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

514:   Not Collective

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

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

525:   Level: advanced

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

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

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

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

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

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

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

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

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

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

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

582:   Logically Collective

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

587:   Level: advanced

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

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

606:   Not Collective

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

615:   Level: advanced

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

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

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

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

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

649:   Not Collective

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

654:   Level: advanced

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

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

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

676:   Not Collective

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

681:   Level: advanced

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

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

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

704:   Logically Collective

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

710:   Level: advanced

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

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

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

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

735:   Logically Collective

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

741:   Level: developer

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

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

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

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

771:   Logically Collective

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

777:   Level: developer

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

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

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

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

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

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

815:   Logically Collective

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

821:   Level: advanced

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

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

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

842:   Not Collective

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

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

850:   Level: advanced

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

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

866:   Not Collective

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

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

874:   Level: advanced

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

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

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

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

897:   Collective

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

902:   Level: beginner

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

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

911:   Currently only supported for  `MATAIJ` matrices.

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

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

927:   Collective

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

932:   Level: intermediate

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

937:   Currently only supported for `MATAIJ` matrices.

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

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

960:   Collective

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

965:   Level: advanced

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

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

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

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

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

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

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

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

1008:   Collective

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

1015:   Options Database Key:
1016: . -mat_view [viewertype]:... - the viewer and its options

1018:   Level: intermediate

1020:   Note:
1021: .vb
1022:     If no value is provided ascii:stdout is used
1023:        ascii[:[filename][:[format][:append]]]    defaults to stdout - format can be one of ascii_info, ascii_info_detail, or ascii_matlab,
1024:                                                   for example ascii::ascii_info prints just the information about the object not all details
1025:                                                   unless :append is given filename opens in write mode, overwriting what was already there
1026:        binary[:[filename][:[format][:append]]]   defaults to the file binaryoutput
1027:        draw[:drawtype[:filename]]                for example, draw:tikz, draw:tikz:figure.tex  or draw:x
1028:        socket[:port]                             defaults to the standard output port
1029:        saws[:communicatorname]                    publishes object to the Scientific Application Webserver (SAWs)
1030: .ve

1032: .seealso: [](ch_matrices), `Mat`, `MatView()`, `PetscObjectViewFromOptions()`, `MatCreate()`
1033: @*/
1034: PetscErrorCode MatViewFromOptions(Mat A, PetscObject obj, const char name[])
1035: {
1036:   PetscFunctionBegin;
1038: #if !defined(PETSC_HAVE_THREADSAFETY)
1039:   if (insidematview) PetscFunctionReturn(PETSC_SUCCESS);
1040: #endif
1041:   PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
1042:   PetscFunctionReturn(PETSC_SUCCESS);
1043: }

1045: /*@
1046:   MatView - display information about a matrix in a variety ways

1048:   Collective on viewer

1050:   Input Parameters:
1051: + mat    - the matrix
1052: - viewer - visualization context

1054:   Options Database Keys:
1055: + -mat_view ::ascii_info           - Prints info on matrix at conclusion of `MatAssemblyEnd()`
1056: . -mat_view ::ascii_info_detail    - Prints more detailed info
1057: . -mat_view                        - Prints matrix in ASCII format
1058: . -mat_view ::ascii_matlab         - Prints matrix in MATLAB format
1059: . -mat_view draw                   - PetscDraws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
1060: . -display <name>                  - Sets display name (default is host)
1061: . -draw_pause <sec>                - Sets number of seconds to pause after display
1062: . -mat_view socket                 - Sends matrix to socket, can be accessed from MATLAB (see Users-Manual: ch_matlab for details)
1063: . -viewer_socket_machine <machine> - -
1064: . -viewer_socket_port <port>       - -
1065: . -mat_view binary                 - save matrix to file in binary format
1066: - -viewer_binary_filename <name>   - -

1068:   Level: beginner

1070:   Notes:
1071:   The available visualization contexts include
1072: +    `PETSC_VIEWER_STDOUT_SELF`   - for sequential matrices
1073: .    `PETSC_VIEWER_STDOUT_WORLD`  - for parallel matrices created on `PETSC_COMM_WORLD`
1074: .    `PETSC_VIEWER_STDOUT_`(comm) - for matrices created on MPI communicator comm
1075: -     `PETSC_VIEWER_DRAW_WORLD`   - graphical display of nonzero structure

1077:   The user can open alternative visualization contexts with
1078: +    `PetscViewerASCIIOpen()`  - Outputs matrix to a specified file
1079: .    `PetscViewerBinaryOpen()` - Outputs matrix in binary to a  specified file; corresponding input uses `MatLoad()`
1080: .    `PetscViewerDrawOpen()`   - Outputs nonzero matrix nonzero structure to an X window display
1081: -    `PetscViewerSocketOpen()` - Outputs matrix to Socket viewer, `PETSCVIEWERSOCKET`. Only the `MATSEQDENSE` and `MATAIJ` types support this viewer.

1083:   The user can call `PetscViewerPushFormat()` to specify the output
1084:   format of ASCII printed objects (when using `PETSC_VIEWER_STDOUT_SELF`,
1085:   `PETSC_VIEWER_STDOUT_WORLD` and `PetscViewerASCIIOpen()`).  Available formats include
1086: +    `PETSC_VIEWER_DEFAULT`           - default, prints matrix contents
1087: .    `PETSC_VIEWER_ASCII_MATLAB`      - prints matrix contents in MATLAB format
1088: .    `PETSC_VIEWER_ASCII_DENSE`       - prints entire matrix including zeros
1089: .    `PETSC_VIEWER_ASCII_COMMON`      - prints matrix contents, using a sparse  format common among all matrix types
1090: .    `PETSC_VIEWER_ASCII_IMPL`        - prints matrix contents, using an implementation-specific format (which is in many cases the same as the default)
1091: .    `PETSC_VIEWER_ASCII_INFO`        - prints basic information about the matrix size and structure (not the matrix entries)
1092: -    `PETSC_VIEWER_ASCII_INFO_DETAIL` - prints more detailed information about the matrix nonzero structure (still not vector or matrix entries)

1094:   The ASCII viewers are only recommended for small matrices on at most a moderate number of processes,
1095:   the program will seemingly hang and take hours for larger matrices, for larger matrices one should use the binary format.

1097:   In the debugger you can do "call MatView(mat,0)" to display the matrix. (The same holds for any PETSc object viewer).

1099:   See the manual page for `MatLoad()` for the exact format of the binary file when the binary
1100:   viewer is used.

1102:   See share/petsc/matlab/PetscBinaryRead.m for a MATLAB code that can read in the binary file when the binary
1103:   viewer is used and lib/petsc/bin/PetscBinaryIO.py for loading them into Python.

1105:   One can use '-mat_view draw -draw_pause -1' to pause the graphical display of matrix nonzero structure,
1106:   and then use the following mouse functions.
1107: .vb
1108:   left mouse: zoom in
1109:   middle mouse: zoom out
1110:   right mouse: continue with the simulation
1111: .ve

1113: .seealso: [](ch_matrices), `Mat`, `PetscViewerPushFormat()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewer`,
1114:           `PetscViewerSocketOpen()`, `PetscViewerBinaryOpen()`, `MatLoad()`, `MatViewFromOptions()`
1115: @*/
1116: PetscErrorCode MatView(Mat mat, PetscViewer viewer)
1117: {
1118:   PetscInt          rows, cols, rbs, cbs;
1119:   PetscBool         isascii, isstring, issaws;
1120:   PetscViewerFormat format;
1121:   PetscMPIInt       size;

1123:   PetscFunctionBegin;
1126:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)mat), &viewer));

1129:   PetscCall(PetscViewerGetFormat(viewer, &format));
1130:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)viewer), &size));
1131:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);

1133: #if !defined(PETSC_HAVE_THREADSAFETY)
1134:   insidematview++;
1135: #endif
1136:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
1137:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
1138:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
1139:   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");

1141:   PetscCall(PetscLogEventBegin(MAT_View, mat, viewer, 0, 0));
1142:   if (isascii) {
1143:     if (!mat->preallocated) {
1144:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been preallocated yet\n"));
1145: #if !defined(PETSC_HAVE_THREADSAFETY)
1146:       insidematview--;
1147: #endif
1148:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1149:       PetscFunctionReturn(PETSC_SUCCESS);
1150:     }
1151:     if (!mat->assembled) {
1152:       PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix has not been assembled yet\n"));
1153: #if !defined(PETSC_HAVE_THREADSAFETY)
1154:       insidematview--;
1155: #endif
1156:       PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1157:       PetscFunctionReturn(PETSC_SUCCESS);
1158:     }
1159:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)mat, viewer));
1160:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1161:       MatNullSpace nullsp, transnullsp;

1163:       PetscCall(PetscViewerASCIIPushTab(viewer));
1164:       PetscCall(MatGetSize(mat, &rows, &cols));
1165:       PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
1166:       if (rbs != 1 || cbs != 1) {
1167:         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" : ""));
1168:         else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT ", bs=%" PetscInt_FMT "%s\n", rows, cols, rbs, mat->bsizes ? " variable blocks set" : ""));
1169:       } else PetscCall(PetscViewerASCIIPrintf(viewer, "rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", rows, cols));
1170:       if (mat->factortype) {
1171:         MatSolverType solver;
1172:         PetscCall(MatFactorGetSolverType(mat, &solver));
1173:         PetscCall(PetscViewerASCIIPrintf(viewer, "package used to perform factorization: %s\n", solver));
1174:       }
1175:       if (mat->ops->getinfo) {
1176:         PetscBool is_constant_or_diagonal;

1178:         // Don't print nonzero information for constant or diagonal matrices, it just adds noise to the output
1179:         PetscCall(PetscObjectTypeCompareAny((PetscObject)mat, &is_constant_or_diagonal, MATCONSTANTDIAGONAL, MATDIAGONAL, ""));
1180:         if (!is_constant_or_diagonal) {
1181:           MatInfo info;

1183:           PetscCall(MatGetInfo(mat, MAT_GLOBAL_SUM, &info));
1184:           PetscCall(PetscViewerASCIIPrintf(viewer, "total: nonzeros=%.f, allocated nonzeros=%.f\n", info.nz_used, info.nz_allocated));
1185:           if (!mat->factortype) PetscCall(PetscViewerASCIIPrintf(viewer, "total number of mallocs used during MatSetValues calls=%" PetscInt_FMT "\n", (PetscInt)info.mallocs));
1186:         }
1187:       }
1188:       PetscCall(MatGetNullSpace(mat, &nullsp));
1189:       PetscCall(MatGetTransposeNullSpace(mat, &transnullsp));
1190:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached null space\n"));
1191:       if (transnullsp && transnullsp != nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached transposed null space\n"));
1192:       PetscCall(MatGetNearNullSpace(mat, &nullsp));
1193:       if (nullsp) PetscCall(PetscViewerASCIIPrintf(viewer, "  has attached near null space\n"));
1194:       PetscCall(PetscViewerASCIIPushTab(viewer));
1195:       PetscCall(MatProductView(mat, viewer));
1196:       PetscCall(PetscViewerASCIIPopTab(viewer));
1197:       if (mat->bsizes && format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1198:         IS tmp;

1200:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)viewer), mat->nblocks, mat->bsizes, PETSC_USE_POINTER, &tmp));
1201:         PetscCall(PetscObjectSetName((PetscObject)tmp, "Block Sizes"));
1202:         PetscCall(PetscViewerASCIIPushTab(viewer));
1203:         PetscCall(ISView(tmp, viewer));
1204:         PetscCall(PetscViewerASCIIPopTab(viewer));
1205:         PetscCall(ISDestroy(&tmp));
1206:       }
1207:     }
1208:   } else if (issaws) {
1209: #if defined(PETSC_HAVE_SAWS)
1210:     PetscMPIInt rank;

1212:     PetscCall(PetscObjectName((PetscObject)mat));
1213:     PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
1214:     if (!((PetscObject)mat)->amsmem && rank == 0) PetscCall(PetscObjectViewSAWs((PetscObject)mat, viewer));
1215: #endif
1216:   } else if (isstring) {
1217:     const char *type;
1218:     PetscCall(MatGetType(mat, &type));
1219:     PetscCall(PetscViewerStringSPrintf(viewer, " MatType: %-7.7s", type));
1220:     PetscTryTypeMethod(mat, view, viewer);
1221:   }
1222:   if ((format == PETSC_VIEWER_NATIVE || format == PETSC_VIEWER_LOAD_BALANCE) && mat->ops->viewnative) {
1223:     PetscCall(PetscViewerASCIIPushTab(viewer));
1224:     PetscUseTypeMethod(mat, viewnative, viewer);
1225:     PetscCall(PetscViewerASCIIPopTab(viewer));
1226:   } else if (mat->ops->view) {
1227:     PetscCall(PetscViewerASCIIPushTab(viewer));
1228:     PetscUseTypeMethod(mat, view, viewer);
1229:     PetscCall(PetscViewerASCIIPopTab(viewer));
1230:   }
1231:   if (isascii) {
1232:     PetscCall(PetscViewerGetFormat(viewer, &format));
1233:     if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerASCIIPopTab(viewer));
1234:   }
1235:   PetscCall(PetscLogEventEnd(MAT_View, mat, viewer, 0, 0));
1236: #if !defined(PETSC_HAVE_THREADSAFETY)
1237:   insidematview--;
1238: #endif
1239:   PetscFunctionReturn(PETSC_SUCCESS);
1240: }

1242: #if defined(PETSC_USE_DEBUG)
1243: #include <../src/sys/totalview/tv_data_display.h>
1244: PETSC_UNUSED static int TV_display_type(const struct _p_Mat *mat)
1245: {
1246:   TV_add_row("Local rows", "int", &mat->rmap->n);
1247:   TV_add_row("Local columns", "int", &mat->cmap->n);
1248:   TV_add_row("Global rows", "int", &mat->rmap->N);
1249:   TV_add_row("Global columns", "int", &mat->cmap->N);
1250:   TV_add_row("Typename", TV_ascii_string_type, ((PetscObject)mat)->type_name);
1251:   return TV_format_OK;
1252: }
1253: #endif

1255: /*@
1256:   MatLoad - Loads a matrix that has been stored in binary/HDF5 format
1257:   with `MatView()`.  The matrix format is determined from the options database.
1258:   Generates a parallel MPI matrix if the communicator has more than one
1259:   processor.  The default matrix type is `MATAIJ`.

1261:   Collective

1263:   Input Parameters:
1264: + mat    - the newly loaded matrix, this needs to have been created with `MatCreate()`
1265:             or some related function before a call to `MatLoad()`
1266: - viewer - `PETSCVIEWERBINARY`/`PETSCVIEWERHDF5` file viewer

1268:   Options Database Key:
1269: . -matload_block_size <bs> - set block size

1271:   Level: beginner

1273:   Notes:
1274:   If the `Mat` type has not yet been given then `MATAIJ` is used, call `MatSetFromOptions()` on the
1275:   `Mat` before calling this routine if you wish to set it from the options database.

1277:   `MatLoad()` automatically loads into the options database any options
1278:   given in the file filename.info where filename is the name of the file
1279:   that was passed to the `PetscViewerBinaryOpen()`. The options in the info
1280:   file will be ignored if you use the -viewer_binary_skip_info option.

1282:   If the type or size of mat is not set before a call to `MatLoad()`, PETSc
1283:   sets the default matrix type AIJ and sets the local and global sizes.
1284:   If type and/or size is already set, then the same are used.

1286:   In parallel, each processor can load a subset of rows (or the
1287:   entire matrix).  This routine is especially useful when a large
1288:   matrix is stored on disk and only part of it is desired on each
1289:   processor.  For example, a parallel solver may access only some of
1290:   the rows from each processor.  The algorithm used here reads
1291:   relatively small blocks of data rather than reading the entire
1292:   matrix and then subsetting it.

1294:   Viewer's `PetscViewerType` must be either `PETSCVIEWERBINARY` or `PETSCVIEWERHDF5`.
1295:   Such viewer can be created using `PetscViewerBinaryOpen()` or `PetscViewerHDF5Open()`,
1296:   or the sequence like
1297: .vb
1298:     `PetscViewer` v;
1299:     `PetscViewerCreate`(`PETSC_COMM_WORLD`,&v);
1300:     `PetscViewerSetType`(v,`PETSCVIEWERBINARY`);
1301:     `PetscViewerSetFromOptions`(v);
1302:     `PetscViewerFileSetMode`(v,`FILE_MODE_READ`);
1303:     `PetscViewerFileSetName`(v,"datafile");
1304: .ve
1305:   The optional `PetscViewerSetFromOptions()` call allows overriding `PetscViewerSetType()` using the option
1306: .vb
1307:   -viewer_type {binary, hdf5}
1308: .ve

1310:   See the example src/ksp/ksp/tutorials/ex27.c with the first approach,
1311:   and src/mat/tutorials/ex10.c with the second approach.

1313:   In case of `PETSCVIEWERBINARY`, a native PETSc binary format is used. Each of the blocks
1314:   is read onto MPI rank 0 and then shipped to its destination MPI rank, one after another.
1315:   Multiple objects, both matrices and vectors, can be stored within the same file.
1316:   Their `PetscObject` name is ignored; they are loaded in the order of their storage.

1318:   Most users should not need to know the details of the binary storage
1319:   format, since `MatLoad()` and `MatView()` completely hide these details.
1320:   But for anyone who is interested, the standard binary matrix storage
1321:   format is

1323: .vb
1324:     PetscInt    MAT_FILE_CLASSID
1325:     PetscInt    number of rows
1326:     PetscInt    number of columns
1327:     PetscInt    total number of nonzeros
1328:     PetscInt    *number nonzeros in each row
1329:     PetscInt    *column indices of all nonzeros (starting index is zero)
1330:     PetscScalar *values of all nonzeros
1331: .ve
1332:   If PETSc was not configured with `--with-64-bit-indices` then only `MATMPIAIJ` matrices with more than `PETSC_INT_MAX` non-zeros can be
1333:   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
1334:   case will not fit in a (32-bit) `PetscInt` the value `PETSC_INT_MAX` is used for the header entry `total number of nonzeros`.

1336:   PETSc automatically does the byte swapping for
1337:   machines that store the bytes reversed. Thus if you write your own binary
1338:   read/write routines you have to swap the bytes; see `PetscBinaryRead()`
1339:   and `PetscBinaryWrite()` to see how this may be done.

1341:   In case of `PETSCVIEWERHDF5`, a parallel HDF5 reader is used.
1342:   Each processor's chunk is loaded independently by its owning MPI process.
1343:   Multiple objects, both matrices and vectors, can be stored within the same file.
1344:   They are looked up by their PetscObject name.

1346:   As the MATLAB MAT-File Version 7.3 format is also a HDF5 flavor, we decided to use
1347:   by default the same structure and naming of the AIJ arrays and column count
1348:   within the HDF5 file. This means that a MAT file saved with -v7.3 flag, e.g.
1349: .vb
1350:   save example.mat A b -v7.3
1351: .ve
1352:   can be directly read by this routine (see Reference 1 for details).

1354:   Depending on your MATLAB version, this format might be a default,
1355:   otherwise you can set it as default in Preferences.

1357:   Unless -nocompression flag is used to save the file in MATLAB,
1358:   PETSc must be configured with ZLIB package.

1360:   See also examples src/mat/tutorials/ex10.c and src/ksp/ksp/tutorials/ex27.c

1362:   This reader currently supports only real `MATSEQAIJ`, `MATMPIAIJ`, `MATSEQDENSE` and `MATMPIDENSE` matrices for `PETSCVIEWERHDF5`

1364:   Corresponding `MatView()` is not yet implemented.

1366:   The loaded matrix is actually a transpose of the original one in MATLAB,
1367:   unless you push `PETSC_VIEWER_HDF5_MAT` format (see examples above).
1368:   With this format, matrix is automatically transposed by PETSc,
1369:   unless the matrix is marked as SPD or symmetric
1370:   (see `MatSetOption()`, `MAT_SPD`, `MAT_SYMMETRIC`).

1372:   See MATLAB Documentation on `save()`, <https://www.mathworks.com/help/matlab/ref/save.html#btox10b-1-version>

1374: .seealso: [](ch_matrices), `Mat`, `PetscViewerBinaryOpen()`, `PetscViewerSetType()`, `MatView()`, `VecLoad()`
1375:  @*/
1376: PetscErrorCode MatLoad(Mat mat, PetscViewer viewer)
1377: {
1378:   PetscBool flg;

1380:   PetscFunctionBegin;

1384:   if (!((PetscObject)mat)->type_name) PetscCall(MatSetType(mat, MATAIJ));

1386:   flg = PETSC_FALSE;
1387:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_symmetric", &flg, NULL));
1388:   if (flg) {
1389:     PetscCall(MatSetOption(mat, MAT_SYMMETRIC, PETSC_TRUE));
1390:     PetscCall(MatSetOption(mat, MAT_SYMMETRY_ETERNAL, PETSC_TRUE));
1391:   }
1392:   flg = PETSC_FALSE;
1393:   PetscCall(PetscOptionsGetBool(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matload_spd", &flg, NULL));
1394:   if (flg) PetscCall(MatSetOption(mat, MAT_SPD, PETSC_TRUE));

1396:   PetscCall(PetscLogEventBegin(MAT_Load, mat, viewer, 0, 0));
1397:   PetscUseTypeMethod(mat, load, viewer);
1398:   PetscCall(PetscLogEventEnd(MAT_Load, mat, viewer, 0, 0));
1399:   PetscFunctionReturn(PETSC_SUCCESS);
1400: }

1402: static PetscErrorCode MatDestroy_Redundant(Mat_Redundant **redundant)
1403: {
1404:   Mat_Redundant *redund = *redundant;

1406:   PetscFunctionBegin;
1407:   if (redund) {
1408:     if (redund->matseq) { /* via MatCreateSubMatrices()  */
1409:       PetscCall(ISDestroy(&redund->isrow));
1410:       PetscCall(ISDestroy(&redund->iscol));
1411:       PetscCall(MatDestroySubMatrices(1, &redund->matseq));
1412:     } else {
1413:       PetscCall(PetscFree2(redund->send_rank, redund->recv_rank));
1414:       PetscCall(PetscFree(redund->sbuf_j));
1415:       PetscCall(PetscFree(redund->sbuf_a));
1416:       for (PetscInt i = 0; i < redund->nrecvs; i++) {
1417:         PetscCall(PetscFree(redund->rbuf_j[i]));
1418:         PetscCall(PetscFree(redund->rbuf_a[i]));
1419:       }
1420:       PetscCall(PetscFree4(redund->sbuf_nz, redund->rbuf_nz, redund->rbuf_j, redund->rbuf_a));
1421:     }

1423:     if (redund->subcomm) PetscCall(PetscCommDestroy(&redund->subcomm));
1424:     PetscCall(PetscFree(redund));
1425:   }
1426:   PetscFunctionReturn(PETSC_SUCCESS);
1427: }

1429: /*@
1430:   MatDestroy - Frees space taken by a matrix.

1432:   Collective

1434:   Input Parameter:
1435: . A - the matrix

1437:   Level: beginner

1439:   Developer Note:
1440:   Some special arrays of matrices are not destroyed in this routine but instead by the routines called by
1441:   `MatDestroySubMatrices()`. Thus one must be sure that any changes here must also be made in those routines.
1442:   `MatHeaderMerge()` and `MatHeaderReplace()` also manipulate the data in the `Mat` object and likely need changes
1443:   if changes are needed here.

1445: .seealso: [](ch_matrices), `Mat`, `MatCreate()`
1446: @*/
1447: PetscErrorCode MatDestroy(Mat *A)
1448: {
1449:   PetscFunctionBegin;
1450:   if (!*A) PetscFunctionReturn(PETSC_SUCCESS);
1452:   if (--((PetscObject)*A)->refct > 0) {
1453:     *A = NULL;
1454:     PetscFunctionReturn(PETSC_SUCCESS);
1455:   }

1457:   /* if memory was published with SAWs then destroy it */
1458:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*A));
1459:   PetscTryTypeMethod(*A, destroy);

1461:   PetscCall(PetscFree((*A)->factorprefix));
1462:   PetscCall(PetscFree((*A)->defaultvectype));
1463:   PetscCall(PetscFree((*A)->defaultrandtype));
1464:   PetscCall(PetscFree((*A)->bsizes));
1465:   PetscCall(PetscFree((*A)->solvertype));
1466:   for (PetscInt i = 0; i < MAT_FACTOR_NUM_TYPES; i++) PetscCall(PetscFree((*A)->preferredordering[i]));
1467:   if ((*A)->redundant && (*A)->redundant->matseq[0] == *A) (*A)->redundant->matseq[0] = NULL;
1468:   PetscCall(MatDestroy_Redundant(&(*A)->redundant));
1469:   PetscCall(MatProductClear(*A));
1470:   PetscCall(MatNullSpaceDestroy(&(*A)->nullsp));
1471:   PetscCall(MatNullSpaceDestroy(&(*A)->transnullsp));
1472:   PetscCall(MatNullSpaceDestroy(&(*A)->nearnullsp));
1473:   PetscCall(MatDestroy(&(*A)->schur));
1474:   PetscCall(PetscLayoutDestroy(&(*A)->rmap));
1475:   PetscCall(PetscLayoutDestroy(&(*A)->cmap));
1476:   PetscCall(PetscHeaderDestroy(A));
1477:   PetscFunctionReturn(PETSC_SUCCESS);
1478: }

1480: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1481: /*@
1482:   MatSetValues - Inserts or adds a block of values into a matrix.
1483:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1484:   MUST be called after all calls to `MatSetValues()` have been completed.

1486:   Not Collective

1488:   Input Parameters:
1489: + mat  - the matrix
1490: . m    - the number of rows
1491: . idxm - the global indices of the rows
1492: . n    - the number of columns
1493: . idxn - the global indices of the columns
1494: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1495:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1496: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1498:   Level: beginner

1500:   Notes:
1501:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1502:   options cannot be mixed without intervening calls to the assembly
1503:   routines.

1505:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1506:   as well as in C.

1508:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1509:   simply ignored. This allows easily inserting element stiffness matrices
1510:   with homogeneous Dirichlet boundary conditions that you don't want represented
1511:   in the matrix.

1513:   Efficiency Alert:
1514:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1515:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1517:   Fortran Notes:
1518:   If any of `idxm`, `idxn`, and `v` are scalars pass them using, for example,
1519: .vb
1520:   call MatSetValues(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
1521: .ve

1523:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1525:   Developer Note:
1526:   This is labeled with C so does not automatically generate Fortran stubs and interfaces
1527:   because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.

1529: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1530:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1531: @*/
1532: PetscErrorCode MatSetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
1533: {
1534:   PetscFunctionBeginHot;
1537:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1538:   PetscAssertPointer(idxm, 3);
1539:   PetscAssertPointer(idxn, 5);
1540:   MatCheckPreallocated(mat, 1);

1542:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
1543:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");

1545:   if (PetscDefined(USE_DEBUG)) {
1546:     PetscInt i, j;

1548:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1549:     if (v) {
1550:       for (i = 0; i < m; i++) {
1551:         for (j = 0; j < n; j++) {
1552:           if (mat->erroriffailure && PetscIsInfOrNanScalar(v[i * n + j]))
1553: #if defined(PETSC_USE_COMPLEX)
1554:             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]);
1555: #else
1556:             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]);
1557: #endif
1558:         }
1559:       }
1560:     }
1561:     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);
1562:     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);
1563:   }

1565:   if (mat->assembled) {
1566:     mat->was_assembled = PETSC_TRUE;
1567:     mat->assembled     = PETSC_FALSE;
1568:   }
1569:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1570:   PetscUseTypeMethod(mat, setvalues, m, idxm, n, idxn, v, addv);
1571:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1572:   PetscFunctionReturn(PETSC_SUCCESS);
1573: }

1575: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1576: /*@
1577:   MatSetValuesIS - Inserts or adds a block of values into a matrix using an `IS` to indicate the rows and columns
1578:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
1579:   MUST be called after all calls to `MatSetValues()` have been completed.

1581:   Not Collective

1583:   Input Parameters:
1584: + mat  - the matrix
1585: . ism  - the rows to provide
1586: . isn  - the columns to provide
1587: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1588:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1589: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

1591:   Level: beginner

1593:   Notes:
1594:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1596:   Calls to `MatSetValues()` with the `INSERT_VALUES` and `ADD_VALUES`
1597:   options cannot be mixed without intervening calls to the assembly
1598:   routines.

1600:   `MatSetValues()` uses 0-based row and column numbers in Fortran
1601:   as well as in C.

1603:   Negative indices may be passed in `ism` and `isn`, these rows and columns are
1604:   simply ignored. This allows easily inserting element stiffness matrices
1605:   with homogeneous Dirichlet boundary conditions that you don't want represented
1606:   in the matrix.

1608:   Fortran Note:
1609:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1611:   Efficiency Alert:
1612:   The routine `MatSetValuesBlocked()` may offer much better efficiency
1613:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1615:   This is currently not optimized for any particular `ISType`

1617: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatSetValues()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1618:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1619: @*/
1620: PetscErrorCode MatSetValuesIS(Mat mat, IS ism, IS isn, const PetscScalar v[], InsertMode addv)
1621: {
1622:   PetscInt        m, n;
1623:   const PetscInt *rows, *cols;

1625:   PetscFunctionBeginHot;
1627:   PetscCall(ISGetIndices(ism, &rows));
1628:   PetscCall(ISGetIndices(isn, &cols));
1629:   PetscCall(ISGetLocalSize(ism, &m));
1630:   PetscCall(ISGetLocalSize(isn, &n));
1631:   PetscCall(MatSetValues(mat, m, rows, n, cols, v, addv));
1632:   PetscCall(ISRestoreIndices(ism, &rows));
1633:   PetscCall(ISRestoreIndices(isn, &cols));
1634:   PetscFunctionReturn(PETSC_SUCCESS);
1635: }

1637: /*@
1638:   MatSetValuesRowLocal - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1639:   values into a matrix

1641:   Not Collective

1643:   Input Parameters:
1644: + mat - the matrix
1645: . row - the (block) row to set
1646: - 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.
1647:         See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

1649:   Level: intermediate

1651:   Notes:
1652:   The values, `v`, are column-oriented (for the block version) and sorted

1654:   All the nonzero values in `row` must be provided

1656:   The matrix must have previously had its column indices set, likely by having been assembled.

1658:   `row` must belong to this MPI process

1660:   Fortran Note:
1661:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1663: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1664:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetValuesRow()`, `MatSetLocalToGlobalMapping()`
1665: @*/
1666: PetscErrorCode MatSetValuesRowLocal(Mat mat, PetscInt row, const PetscScalar v[])
1667: {
1668:   PetscInt globalrow;

1670:   PetscFunctionBegin;
1673:   PetscAssertPointer(v, 3);
1674:   PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, 1, &row, &globalrow));
1675:   PetscCall(MatSetValuesRow(mat, globalrow, v));
1676:   PetscFunctionReturn(PETSC_SUCCESS);
1677: }

1679: /*@
1680:   MatSetValuesRow - Inserts a row (block row for `MATBAIJ` matrices) of nonzero
1681:   values into a matrix

1683:   Not Collective

1685:   Input Parameters:
1686: + mat - the matrix
1687: . row - the (block) row to set
1688: - 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

1690:   Level: advanced

1692:   Notes:
1693:   The values, `v`, are column-oriented for the block version.

1695:   All the nonzeros in `row` must be provided

1697:   THE MATRIX MUST HAVE PREVIOUSLY HAD ITS COLUMN INDICES SET. IT IS RARE THAT THIS ROUTINE IS USED, usually `MatSetValues()` is used.

1699:   `row` must belong to this process

1701: .seealso: [](ch_matrices), `Mat`, `MatSetValues()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
1702:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
1703: @*/
1704: PetscErrorCode MatSetValuesRow(Mat mat, PetscInt row, const PetscScalar v[])
1705: {
1706:   PetscFunctionBeginHot;
1709:   MatCheckPreallocated(mat, 1);
1710:   PetscAssertPointer(v, 3);
1711:   PetscCheck(mat->insertmode != ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add and insert values");
1712:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
1713:   mat->insertmode = INSERT_VALUES;

1715:   if (mat->assembled) {
1716:     mat->was_assembled = PETSC_TRUE;
1717:     mat->assembled     = PETSC_FALSE;
1718:   }
1719:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
1720:   PetscUseTypeMethod(mat, setvaluesrow, row, v);
1721:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
1722:   PetscFunctionReturn(PETSC_SUCCESS);
1723: }

1725: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
1726: /*@
1727:   MatSetValuesStencil - Inserts or adds a block of values into a matrix.
1728:   Using structured grid indexing

1730:   Not Collective

1732:   Input Parameters:
1733: + mat  - the matrix
1734: . m    - number of rows being entered
1735: . idxm - grid coordinates (and component number when dof > 1) for matrix rows being entered
1736: . n    - number of columns being entered
1737: . idxn - grid coordinates (and component number when dof > 1) for matrix columns being entered
1738: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1739:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1740: - addv - either `ADD_VALUES` to add to existing entries at that location or `INSERT_VALUES` to replace existing entries with new values

1742:   Level: beginner

1744:   Notes:
1745:   By default the values, `v`, are row-oriented.  See `MatSetOption()` for other options.

1747:   Calls to `MatSetValuesStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1748:   options cannot be mixed without intervening calls to the assembly
1749:   routines.

1751:   The grid coordinates are across the entire grid, not just the local portion

1753:   `MatSetValuesStencil()` uses 0-based row and column numbers in Fortran
1754:   as well as in C.

1756:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1758:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1759:   or call `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1761:   The columns and rows in the stencil passed in MUST be contained within the
1762:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1763:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1764:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1765:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1767:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
1768:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
1769:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
1770:   `DM_BOUNDARY_PERIODIC` boundary type.

1772:   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
1773:   a single value per point) you can skip filling those indices.

1775:   Inspired by the structured grid interface to the HYPRE package
1776:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1778:   Fortran Note:
1779:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1781:   Efficiency Alert:
1782:   The routine `MatSetValuesBlockedStencil()` may offer much better efficiency
1783:   for users of block sparse formats (`MATSEQBAIJ` and `MATMPIBAIJ`).

1785: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`
1786:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`
1787: @*/
1788: PetscErrorCode MatSetValuesStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1789: {
1790:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1791:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1792:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1794:   PetscFunctionBegin;
1795:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1798:   PetscAssertPointer(idxm, 3);
1799:   PetscAssertPointer(idxn, 5);

1801:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1802:     jdxm = buf;
1803:     jdxn = buf + m;
1804:   } else {
1805:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1806:     jdxm = bufm;
1807:     jdxn = bufn;
1808:   }
1809:   for (i = 0; i < m; i++) {
1810:     for (j = 0; j < 3 - sdim; j++) dxm++;
1811:     tmp = *dxm++ - starts[0];
1812:     for (j = 0; j < dim - 1; j++) {
1813:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1814:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1815:     }
1816:     if (mat->stencil.noc) dxm++;
1817:     jdxm[i] = tmp;
1818:   }
1819:   for (i = 0; i < n; i++) {
1820:     for (j = 0; j < 3 - sdim; j++) dxn++;
1821:     tmp = *dxn++ - starts[0];
1822:     for (j = 0; j < dim - 1; j++) {
1823:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1824:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1825:     }
1826:     if (mat->stencil.noc) dxn++;
1827:     jdxn[i] = tmp;
1828:   }
1829:   PetscCall(MatSetValuesLocal(mat, m, jdxm, n, jdxn, v, addv));
1830:   PetscCall(PetscFree2(bufm, bufn));
1831:   PetscFunctionReturn(PETSC_SUCCESS);
1832: }

1834: /*@
1835:   MatSetValuesBlockedStencil - Inserts or adds a block of values into a matrix.
1836:   Using structured grid indexing

1838:   Not Collective

1840:   Input Parameters:
1841: + mat  - the matrix
1842: . m    - number of rows being entered
1843: . idxm - grid coordinates for matrix rows being entered
1844: . n    - number of columns being entered
1845: . idxn - grid coordinates for matrix columns being entered
1846: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
1847:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
1848: - addv - either `ADD_VALUES` to add to existing entries or `INSERT_VALUES` to replace existing entries with new values

1850:   Level: beginner

1852:   Notes:
1853:   By default the values, `v`, are row-oriented and unsorted.
1854:   See `MatSetOption()` for other options.

1856:   Calls to `MatSetValuesBlockedStencil()` with the `INSERT_VALUES` and `ADD_VALUES`
1857:   options cannot be mixed without intervening calls to the assembly
1858:   routines.

1860:   The grid coordinates are across the entire grid, not just the local portion

1862:   `MatSetValuesBlockedStencil()` uses 0-based row and column numbers in Fortran
1863:   as well as in C.

1865:   For setting/accessing vector values via array coordinates you can use the `DMDAVecGetArray()` routine

1867:   In order to use this routine you must either obtain the matrix with `DMCreateMatrix()`
1868:   or call `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()` and `MatSetStencil()` first.

1870:   The columns and rows in the stencil passed in MUST be contained within the
1871:   ghost region of the given process as set with DMDACreateXXX() or `MatSetStencil()`. For example,
1872:   if you create a `DMDA` with an overlap of one grid level and on a particular process its first
1873:   local nonghost x logical coordinate is 6 (so its first ghost x logical coordinate is 5) the
1874:   first i index you can use in your column and row indices in `MatSetStencil()` is 5.

1876:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
1877:   simply ignored. This allows easily inserting element stiffness matrices
1878:   with homogeneous Dirichlet boundary conditions that you don't want represented
1879:   in the matrix.

1881:   Inspired by the structured grid interface to the HYPRE package
1882:   (https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods)

1884:   Fortran Notes:
1885:   `idxm` and `idxn` should be declared as
1886: .vb
1887:     MatStencil idxm(4,m),idxn(4,n)
1888: .ve
1889:   and the values inserted using
1890: .vb
1891:     idxm(MatStencil_i,1) = i
1892:     idxm(MatStencil_j,1) = j
1893:     idxm(MatStencil_k,1) = k
1894:    etc
1895: .ve

1897:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

1899: .seealso: [](ch_matrices), `Mat`, `DMDA`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`
1900:           `MatSetValues()`, `MatSetValuesStencil()`, `MatSetStencil()`, `DMCreateMatrix()`, `DMDAVecGetArray()`, `MatStencil`,
1901:           `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`
1902: @*/
1903: PetscErrorCode MatSetValuesBlockedStencil(Mat mat, PetscInt m, const MatStencil idxm[], PetscInt n, const MatStencil idxn[], const PetscScalar v[], InsertMode addv)
1904: {
1905:   PetscInt  buf[8192], *bufm = NULL, *bufn = NULL, *jdxm, *jdxn;
1906:   PetscInt  j, i, dim = mat->stencil.dim, *dims = mat->stencil.dims + 1, tmp;
1907:   PetscInt *starts = mat->stencil.starts, *dxm = (PetscInt *)idxm, *dxn = (PetscInt *)idxn, sdim = dim - (1 - (PetscInt)mat->stencil.noc);

1909:   PetscFunctionBegin;
1910:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
1913:   PetscAssertPointer(idxm, 3);
1914:   PetscAssertPointer(idxn, 5);
1915:   PetscAssertPointer(v, 6);

1917:   if ((m + n) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
1918:     jdxm = buf;
1919:     jdxn = buf + m;
1920:   } else {
1921:     PetscCall(PetscMalloc2(m, &bufm, n, &bufn));
1922:     jdxm = bufm;
1923:     jdxn = bufn;
1924:   }
1925:   for (i = 0; i < m; i++) {
1926:     for (j = 0; j < 3 - sdim; j++) dxm++;
1927:     tmp = *dxm++ - starts[0];
1928:     for (j = 0; j < sdim - 1; j++) {
1929:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1930:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
1931:     }
1932:     dxm++;
1933:     jdxm[i] = tmp;
1934:   }
1935:   for (i = 0; i < n; i++) {
1936:     for (j = 0; j < 3 - sdim; j++) dxn++;
1937:     tmp = *dxn++ - starts[0];
1938:     for (j = 0; j < sdim - 1; j++) {
1939:       if ((*dxn++ - starts[j + 1]) < 0 || tmp < 0) tmp = -1;
1940:       else tmp = tmp * dims[j] + *(dxn - 1) - starts[j + 1];
1941:     }
1942:     dxn++;
1943:     jdxn[i] = tmp;
1944:   }
1945:   PetscCall(MatSetValuesBlockedLocal(mat, m, jdxm, n, jdxn, v, addv));
1946:   PetscCall(PetscFree2(bufm, bufn));
1947:   PetscFunctionReturn(PETSC_SUCCESS);
1948: }

1950: /*@
1951:   MatSetStencil - Sets the grid information for setting values into a matrix via
1952:   `MatSetValuesStencil()`

1954:   Not Collective

1956:   Input Parameters:
1957: + mat    - the matrix
1958: . dim    - dimension of the grid 1, 2, or 3
1959: . dims   - number of grid points in x, y, and z direction, including ghost points on your processor
1960: . starts - starting point of ghost nodes on your processor in x, y, and z direction
1961: - dof    - number of degrees of freedom per node

1963:   Level: beginner

1965:   Notes:
1966:   Inspired by the structured grid interface to the HYPRE package
1967:   (www.llnl.gov/CASC/hyper)

1969:   For matrices generated with `DMCreateMatrix()` this routine is automatically called and so not needed by the
1970:   user.

1972: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`
1973:           `MatSetValues()`, `MatSetValuesBlockedStencil()`, `MatSetValuesStencil()`
1974: @*/
1975: PetscErrorCode MatSetStencil(Mat mat, PetscInt dim, const PetscInt dims[], const PetscInt starts[], PetscInt dof)
1976: {
1977:   PetscFunctionBegin;
1979:   PetscAssertPointer(dims, 3);
1980:   PetscAssertPointer(starts, 4);

1982:   mat->stencil.dim = dim + (dof > 1);
1983:   for (PetscInt i = 0; i < dim; i++) {
1984:     mat->stencil.dims[i]   = dims[dim - i - 1]; /* copy the values in backwards */
1985:     mat->stencil.starts[i] = starts[dim - i - 1];
1986:   }
1987:   mat->stencil.dims[dim]   = dof;
1988:   mat->stencil.starts[dim] = 0;
1989:   mat->stencil.noc         = (PetscBool)(dof == 1);
1990:   PetscFunctionReturn(PETSC_SUCCESS);
1991: }

1993: /*@
1994:   MatSetValuesBlocked - Inserts or adds a block of values into a matrix.

1996:   Not Collective

1998:   Input Parameters:
1999: + mat  - the matrix
2000: . m    - the number of block rows
2001: . idxm - the global block indices
2002: . n    - the number of block columns
2003: . idxn - the global block indices
2004: . v    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2005:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2006: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` replaces existing entries with new values

2008:   Level: intermediate

2010:   Notes:
2011:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call
2012:   MatXXXXSetPreallocation() or `MatSetUp()` before using this routine.

2014:   The `m` and `n` count the NUMBER of blocks in the row direction and column direction,
2015:   NOT the total number of rows/columns; for example, if the block size is 2 and
2016:   you are passing in values for rows 2,3,4,5  then `m` would be 2 (not 4).
2017:   The values in `idxm` would be 1 2; that is the first index for each block divided by
2018:   the block size.

2020:   You must call `MatSetBlockSize()` when constructing this matrix (before
2021:   preallocating it).

2023:   By default, the values, `v`, are stored in row-major order. See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2025:   Calls to `MatSetValuesBlocked()` with the `INSERT_VALUES` and `ADD_VALUES`
2026:   options cannot be mixed without intervening calls to the assembly
2027:   routines.

2029:   `MatSetValuesBlocked()` uses 0-based row and column numbers in Fortran
2030:   as well as in C.

2032:   Negative indices may be passed in `idxm` and `idxn`, these rows and columns are
2033:   simply ignored. This allows easily inserting element stiffness matrices
2034:   with homogeneous Dirichlet boundary conditions that you don't want represented
2035:   in the matrix.

2037:   Each time an entry is set within a sparse matrix via `MatSetValues()`,
2038:   internal searching must be done to determine where to place the
2039:   data in the matrix storage space.  By instead inserting blocks of
2040:   entries via `MatSetValuesBlocked()`, the overhead of matrix assembly is
2041:   reduced.

2043:   Example:
2044: .vb
2045:    Suppose m=n=2 and block size(bs) = 2 The array is

2047:    1  2  | 3  4
2048:    5  6  | 7  8
2049:    - - - | - - -
2050:    9  10 | 11 12
2051:    13 14 | 15 16

2053:    v[] should be passed in like
2054:    v[] = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

2056:   If you are not using row-oriented storage of v (that is you called MatSetOption(mat,MAT_ROW_ORIENTED,PETSC_FALSE)) then
2057:    v[] = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16]
2058: .ve

2060:   Fortran Notes:
2061:   If any of `idmx`, `idxn`, and `v` are scalars pass them using, for example,
2062: .vb
2063:   call MatSetValuesBlocked(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES, ierr)
2064: .ve

2066:   If `v` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2068: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesBlockedLocal()`
2069: @*/
2070: PetscErrorCode MatSetValuesBlocked(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
2071: {
2072:   PetscFunctionBeginHot;
2075:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2076:   PetscAssertPointer(idxm, 3);
2077:   PetscAssertPointer(idxn, 5);
2078:   MatCheckPreallocated(mat, 1);
2079:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2080:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2081:   if (PetscDefined(USE_DEBUG)) {
2082:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2083:     PetscCheck(mat->ops->setvaluesblocked || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2084:   }
2085:   if (PetscDefined(USE_DEBUG)) {
2086:     PetscInt rbs, cbs, M, N, i;
2087:     PetscCall(MatGetBlockSizes(mat, &rbs, &cbs));
2088:     PetscCall(MatGetSize(mat, &M, &N));
2089:     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);
2090:     for (i = 0; i < n; i++)
2091:       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);
2092:   }
2093:   if (mat->assembled) {
2094:     mat->was_assembled = PETSC_TRUE;
2095:     mat->assembled     = PETSC_FALSE;
2096:   }
2097:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2098:   if (mat->ops->setvaluesblocked) {
2099:     PetscUseTypeMethod(mat, setvaluesblocked, m, idxm, n, idxn, v, addv);
2100:   } else {
2101:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *iidxm, *iidxn;
2102:     PetscInt i, j, bs, cbs;

2104:     PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
2105:     if ((m * bs + n * cbs) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2106:       iidxm = buf;
2107:       iidxn = buf + m * bs;
2108:     } else {
2109:       PetscCall(PetscMalloc2(m * bs, &bufr, n * cbs, &bufc));
2110:       iidxm = bufr;
2111:       iidxn = bufc;
2112:     }
2113:     for (i = 0; i < m; i++) {
2114:       for (j = 0; j < bs; j++) iidxm[i * bs + j] = bs * idxm[i] + j;
2115:     }
2116:     if (m != n || bs != cbs || idxm != idxn) {
2117:       for (i = 0; i < n; i++) {
2118:         for (j = 0; j < cbs; j++) iidxn[i * cbs + j] = cbs * idxn[i] + j;
2119:       }
2120:     } else iidxn = iidxm;
2121:     PetscCall(MatSetValues(mat, m * bs, iidxm, n * cbs, iidxn, v, addv));
2122:     PetscCall(PetscFree2(bufr, bufc));
2123:   }
2124:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2125:   PetscFunctionReturn(PETSC_SUCCESS);
2126: }

2128: /*@
2129:   MatGetValues - Gets a block of local values from a matrix.

2131:   Not Collective; can only return values that are owned by the give process

2133:   Input Parameters:
2134: + mat  - the matrix
2135: . v    - a logically two-dimensional array for storing the values
2136: . m    - the number of rows
2137: . idxm - the  global indices of the rows
2138: . n    - the number of columns
2139: - idxn - the global indices of the columns

2141:   Level: advanced

2143:   Notes:
2144:   The user must allocate space (m*n `PetscScalar`s) for the values, `v`.
2145:   The values, `v`, are then returned in a row-oriented format,
2146:   analogous to that used by default in `MatSetValues()`.

2148:   `MatGetValues()` uses 0-based row and column numbers in
2149:   Fortran as well as in C.

2151:   `MatGetValues()` requires that the matrix has been assembled
2152:   with `MatAssemblyBegin()`/`MatAssemblyEnd()`.  Thus, calls to
2153:   `MatSetValues()` and `MatGetValues()` CANNOT be made in succession
2154:   without intermediate matrix assembly.

2156:   Negative row or column indices will be ignored and those locations in `v` will be
2157:   left unchanged.

2159:   For the standard row-based matrix formats, `idxm` can only contain rows owned by the requesting MPI process.
2160:   That is, rows with global index greater than or equal to rstart and less than rend where rstart and rend are obtainable
2161:   from `MatGetOwnershipRange`(mat,&rstart,&rend).

2163: .seealso: [](ch_matrices), `Mat`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatSetValues()`, `MatGetOwnershipRange()`, `MatGetValuesLocal()`, `MatGetValue()`
2164: @*/
2165: PetscErrorCode MatGetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], PetscScalar v[])
2166: {
2167:   PetscFunctionBegin;
2170:   if (!m || !n) PetscFunctionReturn(PETSC_SUCCESS);
2171:   PetscAssertPointer(idxm, 3);
2172:   PetscAssertPointer(idxn, 5);
2173:   PetscAssertPointer(v, 6);
2174:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2175:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2176:   MatCheckPreallocated(mat, 1);

2178:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2179:   PetscUseTypeMethod(mat, getvalues, m, idxm, n, idxn, v);
2180:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2181:   PetscFunctionReturn(PETSC_SUCCESS);
2182: }

2184: /*@
2185:   MatGetValuesLocal - retrieves values from certain locations in a matrix using the local numbering of the indices
2186:   defined previously by `MatSetLocalToGlobalMapping()`

2188:   Not Collective

2190:   Input Parameters:
2191: + mat  - the matrix
2192: . nrow - number of rows
2193: . irow - the row local indices
2194: . ncol - number of columns
2195: - icol - the column local indices

2197:   Output Parameter:
2198: . y - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2199:       See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.

2201:   Level: advanced

2203:   Notes:
2204:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine.

2206:   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,
2207:   are greater than or equal to rstart and less than rend where rstart and rend are obtainable from `MatGetOwnershipRange`(mat,&rstart,&rend). One can
2208:   determine if the resulting global row associated with the local row r is owned by the requesting MPI process by applying the `ISLocalToGlobalMapping` set
2209:   with `MatSetLocalToGlobalMapping()`.

