1879: - addv - either `ADD_VALUES` to add to existing entries or `INSERT_VALUES` to replace existing entries with new values

1881:   Level: beginner

1883:   Notes:
1884:   By default the values, `v`, are row-oriented and unsorted.
1885:   See `MatSetOption()` for other options.

1887:   Calls to `MatSetValuesBlockedStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1888:   options cannot be mixed without intervening calls to the assembly
1889:   routines.

1891:   The grid coordinates are across the entire grid, not just the local portion

1893:   `MatSetValuesBlockedStencil()` uses 0-based row and column numbers in Fortran
1894:   as well as in C.

1896:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1898:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1899:   or call `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1901:   The columns and rows in the stencil passed in MUST be contained within the
1902:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1903:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1904:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1905:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1907:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1908:   simply ignored. This allows easily inserting element stiffness matrices
1909:   with homogeneous Dirichlet boundary conditions that you don't want represented
1910:   in the matrix.

1912:   Inspired by the structured grid interface to the HYPRE package
1913:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1915:   Fortran Notes:
1916:   `idxm` and `idxn` should be declared as
1917: .vb
1918:     MatStencil idxm(4,m),idxn(4,n)
1919: .ve
1920:   and the values inserted using
1921: .vb
1922:     idxm(MatStencil_i,1) = i
1923:     idxm(MatStencil_j,1) = j
1924:     idxm(MatStencil_k,1) = k
1925:    etc
1926: .ve

1928:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1930: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`
1931:           `MatSetValues()`, `MatSetValuesStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`,
1932:           `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`
1933: @*/
1934: PetscErrorCode MatSetValuesBlockedStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1935: {
1936:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1937:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1938:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1940:   PetscFunctionBegin;
1941:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1944:   PetscAssertPointer(idxm, 3);
1945:   PetscAssertPointer(idxn, 5);
1946:   PetscAssertPointer(v, 6);

1948:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1949:     jdxm = buf;
1950:     jdxn = buf + m;
1951:   } else {
1952:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1953:     jdxm = bufm;
1954:     jdxn = bufn;
1955:   }
1956:   for (i = 0; i < m; i++) {
1957:     for (j = 0; j < 3 - sdim; j++) dxm++;
1958:     tmp = *dxm++ - starts[0];
1959:     for (j = 0; j < sdim - 1; j++) {
1960:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1961:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1962:     }
1963:     dxm++;
1964:     jdxm[i] = tmp;
1965:   }
1966:   for (i = 0; i < n; i++) {
1967:     for (j = 0; j < 3 - sdim; j++) dxn++;
1968:     tmp = *dxn++ - starts[0];
1969:     for (j = 0; j < sdim - 1; j++) {
1970:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1971:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1972:     }
1973:     dxn++;
1974:     jdxn[i] = tmp;
1975:   }
1976:   PetscCall(MatSetValuesBlockedLocal(mat, m, jdxm, n, jdxn, v, addv));
1977:   PetscCall(PetscFree2(bufm, bufn));
1978:   PetscFunctionReturn(PETSC_SUCCESS);
1979: }

1981: /*@
1982:   MatSetStencil - Sets the grid information for setting values into a matrix via
1983:   `MatSetValuesStencil()`

1985:   Not Collective

1987:   Input Parameters:
1988: + mat    - the matrix
1989: . dim    - dimension of the grid 1, 2, or 3
1990: . dims   - number of grid points in x, y, and z direction, including ghost points on your processor
1991: . starts - starting point of ghost nodes on your processor in x, y, and z direction
1992: - dof    - number of degrees of freedom per node

1994:   Level: beginner

1996:   Notes:
1997:   Inspired by the structured grid interface to the HYPRE package
1998:   (www.llnl.gov/CASC/hyper)

2000:   For matrices generated with `DMCreateMatrix()` this routine is automatically called and so not needed by the
2001:   user.

2003: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`
2004:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetValuesStencil()`
2005: @*/
2006: PetscErrorCode MatSetStencil(Mat mat, PetscInt dim, const PetscInt dims[], const PetscInt starts[], PetscInt dof)
2007: {
2008:   PetscFunctionBegin;
2010:   PetscAssertPointer(dims, 3);
2011:   PetscAssertPointer(starts, 4);

2013:   mat->stencil.dim = dim + (dof > 1);
2014:   for (PetscInt i = 0; i < dim; i++) {
2015:     mat->stencil.dims[i]   = dims[dim - i - 1]; /* copy the values in backwards */
2016:     mat->stencil.starts[i] = starts[dim - i - 1];
2017:   }
2018:   mat->stencil.dims[dim]   = dof;
2019:   mat->stencil.starts[dim] = 0;
2020:   mat->stencil.noc         = (PetscBool)(dof == 1);
2021:   PetscFunctionReturn(PETSC_SUCCESS);
2022: }

2024: /*@
2025:   MatSetValuesBlocked - Inserts or adds a block of values into a matrix.

2027:   Not Collective

2029:   Input Parameters:
2030: + mat  - the matrix
2031: . m    - the number of block rows
2032: . idxm - the global block indices
2033: . n    - the number of block columns
2034: . idxn - the global block indices
2035: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2036:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2037: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` replaces existing entries with new values

2039:   Level: intermediate

2041:   Notes:
2042:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call
2043:   MatXXXXSetPreallocation() or `MatSetUp()` before using this routine.

2045:   The `m` and `n` count the NUMBER of blocks in the row direction and column direction,
2046:   NOT the total number of rows/columns; for example, if the block size is 2 and
2047:   you are passing in values for rows 2,3,4,5  then `m` would be 2 (not 4).
2048:   The values in `idxm` would be 1 2; that is the first index for each block divided by
2049:   the block size.

2051:   You must call `MatSetBlockSize()` when constructing this matrix (before
2052:   preallocating it).

2054:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2056:   Calls to `MatSetValuesBlocked()` with the `INSERT_VALUES` and `ADD_VALUES`
2057:   options cannot be mixed without intervening calls to the assembly
2058:   routines.

2060:   `MatSetValuesBlocked()` uses 0-based row and column numbers in Fortran
2061:   as well as in C.

2063:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
2064:   simply ignored. This allows easily inserting element stiffness matrices
2065:   with homogeneous Dirichlet boundary conditions that you don't want represented
2066:   in the matrix.

2068:   Each time an entry is set within a sparse matrix via `MatSetValues()`,
2069:   internal searching must be done to determine where to place the
2070:   data in the matrix storage space.  By instead inserting blocks of
2071:   entries via `MatSetValuesBlocked()`, the overhead of matrix assembly is
2072:   reduced.

2074:   Example:
2075: .vb
2076:    Suppose m=n=2 and block size(bs) = 2 The array is

2078:    1  2  | 3  4
2079:    5  6  | 7  8
2080:    - - - | - - -
2081:    9  10 | 11 12
2082:    13 14 | 15 16

2084:    v[] should be passed in like
2085:    v[] = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

2087:   If you are not using row-oriented storage of v (that is you called MatSetOption(mat,MAT_ROW_ORIENTED,PETSC_FALSE)) then
2088:    v[] = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16]
2089: .ve

2091:   Fortran Notes:
2092:   If any of `idmx`, `idxn`, and `v` are scalars pass them using, for example,
2093: .vb
2094:   call MatSetValuesBlocked(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
2095: .ve

2097:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2099: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesBlockedLocal()`
2100: @*/
2101: PetscErrorCode MatSetValuesBlocked(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
2102: {
2103:   PetscFunctionBeginHot;
2106:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2107:   PetscAssertPointer(idxm, 3);
2108:   PetscAssertPointer(idxn, 5);
2109:   MatCheckPreallocated(mat, 1);
2110:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2111:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2112:   if (PetscDefined(USE_DEBUG)) {
2113:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2114:     PetscCheck(mat->ops->setvaluesblocked || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2115:   }
2116:   if (PetscDefined(USE_DEBUG)) {
2117:     PetscInt rbs, cbs, M, N, i;
2118:     PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
2119:     PetscCall(MatGetSize(mat, &M, &N));
2120:     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);
2121:     for (i = 0; i < n; i++)
2122:       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);
2123:   }
2124:   if (mat->assembled) {
2125:     mat->was_assembled = PETSC_TRUE;
2126:     mat->assembled     = PETSC_FALSE;
2127:   }
2128:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2129:   if (mat->ops->setvaluesblocked) {
2130:     PetscUseTypeMethod(mat, setvaluesblocked, m, idxm, n, idxn, v, addv);
2131:   } else {
2132:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *iidxm, *iidxn;
2133:     PetscInt i, j, bs, cbs;

2135:     PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
2136:     if ((m * bs + n * cbs) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2137:       iidxm = buf;
2138:       iidxn = buf + m * bs;
2139:     } else {
2140:       PetscCall(PetscMalloc2(m * bs, &bufr, n * cbs, &bufc));
2141:       iidxm = bufr;
2142:       iidxn = bufc;
2143:     }
2144:     for (i = 0; i < m; i++) {
2145:       for (j = 0; j < bs; j++) iidxm[i * bs + j] = bs * idxm[i] + j;
2146:     }
2147:     if (m != n || bs != cbs || idxm != idxn) {
2148:       for (i = 0; i < n; i++) {
2149:         for (j = 0; j < cbs; j++) iidxn[i * cbs + j] = cbs * idxn[i] + j;
2150:       }
2151:     } else iidxn = iidxm;
2152:     PetscCall(MatSetValues(mat, m * bs, iidxm, n * cbs, iidxn, v, addv));
2153:     PetscCall(PetscFree2(bufr, bufc));
2154:   }
2155:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2156:   PetscFunctionReturn(PETSC_SUCCESS);
2157: }

2159: /*@
2160:   MatGetValues - Gets a block of local values from a matrix.

2162:   Not Collective; can only return values that are owned by the give process

2164:   Input Parameters:
2165: + mat  - the matrix
2166: . v    - a logically two-dimensional array for storing the values
2167: . m    - the number of rows
2168: . idxm - the  global indices of the rows
2169: . n    - the number of columns
2170: - idxn - the global indices of the columns

2172:   Level: advanced

2174:   Notes:
2175:   The user must allocate space (m*n `PetscScalar`s) for the values, `v`.
2176:   The values, `v`, are then returned in a row-oriented format,
2177:   analogous to that used by default in `MatSetValues()`.

2179:   `MatGetValues()` uses 0-based row and column numbers in
2180:   Fortran as well as in C.

2182:   `MatGetValues()` requires that the matrix has been assembled
2183:   with `MatAssemblyBegin()`/`MatAssemblyEnd()`.  Thus, calls to
2184:   `MatSetValues()` and `MatGetValues()` CANNOT be made in succession
2185:   without intermediate matrix assembly.

2187:   Negative row or column indices will be ignored and those locations in `v` will be
2188:   left unchanged.

2190:   For the standard row-based matrix formats, `idxm` can only contain rows owned by the requesting MPI process.
2191:   That is, rows with global index greater than or equal to rstart and less than rend where rstart and rend are obtainable
2192:   from `MatGetOwnershipRange`(mat,&rstart,&rend).

2194: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatSetValues()`, `MatGetOwnershipRange()`, `MatGetValuesLocal()`, `MatGetValue()`
2195: @*/
2196: PetscErrorCode MatGetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], PetscScalar v[])
2197: {
2198:   PetscFunctionBegin;
2201:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS);
2202:   PetscAssertPointer(idxm, 3);
2203:   PetscAssertPointer(idxn, 5);
2204:   PetscAssertPointer(v, 6);
2205:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2206:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2207:   MatCheckPreallocated(mat, 1);

2209:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2210:   PetscUseTypeMethod(mat, getvalues, m, idxm, n, idxn, v);
2211:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2212:   PetscFunctionReturn(PETSC_SUCCESS);
2213: }

2215: /*@
2216:   MatGetValuesLocal - retrieves values from certain locations in a matrix using the local numbering of the indices
2217:   defined previously by `MatSetLocalToGlobalMapping()`

2219:   Not Collective

2221:   Input Parameters:
2222: + mat  - the matrix
2223: . nrow - number of rows
2224: . irow - the row local indices
2225: . ncol - number of columns
2226: - icol - the column local indices

2228:   Output Parameter:
2229: . y - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2230:       See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2232:   Level: advanced

2234:   Notes:
2235:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine.

2237:   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,
2238:   are greater than or equal to rstart and less than rend where rstart and rend are obtainable from `MatGetOwnershipRange`(mat,&rstart,&rend). One can
2239:   determine if the resulting global row associated with the local row r is owned by the requesting MPI process by applying the `ISLocalToGlobalMapping` set
2240:   with `MatSetLocalToGlobalMapping()`.

2242: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2243:           `MatSetValuesLocal()`, `MatGetValues()`
2244: @*/
2245: PetscErrorCode MatGetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], PetscScalar y[])
2246: {
2247:   PetscFunctionBeginHot;
2250:   MatCheckPreallocated(mat, 1);
2251:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to retrieve */
2252:   PetscAssertPointer(irow, 3);
2253:   PetscAssertPointer(icol, 5);
2254:   if (PetscDefined(USE_DEBUG)) {
2255:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2256:     PetscCheck(mat->ops->getvalueslocal || mat->ops->getvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2257:   }
2258:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2259:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2260:   if (mat->ops->getvalueslocal) PetscUseTypeMethod(mat, getvalueslocal, nrow, irow, ncol, icol, y);
2261:   else {
2262:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *irowm, *icolm;
2263:     if ((nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2264:       irowm = buf;
2265:       icolm = buf + nrow;
2266:     } else {
2267:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2268:       irowm = bufr;
2269:       icolm = bufc;
2270:     }
2271:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global row mapping (See MatSetLocalToGlobalMapping()).");
2272:     PetscCheck(mat->cmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global column mapping (See MatSetLocalToGlobalMapping()).");
2273:     PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, irowm));
2274:     PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, icolm));
2275:     PetscCall(MatGetValues(mat, nrow, irowm, ncol, icolm, y));
2276:     PetscCall(PetscFree2(bufr, bufc));
2277:   }
2278:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2279:   PetscFunctionReturn(PETSC_SUCCESS);
2280: }

2282: /*@
2283:   MatSetValuesBatch - Adds (`ADD_VALUES`) many blocks of values into a matrix at once. The blocks must all be square and
2284:   the same size. Currently, this can only be called once and creates the given matrix.

2286:   Not Collective

2288:   Input Parameters:
2289: + mat  - the matrix
2290: . nb   - the number of blocks
2291: . bs   - the number of rows (and columns) in each block
2292: . rows - a concatenation of the rows for each block
2293: - v    - a concatenation of logically two-dimensional arrays of values

2295:   Level: advanced

2297:   Notes:
2298:   `MatSetPreallocationCOO()` and `MatSetValuesCOO()` may be a better way to provide the values

2300:   In the future, we will extend this routine to handle rectangular blocks, and to allow multiple calls for a given matrix.

2302: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
2303:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
2304: @*/
2305: PetscErrorCode MatSetValuesBatch(Mat mat, PetscInt nb, PetscInt bs, PetscInt rows[], const PetscScalar v[])
2306: {
2307:   PetscFunctionBegin;
2310:   PetscAssertPointer(rows, 4);
2311:   PetscAssertPointer(v, 5);
2312:   PetscAssert(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

2314:   PetscCall(PetscLogEventBegin(MAT_SetValuesBatch, mat, 0, 0, 0));
2315:   if (mat->ops->setvaluesbatch) PetscUseTypeMethod(mat, setvaluesbatch, nb, bs, rows, v);
2316:   else {
2317:     for (PetscInt b = 0; b < nb; ++b) PetscCall(MatSetValues(mat, bs, &rows[b * bs], bs, &rows[b * bs], &v[b * bs * bs], ADD_VALUES));
2318:   }
2319:   PetscCall(PetscLogEventEnd(MAT_SetValuesBatch, mat, 0, 0, 0));
2320:   PetscFunctionReturn(PETSC_SUCCESS);
2321: }

2323: /*@
2324:   MatSetLocalToGlobalMapping - Sets a local-to-global numbering for use by
2325:   the routine `MatSetValuesLocal()` to allow users to insert matrix entries
2326:   using a local (per-processor) numbering.

2328:   Not Collective

2330:   Input Parameters:
2331: + x        - the matrix
2332: . rmapping - row mapping created with `ISLocalToGlobalMappingCreate()` or `ISLocalToGlobalMappingCreateIS()`
2333: - cmapping - column mapping

2335:   Level: intermediate

2337:   Note:
2338:   If the matrix is obtained with `DMCreateMatrix()` then this may already have been called on the matrix

2340: .seealso: [](ch_matrices), `Mat`, `DM`, `DMCreateMatrix()`, `MatGetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesLocal()`, `MatGetValuesLocal()`
2341: @*/
2342: PetscErrorCode MatSetLocalToGlobalMapping(Mat x, ISLocalToGlobalMapping rmapping, ISLocalToGlobalMapping cmapping)
2343: {
2344:   PetscFunctionBegin;
2349:   if (x->ops->setlocaltoglobalmapping) PetscUseTypeMethod(x, setlocaltoglobalmapping, rmapping, cmapping);
2350:   else {
2351:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->rmap, rmapping));
2352:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->cmap, cmapping));
2353:   }
2354:   PetscFunctionReturn(PETSC_SUCCESS);
2355: }

2357: /*@
2358:   MatGetLocalToGlobalMapping - Gets the local-to-global numbering set by `MatSetLocalToGlobalMapping()`

2360:   Not Collective

2362:   Input Parameter:
2363: . A - the matrix

2365:   Output Parameters:
2366: + rmapping - row mapping
2367: - cmapping - column mapping

2369:   Level: advanced

2371: .seealso: [](ch_matrices), `Mat`, `MatSetLocalToGlobalMapping()`, `MatSetValuesLocal()`
2372: @*/
2373: PetscErrorCode MatGetLocalToGlobalMapping(Mat A, ISLocalToGlobalMapping *rmapping, ISLocalToGlobalMapping *cmapping)
2374: {
2375:   PetscFunctionBegin;
2378:   if (rmapping) {
2379:     PetscAssertPointer(rmapping, 2);
2380:     *rmapping = A->rmap->mapping;
2381:   }
2382:   if (cmapping) {
2383:     PetscAssertPointer(cmapping, 3);
2384:     *cmapping = A->cmap->mapping;
2385:   }
2386:   PetscFunctionReturn(PETSC_SUCCESS);
2387: }

2389: /*@
2390:   MatSetLayouts - Sets the `PetscLayout` objects for rows and columns of a matrix

2392:   Logically Collective

2394:   Input Parameters:
2395: + A    - the matrix
2396: . rmap - row layout
2397: - cmap - column layout

2399:   Level: advanced

2401:   Note:
2402:   The `PetscLayout` objects are usually created automatically for the matrix so this routine rarely needs to be called.

2404: .seealso: [](ch_matrices), `Mat`, `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatGetLayouts()`
2405: @*/
2406: PetscErrorCode MatSetLayouts(Mat A, PetscLayout rmap, PetscLayout cmap)
2407: {
2408:   PetscFunctionBegin;
2410:   PetscCall(PetscLayoutReference(rmap, &A->rmap));
2411:   PetscCall(PetscLayoutReference(cmap, &A->cmap));
2412:   PetscFunctionReturn(PETSC_SUCCESS);
2413: }

2415: /*@
2416:   MatGetLayouts - Gets the `PetscLayout` objects for rows and columns

2418:   Not Collective

2420:   Input Parameter:
2421: . A - the matrix

2423:   Output Parameters:
2424: + rmap - row layout
2425: - cmap - column layout

2427:   Level: advanced

2429: .seealso: [](ch_matrices), `Mat`, [Matrix Layouts](sec_matlayout), `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatSetLayouts()`
2430: @*/
2431: PetscErrorCode MatGetLayouts(Mat A, PetscLayout *rmap, PetscLayout *cmap)
2432: {
2433:   PetscFunctionBegin;
2436:   if (rmap) {
2437:     PetscAssertPointer(rmap, 2);
2438:     *rmap = A->rmap;
2439:   }
2440:   if (cmap) {
2441:     PetscAssertPointer(cmap, 3);
2442:     *cmap = A->cmap;
2443:   }
2444:   PetscFunctionReturn(PETSC_SUCCESS);
2445: }

2447: /*@
2448:   MatSetValuesLocal - Inserts or adds values into certain locations of a matrix,
2449:   using a local numbering of the rows and columns.

2451:   Not Collective

2453:   Input Parameters:
2454: + mat  - the matrix
2455: . nrow - number of rows
2456: . irow - the row local indices
2457: . ncol - number of columns
2458: . icol - the column local indices
2459: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2460:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2461: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2463:   Level: intermediate

2465:   Notes:
2466:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine

2468:   Calls to `MatSetValuesLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2469:   options cannot be mixed without intervening calls to the assembly
2470:   routines.

2472:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2473:   MUST be called after all calls to `MatSetValuesLocal()` have been completed.

2475:   Fortran Notes:
2476:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2477: .vb
2478:   call MatSetValuesLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2479: .ve

2481:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2483: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2484:           `MatGetValuesLocal()`
2485: @*/
2486: PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2487: {
2488:   PetscFunctionBeginHot;
2491:   MatCheckPreallocated(mat, 1);
2492:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2493:   PetscAssertPointer(irow, 3);
2494:   PetscAssertPointer(icol, 5);
2495:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2496:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2497:   if (PetscDefined(USE_DEBUG)) {
2498:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2499:     PetscCheck(mat->ops->setvalueslocal || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2500:   }

2502:   if (mat->assembled) {
2503:     mat->was_assembled = PETSC_TRUE;
2504:     mat->assembled     = PETSC_FALSE;
2505:   }
2506:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2507:   if (mat->ops->setvalueslocal) PetscUseTypeMethod(mat, setvalueslocal, nrow, irow, ncol, icol, y, addv);
2508:   else {
2509:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2510:     const PetscInt *irowm, *icolm;

2512:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2513:       bufr  = buf;
2514:       bufc  = buf + nrow;
2515:       irowm = bufr;
2516:       icolm = bufc;
2517:     } else {
2518:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2519:       irowm = bufr;
2520:       icolm = bufc;
2521:     }
2522:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, bufr));
2523:     else irowm = irow;
2524:     if (mat->cmap->mapping) {
2525:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, bufc));
2526:       else icolm = irowm;
2527:     } else icolm = icol;
2528:     PetscCall(MatSetValues(mat, nrow, irowm, ncol, icolm, y, addv));
2529:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2530:   }
2531:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2532:   PetscFunctionReturn(PETSC_SUCCESS);
2533: }

2535: /*@
2536:   MatSetValuesBlockedLocal - Inserts or adds values into certain locations of a matrix,
2537:   using a local ordering of the nodes a block at a time.

2539:   Not Collective

2541:   Input Parameters:
2542: + mat  - the matrix
2543: . nrow - number of rows
2544: . irow - the row local indices
2545: . ncol - number of columns
2546: . icol - the column local indices
2547: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2548:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2549: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2551:   Level: intermediate

2553:   Notes:
2554:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetBlockSize()` and `MatSetLocalToGlobalMapping()`
2555:   before using this routineBefore calling `MatSetValuesLocal()`, the user must first set the

2557:   Calls to `MatSetValuesBlockedLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2558:   options cannot be mixed without intervening calls to the assembly
2559:   routines.

2561:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2562:   MUST be called after all calls to `MatSetValuesBlockedLocal()` have been completed.

2564:   Fortran Notes:
2565:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2566: .vb
2567:   call MatSetValuesBlockedLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2568: .ve

2570:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2572: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`,
2573:           `MatSetValuesLocal()`, `MatSetValuesBlocked()`
2574: @*/
2575: PetscErrorCode MatSetValuesBlockedLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2576: {
2577:   PetscFunctionBeginHot;
2580:   MatCheckPreallocated(mat, 1);
2581:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2582:   PetscAssertPointer(irow, 3);
2583:   PetscAssertPointer(icol, 5);
2584:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2585:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2586:   if (PetscDefined(USE_DEBUG)) {
2587:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2588:     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);
2589:   }

2591:   if (mat->assembled) {
2592:     mat->was_assembled = PETSC_TRUE;
2593:     mat->assembled     = PETSC_FALSE;
2594:   }
2595:   if (PetscUnlikelyDebug(mat->rmap->mapping)) { /* Condition on the mapping existing, because MatSetValuesBlockedLocal_IS does not require it to be set. */
2596:     PetscInt irbs, rbs;
2597:     PetscCall(MatGetBlockSizes(mat, &rbs, NULL));
2598:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->rmap->mapping, &irbs));
2599:     PetscCheck(rbs == irbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different row block sizes! mat %" PetscInt_FMT ", row l2g map %" PetscInt_FMT, rbs, irbs);
2600:   }
2601:   if (PetscUnlikelyDebug(mat->cmap->mapping)) {
2602:     PetscInt icbs, cbs;
2603:     PetscCall(MatGetBlockSizes(mat, NULL, &cbs));
2604:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->cmap->mapping, &icbs));
2605:     PetscCheck(cbs == icbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different col block sizes! mat %" PetscInt_FMT ", col l2g map %" PetscInt_FMT, cbs, icbs);
2606:   }
2607:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2608:   if (mat->ops->setvaluesblockedlocal) PetscUseTypeMethod(mat, setvaluesblockedlocal, nrow, irow, ncol, icol, y, addv);
2609:   else {
2610:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2611:     const PetscInt *irowm, *icolm;

2613:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= ((PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf))) {
2614:       bufr  = buf;
2615:       bufc  = buf + nrow;
2616:       irowm = bufr;
2617:       icolm = bufc;
2618:     } else {
2619:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2620:       irowm = bufr;
2621:       icolm = bufc;
2622:     }
2623:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->rmap->mapping, nrow, irow, bufr));
2624:     else irowm = irow;
2625:     if (mat->cmap->mapping) {
2626:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->cmap->mapping, ncol, icol, bufc));
2627:       else icolm = irowm;
2628:     } else icolm = icol;
2629:     PetscCall(MatSetValuesBlocked(mat, nrow, irowm, ncol, icolm, y, addv));
2630:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2631:   }
2632:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2633:   PetscFunctionReturn(PETSC_SUCCESS);
2634: }

2636: /*@
2637:   MatMultDiagonalBlock - Computes the matrix-vector product, $y = Dx$. Where `D` is defined by the inode or block structure of the diagonal

2639:   Collective

2641:   Input Parameters:
2642: + mat - the matrix
2643: - x   - the vector to be multiplied

2645:   Output Parameter:
2646: . y - the result

2648:   Level: developer

2650:   Note:
2651:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2652:   call `MatMultDiagonalBlock`(A,y,y).

2654: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2655: @*/
2656: PetscErrorCode MatMultDiagonalBlock(Mat mat, Vec x, Vec y)
2657: {
2658:   PetscFunctionBegin;

2664:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2665:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2666:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2667:   MatCheckPreallocated(mat, 1);

2669:   PetscUseTypeMethod(mat, multdiagonalblock, x, y);
2670:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2671:   PetscFunctionReturn(PETSC_SUCCESS);
2672: }

2674: /*@
2675:   MatMult - Computes the matrix-vector product, $y = Ax$.

2677:   Neighbor-wise Collective

2679:   Input Parameters:
2680: + mat - the matrix
2681: - x   - the vector to be multiplied

2683:   Output Parameter:
2684: . y - the result

2686:   Level: beginner

2688:   Note:
2689:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2690:   call `MatMult`(A,y,y).

2692: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2693: @*/
2694: PetscErrorCode MatMult(Mat mat, Vec x, Vec y)
2695: {
2696:   PetscFunctionBegin;
2700:   VecCheckAssembled(x);
2702:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2703:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2704:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2705:   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);
2706:   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);
2707:   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);
2708:   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);
2709:   PetscCall(VecSetErrorIfLocked(y, 3));
2710:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2711:   MatCheckPreallocated(mat, 1);

2713:   PetscCall(VecLockReadPush(x));
2714:   PetscCall(PetscLogEventBegin(MAT_Mult, mat, x, y, 0));
2715:   PetscUseTypeMethod(mat, mult, x, y);
2716:   PetscCall(PetscLogEventEnd(MAT_Mult, mat, x, y, 0));
2717:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2718:   PetscCall(VecLockReadPop(x));
2719:   PetscFunctionReturn(PETSC_SUCCESS);
2720: }

2722: /*@
2723:   MatMultTranspose - Computes matrix transpose times a vector $y = A^T * x$.

2725:   Neighbor-wise Collective

2727:   Input Parameters:
2728: + mat - the matrix
2729: - x   - the vector to be multiplied

2731:   Output Parameter:
2732: . y - the result

2734:   Level: beginner

2736:   Notes:
2737:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2738:   call `MatMultTranspose`(A,y,y).

2740:   For complex numbers this does NOT compute the Hermitian (complex conjugate) transpose multiple,
2741:   use `MatMultHermitianTranspose()`

2743: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatMultHermitianTranspose()`, `MatTranspose()`
2744: @*/
2745: PetscErrorCode MatMultTranspose(Mat mat, Vec x, Vec y)
2746: {
2747:   PetscErrorCode (*op)(Mat, Vec, Vec) = NULL;

2749:   PetscFunctionBegin;
2753:   VecCheckAssembled(x);

2756:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2757:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2758:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2759:   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);
2760:   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);
2761:   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);
2762:   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);
2763:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2764:   MatCheckPreallocated(mat, 1);

2766:   if (!mat->ops->multtranspose) {
2767:     if (mat->symmetric == PETSC_BOOL3_TRUE && mat->ops->mult) op = mat->ops->mult;
2768:     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);
2769:   } else op = mat->ops->multtranspose;
2770:   PetscCall(PetscLogEventBegin(MAT_MultTranspose, mat, x, y, 0));
2771:   PetscCall(VecLockReadPush(x));
2772:   PetscCall((*op)(mat, x, y));
2773:   PetscCall(VecLockReadPop(x));
2774:   PetscCall(PetscLogEventEnd(MAT_MultTranspose, mat, x, y, 0));
2775:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2776:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2777:   PetscFunctionReturn(PETSC_SUCCESS);
2778: }

2780: /*@
2781:   MatMultHermitianTranspose - Computes matrix Hermitian-transpose times a vector $y = A^H * x$.

2783:   Neighbor-wise Collective

2785:   Input Parameters:
2786: + mat - the matrix
2787: - x   - the vector to be multiplied

2789:   Output Parameter:
2790: . y - the result

2792:   Level: beginner

2794:   Notes:
2795:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2796:   call `MatMultHermitianTranspose`(A,y,y).

2798:   Also called the conjugate transpose, complex conjugate transpose, or adjoint.

2800:   For real numbers `MatMultTranspose()` and `MatMultHermitianTranspose()` are identical.

2802: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultHermitianTransposeAdd()`, `MatMultTranspose()`
2803: @*/
2804: PetscErrorCode MatMultHermitianTranspose(Mat mat, Vec x, Vec y)
2805: {
2806:   PetscFunctionBegin;

2812:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2813:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2814:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2815:   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);
2816:   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);
2817:   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);
2818:   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);
2819:   MatCheckPreallocated(mat, 1);

2821:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTranspose, mat, x, y, 0));
2822: #if defined(PETSC_USE_COMPLEX)
2823:   if (mat->ops->multhermitiantranspose || (mat->hermitian == PETSC_BOOL3_TRUE && mat->ops->mult)) {
2824:     PetscCall(VecLockReadPush(x));
2825:     if (mat->ops->multhermitiantranspose) PetscUseTypeMethod(mat, multhermitiantranspose, x, y);
2826:     else PetscUseTypeMethod(mat, mult, x, y);
2827:     PetscCall(VecLockReadPop(x));
2828:   } else {
2829:     Vec w;
2830:     PetscCall(VecDuplicate(x, &w));
2831:     PetscCall(VecCopy(x, w));
2832:     PetscCall(VecConjugate(w));
2833:     PetscCall(MatMultTranspose(mat, w, y));
2834:     PetscCall(VecDestroy(&w));
2835:     PetscCall(VecConjugate(y));
2836:   }
2837:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2838: #else
2839:   PetscCall(MatMultTranspose(mat, x, y));
2840: #endif
2841:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTranspose, mat, x, y, 0));
2842:   PetscFunctionReturn(PETSC_SUCCESS);
2843: }

2845: /*@
2846:   MatMultAdd -  Computes $v3 = v2 + A * v1$.

2848:   Neighbor-wise Collective

2850:   Input Parameters:
2851: + mat - the matrix
2852: . v1  - the vector to be multiplied by `mat`
2853: - v2  - the vector to be added to the result

2855:   Output Parameter:
2856: . v3 - the result

2858:   Level: beginner

2860:   Note:
2861:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2862:   call `MatMultAdd`(A,v1,v2,v1).

2864: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMult()`, `MatMultTransposeAdd()`
2865: @*/
2866: PetscErrorCode MatMultAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2867: {
2868:   PetscFunctionBegin;

2875:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2876:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2877:   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);
2878:   /* 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);
2879:      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); */
2880:   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);
2881:   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);
2882:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2883:   MatCheckPreallocated(mat, 1);

2885:   PetscCall(PetscLogEventBegin(MAT_MultAdd, mat, v1, v2, v3));
2886:   PetscCall(VecLockReadPush(v1));
2887:   PetscUseTypeMethod(mat, multadd, v1, v2, v3);
2888:   PetscCall(VecLockReadPop(v1));
2889:   PetscCall(PetscLogEventEnd(MAT_MultAdd, mat, v1, v2, v3));
2890:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2891:   PetscFunctionReturn(PETSC_SUCCESS);
2892: }

2894: /*@
2895:   MatMultTransposeAdd - Computes $v3 = v2 + A^T * v1$.

2897:   Neighbor-wise Collective

2899:   Input Parameters:
2900: + mat - the matrix
2901: . v1  - the vector to be multiplied by the transpose of the matrix
2902: - v2  - the vector to be added to the result

2904:   Output Parameter:
2905: . v3 - the result

2907:   Level: beginner

2909:   Note:
2910:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2911:   call `MatMultTransposeAdd`(A,v1,v2,v1).

2913: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2914: @*/
2915: PetscErrorCode MatMultTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2916: {
2917:   PetscErrorCode (*op)(Mat, Vec, Vec, Vec) = (!mat->ops->multtransposeadd && mat->symmetric) ? mat->ops->multadd : mat->ops->multtransposeadd;

2919:   PetscFunctionBegin;

2926:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2927:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2928:   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);
2929:   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);
2930:   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);
2931:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2932:   PetscCheck(op, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2933:   MatCheckPreallocated(mat, 1);

2935:   PetscCall(PetscLogEventBegin(MAT_MultTransposeAdd, mat, v1, v2, v3));
2936:   PetscCall(VecLockReadPush(v1));
2937:   PetscCall((*op)(mat, v1, v2, v3));
2938:   PetscCall(VecLockReadPop(v1));
2939:   PetscCall(PetscLogEventEnd(MAT_MultTransposeAdd, mat, v1, v2, v3));
2940:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2941:   PetscFunctionReturn(PETSC_SUCCESS);
2942: }

2944: /*@
2945:   MatMultHermitianTransposeAdd - Computes $v3 = v2 + A^H * v1$.

2947:   Neighbor-wise Collective

2949:   Input Parameters:
2950: + mat - the matrix
2951: . v1  - the vector to be multiplied by the Hermitian transpose
2952: - v2  - the vector to be added to the result

2954:   Output Parameter:
2955: . v3 - the result

2957:   Level: beginner

2959:   Note:
2960:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2961:   call `MatMultHermitianTransposeAdd`(A,v1,v2,v1).

2963: .seealso: [](ch_matrices), `Mat`, `MatMultHermitianTranspose()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2964: @*/
2965: PetscErrorCode MatMultHermitianTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2966: {
2967:   PetscFunctionBegin;

2974:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2975:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2976:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2977:   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);
2978:   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);
2979:   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);
2980:   MatCheckPreallocated(mat, 1);

2982:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2983:   PetscCall(VecLockReadPush(v1));
2984:   if (mat->ops->multhermitiantransposeadd) PetscUseTypeMethod(mat, multhermitiantransposeadd, v1, v2, v3);
2985:   else {
2986:     Vec w, z;
2987:     PetscCall(VecDuplicate(v1, &w));
2988:     PetscCall(VecCopy(v1, w));
2989:     PetscCall(VecConjugate(w));
2990:     PetscCall(VecDuplicate(v3, &z));
2991:     PetscCall(MatMultTranspose(mat, w, z));
2992:     PetscCall(VecDestroy(&w));
2993:     PetscCall(VecConjugate(z));
2994:     if (v2 != v3) {
2995:       PetscCall(VecWAXPY(v3, 1.0, v2, z));
2996:     } else {
2997:       PetscCall(VecAXPY(v3, 1.0, z));
2998:     }
2999:     PetscCall(VecDestroy(&z));
3000:   }
3001:   PetscCall(VecLockReadPop(v1));
3002:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
3003:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
3004:   PetscFunctionReturn(PETSC_SUCCESS);
3005: }

3007: /*@
3008:   MatGetFactorType - gets the type of factorization a matrix is

3010:   Not Collective

3012:   Input Parameter:
3013: . mat - the matrix

3015:   Output Parameter:
3016: . 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`

3018:   Level: intermediate

3020: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatSetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3021:           `MAT_FACTOR_ICC`,`MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3022: @*/
3023: PetscErrorCode MatGetFactorType(Mat mat, MatFactorType *t)
3024: {
3025:   PetscFunctionBegin;
3028:   PetscAssertPointer(t, 2);
3029:   *t = mat->factortype;
3030:   PetscFunctionReturn(PETSC_SUCCESS);
3031: }

3033: /*@
3034:   MatSetFactorType - sets the type of factorization a matrix is

3036:   Logically Collective

3038:   Input Parameters:
3039: + mat - the matrix
3040: - 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`

3042:   Level: intermediate

3044: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatGetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3045:           `MAT_FACTOR_ICC`,`MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3046: @*/
3047: PetscErrorCode MatSetFactorType(Mat mat, MatFactorType t)
3048: {
3049:   PetscFunctionBegin;
3052:   mat->factortype = t;
3053:   PetscFunctionReturn(PETSC_SUCCESS);
3054: }

3056: /*@
3057:   MatGetInfo - Returns information about matrix storage (number of
3058:   nonzeros, memory, etc.).

3060:   Collective if `MAT_GLOBAL_MAX` or `MAT_GLOBAL_SUM` is used as the flag

3062:   Input Parameters:
3063: + mat  - the matrix
3064: - 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)

3066:   Output Parameter:
3067: . info - matrix information context

3069:   Options Database Key:
3070: . -mat_view ::ascii_info - print matrix info to `PETSC_STDOUT`

3072:   Level: intermediate

3074:   Notes:
3075:   The `MatInfo` context contains a variety of matrix data, including
3076:   number of nonzeros allocated and used, number of mallocs during
3077:   matrix assembly, etc.  Additional information for factored matrices
3078:   is provided (such as the fill ratio, number of mallocs during
3079:   factorization, etc.).

3081:   Example:
3082:   See the file ${PETSC_DIR}/include/petscmat.h for a complete list of
3083:   data within the `MatInfo` context.  For example,
3084: .vb
3085:       MatInfo info;
3086:       Mat     A;
3087:       double  mal, nz_a, nz_u;

3089:       MatGetInfo(A, MAT_LOCAL, &info);
3090:       mal  = info.mallocs;
3091:       nz_a = info.nz_allocated;
3092: .ve

3094: .seealso: [](ch_matrices), `Mat`, `MatInfo`, `MatStashGetInfo()`
3095: @*/
3096: PetscErrorCode MatGetInfo(Mat mat, MatInfoType flag, MatInfo *info)
3097: {
3098:   PetscFunctionBegin;
3101:   PetscAssertPointer(info, 3);
3102:   MatCheckPreallocated(mat, 1);
3103:   PetscUseTypeMethod(mat, getinfo, flag, info);
3104:   PetscFunctionReturn(PETSC_SUCCESS);
3105: }

3107: /*
3108:    This is used by external packages where it is not easy to get the info from the actual
3109:    matrix factorization.
3110: */
3111: PetscErrorCode MatGetInfo_External(Mat A, MatInfoType flag, MatInfo *info)
3112: {
3113:   PetscFunctionBegin;
3114:   PetscCall(PetscMemzero(info, sizeof(MatInfo)));
3115:   PetscFunctionReturn(PETSC_SUCCESS);
3116: }

3118: /*@
3119:   MatLUFactor - Performs in-place LU factorization of matrix.

3121:   Collective

3123:   Input Parameters:
3124: + mat  - the matrix
3125: . row  - row permutation
3126: . col  - column permutation
3127: - info - options for factorization, includes
3128: .vb
3129:           fill - expected fill as ratio of original fill.
3130:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3131:                    Run with the option -info to determine an optimal value to use
3132: .ve

3134:   Level: developer

3136:   Notes:
3137:   Most users should employ the `KSP` interface for linear solvers
3138:   instead of working directly with matrix algebra routines such as this.
3139:   See, e.g., `KSPCreate()`.

3141:   This changes the state of the matrix to a factored matrix; it cannot be used
3142:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3144:   This is really in-place only for dense matrices, the preferred approach is to use `MatGetFactor()`, `MatLUFactorSymbolic()`, and `MatLUFactorNumeric()`
3145:   when not using `KSP`.

3147:   Fortran Note:
3148:   A valid (non-null) `info` argument must be provided

3150: .seealso: [](ch_matrices), [Matrix Factorization](sec_matfactor), `Mat`, `MatFactorType`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
3151:           `MatGetOrdering()`, `MatSetUnfactored()`, `MatFactorInfo`, `MatGetFactor()`
3152: @*/
3153: PetscErrorCode MatLUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3154: {
3155:   MatFactorInfo tinfo;

3157:   PetscFunctionBegin;
3161:   if (info) PetscAssertPointer(info, 4);
3163:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3164:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3165:   MatCheckPreallocated(mat, 1);
3166:   if (!info) {
3167:     PetscCall(MatFactorInfoInitialize(&tinfo));
3168:     info = &tinfo;
3169:   }

3171:   PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, row, col, 0));
3172:   PetscUseTypeMethod(mat, lufactor, row, col, info);
3173:   PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, row, col, 0));
3174:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3175:   PetscFunctionReturn(PETSC_SUCCESS);
3176: }

3178: /*@
3179:   MatILUFactor - Performs in-place ILU factorization of matrix.

