Actual source code: cdiagonal.c

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

  3: typedef struct {
  4:   PetscScalar diag;
  5: } Mat_ConstantDiagonal;

  7: static PetscErrorCode MatAXPY_ConstantDiagonal(Mat Y, PetscScalar a, Mat X, MatStructure str)
  8: {
  9:   Mat_ConstantDiagonal *yctx = (Mat_ConstantDiagonal *)Y->data;
 10:   Mat_ConstantDiagonal *xctx = (Mat_ConstantDiagonal *)X->data;

 12:   PetscFunctionBegin;
 13:   yctx->diag += a * xctx->diag;
 14:   PetscFunctionReturn(PETSC_SUCCESS);
 15: }

 17: static PetscErrorCode MatEqual_ConstantDiagonal(Mat Y, Mat X, PetscBool *equal)
 18: {
 19:   Mat_ConstantDiagonal *yctx = (Mat_ConstantDiagonal *)Y->data;
 20:   Mat_ConstantDiagonal *xctx = (Mat_ConstantDiagonal *)X->data;

 22:   PetscFunctionBegin;
 23:   *equal = (yctx->diag == xctx->diag) ? PETSC_TRUE : PETSC_FALSE;
 24:   PetscFunctionReturn(PETSC_SUCCESS);
 25: }

 27: static PetscErrorCode MatGetRow_ConstantDiagonal(Mat A, PetscInt row, PetscInt *ncols, PetscInt *cols[], PetscScalar *vals[])
 28: {
 29:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)A->data;

 31:   PetscFunctionBegin;
 32:   if (ncols) *ncols = 1;
 33:   if (cols) {
 34:     PetscCall(PetscMalloc1(1, cols));
 35:     (*cols)[0] = row;
 36:   }
 37:   if (vals) {
 38:     PetscCall(PetscMalloc1(1, vals));
 39:     (*vals)[0] = ctx->diag;
 40:   }
 41:   PetscFunctionReturn(PETSC_SUCCESS);
 42: }

 44: static PetscErrorCode MatRestoreRow_ConstantDiagonal(Mat A, PetscInt row, PetscInt *ncols, PetscInt *cols[], PetscScalar *vals[])
 45: {
 46:   PetscFunctionBegin;
 47:   if (cols) PetscCall(PetscFree(*cols));
 48:   if (vals) PetscCall(PetscFree(*vals));
 49:   PetscFunctionReturn(PETSC_SUCCESS);
 50: }

 52: static PetscErrorCode MatMultAdd_ConstantDiagonal(Mat mat, Vec v1, Vec v2, Vec v3)
 53: {
 54:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)mat->data;

 56:   PetscFunctionBegin;
 57:   if (v2 == v3) PetscCall(VecAXPBY(v3, ctx->diag, 1.0, v1));
 58:   else PetscCall(VecAXPBYPCZ(v3, ctx->diag, 1.0, 0.0, v1, v2));
 59:   PetscFunctionReturn(PETSC_SUCCESS);
 60: }

 62: static PetscErrorCode MatMultHermitianTransposeAdd_ConstantDiagonal(Mat mat, Vec v1, Vec v2, Vec v3)
 63: {
 64:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)mat->data;

 66:   PetscFunctionBegin;
 67:   if (v2 == v3) PetscCall(VecAXPBY(v3, PetscConj(ctx->diag), 1.0, v1));
 68:   else PetscCall(VecAXPBYPCZ(v3, PetscConj(ctx->diag), 1.0, 0.0, v1, v2));
 69:   PetscFunctionReturn(PETSC_SUCCESS);
 70: }

 72: static PetscErrorCode MatNorm_ConstantDiagonal(Mat A, NormType type, PetscReal *nrm)
 73: {
 74:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)A->data;

 76:   PetscFunctionBegin;
 77:   PetscCheck(type == NORM_FROBENIUS || type == NORM_2 || type == NORM_1 || type == NORM_INFINITY, PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unsupported norm");
 78:   *nrm = PetscAbsScalar(ctx->diag);
 79:   PetscFunctionReturn(PETSC_SUCCESS);
 80: }

 82: static PetscErrorCode MatCreateSubMatrices_ConstantDiagonal(Mat A, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])
 83: {
 84:   Mat B;

 86:   PetscFunctionBegin;
 87:   PetscCall(MatConvert(A, MATAIJ, MAT_INITIAL_MATRIX, &B));
 88:   PetscCall(MatCreateSubMatrices(B, n, irow, icol, scall, submat));
 89:   PetscCall(MatDestroy(&B));
 90:   PetscFunctionReturn(PETSC_SUCCESS);
 91: }

