Actual source code: diagonal.c

  1: #include <petsc/private/matimpl.h>

  3: typedef struct {
  4:   Vec              diag;
  5:   PetscBool        diag_valid;
  6:   Vec              inv_diag;
  7:   PetscBool        inv_diag_valid;
  8:   PetscObjectState diag_state, inv_diag_state;
  9:   PetscInt        *col;
 10:   PetscScalar     *val;
 11: } Mat_Diagonal;

 13: static PetscErrorCode MatDiagonalSetUpDiagonal(Mat A)
 14: {
 15:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

 17:   PetscFunctionBegin;
 18:   if (!ctx->diag_valid) {
 19:     PetscAssert(ctx->inv_diag_valid, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Neither diagonal nor inverse diagonal is in a valid state");
 20:     PetscCall(VecCopy(ctx->inv_diag, ctx->diag));
 21:     PetscCall(VecReciprocal(ctx->diag));
 22:     ctx->diag_valid = PETSC_TRUE;
 23:   }
 24:   PetscFunctionReturn(PETSC_SUCCESS);
 25: }

 27: static PetscErrorCode MatDiagonalSetUpInverseDiagonal(Mat A)
 28: {
 29:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

 31:   PetscFunctionBegin;
 32:   if (!ctx->inv_diag_valid) {
 33:     PetscAssert(ctx->diag_valid, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Neither diagonal nor inverse diagonal is in a valid state");
 34:     PetscCall(VecCopy(ctx->diag, ctx->inv_diag));
 35:     PetscCall(VecReciprocal(ctx->inv_diag));
 36:     ctx->inv_diag_valid = PETSC_TRUE;
 37:   }
 38:   PetscFunctionReturn(PETSC_SUCCESS);
 39: }

 41: static PetscErrorCode MatAXPY_Diagonal(Mat Y, PetscScalar a, Mat X, MatStructure str)
 42: {
 43:   Mat_Diagonal *yctx = (Mat_Diagonal *)Y->data;
 44:   Mat_Diagonal *xctx = (Mat_Diagonal *)X->data;

 46:   PetscFunctionBegin;
 47:   PetscCall(MatDiagonalSetUpDiagonal(Y));
 48:   PetscCall(MatDiagonalSetUpDiagonal(X));
 49:   PetscCall(VecAXPY(yctx->diag, a, xctx->diag));
 50:   yctx->inv_diag_valid = PETSC_FALSE;
 51:   PetscFunctionReturn(PETSC_SUCCESS);
 52: }

 54: static PetscErrorCode MatGetRow_Diagonal(Mat A, PetscInt row, PetscInt *ncols, PetscInt **cols, PetscScalar **vals)
 55: {
 56:   Mat_Diagonal *mat = (Mat_Diagonal *)A->data;

 58:   PetscFunctionBegin;
 59:   if (ncols) *ncols = 1;
 60:   if (cols) {
 61:     if (!mat->col) PetscCall(PetscMalloc1(1, &mat->col));
 62:     *mat->col = row;
 63:     *cols     = mat->col;
 64:   }
 65:   if (vals) {
 66:     const PetscScalar *v;

 68:     if (!mat->val) PetscCall(PetscMalloc1(1, &mat->val));
 69:     PetscCall(VecGetArrayRead(mat->diag, &v));
 70:     *mat->val = v[row];
 71:     *vals     = mat->val;
 72:     PetscCall(VecRestoreArrayRead(mat->diag, &v));
 73:   }
 74:   PetscFunctionReturn(PETSC_SUCCESS);
 75: }

 77: static PetscErrorCode MatRestoreRow_Diagonal(Mat A, PetscInt row, PetscInt *ncols, PetscInt **cols, PetscScalar **vals)
 78: {
 79:   PetscFunctionBegin;
 80:   PetscFunctionReturn(PETSC_SUCCESS);
 81: }

 83: static PetscErrorCode MatMult_Diagonal(Mat A, Vec x, Vec y)
 84: {
 85:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

 87:   PetscFunctionBegin;
 88:   PetscCall(MatDiagonalSetUpDiagonal(A));
 89:   PetscCall(VecPointwiseMult(y, ctx->diag, x));
 90:   PetscFunctionReturn(PETSC_SUCCESS);
 91: }