2211: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2212:           `MatSetValuesLocal()`, `MatGetValues()`
2213: @*/
2214: PetscErrorCode MatGetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], PetscScalar y[])
2215: {
2216:   PetscFunctionBeginHot;
2219:   MatCheckPreallocated(mat, 1);
2220:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to retrieve */
2221:   PetscAssertPointer(irow, 3);
2222:   PetscAssertPointer(icol, 5);
2223:   if (PetscDefined(USE_DEBUG)) {
2224:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2225:     PetscCheck(mat->ops->getvalueslocal || mat->ops->getvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2226:   }
2227:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2228:   PetscCall(PetscLogEventBegin(MAT_GetValues, mat, 0, 0, 0));
2229:   if (mat->ops->getvalueslocal) PetscUseTypeMethod(mat, getvalueslocal, nrow, irow, ncol, icol, y);
2230:   else {
2231:     PetscInt buf[8192], *bufr = NULL, *bufc = NULL, *irowm, *icolm;
2232:     if ((nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2233:       irowm = buf;
2234:       icolm = buf + nrow;
2235:     } else {
2236:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2237:       irowm = bufr;
2238:       icolm = bufc;
2239:     }
2240:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global row mapping (See MatSetLocalToGlobalMapping()).");
2241:     PetscCheck(mat->cmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MatGetValuesLocal() cannot proceed without local-to-global column mapping (See MatSetLocalToGlobalMapping()).");
2242:     PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, irowm));
2243:     PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, icolm));
2244:     PetscCall(MatGetValues(mat, nrow, irowm, ncol, icolm, y));
2245:     PetscCall(PetscFree2(bufr, bufc));
2246:   }
2247:   PetscCall(PetscLogEventEnd(MAT_GetValues, mat, 0, 0, 0));
2248:   PetscFunctionReturn(PETSC_SUCCESS);
2249: }

2251: /*@
2252:   MatSetValuesBatch - Adds (`ADD_VALUES`) many blocks of values into a matrix at once. The blocks must all be square and
2253:   the same size. Currently, this can only be called once and creates the given matrix.

2255:   Not Collective

2257:   Input Parameters:
2258: + mat  - the matrix
2259: . nb   - the number of blocks
2260: . bs   - the number of rows (and columns) in each block
2261: . rows - a concatenation of the rows for each block
2262: - v    - a concatenation of logically two-dimensional arrays of values

2264:   Level: advanced

2266:   Notes:
2267:   `MatSetPreallocationCOO()` and `MatSetValuesCOO()` may be a better way to provide the values

2269:   In the future, we will extend this routine to handle rectangular blocks, and to allow multiple calls for a given matrix.

2271: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValuesBlocked()`, `MatSetValuesLocal()`,
2272:           `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`, `MatSetValues()`, `MatSetPreallocationCOO()`, `MatSetValuesCOO()`
2273: @*/
2274: PetscErrorCode MatSetValuesBatch(Mat mat, PetscInt nb, PetscInt bs, PetscInt rows[], const PetscScalar v[])
2275: {
2276:   PetscFunctionBegin;
2279:   PetscAssertPointer(rows, 4);
2280:   PetscAssertPointer(v, 5);
2281:   PetscAssert(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

2283:   PetscCall(PetscLogEventBegin(MAT_SetValuesBatch, mat, 0, 0, 0));
2284:   if (mat->ops->setvaluesbatch) PetscUseTypeMethod(mat, setvaluesbatch, nb, bs, rows, v);
2285:   else {
2286:     for (PetscInt b = 0; b < nb; ++b) PetscCall(MatSetValues(mat, bs, &rows[b * bs], bs, &rows[b * bs], &v[b * bs * bs], ADD_VALUES));
2287:   }
2288:   PetscCall(PetscLogEventEnd(MAT_SetValuesBatch, mat, 0, 0, 0));
2289:   PetscFunctionReturn(PETSC_SUCCESS);
2290: }

2292: /*@
2293:   MatSetLocalToGlobalMapping - Sets a local-to-global numbering for use by
2294:   the routine `MatSetValuesLocal()` to allow users to insert matrix entries
2295:   using a local (per-processor) numbering.

2297:   Not Collective

2299:   Input Parameters:
2300: + x        - the matrix
2301: . rmapping - row mapping created with `ISLocalToGlobalMappingCreate()` or `ISLocalToGlobalMappingCreateIS()`
2302: - cmapping - column mapping

2304:   Level: intermediate

2306:   Note:
2307:   If the matrix is obtained with `DMCreateMatrix()` then this may already have been called on the matrix

2309: .seealso: [](ch_matrices), `Mat`, `DM`, `DMCreateMatrix()`, `MatGetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetValuesLocal()`, `MatGetValuesLocal()`
2310: @*/
2311: PetscErrorCode MatSetLocalToGlobalMapping(Mat x, ISLocalToGlobalMapping rmapping, ISLocalToGlobalMapping cmapping)
2312: {
2313:   PetscFunctionBegin;
2318:   if (x->ops->setlocaltoglobalmapping) PetscUseTypeMethod(x, setlocaltoglobalmapping, rmapping, cmapping);
2319:   else {
2320:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->rmap, rmapping));
2321:     PetscCall(PetscLayoutSetISLocalToGlobalMapping(x->cmap, cmapping));
2322:   }
2323:   PetscFunctionReturn(PETSC_SUCCESS);
2324: }

2326: /*@
2327:   MatGetLocalToGlobalMapping - Gets the local-to-global numbering set by `MatSetLocalToGlobalMapping()`

2329:   Not Collective

2331:   Input Parameter:
2332: . A - the matrix

2334:   Output Parameters:
2335: + rmapping - row mapping
2336: - cmapping - column mapping

2338:   Level: advanced

2340: .seealso: [](ch_matrices), `Mat`, `MatSetLocalToGlobalMapping()`, `MatSetValuesLocal()`
2341: @*/
2342: PetscErrorCode MatGetLocalToGlobalMapping(Mat A, ISLocalToGlobalMapping *rmapping, ISLocalToGlobalMapping *cmapping)
2343: {
2344:   PetscFunctionBegin;
2347:   if (rmapping) {
2348:     PetscAssertPointer(rmapping, 2);
2349:     *rmapping = A->rmap->mapping;
2350:   }
2351:   if (cmapping) {
2352:     PetscAssertPointer(cmapping, 3);
2353:     *cmapping = A->cmap->mapping;
2354:   }
2355:   PetscFunctionReturn(PETSC_SUCCESS);
2356: }

2358: /*@
2359:   MatSetLayouts - Sets the `PetscLayout` objects for rows and columns of a matrix

2361:   Logically Collective

2363:   Input Parameters:
2364: + A    - the matrix
2365: . rmap - row layout
2366: - cmap - column layout

2368:   Level: advanced

2370:   Note:
2371:   The `PetscLayout` objects are usually created automatically for the matrix so this routine rarely needs to be called.

2373: .seealso: [](ch_matrices), `Mat`, `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatGetLayouts()`
2374: @*/
2375: PetscErrorCode MatSetLayouts(Mat A, PetscLayout rmap, PetscLayout cmap)
2376: {
2377:   PetscFunctionBegin;
2379:   PetscCall(PetscLayoutReference(rmap, &A->rmap));
2380:   PetscCall(PetscLayoutReference(cmap, &A->cmap));
2381:   PetscFunctionReturn(PETSC_SUCCESS);
2382: }

2384: /*@
2385:   MatGetLayouts - Gets the `PetscLayout` objects for rows and columns

2387:   Not Collective

2389:   Input Parameter:
2390: . A - the matrix

2392:   Output Parameters:
2393: + rmap - row layout
2394: - cmap - column layout

2396:   Level: advanced

2398: .seealso: [](ch_matrices), `Mat`, [Matrix Layouts](sec_matlayout), `PetscLayout`, `MatCreateVecs()`, `MatGetLocalToGlobalMapping()`, `MatSetLayouts()`
2399: @*/
2400: PetscErrorCode MatGetLayouts(Mat A, PetscLayout *rmap, PetscLayout *cmap)
2401: {
2402:   PetscFunctionBegin;
2405:   if (rmap) {
2406:     PetscAssertPointer(rmap, 2);
2407:     *rmap = A->rmap;
2408:   }
2409:   if (cmap) {
2410:     PetscAssertPointer(cmap, 3);
2411:     *cmap = A->cmap;
2412:   }
2413:   PetscFunctionReturn(PETSC_SUCCESS);
2414: }

2416: /*@
2417:   MatSetValuesLocal - Inserts or adds values into certain locations of a matrix,
2418:   using a local numbering of the rows and columns.

2420:   Not Collective

2422:   Input Parameters:
2423: + mat  - the matrix
2424: . nrow - number of rows
2425: . irow - the row local indices
2426: . ncol - number of columns
2427: . icol - the column local indices
2428: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2429:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2430: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2432:   Level: intermediate

2434:   Notes:
2435:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine

2437:   Calls to `MatSetValuesLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2438:   options cannot be mixed without intervening calls to the assembly
2439:   routines.

2441:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2442:   MUST be called after all calls to `MatSetValuesLocal()` have been completed.

2444:   Fortran Notes:
2445:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2446: .vb
2447:   call MatSetValuesLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2448: .ve

2450:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2452: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
2453:           `MatGetValuesLocal()`
2454: @*/
2455: PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2456: {
2457:   PetscFunctionBeginHot;
2460:   MatCheckPreallocated(mat, 1);
2461:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2462:   PetscAssertPointer(irow, 3);
2463:   PetscAssertPointer(icol, 5);
2464:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2465:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2466:   if (PetscDefined(USE_DEBUG)) {
2467:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2468:     PetscCheck(mat->ops->setvalueslocal || mat->ops->setvalues, PETSC_COMM_SELF, PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2469:   }

2471:   if (mat->assembled) {
2472:     mat->was_assembled = PETSC_TRUE;
2473:     mat->assembled     = PETSC_FALSE;
2474:   }
2475:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2476:   if (mat->ops->setvalueslocal) PetscUseTypeMethod(mat, setvalueslocal, nrow, irow, ncol, icol, y, addv);
2477:   else {
2478:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2479:     const PetscInt *irowm, *icolm;

2481:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= (PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf)) {
2482:       bufr  = buf;
2483:       bufc  = buf + nrow;
2484:       irowm = bufr;
2485:       icolm = bufc;
2486:     } else {
2487:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2488:       irowm = bufr;
2489:       icolm = bufc;
2490:     }
2491:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApply(mat->rmap->mapping, nrow, irow, bufr));
2492:     else irowm = irow;
2493:     if (mat->cmap->mapping) {
2494:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApply(mat->cmap->mapping, ncol, icol, bufc));
2495:       else icolm = irowm;
2496:     } else icolm = icol;
2497:     PetscCall(MatSetValues(mat, nrow, irowm, ncol, icolm, y, addv));
2498:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2499:   }
2500:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2501:   PetscFunctionReturn(PETSC_SUCCESS);
2502: }

2504: /*@
2505:   MatSetValuesBlockedLocal - Inserts or adds values into certain locations of a matrix,
2506:   using a local ordering of the nodes a block at a time.

2508:   Not Collective

2510:   Input Parameters:
2511: + mat  - the matrix
2512: . nrow - number of rows
2513: . irow - the row local indices
2514: . ncol - number of columns
2515: . icol - the column local indices
2516: . y    - a one-dimensional array that contains the values implicitly stored as a two-dimensional array, by default in row-major order.
2517:          See `MAT_ROW_ORIENTED` in `MatSetOption()` for how to use column-major order.
2518: - addv - either `ADD_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values

2520:   Level: intermediate

2522:   Notes:
2523:   If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetBlockSize()` and `MatSetLocalToGlobalMapping()`
2524:   before using this routineBefore calling `MatSetValuesLocal()`, the user must first set the

2526:   Calls to `MatSetValuesBlockedLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
2527:   options cannot be mixed without intervening calls to the assembly
2528:   routines.

2530:   These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
2531:   MUST be called after all calls to `MatSetValuesBlockedLocal()` have been completed.

2533:   Fortran Notes:
2534:   If any of `irow`, `icol`, and `y` are scalars pass them using, for example,
2535: .vb
2536:   call MatSetValuesBlockedLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES, ierr)
2537: .ve

2539:   If `y` is a two-dimensional array use `reshape()` to pass it as a one dimensional array

2541: .seealso: [](ch_matrices), `Mat`, `MatSetBlockSize()`, `MatSetLocalToGlobalMapping()`, `MatAssemblyBegin()`, `MatAssemblyEnd()`,
2542:           `MatSetValuesLocal()`, `MatSetValuesBlocked()`
2543: @*/
2544: PetscErrorCode MatSetValuesBlockedLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
2545: {
2546:   PetscFunctionBeginHot;
2549:   MatCheckPreallocated(mat, 1);
2550:   if (!nrow || !ncol) PetscFunctionReturn(PETSC_SUCCESS); /* no values to insert */
2551:   PetscAssertPointer(irow, 3);
2552:   PetscAssertPointer(icol, 5);
2553:   if (mat->insertmode == NOT_SET_VALUES) mat->insertmode = addv;
2554:   else PetscCheck(mat->insertmode == addv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot mix add values and insert values");
2555:   if (PetscDefined(USE_DEBUG)) {
2556:     PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2557:     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);
2558:   }

2560:   if (mat->assembled) {
2561:     mat->was_assembled = PETSC_TRUE;
2562:     mat->assembled     = PETSC_FALSE;
2563:   }
2564:   if (PetscUnlikelyDebug(mat->rmap->mapping)) { /* Condition on the mapping existing, because MatSetValuesBlockedLocal_IS does not require it to be set. */
2565:     PetscInt irbs, rbs;
2566:     PetscCall(MatGetBlockSizes(mat, &rbs, NULL));
2567:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->rmap->mapping, &irbs));
2568:     PetscCheck(rbs == irbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different row block sizes! mat %" PetscInt_FMT ", row l2g map %" PetscInt_FMT, rbs, irbs);
2569:   }
2570:   if (PetscUnlikelyDebug(mat->cmap->mapping)) {
2571:     PetscInt icbs, cbs;
2572:     PetscCall(MatGetBlockSizes(mat, NULL, &cbs));
2573:     PetscCall(ISLocalToGlobalMappingGetBlockSize(mat->cmap->mapping, &icbs));
2574:     PetscCheck(cbs == icbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Different col block sizes! mat %" PetscInt_FMT ", col l2g map %" PetscInt_FMT, cbs, icbs);
2575:   }
2576:   PetscCall(PetscLogEventBegin(MAT_SetValues, mat, 0, 0, 0));
2577:   if (mat->ops->setvaluesblockedlocal) PetscUseTypeMethod(mat, setvaluesblockedlocal, nrow, irow, ncol, icol, y, addv);
2578:   else {
2579:     PetscInt        buf[8192], *bufr = NULL, *bufc = NULL;
2580:     const PetscInt *irowm, *icolm;

2582:     if ((!mat->rmap->mapping && !mat->cmap->mapping) || (nrow + ncol) <= ((PetscInt)PETSC_STATIC_ARRAY_LENGTH(buf))) {
2583:       bufr  = buf;
2584:       bufc  = buf + nrow;
2585:       irowm = bufr;
2586:       icolm = bufc;
2587:     } else {
2588:       PetscCall(PetscMalloc2(nrow, &bufr, ncol, &bufc));
2589:       irowm = bufr;
2590:       icolm = bufc;
2591:     }
2592:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->rmap->mapping, nrow, irow, bufr));
2593:     else irowm = irow;
2594:     if (mat->cmap->mapping) {
2595:       if (mat->cmap->mapping != mat->rmap->mapping || ncol != nrow || icol != irow) PetscCall(ISLocalToGlobalMappingApplyBlock(mat->cmap->mapping, ncol, icol, bufc));
2596:       else icolm = irowm;
2597:     } else icolm = icol;
2598:     PetscCall(MatSetValuesBlocked(mat, nrow, irowm, ncol, icolm, y, addv));
2599:     if (bufr != buf) PetscCall(PetscFree2(bufr, bufc));
2600:   }
2601:   PetscCall(PetscLogEventEnd(MAT_SetValues, mat, 0, 0, 0));
2602:   PetscFunctionReturn(PETSC_SUCCESS);
2603: }

2605: /*@
2606:   MatMultDiagonalBlock - Computes the matrix-vector product, $y = Dx$. Where `D` is defined by the inode or block structure of the diagonal

2608:   Collective

2610:   Input Parameters:
2611: + mat - the matrix
2612: - x   - the vector to be multiplied

2614:   Output Parameter:
2615: . y - the result

2617:   Level: developer

2619:   Note:
2620:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2621:   call `MatMultDiagonalBlock`(A,y,y).

2623: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2624: @*/
2625: PetscErrorCode MatMultDiagonalBlock(Mat mat, Vec x, Vec y)
2626: {
2627:   PetscFunctionBegin;

2633:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2634:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2635:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2636:   MatCheckPreallocated(mat, 1);

2638:   PetscUseTypeMethod(mat, multdiagonalblock, x, y);
2639:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2640:   PetscFunctionReturn(PETSC_SUCCESS);
2641: }

2643: /*@
2644:   MatMult - Computes the matrix-vector product, $y = Ax$.

2646:   Neighbor-wise Collective

2648:   Input Parameters:
2649: + mat - the matrix
2650: - x   - the vector to be multiplied

2652:   Output Parameter:
2653: . y - the result

2655:   Level: beginner

2657:   Note:
2658:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2659:   call `MatMult`(A,y,y).

2661: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
2662: @*/
2663: PetscErrorCode MatMult(Mat mat, Vec x, Vec y)
2664: {
2665:   PetscFunctionBegin;
2669:   VecCheckAssembled(x);
2671:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2672:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2673:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2674:   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);
2675:   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);
2676:   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);
2677:   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);
2678:   PetscCall(VecSetErrorIfLocked(y, 3));
2679:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2680:   MatCheckPreallocated(mat, 1);

2682:   PetscCall(VecLockReadPush(x));
2683:   PetscCall(PetscLogEventBegin(MAT_Mult, mat, x, y, 0));
2684:   PetscUseTypeMethod(mat, mult, x, y);
2685:   PetscCall(PetscLogEventEnd(MAT_Mult, mat, x, y, 0));
2686:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2687:   PetscCall(VecLockReadPop(x));
2688:   PetscFunctionReturn(PETSC_SUCCESS);
2689: }

2691: /*@
2692:   MatMultTranspose - Computes matrix transpose times a vector $y = A^T * x$.

2694:   Neighbor-wise Collective

2696:   Input Parameters:
2697: + mat - the matrix
2698: - x   - the vector to be multiplied

2700:   Output Parameter:
2701: . y - the result

2703:   Level: beginner

2705:   Notes:
2706:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2707:   call `MatMultTranspose`(A,y,y).

2709:   For complex numbers this does NOT compute the Hermitian (complex conjugate) transpose multiple,
2710:   use `MatMultHermitianTranspose()`

2712: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatMultHermitianTranspose()`, `MatTranspose()`
2713: @*/
2714: PetscErrorCode MatMultTranspose(Mat mat, Vec x, Vec y)
2715: {
2716:   PetscErrorCode (*op)(Mat, Vec, Vec) = NULL;

2718:   PetscFunctionBegin;
2722:   VecCheckAssembled(x);

2725:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2726:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2727:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2728:   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);
2729:   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);
2730:   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);
2731:   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);
2732:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2733:   MatCheckPreallocated(mat, 1);

2735:   if (!mat->ops->multtranspose) {
2736:     if (mat->symmetric == PETSC_BOOL3_TRUE && mat->ops->mult) op = mat->ops->mult;
2737:     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);
2738:   } else op = mat->ops->multtranspose;
2739:   PetscCall(PetscLogEventBegin(MAT_MultTranspose, mat, x, y, 0));
2740:   PetscCall(VecLockReadPush(x));
2741:   PetscCall((*op)(mat, x, y));
2742:   PetscCall(VecLockReadPop(x));
2743:   PetscCall(PetscLogEventEnd(MAT_MultTranspose, mat, x, y, 0));
2744:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2745:   if (mat->erroriffailure) PetscCall(VecValidValues_Internal(y, 3, PETSC_FALSE));
2746:   PetscFunctionReturn(PETSC_SUCCESS);
2747: }

2749: /*@
2750:   MatMultHermitianTranspose - Computes matrix Hermitian-transpose times a vector $y = A^H * x$.

2752:   Neighbor-wise Collective

2754:   Input Parameters:
2755: + mat - the matrix
2756: - x   - the vector to be multiplied

2758:   Output Parameter:
2759: . y - the result

2761:   Level: beginner

2763:   Notes:
2764:   The vectors `x` and `y` cannot be the same.  I.e., one cannot
2765:   call `MatMultHermitianTranspose`(A,y,y).

2767:   Also called the conjugate transpose, complex conjugate transpose, or adjoint.

2769:   For real numbers `MatMultTranspose()` and `MatMultHermitianTranspose()` are identical.

2771: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `MatMultHermitianTransposeAdd()`, `MatMultTranspose()`
2772: @*/
2773: PetscErrorCode MatMultHermitianTranspose(Mat mat, Vec x, Vec y)
2774: {
2775:   PetscFunctionBegin;

2781:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2782:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2783:   PetscCheck(x != y, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "x and y must be different vectors");
2784:   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);
2785:   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);
2786:   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);
2787:   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);
2788:   MatCheckPreallocated(mat, 1);

2790:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTranspose, mat, x, y, 0));
2791: #if defined(PETSC_USE_COMPLEX)
2792:   if (mat->ops->multhermitiantranspose || (mat->hermitian == PETSC_BOOL3_TRUE && mat->ops->mult)) {
2793:     PetscCall(VecLockReadPush(x));
2794:     if (mat->ops->multhermitiantranspose) PetscUseTypeMethod(mat, multhermitiantranspose, x, y);
2795:     else PetscUseTypeMethod(mat, mult, x, y);
2796:     PetscCall(VecLockReadPop(x));
2797:   } else {
2798:     Vec w;
2799:     PetscCall(VecDuplicate(x, &w));
2800:     PetscCall(VecCopy(x, w));
2801:     PetscCall(VecConjugate(w));
2802:     PetscCall(MatMultTranspose(mat, w, y));
2803:     PetscCall(VecDestroy(&w));
2804:     PetscCall(VecConjugate(y));
2805:   }
2806:   PetscCall(PetscObjectStateIncrease((PetscObject)y));
2807: #else
2808:   PetscCall(MatMultTranspose(mat, x, y));
2809: #endif
2810:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTranspose, mat, x, y, 0));
2811:   PetscFunctionReturn(PETSC_SUCCESS);
2812: }

2814: /*@
2815:   MatMultAdd -  Computes $v3 = v2 + A * v1$.

2817:   Neighbor-wise Collective

2819:   Input Parameters:
2820: + mat - the matrix
2821: . v1  - the vector to be multiplied by `mat`
2822: - v2  - the vector to be added to the result

2824:   Output Parameter:
2825: . v3 - the result

2827:   Level: beginner

2829:   Note:
2830:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2831:   call `MatMultAdd`(A,v1,v2,v1).

2833: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMult()`, `MatMultTransposeAdd()`
2834: @*/
2835: PetscErrorCode MatMultAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2836: {
2837:   PetscFunctionBegin;

2844:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2845:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2846:   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);
2847:   /* 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);
2848:      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); */
2849:   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);
2850:   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);
2851:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2852:   MatCheckPreallocated(mat, 1);

2854:   PetscCall(PetscLogEventBegin(MAT_MultAdd, mat, v1, v2, v3));
2855:   PetscCall(VecLockReadPush(v1));
2856:   PetscUseTypeMethod(mat, multadd, v1, v2, v3);
2857:   PetscCall(VecLockReadPop(v1));
2858:   PetscCall(PetscLogEventEnd(MAT_MultAdd, mat, v1, v2, v3));
2859:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2860:   PetscFunctionReturn(PETSC_SUCCESS);
2861: }

2863: /*@
2864:   MatMultTransposeAdd - Computes $v3 = v2 + A^T * v1$.

2866:   Neighbor-wise Collective

2868:   Input Parameters:
2869: + mat - the matrix
2870: . v1  - the vector to be multiplied by the transpose of the matrix
2871: - v2  - the vector to be added to the result

2873:   Output Parameter:
2874: . v3 - the result

2876:   Level: beginner

2878:   Note:
2879:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2880:   call `MatMultTransposeAdd`(A,v1,v2,v1).

2882: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2883: @*/
2884: PetscErrorCode MatMultTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2885: {
2886:   PetscErrorCode (*op)(Mat, Vec, Vec, Vec) = (!mat->ops->multtransposeadd && mat->symmetric) ? mat->ops->multadd : mat->ops->multtransposeadd;

2888:   PetscFunctionBegin;

2895:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2896:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2897:   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);
2898:   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);
2899:   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);
2900:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2901:   PetscCheck(op, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)mat)->type_name);
2902:   MatCheckPreallocated(mat, 1);

2904:   PetscCall(PetscLogEventBegin(MAT_MultTransposeAdd, mat, v1, v2, v3));
2905:   PetscCall(VecLockReadPush(v1));
2906:   PetscCall((*op)(mat, v1, v2, v3));
2907:   PetscCall(VecLockReadPop(v1));
2908:   PetscCall(PetscLogEventEnd(MAT_MultTransposeAdd, mat, v1, v2, v3));
2909:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2910:   PetscFunctionReturn(PETSC_SUCCESS);
2911: }

2913: /*@
2914:   MatMultHermitianTransposeAdd - Computes $v3 = v2 + A^H * v1$.

2916:   Neighbor-wise Collective

2918:   Input Parameters:
2919: + mat - the matrix
2920: . v1  - the vector to be multiplied by the Hermitian transpose
2921: - v2  - the vector to be added to the result

2923:   Output Parameter:
2924: . v3 - the result

2926:   Level: beginner

2928:   Note:
2929:   The vectors `v1` and `v3` cannot be the same.  I.e., one cannot
2930:   call `MatMultHermitianTransposeAdd`(A,v1,v2,v1).

2932: .seealso: [](ch_matrices), `Mat`, `MatMultHermitianTranspose()`, `MatMultTranspose()`, `MatMultAdd()`, `MatMult()`
2933: @*/
2934: PetscErrorCode MatMultHermitianTransposeAdd(Mat mat, Vec v1, Vec v2, Vec v3)
2935: {
2936:   PetscFunctionBegin;

2943:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
2944:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2945:   PetscCheck(v1 != v3, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "v1 and v3 must be different vectors");
2946:   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);
2947:   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);
2948:   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);
2949:   MatCheckPreallocated(mat, 1);

2951:   PetscCall(PetscLogEventBegin(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2952:   PetscCall(VecLockReadPush(v1));
2953:   if (mat->ops->multhermitiantransposeadd) PetscUseTypeMethod(mat, multhermitiantransposeadd, v1, v2, v3);
2954:   else {
2955:     Vec w, z;
2956:     PetscCall(VecDuplicate(v1, &w));
2957:     PetscCall(VecCopy(v1, w));
2958:     PetscCall(VecConjugate(w));
2959:     PetscCall(VecDuplicate(v3, &z));
2960:     PetscCall(MatMultTranspose(mat, w, z));
2961:     PetscCall(VecDestroy(&w));
2962:     PetscCall(VecConjugate(z));
2963:     if (v2 != v3) {
2964:       PetscCall(VecWAXPY(v3, 1.0, v2, z));
2965:     } else {
2966:       PetscCall(VecAXPY(v3, 1.0, z));
2967:     }
2968:     PetscCall(VecDestroy(&z));
2969:   }
2970:   PetscCall(VecLockReadPop(v1));
2971:   PetscCall(PetscLogEventEnd(MAT_MultHermitianTransposeAdd, mat, v1, v2, v3));
2972:   PetscCall(PetscObjectStateIncrease((PetscObject)v3));
2973:   PetscFunctionReturn(PETSC_SUCCESS);
2974: }

2976: /*@
2977:   MatGetFactorType - gets the type of factorization a matrix is

2979:   Not Collective

2981:   Input Parameter:
2982: . mat - the matrix

2984:   Output Parameter:
2985: . 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`

2987:   Level: intermediate

2989: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatSetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
2990:           `MAT_FACTOR_ICC`,`MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
2991: @*/
2992: PetscErrorCode MatGetFactorType(Mat mat, MatFactorType *t)
2993: {
2994:   PetscFunctionBegin;
2997:   PetscAssertPointer(t, 2);
2998:   *t = mat->factortype;
2999:   PetscFunctionReturn(PETSC_SUCCESS);
3000: }

3002: /*@
3003:   MatSetFactorType - sets the type of factorization a matrix is

3005:   Logically Collective

3007:   Input Parameters:
3008: + mat - the matrix
3009: - 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`

3011:   Level: intermediate

3013: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatGetFactor()`, `MatGetFactorType()`, `MAT_FACTOR_NONE`, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ILU`,
3014:           `MAT_FACTOR_ICC`,`MAT_FACTOR_ILUDT`, `MAT_FACTOR_QR`
3015: @*/
3016: PetscErrorCode MatSetFactorType(Mat mat, MatFactorType t)
3017: {
3018:   PetscFunctionBegin;
3021:   mat->factortype = t;
3022:   PetscFunctionReturn(PETSC_SUCCESS);
3023: }

3025: /*@
3026:   MatGetInfo - Returns information about matrix storage (number of
3027:   nonzeros, memory, etc.).

3029:   Collective if `MAT_GLOBAL_MAX` or `MAT_GLOBAL_SUM` is used as the flag

3031:   Input Parameters:
3032: + mat  - the matrix
3033: - 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)

3035:   Output Parameter:
3036: . info - matrix information context

3038:   Options Database Key:
3039: . -mat_view ::ascii_info - print matrix info to `PETSC_STDOUT`

3041:   Level: intermediate

3043:   Notes:
3044:   The `MatInfo` context contains a variety of matrix data, including
3045:   number of nonzeros allocated and used, number of mallocs during
3046:   matrix assembly, etc.  Additional information for factored matrices
3047:   is provided (such as the fill ratio, number of mallocs during
3048:   factorization, etc.).

3050:   Example:
3051:   See the file ${PETSC_DIR}/include/petscmat.h for a complete list of
3052:   data within the `MatInfo` context.  For example,
3053: .vb
3054:       MatInfo info;
3055:       Mat     A;
3056:       double  mal, nz_a, nz_u;

3058:       MatGetInfo(A, MAT_LOCAL, &info);
3059:       mal  = info.mallocs;
3060:       nz_a = info.nz_allocated;
3061: .ve

3063: .seealso: [](ch_matrices), `Mat`, `MatInfo`, `MatStashGetInfo()`
3064: @*/
3065: PetscErrorCode MatGetInfo(Mat mat, MatInfoType flag, MatInfo *info)
3066: {
3067:   PetscFunctionBegin;
3070:   PetscAssertPointer(info, 3);
3071:   MatCheckPreallocated(mat, 1);
3072:   PetscUseTypeMethod(mat, getinfo, flag, info);
3073:   PetscFunctionReturn(PETSC_SUCCESS);
3074: }

3076: /*
3077:    This is used by external packages where it is not easy to get the info from the actual
3078:    matrix factorization.
3079: */
3080: PetscErrorCode MatGetInfo_External(Mat A, MatInfoType flag, MatInfo *info)
3081: {
3082:   PetscFunctionBegin;
3083:   PetscCall(PetscMemzero(info, sizeof(MatInfo)));
3084:   PetscFunctionReturn(PETSC_SUCCESS);
3085: }

3087: /*@
3088:   MatLUFactor - Performs in-place LU factorization of matrix.

3090:   Collective

3092:   Input Parameters:
3093: + mat  - the matrix
3094: . row  - row permutation
3095: . col  - column permutation
3096: - info - options for factorization, includes
3097: .vb
3098:           fill - expected fill as ratio of original fill.
3099:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3100:                    Run with the option -info to determine an optimal value to use
3101: .ve

3103:   Level: developer

3105:   Notes:
3106:   Most users should employ the `KSP` interface for linear solvers
3107:   instead of working directly with matrix algebra routines such as this.
3108:   See, e.g., `KSPCreate()`.

3110:   This changes the state of the matrix to a factored matrix; it cannot be used
3111:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3113:   This is really in-place only for dense matrices, the preferred approach is to use `MatGetFactor()`, `MatLUFactorSymbolic()`, and `MatLUFactorNumeric()`
3114:   when not using `KSP`.

3116:   Fortran Note:
3117:   A valid (non-null) `info` argument must be provided

3119: .seealso: [](ch_matrices), [Matrix Factorization](sec_matfactor), `Mat`, `MatFactorType`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`,
3120:           `MatGetOrdering()`, `MatSetUnfactored()`, `MatFactorInfo`, `MatGetFactor()`
3121: @*/
3122: PetscErrorCode MatLUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3123: {
3124:   MatFactorInfo tinfo;

3126:   PetscFunctionBegin;
3130:   if (info) PetscAssertPointer(info, 4);
3132:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3133:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3134:   MatCheckPreallocated(mat, 1);
3135:   if (!info) {
3136:     PetscCall(MatFactorInfoInitialize(&tinfo));
3137:     info = &tinfo;
3138:   }

3140:   PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, row, col, 0));
3141:   PetscUseTypeMethod(mat, lufactor, row, col, info);
3142:   PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, row, col, 0));
3143:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3144:   PetscFunctionReturn(PETSC_SUCCESS);
3145: }

3147: /*@
3148:   MatILUFactor - Performs in-place ILU factorization of matrix.

3150:   Collective

3152:   Input Parameters:
3153: + mat  - the matrix
3154: . row  - row permutation
3155: . col  - column permutation
3156: - info - structure containing
3157: .vb
3158:       levels - number of levels of fill.
3159:       expected fill - as ratio of original fill.
3160:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
3161:                 missing diagonal entries)
3162: .ve

3164:   Level: developer

3166:   Notes:
3167:   Most users should employ the `KSP` interface for linear solvers
3168:   instead of working directly with matrix algebra routines such as this.
3169:   See, e.g., `KSPCreate()`.

3171:   Probably really in-place only when level of fill is zero, otherwise allocates
3172:   new space to store factored matrix and deletes previous memory. The preferred approach is to use `MatGetFactor()`, `MatILUFactorSymbolic()`, and `MatILUFactorNumeric()`
3173:   when not using `KSP`.

3175:   Fortran Note:
3176:   A valid (non-null) `info` argument must be provided

3178: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatILUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
3179: @*/
3180: PetscErrorCode MatILUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)
3181: {
3182:   PetscFunctionBegin;
3186:   PetscAssertPointer(info, 4);
3188:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
3189:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3190:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3191:   MatCheckPreallocated(mat, 1);

3193:   PetscCall(PetscLogEventBegin(MAT_ILUFactor, mat, row, col, 0));
3194:   PetscUseTypeMethod(mat, ilufactor, row, col, info);
3195:   PetscCall(PetscLogEventEnd(MAT_ILUFactor, mat, row, col, 0));
3196:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3197:   PetscFunctionReturn(PETSC_SUCCESS);
3198: }

3200: /*@
3201:   MatLUFactorSymbolic - Performs symbolic LU factorization of matrix.
3202:   Call this routine before calling `MatLUFactorNumeric()` and after `MatGetFactor()`.

3204:   Collective

3206:   Input Parameters:
3207: + fact - the factor matrix obtained with `MatGetFactor()`
3208: . mat  - the matrix
3209: . row  - the row permutation
3210: . col  - the column permutation
3211: - info - options for factorization, includes
3212: .vb
3213:           fill - expected fill as ratio of original fill. Run with the option -info to determine an optimal value to use
3214:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3215: .ve

3217:   Level: developer

3219:   Notes:
3220:   See [Matrix Factorization](sec_matfactor) for additional information about factorizations

3222:   Most users should employ the simplified `KSP` interface for linear solvers
3223:   instead of working directly with matrix algebra routines such as this.
3224:   See, e.g., `KSPCreate()`.

3226:   Fortran Note:
3227:   A valid (non-null) `info` argument must be provided

3229: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`, `MatFactorInfoInitialize()`
3230: @*/
3231: PetscErrorCode MatLUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
3232: {
3233:   MatFactorInfo tinfo;

3235:   PetscFunctionBegin;
3240:   if (info) PetscAssertPointer(info, 5);
3243:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3244:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3245:   MatCheckPreallocated(mat, 2);
3246:   if (!info) {
3247:     PetscCall(MatFactorInfoInitialize(&tinfo));
3248:     info = &tinfo;
3249:   }

3251:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorSymbolic, mat, row, col, 0));
3252:   PetscUseTypeMethod(fact, lufactorsymbolic, mat, row, col, info);
3253:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorSymbolic, mat, row, col, 0));
3254:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3255:   PetscFunctionReturn(PETSC_SUCCESS);
3256: }

3258: /*@
3259:   MatLUFactorNumeric - Performs numeric LU factorization of a matrix.
3260:   Call this routine after first calling `MatLUFactorSymbolic()` and `MatGetFactor()`.

3262:   Collective

3264:   Input Parameters:
3265: + fact - the factor matrix obtained with `MatGetFactor()`
3266: . mat  - the matrix
3267: - info - options for factorization

3269:   Level: developer

3271:   Notes:
3272:   See `MatLUFactor()` for in-place factorization.  See
3273:   `MatCholeskyFactorNumeric()` for the symmetric, positive definite case.

3275:   Most users should employ the `KSP` interface for linear solvers
3276:   instead of working directly with matrix algebra routines such as this.
3277:   See, e.g., `KSPCreate()`.

3279:   Fortran Note:
3280:   A valid (non-null) `info` argument must be provided

3282: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactorSymbolic()`, `MatLUFactor()`, `MatCholeskyFactor()`
3283: @*/
3284: PetscErrorCode MatLUFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3285: {
3286:   MatFactorInfo tinfo;

3288:   PetscFunctionBegin;
3293:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3294:   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,
3295:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3297:   MatCheckPreallocated(mat, 2);
3298:   if (!info) {
3299:     PetscCall(MatFactorInfoInitialize(&tinfo));
3300:     info = &tinfo;
3301:   }

3303:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_LUFactorNumeric, mat, fact, 0, 0));
3304:   else PetscCall(PetscLogEventBegin(MAT_LUFactor, mat, fact, 0, 0));
3305:   PetscUseTypeMethod(fact, lufactornumeric, mat, info);
3306:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_LUFactorNumeric, mat, fact, 0, 0));
3307:   else PetscCall(PetscLogEventEnd(MAT_LUFactor, mat, fact, 0, 0));
3308:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3309:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3310:   PetscFunctionReturn(PETSC_SUCCESS);
3311: }

3313: /*@
3314:   MatCholeskyFactor - Performs in-place Cholesky factorization of a
3315:   symmetric matrix.

3317:   Collective

3319:   Input Parameters:
3320: + mat  - the matrix
3321: . perm - row and column permutations
3322: - info - expected fill as ratio of original fill

3324:   Level: developer

3326:   Notes:
3327:   See `MatLUFactor()` for the nonsymmetric case.  See also `MatGetFactor()`,
3328:   `MatCholeskyFactorSymbolic()`, and `MatCholeskyFactorNumeric()`.

3330:   Most users should employ the `KSP` interface for linear solvers
3331:   instead of working directly with matrix algebra routines such as this.
3332:   See, e.g., `KSPCreate()`.

3334:   Fortran Note:
3335:   A valid (non-null) `info` argument must be provided

3337: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatLUFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactorNumeric()`
3338:           `MatGetOrdering()`
3339: @*/
3340: PetscErrorCode MatCholeskyFactor(Mat mat, IS perm, const MatFactorInfo *info)
3341: {
3342:   MatFactorInfo tinfo;

3344:   PetscFunctionBegin;
3347:   if (info) PetscAssertPointer(info, 3);
3349:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3350:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3351:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3352:   MatCheckPreallocated(mat, 1);
3353:   if (!info) {
3354:     PetscCall(MatFactorInfoInitialize(&tinfo));
3355:     info = &tinfo;
3356:   }

3358:   PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, perm, 0, 0));
3359:   PetscUseTypeMethod(mat, choleskyfactor, perm, info);
3360:   PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, perm, 0, 0));
3361:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3362:   PetscFunctionReturn(PETSC_SUCCESS);
3363: }

3365: /*@
3366:   MatCholeskyFactorSymbolic - Performs symbolic Cholesky factorization
3367:   of a symmetric matrix.

3369:   Collective

3371:   Input Parameters:
3372: + fact - the factor matrix obtained with `MatGetFactor()`
3373: . mat  - the matrix
3374: . perm - row and column permutations
3375: - info - options for factorization, includes
3376: .vb
3377:           fill - expected fill as ratio of original fill.
3378:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3379:                    Run with the option -info to determine an optimal value to use
3380: .ve

3382:   Level: developer

3384:   Notes:
3385:   See `MatLUFactorSymbolic()` for the nonsymmetric case.  See also
3386:   `MatCholeskyFactor()` and `MatCholeskyFactorNumeric()`.

3388:   Most users should employ the `KSP` interface for linear solvers
3389:   instead of working directly with matrix algebra routines such as this.
3390:   See, e.g., `KSPCreate()`.

3392:   Fortran Note:
3393:   A valid (non-null) `info` argument must be provided

3395: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactor()`, `MatCholeskyFactorNumeric()`
3396:           `MatGetOrdering()`
3397: @*/
3398: PetscErrorCode MatCholeskyFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
3399: {
3400:   MatFactorInfo tinfo;

3402:   PetscFunctionBegin;
3406:   if (info) PetscAssertPointer(info, 4);
3409:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "Matrix must be square");
3410:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3411:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3412:   MatCheckPreallocated(mat, 2);
3413:   if (!info) {
3414:     PetscCall(MatFactorInfoInitialize(&tinfo));
3415:     info = &tinfo;
3416:   }

3418:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3419:   PetscUseTypeMethod(fact, choleskyfactorsymbolic, mat, perm, info);
3420:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorSymbolic, mat, perm, 0, 0));
3421:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3422:   PetscFunctionReturn(PETSC_SUCCESS);
3423: }

3425: /*@
3426:   MatCholeskyFactorNumeric - Performs numeric Cholesky factorization
3427:   of a symmetric matrix. Call this routine after first calling `MatGetFactor()` and
3428:   `MatCholeskyFactorSymbolic()`.

3430:   Collective

3432:   Input Parameters:
3433: + fact - the factor matrix obtained with `MatGetFactor()`, where the factored values are stored
3434: . mat  - the initial matrix that is to be factored
3435: - info - options for factorization

3437:   Level: developer

3439:   Note:
3440:   Most users should employ the `KSP` interface for linear solvers
3441:   instead of working directly with matrix algebra routines such as this.
3442:   See, e.g., `KSPCreate()`.

3444:   Fortran Note:
3445:   A valid (non-null) `info` argument must be provided

3447: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatCholeskyFactorSymbolic()`, `MatCholeskyFactor()`, `MatLUFactorNumeric()`
3448: @*/
3449: PetscErrorCode MatCholeskyFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3450: {
3451:   MatFactorInfo tinfo;

3453:   PetscFunctionBegin;
3458:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3459:   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,
3460:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);
3461:   MatCheckPreallocated(mat, 2);
3462:   if (!info) {
3463:     PetscCall(MatFactorInfoInitialize(&tinfo));
3464:     info = &tinfo;
3465:   }

3467:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3468:   else PetscCall(PetscLogEventBegin(MAT_CholeskyFactor, mat, fact, 0, 0));
3469:   PetscUseTypeMethod(fact, choleskyfactornumeric, mat, info);
3470:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_CholeskyFactorNumeric, mat, fact, 0, 0));
3471:   else PetscCall(PetscLogEventEnd(MAT_CholeskyFactor, mat, fact, 0, 0));
3472:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3473:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3474:   PetscFunctionReturn(PETSC_SUCCESS);
3475: }

3477: /*@
3478:   MatQRFactor - Performs in-place QR factorization of matrix.

3480:   Collective

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

3492:   Level: developer

3494:   Notes:
3495:   Most users should employ the `KSP` interface for linear solvers
3496:   instead of working directly with matrix algebra routines such as this.
3497:   See, e.g., `KSPCreate()`.

3499:   This changes the state of the matrix to a factored matrix; it cannot be used
3500:   for example with `MatSetValues()` unless one first calls `MatSetUnfactored()`.

3502:   Fortran Note:
3503:   A valid (non-null) `info` argument must be provided

3505: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactorSymbolic()`, `MatQRFactorNumeric()`, `MatLUFactor()`,
3506:           `MatSetUnfactored()`
3507: @*/
3508: PetscErrorCode MatQRFactor(Mat mat, IS col, const MatFactorInfo *info)
3509: {
3510:   PetscFunctionBegin;
3513:   if (info) PetscAssertPointer(info, 3);
3515:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3516:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3517:   MatCheckPreallocated(mat, 1);
3518:   PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, col, 0, 0));
3519:   PetscUseMethod(mat, "MatQRFactor_C", (Mat, IS, const MatFactorInfo *), (mat, col, info));
3520:   PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, col, 0, 0));
3521:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
3522:   PetscFunctionReturn(PETSC_SUCCESS);
3523: }

3525: /*@
3526:   MatQRFactorSymbolic - Performs symbolic QR factorization of matrix.
3527:   Call this routine after `MatGetFactor()` but before calling `MatQRFactorNumeric()`.

3529:   Collective

3531:   Input Parameters:
3532: + fact - the factor matrix obtained with `MatGetFactor()`
3533: . mat  - the matrix
3534: . col  - column permutation
3535: - info - options for factorization, includes
3536: .vb
3537:           fill - expected fill as ratio of original fill.
3538:           dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
3539:                    Run with the option -info to determine an optimal value to use
3540: .ve

3542:   Level: developer

3544:   Note:
3545:   Most users should employ the `KSP` interface for linear solvers
3546:   instead of working directly with matrix algebra routines such as this.
3547:   See, e.g., `KSPCreate()`.

3549:   Fortran Note:
3550:   A valid (non-null) `info` argument must be provided

3552: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatFactorInfo`, `MatQRFactor()`, `MatQRFactorNumeric()`, `MatLUFactor()`, `MatFactorInfoInitialize()`
3553: @*/
3554: PetscErrorCode MatQRFactorSymbolic(Mat fact, Mat mat, IS col, const MatFactorInfo *info)
3555: {
3556:   MatFactorInfo tinfo;

3558:   PetscFunctionBegin;
3562:   if (info) PetscAssertPointer(info, 4);
3565:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3566:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3567:   MatCheckPreallocated(mat, 2);
3568:   if (!info) {
3569:     PetscCall(MatFactorInfoInitialize(&tinfo));
3570:     info = &tinfo;
3571:   }

3573:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorSymbolic, fact, mat, col, 0));
3574:   PetscUseMethod(fact, "MatQRFactorSymbolic_C", (Mat, Mat, IS, const MatFactorInfo *), (fact, mat, col, info));
3575:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorSymbolic, fact, mat, col, 0));
3576:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3577:   PetscFunctionReturn(PETSC_SUCCESS);
3578: }

3580: /*@
3581:   MatQRFactorNumeric - Performs numeric QR factorization of a matrix.
3582:   Call this routine after first calling `MatGetFactor()`, and `MatQRFactorSymbolic()`.

3584:   Collective

3586:   Input Parameters:
3587: + fact - the factor matrix obtained with `MatGetFactor()`
3588: . mat  - the matrix
3589: - info - options for factorization

3591:   Level: developer

3593:   Notes:
3594:   See `MatQRFactor()` for in-place factorization.

3596:   Most users should employ the `KSP` interface for linear solvers
3597:   instead of working directly with matrix algebra routines such as this.
3598:   See, e.g., `KSPCreate()`.

3600:   Fortran Note:
3601:   A valid (non-null) `info` argument must be provided

3603: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorInfo`, `MatGetFactor()`, `MatQRFactor()`, `MatQRFactorSymbolic()`, `MatLUFactor()`
3604: @*/
3605: PetscErrorCode MatQRFactorNumeric(Mat fact, Mat mat, const MatFactorInfo *info)
3606: {
3607:   MatFactorInfo tinfo;

3609:   PetscFunctionBegin;
3614:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3615:   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,
3616:              mat->rmap->N, (fact)->rmap->N, mat->cmap->N, (fact)->cmap->N);

3618:   MatCheckPreallocated(mat, 2);
3619:   if (!info) {
3620:     PetscCall(MatFactorInfoInitialize(&tinfo));
3621:     info = &tinfo;
3622:   }

3624:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_QRFactorNumeric, mat, fact, 0, 0));
3625:   else PetscCall(PetscLogEventBegin(MAT_QRFactor, mat, fact, 0, 0));
3626:   PetscUseMethod(fact, "MatQRFactorNumeric_C", (Mat, Mat, const MatFactorInfo *), (fact, mat, info));
3627:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_QRFactorNumeric, mat, fact, 0, 0));
3628:   else PetscCall(PetscLogEventEnd(MAT_QRFactor, mat, fact, 0, 0));
3629:   PetscCall(MatViewFromOptions(fact, NULL, "-mat_factor_view"));
3630:   PetscCall(PetscObjectStateIncrease((PetscObject)fact));
3631:   PetscFunctionReturn(PETSC_SUCCESS);
3632: }

3634: /*@
3635:   MatSolve - Solves $A x = b$, given a factored matrix.

3637:   Neighbor-wise Collective

3639:   Input Parameters:
3640: + mat - the factored matrix
3641: - b   - the right-hand-side vector

3643:   Output Parameter:
3644: . x - the result vector

3646:   Level: developer

3648:   Notes:
3649:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3650:   call `MatSolve`(A,x,x).

3652:   Most users should employ the `KSP` interface for linear solvers
3653:   instead of working directly with matrix algebra routines such as this.
3654:   See, e.g., `KSPCreate()`.