 93: static PetscErrorCode MatDuplicate_ConstantDiagonal(Mat A, MatDuplicateOption op, Mat *B)
 94: {
 95:   Mat_ConstantDiagonal *actx = (Mat_ConstantDiagonal *)A->data;

 97:   PetscFunctionBegin;
 98:   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
 99:   PetscCall(MatSetSizes(*B, A->rmap->n, A->cmap->n, A->rmap->N, A->cmap->N));
100:   PetscCall(MatSetBlockSizesFromMats(*B, A, A));
101:   PetscCall(MatSetType(*B, MATCONSTANTDIAGONAL));
102:   PetscCall(PetscLayoutReference(A->rmap, &(*B)->rmap));
103:   PetscCall(PetscLayoutReference(A->cmap, &(*B)->cmap));
104:   if (op == MAT_COPY_VALUES) {
105:     Mat_ConstantDiagonal *bctx = (Mat_ConstantDiagonal *)(*B)->data;
106:     bctx->diag                 = actx->diag;
107:   }
108:   PetscFunctionReturn(PETSC_SUCCESS);
109: }

111: static PetscErrorCode MatDestroy_ConstantDiagonal(Mat mat)
112: {
113:   PetscFunctionBegin;
114:   PetscCall(PetscFree(mat->data));
115:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatConstantDiagonalGetConstant_C", NULL));
116:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_constantdiagonal_constantdiagonal_C", NULL));
117:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_constantdiagonal_diagonal_C", NULL));
118:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_diagonal_constantdiagonal_C", NULL));
119:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_constantdiagonal_seqdense_C", NULL));
120:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_constantdiagonal_mpidense_C", NULL));
121:   PetscCall(PetscObjectComposeFunction((PetscObject)mat, "MatProductSetFromOptions_anytype_C", NULL));
122:   PetscFunctionReturn(PETSC_SUCCESS);
123: }

125: static PetscErrorCode MatView_ConstantDiagonal(Mat J, PetscViewer viewer)
126: {
127:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;
128:   PetscBool             isascii;

130:   PetscFunctionBegin;
131:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
132:   if (isascii) {
133:     PetscViewerFormat format;

135:     PetscCall(PetscViewerGetFormat(viewer, &format));
136:     if (format == PETSC_VIEWER_ASCII_FACTOR_INFO || format == PETSC_VIEWER_ASCII_INFO) PetscFunctionReturn(PETSC_SUCCESS);
137:     if (PetscImaginaryPart(ctx->diag) == 0) {
138:       PetscCall(PetscViewerASCIIPrintf(viewer, "Diagonal value: %g\n", (double)PetscRealPart(ctx->diag)));
139:     } else {
140:       PetscCall(PetscViewerASCIIPrintf(viewer, "Diagonal value: %g + i %g\n", (double)PetscRealPart(ctx->diag), (double)PetscImaginaryPart(ctx->diag)));
141:     }
142:   }
143:   PetscFunctionReturn(PETSC_SUCCESS);
144: }

146: static PetscErrorCode MatMult_ConstantDiagonal(Mat J, Vec x, Vec y)
147: {
148:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;

150:   PetscFunctionBegin;
151:   PetscCall(VecAXPBY(y, ctx->diag, 0.0, x));
152:   PetscFunctionReturn(PETSC_SUCCESS);
153: }

155: static PetscErrorCode MatMultHermitianTranspose_ConstantDiagonal(Mat J, Vec x, Vec y)
156: {
157:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;

159:   PetscFunctionBegin;
160:   PetscCall(VecAXPBY(y, PetscConj(ctx->diag), 0.0, x));
161:   PetscFunctionReturn(PETSC_SUCCESS);
162: }

164: static PetscErrorCode MatGetDiagonal_ConstantDiagonal(Mat J, Vec x)
165: {
166:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;

168:   PetscFunctionBegin;
169:   PetscCall(VecSet(x, ctx->diag));
170:   PetscFunctionReturn(PETSC_SUCCESS);
171: }

173: static PetscErrorCode MatShift_ConstantDiagonal(Mat Y, PetscScalar a)
174: {
175:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

177:   PetscFunctionBegin;
178:   ctx->diag += a;
179:   PetscFunctionReturn(PETSC_SUCCESS);
180: }

182: static PetscErrorCode MatScale_ConstantDiagonal(Mat Y, PetscScalar a)
183: {
184:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