 93: static PetscErrorCode MatMultAdd_Diagonal(Mat mat, Vec v1, Vec v2, Vec v3)
 94: {
 95:   Mat_Diagonal *ctx = (Mat_Diagonal *)mat->data;

 97:   PetscFunctionBegin;
 98:   PetscCall(MatDiagonalSetUpDiagonal(mat));
 99:   if (v2 != v3) {
100:     PetscCall(VecPointwiseMult(v3, ctx->diag, v1));
101:     PetscCall(VecAXPY(v3, 1.0, v2));
102:   } else {
103:     Vec w;
104:     PetscCall(VecDuplicate(v3, &w));
105:     PetscCall(VecPointwiseMult(w, ctx->diag, v1));
106:     PetscCall(VecAXPY(v3, 1.0, w));
107:     PetscCall(VecDestroy(&w));
108:   }
109:   PetscFunctionReturn(PETSC_SUCCESS);
110: }

112: static PetscErrorCode MatNorm_Diagonal(Mat A, NormType type, PetscReal *nrm)
113: {
114:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

116:   PetscFunctionBegin;
117:   PetscCall(MatDiagonalSetUpDiagonal(A));
118:   type = (type == NORM_FROBENIUS) ? NORM_2 : NORM_INFINITY;
119:   PetscCall(VecNorm(ctx->diag, type, nrm));
120:   PetscFunctionReturn(PETSC_SUCCESS);
121: }

123: static PetscErrorCode MatDuplicate_Diagonal(Mat A, MatDuplicateOption op, Mat *B)
124: {
125:   Mat_Diagonal *actx = (Mat_Diagonal *)A->data;

127:   PetscFunctionBegin;
128:   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
129:   PetscCall(MatSetSizes(*B, A->rmap->n, A->cmap->n, A->rmap->N, A->cmap->N));
130:   PetscCall(MatSetBlockSizesFromMats(*B, A, A));
131:   PetscCall(MatSetType(*B, MATDIAGONAL));
132:   PetscCall(PetscLayoutReference(A->rmap, &(*B)->rmap));
133:   PetscCall(PetscLayoutReference(A->cmap, &(*B)->cmap));
134:   if (op == MAT_COPY_VALUES) {
135:     Mat_Diagonal *bctx = (Mat_Diagonal *)(*B)->data;

137:     PetscCall(MatSetUp(A));
138:     PetscCall(MatSetUp(*B));
139:     PetscCall(VecCopy(actx->diag, bctx->diag));
140:     PetscCall(VecCopy(actx->inv_diag, bctx->inv_diag));
141:     bctx->diag_valid     = actx->diag_valid;
142:     bctx->inv_diag_valid = actx->inv_diag_valid;
143:   }
144:   PetscFunctionReturn(PETSC_SUCCESS);
145: }

147: /*@
148:   MatDiagonalGetDiagonal - Get the diagonal of a `MATDIAGONAL`

150:   Input Parameter:
151: . A - the `MATDIAGONAL`

153:   Output Parameter:
154: . diag - the `Vec` that defines the diagonal

156:   Level: developer

158:   Note:
159:   The user must call
160:   `MatDiagonalRestoreDiagonal()` before using the matrix again.

162:   For a copy of the diagonal values, rather than a reference, use `MatGetDiagonal()`

164:   Any changes to the obtained vector immediately change the action of the `Mat`. The matrix can be changed more efficiently by accessing this vector and changing its values, instead of filling a work vector and using `MatDiagonalSet()`

166: .seealso: [](ch_matrices), `MATDIAGONAL`, `MatCreateDiagonal()`, `MatDiagonalRestoreDiagonal()`, `MatDiagonalGetInverseDiagonal()`, `MatGetDiagonal()`
167: @*/
168: PetscErrorCode MatDiagonalGetDiagonal(Mat A, Vec *diag)
169: {
170:   PetscFunctionBegin;
172:   PetscAssertPointer(diag, 2);
173:   *diag = NULL;
174:   PetscUseMethod((PetscObject)A, "MatDiagonalGetDiagonal_C", (Mat, Vec *), (A, diag));
175:   PetscFunctionReturn(PETSC_SUCCESS);
176: }