3656: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactor()`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
3657: @*/
3658: PetscErrorCode MatSolve(Mat mat, Vec b, Vec x)
3659: {
3660:   PetscFunctionBegin;
3665:   PetscCheckSameComm(mat, 1, b, 2);
3666:   PetscCheckSameComm(mat, 1, x, 3);
3667:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3668:   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);
3669:   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);
3670:   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);
3671:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3672:   MatCheckPreallocated(mat, 1);

3674:   PetscCall(PetscLogEventBegin(MAT_Solve, mat, b, x, 0));
3675:   PetscCall(VecFlag(x, mat->factorerrortype));
3676:   if (mat->factorerrortype) PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
3677:   else PetscUseTypeMethod(mat, solve, b, x);
3678:   PetscCall(PetscLogEventEnd(MAT_Solve, mat, b, x, 0));
3679:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3680:   PetscFunctionReturn(PETSC_SUCCESS);
3681: }

3683: static PetscErrorCode MatMatSolve_Basic(Mat A, Mat B, Mat X, PetscBool trans)
3684: {
3685:   Vec      b, x;
3686:   PetscInt N, i;
3687:   PetscErrorCode (*f)(Mat, Vec, Vec);
3688:   PetscBool Abound, Bneedconv = PETSC_FALSE, Xneedconv = PETSC_FALSE;

3690:   PetscFunctionBegin;
3691:   if (A->factorerrortype) {
3692:     PetscCall(PetscInfo(A, "MatFactorError %d\n", A->factorerrortype));
3693:     PetscCall(MatSetInf(X));
3694:     PetscFunctionReturn(PETSC_SUCCESS);
3695:   }
3696:   f = (!trans || (!A->ops->solvetranspose && A->symmetric)) ? A->ops->solve : A->ops->solvetranspose;
3697:   PetscCheck(f, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Mat type %s", ((PetscObject)A)->type_name);
3698:   PetscCall(MatBoundToCPU(A, &Abound));
3699:   if (!Abound) {
3700:     PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &Bneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3701:     PetscCall(PetscObjectTypeCompareAny((PetscObject)X, &Xneedconv, MATSEQDENSE, MATMPIDENSE, ""));
3702:   }
3703: #if PetscDefined(HAVE_CUDA)
3704:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSECUDA, MAT_INPLACE_MATRIX, &B));
3705:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSECUDA, MAT_INPLACE_MATRIX, &X));
3706: #elif PetscDefined(HAVE_HIP)
3707:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSEHIP, MAT_INPLACE_MATRIX, &B));
3708:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSEHIP, MAT_INPLACE_MATRIX, &X));
3709: #endif
3710:   PetscCall(MatGetSize(B, NULL, &N));
3711:   for (i = 0; i < N; i++) {
3712:     PetscCall(MatDenseGetColumnVecRead(B, i, &b));
3713:     PetscCall(MatDenseGetColumnVecWrite(X, i, &x));
3714:     PetscCall((*f)(A, b, x));
3715:     PetscCall(MatDenseRestoreColumnVecWrite(X, i, &x));
3716:     PetscCall(MatDenseRestoreColumnVecRead(B, i, &b));
3717:   }
3718:   if (Bneedconv) PetscCall(MatConvert(B, MATDENSE, MAT_INPLACE_MATRIX, &B));
3719:   if (Xneedconv) PetscCall(MatConvert(X, MATDENSE, MAT_INPLACE_MATRIX, &X));
3720:   PetscFunctionReturn(PETSC_SUCCESS);
3721: }

3723: /*@
3724:   MatMatSolve - Solves $A X = B$, given a factored matrix.

3726:   Neighbor-wise Collective

3728:   Input Parameters:
3729: + A - the factored matrix
3730: - B - the right-hand-side matrix `MATDENSE` (or sparse `MATAIJ`-- when using MUMPS)

3732:   Output Parameter:
3733: . X - the result matrix (dense matrix)

3735:   Level: developer

3737:   Note:
3738:   If `B` is a `MATDENSE` matrix then one can call `MatMatSolve`(A,B,B) except with `MATSOLVERMKL_CPARDISO`;
3739:   otherwise, `B` and `X` cannot be the same.

3741: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3742: @*/
3743: PetscErrorCode MatMatSolve(Mat A, Mat B, Mat X)
3744: {
3745:   PetscFunctionBegin;
3750:   PetscCheckSameComm(A, 1, B, 2);
3751:   PetscCheckSameComm(A, 1, X, 3);
3752:   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);
3753:   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);
3754:   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");
3755:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3756:   MatCheckPreallocated(A, 1);

3758:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3759:   if (!A->ops->matsolve) {
3760:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolve\n", ((PetscObject)A)->type_name));
3761:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_FALSE));
3762:   } else PetscUseTypeMethod(A, matsolve, B, X);
3763:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3764:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3765:   PetscFunctionReturn(PETSC_SUCCESS);
3766: }

3768: /*@
3769:   MatMatSolveTranspose - Solves $A^T X = B $, given a factored matrix.

3771:   Neighbor-wise Collective

3773:   Input Parameters:
3774: + A - the factored matrix
3775: - B - the right-hand-side matrix  (`MATDENSE` matrix)

3777:   Output Parameter:
3778: . X - the result matrix (dense matrix)

3780:   Level: developer

3782:   Note:
3783:   The matrices `B` and `X` cannot be the same.  I.e., one cannot
3784:   call `MatMatSolveTranspose`(A,X,X).

3786: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolveTranspose()`, `MatMatSolve()`, `MatLUFactor()`, `MatCholeskyFactor()`
3787: @*/
3788: PetscErrorCode MatMatSolveTranspose(Mat A, Mat B, Mat X)
3789: {
3790:   PetscFunctionBegin;
3795:   PetscCheckSameComm(A, 1, B, 2);
3796:   PetscCheckSameComm(A, 1, X, 3);
3797:   PetscCheck(X != B, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3798:   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);
3799:   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);
3800:   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);
3801:   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");
3802:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3803:   MatCheckPreallocated(A, 1);

3805:   PetscCall(PetscLogEventBegin(MAT_MatSolve, A, B, X, 0));
3806:   if (!A->ops->matsolvetranspose) {
3807:     PetscCall(PetscInfo(A, "Mat type %s using basic MatMatSolveTranspose\n", ((PetscObject)A)->type_name));
3808:     PetscCall(MatMatSolve_Basic(A, B, X, PETSC_TRUE));
3809:   } else PetscUseTypeMethod(A, matsolvetranspose, B, X);
3810:   PetscCall(PetscLogEventEnd(MAT_MatSolve, A, B, X, 0));
3811:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3812:   PetscFunctionReturn(PETSC_SUCCESS);
3813: }

3815: /*@
3816:   MatMatTransposeSolve - Solves $A X = B^T$, given a factored matrix.

3818:   Neighbor-wise Collective

3820:   Input Parameters:
3821: + A  - the factored matrix
3822: - Bt - the transpose of right-hand-side matrix as a `MATDENSE`

3824:   Output Parameter:
3825: . X - the result matrix (dense matrix)

3827:   Level: developer

3829:   Note:
3830:   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
3831:   format on the host processor and call `MatMatTransposeSolve()` to implement MUMPS' `MatMatSolve()`.

3833: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatMatSolve()`, `MatMatSolveTranspose()`, `MatLUFactor()`, `MatCholeskyFactor()`
3834: @*/
3835: PetscErrorCode MatMatTransposeSolve(Mat A, Mat Bt, Mat X)
3836: {
3837:   PetscFunctionBegin;
3842:   PetscCheckSameComm(A, 1, Bt, 2);
3843:   PetscCheckSameComm(A, 1, X, 3);

3845:   PetscCheck(X != Bt, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_IDN, "X and B must be different matrices");
3846:   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);
3847:   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);
3848:   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");
3849:   if (!A->rmap->N && !A->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3850:   PetscCheck(A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
3851:   MatCheckPreallocated(A, 1);

3853:   PetscCall(PetscLogEventBegin(MAT_MatTrSolve, A, Bt, X, 0));
3854:   PetscUseTypeMethod(A, mattransposesolve, Bt, X);
3855:   PetscCall(PetscLogEventEnd(MAT_MatTrSolve, A, Bt, X, 0));
3856:   PetscCall(PetscObjectStateIncrease((PetscObject)X));
3857:   PetscFunctionReturn(PETSC_SUCCESS);
3858: }

3860: /*@
3861:   MatForwardSolve - Solves $ L x = b $, given a factored matrix, $A = LU $, or
3862:   $U^T*D^(1/2) x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3864:   Neighbor-wise Collective

3866:   Input Parameters:
3867: + mat - the factored matrix
3868: - b   - the right-hand-side vector

3870:   Output Parameter:
3871: . x - the result vector

3873:   Level: developer

3875:   Notes:
3876:   `MatSolve()` should be used for most applications, as it performs
3877:   a forward solve followed by a backward solve.

3879:   The vectors `b` and `x` cannot be the same,  i.e., one cannot
3880:   call `MatForwardSolve`(A,x,x).

3882:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
3883:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
3884:   `MatForwardSolve()` solves $U^T*D y = b$, and
3885:   `MatBackwardSolve()` solves $U x = y$.
3886:   Thus they do not provide a symmetric preconditioner.

3888: .seealso: [](ch_matrices), `Mat`, `MatBackwardSolve()`, `MatGetFactor()`, `MatSolve()`
3889: @*/
3890: PetscErrorCode MatForwardSolve(Mat mat, Vec b, Vec x)
3891: {
3892:   PetscFunctionBegin;
3897:   PetscCheckSameComm(mat, 1, b, 2);
3898:   PetscCheckSameComm(mat, 1, x, 3);
3899:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3900:   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);
3901:   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);
3902:   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);
3903:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3904:   MatCheckPreallocated(mat, 1);

3906:   PetscCall(PetscLogEventBegin(MAT_ForwardSolve, mat, b, x, 0));
3907:   PetscUseTypeMethod(mat, forwardsolve, b, x);
3908:   PetscCall(PetscLogEventEnd(MAT_ForwardSolve, mat, b, x, 0));
3909:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3910:   PetscFunctionReturn(PETSC_SUCCESS);
3911: }

3913: /*@
3914:   MatBackwardSolve - Solves $U x = b$, given a factored matrix, $A = LU$.
3915:   $D^(1/2) U x = b$, given a factored symmetric matrix, $A = U^T*D*U$,

3917:   Neighbor-wise Collective

3919:   Input Parameters:
3920: + mat - the factored matrix
3921: - b   - the right-hand-side vector

3923:   Output Parameter:
3924: . x - the result vector

3926:   Level: developer

3928:   Notes:
3929:   `MatSolve()` should be used for most applications, as it performs
3930:   a forward solve followed by a backward solve.

3932:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3933:   call `MatBackwardSolve`(A,x,x).

3935:   For matrix in `MATSEQBAIJ` format with block size larger than 1,
3936:   the diagonal blocks are not implemented as $D = D^(1/2) * D^(1/2)$ yet.
3937:   `MatForwardSolve()` solves $U^T*D y = b$, and
3938:   `MatBackwardSolve()` solves $U x = y$.
3939:   Thus they do not provide a symmetric preconditioner.

3941: .seealso: [](ch_matrices), `Mat`, `MatForwardSolve()`, `MatGetFactor()`, `MatSolve()`
3942: @*/
3943: PetscErrorCode MatBackwardSolve(Mat mat, Vec b, Vec x)
3944: {
3945:   PetscFunctionBegin;
3950:   PetscCheckSameComm(mat, 1, b, 2);
3951:   PetscCheckSameComm(mat, 1, x, 3);
3952:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
3953:   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);
3954:   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);
3955:   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);
3956:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
3957:   MatCheckPreallocated(mat, 1);

3959:   PetscCall(PetscLogEventBegin(MAT_BackwardSolve, mat, b, x, 0));
3960:   PetscUseTypeMethod(mat, backwardsolve, b, x);
3961:   PetscCall(PetscLogEventEnd(MAT_BackwardSolve, mat, b, x, 0));
3962:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
3963:   PetscFunctionReturn(PETSC_SUCCESS);
3964: }

3966: /*@
3967:   MatSolveAdd - Computes $x = y + A^{-1}*b$, given a factored matrix.

3969:   Neighbor-wise Collective

3971:   Input Parameters:
3972: + mat - the factored matrix
3973: . b   - the right-hand-side vector
3974: - y   - the vector to be added to

3976:   Output Parameter:
3977: . x - the result vector

3979:   Level: developer

3981:   Note:
3982:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
3983:   call `MatSolveAdd`(A,x,y,x).

3985: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolve()`, `MatGetFactor()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`
3986: @*/
3987: PetscErrorCode MatSolveAdd(Mat mat, Vec b, Vec y, Vec x)
3988: {
3989:   PetscScalar one = 1.0;
3990:   Vec         tmp;

3992:   PetscFunctionBegin;
3998:   PetscCheckSameComm(mat, 1, b, 2);
3999:   PetscCheckSameComm(mat, 1, y, 3);
4000:   PetscCheckSameComm(mat, 1, x, 4);
4001:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4002:   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);
4003:   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);
4004:   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);
4005:   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);
4006:   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);
4007:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4008:   MatCheckPreallocated(mat, 1);

4010:   PetscCall(PetscLogEventBegin(MAT_SolveAdd, mat, b, x, y));
4011:   PetscCall(VecFlag(x, mat->factorerrortype));
4012:   if (mat->factorerrortype) {
4013:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4014:   } else if (mat->ops->solveadd) {
4015:     PetscUseTypeMethod(mat, solveadd, b, y, x);
4016:   } else {
4017:     /* do the solve then the add manually */
4018:     if (x != y) {
4019:       PetscCall(MatSolve(mat, b, x));
4020:       PetscCall(VecAXPY(x, one, y));
4021:     } else {
4022:       PetscCall(VecDuplicate(x, &tmp));
4023:       PetscCall(VecCopy(x, tmp));
4024:       PetscCall(MatSolve(mat, b, x));
4025:       PetscCall(VecAXPY(x, one, tmp));
4026:       PetscCall(VecDestroy(&tmp));
4027:     }
4028:   }
4029:   PetscCall(PetscLogEventEnd(MAT_SolveAdd, mat, b, x, y));
4030:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4031:   PetscFunctionReturn(PETSC_SUCCESS);
4032: }

4034: /*@
4035:   MatSolveTranspose - Solves $A^T x = b$, given a factored matrix.

4037:   Neighbor-wise Collective

4039:   Input Parameters:
4040: + mat - the factored matrix
4041: - b   - the right-hand-side vector

4043:   Output Parameter:
4044: . x - the result vector

4046:   Level: developer

4048:   Notes:
4049:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4050:   call `MatSolveTranspose`(A,x,x).

4052:   Most users should employ the `KSP` interface for linear solvers
4053:   instead of working directly with matrix algebra routines such as this.
4054:   See, e.g., `KSPCreate()`.

4056: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `KSP`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTransposeAdd()`
4057: @*/
4058: PetscErrorCode MatSolveTranspose(Mat mat, Vec b, Vec x)
4059: {
4060:   PetscErrorCode (*f)(Mat, Vec, Vec) = (!mat->ops->solvetranspose && mat->symmetric) ? mat->ops->solve : mat->ops->solvetranspose;

4062:   PetscFunctionBegin;
4067:   PetscCheckSameComm(mat, 1, b, 2);
4068:   PetscCheckSameComm(mat, 1, x, 3);
4069:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4070:   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);
4071:   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);
4072:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4073:   MatCheckPreallocated(mat, 1);
4074:   PetscCall(PetscLogEventBegin(MAT_SolveTranspose, mat, b, x, 0));
4075:   PetscCall(VecFlag(x, mat->factorerrortype));
4076:   if (mat->factorerrortype) {
4077:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4078:   } else {
4079:     PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Matrix type %s", ((PetscObject)mat)->type_name);
4080:     PetscCall((*f)(mat, b, x));
4081:   }
4082:   PetscCall(PetscLogEventEnd(MAT_SolveTranspose, mat, b, x, 0));
4083:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4084:   PetscFunctionReturn(PETSC_SUCCESS);
4085: }

4087: /*@
4088:   MatSolveTransposeAdd - Computes $x = y + A^{-T} b$
4089:   factored matrix.

4091:   Neighbor-wise Collective

4093:   Input Parameters:
4094: + mat - the factored matrix
4095: . b   - the right-hand-side vector
4096: - y   - the vector to be added to

4098:   Output Parameter:
4099: . x - the result vector

4101:   Level: developer

4103:   Note:
4104:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
4105:   call `MatSolveTransposeAdd`(A,x,y,x).

4107: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatSolve()`, `MatSolveAdd()`, `MatSolveTranspose()`
4108: @*/
4109: PetscErrorCode MatSolveTransposeAdd(Mat mat, Vec b, Vec y, Vec x)
4110: {
4111:   PetscScalar one = 1.0;
4112:   Vec         tmp;
4113:   PetscErrorCode (*f)(Mat, Vec, Vec, Vec) = (!mat->ops->solvetransposeadd && mat->symmetric) ? mat->ops->solveadd : mat->ops->solvetransposeadd;

4115:   PetscFunctionBegin;
4121:   PetscCheckSameComm(mat, 1, b, 2);
4122:   PetscCheckSameComm(mat, 1, y, 3);
4123:   PetscCheckSameComm(mat, 1, x, 4);
4124:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
4125:   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);
4126:   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);
4127:   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);
4128:   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);
4129:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);
4130:   MatCheckPreallocated(mat, 1);

4132:   PetscCall(PetscLogEventBegin(MAT_SolveTransposeAdd, mat, b, x, y));
4133:   PetscCall(VecFlag(x, mat->factorerrortype));
4134:   if (mat->factorerrortype) {
4135:     PetscCall(PetscInfo(mat, "MatFactorError %d\n", mat->factorerrortype));
4136:   } else if (f) {
4137:     PetscCall((*f)(mat, b, y, x));
4138:   } else {
4139:     /* do the solve then the add manually */
4140:     if (x != y) {
4141:       PetscCall(MatSolveTranspose(mat, b, x));
4142:       PetscCall(VecAXPY(x, one, y));
4143:     } else {
4144:       PetscCall(VecDuplicate(x, &tmp));
4145:       PetscCall(VecCopy(x, tmp));
4146:       PetscCall(MatSolveTranspose(mat, b, x));
4147:       PetscCall(VecAXPY(x, one, tmp));
4148:       PetscCall(VecDestroy(&tmp));
4149:     }
4150:   }
4151:   PetscCall(PetscLogEventEnd(MAT_SolveTransposeAdd, mat, b, x, y));
4152:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4153:   PetscFunctionReturn(PETSC_SUCCESS);
4154: }

4156: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
4157: /*@
4158:   MatSOR - Computes relaxation (SOR, Gauss-Seidel) sweeps.

4160:   Neighbor-wise Collective

4162:   Input Parameters:
4163: + mat   - the matrix
4164: . b     - the right-hand side
4165: . omega - the relaxation factor
4166: . flag  - flag indicating the type of SOR (see below)
4167: . shift - diagonal shift
4168: . its   - the number of iterations
4169: - lits  - the number of local iterations

4171:   Output Parameter:
4172: . x - the solution (can contain an initial guess, use option `SOR_ZERO_INITIAL_GUESS` to indicate no guess)

4174:   SOR Flags:
4175: +     `SOR_FORWARD_SWEEP` - forward SOR
4176: .     `SOR_BACKWARD_SWEEP` - backward SOR
4177: .     `SOR_SYMMETRIC_SWEEP` - SSOR (symmetric SOR)
4178: .     `SOR_LOCAL_FORWARD_SWEEP` - local forward SOR
4179: .     `SOR_LOCAL_BACKWARD_SWEEP` - local forward SOR
4180: .     `SOR_LOCAL_SYMMETRIC_SWEEP` - local SSOR
4181: .     `SOR_EISENSTAT` - SOR with Eisenstat trick
4182: .     `SOR_APPLY_UPPER`, `SOR_APPLY_LOWER` - applies upper/lower triangular part of matrix to vector (with `omega`)
4183: -     `SOR_ZERO_INITIAL_GUESS` - zero initial guess

4185:   Level: developer

4187:   Notes:
4188:   `SOR_LOCAL_FORWARD_SWEEP`, `SOR_LOCAL_BACKWARD_SWEEP`, and
4189:   `SOR_LOCAL_SYMMETRIC_SWEEP` perform separate independent smoothings
4190:   on each processor.

4192:   Application programmers will not generally use `MatSOR()` directly,
4193:   but instead will employ `PCSOR` or `PCEISENSTAT`

4195:   For `MATBAIJ`, `MATSBAIJ`, and `MATAIJ` matrices with inodes, this does a block SOR smoothing, otherwise it does a pointwise smoothing.
4196:   For `MATAIJ` matrices with inodes, the block sizes are determined by the inode sizes, not the block size set with `MatSetBlockSize()`

4198:   Vectors `x` and `b` CANNOT be the same

4200:   The flags are implemented as bitwise inclusive or operations.
4201:   For example, use (`SOR_ZERO_INITIAL_GUESS` | `SOR_SYMMETRIC_SWEEP`)
4202:   to specify a zero initial guess for SSOR.

4204:   Developer Note:
4205:   We should add block SOR support for `MATAIJ` matrices with block size set to greater than one and no inodes

4207: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `KSP`, `PC`, `MatGetFactor()`
4208: @*/
4209: PetscErrorCode MatSOR(Mat mat, Vec b, PetscReal omega, MatSORType flag, PetscReal shift, PetscInt its, PetscInt lits, Vec x)
4210: {
4211:   PetscFunctionBegin;
4216:   PetscCheckSameComm(mat, 1, b, 2);
4217:   PetscCheckSameComm(mat, 1, x, 8);
4218:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4219:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4220:   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);
4221:   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);
4222:   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);
4223:   PetscCheck(its > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires global its %" PetscInt_FMT " positive", its);
4224:   PetscCheck(lits > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires local its %" PetscInt_FMT " positive", lits);
4225:   PetscCheck(b != x, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "b and x vector cannot be the same");

4227:   MatCheckPreallocated(mat, 1);
4228:   PetscCall(PetscLogEventBegin(MAT_SOR, mat, b, x, 0));
4229:   PetscUseTypeMethod(mat, sor, b, omega, flag, shift, its, lits, x);
4230:   PetscCall(PetscLogEventEnd(MAT_SOR, mat, b, x, 0));
4231:   PetscCall(PetscObjectStateIncrease((PetscObject)x));
4232:   PetscFunctionReturn(PETSC_SUCCESS);
4233: }

4235: /*
4236:       Default matrix copy routine.
4237: */
4238: PetscErrorCode MatCopy_Basic(Mat A, Mat B, MatStructure str)
4239: {
4240:   PetscInt           i, rstart = 0, rend = 0, nz;
4241:   const PetscInt    *cwork;
4242:   const PetscScalar *vwork;

4244:   PetscFunctionBegin;
4245:   if (B->assembled) PetscCall(MatZeroEntries(B));
4246:   if (str == SAME_NONZERO_PATTERN) {
4247:     PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
4248:     for (i = rstart; i < rend; i++) {
4249:       PetscCall(MatGetRow(A, i, &nz, &cwork, &vwork));
4250:       PetscCall(MatSetValues(B, 1, &i, nz, cwork, vwork, INSERT_VALUES));
4251:       PetscCall(MatRestoreRow(A, i, &nz, &cwork, &vwork));
4252:     }
4253:   } else {
4254:     PetscCall(MatAYPX(B, 0.0, A, str));
4255:   }
4256:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4257:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4258:   PetscFunctionReturn(PETSC_SUCCESS);
4259: }

4261: /*@
4262:   MatCopy - Copies a matrix to another matrix.

4264:   Collective

4266:   Input Parameters:
4267: + A   - the matrix
4268: - str - `SAME_NONZERO_PATTERN` or `DIFFERENT_NONZERO_PATTERN`

4270:   Output Parameter:
4271: . B - where the copy is put

4273:   Level: intermediate

4275:   Notes:
4276:   If you use `SAME_NONZERO_PATTERN`, then the two matrices must have the same nonzero pattern or the routine will crash.

4278:   `MatCopy()` copies the matrix entries of a matrix to another existing
4279:   matrix (after first zeroing the second matrix).  A related routine is
4280:   `MatConvert()`, which first creates a new matrix and then copies the data.

4282: .seealso: [](ch_matrices), `Mat`, `MatConvert()`, `MatDuplicate()`
4283: @*/
4284: PetscErrorCode MatCopy(Mat A, Mat B, MatStructure str)
4285: {
4286:   PetscInt i;

4288:   PetscFunctionBegin;
4293:   PetscCheckSameComm(A, 1, B, 2);
4294:   MatCheckPreallocated(B, 2);
4295:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4296:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4297:   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,
4298:              A->cmap->N, B->cmap->N);
4299:   MatCheckPreallocated(A, 1);
4300:   if (A == B) PetscFunctionReturn(PETSC_SUCCESS);

4302:   PetscCall(PetscLogEventBegin(MAT_Copy, A, B, 0, 0));
4303:   if (A->ops->copy) PetscUseTypeMethod(A, copy, B, str);
4304:   else PetscCall(MatCopy_Basic(A, B, str));

4306:   B->stencil.dim = A->stencil.dim;
4307:   B->stencil.noc = A->stencil.noc;
4308:   for (i = 0; i <= A->stencil.dim + (A->stencil.noc ? 0 : -1); i++) {
4309:     B->stencil.dims[i]   = A->stencil.dims[i];
4310:     B->stencil.starts[i] = A->stencil.starts[i];
4311:   }

4313:   PetscCall(PetscLogEventEnd(MAT_Copy, A, B, 0, 0));
4314:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
4315:   PetscFunctionReturn(PETSC_SUCCESS);
4316: }

4318: /*@
4319:   MatConvert - Converts a matrix to another matrix, either of the same
4320:   or different type.

4322:   Collective

4324:   Input Parameters:
4325: + mat     - the matrix
4326: . newtype - new matrix type.  Use `MATSAME` to create a new matrix of the
4327:             same type as the original matrix.
4328: - reuse   - denotes if the destination matrix is to be created or reused.
4329:             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
4330:             `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).

4332:   Output Parameter:
4333: . M - pointer to place new matrix

4335:   Level: intermediate

4337:   Notes:
4338:   `MatConvert()` first creates a new matrix and then copies the data from
4339:   the first matrix.  A related routine is `MatCopy()`, which copies the matrix
4340:   entries of one matrix to another already existing matrix context.

4342:   Cannot be used to convert a sequential matrix to parallel or parallel to sequential,
4343:   the MPI communicator of the generated matrix is always the same as the communicator
4344:   of the input matrix.

4346: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatDuplicate()`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
4347: @*/
4348: PetscErrorCode MatConvert(Mat mat, MatType newtype, MatReuse reuse, Mat *M)
4349: {
4350:   PetscBool  sametype, issame, flg;
4351:   PetscBool3 issymmetric, ishermitian;
4352:   char       convname[256], mtype[256];
4353:   Mat        B;

4355:   PetscFunctionBegin;
4358:   PetscAssertPointer(M, 4);
4359:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4360:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4361:   MatCheckPreallocated(mat, 1);

4363:   PetscCall(PetscOptionsGetString(((PetscObject)mat)->options, ((PetscObject)mat)->prefix, "-matconvert_type", mtype, sizeof(mtype), &flg));
4364:   if (flg) newtype = mtype;

4366:   PetscCall(PetscObjectTypeCompare((PetscObject)mat, newtype, &sametype));
4367:   PetscCall(PetscStrcmp(newtype, "same", &issame));
4368:   PetscCheck(!(reuse == MAT_INPLACE_MATRIX) || !(mat != *M), PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires same input and output matrix");
4369:   if (reuse == MAT_REUSE_MATRIX) {
4371:     PetscCheck(mat != *M, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_REUSE_MATRIX means reuse matrix in final argument, perhaps you mean MAT_INPLACE_MATRIX");
4372:   }

4374:   if ((reuse == MAT_INPLACE_MATRIX) && (issame || sametype)) {
4375:     PetscCall(PetscInfo(mat, "Early return for inplace %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4376:     PetscFunctionReturn(PETSC_SUCCESS);
4377:   }

4379:   /* Cache Mat options because some converters use MatHeaderReplace  */
4380:   issymmetric = mat->symmetric;
4381:   ishermitian = mat->hermitian;

4383:   if ((sametype || issame) && (reuse == MAT_INITIAL_MATRIX) && mat->ops->duplicate) {
4384:     PetscCall(PetscInfo(mat, "Calling duplicate for initial matrix %s %d %d\n", ((PetscObject)mat)->type_name, sametype, issame));
4385:     PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4386:   } else {
4387:     PetscErrorCode (*conv)(Mat, MatType, MatReuse, Mat *) = NULL;
4388:     const char *prefix[3]                                 = {"seq", "mpi", ""};
4389:     PetscInt    i;
4390:     /*
4391:        Order of precedence:
4392:        0) See if newtype is a superclass of the current matrix.
4393:        1) See if a specialized converter is known to the current matrix.
4394:        2) See if a specialized converter is known to the desired matrix class.
4395:        3) See if a good general converter is registered for the desired class
4396:           (as of 6/27/03 only MATMPIADJ falls into this category).
4397:        4) See if a good general converter is known for the current matrix.
4398:        5) Use a really basic converter.
4399:     */

4401:     /* 0) See if newtype is a superclass of the current matrix.
4402:           i.e mat is mpiaij and newtype is aij */
4403:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4404:       PetscCall(PetscStrncpy(convname, prefix[i], sizeof(convname)));
4405:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4406:       PetscCall(PetscStrcmp(convname, ((PetscObject)mat)->type_name, &flg));
4407:       PetscCall(PetscInfo(mat, "Check superclass %s %s -> %d\n", convname, ((PetscObject)mat)->type_name, flg));
4408:       if (flg) {
4409:         if (reuse == MAT_INPLACE_MATRIX) {
4410:           PetscCall(PetscInfo(mat, "Early return\n"));
4411:           PetscFunctionReturn(PETSC_SUCCESS);
4412:         } else if (reuse == MAT_INITIAL_MATRIX && mat->ops->duplicate) {
4413:           PetscCall(PetscInfo(mat, "Calling MatDuplicate\n"));
4414:           PetscUseTypeMethod(mat, duplicate, MAT_COPY_VALUES, M);
4415:           PetscFunctionReturn(PETSC_SUCCESS);
4416:         } else if (reuse == MAT_REUSE_MATRIX && mat->ops->copy) {
4417:           PetscCall(PetscInfo(mat, "Calling MatCopy\n"));
4418:           PetscCall(MatCopy(mat, *M, SAME_NONZERO_PATTERN));
4419:           PetscFunctionReturn(PETSC_SUCCESS);
4420:         }
4421:       }
4422:     }
4423:     /* 1) See if a specialized converter is known to the current matrix and the desired class */
4424:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4425:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4426:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4427:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4428:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4429:       PetscCall(PetscStrlcat(convname, issame ? ((PetscObject)mat)->type_name : newtype, sizeof(convname)));
4430:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4431:       PetscCall(PetscObjectQueryFunction((PetscObject)mat, convname, &conv));
4432:       PetscCall(PetscInfo(mat, "Check specialized (1) %s (%s) -> %d\n", convname, ((PetscObject)mat)->type_name, !!conv));
4433:       if (conv) goto foundconv;
4434:     }

4436:     /* 2)  See if a specialized converter is known to the desired matrix class. */
4437:     PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &B));
4438:     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
4439:     PetscCall(MatSetType(B, newtype));
4440:     for (i = 0; i < (PetscInt)PETSC_STATIC_ARRAY_LENGTH(prefix); i++) {
4441:       PetscCall(PetscStrncpy(convname, "MatConvert_", sizeof(convname)));
4442:       PetscCall(PetscStrlcat(convname, ((PetscObject)mat)->type_name, sizeof(convname)));
4443:       PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
4444:       PetscCall(PetscStrlcat(convname, prefix[i], sizeof(convname)));
4445:       PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
4446:       PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
4447:       PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
4448:       PetscCall(PetscInfo(mat, "Check specialized (2) %s (%s) -> %d\n", convname, ((PetscObject)B)->type_name, !!conv));
4449:       if (conv) {
4450:         PetscCall(MatDestroy(&B));
4451:         goto foundconv;
4452:       }
4453:     }

4455:     /* 3) See if a good general converter is registered for the desired class */
4456:     conv = B->ops->convertfrom;
4457:     PetscCall(PetscInfo(mat, "Check convertfrom (%s) -> %d\n", ((PetscObject)B)->type_name, !!conv));
4458:     PetscCall(MatDestroy(&B));
4459:     if (conv) goto foundconv;

4461:     /* 4) See if a good general converter is known for the current matrix */
4462:     if (mat->ops->convert) conv = mat->ops->convert;
4463:     PetscCall(PetscInfo(mat, "Check general convert (%s) -> %d\n", ((PetscObject)mat)->type_name, !!conv));
4464:     if (conv) goto foundconv;

4466:     /* 5) Use a really basic converter. */
4467:     PetscCall(PetscInfo(mat, "Using MatConvert_Basic\n"));
4468:     conv = MatConvert_Basic;

4470:   foundconv:
4471:     PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4472:     PetscCall((*conv)(mat, newtype, reuse, M));
4473:     if (mat->rmap->mapping && mat->cmap->mapping && !(*M)->rmap->mapping && !(*M)->cmap->mapping) {
4474:       /* the block sizes must be same if the mappings are copied over */
4475:       (*M)->rmap->bs = mat->rmap->bs;
4476:       (*M)->cmap->bs = mat->cmap->bs;
4477:       PetscCall(PetscObjectReference((PetscObject)mat->rmap->mapping));
4478:       PetscCall(PetscObjectReference((PetscObject)mat->cmap->mapping));
4479:       (*M)->rmap->mapping = mat->rmap->mapping;
4480:       (*M)->cmap->mapping = mat->cmap->mapping;
4481:     }
4482:     (*M)->stencil.dim = mat->stencil.dim;
4483:     (*M)->stencil.noc = mat->stencil.noc;
4484:     for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4485:       (*M)->stencil.dims[i]   = mat->stencil.dims[i];
4486:       (*M)->stencil.starts[i] = mat->stencil.starts[i];
4487:     }
4488:     PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4489:   }
4490:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));

4492:   /* Copy Mat options */
4493:   if (issymmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PETSC_TRUE));
4494:   else if (issymmetric == PETSC_BOOL3_FALSE) PetscCall(MatSetOption(*M, MAT_SYMMETRIC, PETSC_FALSE));
4495:   if (ishermitian == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PETSC_TRUE));
4496:   else if (ishermitian == PETSC_BOOL3_FALSE) PetscCall(MatSetOption(*M, MAT_HERMITIAN, PETSC_FALSE));
4497:   PetscFunctionReturn(PETSC_SUCCESS);
4498: }

4500: /*@
4501:   MatFactorGetSolverType - Returns name of the package providing the factorization routines

4503:   Not Collective

4505:   Input Parameter:
4506: . mat - the matrix, must be a factored matrix

4508:   Output Parameter:
4509: . type - the string name of the package (do not free this string)

4511:   Level: intermediate

4513: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSolverType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`
4514: @*/
4515: PetscErrorCode MatFactorGetSolverType(Mat mat, MatSolverType *type)
4516: {
4517:   PetscErrorCode (*conv)(Mat, MatSolverType *);

4519:   PetscFunctionBegin;
4522:   PetscAssertPointer(type, 2);
4523:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
4524:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorGetSolverType_C", &conv));
4525:   if (conv) PetscCall((*conv)(mat, type));
4526:   else *type = MATSOLVERPETSC;
4527:   PetscFunctionReturn(PETSC_SUCCESS);
4528: }

4530: typedef struct _MatSolverTypeForSpecifcType *MatSolverTypeForSpecifcType;
4531: struct _MatSolverTypeForSpecifcType {
4532:   MatType mtype;
4533:   /* no entry for MAT_FACTOR_NONE */
4534:   PetscErrorCode (*createfactor[MAT_FACTOR_NUM_TYPES - 1])(Mat, MatFactorType, Mat *);
4535:   MatSolverTypeForSpecifcType next;
4536: };

4538: typedef struct _MatSolverTypeHolder *MatSolverTypeHolder;
4539: struct _MatSolverTypeHolder {
4540:   char                       *name;
4541:   MatSolverTypeForSpecifcType handlers;
4542:   MatSolverTypeHolder         next;
4543: };

4545: static MatSolverTypeHolder MatSolverTypeHolders = NULL;

4547: /*@C
4548:   MatSolverTypeRegister - Registers a `MatSolverType` that works for a particular matrix type

4550:   Logically Collective, No Fortran Support

4552:   Input Parameters:
4553: + package      - name of the package, for example `petsc` or `superlu`
4554: . mtype        - the matrix type that works with this package
4555: . ftype        - the type of factorization supported by the package
4556: - createfactor - routine that will create the factored matrix ready to be used

4558:   Level: developer

4560: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorGetSolverType()`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`,
4561:   `MatGetFactor()`
4562: @*/
4563: PetscErrorCode MatSolverTypeRegister(MatSolverType package, MatType mtype, MatFactorType ftype, PetscErrorCode (*createfactor)(Mat, MatFactorType, Mat *))
4564: {
4565:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev = NULL;
4566:   PetscBool                   flg;
4567:   MatSolverTypeForSpecifcType inext, iprev = NULL;

4569:   PetscFunctionBegin;
4570:   PetscCall(MatInitializePackage());
4571:   if (!next) {
4572:     PetscCall(PetscNew(&MatSolverTypeHolders));
4573:     PetscCall(PetscStrallocpy(package, &MatSolverTypeHolders->name));
4574:     PetscCall(PetscNew(&MatSolverTypeHolders->handlers));
4575:     PetscCall(PetscStrallocpy(mtype, (char **)&MatSolverTypeHolders->handlers->mtype));
4576:     MatSolverTypeHolders->handlers->createfactor[(int)ftype - 1] = createfactor;
4577:     PetscFunctionReturn(PETSC_SUCCESS);
4578:   }
4579:   while (next) {
4580:     PetscCall(PetscStrcasecmp(package, next->name, &flg));
4581:     if (flg) {
4582:       PetscCheck(next->handlers, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatSolverTypeHolder is missing handlers");
4583:       inext = next->handlers;
4584:       while (inext) {
4585:         PetscCall(PetscStrcasecmp(mtype, inext->mtype, &flg));
4586:         if (flg) {
4587:           inext->createfactor[(int)ftype - 1] = createfactor;
4588:           PetscFunctionReturn(PETSC_SUCCESS);
4589:         }
4590:         iprev = inext;
4591:         inext = inext->next;
4592:       }
4593:       PetscCall(PetscNew(&iprev->next));
4594:       PetscCall(PetscStrallocpy(mtype, (char **)&iprev->next->mtype));
4595:       iprev->next->createfactor[(int)ftype - 1] = createfactor;
4596:       PetscFunctionReturn(PETSC_SUCCESS);
4597:     }
4598:     prev = next;
4599:     next = next->next;
4600:   }
4601:   PetscCall(PetscNew(&prev->next));
4602:   PetscCall(PetscStrallocpy(package, &prev->next->name));
4603:   PetscCall(PetscNew(&prev->next->handlers));
4604:   PetscCall(PetscStrallocpy(mtype, (char **)&prev->next->handlers->mtype));
4605:   prev->next->handlers->createfactor[(int)ftype - 1] = createfactor;
4606:   PetscFunctionReturn(PETSC_SUCCESS);
4607: }

4609: /*@C
4610:   MatSolverTypeGet - Gets the function that creates the factor matrix if it exist

4612:   Input Parameters:
4613: + 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
4614: . ftype - the type of factorization supported by the type
4615: - mtype - the matrix type that works with this type

4617:   Output Parameters:
4618: + foundtype    - `PETSC_TRUE` if the type was registered
4619: . foundmtype   - `PETSC_TRUE` if the type supports the requested mtype
4620: - createfactor - routine that will create the factored matrix ready to be used or `NULL` if not found

4622:   Calling sequence of `createfactor`:
4623: + A     - the matrix providing the factor matrix
4624: . ftype - the `MatFactorType` of the factor requested
4625: - B     - the new factor matrix that responds to MatXXFactorSymbolic,Numeric() functions, such as `MatLUFactorSymbolic()`

4627:   Level: developer

4629:   Note:
4630:   When `type` is `NULL` the available functions are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4631:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4632:   For example if one configuration had `--download-mumps` while a different one had `--download-superlu_dist`.

4634: .seealso: [](ch_matrices), `Mat`, `MatFactorType`, `MatType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatSolverTypeRegister()`, `MatGetFactor()`,
4635:           `MatInitializePackage()`
4636: @*/
4637: PetscErrorCode MatSolverTypeGet(MatSolverType type, MatType mtype, MatFactorType ftype, PetscBool *foundtype, PetscBool *foundmtype, PetscErrorCode (**createfactor)(Mat A, MatFactorType ftype, Mat *B))
4638: {
4639:   MatSolverTypeHolder         next = MatSolverTypeHolders;
4640:   PetscBool                   flg;
4641:   MatSolverTypeForSpecifcType inext;

4643:   PetscFunctionBegin;
4644:   if (foundtype) *foundtype = PETSC_FALSE;
4645:   if (foundmtype) *foundmtype = PETSC_FALSE;
4646:   if (createfactor) *createfactor = NULL;

4648:   if (type) {
4649:     while (next) {
4650:       PetscCall(PetscStrcasecmp(type, next->name, &flg));
4651:       if (flg) {
4652:         if (foundtype) *foundtype = PETSC_TRUE;
4653:         inext = next->handlers;
4654:         while (inext) {
4655:           PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4656:           if (flg) {
4657:             if (foundmtype) *foundmtype = PETSC_TRUE;
4658:             if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4659:             PetscFunctionReturn(PETSC_SUCCESS);
4660:           }
4661:           inext = inext->next;
4662:         }
4663:       }
4664:       next = next->next;
4665:     }
4666:   } else {
4667:     while (next) {
4668:       inext = next->handlers;
4669:       while (inext) {
4670:         PetscCall(PetscStrcmp(mtype, inext->mtype, &flg));
4671:         if (flg && inext->createfactor[(int)ftype - 1]) {
4672:           if (foundtype) *foundtype = PETSC_TRUE;
4673:           if (foundmtype) *foundmtype = PETSC_TRUE;
4674:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4675:           PetscFunctionReturn(PETSC_SUCCESS);
4676:         }
4677:         inext = inext->next;
4678:       }
4679:       next = next->next;
4680:     }
4681:     /* try with base classes inext->mtype */
4682:     next = MatSolverTypeHolders;
4683:     while (next) {
4684:       inext = next->handlers;
4685:       while (inext) {
4686:         PetscCall(PetscStrbeginswith(mtype, inext->mtype, &flg));
4687:         if (flg && inext->createfactor[(int)ftype - 1]) {
4688:           if (foundtype) *foundtype = PETSC_TRUE;
4689:           if (foundmtype) *foundmtype = PETSC_TRUE;
4690:           if (createfactor) *createfactor = inext->createfactor[(int)ftype - 1];
4691:           PetscFunctionReturn(PETSC_SUCCESS);
4692:         }
4693:         inext = inext->next;
4694:       }
4695:       next = next->next;
4696:     }
4697:   }
4698:   PetscFunctionReturn(PETSC_SUCCESS);
4699: }

4701: PetscErrorCode MatSolverTypeDestroy(void)
4702: {
4703:   MatSolverTypeHolder         next = MatSolverTypeHolders, prev;
4704:   MatSolverTypeForSpecifcType inext, iprev;

4706:   PetscFunctionBegin;
4707:   while (next) {
4708:     PetscCall(PetscFree(next->name));
4709:     inext = next->handlers;
4710:     while (inext) {
4711:       PetscCall(PetscFree(inext->mtype));
4712:       iprev = inext;
4713:       inext = inext->next;
4714:       PetscCall(PetscFree(iprev));
4715:     }
4716:     prev = next;
4717:     next = next->next;
4718:     PetscCall(PetscFree(prev));
4719:   }
4720:   MatSolverTypeHolders = NULL;
4721:   PetscFunctionReturn(PETSC_SUCCESS);
4722: }

4724: /*@
4725:   MatFactorGetCanUseOrdering - Indicates if the factorization can use the ordering provided in `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`

4727:   Logically Collective

4729:   Input Parameter:
4730: . mat - the matrix

4732:   Output Parameter:
4733: . flg - `PETSC_TRUE` if uses the ordering

4735:   Level: developer

4737:   Note:
4738:   Most internal PETSc factorizations use the ordering passed to the factorization routine but external
4739:   packages do not, thus we want to skip generating the ordering when it is not needed or used.

4741: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4742: @*/
4743: PetscErrorCode MatFactorGetCanUseOrdering(Mat mat, PetscBool *flg)
4744: {
4745:   PetscFunctionBegin;
4746:   *flg = mat->canuseordering;
4747:   PetscFunctionReturn(PETSC_SUCCESS);
4748: }

4750: /*@
4751:   MatFactorGetPreferredOrdering - The preferred ordering for a particular matrix factor object

4753:   Logically Collective

4755:   Input Parameters:
4756: + mat   - the matrix obtained with `MatGetFactor()`
4757: - ftype - the factorization type to be used

4759:   Output Parameter:
4760: . otype - the preferred ordering type

4762:   Level: developer

4764: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatFactorType`, `MatOrderingType`, `MatCopy()`, `MatDuplicate()`, `MatGetFactorAvailable()`, `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatCholeskyFactorSymbolic()`
4765: @*/
4766: PetscErrorCode MatFactorGetPreferredOrdering(Mat mat, MatFactorType ftype, MatOrderingType *otype)
4767: {
4768:   PetscFunctionBegin;
4769:   *otype = mat->preferredordering[ftype];
4770:   PetscCheck(*otype, PETSC_COMM_SELF, PETSC_ERR_PLIB, "MatFactor did not have a preferred ordering");
4771:   PetscFunctionReturn(PETSC_SUCCESS);
4772: }

4774: /*@
4775:   MatGetFactor - Returns a matrix suitable to calls to MatXXFactorSymbolic,Numeric()

4777:   Collective

4779:   Input Parameters:
4780: + mat   - the matrix
4781: . 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
4782:           the other criteria is returned
4783: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4785:   Output Parameter:
4786: . f - the factor matrix used with MatXXFactorSymbolic,Numeric() calls. Can be `NULL` in some cases, see notes below.

4788:   Options Database Keys:
4789: + -pc_factor_mat_solver_type <type>    - choose the type at run time. When using `KSP` solvers
4790: . -pc_factor_mat_factor_on_host <bool> - do mat factorization on host (with device matrices). Default is doing it on device
4791: - -pc_factor_mat_solve_on_host <bool>  - do mat solve on host (with device matrices). Default is doing it on device

4793:   Level: intermediate

4795:   Notes:
4796:   The return matrix can be `NULL` if the requested factorization is not available, since some combinations of matrix types and factorization
4797:   types registered with `MatSolverTypeRegister()` cannot be fully tested if not at runtime.

4799:   Users usually access the factorization solvers via `KSP`

4801:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
4802:   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

4804:   When `type` is `NULL` the available results are searched for based on the order of the calls to `MatSolverTypeRegister()` in `MatInitializePackage()`.
4805:   Since different PETSc configurations may have different external solvers, seemingly identical runs with different PETSc configurations may use a different solver.
4806:   For example if one configuration had --download-mumps while a different one had --download-superlu_dist.

4808:   Some of the packages have options for controlling the factorization, these are in the form -prefix_mat_packagename_packageoption
4809:   where prefix is normally obtained from the calling `KSP`/`PC`. If `MatGetFactor()` is called directly one can set
4810:   call `MatSetOptionsPrefixFactor()` on the originating matrix or  `MatSetOptionsPrefix()` on the resulting factor matrix.

4812:   Developer Note:
4813:   This should actually be called `MatCreateFactor()` since it creates a new factor object

4815: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `KSP`, `MatSolverType`, `MatFactorType`, `MatCopy()`, `MatDuplicate()`,
4816:           `MatGetFactorAvailable()`, `MatFactorGetCanUseOrdering()`, `MatSolverTypeRegister()`, `MatSolverTypeGet()`
4817:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatInitializePackage()`
4818: @*/
4819: PetscErrorCode MatGetFactor(Mat mat, MatSolverType type, MatFactorType ftype, Mat *f)
4820: {
4821:   PetscBool foundtype, foundmtype, shell, hasop = PETSC_FALSE;
4822:   PetscErrorCode (*conv)(Mat, MatFactorType, Mat *);

4824:   PetscFunctionBegin;

4828:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4829:   MatCheckPreallocated(mat, 1);

4831:   PetscCall(MatIsShell(mat, &shell));
4832:   if (shell) PetscCall(MatHasOperation(mat, MATOP_GET_FACTOR, &hasop));
4833:   if (hasop) {
4834:     PetscUseTypeMethod(mat, getfactor, type, ftype, f);
4835:     PetscFunctionReturn(PETSC_SUCCESS);
4836:   }

4838:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, &foundtype, &foundmtype, &conv));
4839:   if (!foundtype) {
4840:     if (type) {
4841:       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],
4842:               ((PetscObject)mat)->type_name, type);
4843:     } else {
4844:       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);
4845:     }
4846:   }
4847:   PetscCheck(foundmtype, PetscObjectComm((PetscObject)mat), PETSC_ERR_MISSING_FACTOR, "MatSolverType %s does not support matrix type %s", type, ((PetscObject)mat)->type_name);
4848:   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);

4850:   PetscCall((*conv)(mat, ftype, f));
4851:   if (mat->factorprefix) PetscCall(MatSetOptionsPrefix(*f, mat->factorprefix));
4852:   PetscFunctionReturn(PETSC_SUCCESS);
4853: }

4855: /*@
4856:   MatGetFactorAvailable - Returns a flag if matrix supports particular type and factor type

4858:   Not Collective

4860:   Input Parameters:
4861: + mat   - the matrix
4862: . type  - name of solver type, for example, `superlu`, `petsc` (to use PETSc's default)
4863: - ftype - factor type, `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`

4865:   Output Parameter:
4866: . flg - PETSC_TRUE if the factorization is available

4868:   Level: intermediate

4870:   Notes:
4871:   Some PETSc matrix formats have alternative solvers available that are contained in alternative packages
4872:   such as pastix, superlu, mumps etc.

4874:   PETSc must have been ./configure to use the external solver, using the option --download-package

4876:   Developer Note:
4877:   This should actually be called `MatCreateFactorAvailable()` since `MatGetFactor()` creates a new factor object

4879: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatSolverType`, `MatFactorType`, `MatGetFactor()`, `MatCopy()`, `MatDuplicate()`, `MatSolverTypeRegister()`,
4880:           `MAT_FACTOR_LU`, `MAT_FACTOR_CHOLESKY`, `MAT_FACTOR_ICC`, `MAT_FACTOR_ILU`, `MAT_FACTOR_QR`, `MatSolverTypeGet()`
4881: @*/
4882: PetscErrorCode MatGetFactorAvailable(Mat mat, MatSolverType type, MatFactorType ftype, PetscBool *flg)
4883: {
4884:   PetscErrorCode (*gconv)(Mat, MatFactorType, Mat *);

4886:   PetscFunctionBegin;
4888:   PetscAssertPointer(flg, 4);

4890:   *flg = PETSC_FALSE;
4891:   if (!((PetscObject)mat)->type_name) PetscFunctionReturn(PETSC_SUCCESS);

4893:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4894:   MatCheckPreallocated(mat, 1);

4896:   PetscCall(MatSolverTypeGet(type, ((PetscObject)mat)->type_name, ftype, NULL, NULL, &gconv));
4897:   *flg = gconv ? PETSC_TRUE : PETSC_FALSE;
4898:   PetscFunctionReturn(PETSC_SUCCESS);
4899: }

4901: /*@
4902:   MatDuplicate - Duplicates a matrix including the non-zero structure.