186:   PetscFunctionBegin;
187:   ctx->diag *= a;
188:   PetscFunctionReturn(PETSC_SUCCESS);
189: }

191: static PetscErrorCode MatZeroEntries_ConstantDiagonal(Mat Y)
192: {
193:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

195:   PetscFunctionBegin;
196:   ctx->diag = 0.0;
197:   PetscFunctionReturn(PETSC_SUCCESS);
198: }

200: static PetscErrorCode MatConjugate_ConstantDiagonal(Mat Y)
201: {
202:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

204:   PetscFunctionBegin;
205:   ctx->diag = PetscConj(ctx->diag);
206:   PetscFunctionReturn(PETSC_SUCCESS);
207: }

209: static PetscErrorCode MatTranspose_ConstantDiagonal(Mat A, MatReuse reuse, Mat *matout)
210: {
211:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)A->data;

213:   PetscFunctionBegin;
214:   if (reuse == MAT_INPLACE_MATRIX) {
215:     PetscLayout tmplayout = A->rmap;

217:     A->rmap = A->cmap;
218:     A->cmap = tmplayout;
219:   } else {
220:     if (reuse == MAT_INITIAL_MATRIX) {
221:       PetscCall(MatCreateConstantDiagonal(PetscObjectComm((PetscObject)A), A->cmap->n, A->rmap->n, A->cmap->N, A->rmap->N, ctx->diag, matout));
222:     } else {
223:       PetscCall(MatZeroEntries(*matout));
224:       PetscCall(MatShift(*matout, ctx->diag));
225:     }
226:   }
227:   PetscFunctionReturn(PETSC_SUCCESS);
228: }

230: static PetscErrorCode MatSetRandom_ConstantDiagonal(Mat A, PetscRandom rand)
231: {
232:   PetscMPIInt           rank;
233:   MPI_Comm              comm;
234:   PetscScalar           v   = 0.0;
235:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)A->data;

237:   PetscFunctionBegin;
238:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
239:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
240:   if (!rank) PetscCall(PetscRandomGetValue(rand, &v));
241:   PetscCallMPI(MPI_Bcast(&v, 1, MPIU_SCALAR, 0, comm));
242:   ctx->diag = v;
243:   PetscFunctionReturn(PETSC_SUCCESS);
244: }

246: static PetscErrorCode MatSolve_ConstantDiagonal(Mat matin, Vec b, Vec x)
247: {
248:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)matin->data;

250:   PetscFunctionBegin;
251:   if (ctx->diag == 0.0) matin->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
252:   else matin->factorerrortype = MAT_FACTOR_NOERROR;
253:   PetscCall(VecAXPBY(x, 1.0 / ctx->diag, 0.0, b));
254:   PetscFunctionReturn(PETSC_SUCCESS);
255: }

257: static PetscErrorCode MatSOR_ConstantDiagonal(Mat matin, Vec x, PetscReal omega, MatSORType flag, PetscReal fshift, PetscInt its, PetscInt lits, Vec y)
258: {
259:   PetscFunctionBegin;
260:   PetscCall(MatSolve_ConstantDiagonal(matin, x, y));
261:   PetscFunctionReturn(PETSC_SUCCESS);
262: }

264: static PetscErrorCode MatGetInfo_ConstantDiagonal(Mat A, MatInfoType flag, MatInfo *info)
265: {
266:   PetscFunctionBegin;
267:   info->block_size   = 1.0;
268:   info->nz_allocated = 1.0;
269:   info->nz_used      = 1.0;
270:   info->nz_unneeded  = 0.0;
271:   info->assemblies   = A->num_ass;
272:   info->mallocs      = 0.0;
273:   info->memory       = 0; /* REVIEW ME */
274:   if (A->factortype) {
275:     info->fill_ratio_given  = 1.0;
276:     info->fill_ratio_needed = 1.0;
277:     info->factor_mallocs    = 0.0;
278:   } else {
279:     info->fill_ratio_given  = 0;
280:     info->fill_ratio_needed = 0;
281:     info->factor_mallocs    = 0;
282:   }
283:   PetscFunctionReturn(PETSC_SUCCESS);
284: }

286: /*@
287:   MatCreateConstantDiagonal - Creates a matrix with a uniform value along the diagonal