178: static PetscErrorCode MatDiagonalGetDiagonal_Diagonal(Mat A, Vec *diag)
179: {
180:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

182:   PetscFunctionBegin;
183:   PetscCall(MatSetUp(A));
184:   PetscCall(MatDiagonalSetUpDiagonal(A));
185:   *diag = ctx->diag;
186:   PetscCall(PetscObjectStateGet((PetscObject)*diag, &ctx->diag_state));
187:   PetscFunctionReturn(PETSC_SUCCESS);
188: }

190: /*@
191:   MatDiagonalRestoreDiagonal - Restore the diagonal of a `MATDIAGONAL`

193:   Input Parameters:
194: + A    - the `MATDIAGONAL`
195: - diag - the `Vec` obtained from `MatDiagonalGetDiagonal()`

197:   Level: developer

199:   Note:
200:   Use `MatDiagonalSet()` to change the values by copy, rather than reference.

202: .seealso: [](ch_matrices), `MATDIAGONAL`, `MatCreateDiagonal()`, `MatDiagonalGetDiagonal()`
203: @*/
204: PetscErrorCode MatDiagonalRestoreDiagonal(Mat A, Vec *diag)
205: {
206:   PetscFunctionBegin;
208:   PetscAssertPointer(diag, 2);
209:   PetscUseMethod((PetscObject)A, "MatDiagonalRestoreDiagonal_C", (Mat, Vec *), (A, diag));
210:   PetscFunctionReturn(PETSC_SUCCESS);
211: }

213: static PetscErrorCode MatDiagonalRestoreDiagonal_Diagonal(Mat A, Vec *diag)
214: {
215:   Mat_Diagonal    *ctx = (Mat_Diagonal *)A->data;
216:   PetscObjectState diag_state;

218:   PetscFunctionBegin;
219:   PetscCheck(ctx->diag == *diag, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Restored a different diagonal vector");
220:   ctx->diag_valid = PETSC_TRUE;
221:   PetscCall(PetscObjectStateGet((PetscObject)*diag, &diag_state));
222:   if (ctx->diag_state != diag_state) {
223:     PetscCall(PetscObjectStateIncrease((PetscObject)A));
224:     ctx->inv_diag_valid = PETSC_FALSE;
225:   }
226:   *diag = NULL;
227:   PetscFunctionReturn(PETSC_SUCCESS);
228: }

230: /*@
231:   MatDiagonalGetInverseDiagonal - Get the inverse diagonal of a `MATDIAGONAL`

233:   Input Parameter:
234: . A - the `MATDIAGONAL`

236:   Output Parameter:
237: . inv_diag - the `Vec` that defines the inverse diagonal

239:   Level: developer

241:   Note:
242:   The user must call
243:   `MatDiagonalRestoreInverseDiagonal()` before using the matrix again.

245:   If a matrix is created only to call `MatSolve()` (which happens for `MATLMVMDIAGBROYDEN`),
246:   using `MatDiagonalGetInverseDiagonal()` and `MatDiagonalRestoreInverseDiagonal()` avoids copies
247:   and avoids any call to `VecReciprocal()`.

249: .seealso: [](ch_matrices), `MATDIAGONAL`, `MatCreateDiagonal()`, `MatDiagonalRestoreInverseDiagonal()`, `MatDiagonalGetDiagonal()`, `MATLMVMBROYDEN`, `MatSolve()`
250: @*/
251: PetscErrorCode MatDiagonalGetInverseDiagonal(Mat A, Vec *inv_diag)
252: {
253:   PetscFunctionBegin;
255:   PetscAssertPointer(inv_diag, 2);
256:   *inv_diag = NULL;
257:   PetscUseMethod((PetscObject)A, "MatDiagonalGetInverseDiagonal_C", (Mat, Vec *), (A, inv_diag));
258:   PetscFunctionReturn(PETSC_SUCCESS);
259: }

261: static PetscErrorCode MatDiagonalGetInverseDiagonal_Diagonal(Mat A, Vec *inv_diag)
262: {
263:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