4904:   Collective

4906:   Input Parameters:
4907: + mat - the matrix
4908: - op  - One of `MAT_DO_NOT_COPY_VALUES`, `MAT_COPY_VALUES`, or `MAT_SHARE_NONZERO_PATTERN`.
4909:         See the manual page for `MatDuplicateOption()` for an explanation of these options.

4911:   Output Parameter:
4912: . M - pointer to place new matrix

4914:   Level: intermediate

4916:   Notes:
4917:   You cannot change the nonzero pattern for the parent or child matrix later if you use `MAT_SHARE_NONZERO_PATTERN`.

4919:   If `op` is not `MAT_COPY_VALUES` the numerical values in the new matrix are zeroed.

4921:   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.

4923:   When original mat is a product of matrix operation, e.g., an output of `MatMatMult()` or `MatCreateSubMatrix()`, only the matrix data structure of `mat`
4924:   is duplicated and the internal data structures created for the reuse of previous matrix operations are not duplicated.
4925:   User should not use `MatDuplicate()` to create new matrix `M` if `M` is intended to be reused as the product of matrix operation.

4927: .seealso: [](ch_matrices), `Mat`, `MatCopy()`, `MatConvert()`, `MatDuplicateOption`
4928: @*/
4929: PetscErrorCode MatDuplicate(Mat mat, MatDuplicateOption op, Mat *M)
4930: {
4931:   Mat               B;
4932:   VecType           vtype;
4933:   PetscInt          i;
4934:   PetscObject       dm, container_h, container_d;
4935:   PetscErrorCodeFn *viewf;

4937:   PetscFunctionBegin;
4940:   PetscAssertPointer(M, 3);
4941:   PetscCheck(op != MAT_COPY_VALUES || mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "MAT_COPY_VALUES not allowed for unassembled matrix");
4942:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4943:   MatCheckPreallocated(mat, 1);

4945:   PetscCall(PetscLogEventBegin(MAT_Convert, mat, 0, 0, 0));
4946:   PetscUseTypeMethod(mat, duplicate, op, M);
4947:   PetscCall(PetscLogEventEnd(MAT_Convert, mat, 0, 0, 0));
4948:   B = *M;

4950:   PetscCall(MatGetOperation(mat, MATOP_VIEW, &viewf));
4951:   if (viewf) PetscCall(MatSetOperation(B, MATOP_VIEW, viewf));
4952:   PetscCall(MatGetVecType(mat, &vtype));
4953:   PetscCall(MatSetVecType(B, vtype));

4955:   B->stencil.dim = mat->stencil.dim;
4956:   B->stencil.noc = mat->stencil.noc;
4957:   for (i = 0; i <= mat->stencil.dim + (mat->stencil.noc ? 0 : -1); i++) {
4958:     B->stencil.dims[i]   = mat->stencil.dims[i];
4959:     B->stencil.starts[i] = mat->stencil.starts[i];
4960:   }

4962:   B->nooffproczerorows = mat->nooffproczerorows;
4963:   B->nooffprocentries  = mat->nooffprocentries;

4965:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_dm", &dm));
4966:   if (dm) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_dm", dm));
4967:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Host", &container_h));
4968:   if (container_h) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Host", container_h));
4969:   PetscCall(PetscObjectQuery((PetscObject)mat, "__PETSc_MatCOOStruct_Device", &container_d));
4970:   if (container_d) PetscCall(PetscObjectCompose((PetscObject)B, "__PETSc_MatCOOStruct_Device", container_d));
4971:   if (op == MAT_COPY_VALUES) PetscCall(MatPropagateSymmetryOptions(mat, B));
4972:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
4973:   PetscFunctionReturn(PETSC_SUCCESS);
4974: }

4976: /*@
4977:   MatGetDiagonal - Gets the diagonal of a matrix as a `Vec`

4979:   Logically Collective

4981:   Input Parameter:
4982: . mat - the matrix

4984:   Output Parameter:
4985: . v - the diagonal of the matrix

4987:   Level: intermediate

4989:   Note:
4990:   If `mat` has local sizes `n` x `m`, this routine fills the first `ndiag = min(n, m)` entries
4991:   of `v` with the diagonal values. Thus `v` must have local size of at least `ndiag`. If `v`
4992:   is larger than `ndiag`, the values of the remaining entries are unspecified.

4994:   Currently only correct in parallel for square matrices.

4996: .seealso: [](ch_matrices), `Mat`, `Vec`, `MatGetRow()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`
4997: @*/
4998: PetscErrorCode MatGetDiagonal(Mat mat, Vec v)
4999: {
5000:   PetscFunctionBegin;
5004:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5005:   MatCheckPreallocated(mat, 1);
5006:   if (PetscDefined(USE_DEBUG)) {
5007:     PetscInt nv, row, col, ndiag;

5009:     PetscCall(VecGetLocalSize(v, &nv));
5010:     PetscCall(MatGetLocalSize(mat, &row, &col));
5011:     ndiag = PetscMin(row, col);
5012:     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);
5013:   }

5015:   PetscUseTypeMethod(mat, getdiagonal, v);
5016:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5017:   PetscFunctionReturn(PETSC_SUCCESS);
5018: }

5020: /*@
5021:   MatGetRowMin - Gets the minimum value (of the real part) of each
5022:   row of the matrix

5024:   Logically Collective

5026:   Input Parameter:
5027: . mat - the matrix

5029:   Output Parameters:
5030: + v   - the vector for storing the maximums
5031: - idx - the indices of the column found for each row (optional, pass `NULL` if not needed)

5033:   Level: intermediate

5035:   Note:
5036:   The result of this call are the same as if one converted the matrix to dense format
5037:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5039:   This code is only implemented for a couple of matrix formats.

5041: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`,
5042:           `MatGetRowMax()`
5043: @*/
5044: PetscErrorCode MatGetRowMin(Mat mat, Vec v, PetscInt idx[])
5045: {
5046:   PetscFunctionBegin;
5050:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5052:   if (!mat->cmap->N) {
5053:     PetscCall(VecSet(v, PETSC_MAX_REAL));
5054:     if (idx) {
5055:       PetscInt i, m = mat->rmap->n;
5056:       for (i = 0; i < m; i++) idx[i] = -1;
5057:     }
5058:   } else {
5059:     MatCheckPreallocated(mat, 1);
5060:   }
5061:   PetscUseTypeMethod(mat, getrowmin, v, idx);
5062:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5063:   PetscFunctionReturn(PETSC_SUCCESS);
5064: }

5066: /*@
5067:   MatGetRowMinAbs - Gets the minimum value (in absolute value) of each
5068:   row of the matrix

5070:   Logically Collective

5072:   Input Parameter:
5073: . mat - the matrix

5075:   Output Parameters:
5076: + v   - the vector for storing the minimums
5077: - idx - the indices of the column found for each row (or `NULL` if not needed)

5079:   Level: intermediate

5081:   Notes:
5082:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5083:   row is 0 (the first column).

5085:   This code is only implemented for a couple of matrix formats.

5087: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`
5088: @*/
5089: PetscErrorCode MatGetRowMinAbs(Mat mat, Vec v, PetscInt idx[])
5090: {
5091:   PetscFunctionBegin;
5095:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5096:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

5098:   if (!mat->cmap->N) {
5099:     PetscCall(VecSet(v, 0.0));
5100:     if (idx) {
5101:       PetscInt i, m = mat->rmap->n;
5102:       for (i = 0; i < m; i++) idx[i] = -1;
5103:     }
5104:   } else {
5105:     MatCheckPreallocated(mat, 1);
5106:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5107:     PetscUseTypeMethod(mat, getrowminabs, v, idx);
5108:   }
5109:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5110:   PetscFunctionReturn(PETSC_SUCCESS);
5111: }

5113: /*@
5114:   MatGetRowMax - Gets the maximum value (of the real part) of each
5115:   row of the matrix

5117:   Logically Collective

5119:   Input Parameter:
5120: . mat - the matrix

5122:   Output Parameters:
5123: + v   - the vector for storing the maximums
5124: - idx - the indices of the column found for each row (optional, otherwise pass `NULL`)

5126:   Level: intermediate

5128:   Notes:
5129:   The result of this call are the same as if one converted the matrix to dense format
5130:   and found the minimum value in each row (i.e. the implicit zeros are counted as zeros).

5132:   This code is only implemented for a couple of matrix formats.

5134: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMaxAbs()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5135: @*/
5136: PetscErrorCode MatGetRowMax(Mat mat, Vec v, PetscInt idx[])
5137: {
5138:   PetscFunctionBegin;
5142:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5144:   if (!mat->cmap->N) {
5145:     PetscCall(VecSet(v, PETSC_MIN_REAL));
5146:     if (idx) {
5147:       PetscInt i, m = mat->rmap->n;
5148:       for (i = 0; i < m; i++) idx[i] = -1;
5149:     }
5150:   } else {
5151:     MatCheckPreallocated(mat, 1);
5152:     PetscUseTypeMethod(mat, getrowmax, v, idx);
5153:   }
5154:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5155:   PetscFunctionReturn(PETSC_SUCCESS);
5156: }

5158: /*@
5159:   MatGetRowMaxAbs - Gets the maximum value (in absolute value) of each
5160:   row of the matrix

5162:   Logically Collective

5164:   Input Parameter:
5165: . mat - the matrix

5167:   Output Parameters:
5168: + v   - the vector for storing the maximums
5169: - idx - the indices of the column found for each row (or `NULL` if not needed)

5171:   Level: intermediate

5173:   Notes:
5174:   if a row is completely empty or has only 0.0 values, then the `idx` value for that
5175:   row is 0 (the first column).

5177:   This code is only implemented for a couple of matrix formats.

5179: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowSum()`, `MatGetRowMin()`, `MatGetRowMinAbs()`
5180: @*/
5181: PetscErrorCode MatGetRowMaxAbs(Mat mat, Vec v, PetscInt idx[])
5182: {
5183:   PetscFunctionBegin;
5187:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");

5189:   if (!mat->cmap->N) {
5190:     PetscCall(VecSet(v, 0.0));
5191:     if (idx) {
5192:       PetscInt i, m = mat->rmap->n;
5193:       for (i = 0; i < m; i++) idx[i] = -1;
5194:     }
5195:   } else {
5196:     MatCheckPreallocated(mat, 1);
5197:     if (idx) PetscCall(PetscArrayzero(idx, mat->rmap->n));
5198:     PetscUseTypeMethod(mat, getrowmaxabs, v, idx);
5199:   }
5200:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5201:   PetscFunctionReturn(PETSC_SUCCESS);
5202: }

5204: /*@
5205:   MatGetRowSumAbs - Gets the sum value (in absolute value) of each row of the matrix

5207:   Logically Collective

5209:   Input Parameter:
5210: . mat - the matrix

5212:   Output Parameter:
5213: . v - the vector for storing the sum

5215:   Level: intermediate

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

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

5229:   if (!mat->cmap->N) {
5230:     PetscCall(VecSet(v, 0.0));
5231:   } else {
5232:     MatCheckPreallocated(mat, 1);
5233:     PetscUseTypeMethod(mat, getrowsumabs, v);
5234:   }
5235:   PetscCall(PetscObjectStateIncrease((PetscObject)v));
5236:   PetscFunctionReturn(PETSC_SUCCESS);
5237: }

5239: /*@
5240:   MatGetRowSum - Gets the sum of each row of the matrix

5242:   Logically or Neighborhood Collective

5244:   Input Parameter:
5245: . mat - the matrix

5247:   Output Parameter:
5248: . v - the vector for storing the sum of rows

5250:   Level: intermediate

5252:   Note:
5253:   This code is slow since it is not currently specialized for different formats

5255: .seealso: [](ch_matrices), `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMaxAbs()`, `MatGetRowMinAbs()`, `MatGetRowSumAbs()`
5256: @*/
5257: PetscErrorCode MatGetRowSum(Mat mat, Vec v)
5258: {
5259:   Vec ones;

5261:   PetscFunctionBegin;
5265:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5266:   MatCheckPreallocated(mat, 1);
5267:   PetscCall(MatCreateVecs(mat, &ones, NULL));
5268:   PetscCall(VecSet(ones, 1.));
5269:   PetscCall(MatMult(mat, ones, v));
5270:   PetscCall(VecDestroy(&ones));
5271:   PetscFunctionReturn(PETSC_SUCCESS);
5272: }

5274: /*@
5275:   MatTransposeSetPrecursor - Set the matrix from which the second matrix will receive numerical transpose data with a call to `MatTranspose`(A,`MAT_REUSE_MATRIX`,&B)
5276:   when B was not obtained with `MatTranspose`(A,`MAT_INITIAL_MATRIX`,&B)

5278:   Collective

5280:   Input Parameter:
5281: . mat - the matrix to provide the transpose

5283:   Output Parameter:
5284: . 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

5286:   Level: advanced

5288:   Note:
5289:   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
5290:   routine allows bypassing that call.

5292: .seealso: [](ch_matrices), `Mat`, `MatTransposeSymbolic()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5293: @*/
5294: PetscErrorCode MatTransposeSetPrecursor(Mat mat, Mat B)
5295: {
5296:   MatParentState *rb = NULL;

5298:   PetscFunctionBegin;
5299:   PetscCall(PetscNew(&rb));
5300:   rb->id    = ((PetscObject)mat)->id;
5301:   rb->state = 0;
5302:   PetscCall(MatGetNonzeroState(mat, &rb->nonzerostate));
5303:   PetscCall(PetscObjectContainerCompose((PetscObject)B, "MatTransposeParent", rb, PetscCtxDestroyDefault));
5304:   PetscFunctionReturn(PETSC_SUCCESS);
5305: }

5307: /*@
5308:   MatTranspose - Computes the transpose of a matrix, either in-place or out-of-place.

5310:   Collective

5312:   Input Parameters:
5313: + mat   - the matrix to transpose
5314: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5316:   Output Parameter:
5317: . B - the transpose of the matrix

5319:   Level: intermediate

5321:   Notes:
5322:   If you use `MAT_INPLACE_MATRIX` then you must pass in `&mat` for `B`

5324:   `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
5325:   transpose, call `MatTransposeSetPrecursor(mat, B)` before calling this routine.

5327:   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.

5329:   Consider using `MatCreateTranspose()` instead if you only need a matrix that behaves like the transpose but don't need the storage to be changed.
5330:   For example, the result of `MatCreateTranspose()` will compute the transpose of the given matrix times a vector for matrix-vector products computed with `MatMult()`.

5332:   If `mat` is unchanged from the last call this function returns immediately without recomputing the result

5334:   If you only need the symbolic transpose of a matrix, and not the numerical values, use `MatTransposeSymbolic()`

5336: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`,
5337:           `MatTransposeSymbolic()`, `MatCreateTranspose()`
5338: @*/
5339: PetscErrorCode MatTranspose(Mat mat, MatReuse reuse, Mat *B)
5340: {
5341:   PetscContainer  rB = NULL;
5342:   MatParentState *rb = NULL;

5344:   PetscFunctionBegin;
5347:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5348:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5349:   PetscCheck(reuse != MAT_INPLACE_MATRIX || mat == *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX requires last matrix to match first");
5350:   PetscCheck(reuse != MAT_REUSE_MATRIX || mat != *B, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Perhaps you mean MAT_INPLACE_MATRIX");
5351:   MatCheckPreallocated(mat, 1);
5352:   if (reuse == MAT_REUSE_MATRIX) {
5353:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5354:     PetscCheck(rB, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose(). Suggest MatTransposeSetPrecursor().");
5355:     PetscCall(PetscContainerGetPointer(rB, (void **)&rb));
5356:     PetscCheck(rb->id == ((PetscObject)mat)->id, PetscObjectComm((PetscObject)*B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5357:     if (rb->state == ((PetscObject)mat)->state) PetscFunctionReturn(PETSC_SUCCESS);
5358:   }

5360:   PetscCall(PetscLogEventBegin(MAT_Transpose, mat, 0, 0, 0));
5361:   if (reuse != MAT_INPLACE_MATRIX || mat->symmetric != PETSC_BOOL3_TRUE) {
5362:     PetscUseTypeMethod(mat, transpose, reuse, B);
5363:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5364:   }
5365:   PetscCall(PetscLogEventEnd(MAT_Transpose, mat, 0, 0, 0));

5367:   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatTransposeSetPrecursor(mat, *B));
5368:   if (reuse != MAT_INPLACE_MATRIX) {
5369:     PetscCall(PetscObjectQuery((PetscObject)*B, "MatTransposeParent", (PetscObject *)&rB));
5370:     PetscCall(PetscContainerGetPointer(rB, (void **)&rb));
5371:     rb->state        = ((PetscObject)mat)->state;
5372:     rb->nonzerostate = mat->nonzerostate;
5373:   }
5374:   PetscFunctionReturn(PETSC_SUCCESS);
5375: }

5377: /*@
5378:   MatTransposeSymbolic - Computes the symbolic part of the transpose of a matrix.

5380:   Collective

5382:   Input Parameter:
5383: . A - the matrix to transpose

5385:   Output Parameter:
5386: . 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
5387:       numerical portion.

5389:   Level: intermediate

5391:   Note:
5392:   This is not supported for many matrix types, use `MatTranspose()` in those cases

5394: .seealso: [](ch_matrices), `Mat`, `MatTransposeSetPrecursor()`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`
5395: @*/
5396: PetscErrorCode MatTransposeSymbolic(Mat A, Mat *B)
5397: {
5398:   PetscFunctionBegin;
5401:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5402:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5403:   PetscCall(PetscLogEventBegin(MAT_Transpose, A, 0, 0, 0));
5404:   PetscUseTypeMethod(A, transposesymbolic, B);
5405:   PetscCall(PetscLogEventEnd(MAT_Transpose, A, 0, 0, 0));

5407:   PetscCall(MatTransposeSetPrecursor(A, *B));
5408:   PetscFunctionReturn(PETSC_SUCCESS);
5409: }

5411: PetscErrorCode MatTransposeCheckNonzeroState_Private(Mat A, Mat B)
5412: {
5413:   PetscContainer  rB;
5414:   MatParentState *rb;

5416:   PetscFunctionBegin;
5419:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5420:   PetscCheck(!A->factortype, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5421:   PetscCall(PetscObjectQuery((PetscObject)B, "MatTransposeParent", (PetscObject *)&rB));
5422:   PetscCheck(rB, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from call to MatTranspose()");
5423:   PetscCall(PetscContainerGetPointer(rB, (void **)&rb));
5424:   PetscCheck(rb->id == ((PetscObject)A)->id, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONG, "Reuse matrix used was not generated from input matrix");
5425:   PetscCheck(rb->nonzerostate == A->nonzerostate, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Reuse matrix has changed nonzero structure");
5426:   PetscFunctionReturn(PETSC_SUCCESS);
5427: }

5429: /*@
5430:   MatIsTranspose - Test whether a matrix is another one's transpose,
5431:   or its own, in which case it tests symmetry.

5433:   Collective

5435:   Input Parameters:
5436: + A   - the matrix to test
5437: . B   - the matrix to test against, this can equal the first parameter
5438: - tol - tolerance, differences between entries smaller than this are counted as zero

5440:   Output Parameter:
5441: . flg - the result

5443:   Level: intermediate

5445:   Notes:
5446:   The sequential algorithm has a running time of the order of the number of nonzeros; the parallel
5447:   test involves parallel copies of the block off-diagonal parts of the matrix.

5449: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`
5450: @*/
5451: PetscErrorCode MatIsTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5452: {
5453:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5455:   PetscFunctionBegin;
5458:   PetscAssertPointer(flg, 4);
5459:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsTranspose_C", &f));
5460:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsTranspose_C", &g));
5461:   *flg = PETSC_FALSE;
5462:   if (f && g) {
5463:     PetscCheck(f == g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for symmetry test");
5464:     PetscCall((*f)(A, B, tol, flg));
5465:   } else {
5466:     MatType mattype;

5468:     PetscCall(MatGetType(f ? B : A, &mattype));
5469:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Matrix of type %s does not support checking for transpose", mattype);
5470:   }
5471:   PetscFunctionReturn(PETSC_SUCCESS);
5472: }

5474: /*@
5475:   MatHermitianTranspose - Computes an in-place or out-of-place Hermitian transpose of a matrix in complex conjugate.

5477:   Collective

5479:   Input Parameters:
5480: + mat   - the matrix to transpose and complex conjugate
5481: - reuse - either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`

5483:   Output Parameter:
5484: . B - the Hermitian transpose

5486:   Level: intermediate

5488: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`
5489: @*/
5490: PetscErrorCode MatHermitianTranspose(Mat mat, MatReuse reuse, Mat *B)
5491: {
5492:   PetscFunctionBegin;
5493:   PetscCall(MatTranspose(mat, reuse, B));
5494: #if defined(PETSC_USE_COMPLEX)
5495:   PetscCall(MatConjugate(*B));
5496: #endif
5497:   PetscFunctionReturn(PETSC_SUCCESS);
5498: }

5500: /*@
5501:   MatIsHermitianTranspose - Test whether a matrix is another one's Hermitian transpose,

5503:   Collective

5505:   Input Parameters:
5506: + A   - the matrix to test
5507: . B   - the matrix to test against, this can equal the first parameter
5508: - tol - tolerance, differences between entries smaller than this are counted as zero

5510:   Output Parameter:
5511: . flg - the result

5513:   Level: intermediate

5515:   Notes:
5516:   Only available for `MATAIJ` matrices.

5518:   The sequential algorithm
5519:   has a running time of the order of the number of nonzeros; the parallel
5520:   test involves parallel copies of the block off-diagonal parts of the matrix.

5522: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsTranspose()`
5523: @*/
5524: PetscErrorCode MatIsHermitianTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
5525: {
5526:   PetscErrorCode (*f)(Mat, Mat, PetscReal, PetscBool *), (*g)(Mat, Mat, PetscReal, PetscBool *);

5528:   PetscFunctionBegin;
5531:   PetscAssertPointer(flg, 4);
5532:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatIsHermitianTranspose_C", &f));
5533:   PetscCall(PetscObjectQueryFunction((PetscObject)B, "MatIsHermitianTranspose_C", &g));
5534:   if (f && g) {
5535:     PetscCheck(f != g, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_NOTSAMETYPE, "Matrices do not have the same comparator for Hermitian test");
5536:     PetscCall((*f)(A, B, tol, flg));
5537:   }
5538:   PetscFunctionReturn(PETSC_SUCCESS);
5539: }

5541: /*@
5542:   MatPermute - Creates a new matrix with rows and columns permuted from the
5543:   original.

5545:   Collective

5547:   Input Parameters:
5548: + mat - the matrix to permute
5549: . row - row permutation, each processor supplies only the permutation for its rows
5550: - col - column permutation, each processor supplies only the permutation for its columns

5552:   Output Parameter:
5553: . B - the permuted matrix

5555:   Level: advanced

5557:   Note:
5558:   The index sets map from row/col of permuted matrix to row/col of original matrix.
5559:   The index sets should be on the same communicator as mat and have the same local sizes.

5561:   Developer Note:
5562:   If you want to implement `MatPermute()` for a matrix type, and your approach doesn't
5563:   exploit the fact that row and col are permutations, consider implementing the
5564:   more general `MatCreateSubMatrix()` instead.

5566: .seealso: [](ch_matrices), `Mat`, `MatGetOrdering()`, `ISAllGather()`, `MatCreateSubMatrix()`
5567: @*/
5568: PetscErrorCode MatPermute(Mat mat, IS row, IS col, Mat *B)
5569: {
5570:   PetscFunctionBegin;
5575:   PetscAssertPointer(B, 4);
5576:   PetscCheckSameComm(mat, 1, row, 2);
5577:   if (row != col) PetscCheckSameComm(row, 2, col, 3);
5578:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5579:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5580:   PetscCheck(mat->ops->permute || mat->ops->createsubmatrix, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatPermute not available for Mat type %s", ((PetscObject)mat)->type_name);
5581:   MatCheckPreallocated(mat, 1);

5583:   if (mat->ops->permute) {
5584:     PetscUseTypeMethod(mat, permute, row, col, B);
5585:     PetscCall(PetscObjectStateIncrease((PetscObject)*B));
5586:   } else {
5587:     PetscCall(MatCreateSubMatrix(mat, row, col, MAT_INITIAL_MATRIX, B));
5588:   }
5589:   PetscFunctionReturn(PETSC_SUCCESS);
5590: }

5592: /*@
5593:   MatEqual - Compares two matrices.

5595:   Collective

5597:   Input Parameters:
5598: + A - the first matrix
5599: - B - the second matrix

5601:   Output Parameter:
5602: . flg - `PETSC_TRUE` if the matrices are equal; `PETSC_FALSE` otherwise.

5604:   Level: intermediate

5606:   Note:
5607:   If either of the matrix is "matrix-free", meaning the matrix entries are not stored explicitly then equality is determined by comparing
5608:   the results of several matrix-vector product using randomly created vectors, see `MatMultEqual()`.

5610: .seealso: [](ch_matrices), `Mat`, `MatMultEqual()`
5611: @*/
5612: PetscErrorCode MatEqual(Mat A, Mat B, PetscBool *flg)
5613: {
5614:   PetscFunctionBegin;
5619:   PetscAssertPointer(flg, 3);
5620:   PetscCheckSameComm(A, 1, B, 2);
5621:   MatCheckPreallocated(A, 1);
5622:   MatCheckPreallocated(B, 2);
5623:   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5624:   PetscCheck(B->assembled, PetscObjectComm((PetscObject)B), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5625:   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,
5626:              B->cmap->N);
5627:   if (A->ops->equal && A->ops->equal == B->ops->equal) {
5628:     PetscUseTypeMethod(A, equal, B, flg);
5629:   } else {
5630:     PetscCall(MatMultEqual(A, B, 10, flg));
5631:   }
5632:   PetscFunctionReturn(PETSC_SUCCESS);
5633: }

5635: /*@
5636:   MatDiagonalScale - Scales a matrix on the left and right by diagonal
5637:   matrices that are stored as vectors.  Either of the two scaling
5638:   matrices can be `NULL`.

5640:   Collective

5642:   Input Parameters:
5643: + mat - the matrix to be scaled
5644: . l   - the left scaling vector (or `NULL`)
5645: - r   - the right scaling vector (or `NULL`)

5647:   Level: intermediate

5649:   Note:
5650:   `MatDiagonalScale()` computes $A = LAR$, where
5651:   L = a diagonal matrix (stored as a vector), R = a diagonal matrix (stored as a vector)
5652:   The L scales the rows of the matrix, the R scales the columns of the matrix.

5654: .seealso: [](ch_matrices), `Mat`, `MatScale()`, `MatShift()`, `MatDiagonalSet()`
5655: @*/
5656: PetscErrorCode MatDiagonalScale(Mat mat, Vec l, Vec r)
5657: {
5658:   PetscFunctionBegin;
5661:   if (l) {
5663:     PetscCheckSameComm(mat, 1, l, 2);
5664:   }
5665:   if (r) {
5667:     PetscCheckSameComm(mat, 1, r, 3);
5668:   }
5669:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5670:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5671:   MatCheckPreallocated(mat, 1);
5672:   if (!l && !r) PetscFunctionReturn(PETSC_SUCCESS);

5674:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5675:   PetscUseTypeMethod(mat, diagonalscale, l, r);
5676:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5677:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5678:   if (l != r) mat->symmetric = PETSC_BOOL3_FALSE;
5679:   PetscFunctionReturn(PETSC_SUCCESS);
5680: }

5682: /*@
5683:   MatScale - Scales all elements of a matrix by a given number.

5685:   Logically Collective

5687:   Input Parameters:
5688: + mat - the matrix to be scaled
5689: - a   - the scaling value

5691:   Level: intermediate

5693: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
5694: @*/
5695: PetscErrorCode MatScale(Mat mat, PetscScalar a)
5696: {
5697:   PetscFunctionBegin;
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");
5703:   MatCheckPreallocated(mat, 1);

5705:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
5706:   if (a != (PetscScalar)1.0) {
5707:     PetscUseTypeMethod(mat, scale, a);
5708:     PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5709:   }
5710:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
5711:   PetscFunctionReturn(PETSC_SUCCESS);
5712: }

5714: /*@
5715:   MatNorm - Calculates various norms of a matrix.

5717:   Collective

5719:   Input Parameters:
5720: + mat  - the matrix
5721: - type - the type of norm, `NORM_1`, `NORM_FROBENIUS`, `NORM_INFINITY`

5723:   Output Parameter:
5724: . nrm - the resulting norm

5726:   Level: intermediate

5728: .seealso: [](ch_matrices), `Mat`
5729: @*/
5730: PetscErrorCode MatNorm(Mat mat, NormType type, PetscReal *nrm)
5731: {
5732:   PetscFunctionBegin;
5735:   PetscAssertPointer(nrm, 3);

5737:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
5738:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
5739:   MatCheckPreallocated(mat, 1);

5741:   PetscUseTypeMethod(mat, norm, type, nrm);
5742:   PetscFunctionReturn(PETSC_SUCCESS);
5743: }

5745: /*
5746:      This variable is used to prevent counting of MatAssemblyBegin() that
5747:    are called from within a MatAssemblyEnd().
5748: */
5749: static PetscInt MatAssemblyEnd_InUse = 0;
5750: /*@
5751:   MatAssemblyBegin - Begins assembling the matrix.  This routine should
5752:   be called after completing all calls to `MatSetValues()`.

5754:   Collective

5756:   Input Parameters:
5757: + mat  - the matrix
5758: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5760:   Level: beginner

5762:   Notes:
5763:   `MatSetValues()` generally caches the values that belong to other MPI processes.  The matrix is ready to
5764:   use only after `MatAssemblyBegin()` and `MatAssemblyEnd()` have been called.

5766:   Use `MAT_FLUSH_ASSEMBLY` when switching between `ADD_VALUES` and `INSERT_VALUES`
5767:   in `MatSetValues()`; use `MAT_FINAL_ASSEMBLY` for the final assembly before
5768:   using the matrix.

5770:   ALL processes that share a matrix MUST call `MatAssemblyBegin()` and `MatAssemblyEnd()` the SAME NUMBER of times, and each time with the
5771:   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
5772:   a global collective operation requiring all processes that share the matrix.

5774:   Space for preallocated nonzeros that is not filled by a call to `MatSetValues()` or a related routine are compressed
5775:   out by assembly. If you intend to use that extra space on a subsequent assembly, be sure to insert explicit zeros
5776:   before `MAT_FINAL_ASSEMBLY` so the space is not compressed out.

5778: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssembled()`
5779: @*/
5780: PetscErrorCode MatAssemblyBegin(Mat mat, MatAssemblyType type)
5781: {
5782:   PetscFunctionBegin;
5785:   MatCheckPreallocated(mat, 1);
5786:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix. Did you forget to call MatSetUnfactored()?");
5787:   if (mat->assembled) {
5788:     mat->was_assembled = PETSC_TRUE;
5789:     mat->assembled     = PETSC_FALSE;
5790:   }

5792:   if (!MatAssemblyEnd_InUse) {
5793:     PetscCall(PetscLogEventBegin(MAT_AssemblyBegin, mat, 0, 0, 0));
5794:     PetscTryTypeMethod(mat, assemblybegin, type);
5795:     PetscCall(PetscLogEventEnd(MAT_AssemblyBegin, mat, 0, 0, 0));
5796:   } else PetscTryTypeMethod(mat, assemblybegin, type);
5797:   PetscFunctionReturn(PETSC_SUCCESS);
5798: }

5800: /*@
5801:   MatAssembled - Indicates if a matrix has been assembled and is ready for
5802:   use; for example, in matrix-vector product.

5804:   Not Collective

5806:   Input Parameter:
5807: . mat - the matrix

5809:   Output Parameter:
5810: . assembled - `PETSC_TRUE` or `PETSC_FALSE`

5812:   Level: advanced

5814: .seealso: [](ch_matrices), `Mat`, `MatAssemblyEnd()`, `MatSetValues()`, `MatAssemblyBegin()`
5815: @*/
5816: PetscErrorCode MatAssembled(Mat mat, PetscBool *assembled)
5817: {
5818:   PetscFunctionBegin;
5820:   PetscAssertPointer(assembled, 2);
5821:   *assembled = mat->assembled;
5822:   PetscFunctionReturn(PETSC_SUCCESS);
5823: }

5825: /*@
5826:   MatAssemblyEnd - Completes assembling the matrix.  This routine should
5827:   be called after `MatAssemblyBegin()`.

5829:   Collective

5831:   Input Parameters:
5832: + mat  - the matrix
5833: - type - type of assembly, either `MAT_FLUSH_ASSEMBLY` or `MAT_FINAL_ASSEMBLY`

5835:   Options Database Keys:
5836: + -mat_view ::ascii_info             - Prints info on matrix at conclusion of `MatAssemblyEnd()`
5837: . -mat_view ::ascii_info_detail      - Prints more detailed info
5838: . -mat_view                          - Prints matrix in ASCII format
5839: . -mat_view ::ascii_matlab           - Prints matrix in MATLAB format
5840: . -mat_view draw                     - draws nonzero structure of matrix, using `MatView()` and `PetscDrawOpenX()`.
5841: . -display <name>                    - Sets display name (default is host)
5842: . -draw_pause <sec>                  - Sets number of seconds to pause after display
5843: . -mat_view socket                   - Sends matrix to socket, can be accessed from MATLAB (See [Using MATLAB with PETSc](ch_matlab))
5844: . -viewer_socket_machine <machine>   - Machine to use for socket
5845: . -viewer_socket_port <port>         - Port number to use for socket
5846: - -mat_view binary:filename[:append] - Save matrix to file in binary format

5848:   Level: beginner

5850: .seealso: [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatSetValues()`, `PetscDrawOpenX()`, `PetscDrawCreate()`, `MatView()`, `MatAssembled()`, `PetscViewerSocketOpen()`
5851: @*/
5852: PetscErrorCode MatAssemblyEnd(Mat mat, MatAssemblyType type)
5853: {
5854:   static PetscInt inassm = 0;
5855:   PetscBool       flg    = PETSC_FALSE;

5857:   PetscFunctionBegin;

5861:   inassm++;
5862:   MatAssemblyEnd_InUse++;
5863:   if (MatAssemblyEnd_InUse == 1) { /* Do the logging only the first time through */
5864:     PetscCall(PetscLogEventBegin(MAT_AssemblyEnd, mat, 0, 0, 0));
5865:     PetscTryTypeMethod(mat, assemblyend, type);
5866:     PetscCall(PetscLogEventEnd(MAT_AssemblyEnd, mat, 0, 0, 0));
5867:   } else PetscTryTypeMethod(mat, assemblyend, type);

5869:   /* Flush assembly is not a true assembly */
5870:   if (type != MAT_FLUSH_ASSEMBLY) {
5871:     if (mat->num_ass) {
5872:       if (!mat->symmetry_eternal) {
5873:         mat->symmetric = PETSC_BOOL3_UNKNOWN;
5874:         mat->hermitian = PETSC_BOOL3_UNKNOWN;
5875:       }
5876:       if (!mat->structural_symmetry_eternal && mat->ass_nonzerostate != mat->nonzerostate) mat->structurally_symmetric = PETSC_BOOL3_UNKNOWN;
5877:       if (!mat->spd_eternal) mat->spd = PETSC_BOOL3_UNKNOWN;
5878:     }
5879:     mat->num_ass++;
5880:     mat->assembled        = PETSC_TRUE;
5881:     mat->ass_nonzerostate = mat->nonzerostate;
5882:   }

5884:   mat->insertmode = NOT_SET_VALUES;
5885:   MatAssemblyEnd_InUse--;
5886:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
5887:   if (inassm == 1 && type != MAT_FLUSH_ASSEMBLY) {
5888:     PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));

5890:     if (mat->checksymmetryonassembly) {
5891:       PetscCall(MatIsSymmetric(mat, mat->checksymmetrytol, &flg));
5892:       if (flg) {
5893:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
5894:       } else {
5895:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)mat), "Matrix is not symmetric (tolerance %g)\n", (double)mat->checksymmetrytol));
5896:       }
5897:     }
5898:     if (mat->nullsp && mat->checknullspaceonassembly) PetscCall(MatNullSpaceTest(mat->nullsp, mat, NULL));
5899:   }
5900:   inassm--;
5901:   PetscFunctionReturn(PETSC_SUCCESS);
5902: }

5904: // PetscClangLinter pragma disable: -fdoc-section-header-unknown
5905: /*@
5906:   MatSetOption - Sets a parameter option for a matrix. Some options
5907:   may be specific to certain storage formats.  Some options
5908:   determine how values will be inserted (or added). Sorted,
5909:   row-oriented input will generally assemble the fastest. The default
5910:   is row-oriented.

5912:   Logically Collective for certain operations, such as `MAT_SPD`, not collective for `MAT_ROW_ORIENTED`, see `MatOption`

5914:   Input Parameters:
5915: + mat - the matrix
5916: . op  - the option, one of those listed below (and possibly others),
5917: - flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

5919:   Options Describing Matrix Structure:
5920: + `MAT_SPD`                         - symmetric positive definite
5921: . `MAT_SYMMETRIC`                   - symmetric in terms of both structure and value
5922: . `MAT_HERMITIAN`                   - transpose is the complex conjugation
5923: . `MAT_STRUCTURALLY_SYMMETRIC`      - symmetric nonzero structure
5924: . `MAT_SYMMETRY_ETERNAL`            - indicates the symmetry (or Hermitian structure) or its absence will persist through any changes to the matrix
5925: . `MAT_STRUCTURAL_SYMMETRY_ETERNAL` - indicates the structural symmetry or its absence will persist through any changes to the matrix
5926: . `MAT_SPD_ETERNAL`                 - indicates the value of `MAT_SPD` (true or false) will persist through any changes to the matrix

5928:    These are not really options of the matrix, they are knowledge about the structure of the matrix that users may provide so that they
5929:    do not need to be computed (usually at a high cost)

5931:    Options For Use with `MatSetValues()`:
5932:    Insert a logically dense subblock, which can be
5933: . `MAT_ROW_ORIENTED`                - row-oriented (default)

5935:    These options reflect the data you pass in with `MatSetValues()`; it has
5936:    nothing to do with how the data is stored internally in the matrix
5937:    data structure.

5939:    When (re)assembling a matrix, we can restrict the input for
5940:    efficiency/debugging purposes.  These options include
5941: . `MAT_NEW_NONZERO_LOCATIONS`       - additional insertions will be allowed if they generate a new nonzero (slow)
5942: . `MAT_FORCE_DIAGONAL_ENTRIES`      - forces diagonal entries to be allocated
5943: . `MAT_IGNORE_OFF_PROC_ENTRIES`     - drops off-processor entries
5944: . `MAT_NEW_NONZERO_LOCATION_ERR`    - generates an error for new matrix entry
5945: . `MAT_USE_HASH_TABLE`              - uses a hash table to speed up matrix assembly
5946: . `MAT_NO_OFF_PROC_ENTRIES`         - you know each process will only set values for its own rows, will generate an error if
5947:         any process sets values for another process. This avoids all reductions in the MatAssembly routines and thus improves
5948:         performance for very large process counts.
5949: - `MAT_SUBSET_OFF_PROC_ENTRIES`     - you know that the first assembly after setting this flag will set a superset
5950:         of the off-process entries required for all subsequent assemblies. This avoids a rendezvous step in the MatAssembly
5951:         functions, instead sending only neighbor messages.

5953:   Level: intermediate

5955:   Notes:
5956:   Except for `MAT_UNUSED_NONZERO_LOCATION_ERR` and  `MAT_ROW_ORIENTED` all processes that share the matrix must pass the same value in flg!

5958:   Some options are relevant only for particular matrix types and
5959:   are thus ignored by others.  Other options are not supported by
5960:   certain matrix types and will generate an error message if set.

5962:   If using Fortran to compute a matrix, one may need to
5963:   use the column-oriented option (or convert to the row-oriented
5964:   format).

5966:   `MAT_NEW_NONZERO_LOCATIONS` set to `PETSC_FALSE` indicates that any add or insertion
5967:   that would generate a new entry in the nonzero structure is instead
5968:   ignored.  Thus, if memory has not already been allocated for this particular
5969:   data, then the insertion is ignored. For dense matrices, in which
5970:   the entire array is allocated, no entries are ever ignored.
5971:   Set after the first `MatAssemblyEnd()`. If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

5973:   `MAT_NEW_NONZERO_LOCATION_ERR` set to PETSC_TRUE indicates that any add or insertion
5974:   that would generate a new entry in the nonzero structure instead produces
5975:   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

5977:   `MAT_NEW_NONZERO_ALLOCATION_ERR` set to `PETSC_TRUE` indicates that any add or insertion
5978:   that would generate a new entry that has not been preallocated will
5979:   instead produce an error. (Currently supported for `MATAIJ` and `MATBAIJ` formats
5980:   only.) This is a useful flag when debugging matrix memory preallocation.
5981:   If this option is set, then the `MatAssemblyBegin()`/`MatAssemblyEnd()` processes has one less global reduction

5983:   `MAT_IGNORE_OFF_PROC_ENTRIES` set to `PETSC_TRUE` indicates entries destined for
5984:   other processors should be dropped, rather than stashed.
5985:   This is useful if you know that the "owning" processor is also
5986:   always generating the correct matrix entries, so that PETSc need
5987:   not transfer duplicate entries generated on another processor.

5989:   `MAT_USE_HASH_TABLE` indicates that a hash table be used to improve the
5990:   searches during matrix assembly. When this flag is set, the hash table
5991:   is created during the first matrix assembly. This hash table is
5992:   used the next time through, during `MatSetValues()`/`MatSetValuesBlocked()`
5993:   to improve the searching of indices. `MAT_NEW_NONZERO_LOCATIONS` flag
5994:   should be used with `MAT_USE_HASH_TABLE` flag. This option is currently
5995:   supported by `MATMPIBAIJ` format only.

5997:   `MAT_KEEP_NONZERO_PATTERN` indicates when `MatZeroRows()` is called the zeroed entries
5998:   are kept in the nonzero structure. This flag is not used for `MatZeroRowsColumns()`

6000:   `MAT_IGNORE_ZERO_ENTRIES` - for `MATAIJ` and `MATIS` matrices this will stop zero values from creating
6001:   a zero location in the matrix

6003:   `MAT_USE_INODES` - indicates using inode version of the code - works with `MATAIJ` matrix types

6005:   `MAT_NO_OFF_PROC_ZERO_ROWS` - you know each process will only zero its own rows. This avoids all reductions in the
6006:   zero row routines and thus improves performance for very large process counts.

6008:   `MAT_IGNORE_LOWER_TRIANGULAR` - For `MATSBAIJ` matrices will ignore any insertions you make in the lower triangular
6009:   part of the matrix (since they should match the upper triangular part).

6011:   `MAT_SORTED_FULL` - each process provides exactly its local rows; all column indices for a given row are passed in a
6012:   single call to `MatSetValues()`, preallocation is perfect, row-oriented, `INSERT_VALUES` is used. Common
6013:   with finite difference schemes with non-periodic boundary conditions.

6015:   Developer Note:
6016:   `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, and `MAT_SPD_ETERNAL` are used by `MatAssemblyEnd()` and in other
6017:   places where otherwise the value of `MAT_SYMMETRIC`, `MAT_STRUCTURALLY_SYMMETRIC` or `MAT_SPD` would need to be changed back
6018:   to `PETSC_BOOL3_UNKNOWN` because the matrix values had changed so the code cannot be certain that the related property had
6019:   not changed.

6021: .seealso: [](ch_matrices), `MatOption`, `Mat`, `MatGetOption()`
6022: @*/
6023: PetscErrorCode MatSetOption(Mat mat, MatOption op, PetscBool flg)
6024: {
6025:   PetscFunctionBegin;
6027:   if (op > 0) {
6030:   }

6032:   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);

6034:   switch (op) {
6035:   case MAT_FORCE_DIAGONAL_ENTRIES:
6036:     mat->force_diagonals = flg;
6037:     PetscFunctionReturn(PETSC_SUCCESS);
6038:   case MAT_NO_OFF_PROC_ENTRIES:
6039:     mat->nooffprocentries = flg;
6040:     PetscFunctionReturn(PETSC_SUCCESS);
6041:   case MAT_SUBSET_OFF_PROC_ENTRIES:
6042:     mat->assembly_subset = flg;
6043:     if (!mat->assembly_subset) { /* See the same logic in VecAssembly wrt VEC_SUBSET_OFF_PROC_ENTRIES */
6044: #if !defined(PETSC_HAVE_MPIUNI)
6045:       PetscCall(MatStashScatterDestroy_BTS(&mat->stash));
6046: #endif
6047:       mat->stash.first_assembly_done = PETSC_FALSE;
6048:     }
6049:     PetscFunctionReturn(PETSC_SUCCESS);
6050:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6051:     mat->nooffproczerorows = flg;
6052:     PetscFunctionReturn(PETSC_SUCCESS);
6053:   case MAT_SPD:
6054:     if (flg) {
6055:       mat->spd                    = PETSC_BOOL3_TRUE;
6056:       mat->symmetric              = PETSC_BOOL3_TRUE;
6057:       mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6058:     } else {
6059:       mat->spd = PETSC_BOOL3_FALSE;
6060:     }
6061:     break;
6062:   case MAT_SYMMETRIC:
6063:     mat->symmetric = PetscBoolToBool3(flg);
6064:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6065: #if !defined(PETSC_USE_COMPLEX)
6066:     mat->hermitian = PetscBoolToBool3(flg);
6067: #endif
6068:     break;
6069:   case MAT_HERMITIAN:
6070:     mat->hermitian = PetscBoolToBool3(flg);
6071:     if (flg) mat->structurally_symmetric = PETSC_BOOL3_TRUE;
6072: #if !defined(PETSC_USE_COMPLEX)
6073:     mat->symmetric = PetscBoolToBool3(flg);
6074: #endif
6075:     break;
6076:   case MAT_STRUCTURALLY_SYMMETRIC:
6077:     mat->structurally_symmetric = PetscBoolToBool3(flg);
6078:     break;
6079:   case MAT_SYMMETRY_ETERNAL:
6080:     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");
6081:     mat->symmetry_eternal = flg;
6082:     if (flg) mat->structural_symmetry_eternal = PETSC_TRUE;
6083:     break;
6084:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6085:     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");
6086:     mat->structural_symmetry_eternal = flg;
6087:     break;
6088:   case MAT_SPD_ETERNAL:
6089:     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");
6090:     mat->spd_eternal = flg;
6091:     if (flg) {
6092:       mat->structural_symmetry_eternal = PETSC_TRUE;
6093:       mat->symmetry_eternal            = PETSC_TRUE;
6094:     }
6095:     break;
6096:   case MAT_STRUCTURE_ONLY:
6097:     mat->structure_only = flg;
6098:     break;
6099:   case MAT_SORTED_FULL:
6100:     mat->sortedfull = flg;
6101:     break;
6102:   default:
6103:     break;
6104:   }
6105:   PetscTryTypeMethod(mat, setoption, op, flg);
6106:   PetscFunctionReturn(PETSC_SUCCESS);
6107: }

6109: /*@
6110:   MatGetOption - Gets a parameter option that has been set for a matrix.

6112:   Logically Collective

6114:   Input Parameters:
6115: + mat - the matrix
6116: - op  - the option, this only responds to certain options, check the code for which ones

6118:   Output Parameter:
6119: . flg - turn the option on (`PETSC_TRUE`) or off (`PETSC_FALSE`)

6121:   Level: intermediate

6123:   Notes:
6124:   Can only be called after `MatSetSizes()` and `MatSetType()` have been set.

6126:   Certain option values may be unknown, for those use the routines `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, or
6127:   `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`

6129: .seealso: [](ch_matrices), `Mat`, `MatOption`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`,
6130:     `MatIsSymmetricKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
6131: @*/
6132: PetscErrorCode MatGetOption(Mat mat, MatOption op, PetscBool *flg)
6133: {
6134:   PetscFunctionBegin;

6138:   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);
6139:   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()");

6141:   switch (op) {
6142:   case MAT_NO_OFF_PROC_ENTRIES:
6143:     *flg = mat->nooffprocentries;
6144:     break;
6145:   case MAT_NO_OFF_PROC_ZERO_ROWS:
6146:     *flg = mat->nooffproczerorows;
6147:     break;
6148:   case MAT_SYMMETRIC:
6149:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSymmetric() or MatIsSymmetricKnown()");
6150:     break;
6151:   case MAT_HERMITIAN:
6152:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsHermitian() or MatIsHermitianKnown()");
6153:     break;
6154:   case MAT_STRUCTURALLY_SYMMETRIC:
6155:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsStructurallySymmetric() or MatIsStructurallySymmetricKnown()");
6156:     break;
6157:   case MAT_SPD:
6158:     SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Use MatIsSPDKnown()");
6159:     break;
6160:   case MAT_SYMMETRY_ETERNAL:
6161:     *flg = mat->symmetry_eternal;
6162:     break;
6163:   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
6164:     *flg = mat->symmetry_eternal;
6165:     break;
6166:   default:
6167:     break;
6168:   }
6169:   PetscFunctionReturn(PETSC_SUCCESS);
6170: }

6172: /*@
6173:   MatZeroEntries - Zeros all entries of a matrix.  For sparse matrices
6174:   this routine retains the old nonzero structure.

6176:   Logically Collective

6178:   Input Parameter:
6179: . mat - the matrix

6181:   Level: intermediate

6183:   Note:
6184:   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.
6185:   See the Performance chapter of the users manual for information on preallocating matrices.

6187: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`
6188: @*/
6189: PetscErrorCode MatZeroEntries(Mat mat)
6190: {
6191:   PetscFunctionBegin;
6194:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6195:   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");
6196:   MatCheckPreallocated(mat, 1);

6198:   PetscCall(PetscLogEventBegin(MAT_ZeroEntries, mat, 0, 0, 0));
6199:   PetscUseTypeMethod(mat, zeroentries);
6200:   PetscCall(PetscLogEventEnd(MAT_ZeroEntries, mat, 0, 0, 0));
6201:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6202:   PetscFunctionReturn(PETSC_SUCCESS);
6203: }

6205: /*@
6206:   MatZeroRowsColumns - Zeros all entries (except possibly the main diagonal)
6207:   of a set of rows and columns of a matrix.