289:   Collective

291:   Input Parameters:
292: + comm - MPI communicator
293: . m    - number of local rows (or `PETSC_DECIDE` to have calculated if `M` is given)
294:            This value should be the same as the local size used in creating the
295:            y vector for the matrix-vector product y = Ax.
296: . n    - This value should be the same as the local size used in creating the
297:        x vector for the matrix-vector product y = Ax. (or `PETSC_DECIDE` to have
298:        calculated if `N` is given) For square matrices n is almost always `m`.
299: . M    - number of global rows (or `PETSC_DETERMINE` to have calculated if m is given)
300: . N    - number of global columns (or `PETSC_DETERMINE` to have calculated if n is given)
301: - diag - the diagonal value

303:   Output Parameter:
304: . J - the diagonal matrix

306:   Level: advanced

308:   Notes:
309:   Only supports square matrices with the same number of local rows and columns

311: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `MATCONSTANTDIAGONAL`, `MatScale()`, `MatShift()`, `MatMult()`, `MatGetDiagonal()`, `MatGetFactor()`, `MatSolve()`
312: @*/
313: PetscErrorCode MatCreateConstantDiagonal(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscScalar diag, Mat *J)
314: {
315:   PetscFunctionBegin;
316:   PetscCall(MatCreate(comm, J));
317:   PetscCall(MatSetSizes(*J, m, n, M, N));
318:   PetscCall(MatSetType(*J, MATCONSTANTDIAGONAL));
319:   PetscCall(MatShift(*J, diag));
320:   PetscCall(MatSetUp(*J));
321:   PetscFunctionReturn(PETSC_SUCCESS);
322: }

324: /*@
325:   MatConstantDiagonalGetConstant - Get the scalar constant of a constant diagonal matrix

327:   Not collective

329:   Input Parameter:
330: . mat - a `MATCONSTANTDIAGONAL`

332:   Output Parameter:
333: . value - the scalar value

335:   Level: developer

337: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `MATCONSTANTDIAGONAL`
338: @*/
339: PetscErrorCode MatConstantDiagonalGetConstant(Mat mat, PetscScalar *value)
340: {
341:   PetscFunctionBegin;
342:   PetscUseMethod(mat, "MatConstantDiagonalGetConstant_C", (Mat, PetscScalar *), (mat, value));
343:   PetscFunctionReturn(PETSC_SUCCESS);
344: }

346: static PetscErrorCode MatConstantDiagonalGetConstant_ConstantDiagonal(Mat mat, PetscScalar *value)
347: {
348:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)mat->data;

350:   PetscFunctionBegin;
351:   *value = ctx->diag;
352:   PetscFunctionReturn(PETSC_SUCCESS);
353: }

355: static PetscErrorCode MatProductNumeric_ConstDiag_Dense(Mat C)
356: {
357:   Mat_ConstantDiagonal *p = (Mat_ConstantDiagonal *)C->product->A->data;

359:   PetscFunctionBegin;
360:   MatCheckProduct(C, 1);
361:   PetscCall(MatCopy(C->product->B, C, SAME_NONZERO_PATTERN));
362:   PetscCall(MatScale(C, p->diag));
363:   PetscFunctionReturn(PETSC_SUCCESS);
364: }

366: static PetscErrorCode MatProductSymbolic_ConstDiag_Dense(Mat C)
367: {
368:   Mat      A, B;
369:   PetscInt n, N, m, M;

371:   PetscFunctionBegin;
372:   MatCheckProduct(C, 1);
373:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
374:   A = C->product->A;
375:   B = C->product->B;
376:   PetscCall(MatGetLocalSize(B, NULL, &n));
377:   PetscCall(MatGetSize(B, NULL, &N));
378:   PetscCall(MatGetLocalSize(A, &m, NULL));
379:   PetscCall(MatGetSize(A, &M, NULL));
380:   PetscCall(MatSetSizes(C, m, n, M, N));
381:   PetscCall(MatSetType(C, ((PetscObject)B)->type_name));
382:   PetscCall(MatSetUp(C));
383:   C->ops->productnumeric = MatProductNumeric_ConstDiag_Dense;
384:   PetscFunctionReturn(PETSC_SUCCESS);
385: }

387: /* PtAP for constantdiagonal * constantdiagonal: C = alpha * beta^2 * I */
388: static PetscErrorCode MatProductNumeric_PtAP_ConstDiag_ConstDiag(Mat C)
389: {
390:   Mat                   A = C->product->A, P = C->product->B;
391:   Mat_ConstantDiagonal *a = (Mat_ConstantDiagonal *)A->data, *p = (Mat_ConstantDiagonal *)P->data, *c = (Mat_ConstantDiagonal *)C->data;