265:   PetscFunctionBegin;
266:   PetscCall(MatSetUp(A));
267:   PetscCall(MatDiagonalSetUpInverseDiagonal(A));
268:   *inv_diag = ctx->inv_diag;
269:   PetscCall(PetscObjectStateGet((PetscObject)*inv_diag, &ctx->inv_diag_state));
270:   PetscFunctionReturn(PETSC_SUCCESS);
271: }

273: /*@
274:   MatDiagonalRestoreInverseDiagonal - Restore the inverse diagonal of a `MATDIAGONAL`

276:   Input Parameters:
277: + A        - the `MATDIAGONAL`
278: - inv_diag - the `Vec` obtained from `MatDiagonalGetInverseDiagonal()`

280:   Level: developer

282: .seealso: [](ch_matrices), `MATDIAGONAL`, `MatCreateDiagonal()`, `MatDiagonalGetInverseDiagonal()`
283: @*/
284: PetscErrorCode MatDiagonalRestoreInverseDiagonal(Mat A, Vec *inv_diag)
285: {
286:   PetscFunctionBegin;
288:   PetscAssertPointer(inv_diag, 2);
289:   PetscUseMethod((PetscObject)A, "MatDiagonalRestoreInverseDiagonal_C", (Mat, Vec *), (A, inv_diag));
290:   PetscFunctionReturn(PETSC_SUCCESS);
291: }

293: static PetscErrorCode MatDiagonalRestoreInverseDiagonal_Diagonal(Mat A, Vec *inv_diag)
294: {
295:   Mat_Diagonal    *ctx = (Mat_Diagonal *)A->data;
296:   PetscObjectState inv_diag_state;

298:   PetscFunctionBegin;
299:   PetscCheck(ctx->inv_diag == *inv_diag, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Restored a different diagonal vector");
300:   ctx->inv_diag_valid = PETSC_TRUE;
301:   PetscCall(PetscObjectStateGet((PetscObject)*inv_diag, &inv_diag_state));
302:   if (ctx->inv_diag_state != inv_diag_state) {
303:     PetscCall(PetscObjectStateIncrease((PetscObject)A));
304:     ctx->diag_valid = PETSC_FALSE;
305:   }
306:   *inv_diag = NULL;
307:   PetscFunctionReturn(PETSC_SUCCESS);
308: }

310: static PetscErrorCode MatDestroy_Diagonal(Mat mat)
311: {
312:   Mat_Diagonal *ctx = (Mat_Diagonal *)mat->data;

314:   PetscFunctionBegin;
315:   PetscCall(VecDestroy(&ctx->diag));
316:   PetscCall(VecDestroy(&ctx->inv_diag));
317:   PetscCall(PetscFree(ctx->col));
318:   PetscCall(PetscFree(ctx->val));
319:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatDiagonalGetDiagonal_C", NULL));
320:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatDiagonalRestoreDiagonal_C", NULL));
321:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatDiagonalGetInverseDiagonal_C", NULL));
322:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatDiagonalRestoreInverseDiagonal_C", NULL));
323:   PetscCall(PetscFree(mat->data));
324:   mat->structural_symmetry_eternal = PETSC_FALSE;
325:   mat->symmetry_eternal            = PETSC_FALSE;
326:   PetscFunctionReturn(PETSC_SUCCESS);
327: }

329: static PetscErrorCode MatView_Diagonal(Mat J, PetscViewer viewer)
330: {
331:   Mat_Diagonal *ctx = (Mat_Diagonal *)J->data;
332:   PetscBool     iascii;

334:   PetscFunctionBegin;
335:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
336:   if (iascii) {
337:     PetscViewerFormat format;

339:     PetscCall(PetscViewerGetFormat(viewer, &format));
340:     if (format == PETSC_VIEWER_ASCII_FACTOR_INFO || format == PETSC_VIEWER_ASCII_INFO) PetscFunctionReturn(PETSC_SUCCESS);
341:     PetscCall(MatDiagonalSetUpDiagonal(J));
342:     PetscCall(VecView(ctx->diag, viewer));
343:   }
344:   PetscFunctionReturn(PETSC_SUCCESS);
345: }