6209:   Collective

6211:   Input Parameters:
6212: + mat     - the matrix
6213: . numRows - the number of rows/columns to zero
6214: . rows    - the global row indices
6215: . diag    - value put in the diagonal of the eliminated rows
6216: . x       - optional vector of the solution for zeroed rows (other entries in vector are not used), these must be set before this call
6217: - b       - optional vector of the right-hand side, that will be adjusted by provided solution entries

6219:   Level: intermediate

6221:   Notes:
6222:   This routine, along with `MatZeroRows()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6224:   For each zeroed row, the value of the corresponding `b` is set to diag times the value of the corresponding `x`.
6225:   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

6227:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6228:   Krylov method to take advantage of the known solution on the zeroed rows.

6230:   For the parallel case, all processes that share the matrix (i.e.,
6231:   those in the communicator used for matrix creation) MUST call this
6232:   routine, regardless of whether any rows being zeroed are owned by
6233:   them.

6235:   Unlike `MatZeroRows()`, this ignores the `MAT_KEEP_NONZERO_PATTERN` option value set with `MatSetOption()`, it merely zeros those entries in the matrix, but never
6236:   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
6237:   missing.

6239:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6240:   list only rows local to itself).

6242:   The option `MAT_NO_OFF_PROC_ZERO_ROWS` does not apply to this routine.

6244: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRows()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6245:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6246: @*/
6247: PetscErrorCode MatZeroRowsColumns(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6248: {
6249:   PetscFunctionBegin;
6252:   if (numRows) PetscAssertPointer(rows, 3);
6253:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6254:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6255:   MatCheckPreallocated(mat, 1);

6257:   PetscUseTypeMethod(mat, zerorowscolumns, numRows, rows, diag, x, b);
6258:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6259:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6260:   PetscFunctionReturn(PETSC_SUCCESS);
6261: }

6263: /*@
6264:   MatZeroRowsColumnsIS - Zeros all entries (except possibly the main diagonal)
6265:   of a set of rows and columns of a matrix.

6267:   Collective

6269:   Input Parameters:
6270: + mat  - the matrix
6271: . is   - the rows to zero
6272: . diag - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6273: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6274: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6276:   Level: intermediate

6278:   Note:
6279:   See `MatZeroRowsColumns()` for details on how this routine operates.

6281: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6282:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRows()`, `MatZeroRowsColumnsStencil()`
6283: @*/
6284: PetscErrorCode MatZeroRowsColumnsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6285: {
6286:   PetscInt        numRows;
6287:   const PetscInt *rows;

6289:   PetscFunctionBegin;
6294:   PetscCall(ISGetLocalSize(is, &numRows));
6295:   PetscCall(ISGetIndices(is, &rows));
6296:   PetscCall(MatZeroRowsColumns(mat, numRows, rows, diag, x, b));
6297:   PetscCall(ISRestoreIndices(is, &rows));
6298:   PetscFunctionReturn(PETSC_SUCCESS);
6299: }

6301: /*@
6302:   MatZeroRows - Zeros all entries (except possibly the main diagonal)
6303:   of a set of rows of a matrix.

6305:   Collective

6307:   Input Parameters:
6308: + mat     - the matrix
6309: . numRows - the number of rows to zero
6310: . rows    - the global row indices
6311: . diag    - value put in the diagonal of the zeroed rows
6312: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used), these must be set before this call
6313: - b       - optional vector of right-hand side, that will be adjusted by provided solution entries

6315:   Level: intermediate

6317:   Notes:
6318:   This routine, along with `MatZeroRowsColumns()`, is typically used to eliminate known Dirichlet boundary conditions from a linear system.

6320:   For each zeroed row, the value of the corresponding `b` is set to `diag` times the value of the corresponding `x`.

6322:   If the resulting linear system is to be solved with `KSP` then one can (but does not have to) call `KSPSetInitialGuessNonzero()` to allow the
6323:   Krylov method to take advantage of the known solution on the zeroed rows.

6325:   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)
6326:   from the matrix.

6328:   Unlike `MatZeroRowsColumns()` for the `MATAIJ` and `MATBAIJ` matrix formats this removes the old nonzero structure, from the eliminated rows of the matrix
6329:   but does not release memory.  Because of this removal matrix-vector products with the adjusted matrix will be a bit faster. For the dense
6330:   formats this does not alter the nonzero structure.

6332:   If the option `MatSetOption`(mat,`MAT_KEEP_NONZERO_PATTERN`,`PETSC_TRUE`) the nonzero structure
6333:   of the matrix is not changed the values are
6334:   merely zeroed.

6336:   The user can set a value in the diagonal entry (or for the `MATAIJ` format
6337:   formats can optionally remove the main diagonal entry from the
6338:   nonzero structure as well, by passing 0.0 as the final argument).

6340:   For the parallel case, all processes that share the matrix (i.e.,
6341:   those in the communicator used for matrix creation) MUST call this
6342:   routine, regardless of whether any rows being zeroed are owned by
6343:   them.

6345:   Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to
6346:   list only rows local to itself).

6348:   You can call `MatSetOption`(mat,`MAT_NO_OFF_PROC_ZERO_ROWS`,`PETSC_TRUE`) if each process indicates only rows it
6349:   owns that are to be zeroed. This saves a global synchronization in the implementation.

6351: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6352:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `PCREDISTRIBUTE`, `MAT_KEEP_NONZERO_PATTERN`
6353: @*/
6354: PetscErrorCode MatZeroRows(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6355: {
6356:   PetscFunctionBegin;
6359:   if (numRows) PetscAssertPointer(rows, 3);
6360:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6361:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6362:   MatCheckPreallocated(mat, 1);

6364:   PetscUseTypeMethod(mat, zerorows, numRows, rows, diag, x, b);
6365:   PetscCall(MatViewFromOptions(mat, NULL, "-mat_view"));
6366:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6367:   PetscFunctionReturn(PETSC_SUCCESS);
6368: }

6370: /*@
6371:   MatZeroRowsIS - Zeros all entries (except possibly the main diagonal)
6372:   of a set of rows of a matrix indicated by an `IS`

6374:   Collective

6376:   Input Parameters:
6377: + mat  - the matrix
6378: . is   - index set, `IS`, of rows to remove (if `NULL` then no row is removed)
6379: . diag - value put in all diagonals of eliminated rows
6380: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6381: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6383:   Level: intermediate

6385:   Note:
6386:   See `MatZeroRows()` for details on how this routine operates.

6388: .seealso: [](ch_matrices), `Mat`, `MatZeroRows()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6389:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`, `IS`
6390: @*/
6391: PetscErrorCode MatZeroRowsIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6392: {
6393:   PetscInt        numRows = 0;
6394:   const PetscInt *rows    = NULL;

6396:   PetscFunctionBegin;
6399:   if (is) {
6401:     PetscCall(ISGetLocalSize(is, &numRows));
6402:     PetscCall(ISGetIndices(is, &rows));
6403:   }
6404:   PetscCall(MatZeroRows(mat, numRows, rows, diag, x, b));
6405:   if (is) PetscCall(ISRestoreIndices(is, &rows));
6406:   PetscFunctionReturn(PETSC_SUCCESS);
6407: }

6409: /*@
6410:   MatZeroRowsStencil - Zeros all entries (except possibly the main diagonal)
6411:   of a set of rows of a matrix indicated by a `MatStencil`. These rows must be local to the process.

6413:   Collective

6415:   Input Parameters:
6416: + mat     - the matrix
6417: . numRows - the number of rows to remove
6418: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows indicated by an array of `MatStencil`
6419: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6420: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6421: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6423:   Level: intermediate

6425:   Notes:
6426:   See `MatZeroRows()` for details on how this routine operates.

6428:   The grid coordinates are across the entire grid, not just the local portion

6430:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6431:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6432:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6433:   `DM_BOUNDARY_PERIODIC` boundary type.

6435:   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
6436:   a single value per point) you can skip filling those indices.

6438:   Fortran Note:
6439:   `idxm` and `idxn` should be declared as
6440: .vb
6441:     MatStencil idxm(4, m)
6442: .ve
6443:   and the values inserted using
6444: .vb
6445:     idxm(MatStencil_i, 1) = i
6446:     idxm(MatStencil_j, 1) = j
6447:     idxm(MatStencil_k, 1) = k
6448:     idxm(MatStencil_c, 1) = c
6449:    etc
6450: .ve

6452: .seealso: [](ch_matrices), `Mat`, `MatStencil`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRows()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6453:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6454: @*/
6455: PetscErrorCode MatZeroRowsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6456: {
6457:   PetscInt  dim    = mat->stencil.dim;
6458:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6459:   PetscInt *dims   = mat->stencil.dims + 1;
6460:   PetscInt *starts = mat->stencil.starts;
6461:   PetscInt *dxm    = (PetscInt *)rows;
6462:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6464:   PetscFunctionBegin;
6467:   if (numRows) PetscAssertPointer(rows, 3);

6469:   PetscCall(PetscMalloc1(numRows, &jdxm));
6470:   for (i = 0; i < numRows; ++i) {
6471:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6472:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6473:     /* Local index in X dir */
6474:     tmp = *dxm++ - starts[0];
6475:     /* Loop over remaining dimensions */
6476:     for (j = 0; j < dim - 1; ++j) {
6477:       /* If nonlocal, set index to be negative */
6478:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6479:       /* Update local index */
6480:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6481:     }
6482:     /* Skip component slot if necessary */
6483:     if (mat->stencil.noc) dxm++;
6484:     /* Local row number */
6485:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6486:   }
6487:   PetscCall(MatZeroRowsLocal(mat, numNewRows, jdxm, diag, x, b));
6488:   PetscCall(PetscFree(jdxm));
6489:   PetscFunctionReturn(PETSC_SUCCESS);
6490: }

6492: /*@
6493:   MatZeroRowsColumnsStencil - Zeros all row and column entries (except possibly the main diagonal)
6494:   of a set of rows and columns of a matrix.

6496:   Collective

6498:   Input Parameters:
6499: + mat     - the matrix
6500: . numRows - the number of rows/columns to remove
6501: . rows    - the grid coordinates (and component number when dof > 1) for matrix rows
6502: . diag    - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry)
6503: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6504: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6506:   Level: intermediate

6508:   Notes:
6509:   See `MatZeroRowsColumns()` for details on how this routine operates.

6511:   The grid coordinates are across the entire grid, not just the local portion

6513:   For periodic boundary conditions use negative indices for values to the left (below 0; that are to be
6514:   obtained by wrapping values from right edge). For values to the right of the last entry using that index plus one
6515:   etc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the
6516:   `DM_BOUNDARY_PERIODIC` boundary type.

6518:   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
6519:   a single value per point) you can skip filling those indices.

6521:   Fortran Note:
6522:   `idxm` and `idxn` should be declared as
6523: .vb
6524:     MatStencil idxm(4, m)
6525: .ve
6526:   and the values inserted using
6527: .vb
6528:     idxm(MatStencil_i, 1) = i
6529:     idxm(MatStencil_j, 1) = j
6530:     idxm(MatStencil_k, 1) = k
6531:     idxm(MatStencil_c, 1) = c
6532:     etc
6533: .ve

6535: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6536:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRows()`
6537: @*/
6538: PetscErrorCode MatZeroRowsColumnsStencil(Mat mat, PetscInt numRows, const MatStencil rows[], PetscScalar diag, Vec x, Vec b)
6539: {
6540:   PetscInt  dim    = mat->stencil.dim;
6541:   PetscInt  sdim   = dim - (1 - (PetscInt)mat->stencil.noc);
6542:   PetscInt *dims   = mat->stencil.dims + 1;
6543:   PetscInt *starts = mat->stencil.starts;
6544:   PetscInt *dxm    = (PetscInt *)rows;
6545:   PetscInt *jdxm, i, j, tmp, numNewRows = 0;

6547:   PetscFunctionBegin;
6550:   if (numRows) PetscAssertPointer(rows, 3);

6552:   PetscCall(PetscMalloc1(numRows, &jdxm));
6553:   for (i = 0; i < numRows; ++i) {
6554:     /* Skip unused dimensions (they are ordered k, j, i, c) */
6555:     for (j = 0; j < 3 - sdim; ++j) dxm++;
6556:     /* Local index in X dir */
6557:     tmp = *dxm++ - starts[0];
6558:     /* Loop over remaining dimensions */
6559:     for (j = 0; j < dim - 1; ++j) {
6560:       /* If nonlocal, set index to be negative */
6561:       if ((*dxm++ - starts[j + 1]) < 0 || tmp < 0) tmp = PETSC_INT_MIN;
6562:       /* Update local index */
6563:       else tmp = tmp * dims[j] + *(dxm - 1) - starts[j + 1];
6564:     }
6565:     /* Skip component slot if necessary */
6566:     if (mat->stencil.noc) dxm++;
6567:     /* Local row number */
6568:     if (tmp >= 0) jdxm[numNewRows++] = tmp;
6569:   }
6570:   PetscCall(MatZeroRowsColumnsLocal(mat, numNewRows, jdxm, diag, x, b));
6571:   PetscCall(PetscFree(jdxm));
6572:   PetscFunctionReturn(PETSC_SUCCESS);
6573: }

6575: /*@
6576:   MatZeroRowsLocal - Zeros all entries (except possibly the main diagonal)
6577:   of a set of rows of a matrix; using local numbering of rows.

6579:   Collective

6581:   Input Parameters:
6582: + mat     - the matrix
6583: . numRows - the number of rows to remove
6584: . rows    - the local row indices
6585: . diag    - value put in all diagonals of eliminated rows
6586: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6587: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6589:   Level: intermediate

6591:   Notes:
6592:   Before calling `MatZeroRowsLocal()`, the user must first set the
6593:   local-to-global mapping by calling MatSetLocalToGlobalMapping(), this is often already set for matrices obtained with `DMCreateMatrix()`.

6595:   See `MatZeroRows()` for details on how this routine operates.

6597: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRows()`, `MatSetOption()`,
6598:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6599: @*/
6600: PetscErrorCode MatZeroRowsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6601: {
6602:   PetscFunctionBegin;
6605:   if (numRows) PetscAssertPointer(rows, 3);
6606:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6607:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6608:   MatCheckPreallocated(mat, 1);

6610:   if (mat->ops->zerorowslocal) {
6611:     PetscUseTypeMethod(mat, zerorowslocal, numRows, rows, diag, x, b);
6612:   } else {
6613:     IS        is, newis;
6614:     PetscInt *newRows, nl = 0;

6616:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6617:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6618:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6619:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6620:     for (PetscInt i = 0; i < numRows; i++)
6621:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6622:     PetscUseTypeMethod(mat, zerorows, nl, newRows, diag, x, b);
6623:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6624:     PetscCall(ISDestroy(&newis));
6625:     PetscCall(ISDestroy(&is));
6626:   }
6627:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6628:   PetscFunctionReturn(PETSC_SUCCESS);
6629: }

6631: /*@
6632:   MatZeroRowsLocalIS - Zeros all entries (except possibly the main diagonal)
6633:   of a set of rows of a matrix; using local numbering of rows.

6635:   Collective

6637:   Input Parameters:
6638: + mat  - the matrix
6639: . is   - index set of rows to remove
6640: . diag - value put in all diagonals of eliminated rows
6641: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6642: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6644:   Level: intermediate

6646:   Notes:
6647:   Before calling `MatZeroRowsLocalIS()`, the user must first set the
6648:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6650:   See `MatZeroRows()` for details on how this routine operates.

6652: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRows()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6653:           `MatZeroRowsColumnsLocal()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6654: @*/
6655: PetscErrorCode MatZeroRowsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6656: {
6657:   PetscInt        numRows;
6658:   const PetscInt *rows;

6660:   PetscFunctionBegin;
6664:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6665:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6666:   MatCheckPreallocated(mat, 1);

6668:   PetscCall(ISGetLocalSize(is, &numRows));
6669:   PetscCall(ISGetIndices(is, &rows));
6670:   PetscCall(MatZeroRowsLocal(mat, numRows, rows, diag, x, b));
6671:   PetscCall(ISRestoreIndices(is, &rows));
6672:   PetscFunctionReturn(PETSC_SUCCESS);
6673: }

6675: /*@
6676:   MatZeroRowsColumnsLocal - Zeros all entries (except possibly the main diagonal)
6677:   of a set of rows and columns of a matrix; using local numbering of rows.

6679:   Collective

6681:   Input Parameters:
6682: + mat     - the matrix
6683: . numRows - the number of rows to remove
6684: . rows    - the global row indices
6685: . diag    - value put in all diagonals of eliminated rows
6686: . x       - optional vector of solutions for zeroed rows (other entries in vector are not used)
6687: - b       - optional vector of right-hand side, that will be adjusted by provided solution

6689:   Level: intermediate

6691:   Notes:
6692:   Before calling `MatZeroRowsColumnsLocal()`, the user must first set the
6693:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6695:   See `MatZeroRowsColumns()` for details on how this routine operates.

6697: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6698:           `MatZeroRows()`, `MatZeroRowsColumnsLocalIS()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6699: @*/
6700: PetscErrorCode MatZeroRowsColumnsLocal(Mat mat, PetscInt numRows, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
6701: {
6702:   PetscFunctionBegin;
6705:   if (numRows) PetscAssertPointer(rows, 3);
6706:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6707:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6708:   MatCheckPreallocated(mat, 1);

6710:   if (mat->ops->zerorowscolumnslocal) {
6711:     PetscUseTypeMethod(mat, zerorowscolumnslocal, numRows, rows, diag, x, b);
6712:   } else {
6713:     IS        is, newis;
6714:     PetscInt *newRows, nl = 0;

6716:     PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Need to provide local to global mapping to matrix first");
6717:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numRows, rows, PETSC_USE_POINTER, &is));
6718:     PetscCall(ISLocalToGlobalMappingApplyIS(mat->rmap->mapping, is, &newis));
6719:     PetscCall(ISGetIndices(newis, (const PetscInt **)&newRows));
6720:     for (PetscInt i = 0; i < numRows; i++)
6721:       if (newRows[i] > -1) newRows[nl++] = newRows[i];
6722:     PetscUseTypeMethod(mat, zerorowscolumns, nl, newRows, diag, x, b);
6723:     PetscCall(ISRestoreIndices(newis, (const PetscInt **)&newRows));
6724:     PetscCall(ISDestroy(&newis));
6725:     PetscCall(ISDestroy(&is));
6726:   }
6727:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
6728:   PetscFunctionReturn(PETSC_SUCCESS);
6729: }

6731: /*@
6732:   MatZeroRowsColumnsLocalIS - Zeros all entries (except possibly the main diagonal)
6733:   of a set of rows and columns of a matrix; using local numbering of rows.

6735:   Collective

6737:   Input Parameters:
6738: + mat  - the matrix
6739: . is   - index set of rows to remove
6740: . diag - value put in all diagonals of eliminated rows
6741: . x    - optional vector of solutions for zeroed rows (other entries in vector are not used)
6742: - b    - optional vector of right-hand side, that will be adjusted by provided solution

6744:   Level: intermediate

6746:   Notes:
6747:   Before calling `MatZeroRowsColumnsLocalIS()`, the user must first set the
6748:   local-to-global mapping by calling `MatSetLocalToGlobalMapping()`, this is often already set for matrices obtained with `DMCreateMatrix()`.

6750:   See `MatZeroRowsColumns()` for details on how this routine operates.

6752: .seealso: [](ch_matrices), `Mat`, `MatZeroRowsIS()`, `MatZeroRowsColumns()`, `MatZeroRowsLocalIS()`, `MatZeroRowsStencil()`, `MatZeroEntries()`, `MatZeroRowsLocal()`, `MatSetOption()`,
6753:           `MatZeroRowsColumnsLocal()`, `MatZeroRows()`, `MatZeroRowsColumnsIS()`, `MatZeroRowsColumnsStencil()`
6754: @*/
6755: PetscErrorCode MatZeroRowsColumnsLocalIS(Mat mat, IS is, PetscScalar diag, Vec x, Vec b)
6756: {
6757:   PetscInt        numRows;
6758:   const PetscInt *rows;

6760:   PetscFunctionBegin;
6764:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
6765:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
6766:   MatCheckPreallocated(mat, 1);

6768:   PetscCall(ISGetLocalSize(is, &numRows));
6769:   PetscCall(ISGetIndices(is, &rows));
6770:   PetscCall(MatZeroRowsColumnsLocal(mat, numRows, rows, diag, x, b));
6771:   PetscCall(ISRestoreIndices(is, &rows));
6772:   PetscFunctionReturn(PETSC_SUCCESS);
6773: }

6775: /*@
6776:   MatGetSize - Returns the numbers of rows and columns in a matrix.

6778:   Not Collective

6780:   Input Parameter:
6781: . mat - the matrix

6783:   Output Parameters:
6784: + m - the number of global rows
6785: - n - the number of global columns

6787:   Level: beginner

6789:   Note:
6790:   Both output parameters can be `NULL` on input.

6792: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetLocalSize()`
6793: @*/
6794: PetscErrorCode MatGetSize(Mat mat, PetscInt *m, PetscInt *n)
6795: {
6796:   PetscFunctionBegin;
6798:   if (m) *m = mat->rmap->N;
6799:   if (n) *n = mat->cmap->N;
6800:   PetscFunctionReturn(PETSC_SUCCESS);
6801: }

6803: /*@
6804:   MatGetLocalSize - For most matrix formats, excluding `MATELEMENTAL` and `MATSCALAPACK`, Returns the number of local rows and local columns
6805:   of a matrix. For all matrices this is the local size of the left and right vectors as returned by `MatCreateVecs()`.

6807:   Not Collective

6809:   Input Parameter:
6810: . mat - the matrix

6812:   Output Parameters:
6813: + m - the number of local rows, use `NULL` to not obtain this value
6814: - n - the number of local columns, use `NULL` to not obtain this value

6816:   Level: beginner

6818: .seealso: [](ch_matrices), `Mat`, `MatSetSizes()`, `MatGetSize()`
6819: @*/
6820: PetscErrorCode MatGetLocalSize(Mat mat, PetscInt *m, PetscInt *n)
6821: {
6822:   PetscFunctionBegin;
6824:   if (m) PetscAssertPointer(m, 2);
6825:   if (n) PetscAssertPointer(n, 3);
6826:   if (m) *m = mat->rmap->n;
6827:   if (n) *n = mat->cmap->n;
6828:   PetscFunctionReturn(PETSC_SUCCESS);
6829: }

6831: /*@
6832:   MatGetOwnershipRangeColumn - Returns the range of matrix columns associated with rows of a
6833:   vector one multiplies this matrix by that are owned by this processor.

6835:   Not Collective, unless matrix has not been allocated, then collective

6837:   Input Parameter:
6838: . mat - the matrix

6840:   Output Parameters:
6841: + m - the global index of the first local column, use `NULL` to not obtain this value
6842: - n - one more than the global index of the last local column, use `NULL` to not obtain this value

6844:   Level: developer

6846:   Notes:
6847:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6849:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6850:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6852:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6853:   the local values in the matrix.

6855:   Returns the columns of the "diagonal block" for most sparse matrix formats. See [Matrix
6856:   Layouts](sec_matlayout) for details on matrix layouts.

6858: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
6859:           `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
6860: @*/
6861: PetscErrorCode MatGetOwnershipRangeColumn(Mat mat, PetscInt *m, PetscInt *n)
6862: {
6863:   PetscFunctionBegin;
6866:   if (m) PetscAssertPointer(m, 2);
6867:   if (n) PetscAssertPointer(n, 3);
6868:   MatCheckPreallocated(mat, 1);
6869:   if (m) *m = mat->cmap->rstart;
6870:   if (n) *n = mat->cmap->rend;
6871:   PetscFunctionReturn(PETSC_SUCCESS);
6872: }

6874: /*@
6875:   MatGetOwnershipRange - For matrices that own values by row, excludes `MATELEMENTAL` and `MATSCALAPACK`, returns the range of matrix rows owned by
6876:   this MPI process.

6878:   Not Collective

6880:   Input Parameter:
6881: . mat - the matrix

6883:   Output Parameters:
6884: + m - the global index of the first local row, use `NULL` to not obtain this value
6885: - n - one more than the global index of the last local row, use `NULL` to not obtain this value

6887:   Level: beginner

6889:   Notes:
6890:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6892:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6893:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6895:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6896:   the local values in the matrix.

6898:   The high argument is one more than the last element stored locally.

6900:   For all matrices  it returns the range of matrix rows associated with rows of a vector that
6901:   would contain the result of a matrix vector product with this matrix. See [Matrix
6902:   Layouts](sec_matlayout) for details on matrix layouts.

6904: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscSplitOwnership()`,
6905:           `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`, `DMDAGetGhostCorners()`, `DM`
6906: @*/
6907: PetscErrorCode MatGetOwnershipRange(Mat mat, PetscInt *m, PetscInt *n)
6908: {
6909:   PetscFunctionBegin;
6912:   if (m) PetscAssertPointer(m, 2);
6913:   if (n) PetscAssertPointer(n, 3);
6914:   MatCheckPreallocated(mat, 1);
6915:   if (m) *m = mat->rmap->rstart;
6916:   if (n) *n = mat->rmap->rend;
6917:   PetscFunctionReturn(PETSC_SUCCESS);
6918: }

6920: /*@C
6921:   MatGetOwnershipRanges - For matrices that own values by row, excludes `MATELEMENTAL` and
6922:   `MATSCALAPACK`, returns the range of matrix rows owned by each process.

6924:   Not Collective, unless matrix has not been allocated

6926:   Input Parameter:
6927: . mat - the matrix

6929:   Output Parameter:
6930: . ranges - start of each processors portion plus one more than the total length at the end, of length `size` + 1
6931:            where `size` is the number of MPI processes used by `mat`

6933:   Level: beginner

6935:   Notes:
6936:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6938:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6939:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6941:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6942:   the local values in the matrix.

6944:   For all matrices  it returns the ranges of matrix rows associated with rows of a vector that
6945:   would contain the result of a matrix vector product with this matrix. See [Matrix
6946:   Layouts](sec_matlayout) for details on matrix layouts.

6948: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`,
6949:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `MatSetSizes()`, `MatCreateAIJ()`,
6950:           `DMDAGetGhostCorners()`, `DM`
6951: @*/
6952: PetscErrorCode MatGetOwnershipRanges(Mat mat, const PetscInt *ranges[])
6953: {
6954:   PetscFunctionBegin;
6957:   MatCheckPreallocated(mat, 1);
6958:   PetscCall(PetscLayoutGetRanges(mat->rmap, ranges));
6959:   PetscFunctionReturn(PETSC_SUCCESS);
6960: }

6962: /*@C
6963:   MatGetOwnershipRangesColumn - Returns the ranges of matrix columns associated with rows of a
6964:   vector one multiplies this vector by that are owned by each processor.

6966:   Not Collective, unless matrix has not been allocated

6968:   Input Parameter:
6969: . mat - the matrix

6971:   Output Parameter:
6972: . ranges - start of each processors portion plus one more than the total length at the end

6974:   Level: beginner

6976:   Notes:
6977:   If the `Mat` was obtained from a `DM` with `DMCreateMatrix()`, then the range values are determined by the specific `DM`.

6979:   If the `Mat` was created directly the range values are determined by the local size passed to `MatSetSizes()` or `MatCreateAIJ()`.
6980:   If `PETSC_DECIDE` was passed as the local size, then the vector uses default values for the range using `PetscSplitOwnership()`.

6982:   For certain `DM`, such as `DMDA`, it is better to use `DM` specific routines, such as `DMDAGetGhostCorners()`, to determine
6983:   the local values in the matrix.

6985:   Returns the columns of the "diagonal blocks", for most sparse matrix formats. See [Matrix
6986:   Layouts](sec_matlayout) for details on matrix layouts.

6988: .seealso: [](ch_matrices), `Mat`, `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRanges()`,
6989:           `PetscSplitOwnership()`, `PetscSplitOwnershipBlock()`, `PetscLayout`, `MatSetSizes()`, `MatCreateAIJ()`,
6990:           `DMDAGetGhostCorners()`, `DM`
6991: @*/
6992: PetscErrorCode MatGetOwnershipRangesColumn(Mat mat, const PetscInt *ranges[])
6993: {
6994:   PetscFunctionBegin;
6997:   MatCheckPreallocated(mat, 1);
6998:   PetscCall(PetscLayoutGetRanges(mat->cmap, ranges));
6999:   PetscFunctionReturn(PETSC_SUCCESS);
7000: }

7002: /*@
7003:   MatGetOwnershipIS - Get row and column ownership of a matrices' values as index sets.

7005:   Not Collective

7007:   Input Parameter:
7008: . A - matrix

7010:   Output Parameters:
7011: + rows - rows in which this process owns elements, , use `NULL` to not obtain this value
7012: - cols - columns in which this process owns elements, use `NULL` to not obtain this value

7014:   Level: intermediate

7016:   Note:
7017:   You should call `ISDestroy()` on the returned `IS`

7019:   For most matrices, excluding `MATELEMENTAL` and `MATSCALAPACK`, this corresponds to values
7020:   returned by `MatGetOwnershipRange()`, `MatGetOwnershipRangeColumn()`. For `MATELEMENTAL` and
7021:   `MATSCALAPACK` the ownership is more complicated. See [Matrix Layouts](sec_matlayout) for
7022:   details on matrix layouts.

7024: .seealso: [](ch_matrices), `IS`, `Mat`, `MatGetOwnershipRanges()`, `MatSetValues()`, `MATELEMENTAL`, `MATSCALAPACK`
7025: @*/
7026: PetscErrorCode MatGetOwnershipIS(Mat A, IS *rows, IS *cols)
7027: {
7028:   PetscErrorCode (*f)(Mat, IS *, IS *);

7030:   PetscFunctionBegin;
7033:   MatCheckPreallocated(A, 1);
7034:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatGetOwnershipIS_C", &f));
7035:   if (f) {
7036:     PetscCall((*f)(A, rows, cols));
7037:   } else { /* Create a standard row-based partition, each process is responsible for ALL columns in their row block */
7038:     if (rows) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->rmap->n, A->rmap->rstart, 1, rows));
7039:     if (cols) PetscCall(ISCreateStride(PETSC_COMM_SELF, A->cmap->N, 0, 1, cols));
7040:   }
7041:   PetscFunctionReturn(PETSC_SUCCESS);
7042: }

7044: /*@
7045:   MatILUFactorSymbolic - Performs symbolic ILU factorization of a matrix obtained with `MatGetFactor()`
7046:   Uses levels of fill only, not drop tolerance. Use `MatLUFactorNumeric()`
7047:   to complete the factorization.

7049:   Collective

7051:   Input Parameters:
7052: + fact - the factorized matrix obtained with `MatGetFactor()`
7053: . mat  - the matrix
7054: . row  - row permutation
7055: . col  - column permutation
7056: - info - structure containing
7057: .vb
7058:       levels - number of levels of fill.
7059:       expected fill - as ratio of original fill.
7060:       1 or 0 - indicating force fill on diagonal (improves robustness for matrices
7061:                 missing diagonal entries)
7062: .ve

7064:   Level: developer

7066:   Notes:
7067:   See [Matrix Factorization](sec_matfactor) for additional information.

7069:   Most users should employ the `KSP` interface for linear solvers
7070:   instead of working directly with matrix algebra routines such as this.
7071:   See, e.g., `KSPCreate()`.

7073:   Uses the definition of level of fill as in Y. Saad, {cite}`saad2003`

7075:   Fortran Note:
7076:   A valid (non-null) `info` argument must be provided

7078: .seealso: [](ch_matrices), `Mat`, [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatLUFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
7079:           `MatGetOrdering()`, `MatFactorInfo`
7080: @*/
7081: PetscErrorCode MatILUFactorSymbolic(Mat fact, Mat mat, IS row, IS col, const MatFactorInfo *info)
7082: {
7083:   PetscFunctionBegin;
7088:   PetscAssertPointer(info, 5);
7089:   PetscAssertPointer(fact, 1);
7090:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels of fill negative %" PetscInt_FMT, (PetscInt)info->levels);
7091:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7092:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7093:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7094:   MatCheckPreallocated(mat, 2);

7096:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ILUFactorSymbolic, mat, row, col, 0));
7097:   PetscUseTypeMethod(fact, ilufactorsymbolic, mat, row, col, info);
7098:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ILUFactorSymbolic, mat, row, col, 0));
7099:   PetscFunctionReturn(PETSC_SUCCESS);
7100: }

7102: /*@
7103:   MatICCFactorSymbolic - Performs symbolic incomplete
7104:   Cholesky factorization for a symmetric matrix.  Use
7105:   `MatCholeskyFactorNumeric()` to complete the factorization.

7107:   Collective

7109:   Input Parameters:
7110: + fact - the factorized matrix obtained with `MatGetFactor()`
7111: . mat  - the matrix to be factored
7112: . perm - row and column permutation
7113: - info - structure containing
7114: .vb
7115:       levels - number of levels of fill.
7116:       expected fill - as ratio of original fill.
7117: .ve

7119:   Level: developer

7121:   Notes:
7122:   Most users should employ the `KSP` interface for linear solvers
7123:   instead of working directly with matrix algebra routines such as this.
7124:   See, e.g., `KSPCreate()`.

7126:   This uses the definition of level of fill as in Y. Saad {cite}`saad2003`

7128:   Fortran Note:
7129:   A valid (non-null) `info` argument must be provided

7131: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactorNumeric()`, `MatCholeskyFactor()`, `MatFactorInfo`
7132: @*/
7133: PetscErrorCode MatICCFactorSymbolic(Mat fact, Mat mat, IS perm, const MatFactorInfo *info)
7134: {
7135:   PetscFunctionBegin;
7139:   PetscAssertPointer(info, 4);
7140:   PetscAssertPointer(fact, 1);
7141:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7142:   PetscCheck(info->levels >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Levels negative %" PetscInt_FMT, (PetscInt)info->levels);
7143:   PetscCheck(info->fill >= 1.0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Expected fill less than 1.0 %g", (double)info->fill);
7144:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7145:   MatCheckPreallocated(mat, 2);

7147:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventBegin(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7148:   PetscUseTypeMethod(fact, iccfactorsymbolic, mat, perm, info);
7149:   if (!fact->trivialsymbolic) PetscCall(PetscLogEventEnd(MAT_ICCFactorSymbolic, mat, perm, 0, 0));
7150:   PetscFunctionReturn(PETSC_SUCCESS);
7151: }

7153: /*@C
7154:   MatCreateSubMatrices - Extracts several submatrices from a matrix. If submat
7155:   points to an array of valid matrices, they may be reused to store the new
7156:   submatrices.

7158:   Collective

7160:   Input Parameters:
7161: + mat   - the matrix
7162: . n     - the number of submatrixes to be extracted (on this processor, may be zero)
7163: . irow  - index set of rows to extract
7164: . icol  - index set of columns to extract
7165: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7167:   Output Parameter:
7168: . submat - the array of submatrices

7170:   Level: advanced

7172:   Notes:
7173:   `MatCreateSubMatrices()` can extract ONLY sequential submatrices
7174:   (from both sequential and parallel matrices). Use `MatCreateSubMatrix()`
7175:   to extract a parallel submatrix.

7177:   Some matrix types place restrictions on the row and column
7178:   indices, such as that they be sorted or that they be equal to each other.

7180:   The index sets may not have duplicate entries.

7182:   When extracting submatrices from a parallel matrix, each processor can
7183:   form a different submatrix by setting the rows and columns of its
7184:   individual index sets according to the local submatrix desired.

7186:   When finished using the submatrices, the user should destroy
7187:   them with `MatDestroySubMatrices()`.

7189:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
7190:   original matrix has not changed from that last call to `MatCreateSubMatrices()`.

7192:   This routine creates the matrices in submat; you should NOT create them before
7193:   calling it. It also allocates the array of matrix pointers submat.

7195:   For `MATBAIJ` matrices the index sets must respect the block structure, that is if they
7196:   request one row/column in a block, they must request all rows/columns that are in
7197:   that block. For example, if the block size is 2 you cannot request just row 0 and
7198:   column 0.

7200:   Fortran Note:
7201: .vb
7202:   Mat, pointer :: submat(:)
7203: .ve

7205: .seealso: [](ch_matrices), `Mat`, `MatDestroySubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7206: @*/
7207: PetscErrorCode MatCreateSubMatrices(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7208: {
7209:   PetscInt  i;
7210:   PetscBool eq;

7212:   PetscFunctionBegin;
7215:   if (n) {
7216:     PetscAssertPointer(irow, 3);
7218:     PetscAssertPointer(icol, 4);
7220:   }
7221:   PetscAssertPointer(submat, 6);
7222:   if (n && scall == MAT_REUSE_MATRIX) {
7223:     PetscAssertPointer(*submat, 6);
7225:   }
7226:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7227:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7228:   MatCheckPreallocated(mat, 1);
7229:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7230:   PetscUseTypeMethod(mat, createsubmatrices, n, irow, icol, scall, submat);
7231:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7232:   for (i = 0; i < n; i++) {
7233:     (*submat)[i]->factortype = MAT_FACTOR_NONE; /* in case in place factorization was previously done on submatrix */
7234:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7235:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7236: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
7237:     if (mat->boundtocpu && mat->bindingpropagates) {
7238:       PetscCall(MatBindToCPU((*submat)[i], PETSC_TRUE));
7239:       PetscCall(MatSetBindingPropagates((*submat)[i], PETSC_TRUE));
7240:     }
7241: #endif
7242:   }
7243:   PetscFunctionReturn(PETSC_SUCCESS);
7244: }

7246: /*@C
7247:   MatCreateSubMatricesMPI - Extracts MPI submatrices across a sub communicator of `mat` (by pairs of `IS` that may live on subcomms).

7249:   Collective

7251:   Input Parameters:
7252: + mat   - the matrix
7253: . n     - the number of submatrixes to be extracted
7254: . irow  - index set of rows to extract
7255: . icol  - index set of columns to extract
7256: - scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

7258:   Output Parameter:
7259: . submat - the array of submatrices

7261:   Level: advanced

7263:   Note:
7264:   This is used by `PCGASM`

7266: .seealso: [](ch_matrices), `Mat`, `PCGASM`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRow()`, `MatGetDiagonal()`, `MatReuse`
7267: @*/
7268: PetscErrorCode MatCreateSubMatricesMPI(Mat mat, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
7269: {
7270:   PetscInt  i;
7271:   PetscBool eq;

7273:   PetscFunctionBegin;
7276:   if (n) {
7277:     PetscAssertPointer(irow, 3);
7279:     PetscAssertPointer(icol, 4);
7281:   }
7282:   PetscAssertPointer(submat, 6);
7283:   if (n && scall == MAT_REUSE_MATRIX) {
7284:     PetscAssertPointer(*submat, 6);
7286:   }
7287:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7288:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7289:   MatCheckPreallocated(mat, 1);

7291:   PetscCall(PetscLogEventBegin(MAT_CreateSubMats, mat, 0, 0, 0));
7292:   PetscUseTypeMethod(mat, createsubmatricesmpi, n, irow, icol, scall, submat);
7293:   PetscCall(PetscLogEventEnd(MAT_CreateSubMats, mat, 0, 0, 0));
7294:   for (i = 0; i < n; i++) {
7295:     PetscCall(ISEqualUnsorted(irow[i], icol[i], &eq));
7296:     if (eq) PetscCall(MatPropagateSymmetryOptions(mat, (*submat)[i]));
7297:   }
7298:   PetscFunctionReturn(PETSC_SUCCESS);
7299: }

7301: /*@C
7302:   MatDestroyMatrices - Destroys an array of matrices

7304:   Collective

7306:   Input Parameters:
7307: + n   - the number of local matrices
7308: - mat - the matrices (this is a pointer to the array of matrices)

7310:   Level: advanced

7312:   Notes:
7313:   Frees not only the matrices, but also the array that contains the matrices

7315:   For matrices obtained with  `MatCreateSubMatrices()` use `MatDestroySubMatrices()`

7317: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroySubMatrices()`
7318: @*/
7319: PetscErrorCode MatDestroyMatrices(PetscInt n, Mat *mat[])
7320: {
7321:   PetscInt i;

7323:   PetscFunctionBegin;
7324:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7325:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7326:   PetscAssertPointer(mat, 2);

7328:   for (i = 0; i < n; i++) PetscCall(MatDestroy(&(*mat)[i]));

7330:   /* memory is allocated even if n = 0 */
7331:   PetscCall(PetscFree(*mat));
7332:   PetscFunctionReturn(PETSC_SUCCESS);
7333: }

7335: /*@C
7336:   MatDestroySubMatrices - Destroys a set of matrices obtained with `MatCreateSubMatrices()`.

7338:   Collective

7340:   Input Parameters:
7341: + n   - the number of local matrices
7342: - mat - the matrices (this is a pointer to the array of matrices, to match the calling sequence of `MatCreateSubMatrices()`)

7344:   Level: advanced

7346:   Note:
7347:   Frees not only the matrices, but also the array that contains the matrices

7349: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7350: @*/
7351: PetscErrorCode MatDestroySubMatrices(PetscInt n, Mat *mat[])
7352: {
7353:   Mat mat0;

7355:   PetscFunctionBegin;
7356:   if (!*mat) PetscFunctionReturn(PETSC_SUCCESS);
7357:   /* mat[] is an array of length n+1, see MatCreateSubMatrices_xxx() */
7358:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to destroy negative number of matrices %" PetscInt_FMT, n);
7359:   PetscAssertPointer(mat, 2);

7361:   mat0 = (*mat)[0];
7362:   if (mat0 && mat0->ops->destroysubmatrices) {
7363:     PetscCall((*mat0->ops->destroysubmatrices)(n, mat));
7364:   } else {
7365:     PetscCall(MatDestroyMatrices(n, mat));
7366:   }
7367:   PetscFunctionReturn(PETSC_SUCCESS);
7368: }

7370: /*@
7371:   MatGetSeqNonzeroStructure - Extracts the nonzero structure from a matrix and stores it, in its entirety, on each process

7373:   Collective

7375:   Input Parameter:
7376: . mat - the matrix

7378:   Output Parameter:
7379: . matstruct - the sequential matrix with the nonzero structure of `mat`

7381:   Level: developer

7383: .seealso: [](ch_matrices), `Mat`, `MatDestroySeqNonzeroStructure()`, `MatCreateSubMatrices()`, `MatDestroyMatrices()`
7384: @*/
7385: PetscErrorCode MatGetSeqNonzeroStructure(Mat mat, Mat *matstruct)
7386: {
7387:   PetscFunctionBegin;
7389:   PetscAssertPointer(matstruct, 2);

7392:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7393:   MatCheckPreallocated(mat, 1);

7395:   PetscCall(PetscLogEventBegin(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7396:   PetscUseTypeMethod(mat, getseqnonzerostructure, matstruct);
7397:   PetscCall(PetscLogEventEnd(MAT_GetSeqNonzeroStructure, mat, 0, 0, 0));
7398:   PetscFunctionReturn(PETSC_SUCCESS);
7399: }

7401: /*@C
7402:   MatDestroySeqNonzeroStructure - Destroys matrix obtained with `MatGetSeqNonzeroStructure()`.

7404:   Collective

7406:   Input Parameter:
7407: . mat - the matrix

7409:   Level: advanced

7411:   Note:
7412:   This is not needed, one can just call `MatDestroy()`

7414: .seealso: [](ch_matrices), `Mat`, `MatGetSeqNonzeroStructure()`
7415: @*/
7416: PetscErrorCode MatDestroySeqNonzeroStructure(Mat *mat)
7417: {
7418:   PetscFunctionBegin;
7419:   PetscAssertPointer(mat, 1);
7420:   PetscCall(MatDestroy(mat));
7421:   PetscFunctionReturn(PETSC_SUCCESS);
7422: }

7424: /*@
7425:   MatIncreaseOverlap - Given a set of submatrices indicated by index sets,
7426:   replaces the index sets by larger ones that represent submatrices with
7427:   additional overlap.

7429:   Collective

7431:   Input Parameters:
7432: + mat - the matrix
7433: . n   - the number of index sets
7434: . is  - the array of index sets (these index sets will changed during the call)
7435: - ov  - the additional overlap requested

7437:   Options Database Key:
7438: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7440:   Level: developer

7442:   Note:
7443:   The computed overlap preserves the matrix block sizes when the blocks are square.
7444:   That is: if a matrix nonzero for a given block would increase the overlap all columns associated with
7445:   that block are included in the overlap regardless of whether each specific column would increase the overlap.

7447: .seealso: [](ch_matrices), `Mat`, `PCASM`, `MatSetBlockSize()`, `MatIncreaseOverlapSplit()`, `MatCreateSubMatrices()`
7448: @*/
7449: PetscErrorCode MatIncreaseOverlap(Mat mat, PetscInt n, IS is[], PetscInt ov)
7450: {
7451:   PetscInt i, bs, cbs;

7453:   PetscFunctionBegin;
7457:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7458:   if (n) {
7459:     PetscAssertPointer(is, 3);
7461:   }
7462:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7463:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7464:   MatCheckPreallocated(mat, 1);

7466:   if (!ov || !n) PetscFunctionReturn(PETSC_SUCCESS);
7467:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7468:   PetscUseTypeMethod(mat, increaseoverlap, n, is, ov);
7469:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7470:   PetscCall(MatGetBlockSizes(mat, &bs, &cbs));
7471:   if (bs == cbs) {
7472:     for (i = 0; i < n; i++) PetscCall(ISSetBlockSize(is[i], bs));
7473:   }
7474:   PetscFunctionReturn(PETSC_SUCCESS);
7475: }

7477: PetscErrorCode MatIncreaseOverlapSplit_Single(Mat, IS *, PetscInt);

7479: /*@
7480:   MatIncreaseOverlapSplit - Given a set of submatrices indicated by index sets across
7481:   a sub communicator, replaces the index sets by larger ones that represent submatrices with
7482:   additional overlap.

7484:   Collective

7486:   Input Parameters:
7487: + mat - the matrix
7488: . n   - the number of index sets
7489: . is  - the array of index sets (these index sets will changed during the call)
7490: - ov  - the additional overlap requested

7492:   `   Options Database Key:
7493: . -mat_increase_overlap_scalable - use a scalable algorithm to compute the overlap (supported by MPIAIJ matrix)

7495:   Level: developer

7497: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatIncreaseOverlap()`
7498: @*/
7499: PetscErrorCode MatIncreaseOverlapSplit(Mat mat, PetscInt n, IS is[], PetscInt ov)
7500: {
7501:   PetscInt i;

7503:   PetscFunctionBegin;
7506:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Must have one or more domains, you have %" PetscInt_FMT, n);
7507:   if (n) {
7508:     PetscAssertPointer(is, 3);
7510:   }
7511:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
7512:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
7513:   MatCheckPreallocated(mat, 1);
7514:   if (!ov) PetscFunctionReturn(PETSC_SUCCESS);
7515:   PetscCall(PetscLogEventBegin(MAT_IncreaseOverlap, mat, 0, 0, 0));
7516:   for (i = 0; i < n; i++) PetscCall(MatIncreaseOverlapSplit_Single(mat, &is[i], ov));
7517:   PetscCall(PetscLogEventEnd(MAT_IncreaseOverlap, mat, 0, 0, 0));
7518:   PetscFunctionReturn(PETSC_SUCCESS);
7519: }

7521: /*@
7522:   MatGetBlockSize - Returns the matrix block size.

7524:   Not Collective

7526:   Input Parameter:
7527: . mat - the matrix

7529:   Output Parameter:
7530: . bs - block size

7532:   Level: intermediate

7534:   Notes:
7535:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.

7537:   If the block size has not been set yet this routine returns 1.

7539: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSizes()`
7540: @*/
7541: PetscErrorCode MatGetBlockSize(Mat mat, PetscInt *bs)
7542: {
7543:   PetscFunctionBegin;
7545:   PetscAssertPointer(bs, 2);
7546:   *bs = mat->rmap->bs;
7547:   PetscFunctionReturn(PETSC_SUCCESS);
7548: }

7550: /*@
7551:   MatGetBlockSizes - Returns the matrix block row and column sizes.

7553:   Not Collective

7555:   Input Parameter:
7556: . mat - the matrix

7558:   Output Parameters:
7559: + rbs - row block size
7560: - cbs - column block size

7562:   Level: intermediate

7564:   Notes:
7565:   Block row formats are `MATBAIJ` and `MATSBAIJ` ALWAYS have square block storage in the matrix.
7566:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.

7568:   If a block size has not been set yet this routine returns 1.

7570: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatSetBlockSizes()`
7571: @*/
7572: PetscErrorCode MatGetBlockSizes(Mat mat, PetscInt *rbs, PetscInt *cbs)
7573: {
7574:   PetscFunctionBegin;
7576:   if (rbs) PetscAssertPointer(rbs, 2);
7577:   if (cbs) PetscAssertPointer(cbs, 3);
7578:   if (rbs) *rbs = mat->rmap->bs;
7579:   if (cbs) *cbs = mat->cmap->bs;
7580:   PetscFunctionReturn(PETSC_SUCCESS);
7581: }

7583: /*@
7584:   MatSetBlockSize - Sets the matrix block size.

7586:   Logically Collective

7588:   Input Parameters:
7589: + mat - the matrix
7590: - bs  - block size

7592:   Level: intermediate

7594:   Notes:
7595:   Block row formats are `MATBAIJ` and `MATSBAIJ` formats ALWAYS have square block storage in the matrix.
7596:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

7598:   For `MATAIJ` matrix format, this function can be called at a later stage, provided that the specified block size
7599:   is compatible with the matrix local sizes.

7601: .seealso: [](ch_matrices), `Mat`, `MATBAIJ`, `MATSBAIJ`, `MATAIJ`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`
7602: @*/
7603: PetscErrorCode MatSetBlockSize(Mat mat, PetscInt bs)
7604: {
7605:   PetscFunctionBegin;
7608:   PetscCall(MatSetBlockSizes(mat, bs, bs));
7609:   PetscFunctionReturn(PETSC_SUCCESS);
7610: }

7612: typedef struct {
7613:   PetscInt         n;
7614:   IS              *is;
7615:   Mat             *mat;
7616:   PetscObjectState nonzerostate;
7617:   Mat              C;
7618: } EnvelopeData;

7620: static PetscErrorCode EnvelopeDataDestroy(void **ptr)
7621: {
7622:   EnvelopeData *edata = (EnvelopeData *)*ptr;

7624:   PetscFunctionBegin;
7625:   for (PetscInt i = 0; i < edata->n; i++) PetscCall(ISDestroy(&edata->is[i]));
7626:   PetscCall(PetscFree(edata->is));
7627:   PetscCall(PetscFree(edata));
7628:   PetscFunctionReturn(PETSC_SUCCESS);
7629: }

7631: /*@
7632:   MatComputeVariableBlockEnvelope - Given a matrix whose nonzeros are in blocks along the diagonal this computes and stores
7633:   the sizes of these blocks in the matrix. An individual block may lie over several processes.