3181:   Collective

3183:   Input Parameters:
3184: + mat  - the matrix
3185: . row  - row permutation
3186: . col  - column permutation
3187: - info - structure containing
3188: .vb
3189:       levels - number of levels of fill.
3190:       expected fill - as ratio of original fill.
3191:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
3192:                 missing diagonal entries)
3193: .ve

3195:   Level: developer

3197:   Notes:
3198:   Most users should employ the `KSP` interface for linear solvers
3199:   instead of working directly with matrix algebra routines such as this.
3200:   See, e.g., `KSPCreate()`.

3202:   Probably really in-place only when level of fill is zero, otherwise allocates
3203:   new space to store factored matrix and deletes previous memory. The preferred approach is to use `MatGetFactor()`, `MatILUFactorSymbolic()`, and `MatILUFactorNumeric()`
3204:   when not using `KSP`.

3206:   Fortran Note:
3207:   A valid (non-null) `info` argument must be provided

3209: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatILUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
3210: @*/
3211: PetscErrorCode MatILUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3212: {
3213:   PetscFunctionBegin;
3217:   PetscAssertPointer(info, 4);
3219:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
3220:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3221:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3222:   MatCheckPreallocated(mat, 1);

3224:   PetscCall(PetscLogEventBegin(MAT_ILUFactor, mat, row, col, 0));
3225:   PetscUseTypeMethod(mat, ilufactor, row, col, info);
3226:   PetscCall(PetscLogEventEnd(MAT_ILUFactor, mat, row, col, 0));
3227:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3228:   PetscFunctionReturn(PETSC_SUCCESS);
3229: }

3231: /*@
3232:   MatLUFactorSymbolic - Performs symbolic LU factorization of matrix.
3233:   Call this routine before calling `MatLUFactorNumeric()` and after `MatGetFactor()`.

3235:   Collective

3237:   Input Parameters:
3238: + fact - the factor matrix obtained with `MatGetFactor()`
3239: . mat  - the matrix
3240: . row  - the row permutation
3241: . col  - the column permutation
3242: - info - options for factorization, includes
3243: .vb
3244:           fill - expected fill as ratio of original fill. Run with the option -info to determine an optimal value to use
3245:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3246: .ve

3248:   Level: developer

3250:   Notes:
3251:   See [Matrix Factorization](sec_matfactor) for additional information about factorizations

3253:   Most users should employ the simplified `KSP` interface for linear solvers
3254:   instead of working directly with matrix algebra routines such as this.
3255:   See, e.g., `KSPCreate()`.

3257:   Fortran Note:
3258:   A valid (non-null) `info` argument must be provided

3260: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`, `MatFactorInfoInitialize()`
3261: @*/
3262: PetscErrorCode MatLUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
3263: {
3264:   MatFactorInfo tinfo;

3266:   PetscFunctionBegin;
3271:   if (info) PetscAssertPointer(info, 5);
3274:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3275:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3276:   MatCheckPreallocated(mat, 2);
3277:   if (!info) {
3278:     PetscCall(MatFactorInfoInitialize(&tinfo));
3279:     info = &tinfo;
3280:   }

3282:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorSymbolic, mat, row, col, 0));
3283:   PetscUseTypeMethod(fact, lufactorsymbolic, mat, row, col, info);
3284:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorSymbolic, mat, row, col, 0));
3285:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3286:   PetscFunctionReturn(PETSC_SUCCESS);
3287: }

3289: /*@
3290:   MatLUFactorNumeric - Performs numeric LU factorization of a matrix.
3291:   Call this routine after first calling `MatLUFactorSymbolic()` and `MatGetFactor()`.

3293:   Collective

3295:   Input Parameters:
3296: + fact - the factor matrix obtained with `MatGetFactor()`
3297: . mat  - the matrix
3298: - info - options for factorization

3300:   Level: developer

3302:   Notes:
3303:   See `MatLUFactor()` for in-place factorization.  See
3304:   `MatCholeskyFactorNumeric()` for the symmetric, positive definite case.

3306:   Most users should employ the `KSP` interface for linear solvers
3307:   instead of working directly with matrix algebra routines such as this.
3308:   See, e.g., `KSPCreate()`.

3310:   Fortran Note:
3311:   A valid (non-null) `info` argument must be provided

3313: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactorSymbolic()`, `MatLUFactor()`, `MatCholeskyFactor()`
3314: @*/
3315: PetscErrorCode MatLUFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3316: {
3317:   MatFactorInfo tinfo;

3319:   PetscFunctionBegin;
3324:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3325:   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,
3326:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3328:   MatCheckPreallocated(mat, 2);
3329:   if (!info) {
3330:     PetscCall(MatFactorInfoInitialize(&tinfo));
3331:     info = &tinfo;
3332:   }

3334:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorNumeric, mat, fact, 0, 0));
3335:   else PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, fact, 0, 0));
3336:   PetscUseTypeMethod(fact, lufactornumeric, mat, info);
3337:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorNumeric, mat, fact, 0, 0));
3338:   else PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, fact, 0, 0));
3339:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3340:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3341:   PetscFunctionReturn(PETSC_SUCCESS);
3342: }

3344: /*@
3345:   MatCholeskyFactor - Performs in-place Cholesky factorization of a
3346:   symmetric matrix.

3348:   Collective

3350:   Input Parameters:
3351: + mat  - the matrix
3352: . perm - row and column permutations
3353: - info - expected fill as ratio of original fill

3355:   Level: developer

3357:   Notes:
3358:   See `MatLUFactor()` for the nonsymmetric case.  See also `MatGetFactor()`,
3359:   `MatCholeskyFactorSymbolic()`, and `MatCholeskyFactorNumeric()`.

3361:   Most users should employ the `KSP` interface for linear solvers
3362:   instead of working directly with matrix algebra routines such as this.
3363:   See, e.g., `KSPCreate()`.

3365:   Fortran Note:
3366:   A valid (non-null) `info` argument must be provided

3368: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactorNumeric()`
3369:           `MatGetOrdering()`
3370: @*/
3371: PetscErrorCode MatCholeskyFactor(Mat mat, IS perm, const MatFactorInfo *info)
3372: {
3373:   MatFactorInfo tinfo;

3375:   PetscFunctionBegin;
3378:   if (info) PetscAssertPointer(info, 3);
3380:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3381:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3382:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3383:   MatCheckPreallocated(mat, 1);
3384:   if (!info) {
3385:     PetscCall(MatFactorInfoInitialize(&tinfo));
3386:     info = &tinfo;
3387:   }

3389:   PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, perm, 0, 0));
3390:   PetscUseTypeMethod(mat, choleskyfactor, perm, info);
3391:   PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, perm, 0, 0));
3392:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3393:   PetscFunctionReturn(PETSC_SUCCESS);
3394: }

3396: /*@
3397:   MatCholeskyFactorSymbolic - Performs symbolic Cholesky factorization
3398:   of a symmetric matrix.

3400:   Collective

3402:   Input Parameters:
3403: + fact - the factor matrix obtained with `MatGetFactor()`
3404: . mat  - the matrix
3405: . perm - row and column permutations
3406: - info - options for factorization, includes
3407: .vb
3408:           fill - expected fill as ratio of original fill.
3409:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3410:                    Run with the option -info to determine an optimal value to use
3411: .ve

3413:   Level: developer

3415:   Notes:
3416:   See `MatLUFactorSymbolic()` for the nonsymmetric case.  See also
3417:   `MatCholeskyFactor()` and `MatCholeskyFactorNumeric()`.

3419:   Most users should employ the `KSP` interface for linear solvers
3420:   instead of working directly with matrix algebra routines such as this.
3421:   See, e.g., `KSPCreate()`.

3423:   Fortran Note:
3424:   A valid (non-null) `info` argument must be provided

3426: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactor()`, `MatCholeskyFactorNumeric()`
3427:           `MatGetOrdering()`
3428: @*/
3429: PetscErrorCode MatCholeskyFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
3430: {
3431:   MatFactorInfo tinfo;

3433:   PetscFunctionBegin;
3437:   if (info) PetscAssertPointer(info, 4);
3440:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3441:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3442:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3443:   MatCheckPreallocated(mat, 2);
3444:   if (!info) {
3445:     PetscCall(MatFactorInfoInitialize(&tinfo));
3446:     info = &tinfo;
3447:   }

3449:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3450:   PetscUseTypeMethod(fact, choleskyfactorsymbolic, mat, perm, info);
3451:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3452:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3453:   PetscFunctionReturn(PETSC_SUCCESS);
3454: }

3456: /*@
3457:   MatCholeskyFactorNumeric - Performs numeric Cholesky factorization
3458:   of a symmetric matrix. Call this routine after first calling `MatGetFactor()` and
3459:   `MatCholeskyFactorSymbolic()`.

3461:   Collective

3463:   Input Parameters:
3464: + fact - the factor matrix obtained with `MatGetFactor()`, where the factored values are stored
3465: . mat  - the initial matrix that is to be factored
3466: - info - options for factorization

3468:   Level: developer

3470:   Note:
3471:   Most users should employ the `KSP` interface for linear solvers
3472:   instead of working directly with matrix algebra routines such as this.
3473:   See, e.g., `KSPCreate()`.

3475:   Fortran Note:
3476:   A valid (non-null) `info` argument must be provided

3478: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactor()`, `MatLUFactorNumeric()`
3479: @*/
3480: PetscErrorCode MatCholeskyFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3481: {
3482:   MatFactorInfo tinfo;

3484:   PetscFunctionBegin;
3489:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3490:   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,
3491:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);
3492:   MatCheckPreallocated(mat, 2);
3493:   if (!info) {
3494:     PetscCall(MatFactorInfoInitialize(&tinfo));
3495:     info = &tinfo;
3496:   }

3498:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3499:   else PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, fact, 0, 0));
3500:   PetscUseTypeMethod(fact, choleskyfactornumeric, mat, info);
3501:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3502:   else PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, fact, 0, 0));
3503:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3504:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3505:   PetscFunctionReturn(PETSC_SUCCESS);
3506: }

3508: /*@
3509:   MatQRFactor - Performs in-place QR factorization of matrix.

3511:   Collective

3513:   Input Parameters:
3514: + mat  - the matrix
3515: . col  - column permutation
3516: - info - options for factorization, includes
3517: .vb
3518:           fill - expected fill as ratio of original fill.
3519:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3520:                    Run with the option -info to determine an optimal value to use
3521: .ve

3523:   Level: developer

3525:   Notes:
3526:   Most users should employ the `KSP` interface for linear solvers
3527:   instead of working directly with matrix algebra routines such as this.
3528:   See, e.g., `KSPCreate()`.

3530:   This changes the state of the matrix to a factored matrix; it cannot be used
3531:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3533:   Fortran Note:
3534:   A valid (non-null) `info` argument must be provided

3536: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactorSymbolic()`, `MatQRFactorNumeric()`, `MatLUFactor()`,
3537:           `MatSetUnfactored()`
3538: @*/
3539: PetscErrorCode MatQRFactor(Mat mat, IS col, const MatFactorInfo *info)
3540: {
3541:   PetscFunctionBegin;
3544:   if (info) PetscAssertPointer(info, 3);
3546:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3547:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3548:   MatCheckPreallocated(mat, 1);
3549:   PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, col, 0, 0));
3550:   PetscUseMethod(mat, "MatQRFactor_C", (Mat, IS, const MatFactorInfo *), (mat, col, info));
3551:   PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, col, 0, 0));
3552:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3553:   PetscFunctionReturn(PETSC_SUCCESS);
3554: }

3556: /*@
3557:   MatQRFactorSymbolic - Performs symbolic QR factorization of matrix.
3558:   Call this routine after `MatGetFactor()` but before calling `MatQRFactorNumeric()`.

3560:   Collective

3562:   Input Parameters:
3563: + fact - the factor matrix obtained with `MatGetFactor()`
3564: . mat  - the matrix
3565: . col  - column permutation
3566: - info - options for factorization, includes
3567: .vb
3568:           fill - expected fill as ratio of original fill.
3569:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3570:                    Run with the option -info to determine an optimal value to use
3571: .ve

3573:   Level: developer

3575:   Note:
3576:   Most users should employ the `KSP` interface for linear solvers
3577:   instead of working directly with matrix algebra routines such as this.
3578:   See, e.g., `KSPCreate()`.

3580:   Fortran Note:
3581:   A valid (non-null) `info` argument must be provided

3583: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatQRFactor()`, `MatQRFactorNumeric()`, `MatLUFactor()`, `MatFactorInfoInitialize()`
3584: @*/
3585: PetscErrorCode MatQRFactorSymbolic(Mat fact, Mat mat, IS col, const MatFactorInfo *info)
3586: {
3587:   MatFactorInfo tinfo;

3589:   PetscFunctionBegin;
3593:   if (info) PetscAssertPointer(info, 4);
3596:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3597:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3598:   MatCheckPreallocated(mat, 2);
3599:   if (!info) {
3600:     PetscCall(MatFactorInfoInitialize(&tinfo));
3601:     info = &tinfo;
3602:   }

3604:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorSymbolic, fact, mat, col, 0));
3605:   PetscUseMethod(fact, "MatQRFactorSymbolic_C", (Mat, Mat, IS, const MatFactorInfo *), (fact, mat, col, info));
3606:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorSymbolic, fact, mat, col, 0));
3607:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3608:   PetscFunctionReturn(PETSC_SUCCESS);
3609: }

3611: /*@
3612:   MatQRFactorNumeric - Performs numeric QR factorization of a matrix.
3613:   Call this routine after first calling `MatGetFactor()`, and `MatQRFactorSymbolic()`.

3615:   Collective

3617:   Input Parameters:
3618: + fact - the factor matrix obtained with `MatGetFactor()`
3619: . mat  - the matrix
3620: - info - options for factorization

3622:   Level: developer

3624:   Notes:
3625:   See `MatQRFactor()` for in-place factorization.

3627:   Most users should employ the `KSP` interface for linear solvers
3628:   instead of working directly with matrix algebra routines such as this.
3629:   See, e.g., `KSPCreate()`.

3631:   Fortran Note:
3632:   A valid (non-null) `info` argument must be provided

3634: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactor()`, `MatQRFactorSymbolic()`, `MatLUFactor()`
3635: @*/
3636: PetscErrorCode MatQRFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3637: {
3638:   MatFactorInfo tinfo;

3640:   PetscFunctionBegin;
3645:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3646:   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,
3647:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3649:   MatCheckPreallocated(mat, 2);
3650:   if (!info) {
3651:     PetscCall(MatFactorInfoInitialize(&tinfo));
3652:     info = &tinfo;
3653:   }

3655:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorNumeric, mat, fact, 0, 0));
3656:   else PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, fact, 0, 0));
3657:   PetscUseMethod(fact, "MatQRFactorNumeric_C", (Mat, Mat, const MatFactorInfo *), (fact, mat, info));
3658:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorNumeric, mat, fact, 0, 0));
3659:   else PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, fact, 0, 0));
3660:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3661:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3662:   PetscFunctionReturn(PETSC_SUCCESS);
3663: }

3665: /*@
3666:   MatSolve - Solves $A x = b$, given a factored matrix.

3668:   Neighbor-wise Collective

3670:   Input Parameters:
3671: + mat - the factored matrix
3672: - b   - the right-hand-side vector

3674:   Output Parameter:
3675: . x - the result vector

3677:   Level: developer

3679:   Notes:
3680:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3681:   call `MatSolve`(A,x,x).

3683:   Most users should employ the `KSP` interface for linear solvers
3684:   instead of working directly with matrix algebra routines such as this.
3685:   See, e.g., `KSPCreate()`.

3687: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
3688: @*/
3689: PetscErrorCode MatSolve(Mat mat, Vec b, Vec x)
3690: {
3691:   PetscFunctionBegin;
3696:   PetscCheckSameComm(mat, 1, b, 2);
3697:   PetscCheckSameComm(mat, 1, x, 3);
3698:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3699:   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);
3700:   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);
3701:   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);
3702:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3703:   MatCheckPreallocated(mat, 1);

3705:   PetscCall(PetscLogEventBegin(MAT_Solve, mat, b, x, 0));
3706:   PetscCall(VecFlag(x, mat->factorerrortype));
3707:   if (mat->factorerrortype) PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
3708:   else PetscUseTypeMethod(mat, solve, b, x);
3709:   PetscCall(PetscLogEventEnd(MAT_Solve, mat, b, x, 0));
3710:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3711:   PetscFunctionReturn(PETSC_SUCCESS);
3712: }

3714: static PetscErrorCode MatMatSolve_Basic(Mat A, Mat B, Mat X, PetscBool trans)
3715: {
3716:   Vec      b, x;
3717:   PetscInt N, i;
3718:   PetscErrorCode (*f)(Mat, Vec, Vec);
3719:   PetscBool Abound, Bneedconv = PETSC_FALSE, Xneedconv = PETSC_FALSE;

3721:   PetscFunctionBegin;
3722:   if (A->factorerrortype) {
3723:     PetscCall(PetscInfo(A, "MatFactorError %d\n", A->factorerrortype));
3724:     PetscCall(MatSetInf(X));
3725:     PetscFunctionReturn(PETSC_SUCCESS);
3726:   }
3727:   f = (!trans || (!A->ops->solvetranspose && A->symmetric)) ? A->ops->solve : A->ops->solvetranspose;
3728:   PetscCheck(f, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)A)->type_name);
3729:   PetscCall(MatBoundToCPU(A, &Abound));
3730:   if (!Abound) {
3731:     PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &Bneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3732:     PetscCall(PetscObjectTypeCompareAny((PetscObject)X, &Xneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3733:   }
3734: #if PetscDefined(HAVE_CUDA)
3735:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSECUDA, MAT_INPLACE_MATRIX, &B));
3736:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSECUDA, MAT_INPLACE_MATRIX, &X));
3737: #elif PetscDefined(HAVE_HIP)
3738:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSEHIP, MAT_INPLACE_MATRIX, &B));
3739:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSEHIP, MAT_INPLACE_MATRIX, &X));
3740: #endif
3741:   PetscCall(MatGetSize(B, NULL, &N));
3742:   for (i = 0; i < N; i++) {
3743:     PetscCall(MatDenseGetColumnVecRead(B, i, &b));
3744:     PetscCall(MatDenseGetColumnVecWrite(X, i, &x));
3745:     PetscCall((*f)(A, b, x));
3746:     PetscCall(MatDenseRestoreColumnVecWrite(X, i, &x));
3747:     PetscCall(MatDenseRestoreColumnVecRead(B, i, &b));
3748:   }
3749:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSE, MAT_INPLACE_MATRIX, &B));
3750:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSE, MAT_INPLACE_MATRIX, &X));
3751:   PetscFunctionReturn(PETSC_SUCCESS);
3752: }

3754: /*@
3755:   MatMatSolve - Solves $A X = B$, given a factored matrix.

3757:   Neighbor-wise Collective

3759:   Input Parameters:
3760: + A - the factored matrix
3761: - B - the right-hand-side matrix `MATDENSE` (or sparse `MATAIJ`-- when using MUMPS)

3763:   Output Parameter:
3764: . X - the result matrix (dense matrix)

3766:   Level: developer

3768:   Note:
3769:   If `B` is a `MATDENSE` matrix then one can call `MatMatSolve`(A,B,B) except with `MATSOLVERMKL_CPARDISO`;
3770:   otherwise, `B` and `X` cannot be the same.

3772: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3773: @*/
3774: PetscErrorCode MatMatSolve(Mat A, Mat B, Mat X)
3775: {
3776:   PetscFunctionBegin;
3781:   PetscCheckSameComm(A, 1, B, 2);
3782:   PetscCheckSameComm(A, 1, X, 3);
3783:   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);
3784:   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);
3785:   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");
3786:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3787:   MatCheckPreallocated(A, 1);

3789:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3790:   if (!A->ops->matsolve) {
3791:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolve\n", ((PetscObject)A)->type_name));
3792:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_FALSE));
3793:   } else PetscUseTypeMethod(A, matsolve, B, X);
3794:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3795:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3796:   PetscFunctionReturn(PETSC_SUCCESS);
3797: }

3799: /*@
3800:   MatMatSolveTranspose - Solves $A^T X = B $, given a factored matrix.

3802:   Neighbor-wise Collective

3804:   Input Parameters:
3805: + A - the factored matrix
3806: - B - the right-hand-side matrix  (`MATDENSE` matrix)

3808:   Output Parameter:
3809: . X - the result matrix (dense matrix)

3811:   Level: developer

3813:   Note:
3814:   The matrices `B` and `X` cannot be the same.  I.e., one cannot
3815:   call `MatMatSolveTranspose`(A,X,X).

3817: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolveTranspose()`, `MatMatSolve()`, `MatLUFactor()`, `MatCholeskyFactor()`
3818: @*/
3819: PetscErrorCode MatMatSolveTranspose(Mat A, Mat B, Mat X)
3820: {
3821:   PetscFunctionBegin;
3826:   PetscCheckSameComm(A, 1, B, 2);
3827:   PetscCheckSameComm(A, 1, X, 3);
3828:   PetscCheck(X != B, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3829:   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);
3830:   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);
3831:   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);
3832:   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");
3833:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3834:   MatCheckPreallocated(A, 1);

3836:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3837:   if (!A->ops->matsolvetranspose) {
3838:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolveTranspose\n", ((PetscObject)A)->type_name));
3839:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_TRUE));
3840:   } else PetscUseTypeMethod(A, matsolvetranspose, B, X);
3841:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3842:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3843:   PetscFunctionReturn(PETSC_SUCCESS);
3844: }

3846: /*@
3847:   MatMatTransposeSolve - Solves $A X = B^T$, given a factored matrix.

3849:   Neighbor-wise Collective

3851:   Input Parameters:
3852: + A  - the factored matrix
3853: - Bt - the transpose of right-hand-side matrix as a `MATDENSE`

3855:   Output Parameter:
3856: . X - the result matrix (dense matrix)

3858:   Level: developer

3860:   Note:
3861:   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
3862:   format on the host processor and call `MatMatTransposeSolve()` to implement MUMPS' `MatMatSolve()`.

3864: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatMatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3865: @*/
3866: PetscErrorCode MatMatTransposeSolve(Mat A, Mat Bt, Mat X)
3867: {
3868:   PetscFunctionBegin;
3873:   PetscCheckSameComm(A, 1, Bt, 2);
3874:   PetscCheckSameComm(A, 1, X, 3);

3876:   PetscCheck(X != Bt, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3877:   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);
3878:   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);
3879:   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");
3880:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3881:   PetscCheck(A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
3882:   MatCheckPreallocated(A, 1);

3884:   PetscCall(PetscLogEventBegin(MAT_MatTrSolve, A, Bt, X, 0));
3885:   PetscUseTypeMethod(A, mattransposesolve, Bt, X);
3886:   PetscCall(PetscLogEventEnd(MAT_MatTrSolve, A, Bt, X, 0));
3887:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3888:   PetscFunctionReturn(PETSC_SUCCESS);
3889: }

3891: /*@
3892:   MatForwardSolve - Solves $ L x = b $, given a factored matrix, $A = LU $, or
3893:   $U^T*D^(1/2) x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3895:   Neighbor-wise Collective

3897:   Input Parameters:
3898: + mat - the factored matrix
3899: - b   - the right-hand-side vector

3901:   Output Parameter:
3902: . x - the result vector

3904:   Level: developer

3906:   Notes:
3907:   `MatSolve()` should be used for most applications, as it performs
3908:   a forward solve followed by a backward solve.

3910:   The vectors `b` and `x` cannot be the same,  i.e., one cannot
3911:   call `MatForwardSolve`(A,x,x).

3913:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
3914:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
3915:   `MatForwardSolve()` solves $U^T*D y = b$, and
3916:   `MatBackwardSolve()` solves $U x = y$.
3917:   Thus they do not provide a symmetric preconditioner.

3919: .seealso: [](ch_matrices), `Mat`, `MatBackwardSolve()`, `MatGetFactor()`, `MatSolve()`
3920: @*/
3921: PetscErrorCode MatForwardSolve(Mat mat, Vec b, Vec x)
3922: {
3923:   PetscFunctionBegin;
3928:   PetscCheckSameComm(mat, 1, b, 2);
3929:   PetscCheckSameComm(mat, 1, x, 3);
3930:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3931:   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);
3932:   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);
3933:   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);
3934:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3935:   MatCheckPreallocated(mat, 1);

3937:   PetscCall(PetscLogEventBegin(MAT_ForwardSolve, mat, b, x, 0));
3938:   PetscUseTypeMethod(mat, forwardsolve, b, x);
3939:   PetscCall(PetscLogEventEnd(MAT_ForwardSolve, mat, b, x, 0));
3940:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3941:   PetscFunctionReturn(PETSC_SUCCESS);
3942: }

3944: /*@
3945:   MatBackwardSolve - Solves $U x = b$, given a factored matrix, $A = LU$.
3946:   $D^(1/2) U x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3948:   Neighbor-wise Collective

3950:   Input Parameters:
3951: + mat - the factored matrix
3952: - b   - the right-hand-side vector

3954:   Output Parameter:
3955: . x - the result vector

3957:   Level: developer

3959:   Notes:
3960:   `MatSolve()` should be used for most applications, as it performs
3961:   a forward solve followed by a backward solve.

3963:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3964:   call `MatBackwardSolve`(A,x,x).

3966:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
3967:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
3968:   `MatForwardSolve()` solves $U^T*D y = b$, and
3969:   `MatBackwardSolve()` solves $U x = y$.
3970:   Thus they do not provide a symmetric preconditioner.

3972: .seealso: [](ch_matrices), `Mat`, `MatForwardSolve()`, `MatGetFactor()`, `MatSolve()`
3973: @*/
3974: PetscErrorCode MatBackwardSolve(Mat mat, Vec b, Vec x)
3975: {
3976:   PetscFunctionBegin;
3981:   PetscCheckSameComm(mat, 1, b, 2);
3982:   PetscCheckSameComm(mat, 1, x, 3);
3983:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3984:   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);
3985:   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);
3986:   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);
3987:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3988:   MatCheckPreallocated(mat, 1);

3990:   PetscCall(PetscLogEventBegin(MAT_BackwardSolve, mat, b, x, 0));
3991:   PetscUseTypeMethod(mat, backwardsolve, b, x);
3992:   PetscCall(PetscLogEventEnd(MAT_BackwardSolve, mat, b, x, 0));
3993:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3994:   PetscFunctionReturn(PETSC_SUCCESS);
3995: }

3997: /*@
3998:   MatSolveAdd - Computes $x = y + A^{-1}*b$, given a factored matrix.

4000:   Neighbor-wise Collective

4002:   Input Parameters:
4003: + mat - the factored matrix
4004: . b   - the right-hand-side vector
4005: - y   - the vector to be added to

4007:   Output Parameter:
4008: . x - the result vector

4010:   Level: developer

4012:   Note:
4013:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4014:   call `MatSolveAdd`(A,x,y,x).

4016: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolve()`, `MatGetFactor()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
4017: @*/
4018: PetscErrorCode MatSolveAdd(Mat mat, Vec b, Vec y, Vec x)
4019: {
4020:   PetscScalar one = 1.0;
4021:   Vec         tmp;

4023:   PetscFunctionBegin;
4029:   PetscCheckSameComm(mat, 1, b, 2);
4030:   PetscCheckSameComm(mat, 1, y, 3);
4031:   PetscCheckSameComm(mat, 1, x, 4);
4032:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4033:   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);
4034:   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);
4035:   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);
4036:   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);
4037:   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);
4038:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4039:   MatCheckPreallocated(mat, 1);

4041:   PetscCall(PetscLogEventBegin(MAT_SolveAdd, mat, b, x, y));
4042:   PetscCall(VecFlag(x, mat->factorerrortype));
4043:   if (mat->factorerrortype) {
4044:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4045:   } else if (mat->ops->solveadd) {
4046:     PetscUseTypeMethod(mat, solveadd, b, y, x);
4047:   } else {
4048:     /* do the solve then the add manually */
4049:     if (x != y) {
4050:       PetscCall(MatSolve(mat, b, x));
4051:       PetscCall(VecAXPY(x, one, y));
4052:     } else {
4053:       PetscCall(VecDuplicate(x, &tmp));
4054:       PetscCall(VecCopy(x, tmp));
4055:       PetscCall(MatSolve(mat, b, x));
4056:       PetscCall(VecAXPY(x, one, tmp));
4057:       PetscCall(VecDestroy(&tmp));
4058:     }
4059:   }
4060:   PetscCall(PetscLogEventEnd(MAT_SolveAdd, mat, b, x, y));
4061:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4062:   PetscFunctionReturn(PETSC_SUCCESS);
4063: }

4065: /*@
4066:   MatSolveTranspose - Solves $A^T x = b$, given a factored matrix.

4068:   Neighbor-wise Collective

4070:   Input Parameters:
4071: + mat - the factored matrix
4072: - b   - the right-hand-side vector

4074:   Output Parameter:
4075: . x - the result vector

4077:   Level: developer

4079:   Notes:
4080:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4081:   call `MatSolveTranspose`(A,x,x).

4083:   Most users should employ the `KSP` interface for linear solvers
4084:   instead of working directly with matrix algebra routines such as this.
4085:   See, e.g., `KSPCreate()`.

4087: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `KSP`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTransposeAdd()`
4088: @*/
4089: PetscErrorCode MatSolveTranspose(Mat mat, Vec b, Vec x)
4090: {
4091:   PetscErrorCode (*f)(Mat, Vec, Vec) = (!mat->ops->solvetranspose && mat->symmetric) ? mat->ops->solve : mat->ops->solvetranspose;

4093:   PetscFunctionBegin;
4098:   PetscCheckSameComm(mat, 1, b, 2);
4099:   PetscCheckSameComm(mat, 1, x, 3);
4100:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4101:   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);
4102:   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);
4103:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4104:   MatCheckPreallocated(mat, 1);
4105:   PetscCall(PetscLogEventBegin(MAT_SolveTranspose, mat, b, x, 0));
4106:   PetscCall(VecFlag(x, mat->factorerrortype));
4107:   if (mat->factorerrortype) {
4108:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4109:   } else {
4110:     PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Matrix type %s", ((PetscObject)mat)->type_name);
4111:     PetscCall((*f)(mat, b, x));
4112:   }
4113:   PetscCall(PetscLogEventEnd(MAT_SolveTranspose, mat, b, x, 0));
4114:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4115:   PetscFunctionReturn(PETSC_SUCCESS);
4116: }

4118: /*@
4119:   MatSolveTransposeAdd - Computes $x = y + A^{-T} b$
4120:   factored matrix.

4122:   Neighbor-wise Collective

4124:   Input Parameters:
4125: + mat - the factored matrix
4126: . b   - the right-hand-side vector
4127: - y   - the vector to be added to

4129:   Output Parameter:
4130: . x - the result vector

4132:   Level: developer

4134:   Note:
4135:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4136:   call `MatSolveTransposeAdd`(A,x,y,x).

4138: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTranspose()`
4139: @*/
4140: PetscErrorCode MatSolveTransposeAdd(Mat mat, Vec b, Vec y, Vec x)
4141: {
4142:   PetscScalar one = 1.0;
4143:   Vec         tmp;
4144:   PetscErrorCode (*f)(Mat, Vec, Vec, Vec) = (!mat->ops->solvetransposeadd && mat->symmetric) ? mat->ops->solveadd : mat->ops->solvetransposeadd;

4146:   PetscFunctionBegin;
4152:   PetscCheckSameComm(mat, 1, b, 2);
4153:   PetscCheckSameComm(mat, 1, y, 3);
4154:   PetscCheckSameComm(mat, 1, x, 4);
4155:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4156:   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);
4157:   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);
4158:   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);
4159:   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);
4160:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4161:   MatCheckPreallocated(mat, 1);

4163:   PetscCall(PetscLogEventBegin(MAT_SolveTransposeAdd, mat, b, x, y));
4164:   PetscCall(VecFlag(x, mat->factorerrortype));
4165:   if (mat->factorerrortype) {
4166:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4167:   } else if (f) {
4168:     PetscCall((*f)(mat, b, y, x));
4169:   } else {
4170:     /* do the solve then the add manually */
4171:     if (x != y) {
4172:       PetscCall(MatSolveTranspose(mat, b, x));
4173:       PetscCall(VecAXPY(x, one, y));
4174:     } else {
4175:       PetscCall(VecDuplicate(x, &tmp));
4176:       PetscCall(VecCopy(x, tmp));
4177:       PetscCall(MatSolveTranspose(mat, b, x));
4178:       PetscCall(VecAXPY(x, one, tmp));
4179:       PetscCall(VecDestroy(&tmp));
4180:     }
4181:   }
4182:   PetscCall(PetscLogEventEnd(MAT_SolveTransposeAdd, mat, b, x, y));
4183:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4184:   PetscFunctionReturn(PETSC_SUCCESS);
4185: }

4187: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
4188: /*@
4189:   MatSOR - Computes relaxation (SOR, Gauss-Seidel) sweeps.

4191:   Neighbor-wise Collective

4193:   Input Parameters:
4194: + mat   - the matrix
4195: . b     - the right-hand side
4196: . omega - the relaxation factor
4197: . flag  - flag indicating the type of SOR (see below)
4198: . shift - diagonal shift
4199: . its   - the number of iterations
4200: - lits  - the number of local iterations

4202:   Output Parameter:
4203: . x - the solution (can contain an initial guess, use option `SOR_ZERO_INITIAL_GUESS` to indicate no guess)

4205:   SOR Flags:
4206: +     `SOR_FORWARD_SWEEP` - forward SOR
4207: .     `SOR_BACKWARD_SWEEP` - backward SOR
4208: .     `SOR_SYMMETRIC_SWEEP` - SSOR (symmetric SOR)
4209: .     `SOR_LOCAL_FORWARD_SWEEP` - local forward SOR
4210: .     `SOR_LOCAL_BACKWARD_SWEEP` - local forward SOR
4211: .     `SOR_LOCAL_SYMMETRIC_SWEEP` - local SSOR
4212: .     `SOR_EISENSTAT` - SOR with Eisenstat trick
4213: .     `SOR_APPLY_UPPER`, `SOR_APPLY_LOWER` - applies upper/lower triangular part of matrix to vector (with `omega`)
4214: -     `SOR_ZERO_INITIAL_GUESS` - zero initial guess

4216:   Level: developer

4218:   Notes:
4219:   `SOR_LOCAL_FORWARD_SWEEP`, `SOR_LOCAL_BACKWARD_SWEEP`, and
4220:   `SOR_LOCAL_SYMMETRIC_SWEEP` perform separate independent smoothings
4221:   on each processor.

4223:   Application programmers will not generally use `MatSOR()` directly,
4224:   but instead will employ `PCSOR` or `PCEISENSTAT`

4226:   For `MATBAIJ`, `MATSBAIJ`, and `MATAIJ` matrices with inodes, this does a block SOR smoothing, otherwise it does a pointwise smoothing.
4227:   For `MATAIJ` matrices with inodes, the block sizes are determined by the inode sizes, not the block size set with `MatSetBlockSize()`

4229:   Vectors `x` and `b` CANNOT be the same

4231:   The flags are implemented as bitwise inclusive or operations.
4232:   For example, use (`SOR_ZERO_INITIAL_GUESS` | `SOR_SYMMETRIC_SWEEP`)
4233:   to specify a zero initial guess for SSOR.

4235:   Developer Note:
4236:   We should add block SOR support for `MATAIJ` matrices with block size set to greater than one and no inodes

4238: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `KSP`, `PC`, `MatGetFactor()`
4239: @*/
4240: PetscErrorCode MatSOR(Mat mat, Vec b, PetscReal omega, MatSORType flag, PetscReal shift, PetscInt its, PetscInt lits, Vec x)
4241: {
4242:   PetscFunctionBegin;
4247:   PetscCheckSameComm(mat, 1, b, 2);
4248:   PetscCheckSameComm(mat, 1, x, 8);
4249:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4250:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4251:   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);
4252:   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);
4253:   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);
4254:   PetscCheck(its > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires global its %" PetscInt_FMT " positive", its);
4255:   PetscCheck(lits > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires local its %" PetscInt_FMT " positive", lits);
4256:   PetscCheck(b != x, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "b and x vector cannot be the same");

4258:   MatCheckPreallocated(mat, 1);
4259:   PetscCall(PetscLogEventBegin(MAT_SOR, mat, b, x, 0));
4260:   PetscUseTypeMethod(mat, sor, b, omega, flag, shift, its, lits, x);
4261:   PetscCall(PetscLogEventEnd(MAT_SOR, mat, b, x, 0));
4262:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4263:   PetscFunctionReturn(PETSC_SUCCESS);
4264: }

4266: /*
4267:       Default matrix copy routine.
4268: */
4269: PetscErrorCode MatCopy_Basic(Mat A, Mat B, MatStructure str)
4270: {
4271:   PetscInt           i, rstart = 0, rend = 0, nz;
4272:   const PetscInt    *cwork;
4273:   const PetscScalar *vwork;

4275:   PetscFunctionBegin;
4276:   if (B->assembled) PetscCall(MatZeroEntries(B));
4277:   if (str == SAME_NONZERO_PATTERN) {
4278:     PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
4279:     for (i = rstart; i < rend; i++) {
4280:       PetscCall(MatGetRow(A, i, &nz, &cwork, &vwork));
4281:       PetscCall(MatSetValues(B, 1, &i, nz, cwork, vwork, INSERT_VALUES));
4282:       PetscCall(MatRestoreRow(A, i, &nz, &cwork, &vwork));
4283:     }
4284:   } else {
4285:     PetscCall(MatAYPX(B, 0.0, A, str));
4286:   }
4287:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4288:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4289:   PetscFunctionReturn(PETSC_SUCCESS);
4290: }

4292: /*@
4293:   MatCopy - Copies a matrix to another matrix.

4295:   Collective

4297:   Input Parameters:
4298: + A   - the matrix
4299: - str - `SAME_NONZERO_PATTERN` or `DIFFERENT_NONZERO_PATTERN`

4301:   Output Parameter:
4302: . B - where the copy is put

4304:   Level: intermediate

4306:   Notes:
4307:   If you use `SAME_NONZERO_PATTERN`, then the two matrices must have the same nonzero pattern or the routine will crash.

4309:   `MatCopy()` copies the matrix entries of a matrix to another existing
4310:   matrix (after first zeroing the second matrix).  A related routine is
4311:   `MatConvert()`, which first creates a new matrix and then copies the data.

4313: .seealso: [](ch_matrices), `Mat`, `MatConvert()`, `MatDuplicate()`
4314: @*/
4315: PetscErrorCode MatCopy(Mat A, Mat B, MatStructure str)
4316: {
4317:   PetscInt i;

4319:   PetscFunctionBegin;
4324:   PetscCheckSameComm(A, 1, B, 2);
4325:   MatCheckPreallocated(B, 2);
4326:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4327:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4328:   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,
4329:              A->cmap->N, B->cmap->N);
4330:   MatCheckPreallocated(A, 1);
4331:   if (A == B) PetscFunctionReturn(PETSC_SUCCESS);

4333:   PetscCall(PetscLogEventBegin(MAT_Copy, A, B, 0, 0));
4334:   if (A->ops->copy) PetscUseTypeMethod(A, copy, B, str);
4335:   else PetscCall(MatCopy_Basic(A, B, str));

4337:   B->stencil.dim = A->stencil.dim;
4338:   B->stencil.noc = A->stencil.noc;
4339:   for (i = 0; i <= A->stencil.dim + (A->stencil.noc ? 0 : -1); i++) {
4340:     B->stencil.dims[i]   = A->stencil.dims[i];
4341:     B->stencil.starts[i] = A->stencil.starts[i];
4342:   }

4344:   PetscCall(PetscLogEventEnd(MAT_Copy, A, B, 0, 0));
4345:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
4346:   PetscFunctionReturn(PETSC_SUCCESS);
4347: }

4349: /*@
4350:   MatConvert - Converts a matrix to another matrix, either of the same
4351:   or different type.

4353:   Collective

4355:   Input Parameters:
4356: + mat     - the matrix
4357: . newtype - new matrix type.  Use `MATSAME` to create a new matrix of the
4358:             same type as the original matrix.
4359: - reuse   - denotes if the destination matrix is to be created or reused.
4360:             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
4361:             `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).

4363:   Output Parameter:
4364: . M - pointer to place new matrix

4366:   Level: intermediate

4368:   Notes:
4369:   `MatConvert()` first creates a new matrix and then copies the data from
4370:   the first matrix.  A related routine is `MatCopy()`, which copies the matrix
4371:   entries of one matrix to another already existing matrix context.

4373:   Cannot be used to convert a sequential matrix to parallel or parallel to sequential,
4374:   the MPI communicator of the generated matrix is always the same as the communicator
4375:   of the input matrix.