347: static PetscErrorCode MatGetDiagonal_Diagonal(Mat J, Vec x)
348: {
349:   Mat_Diagonal *ctx = (Mat_Diagonal *)J->data;

351:   PetscFunctionBegin;
352:   PetscCall(MatDiagonalSetUpDiagonal(J));
353:   PetscCall(VecCopy(ctx->diag, x));
354:   PetscFunctionReturn(PETSC_SUCCESS);
355: }

357: static PetscErrorCode MatDiagonalSet_Diagonal(Mat J, Vec D, InsertMode is)
358: {
359:   Mat_Diagonal *ctx = (Mat_Diagonal *)J->data;

361:   PetscFunctionBegin;
362:   switch (is) {
363:   case ADD_VALUES:
364:   case ADD_ALL_VALUES:
365:   case ADD_BC_VALUES:
366:     PetscCall(MatDiagonalSetUpDiagonal(J));
367:     PetscCall(VecAXPY(ctx->diag, 1.0, D));
368:     ctx->inv_diag_valid = PETSC_FALSE;
369:     break;
370:   case INSERT_VALUES:
371:   case INSERT_BC_VALUES:
372:   case INSERT_ALL_VALUES:
373:     PetscCall(MatSetUp(J));
374:     PetscCall(VecCopy(D, ctx->diag));
375:     ctx->diag_valid     = PETSC_TRUE;
376:     ctx->inv_diag_valid = PETSC_FALSE;
377:     break;
378:   case MAX_VALUES:
379:     PetscCall(MatDiagonalSetUpDiagonal(J));
380:     PetscCall(VecPointwiseMax(ctx->diag, D, ctx->diag));
381:     ctx->inv_diag_valid = PETSC_FALSE;
382:     break;
383:   case MIN_VALUES:
384:     PetscCall(MatDiagonalSetUpDiagonal(J));
385:     PetscCall(VecPointwiseMin(ctx->diag, D, ctx->diag));
386:     ctx->inv_diag_valid = PETSC_FALSE;
387:     break;
388:   case NOT_SET_VALUES:
389:     break;
390:   }
391:   PetscFunctionReturn(PETSC_SUCCESS);
392: }

394: static PetscErrorCode MatShift_Diagonal(Mat Y, PetscScalar a)
395: {
396:   Mat_Diagonal *ctx = (Mat_Diagonal *)Y->data;

398:   PetscFunctionBegin;
399:   PetscCall(MatDiagonalSetUpDiagonal(Y));
400:   PetscCall(VecShift(ctx->diag, a));
401:   ctx->inv_diag_valid = PETSC_FALSE;
402:   PetscFunctionReturn(PETSC_SUCCESS);
403: }

405: static PetscErrorCode MatScale_Diagonal(Mat Y, PetscScalar a)
406: {
407:   Mat_Diagonal *ctx = (Mat_Diagonal *)Y->data;

409:   PetscFunctionBegin;
410:   PetscCall(MatSetUp(Y));
411:   PetscCall(MatDiagonalSetUpDiagonal(Y));
412:   PetscCall(VecScale(ctx->diag, a));
413:   ctx->inv_diag_valid = PETSC_FALSE;
414:   PetscFunctionReturn(PETSC_SUCCESS);
415: }

417: static PetscErrorCode MatDiagonalScale_Diagonal(Mat Y, Vec l, Vec r)
418: {
419:   Mat_Diagonal *ctx = (Mat_Diagonal *)Y->data;

421:   PetscFunctionBegin;
422:   PetscCall(MatDiagonalSetUpDiagonal(Y));
423:   if (l) {
424:     PetscCall(VecPointwiseMult(ctx->diag, ctx->diag, l));
425:     ctx->inv_diag_valid = PETSC_FALSE;
426:   }
427:   if (r) {
428:     PetscCall(VecPointwiseMult(ctx->diag, ctx->diag, r));
429:     ctx->inv_diag_valid = PETSC_FALSE;
430:   }
431:   PetscFunctionReturn(PETSC_SUCCESS);
432: }

434: static PetscErrorCode MatSetUp_Diagonal(Mat A)
435: {
436:   Mat_Diagonal *ctx = (Mat_Diagonal *)A->data;