7635:   Collective

7637:   Input Parameter:
7638: . mat - the matrix

7640:   Level: intermediate

7642:   Notes:
7643:   There can be zeros within the blocks

7645:   The blocks can overlap between processes, including laying on more than two processes

7647: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatSetVariableBlockSizes()`
7648: @*/
7649: PetscErrorCode MatComputeVariableBlockEnvelope(Mat mat)
7650: {
7651:   PetscInt           n, *sizes, *starts, i = 0, env = 0, tbs = 0, lblocks = 0, rstart, II, ln = 0, cnt = 0, cstart, cend;
7652:   PetscInt          *diag, *odiag, sc;
7653:   VecScatter         scatter;
7654:   PetscScalar       *seqv;
7655:   const PetscScalar *parv;
7656:   const PetscInt    *ia, *ja;
7657:   PetscBool          set, flag, done;
7658:   Mat                AA = mat, A;
7659:   MPI_Comm           comm;
7660:   PetscMPIInt        rank, size, tag;
7661:   MPI_Status         status;
7662:   PetscContainer     container;
7663:   EnvelopeData      *edata;
7664:   Vec                seq, par;
7665:   IS                 isglobal;

7667:   PetscFunctionBegin;
7669:   PetscCall(MatIsSymmetricKnown(mat, &set, &flag));
7670:   if (!set || !flag) {
7671:     /* TODO: only needs nonzero structure of transpose */
7672:     PetscCall(MatTranspose(mat, MAT_INITIAL_MATRIX, &AA));
7673:     PetscCall(MatAXPY(AA, 1.0, mat, DIFFERENT_NONZERO_PATTERN));
7674:   }
7675:   PetscCall(MatAIJGetLocalMat(AA, &A));
7676:   PetscCall(MatGetRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7677:   PetscCheck(done, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unable to get IJ structure from matrix");

7679:   PetscCall(MatGetLocalSize(mat, &n, NULL));
7680:   PetscCall(PetscObjectGetNewTag((PetscObject)mat, &tag));
7681:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
7682:   PetscCallMPI(MPI_Comm_size(comm, &size));
7683:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

7685:   PetscCall(PetscMalloc2(n, &sizes, n, &starts));

7687:   if (rank > 0) {
7688:     PetscCallMPI(MPI_Recv(&env, 1, MPIU_INT, rank - 1, tag, comm, &status));
7689:     PetscCallMPI(MPI_Recv(&tbs, 1, MPIU_INT, rank - 1, tag, comm, &status));
7690:   }
7691:   PetscCall(MatGetOwnershipRange(mat, &rstart, NULL));
7692:   for (i = 0; i < n; i++) {
7693:     env = PetscMax(env, ja[ia[i + 1] - 1]);
7694:     II  = rstart + i;
7695:     if (env == II) {
7696:       starts[lblocks]  = tbs;
7697:       sizes[lblocks++] = 1 + II - tbs;
7698:       tbs              = 1 + II;
7699:     }
7700:   }
7701:   if (rank < size - 1) {
7702:     PetscCallMPI(MPI_Send(&env, 1, MPIU_INT, rank + 1, tag, comm));
7703:     PetscCallMPI(MPI_Send(&tbs, 1, MPIU_INT, rank + 1, tag, comm));
7704:   }

7706:   PetscCall(MatRestoreRowIJ(A, 0, PETSC_FALSE, PETSC_FALSE, &n, &ia, &ja, &done));
7707:   if (!set || !flag) PetscCall(MatDestroy(&AA));
7708:   PetscCall(MatDestroy(&A));

7710:   PetscCall(PetscNew(&edata));
7711:   PetscCall(MatGetNonzeroState(mat, &edata->nonzerostate));
7712:   edata->n = lblocks;
7713:   /* create IS needed for extracting blocks from the original matrix */
7714:   PetscCall(PetscMalloc1(lblocks, &edata->is));
7715:   for (PetscInt i = 0; i < lblocks; i++) PetscCall(ISCreateStride(PETSC_COMM_SELF, sizes[i], starts[i], 1, &edata->is[i]));

7717:   /* Create the resulting inverse matrix nonzero structure with preallocation information */
7718:   PetscCall(MatCreate(PetscObjectComm((PetscObject)mat), &edata->C));
7719:   PetscCall(MatSetSizes(edata->C, mat->rmap->n, mat->cmap->n, mat->rmap->N, mat->cmap->N));
7720:   PetscCall(MatSetBlockSizesFromMats(edata->C, mat, mat));
7721:   PetscCall(MatSetType(edata->C, MATAIJ));

7723:   /* Communicate the start and end of each row, from each block to the correct rank */
7724:   /* TODO: Use PetscSF instead of VecScatter */
7725:   for (PetscInt i = 0; i < lblocks; i++) ln += sizes[i];
7726:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, 2 * ln, &seq));
7727:   PetscCall(VecGetArrayWrite(seq, &seqv));
7728:   for (PetscInt i = 0; i < lblocks; i++) {
7729:     for (PetscInt j = 0; j < sizes[i]; j++) {
7730:       seqv[cnt]     = starts[i];
7731:       seqv[cnt + 1] = starts[i] + sizes[i];
7732:       cnt += 2;
7733:     }
7734:   }
7735:   PetscCall(VecRestoreArrayWrite(seq, &seqv));
7736:   PetscCallMPI(MPI_Scan(&cnt, &sc, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)mat)));
7737:   sc -= cnt;
7738:   PetscCall(VecCreateMPI(PetscObjectComm((PetscObject)mat), 2 * mat->rmap->n, 2 * mat->rmap->N, &par));
7739:   PetscCall(ISCreateStride(PETSC_COMM_SELF, cnt, sc, 1, &isglobal));
7740:   PetscCall(VecScatterCreate(seq, NULL, par, isglobal, &scatter));
7741:   PetscCall(ISDestroy(&isglobal));
7742:   PetscCall(VecScatterBegin(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7743:   PetscCall(VecScatterEnd(scatter, seq, par, INSERT_VALUES, SCATTER_FORWARD));
7744:   PetscCall(VecScatterDestroy(&scatter));
7745:   PetscCall(VecDestroy(&seq));
7746:   PetscCall(MatGetOwnershipRangeColumn(mat, &cstart, &cend));
7747:   PetscCall(PetscMalloc2(mat->rmap->n, &diag, mat->rmap->n, &odiag));
7748:   PetscCall(VecGetArrayRead(par, &parv));
7749:   cnt = 0;
7750:   PetscCall(MatGetSize(mat, NULL, &n));
7751:   for (PetscInt i = 0; i < mat->rmap->n; i++) {
7752:     PetscInt start, end, d = 0, od = 0;

7754:     start = (PetscInt)PetscRealPart(parv[cnt]);
7755:     end   = (PetscInt)PetscRealPart(parv[cnt + 1]);
7756:     cnt += 2;

7758:     if (start < cstart) {
7759:       od += cstart - start + n - cend;
7760:       d += cend - cstart;
7761:     } else if (start < cend) {
7762:       od += n - cend;
7763:       d += cend - start;
7764:     } else od += n - start;
7765:     if (end <= cstart) {
7766:       od -= cstart - end + n - cend;
7767:       d -= cend - cstart;
7768:     } else if (end < cend) {
7769:       od -= n - cend;
7770:       d -= cend - end;
7771:     } else od -= n - end;

7773:     odiag[i] = od;
7774:     diag[i]  = d;
7775:   }
7776:   PetscCall(VecRestoreArrayRead(par, &parv));
7777:   PetscCall(VecDestroy(&par));
7778:   PetscCall(MatXAIJSetPreallocation(edata->C, mat->rmap->bs, diag, odiag, NULL, NULL));
7779:   PetscCall(PetscFree2(diag, odiag));
7780:   PetscCall(PetscFree2(sizes, starts));

7782:   PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
7783:   PetscCall(PetscContainerSetPointer(container, edata));
7784:   PetscCall(PetscContainerSetCtxDestroy(container, EnvelopeDataDestroy));
7785:   PetscCall(PetscObjectCompose((PetscObject)mat, "EnvelopeData", (PetscObject)container));
7786:   PetscCall(PetscObjectDereference((PetscObject)container));
7787:   PetscFunctionReturn(PETSC_SUCCESS);
7788: }

7790: /*@
7791:   MatInvertVariableBlockEnvelope - set matrix C to be the inverted block diagonal of matrix A

7793:   Collective

7795:   Input Parameters:
7796: + A     - the matrix
7797: - reuse - indicates if the `C` matrix was obtained from a previous call to this routine

7799:   Output Parameter:
7800: . C - matrix with inverted block diagonal of `A`

7802:   Level: advanced

7804:   Note:
7805:   For efficiency the matrix `A` should have all the nonzero entries clustered in smallish blocks along the diagonal.

7807: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatComputeBlockDiagonal()`
7808: @*/
7809: PetscErrorCode MatInvertVariableBlockEnvelope(Mat A, MatReuse reuse, Mat *C)
7810: {
7811:   PetscContainer   container;
7812:   EnvelopeData    *edata;
7813:   PetscObjectState nonzerostate;

7815:   PetscFunctionBegin;
7816:   PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7817:   if (!container) {
7818:     PetscCall(MatComputeVariableBlockEnvelope(A));
7819:     PetscCall(PetscObjectQuery((PetscObject)A, "EnvelopeData", (PetscObject *)&container));
7820:   }
7821:   PetscCall(PetscContainerGetPointer(container, (void **)&edata));
7822:   PetscCall(MatGetNonzeroState(A, &nonzerostate));
7823:   PetscCheck(nonzerostate <= edata->nonzerostate, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Cannot handle changes to matrix nonzero structure");
7824:   PetscCheck(reuse != MAT_REUSE_MATRIX || *C == edata->C, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "C matrix must be the same as previously output");

7826:   PetscCall(MatCreateSubMatrices(A, edata->n, edata->is, edata->is, MAT_INITIAL_MATRIX, &edata->mat));
7827:   *C = edata->C;

7829:   for (PetscInt i = 0; i < edata->n; i++) {
7830:     Mat          D;
7831:     PetscScalar *dvalues;

7833:     PetscCall(MatConvert(edata->mat[i], MATSEQDENSE, MAT_INITIAL_MATRIX, &D));
7834:     PetscCall(MatSetOption(*C, MAT_ROW_ORIENTED, PETSC_FALSE));
7835:     PetscCall(MatSeqDenseInvert(D));
7836:     PetscCall(MatDenseGetArray(D, &dvalues));
7837:     PetscCall(MatSetValuesIS(*C, edata->is[i], edata->is[i], dvalues, INSERT_VALUES));
7838:     PetscCall(MatDestroy(&D));
7839:   }
7840:   PetscCall(MatDestroySubMatrices(edata->n, &edata->mat));
7841:   PetscCall(MatAssemblyBegin(*C, MAT_FINAL_ASSEMBLY));
7842:   PetscCall(MatAssemblyEnd(*C, MAT_FINAL_ASSEMBLY));
7843:   PetscFunctionReturn(PETSC_SUCCESS);
7844: }

7846: /*@
7847:   MatSetVariableBlockSizes - Sets diagonal point-blocks of the matrix that need not be of the same size

7849:   Not Collective

7851:   Input Parameters:
7852: + mat     - the matrix
7853: . nblocks - the number of blocks on this process, each block can only exist on a single process
7854: - bsizes  - the block sizes

7856:   Level: intermediate

7858:   Notes:
7859:   Currently used by `PCVPBJACOBI` for `MATAIJ` matrices

7861:   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.

7863: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatGetVariableBlockSizes()`,
7864:           `MatComputeVariableBlockEnvelope()`, `PCVPBJACOBI`
7865: @*/
7866: PetscErrorCode MatSetVariableBlockSizes(Mat mat, PetscInt nblocks, const PetscInt bsizes[])
7867: {
7868:   PetscInt ncnt = 0, nlocal;

7870:   PetscFunctionBegin;
7872:   PetscCall(MatGetLocalSize(mat, &nlocal, NULL));
7873:   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);
7874:   for (PetscInt i = 0; i < nblocks; i++) ncnt += bsizes[i];
7875:   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);
7876:   PetscCall(PetscFree(mat->bsizes));
7877:   mat->nblocks = nblocks;
7878:   PetscCall(PetscMalloc1(nblocks, &mat->bsizes));
7879:   PetscCall(PetscArraycpy(mat->bsizes, bsizes, nblocks));
7880:   PetscFunctionReturn(PETSC_SUCCESS);
7881: }

7883: /*@C
7884:   MatGetVariableBlockSizes - Gets a diagonal blocks of the matrix that need not be of the same size

7886:   Not Collective; No Fortran Support

7888:   Input Parameter:
7889: . mat - the matrix

7891:   Output Parameters:
7892: + nblocks - the number of blocks on this process
7893: - bsizes  - the block sizes

7895:   Level: intermediate

7897: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`, `MatGetBlockSizes()`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
7898: @*/
7899: PetscErrorCode MatGetVariableBlockSizes(Mat mat, PetscInt *nblocks, const PetscInt *bsizes[])
7900: {
7901:   PetscFunctionBegin;
7903:   if (nblocks) *nblocks = mat->nblocks;
7904:   if (bsizes) *bsizes = mat->bsizes;
7905:   PetscFunctionReturn(PETSC_SUCCESS);
7906: }

7908: /*@
7909:   MatSelectVariableBlockSizes - When creating a submatrix, pass on the variable block sizes

7911:   Not Collective

7913:   Input Parameter:
7914: + subA  - the submatrix
7915: . A     - the original matrix
7916: - isrow - The `IS` of selected rows for the submatrix, must be sorted

7918:   Level: developer

7920:   Notes:
7921:   If the index set is not sorted or contains off-process entries, this function will do nothing.

7923: .seealso: [](ch_matrices), `Mat`, `MatSetVariableBlockSizes()`, `MatComputeVariableBlockEnvelope()`
7924: @*/
7925: PetscErrorCode MatSelectVariableBlockSizes(Mat subA, Mat A, IS isrow)
7926: {
7927:   const PetscInt *rows;
7928:   PetscInt        n, rStart, rEnd, Nb = 0;
7929:   PetscBool       flg = A->bsizes ? PETSC_TRUE : PETSC_FALSE;

7931:   PetscFunctionBegin;
7932:   // The code for block size extraction does not support an unsorted IS
7933:   if (flg) PetscCall(ISSorted(isrow, &flg));
7934:   // We don't support originally off-diagonal blocks
7935:   if (flg) {
7936:     PetscCall(MatGetOwnershipRange(A, &rStart, &rEnd));
7937:     PetscCall(ISGetLocalSize(isrow, &n));
7938:     PetscCall(ISGetIndices(isrow, &rows));
7939:     for (PetscInt i = 0; i < n && flg; ++i) {
7940:       if (rows[i] < rStart || rows[i] >= rEnd) flg = PETSC_FALSE;
7941:     }
7942:     PetscCall(ISRestoreIndices(isrow, &rows));
7943:   }
7944:   // quiet return if we can't extract block size
7945:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &flg, 1, MPI_C_BOOL, MPI_LAND, PetscObjectComm((PetscObject)subA)));
7946:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

7948:   // extract block sizes
7949:   PetscCall(ISGetIndices(isrow, &rows));
7950:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
7951:     PetscBool occupied = PETSC_FALSE;

7953:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
7954:       const PetscInt row = gr + br;

7956:       if (i == n) break;
7957:       if (rows[i] == row) {
7958:         occupied = PETSC_TRUE;
7959:         ++i;
7960:       }
7961:       while (i < n && rows[i] < row) ++i;
7962:     }
7963:     gr += A->bsizes[b];
7964:     if (occupied) ++Nb;
7965:   }
7966:   subA->nblocks = Nb;
7967:   PetscCall(PetscFree(subA->bsizes));
7968:   PetscCall(PetscMalloc1(subA->nblocks, &subA->bsizes));
7969:   PetscInt sb = 0;
7970:   for (PetscInt b = 0, gr = rStart, i = 0; b < A->nblocks; ++b) {
7971:     if (sb < subA->nblocks) subA->bsizes[sb] = 0;
7972:     for (PetscInt br = 0; br < A->bsizes[b]; ++br) {
7973:       const PetscInt row = gr + br;

7975:       if (i == n) break;
7976:       if (rows[i] == row) {
7977:         ++subA->bsizes[sb];
7978:         ++i;
7979:       }
7980:       while (i < n && rows[i] < row) ++i;
7981:     }
7982:     gr += A->bsizes[b];
7983:     if (sb < subA->nblocks && subA->bsizes[sb]) ++sb;
7984:   }
7985:   PetscCheck(sb == subA->nblocks, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of blocks %" PetscInt_FMT " != %" PetscInt_FMT, sb, subA->nblocks);
7986:   PetscInt nlocal, ncnt = 0;
7987:   PetscCall(MatGetLocalSize(subA, &nlocal, NULL));
7988:   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);
7989:   for (PetscInt i = 0; i < subA->nblocks; i++) ncnt += subA->bsizes[i];
7990:   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);
7991:   PetscCall(ISRestoreIndices(isrow, &rows));
7992:   PetscFunctionReturn(PETSC_SUCCESS);
7993: }

7995: /*@
7996:   MatSetBlockSizes - Sets the matrix block row and column sizes.

7998:   Logically Collective

8000:   Input Parameters:
8001: + mat - the matrix
8002: . rbs - row block size
8003: - cbs - column block size

8005:   Level: intermediate

8007:   Notes:
8008:   Block row formats are `MATBAIJ` and  `MATSBAIJ`. These formats ALWAYS have square block storage in the matrix.
8009:   If you pass a different block size for the columns than the rows, the row block size determines the square block storage.
8010:   This must be called before `MatSetUp()` or MatXXXSetPreallocation() (or will default to 1) and the block size cannot be changed later.

8012:   For `MATAIJ` matrix this function can be called at a later stage, provided that the specified block sizes
8013:   are compatible with the matrix local sizes.

8015:   The row and column block size determine the blocksize of the "row" and "column" vectors returned by `MatCreateVecs()`.

8017: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSize()`, `MatGetBlockSizes()`
8018: @*/
8019: PetscErrorCode MatSetBlockSizes(Mat mat, PetscInt rbs, PetscInt cbs)
8020: {
8021:   PetscFunctionBegin;
8025:   PetscTryTypeMethod(mat, setblocksizes, rbs, cbs);
8026:   if (mat->rmap->refcnt) {
8027:     ISLocalToGlobalMapping l2g  = NULL;
8028:     PetscLayout            nmap = NULL;

8030:     PetscCall(PetscLayoutDuplicate(mat->rmap, &nmap));
8031:     if (mat->rmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->rmap->mapping, &l2g));
8032:     PetscCall(PetscLayoutDestroy(&mat->rmap));
8033:     mat->rmap          = nmap;
8034:     mat->rmap->mapping = l2g;
8035:   }
8036:   if (mat->cmap->refcnt) {
8037:     ISLocalToGlobalMapping l2g  = NULL;
8038:     PetscLayout            nmap = NULL;

8040:     PetscCall(PetscLayoutDuplicate(mat->cmap, &nmap));
8041:     if (mat->cmap->mapping) PetscCall(ISLocalToGlobalMappingDuplicate(mat->cmap->mapping, &l2g));
8042:     PetscCall(PetscLayoutDestroy(&mat->cmap));
8043:     mat->cmap          = nmap;
8044:     mat->cmap->mapping = l2g;
8045:   }
8046:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, rbs));
8047:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, cbs));
8048:   PetscFunctionReturn(PETSC_SUCCESS);
8049: }

8051: /*@
8052:   MatSetBlockSizesFromMats - Sets the matrix block row and column sizes to match a pair of matrices

8054:   Logically Collective

8056:   Input Parameters:
8057: + mat     - the matrix
8058: . fromRow - matrix from which to copy row block size
8059: - fromCol - matrix from which to copy column block size (can be same as fromRow)

8061:   Level: developer

8063: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`, `MatGetBlockSize()`, `MatSetBlockSizes()`
8064: @*/
8065: PetscErrorCode MatSetBlockSizesFromMats(Mat mat, Mat fromRow, Mat fromCol)
8066: {
8067:   PetscFunctionBegin;
8071:   PetscCall(PetscLayoutSetBlockSize(mat->rmap, fromRow->rmap->bs));
8072:   PetscCall(PetscLayoutSetBlockSize(mat->cmap, fromCol->cmap->bs));
8073:   PetscFunctionReturn(PETSC_SUCCESS);
8074: }

8076: /*@
8077:   MatResidual - Default routine to calculate the residual r = b - Ax

8079:   Collective

8081:   Input Parameters:
8082: + mat - the matrix
8083: . b   - the right-hand-side
8084: - x   - the approximate solution

8086:   Output Parameter:
8087: . r - location to store the residual

8089:   Level: developer

8091: .seealso: [](ch_matrices), `Mat`, `MatMult()`, `MatMultAdd()`, `PCMGSetResidual()`
8092: @*/
8093: PetscErrorCode MatResidual(Mat mat, Vec b, Vec x, Vec r)
8094: {
8095:   PetscFunctionBegin;
8101:   MatCheckPreallocated(mat, 1);
8102:   PetscCall(PetscLogEventBegin(MAT_Residual, mat, 0, 0, 0));
8103:   if (!mat->ops->residual) {
8104:     PetscCall(MatMult(mat, x, r));
8105:     PetscCall(VecAYPX(r, -1.0, b));
8106:   } else {
8107:     PetscUseTypeMethod(mat, residual, b, x, r);
8108:   }
8109:   PetscCall(PetscLogEventEnd(MAT_Residual, mat, 0, 0, 0));
8110:   PetscFunctionReturn(PETSC_SUCCESS);
8111: }

8113: /*@C
8114:   MatGetRowIJ - Returns the compressed row storage i and j indices for the local rows of a sparse matrix

8116:   Collective

8118:   Input Parameters:
8119: + mat             - the matrix
8120: . shift           - 0 or 1 indicating we want the indices starting at 0 or 1
8121: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8122: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE`  indicating if the nonzero structure of the
8123:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8124:                  always used.

8126:   Output Parameters:
8127: + n    - number of local rows in the (possibly compressed) matrix, use `NULL` if not needed
8128: . 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
8129: . ja   - the column indices, use `NULL` if not needed
8130: - done - indicates if the routine actually worked and returned appropriate ia[] and ja[] arrays; callers
8131:            are responsible for handling the case when done == `PETSC_FALSE` and ia and ja are not set

8133:   Level: developer

8135:   Notes:
8136:   You CANNOT change any of the ia[] or ja[] values.

8138:   Use `MatRestoreRowIJ()` when you are finished accessing the ia[] and ja[] values.

8140:   Fortran Notes:
8141:   Use
8142: .vb
8143:     PetscInt, pointer :: ia(:),ja(:)
8144:     call MatGetRowIJ(mat,shift,symmetric,inodecompressed,n,ia,ja,done,ierr)
8145:     ! Access the ith and jth entries via ia(i) and ja(j)
8146: .ve

8148: .seealso: [](ch_matrices), `Mat`, `MATAIJ`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`, `MatSeqAIJGetArray()`
8149: @*/
8150: PetscErrorCode MatGetRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8151: {
8152:   PetscFunctionBegin;
8155:   if (n) PetscAssertPointer(n, 5);
8156:   if (ia) PetscAssertPointer(ia, 6);
8157:   if (ja) PetscAssertPointer(ja, 7);
8158:   if (done) PetscAssertPointer(done, 8);
8159:   MatCheckPreallocated(mat, 1);
8160:   if (!mat->ops->getrowij && done) *done = PETSC_FALSE;
8161:   else {
8162:     if (done) *done = PETSC_TRUE;
8163:     PetscCall(PetscLogEventBegin(MAT_GetRowIJ, mat, 0, 0, 0));
8164:     PetscUseTypeMethod(mat, getrowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8165:     PetscCall(PetscLogEventEnd(MAT_GetRowIJ, mat, 0, 0, 0));
8166:   }
8167:   PetscFunctionReturn(PETSC_SUCCESS);
8168: }

8170: /*@C
8171:   MatGetColumnIJ - Returns the compressed column storage i and j indices for sequential matrices.

8173:   Collective

8175:   Input Parameters:
8176: + mat             - the matrix
8177: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8178: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be
8179:                 symmetrized
8180: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8181:                  inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8182:                  always used.

8184:   Output Parameters:
8185: + n    - number of columns in the (possibly compressed) matrix
8186: . ia   - the column pointers; that is ia[0] = 0, ia[col] = i[col-1] + number of elements in that col of the matrix
8187: . ja   - the row indices
8188: - done - `PETSC_TRUE` or `PETSC_FALSE`, indicating whether the values have been returned

8190:   Level: developer

8192: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8193: @*/
8194: PetscErrorCode MatGetColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8195: {
8196:   PetscFunctionBegin;
8199:   PetscAssertPointer(n, 5);
8200:   if (ia) PetscAssertPointer(ia, 6);
8201:   if (ja) PetscAssertPointer(ja, 7);
8202:   PetscAssertPointer(done, 8);
8203:   MatCheckPreallocated(mat, 1);
8204:   if (!mat->ops->getcolumnij) *done = PETSC_FALSE;
8205:   else {
8206:     *done = PETSC_TRUE;
8207:     PetscUseTypeMethod(mat, getcolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8208:   }
8209:   PetscFunctionReturn(PETSC_SUCCESS);
8210: }

8212: /*@C
8213:   MatRestoreRowIJ - Call after you are completed with the ia,ja indices obtained with `MatGetRowIJ()`.

8215:   Collective

8217:   Input Parameters:
8218: + mat             - the matrix
8219: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8220: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8221: . inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8222:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8223:                     always used.
8224: . n               - size of (possibly compressed) matrix
8225: . ia              - the row pointers
8226: - ja              - the column indices

8228:   Output Parameter:
8229: . done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8231:   Level: developer

8233:   Note:
8234:   This routine zeros out `n`, `ia`, and `ja`. This is to prevent accidental
8235:   us of the array after it has been restored. If you pass `NULL`, it will
8236:   not zero the pointers.  Use of ia or ja after `MatRestoreRowIJ()` is invalid.

8238: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatRestoreColumnIJ()`
8239: @*/
8240: PetscErrorCode MatRestoreRowIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8241: {
8242:   PetscFunctionBegin;
8245:   if (ia) PetscAssertPointer(ia, 6);
8246:   if (ja) PetscAssertPointer(ja, 7);
8247:   if (done) PetscAssertPointer(done, 8);
8248:   MatCheckPreallocated(mat, 1);

8250:   if (!mat->ops->restorerowij && done) *done = PETSC_FALSE;
8251:   else {
8252:     if (done) *done = PETSC_TRUE;
8253:     PetscUseTypeMethod(mat, restorerowij, shift, symmetric, inodecompressed, n, ia, ja, done);
8254:     if (n) *n = 0;
8255:     if (ia) *ia = NULL;
8256:     if (ja) *ja = NULL;
8257:   }
8258:   PetscFunctionReturn(PETSC_SUCCESS);
8259: }

8261: /*@C
8262:   MatRestoreColumnIJ - Call after you are completed with the ia,ja indices obtained with `MatGetColumnIJ()`.

8264:   Collective

8266:   Input Parameters:
8267: + mat             - the matrix
8268: . shift           - 1 or zero indicating we want the indices starting at 0 or 1
8269: . symmetric       - `PETSC_TRUE` or `PETSC_FALSE` indicating the matrix data structure should be symmetrized
8270: - inodecompressed - `PETSC_TRUE` or `PETSC_FALSE` indicating if the nonzero structure of the
8271:                     inodes or the nonzero elements is wanted. For `MATBAIJ` matrices the compressed version is
8272:                     always used.

8274:   Output Parameters:
8275: + n    - size of (possibly compressed) matrix
8276: . ia   - the column pointers
8277: . ja   - the row indices
8278: - done - `PETSC_TRUE` or `PETSC_FALSE` indicated that the values have been returned

8280:   Level: developer

8282: .seealso: [](ch_matrices), `Mat`, `MatGetColumnIJ()`, `MatRestoreRowIJ()`
8283: @*/
8284: PetscErrorCode MatRestoreColumnIJ(Mat mat, PetscInt shift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
8285: {
8286:   PetscFunctionBegin;
8289:   if (ia) PetscAssertPointer(ia, 6);
8290:   if (ja) PetscAssertPointer(ja, 7);
8291:   PetscAssertPointer(done, 8);
8292:   MatCheckPreallocated(mat, 1);

8294:   if (!mat->ops->restorecolumnij) *done = PETSC_FALSE;
8295:   else {
8296:     *done = PETSC_TRUE;
8297:     PetscUseTypeMethod(mat, restorecolumnij, shift, symmetric, inodecompressed, n, ia, ja, done);
8298:     if (n) *n = 0;
8299:     if (ia) *ia = NULL;
8300:     if (ja) *ja = NULL;
8301:   }
8302:   PetscFunctionReturn(PETSC_SUCCESS);
8303: }

8305: /*@
8306:   MatColoringPatch - Used inside matrix coloring routines that use `MatGetRowIJ()` and/or
8307:   `MatGetColumnIJ()`.

8309:   Collective

8311:   Input Parameters:
8312: + mat        - the matrix
8313: . ncolors    - maximum color value
8314: . n          - number of entries in colorarray
8315: - colorarray - array indicating color for each column

8317:   Output Parameter:
8318: . iscoloring - coloring generated using colorarray information

8320:   Level: developer

8322: .seealso: [](ch_matrices), `Mat`, `MatGetRowIJ()`, `MatGetColumnIJ()`
8323: @*/
8324: PetscErrorCode MatColoringPatch(Mat mat, PetscInt ncolors, PetscInt n, ISColoringValue colorarray[], ISColoring *iscoloring)
8325: {
8326:   PetscFunctionBegin;
8329:   PetscAssertPointer(colorarray, 4);
8330:   PetscAssertPointer(iscoloring, 5);
8331:   MatCheckPreallocated(mat, 1);

8333:   if (!mat->ops->coloringpatch) {
8334:     PetscCall(ISColoringCreate(PetscObjectComm((PetscObject)mat), ncolors, n, colorarray, PETSC_OWN_POINTER, iscoloring));
8335:   } else {
8336:     PetscUseTypeMethod(mat, coloringpatch, ncolors, n, colorarray, iscoloring);
8337:   }
8338:   PetscFunctionReturn(PETSC_SUCCESS);
8339: }

8341: /*@
8342:   MatSetUnfactored - Resets a factored matrix to be treated as unfactored.

8344:   Logically Collective

8346:   Input Parameter:
8347: . mat - the factored matrix to be reset

8349:   Level: developer

8351:   Notes:
8352:   This routine should be used only with factored matrices formed by in-place
8353:   factorization via ILU(0) (or by in-place LU factorization for the `MATSEQDENSE`
8354:   format).  This option can save memory, for example, when solving nonlinear
8355:   systems with a matrix-free Newton-Krylov method and a matrix-based, in-place
8356:   ILU(0) preconditioner.

8358:   One can specify in-place ILU(0) factorization by calling
8359: .vb
8360:      PCType(pc,PCILU);
8361:      PCFactorSeUseInPlace(pc);
8362: .ve
8363:   or by using the options -pc_type ilu -pc_factor_in_place

8365:   In-place factorization ILU(0) can also be used as a local
8366:   solver for the blocks within the block Jacobi or additive Schwarz
8367:   methods (runtime option: -sub_pc_factor_in_place).  See Users-Manual: ch_pc
8368:   for details on setting local solver options.

8370:   Most users should employ the `KSP` interface for linear solvers
8371:   instead of working directly with matrix algebra routines such as this.
8372:   See, e.g., `KSPCreate()`.

8374: .seealso: [](ch_matrices), `Mat`, `PCFactorSetUseInPlace()`, `PCFactorGetUseInPlace()`
8375: @*/
8376: PetscErrorCode MatSetUnfactored(Mat mat)
8377: {
8378:   PetscFunctionBegin;
8381:   MatCheckPreallocated(mat, 1);
8382:   mat->factortype = MAT_FACTOR_NONE;
8383:   if (!mat->ops->setunfactored) PetscFunctionReturn(PETSC_SUCCESS);
8384:   PetscUseTypeMethod(mat, setunfactored);
8385:   PetscFunctionReturn(PETSC_SUCCESS);
8386: }

8388: /*@
8389:   MatCreateSubMatrix - Gets a single submatrix on the same number of processors
8390:   as the original matrix.

8392:   Collective

8394:   Input Parameters:
8395: + mat   - the original matrix
8396: . isrow - parallel `IS` containing the rows this processor should obtain
8397: . 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.
8398: - cll   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

8400:   Output Parameter:
8401: . newmat - the new submatrix, of the same type as the original matrix

8403:   Level: advanced

8405:   Notes:
8406:   The submatrix will be able to be multiplied with vectors using the same layout as `iscol`.

8408:   Some matrix types place restrictions on the row and column indices, such
8409:   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;
8410:   for example, if the block size is 3 one cannot select the 0 and 2 rows without selecting the 1 row.

8412:   The index sets may not have duplicate entries.

8414:   The first time this is called you should use a cll of `MAT_INITIAL_MATRIX`,
8415:   the `MatCreateSubMatrix()` routine will create the newmat for you. Any additional calls
8416:   to this routine with a mat of the same nonzero structure and with a call of `MAT_REUSE_MATRIX`
8417:   will reuse the matrix generated the first time.  You should call `MatDestroy()` on `newmat` when
8418:   you are finished using it.

8420:   The communicator of the newly obtained matrix is ALWAYS the same as the communicator of
8421:   the input matrix.

8423:   If `iscol` is `NULL` then all columns are obtained (not supported in Fortran).

8425:   If `isrow` and `iscol` have a nontrivial block-size, then the resulting matrix has this block-size as well. This feature
8426:   is used by `PCFIELDSPLIT` to allow easy nesting of its use.

8428:   Example usage:
8429:   Consider the following 8x8 matrix with 34 non-zero values, that is
8430:   assembled across 3 processors. Let's assume that proc0 owns 3 rows,
8431:   proc1 owns 3 rows, proc2 owns 2 rows. This division can be shown
8432:   as follows
8433: .vb
8434:             1  2  0  |  0  3  0  |  0  4
8435:     Proc0   0  5  6  |  7  0  0  |  8  0
8436:             9  0 10  | 11  0  0  | 12  0
8437:     -------------------------------------
8438:            13  0 14  | 15 16 17  |  0  0
8439:     Proc1   0 18  0  | 19 20 21  |  0  0
8440:             0  0  0  | 22 23  0  | 24  0
8441:     -------------------------------------
8442:     Proc2  25 26 27  |  0  0 28  | 29  0
8443:            30  0  0  | 31 32 33  |  0 34
8444: .ve

8446:   Suppose `isrow` = [0 1 | 4 | 6 7] and `iscol` = [1 2 | 3 4 5 | 6].  The resulting submatrix is

8448: .vb
8449:             2  0  |  0  3  0  |  0
8450:     Proc0   5  6  |  7  0  0  |  8
8451:     -------------------------------
8452:     Proc1  18  0  | 19 20 21  |  0
8453:     -------------------------------
8454:     Proc2  26 27  |  0  0 28  | 29
8455:             0  0  | 31 32 33  |  0
8456: .ve

8458: .seealso: [](ch_matrices), `Mat`, `MatCreateSubMatrices()`, `MatCreateSubMatricesMPI()`, `MatCreateSubMatrixVirtual()`, `MatSubMatrixVirtualUpdate()`
8459: @*/
8460: PetscErrorCode MatCreateSubMatrix(Mat mat, IS isrow, IS iscol, MatReuse cll, Mat *newmat)
8461: {
8462:   PetscMPIInt size;
8463:   Mat        *local;
8464:   IS          iscoltmp;
8465:   PetscBool   flg;

8467:   PetscFunctionBegin;
8471:   PetscAssertPointer(newmat, 5);
8474:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
8475:   PetscCheck(cll != MAT_IGNORE_MATRIX, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Cannot use MAT_IGNORE_MATRIX");

8477:   MatCheckPreallocated(mat, 1);
8478:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));

8480:   if (!iscol || isrow == iscol) {
8481:     PetscBool   stride;
8482:     PetscMPIInt grabentirematrix = 0, grab;
8483:     PetscCall(PetscObjectTypeCompare((PetscObject)isrow, ISSTRIDE, &stride));
8484:     if (stride) {
8485:       PetscInt first, step, n, rstart, rend;
8486:       PetscCall(ISStrideGetInfo(isrow, &first, &step));
8487:       if (step == 1) {
8488:         PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
8489:         if (rstart == first) {
8490:           PetscCall(ISGetLocalSize(isrow, &n));
8491:           if (n == rend - rstart) grabentirematrix = 1;
8492:         }
8493:       }
8494:     }
8495:     PetscCallMPI(MPIU_Allreduce(&grabentirematrix, &grab, 1, MPI_INT, MPI_MIN, PetscObjectComm((PetscObject)mat)));
8496:     if (grab) {
8497:       PetscCall(PetscInfo(mat, "Getting entire matrix as submatrix\n"));
8498:       if (cll == MAT_INITIAL_MATRIX) {
8499:         *newmat = mat;
8500:         PetscCall(PetscObjectReference((PetscObject)mat));
8501:       }
8502:       PetscFunctionReturn(PETSC_SUCCESS);
8503:     }
8504:   }

8506:   if (!iscol) {
8507:     PetscCall(ISCreateStride(PetscObjectComm((PetscObject)mat), mat->cmap->n, mat->cmap->rstart, 1, &iscoltmp));
8508:   } else {
8509:     iscoltmp = iscol;
8510:   }

8512:   /* if original matrix is on just one processor then use submatrix generated */
8513:   if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1 && cll == MAT_REUSE_MATRIX) {
8514:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_REUSE_MATRIX, &newmat));
8515:     goto setproperties;
8516:   } else if (mat->ops->createsubmatrices && !mat->ops->createsubmatrix && size == 1) {
8517:     PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscoltmp, MAT_INITIAL_MATRIX, &local));
8518:     *newmat = *local;
8519:     PetscCall(PetscFree(local));
8520:     goto setproperties;
8521:   } else if (!mat->ops->createsubmatrix) {
8522:     /* Create a new matrix type that implements the operation using the full matrix */
8523:     PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8524:     switch (cll) {
8525:     case MAT_INITIAL_MATRIX:
8526:       PetscCall(MatCreateSubMatrixVirtual(mat, isrow, iscoltmp, newmat));
8527:       break;
8528:     case MAT_REUSE_MATRIX:
8529:       PetscCall(MatSubMatrixVirtualUpdate(*newmat, mat, isrow, iscoltmp));
8530:       break;
8531:     default:
8532:       SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "Invalid MatReuse, must be either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX");
8533:     }
8534:     PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));
8535:     goto setproperties;
8536:   }

8538:   PetscCall(PetscLogEventBegin(MAT_CreateSubMat, mat, 0, 0, 0));
8539:   PetscUseTypeMethod(mat, createsubmatrix, isrow, iscoltmp, cll, newmat);
8540:   PetscCall(PetscLogEventEnd(MAT_CreateSubMat, mat, 0, 0, 0));

8542: setproperties:
8543:   if ((*newmat)->symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->structurally_symmetric == PETSC_BOOL3_UNKNOWN && (*newmat)->spd == PETSC_BOOL3_UNKNOWN && (*newmat)->hermitian == PETSC_BOOL3_UNKNOWN) {
8544:     PetscCall(ISEqualUnsorted(isrow, iscoltmp, &flg));
8545:     if (flg) PetscCall(MatPropagateSymmetryOptions(mat, *newmat));
8546:   }
8547:   if (!iscol) PetscCall(ISDestroy(&iscoltmp));
8548:   if (*newmat && cll == MAT_INITIAL_MATRIX) PetscCall(PetscObjectStateIncrease((PetscObject)*newmat));
8549:   if (!iscol || isrow == iscol) PetscCall(MatSelectVariableBlockSizes(*newmat, mat, isrow));
8550:   PetscFunctionReturn(PETSC_SUCCESS);
8551: }

8553: /*@
8554:   MatPropagateSymmetryOptions - Propagates symmetry options set on a matrix to another matrix

8556:   Not Collective

8558:   Input Parameters:
8559: + A - the matrix we wish to propagate options from
8560: - B - the matrix we wish to propagate options to

8562:   Level: beginner

8564:   Note:
8565:   Propagates the options associated to `MAT_SYMMETRY_ETERNAL`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_HERMITIAN`, `MAT_SPD`, `MAT_SYMMETRIC`, and `MAT_STRUCTURAL_SYMMETRY_ETERNAL`

8567: .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MatIsSymmetricKnown()`, `MatIsSPDKnown()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetricKnown()`
8568: @*/
8569: PetscErrorCode MatPropagateSymmetryOptions(Mat A, Mat B)
8570: {
8571:   PetscFunctionBegin;
8574:   B->symmetry_eternal            = A->symmetry_eternal;
8575:   B->structural_symmetry_eternal = A->structural_symmetry_eternal;
8576:   B->symmetric                   = A->symmetric;
8577:   B->structurally_symmetric      = A->structurally_symmetric;
8578:   B->spd                         = A->spd;
8579:   B->hermitian                   = A->hermitian;
8580:   PetscFunctionReturn(PETSC_SUCCESS);
8581: }

8583: /*@
8584:   MatStashSetInitialSize - sets the sizes of the matrix stash, that is
8585:   used during the assembly process to store values that belong to
8586:   other processors.

8588:   Not Collective

8590:   Input Parameters:
8591: + mat   - the matrix
8592: . size  - the initial size of the stash.
8593: - bsize - the initial size of the block-stash(if used).

8595:   Options Database Keys:
8596: + -matstash_initial_size <size> or <size0,size1,...sizep-1>            - set initial size
8597: - -matstash_block_initial_size <bsize>  or <bsize0,bsize1,...bsizep-1> - set initial block size

8599:   Level: intermediate

8601:   Notes:
8602:   The block-stash is used for values set with `MatSetValuesBlocked()` while
8603:   the stash is used for values set with `MatSetValues()`

8605:   Run with the option -info and look for output of the form
8606:   MatAssemblyBegin_MPIXXX:Stash has MM entries, uses nn mallocs.
8607:   to determine the appropriate value, MM, to use for size and
8608:   MatAssemblyBegin_MPIXXX:Block-Stash has BMM entries, uses nn mallocs.
8609:   to determine the value, BMM to use for bsize

8611: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashGetInfo()`
8612: @*/
8613: PetscErrorCode MatStashSetInitialSize(Mat mat, PetscInt size, PetscInt bsize)
8614: {
8615:   PetscFunctionBegin;
8618:   PetscCall(MatStashSetInitialSize_Private(&mat->stash, size));
8619:   PetscCall(MatStashSetInitialSize_Private(&mat->bstash, bsize));
8620:   PetscFunctionReturn(PETSC_SUCCESS);
8621: }

8623: /*@
8624:   MatInterpolateAdd - $w = y + A*x$ or $A^T*x$ depending on the shape of
8625:   the matrix

8627:   Neighbor-wise Collective

8629:   Input Parameters:
8630: + A - the matrix
8631: . x - the vector to be multiplied by the interpolation operator
8632: - y - the vector to be added to the result

8634:   Output Parameter:
8635: . w - the resulting vector

8637:   Level: intermediate

8639:   Notes:
8640:   `w` may be the same vector as `y`.

8642:   This allows one to use either the restriction or interpolation (its transpose)
8643:   matrix to do the interpolation

8645: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8646: @*/
8647: PetscErrorCode MatInterpolateAdd(Mat A, Vec x, Vec y, Vec w)
8648: {
8649:   PetscInt M, N, Ny;

8651:   PetscFunctionBegin;
8656:   PetscCall(MatGetSize(A, &M, &N));
8657:   PetscCall(VecGetSize(y, &Ny));
8658:   if (M == Ny) {
8659:     PetscCall(MatMultAdd(A, x, y, w));
8660:   } else {
8661:     PetscCall(MatMultTransposeAdd(A, x, y, w));
8662:   }
8663:   PetscFunctionReturn(PETSC_SUCCESS);
8664: }

8666: /*@
8667:   MatInterpolate - $y = A*x$ or $A^T*x$ depending on the shape of
8668:   the matrix

8670:   Neighbor-wise Collective

8672:   Input Parameters:
8673: + A - the matrix
8674: - x - the vector to be interpolated

8676:   Output Parameter:
8677: . y - the resulting vector

8679:   Level: intermediate

8681:   Note:
8682:   This allows one to use either the restriction or interpolation (its transpose)
8683:   matrix to do the interpolation

8685: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatRestrict()`, `PCMG`
8686: @*/
8687: PetscErrorCode MatInterpolate(Mat A, Vec x, Vec y)
8688: {
8689:   PetscInt M, N, Ny;

8691:   PetscFunctionBegin;
8695:   PetscCall(MatGetSize(A, &M, &N));
8696:   PetscCall(VecGetSize(y, &Ny));
8697:   if (M == Ny) {
8698:     PetscCall(MatMult(A, x, y));
8699:   } else {
8700:     PetscCall(MatMultTranspose(A, x, y));
8701:   }
8702:   PetscFunctionReturn(PETSC_SUCCESS);
8703: }

8705: /*@
8706:   MatRestrict - $y = A*x$ or $A^T*x$

8708:   Neighbor-wise Collective

8710:   Input Parameters:
8711: + A - the matrix
8712: - x - the vector to be restricted

8714:   Output Parameter:
8715: . y - the resulting vector

8717:   Level: intermediate

8719:   Note:
8720:   This allows one to use either the restriction or interpolation (its transpose)
8721:   matrix to do the restriction

8723: .seealso: [](ch_matrices), `Mat`, `MatMultAdd()`, `MatMultTransposeAdd()`, `MatInterpolate()`, `PCMG`
8724: @*/
8725: PetscErrorCode MatRestrict(Mat A, Vec x, Vec y)
8726: {
8727:   PetscInt M, N, Nx;

8729:   PetscFunctionBegin;
8733:   PetscCall(MatGetSize(A, &M, &N));
8734:   PetscCall(VecGetSize(x, &Nx));
8735:   if (M == Nx) {
8736:     PetscCall(MatMultTranspose(A, x, y));
8737:   } else {
8738:     PetscCall(MatMult(A, x, y));
8739:   }
8740:   PetscFunctionReturn(PETSC_SUCCESS);
8741: }

8743: /*@
8744:   MatMatInterpolateAdd - $Y = W + A*X$ or $W + A^T*X$ depending on the shape of `A`

8746:   Neighbor-wise Collective

8748:   Input Parameters:
8749: + A - the matrix
8750: . x - the input dense matrix to be multiplied
8751: - w - the input dense matrix to be added to the result

8753:   Output Parameter:
8754: . y - the output dense matrix

8756:   Level: intermediate

8758:   Note:
8759:   This allows one to use either the restriction or interpolation (its transpose)
8760:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8761:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8763: .seealso: [](ch_matrices), `Mat`, `MatInterpolateAdd()`, `MatMatInterpolate()`, `MatMatRestrict()`, `PCMG`
8764: @*/
8765: PetscErrorCode MatMatInterpolateAdd(Mat A, Mat x, Mat w, Mat *y)
8766: {
8767:   PetscInt  M, N, Mx, Nx, Mo, My = 0, Ny = 0;
8768:   PetscBool trans = PETSC_TRUE;
8769:   MatReuse  reuse = MAT_INITIAL_MATRIX;

8771:   PetscFunctionBegin;
8777:   PetscCall(MatGetSize(A, &M, &N));
8778:   PetscCall(MatGetSize(x, &Mx, &Nx));
8779:   if (N == Mx) trans = PETSC_FALSE;
8780:   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);
8781:   Mo = trans ? N : M;
8782:   if (*y) {
8783:     PetscCall(MatGetSize(*y, &My, &Ny));
8784:     if (Mo == My && Nx == Ny) {
8785:       reuse = MAT_REUSE_MATRIX;
8786:     } else {
8787:       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);
8788:       PetscCall(MatDestroy(y));
8789:     }
8790:   }

8792:   if (w && *y == w) { /* this is to minimize changes in PCMG */
8793:     PetscBool flg;

8795:     PetscCall(PetscObjectQuery((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject *)&w));
8796:     if (w) {
8797:       PetscInt My, Ny, Mw, Nw;

8799:       PetscCall(PetscObjectTypeCompare((PetscObject)*y, ((PetscObject)w)->type_name, &flg));
8800:       PetscCall(MatGetSize(*y, &My, &Ny));
8801:       PetscCall(MatGetSize(w, &Mw, &Nw));
8802:       if (!flg || My != Mw || Ny != Nw) w = NULL;
8803:     }
8804:     if (!w) {
8805:       PetscCall(MatDuplicate(*y, MAT_COPY_VALUES, &w));
8806:       PetscCall(PetscObjectCompose((PetscObject)*y, "__MatMatIntAdd_w", (PetscObject)w));
8807:       PetscCall(PetscObjectDereference((PetscObject)w));
8808:     } else {
8809:       PetscCall(MatCopy(*y, w, UNKNOWN_NONZERO_PATTERN));
8810:     }
8811:   }
8812:   if (!trans) {
8813:     PetscCall(MatMatMult(A, x, reuse, PETSC_DETERMINE, y));
8814:   } else {
8815:     PetscCall(MatTransposeMatMult(A, x, reuse, PETSC_DETERMINE, y));
8816:   }
8817:   if (w) PetscCall(MatAXPY(*y, 1.0, w, UNKNOWN_NONZERO_PATTERN));
8818:   PetscFunctionReturn(PETSC_SUCCESS);
8819: }

8821: /*@
8822:   MatMatInterpolate - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8824:   Neighbor-wise Collective

8826:   Input Parameters:
8827: + A - the matrix
8828: - x - the input dense matrix

8830:   Output Parameter:
8831: . y - the output dense matrix

8833:   Level: intermediate

8835:   Note:
8836:   This allows one to use either the restriction or interpolation (its transpose)
8837:   matrix to do the interpolation. `y` matrix can be reused if already created with the proper sizes,
8838:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8840: .seealso: [](ch_matrices), `Mat`, `MatInterpolate()`, `MatRestrict()`, `MatMatRestrict()`, `PCMG`
8841: @*/
8842: PetscErrorCode MatMatInterpolate(Mat A, Mat x, Mat *y)
8843: {
8844:   PetscFunctionBegin;
8845:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
8846:   PetscFunctionReturn(PETSC_SUCCESS);
8847: }

8849: /*@
8850:   MatMatRestrict - $Y = A*X$ or $A^T*X$ depending on the shape of `A`

8852:   Neighbor-wise Collective

8854:   Input Parameters:
8855: + A - the matrix
8856: - x - the input dense matrix

8858:   Output Parameter:
8859: . y - the output dense matrix

8861:   Level: intermediate

8863:   Note:
8864:   This allows one to use either the restriction or interpolation (its transpose)
8865:   matrix to do the restriction. `y` matrix can be reused if already created with the proper sizes,
8866:   otherwise it will be recreated. `y` must be initialized to `NULL` if not supplied.