4377: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatDuplicate()`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
4378: @*/
4379: PetscErrorCode MatConvert(Mat mat, MatType newtype, MatReuse reuse, Mat *M)
4380: {
4381:   PetscBool  sametype, issame, flg;
4382:   PetscBool3 issymmetric, ishermitian;
4383:   char       convname[256], mtype[256];
4384:   Mat        B;

4386:   PetscFunctionBegin;
4389:   PetscAssertPointer(M, 4);
4390:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4391:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4392:   MatCheckPreallocated(mat, 1);

4394:   PetscCall(PetscOptionsGetString(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matconvert_type", mtype, sizeof(mtype), &flg));
4395:   if (flg) newtype = mtype;

4397:   PetscCall(PetscObjectTypeCompare((PetscObject)mat, newtype, &sametype));
4398:   PetscCall(PetscStrcmp(newtype, "same", &issame));
4399:   PetscCheck(!(reuse == MAT_INPLACE_MATRIX) || !(mat != *M), PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires same input and output matrix");
4400:   if (reuse == MAT_REUSE_MATRIX) {
4402:     PetscCheck(mat != *M, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_REUSE_MATRIX means reuse matrix in final argument, perhaps you mean MAT_INPLACE_MATRIX");
4403:   }

4405:   if ((reuse == MAT_INPLACE_MATRIX) && (issame || sametype)) {
4406:     PetscCall(PetscInfo(mat, "Early return for inplace %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4407:     PetscFunctionReturn(PETSC_SUCCESS);
4408:   }

4410:   /* Cache Mat options because some converters use MatHeaderReplace  */
4411:   issymmetric = mat->symmetric;
4412:   ishermitian = mat->hermitian;

4414:   if ((sametype || issame) && (reuse == MAT_INITIAL_MATRIX) && mat->ops->duplicate) {
4415:     PetscCall(PetscInfo(mat, "Calling duplicate for initial matrix %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4416:     PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4417:   } else {
4418:     PetscErrorCode (*conv)(Mat, MatType, MatReuse, Mat *) = NULL;
4419:     const char *prefix[3]                                 = {"seq", "mpi", ""};
4420:     PetscInt    i;
4421:     /*
4422:        Order of precedence:
4423:        0) See if newtype is a superclass of the current matrix.
4424:        1) See if a specialized converter is known to the current matrix.
4425:        2) See if a specialized converter is known to the desired matrix class.
4426:        3) See if a good general converter is registered for the desired class
4427:           (as of 6/27/03 only MATMPIADJ falls into this category).
4428:        4) See if a good general converter is known for the current matrix.
4429:        5) Use a really basic converter.
4430:     */

4432:     /* 0) See if newtype is a superclass of the current matrix.
4433:           i.e mat is mpiaij and newtype is aij */
4434:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4435:       PetscCall(PetscStrncpy(convname, prefix[i], sizeof(convname)));
4436:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4437:       PetscCall(PetscStrcmp(convname, ((PetscObject)mat)->type_name, &flg));
4438:       PetscCall(PetscInfo(mat, "Check superclass %s %s -> %d\n", convname, ((PetscObject)mat)->type_name, flg));
4439:       if (flg) {
4440:         if (reuse == MAT_INPLACE_MATRIX) {
4441:           PetscCall(PetscInfo(mat, "Early return\n"));
4442:           PetscFunctionReturn(PETSC_SUCCESS);
4443:         } else if (reuse == MAT_INITIAL_MATRIX && mat->ops->duplicate) {
4444:           PetscCall(PetscInfo(mat, "Calling MatDuplicate\n"));
4445:           PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4446:           PetscFunctionReturn(PETSC_SUCCESS);
4447:         } else if (reuse == MAT_REUSE_MATRIX && mat->ops->copy) {
4448:           PetscCall(PetscInfo(mat, "Calling MatCopy\n"));
4449:           PetscCall(MatCopy(mat, *M, SAME_NONZERO_PATTERN));
4450:           PetscFunctionReturn(PETSC_SUCCESS);
4451:         }
4452:       }
4453:     }
4454:     /* 1) See if a specialized converter is known to the current matrix and the desired class */
4455:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4456:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4457:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4458:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4459:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4460:       PetscCall(PetscStrlcat(convname, issame ? ((PetscObject)mat)->type_name : newtype, sizeof(convname)));
4461:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4462:       PetscCall(PetscObjectQueryFunction((PetscObject)mat, convname, &conv));
4463:       PetscCall(PetscInfo(mat, "Check specialized (1) %s (%s) -> %d\n", convname, ((PetscObject)mat)->type_name, !!conv));
4464:       if (conv) goto foundconv;
4465:     }

4467:     /* 2)  See if a specialized converter is known to the desired matrix class. */
4468:     PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &B));
4469:     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
4470:     PetscCall(MatSetType(B, newtype));
4471:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4472:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4473:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4474:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4475:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4476:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4477:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4478:       PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
4479:       PetscCall(PetscInfo(mat, "Check specialized (2) %s (%s) -> %d\n", convname, ((PetscObject)B)->type_name, !!conv));
4480:       if (conv) {
4481:         PetscCall(MatDestroy(&B));
4482:         goto foundconv;
4483:       }
4484:     }

4486:     /* 3) See if a good general converter is registered for the desired class */
4487:     conv = B->ops->convertfrom;
4488:     PetscCall(PetscInfo(mat, "Check convertfrom (%s) -> %d\n", ((PetscObject)B)->type_name, !!conv));
4489:     PetscCall(MatDestroy(&B));
4490:     if (conv) goto foundconv;

4492:     /* 4) See if a good general converter is known for the current matrix */
4493:     if (mat->ops->convert) conv = mat->ops->convert;
4494:     PetscCall(PetscInfo(mat, "Check general convert (%s) -> %d\n", ((PetscObject)mat)->type_name, !!conv));
4495:     if (conv) goto foundconv;

4497:     /* 5) Use a really basic converter. */
4498:     PetscCall(PetscInfo(mat, "Using MatConvert_Basic\n"));
4499:     conv = MatConvert_Basic;

4501:   foundconv:
4502:     PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4503:     PetscCall((*conv)(mat, newtype, reuse, M));
4504:     if (mat->rmap->mapping && mat->cmap->mapping && !(*M)->rmap->mapping && !(*M)->cmap->mapping) {
4505:       /* the block sizes must be same if the mappings are copied over */
4506:       (*M)->rmap->bs = mat->rmap->bs;
4507:       (*M)->cmap->bs = mat->cmap->bs;
4508:       PetscCall(PetscObjectReference((PetscObject)mat->rmap->mapping));
4509:       PetscCall(PetscObjectReference((PetscObject)mat->cmap->mapping));
4510:       (*M)->rmap->mapping = mat->rmap->mapping;
4511:       (*M)->cmap->mapping = mat->cmap->mapping;
4512:     }
4513:     (*M)->stencil.dim = mat->stencil.dim;
4514:     (*M)->stencil.noc = mat->stencil.noc;
4515:     for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4516:       (*M)->stencil.dims[i]   = mat->stencil.dims[i];
4517:       (*M)->stencil.starts[i] = mat->stencil.starts[i];
4518:     }
4519:     PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4520:   }
4521:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));

4523:   /* Copy Mat options */
4524:   if (issymmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PETSC_TRUE));
4525:   else if (issymmetric == PETSC_BOOL3_FALSE) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PETSC_FALSE));
4526:   if (ishermitian == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PETSC_TRUE));
4527:   else if (ishermitian == PETSC_BOOL3_FALSE) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PETSC_FALSE));
4528:   PetscFunctionReturn(PETSC_SUCCESS);
4529: }

4531: /*@
4532:   MatFactorGetSolverType - Returns name of the package providing the factorization routines

4534:   Not Collective

4536:   Input Parameter:
4537: . mat - the matrix, must be a factored matrix

4539:   Output Parameter:
4540: . type - the string name of the package (do not free this string)

4542:   Level: intermediate

4544: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolverType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`
4545: @*/
4546: PetscErrorCode MatFactorGetSolverType(Mat mat, MatSolverType *type)
4547: {
4548:   PetscErrorCode (*conv)(Mat, MatSolverType *);

4550:   PetscFunctionBegin;
4553:   PetscAssertPointer(type, 2);
4554:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
4555:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorGetSolverType_C", &conv));
4556:   if (conv) PetscCall((*conv)(mat, type));
4557:   else *type = MATSOLVERPETSC;
4558:   PetscFunctionReturn(PETSC_SUCCESS);
4559: }

4561: typedef struct _MatSolverTypeForSpecifcType *MatSolverTypeForSpecifcType;
4562: struct _MatSolverTypeForSpecifcType {
4563:   MatType mtype;
4564:   /* no entry for MAT_FACTOR_NONE */
4565:   PetscErrorCode (*createfactor[MAT_FACTOR_NUM_TYPES - 1])(Mat, MatFactorType, Mat *);
4566:   MatSolverTypeForSpecifcType next;
4567: };

4569: typedef struct _MatSolverTypeHolder *MatSolverTypeHolder;
4570: struct _MatSolverTypeHolder {
4571:   char                       *name;
4572:   MatSolverTypeForSpecifcType handlers;
4573:   MatSolverTypeHolder         next;
4574: };

4576: static MatSolverTypeHolder MatSolverTypeHolders = NULL;

4578: /*@C
4579:   MatSolverTypeRegister - Registers a `MatSolverType` that works for a particular matrix type

4581:   Logically Collective, No Fortran Support

4583:   Input Parameters:
4584: + package      - name of the package, for example `petsc` or `superlu`
4585: . mtype        - the matrix type that works with this package
4586: . ftype        - the type of factorization supported by the package
4587: - createfactor - routine that will create the factored matrix ready to be used

4589:   Level: developer

4591: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorGetSolverType()`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`,
4592:   `MatGetFactor()`
4593: @*/
4594: PetscErrorCode MatSolverTypeRegister(MatSolverType package, MatType mtype, MatFactorType ftype, PetscErrorCode (*createfactor)(Mat, MatFactorType, Mat *))
4595: {
4596:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev = NULL;
4597:   PetscBool                   flg;
4598:   MatSolverTypeForSpecifcType inext, iprev = NULL;

4600:   PetscFunctionBegin;
4601:   PetscCall(MatInitializePackage());
4602:   if (!next) {
4603:     PetscCall(PetscNew(&MatSolverTypeHolders));
4604:     PetscCall(PetscStrallocpy(package, &MatSolverTypeHolders->name));
4605:     PetscCall(PetscNew(&MatSolverTypeHolders->handlers));
4606:     PetscCall(PetscStrallocpy(mtype, (char **)&MatSolverTypeHolders->handlers->mtype));
4607:     MatSolverTypeHolders->handlers->createfactor[(int)ftype - 1] = createfactor;
4608:     PetscFunctionReturn(PETSC_SUCCESS);
4609:   }
4610:   while (next) {
4611:     PetscCall(PetscStrcasecmp(package, next->name, &flg));
4612:     if (flg) {
4613:       PetscCheck(next->handlers, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatSolverTypeHolder is missing handlers");
4614:       inext = next->handlers;
4615:       while (inext) {
4616:         PetscCall(PetscStrcasecmp(mtype, inext->mtype, &flg));
4617:         if (flg) {
4618:           inext->createfactor[(int)ftype - 1] = createfactor;
4619:           PetscFunctionReturn(PETSC_SUCCESS);
4620:         }
4621:         iprev = inext;
4622:         inext = inext->next;
4623:       }
4624:       PetscCall(PetscNew(&iprev->next));
4625:       PetscCall(PetscStrallocpy(mtype, (char **)&iprev->next->mtype));
4626:       iprev->next->createfactor[(int)ftype - 1] = createfactor;
4627:       PetscFunctionReturn(PETSC_SUCCESS);
4628:     }
4629:     prev = next;
4630:     next = next->next;
4631:   }
4632:   PetscCall(PetscNew(&prev->next));
4633:   PetscCall(PetscStrallocpy(package, &prev->next->name));
4634:   PetscCall(PetscNew(&prev->next->handlers));
4635:   PetscCall(PetscStrallocpy(mtype, (char **)&prev->next->handlers->mtype));
4636:   prev->next->handlers->createfactor[(int)ftype - 1] = createfactor;
4637:   PetscFunctionReturn(PETSC_SUCCESS);
4638: }

4640: /*@C
4641:   MatSolverTypeGet - Gets the function that creates the factor matrix if it exist

4643:   Input Parameters:
4644: + 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
4645: . ftype - the type of factorization supported by the type
4646: - mtype - the matrix type that works with this type

4648:   Output Parameters:
4649: + foundtype    - `PETSC_TRUE` if the type was registered
4650: . foundmtype   - `PETSC_TRUE` if the type supports the requested mtype
4651: - createfactor - routine that will create the factored matrix ready to be used or `NULL` if not found

4653:   Calling sequence of `createfactor`:
4654: + A     - the matrix providing the factor matrix
4655: . ftype - the `MatFactorType` of the factor requested
4656: - B     - the new factor matrix that responds to MatXXFactorSymbolic,Numeric() functions, such as `MatLUFactorSymbolic()`

4658:   Level: developer

4660:   Note:
4661:   When `type` is `NULL` the available functions are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4662:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4663:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4665: .seealso: [](ch_matrices), `Mat`, `MatFactorType`, `MatType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatSolverTypeRegister()`, `MatGetFactor()`,
4666:           `MatInitializePackage()`
4667: @*/
4668: PetscErrorCode MatSolverTypeGet(MatSolverType type, MatType mtype, MatFactorType ftype, PetscBool *foundtype, PetscBool *foundmtype, PetscErrorCode (**createfactor)(Mat A, MatFactorType ftype, Mat *B))
4669: {
4670:   MatSolverTypeHolder         next = MatSolverTypeHolders;
4671:   PetscBool                   flg;
4672:   MatSolverTypeForSpecifcType inext;

4674:   PetscFunctionBegin;
4675:   if (foundtype) *foundtype = PETSC_FALSE;
4676:   if (foundmtype) *foundmtype = PETSC_FALSE;
4677:   if (createfactor) *createfactor = NULL;

4679:   if (type) {
4680:     while (next) {
4681:       PetscCall(PetscStrcasecmp(type, next->name, &flg));
4682:       if (flg) {
4683:         if (foundtype) *foundtype = PETSC_TRUE;
4684:         inext = next->handlers;
4685:         while (inext) {
4686:           PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4687:           if (flg) {
4688:             if (foundmtype) *foundmtype = PETSC_TRUE;
4689:             if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4690:             PetscFunctionReturn(PETSC_SUCCESS);
4691:           }
4692:           inext = inext->next;
4693:         }
4694:       }
4695:       next = next->next;
4696:     }
4697:   } else {
4698:     while (next) {
4699:       inext = next->handlers;
4700:       while (inext) {
4701:         PetscCall(PetscStrcmp(mtype, inext->mtype, &flg));
4702:         if (flg && inext->createfactor[(int)ftype - 1]) {
4703:           if (foundtype) *foundtype = PETSC_TRUE;
4704:           if (foundmtype) *foundmtype = PETSC_TRUE;
4705:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4706:           PetscFunctionReturn(PETSC_SUCCESS);
4707:         }
4708:         inext = inext->next;
4709:       }
4710:       next = next->next;
4711:     }
4712:     /* try with base classes inext->mtype */
4713:     next = MatSolverTypeHolders;
4714:     while (next) {
4715:       inext = next->handlers;
4716:       while (inext) {
4717:         PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4718:         if (flg && inext->createfactor[(int)ftype - 1]) {
4719:           if (foundtype) *foundtype = PETSC_TRUE;
4720:           if (foundmtype) *foundmtype = PETSC_TRUE;
4721:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4722:           PetscFunctionReturn(PETSC_SUCCESS);
4723:         }
4724:         inext = inext->next;
4725:       }
4726:       next = next->next;
4727:     }
4728:   }
4729:   PetscFunctionReturn(PETSC_SUCCESS);
4730: }

4732: PetscErrorCode MatSolverTypeDestroy(void)
4733: {
4734:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev;
4735:   MatSolverTypeForSpecifcType inext, iprev;

4737:   PetscFunctionBegin;
4738:   while (next) {
4739:     PetscCall(PetscFree(next->name));
4740:     inext = next->handlers;
4741:     while (inext) {
4742:       PetscCall(PetscFree(inext->mtype));
4743:       iprev = inext;
4744:       inext = inext->next;
4745:       PetscCall(PetscFree(iprev));
4746:     }
4747:     prev = next;
4748:     next = next->next;
4749:     PetscCall(PetscFree(prev));
4750:   }
4751:   MatSolverTypeHolders = NULL;
4752:   PetscFunctionReturn(PETSC_SUCCESS);
4753: }

4755: /*@
4756:   MatFactorGetCanUseOrdering - Indicates if the factorization can use the ordering provided in `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`

4758:   Logically Collective

4760:   Input Parameter:
4761: . mat - the matrix

4763:   Output Parameter:
4764: . flg - `PETSC_TRUE` if uses the ordering

4766:   Level: developer

4768:   Note:
4769:   Most internal PETSc factorizations use the ordering passed to the factorization routine but external
4770:   packages do not, thus we want to skip generating the ordering when it is not needed or used.

4772: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4773: @*/
4774: PetscErrorCode MatFactorGetCanUseOrdering(Mat mat, PetscBool *flg)
4775: {
4776:   PetscFunctionBegin;
4777:   *flg = mat->canuseordering;
4778:   PetscFunctionReturn(PETSC_SUCCESS);
4779: }

4781: /*@
4782:   MatFactorGetPreferredOrdering - The preferred ordering for a particular matrix factor object

4784:   Logically Collective

4786:   Input Parameters:
4787: + mat   - the matrix obtained with `MatGetFactor()`
4788: - ftype - the factorization type to be used

4790:   Output Parameter:
4791: . otype - the preferred ordering type

4793:   Level: developer

4795: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatOrderingType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4796: @*/
4797: PetscErrorCode MatFactorGetPreferredOrdering(Mat mat, MatFactorType ftype, MatOrderingType *otype)
4798: {
4799:   PetscFunctionBegin;
4800:   *otype = mat->preferredordering[ftype];
4801:   PetscCheck(*otype, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatFactor did not have a preferred ordering");
4802:   PetscFunctionReturn(PETSC_SUCCESS);
4803: }

4805: /*@
4806:   MatGetFactor - Returns a matrix suitable to calls to MatXXFactorSymbolic,Numeric()

4808:   Collective

4810:   Input Parameters:
4811: + mat   - the matrix
4812: . type  - name of solver type, for example, `superlu`, `petsc` (to use PETSc's solver if it is available), if this is 'NULL', then the first result that satisfies
4813:           the other criteria is returned
4814: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4816:   Output Parameter:
4817: . f - the factor matrix used with MatXXFactorSymbolic,Numeric() calls. Can be `NULL` in some cases, see notes below.

4819:   Options Database Keys:
4820: + -pc_factor_mat_solver_type <type>    - choose the type at run time. When using `KSP` solvers
4821: . -pc_factor_mat_factor_on_host <bool> - do mat factorization on host (with device matrices). Default is doing it on device
4822: - -pc_factor_mat_solve_on_host <bool>  - do mat solve on host (with device matrices). Default is doing it on device

4824:   Level: intermediate

4826:   Notes:
4827:   The return matrix can be `NULL` if the requested factorization is not available, since some combinations of matrix types and factorization
4828:   types registered with `MatSolverTypeRegister()` cannot be fully tested if not at runtime.

4830:   Users usually access the factorization solvers via `KSP`

4832:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
4833:   such as pastix, superlu, mumps etc. PETSc must have been ./configure to use the external solver, using the option --download-package or --with-package-dir

4835:   When `type` is `NULL` the available results are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4836:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4837:   For example if one configuration had --download-mumps while a different one had --download-superlu_dist.

4839:   Some of the packages have options for controlling the factorization, these are in the form -prefix_mat_packagename_packageoption
4840:   where prefix is normally obtained from the calling `KSP`/`PC`. If `MatGetFactor()` is called directly one can set
4841:   call `MatSetOptionsPrefixFactor()` on the originating matrix or  `MatSetOptionsPrefix()` on the resulting factor matrix.

4843:   Developer Note:
4844:   This should actually be called `MatCreateFactor()` since it creates a new factor object

4846: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `KSP`, `MatSolverType`, `MatFactorType`, `MatCopy()`, `MatDuplicate()`,
4847:           `MatGetFactorAvailable()`, `MatFactorGetCanUseOrdering()`, `MatSolverTypeRegister()`, `MatSolverTypeGet()`
4848:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatInitializePackage()`
4849: @*/
4850: PetscErrorCode MatGetFactor(Mat mat, MatSolverType type, MatFactorType ftype, Mat *f)
4851: {
4852:   PetscBool foundtype, foundmtype, shell, hasop = PETSC_FALSE;
4853:   PetscErrorCode (*conv)(Mat, MatFactorType, Mat *);

4855:   PetscFunctionBegin;

4859:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4860:   MatCheckPreallocated(mat, 1);

4862:   PetscCall(MatIsShell(mat, &shell));
4863:   if (shell) PetscCall(MatHasOperation(mat, MATOP_GET_FACTOR, &hasop));
4864:   if (hasop) {
4865:     PetscUseTypeMethod(mat, getfactor, type, ftype, f);
4866:     PetscFunctionReturn(PETSC_SUCCESS);
4867:   }

4869:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, &foundtype, &foundmtype, &conv));
4870:   if (!foundtype) {
4871:     if (type) {
4872:       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],
4873:               ((PetscObject)mat)->type_name, type);
4874:     } else {
4875:       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);
4876:     }
4877:   }
4878:   PetscCheck(foundmtype, PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "MatSolverType %s does not support matrix type %s", type, ((PetscObject)mat)->type_name);
4879:   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);

4881:   PetscCall((*conv)(mat, ftype, f));
4882:   if (mat->factorprefix) PetscCall(MatSetOptionsPrefix(*f, mat->factorprefix));
4883:   PetscFunctionReturn(PETSC_SUCCESS);
4884: }

4886: /*@
4887:   MatGetFactorAvailable - Returns a flag if matrix supports particular type and factor type

4889:   Not Collective

4891:   Input Parameters:
4892: + mat   - the matrix
4893: . type  - name of solver type, for example, `superlu`, `petsc` (to use PETSc's default)
4894: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4896:   Output Parameter:
4897: . flg - PETSC_TRUE if the factorization is available

4899:   Level: intermediate

4901:   Notes:
4902:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
4903:   such as pastix, superlu, mumps etc.

4905:   PETSc must have been ./configure to use the external solver, using the option --download-package

4907:   Developer Note:
4908:   This should actually be called `MatCreateFactorAvailable()` since `MatGetFactor()` creates a new factor object

4910: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolverType`, `MatFactorType`, `MatGetFactor()`, `MatCopy()`, `MatDuplicate()`, `MatSolverTypeRegister()`,
4911:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatSolverTypeGet()`
4912: @*/
4913: PetscErrorCode MatGetFactorAvailable(Mat mat, MatSolverType type, MatFactorType ftype, PetscBool *flg)
4914: {
4915:   PetscErrorCode (*gconv)(Mat, MatFactorType, Mat *);

4917:   PetscFunctionBegin;
4919:   PetscAssertPointer(flg, 4);

4921:   *flg = PETSC_FALSE;
4922:   if (!((PetscObject)mat)->type_name) PetscFunctionReturn(PETSC_SUCCESS);

4924:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4925:   MatCheckPreallocated(mat, 1);

4927:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, NULL, NULL, &gconv));
4928:   *flg = gconv ? PETSC_TRUE : PETSC_FALSE;
4929:   PetscFunctionReturn(PETSC_SUCCESS);
4930: }

4932: /*@
4933:   MatDuplicate - Duplicates a matrix including the non-zero structure.

4935:   Collective

4937:   Input Parameters:
4938: + mat - the matrix
4939: - op  - One of `MAT_DO_NOT_COPY_VALUES`, `MAT_COPY_VALUES`, or `MAT_SHARE_NONZERO_PATTERN`.
4940:         See the manual page for `MatDuplicateOption()` for an explanation of these options.

4942:   Output Parameter:
4943: . M - pointer to place new matrix

4945:   Level: intermediate

4947:   Notes:
4948:   You cannot change the nonzero pattern for the parent or child matrix later if you use `MAT_SHARE_NONZERO_PATTERN`.

4950:   If `op` is not `MAT_COPY_VALUES` the numerical values in the new matrix are zeroed.

4952:   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.

4954:   When original mat is a product of matrix operation, e.g., an output of `MatMatMult()` or `MatCreateSubMatrix()`, only the matrix data structure of `mat`
4955:   is duplicated and the internal data structures created for the reuse of previous matrix operations are not duplicated.
4956:   User should not use `MatDuplicate()` to create new matrix `M` if `M` is intended to be reused as the product of matrix operation.

4958: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatConvert()`, `MatDuplicateOption`
4959: @*/
4960: PetscErrorCode MatDuplicate(Mat mat, MatDuplicateOption op, Mat *M)
4961: {
4962:   Mat               B;
4963:   VecType           vtype;
4964:   PetscInt          i;
4965:   PetscObject       dm, container_h, container_d;
4966:   PetscErrorCodeFn *viewf;

4968:   PetscFunctionBegin;
4971:   PetscAssertPointer(M, 3);
4972:   PetscCheck(op != MAT_COPY_VALUES || mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MAT_COPY_VALUES not allowed for unassembled matrix");
4973:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4974:   MatCheckPreallocated(mat, 1);

4976:   PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4977:   PetscUseTypeMethod(mat, duplicate, op, M);
4978:   PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4979:   B = *M;

4981:   PetscCall(MatGetOperation(mat, MATOP_VIEW, &viewf));
4982:   if (viewf) PetscCall(MatSetOperation(B, MATOP_VIEW, viewf));
4983:   PetscCall(MatGetVecType(mat, &vtype));
4984:   PetscCall(MatSetVecType(B, vtype));

4986:   B->stencil.dim = mat->stencil.dim;
4987:   B->stencil.noc = mat->stencil.noc;
4988:   for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4989:     B->stencil.dims[i]   = mat->stencil.dims[i];
4990:     B->stencil.starts[i] = mat->stencil.starts[i];
4991:   }

4993:   B->nooffproczerorows = mat->nooffproczerorows;
4994:   B->nooffprocentries  = mat->nooffprocentries;

4996:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_dm", &dm));
4997:   if (dm) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_dm", dm));
4998:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Host", &container_h));
4999:   if (container_h) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Host", container_h));
5000:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Device", &container_d));
5001:   if (container_d) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Device", container_d));
5002:   if (op == MAT_COPY_VALUES) PetscCall(MatPropagateSymmetryOptions(mat, B));
5003:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
5004:   PetscFunctionReturn(PETSC_SUCCESS);
5005: }

5007: /*@
5008:   MatGetDiagonal - Gets the diagonal of a matrix as a `Vec`

5010:   Logically Collective

5012:   Input Parameter:
5013: . mat - the matrix

5015:   Output Parameter:
5016: . v - the diagonal of the matrix

5018:   Level: intermediate

5020:   Note:
5021:   If `mat` has local sizes `n` x `m`, this routine fills the first `ndiag = min(n, m)` entries
5022:   of `v` with the diagonal values. Thus `v` must have local size of at least `ndiag`. If `v`
5023:   is larger than `ndiag`, the values of the remaining entries are unspecified.

5025:   Currently only correct in parallel for square matrices.

5027: .seealso: [](ch_matrices), `Mat`, `Vec`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`
5028: @*/
5029: PetscErrorCode MatGetDiagonal(Mat mat, Vec v)
5030: {
5031:   PetscFunctionBegin;
5035:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5036:   MatCheckPreallocated(mat, 1);
5037:   if (PetscDefined(USE_DEBUG)) {
5038:     PetscInt nv, row, col, ndiag;

5040:     PetscCall(VecGetLocalSize(v, &nv));
5041:     PetscCall(MatGetLocalSize(mat, &row, &col));
5042:     ndiag = PetscMin(row, col);
5043:     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);
5044:   }

5046:   PetscUseTypeMethod(mat, getdiagonal, v);
5047:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5048:   PetscFunctionReturn(PETSC_SUCCESS);
5049: }

5051: /*@
5052:   MatGetRowMin - Gets the minimum value (of the real part) of each
5053:   row of the matrix

5055:   Logically Collective

5057:   Input Parameter:
5058: . mat - the matrix

5060:   Output Parameters:
5061: + v   - the vector for storing the maximums
5062: - idx - the indices of the column found for each row (optional, pass `NULL` if not needed)

5064:   Level: intermediate

5066:   Note:
5067:   The result of this call are the same as if one converted the matrix to dense format
5068:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5070:   This code is only implemented for a couple of matrix formats.

5072: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`,
5073:           `MatGetRowMax()`
5074: @*/
5075: PetscErrorCode MatGetRowMin(Mat mat, Vec v, PetscInt idx[])
5076: {
5077:   PetscFunctionBegin;
5081:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5083:   if (!mat->cmap->N) {
5084:     PetscCall(VecSet(v, PETSC_MAX_REAL));
5085:     if (idx) {
5086:       PetscInt i, m = mat->rmap->n;
5087:       for (i = 0; i < m; i++) idx[i] = -1;
5088:     }
5089:   } else {
5090:     MatCheckPreallocated(mat, 1);
5091:   }
5092:   PetscUseTypeMethod(mat, getrowmin, v, idx);
5093:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5094:   PetscFunctionReturn(PETSC_SUCCESS);
5095: }

5097: /*@
5098:   MatGetRowMinAbs - Gets the minimum value (in absolute value) of each
5099:   row of the matrix

5101:   Logically Collective

5103:   Input Parameter:
5104: . mat - the matrix

5106:   Output Parameters:
5107: + v   - the vector for storing the minimums
5108: - idx - the indices of the column found for each row (or `NULL` if not needed)

5110:   Level: intermediate

5112:   Notes:
5113:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5114:   row is 0 (the first column).

5116:   This code is only implemented for a couple of matrix formats.

5118: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`
5119: @*/
5120: PetscErrorCode MatGetRowMinAbs(Mat mat, Vec v, PetscInt idx[])
5121: {
5122:   PetscFunctionBegin;
5126:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5127:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

5129:   if (!mat->cmap->N) {
5130:     PetscCall(VecSet(v, 0.0));
5131:     if (idx) {
5132:       PetscInt i, m = mat->rmap->n;
5133:       for (i = 0; i < m; i++) idx[i] = -1;
5134:     }
5135:   } else {
5136:     MatCheckPreallocated(mat, 1);
5137:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5138:     PetscUseTypeMethod(mat, getrowminabs, v, idx);
5139:   }
5140:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5141:   PetscFunctionReturn(PETSC_SUCCESS);
5142: }

5144: /*@
5145:   MatGetRowMax - Gets the maximum value (of the real part) of each
5146:   row of the matrix

5148:   Logically Collective

5150:   Input Parameter:
5151: . mat - the matrix

5153:   Output Parameters:
5154: + v   - the vector for storing the maximums
5155: - idx - the indices of the column found for each row (optional, otherwise pass `NULL`)

5157:   Level: intermediate

5159:   Notes:
5160:   The result of this call are the same as if one converted the matrix to dense format
5161:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5163:   This code is only implemented for a couple of matrix formats.

5165: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5166: @*/
5167: PetscErrorCode MatGetRowMax(Mat mat, Vec v, PetscInt idx[])
5168: {
5169:   PetscFunctionBegin;
5173:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5175:   if (!mat->cmap->N) {
5176:     PetscCall(VecSet(v, PETSC_MIN_REAL));
5177:     if (idx) {
5178:       PetscInt i, m = mat->rmap->n;
5179:       for (i = 0; i < m; i++) idx[i] = -1;
5180:     }
5181:   } else {
5182:     MatCheckPreallocated(mat, 1);
5183:     PetscUseTypeMethod(mat, getrowmax, v, idx);
5184:   }
5185:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5186:   PetscFunctionReturn(PETSC_SUCCESS);
5187: }

5189: /*@
5190:   MatGetRowMaxAbs - Gets the maximum value (in absolute value) of each
5191:   row of the matrix

5193:   Logically Collective

5195:   Input Parameter:
5196: . mat - the matrix

5198:   Output Parameters:
5199: + v   - the vector for storing the maximums
5200: - idx - the indices of the column found for each row (or `NULL` if not needed)

5202:   Level: intermediate

5204:   Notes:
5205:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5206:   row is 0 (the first column).

5208:   This code is only implemented for a couple of matrix formats.

5210: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowSum()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5211: @*/
5212: PetscErrorCode MatGetRowMaxAbs(Mat mat, Vec v, PetscInt idx[])
5213: {
5214:   PetscFunctionBegin;
5218:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5220:   if (!mat->cmap->N) {
5221:     PetscCall(VecSet(v, 0.0));
5222:     if (idx) {
5223:       PetscInt i, m = mat->rmap->n;
5224:       for (i = 0; i < m; i++) idx[i] = -1;
5225:     }
5226:   } else {
5227:     MatCheckPreallocated(mat, 1);
5228:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5229:     PetscUseTypeMethod(mat, getrowmaxabs, v, idx);
5230:   }
5231:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5232:   PetscFunctionReturn(PETSC_SUCCESS);
5233: }

5235: /*@
5236:   MatGetRowSumAbs - Gets the sum value (in absolute value) of each row of the matrix

5238:   Logically Collective

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

5243:   Output Parameter:
5244: . v - the vector for storing the sum

5246:   Level: intermediate

5248:   This code is only implemented for a couple of matrix formats.

5250: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5251: @*/
5252: PetscErrorCode MatGetRowSumAbs(Mat mat, Vec v)
5253: {
5254:   PetscFunctionBegin;
5258:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5260:   if (!mat->cmap->N) {
5261:     PetscCall(VecSet(v, 0.0));
5262:   } else {
5263:     MatCheckPreallocated(mat, 1);
5264:     PetscUseTypeMethod(mat, getrowsumabs, v);
5265:   }
5266:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5267:   PetscFunctionReturn(PETSC_SUCCESS);
5268: }

5270: /*@
5271:   MatGetRowSum - Gets the sum of each row of the matrix

5273:   Logically or Neighborhood Collective

5275:   Input Parameter:
5276: . mat - the matrix

5278:   Output Parameter:
5279: . v - the vector for storing the sum of rows

5281:   Level: intermediate

5283:   Note:
5284:   This code is slow since it is not currently specialized for different formats

5286: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`, `MatGetRowSumAbs()`
5287: @*/
5288: PetscErrorCode MatGetRowSum(Mat mat, Vec v)
5289: {
5290:   Vec ones;

5292:   PetscFunctionBegin;
5296:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5297:   MatCheckPreallocated(mat, 1);
5298:   PetscCall(MatCreateVecs(mat, &ones, NULL));
5299:   PetscCall(VecSet(ones, 1.));
5300:   PetscCall(MatMult(mat, ones, v));
5301:   PetscCall(VecDestroy(&ones));
5302:   PetscFunctionReturn(PETSC_SUCCESS);
5303: }

5305: /*@
5306:   MatTransposeSetPrecursor - Set the matrix from which the second matrix will receive numerical transpose data with a call to `MatTranspose`(A,`MAT_REUSE_MATRIX`,&B)
5307:   when B was not obtained with `MatTranspose`(A,`MAT_INITIAL_MATRIX`,&B)

5309:   Collective

5311:   Input Parameter:
5312: . mat - the matrix to provide the transpose

5314:   Output Parameter:
5315: . 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

5317:   Level: advanced

5319:   Note:
5320:   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
5321:   routine allows bypassing that call.

5323: .seealso: [](ch_matrices), `Mat`, `MatTransposeSymbolic()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5324: @*/
5325: PetscErrorCode MatTransposeSetPrecursor(Mat mat, Mat B)
5326: {
5327:   MatParentState *rb = NULL;

5329:   PetscFunctionBegin;
5330:   PetscCall(PetscNew(&rb));
5331:   rb->id    = ((PetscObject)mat)->id;
5332:   rb->state = 0;
5333:   PetscCall(MatGetNonzeroState(mat, &rb->nonzerostate));
5334:   PetscCall(PetscObjectContainerCompose((PetscObject)B, "MatTransposeParent", rb, PetscCtxDestroyDefault));
5335:   PetscFunctionReturn(PETSC_SUCCESS);
5336: }

5338: /*@
5339:   MatTranspose - Computes the transpose of a matrix, either in-place or out-of-place.

5341:   Collective

5343:   Input Parameters:
5344: + mat   - the matrix to transpose
5345: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5347:   Output Parameter:
5348: . B - the transpose of the matrix

5350:   Level: intermediate

5352:   Notes:
5353:   If you use `MAT_INPLACE_MATRIX` then you must pass in `&mat` for `B`

5355:   `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
5356:   transpose, call `MatTransposeSetPrecursor(mat, B)` before calling this routine.

5358:   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.

5360:   Consider using `MatCreateTranspose()` instead if you only need a matrix that behaves like the transpose but don't need the storage to be changed.
5361:   For example, the result of `MatCreateTranspose()` will compute the transpose of the given matrix times a vector for matrix-vector products computed with `MatMult()`.

5363:   If `mat` is unchanged from the last call this function returns immediately without recomputing the result

5365:   If you only need the symbolic transpose of a matrix, and not the numerical values, use `MatTransposeSymbolic()`

5367: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`,
5368:           `MatTransposeSymbolic()`, `MatCreateTranspose()`
5369: @*/
5370: PetscErrorCode MatTranspose(Mat mat, MatReuse reuse, Mat *B)
5371: {
5372:   PetscContainer  rB = NULL;
5373:   MatParentState *rb = NULL;

5375:   PetscFunctionBegin;
5378:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5379:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5380:   PetscCheck(reuse != MAT_INPLACE_MATRIX || mat == *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires last matrix to match first");
5381:   PetscCheck(reuse != MAT_REUSE_MATRIX || mat != *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Perhaps you mean MAT_INPLACE_MATRIX");
5382:   MatCheckPreallocated(mat, 1);
5383:   if (reuse == MAT_REUSE_MATRIX) {
5384:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5385:     PetscCheck(rB, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose(). Suggest MatTransposeSetPrecursor().");
5386:     PetscCall(PetscContainerGetPointer(rB, (void **)&rb));
5387:     PetscCheck(rb->id == ((PetscObject)mat)->id, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5388:     if (rb->state == ((PetscObject)mat)->state) PetscFunctionReturn(PETSC_SUCCESS);
5389:   }

5391:   PetscCall(PetscLogEventBegin(MAT_Transpose, mat, 0, 0, 0));
5392:   if (reuse != MAT_INPLACE_MATRIX || mat->symmetric != PETSC_BOOL3_TRUE) {
5393:     PetscUseTypeMethod(mat, transpose, reuse, B);
5394:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5395:   }
5396:   PetscCall(PetscLogEventEnd(MAT_Transpose, mat, 0, 0, 0));

5398:   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatTransposeSetPrecursor(mat, *B));
5399:   if (reuse != MAT_INPLACE_MATRIX) {
5400:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5401:     PetscCall(PetscContainerGetPointer(rB, (void **)&rb));
5402:     rb->state        = ((PetscObject)mat)->state;
5403:     rb->nonzerostate = mat->nonzerostate;
5404:   }
5405:   PetscFunctionReturn(PETSC_SUCCESS);
5406: }

5408: /*@
5409:   MatTransposeSymbolic - Computes the symbolic part of the transpose of a matrix.

5411:   Collective

5413:   Input Parameter:
5414: . A - the matrix to transpose

5416:   Output Parameter:
5417: . 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
5418:       numerical portion.

5420:   Level: intermediate

5422:   Note:
5423:   This is not supported for many matrix types, use `MatTranspose()` in those cases

5425: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5426: @*/
5427: PetscErrorCode MatTransposeSymbolic(Mat A, Mat *B)
5428: {
5429:   PetscFunctionBegin;
5432:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5433:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5434:   PetscCall(PetscLogEventBegin(MAT_Transpose, A, 0, 0, 0));
5435:   PetscUseTypeMethod(A, transposesymbolic, B);
5436:   PetscCall(PetscLogEventEnd(MAT_Transpose, A, 0, 0, 0));

5438:   PetscCall(MatTransposeSetPrecursor(A, *B));
5439:   PetscFunctionReturn(PETSC_SUCCESS);
5440: }

5442: PetscErrorCode MatTransposeCheckNonzeroState_Private(Mat A, Mat B)
5443: {
5444:   PetscContainer  rB;
5445:   MatParentState *rb;

5447:   PetscFunctionBegin;
5450:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5451:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5452:   PetscCall(PetscObjectQuery((PetscObject)B, "MatTransposeParent", (PetscObject *)&rB));
5453:   PetscCheck(rB, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose()");
5454:   PetscCall(PetscContainerGetPointer(rB, (void **)&rb));
5455:   PetscCheck(rb->id == ((PetscObject)A)->id, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5456:   PetscCheck(rb->nonzerostate == A->nonzerostate, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Reuse matrix has changed nonzero structure");
5457:   PetscFunctionReturn(PETSC_SUCCESS);
5458: }

5460: /*@
5461:   MatIsTranspose - Test whether a matrix is another one's transpose,
5462:   or its own, in which case it tests symmetry.

5464:   Collective

5466:   Input Parameters:
5467: + A   - the matrix to test
5468: . B   - the matrix to test against, this can equal the first parameter
5469: - tol - tolerance, differences between entries smaller than this are counted as zero

5471:   Output Parameter:
5472: . flg - the result

5474:   Level: intermediate

5476:   Notes:
5477:   The sequential algorithm has a running time of the order of the number of nonzeros; the parallel
5478:   test involves parallel copies of the block off-diagonal parts of the matrix.

5480: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`
5481: @*/
5482: PetscErrorCode MatIsTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5483: {
5484:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5486:   PetscFunctionBegin;
5489:   PetscAssertPointer(flg, 4);
5490:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsTranspose_C", &f));
5491:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsTranspose_C", &g));
5492:   *flg = PETSC_FALSE;
5493:   if (f && g) {
5494:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for symmetry test");
5495:     PetscCall((*f)(A, B, tol, flg));
5496:   } else {
5497:     MatType mattype;

5499:     PetscCall(MatGetType(f ? B : A, &mattype));
5500:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for transpose", mattype);
5501:   }
5502:   PetscFunctionReturn(PETSC_SUCCESS);
5503: }

5505: /*@
5506:   MatHermitianTranspose - Computes an in-place or out-of-place Hermitian transpose of a matrix in complex conjugate.

5508:   Collective

5510:   Input Parameters:
5511: + mat   - the matrix to transpose and complex conjugate
5512: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5514:   Output Parameter:
5515: . B - the Hermitian transpose

5517:   Level: intermediate

5519: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`
5520: @*/
5521: PetscErrorCode MatHermitianTranspose(Mat mat, MatReuse reuse, Mat *B)
5522: {
5523:   PetscFunctionBegin;
5524:   PetscCall(MatTranspose(mat, reuse, B));
5525: #if defined(PETSC_USE_COMPLEX)
5526:   PetscCall(MatConjugate(*B));
5527: #endif
5528:   PetscFunctionReturn(PETSC_SUCCESS);
5529: }

5531: /*@
5532:   MatIsHermitianTranspose - Test whether a matrix is another one's Hermitian transpose,

5534:   Collective

5536:   Input Parameters:
5537: + A   - the matrix to test
5538: . B   - the matrix to test against, this can equal the first parameter
5539: - tol - tolerance, differences between entries smaller than this are counted as zero

5541:   Output Parameter:
5542: . flg - the result

5544:   Level: intermediate

5546:   Notes:
5547:   Only available for `MATAIJ` matrices.

5549:   The sequential algorithm
5550:   has a running time of the order of the number of nonzeros; the parallel
5551:   test involves parallel copies of the block off-diagonal parts of the matrix.

5553: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsTranspose()`
5554: @*/
5555: PetscErrorCode MatIsHermitianTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5556: {
5557:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5559:   PetscFunctionBegin;
5562:   PetscAssertPointer(flg, 4);
5563:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsHermitianTranspose_C", &f));
5564:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsHermitianTranspose_C", &g));
5565:   if (f && g) {
5566:     PetscCheck(f != g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for Hermitian test");
5567:     PetscCall((*f)(A, B, tol, flg));
5568:   }
5569:   PetscFunctionReturn(PETSC_SUCCESS);
5570: }

5572: /*@
5573:   MatPermute - Creates a new matrix with rows and columns permuted from the
5574:   original.