438:   PetscFunctionBegin;
439:   if (!ctx->diag) {
440:     PetscCall(PetscLayoutSetUp(A->cmap));
441:     PetscCall(PetscLayoutSetUp(A->rmap));
442:     PetscCall(MatCreateVecs(A, &ctx->diag, NULL));
443:     PetscCall(VecDuplicate(ctx->diag, &ctx->inv_diag));
444:     PetscCall(VecZeroEntries(ctx->diag));
445:     ctx->diag_valid = PETSC_TRUE;
446:   }
447:   A->assembled = PETSC_TRUE;
448:   PetscFunctionReturn(PETSC_SUCCESS);
449: }

451: static PetscErrorCode MatZeroEntries_Diagonal(Mat Y)
452: {
453:   Mat_Diagonal *ctx = (Mat_Diagonal *)Y->data;

455:   PetscFunctionBegin;
456:   PetscCall(MatSetUp(Y));
457:   PetscCall(VecZeroEntries(ctx->diag));
458:   ctx->diag_valid     = PETSC_TRUE;
459:   ctx->inv_diag_valid = PETSC_FALSE;
460:   PetscFunctionReturn(PETSC_SUCCESS);
461: }

463: static PetscErrorCode MatSolve_Diagonal(Mat matin, Vec b, Vec x)
464: {
465:   Mat_Diagonal *ctx = (Mat_Diagonal *)matin->data;

467:   PetscFunctionBegin;
468:   PetscCall(MatDiagonalSetUpInverseDiagonal(matin));
469:   PetscCall(VecPointwiseMult(x, b, ctx->inv_diag));
470:   PetscFunctionReturn(PETSC_SUCCESS);
471: }

473: static PetscErrorCode MatGetInfo_Diagonal(Mat A, MatInfoType flag, MatInfo *info)
474: {
475:   PetscFunctionBegin;
476:   info->block_size        = 1.0;
477:   info->nz_allocated      = A->cmap->N;
478:   info->nz_used           = A->cmap->N;
479:   info->nz_unneeded       = 0.0;
480:   info->assemblies        = A->num_ass;
481:   info->mallocs           = 0.0;
482:   info->memory            = 0;
483:   info->fill_ratio_given  = 0;
484:   info->fill_ratio_needed = 0;
485:   info->factor_mallocs    = 0;
486:   PetscFunctionReturn(PETSC_SUCCESS);
487: }

489: /*@
490:   MatCreateDiagonal - Creates a matrix defined by a given vector along its diagonal.

492:   Collective

494:   Input Parameter:
495: . diag - vector for the diagonal

497:   Output Parameter:
498: . J - the diagonal matrix

500:   Level: advanced

502:   Notes:
503:   Only supports square matrices with the same number of local rows and columns.

505:   The input vector `diag` will be referenced internally: any changes to `diag`
506:   will affect the matrix `J`.

508: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `MATCONSTANTDIAGONAL`, `MatScale()`, `MatShift()`, `MatMult()`, `MatGetDiagonal()`, `MatSolve()`
509:           `MatDiagonalRestoreInverseDiagonal()`, `MatDiagonalGetDiagonal()`, `MatDiagonalRestoreDiagonal()`, `MatDiagonalGetInverseDiagonal()`
510: @*/
511: PetscErrorCode MatCreateDiagonal(Vec diag, Mat *J)
512: {
513:   PetscFunctionBegin;
515:   PetscCall(MatCreate(PetscObjectComm((PetscObject)diag), J));
516:   PetscInt m, M;
517:   PetscCall(VecGetLocalSize(diag, &m));
518:   PetscCall(VecGetSize(diag, &M));
519:   PetscCall(MatSetSizes(*J, m, m, M, M));
520:   PetscCall(MatSetType(*J, MATDIAGONAL));