8868: .seealso: [](ch_matrices), `Mat`, `MatRestrict()`, `MatInterpolate()`, `MatMatInterpolate()`, `PCMG`
8869: @*/
8870: PetscErrorCode MatMatRestrict(Mat A, Mat x, Mat *y)
8871: {
8872:   PetscFunctionBegin;
8873:   PetscCall(MatMatInterpolateAdd(A, x, NULL, y));
8874:   PetscFunctionReturn(PETSC_SUCCESS);
8875: }

8877: /*@
8878:   MatGetNullSpace - retrieves the null space of a matrix.

8880:   Logically Collective

8882:   Input Parameters:
8883: + mat    - the matrix
8884: - nullsp - the null space object

8886:   Level: developer

8888: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetNullSpace()`, `MatNullSpace`
8889: @*/
8890: PetscErrorCode MatGetNullSpace(Mat mat, MatNullSpace *nullsp)
8891: {
8892:   PetscFunctionBegin;
8894:   PetscAssertPointer(nullsp, 2);
8895:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->nullsp) ? mat->transnullsp : mat->nullsp;
8896:   PetscFunctionReturn(PETSC_SUCCESS);
8897: }

8899: /*@C
8900:   MatGetNullSpaces - gets the null spaces, transpose null spaces, and near null spaces from an array of matrices

8902:   Logically Collective

8904:   Input Parameters:
8905: + n   - the number of matrices
8906: - mat - the array of matrices

8908:   Output Parameters:
8909: . nullsp - an array of null spaces, `NULL` for each matrix that does not have a null space, length 3 * `n`

8911:   Level: developer

8913:   Note:
8914:   Call `MatRestoreNullspaces()` to provide these to another array of matrices

8916: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
8917:           `MatNullSpaceRemove()`, `MatRestoreNullSpaces()`
8918: @*/
8919: PetscErrorCode MatGetNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
8920: {
8921:   PetscFunctionBegin;
8922:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
8923:   PetscAssertPointer(mat, 2);
8924:   PetscAssertPointer(nullsp, 3);

8926:   PetscCall(PetscCalloc1(3 * n, nullsp));
8927:   for (PetscInt i = 0; i < n; i++) {
8929:     (*nullsp)[i] = mat[i]->nullsp;
8930:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[i]));
8931:     (*nullsp)[n + i] = mat[i]->nearnullsp;
8932:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[n + i]));
8933:     (*nullsp)[2 * n + i] = mat[i]->transnullsp;
8934:     PetscCall(PetscObjectReference((PetscObject)(*nullsp)[2 * n + i]));
8935:   }
8936:   PetscFunctionReturn(PETSC_SUCCESS);
8937: }

8939: /*@C
8940:   MatRestoreNullSpaces - sets the null spaces, transpose null spaces, and near null spaces obtained with `MatGetNullSpaces()` for an array of matrices

8942:   Logically Collective

8944:   Input Parameters:
8945: + n      - the number of matrices
8946: . mat    - the array of matrices
8947: - nullsp - an array of null spaces

8949:   Level: developer

8951:   Note:
8952:   Call `MatGetNullSpaces()` to create `nullsp`

8954: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`,
8955:           `MatNullSpaceRemove()`, `MatGetNullSpaces()`
8956: @*/
8957: PetscErrorCode MatRestoreNullSpaces(PetscInt n, Mat mat[], MatNullSpace *nullsp[])
8958: {
8959:   PetscFunctionBegin;
8960:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of matrices %" PetscInt_FMT " must be non-negative", n);
8961:   PetscAssertPointer(mat, 2);
8962:   PetscAssertPointer(nullsp, 3);
8963:   PetscAssertPointer(*nullsp, 3);

8965:   for (PetscInt i = 0; i < n; i++) {
8967:     PetscCall(MatSetNullSpace(mat[i], (*nullsp)[i]));
8968:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[i]));
8969:     PetscCall(MatSetNearNullSpace(mat[i], (*nullsp)[n + i]));
8970:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[n + i]));
8971:     PetscCall(MatSetTransposeNullSpace(mat[i], (*nullsp)[2 * n + i]));
8972:     PetscCall(PetscObjectDereference((PetscObject)(*nullsp)[2 * n + i]));
8973:   }
8974:   PetscCall(PetscFree(*nullsp));
8975:   PetscFunctionReturn(PETSC_SUCCESS);
8976: }

8978: /*@
8979:   MatSetNullSpace - attaches a null space to a matrix.

8981:   Logically Collective

8983:   Input Parameters:
8984: + mat    - the matrix
8985: - nullsp - the null space object

8987:   Level: advanced

8989:   Notes:
8990:   This null space is used by the `KSP` linear solvers to solve singular systems.

8992:   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`

8994:   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
8995:   to zero but the linear system will still be solved in a least squares sense.

8997:   The fundamental theorem of linear algebra (Gilbert Strang, Introduction to Applied Mathematics, page 72) states that
8998:   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 $A^T$, $R(A^T)$.
8999:   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
9000:   $n(A^T))$ 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
9001:   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 $n(A^T)$.
9002:   This  $\hat{b}$ can be obtained by calling `MatNullSpaceRemove()` with the null space of the transpose of the matrix.

9004:   If the matrix is known to be symmetric because it is an `MATSBAIJ` matrix or one has called
9005:   `MatSetOption`(mat,`MAT_SYMMETRIC` or possibly `MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`); this
9006:   routine also automatically calls `MatSetTransposeNullSpace()`.

9008:   The user should call `MatNullSpaceDestroy()`.

9010: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetTransposeNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`,
9011:           `KSPSetPCSide()`
9012: @*/
9013: PetscErrorCode MatSetNullSpace(Mat mat, MatNullSpace nullsp)
9014: {
9015:   PetscFunctionBegin;
9018:   if (nullsp) PetscCall(PetscObjectReference((PetscObject)nullsp));
9019:   PetscCall(MatNullSpaceDestroy(&mat->nullsp));
9020:   mat->nullsp = nullsp;
9021:   if (mat->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetTransposeNullSpace(mat, nullsp));
9022:   PetscFunctionReturn(PETSC_SUCCESS);
9023: }

9025: /*@
9026:   MatGetTransposeNullSpace - retrieves the null space of the transpose of a matrix.

9028:   Logically Collective

9030:   Input Parameters:
9031: + mat    - the matrix
9032: - nullsp - the null space object

9034:   Level: developer

9036: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatSetTransposeNullSpace()`, `MatSetNullSpace()`, `MatGetNullSpace()`
9037: @*/
9038: PetscErrorCode MatGetTransposeNullSpace(Mat mat, MatNullSpace *nullsp)
9039: {
9040:   PetscFunctionBegin;
9043:   PetscAssertPointer(nullsp, 2);
9044:   *nullsp = (mat->symmetric == PETSC_BOOL3_TRUE && !mat->transnullsp) ? mat->nullsp : mat->transnullsp;
9045:   PetscFunctionReturn(PETSC_SUCCESS);
9046: }

9048: /*@
9049:   MatSetTransposeNullSpace - attaches the null space of a transpose of a matrix to the matrix

9051:   Logically Collective

9053:   Input Parameters:
9054: + mat    - the matrix
9055: - nullsp - the null space object

9057:   Level: advanced

9059:   Notes:
9060:   This allows solving singular linear systems defined by the transpose of the matrix using `KSP` solvers with left preconditioning.

9062:   See `MatSetNullSpace()`

9064: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatSetNullSpace()`, `MatGetTransposeNullSpace()`, `MatNullSpaceRemove()`, `KSPSetPCSide()`
9065: @*/
9066: PetscErrorCode MatSetTransposeNullSpace(Mat mat, MatNullSpace nullsp)
9067: {
9068:   PetscFunctionBegin;
9071:   if (nullsp) PetscCall(PetscObjectReference((PetscObject)nullsp));
9072:   PetscCall(MatNullSpaceDestroy(&mat->transnullsp));
9073:   mat->transnullsp = nullsp;
9074:   PetscFunctionReturn(PETSC_SUCCESS);
9075: }

9077: /*@
9078:   MatSetNearNullSpace - attaches a null space to a matrix, which is often the null space (rigid body modes) of the operator without boundary conditions
9079:   This null space will be used to provide near null space vectors to a multigrid preconditioner built from this matrix.

9081:   Logically Collective

9083:   Input Parameters:
9084: + mat    - the matrix
9085: - nullsp - the null space object

9087:   Level: advanced

9089:   Notes:
9090:   Overwrites any previous near null space that may have been attached

9092:   You can remove the null space by calling this routine with an `nullsp` of `NULL`

9094: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatCreate()`, `MatNullSpaceCreate()`, `MatSetNullSpace()`, `MatNullSpaceCreateRigidBody()`, `MatGetNearNullSpace()`
9095: @*/
9096: PetscErrorCode MatSetNearNullSpace(Mat mat, MatNullSpace nullsp)
9097: {
9098:   PetscFunctionBegin;
9102:   MatCheckPreallocated(mat, 1);
9103:   if (nullsp) PetscCall(PetscObjectReference((PetscObject)nullsp));
9104:   PetscCall(MatNullSpaceDestroy(&mat->nearnullsp));
9105:   mat->nearnullsp = nullsp;
9106:   PetscFunctionReturn(PETSC_SUCCESS);
9107: }

9109: /*@
9110:   MatGetNearNullSpace - Get null space attached with `MatSetNearNullSpace()`

9112:   Not Collective

9114:   Input Parameter:
9115: . mat - the matrix

9117:   Output Parameter:
9118: . nullsp - the null space object, `NULL` if not set

9120:   Level: advanced

9122: .seealso: [](ch_matrices), `Mat`, `MatNullSpace`, `MatSetNearNullSpace()`, `MatGetNullSpace()`, `MatNullSpaceCreate()`
9123: @*/
9124: PetscErrorCode MatGetNearNullSpace(Mat mat, MatNullSpace *nullsp)
9125: {
9126:   PetscFunctionBegin;
9129:   PetscAssertPointer(nullsp, 2);
9130:   MatCheckPreallocated(mat, 1);
9131:   *nullsp = mat->nearnullsp;
9132:   PetscFunctionReturn(PETSC_SUCCESS);
9133: }

9135: /*@
9136:   MatICCFactor - Performs in-place incomplete Cholesky factorization of matrix.

9138:   Collective

9140:   Input Parameters:
9141: + mat  - the matrix
9142: . row  - row/column permutation
9143: - info - information on desired factorization process

9145:   Level: developer

9147:   Notes:
9148:   Probably really in-place only when level of fill is zero, otherwise allocates
9149:   new space to store factored matrix and deletes previous memory.

9151:   Most users should employ the `KSP` interface for linear solvers
9152:   instead of working directly with matrix algebra routines such as this.
9153:   See, e.g., `KSPCreate()`.

9155:   Fortran Note:
9156:   A valid (non-null) `info` argument must be provided

9158: .seealso: [](ch_matrices), `Mat`, `MatFactorInfo`, `MatGetFactor()`, `MatICCFactorSymbolic()`, `MatLUFactorNumeric()`, `MatCholeskyFactor()`
9159: @*/
9160: PetscErrorCode MatICCFactor(Mat mat, IS row, const MatFactorInfo *info)
9161: {
9162:   PetscFunctionBegin;
9166:   PetscAssertPointer(info, 3);
9167:   PetscCheck(mat->rmap->N == mat->cmap->N, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONG, "matrix must be square");
9168:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
9169:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
9170:   MatCheckPreallocated(mat, 1);
9171:   PetscUseTypeMethod(mat, iccfactor, row, info);
9172:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9173:   PetscFunctionReturn(PETSC_SUCCESS);
9174: }

9176: /*@
9177:   MatDiagonalScaleLocal - Scales columns of a matrix given the scaling values including the
9178:   ghosted ones.

9180:   Not Collective

9182:   Input Parameters:
9183: + mat  - the matrix
9184: - diag - the diagonal values, including ghost ones

9186:   Level: developer

9188:   Notes:
9189:   Works only for `MATMPIAIJ` and `MATMPIBAIJ` matrices

9191:   This allows one to avoid during communication to perform the scaling that must be done with `MatDiagonalScale()`

9193: .seealso: [](ch_matrices), `Mat`, `MatDiagonalScale()`
9194: @*/
9195: PetscErrorCode MatDiagonalScaleLocal(Mat mat, Vec diag)
9196: {
9197:   PetscMPIInt size;

9199:   PetscFunctionBegin;

9204:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must be already assembled");
9205:   PetscCall(PetscLogEventBegin(MAT_Scale, mat, 0, 0, 0));
9206:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
9207:   if (size == 1) {
9208:     PetscInt n, m;
9209:     PetscCall(VecGetSize(diag, &n));
9210:     PetscCall(MatGetSize(mat, NULL, &m));
9211:     PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supported for sequential matrices when no ghost points/periodic conditions");
9212:     PetscCall(MatDiagonalScale(mat, NULL, diag));
9213:   } else {
9214:     PetscUseMethod(mat, "MatDiagonalScaleLocal_C", (Mat, Vec), (mat, diag));
9215:   }
9216:   PetscCall(PetscLogEventEnd(MAT_Scale, mat, 0, 0, 0));
9217:   PetscCall(PetscObjectStateIncrease((PetscObject)mat));
9218:   PetscFunctionReturn(PETSC_SUCCESS);
9219: }

9221: /*@
9222:   MatGetInertia - Gets the inertia from a factored matrix

9224:   Collective

9226:   Input Parameter:
9227: . mat - the matrix

9229:   Output Parameters:
9230: + nneg  - number of negative eigenvalues
9231: . nzero - number of zero eigenvalues
9232: - npos  - number of positive eigenvalues

9234:   Level: advanced

9236:   Note:
9237:   Matrix must have been factored by `MatCholeskyFactor()`

9239: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatCholeskyFactor()`
9240: @*/
9241: PetscErrorCode MatGetInertia(Mat mat, PetscInt *nneg, PetscInt *nzero, PetscInt *npos)
9242: {
9243:   PetscFunctionBegin;
9246:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9247:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Numeric factor mat is not assembled");
9248:   PetscUseTypeMethod(mat, getinertia, nneg, nzero, npos);
9249:   PetscFunctionReturn(PETSC_SUCCESS);
9250: }

9252: /*@C
9253:   MatSolves - Solves $A x = b$, given a factored matrix, for a collection of vectors

9255:   Neighbor-wise Collective

9257:   Input Parameters:
9258: + mat - the factored matrix obtained with `MatGetFactor()`
9259: - b   - the right-hand-side vectors

9261:   Output Parameter:
9262: . x - the result vectors

9264:   Level: developer

9266:   Note:
9267:   The vectors `b` and `x` cannot be the same.  I.e., one cannot
9268:   call `MatSolves`(A,x,x).

9270: .seealso: [](ch_matrices), `Mat`, `Vecs`, `MatSolveAdd()`, `MatSolveTranspose()`, `MatSolveTransposeAdd()`, `MatSolve()`
9271: @*/
9272: PetscErrorCode MatSolves(Mat mat, Vecs b, Vecs x)
9273: {
9274:   PetscFunctionBegin;
9277:   PetscCheck(x != b, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_IDN, "x and b must be different vectors");
9278:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Unfactored matrix");
9279:   if (!mat->rmap->N && !mat->cmap->N) PetscFunctionReturn(PETSC_SUCCESS);

9281:   MatCheckPreallocated(mat, 1);
9282:   PetscCall(PetscLogEventBegin(MAT_Solves, mat, 0, 0, 0));
9283:   PetscUseTypeMethod(mat, solves, b, x);
9284:   PetscCall(PetscLogEventEnd(MAT_Solves, mat, 0, 0, 0));
9285:   PetscFunctionReturn(PETSC_SUCCESS);
9286: }

9288: /*@
9289:   MatIsSymmetric - Test whether a matrix is symmetric

9291:   Collective

9293:   Input Parameters:
9294: + A   - the matrix to test
9295: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact transpose)

9297:   Output Parameter:
9298: . flg - the result

9300:   Level: intermediate

9302:   Notes:
9303:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9305:   If the matrix does not yet know if it is symmetric or not this can be an expensive operation, also available `MatIsSymmetricKnown()`

9307:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9308:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9310: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetricKnown()`,
9311:           `MAT_SYMMETRIC`, `MAT_SYMMETRY_ETERNAL`
9312: @*/
9313: PetscErrorCode MatIsSymmetric(Mat A, PetscReal tol, PetscBool *flg)
9314: {
9315:   PetscFunctionBegin;
9317:   PetscAssertPointer(flg, 3);
9318:   if (A->symmetric != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->symmetric);
9319:   else {
9320:     if (A->ops->issymmetric) PetscUseTypeMethod(A, issymmetric, tol, flg);
9321:     else PetscCall(MatIsTranspose(A, A, tol, flg));
9322:     if (!tol) PetscCall(MatSetOption(A, MAT_SYMMETRIC, *flg));
9323:   }
9324:   PetscFunctionReturn(PETSC_SUCCESS);
9325: }

9327: /*@
9328:   MatIsHermitian - Test whether a matrix is Hermitian

9330:   Collective

9332:   Input Parameters:
9333: + A   - the matrix to test
9334: - tol - difference between value and its transpose less than this amount counts as equal (use 0.0 for exact Hermitian)

9336:   Output Parameter:
9337: . flg - the result

9339:   Level: intermediate

9341:   Notes:
9342:   For real numbers `MatIsSymmetric()` and `MatIsHermitian()` return identical results

9344:   If the matrix does not yet know if it is Hermitian or not this can be an expensive operation, also available `MatIsHermitianKnown()`

9346:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9347:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMEMTRY_ETERNAL`,`PETSC_TRUE`)

9349: .seealso: [](ch_matrices), `Mat`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitianKnown()`, `MatIsStructurallySymmetric()`, `MatSetOption()`,
9350:           `MatIsSymmetricKnown()`, `MatIsSymmetric()`, `MAT_HERMITIAN`, `MAT_SYMMETRY_ETERNAL`
9351: @*/
9352: PetscErrorCode MatIsHermitian(Mat A, PetscReal tol, PetscBool *flg)
9353: {
9354:   PetscFunctionBegin;
9356:   PetscAssertPointer(flg, 3);
9357:   if (A->hermitian != PETSC_BOOL3_UNKNOWN && !tol) *flg = PetscBool3ToBool(A->hermitian);
9358:   else {
9359:     if (A->ops->ishermitian) PetscUseTypeMethod(A, ishermitian, tol, flg);
9360:     else PetscCall(MatIsHermitianTranspose(A, A, tol, flg));
9361:     if (!tol) PetscCall(MatSetOption(A, MAT_HERMITIAN, *flg));
9362:   }
9363:   PetscFunctionReturn(PETSC_SUCCESS);
9364: }

9366: /*@
9367:   MatIsSymmetricKnown - Checks if a matrix knows if it is symmetric or not and its symmetric state

9369:   Not Collective

9371:   Input Parameter:
9372: . A - the matrix to check

9374:   Output Parameters:
9375: + set - `PETSC_TRUE` if the matrix knows its symmetry state (this tells you if the next flag is valid)
9376: - flg - the result (only valid if set is `PETSC_TRUE`)

9378:   Level: advanced

9380:   Notes:
9381:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsSymmetric()`
9382:   if you want it explicitly checked

9384:   One can declare that a matrix is symmetric with `MatSetOption`(mat,`MAT_SYMMETRIC`,`PETSC_TRUE`) and if it is known to remain symmetric
9385:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9387: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9388: @*/
9389: PetscErrorCode MatIsSymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9390: {
9391:   PetscFunctionBegin;
9393:   PetscAssertPointer(set, 2);
9394:   PetscAssertPointer(flg, 3);
9395:   if (A->symmetric != PETSC_BOOL3_UNKNOWN) {
9396:     *set = PETSC_TRUE;
9397:     *flg = PetscBool3ToBool(A->symmetric);
9398:   } else {
9399:     *set = PETSC_FALSE;
9400:   }
9401:   PetscFunctionReturn(PETSC_SUCCESS);
9402: }

9404: /*@
9405:   MatIsSPDKnown - Checks if a matrix knows if it is symmetric positive definite or not and its symmetric positive definite state

9407:   Not Collective

9409:   Input Parameter:
9410: . A - the matrix to check

9412:   Output Parameters:
9413: + set - `PETSC_TRUE` if the matrix knows its symmetric positive definite state (this tells you if the next flag is valid)
9414: - flg - the result (only valid if set is `PETSC_TRUE`)

9416:   Level: advanced

9418:   Notes:
9419:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`).

9421:   One can declare that a matrix is SPD with `MatSetOption`(mat,`MAT_SPD`,`PETSC_TRUE`) and if it is known to remain SPD
9422:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SPD_ETERNAL`,`PETSC_TRUE`)

9424: .seealso: [](ch_matrices), `Mat`, `MAT_SPD_ETERNAL`, `MAT_SPD`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9425: @*/
9426: PetscErrorCode MatIsSPDKnown(Mat A, PetscBool *set, PetscBool *flg)
9427: {
9428:   PetscFunctionBegin;
9430:   PetscAssertPointer(set, 2);
9431:   PetscAssertPointer(flg, 3);
9432:   if (A->spd != PETSC_BOOL3_UNKNOWN) {
9433:     *set = PETSC_TRUE;
9434:     *flg = PetscBool3ToBool(A->spd);
9435:   } else {
9436:     *set = PETSC_FALSE;
9437:   }
9438:   PetscFunctionReturn(PETSC_SUCCESS);
9439: }

9441: /*@
9442:   MatIsHermitianKnown - Checks if a matrix knows if it is Hermitian or not and its Hermitian state

9444:   Not Collective

9446:   Input Parameter:
9447: . A - the matrix to check

9449:   Output Parameters:
9450: + set - `PETSC_TRUE` if the matrix knows its Hermitian state (this tells you if the next flag is valid)
9451: - flg - the result (only valid if set is `PETSC_TRUE`)

9453:   Level: advanced

9455:   Notes:
9456:   Does not check the matrix values directly, so this may return unknown (set = `PETSC_FALSE`). Use `MatIsHermitian()`
9457:   if you want it explicitly checked

9459:   One can declare that a matrix is Hermitian with `MatSetOption`(mat,`MAT_HERMITIAN`,`PETSC_TRUE`) and if it is known to remain Hermitian
9460:   after changes to the matrices values one can call `MatSetOption`(mat,`MAT_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9462: .seealso: [](ch_matrices), `Mat`, `MAT_SYMMETRY_ETERNAL`, `MAT_HERMITIAN`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`
9463: @*/
9464: PetscErrorCode MatIsHermitianKnown(Mat A, PetscBool *set, PetscBool *flg)
9465: {
9466:   PetscFunctionBegin;
9468:   PetscAssertPointer(set, 2);
9469:   PetscAssertPointer(flg, 3);
9470:   if (A->hermitian != PETSC_BOOL3_UNKNOWN) {
9471:     *set = PETSC_TRUE;
9472:     *flg = PetscBool3ToBool(A->hermitian);
9473:   } else {
9474:     *set = PETSC_FALSE;
9475:   }
9476:   PetscFunctionReturn(PETSC_SUCCESS);
9477: }

9479: /*@
9480:   MatIsStructurallySymmetric - Test whether a matrix is structurally symmetric

9482:   Collective

9484:   Input Parameter:
9485: . A - the matrix to test

9487:   Output Parameter:
9488: . flg - the result

9490:   Level: intermediate

9492:   Notes:
9493:   If the matrix does yet know it is structurally symmetric this can be an expensive operation, also available `MatIsStructurallySymmetricKnown()`

9495:   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
9496:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9498: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MAT_STRUCTURAL_SYMMETRY_ETERNAL`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsSymmetric()`, `MatSetOption()`, `MatIsStructurallySymmetricKnown()`
9499: @*/
9500: PetscErrorCode MatIsStructurallySymmetric(Mat A, PetscBool *flg)
9501: {
9502:   PetscFunctionBegin;
9504:   PetscAssertPointer(flg, 2);
9505:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9506:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9507:   } else {
9508:     PetscUseTypeMethod(A, isstructurallysymmetric, flg);
9509:     PetscCall(MatSetOption(A, MAT_STRUCTURALLY_SYMMETRIC, *flg));
9510:   }
9511:   PetscFunctionReturn(PETSC_SUCCESS);
9512: }

9514: /*@
9515:   MatIsStructurallySymmetricKnown - Checks if a matrix knows if it is structurally symmetric or not and its structurally symmetric state

9517:   Not Collective

9519:   Input Parameter:
9520: . A - the matrix to check

9522:   Output Parameters:
9523: + set - PETSC_TRUE if the matrix knows its structurally symmetric state (this tells you if the next flag is valid)
9524: - flg - the result (only valid if set is PETSC_TRUE)

9526:   Level: advanced

9528:   Notes:
9529:   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
9530:   symmetric after changes to the matrices values one can call `MatSetOption`(mat,`MAT_STRUCTURAL_SYMMETRY_ETERNAL`,`PETSC_TRUE`)

9532:   Use `MatIsStructurallySymmetric()` to explicitly check if a matrix is structurally symmetric (this is an expensive operation)

9534: .seealso: [](ch_matrices), `Mat`, `MAT_STRUCTURALLY_SYMMETRIC`, `MatTranspose()`, `MatIsTranspose()`, `MatIsHermitian()`, `MatIsStructurallySymmetric()`, `MatSetOption()`, `MatIsSymmetric()`, `MatIsHermitianKnown()`
9535: @*/
9536: PetscErrorCode MatIsStructurallySymmetricKnown(Mat A, PetscBool *set, PetscBool *flg)
9537: {
9538:   PetscFunctionBegin;
9540:   PetscAssertPointer(set, 2);
9541:   PetscAssertPointer(flg, 3);
9542:   if (A->structurally_symmetric != PETSC_BOOL3_UNKNOWN) {
9543:     *set = PETSC_TRUE;
9544:     *flg = PetscBool3ToBool(A->structurally_symmetric);
9545:   } else {
9546:     *set = PETSC_FALSE;
9547:   }
9548:   PetscFunctionReturn(PETSC_SUCCESS);
9549: }

9551: /*@
9552:   MatStashGetInfo - Gets how many values are currently in the matrix stash, i.e. need
9553:   to be communicated to other processors during the `MatAssemblyBegin()`/`MatAssemblyEnd()` process

9555:   Not Collective

9557:   Input Parameter:
9558: . mat - the matrix

9560:   Output Parameters:
9561: + nstash    - the size of the stash
9562: . reallocs  - the number of additional mallocs incurred.
9563: . bnstash   - the size of the block stash
9564: - breallocs - the number of additional mallocs incurred.in the block stash

9566:   Level: advanced

9568: .seealso: [](ch_matrices), `MatAssemblyBegin()`, `MatAssemblyEnd()`, `Mat`, `MatStashSetInitialSize()`
9569: @*/
9570: PetscErrorCode MatStashGetInfo(Mat mat, PetscInt *nstash, PetscInt *reallocs, PetscInt *bnstash, PetscInt *breallocs)
9571: {
9572:   PetscFunctionBegin;
9573:   PetscCall(MatStashGetInfo_Private(&mat->stash, nstash, reallocs));
9574:   PetscCall(MatStashGetInfo_Private(&mat->bstash, bnstash, breallocs));
9575:   PetscFunctionReturn(PETSC_SUCCESS);
9576: }

9578: /*@
9579:   MatCreateVecs - Get vector(s) compatible with the matrix, i.e. with the same
9580:   parallel layout, `PetscLayout` for rows and columns

9582:   Collective

9584:   Input Parameter:
9585: . mat - the matrix

9587:   Output Parameters:
9588: + right - (optional) vector that the matrix can be multiplied against
9589: - left  - (optional) vector that the matrix vector product can be stored in

9591:   Level: advanced

9593:   Notes:
9594:   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()`.

9596:   These are new vectors which are not owned by the mat, they should be destroyed in `VecDestroy()` when no longer needed

9598: .seealso: [](ch_matrices), `Mat`, `Vec`, `VecCreate()`, `VecDestroy()`, `DMCreateGlobalVector()`
9599: @*/
9600: PetscErrorCode MatCreateVecs(Mat mat, Vec *right, Vec *left)
9601: {
9602:   PetscFunctionBegin;
9605:   if (mat->ops->getvecs) {
9606:     PetscUseTypeMethod(mat, getvecs, right, left);
9607:   } else {
9608:     if (right) {
9609:       PetscCheck(mat->cmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for columns not yet setup");
9610:       PetscCall(VecCreateWithLayout_Private(mat->cmap, right));
9611:       PetscCall(VecSetType(*right, mat->defaultvectype));
9612: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9613:       if (mat->boundtocpu && mat->bindingpropagates) {
9614:         PetscCall(VecSetBindingPropagates(*right, PETSC_TRUE));
9615:         PetscCall(VecBindToCPU(*right, PETSC_TRUE));
9616:       }
9617: #endif
9618:     }
9619:     if (left) {
9620:       PetscCheck(mat->rmap->n >= 0, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "PetscLayout for rows not yet setup");
9621:       PetscCall(VecCreateWithLayout_Private(mat->rmap, left));
9622:       PetscCall(VecSetType(*left, mat->defaultvectype));
9623: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
9624:       if (mat->boundtocpu && mat->bindingpropagates) {
9625:         PetscCall(VecSetBindingPropagates(*left, PETSC_TRUE));
9626:         PetscCall(VecBindToCPU(*left, PETSC_TRUE));
9627:       }
9628: #endif
9629:     }
9630:   }
9631:   PetscFunctionReturn(PETSC_SUCCESS);
9632: }

9634: /*@
9635:   MatFactorInfoInitialize - Initializes a `MatFactorInfo` data structure
9636:   with default values.

9638:   Not Collective

9640:   Input Parameter:
9641: . info - the `MatFactorInfo` data structure

9643:   Level: developer

9645:   Notes:
9646:   The solvers are generally used through the `KSP` and `PC` objects, for example
9647:   `PCLU`, `PCILU`, `PCCHOLESKY`, `PCICC`

9649:   Once the data structure is initialized one may change certain entries as desired for the particular factorization to be performed

9651: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorInfo`
9652: @*/
9653: PetscErrorCode MatFactorInfoInitialize(MatFactorInfo *info)
9654: {
9655:   PetscFunctionBegin;
9656:   PetscCall(PetscMemzero(info, sizeof(MatFactorInfo)));
9657:   PetscFunctionReturn(PETSC_SUCCESS);
9658: }

9660: /*@
9661:   MatFactorSetSchurIS - Set indices corresponding to the Schur complement you wish to have computed

9663:   Collective

9665:   Input Parameters:
9666: + mat - the factored matrix
9667: - is  - the index set defining the Schur indices (0-based)

9669:   Level: advanced

9671:   Notes:
9672:   Call `MatFactorSolveSchurComplement()` or `MatFactorSolveSchurComplementTranspose()` after this call to solve a Schur complement system.

9674:   You can call `MatFactorGetSchurComplement()` or `MatFactorCreateSchurComplement()` after this call.

9676:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9678: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorGetSchurComplement()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSolveSchurComplement()`,
9679:           `MatFactorSolveSchurComplementTranspose()`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9680: @*/
9681: PetscErrorCode MatFactorSetSchurIS(Mat mat, IS is)
9682: {
9683:   PetscErrorCode (*f)(Mat, IS);

9685:   PetscFunctionBegin;
9690:   PetscCheckSameComm(mat, 1, is, 2);
9691:   PetscCheck(mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Only for factored matrix");
9692:   PetscCall(PetscObjectQueryFunction((PetscObject)mat, "MatFactorSetSchurIS_C", &f));
9693:   PetscCheck(f, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "The selected MatSolverType does not support Schur complement computation. You should use MATSOLVERMUMPS or MATSOLVERMKL_PARDISO");
9694:   PetscCall(MatDestroy(&mat->schur));
9695:   PetscCall((*f)(mat, is));
9696:   PetscCheck(mat->schur, PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "Schur complement has not been created");
9697:   PetscFunctionReturn(PETSC_SUCCESS);
9698: }

9700: /*@
9701:   MatFactorCreateSchurComplement - Create a Schur complement matrix object using Schur data computed during the factorization step

9703:   Logically Collective

9705:   Input Parameters:
9706: + F      - the factored matrix obtained by calling `MatGetFactor()`
9707: . S      - location where to return the Schur complement, can be `NULL`
9708: - status - the status of the Schur complement matrix, can be `NULL`

9710:   Level: advanced

9712:   Notes:
9713:   You must call `MatFactorSetSchurIS()` before calling this routine.

9715:   This functionality is only supported for `MATSOLVERMUMPS` and `MATSOLVERMKL_PARDISO`

9717:   The routine provides a copy of the Schur matrix stored within the solver data structures.
9718:   The caller must destroy the object when it is no longer needed.
9719:   If `MatFactorInvertSchurComplement()` has been called, the routine gets back the inverse.

9721:   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)

9723:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9725:   Developer Note:
9726:   The reason this routine exists is because the representation of the Schur complement within the factor matrix may be different than a standard PETSc
9727:   matrix representation and we normally do not want to use the time or memory to make a copy as a regular PETSc matrix.

9729: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorSchurStatus`, `MATSOLVERMUMPS`, `MATSOLVERMKL_PARDISO`
9730: @*/
9731: PetscErrorCode MatFactorCreateSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9732: {
9733:   PetscFunctionBegin;
9735:   if (S) PetscAssertPointer(S, 2);
9736:   if (status) PetscAssertPointer(status, 3);
9737:   if (S) {
9738:     PetscErrorCode (*f)(Mat, Mat *);

9740:     PetscCall(PetscObjectQueryFunction((PetscObject)F, "MatFactorCreateSchurComplement_C", &f));
9741:     if (f) {
9742:       PetscCall((*f)(F, S));
9743:     } else {
9744:       PetscCall(MatDuplicate(F->schur, MAT_COPY_VALUES, S));
9745:     }
9746:   }
9747:   if (status) *status = F->schur_status;
9748:   PetscFunctionReturn(PETSC_SUCCESS);
9749: }

9751: /*@
9752:   MatFactorGetSchurComplement - Gets access to a Schur complement matrix using the current Schur data within a factored matrix

9754:   Logically Collective

9756:   Input Parameters:
9757: + F      - the factored matrix obtained by calling `MatGetFactor()`
9758: . S      - location where to return the Schur complement, can be `NULL`
9759: - status - the status of the Schur complement matrix, can be `NULL`

9761:   Level: advanced

9763:   Notes:
9764:   You must call `MatFactorSetSchurIS()` before calling this routine.

9766:   Schur complement mode is currently implemented for sequential matrices with factor type of `MATSOLVERMUMPS`

9768:   The routine returns a the Schur Complement stored within the data structures of the solver.

9770:   If `MatFactorInvertSchurComplement()` has previously been called, the returned matrix is actually the inverse of the Schur complement.

9772:   The returned matrix should not be destroyed; the caller should call `MatFactorRestoreSchurComplement()` when the object is no longer needed.

9774:   Use `MatFactorCreateSchurComplement()` to create a copy of the Schur complement matrix that is within a factored matrix

9776:   See `MatCreateSchurComplement()` or `MatGetSchurComplement()` for ways to create virtual or approximate Schur complements.

9778: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorRestoreSchurComplement()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9779: @*/
9780: PetscErrorCode MatFactorGetSchurComplement(Mat F, Mat *S, MatFactorSchurStatus *status)
9781: {
9782:   PetscFunctionBegin;
9784:   if (S) {
9785:     PetscAssertPointer(S, 2);
9786:     *S = F->schur;
9787:   }
9788:   if (status) {
9789:     PetscAssertPointer(status, 3);
9790:     *status = F->schur_status;
9791:   }
9792:   PetscFunctionReturn(PETSC_SUCCESS);
9793: }

9795: static PetscErrorCode MatFactorUpdateSchurStatus_Private(Mat F)
9796: {
9797:   Mat S = F->schur;

9799:   PetscFunctionBegin;
9800:   switch (F->schur_status) {
9801:   case MAT_FACTOR_SCHUR_UNFACTORED: // fall-through
9802:   case MAT_FACTOR_SCHUR_INVERTED:
9803:     if (S) {
9804:       S->ops->solve             = NULL;
9805:       S->ops->matsolve          = NULL;
9806:       S->ops->solvetranspose    = NULL;
9807:       S->ops->matsolvetranspose = NULL;
9808:       S->ops->solveadd          = NULL;
9809:       S->ops->solvetransposeadd = NULL;
9810:       S->factortype             = MAT_FACTOR_NONE;
9811:       PetscCall(PetscFree(S->solvertype));
9812:     }
9813:   case MAT_FACTOR_SCHUR_FACTORED: // fall-through
9814:     break;
9815:   default:
9816:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9817:   }
9818:   PetscFunctionReturn(PETSC_SUCCESS);
9819: }

9821: /*@
9822:   MatFactorRestoreSchurComplement - Restore the Schur complement matrix object obtained from a call to `MatFactorGetSchurComplement()`

9824:   Logically Collective

9826:   Input Parameters:
9827: + F      - the factored matrix obtained by calling `MatGetFactor()`
9828: . S      - location where the Schur complement is stored
9829: - status - the status of the Schur complement matrix (see `MatFactorSchurStatus`)

9831:   Level: advanced

9833: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorCreateSchurComplement()`, `MatFactorSchurStatus`
9834: @*/
9835: PetscErrorCode MatFactorRestoreSchurComplement(Mat F, Mat *S, MatFactorSchurStatus status)
9836: {
9837:   PetscFunctionBegin;
9839:   if (S) {
9841:     *S = NULL;
9842:   }
9843:   F->schur_status = status;
9844:   PetscCall(MatFactorUpdateSchurStatus_Private(F));
9845:   PetscFunctionReturn(PETSC_SUCCESS);
9846: }

9848: /*@
9849:   MatFactorSolveSchurComplementTranspose - Solve the transpose of the Schur complement system computed during the factorization step

9851:   Logically Collective

9853:   Input Parameters:
9854: + F   - the factored matrix obtained by calling `MatGetFactor()`
9855: . rhs - location where the right-hand side of the Schur complement system is stored
9856: - sol - location where the solution of the Schur complement system has to be returned

9858:   Level: advanced

9860:   Notes:
9861:   The sizes of the vectors should match the size of the Schur complement

9863:   Must be called after `MatFactorSetSchurIS()`

9865: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplement()`
9866: @*/
9867: PetscErrorCode MatFactorSolveSchurComplementTranspose(Mat F, Vec rhs, Vec sol)
9868: {
9869:   PetscFunctionBegin;
9876:   PetscCheckSameComm(F, 1, rhs, 2);
9877:   PetscCheckSameComm(F, 1, sol, 3);
9878:   PetscCall(MatFactorFactorizeSchurComplement(F));
9879:   switch (F->schur_status) {
9880:   case MAT_FACTOR_SCHUR_FACTORED:
9881:     PetscCall(MatSolveTranspose(F->schur, rhs, sol));
9882:     break;
9883:   case MAT_FACTOR_SCHUR_INVERTED:
9884:     PetscCall(MatMultTranspose(F->schur, rhs, sol));
9885:     break;
9886:   default:
9887:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9888:   }
9889:   PetscFunctionReturn(PETSC_SUCCESS);
9890: }

9892: /*@
9893:   MatFactorSolveSchurComplement - Solve the Schur complement system computed during the factorization step

9895:   Logically Collective

9897:   Input Parameters:
9898: + F   - the factored matrix obtained by calling `MatGetFactor()`
9899: . rhs - location where the right-hand side of the Schur complement system is stored
9900: - sol - location where the solution of the Schur complement system has to be returned

9902:   Level: advanced

9904:   Notes:
9905:   The sizes of the vectors should match the size of the Schur complement

9907:   Must be called after `MatFactorSetSchurIS()`

9909: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorSolveSchurComplementTranspose()`
9910: @*/
9911: PetscErrorCode MatFactorSolveSchurComplement(Mat F, Vec rhs, Vec sol)
9912: {
9913:   PetscFunctionBegin;
9920:   PetscCheckSameComm(F, 1, rhs, 2);
9921:   PetscCheckSameComm(F, 1, sol, 3);
9922:   PetscCall(MatFactorFactorizeSchurComplement(F));
9923:   switch (F->schur_status) {
9924:   case MAT_FACTOR_SCHUR_FACTORED:
9925:     PetscCall(MatSolve(F->schur, rhs, sol));
9926:     break;
9927:   case MAT_FACTOR_SCHUR_INVERTED:
9928:     PetscCall(MatMult(F->schur, rhs, sol));
9929:     break;
9930:   default:
9931:     SETERRQ(PetscObjectComm((PetscObject)F), PETSC_ERR_SUP, "Unhandled MatFactorSchurStatus %d", F->schur_status);
9932:   }
9933:   PetscFunctionReturn(PETSC_SUCCESS);
9934: }

9936: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseInvertFactors_Private(Mat);
9937: #if PetscDefined(HAVE_CUDA)
9938: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode MatSeqDenseCUDAInvertFactors_Internal(Mat);
9939: #endif

9941: /* Schur status updated in the interface */
9942: static PetscErrorCode MatFactorInvertSchurComplement_Private(Mat F)
9943: {
9944:   Mat S = F->schur;

9946:   PetscFunctionBegin;
9947:   if (S) {
9948:     PetscMPIInt size;
9949:     PetscBool   isdense, isdensecuda;

9951:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)S), &size));
9952:     PetscCheck(size <= 1, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not yet implemented");
9953:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSE, &isdense));
9954:     PetscCall(PetscObjectTypeCompare((PetscObject)S, MATSEQDENSECUDA, &isdensecuda));
9955:     PetscCheck(isdense || isdensecuda, PetscObjectComm((PetscObject)S), PETSC_ERR_SUP, "Not implemented for type %s", ((PetscObject)S)->type_name);
9956:     PetscCall(PetscLogEventBegin(MAT_FactorInvS, F, 0, 0, 0));
9957:     if (isdense) {
9958:       PetscCall(MatSeqDenseInvertFactors_Private(S));
9959:     } else if (isdensecuda) {
9960: #if defined(PETSC_HAVE_CUDA)
9961:       PetscCall(MatSeqDenseCUDAInvertFactors_Internal(S));
9962: #endif
9963:     }
9964:     // HIP??????????????
9965:     PetscCall(PetscLogEventEnd(MAT_FactorInvS, F, 0, 0, 0));
9966:   }
9967:   PetscFunctionReturn(PETSC_SUCCESS);
9968: }

9970: /*@
9971:   MatFactorInvertSchurComplement - Invert the Schur complement matrix computed during the factorization step

9973:   Logically Collective

9975:   Input Parameter:
9976: . F - the factored matrix obtained by calling `MatGetFactor()`

9978:   Level: advanced

9980:   Notes:
9981:   Must be called after `MatFactorSetSchurIS()`.

9983:   Call `MatFactorGetSchurComplement()` or  `MatFactorCreateSchurComplement()` AFTER this call to actually compute the inverse and get access to it.

9985: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorGetSchurComplement()`, `MatFactorCreateSchurComplement()`
9986: @*/
9987: PetscErrorCode MatFactorInvertSchurComplement(Mat F)
9988: {
9989:   PetscFunctionBegin;
9992:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED) PetscFunctionReturn(PETSC_SUCCESS);
9993:   PetscCall(MatFactorFactorizeSchurComplement(F));
9994:   PetscCall(MatFactorInvertSchurComplement_Private(F));
9995:   F->schur_status = MAT_FACTOR_SCHUR_INVERTED;
9996:   PetscFunctionReturn(PETSC_SUCCESS);
9997: }

9999: /*@
10000:   MatFactorFactorizeSchurComplement - Factorize the Schur complement matrix computed during the factorization step

10002:   Logically Collective

10004:   Input Parameter:
10005: . F - the factored matrix obtained by calling `MatGetFactor()`

10007:   Level: advanced

10009:   Note:
10010:   Must be called after `MatFactorSetSchurIS()`

10012: .seealso: [](ch_matrices), `Mat`, `MatGetFactor()`, `MatFactorSetSchurIS()`, `MatFactorInvertSchurComplement()`
10013: @*/
10014: PetscErrorCode MatFactorFactorizeSchurComplement(Mat F)
10015: {
10016:   MatFactorInfo info;

10018:   PetscFunctionBegin;
10021:   if (F->schur_status == MAT_FACTOR_SCHUR_INVERTED || F->schur_status == MAT_FACTOR_SCHUR_FACTORED) PetscFunctionReturn(PETSC_SUCCESS);
10022:   PetscCall(PetscLogEventBegin(MAT_FactorFactS, F, 0, 0, 0));
10023:   PetscCall(PetscMemzero(&info, sizeof(MatFactorInfo)));
10024:   if (F->factortype == MAT_FACTOR_CHOLESKY) { /* LDL^t regarded as Cholesky */
10025:     PetscCall(MatCholeskyFactor(F->schur, NULL, &info));
10026:   } else {
10027:     PetscCall(MatLUFactor(F->schur, NULL, NULL, &info));
10028:   }
10029:   PetscCall(PetscLogEventEnd(MAT_FactorFactS, F, 0, 0, 0));
10030:   F->schur_status = MAT_FACTOR_SCHUR_FACTORED;
10031:   PetscFunctionReturn(PETSC_SUCCESS);
10032: }

10034: /*@
10035:   MatPtAP - Creates the matrix product $C = P^T * A * P$

10037:   Neighbor-wise Collective

10039:   Input Parameters:
10040: + A     - the matrix
10041: . P     - the projection matrix
10042: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10043: - 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
10044:           if the result is a dense matrix this is irrelevant

10046:   Output Parameter:
10047: . C - the product matrix

10049:   Level: intermediate

10051:   Notes:
10052:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10054:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_PtAP`
10055:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10057:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10059:   Developer Note:
10060:   For matrix types without special implementation the function fallbacks to `MatMatMult()` followed by `MatTransposeMatMult()`.

10062: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatRARt()`
10063: @*/
10064: PetscErrorCode MatPtAP(Mat A, Mat P, MatReuse scall, PetscReal fill, Mat *C)
10065: {
10066:   PetscFunctionBegin;
10067:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10068:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10070:   if (scall == MAT_INITIAL_MATRIX) {
10071:     PetscCall(MatProductCreate(A, P, NULL, C));
10072:     PetscCall(MatProductSetType(*C, MATPRODUCT_PtAP));
10073:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10074:     PetscCall(MatProductSetFill(*C, fill));

10076:     (*C)->product->api_user = PETSC_TRUE;
10077:     PetscCall(MatProductSetFromOptions(*C));
10078:     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);
10079:     PetscCall(MatProductSymbolic(*C));
10080:   } else { /* scall == MAT_REUSE_MATRIX */
10081:     PetscCall(MatProductReplaceMats(A, P, NULL, *C));
10082:   }

10084:   PetscCall(MatProductNumeric(*C));
10085:   (*C)->symmetric = A->symmetric;
10086:   (*C)->spd       = A->spd;
10087:   PetscFunctionReturn(PETSC_SUCCESS);
10088: }

10090: /*@
10091:   MatRARt - Creates the matrix product $C = R * A * R^T$

10093:   Neighbor-wise Collective

10095:   Input Parameters:
10096: + A     - the matrix
10097: . R     - the projection matrix
10098: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10099: - fill  - expected fill as ratio of nnz(C)/nnz(A), use `PETSC_DETERMINE` or `PETSC_CURRENT` if you do not have a good estimate
10100:           if the result is a dense matrix this is irrelevant

10102:   Output Parameter:
10103: . C - the product matrix

10105:   Level: intermediate

10107:   Notes:
10108:   `C` will be created and must be destroyed by the user with `MatDestroy()`.

10110:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_RARt`
10111:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10113:   This routine is currently only implemented for pairs of `MATAIJ` matrices and classes
10114:   which inherit from `MATAIJ`. Due to PETSc sparse matrix block row distribution among processes,
10115:   the parallel `MatRARt()` is implemented computing the explicit transpose of `R`, which can be very expensive.
10116:   We recommend using `MatPtAP()` when possible.

10118:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10120: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MatMatMult()`, `MatPtAP()`
10121: @*/
10122: PetscErrorCode MatRARt(Mat A, Mat R, MatReuse scall, PetscReal fill, Mat *C)
10123: {
10124:   PetscFunctionBegin;
10125:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*C, 5);
10126:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10128:   if (scall == MAT_INITIAL_MATRIX) {
10129:     PetscCall(MatProductCreate(A, R, NULL, C));
10130:     PetscCall(MatProductSetType(*C, MATPRODUCT_RARt));
10131:     PetscCall(MatProductSetAlgorithm(*C, "default"));
10132:     PetscCall(MatProductSetFill(*C, fill));

10134:     (*C)->product->api_user = PETSC_TRUE;
10135:     PetscCall(MatProductSetFromOptions(*C));
10136:     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);
10137:     PetscCall(MatProductSymbolic(*C));
10138:   } else { /* scall == MAT_REUSE_MATRIX */
10139:     PetscCall(MatProductReplaceMats(A, R, NULL, *C));
10140:   }

10142:   PetscCall(MatProductNumeric(*C));
10143:   if (A->symmetric == PETSC_BOOL3_TRUE) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10144:   PetscFunctionReturn(PETSC_SUCCESS);
10145: }

10147: static PetscErrorCode MatProduct_Private(Mat A, Mat B, MatReuse scall, PetscReal fill, MatProductType ptype, Mat *C)
10148: {
10149:   PetscBool flg = PETSC_TRUE;

10151:   PetscFunctionBegin;
10152:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX product not supported");
10153:   if (scall == MAT_INITIAL_MATRIX) {
10154:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_INITIAL_MATRIX and product type %s\n", MatProductTypes[ptype]));
10155:     PetscCall(MatProductCreate(A, B, NULL, C));
10156:     PetscCall(MatProductSetAlgorithm(*C, MATPRODUCTALGORITHMDEFAULT));
10157:     PetscCall(MatProductSetFill(*C, fill));
10158:   } else { /* scall == MAT_REUSE_MATRIX */
10159:     Mat_Product *product = (*C)->product;

10161:     PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)*C, &flg, MATSEQDENSE, MATMPIDENSE, ""));
10162:     if (flg && product && product->type != ptype) {
10163:       PetscCall(MatProductClear(*C));
10164:       product = NULL;
10165:     }
10166:     PetscCall(PetscInfo(A, "Calling MatProduct API with MAT_REUSE_MATRIX %s product present and product type %s\n", product ? "with" : "without", MatProductTypes[ptype]));
10167:     if (!product) { /* user provide the dense matrix *C without calling MatProductCreate() or reusing it from previous calls */
10168:       PetscCheck(flg, PetscObjectComm((PetscObject)*C), PETSC_ERR_SUP, "Call MatProductCreate() first");
10169:       PetscCall(MatProductCreate_Private(A, B, NULL, *C));
10170:       product        = (*C)->product;
10171:       product->fill  = fill;
10172:       product->clear = PETSC_TRUE;
10173:     } else { /* user may change input matrices A or B when MAT_REUSE_MATRIX */
10174:       flg = PETSC_FALSE;
10175:       PetscCall(MatProductReplaceMats(A, B, NULL, *C));
10176:     }
10177:   }
10178:   if (flg) {
10179:     (*C)->product->api_user = PETSC_TRUE;
10180:     PetscCall(MatProductSetType(*C, ptype));
10181:     PetscCall(MatProductSetFromOptions(*C));
10182:     PetscCall(MatProductSymbolic(*C));
10183:   }
10184:   PetscCall(MatProductNumeric(*C));
10185:   PetscFunctionReturn(PETSC_SUCCESS);
10186: }

10188: /*@
10189:   MatMatMult - Performs matrix-matrix multiplication $ C=A*B $.