5576:   Collective

5578:   Input Parameters:
5579: + mat - the matrix to permute
5580: . row - row permutation, each processor supplies only the permutation for its rows
5581: - col - column permutation, each processor supplies only the permutation for its columns

5583:   Output Parameter:
5584: . B - the permuted matrix

5586:   Level: advanced

5588:   Note:
5589:   The index sets map from row/col of permuted matrix to row/col of original matrix.
5590:   The index sets should be on the same communicator as mat and have the same local sizes.

5592:   Developer Note:
5593:   If you want to implement `MatPermute()` for a matrix type, and your approach doesn't
5594:   exploit the fact that row and col are permutations, consider implementing the
5595:   more general `MatCreateSubMatrix()` instead.

5597: .seealso: [](ch_matrices), `Mat`, `MatGetOrdering()`, `ISAllGather()`, `MatCreateSubMatrix()`
5598: @*/
5599: PetscErrorCode MatPermute(Mat mat, IS row, IS col, Mat *B)
5600: {
5601:   PetscFunctionBegin;
5606:   PetscAssertPointer(B, 4);
5607:   PetscCheckSameComm(mat, 1, row, 2);
5608:   if (row != col) PetscCheckSameComm(row, 2, col, 3);
5609:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5610:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5611:   PetscCheck(mat->ops->permute || mat->ops->createsubmatrix, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatPermute not available for Mat type %s", ((PetscObject)mat)->type_name);
5612:   MatCheckPreallocated(mat, 1);

5614:   if (mat->ops->permute) {
5615:     PetscUseTypeMethod(mat, permute, row, col, B);
5616:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5617:   } else {
5618:     PetscCall(MatCreateSubMatrix(mat, row, col, MAT_INITIAL_MATRIX, B));
5619:   }
5620:   PetscFunctionReturn(PETSC_SUCCESS);
5621: }

5623: /*@
5624:   MatEqual - Compares two matrices.

5626:   Collective

5628:   Input Parameters:
5629: + A - the first matrix
5630: - B - the second matrix

5632:   Output Parameter:
5633: . flg - `PETSC_TRUE` if the matrices are equal; `PETSC_FALSE` otherwise.

5635:   Level: intermediate

5637:   Note:
5638:   If either of the matrix is "matrix-free", meaning the matrix entries are not stored explicitly then equality is determined by comparing
5639:   the results of several matrix-vector product using randomly created vectors, see `MatMultEqual()`.

5641: .seealso: [](ch_matrices), `Mat`, `MatMultEqual()`
5642: @*/
5643: PetscErrorCode MatEqual(Mat A, Mat B, PetscBool *flg)
5644: {
5645:   PetscFunctionBegin;
5650:   PetscAssertPointer(flg, 3);
5651:   PetscCheckSameComm(A, 1, B, 2);
5652:   MatCheckPreallocated(A, 1);
5653:   MatCheckPreallocated(B, 2);
5654:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5655:   PetscCheck(B->assembled, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5656:   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,
5657:              B->cmap->N);
5658:   if (A->ops->equal && A->ops->equal == B->ops->equal) {
5659:     PetscUseTypeMethod(A, equal, B, flg);
5660:   } else {
5661:     PetscCall(MatMultEqual(A, B, 10, flg));
5662:   }
5663:   PetscFunctionReturn(PETSC_SUCCESS);
5664: }

5666: /*@
5667:   MatDiagonalScale - Scales a matrix on the left and right by diagonal
5668:   matrices that are stored as vectors.  Either of the two scaling
5669:   matrices can be `NULL`.

5671:   Collective

5673:   Input Parameters:
5674: + mat - the matrix to be scaled
5675: . l   - the left scaling vector (or `NULL`)
5676: - r   - the right scaling vector (or `NULL`)

5678:   Level: intermediate

5680:   Note:
5681:   `MatDiagonalScale()` computes $A = LAR$, where
5682:   L = a diagonal matrix (stored as a vector), R = a diagonal matrix (stored as a vector)
5683:   The L scales the rows of the matrix, the R scales the columns of the matrix.

5685: .seealso: [](ch_matrices), `Mat`, `MatScale()`, `MatShift()`, `MatDiagonalSet()`
5686: @*/
5687: PetscErrorCode MatDiagonalScale(Mat mat, Vec l, Vec r)
5688: {
5689:   PetscFunctionBegin;
5692:   if (l) {
5694:     PetscCheckSameComm(mat, 1, l, 2);
5695:   }
5696:   if (r) {
5698:     PetscCheckSameComm(mat, 1, r, 3);
5699:   }
5700:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5701:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5702:   MatCheckPreallocated(mat, 1);
5703:   if (!l && !r) PetscFunctionReturn(PETSC_SUCCESS);

5705:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5706:   PetscUseTypeMethod(mat, diagonalscale, l, r);
5707:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5708:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5709:   if (l != r) mat->symmetric = PETSC_BOOL3_FALSE;
5710:   PetscFunctionReturn(PETSC_SUCCESS);
5711: }

5713: /*@
5714:   MatScale - Scales all elements of a matrix by a given number.

5716:   Logically Collective

5718:   Input Parameters:
5719: + mat - the matrix to be scaled
5720: - a   - the scaling value

5722:   Level: intermediate

5724: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
5725: @*/
5726: PetscErrorCode MatScale(Mat mat, PetscScalar a)
5727: {
5728:   PetscFunctionBegin;
5731:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5732:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5734:   MatCheckPreallocated(mat, 1);

5736:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5737:   if (a != (PetscScalar)1.0) {
5738:     PetscUseTypeMethod(mat, scale, a);
5739:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5740:   }
5741:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5742:   PetscFunctionReturn(PETSC_SUCCESS);
5743: }

5745: /*@
5746:   MatNorm - Calculates various norms of a matrix.

5748:   Collective

5750:   Input Parameters:
5751: + mat  - the matrix
5752: - type - the type of norm, `NORM_1`, `NORM_FROBENIUS`, `NORM_INFINITY`

5754:   Output Parameter:
5755: . nrm - the resulting norm

5757:   Level: intermediate

5759: .seealso: [](ch_matrices), `Mat`
5760: @*/
5761: PetscErrorCode MatNorm(Mat mat, NormType type, PetscReal *nrm)
5762: {
5763:   PetscFunctionBegin;
5766:   PetscAssertPointer(nrm, 3);

5768:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5769:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5770:   MatCheckPreallocated(mat, 1);

5772:   PetscUseTypeMethod(mat, norm, type, nrm);
5773:   PetscFunctionReturn(PETSC_SUCCESS);
5774: }

5776: /*
5777:      This variable is used to prevent counting of MatAssemblyBegin() that
5778:    are called from within a MatAssemblyEnd().
5779: */
5780: static PetscInt MatAssemblyEnd_InUse = 0;
5781: /*@
5782:   MatAssemblyBegin - Begins assembling the matrix.  This routine should
5783:   be called after completing all calls to `MatSetValues()`.

5785:   Collective

5787:   Input Parameters:
5788: + mat  - the matrix
5789: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5791:   Level: beginner

5793:   Notes:
5794:   `MatSetValues()` generally caches the values that belong to other MPI processes.  The matrix is ready to
5795:   use only after `MatAssemblyBegin()` and `MatAssemblyEnd()` have been called.

5797:   Use `MAT_FLUSH_ASSEMBLY` when switching between `ADD_VALUES` and `INSERT_VALUES`
5798:   in `MatSetValues()`; use `MAT_FINAL_ASSEMBLY` for the final assembly before
5799:   using the matrix.

5801:   ALL processes that share a matrix MUST call `MatAssemblyBegin()` and `MatAssemblyEnd()` the SAME NUMBER of times, and each time with the
5802:   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
5803:   a global collective operation requiring all processes that share the matrix.

5805:   Space for preallocated nonzeros that is not filled by a call to `MatSetValues()` or a related routine are compressed
5806:   out by assembly. If you intend to use that extra space on a subsequent assembly, be sure to insert explicit zeros
5807:   before `MAT_FINAL_ASSEMBLY` so the space is not compressed out.

5809: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssembled()`
5810: @*/
5811: PetscErrorCode MatAssemblyBegin(Mat mat, MatAssemblyType type)
5812: {
5813:   PetscFunctionBegin;
5816:   MatCheckPreallocated(mat, 1);
5817:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix. Did you forget to call MatSetUnfactored()?");
5818:   if (mat->assembled) {
5819:     mat->was_assembled = PETSC_TRUE;
5820:     mat->assembled     = PETSC_FALSE;
5821:   }

5823:   if (!MatAssemblyEnd_InUse) {
5824:     PetscCall(PetscLogEventBegin(MAT_AssemblyBegin, mat, 0, 0, 0));
5825:     PetscTryTypeMethod(mat, assemblybegin, type);
5826:     PetscCall(PetscLogEventEnd(MAT_AssemblyBegin, mat, 0, 0, 0));
5827:   } else PetscTryTypeMethod(mat, assemblybegin, type);
5828:   PetscFunctionReturn(PETSC_SUCCESS);
5829: }

5831: /*@
5832:   MatAssembled - Indicates if a matrix has been assembled and is ready for
5833:   use; for example, in matrix-vector product.

5835:   Not Collective

5837:   Input Parameter:
5838: . mat - the matrix

5840:   Output Parameter:
5841: . assembled - `PETSC_TRUE` or `PETSC_FALSE`

5843:   Level: advanced

5845: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssemblyBegin()`
5846: @*/
5847: PetscErrorCode MatAssembled(Mat mat, PetscBool *assembled)
5848: {
5849:   PetscFunctionBegin;
5851:   PetscAssertPointer(assembled, 2);
5852:   *assembled = mat->assembled;
5853:   PetscFunctionReturn(PETSC_SUCCESS);
5854: }

5856: /*@
5857:   MatAssemblyEnd - Completes assembling the matrix.  This routine should
5858:   be called after `MatAssemblyBegin()`.

5860:   Collective

5862:   Input Parameters:
5863: + mat  - the matrix
5864: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5866:   Options Database Keys:
5867: + -mat_view ::ascii_info             - Prints info on matrix at conclusion of `MatAssemblyEnd()`
5868: . -mat_view ::ascii_info_detail      - Prints more detailed info
5869: . -mat_view                          - Prints matrix in ASCII format
5870: . -mat_view ::ascii_matlab           - Prints matrix in MATLAB format
5871: . -mat_view draw                     - draws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
5872: . -display <name>                    - Sets display name (default is host)
5873: . -draw_pause <sec>                  - Sets number of seconds to pause after display
5874: . -mat_view socket                   - Sends matrix to socket, can be accessed from MATLAB (See [Using MATLAB with PETSc](ch_matlab))
5875: . -viewer_socket_machine <machine>   - Machine to use for socket
5876: . -viewer_socket_port <port>         - Port number to use for socket
5877: - -mat_view binary:filename[:append] - Save matrix to file in binary format

5879:   Level: beginner

5881: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatSetValues()`, `PetscDrawOpenX()`, `PetscDrawCreate()`, `MatView()`, `MatAssembled()`, `PetscViewerSocketOpen()`
5882: @*/
5883: PetscErrorCode MatAssemblyEnd(Mat mat, MatAssemblyType type)
5884: {
5885:   static PetscInt inassm = 0;
5886:   PetscBool       flg    = PETSC_FALSE;

5888:   PetscFunctionBegin;

5892:   inassm++;
5893:   MatAssemblyEnd_InUse++;
5894:   if (MatAssemblyEnd_InUse == 1) { /* Do the logging only the first time through */
5895:     PetscCall(PetscLogEventBegin(MAT_AssemblyEnd, mat, 0, 0, 0));
5896:     PetscTryTypeMethod(mat, assemblyend, type);
5897:     PetscCall(PetscLogEventEnd(MAT_AssemblyEnd, mat, 0, 0, 0));
5898:   } else PetscTryTypeMethod(mat, assemblyend, type);

5900:   /* Flush assembly is not a true assembly */
5901:   if (type != MAT_FLUSH_ASSEMBLY) {
5902:     if (mat->num_ass) {
5903:       if (!mat->symmetry_eternal) {
5904:         mat->symmetric = PETSC_BOOL3_UNKNOWN;
5905:         mat->hermitian = PETSC_BOOL3_UNKNOWN;
5906:       }
5907:       if (!mat->structural_symmetry_eternal && mat->ass_nonzerostate != mat->nonzerostate) mat->structurally_symmetric = PETSC_BOOL3_UNKNOWN;
5908:       if (!mat->spd_eternal) mat->spd = PETSC_BOOL3_UNKNOWN;
5909:     }
5910:     mat->num_ass++;
5911:     mat->assembled        = PETSC_TRUE;
5912:     mat->ass_nonzerostate = mat->nonzerostate;
5913:   }

5915:   mat->insertmode = NOT_SET_VALUES;
5916:   MatAssemblyEnd_InUse--;
5917:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5918:   if (inassm == 1 && type != MAT_FLUSH_ASSEMBLY) {
5919:     PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));

5921:     if (mat->checksymmetryonassembly) {
5922:       PetscCall(MatIsSymmetric(mat, mat->checksymmetrytol, &flg));
5923:       if (flg) {
5924:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
5925:       } else {
5926:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is not symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
5927:       }
5928:     }
5929:     if (mat->nullsp && mat->checknullspaceonassembly) PetscCall(MatNullSpaceTest(mat->nullsp, mat, NULL));
5930:   }
5931:   inassm--;
5932:   PetscFunctionReturn(PETSC_SUCCESS);
5933: }

5935: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
5936: /*@
5937:   MatSetOption - Sets a parameter option for a matrix. Some options
5938:   may be specific to certain storage formats.  Some options
5939:   determine how values will be inserted (or added). Sorted,
5940:   row-oriented input will generally assemble the fastest. The default
5941:   is row-oriented.

5943:   Logically Collective for certain operations, such as `MAT_SPD`, not collective for `MAT_ROW_ORIENTED`, see `MatOption`

5945:   Input Parameters:
5946: + mat - the matrix
5947: . op  - the option, one of those listed below (and possibly others),
5948: - flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

5950:   Options Describing Matrix Structure:
5951: + `MAT_SPD`                         - symmetric positive definite
5952: . `MAT_SYMMETRIC`                   - symmetric in terms of both structure and value
5953: . `MAT_HERMITIAN`                   - transpose is the complex conjugation
5954: . `MAT_STRUCTURALLY_SYMMETRIC`      - symmetric nonzero structure
5955: . `MAT_SYMMETRY_ETERNAL`            - indicates the symmetry (or Hermitian structure) or its absence will persist through any changes to the matrix
5956: . `MAT_STRUCTURAL_SYMMETRY_ETERNAL` - indicates the structural symmetry or its absence will persist through any changes to the matrix
5957: . `MAT_SPD_ETERNAL`                 - indicates the value of `MAT_SPD` (true or false) will persist through any changes to the matrix

5959:    These are not really options of the matrix, they are knowledge about the structure of the matrix that users may provide so that they
5960:    do not need to be computed (usually at a high cost)

5962:    Options For Use with `MatSetValues()`:
5963:    Insert a logically dense subblock, which can be
5964: . `MAT_ROW_ORIENTED`                - row-oriented (default)

5966:    These options reflect the data you pass in with `MatSetValues()`; it has
5967:    nothing to do with how the data is stored internally in the matrix
5968:    data structure.

5970:    When (re)assembling a matrix, we can restrict the input for
5971:    efficiency/debugging purposes.  These options include
5972: . `MAT_NEW_NONZERO_LOCATIONS`       - additional insertions will be allowed if they generate a new nonzero (slow)
5973: . `MAT_FORCE_DIAGONAL_ENTRIES`      - forces diagonal entries to be allocated
5974: . `MAT_IGNORE_OFF_PROC_ENTRIES`     - drops off-processor entries
5975: . `MAT_NEW_NONZERO_LOCATION_ERR`    - generates an error for new matrix entry
5976: . `MAT_USE_HASH_TABLE`              - uses a hash table to speed up matrix assembly
5977: . `MAT_NO_OFF_PROC_ENTRIES`         - you know each process will only set values for its own rows, will generate an error if
5978:         any process sets values for another process. This avoids all reductions in the MatAssembly routines and thus improves
5979:         performance for very large process counts.
5980: - `MAT_SUBSET_OFF_PROC_ENTRIES`     - you know that the first assembly after setting this flag will set a superset
5981:         of the off-process entries required for all subsequent assemblies. This avoids a rendezvous step in the MatAssembly
5982:         functions, instead sending only neighbor messages.

5984:   Level: intermediate

5986:   Notes:
5987:   Except for `MAT_UNUSED_NONZERO_LOCATION_ERR` and  `MAT_ROW_ORIENTED` all processes that share the matrix must pass the same value in flg!

5989:   Some options are relevant only for particular matrix types and
5990:   are thus ignored by others.  Other options are not supported by
5991:   certain matrix types and will generate an error message if set.

5993:   If using Fortran to compute a matrix, one may need to
5994:   use the column-oriented option (or convert to the row-oriented
5995:   format).

5997:   `MAT_NEW_NONZERO_LOCATIONS` set to `PETSC_FALSE` indicates that any add or insertion
5998:   that would generate a new entry in the nonzero structure is instead
5999:   ignored.  Thus, if memory has not already been allocated for this particular
6000:   data, then the insertion is ignored. For dense matrices, in which
6001:   the entire array is allocated, no entries are ever ignored.
6002:   Set after the first `MatAssemblyEnd()`. If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6004:   `MAT_NEW_NONZERO_LOCATION_ERR` set to PETSC_TRUE indicates that any add or insertion
6005:   that would generate a new entry in the nonzero structure instead produces
6006:   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

6008:   `MAT_NEW_NONZERO_ALLOCATION_ERR` set to `PETSC_TRUE` indicates that any add or insertion
6009:   that would generate a new entry that has not been preallocated will
6010:   instead produce an error. (Currently supported for `MATAIJ` and `MATBAIJ` formats
6011:   only.) This is a useful flag when debugging matrix memory preallocation.
6012:   If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

6014:   `MAT_IGNORE_OFF_PROC_ENTRIES` set to `PETSC_TRUE` indicates entries destined for
6015:   other processors should be dropped, rather than stashed.
6016:   This is useful if you know that the "owning" processor is also
6017:   always generating the correct matrix entries, so that PETSc need
6018:   not transfer duplicate entries generated on another processor.

6020:   `MAT_USE_HASH_TABLE` indicates that a hash table be used to improve the
6021:   searches during matrix assembly. When this flag is set, the hash table
6022:   is created during the first matrix assembly. This hash table is
6023:   used the next time through, during `MatSetValues()`/`MatSetValuesBlocked()`
6024:   to improve the searching of indices. `MAT_NEW_NONZERO_LOCATIONS` flag
6025:   should be used with `MAT_USE_HASH_TABLE` flag. This option is currently
6026:   supported by `MATMPIBAIJ` format only.

6028:   `MAT_KEEP_NONZERO_PATTERN` indicates when `MatZeroRows()` is called the zeroed entries
6029:   are kept in the nonzero structure. This flag is not used for `MatZeroRowsColumns()`

6031:   `MAT_IGNORE_ZERO_ENTRIES` - for `MATAIJ` and `MATIS` matrices this will stop zero values from creating
6032:   a zero location in the matrix

6034:   `MAT_USE_INODES` - indicates using inode version of the code - works with `MATAIJ` matrix types

6036:   `MAT_NO_OFF_PROC_ZERO_ROWS` - you know each process will only zero its own rows. This avoids all reductions in the
6037:   zero row routines and thus improves performance for very large process counts.

6039:   `MAT_IGNORE_LOWER_TRIANGULAR` - For `MATSBAIJ` matrices will ignore any insertions you make in the lower triangular
6040:   part of the matrix (since they should match the upper triangular part).

6042:   `MAT_SORTED_FULL` - each process provides exactly its local rows; all column indices for a given row are passed in a
6043:   single call to `MatSetValues()`, preallocation is perfect, row-oriented, `INSERT_VALUES` is used. Common
6044:   with finite difference schemes with non-periodic boundary conditions.

6046:   Developer Note:
6047:   `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, and `MAT_SPD_ETERNAL` are used by `MatAssemblyEnd()` and in other
6048:   places where otherwise the value of `MAT_SYMMETRIC`, `MAT_STRUCTURALLY_SYMMETRIC` or `MAT_SPD` would need to be changed back
6049:   to `PETSC_BOOL3_UNKNOWN` because the matrix values had changed so the code cannot be certain that the related property had
6050:   not changed.

6052: .seealso: [](ch_matrices), `MatOption`, `Mat`, `MatGetOption()`
6053: @*/
6054: PetscErrorCode MatSetOption(Mat mat, MatOption op, PetscBool flg)
6055: {
6056:   PetscFunctionBegin;
6058:   if (op > 0) {
6061:   }

6063:   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);

6065:   switch (op) {
6066:   case MAT_FORCE_DIAGONAL_ENTRIES:
6067:     mat->force_diagonals = flg;
6068:     PetscFunctionReturn(PETSC_SUCCESS);
6069:   case MAT_NO_OFF_PROC_ENTRIES:
6070:     mat->nooffprocentries = flg;
6071:     PetscFunctionReturn(PETSC_SUCCESS);
6072:   case MAT_SUBSET_OFF_PROC_ENTRIES:
6073:     mat->assembly_subset = flg;
6074:     if (!mat->assembly_subset) { /* See the same logic in VecAssembly wrt VEC_SUBSET_OFF_PROC_ENTRIES */
6075: #if !defined(PETSC_HAVE_MPIUNI)
6076:       PetscCall(MatStashScatterDestroy_BTS(&mat->stash));
6077: #endif
6078:       mat->stash.first_assembly_done = PETSC_FALSE;
6079:     }
6080:     PetscFunctionReturn(PETSC_SUCCESS);
6081:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6082:     mat->nooffproczerorows = flg;
6083:     PetscFunctionReturn(PETSC_SUCCESS);
6084:   case MAT_SPD:
6085:     if (flg) {
6086:       mat->spd                    = PETSC_BOOL3_TRUE;
6087:       mat->symmetric              = PETSC_BOOL3_TRUE;
6088:       mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6089:     } else {
6090:       mat->spd = PETSC_BOOL3_FALSE;
6091:     }
6092:     break;
6093:   case MAT_SYMMETRIC:
6094:     mat->symmetric = PetscBoolToBool3(flg);
6095:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6096: #if !defined(PETSC_USE_COMPLEX)
6097:     mat->hermitian = PetscBoolToBool3(flg);
6098: #endif
6099:     break;
6100:   case MAT_HERMITIAN:
6101:     mat->hermitian = PetscBoolToBool3(flg);
6102:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6103: #if !defined(PETSC_USE_COMPLEX)
6104:     mat->symmetric = PetscBoolToBool3(flg);
6105: #endif
6106:     break;
6107:   case MAT_STRUCTURALLY_SYMMETRIC:
6108:     mat->structurally_symmetric = PetscBoolToBool3(flg);
6109:     break;
6110:   case MAT_SYMMETRY_ETERNAL:
6111:     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");
6112:     mat->symmetry_eternal = flg;
6113:     if (flg) mat->structural_symmetry_eternal = PETSC_TRUE;
6114:     break;
6115:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6116:     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");
6117:     mat->structural_symmetry_eternal = flg;
6118:     break;
6119:   case MAT_SPD_ETERNAL:
6120:     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");
6121:     mat->spd_eternal = flg;
6122:     if (flg) {
6123:       mat->structural_symmetry_eternal = PETSC_TRUE;
6124:       mat->symmetry_eternal            = PETSC_TRUE;
6125:     }
6126:     break;
6127:   case MAT_STRUCTURE_ONLY:
6128:     mat->structure_only = flg;
6129:     break;
6130:   case MAT_SORTED_FULL:
6131:     mat->sortedfull = flg;
6132:     break;
6133:   default:
6134:     break;
6135:   }
6136:   PetscTryTypeMethod(mat, setoption, op, flg);
6137:   PetscFunctionReturn(PETSC_SUCCESS);
6138: }

6140: /*@
6141:   MatGetOption - Gets a parameter option that has been set for a matrix.

6143:   Logically Collective

6145:   Input Parameters:
6146: + mat - the matrix
6147: - op  - the option, this only responds to certain options, check the code for which ones

6149:   Output Parameter:
6150: . flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6152:   Level: intermediate

6154:   Notes:
6155:   Can only be called after `MatSetSizes()` and `MatSetType()` have been set.

6157:   Certain option values may be unknown, for those use the routines `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, or
6158:   `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`

6160: .seealso: [](ch_matrices), `Mat`, `MatOption`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`,
6161:     `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
6162: @*/
6163: PetscErrorCode MatGetOption(Mat mat, MatOption op, PetscBool *flg)
6164: {
6165:   PetscFunctionBegin;

6169:   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);
6170:   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()");

6172:   switch (op) {
6173:   case MAT_NO_OFF_PROC_ENTRIES:
6174:     *flg = mat->nooffprocentries;
6175:     break;
6176:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6177:     *flg = mat->nooffproczerorows;
6178:     break;
6179:   case MAT_SYMMETRIC:
6180:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSymmetric() or MatIsSymmetricKnown()");
6181:     break;
6182:   case MAT_HERMITIAN:
6183:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsHermitian() or MatIsHermitianKnown()");
6184:     break;
6185:   case MAT_STRUCTURALLY_SYMMETRIC:
6186:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsStructurallySymmetric() or MatIsStructurallySymmetricKnown()");
6187:     break;
6188:   case MAT_SPD:
6189:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSPDKnown()");
6190:     break;
6191:   case MAT_SYMMETRY_ETERNAL:
6192:     *flg = mat->symmetry_eternal;
6193:     break;
6194:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6195:     *flg = mat->symmetry_eternal;
6196:     break;
6197:   default:
6198:     break;
6199:   }
6200:   PetscFunctionReturn(PETSC_SUCCESS);
6201: }

6203: /*@
6204:   MatZeroEntries - Zeros all entries of a matrix.  For sparse matrices
6205:   this routine retains the old nonzero structure.

6207:   Logically Collective

6209:   Input Parameter:
6210: . mat - the matrix

6212:   Level: intermediate

6214:   Note:
6215:   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.
6216:   See the Performance chapter of the users manual for information on preallocating matrices.

6218: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`
6219: @*/
6220: PetscErrorCode MatZeroEntries(Mat mat)
6221: {
6222:   PetscFunctionBegin;
6225:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6226:   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");
6227:   MatCheckPreallocated(mat, 1);

6229:   PetscCall(PetscLogEventBegin(MAT_ZeroEntries, mat, 0, 0, 0));
6230:   PetscUseTypeMethod(mat, zeroentries);
6231:   PetscCall(PetscLogEventEnd(MAT_ZeroEntries, mat, 0, 0, 0));
6232:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6233:   PetscFunctionReturn(PETSC_SUCCESS);
6234: }

6236: /*@
6237:   MatZeroRowsColumns - Zeros all entries (except possibly the main diagonal)
6238:   of a set of rows and columns of a matrix.

6240:   Collective

6242:   Input Parameters:
6243: + mat     - the matrix
6244: . numRows - the number of rows/columns to zero
6245: . rows    - the global row indices
6246: . diag    - value put in the diagonal of the eliminated rows
6247: . x       - optional vector of the solution for zeroed rows (other entries in vector are not used), these must be set before this call
6248: - b       - optional vector of the right-hand side, that will be adjusted by provided solution entries

6250:   Level: intermediate

6252:   Notes:
6253:   This routine, along with `MatZeroRows()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6255:   For each zeroed row, the value of the corresponding `b` is set to diag times the value of the corresponding `x`.
6256:   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

6258:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6259:   Krylov method to take advantage of the known solution on the zeroed rows.

6261:   For the parallel case, all processes that share the matrix (i.e.,
6262:   those in the communicator used for matrix creation) MUST call this
6263:   routine, regardless of whether any rows being zeroed are owned by
6264:   them.

6266:   Unlike `MatZeroRows()`, this ignores the `MAT_KEEP_NONZERO_PATTERN` option value set with `MatSetOption()`, it merely zeros those entries in the matrix, but never
6267:   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
6268:   missing.

6270:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6271:   list only rows local to itself).

6273:   The option `MAT_NO_OFF_PROC_ZERO_ROWS` does not apply to this routine.

6275: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRows()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6276:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6277: @*/
6278: PetscErrorCode MatZeroRowsColumns(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6279: {
6280:   PetscFunctionBegin;
6283:   if (numRows) PetscAssertPointer(rows, 3);
6284:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6285:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6286:   MatCheckPreallocated(mat, 1);

6288:   PetscUseTypeMethod(mat, zerorowscolumns, numRows, rows, diag, x, b);
6289:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6290:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6291:   PetscFunctionReturn(PETSC_SUCCESS);
6292: }

6294: /*@
6295:   MatZeroRowsColumnsIS - Zeros all entries (except possibly the main diagonal)
6296:   of a set of rows and columns of a matrix.

6298:   Collective

6300:   Input Parameters:
6301: + mat  - the matrix
6302: . is   - the rows to zero
6303: . diag - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6304: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6305: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6307:   Level: intermediate

6309:   Note:
6310:   See `MatZeroRowsColumns()` for details on how this routine operates.

6312: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6313:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRows()`, `MatZeroRowsColumnsStencil()`
6314: @*/
6315: PetscErrorCode MatZeroRowsColumnsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6316: {
6317:   PetscInt        numRows;
6318:   const PetscInt *rows;

6320:   PetscFunctionBegin;
6325:   PetscCall(ISGetLocalSize(is, &numRows));
6326:   PetscCall(ISGetIndices(is, &rows));
6327:   PetscCall(MatZeroRowsColumns(mat, numRows, rows, diag, x, b));
6328:   PetscCall(ISRestoreIndices(is, &rows));
6329:   PetscFunctionReturn(PETSC_SUCCESS);
6330: }

6332: /*@
6333:   MatZeroRows - Zeros all entries (except possibly the main diagonal)
6334:   of a set of rows of a matrix.

6336:   Collective

6338:   Input Parameters:
6339: + mat     - the matrix
6340: . numRows - the number of rows to zero
6341: . rows    - the global row indices
6342: . diag    - value put in the diagonal of the zeroed rows
6343: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used), these must be set before this call
6344: - b       - optional vector of right-hand side, that will be adjusted by provided solution entries

6346:   Level: intermediate

6348:   Notes:
6349:   This routine, along with `MatZeroRowsColumns()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6351:   For each zeroed row, the value of the corresponding `b` is set to `diag` times the value of the corresponding `x`.

6353:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6354:   Krylov method to take advantage of the known solution on the zeroed rows.

6356:   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)
6357:   from the matrix.

6359:   Unlike `MatZeroRowsColumns()` for the `MATAIJ` and `MATBAIJ` matrix formats this removes the old nonzero structure, from the eliminated rows of the matrix
6360:   but does not release memory.  Because of this removal matrix-vector products with the adjusted matrix will be a bit faster. For the dense
6361:   formats this does not alter the nonzero structure.

6363:   If the option `MatSetOption`(mat,`MAT_KEEP_NONZERO_PATTERN`,`PETSC_TRUE`) the nonzero structure
6364:   of the matrix is not changed the values are
6365:   merely zeroed.

6367:   The user can set a value in the diagonal entry (or for the `MATAIJ` format
6368:   formats can optionally remove the main diagonal entry from the
6369:   nonzero structure as well, by passing 0.0 as the final argument).

6371:   For the parallel case, all processes that share the matrix (i.e.,
6372:   those in the communicator used for matrix creation) MUST call this
6373:   routine, regardless of whether any rows being zeroed are owned by
6374:   them.

6376:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6377:   list only rows local to itself).

6379:   You can call `MatSetOption`(mat,`MAT_NO_OFF_PROC_ZERO_ROWS`,`PETSC_TRUE`) if each process indicates only rows it
6380:   owns that are to be zeroed. This saves a global synchronization in the implementation.

6382: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6383:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `PCREDISTRIBUTE`, `MAT_KEEP_NONZERO_PATTERN`
6384: @*/
6385: PetscErrorCode MatZeroRows(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6386: {
6387:   PetscFunctionBegin;
6390:   if (numRows) PetscAssertPointer(rows, 3);
6391:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6392:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6393:   MatCheckPreallocated(mat, 1);

6395:   PetscUseTypeMethod(mat, zerorows, numRows, rows, diag, x, b);
6396:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6397:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6398:   PetscFunctionReturn(PETSC_SUCCESS);
6399: }

6401: /*@
6402:   MatZeroRowsIS - Zeros all entries (except possibly the main diagonal)
6403:   of a set of rows of a matrix indicated by an `IS`

6405:   Collective

6407:   Input Parameters:
6408: + mat  - the matrix
6409: . is   - index set, `IS`, of rows to remove (if `NULL` then no row is removed)
6410: . diag - value put in all diagonals of eliminated rows
6411: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6412: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6414:   Level: intermediate

6416:   Note:
6417:   See `MatZeroRows()` for details on how this routine operates.

6419: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6420:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `IS`
6421: @*/
6422: PetscErrorCode MatZeroRowsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6423: {
6424:   PetscInt        numRows = 0;
6425:   const PetscInt *rows    = NULL;

6427:   PetscFunctionBegin;
6430:   if (is) {
6432:     PetscCall(ISGetLocalSize(is, &numRows));
6433:     PetscCall(ISGetIndices(is, &rows));
6434:   }
6435:   PetscCall(MatZeroRows(mat, numRows, rows, diag, x, b));
6436:   if (is) PetscCall(ISRestoreIndices(is, &rows));
6437:   PetscFunctionReturn(PETSC_SUCCESS);
6438: }

6440: /*@
6441:   MatZeroRowsStencil - Zeros all entries (except possibly the main diagonal)
6442:   of a set of rows of a matrix indicated by a `MatStencil`. These rows must be local to the process.

6444:   Collective

6446:   Input Parameters:
6447: + mat     - the matrix
6448: . numRows - the number of rows to remove
6449: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows indicated by an array of `MatStencil`
6450: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6451: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6452: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6454:   Level: intermediate

6456:   Notes:
6457:   See `MatZeroRows()` for details on how this routine operates.

6459:   The grid coordinates are across the entire grid, not just the local portion

6461:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6462:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6463:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6464:   `DM_BOUNDARY_PERIODIC` boundary type.

6466:   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
6467:   a single value per point) you can skip filling those indices.

6469:   Fortran Note:
6470:   `idxm` and `idxn` should be declared as
6471: .vb
6472:     MatStencil idxm(4, m)
6473: .ve
6474:   and the values inserted using
6475: .vb
6476:     idxm(MatStencil_i, 1) = i
6477:     idxm(MatStencil_j, 1) = j
6478:     idxm(MatStencil_k, 1) = k
6479:     idxm(MatStencil_c, 1) = c
6480:    etc
6481: .ve

6483: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRows()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6484:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6485: @*/
6486: PetscErrorCode MatZeroRowsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6487: {
6488:   PetscInt  dim    = mat->stencil.dim;
6489:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6490:   PetscInt *dims   = mat->stencil.dims + 1;
6491:   PetscInt *starts = mat->stencil.starts;
6492:   PetscInt *dxm    = (PetscInt *)rows;
6493:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6495:   PetscFunctionBegin;
6498:   if (numRows) PetscAssertPointer(rows, 3);

6500:   PetscCall(PetscMalloc1(numRows, &jdxm));
6501:   for (i = 0; i < numRows; ++i) {
6502:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6503:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6504:     /* Local index in X dir */
6505:     tmp = *dxm++ - starts[0];
6506:     /* Loop over remaining dimensions */
6507:     for (j = 0; j < dim - 1; ++j) {
6508:       /* If nonlocal, set index to be negative */
6509:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6510:       /* Update local index */
6511:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6512:     }
6513:     /* Skip component slot if necessary */
6514:     if (mat->stencil.noc) dxm++;
6515:     /* Local row number */
6516:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6517:   }
6518:   PetscCall(MatZeroRowsLocal(mat, numNewRows, jdxm, diag, x, b));
6519:   PetscCall(PetscFree(jdxm));
6520:   PetscFunctionReturn(PETSC_SUCCESS);
6521: }

6523: /*@
6524:   MatZeroRowsColumnsStencil - Zeros all row and column entries (except possibly the main diagonal)
6525:   of a set of rows and columns of a matrix.

6527:   Collective

6529:   Input Parameters:
6530: + mat     - the matrix
6531: . numRows - the number of rows/columns to remove
6532: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows
6533: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6534: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6535: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6537:   Level: intermediate

6539:   Notes:
6540:   See `MatZeroRowsColumns()` for details on how this routine operates.

6542:   The grid coordinates are across the entire grid, not just the local portion

6544:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6545:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6546:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6547:   `DM_BOUNDARY_PERIODIC` boundary type.

6549:   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
6550:   a single value per point) you can skip filling those indices.

6552:   Fortran Note:
6553:   `idxm` and `idxn` should be declared as
6554: .vb
6555:     MatStencil idxm(4, m)
6556: .ve
6557:   and the values inserted using
6558: .vb
6559:     idxm(MatStencil_i, 1) = i
6560:     idxm(MatStencil_j, 1) = j
6561:     idxm(MatStencil_k, 1) = k
6562:     idxm(MatStencil_c, 1) = c
6563:     etc
6564: .ve

6566: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6567:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRows()`
6568: @*/
6569: PetscErrorCode MatZeroRowsColumnsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6570: {
6571:   PetscInt  dim    = mat->stencil.dim;
6572:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6573:   PetscInt *dims   = mat->stencil.dims + 1;
6574:   PetscInt *starts = mat->stencil.starts;
6575:   PetscInt *dxm    = (PetscInt *)rows;
6576:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6578:   PetscFunctionBegin;
6581:   if (numRows) PetscAssertPointer(rows, 3);

6583:   PetscCall(PetscMalloc1(numRows, &jdxm));
6584:   for (i = 0; i < numRows; ++i) {
6585:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6586:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6587:     /* Local index in X dir */
6588:     tmp = *dxm++ - starts[0];
6589:     /* Loop over remaining dimensions */
6590:     for (j = 0; j < dim - 1; ++j) {
6591:       /* If nonlocal, set index to be negative */
6592:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6593:       /* Update local index */
6594:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6595:     }
6596:     /* Skip component slot if necessary */
6597:     if (mat->stencil.noc) dxm++;
6598:     /* Local row number */
6599:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6600:   }
6601:   PetscCall(MatZeroRowsColumnsLocal(mat, numNewRows, jdxm, diag, x, b));
6602:   PetscCall(PetscFree(jdxm));
6603:   PetscFunctionReturn(PETSC_SUCCESS);
6604: }

6606: /*@
6607:   MatZeroRowsLocal - Zeros all entries (except possibly the main diagonal)
6608:   of a set of rows of a matrix; using local numbering of rows.

6610:   Collective

6612:   Input Parameters:
6613: + mat     - the matrix
6614: . numRows - the number of rows to remove
6615: . rows    - the local row indices
6616: . diag    - value put in all diagonals of eliminated rows
6617: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6618: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6620:   Level: intermediate

6622:   Notes:
6623:   Before calling `MatZeroRowsLocal()`, the user must first set the
6624:   local-to-global mapping by calling MatSetLocalToGlobalMapping(), this is often already set for matrices obtained with `DMCreateMatrix()`.

6626:   See `MatZeroRows()` for details on how this routine operates.

6628: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRows()`, `MatSetOption()`,
6629:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6630: @*/
6631: PetscErrorCode MatZeroRowsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6632: {
6633:   PetscFunctionBegin;
6636:   if (numRows) PetscAssertPointer(rows, 3);
6637:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6638:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6639:   MatCheckPreallocated(mat, 1);

6641:   if (mat->ops->zerorowslocal) {
6642:     PetscUseTypeMethod(mat, zerorowslocal, numRows, rows, diag, x, b);
6643:   } else {
6644:     IS        is, newis;
6645:     PetscInt *newRows, nl = 0;

6647:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6648:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6649:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6650:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6651:     for (PetscInt i = 0; i < numRows; i++)
6652:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6653:     PetscUseTypeMethod(mat, zerorows, nl, newRows, diag, x, b);
6654:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6655:     PetscCall(ISDestroy(&newis));
6656:     PetscCall(ISDestroy(&is));
6657:   }
6658:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6659:   PetscFunctionReturn(PETSC_SUCCESS);
6660: }

6662: /*@
6663:   MatZeroRowsLocalIS - Zeros all entries (except possibly the main diagonal)
6664:   of a set of rows of a matrix; using local numbering of rows.

6666:   Collective

6668:   Input Parameters:
6669: + mat  - the matrix
6670: . is   - index set of rows to remove
6671: . diag - value put in all diagonals of eliminated rows
6672: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6673: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6675:   Level: intermediate

6677:   Notes:
6678:   Before calling `MatZeroRowsLocalIS()`, the user must first set the
6679:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6681:   See `MatZeroRows()` for details on how this routine operates.

6683: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRows()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6684:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6685: @*/
6686: PetscErrorCode MatZeroRowsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6687: {
6688:   PetscInt        numRows;
6689:   const PetscInt *rows;

6691:   PetscFunctionBegin;
6695:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6696:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6697:   MatCheckPreallocated(mat, 1);

6699:   PetscCall(ISGetLocalSize(is, &numRows));
6700:   PetscCall(ISGetIndices(is, &rows));
6701:   PetscCall(MatZeroRowsLocal(mat, numRows, rows, diag, x, b));
6702:   PetscCall(ISRestoreIndices(is, &rows));
6703:   PetscFunctionReturn(PETSC_SUCCESS);
6704: }

6706: /*@
6707:   MatZeroRowsColumnsLocal - Zeros all entries (except possibly the main diagonal)
6708:   of a set of rows and columns of a matrix; using local numbering of rows.

6710:   Collective

6712:   Input Parameters:
6713: + mat     - the matrix
6714: . numRows - the number of rows to remove
6715: . rows    - the global row indices
6716: . diag    - value put in all diagonals of eliminated rows
6717: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6718: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6720:   Level: intermediate

6722:   Notes:
6723:   Before calling `MatZeroRowsColumnsLocal()`, the user must first set the
6724:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6726:   See `MatZeroRowsColumns()` for details on how this routine operates.

6728: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6729:           `MatZeroRows()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6730: @*/
6731: PetscErrorCode MatZeroRowsColumnsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6732: {
6733:   PetscFunctionBegin;
6736:   if (numRows) PetscAssertPointer(rows, 3);
6737:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6738:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6739:   MatCheckPreallocated(mat, 1);

6741:   if (mat->ops->zerorowscolumnslocal) {
6742:     PetscUseTypeMethod(mat, zerorowscolumnslocal, numRows, rows, diag, x, b);
6743:   } else {
6744:     IS        is, newis;
6745:     PetscInt *newRows, nl = 0;

6747:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6748:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6749:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6750:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6751:     for (PetscInt i = 0; i < numRows; i++)
6752:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6753:     PetscUseTypeMethod(mat, zerorowscolumns, nl, newRows, diag, x, b);
6754:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6755:     PetscCall(ISDestroy(&newis));
6756:     PetscCall(ISDestroy(&is));
6757:   }
6758:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6759:   PetscFunctionReturn(PETSC_SUCCESS);
6760: }

6762: /*@
6763:   MatZeroRowsColumnsLocalIS - Zeros all entries (except possibly the main diagonal)
6764:   of a set of rows and columns of a matrix; using local numbering of rows.