522:   PetscLayout map;
523:   PetscCall(VecGetLayout(diag, &map));
524:   PetscCall(MatSetLayouts(*J, map, map));
525:   Mat_Diagonal *ctx = (Mat_Diagonal *)(*J)->data;
526:   PetscCall(PetscObjectReference((PetscObject)diag));
527:   PetscCall(VecDestroy(&ctx->diag));
528:   PetscCall(VecDestroy(&ctx->inv_diag));
529:   ctx->diag           = diag;
530:   ctx->diag_valid     = PETSC_TRUE;
531:   ctx->inv_diag_valid = PETSC_FALSE;
532:   VecType type;
533:   PetscCall(VecDuplicate(ctx->diag, &ctx->inv_diag));
534:   PetscCall(VecGetType(diag, &type));
535:   PetscCall(PetscFree((*J)->defaultvectype));
536:   PetscCall(PetscStrallocpy(type, &(*J)->defaultvectype));
537:   PetscCall(MatSetUp(*J));
538:   ctx->col = NULL;
539:   ctx->val = NULL;
540:   PetscFunctionReturn(PETSC_SUCCESS);
541: }

543: /*MC
544:    MATDIAGONAL - MATDIAGONAL = "diagonal" - A diagonal matrix type with the diagonal implemented as a `Vec`.  Useful for
545:    cases where `VecPointwiseMult()` or `VecPointwiseDivide()` should be thought of as the actions of a linear operator.

547:   Level: advanced

549: .seealso: [](ch_matrices), `Mat`, `MatCreateDiagonal()`, `MatDiagonalRestoreInverseDiagonal()`, `MatDiagonalGetDiagonal()`, `MatDiagonalRestoreDiagonal()`, `MatDiagonalGetInverseDiagonal()`
550: M*/
551: PETSC_INTERN PetscErrorCode MatCreate_Diagonal(Mat A)
552: {
553:   Mat_Diagonal *ctx;

555:   PetscFunctionBegin;
556:   PetscCall(PetscNew(&ctx));
557:   A->data = (void *)ctx;

559:   A->structurally_symmetric      = PETSC_BOOL3_TRUE;
560:   A->structural_symmetry_eternal = PETSC_TRUE;
561:   A->symmetry_eternal            = PETSC_TRUE;
562:   A->symmetric                   = PETSC_BOOL3_TRUE;
563:   if (!PetscDefined(USE_COMPLEX)) A->hermitian = PETSC_BOOL3_TRUE;

565:   A->ops->getrow           = MatGetRow_Diagonal;
566:   A->ops->restorerow       = MatRestoreRow_Diagonal;
567:   A->ops->mult             = MatMult_Diagonal;
568:   A->ops->multadd          = MatMultAdd_Diagonal;
569:   A->ops->multtranspose    = MatMult_Diagonal;
570:   A->ops->multtransposeadd = MatMultAdd_Diagonal;
571:   A->ops->norm             = MatNorm_Diagonal;
572:   A->ops->duplicate        = MatDuplicate_Diagonal;
573:   A->ops->solve            = MatSolve_Diagonal;
574:   A->ops->solvetranspose   = MatSolve_Diagonal;
575:   A->ops->shift            = MatShift_Diagonal;
576:   A->ops->scale            = MatScale_Diagonal;
577:   A->ops->diagonalscale    = MatDiagonalScale_Diagonal;
578:   A->ops->getdiagonal      = MatGetDiagonal_Diagonal;
579:   A->ops->diagonalset      = MatDiagonalSet_Diagonal;
580:   A->ops->view             = MatView_Diagonal;
581:   A->ops->zeroentries      = MatZeroEntries_Diagonal;
582:   A->ops->destroy          = MatDestroy_Diagonal;
583:   A->ops->getinfo          = MatGetInfo_Diagonal;
584:   A->ops->axpy             = MatAXPY_Diagonal;
585:   A->ops->setup            = MatSetUp_Diagonal;

587:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatDiagonalGetDiagonal_C", MatDiagonalGetDiagonal_Diagonal));
588:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatDiagonalRestoreDiagonal_C", MatDiagonalRestoreDiagonal_Diagonal));
589:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatDiagonalGetInverseDiagonal_C", MatDiagonalGetInverseDiagonal_Diagonal));
590:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatDiagonalRestoreInverseDiagonal_C", MatDiagonalRestoreInverseDiagonal_Diagonal));
591:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATDIAGONAL));
592:   PetscFunctionReturn(PETSC_SUCCESS);
593: }