10191:   Neighbor-wise Collective

10193:   Input Parameters:
10194: + A     - the left matrix
10195: . B     - the right matrix
10196: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10197: - 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
10198:           if the result is a dense matrix this is irrelevant

10200:   Output Parameter:
10201: . C - the product matrix

10203:   Notes:
10204:   Unless scall is `MAT_REUSE_MATRIX` C will be created.

10206:   `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
10207:   call to this function with `MAT_INITIAL_MATRIX`.

10209:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value actually needed.

10211:   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`,
10212:   rather than first having `MatMatMult()` create it for you. You can NEVER do this if the matrix `C` is sparse.

10214:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10216:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AB`
10217:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10219:   Example of Usage:
10220: .vb
10221:      MatProductCreate(A,B,NULL,&C);
10222:      MatProductSetType(C,MATPRODUCT_AB);
10223:      MatProductSymbolic(C);
10224:      MatProductNumeric(C); // compute C=A * B
10225:      MatProductReplaceMats(A1,B1,NULL,C); // compute C=A1 * B1
10226:      MatProductNumeric(C);
10227:      MatProductReplaceMats(A2,NULL,NULL,C); // compute C=A2 * B1
10228:      MatProductNumeric(C);
10229: .ve

10231:   Level: intermediate

10233: .seealso: [](ch_matrices), `Mat`, `MatProductType`, `MATPRODUCT_AB`, `MatTransposeMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`, `MatProductCreate()`, `MatProductSymbolic()`, `MatProductReplaceMats()`, `MatProductNumeric()`
10234: @*/
10235: PetscErrorCode MatMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10236: {
10237:   PetscFunctionBegin;
10238:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AB, C));
10239:   PetscFunctionReturn(PETSC_SUCCESS);
10240: }

10242: /*@
10243:   MatMatTransposeMult - Performs matrix-matrix multiplication $C = A*B^T$.

10245:   Neighbor-wise Collective

10247:   Input Parameters:
10248: + A     - the left matrix
10249: . B     - the right matrix
10250: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10251: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10253:   Output Parameter:
10254: . C - the product matrix

10256:   Options Database Key:
10257: . -matmattransmult_mpidense_mpidense_via {allgatherv,cyclic} - Choose between algorithms for `MATMPIDENSE` matrices: the
10258:               first redundantly copies the transposed `B` matrix on each process and requires O(log P) communication complexity;
10259:               the second never stores more than one portion of the `B` matrix at a time but requires O(P) communication complexity.

10261:   Level: intermediate

10263:   Notes:
10264:   C will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10266:   `MAT_REUSE_MATRIX` can only be used if the matrices A and B have the same nonzero pattern as in the previous call

10268:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10269:   actually needed.

10271:   This routine is currently only implemented for pairs of `MATSEQAIJ` matrices, for the `MATSEQDENSE` class,
10272:   and for pairs of `MATMPIDENSE` matrices.

10274:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABt`
10275:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10277:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10279: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABt`, `MatMatMult()`, `MatTransposeMatMult()` `MatPtAP()`, `MatProductAlgorithm`, `MatProductType`
10280: @*/
10281: PetscErrorCode MatMatTransposeMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10282: {
10283:   PetscFunctionBegin;
10284:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_ABt, C));
10285:   if (A == B) PetscCall(MatSetOption(*C, MAT_SYMMETRIC, PETSC_TRUE));
10286:   PetscFunctionReturn(PETSC_SUCCESS);
10287: }

10289: /*@
10290:   MatTransposeMatMult - Performs matrix-matrix multiplication $C = A^T*B$.

10292:   Neighbor-wise Collective

10294:   Input Parameters:
10295: + A     - the left matrix
10296: . B     - the right matrix
10297: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10298: - fill  - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use `PETSC_DETERMINE` or `PETSC_CURRENT` if not known

10300:   Output Parameter:
10301: . C - the product matrix

10303:   Level: intermediate

10305:   Notes:
10306:   `C` will be created if `MAT_INITIAL_MATRIX` and must be destroyed by the user with `MatDestroy()`.

10308:   `MAT_REUSE_MATRIX` can only be used if `A` and `B` have the same nonzero pattern as in the previous call.

10310:   This is a convenience routine that wraps the use of `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_AtB`
10311:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10313:   To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value
10314:   actually needed.

10316:   This routine is currently implemented for pairs of `MATAIJ` matrices and pairs of `MATSEQDENSE` matrices and classes
10317:   which inherit from `MATSEQAIJ`.  `C` will be of the same type as the input matrices.

10319:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10321: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_AtB`, `MatMatMult()`, `MatMatTransposeMult()`, `MatPtAP()`
10322: @*/
10323: PetscErrorCode MatTransposeMatMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
10324: {
10325:   PetscFunctionBegin;
10326:   PetscCall(MatProduct_Private(A, B, scall, fill, MATPRODUCT_AtB, C));
10327:   PetscFunctionReturn(PETSC_SUCCESS);
10328: }

10330: /*@
10331:   MatMatMatMult - Performs matrix-matrix-matrix multiplication D=A*B*C.

10333:   Neighbor-wise Collective

10335:   Input Parameters:
10336: + A     - the left matrix
10337: . B     - the middle matrix
10338: . C     - the right matrix
10339: . scall - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
10340: - 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
10341:           if the result is a dense matrix this is irrelevant

10343:   Output Parameter:
10344: . D - the product matrix

10346:   Level: intermediate

10348:   Notes:
10349:   Unless `scall` is `MAT_REUSE_MATRIX` `D` will be created.

10351:   `MAT_REUSE_MATRIX` can only be used if the matrices `A`, `B`, and `C` have the same nonzero pattern as in the previous call

10353:   This is a convenience routine that wraps the use of the `MatProductCreate()` with a `MatProductType` of `MATPRODUCT_ABC`
10354:   functionality into a single function call. For more involved matrix-matrix operations see `MatProductCreate()`.

10356:   To determine the correct fill value, run with `-info` and search for the string "Fill ratio" to see the value
10357:   actually needed.

10359:   If you have many matrices with the same non-zero structure to multiply, you
10360:   should use `MAT_REUSE_MATRIX` in all calls but the first

10362:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

10364: .seealso: [](ch_matrices), `Mat`, `MatProductCreate()`, `MATPRODUCT_ABC`, `MatMatMult`, `MatPtAP()`, `MatMatTransposeMult()`, `MatTransposeMatMult()`
10365: @*/
10366: PetscErrorCode MatMatMatMult(Mat A, Mat B, Mat C, MatReuse scall, PetscReal fill, Mat *D)
10367: {
10368:   PetscFunctionBegin;
10369:   if (scall == MAT_REUSE_MATRIX) MatCheckProduct(*D, 6);
10370:   PetscCheck(scall != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");

10372:   if (scall == MAT_INITIAL_MATRIX) {
10373:     PetscCall(MatProductCreate(A, B, C, D));
10374:     PetscCall(MatProductSetType(*D, MATPRODUCT_ABC));
10375:     PetscCall(MatProductSetAlgorithm(*D, "default"));
10376:     PetscCall(MatProductSetFill(*D, fill));

10378:     (*D)->product->api_user = PETSC_TRUE;
10379:     PetscCall(MatProductSetFromOptions(*D));
10380:     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,
10381:                ((PetscObject)C)->type_name);
10382:     PetscCall(MatProductSymbolic(*D));
10383:   } else { /* user may change input matrices when REUSE */
10384:     PetscCall(MatProductReplaceMats(A, B, C, *D));
10385:   }
10386:   PetscCall(MatProductNumeric(*D));
10387:   PetscFunctionReturn(PETSC_SUCCESS);
10388: }

10390: /*@
10391:   MatCreateRedundantMatrix - Create redundant matrices and put them into processors of subcommunicators.

10393:   Collective

10395:   Input Parameters:
10396: + mat      - the matrix
10397: . nsubcomm - the number of subcommunicators (= number of redundant parallel or sequential matrices)
10398: . subcomm  - MPI communicator split from the communicator where mat resides in (or `MPI_COMM_NULL` if nsubcomm is used)
10399: - reuse    - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10401:   Output Parameter:
10402: . matredundant - redundant matrix

10404:   Level: advanced

10406:   Notes:
10407:   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the
10408:   original matrix has not changed from that last call to `MatCreateRedundantMatrix()`.

10410:   This routine creates the duplicated matrices in the subcommunicators; you should NOT create them before
10411:   calling it.

10413:   `PetscSubcommCreate()` can be used to manage the creation of the subcomm but need not be.

10415: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `PetscSubcommCreate()`, `PetscSubcomm`
10416: @*/
10417: PetscErrorCode MatCreateRedundantMatrix(Mat mat, PetscInt nsubcomm, MPI_Comm subcomm, MatReuse reuse, Mat *matredundant)
10418: {
10419:   MPI_Comm       comm;
10420:   PetscMPIInt    size;
10421:   PetscInt       mloc_sub, nloc_sub, rstart, rend, M = mat->rmap->N, N = mat->cmap->N, bs = mat->rmap->bs;
10422:   Mat_Redundant *redund     = NULL;
10423:   PetscSubcomm   psubcomm   = NULL;
10424:   MPI_Comm       subcomm_in = subcomm;
10425:   Mat           *matseq;
10426:   IS             isrow, iscol;
10427:   PetscBool      newsubcomm = PETSC_FALSE;

10429:   PetscFunctionBegin;
10431:   if (nsubcomm && reuse == MAT_REUSE_MATRIX) {
10432:     PetscAssertPointer(*matredundant, 5);
10434:   }

10436:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
10437:   if (size == 1 || nsubcomm == 1) {
10438:     if (reuse == MAT_INITIAL_MATRIX) {
10439:       PetscCall(MatDuplicate(mat, MAT_COPY_VALUES, matredundant));
10440:     } else {
10441:       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");
10442:       PetscCall(MatCopy(mat, *matredundant, SAME_NONZERO_PATTERN));
10443:     }
10444:     PetscFunctionReturn(PETSC_SUCCESS);
10445:   }

10447:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10448:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10449:   MatCheckPreallocated(mat, 1);

10451:   PetscCall(PetscLogEventBegin(MAT_RedundantMat, mat, 0, 0, 0));
10452:   if (subcomm_in == MPI_COMM_NULL && reuse == MAT_INITIAL_MATRIX) { /* get subcomm if user does not provide subcomm */
10453:     /* create psubcomm, then get subcomm */
10454:     PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10455:     PetscCallMPI(MPI_Comm_size(comm, &size));
10456:     PetscCheck(nsubcomm >= 1 && nsubcomm <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "nsubcomm must between 1 and %d", size);

10458:     PetscCall(PetscSubcommCreate(comm, &psubcomm));
10459:     PetscCall(PetscSubcommSetNumber(psubcomm, nsubcomm));
10460:     PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_CONTIGUOUS));
10461:     PetscCall(PetscSubcommSetFromOptions(psubcomm));
10462:     PetscCall(PetscCommDuplicate(PetscSubcommChild(psubcomm), &subcomm, NULL));
10463:     newsubcomm = PETSC_TRUE;
10464:     PetscCall(PetscSubcommDestroy(&psubcomm));
10465:   }

10467:   /* get isrow, iscol and a local sequential matrix matseq[0] */
10468:   if (reuse == MAT_INITIAL_MATRIX) {
10469:     mloc_sub = PETSC_DECIDE;
10470:     nloc_sub = PETSC_DECIDE;
10471:     if (bs < 1) {
10472:       PetscCall(PetscSplitOwnership(subcomm, &mloc_sub, &M));
10473:       PetscCall(PetscSplitOwnership(subcomm, &nloc_sub, &N));
10474:     } else {
10475:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &mloc_sub, &M));
10476:       PetscCall(PetscSplitOwnershipBlock(subcomm, bs, &nloc_sub, &N));
10477:     }
10478:     PetscCallMPI(MPI_Scan(&mloc_sub, &rend, 1, MPIU_INT, MPI_SUM, subcomm));
10479:     rstart = rend - mloc_sub;
10480:     PetscCall(ISCreateStride(PETSC_COMM_SELF, mloc_sub, rstart, 1, &isrow));
10481:     PetscCall(ISCreateStride(PETSC_COMM_SELF, N, 0, 1, &iscol));
10482:     PetscCall(ISSetIdentity(iscol));
10483:   } else { /* reuse == MAT_REUSE_MATRIX */
10484:     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");
10485:     /* retrieve subcomm */
10486:     PetscCall(PetscObjectGetComm((PetscObject)*matredundant, &subcomm));
10487:     redund = (*matredundant)->redundant;
10488:     isrow  = redund->isrow;
10489:     iscol  = redund->iscol;
10490:     matseq = redund->matseq;
10491:   }
10492:   PetscCall(MatCreateSubMatrices(mat, 1, &isrow, &iscol, reuse, &matseq));

10494:   /* get matredundant over subcomm */
10495:   if (reuse == MAT_INITIAL_MATRIX) {
10496:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], nloc_sub, reuse, matredundant));

10498:     /* create a supporting struct and attach it to C for reuse */
10499:     PetscCall(PetscNew(&redund));
10500:     (*matredundant)->redundant = redund;
10501:     redund->isrow              = isrow;
10502:     redund->iscol              = iscol;
10503:     redund->matseq             = matseq;
10504:     if (newsubcomm) {
10505:       redund->subcomm = subcomm;
10506:     } else {
10507:       redund->subcomm = MPI_COMM_NULL;
10508:     }
10509:   } else {
10510:     PetscCall(MatCreateMPIMatConcatenateSeqMat(subcomm, matseq[0], PETSC_DECIDE, reuse, matredundant));
10511:   }
10512: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
10513:   if (matseq[0]->boundtocpu && matseq[0]->bindingpropagates) {
10514:     PetscCall(MatBindToCPU(*matredundant, PETSC_TRUE));
10515:     PetscCall(MatSetBindingPropagates(*matredundant, PETSC_TRUE));
10516:   }
10517: #endif
10518:   PetscCall(PetscLogEventEnd(MAT_RedundantMat, mat, 0, 0, 0));
10519:   PetscFunctionReturn(PETSC_SUCCESS);
10520: }

10522: /*@C
10523:   MatGetMultiProcBlock - Create multiple 'parallel submatrices' from
10524:   a given `Mat`. Each submatrix can span multiple procs.

10526:   Collective

10528:   Input Parameters:
10529: + mat     - the matrix
10530: . subComm - the sub communicator obtained as if by `MPI_Comm_split(PetscObjectComm((PetscObject)mat))`
10531: - scall   - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

10533:   Output Parameter:
10534: . subMat - parallel sub-matrices each spanning a given `subcomm`

10536:   Level: advanced

10538:   Notes:
10539:   The submatrix partition across processors is dictated by `subComm` a
10540:   communicator obtained by `MPI_comm_split()` or via `PetscSubcommCreate()`. The `subComm`
10541:   is not restricted to be grouped with consecutive original MPI processes.

10543:   Due the `MPI_Comm_split()` usage, the parallel layout of the submatrices
10544:   map directly to the layout of the original matrix [wrt the local
10545:   row,col partitioning]. So the original 'DiagonalMat' naturally maps
10546:   into the 'DiagonalMat' of the `subMat`, hence it is used directly from
10547:   the `subMat`. However the offDiagMat looses some columns - and this is
10548:   reconstructed with `MatSetValues()`

10550:   This is used by `PCBJACOBI` when a single block spans multiple MPI processes.

10552: .seealso: [](ch_matrices), `Mat`, `MatCreateRedundantMatrix()`, `MatCreateSubMatrices()`, `PCBJACOBI`
10553: @*/
10554: PetscErrorCode MatGetMultiProcBlock(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
10555: {
10556:   PetscMPIInt commsize, subCommSize;

10558:   PetscFunctionBegin;
10559:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &commsize));
10560:   PetscCallMPI(MPI_Comm_size(subComm, &subCommSize));
10561:   PetscCheck(subCommSize <= commsize, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_OUTOFRANGE, "CommSize %d < SubCommZize %d", commsize, subCommSize);

10563:   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");
10564:   PetscCall(PetscLogEventBegin(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10565:   PetscUseTypeMethod(mat, getmultiprocblock, subComm, scall, subMat);
10566:   PetscCall(PetscLogEventEnd(MAT_GetMultiProcBlock, mat, 0, 0, 0));
10567:   PetscFunctionReturn(PETSC_SUCCESS);
10568: }

10570: /*@
10571:   MatGetLocalSubMatrix - Gets a reference to a submatrix specified in local numbering

10573:   Not Collective

10575:   Input Parameters:
10576: + mat   - matrix to extract local submatrix from
10577: . isrow - local row indices for submatrix
10578: - iscol - local column indices for submatrix

10580:   Output Parameter:
10581: . submat - the submatrix

10583:   Level: intermediate

10585:   Notes:
10586:   `submat` should be disposed of with `MatRestoreLocalSubMatrix()`.

10588:   Depending on the format of `mat`, the returned `submat` may not implement `MatMult()`.  Its communicator may be
10589:   the same as `mat`, it may be `PETSC_COMM_SELF`, or some other sub-communictor of `mat`'s.

10591:   `submat` always implements `MatSetValuesLocal()`.  If `isrow` and `iscol` have the same block size, then
10592:   `MatSetValuesBlockedLocal()` will also be implemented.

10594:   `mat` must have had a `ISLocalToGlobalMapping` provided to it with `MatSetLocalToGlobalMapping()`.
10595:   Matrices obtained with `DMCreateMatrix()` generally already have the local to global mapping provided.

10597: .seealso: [](ch_matrices), `Mat`, `MatRestoreLocalSubMatrix()`, `MatCreateLocalRef()`, `MatSetLocalToGlobalMapping()`
10598: @*/
10599: PetscErrorCode MatGetLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10600: {
10601:   PetscFunctionBegin;
10605:   PetscCheckSameComm(isrow, 2, iscol, 3);
10606:   PetscAssertPointer(submat, 4);
10607:   PetscCheck(mat->rmap->mapping, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Matrix must have local to global mapping provided before this call");

10609:   if (mat->ops->getlocalsubmatrix) {
10610:     PetscUseTypeMethod(mat, getlocalsubmatrix, isrow, iscol, submat);
10611:   } else {
10612:     PetscCall(MatCreateLocalRef(mat, isrow, iscol, submat));
10613:   }
10614:   (*submat)->assembled = mat->assembled;
10615:   PetscFunctionReturn(PETSC_SUCCESS);
10616: }

10618: /*@
10619:   MatRestoreLocalSubMatrix - Restores a reference to a submatrix specified in local numbering obtained with `MatGetLocalSubMatrix()`

10621:   Not Collective

10623:   Input Parameters:
10624: + mat    - matrix to extract local submatrix from
10625: . isrow  - local row indices for submatrix
10626: . iscol  - local column indices for submatrix
10627: - submat - the submatrix

10629:   Level: intermediate

10631: .seealso: [](ch_matrices), `Mat`, `MatGetLocalSubMatrix()`
10632: @*/
10633: PetscErrorCode MatRestoreLocalSubMatrix(Mat mat, IS isrow, IS iscol, Mat *submat)
10634: {
10635:   PetscFunctionBegin;
10639:   PetscCheckSameComm(isrow, 2, iscol, 3);
10640:   PetscAssertPointer(submat, 4);

10643:   if (mat->ops->restorelocalsubmatrix) {
10644:     PetscUseTypeMethod(mat, restorelocalsubmatrix, isrow, iscol, submat);
10645:   } else {
10646:     PetscCall(MatDestroy(submat));
10647:   }
10648:   *submat = NULL;
10649:   PetscFunctionReturn(PETSC_SUCCESS);
10650: }

10652: /*@
10653:   MatFindZeroDiagonals - Finds all the rows of a matrix that have zero or no diagonal entry in the matrix

10655:   Collective

10657:   Input Parameter:
10658: . mat - the matrix

10660:   Output Parameter:
10661: . is - if any rows have zero diagonals this contains the list of them

10663:   Level: developer

10665: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10666: @*/
10667: PetscErrorCode MatFindZeroDiagonals(Mat mat, IS *is)
10668: {
10669:   PetscFunctionBegin;
10672:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10673:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10675:   if (!mat->ops->findzerodiagonals) {
10676:     Vec                diag;
10677:     const PetscScalar *a;
10678:     PetscInt          *rows;
10679:     PetscInt           rStart, rEnd, r, nrow = 0;

10681:     PetscCall(MatCreateVecs(mat, &diag, NULL));
10682:     PetscCall(MatGetDiagonal(mat, diag));
10683:     PetscCall(MatGetOwnershipRange(mat, &rStart, &rEnd));
10684:     PetscCall(VecGetArrayRead(diag, &a));
10685:     for (r = 0; r < rEnd - rStart; ++r)
10686:       if (a[r] == 0.0) ++nrow;
10687:     PetscCall(PetscMalloc1(nrow, &rows));
10688:     nrow = 0;
10689:     for (r = 0; r < rEnd - rStart; ++r)
10690:       if (a[r] == 0.0) rows[nrow++] = r + rStart;
10691:     PetscCall(VecRestoreArrayRead(diag, &a));
10692:     PetscCall(VecDestroy(&diag));
10693:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)mat), nrow, rows, PETSC_OWN_POINTER, is));
10694:   } else {
10695:     PetscUseTypeMethod(mat, findzerodiagonals, is);
10696:   }
10697:   PetscFunctionReturn(PETSC_SUCCESS);
10698: }

10700: /*@
10701:   MatFindOffBlockDiagonalEntries - Finds all the rows of a matrix that have entries outside of the main diagonal block (defined by the matrix block size)

10703:   Collective

10705:   Input Parameter:
10706: . mat - the matrix

10708:   Output Parameter:
10709: . is - contains the list of rows with off block diagonal entries

10711:   Level: developer

10713: .seealso: [](ch_matrices), `Mat`, `MatMultTranspose()`, `MatMultAdd()`, `MatMultTransposeAdd()`
10714: @*/
10715: PetscErrorCode MatFindOffBlockDiagonalEntries(Mat mat, IS *is)
10716: {
10717:   PetscFunctionBegin;
10720:   PetscCheck(mat->assembled, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10721:   PetscCheck(!mat->factortype, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");

10723:   PetscUseTypeMethod(mat, findoffblockdiagonalentries, is);
10724:   PetscFunctionReturn(PETSC_SUCCESS);
10725: }

10727: /*@C
10728:   MatInvertBlockDiagonal - Inverts the block diagonal entries.

10730:   Collective; No Fortran Support

10732:   Input Parameter:
10733: . mat - the matrix

10735:   Output Parameter:
10736: . values - the block inverses in column major order (FORTRAN-like)

10738:   Level: advanced

10740:   Notes:
10741:   The size of the blocks is determined by the block size of the matrix.

10743:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10745:   The blocks all have the same size, use `MatInvertVariableBlockDiagonal()` for variable block size

10747: .seealso: [](ch_matrices), `Mat`, `MatInvertVariableBlockEnvelope()`, `MatInvertBlockDiagonalMat()`
10748: @*/
10749: PetscErrorCode MatInvertBlockDiagonal(Mat mat, const PetscScalar *values[])
10750: {
10751:   PetscFunctionBegin;
10753:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10754:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10755:   PetscUseTypeMethod(mat, invertblockdiagonal, values);
10756:   PetscFunctionReturn(PETSC_SUCCESS);
10757: }

10759: /*@
10760:   MatInvertVariableBlockDiagonal - Inverts the point block diagonal entries.

10762:   Collective; No Fortran Support

10764:   Input Parameters:
10765: + mat     - the matrix
10766: . nblocks - the number of blocks on the process, set with `MatSetVariableBlockSizes()`
10767: - bsizes  - the size of each block on the process, set with `MatSetVariableBlockSizes()`

10769:   Output Parameter:
10770: . values - the block inverses in column major order (FORTRAN-like)

10772:   Level: advanced

10774:   Notes:
10775:   Use `MatInvertBlockDiagonal()` if all blocks have the same size

10777:   The blocks never overlap between two MPI processes, use `MatInvertVariableBlockEnvelope()` for that case

10779: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`, `MatSetVariableBlockSizes()`, `MatInvertVariableBlockEnvelope()`
10780: @*/
10781: PetscErrorCode MatInvertVariableBlockDiagonal(Mat mat, PetscInt nblocks, const PetscInt bsizes[], PetscScalar values[])
10782: {
10783:   PetscFunctionBegin;
10785:   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
10786:   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
10787:   PetscUseTypeMethod(mat, invertvariableblockdiagonal, nblocks, bsizes, values);
10788:   PetscFunctionReturn(PETSC_SUCCESS);
10789: }

10791: /*@
10792:   MatInvertBlockDiagonalMat - set the values of matrix C to be the inverted block diagonal of matrix A

10794:   Collective

10796:   Input Parameters:
10797: + A - the matrix
10798: - C - matrix with inverted block diagonal of `A`.  This matrix should be created and may have its type set.

10800:   Level: advanced

10802:   Note:
10803:   The blocksize of the matrix is used to determine the blocks on the diagonal of `C`

10805: .seealso: [](ch_matrices), `Mat`, `MatInvertBlockDiagonal()`
10806: @*/
10807: PetscErrorCode MatInvertBlockDiagonalMat(Mat A, Mat C)
10808: {
10809:   const PetscScalar *vals;
10810:   PetscInt          *dnnz;
10811:   PetscInt           m, rstart, rend, bs, i, j;

10813:   PetscFunctionBegin;
10814:   PetscCall(MatInvertBlockDiagonal(A, &vals));
10815:   PetscCall(MatGetBlockSize(A, &bs));
10816:   PetscCall(MatGetLocalSize(A, &m, NULL));
10817:   PetscCall(MatSetLayouts(C, A->rmap, A->cmap));
10818:   PetscCall(MatSetBlockSizes(C, A->rmap->bs, A->cmap->bs));
10819:   PetscCall(PetscMalloc1(m / bs, &dnnz));
10820:   for (j = 0; j < m / bs; j++) dnnz[j] = 1;
10821:   PetscCall(MatXAIJSetPreallocation(C, bs, dnnz, NULL, NULL, NULL));
10822:   PetscCall(PetscFree(dnnz));
10823:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
10824:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_FALSE));
10825:   for (i = rstart / bs; i < rend / bs; i++) PetscCall(MatSetValuesBlocked(C, 1, &i, 1, &i, &vals[(i - rstart / bs) * bs * bs], INSERT_VALUES));
10826:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
10827:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
10828:   PetscCall(MatSetOption(C, MAT_ROW_ORIENTED, PETSC_TRUE));
10829:   PetscFunctionReturn(PETSC_SUCCESS);
10830: }

10832: /*@
10833:   MatTransposeColoringDestroy - Destroys a coloring context for matrix product $C = A*B^T$ that was created
10834:   via `MatTransposeColoringCreate()`.

10836:   Collective

10838:   Input Parameter:
10839: . c - coloring context

10841:   Level: intermediate

10843: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`
10844: @*/
10845: PetscErrorCode MatTransposeColoringDestroy(MatTransposeColoring *c)
10846: {
10847:   MatTransposeColoring matcolor = *c;

10849:   PetscFunctionBegin;
10850:   if (!matcolor) PetscFunctionReturn(PETSC_SUCCESS);
10851:   if (--((PetscObject)matcolor)->refct > 0) {
10852:     matcolor = NULL;
10853:     PetscFunctionReturn(PETSC_SUCCESS);
10854:   }

10856:   PetscCall(PetscFree3(matcolor->ncolumns, matcolor->nrows, matcolor->colorforrow));
10857:   PetscCall(PetscFree(matcolor->rows));
10858:   PetscCall(PetscFree(matcolor->den2sp));
10859:   PetscCall(PetscFree(matcolor->colorforcol));
10860:   PetscCall(PetscFree(matcolor->columns));
10861:   if (matcolor->brows > 0) PetscCall(PetscFree(matcolor->lstart));
10862:   PetscCall(PetscHeaderDestroy(c));
10863:   PetscFunctionReturn(PETSC_SUCCESS);
10864: }

10866: /*@
10867:   MatTransColoringApplySpToDen - Given a symbolic matrix product $C = A*B^T$ for which
10868:   a `MatTransposeColoring` context has been created, computes a dense $B^T$ by applying
10869:   `MatTransposeColoring` to sparse `B`.

10871:   Collective

10873:   Input Parameters:
10874: + coloring - coloring context created with `MatTransposeColoringCreate()`
10875: - B        - sparse matrix

10877:   Output Parameter:
10878: . Btdense - dense matrix $B^T$

10880:   Level: developer

10882:   Note:
10883:   These are used internally for some implementations of `MatRARt()`

10885: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplyDenToSp()`
10886: @*/
10887: PetscErrorCode MatTransColoringApplySpToDen(MatTransposeColoring coloring, Mat B, Mat Btdense)
10888: {
10889:   PetscFunctionBegin;

10894:   PetscCall((*B->ops->transcoloringapplysptoden)(coloring, B, Btdense));
10895:   PetscFunctionReturn(PETSC_SUCCESS);
10896: }

10898: /*@
10899:   MatTransColoringApplyDenToSp - Given a symbolic matrix product $C_{sp} = A*B^T$ for which
10900:   a `MatTransposeColoring` context has been created and a dense matrix $C_{den} = A*B^T_{dense}$
10901:   in which `B^T_{dens}` is obtained from `MatTransColoringApplySpToDen()`, recover sparse matrix
10902:   $C_{sp}$ from $C_{den}$.

10904:   Collective

10906:   Input Parameters:
10907: + matcoloring - coloring context created with `MatTransposeColoringCreate()`
10908: - Cden        - matrix product of a sparse matrix and a dense matrix Btdense

10910:   Output Parameter:
10911: . Csp - sparse matrix

10913:   Level: developer

10915:   Note:
10916:   These are used internally for some implementations of `MatRARt()`

10918: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringCreate()`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`
10919: @*/
10920: PetscErrorCode MatTransColoringApplyDenToSp(MatTransposeColoring matcoloring, Mat Cden, Mat Csp)
10921: {
10922:   PetscFunctionBegin;

10927:   PetscCall((*Csp->ops->transcoloringapplydentosp)(matcoloring, Cden, Csp));
10928:   PetscCall(MatAssemblyBegin(Csp, MAT_FINAL_ASSEMBLY));
10929:   PetscCall(MatAssemblyEnd(Csp, MAT_FINAL_ASSEMBLY));
10930:   PetscFunctionReturn(PETSC_SUCCESS);
10931: }

10933: /*@
10934:   MatTransposeColoringCreate - Creates a matrix coloring context for the matrix product $C = A*B^T$.

10936:   Collective

10938:   Input Parameters:
10939: + mat        - the matrix product C
10940: - iscoloring - the coloring of the matrix; usually obtained with `MatColoringCreate()` or `DMCreateColoring()`

10942:   Output Parameter:
10943: . color - the new coloring context

10945:   Level: intermediate

10947: .seealso: [](ch_matrices), `Mat`, `MatTransposeColoringDestroy()`, `MatTransColoringApplySpToDen()`,
10948:           `MatTransColoringApplyDenToSp()`
10949: @*/
10950: PetscErrorCode MatTransposeColoringCreate(Mat mat, ISColoring iscoloring, MatTransposeColoring *color)
10951: {
10952:   MatTransposeColoring c;
10953:   MPI_Comm             comm;

10955:   PetscFunctionBegin;
10956:   PetscAssertPointer(color, 3);

10958:   PetscCall(PetscLogEventBegin(MAT_TransposeColoringCreate, mat, 0, 0, 0));
10959:   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
10960:   PetscCall(PetscHeaderCreate(c, MAT_TRANSPOSECOLORING_CLASSID, "MatTransposeColoring", "Matrix product C=A*B^T via coloring", "Mat", comm, MatTransposeColoringDestroy, NULL));
10961:   c->ctype = iscoloring->ctype;
10962:   PetscUseTypeMethod(mat, transposecoloringcreate, iscoloring, c);
10963:   *color = c;
10964:   PetscCall(PetscLogEventEnd(MAT_TransposeColoringCreate, mat, 0, 0, 0));
10965:   PetscFunctionReturn(PETSC_SUCCESS);
10966: }

10968: /*@
10969:   MatGetNonzeroState - Returns a 64-bit integer representing the current state of nonzeros in the matrix. If the
10970:   matrix has had new nonzero locations added to (or removed from) the matrix since the previous call, the value will be larger.

10972:   Not Collective

10974:   Input Parameter:
10975: . mat - the matrix

10977:   Output Parameter:
10978: . state - the current state

10980:   Level: intermediate

10982:   Notes:
10983:   You can only compare states from two different calls to the SAME matrix, you cannot compare calls between
10984:   different matrices

10986:   Use `PetscObjectStateGet()` to check for changes to the numerical values in a matrix

10988:   Use the result of `PetscObjectGetId()` to compare if a previously checked matrix is the same as the current matrix, do not compare object pointers.

10990: .seealso: [](ch_matrices), `Mat`, `PetscObjectStateGet()`, `PetscObjectGetId()`
10991: @*/
10992: PetscErrorCode MatGetNonzeroState(Mat mat, PetscObjectState *state)
10993: {
10994:   PetscFunctionBegin;
10996:   *state = mat->nonzerostate;
10997:   PetscFunctionReturn(PETSC_SUCCESS);
10998: }

11000: /*@
11001:   MatCreateMPIMatConcatenateSeqMat - Creates a single large PETSc matrix by concatenating sequential
11002:   matrices from each processor

11004:   Collective

11006:   Input Parameters:
11007: + comm   - the communicators the parallel matrix will live on
11008: . seqmat - the input sequential matrices
11009: . n      - number of local columns (or `PETSC_DECIDE`)
11010: - reuse  - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`

11012:   Output Parameter:
11013: . mpimat - the parallel matrix generated

11015:   Level: developer

11017:   Note:
11018:   The number of columns of the matrix in EACH processor MUST be the same.

11020: .seealso: [](ch_matrices), `Mat`
11021: @*/
11022: PetscErrorCode MatCreateMPIMatConcatenateSeqMat(MPI_Comm comm, Mat seqmat, PetscInt n, MatReuse reuse, Mat *mpimat)
11023: {
11024:   PetscMPIInt size;

11026:   PetscFunctionBegin;
11027:   PetscCallMPI(MPI_Comm_size(comm, &size));
11028:   if (size == 1) {
11029:     if (reuse == MAT_INITIAL_MATRIX) {
11030:       PetscCall(MatDuplicate(seqmat, MAT_COPY_VALUES, mpimat));
11031:     } else {
11032:       PetscCall(MatCopy(seqmat, *mpimat, SAME_NONZERO_PATTERN));
11033:     }
11034:     PetscFunctionReturn(PETSC_SUCCESS);
11035:   }

11037:   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");

11039:   PetscCall(PetscLogEventBegin(MAT_Merge, seqmat, 0, 0, 0));
11040:   PetscCall((*seqmat->ops->creatempimatconcatenateseqmat)(comm, seqmat, n, reuse, mpimat));
11041:   PetscCall(PetscLogEventEnd(MAT_Merge, seqmat, 0, 0, 0));
11042:   PetscFunctionReturn(PETSC_SUCCESS);
11043: }

11045: /*@
11046:   MatSubdomainsCreateCoalesce - Creates index subdomains by coalescing adjacent MPI processes' ownership ranges.

11048:   Collective

11050:   Input Parameters:
11051: + A - the matrix to create subdomains from
11052: - N - requested number of subdomains

11054:   Output Parameters:
11055: + n   - number of subdomains resulting on this MPI process
11056: - iss - `IS` list with indices of subdomains on this MPI process

11058:   Level: advanced

11060:   Note:
11061:   The number of subdomains must be smaller than the communicator size

11063: .seealso: [](ch_matrices), `Mat`, `IS`
11064: @*/
11065: PetscErrorCode MatSubdomainsCreateCoalesce(Mat A, PetscInt N, PetscInt *n, IS *iss[])
11066: {
11067:   MPI_Comm    comm, subcomm;
11068:   PetscMPIInt size, rank, color;
11069:   PetscInt    rstart, rend, k;

11071:   PetscFunctionBegin;
11072:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
11073:   PetscCallMPI(MPI_Comm_size(comm, &size));
11074:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
11075:   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);
11076:   *n    = 1;
11077:   k     = size / N + (size % N > 0); /* There are up to k ranks to a color */
11078:   color = rank / k;
11079:   PetscCallMPI(MPI_Comm_split(comm, color, rank, &subcomm));
11080:   PetscCall(PetscMalloc1(1, iss));
11081:   PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
11082:   PetscCall(ISCreateStride(subcomm, rend - rstart, rstart, 1, iss[0]));
11083:   PetscCallMPI(MPI_Comm_free(&subcomm));
11084:   PetscFunctionReturn(PETSC_SUCCESS);
11085: }

11087: /*@
11088:   MatGalerkin - Constructs the coarse grid problem matrix via Galerkin projection.

11090:   If the interpolation and restriction operators are the same, uses `MatPtAP()`.
11091:   If they are not the same, uses `MatMatMatMult()`.

11093:   Once the coarse grid problem is constructed, correct for interpolation operators
11094:   that are not of full rank, which can legitimately happen in the case of non-nested
11095:   geometric multigrid.

11097:   Input Parameters:
11098: + restrct     - restriction operator
11099: . dA          - fine grid matrix
11100: . interpolate - interpolation operator
11101: . reuse       - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
11102: - fill        - expected fill, use `PETSC_DETERMINE` or `PETSC_DETERMINE` if you do not have a good estimate

11104:   Output Parameter:
11105: . A - the Galerkin coarse matrix

11107:   Options Database Key:
11108: . -pc_mg_galerkin <both,pmat,mat,none> - for what matrices the Galerkin process should be used

11110:   Level: developer

11112:   Note:
11113:   The deprecated `PETSC_DEFAULT` in `fill` also means use the current value

11115: .seealso: [](ch_matrices), `Mat`, `MatPtAP()`, `MatMatMatMult()`
11116: @*/
11117: PetscErrorCode MatGalerkin(Mat restrct, Mat dA, Mat interpolate, MatReuse reuse, PetscReal fill, Mat *A)
11118: {
11119:   IS  zerorows;
11120:   Vec diag;

11122:   PetscFunctionBegin;
11123:   PetscCheck(reuse != MAT_INPLACE_MATRIX, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Inplace product not supported");
11124:   /* Construct the coarse grid matrix */
11125:   if (interpolate == restrct) {
11126:     PetscCall(MatPtAP(dA, interpolate, reuse, fill, A));
11127:   } else {
11128:     PetscCall(MatMatMatMult(restrct, dA, interpolate, reuse, fill, A));
11129:   }

11131:   /* If the interpolation matrix is not of full rank, A will have zero rows.
11132:      This can legitimately happen in the case of non-nested geometric multigrid.
11133:      In that event, we set the rows of the matrix to the rows of the identity,
11134:      ignoring the equations (as the RHS will also be zero). */

11136:   PetscCall(MatFindZeroRows(*A, &zerorows));

11138:   if (zerorows != NULL) { /* if there are any zero rows */
11139:     PetscCall(MatCreateVecs(*A, &diag, NULL));
11140:     PetscCall(MatGetDiagonal(*A, diag));
11141:     PetscCall(VecISSet(diag, zerorows, 1.0));
11142:     PetscCall(MatDiagonalSet(*A, diag, INSERT_VALUES));
11143:     PetscCall(VecDestroy(&diag));
11144:     PetscCall(ISDestroy(&zerorows));
11145:   }
11146:   PetscFunctionReturn(PETSC_SUCCESS);
11147: }

11149: /*@C
11150:   MatSetOperation - Allows user to set a matrix operation for any matrix type

11152:   Logically Collective

11154:   Input Parameters:
11155: + mat - the matrix
11156: . op  - the name of the operation
11157: - f   - the function that provides the operation

11159:   Level: developer

11161:   Example Usage:
11162: .vb
11163:   extern PetscErrorCode usermult(Mat, Vec, Vec);

11165:   PetscCall(MatCreateXXX(comm, ..., &A));
11166:   PetscCall(MatSetOperation(A, MATOP_MULT, (PetscErrorCodeFn *)usermult));
11167: .ve

11169:   Notes:
11170:   See the file `include/petscmat.h` for a complete list of matrix
11171:   operations, which all have the form MATOP_<OPERATION>, where
11172:   <OPERATION> is the name (in all capital letters) of the
11173:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11175:   All user-provided functions (except for `MATOP_DESTROY`) should have the same calling
11176:   sequence as the usual matrix interface routines, since they
11177:   are intended to be accessed via the usual matrix interface
11178:   routines, e.g.,
11179: .vb
11180:   MatMult(Mat, Vec, Vec) -> usermult(Mat, Vec, Vec)
11181: .ve

11183:   In particular each function MUST return `PETSC_SUCCESS` on success and
11184:   nonzero on failure.

11186:   This routine is distinct from `MatShellSetOperation()` in that it can be called on any matrix type.

11188: .seealso: [](ch_matrices), `Mat`, `MatGetOperation()`, `MatCreateShell()`, `MatShellSetContext()`, `MatShellSetOperation()`
11189: @*/
11190: PetscErrorCode MatSetOperation(Mat mat, MatOperation op, PetscErrorCodeFn *f)
11191: {
11192:   PetscFunctionBegin;
11194:   if (op == MATOP_VIEW && !mat->ops->viewnative && f != (PetscErrorCodeFn *)mat->ops->view) mat->ops->viewnative = mat->ops->view;
11195:   (((PetscErrorCodeFn **)mat->ops)[op]) = f;
11196:   PetscFunctionReturn(PETSC_SUCCESS);
11197: }

11199: /*@C
11200:   MatGetOperation - Gets a matrix operation for any matrix type.

11202:   Not Collective

11204:   Input Parameters:
11205: + mat - the matrix
11206: - op  - the name of the operation

11208:   Output Parameter:
11209: . f - the function that provides the operation

11211:   Level: developer

11213:   Example Usage:
11214: .vb
11215:   PetscErrorCode (*usermult)(Mat, Vec, Vec);

11217:   MatGetOperation(A, MATOP_MULT, (PetscErrorCodeFn **)&usermult);
11218: .ve

11220:   Notes:
11221:   See the file `include/petscmat.h` for a complete list of matrix
11222:   operations, which all have the form MATOP_<OPERATION>, where
11223:   <OPERATION> is the name (in all capital letters) of the
11224:   user interface routine (e.g., `MatMult()` -> `MATOP_MULT`).

11226:   This routine is distinct from `MatShellGetOperation()` in that it can be called on any matrix type.

11228: .seealso: [](ch_matrices), `Mat`, `MatSetOperation()`, `MatCreateShell()`, `MatShellGetContext()`, `MatShellGetOperation()`
11229: @*/
11230: PetscErrorCode MatGetOperation(Mat mat, MatOperation op, PetscErrorCodeFn **f)
11231: {
11232:   PetscFunctionBegin;
11234:   *f = (((PetscErrorCodeFn **)mat->ops)[op]);
11235:   PetscFunctionReturn(PETSC_SUCCESS);
11236: }

11238: /*@
11239:   MatHasOperation - Determines whether the given matrix supports the particular operation.

11241:   Not Collective

11243:   Input Parameters:
11244: + mat - the matrix
11245: - op  - the operation, for example, `MATOP_GET_DIAGONAL`

11247:   Output Parameter:
11248: . has - either `PETSC_TRUE` or `PETSC_FALSE`

11250:   Level: advanced

11252:   Note:
11253:   See `MatSetOperation()` for additional discussion on naming convention and usage of `op`.

11255: .seealso: [](ch_matrices), `Mat`, `MatCreateShell()`, `MatGetOperation()`, `MatSetOperation()`
11256: @*/
11257: PetscErrorCode MatHasOperation(Mat mat, MatOperation op, PetscBool *has)
11258: {
11259:   PetscFunctionBegin;
11261:   PetscAssertPointer(has, 3);
11262:   if (mat->ops->hasoperation) {
11263:     PetscUseTypeMethod(mat, hasoperation, op, has);
11264:   } else {
11265:     if (((void **)mat->ops)[op]) *has = PETSC_TRUE;
11266:     else {
11267:       *has = PETSC_FALSE;
11268:       if (op == MATOP_CREATE_SUBMATRIX) {
11269:         PetscMPIInt size;

11271:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat), &size));
11272:         if (size == 1) PetscCall(MatHasOperation(mat, MATOP_CREATE_SUBMATRICES, has));
11273:       }
11274:     }
11275:   }
11276:   PetscFunctionReturn(PETSC_SUCCESS);
11277: }

11279: /*@
11280:   MatHasCongruentLayouts - Determines whether the rows and columns layouts of the matrix are congruent

11282:   Collective

11284:   Input Parameter:
11285: . mat - the matrix

11287:   Output Parameter:
11288: . cong - either `PETSC_TRUE` or `PETSC_FALSE`

11290:   Level: beginner

11292: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatSetSizes()`, `PetscLayout`
11293: @*/
11294: PetscErrorCode MatHasCongruentLayouts(Mat mat, PetscBool *cong)
11295: {
11296:   PetscFunctionBegin;
11299:   PetscAssertPointer(cong, 2);
11300:   if (!mat->rmap || !mat->cmap) {
11301:     *cong = mat->rmap == mat->cmap ? PETSC_TRUE : PETSC_FALSE;
11302:     PetscFunctionReturn(PETSC_SUCCESS);
11303:   }
11304:   if (mat->congruentlayouts == PETSC_DECIDE) { /* first time we compare rows and cols layouts */
11305:     PetscCall(PetscLayoutSetUp(mat->rmap));
11306:     PetscCall(PetscLayoutSetUp(mat->cmap));
11307:     PetscCall(PetscLayoutCompare(mat->rmap, mat->cmap, cong));
11308:     if (*cong) mat->congruentlayouts = 1;
11309:     else mat->congruentlayouts = 0;
11310:   } else *cong = mat->congruentlayouts ? PETSC_TRUE : PETSC_FALSE;
11311:   PetscFunctionReturn(PETSC_SUCCESS);
11312: }

11314: PetscErrorCode MatSetInf(Mat A)
11315: {
11316:   PetscFunctionBegin;
11317:   PetscUseTypeMethod(A, setinf);
11318:   PetscFunctionReturn(PETSC_SUCCESS);
11319: }

11321: /*@
11322:   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
11323:   and possibly removes small values from the graph structure.

11325:   Collective

11327:   Input Parameters:
11328: + A       - the matrix
11329: . sym     - `PETSC_TRUE` indicates that the graph should be symmetrized
11330: . scale   - `PETSC_TRUE` indicates that the graph edge weights should be symmetrically scaled with the diagonal entry
11331: . filter  - filter value - < 0: does nothing; == 0: removes only 0.0 entries; otherwise: removes entries with abs(entries) <= value
11332: . num_idx - size of 'index' array
11333: - index   - array of block indices to use for graph strength of connection weight

11335:   Output Parameter:
11336: . graph - the resulting graph

11338:   Level: advanced

11340: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `PCGAMG`
11341: @*/
11342: PetscErrorCode MatCreateGraph(Mat A, PetscBool sym, PetscBool scale, PetscReal filter, PetscInt num_idx, PetscInt index[], Mat *graph)
11343: {
11344:   PetscFunctionBegin;
11348:   PetscAssertPointer(graph, 7);
11349:   PetscCall(PetscLogEventBegin(MAT_CreateGraph, A, 0, 0, 0));
11350:   PetscUseTypeMethod(A, creategraph, sym, scale, filter, num_idx, index, graph);
11351:   PetscCall(PetscLogEventEnd(MAT_CreateGraph, A, 0, 0, 0));
11352:   PetscFunctionReturn(PETSC_SUCCESS);
11353: }

11355: /*@
11356:   MatEliminateZeros - eliminate the nondiagonal zero entries in place from the nonzero structure of a sparse `Mat` in place,
11357:   meaning the same memory is used for the matrix, and no new memory is allocated.

11359:   Collective

11361:   Input Parameters:
11362: + A    - the matrix
11363: - 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

11365:   Level: intermediate

11367:   Developer Note:
11368:   The entries in the sparse matrix data structure are shifted to fill in the unneeded locations in the data. Thus the end
11369:   of the arrays in the data structure are unneeded.

11371: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateGraph()`, `MatFilter()`
11372: @*/
11373: PetscErrorCode MatEliminateZeros(Mat A, PetscBool keep)
11374: {
11375:   PetscFunctionBegin;
11377:   PetscUseTypeMethod(A, eliminatezeros, keep);
11378:   PetscFunctionReturn(PETSC_SUCCESS);
11379: }

11381: /*@C
11382:   MatGetCurrentMemType - Get the memory location of the matrix

11384:   Not Collective, but the result will be the same on all MPI processes

11386:   Input Parameter:
11387: . A - the matrix whose memory type we are checking

11389:   Output Parameter:
11390: . m - the memory type

11392:   Level: intermediate

11394: .seealso: [](ch_matrices), `Mat`, `MatBoundToCPU()`, `PetscMemType`
11395: @*/
11396: PetscErrorCode MatGetCurrentMemType(Mat A, PetscMemType *m)
11397: {
11398:   PetscFunctionBegin;
11400:   PetscAssertPointer(m, 2);
11401:   if (A->ops->getcurrentmemtype) PetscUseTypeMethod(A, getcurrentmemtype, m);
11402:   else *m = PETSC_MEMTYPE_HOST;
11403:   PetscFunctionReturn(PETSC_SUCCESS);
11404: }