6766:   Collective

6768:   Input Parameters:
6769: + mat  - the matrix
6770: . is   - index set of rows to remove
6771: . diag - value put in all diagonals of eliminated rows
6772: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6773: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6775:   Level: intermediate

6777:   Notes:
6778:   Before calling `MatZeroRowsColumnsLocalIS()`, the user must first set the
6779:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6781:   See `MatZeroRowsColumns()` for details on how this routine operates.

6783: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6784:           `MatZeroRowsColumnsLocal()`, `MatZeroRows()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6785: @*/
6786: PetscErrorCode MatZeroRowsColumnsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6787: {
6788:   PetscInt        numRows;
6789:   const PetscInt *rows;

6791:   PetscFunctionBegin;
6795:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6796:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6797:   MatCheckPreallocated(mat, 1);

6799:   PetscCall(ISGetLocalSize(is, &numRows));
6800:   PetscCall(ISGetIndices(is, &rows));
6801:   PetscCall(MatZeroRowsColumnsLocal(mat, numRows, rows, diag, x, b));
6802:   PetscCall(ISRestoreIndices(is, &rows));
6803:   PetscFunctionReturn(PETSC_SUCCESS);
6804: }

6806: /*@
6807:   MatGetSize - Returns the numbers of rows and columns in a matrix.

6809:   Not Collective

6811:   Input Parameter:
6812: . mat - the matrix

6814:   Output Parameters:
6815: + m - the number of global rows
6816: - n - the number of global columns

6818:   Level: beginner

6820:   Note:
6821:   Both output parameters can be `NULL` on input.

6823: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetLocalSize()`
6824: @*/
6825: PetscErrorCode MatGetSize(Mat mat, PetscInt *m, PetscInt *n)
6826: {
6827:   PetscFunctionBegin;
6829:   if (m) *m = mat->rmap->N;
6830:   if (n) *n = mat->cmap->N;
6831:   PetscFunctionReturn(PETSC_SUCCESS);
6832: }

6834: /*@
6835:   MatGetLocalSize - For most matrix formats, excluding `MATELEMENTAL` and `MATSCALAPACK`, Returns the number of local rows and local columns
6836:   of a matrix. For all matrices this is the local size of the left and right vectors as returned by `MatCreateVecs()`.

6838:   Not Collective

6840:   Input Parameter:
6841: . mat - the matrix

6843:   Output Parameters:
6844: + m - the number of local rows, use `NULL` to not obtain this value
6845: - n - the number of local columns, use `NULL` to not obtain this value

6847:   Level: beginner

6849: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetSize()`
6850: @*/
6851: PetscErrorCode MatGetLocalSize(Mat mat, PetscInt *m, PetscInt *n)
6852: {
6853:   PetscFunctionBegin;
6855:   if (m) PetscAssertPointer(m, 2);
6856:   if (n) PetscAssertPointer(n, 3);
6857:   if (m) *m = mat->rmap->n;
6858:   if (n) *n = mat->cmap->n;
6859:   PetscFunctionReturn(PETSC_SUCCESS);
6860: }

6862: /*@
6863:   MatGetOwnershipRangeColumn - Returns the range of matrix columns associated with rows of a
6864:   vector one multiplies this matrix by that are owned by this processor.

6866:   Not Collective, unless matrix has not been allocated, then collective

6868:   Input Parameter:
6869: . mat - the matrix

6871:   Output Parameters:
6872: + m - the global index of the first local column, use `NULL` to not obtain this value
6873: - n - one more than the global index of the last local column, use `NULL` to not obtain this value

6875:   Level: developer

6877:   Notes:
6878:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6880:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6881:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6883:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6884:   the local values in the matrix.

6886:   Returns the columns of the "diagonal block" for most sparse matrix formats. See [Matrix
6887:   Layouts](sec_matlayout) for details on matrix layouts.

6889: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
6890:           `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
6891: @*/
6892: PetscErrorCode MatGetOwnershipRangeColumn(Mat mat, PetscInt *m, PetscInt *n)
6893: {
6894:   PetscFunctionBegin;
6897:   if (m) PetscAssertPointer(m, 2);
6898:   if (n) PetscAssertPointer(n, 3);
6899:   MatCheckPreallocated(mat, 1);
6900:   if (m) *m = mat->cmap->rstart;
6901:   if (n) *n = mat->cmap->rend;
6902:   PetscFunctionReturn(PETSC_SUCCESS);
6903: }

6905: /*@
6906:   MatGetOwnershipRange - For matrices that own values by row, excludes `MATELEMENTAL` and `MATSCALAPACK`, returns the range of matrix rows owned by
6907:   this MPI process.

6909:   Not Collective

6911:   Input Parameter:
6912: . mat - the matrix

6914:   Output Parameters:
6915: + m - the global index of the first local row, use `NULL` to not obtain this value
6916: - n - one more than the global index of the last local row, use `NULL` to not obtain this value

6918:   Level: beginner

6920:   Notes:
6921:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6923:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6924:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6926:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6927:   the local values in the matrix.

6929:   The high argument is one more than the last element stored locally.

6931:   For all matrices  it returns the range of matrix rows associated with rows of a vector that
6932:   would contain the result of a matrix vector product with this matrix. See [Matrix
6933:   Layouts](sec_matlayout) for details on matrix layouts.

6935: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscSplitOwnership()`,
6936:           `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
6937: @*/
6938: PetscErrorCode MatGetOwnershipRange(Mat mat, PetscInt *m, PetscInt *n)
6939: {
6940:   PetscFunctionBegin;
6943:   if (m) PetscAssertPointer(m, 2);
6944:   if (n) PetscAssertPointer(n, 3);
6945:   MatCheckPreallocated(mat, 1);
6946:   if (m) *m = mat->rmap->rstart;
6947:   if (n) *n = mat->rmap->rend;
6948:   PetscFunctionReturn(PETSC_SUCCESS);
6949: }

6951: /*@C
6952:   MatGetOwnershipRanges - For matrices that own values by row, excludes `MATELEMENTAL` and
6953:   `MATSCALAPACK`, returns the range of matrix rows owned by each process.

6955:   Not Collective, unless matrix has not been allocated

6957:   Input Parameter:
6958: . mat - the matrix

6960:   Output Parameter:
6961: . ranges - start of each processors portion plus one more than the total length at the end, of length `size` + 1
6962:            where `size` is the number of MPI processes used by `mat`

6964:   Level: beginner

6966:   Notes:
6967:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6969:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6970:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6972:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6973:   the local values in the matrix.

6975:   For all matrices  it returns the ranges of matrix rows associated with rows of a vector that
6976:   would contain the result of a matrix vector product with this matrix. See [Matrix
6977:   Layouts](sec_matlayout) for details on matrix layouts.

6979: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
6980:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `MatSetSizes()`, `MatCreateAIJ()`,
6981:           `DMDAGetGhostCorners()`, `DM`
6982: @*/
6983: PetscErrorCode MatGetOwnershipRanges(Mat mat, const PetscInt *ranges[])
6984: {
6985:   PetscFunctionBegin;
6988:   MatCheckPreallocated(mat, 1);
6989:   PetscCall(PetscLayoutGetRanges(mat->rmap, ranges));
6990:   PetscFunctionReturn(PETSC_SUCCESS);
6991: }

6993: /*@C
6994:   MatGetOwnershipRangesColumn - Returns the ranges of matrix columns associated with rows of a
6995:   vector one multiplies this vector by that are owned by each processor.

6997:   Not Collective, unless matrix has not been allocated

6999:   Input Parameter:
7000: . mat - the matrix

7002:   Output Parameter:
7003: . ranges - start of each processors portion plus one more than the total length at the end

7005:   Level: beginner

7007:   Notes:
7008:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

7010:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
7011:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

7013:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
7014:   the local values in the matrix.

7016:   Returns the columns of the "diagonal blocks", for most sparse matrix formats. See [Matrix
7017:   Layouts](sec_matlayout) for details on matrix layouts.

7019: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRanges()`,
7020:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`,
7021:           `DMDAGetGhostCorners()`, `DM`
7022: @*/
7023: PetscErrorCode MatGetOwnershipRangesColumn(Mat mat, const PetscInt *ranges[])
7024: {
7025:   PetscFunctionBegin;
7028:   MatCheckPreallocated(mat, 1);
7029:   PetscCall(PetscLayoutGetRanges(mat->cmap, ranges));
7030:   PetscFunctionReturn(PETSC_SUCCESS);
7031: }

7033: /*@
7034:   MatGetOwnershipIS - Get row and column ownership of a matrices' values as index sets.

7036:   Not Collective

7038:   Input Parameter:
7039: . A - matrix

7041:   Output Parameters:
7042: + rows - rows in which this process owns elements, , use `NULL` to not obtain this value
7043: - cols - columns in which this process owns elements, use `NULL` to not obtain this value

7045:   Level: intermediate

7047:   Note:
7048:   You should call `ISDestroy()` on the returned `IS`

7050:   For most matrices, excluding `MATELEMENTAL` and `MATSCALAPACK`, this corresponds to values
7051:   returned by `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`. For `MATELEMENTAL` and
7052:   `MATSCALAPACK` the ownership is more complicated. See [Matrix Layouts](sec_matlayout) for
7053:   details on matrix layouts.

7055: .seealso: [](ch_matrices), `IS`, `Mat`, `MatGetOwnershipRanges()`, `MatSetValues()`, `MATELEMENTAL`, `MATSCALAPACK`
7056: @*/
7057: PetscErrorCode MatGetOwnershipIS(Mat A, IS *rows, IS *cols)
7058: {
7059:   PetscErrorCode (*f)(Mat, IS *, IS *);

7061:   PetscFunctionBegin;
7064:   MatCheckPreallocated(A, 1);
7065:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatGetOwnershipIS_C", &f));
7066:   if (f) {
7067:     PetscCall((*f)(A, rows, cols));
7068:   } else { /* Create a standard row-based partition, each process is responsible for ALL columns in their row block */
7069:     if (rows) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->rmap->n, A->rmap->rstart, 1, rows));
7070:     if (cols) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->cmap->N, 0, 1, cols));
7071:   }
7072:   PetscFunctionReturn(PETSC_SUCCESS);
7073: }

7075: /*@
7076:   MatILUFactorSymbolic - Performs symbolic ILU factorization of a matrix obtained with `MatGetFactor()`
7077:   Uses levels of fill only, not drop tolerance. Use `MatLUFactorNumeric()`
7078:   to complete the factorization.

7080:   Collective

7082:   Input Parameters:
7083: + fact - the factorized matrix obtained with `MatGetFactor()`
7084: . mat  - the matrix
7085: . row  - row permutation
7086: . col  - column permutation
7087: - info - structure containing
7088: .vb
7089:       levels - number of levels of fill.
7090:       expected fill - as ratio of original fill.
7091:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
7092:                 missing diagonal entries)
7093: .ve

7095:   Level: developer

7097:   Notes:
7098:   See [Matrix Factorization](sec_matfactor) for additional information.

7100:   Most users should employ the `KSP` interface for linear solvers
7101:   instead of working directly with matrix algebra routines such as this.
7102:   See, e.g., `KSPCreate()`.

7104:   Uses the definition of level of fill as in Y. Saad, {cite}`saad2003`

7106:   Fortran Note:
7107:   A valid (non-null) `info` argument must be provided

7109: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
7110:           `MatGetOrdering()`, `MatFactorInfo`
7111: @*/
7112: PetscErrorCode MatILUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
7113: {
7114:   PetscFunctionBegin;
7119:   PetscAssertPointer(info, 5);
7120:   PetscAssertPointer(fact, 1);
7121:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels of fill negative %" PetscInt_FMT, (PetscInt)info->levels);
7122:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7123:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7124:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7125:   MatCheckPreallocated(mat, 2);

7127:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ILUFactorSymbolic, mat, row, col, 0));
7128:   PetscUseTypeMethod(fact, ilufactorsymbolic, mat, row, col, info);
7129:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ILUFactorSymbolic, mat, row, col, 0));
7130:   PetscFunctionReturn(PETSC_SUCCESS);
7131: }

7133: /*@
7134:   MatICCFactorSymbolic - Performs symbolic incomplete
7135:   Cholesky factorization for a symmetric matrix.  Use
7136:   `MatCholeskyFactorNumeric()` to complete the factorization.

7138:   Collective

7140:   Input Parameters:
7141: + fact - the factorized matrix obtained with `MatGetFactor()`
7142: . mat  - the matrix to be factored
7143: . perm - row and column permutation
7144: - info - structure containing
7145: .vb
7146:       levels - number of levels of fill.
7147:       expected fill - as ratio of original fill.
7148: .ve

7150:   Level: developer

7152:   Notes:
7153:   Most users should employ the `KSP` interface for linear solvers
7154:   instead of working directly with matrix algebra routines such as this.
7155:   See, e.g., `KSPCreate()`.

7157:   This uses the definition of level of fill as in Y. Saad {cite}`saad2003`

7159:   Fortran Note:
7160:   A valid (non-null) `info` argument must be provided

7162: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
7163: @*/
7164: PetscErrorCode MatICCFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
7165: {
7166:   PetscFunctionBegin;
7170:   PetscAssertPointer(info, 4);
7171:   PetscAssertPointer(fact, 1);
7172:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7173:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels negative %" PetscInt_FMT, (PetscInt)info->levels);
7174:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7175:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7176:   MatCheckPreallocated(mat, 2);

7178:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7179:   PetscUseTypeMethod(fact, iccfactorsymbolic, mat, perm, info);
7180:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7181:   PetscFunctionReturn(PETSC_SUCCESS);
7182: }

7184: /*@C
7185:   MatCreateSubMatrices - Extracts several submatrices from a matrix. If submat
7186:   points to an array of valid matrices, they may be reused to store the new
7187:   submatrices.

7189:   Collective

7191:   Input Parameters:
7192: + mat   - the matrix
7193: . n     - the number of submatrixes to be extracted (on this processor, may be zero)
7194: . irow  - index set of rows to extract
7195: . icol  - index set of columns to extract
7196: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7198:   Output Parameter:
7199: . submat - the array of submatrices

7201:   Level: advanced

7203:   Notes:
7204:   `MatCreateSubMatrices()` can extract ONLY sequential submatrices
7205:   (from both sequential and parallel matrices). Use `MatCreateSubMatrix()`
7206:   to extract a parallel submatrix.

7208:   Some matrix types place restrictions on the row and column
7209:   indices, such as that they be sorted or that they be equal to each other.

7211:   The index sets may not have duplicate entries.

7213:   When extracting submatrices from a parallel matrix, each processor can
7214:   form a different submatrix by setting the rows and columns of its
7215:   individual index sets according to the local submatrix desired.

7217:   When finished using the submatrices, the user should destroy
7218:   them with `MatDestroySubMatrices()`.

7220:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
7221:   original matrix has not changed from that last call to `MatCreateSubMatrices()`.

7223:   This routine creates the matrices in submat; you should NOT create them before
7224:   calling it. It also allocates the array of matrix pointers submat.

7226:   For `MATBAIJ` matrices the index sets must respect the block structure, that is if they
7227:   request one row/column in a block, they must request all rows/columns that are in
7228:   that block. For example, if the block size is 2 you cannot request just row 0 and
7229:   column 0.

7231:   Fortran Note:
7232: .vb
7233:   Mat, pointer :: submat(:)
7234: .ve

7236: .seealso: [](ch_matrices), `Mat`, `MatDestroySubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7237: @*/
7238: PetscErrorCode MatCreateSubMatrices(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7239: {
7240:   PetscInt  i;
7241:   PetscBool eq;

7243:   PetscFunctionBegin;
7246:   if (n) {
7247:     PetscAssertPointer(irow, 3);
7249:     PetscAssertPointer(icol, 4);
7251:   }
7252:   PetscAssertPointer(submat, 6);
7253:   if (n && scall == MAT_REUSE_MATRIX) {
7254:     PetscAssertPointer(*submat, 6);
7256:   }
7257:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7258:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7259:   MatCheckPreallocated(mat, 1);
7260:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7261:   PetscUseTypeMethod(mat, createsubmatrices, n, irow, icol, scall, submat);
7262:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7263:   for (i = 0; i < n; i++) {
7264:     (*submat)[i]->factortype = MAT_FACTOR_NONE; /* in case in place factorization was previously done on submatrix */
7265:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7266:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7267: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
7268:     if (mat->boundtocpu && mat->bindingpropagates) {
7269:       PetscCall(MatBindToCPU((*submat)[i], PETSC_TRUE));
7270:       PetscCall(MatSetBindingPropagates((*submat)[i], PETSC_TRUE));
7271:     }
7272: #endif
7273:   }
7274:   PetscFunctionReturn(PETSC_SUCCESS);
7275: }

7277: /*@C
7278:   MatCreateSubMatricesMPI - Extracts MPI submatrices across a sub communicator of `mat` (by pairs of `IS` that may live on subcomms).

7280:   Collective

7282:   Input Parameters:
7283: + mat   - the matrix
7284: . n     - the number of submatrixes to be extracted
7285: . irow  - index set of rows to extract
7286: . icol  - index set of columns to extract
7287: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7289:   Output Parameter:
7290: . submat - the array of submatrices

7292:   Level: advanced

7294:   Note:
7295:   This is used by `PCGASM`

7297: .seealso: [](ch_matrices), `Mat`, `PCGASM`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7298: @*/
7299: PetscErrorCode MatCreateSubMatricesMPI(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7300: {
7301:   PetscInt  i;
7302:   PetscBool eq;

7304:   PetscFunctionBegin;
7307:   if (n) {
7308:     PetscAssertPointer(irow, 3);
7310:     PetscAssertPointer(icol, 4);
7312:   }
7313:   PetscAssertPointer(submat, 6);
7314:   if (n && scall == MAT_REUSE_MATRIX) {
7315:     PetscAssertPointer(*submat, 6);
7317:   }
7318:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7319:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7320:   MatCheckPreallocated(mat, 1);

7322:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7323:   PetscUseTypeMethod(mat, createsubmatricesmpi, n, irow, icol, scall, submat);
7324:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7325:   for (i = 0; i < n; i++) {
7326:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7327:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7328:   }
7329:   PetscFunctionReturn(PETSC_SUCCESS);
7330: }

7332: /*@C
7333:   MatDestroyMatrices - Destroys an array of matrices

7335:   Collective

7337:   Input Parameters:
7338: + n   - the number of local matrices
7339: - mat - the matrices (this is a pointer to the array of matrices)

7341:   Level: advanced

7343:   Notes:
7344:   Frees not only the matrices, but also the array that contains the matrices

7346:   For matrices obtained with  `MatCreateSubMatrices()` use `MatDestroySubMatrices()`

7348: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroySubMatrices()`
7349: @*/
7350: PetscErrorCode MatDestroyMatrices(PetscInt n, Mat *mat[])
7351: {
7352:   PetscInt i;

7354:   PetscFunctionBegin;
7355:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7356:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7357:   PetscAssertPointer(mat, 2);

7359:   for (i = 0; i < n; i++) PetscCall(MatDestroy(&(*mat)[i]));

7361:   /* memory is allocated even if n = 0 */
7362:   PetscCall(PetscFree(*mat));
7363:   PetscFunctionReturn(PETSC_SUCCESS);
7364: }

7366: /*@C
7367:   MatDestroySubMatrices - Destroys a set of matrices obtained with `MatCreateSubMatrices()`.

7369:   Collective

7371:   Input Parameters:
7372: + n   - the number of local matrices
7373: - mat - the matrices (this is a pointer to the array of matrices, to match the calling sequence of `MatCreateSubMatrices()`)

7375:   Level: advanced

7377:   Note:
7378:   Frees not only the matrices, but also the array that contains the matrices

7380: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7381: @*/
7382: PetscErrorCode MatDestroySubMatrices(PetscInt n, Mat *mat[])
7383: {
7384:   Mat mat0;

7386:   PetscFunctionBegin;
7387:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7388:   /* mat[] is an array of length n+1, see MatCreateSubMatrices_xxx() */
7389:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7390:   PetscAssertPointer(mat, 2);

7392:   mat0 = (*mat)[0];
7393:   if (mat0 && mat0->ops->destroysubmatrices) {
7394:     PetscCall((*mat0->ops->destroysubmatrices)(n, mat));
7395:   } else {
7396:     PetscCall(MatDestroyMatrices(n, mat));
7397:   }
7398:   PetscFunctionReturn(PETSC_SUCCESS);
7399: }

7401: /*@
7402:   MatGetSeqNonzeroStructure - Extracts the nonzero structure from a matrix and stores it, in its entirety, on each process

7404:   Collective

7406:   Input Parameter:
7407: . mat - the matrix

7409:   Output Parameter:
7410: . matstruct - the sequential matrix with the nonzero structure of `mat`

7412:   Level: developer

7414: .seealso: [](ch_matrices), `Mat`, `MatDestroySeqNonzeroStructure()`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7415: @*/
7416: PetscErrorCode MatGetSeqNonzeroStructure(Mat mat, Mat *matstruct)
7417: {
7418:   PetscFunctionBegin;
7420:   PetscAssertPointer(matstruct, 2);

7423:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7424:   MatCheckPreallocated(mat, 1);

7426:   PetscCall(PetscLogEventBegin(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7427:   PetscUseTypeMethod(mat, getseqnonzerostructure, matstruct);
7428:   PetscCall(PetscLogEventEnd(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7429:   PetscFunctionReturn(PETSC_SUCCESS);
7430: }

7432: /*@C
7433:   MatDestroySeqNonzeroStructure - Destroys matrix obtained with `MatGetSeqNonzeroStructure()`.

7435:   Collective

7437:   Input Parameter:
7438: . mat - the matrix

7440:   Level: advanced

7442:   Note:
7443:   This is not needed, one can just call `MatDestroy()`

7445: .seealso: [](ch_matrices), `Mat`, `MatGetSeqNonzeroStructure()`
7446: @*/
7447: PetscErrorCode MatDestroySeqNonzeroStructure(Mat *mat)
7448: {
7449:   PetscFunctionBegin;
7450:   PetscAssertPointer(mat, 1);
7451:   PetscCall(MatDestroy(mat));
7452:   PetscFunctionReturn(PETSC_SUCCESS);
7453: }

7455: /*@
7456:   MatIncreaseOverlap - Given a set of submatrices indicated by index sets,
7457:   replaces the index sets by larger ones that represent submatrices with
7458:   additional overlap.

7460:   Collective

7462:   Input Parameters:
7463: + mat - the matrix
7464: . n   - the number of index sets
7465: . is  - the array of index sets (these index sets will changed during the call)
7466: - ov  - the additional overlap requested

7468:   Options Database Key:
7469: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7471:   Level: developer

7473:   Note:
7474:   The computed overlap preserves the matrix block sizes when the blocks are square.
7475:   That is: if a matrix nonzero for a given block would increase the overlap all columns associated with
7476:   that block are included in the overlap regardless of whether each specific column would increase the overlap.

7478: .seealso: [](ch_matrices), `Mat`, `PCASM`, `MatSetBlockSize()`, `MatIncreaseOverlapSplit()`, `MatCreateSubMatrices()`
7479: @*/
7480: PetscErrorCode MatIncreaseOverlap(Mat mat, PetscInt n, IS is[], PetscInt ov)
7481: {
7482:   PetscInt i, bs, cbs;

7484:   PetscFunctionBegin;
7488:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7489:   if (n) {
7490:     PetscAssertPointer(is, 3);
7492:   }
7493:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7494:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7495:   MatCheckPreallocated(mat, 1);

7497:   if (!ov || !n) PetscFunctionReturn(PETSC_SUCCESS);
7498:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7499:   PetscUseTypeMethod(mat, increaseoverlap, n, is, ov);
7500:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7501:   PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
7502:   if (bs == cbs) {
7503:     for (i = 0; i < n; i++) PetscCall(ISSetBlockSize(is[i], bs));
7504:   }
7505:   PetscFunctionReturn(PETSC_SUCCESS);
7506: }

7508: PetscErrorCode MatIncreaseOverlapSplit_Single(Mat, IS *, PetscInt);

7510: /*@
7511:   MatIncreaseOverlapSplit - Given a set of submatrices indicated by index sets across
7512:   a sub communicator, replaces the index sets by larger ones that represent submatrices with
7513:   additional overlap.

7515:   Collective

7517:   Input Parameters:
7518: + mat - the matrix
7519: . n   - the number of index sets
7520: . is  - the array of index sets (these index sets will changed during the call)
7521: - ov  - the additional overlap requested

7523:   `   Options Database Key:
7524: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7526:   Level: developer

7528: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatIncreaseOverlap()`
7529: @*/
7530: PetscErrorCode MatIncreaseOverlapSplit(Mat mat, PetscInt n, IS is[], PetscInt ov)
7531: {
7532:   PetscInt i;

7534:   PetscFunctionBegin;
7537:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7538:   if (n) {
7539:     PetscAssertPointer(is, 3);
7541:   }
7542:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7543:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7544:   MatCheckPreallocated(mat, 1);
7545:   if (!ov) PetscFunctionReturn(PETSC_SUCCESS);
7546:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7547:   for (i = 0; i < n; i++) PetscCall(MatIncreaseOverlapSplit_Single(mat, &is[i], ov));
7548:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7549:   PetscFunctionReturn(PETSC_SUCCESS);
7550: }

7552: /*@
7553:   MatGetBlockSize - Returns the matrix block size.

7555:   Not Collective

7557:   Input Parameter:
7558: . mat - the matrix

7560:   Output Parameter:
7561: . bs - block size

7563:   Level: intermediate

7565:   Notes:
7566:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.

7568:   If the block size has not been set yet this routine returns 1.

7570: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSizes()`
7571: @*/
7572: PetscErrorCode MatGetBlockSize(Mat mat, PetscInt *bs)
7573: {
7574:   PetscFunctionBegin;
7576:   PetscAssertPointer(bs, 2);
7577:   *bs = mat->rmap->bs;
7578:   PetscFunctionReturn(PETSC_SUCCESS);
7579: }

7581: /*@
7582:   MatGetBlockSizes - Returns the matrix block row and column sizes.

7584:   Not Collective

7586:   Input Parameter:
7587: . mat - the matrix

7589:   Output Parameters:
7590: + rbs - row block size
7591: - cbs - column block size

7593:   Level: intermediate

7595:   Notes:
7596:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.
7597:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.

7599:   If a block size has not been set yet this routine returns 1.

7601: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatSetBlockSizes()`
7602: @*/
7603: PetscErrorCode MatGetBlockSizes(Mat mat, PetscInt *rbs, PetscInt *cbs)
7604: {
7605:   PetscFunctionBegin;
7607:   if (rbs) PetscAssertPointer(rbs, 2);
7608:   if (cbs) PetscAssertPointer(cbs, 3);
7609:   if (rbs) *rbs = mat->rmap->bs;
7610:   if (cbs) *cbs = mat->cmap->bs;
7611:   PetscFunctionReturn(PETSC_SUCCESS);
7612: }

7614: /*@
7615:   MatSetBlockSize - Sets the matrix block size.

7617:   Logically Collective

7619:   Input Parameters:
7620: + mat - the matrix
7621: - bs  - block size

7623:   Level: intermediate

7625:   Notes:
7626:   Block row formats are `MATBAIJ` and `MATSBAIJ` formats ALWAYS have square block storage in the matrix.
7627:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

7629:   For `MATAIJ` matrix format, this function can be called at a later stage, provided that the specified block size
7630:   is compatible with the matrix local sizes.

7632: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MATAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`
7633: @*/
7634: PetscErrorCode MatSetBlockSize(Mat mat, PetscInt bs)
7635: {
7636:   PetscFunctionBegin;
7639:   PetscCall(MatSetBlockSizes(mat, bs, bs));
7640:   PetscFunctionReturn(PETSC_SUCCESS);
7641: }

7643: typedef struct {
7644:   PetscInt         n;
7645:   IS              *is;
7646:   Mat             *mat;
7647:   PetscObjectState nonzerostate;
7648:   Mat              C;
7649: } EnvelopeData;

7651: static PetscErrorCode EnvelopeDataDestroy(void **ptr)
7652: {
7653:   EnvelopeData *edata = (EnvelopeData *)*ptr;

7655:   PetscFunctionBegin;
7656:   for (PetscInt i = 0; i < edata->n; i++) PetscCall(ISDestroy(&edata->is[i]));
7657:   PetscCall(PetscFree(edata->is));
7658:   PetscCall(PetscFree(edata));
7659:   PetscFunctionReturn(PETSC_SUCCESS);
7660: }

7662: /*@
7663:   MatComputeVariableBlockEnvelope - Given a matrix whose nonzeros are in blocks along the diagonal this computes and stores
7664:   the sizes of these blocks in the matrix. An individual block may lie over several processes.

7666:   Collective

7668:   Input Parameter:
7669: . mat - the matrix

7671:   Level: intermediate

7673:   Notes:
7674:   There can be zeros within the blocks

7676:   The blocks can overlap between processes, including laying on more than two processes

7678: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatSetVariableBlockSizes()`
7679: @*/
7680: PetscErrorCode MatComputeVariableBlockEnvelope(Mat mat)
7681: {
7682:   PetscInt           n, *sizes, *starts, i = 0, env = 0, tbs = 0, lblocks = 0, rstart, II, ln = 0, cnt = 0, cstart, cend;
7683:   PetscInt          *diag, *odiag, sc;
7684:   VecScatter         scatter;
7685:   PetscScalar       *seqv;
7686:   const PetscScalar *parv;
7687:   const PetscInt    *ia, *ja;
7688:   PetscBool          set, flag, done;
7689:   Mat                AA = mat, A;
7690:   MPI_Comm           comm;
7691:   PetscMPIInt        rank, size, tag;
7692:   MPI_Status         status;
7693:   PetscContainer     container;
7694:   EnvelopeData      *edata;
7695:   Vec                seq, par;
7696:   IS                 isglobal;

7698:   PetscFunctionBegin;
7700:   PetscCall(MatIsSymmetricKnown(mat, &set, &flag));
7701:   if (!set || !flag) {
7702:     /* TODO: only needs nonzero structure of transpose */
7703:     PetscCall(MatTranspose(mat, MAT_INITIAL_MATRIX, &AA));
7704:     PetscCall(MatAXPY(AA, 1.0, mat, DIFFERENT_NONZERO_PATTERN));
7705:   }
7706:   PetscCall(MatAIJGetLocalMat(AA, &A));
7707:   PetscCall(MatGetRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7708:   PetscCheck(done, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unable to get IJ structure from matrix");

7710:   PetscCall(MatGetLocalSize(mat, &n, NULL));
7711:   PetscCall(PetscObjectGetNewTag((PetscObject)mat, &tag));
7712:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
7713:   PetscCallMPI(MPI_Comm_size(comm, &size));
7714:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

7716:   PetscCall(PetscMalloc2(n, &sizes, n, &starts));

7718:   if (rank > 0) {
7719:     PetscCallMPI(MPI_Recv(&env, 1, MPIU_INT, rank - 1, tag, comm, &status));
7720:     PetscCallMPI(MPI_Recv(&tbs, 1, MPIU_INT, rank - 1, tag, comm, &status));
7721:   }
7722:   PetscCall(MatGetOwnershipRange(mat, &rstart, NULL));
7723:   for (i = 0; i < n; i++) {
7724:     env = PetscMax(env, ja[ia[i + 1] - 1]);
7725:     II  = rstart + i;
7726:     if (env == II) {
7727:       starts[lblocks]  = tbs;
7728:       sizes[lblocks++] = 1 + II - tbs;
7729:       tbs              = 1 + II;
7730:     }
7731:   }
7732:   if (rank < size - 1) {
7733:     PetscCallMPI(MPI_Send(&env, 1, MPIU_INT, rank + 1, tag, comm));
7734:     PetscCallMPI(MPI_Send(&tbs, 1, MPIU_INT, rank + 1, tag, comm));
7735:   }

7737:   PetscCall(MatRestoreRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7738:   if (!set || !flag) PetscCall(MatDestroy(&AA));
7739:   PetscCall(MatDestroy(&A));

7741:   PetscCall(PetscNew(&edata));
7742:   PetscCall(MatGetNonzeroState(mat, &edata->nonzerostate));
7743:   edata->n = lblocks;
7744:   /* create IS needed for extracting blocks from the original matrix */
7745:   PetscCall(PetscMalloc1(lblocks, &edata->is));
7746:   for (PetscInt i = 0; i < lblocks; i++) PetscCall(ISCreateStride(PETSC_COMM_SELF, sizes[i], starts[i], 1, &edata->is[i]));

7748:   /* Create the resulting inverse matrix nonzero structure with preallocation information */
7749:   PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &edata->C));
7750:   PetscCall(MatSetSizes(edata->C, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
7751:   PetscCall(MatSetBlockSizesFromMats(edata->C, mat, mat));
7752:   PetscCall(MatSetType(edata->C, MATAIJ));

7754:   /* Communicate the start and end of each row, from each block to the correct rank */
7755:   /* TODO: Use PetscSF instead of VecScatter */
7756:   for (PetscInt i = 0; i < lblocks; i++) ln += sizes[i];
7757:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, 2 * ln, &seq));
7758:   PetscCall(VecGetArrayWrite(seq, &seqv));
7759:   for (PetscInt i = 0; i < lblocks; i++) {
7760:     for (PetscInt j = 0; j < sizes[i]; j++) {
7761:       seqv[cnt]     = starts[i];
7762:       seqv[cnt + 1] = starts[i] + sizes[i];
7763:       cnt += 2;
7764:     }
7765:   }
7766:   PetscCall(VecRestoreArrayWrite(seq, &seqv));
7767:   PetscCallMPI(MPI_Scan(&cnt, &sc, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)mat)));
7768:   sc -= cnt;
7769:   PetscCall(VecCreateMPI(PetscObjectComm((PetscObject)mat), 2 * mat->rmap->n, 2 * mat->rmap->N, &par));
7770:   PetscCall(ISCreateStride(PETSC_COMM_SELF, cnt, sc, 1, &isglobal));
7771:   PetscCall(VecScatterCreate(seq, NULL, par, isglobal, &scatter));
7772:   PetscCall(ISDestroy(&isglobal));
7773:   PetscCall(VecScatterBegin(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7774:   PetscCall(VecScatterEnd(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7775:   PetscCall(VecScatterDestroy(&scatter));
7776:   PetscCall(VecDestroy(&seq));
7777:   PetscCall(MatGetOwnershipRangeColumn(mat, &cstart, &cend));
7778:   PetscCall(PetscMalloc2(mat->rmap->n, &diag, mat->rmap->n, &odiag));
7779:   PetscCall(VecGetArrayRead(par, &parv));
7780:   cnt = 0;
7781:   PetscCall(MatGetSize(mat, NULL, &n));
7782:   for (PetscInt i = 0; i < mat->rmap->n; i++) {
7783:     PetscInt start, end, d = 0, od = 0;

7785:     start = (PetscInt)PetscRealPart(parv[cnt]);
7786:     end   = (PetscInt)PetscRealPart(parv[cnt + 1]);
7787:     cnt += 2;

7789:     if (start < cstart) {
7790:       od += cstart - start + n - cend;
7791:       d += cend - cstart;
7792:     } else if (start < cend) {
7793:       od += n - cend;
7794:       d += cend - start;
7795:     } else od += n - start;
7796:     if (end <= cstart) {
7797:       od -= cstart - end + n - cend;
7798:       d -= cend - cstart;
7799:     } else if (end < cend) {
7800:       od -= n - cend;
7801:       d -= cend - end;
7802:     } else od -= n - end;

7804:     odiag[i] = od;
7805:     diag[i]  = d;
7806:   }
7807:   PetscCall(VecRestoreArrayRead(par, &parv));
7808:   PetscCall(VecDestroy(&par));
7809:   PetscCall(MatXAIJSetPreallocation(edata->C, mat->rmap->bs, diag, odiag, NULL, NULL));
7810:   PetscCall(PetscFree2(diag, odiag));
7811:   PetscCall(PetscFree2(sizes, starts));

7813:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
7814:   PetscCall(PetscContainerSetPointer(container, edata));
7815:   PetscCall(PetscContainerSetCtxDestroy(container, EnvelopeDataDestroy));
7816:   PetscCall(PetscObjectCompose((PetscObject)mat, "EnvelopeData", (PetscObject)container));
7817:   PetscCall(PetscObjectDereference((PetscObject)container));
7818:   PetscFunctionReturn(PETSC_SUCCESS);
7819: }

7821: /*@
7822:   MatInvertVariableBlockEnvelope - set matrix C to be the inverted block diagonal of matrix A

7824:   Collective

7826:   Input Parameters:
7827: + A     - the matrix
7828: - reuse - indicates if the `C` matrix was obtained from a previous call to this routine

7830:   Output Parameter:
7831: . C - matrix with inverted block diagonal of `A`

7833:   Level: advanced

7835:   Note:
7836:   For efficiency the matrix `A` should have all the nonzero entries clustered in smallish blocks along the diagonal.

7838: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatComputeBlockDiagonal()`
7839: @*/
7840: PetscErrorCode MatInvertVariableBlockEnvelope(Mat A, MatReuse reuse, Mat *C)
7841: {
7842:   PetscContainer   container;
7843:   EnvelopeData    *edata;
7844:   PetscObjectState nonzerostate;

7846:   PetscFunctionBegin;
7847:   PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7848:   if (!container) {
7849:     PetscCall(MatComputeVariableBlockEnvelope(A));
7850:     PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7851:   }
7852:   PetscCall(PetscContainerGetPointer(container, (void **)&edata));
7853:   PetscCall(MatGetNonzeroState(A, &nonzerostate));
7854:   PetscCheck(nonzerostate <= edata->nonzerostate, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Cannot handle changes to matrix nonzero structure");
7855:   PetscCheck(reuse != MAT_REUSE_MATRIX || *C == edata->C, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "C matrix must be the same as previously output");

7857:   PetscCall(MatCreateSubMatrices(A, edata->n, edata->is, edata->is, MAT_INITIAL_MATRIX, &edata->mat));
7858:   *C = edata->C;

7860:   for (PetscInt i = 0; i < edata->n; i++) {
7861:     Mat          D;
7862:     PetscScalar *dvalues;

7864:     PetscCall(MatConvert(edata->mat[i], MATSEQDENSE, MAT_INITIAL_MATRIX, &D));
7865:     PetscCall(MatSetOption(*C, MAT_ROW_ORIENTED, PETSC_FALSE));
7866:     PetscCall(MatSeqDenseInvert(D));
7867:     PetscCall(MatDenseGetArray(D, &dvalues));
7868:     PetscCall(MatSetValuesIS(*C, edata->is[i], edata->is[i], dvalues, INSERT_VALUES));
7869:     PetscCall(MatDestroy(&D));
7870:   }
7871:   PetscCall(MatDestroySubMatrices(edata->n, &edata->mat));
7872:   PetscCall(MatAssemblyBegin(*C, MAT_FINAL_ASSEMBLY));
7873:   PetscCall(MatAssemblyEnd(*C, MAT_FINAL_ASSEMBLY));
7874:   PetscFunctionReturn(PETSC_SUCCESS);
7875: }

7877: /*@
7878:   MatSetVariableBlockSizes - Sets diagonal point-blocks of the matrix that need not be of the same size

7880:   Not Collective

7882:   Input Parameters:
7883: + mat     - the matrix
7884: . nblocks - the number of blocks on this process, each block can only exist on a single process
7885: - bsizes  - the block sizes

7887:   Level: intermediate

7889:   Notes:
7890:   Currently used by `PCVPBJACOBI` for `MATAIJ` matrices

7892:   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.

7894: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatGetVariableBlockSizes()`,
7895:           `MatComputeVariableBlockEnvelope()`, `PCVPBJACOBI`
7896: @*/
7897: PetscErrorCode MatSetVariableBlockSizes(Mat mat, PetscInt nblocks, const PetscInt bsizes[])
7898: {
7899:   PetscInt ncnt = 0, nlocal;

7901:   PetscFunctionBegin;
7903:   PetscCall(MatGetLocalSize(mat, &nlocal, NULL));
7904:   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);
7905:   for (PetscInt i = 0; i < nblocks; i++) ncnt += bsizes[i];
7906:   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);
7907:   PetscCall(PetscFree(mat->bsizes));
7908:   mat->nblocks = nblocks;
7909:   PetscCall(PetscMalloc1(nblocks, &mat->bsizes));
7910:   PetscCall(PetscArraycpy(mat->bsizes, bsizes, nblocks));
7911:   PetscFunctionReturn(PETSC_SUCCESS);
7912: }

7914: /*@C
7915:   MatGetVariableBlockSizes - Gets a diagonal blocks of the matrix that need not be of the same size

7917:   Not Collective; No Fortran Support

7919:   Input Parameter:
7920: . mat - the matrix

7922:   Output Parameters:
7923: + nblocks - the number of blocks on this process
7924: - bsizes  - the block sizes

7926:   Level: intermediate

7928: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
7929: @*/
7930: PetscErrorCode MatGetVariableBlockSizes(Mat mat, PetscInt *nblocks, const PetscInt *bsizes[])
7931: {
7932:   PetscFunctionBegin;
7934:   if (nblocks) *nblocks = mat->nblocks;
7935:   if (bsizes) *bsizes = mat->bsizes;
7936:   PetscFunctionReturn(PETSC_SUCCESS);
7937: }

7939: /*@
7940:   MatSelectVariableBlockSizes - When creating a submatrix, pass on the variable block sizes

7942:   Not Collective

7944:   Input Parameter:
7945: + subA  - the submatrix
7946: . A     - the original matrix
7947: - isrow - The `IS` of selected rows for the submatrix, must be sorted

7949:   Level: developer

7951:   Notes:
7952:   If the index set is not sorted or contains off-process entries, this function will do nothing.

7954: .seealso: [](ch_matrices), `Mat`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
7955: @*/
7956: PetscErrorCode MatSelectVariableBlockSizes(Mat subA, Mat A, IS isrow)
7957: {
7958:   const PetscInt *rows;
7959:   PetscInt        n, rStart, rEnd, Nb = 0;
7960:   PetscBool       flg = A->bsizes ? PETSC_TRUE : PETSC_FALSE;

7962:   PetscFunctionBegin;
7963:   // The code for block size extraction does not support an unsorted IS
7964:   if (flg) PetscCall(ISSorted(isrow, &flg));
7965:   // We don't support originally off-diagonal blocks
7966:   if (flg) {
7967:     PetscCall(MatGetOwnershipRange(A, &rStart, &rEnd));
7968:     PetscCall(ISGetLocalSize(isrow, &n));
7969:     PetscCall(ISGetIndices(isrow, &rows));
7970:     for (PetscInt i = 0; i < n && flg; ++i) {
7971:       if (rows[i] < rStart || rows[i] >= rEnd) flg = PETSC_FALSE;
7972:     }
7973:     PetscCall(ISRestoreIndices(isrow, &rows));
7974:   }
7975:   // quiet return if we can't extract block size
7976:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &flg, 1, MPI_C_BOOL, MPI_LAND, PetscObjectComm((PetscObject)subA)));
7977:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

7979:   // extract block sizes
7980:   PetscCall(ISGetIndices(isrow, &rows));
7981:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
7982:     PetscBool occupied = PETSC_FALSE;

7984:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
7985:       const PetscInt row = gr + br;

7987:       if (i == n) break;
7988:       if (rows[i] == row) {
7989:         occupied = PETSC_TRUE;
7990:         ++i;
7991:       }
7992:       while (i < n && rows[i] < row) ++i;
7993:     }
7994:     gr += A->bsizes[b];
7995:     if (occupied) ++Nb;
7996:   }
7997:   subA->nblocks = Nb;
7998:   PetscCall(PetscFree(subA->bsizes));
7999:   PetscCall(PetscMalloc1(subA->nblocks, &subA->bsizes));
8000:   PetscInt sb = 0;
8001:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
8002:     if (sb < subA->nblocks) subA->bsizes[sb] = 0;
8003:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
8004:       const PetscInt row = gr + br;

8006:       if (i == n) break;
8007:       if (rows[i] == row) {
8008:         ++subA->bsizes[sb];
8009:         ++i;
8010:       }
8011:       while (i < n && rows[i] < row) ++i;
8012:     }
8013:     gr += A->bsizes[b];
8014:     if (sb < subA->nblocks && subA->bsizes[sb]) ++sb;
8015:   }
8016:   PetscCheck(sb == subA->nblocks, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of blocks %" PetscInt_FMT " != %" PetscInt_FMT, sb, subA->nblocks);
8017:   PetscInt nlocal, ncnt = 0;
8018:   PetscCall(MatGetLocalSize(subA, &nlocal, NULL));
8019:   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);
8020:   for (PetscInt i = 0; i < subA->nblocks; i++) ncnt += subA->bsizes[i];
8021:   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);
8022:   PetscCall(ISRestoreIndices(isrow, &rows));
8023:   PetscFunctionReturn(PETSC_SUCCESS);
8024: }

8026: /*@
8027:   MatSetBlockSizes - Sets the matrix block row and column sizes.

8029:   Logically Collective

8031:   Input Parameters:
8032: + mat - the matrix
8033: . rbs - row block size
8034: - cbs - column block size

8036:   Level: intermediate

8038:   Notes:
8039:   Block row formats are `MATBAIJ` and  `MATSBAIJ`. These formats ALWAYS have square block storage in the matrix.
8040:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.
8041:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

8043:   For `MATAIJ` matrix this function can be called at a later stage, provided that the specified block sizes
8044:   are compatible with the matrix local sizes.

8046:   The row and column block size determine the blocksize of the "row" and "column" vectors returned by `MatCreateVecs()`.

8048: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatGetBlockSizes()`
8049: @*/
8050: PetscErrorCode MatSetBlockSizes(Mat mat, PetscInt rbs, PetscInt cbs)
8051: {
8052:   PetscFunctionBegin;
8056:   PetscTryTypeMethod(mat, setblocksizes, rbs, cbs);
8057:   if (mat->rmap->refcnt) {
8058:     ISLocalToGlobalMapping l2g  = NULL;
8059:     PetscLayout            nmap = NULL;

8061:     PetscCall(PetscLayoutDuplicate(mat->rmap, &nmap));
8062:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->rmap->mapping, &l2g));
8063:     PetscCall(PetscLayoutDestroy(&mat->rmap));
8064:     mat->rmap          = nmap;
8065:     mat->rmap->mapping = l2g;
8066:   }
8067:   if (mat->cmap->refcnt) {
8068:     ISLocalToGlobalMapping l2g  = NULL;
8069:     PetscLayout            nmap = NULL;

8071:     PetscCall(PetscLayoutDuplicate(mat->cmap, &nmap));
8072:     if (mat->cmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->cmap->mapping, &l2g));
8073:     PetscCall(PetscLayoutDestroy(&mat->cmap));
8074:     mat->cmap          = nmap;
8075:     mat->cmap->mapping = l2g;
8076:   }
8077:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, rbs));
8078:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, cbs));
8079:   PetscFunctionReturn(PETSC_SUCCESS);
8080: }

8082: /*@
8083:   MatSetBlockSizesFromMats - Sets the matrix block row and column sizes to match a pair of matrices

8085:   Logically Collective

8087:   Input Parameters:
8088: + mat     - the matrix
8089: . fromRow - matrix from which to copy row block size
8090: - fromCol - matrix from which to copy column block size (can be same as fromRow)

8092:   Level: developer

8094: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`
8095: @*/
8096: PetscErrorCode MatSetBlockSizesFromMats(Mat mat, Mat fromRow, Mat fromCol)
8097: {
8098:   PetscFunctionBegin;
8102:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, fromRow->rmap->bs));
8103:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, fromCol->cmap->bs));
8104:   PetscFunctionReturn(PETSC_SUCCESS);
8105: }

8107: /*@
8108:   MatResidual - Default routine to calculate the residual r = b - Ax

8110:   Collective

8112:   Input Parameters:
8113: + mat - the matrix
8114: . b   - the right-hand-side
8115: - x   - the approximate solution

8117:   Output Parameter:
8118: . r - location to store the residual

8120:   Level: developer

8122: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `PCMGSetResidual()`
8123: @*/
8124: PetscErrorCode MatResidual(Mat mat, Vec b, Vec x, Vec r)
8125: {
8126:   PetscFunctionBegin;
8132:   MatCheckPreallocated(mat, 1);
8133:   PetscCall(PetscLogEventBegin(MAT_Residual, mat, 0, 0, 0));
8134:   if (!mat->ops->residual) {
8135:     PetscCall(MatMult(mat, x, r));
8136:     PetscCall(VecAYPX(r, -1.0, b));
8137:   } else {
8138:     PetscUseTypeMethod(mat, residual, b, x, r);
8139:   }
8140:   PetscCall(PetscLogEventEnd(MAT_Residual, mat, 0, 0, 0));
8141:   PetscFunctionReturn(PETSC_SUCCESS);
8142: }

8144: /*@C
8145:   MatGetRowIJ - Returns the compressed row storage i and j indices for the local rows of a sparse matrix

8147:   Collective

8149:   Input Parameters:
8150: + mat             - the matrix
8151: . shift           - 0 or 1 indicating we want the indices starting at 0 or 1
8152: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8153: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE`  indicating if the nonzero structure of the
8154:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8155:                  always used.

8157:   Output Parameters:
8158: + n    - number of local rows in the (possibly compressed) matrix, use `NULL` if not needed
8159: . 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
8160: . ja   - the column indices, use `NULL` if not needed
8161: - done - indicates if the routine actually worked and returned appropriate ia[] and ja[] arrays; callers
8162:            are responsible for handling the case when done == `PETSC_FALSE` and ia and ja are not set

8164:   Level: developer

8166:   Notes:
8167:   You CANNOT change any of the ia[] or ja[] values.

8169:   Use `MatRestoreRowIJ()` when you are finished accessing the ia[] and ja[] values.

8171:   Fortran Notes:
8172:   Use
8173: .vb
8174:     PetscInt, pointer :: ia(:),ja(:)
8175:     call MatGetRowIJ(mat,shift,symmetric,inodecompressed,n,ia,ja,done,ierr)
8176:     ! Access the ith and jth entries via ia(i) and ja(j)
8177: .ve

8179: .seealso: [](ch_matrices), `Mat`, `MATAIJ`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`, `MatSeqAIJGetArray()`
8180: @*/
8181: PetscErrorCode MatGetRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8182: {
8183:   PetscFunctionBegin;
8186:   if (n) PetscAssertPointer(n, 5);
8187:   if (ia) PetscAssertPointer(ia, 6);
8188:   if (ja) PetscAssertPointer(ja, 7);
8189:   if (done) PetscAssertPointer(done, 8);
8190:   MatCheckPreallocated(mat, 1);
8191:   if (!mat->ops->getrowij && done) *done = PETSC_FALSE;
8192:   else {
8193:     if (done) *done = PETSC_TRUE;
8194:     PetscCall(PetscLogEventBegin(MAT_GetRowIJ, mat, 0, 0, 0));
8195:     PetscUseTypeMethod(mat, getrowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8196:     PetscCall(PetscLogEventEnd(MAT_GetRowIJ, mat, 0, 0, 0));
8197:   }
8198:   PetscFunctionReturn(PETSC_SUCCESS);
8199: }

8201: /*@C
8202:   MatGetColumnIJ - Returns the compressed column storage i and j indices for sequential matrices.

8204:   Collective

8206:   Input Parameters:
8207: + mat             - the matrix
8208: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8209: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be
8210:                 symmetrized
8211: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8212:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8213:                  always used.

8215:   Output Parameters:
8216: + n    - number of columns in the (possibly compressed) matrix
8217: . ia   - the column pointers; that is ia[0] = 0, ia[col] = i[col-1] + number of elements in that col of the matrix
8218: . ja   - the row indices
8219: - done - `PETSC_TRUE` or `PETSC_FALSE`, indicating whether the values have been returned

8221:   Level: developer

8223: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8224: @*/
8225: PetscErrorCode MatGetColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8226: {
8227:   PetscFunctionBegin;
8230:   PetscAssertPointer(n, 5);
8231:   if (ia) PetscAssertPointer(ia, 6);
8232:   if (ja) PetscAssertPointer(ja, 7);
8233:   PetscAssertPointer(done, 8);
8234:   MatCheckPreallocated(mat, 1);
8235:   if (!mat->ops->getcolumnij) *done = PETSC_FALSE;
8236:   else {
8237:     *done = PETSC_TRUE;
8238:     PetscUseTypeMethod(mat, getcolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8239:   }
8240:   PetscFunctionReturn(PETSC_SUCCESS);
8241: }

8243: /*@C
8244:   MatRestoreRowIJ - Call after you are completed with the ia,ja indices obtained with `MatGetRowIJ()`.

8246:   Collective

8248:   Input Parameters:
8249: + mat             - the matrix
8250: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8251: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8252: . inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8253:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8254:                     always used.
8255: . n               - size of (possibly compressed) matrix
8256: . ia              - the row pointers
8257: - ja              - the column indices

8259:   Output Parameter:
8260: . done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8262:   Level: developer

8264:   Note:
8265:   This routine zeros out `n`, `ia`, and `ja`. This is to prevent accidental
8266:   us of the array after it has been restored. If you pass `NULL`, it will
8267:   not zero the pointers.  Use of ia or ja after `MatRestoreRowIJ()` is invalid.

8269: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8270: @*/
8271: PetscErrorCode MatRestoreRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8272: {
8273:   PetscFunctionBegin;
8276:   if (ia) PetscAssertPointer(ia, 6);
8277:   if (ja) PetscAssertPointer(ja, 7);
8278:   if (done) PetscAssertPointer(done, 8);
8279:   MatCheckPreallocated(mat, 1);

8281:   if (!mat->ops->restorerowij && done) *done = PETSC_FALSE;
8282:   else {
8283:     if (done) *done = PETSC_TRUE;
8284:     PetscUseTypeMethod(mat, restorerowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8285:     if (n) *n = 0;
8286:     if (ia) *ia = NULL;
8287:     if (ja) *ja = NULL;
8288:   }
8289:   PetscFunctionReturn(PETSC_SUCCESS);
8290: }

8292: /*@C
8293:   MatRestoreColumnIJ - Call after you are completed with the ia,ja indices obtained with `MatGetColumnIJ()`.

8295:   Collective

8297:   Input Parameters:
8298: + mat             - the matrix
8299: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8300: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8301: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8302:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8303:                     always used.

8305:   Output Parameters:
8306: + n    - size of (possibly compressed) matrix
8307: . ia   - the column pointers
8308: . ja   - the row indices
8309: - done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8311:   Level: developer

8313: .seealso: [](ch_matrices), `Mat`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`
8314: @*/
8315: PetscErrorCode MatRestoreColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8316: {
8317:   PetscFunctionBegin;
8320:   if (ia) PetscAssertPointer(ia, 6);
8321:   if (ja) PetscAssertPointer(ja, 7);
8322:   PetscAssertPointer(done, 8);
8323:   MatCheckPreallocated(mat, 1);

8325:   if (!mat->ops->restorecolumnij) *done = PETSC_FALSE;
8326:   else {
8327:     *done = PETSC_TRUE;
8328:     PetscUseTypeMethod(mat, restorecolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8329:     if (n) *n = 0;
8330:     if (ia) *ia = NULL;
8331:     if (ja) *ja = NULL;
8332:   }
8333:   PetscFunctionReturn(PETSC_SUCCESS);
8334: }

8336: /*@
8337:   MatColoringPatch - Used inside matrix coloring routines that use `MatGetRowIJ()` and/or
8338:   `MatGetColumnIJ()`.

8340:   Collective

8342:   Input Parameters:
8343: + mat        - the matrix
8344: . ncolors    - maximum color value
8345: . n          - number of entries in colorarray
8346: - colorarray - array indicating color for each column

8348:   Output Parameter:
8349: . iscoloring - coloring generated using colorarray information

8351:   Level: developer

8353: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatGetColumnIJ()`
8354: @*/
8355: PetscErrorCode MatColoringPatch(Mat mat, PetscInt ncolors, PetscInt n, ISColoringValue colorarray[], ISColoring *iscoloring)
8356: {
8357:   PetscFunctionBegin;
8360:   PetscAssertPointer(colorarray, 4);
8361:   PetscAssertPointer(iscoloring, 5);
8362:   MatCheckPreallocated(mat, 1);

8364:   if (!mat->ops->coloringpatch) {
8365:     PetscCall(ISColoringCreate(PetscObjectComm((PetscObject)mat), ncolors, n, colorarray, PETSC_OWN_POINTER, iscoloring));
8366:   } else {
8367:     PetscUseTypeMethod(mat, coloringpatch, ncolors, n, colorarray, iscoloring);
8368:   }
8369:   PetscFunctionReturn(PETSC_SUCCESS);
8370: }

8372: /*@
8373:   MatSetUnfactored - Resets a factored matrix to be treated as unfactored.

8375:   Logically Collective

8377:   Input Parameter:
8378: . mat - the factored matrix to be reset

8380:   Level: developer

8382:   Notes:
8383:   This routine should be used only with factored matrices formed by in-place
8384:   factorization via ILU(0) (or by in-place LU factorization for the `MATSEQDENSE`
8385:   format).  This option can save memory, for example, when solving nonlinear
8386:   systems with a matrix-free Newton-Krylov method and a matrix-based, in-place
8387:   ILU(0) preconditioner.

8389:   One can specify in-place ILU(0) factorization by calling
8390: .vb
8391:      PCType(pc,PCILU);
8392:      PCFactorSeUseInPlace(pc);
8393: .ve
8394:   or by using the options -pc_type ilu -pc_factor_in_place

8396:   In-place factorization ILU(0) can also be used as a local
8397:   solver for the blocks within the block Jacobi or additive Schwarz
8398:   methods (runtime option: -sub_pc_factor_in_place).  See Users-Manual: ch_pc
8399:   for details on setting local solver options.

8401:   Most users should employ the `KSP` interface for linear solvers
8402:   instead of working directly with matrix algebra routines such as this.
8403:   See, e.g., `KSPCreate()`.

8405: .seealso: [](ch_matrices), `Mat`, `PCFactorSetUseInPlace()`, `PCFactorGetUseInPlace()`
8406: @*/
8407: PetscErrorCode MatSetUnfactored(Mat mat)
8408: {
8409:   PetscFunctionBegin;
8412:   MatCheckPreallocated(mat, 1);
8413:   mat->factortype = MAT_FACTOR_NONE;
8414:   if (!mat->ops->setunfactored) PetscFunctionReturn(PETSC_SUCCESS);
8415:   PetscUseTypeMethod(mat, setunfactored);
8416:   PetscFunctionReturn(PETSC_SUCCESS);
8417: }

8419: /*@
8420:   MatCreateSubMatrix - Gets a single submatrix on the same number of processors
8421:   as the original matrix.

8423:   Collective

8425:   Input Parameters:
8426: + mat   - the original matrix
8427: . isrow - parallel `IS` containing the rows this processor should obtain
8428: . 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.
8429: - cll   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

8431:   Output Parameter:
8432: . newmat - the new submatrix, of the same type as the original matrix

8434:   Level: advanced

8436:   Notes:
8437:   The submatrix will be able to be multiplied with vectors using the same layout as `iscol`.

8439:   Some matrix types place restrictions on the row and column indices, such
8440:   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;
8441:   for example, if the block size is 3 one cannot select the 0 and 2 rows without selecting the 1 row.

8443:   The index sets may not have duplicate entries.

8445:   The first time this is called you should use a cll of `MAT_INITIAL_MATRIX`,
8446:   the `MatCreateSubMatrix()` routine will create the newmat for you. Any additional calls
8447:   to this routine with a mat of the same nonzero structure and with a call of `MAT_REUSE_MATRIX`
8448:   will reuse the matrix generated the first time.  You should call `MatDestroy()` on `newmat` when
8449:   you are finished using it.

8451:   The communicator of the newly obtained matrix is ALWAYS the same as the communicator of
8452:   the input matrix.

8454:   If `iscol` is `NULL` then all columns are obtained (not supported in Fortran).

8456:   If `isrow` and `iscol` have a nontrivial block-size, then the resulting matrix has this block-size as well. This feature
8457:   is used by `PCFIELDSPLIT` to allow easy nesting of its use.

8459:   Example usage:
8460:   Consider the following 8x8 matrix with 34 non-zero values, that is
8461:   assembled across 3 processors. Let's assume that proc0 owns 3 rows,
8462:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
8463:   as follows
8464: .vb
8465:             1  2  0  |  0  3  0  |  0  4
8466:     Proc0   0  5  6  |  7  0  0  |  8  0
8467:             9  0 10  | 11  0  0  | 12  0
8468:     -------------------------------------
8469:            13  0 14  | 15 16 17  |  0  0
8470:     Proc1   0 18  0  | 19 20 21  |  0  0
8471:             0  0  0  | 22 23  0  | 24  0
8472:     -------------------------------------
8473:     Proc2  25 26 27  |  0  0 28  | 29  0
8474:            30  0  0  | 31 32 33  |  0 34
8475: .ve

8477:   Suppose `isrow` = [0 1 | 4 | 6 7] and `iscol` = [1 2 | 3 4 5 | 6].  The resulting submatrix is

8479: .vb
8480:             2  0  |  0  3  0  |  0
8481:     Proc0   5  6  |  7  0  0  |  8
8482:     -------------------------------
8483:     Proc1  18  0  | 19 20 21  |  0
8484:     -------------------------------
8485:     Proc2  26 27  |  0  0 28  | 29
8486:             0  0  | 31 32 33  |  0
8487: .ve

8489: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatCreateSubMatricesMPI()`, `MatCreateSubMatrixVirtual()`, `MatSubMatrixVirtualUpdate()`
8490: @*/
8491: PetscErrorCode MatCreateSubMatrix(Mat mat, IS isrow, IS iscol, MatReuse cll, Mat *newmat)
8492: {
8493:   PetscMPIInt size;
8494:   Mat        *local;
8495:   IS          iscoltmp;
8496:   PetscBool   flg;

8498:   PetscFunctionBegin;
8502:   PetscAssertPointer(newmat, 5);
8505:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
8506:   PetscCheck(cll != MAT_IGNORE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_IGNORE_MATRIX");

8508:   MatCheckPreallocated(mat, 1);
8509:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));

8511:   if (!iscol || isrow == iscol) {
8512:     PetscBool   stride;
8513:     PetscMPIInt grabentirematrix = 0, grab;
8514:     PetscCall(PetscObjectTypeCompare((PetscObject)isrow, ISSTRIDE, &stride));
8515:     if (stride) {
8516:       PetscInt first, step, n, rstart, rend;
8517:       PetscCall(ISStrideGetInfo(isrow, &first, &step));
8518:       if (step == 1) {
8519:         PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
8520:         if (rstart == first) {
8521:           PetscCall(ISGetLocalSize(isrow, &n));
8522:           if (n == rend - rstart) grabentirematrix = 1;
8523:         }
8524:       }
8525:     }
8526:     PetscCallMPI(MPIU_Allreduce(&grabentirematrix, &grab, 1, MPI_INT, MPI_MIN, PetscObjectComm((PetscObject)mat)));
8527:     if (grab) {
8528:       PetscCall(PetscInfo(mat, "Getting entire matrix as submatrix\n"));
8529:       if (cll == MAT_INITIAL_MATRIX) {
8530:         *newmat = mat;
8531:         PetscCall(PetscObjectReference((PetscObject)mat));
8532:       }
8533:       PetscFunctionReturn(PETSC_SUCCESS);
8534:     }
8535:   }

8537:   if (!iscol) {
8538:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), mat->cmap->n, mat->cmap->rstart, 1, &iscoltmp));
8539:   } else {
8540:     iscoltmp = iscol;
8541:   }

8543:   /* if original matrix is on just one processor then use submatrix generated */
8544:   if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1 && cll == MAT_REUSE_MATRIX) {
8545:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_REUSE_MATRIX, &newmat));
8546:     goto setproperties;
8547:   } else if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1) {
8548:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_INITIAL_MATRIX, &local));
8549:     *newmat = *local;
8550:     PetscCall(PetscFree(local));
8551:     goto setproperties;
8552:   } else if (!mat->ops->createsubmatrix) {
8553:     /* Create a new matrix type that implements the operation using the full matrix */
8554:     PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8555:     switch (cll) {
8556:     case MAT_INITIAL_MATRIX:
8557:       PetscCall(MatCreateSubMatrixVirtual(mat, isrow, iscoltmp, newmat));
8558:       break;
8559:     case MAT_REUSE_MATRIX:
8560:       PetscCall(MatSubMatrixVirtualUpdate(*newmat, mat, isrow, iscoltmp));
8561:       break;
8562:     default:
8563:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Invalid MatReuse, must be either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX");
8564:     }
8565:     PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));
8566:     goto setproperties;
8567:   }

8569:   PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8570:   PetscUseTypeMethod(mat, createsubmatrix, isrow, iscoltmp, cll, newmat);
8571:   PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));

8573: setproperties:
8574:   if ((*newmat)->symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->structurally_symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->spd == PETSC_BOOL3_UNKNOWN && (*newmat)->hermitian == PETSC_BOOL3_UNKNOWN) {
8575:     PetscCall(ISEqualUnsorted(isrow, iscoltmp, &flg));
8576:     if (flg) PetscCall(MatPropagateSymmetryOptions(mat, *newmat));
8577:   }
8578:   if (!iscol) PetscCall(ISDestroy(&iscoltmp));
8579:   if (*newmat && cll == MAT_INITIAL_MATRIX) PetscCall(PetscObjectStateIncrease((PetscObject)*newmat));
8580:   if (!iscol || isrow == iscol) PetscCall(MatSelectVariableBlockSizes(*newmat, mat, isrow));
8581:   PetscFunctionReturn(PETSC_SUCCESS);
8582: }

8584: /*@
8585:   MatPropagateSymmetryOptions - Propagates symmetry options set on a matrix to another matrix

8587:   Not Collective

8589:   Input Parameters:
8590: + A - the matrix we wish to propagate options from
8591: - B - the matrix we wish to propagate options to

8593:   Level: beginner

8595:   Note:
8596:   Propagates the options associated to `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_HERMITIAN`, `MAT_SPD`, `MAT_SYMMETRIC`, and `MAT_STRUCTURAL_SYMMETRY_ETERNAL`

8598: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatIsSymmetricKnown()`, `MatIsSPDKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
8599: @*/
8600: PetscErrorCode MatPropagateSymmetryOptions(Mat A, Mat B)
8601: {
8602:   PetscFunctionBegin;
8605:   B->symmetry_eternal            = A->symmetry_eternal;
8606:   B->structural_symmetry_eternal = A->structural_symmetry_eternal;
8607:   B->symmetric                   = A->symmetric;
8608:   B->structurally_symmetric      = A->structurally_symmetric;
8609:   B->spd                         = A->spd;
8610:   B->hermitian                   = A->hermitian;
8611:   PetscFunctionReturn(PETSC_SUCCESS);
8612: }

8614: /*@
8615:   MatStashSetInitialSize - sets the sizes of the matrix stash, that is
8616:   used during the assembly process to store values that belong to
8617:   other processors.

8619:   Not Collective

8621:   Input Parameters:
8622: + mat   - the matrix
8623: . size  - the initial size of the stash.
8624: - bsize - the initial size of the block-stash(if used).

8626:   Options Database Keys:
8627: + -matstash_initial_size <size> or <size0,size1,...sizep-1>            - set initial size
8628: - -matstash_block_initial_size <bsize>  or <bsize0,bsize1,...bsizep-1> - set initial block size

8630:   Level: intermediate

8632:   Notes:
8633:   The block-stash is used for values set with `MatSetValuesBlocked()` while
8634:   the stash is used for values set with `MatSetValues()`

8636:   Run with the option -info and look for output of the form
8637:   MatAssemblyBegin_MPIXXX:Stash has MM entries, uses nn mallocs.
8638:   to determine the appropriate value, MM, to use for size and
8639:   MatAssemblyBegin_MPIXXX:Block-Stash has BMM entries, uses nn mallocs.
8640:   to determine the value, BMM to use for bsize

8642: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashGetInfo()`
8643: @*/
8644: PetscErrorCode MatStashSetInitialSize(Mat mat, PetscInt size, PetscInt bsize)
8645: {
8646:   PetscFunctionBegin;
8649:   PetscCall(MatStashSetInitialSize_Private(&mat->stash, size));
8650:   PetscCall(MatStashSetInitialSize_Private(&mat->bstash, bsize));
8651:   PetscFunctionReturn(PETSC_SUCCESS);
8652: }

8654: /*@
8655:   MatInterpolateAdd - $w = y + A*x$ or $A^T*x$ depending on the shape of
8656:   the matrix

8658:   Neighbor-wise Collective

8660:   Input Parameters:
8661: + A - the matrix
8662: . x - the vector to be multiplied by the interpolation operator
8663: - y - the vector to be added to the result

8665:   Output Parameter:
8666: . w - the resulting vector

8668:   Level: intermediate

8670:   Notes:
8671:   `w` may be the same vector as `y`.

8673:   This allows one to use either the restriction or interpolation (its transpose)
8674:   matrix to do the interpolation

8676: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8677: @*/
8678: PetscErrorCode MatInterpolateAdd(Mat A, Vec x, Vec y, Vec w)
8679: {
8680:   PetscInt M, N, Ny;

8682:   PetscFunctionBegin;
8687:   PetscCall(MatGetSize(A, &M, &N));
8688:   PetscCall(VecGetSize(y, &Ny));
8689:   if (M == Ny) {
8690:     PetscCall(MatMultAdd(A, x, y, w));
8691:   } else {
8692:     PetscCall(MatMultTransposeAdd(A, x, y, w));
8693:   }
8694:   PetscFunctionReturn(PETSC_SUCCESS);
8695: }

8697: /*@
8698:   MatInterpolate - $y = A*x$ or $A^T*x$ depending on the shape of
8699:   the matrix

8701:   Neighbor-wise Collective

8703:   Input Parameters:
8704: + A - the matrix
8705: - x - the vector to be interpolated

8707:   Output Parameter:
8708: . y - the resulting vector

8710:   Level: intermediate

8712:   Note:
8713:   This allows one to use either the restriction or interpolation (its transpose)
8714:   matrix to do the interpolation

8716: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8717: @*/
8718: PetscErrorCode MatInterpolate(Mat A, Vec x, Vec y)
8719: {
8720:   PetscInt M, N, Ny;

8722:   PetscFunctionBegin;
8726:   PetscCall(MatGetSize(A, &M, &N));
8727:   PetscCall(VecGetSize(y, &Ny));
8728:   if (M == Ny) {
8729:     PetscCall(MatMult(A, x, y));
8730:   } else {
8731:     PetscCall(MatMultTranspose(A, x, y));
8732:   }
8733:   PetscFunctionReturn(PETSC_SUCCESS);
8734: }

8736: /*@
8737:   MatRestrict - $y = A*x$ or $A^T*x$

8739:   Neighbor-wise Collective

8741:   Input Parameters:
8742: + A - the matrix
8743: - x - the vector to be restricted

8745:   Output Parameter:
8746: . y - the resulting vector

8748:   Level: intermediate

8750:   Note:
8751:   This allows one to use either the restriction or interpolation (its transpose)
8752:   matrix to do the restriction

8754: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatInterpolate()`, `PCMG`
8755: @*/
8756: PetscErrorCode MatRestrict(Mat A, Vec x, Vec y)
8757: {
8758:   PetscInt M, N, Nx;

8760:   PetscFunctionBegin;
8764:   PetscCall(MatGetSize(A, &M, &N));
8765:   PetscCall(VecGetSize(x, &Nx));
8766:   if (M == Nx) {
8767:     PetscCall(MatMultTranspose(A, x, y));
8768:   } else {
8769:     PetscCall(MatMult(A, x, y));
8770:   }
8771:   PetscFunctionReturn(PETSC_SUCCESS);
8772: }

8774: /*@
8775:   MatMatInterpolateAdd - $Y = W + A*X$ or $W + A^T*X$ depending on the shape of `A`

8777:   Neighbor-wise Collective

8779:   Input Parameters:
8780: + A - the matrix
8781: . x - the input dense matrix to be multiplied
8782: - w - the input dense matrix to be added to the result

8784:   Output Parameter:
8785: . y - the output dense matrix

8787:   Level: intermediate

8789:   Note:
8790:   This allows one to use either the restriction or interpolation (its transpose)
8791:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8792:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8794: .seealso: [](ch_matrices), `Mat`, `MatInterpolateAdd()`, `MatMatInterpolate()`, `MatMatRestrict()`, `PCMG`
8795: @*/
8796: PetscErrorCode MatMatInterpolateAdd(Mat A, Mat x, Mat w, Mat *y)
8797: {
8798:   PetscInt  M, N, Mx, Nx, Mo, My = 0, Ny = 0;
8799:   PetscBool trans = PETSC_TRUE;
8800:   MatReuse  reuse = MAT_INITIAL_MATRIX;

8802:   PetscFunctionBegin;
8808:   PetscCall(MatGetSize(A, &M, &N));
8809:   PetscCall(MatGetSize(x, &Mx, &Nx));
8810:   if (N == Mx) trans = PETSC_FALSE;
8811:   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);
8812:   Mo = trans ? N : M;
8813:   if (*y) {
8814:     PetscCall(MatGetSize(*y, &My, &Ny));
8815:     if (Mo == My && Nx == Ny) {
8816:       reuse = MAT_REUSE_MATRIX;
8817:     } else {
8818:       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);
8819:       PetscCall(MatDestroy(y));
8820:     }
8821:   }

8823:   if (w && *y == w) { /* this is to minimize changes in PCMG */
8824:     PetscBool flg;

8826:     PetscCall(PetscObjectQuery((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject *)&w));
8827:     if (w) {
8828:       PetscInt My, Ny, Mw, Nw;

8830:       PetscCall(PetscObjectTypeCompare((PetscObject)*y, ((PetscObject)w)->type_name, &flg));
8831:       PetscCall(MatGetSize(*y, &My, &Ny));
8832:       PetscCall(MatGetSize(w, &Mw, &Nw));
8833:       if (!flg || My != Mw || Ny != Nw) w = NULL;
8834:     }
8835:     if (!w) {
8836:       PetscCall(MatDuplicate(*y, MAT_COPY_VALUES, &w));
8837:       PetscCall(PetscObjectCompose((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject)w));
8838:       PetscCall(PetscObjectDereference((PetscObject)w));
8839:     } else {
8840:       PetscCall(MatCopy(*y, w, UNKNOWN_NONZERO_PATTERN));
8841:     }
8842:   }
8843:   if (!trans) {
8844:     PetscCall(MatMatMult(A, x, reuse, PETSC_DETERMINE, y));
8845:   } else {
8846:     PetscCall(MatTransposeMatMult(A, x, reuse, PETSC_DETERMINE, y));
8847:   }
8848:   if (w) PetscCall(MatAXPY(*y, 1.0, w, UNKNOWN_NONZERO_PATTERN));
8849:   PetscFunctionReturn(PETSC_SUCCESS);
8850: }

8852: /*@
8853:   MatMatInterpolate - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8855:   Neighbor-wise Collective

8857:   Input Parameters:
8858: + A - the matrix
8859: - x - the input dense matrix

8861:   Output Parameter:
8862: . y - the output dense matrix

8864:   Level: intermediate

8866:   Note:
8867:   This allows one to use either the restriction or interpolation (its transpose)
8868:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8869:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8871: .seealso: [](ch_matrices), `Mat`, `MatInterpolate()`, `MatRestrict()`, `MatMatRestrict()`, `PCMG`
8872: @*/
8873: PetscErrorCode MatMatInterpolate(Mat A, Mat x, Mat *y)
8874: {
8875:   PetscFunctionBegin;
8876:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
8877:   PetscFunctionReturn(PETSC_SUCCESS);
8878: }

8880: /*@
8881:   MatMatRestrict - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8883:   Neighbor-wise Collective

8885:   Input Parameters:
8886: + A - the matrix
8887: - x - the input dense matrix

8889:   Output Parameter:
8890: . y - the output dense matrix

8892:   Level: intermediate

8894:   Note:
8895:   This allows one to use either the restriction or interpolation (its transpose)
8896:   matrix to do the restriction. `y` matrix can be reused if already created with the proper sizes,
8897:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8899: .seealso: [](ch_matrices), `Mat`, `MatRestrict()`, `MatInterpolate()`, `MatMatInterpolate()`, `PCMG`
8900: @*/
8901: PetscErrorCode MatMatRestrict(Mat A, Mat x, Mat *y)
8902: {
8903:   PetscFunctionBegin;
8904:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
8905:   PetscFunctionReturn(PETSC_SUCCESS);
8906: }

8908: /*@
8909:   MatGetNullSpace - retrieves the null space of a matrix.

8911:   Logically Collective

8913:   Input Parameters:
8914: + mat    - the matrix
8915: - nullsp - the null space object

8917:   Level: developer

8919: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetNullSpace()`, `MatNullSpace`
8920: @*/
8921: PetscErrorCode MatGetNullSpace(Mat mat, MatNullSpace *nullsp)
8922: {
8923:   PetscFunctionBegin;
8925:   PetscAssertPointer(nullsp, 2);
8926:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->nullsp) ? mat->transnullsp : mat->nullsp;
8927:   PetscFunctionReturn(PETSC_SUCCESS);
8928: }

8930: /*@C
8931:   MatGetNullSpaces - gets the null spaces, transpose null spaces, and near null spaces from an array of matrices

8933:   Logically Collective

8935:   Input Parameters:
8936: + n   - the number of matrices
8937: - mat - the array of matrices

8939:   Output Parameters:
8940: . nullsp - an array of null spaces, `NULL` for each matrix that does not have a null space, length 3 * `n`

8942:   Level: developer

8944:   Note:
8945:   Call `MatRestoreNullspaces()` to provide these to another array of matrices

8947: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
8948:           `MatNullSpaceRemove()`, `MatRestoreNullSpaces()`
8949: @*/
8950: PetscErrorCode MatGetNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
8951: {
8952:   PetscFunctionBegin;
8953:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
8954:   PetscAssertPointer(mat, 2);
8955:   PetscAssertPointer(nullsp, 3);

8957:   PetscCall(PetscCalloc1(3 * n, nullsp));
8958:   for (PetscInt i = 0; i < n; i++) {
8960:     (*nullsp)[i] = mat[i]->nullsp;
8961:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[i]));
8962:     (*nullsp)[n + i] = mat[i]->nearnullsp;
8963:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[n + i]));
8964:     (*nullsp)[2 * n + i] = mat[i]->transnullsp;
8965:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[2 * n + i]));
8966:   }
8967:   PetscFunctionReturn(PETSC_SUCCESS);
8968: }

8970: /*@C
8971:   MatRestoreNullSpaces - sets the null spaces, transpose null spaces, and near null spaces obtained with `MatGetNullSpaces()` for an array of matrices

8973:   Logically Collective

8975:   Input Parameters:
8976: + n      - the number of matrices
8977: . mat    - the array of matrices
8978: - nullsp - an array of null spaces

8980:   Level: developer

8982:   Note:
8983:   Call `MatGetNullSpaces()` to create `nullsp`

8985: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
8986:           `MatNullSpaceRemove()`, `MatGetNullSpaces()`
8987: @*/
8988: PetscErrorCode MatRestoreNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
8989: {
8990:   PetscFunctionBegin;
8991:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
8992:   PetscAssertPointer(mat, 2);
8993:   PetscAssertPointer(nullsp, 3);
8994:   PetscAssertPointer(*nullsp, 3);

8996:   for (PetscInt i = 0; i < n; i++) {
8998:     PetscCall(MatSetNullSpace(mat[i], (*nullsp)[i]));
8999:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[i]));
9000:     PetscCall(MatSetNearNullSpace(mat[i], (*nullsp)[n + i]));
9001:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[n + i]));
9002:     PetscCall(MatSetTransposeNullSpace(mat[i], (*nullsp)[2 * n + i]));
9003:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[2 * n + i]));
9004:   }
9005:   PetscCall(PetscFree(*nullsp));
9006:   PetscFunctionReturn(PETSC_SUCCESS);
9007: }

9009: /*@
9010:   MatSetNullSpace - attaches a null space to a matrix.

9012:   Logically Collective

9014:   Input Parameters:
9015: + mat    - the matrix
9016: - nullsp - the null space object

9018:   Level: advanced

9020:   Notes:
9021:   This null space is used by the `KSP` linear solvers to solve singular systems.

9023:   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`

9025:   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
9026:   to zero but the linear system will still be solved in a least squares sense.

9028:   The fundamental theorem of linear algebra (Gilbert Strang, Introduction to Applied Mathematics, page 72) states that
9029:   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 $A^T$, $R(A^T)$.
9030:   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
9031:   $n(A^T))$ 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
9032:   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 $n(A^T)$.
9033:   This  $\hat{b}$ can be obtained by calling `MatNullSpaceRemove()` with the null space of the transpose of the matrix.

9035:   If the matrix is known to be symmetric because it is an `MATSBAIJ` matrix or one has called
9036:   `MatSetOption`(mat,`MAT_SYMMETRIC` or possibly `MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`); this
9037:   routine also automatically calls `MatSetTransposeNullSpace()`.

9039:   The user should call `MatNullSpaceDestroy()`.

9041: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`,
9042:           `KSPSetPCSide()`
9043: @*/
9044: PetscErrorCode MatSetNullSpace(Mat mat, MatNullSpace nullsp)
9045: {
9046:   PetscFunctionBegin;
9049:   if (nullsp) PetscCall(PetscObjectReference((PetscObject)nullsp));
9050:   PetscCall(MatNullSpaceDestroy(&mat->nullsp));
9051:   mat->nullsp = nullsp;
9052:   if (mat->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetTransposeNullSpace(mat, nullsp));
9053:   PetscFunctionReturn(PETSC_SUCCESS);
9054: }

9056: /*@
9057:   MatGetTransposeNullSpace - retrieves the null space of the transpose of a matrix.

9059:   Logically Collective

9061:   Input Parameters:
9062: + mat    - the matrix
9063: - nullsp - the null space object

9065:   Level: developer

9067: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetTransposeNullSpace()`, `MatSetNullSpace()`, `MatGetNullSpace()`
9068: @*/
9069: PetscErrorCode MatGetTransposeNullSpace(Mat mat, MatNullSpace *nullsp)
9070: {
9071:   PetscFunctionBegin;
9074:   PetscAssertPointer(nullsp, 2);
9075:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->transnullsp) ? mat->nullsp : mat->transnullsp;
9076:   PetscFunctionReturn(PETSC_SUCCESS);
9077: }

9079: /*@
9080:   MatSetTransposeNullSpace - attaches the null space of a transpose of a matrix to the matrix

9082:   Logically Collective

9084:   Input Parameters:
9085: + mat    - the matrix
9086: - nullsp - the null space object

9088:   Level: advanced

9090:   Notes:
9091:   This allows solving singular linear systems defined by the transpose of the matrix using `KSP` solvers with left preconditioning.

9093:   See `MatSetNullSpace()`

9095: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`, `KSPSetPCSide()`
9096: @*/
9097: PetscErrorCode MatSetTransposeNullSpace(Mat mat, MatNullSpace nullsp)
9098: {
9099:   PetscFunctionBegin;
9102:   if (nullsp) PetscCall(PetscObjectReference((PetscObject)nullsp));
9103:   PetscCall(MatNullSpaceDestroy(&mat->transnullsp));
9104:   mat->transnullsp = nullsp;
9105:   PetscFunctionReturn(PETSC_SUCCESS);
9106: }

9108: /*@
9109:   MatSetNearNullSpace - attaches a null space to a matrix, which is often the null space (rigid body modes) of the operator without boundary conditions
9110:   This null space will be used to provide near null space vectors to a multigrid preconditioner built from this matrix.

9112:   Logically Collective

9114:   Input Parameters:
9115: + mat    - the matrix
9116: - nullsp - the null space object

9118:   Level: advanced

9120:   Notes:
9121:   Overwrites any previous near null space that may have been attached

9123:   You can remove the null space by calling this routine with an `nullsp` of `NULL`

9125: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNullSpace()`, `MatNullSpaceCreateRigidBody()`, `MatGetNearNullSpace()`
9126: @*/
9127: PetscErrorCode MatSetNearNullSpace(Mat mat, MatNullSpace nullsp)
9128: {
9129:   PetscFunctionBegin;
9133:   MatCheckPreallocated(mat, 1);
9134:   if (nullsp) PetscCall(PetscObjectReference((PetscObject)nullsp));
9135:   PetscCall(MatNullSpaceDestroy(&mat->nearnullsp));
9136:   mat->nearnullsp = nullsp;
9137:   PetscFunctionReturn(PETSC_SUCCESS);
9138: }

9140: /*@
9141:   MatGetNearNullSpace - Get null space attached with `MatSetNearNullSpace()`

9143:   Not Collective

9145:   Input Parameter:
9146: . mat - the matrix

9148:   Output Parameter:
9149: . nullsp - the null space object, `NULL` if not set

9151:   Level: advanced

9153: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatNullSpaceCreate()`
9154: @*/
9155: PetscErrorCode MatGetNearNullSpace(Mat mat, MatNullSpace *nullsp)
9156: {
9157:   PetscFunctionBegin;
9160:   PetscAssertPointer(nullsp, 2);
9161:   MatCheckPreallocated(mat, 1);
9162:   *nullsp = mat->nearnullsp;
9163:   PetscFunctionReturn(PETSC_SUCCESS);
9164: }

9166: /*@
9167:   MatICCFactor - Performs in-place incomplete Cholesky factorization of matrix.

9169:   Collective

9171:   Input Parameters:
9172: + mat  - the matrix
9173: . row  - row/column permutation
9174: - info - information on desired factorization process

9176:   Level: developer

9178:   Notes:
9179:   Probably really in-place only when level of fill is zero, otherwise allocates
9180:   new space to store factored matrix and deletes previous memory.

9182:   Most users should employ the `KSP` interface for linear solvers
9183:   instead of working directly with matrix algebra routines such as this.
9184:   See, e.g., `KSPCreate()`.

9186:   Fortran Note:
9187:   A valid (non-null) `info` argument must be provided

9189: .seealso: [](ch_matrices), `Mat`, `MatFactorInfo`, `MatGetFactor()`, `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
9190: @*/
9191: PetscErrorCode MatICCFactor(Mat mat, IS row, const MatFactorInfo *info)
9192: {
9193:   PetscFunctionBegin;
9197:   PetscAssertPointer(info, 3);
9198:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
9199:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
9200:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
9201:   MatCheckPreallocated(mat, 1);
9202:   PetscUseTypeMethod(mat, iccfactor, row, info);
9203:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9204:   PetscFunctionReturn(PETSC_SUCCESS);
9205: }

9207: /*@
9208:   MatDiagonalScaleLocal - Scales columns of a matrix given the scaling values including the
9209:   ghosted ones.

9211:   Not Collective

9213:   Input Parameters:
9214: + mat  - the matrix
9215: - diag - the diagonal values, including ghost ones

9217:   Level: developer

9219:   Notes:
9220:   Works only for `MATMPIAIJ` and `MATMPIBAIJ` matrices

9222:   This allows one to avoid during communication to perform the scaling that must be done with `MatDiagonalScale()`

9224: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
9225: @*/
9226: PetscErrorCode MatDiagonalScaleLocal(Mat mat, Vec diag)
9227: {
9228:   PetscMPIInt size;

9230:   PetscFunctionBegin;

9235:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must be already assembled");
9236:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
9237:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
9238:   if (size == 1) {
9239:     PetscInt n, m;
9240:     PetscCall(VecGetSize(diag, &n));
9241:     PetscCall(MatGetSize(mat, NULL, &m));
9242:     PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supported for sequential matrices when no ghost points/periodic conditions");
9243:     PetscCall(MatDiagonalScale(mat, NULL, diag));
9244:   } else {
9245:     PetscUseMethod(mat, "MatDiagonalScaleLocal_C", (Mat, Vec), (mat, diag));
9246:   }
9247:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
9248:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9249:   PetscFunctionReturn(PETSC_SUCCESS);
9250: }

9252: /*@
9253:   MatGetInertia - Gets the inertia from a factored matrix

9255:   Collective

9257:   Input Parameter:
9258: . mat - the matrix

9260:   Output Parameters:
9261: + nneg  - number of negative eigenvalues
9262: . nzero - number of zero eigenvalues
9263: - npos  - number of positive eigenvalues

9265:   Level: advanced

9267:   Note:
9268:   Matrix must have been factored by `MatCholeskyFactor()`

9270: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactor()`
9271: @*/
9272: PetscErrorCode MatGetInertia(Mat mat, PetscInt *nneg, PetscInt *nzero, PetscInt *npos)
9273: {
9274:   PetscFunctionBegin;
9277:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9278:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Numeric factor mat is not assembled");
9279:   PetscUseTypeMethod(mat, getinertia, nneg, nzero, npos);
9280:   PetscFunctionReturn(PETSC_SUCCESS);
9281: }

9283: /*@C
9284:   MatSolves - Solves $A x = b$, given a factored matrix, for a collection of vectors

9286:   Neighbor-wise Collective

9288:   Input Parameters:
9289: + mat - the factored matrix obtained with `MatGetFactor()`
9290: - b   - the right-hand-side vectors

9292:   Output Parameter:
9293: . x - the result vectors

9295:   Level: developer

9297:   Note:
9298:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
9299:   call `MatSolves`(A,x,x).

9301: .seealso: [](ch_matrices), `Mat`, `Vecs`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`, `MatSolve()`
9302: @*/
9303: PetscErrorCode MatSolves(Mat mat, Vecs b, Vecs x)
9304: {
9305:   PetscFunctionBegin;
9308:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
9309:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9310:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);

9312:   MatCheckPreallocated(mat, 1);
9313:   PetscCall(PetscLogEventBegin(MAT_Solves, mat, 0, 0, 0));
9314:   PetscUseTypeMethod(mat, solves, b, x);
9315:   PetscCall(PetscLogEventEnd(MAT_Solves, mat, 0, 0, 0));
9316:   PetscFunctionReturn(PETSC_SUCCESS);
9317: }

9319: /*@
9320:   MatIsSymmetric - Test whether a matrix is symmetric

9322:   Collective

9324:   Input Parameters:
9325: + A   - the matrix to test
9326: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact transpose)

9328:   Output Parameter:
9329: . flg - the result

9331:   Level: intermediate

9333:   Notes:
9334:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9336:   If the matrix does not yet know if it is symmetric or not this can be an expensive operation, also available `MatIsSymmetricKnown()`

9338:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9339:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9341: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetricKnown()`,
9342:           `MAT_SYMMETRIC`, `MAT_SYMMETRY_ETERNAL`
9343: @*/
9344: PetscErrorCode MatIsSymmetric(Mat A, PetscReal tol, PetscBool *flg)
9345: {
9346:   PetscFunctionBegin;
9348:   PetscAssertPointer(flg, 3);
9349:   if (A->symmetric != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->symmetric);
9350:   else {
9351:     if (A->ops->issymmetric) PetscUseTypeMethod(A, issymmetric, tol, flg);
9352:     else PetscCall(MatIsTranspose(A, A, tol, flg));
9353:     if (!tol) PetscCall(MatSetOption(A, MAT_SYMMETRIC, *flg));
9354:   }
9355:   PetscFunctionReturn(PETSC_SUCCESS);
9356: }

9358: /*@
9359:   MatIsHermitian - Test whether a matrix is Hermitian

9361:   Collective

9363:   Input Parameters:
9364: + A   - the matrix to test
9365: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact Hermitian)

9367:   Output Parameter:
9368: . flg - the result

9370:   Level: intermediate

9372:   Notes:
9373:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9375:   If the matrix does not yet know if it is Hermitian or not this can be an expensive operation, also available `MatIsHermitianKnown()`

9377:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9378:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMEMTRY_ETERNAL`,`PETSC_TRUE`)

9380: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetric()`, `MatSetOption()`,
9381:           `MatIsSymmetricKnown()`, `MatIsSymmetric()`, `MAT_HERMITIAN`, `MAT_SYMMETRY_ETERNAL`
9382: @*/
9383: PetscErrorCode MatIsHermitian(Mat A, PetscReal tol, PetscBool *flg)
9384: {
9385:   PetscFunctionBegin;
9387:   PetscAssertPointer(flg, 3);
9388:   if (A->hermitian != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->hermitian);
9389:   else {
9390:     if (A->ops->ishermitian) PetscUseTypeMethod(A, ishermitian, tol, flg);
9391:     else PetscCall(MatIsHermitianTranspose(A, A, tol, flg));
9392:     if (!tol) PetscCall(MatSetOption(A, MAT_HERMITIAN, *flg));
9393:   }
9394:   PetscFunctionReturn(PETSC_SUCCESS);
9395: }

9397: /*@
9398:   MatIsSymmetricKnown - Checks if a matrix knows if it is symmetric or not and its symmetric state

9400:   Not Collective

9402:   Input Parameter:
9403: . A - the matrix to check

9405:   Output Parameters:
9406: + set - `PETSC_TRUE` if the matrix knows its symmetry state (this tells you if the next flag is valid)
9407: - flg - the result (only valid if set is `PETSC_TRUE`)

9409:   Level: advanced

9411:   Notes:
9412:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsSymmetric()`
9413:   if you want it explicitly checked

9415:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9416:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9418: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9419: @*/
9420: PetscErrorCode MatIsSymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9421: {
9422:   PetscFunctionBegin;
9424:   PetscAssertPointer(set, 2);
9425:   PetscAssertPointer(flg, 3);
9426:   if (A->symmetric != PETSC_BOOL3_UNKNOWN) {
9427:     *set = PETSC_TRUE;
9428:     *flg = PetscBool3ToBool(A->symmetric);
9429:   } else {
9430:     *set = PETSC_FALSE;
9431:   }
9432:   PetscFunctionReturn(PETSC_SUCCESS);
9433: }

9435: /*@
9436:   MatIsSPDKnown - Checks if a matrix knows if it is symmetric positive definite or not and its symmetric positive definite state

9438:   Not Collective

9440:   Input Parameter:
9441: . A - the matrix to check

9443:   Output Parameters:
9444: + set - `PETSC_TRUE` if the matrix knows its symmetric positive definite state (this tells you if the next flag is valid)
9445: - flg - the result (only valid if set is `PETSC_TRUE`)

9447:   Level: advanced

9449:   Notes:
9450:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`).

9452:   One can declare that a matrix is SPD with `MatSetOption`(mat,`MAT_SPD`,`PETSC_TRUE`) and if it is known to remain SPD
9453:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SPD_ETERNAL`,`PETSC_TRUE`)

9455: .seealso: [](ch_matrices), `Mat`, `MAT_SPD_ETERNAL`, `MAT_SPD`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9456: @*/
9457: PetscErrorCode MatIsSPDKnown(Mat A, PetscBool *set, PetscBool *flg)
9458: {
9459:   PetscFunctionBegin;
9461:   PetscAssertPointer(set, 2);
9462:   PetscAssertPointer(flg, 3);
9463:   if (A->spd != PETSC_BOOL3_UNKNOWN) {
9464:     *set = PETSC_TRUE;
9465:     *flg = PetscBool3ToBool(A->spd);
9466:   } else {
9467:     *set = PETSC_FALSE;
9468:   }
9469:   PetscFunctionReturn(PETSC_SUCCESS);
9470: }

9472: /*@
9473:   MatIsHermitianKnown - Checks if a matrix knows if it is Hermitian or not and its Hermitian state

9475:   Not Collective

9477:   Input Parameter:
9478: . A - the matrix to check

9480:   Output Parameters:
9481: + set - `PETSC_TRUE` if the matrix knows its Hermitian state (this tells you if the next flag is valid)
9482: - flg - the result (only valid if set is `PETSC_TRUE`)

9484:   Level: advanced

9486:   Notes:
9487:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsHermitian()`
9488:   if you want it explicitly checked

9490:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9491:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9493: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MAT_HERMITIAN`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`
9494: @*/
9495: PetscErrorCode MatIsHermitianKnown(Mat A, PetscBool *set, PetscBool *flg)
9496: {
9497:   PetscFunctionBegin;
9499:   PetscAssertPointer(set, 2);
9500:   PetscAssertPointer(flg, 3);
9501:   if (A->hermitian != PETSC_BOOL3_UNKNOWN) {
9502:     *set = PETSC_TRUE;
9503:     *flg = PetscBool3ToBool(A->hermitian);
9504:   } else {
9505:     *set = PETSC_FALSE;
9506:   }
9507:   PetscFunctionReturn(PETSC_SUCCESS);
9508: }

9510: /*@
9511:   MatIsStructurallySymmetric - Test whether a matrix is structurally symmetric

9513:   Collective

9515:   Input Parameter:
9516: . A - the matrix to test

9518:   Output Parameter:
9519: . flg - the result

9521:   Level: intermediate

9523:   Notes:
9524:   If the matrix does yet know it is structurally symmetric this can be an expensive operation, also available `MatIsStructurallySymmetricKnown()`

9526:   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
9527:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9529: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsSymmetric()`, `MatSetOption()`, `MatIsStructurallySymmetricKnown()`
9530: @*/
9531: PetscErrorCode MatIsStructurallySymmetric(Mat A, PetscBool *flg)
9532: {
9533:   PetscFunctionBegin;
9535:   PetscAssertPointer(flg, 2);
9536:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9537:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9538:   } else {
9539:     PetscUseTypeMethod(A, isstructurallysymmetric, flg);
9540:     PetscCall(MatSetOption(A, MAT_STRUCTURALLY_SYMMETRIC, *flg));
9541:   }
9542:   PetscFunctionReturn(PETSC_SUCCESS);
9543: }

9545: /*@
9546:   MatIsStructurallySymmetricKnown - Checks if a matrix knows if it is structurally symmetric or not and its structurally symmetric state

9548:   Not Collective

9550:   Input Parameter:
9551: . A - the matrix to check

9553:   Output Parameters:
9554: + set - PETSC_TRUE if the matrix knows its structurally symmetric state (this tells you if the next flag is valid)
9555: - flg - the result (only valid if set is PETSC_TRUE)

9557:   Level: advanced

9559:   Notes:
9560:   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
9561:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9563:   Use `MatIsStructurallySymmetric()` to explicitly check if a matrix is structurally symmetric (this is an expensive operation)

9565: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9566: @*/
9567: PetscErrorCode MatIsStructurallySymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9568: {
9569:   PetscFunctionBegin;
9571:   PetscAssertPointer(set, 2);
9572:   PetscAssertPointer(flg, 3);
9573:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9574:     *set = PETSC_TRUE;
9575:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9576:   } else {
9577:     *set = PETSC_FALSE;
9578:   }
9579:   PetscFunctionReturn(PETSC_SUCCESS);
9580: }

9582: /*@
9583:   MatStashGetInfo - Gets how many values are currently in the matrix stash, i.e. need
9584:   to be communicated to other processors during the `MatAssemblyBegin()`/`MatAssemblyEnd()` process

9586:   Not Collective

9588:   Input Parameter:
9589: . mat - the matrix

9591:   Output Parameters:
9592: + nstash    - the size of the stash
9593: . reallocs  - the number of additional mallocs incurred.
9594: . bnstash   - the size of the block stash
9595: - breallocs - the number of additional mallocs incurred.in the block stash

9597:   Level: advanced

9599: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashSetInitialSize()`
9600: @*/
9601: PetscErrorCode MatStashGetInfo(Mat mat, PetscInt *nstash, PetscInt *reallocs, PetscInt *bnstash, PetscInt *breallocs)
9602: {
9603:   PetscFunctionBegin;
9604:   PetscCall(MatStashGetInfo_Private(&mat->stash, nstash, reallocs));
9605:   PetscCall(MatStashGetInfo_Private(&mat->bstash, bnstash, breallocs));
9606:   PetscFunctionReturn(PETSC_SUCCESS);
9607: }

9609: /*@
9610:   MatCreateVecs - Get vector(s) compatible with the matrix, i.e. with the same
9611:   parallel layout, `PetscLayout` for rows and columns

9613:   Collective

9615:   Input Parameter:
9616: . mat - the matrix

9618:   Output Parameters:
9619: + right - (optional) vector that the matrix can be multiplied against
9620: - left  - (optional) vector that the matrix vector product can be stored in

9622:   Level: advanced

9624:   Notes:
9625:   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()`.

9627:   These are new vectors which are not owned by the mat, they should be destroyed in `VecDestroy()` when no longer needed

9629: .seealso: [](ch_matrices), `Mat`, `Vec`, `VecCreate()`, `VecDestroy()`, `DMCreateGlobalVector()`
9630: @*/
9631: PetscErrorCode MatCreateVecs(Mat mat, Vec *right, Vec *left)
9632: {
9633:   PetscFunctionBegin;
9636:   if (mat->ops->getvecs) {
9637:     PetscUseTypeMethod(mat, getvecs, right, left);
9638:   } else {
9639:     if (right) {
9640:       PetscCheck(mat->cmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for columns not yet setup");
9641:       PetscCall(VecCreateWithLayout_Private(mat->cmap, right));
9642:       PetscCall(VecSetType(*right, mat->defaultvectype));
9643: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9644:       if (mat->boundtocpu && mat->bindingpropagates) {
9645:         PetscCall(VecSetBindingPropagates(*right, PETSC_TRUE));
9646:         PetscCall(VecBindToCPU(*right, PETSC_TRUE));
9647:       }
9648: #endif
9649:     }
9650:     if (left) {
9651:       PetscCheck(mat->rmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for rows not yet setup");
9652:       PetscCall(VecCreateWithLayout_Private(mat->rmap, left));
9653:       PetscCall(VecSetType(*left, mat->defaultvectype));
9654: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9655:       if (mat->boundtocpu && mat->bindingpropagates) {
9656:         PetscCall(VecSetBindingPropagates(*left, PETSC_TRUE));
9657:         PetscCall(VecBindToCPU(*left, PETSC_TRUE));
9658:       }
9659: #endif
9660:     }
9661:   }
9662:   PetscFunctionReturn(PETSC_SUCCESS);
9663: }

9665: /*@
9666:   MatFactorInfoInitialize - Initializes a `MatFactorInfo` data structure
9667:   with default values.

9669:   Not Collective

9671:   Input Parameter:
9672: . info - the `MatFactorInfo` data structure

9674:   Level: developer

9676:   Notes:
9677:   The solvers are generally used through the `KSP` and `PC` objects, for example
9678:   `PCLU`, `PCILU`, `PCCHOLESKY`, `PCICC`

9680:   Once the data structure is initialized one may change certain entries as desired for the particular factorization to be performed

9682: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorInfo`
9683: @*/
9684: PetscErrorCode MatFactorInfoInitialize(MatFactorInfo *info)
9685: {
9686:   PetscFunctionBegin;
9687:   PetscCall(PetscMemzero(info, sizeof(MatFactorInfo)));
9688:   PetscFunctionReturn(PETSC_SUCCESS);
9689: }

9691: /*@
9692:   MatFactorSetSchurIS - Set indices corresponding to the Schur complement you wish to have computed

9694:   Collective

9696:   Input Parameters:
9697: + mat - the factored matrix
9698: - is  - the index set defining the Schur indices (0-based)

9700:   Level: advanced

9702:   Notes:
9703:   Call `MatFactorSolveSchurComplement()` or `MatFactorSolveSchurComplementTranspose()` after this call to solve a Schur complement system.

9705:   You can call `MatFactorGetSchurComplement()` or `MatFactorCreateSchurComplement()` after this call.

9707:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9709: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorGetSchurComplement()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSolveSchurComplement()`,
9710:           `MatFactorSolveSchurComplementTranspose()`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9711: @*/
9712: PetscErrorCode MatFactorSetSchurIS(Mat mat, IS is)
9713: {
9714:   PetscErrorCode (*f)(Mat, IS);

9716:   PetscFunctionBegin;
9721:   PetscCheckSameComm(mat, 1, is, 2);
9722:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
9723:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorSetSchurIS_C", &f));
9724:   PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "The selected MatSolverType does not support Schur complement computation. You should use MATSOLVERMUMPS or MATSOLVERMKL_PARDISO");
9725:   PetscCall(MatDestroy(&mat->schur));
9726:   PetscCall((*f)(mat, is));
9727:   PetscCheck(mat->schur, PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "Schur complement has not been created");
9728:   PetscFunctionReturn(PETSC_SUCCESS);
9729: }

9731: /*@
9732:   MatFactorCreateSchurComplement - Create a Schur complement matrix object using Schur data computed during the factorization step

9734:   Logically Collective

9736:   Input Parameters:
9737: + F      - the factored matrix obtained by calling `MatGetFactor()`
9738: . S      - location where to return the Schur complement, can be `NULL`
9739: - status - the status of the Schur complement matrix, can be `NULL`

9741:   Level: advanced

9743:   Notes:
9744:   You must call `MatFactorSetSchurIS()` before calling this routine.

9746:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9748:   The routine provides a copy of the Schur matrix stored within the solver data structures.
9749:   The caller must destroy the object when it is no longer needed.
9750:   If `MatFactorInvertSchurComplement()` has been called, the routine gets back the inverse.

9752:   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)

9754:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9756:   Developer Note:
9757:   The reason this routine exists is because the representation of the Schur complement within the factor matrix may be different than a standard PETSc
9758:   matrix representation and we normally do not want to use the time or memory to make a copy as a regular PETSc matrix.

9760: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorSchurStatus`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9761: @*/
9762: PetscErrorCode MatFactorCreateSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9763: {
9764:   PetscFunctionBegin;
9766:   if (S) PetscAssertPointer(S, 2);
9767:   if (status) PetscAssertPointer(status, 3);
9768:   if (S) {
9769:     PetscErrorCode (*f)(Mat, Mat *);

9771:     PetscCall(PetscObjectQueryFunction((PetscObject)F, "MatFactorCreateSchurComplement_C", &f));
9772:     if (f) {
9773:       PetscCall((*f)(F, S));
9774:     } else {
9775:       PetscCall(MatDuplicate(F->schur, MAT_COPY_VALUES, S));
9776:     }
9777:   }
9778:   if (status) *status = F->schur_status;
9779:   PetscFunctionReturn(PETSC_SUCCESS);
9780: }

9782: /*@
9783:   MatFactorGetSchurComplement - Gets access to a Schur complement matrix using the current Schur data within a factored matrix

9785:   Logically Collective

9787:   Input Parameters:
9788: + F      - the factored matrix obtained by calling `MatGetFactor()`
9789: . S      - location where to return the Schur complement, can be `NULL`
9790: - status - the status of the Schur complement matrix, can be `NULL`

9792:   Level: advanced

9794:   Notes:
9795:   You must call `MatFactorSetSchurIS()` before calling this routine.

9797:   Schur complement mode is currently implemented for sequential matrices with factor type of `MATSOLVERMUMPS`

9799:   The routine returns a the Schur Complement stored within the data structures of the solver.

9801:   If `MatFactorInvertSchurComplement()` has previously been called, the returned matrix is actually the inverse of the Schur complement.

9803:   The returned matrix should not be destroyed; the caller should call `MatFactorRestoreSchurComplement()` when the object is no longer needed.

9805:   Use `MatFactorCreateSchurComplement()` to create a copy of the Schur complement matrix that is within a factored matrix

9807:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9809: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9810: @*/
9811: PetscErrorCode MatFactorGetSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9812: {
9813:   PetscFunctionBegin;
9815:   if (S) {
9816:     PetscAssertPointer(S, 2);
9817:     *S = F->schur;
9818:   }
9819:   if (status) {
9820:     PetscAssertPointer(status, 3);
9821:     *status = F->schur_status;
9822:   }
9823:   PetscFunctionReturn(PETSC_SUCCESS);
9824: }

9826: static PetscErrorCode MatFactorUpdateSchurStatus_Private(Mat F)
9827: {
9828:   Mat S = F->schur;

9830:   PetscFunctionBegin;
9831:   switch (F->schur_status) {
9832:   case MAT_FACTOR_SCHUR_UNFACTORED: // fall-through
9833:   case MAT_FACTOR_SCHUR_INVERTED:
9834:     if (S) {
9835:       S->ops->solve             = NULL;
9836:       S->ops->matsolve          = NULL;
9837:       S->ops->solvetranspose    = NULL;
9838:       S->ops->matsolvetranspose = NULL;
9839:       S->ops->solveadd          = NULL;
9840:       S->ops->solvetransposeadd = NULL;
9841:       S->factortype             = MAT_FACTOR_NONE;
9842:       PetscCall(PetscFree(S->solvertype));
9843:     }
9844:   case MAT_FACTOR_SCHUR_FACTORED: // fall-through
9845:     break;
9846:   default:
9847:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9848:   }
9849:   PetscFunctionReturn(PETSC_SUCCESS);
9850: }

9852: /*@
9853:   MatFactorRestoreSchurComplement - Restore the Schur complement matrix object obtained from a call to `MatFactorGetSchurComplement()`

9855:   Logically Collective

9857:   Input Parameters:
9858: + F      - the factored matrix obtained by calling `MatGetFactor()`
9859: . S      - location where the Schur complement is stored
9860: - status - the status of the Schur complement matrix (see `MatFactorSchurStatus`)

9862:   Level: advanced

9864: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9865: @*/
9866: PetscErrorCode MatFactorRestoreSchurComplement(Mat F, Mat *S, MatFactorSchurStatus status)
9867: {
9868:   PetscFunctionBegin;
9870:   if (S) {
9872:     *S = NULL;
9873:   }
9874:   F->schur_status = status;
9875:   PetscCall(MatFactorUpdateSchurStatus_Private(F));
9876:   PetscFunctionReturn(PETSC_SUCCESS);
9877: }

9879: /*@
9880:   MatFactorSolveSchurComplementTranspose - Solve the transpose of the Schur complement system computed during the factorization step

9882:   Logically Collective

9884:   Input Parameters:
9885: + F   - the factored matrix obtained by calling `MatGetFactor()`
9886: . rhs - location where the right-hand side of the Schur complement system is stored
9887: - sol - location where the solution of the Schur complement system has to be returned

9889:   Level: advanced

9891:   Notes:
9892:   The sizes of the vectors should match the size of the Schur complement

9894:   Must be called after `MatFactorSetSchurIS()`

9896: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplement()`
9897: @*/
9898: PetscErrorCode MatFactorSolveSchurComplementTranspose(Mat F, Vec rhs, Vec sol)
9899: {
9900:   PetscFunctionBegin;
9907:   PetscCheckSameComm(F, 1, rhs, 2);
9908:   PetscCheckSameComm(F, 1, sol, 3);
9909:   PetscCall(MatFactorFactorizeSchurComplement(F));
9910:   switch (F->schur_status) {
9911:   case MAT_FACTOR_SCHUR_FACTORED:
9912:     PetscCall(MatSolveTranspose(F->schur, rhs, sol));
9913:     break;
9914:   case MAT_FACTOR_SCHUR_INVERTED:
9915:     PetscCall(MatMultTranspose(F->schur, rhs, sol));
9916:     break;
9917:   default:
9918:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9919:   }
9920:   PetscFunctionReturn(PETSC_SUCCESS);
9921: }

9923: /*@
9924:   MatFactorSolveSchurComplement - Solve the Schur complement system computed during the factorization step

9926:   Logically Collective

9928:   Input Parameters:
9929: + F   - the factored matrix obtained by calling `MatGetFactor()`
9930: . rhs - location where the right-hand side of the Schur complement system is stored
9931: - sol - location where the solution of the Schur complement system has to be returned

9933:   Level: advanced

9935:   Notes:
9936:   The sizes of the vectors should match the size of the Schur complement

9938:   Must be called after `MatFactorSetSchurIS()`

9940: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplementTranspose()`
9941: @*/
9942: PetscErrorCode MatFactorSolveSchurComplement(Mat F, Vec rhs, Vec sol)
9943: {
9944:   PetscFunctionBegin;
9951:   PetscCheckSameComm(F, 1, rhs, 2);
9952:   PetscCheckSameComm(F, 1, sol, 3);
9953:   PetscCall(MatFactorFactorizeSchurComplement(F));
9954:   switch (F->schur_status) {
9955:   case MAT_FACTOR_SCHUR_FACTORED:
9956:     PetscCall(MatSolve(F->schur, rhs, sol));
9957:     break;
9958:   case MAT_FACTOR_SCHUR_INVERTED:
9959:     PetscCall(MatMult(F->schur, rhs, sol));
9960:     break;
9961:   default:
9962:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9963:   }
9964:   PetscFunctionReturn(PETSC_SUCCESS);
9965: }

9967: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseInvertFactors_Private(Mat);
9968: #if PetscDefined(HAVE_CUDA)
9969: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseCUDAInvertFactors_Internal(Mat);
9970: #endif

9972: /* Schur status updated in the interface */
9973: static PetscErrorCode MatFactorInvertSchurComplement_Private(Mat F)
9974: {
9975:   Mat S = F->schur;

9977:   PetscFunctionBegin;
9978:   if (S) {
9979:     PetscMPIInt size;
9980:     PetscBool   isdense, isdensecuda;

9982:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)S), &size));
9983:     PetscCheck(size <= 1, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not yet implemented");
9984:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSE, &isdense));
9985:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSECUDA, &isdensecuda));
9986:     PetscCheck(isdense || isdensecuda, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not implemented for type %s", ((PetscObject)S)->type_name);
9987:     PetscCall(PetscLogEventBegin(MAT_FactorInvS, F, 0, 0, 0));
9988:     if (isdense) {
9989:       PetscCall(MatSeqDenseInvertFactors_Private(S));
9990:     } else if (isdensecuda) {
9991: #if defined(PETSC_HAVE_CUDA)
9992:       PetscCall(MatSeqDenseCUDAInvertFactors_Internal(S));
9993: #endif
9994:     }
9995:     // HIP??????????????
9996:     PetscCall(PetscLogEventEnd(MAT_FactorInvS, F, 0, 0, 0));
9997:   }
9998:   PetscFunctionReturn(PETSC_SUCCESS);
9999: }

10001: /*@
10002:   MatFactorInvertSchurComplement - Invert the Schur complement matrix computed during the factorization step

10004:   Logically Collective

10006:   Input Parameter:
10007: . F - the factored matrix obtained by calling `MatGetFactor()`

10009:   Level: advanced

10011:   Notes:
10012:   Must be called after `MatFactorSetSchurIS()`.

10014:   Call `MatFactorGetSchurComplement()` or  `MatFactorCreateSchurComplement()` AFTER this call to actually compute the inverse and get access to it.

10016: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorCreateSchurComplement()`
10017: @*/
10018: PetscErrorCode MatFactorInvertSchurComplement(Mat F)
10019: {
10020:   PetscFunctionBegin;
10023:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED) PetscFunctionReturn(PETSC_SUCCESS);
10024:   PetscCall(MatFactorFactorizeSchurComplement(F));
10025:   PetscCall(MatFactorInvertSchurComplement_Private(F));
10026:   F->schur_status = MAT_FACTOR_SCHUR_INVERTED;
10027:   PetscFunctionReturn(PETSC_SUCCESS);
10028: }

10030: /*@
10031:   MatFactorFactorizeSchurComplement - Factorize the Schur complement matrix computed during the factorization step

10033:   Logically Collective

10035:   Input Parameter:
10036: . F - the factored matrix obtained by calling `MatGetFactor()`

10038:   Level: advanced

10040:   Note:
10041:   Must be called after `MatFactorSetSchurIS()`

10043: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorInvertSchurComplement()`
10044: @*/
10045: PetscErrorCode MatFactorFactorizeSchurComplement(Mat F)
10046: {
10047:   MatFactorInfo info;

10049:   PetscFunctionBegin;
10052:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED || F->schur_status == MAT_FACTOR_SCHUR_FACTORED) PetscFunctionReturn(PETSC_SUCCESS);
10053:   PetscCall(PetscLogEventBegin(MAT_FactorFactS, F, 0, 0, 0));
10054:   PetscCall(PetscMemzero(&info, sizeof(MatFactorInfo)));
10055:   if (F->factortype == MAT_FACTOR_CHOLESKY) { /* LDL^t regarded as Cholesky */
10056:     PetscCall(MatCholeskyFactor(F->schur, NULL, &info));
10057:   } else {
10058:     PetscCall(MatLUFactor(F->schur, NULL, NULL, &info));
10059:   }
10060:   PetscCall(PetscLogEventEnd(MAT_FactorFactS, F, 0, 0, 0));
10061:   F->schur_status = MAT_FACTOR_SCHUR_FACTORED;
10062:   PetscFunctionReturn(PETSC_SUCCESS);
10063: }

10065: /*@
10066:   MatPtAP - Creates the matrix product $C = P^T * A * P$

10068:   Neighbor-wise Collective

10070:   Input Parameters:
10071: + A     - the matrix
10072: . P     - the projection matrix
10073: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10074: - 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
10075:           if the result is a dense matrix this is irrelevant

10077:   Output Parameter:
10078: . C - the product matrix

10080:   Level: intermediate

10082:   Notes:
10083:   C will be created and must be destroyed by the user with `MatDestroy()`.

10085:   An alternative approach to this function is to use `MatProductCreate()` and set the desired options before the computation is done

10087:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10089:   Developer Note:
10090:   For matrix types without special implementation the function fallbacks to `MatMatMult()` followed by `MatTransposeMatMult()`.

10092: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatRARt()`
10093: @*/
10094: PetscErrorCode MatPtAP(Mat A, Mat P, MatReuse scall, PetscReal fill, Mat *C)
10095: {
10096:   PetscFunctionBegin;
10097:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10098:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10100:   if (scall == MAT_INITIAL_MATRIX) {
10101:     PetscCall(MatProductCreate(A, P, NULL, C));
10102:     PetscCall(MatProductSetType(*C, MATPRODUCT_PtAP));
10103:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10104:     PetscCall(MatProductSetFill(*C, fill));

10106:     (*C)->product->api_user = PETSC_TRUE;
10107:     PetscCall(MatProductSetFromOptions(*C));
10108:     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);
10109:     PetscCall(MatProductSymbolic(*C));
10110:   } else { /* scall == MAT_REUSE_MATRIX */
10111:     PetscCall(MatProductReplaceMats(A, P, NULL, *C));
10112:   }

10114:   PetscCall(MatProductNumeric(*C));
10115:   (*C)->symmetric = A->symmetric;
10116:   (*C)->spd       = A->spd;
10117:   PetscFunctionReturn(PETSC_SUCCESS);
10118: }

10120: /*@
10121:   MatRARt - Creates the matrix product $C = R * A * R^T$

10123:   Neighbor-wise Collective

10125:   Input Parameters:
10126: + A     - the matrix
10127: . R     - the projection matrix
10128: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10129: - fill  - expected fill as ratio of nnz(C)/nnz(A), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10130:           if the result is a dense matrix this is irrelevant

10132:   Output Parameter:
10133: . C - the product matrix

10135:   Level: intermediate

10137:   Notes:
10138:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10140:   An alternative approach to this function is to use `MatProductCreate()` and set the desired options before the computation is done

10142:   This routine is currently only implemented for pairs of `MATAIJ` matrices and classes
10143:   which inherit from `MATAIJ`. Due to PETSc sparse matrix block row distribution among processes,
10144:   the parallel `MatRARt()` is implemented computing the explicit transpose of `R`, which can be very expensive.
10145:   We recommend using `MatPtAP()` when possible.

10147:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10149: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatPtAP()`
10150: @*/
10151: PetscErrorCode MatRARt(Mat A, Mat R, MatReuse scall, PetscReal fill, Mat *C)
10152: {
10153:   PetscFunctionBegin;
10154:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10155:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10157:   if (scall == MAT_INITIAL_MATRIX) {
10158:     PetscCall(MatProductCreate(A, R, NULL, C));
10159:     PetscCall(MatProductSetType(*C, MATPRODUCT_RARt));
10160:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10161:     PetscCall(MatProductSetFill(*C, fill));

10163:     (*C)->product->api_user = PETSC_TRUE;
10164:     PetscCall(MatProductSetFromOptions(*C));
10165:     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);
10166:     PetscCall(MatProductSymbolic(*C));
10167:   } else { /* scall == MAT_REUSE_MATRIX */
10168:     PetscCall(MatProductReplaceMats(A, R, NULL, *C));
10169:   }

10171:   PetscCall(MatProductNumeric(*C));
10172:   if (A->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10173:   PetscFunctionReturn(PETSC_SUCCESS);
10174: }

10176: static PetscErrorCode MatProduct_Private(Mat A, Mat B, MatReuse scall, PetscReal fill, MatProductType ptype, Mat *C)
10177: {
10178:   PetscBool flg = PETSC_TRUE;

10180:   PetscFunctionBegin;
10181:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX product not supported");
10182:   if (scall == MAT_INITIAL_MATRIX) {
10183:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_INITIAL_MATRIX and product type %s\n", MatProductTypes[ptype]));
10184:     PetscCall(MatProductCreate(A, B, NULL, C));
10185:     PetscCall(MatProductSetAlgorithm(*C, MATPRODUCTALGORITHMDEFAULT));
10186:     PetscCall(MatProductSetFill(*C, fill));
10187:   } else { /* scall == MAT_REUSE_MATRIX */
10188:     Mat_Product *product = (*C)->product;

10190:     PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)*C, &flg, MATSEQDENSE, MATMPIDENSE, ""));
10191:     if (flg && product && product->type != ptype) {
10192:       PetscCall(MatProductClear(*C));
10193:       product = NULL;
10194:     }
10195:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_REUSE_MATRIX %s product present and product type %s\n", product ? "with" : "without", MatProductTypes[ptype]));
10196:     if (!product) { /* user provide the dense matrix *C without calling MatProductCreate() or reusing it from previous calls */
10197:       PetscCheck(flg, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "Call MatProductCreate() first");
10198:       PetscCall(MatProductCreate_Private(A, B, NULL, *C));
10199:       product        = (*C)->product;
10200:       product->fill  = fill;
10201:       product->clear = PETSC_TRUE;
10202:     } else { /* user may change input matrices A or B when MAT_REUSE_MATRIX */
10203:       flg = PETSC_FALSE;
10204:       PetscCall(MatProductReplaceMats(A, B, NULL, *C));
10205:     }
10206:   }
10207:   if (flg) {
10208:     (*C)->product->api_user = PETSC_TRUE;
10209:     PetscCall(MatProductSetType(*C, ptype));
10210:     PetscCall(MatProductSetFromOptions(*C));
10211:     PetscCall(MatProductSymbolic(*C));
10212:   }
10213:   PetscCall(MatProductNumeric(*C));
10214:   PetscFunctionReturn(PETSC_SUCCESS);
10215: }

10217: /*@
10218:   MatMatMult - Performs matrix-matrix multiplication C=A*B.

10220:   Neighbor-wise Collective

10222:   Input Parameters:
10223: + A     - the left matrix
10224: . B     - the right matrix
10225: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10226: - 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
10227:           if the result is a dense matrix this is irrelevant

10229:   Output Parameter:
10230: . C - the product matrix

10232:   Notes:
10233:   Unless scall is `MAT_REUSE_MATRIX` C will be created.

10235:   `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
10236:   call to this function with `MAT_INITIAL_MATRIX`.

10238:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value actually needed.

10240:   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`,
10241:   rather than first having `MatMatMult()` create it for you. You can NEVER do this if the matrix `C` is sparse.

10243:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10245:   Example of Usage:
10246: .vb
10247:      MatProductCreate(A,B,NULL,&C);
10248:      MatProductSetType(C,MATPRODUCT_AB);
10249:      MatProductSymbolic(C);
10250:      MatProductNumeric(C); // compute C=A * B
10251:      MatProductReplaceMats(A1,B1,NULL,C); // compute C=A1 * B1
10252:      MatProductNumeric(C);
10253:      MatProductReplaceMats(A2,NULL,NULL,C); // compute C=A2 * B1
10254:      MatProductNumeric(C);
10255: .ve

10257:   Level: intermediate

10259: .seealso: [](ch_matrices), `Mat`, `MatProductType`, `MATPRODUCT_AB`, `MatTransposeMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`, `MatProductCreate()`, `MatProductSymbolic()`, `MatProductReplaceMats()`, `MatProductNumeric()`
10260: @*/
10261: PetscErrorCode MatMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10262: {
10263:   PetscFunctionBegin;
10264:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AB, C));
10265:   PetscFunctionReturn(PETSC_SUCCESS);
10266: }

10268: /*@
10269:   MatMatTransposeMult - Performs matrix-matrix multiplication $C = A*B^T$.

10271:   Neighbor-wise Collective

10273:   Input Parameters:
10274: + A     - the left matrix
10275: . B     - the right matrix
10276: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10277: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10279:   Output Parameter:
10280: . C - the product matrix

10282:   Options Database Key:
10283: . -matmattransmult_mpidense_mpidense_via {allgatherv,cyclic} - Choose between algorithms for `MATMPIDENSE` matrices: the
10284:               first redundantly copies the transposed `B` matrix on each process and requires O(log P) communication complexity;
10285:               the second never stores more than one portion of the `B` matrix at a time but requires O(P) communication complexity.

10287:   Level: intermediate

10289:   Notes:
10290:   C will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10292:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call

10294:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10295:   actually needed.

10297:   This routine is currently only implemented for pairs of `MATSEQAIJ` matrices, for the `MATSEQDENSE` class,
10298:   and for pairs of `MATMPIDENSE` matrices.

10300:   This routine is shorthand for using `MatProductCreate()` with the `MatProductType` of `MATPRODUCT_ABt`

10302:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10304: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABt`, `MatMatMult()`, `MatTransposeMatMult()` `MatPtAP()`, `MatProductAlgorithm`, `MatProductType`
10305: @*/
10306: PetscErrorCode MatMatTransposeMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10307: {
10308:   PetscFunctionBegin;
10309:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_ABt, C));
10310:   if (A == B) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10311:   PetscFunctionReturn(PETSC_SUCCESS);
10312: }

10314: /*@
10315:   MatTransposeMatMult - Performs matrix-matrix multiplication $C = A^T*B$.

10317:   Neighbor-wise Collective

10319:   Input Parameters:
10320: + A     - the left matrix
10321: . B     - the right matrix
10322: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10323: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10325:   Output Parameter:
10326: . C - the product matrix

10328:   Level: intermediate

10330:   Notes:
10331:   `C` will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10333:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call.

10335:   This routine is shorthand for using `MatProductCreate()` with the `MatProductType` of `MATPRODUCT_AtB`

10337:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10338:   actually needed.

10340:   This routine is currently implemented for pairs of `MATAIJ` matrices and pairs of `MATSEQDENSE` matrices and classes
10341:   which inherit from `MATSEQAIJ`.  `C` will be of the same type as the input matrices.

10343:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10345: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_AtB`, `MatMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`
10346: @*/
10347: PetscErrorCode MatTransposeMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10348: {
10349:   PetscFunctionBegin;
10350:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AtB, C));
10351:   PetscFunctionReturn(PETSC_SUCCESS);
10352: }

10354: /*@
10355:   MatMatMatMult - Performs matrix-matrix-matrix multiplication D=A*B*C.

10357:   Neighbor-wise Collective

10359:   Input Parameters:
10360: + A     - the left matrix
10361: . B     - the middle matrix
10362: . C     - the right matrix
10363: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10364: - 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
10365:           if the result is a dense matrix this is irrelevant

10367:   Output Parameter:
10368: . D - the product matrix

10370:   Level: intermediate

10372:   Notes:
10373:   Unless `scall` is `MAT_REUSE_MATRIX` `D` will be created.

10375:   `MAT_REUSE_MATRIX` can only be used if the matrices `A`, `B`, and `C` have the same nonzero pattern as in the previous call

10377:   This routine is shorthand for using `MatProductCreate()` with the `MatProductType` of `MATPRODUCT_ABC`

10379:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value
10380:   actually needed.

10382:   If you have many matrices with the same non-zero structure to multiply, you
10383:   should use `MAT_REUSE_MATRIX` in all calls but the first

10385:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10387: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABC`, `MatMatMult`, `MatPtAP()`, `MatMatTransposeMult()`, `MatTransposeMatMult()`
10388: @*/
10389: PetscErrorCode MatMatMatMult(Mat A, Mat B, Mat C, MatReuse scall, PetscReal fill, Mat *D)
10390: {
10391:   PetscFunctionBegin;
10392:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*D, 6);
10393:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10395:   if (scall == MAT_INITIAL_MATRIX) {
10396:     PetscCall(MatProductCreate(A, B, C, D));
10397:     PetscCall(MatProductSetType(*D, MATPRODUCT_ABC));
10398:     PetscCall(MatProductSetAlgorithm(*D, "default"));
10399:     PetscCall(MatProductSetFill(*D, fill));

10401:     (*D)->product->api_user = PETSC_TRUE;
10402:     PetscCall(MatProductSetFromOptions(*D));
10403:     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,
10404:                ((PetscObject)C)->type_name);
10405:     PetscCall(MatProductSymbolic(*D));
10406:   } else { /* user may change input matrices when REUSE */
10407:     PetscCall(MatProductReplaceMats(A, B, C, *D));
10408:   }
10409:   PetscCall(MatProductNumeric(*D));
10410:   PetscFunctionReturn(PETSC_SUCCESS);
10411: }

10413: /*@
10414:   MatCreateRedundantMatrix - Create redundant matrices and put them into processors of subcommunicators.

10416:   Collective

10418:   Input Parameters:
10419: + mat      - the matrix
10420: . nsubcomm - the number of subcommunicators (= number of redundant parallel or sequential matrices)
10421: . subcomm  - MPI communicator split from the communicator where mat resides in (or `MPI_COMM_NULL` if nsubcomm is used)
10422: - reuse    - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10424:   Output Parameter:
10425: . matredundant - redundant matrix

10427:   Level: advanced

10429:   Notes:
10430:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
10431:   original matrix has not changed from that last call to `MatCreateRedundantMatrix()`.

10433:   This routine creates the duplicated matrices in the subcommunicators; you should NOT create them before
10434:   calling it.

10436:   `PetscSubcommCreate()` can be used to manage the creation of the subcomm but need not be.

10438: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `PetscSubcommCreate()`, `PetscSubcomm`
10439: @*/
10440: PetscErrorCode MatCreateRedundantMatrix(Mat mat, PetscInt nsubcomm, MPI_Comm subcomm, MatReuse reuse, Mat *matredundant)
10441: {
10442:   MPI_Comm       comm;
10443:   PetscMPIInt    size;
10444:   PetscInt       mloc_sub, nloc_sub, rstart, rend, M = mat->rmap->N, N = mat->cmap->N, bs = mat->rmap->bs;
10445:   Mat_Redundant *redund     = NULL;
10446:   PetscSubcomm   psubcomm   = NULL;
10447:   MPI_Comm       subcomm_in = subcomm;
10448:   Mat           *matseq;
10449:   IS             isrow, iscol;
10450:   PetscBool      newsubcomm = PETSC_FALSE;

10452:   PetscFunctionBegin;
10454:   if (nsubcomm && reuse == MAT_REUSE_MATRIX) {
10455:     PetscAssertPointer(*matredundant, 5);
10457:   }

10459:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
10460:   if (size == 1 || nsubcomm == 1) {
10461:     if (reuse == MAT_INITIAL_MATRIX) {
10462:       PetscCall(MatDuplicate(mat, MAT_COPY_VALUES, matredundant));
10463:     } else {
10464:       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");
10465:       PetscCall(MatCopy(mat, *matredundant, SAME_NONZERO_PATTERN));
10466:     }
10467:     PetscFunctionReturn(PETSC_SUCCESS);
10468:   }

10470:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10471:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10472:   MatCheckPreallocated(mat, 1);

10474:   PetscCall(PetscLogEventBegin(MAT_RedundantMat, mat, 0, 0, 0));
10475:   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
10476:     /* create psubcomm, then get subcomm */
10477:     PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10478:     PetscCallMPI(MPI_Comm_size(comm, &size));
10479:     PetscCheck(nsubcomm >= 1 && nsubcomm <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "nsubcomm must between 1 and %d", size);

10481:     PetscCall(PetscSubcommCreate(comm, &psubcomm));
10482:     PetscCall(PetscSubcommSetNumber(psubcomm, nsubcomm));
10483:     PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_CONTIGUOUS));
10484:     PetscCall(PetscSubcommSetFromOptions(psubcomm));
10485:     PetscCall(PetscCommDuplicate(PetscSubcommChild(psubcomm), &subcomm, NULL));
10486:     newsubcomm = PETSC_TRUE;
10487:     PetscCall(PetscSubcommDestroy(&psubcomm));
10488:   }

10490:   /* get isrow, iscol and a local sequential matrix matseq[0] */
10491:   if (reuse == MAT_INITIAL_MATRIX) {
10492:     mloc_sub = PETSC_DECIDE;
10493:     nloc_sub = PETSC_DECIDE;
10494:     if (bs < 1) {
10495:       PetscCall(PetscSplitOwnership(subcomm, &mloc_sub, &M));
10496:       PetscCall(PetscSplitOwnership(subcomm, &nloc_sub, &N));
10497:     } else {
10498:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &mloc_sub, &M));
10499:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &nloc_sub, &N));
10500:     }
10501:     PetscCallMPI(MPI_Scan(&mloc_sub, &rend, 1, MPIU_INT, MPI_SUM, subcomm));
10502:     rstart = rend - mloc_sub;
10503:     PetscCall(ISCreateStride(PETSC_COMM_SELF, mloc_sub, rstart, 1, &isrow));
10504:     PetscCall(ISCreateStride(PETSC_COMM_SELF, N, 0, 1, &iscol));
10505:     PetscCall(ISSetIdentity(iscol));
10506:   } else { /* reuse == MAT_REUSE_MATRIX */
10507:     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");
10508:     /* retrieve subcomm */
10509:     PetscCall(PetscObjectGetComm((PetscObject)*matredundant, &subcomm));
10510:     redund = (*matredundant)->redundant;
10511:     isrow  = redund->isrow;
10512:     iscol  = redund->iscol;
10513:     matseq = redund->matseq;
10514:   }
10515:   PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscol, reuse, &matseq));

10517:   /* get matredundant over subcomm */
10518:   if (reuse == MAT_INITIAL_MATRIX) {
10519:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], nloc_sub, reuse, matredundant));

10521:     /* create a supporting struct and attach it to C for reuse */
10522:     PetscCall(PetscNew(&redund));
10523:     (*matredundant)->redundant = redund;
10524:     redund->isrow              = isrow;
10525:     redund->iscol              = iscol;
10526:     redund->matseq             = matseq;
10527:     if (newsubcomm) {
10528:       redund->subcomm = subcomm;
10529:     } else {
10530:       redund->subcomm = MPI_COMM_NULL;
10531:     }
10532:   } else {
10533:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], PETSC_DECIDE, reuse, matredundant));
10534:   }
10535: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
10536:   if (matseq[0]->boundtocpu && matseq[0]->bindingpropagates) {
10537:     PetscCall(MatBindToCPU(*matredundant, PETSC_TRUE));
10538:     PetscCall(MatSetBindingPropagates(*matredundant, PETSC_TRUE));
10539:   }
10540: #endif
10541:   PetscCall(PetscLogEventEnd(MAT_RedundantMat, mat, 0, 0, 0));
10542:   PetscFunctionReturn(PETSC_SUCCESS);
10543: }

10545: /*@C
10546:   MatGetMultiProcBlock - Create multiple 'parallel submatrices' from
10547:   a given `Mat`. Each submatrix can span multiple procs.

10549:   Collective

10551:   Input Parameters:
10552: + mat     - the matrix
10553: . subComm - the sub communicator obtained as if by `MPI_Comm_split(PetscObjectComm((PetscObject)mat))`
10554: - scall   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10556:   Output Parameter:
10557: . subMat - parallel sub-matrices each spanning a given `subcomm`

10559:   Level: advanced

10561:   Notes:
10562:   The submatrix partition across processors is dictated by `subComm` a
10563:   communicator obtained by `MPI_comm_split()` or via `PetscSubcommCreate()`. The `subComm`
10564:   is not restricted to be grouped with consecutive original MPI processes.

10566:   Due the `MPI_Comm_split()` usage, the parallel layout of the submatrices
10567:   map directly to the layout of the original matrix [wrt the local
10568:   row,col partitioning]. So the original 'DiagonalMat' naturally maps
10569:   into the 'DiagonalMat' of the `subMat`, hence it is used directly from
10570:   the `subMat`. However the offDiagMat looses some columns - and this is
10571:   reconstructed with `MatSetValues()`

10573:   This is used by `PCBJACOBI` when a single block spans multiple MPI processes.

10575: .seealso: [](ch_matrices), `Mat`, `MatCreateRedundantMatrix()`, `MatCreateSubMatrices()`, `PCBJACOBI`
10576: @*/
10577: PetscErrorCode MatGetMultiProcBlock(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
10578: {
10579:   PetscMPIInt commsize, subCommSize;

10581:   PetscFunctionBegin;
10582:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &commsize));
10583:   PetscCallMPI(MPI_Comm_size(subComm, &subCommSize));
10584:   PetscCheck(subCommSize <= commsize, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "CommSize %d < SubCommZize %d", commsize, subCommSize);

10586:   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");
10587:   PetscCall(PetscLogEventBegin(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10588:   PetscUseTypeMethod(mat, getmultiprocblock, subComm, scall, subMat);
10589:   PetscCall(PetscLogEventEnd(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10590:   PetscFunctionReturn(PETSC_SUCCESS);
10591: }

10593: /*@
10594:   MatGetLocalSubMatrix - Gets a reference to a submatrix specified in local numbering

10596:   Not Collective

10598:   Input Parameters:
10599: + mat   - matrix to extract local submatrix from
10600: . isrow - local row indices for submatrix
10601: - iscol - local column indices for submatrix

10603:   Output Parameter:
10604: . submat - the submatrix

10606:   Level: intermediate

10608:   Notes:
10609:   `submat` should be disposed of with `MatRestoreLocalSubMatrix()`.

10611:   Depending on the format of `mat`, the returned `submat` may not implement `MatMult()`.  Its communicator may be
10612:   the same as `mat`, it may be `PETSC_COMM_SELF`, or some other sub-communictor of `mat`'s.

10614:   `submat` always implements `MatSetValuesLocal()`.  If `isrow` and `iscol` have the same block size, then
10615:   `MatSetValuesBlockedLocal()` will also be implemented.

10617:   `mat` must have had a `ISLocalToGlobalMapping` provided to it with `MatSetLocalToGlobalMapping()`.
10618:   Matrices obtained with `DMCreateMatrix()` generally already have the local to global mapping provided.

10620: .seealso: [](ch_matrices), `Mat`, `MatRestoreLocalSubMatrix()`, `MatCreateLocalRef()`, `MatSetLocalToGlobalMapping()`
10621: @*/
10622: PetscErrorCode MatGetLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10623: {
10624:   PetscFunctionBegin;
10628:   PetscCheckSameComm(isrow, 2, iscol, 3);
10629:   PetscAssertPointer(submat, 4);
10630:   PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must have local to global mapping provided before this call");

10632:   if (mat->ops->getlocalsubmatrix) {
10633:     PetscUseTypeMethod(mat, getlocalsubmatrix, isrow, iscol, submat);
10634:   } else {
10635:     PetscCall(MatCreateLocalRef(mat, isrow, iscol, submat));
10636:   }
10637:   (*submat)->assembled = mat->assembled;
10638:   PetscFunctionReturn(PETSC_SUCCESS);
10639: }

10641: /*@
10642:   MatRestoreLocalSubMatrix - Restores a reference to a submatrix specified in local numbering obtained with `MatGetLocalSubMatrix()`

10644:   Not Collective

10646:   Input Parameters:
10647: + mat    - matrix to extract local submatrix from
10648: . isrow  - local row indices for submatrix
10649: . iscol  - local column indices for submatrix
10650: - submat - the submatrix

10652:   Level: intermediate

10654: .seealso: [](ch_matrices), `Mat`, `MatGetLocalSubMatrix()`
10655: @*/
10656: PetscErrorCode MatRestoreLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10657: {
10658:   PetscFunctionBegin;
10662:   PetscCheckSameComm(isrow, 2, iscol, 3);
10663:   PetscAssertPointer(submat, 4);

10666:   if (mat->ops->restorelocalsubmatrix) {
10667:     PetscUseTypeMethod(mat, restorelocalsubmatrix, isrow, iscol, submat);
10668:   } else {
10669:     PetscCall(MatDestroy(submat));
10670:   }
10671:   *submat = NULL;
10672:   PetscFunctionReturn(PETSC_SUCCESS);
10673: }

10675: /*@
10676:   MatFindZeroDiagonals - Finds all the rows of a matrix that have zero or no diagonal entry in the matrix

10678:   Collective

10680:   Input Parameter:
10681: . mat - the matrix

10683:   Output Parameter:
10684: . is - if any rows have zero diagonals this contains the list of them

10686:   Level: developer

10688: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10689: @*/
10690: PetscErrorCode MatFindZeroDiagonals(Mat mat, IS *is)
10691: {
10692:   PetscFunctionBegin;
10695:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10696:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10698:   if (!mat->ops->findzerodiagonals) {
10699:     Vec                diag;
10700:     const PetscScalar *a;
10701:     PetscInt          *rows;
10702:     PetscInt           rStart, rEnd, r, nrow = 0;

10704:     PetscCall(MatCreateVecs(mat, &diag, NULL));
10705:     PetscCall(MatGetDiagonal(mat, diag));
10706:     PetscCall(MatGetOwnershipRange(mat, &rStart, &rEnd));
10707:     PetscCall(VecGetArrayRead(diag, &a));
10708:     for (r = 0; r < rEnd - rStart; ++r)
10709:       if (a[r] == 0.0) ++nrow;
10710:     PetscCall(PetscMalloc1(nrow, &rows));
10711:     nrow = 0;
10712:     for (r = 0; r < rEnd - rStart; ++r)
10713:       if (a[r] == 0.0) rows[nrow++] = r + rStart;
10714:     PetscCall(VecRestoreArrayRead(diag, &a));
10715:     PetscCall(VecDestroy(&diag));
10716:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)mat), nrow, rows, PETSC_OWN_POINTER, is));
10717:   } else {
10718:     PetscUseTypeMethod(mat, findzerodiagonals, is);
10719:   }
10720:   PetscFunctionReturn(PETSC_SUCCESS);
10721: }

10723: /*@
10724:   MatFindOffBlockDiagonalEntries - Finds all the rows of a matrix that have entries outside of the main diagonal block (defined by the matrix block size)

10726:   Collective

10728:   Input Parameter:
10729: . mat - the matrix

10731:   Output Parameter:
10732: . is - contains the list of rows with off block diagonal entries

10734:   Level: developer

10736: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10737: @*/
10738: PetscErrorCode MatFindOffBlockDiagonalEntries(Mat mat, IS *is)
10739: {
10740:   PetscFunctionBegin;
10743:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10744:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10746:   PetscUseTypeMethod(mat, findoffblockdiagonalentries, is);
10747:   PetscFunctionReturn(PETSC_SUCCESS);
10748: }

10750: /*@C
10751:   MatInvertBlockDiagonal - Inverts the block diagonal entries.

10753:   Collective; No Fortran Support

10755:   Input Parameter:
10756: . mat - the matrix

10758:   Output Parameter:
10759: . values - the block inverses in column major order (FORTRAN-like)

10761:   Level: advanced

10763:   Notes:
10764:   The size of the blocks is determined by the block size of the matrix.

10766:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10768:   The blocks all have the same size, use `MatInvertVariableBlockDiagonal()` for variable block size

10770: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatInvertBlockDiagonalMat()`
10771: @*/
10772: PetscErrorCode MatInvertBlockDiagonal(Mat mat, const PetscScalar *values[])
10773: {
10774:   PetscFunctionBegin;
10776:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10777:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10778:   PetscUseTypeMethod(mat, invertblockdiagonal, values);
10779:   PetscFunctionReturn(PETSC_SUCCESS);
10780: }

10782: /*@
10783:   MatInvertVariableBlockDiagonal - Inverts the point block diagonal entries.

10785:   Collective; No Fortran Support

10787:   Input Parameters:
10788: + mat     - the matrix
10789: . nblocks - the number of blocks on the process, set with `MatSetVariableBlockSizes()`
10790: - bsizes  - the size of each block on the process, set with `MatSetVariableBlockSizes()`

10792:   Output Parameter:
10793: . values - the block inverses in column major order (FORTRAN-like)

10795:   Level: advanced

10797:   Notes:
10798:   Use `MatInvertBlockDiagonal()` if all blocks have the same size

10800:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10802: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatSetVariableBlockSizes()`, `MatInvertVariableBlockEnvelope()`
10803: @*/
10804: PetscErrorCode MatInvertVariableBlockDiagonal(Mat mat, PetscInt nblocks, const PetscInt bsizes[], PetscScalar values[])
10805: {
10806:   PetscFunctionBegin;
10808:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10809:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10810:   PetscUseTypeMethod(mat, invertvariableblockdiagonal, nblocks, bsizes, values);
10811:   PetscFunctionReturn(PETSC_SUCCESS);
10812: }

10814: /*@
10815:   MatInvertBlockDiagonalMat - set the values of matrix C to be the inverted block diagonal of matrix A

10817:   Collective

10819:   Input Parameters:
10820: + A - the matrix
10821: - C - matrix with inverted block diagonal of `A`.  This matrix should be created and may have its type set.

10823:   Level: advanced

10825:   Note:
10826:   The blocksize of the matrix is used to determine the blocks on the diagonal of `C`

10828: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`
10829: @*/
10830: PetscErrorCode MatInvertBlockDiagonalMat(Mat A, Mat C)
10831: {
10832:   const PetscScalar *vals;
10833:   PetscInt          *dnnz;
10834:   PetscInt           m, rstart, rend, bs, i, j;

10836:   PetscFunctionBegin;
10837:   PetscCall(MatInvertBlockDiagonal(A, &vals));
10838:   PetscCall(MatGetBlockSize(A, &bs));
10839:   PetscCall(MatGetLocalSize(A, &m, NULL));
10840:   PetscCall(MatSetLayouts(C, A->rmap, A->cmap));
10841:   PetscCall(MatSetBlockSizes(C, A->rmap->bs, A->cmap->bs));
10842:   PetscCall(PetscMalloc1(m / bs, &dnnz));
10843:   for (j = 0; j < m / bs; j++) dnnz[j] = 1;
10844:   PetscCall(MatXAIJSetPreallocation(C, bs, dnnz, NULL, NULL, NULL));
10845:   PetscCall(PetscFree(dnnz));
10846:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
10847:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_FALSE));
10848:   for (i = rstart / bs; i < rend / bs; i++) PetscCall(MatSetValuesBlocked(C, 1, &i, 1, &i, &vals[(i - rstart / bs) * bs * bs], INSERT_VALUES));
10849:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
10850:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
10851:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_TRUE));
10852:   PetscFunctionReturn(PETSC_SUCCESS);
10853: }

10855: /*@
10856:   MatTransposeColoringDestroy - Destroys a coloring context for matrix product $C = A*B^T$ that was created
10857:   via `MatTransposeColoringCreate()`.

10859:   Collective

10861:   Input Parameter:
10862: . c - coloring context

10864:   Level: intermediate

10866: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`
10867: @*/
10868: PetscErrorCode MatTransposeColoringDestroy(MatTransposeColoring *c)
10869: {
10870:   MatTransposeColoring matcolor = *c;

10872:   PetscFunctionBegin;
10873:   if (!matcolor) PetscFunctionReturn(PETSC_SUCCESS);
10874:   if (--((PetscObject)matcolor)->refct > 0) {
10875:     matcolor = NULL;
10876:     PetscFunctionReturn(PETSC_SUCCESS);
10877:   }

10879:   PetscCall(PetscFree3(matcolor->ncolumns, matcolor->nrows, matcolor->colorforrow));
10880:   PetscCall(PetscFree(matcolor->rows));
10881:   PetscCall(PetscFree(matcolor->den2sp));
10882:   PetscCall(PetscFree(matcolor->colorforcol));
10883:   PetscCall(PetscFree(matcolor->columns));
10884:   if (matcolor->brows > 0) PetscCall(PetscFree(matcolor->lstart));
10885:   PetscCall(PetscHeaderDestroy(c));
10886:   PetscFunctionReturn(PETSC_SUCCESS);
10887: }

10889: /*@
10890:   MatTransColoringApplySpToDen - Given a symbolic matrix product $C = A*B^T$ for which
10891:   a `MatTransposeColoring` context has been created, computes a dense $B^T$ by applying
10892:   `MatTransposeColoring` to sparse `B`.

10894:   Collective

10896:   Input Parameters:
10897: + coloring - coloring context created with `MatTransposeColoringCreate()`
10898: - B        - sparse matrix

10900:   Output Parameter:
10901: . Btdense - dense matrix $B^T$

10903:   Level: developer

10905:   Note:
10906:   These are used internally for some implementations of `MatRARt()`

10908: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplyDenToSp()`
10909: @*/
10910: PetscErrorCode MatTransColoringApplySpToDen(MatTransposeColoring coloring, Mat B, Mat Btdense)
10911: {
10912:   PetscFunctionBegin;

10917:   PetscCall((*B->ops->transcoloringapplysptoden)(coloring, B, Btdense));
10918:   PetscFunctionReturn(PETSC_SUCCESS);
10919: }

10921: /*@
10922:   MatTransColoringApplyDenToSp - Given a symbolic matrix product $C_{sp} = A*B^T$ for which
10923:   a `MatTransposeColoring` context has been created and a dense matrix $C_{den} = A*B^T_{dense}$
10924:   in which `B^T_{dens}` is obtained from `MatTransColoringApplySpToDen()`, recover sparse matrix
10925:   $C_{sp}$ from $C_{den}$.

10927:   Collective

10929:   Input Parameters:
10930: + matcoloring - coloring context created with `MatTransposeColoringCreate()`
10931: - Cden        - matrix product of a sparse matrix and a dense matrix Btdense

10933:   Output Parameter:
10934: . Csp - sparse matrix

10936:   Level: developer

10938:   Note:
10939:   These are used internally for some implementations of `MatRARt()`

10941: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`
10942: @*/
10943: PetscErrorCode MatTransColoringApplyDenToSp(MatTransposeColoring matcoloring, Mat Cden, Mat Csp)
10944: {
10945:   PetscFunctionBegin;

10950:   PetscCall((*Csp->ops->transcoloringapplydentosp)(matcoloring, Cden, Csp));
10951:   PetscCall(MatAssemblyBegin(Csp, MAT_FINAL_ASSEMBLY));
10952:   PetscCall(MatAssemblyEnd(Csp, MAT_FINAL_ASSEMBLY));
10953:   PetscFunctionReturn(PETSC_SUCCESS);
10954: }

10956: /*@
10957:   MatTransposeColoringCreate - Creates a matrix coloring context for the matrix product $C = A*B^T$.

10959:   Collective

10961:   Input Parameters:
10962: + mat        - the matrix product C
10963: - iscoloring - the coloring of the matrix; usually obtained with `MatColoringCreate()` or `DMCreateColoring()`

10965:   Output Parameter:
10966: . color - the new coloring context

10968:   Level: intermediate

10970: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`,
10971:           `MatTransColoringApplyDenToSp()`
10972: @*/
10973: PetscErrorCode MatTransposeColoringCreate(Mat mat, ISColoring iscoloring, MatTransposeColoring *color)
10974: {
10975:   MatTransposeColoring c;
10976:   MPI_Comm             comm;

10978:   PetscFunctionBegin;
10979:   PetscAssertPointer(color, 3);

10981:   PetscCall(PetscLogEventBegin(MAT_TransposeColoringCreate, mat, 0, 0, 0));
10982:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10983:   PetscCall(PetscHeaderCreate(c, MAT_TRANSPOSECOLORING_CLASSID, "MatTransposeColoring", "Matrix product C=A*B^T via coloring", "Mat", comm, MatTransposeColoringDestroy, NULL));
10984:   c->ctype = iscoloring->ctype;
10985:   PetscUseTypeMethod(mat, transposecoloringcreate, iscoloring, c);
10986:   *color = c;
10987:   PetscCall(PetscLogEventEnd(MAT_TransposeColoringCreate, mat, 0, 0, 0));
10988:   PetscFunctionReturn(PETSC_SUCCESS);
10989: }

10991: /*@
10992:   MatGetNonzeroState - Returns a 64-bit integer representing the current state of nonzeros in the matrix. If the
10993:   matrix has had new nonzero locations added to (or removed from) the matrix since the previous call, the value will be larger.

10995:   Not Collective

10997:   Input Parameter:
10998: . mat - the matrix

11000:   Output Parameter:
11001: . state - the current state

11003:   Level: intermediate

11005:   Notes:
11006:   You can only compare states from two different calls to the SAME matrix, you cannot compare calls between
11007:   different matrices

11009:   Use `PetscObjectStateGet()` to check for changes to the numerical values in a matrix

11011:   Use the result of `PetscObjectGetId()` to compare if a previously checked matrix is the same as the current matrix, do not compare object pointers.

11013: .seealso: [](ch_matrices), `Mat`, `PetscObjectStateGet()`, `PetscObjectGetId()`
11014: @*/
11015: PetscErrorCode MatGetNonzeroState(Mat mat, PetscObjectState *state)
11016: {
11017:   PetscFunctionBegin;
11019:   *state = mat->nonzerostate;
11020:   PetscFunctionReturn(PETSC_SUCCESS);
11021: }

11023: /*@
11024:   MatCreateMPIMatConcatenateSeqMat - Creates a single large PETSc matrix by concatenating sequential
11025:   matrices from each processor

11027:   Collective

11029:   Input Parameters:
11030: + comm   - the communicators the parallel matrix will live on
11031: . seqmat - the input sequential matrices
11032: . n      - number of local columns (or `PETSC_DECIDE`)
11033: - reuse  - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

11035:   Output Parameter:
11036: . mpimat - the parallel matrix generated

11038:   Level: developer

11040:   Note:
11041:   The number of columns of the matrix in EACH processor MUST be the same.

11043: .seealso: [](ch_matrices), `Mat`
11044: @*/
11045: PetscErrorCode MatCreateMPIMatConcatenateSeqMat(MPI_Comm comm, Mat seqmat, PetscInt n, MatReuse reuse, Mat *mpimat)
11046: {
11047:   PetscMPIInt size;

11049:   PetscFunctionBegin;
11050:   PetscCallMPI(MPI_Comm_size(comm, &size));
11051:   if (size == 1) {
11052:     if (reuse == MAT_INITIAL_MATRIX) {
11053:       PetscCall(MatDuplicate(seqmat, MAT_COPY_VALUES, mpimat));
11054:     } else {
11055:       PetscCall(MatCopy(seqmat, *mpimat, SAME_NONZERO_PATTERN));
11056:     }
11057:     PetscFunctionReturn(PETSC_SUCCESS);
11058:   }

11060:   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");

11062:   PetscCall(PetscLogEventBegin(MAT_Merge, seqmat, 0, 0, 0));
11063:   PetscCall((*seqmat->ops->creatempimatconcatenateseqmat)(comm, seqmat, n, reuse, mpimat));
11064:   PetscCall(PetscLogEventEnd(MAT_Merge, seqmat, 0, 0, 0));
11065:   PetscFunctionReturn(PETSC_SUCCESS);
11066: }

11068: /*@
11069:   MatSubdomainsCreateCoalesce - Creates index subdomains by coalescing adjacent MPI processes' ownership ranges.

11071:   Collective

11073:   Input Parameters:
11074: + A - the matrix to create subdomains from
11075: - N - requested number of subdomains

11077:   Output Parameters:
11078: + n   - number of subdomains resulting on this MPI process
11079: - iss - `IS` list with indices of subdomains on this MPI process

11081:   Level: advanced

11083:   Note:
11084:   The number of subdomains must be smaller than the communicator size

11086: .seealso: [](ch_matrices), `Mat`, `IS`
11087: @*/
11088: PetscErrorCode MatSubdomainsCreateCoalesce(Mat A, PetscInt N, PetscInt *n, IS *iss[])
11089: {
11090:   MPI_Comm    comm, subcomm;
11091:   PetscMPIInt size, rank, color;
11092:   PetscInt    rstart, rend, k;

11094:   PetscFunctionBegin;
11095:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
11096:   PetscCallMPI(MPI_Comm_size(comm, &size));
11097:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
11098:   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);
11099:   *n    = 1;
11100:   k     = size / N + (size % N > 0); /* There are up to k ranks to a color */
11101:   color = rank / k;
11102:   PetscCallMPI(MPI_Comm_split(comm, color, rank, &subcomm));
11103:   PetscCall(PetscMalloc1(1, iss));
11104:   PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
11105:   PetscCall(ISCreateStride(subcomm, rend - rstart, rstart, 1, iss[0]));
11106:   PetscCallMPI(MPI_Comm_free(&subcomm));
11107:   PetscFunctionReturn(PETSC_SUCCESS);
11108: }

11110: /*@
11111:   MatGalerkin - Constructs the coarse grid problem matrix via Galerkin projection.

11113:   If the interpolation and restriction operators are the same, uses `MatPtAP()`.
11114:   If they are not the same, uses `MatMatMatMult()`.

11116:   Once the coarse grid problem is constructed, correct for interpolation operators
11117:   that are not of full rank, which can legitimately happen in the case of non-nested
11118:   geometric multigrid.

11120:   Input Parameters:
11121: + restrct     - restriction operator
11122: . dA          - fine grid matrix
11123: . interpolate - interpolation operator
11124: . reuse       - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
11125: - fill        - expected fill, use `PETSC_DETERMINE` or `PETSC_DETERMINE` if you do not have a good estimate

11127:   Output Parameter:
11128: . A - the Galerkin coarse matrix

11130:   Options Database Key:
11131: . -pc_mg_galerkin <both,pmat,mat,none> - for what matrices the Galerkin process should be used

11133:   Level: developer

11135:   Note:
11136:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

11138: .seealso: [](ch_matrices), `Mat`, `MatPtAP()`, `MatMatMatMult()`
11139: @*/
11140: PetscErrorCode MatGalerkin(Mat restrct, Mat dA, Mat interpolate, MatReuse reuse, PetscReal fill, Mat *A)
11141: {
11142:   IS  zerorows;
11143:   Vec diag;

11145:   PetscFunctionBegin;
11146:   PetscCheck(reuse != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");
11147:   /* Construct the coarse grid matrix */
11148:   if (interpolate == restrct) {
11149:     PetscCall(MatPtAP(dA, interpolate, reuse, fill, A));
11150:   } else {
11151:     PetscCall(MatMatMatMult(restrct, dA, interpolate, reuse, fill, A));
11152:   }

11154:   /* If the interpolation matrix is not of full rank, A will have zero rows.
11155:      This can legitimately happen in the case of non-nested geometric multigrid.
11156:      In that event, we set the rows of the matrix to the rows of the identity,
11157:      ignoring the equations (as the RHS will also be zero). */

11159:   PetscCall(MatFindZeroRows(*A, &zerorows));

11161:   if (zerorows != NULL) { /* if there are any zero rows */
11162:     PetscCall(MatCreateVecs(*A, &diag, NULL));
11163:     PetscCall(MatGetDiagonal(*A, diag));
11164:     PetscCall(VecISSet(diag, zerorows, 1.0));
11165:     PetscCall(MatDiagonalSet(*A, diag, INSERT_VALUES));
11166:     PetscCall(VecDestroy(&diag));
11167:     PetscCall(ISDestroy(&zerorows));
11168:   }
11169:   PetscFunctionReturn(PETSC_SUCCESS);
11170: }

11172: /*@C
11173:   MatSetOperation - Allows user to set a matrix operation for any matrix type

11175:   Logically Collective

11177:   Input Parameters:
11178: + mat - the matrix
11179: . op  - the name of the operation
11180: - f   - the function that provides the operation

11182:   Level: developer

11184:   Example Usage:
11185: .vb
11186:   extern PetscErrorCode usermult(Mat, Vec, Vec);

11188:   PetscCall(MatCreateXXX(comm, ..., &A));
11189:   PetscCall(MatSetOperation(A, MATOP_MULT, (PetscErrorCodeFn *)usermult));
11190: .ve

11192:   Notes:
11193:   See the file `include/petscmat.h` for a complete list of matrix
11194:   operations, which all have the form MATOP_<OPERATION>, where
11195:   <OPERATION> is the name (in all capital letters) of the
11196:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11198:   All user-provided functions (except for `MATOP_DESTROY`) should have the same calling
11199:   sequence as the usual matrix interface routines, since they
11200:   are intended to be accessed via the usual matrix interface
11201:   routines, e.g.,
11202: .vb
11203:   MatMult(Mat, Vec, Vec) -> usermult(Mat, Vec, Vec)
11204: .ve

11206:   In particular each function MUST return `PETSC_SUCCESS` on success and
11207:   nonzero on failure.

11209:   This routine is distinct from `MatShellSetOperation()` in that it can be called on any matrix type.

11211: .seealso: [](ch_matrices), `Mat`, `MatGetOperation()`, `MatCreateShell()`, `MatShellSetContext()`, `MatShellSetOperation()`
11212: @*/
11213: PetscErrorCode MatSetOperation(Mat mat, MatOperation op, PetscErrorCodeFn *f)
11214: {
11215:   PetscFunctionBegin;
11217:   if (op == MATOP_VIEW && !mat->ops->viewnative && f != (PetscErrorCodeFn *)mat->ops->view) mat->ops->viewnative = mat->ops->view;
11218:   (((PetscErrorCodeFn **)mat->ops)[op]) = f;
11219:   PetscFunctionReturn(PETSC_SUCCESS);
11220: }

11222: /*@C
11223:   MatGetOperation - Gets a matrix operation for any matrix type.

11225:   Not Collective

11227:   Input Parameters:
11228: + mat - the matrix
11229: - op  - the name of the operation

11231:   Output Parameter:
11232: . f - the function that provides the operation

11234:   Level: developer

11236:   Example Usage:
11237: .vb
11238:   PetscErrorCode (*usermult)(Mat, Vec, Vec);

11240:   MatGetOperation(A, MATOP_MULT, (PetscErrorCodeFn **)&usermult);
11241: .ve

11243:   Notes:
11244:   See the file `include/petscmat.h` for a complete list of matrix
11245:   operations, which all have the form MATOP_<OPERATION>, where
11246:   <OPERATION> is the name (in all capital letters) of the
11247:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11249:   This routine is distinct from `MatShellGetOperation()` in that it can be called on any matrix type.

11251: .seealso: [](ch_matrices), `Mat`, `MatSetOperation()`, `MatCreateShell()`, `MatShellGetContext()`, `MatShellGetOperation()`
11252: @*/
11253: PetscErrorCode MatGetOperation(Mat mat, MatOperation op, PetscErrorCodeFn **f)
11254: {
11255:   PetscFunctionBegin;
11257:   *f = (((PetscErrorCodeFn **)mat->ops)[op]);
11258:   PetscFunctionReturn(PETSC_SUCCESS);
11259: }

11261: /*@
11262:   MatHasOperation - Determines whether the given matrix supports the particular operation.

11264:   Not Collective

11266:   Input Parameters:
11267: + mat - the matrix
11268: - op  - the operation, for example, `MATOP_GET_DIAGONAL`

11270:   Output Parameter:
11271: . has - either `PETSC_TRUE` or `PETSC_FALSE`

11273:   Level: advanced

11275:   Note:
11276:   See `MatSetOperation()` for additional discussion on naming convention and usage of `op`.

11278: .seealso: [](ch_matrices), `Mat`, `MatCreateShell()`, `MatGetOperation()`, `MatSetOperation()`
11279: @*/
11280: PetscErrorCode MatHasOperation(Mat mat, MatOperation op, PetscBool *has)
11281: {
11282:   PetscFunctionBegin;
11284:   PetscAssertPointer(has, 3);
11285:   if (mat->ops->hasoperation) {
11286:     PetscUseTypeMethod(mat, hasoperation, op, has);
11287:   } else {
11288:     if (((void **)mat->ops)[op]) *has = PETSC_TRUE;
11289:     else {
11290:       *has = PETSC_FALSE;
11291:       if (op == MATOP_CREATE_SUBMATRIX) {
11292:         PetscMPIInt size;

11294:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
11295:         if (size == 1) PetscCall(MatHasOperation(mat, MATOP_CREATE_SUBMATRICES, has));
11296:       }
11297:     }
11298:   }
11299:   PetscFunctionReturn(PETSC_SUCCESS);
11300: }

11302: /*@
11303:   MatHasCongruentLayouts - Determines whether the rows and columns layouts of the matrix are congruent

11305:   Collective

11307:   Input Parameter:
11308: . mat - the matrix

11310:   Output Parameter:
11311: . cong - either `PETSC_TRUE` or `PETSC_FALSE`

11313:   Level: beginner

11315: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatSetSizes()`, `PetscLayout`
11316: @*/
11317: PetscErrorCode MatHasCongruentLayouts(Mat mat, PetscBool *cong)
11318: {
11319:   PetscFunctionBegin;
11322:   PetscAssertPointer(cong, 2);
11323:   if (!mat->rmap || !mat->cmap) {
11324:     *cong = mat->rmap == mat->cmap ? PETSC_TRUE : PETSC_FALSE;
11325:     PetscFunctionReturn(PETSC_SUCCESS);
11326:   }
11327:   if (mat->congruentlayouts == PETSC_DECIDE) { /* first time we compare rows and cols layouts */
11328:     PetscCall(PetscLayoutSetUp(mat->rmap));
11329:     PetscCall(PetscLayoutSetUp(mat->cmap));
11330:     PetscCall(PetscLayoutCompare(mat->rmap, mat->cmap, cong));
11331:     if (*cong) mat->congruentlayouts = 1;
11332:     else mat->congruentlayouts = 0;
11333:   } else *cong = mat->congruentlayouts ? PETSC_TRUE : PETSC_FALSE;
11334:   PetscFunctionReturn(PETSC_SUCCESS);
11335: }

11337: PetscErrorCode MatSetInf(Mat A)
11338: {
11339:   PetscFunctionBegin;
11340:   PetscUseTypeMethod(A, setinf);
11341:   PetscFunctionReturn(PETSC_SUCCESS);
11342: }

11344: /*@
11345:   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
11346:   and possibly removes small values from the graph structure.

11348:   Collective

11350:   Input Parameters:
11351: + A       - the matrix
11352: . sym     - `PETSC_TRUE` indicates that the graph should be symmetrized
11353: . scale   - `PETSC_TRUE` indicates that the graph edge weights should be symmetrically scaled with the diagonal entry
11354: . filter  - filter value - < 0: does nothing; == 0: removes only 0.0 entries; otherwise: removes entries with abs(entries) <= value
11355: . num_idx - size of 'index' array
11356: - index   - array of block indices to use for graph strength of connection weight

11358:   Output Parameter:
11359: . graph - the resulting graph

11361:   Level: advanced

11363: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PCGAMG`
11364: @*/
11365: PetscErrorCode MatCreateGraph(Mat A, PetscBool sym, PetscBool scale, PetscReal filter, PetscInt num_idx, PetscInt index[], Mat *graph)
11366: {
11367:   PetscFunctionBegin;
11371:   PetscAssertPointer(graph, 7);
11372:   PetscCall(PetscLogEventBegin(MAT_CreateGraph, A, 0, 0, 0));
11373:   PetscUseTypeMethod(A, creategraph, sym, scale, filter, num_idx, index, graph);
11374:   PetscCall(PetscLogEventEnd(MAT_CreateGraph, A, 0, 0, 0));
11375:   PetscFunctionReturn(PETSC_SUCCESS);
11376: }

11378: /*@
11379:   MatEliminateZeros - eliminate the nondiagonal zero entries in place from the nonzero structure of a sparse `Mat` in place,
11380:   meaning the same memory is used for the matrix, and no new memory is allocated.

11382:   Collective

11384:   Input Parameters:
11385: + A    - the matrix
11386: - 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

11388:   Level: intermediate

11390:   Developer Note:
11391:   The entries in the sparse matrix data structure are shifted to fill in the unneeded locations in the data. Thus the end
11392:   of the arrays in the data structure are unneeded.

11394: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateGraph()`, `MatFilter()`
11395: @*/
11396: PetscErrorCode MatEliminateZeros(Mat A, PetscBool keep)
11397: {
11398:   PetscFunctionBegin;
11400:   PetscUseTypeMethod(A, eliminatezeros, keep);
11401:   PetscFunctionReturn(PETSC_SUCCESS);
11402: }

11404: /*@C
11405:   MatGetCurrentMemType - Get the memory location of the matrix

11407:   Not Collective, but the result will be the same on all MPI processes

11409:   Input Parameter:
11410: . A - the matrix whose memory type we are checking

11412:   Output Parameter:
11413: . m - the memory type

11415:   Level: intermediate

11417: .seealso: [](ch_matrices), `Mat`, `MatBoundToCPU()`, `PetscMemType`
11418: @*/
11419: PetscErrorCode MatGetCurrentMemType(Mat A, PetscMemType *m)
11420: {
11421:   PetscFunctionBegin;
11423:   PetscAssertPointer(m, 2);
11424:   if (A->ops->getcurrentmemtype) PetscUseTypeMethod(A, getcurrentmemtype, m);
11425:   else *m = PETSC_MEMTYPE_HOST;
11426:   PetscFunctionReturn(PETSC_SUCCESS);
11427: }