393:   PetscFunctionBegin;
394:   MatCheckProduct(C, 1);
395:   c->diag = a->diag * p->diag * p->diag;
396:   PetscFunctionReturn(PETSC_SUCCESS);
397: }

399: static PetscErrorCode MatProductSymbolic_PtAP_ConstDiag_ConstDiag(Mat C)
400: {
401:   Mat P = C->product->B;

403:   PetscFunctionBegin;
404:   MatCheckProduct(C, 1);
405:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
406:   PetscCall(MatSetSizes(C, P->cmap->n, P->cmap->n, P->cmap->N, P->cmap->N));
407:   PetscCall(MatSetType(C, MATCONSTANTDIAGONAL));
408:   C->assembled           = PETSC_TRUE;
409:   C->ops->productnumeric = MatProductNumeric_PtAP_ConstDiag_ConstDiag;
410:   PetscFunctionReturn(PETSC_SUCCESS);
411: }

413: /* PtAP for constantdiagonal A and diagonal P: C_i = alpha * p_i^2 */
414: static PetscErrorCode MatProductNumeric_PtAP_ConstDiag_Diagonal(Mat C)
415: {
416:   Mat                   A = C->product->A, P = C->product->B;
417:   Mat_ConstantDiagonal *a = (Mat_ConstantDiagonal *)A->data;
418:   Vec                   pdiag, cdiag;

420:   PetscFunctionBegin;
421:   MatCheckProduct(C, 1);
422:   PetscCall(MatDiagonalGetDiagonal(P, &pdiag));
423:   PetscCall(MatDiagonalGetDiagonal(C, &cdiag));
424:   PetscCall(VecPointwiseMult(cdiag, pdiag, pdiag));
425:   PetscCall(VecScale(cdiag, a->diag));
426:   PetscCall(MatDiagonalRestoreDiagonal(C, &cdiag));
427:   PetscCall(MatDiagonalRestoreDiagonal(P, &pdiag));
428:   PetscFunctionReturn(PETSC_SUCCESS);
429: }

431: static PetscErrorCode MatProductSymbolic_PtAP_ConstDiag_Diagonal(Mat C)
432: {
433:   Mat P = C->product->B;
434:   Vec pdiag, cdiag;

436:   PetscFunctionBegin;
437:   MatCheckProduct(C, 1);
438:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
439:   PetscCall(MatSetSizes(C, P->cmap->n, P->cmap->n, P->cmap->N, P->cmap->N));
440:   PetscCall(MatSetType(C, MATDIAGONAL));
441:   PetscCall(MatDiagonalGetDiagonal(P, &pdiag));
442:   PetscCall(VecDuplicate(pdiag, &cdiag));
443:   PetscCall(MatDiagonalSetDiagonal(C, cdiag));
444:   PetscCall(VecDestroy(&cdiag));
445:   PetscCall(MatDiagonalRestoreDiagonal(P, &pdiag));
446:   C->assembled           = PETSC_TRUE;
447:   C->ops->productnumeric = MatProductNumeric_PtAP_ConstDiag_Diagonal;
448:   PetscFunctionReturn(PETSC_SUCCESS);
449: }

451: /* PtAP for diagonal A and constantdiagonal P: C_i = beta^2 * a_i */
452: static PetscErrorCode MatProductNumeric_PtAP_Diagonal_ConstDiag(Mat C)
453: {
454:   Mat                   A = C->product->A, P = C->product->B;
455:   Mat_ConstantDiagonal *p = (Mat_ConstantDiagonal *)P->data;
456:   Vec                   adiag, cdiag;

458:   PetscFunctionBegin;
459:   MatCheckProduct(C, 1);
460:   PetscCall(MatDiagonalGetDiagonal(A, &adiag));
461:   PetscCall(MatDiagonalGetDiagonal(C, &cdiag));
462:   PetscCall(VecCopy(adiag, cdiag));
463:   PetscCall(VecScale(cdiag, p->diag * p->diag));
464:   PetscCall(MatDiagonalRestoreDiagonal(C, &cdiag));
465:   PetscCall(MatDiagonalRestoreDiagonal(A, &adiag));
466:   PetscFunctionReturn(PETSC_SUCCESS);
467: }

469: static PetscErrorCode MatProductSymbolic_PtAP_Diagonal_ConstDiag(Mat C)
470: {
471:   Mat A = C->product->A, P = C->product->B;
472:   Vec adiag, cdiag;

474:   PetscFunctionBegin;
475:   MatCheckProduct(C, 1);
476:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
477:   PetscCall(MatSetSizes(C, P->cmap->n, P->cmap->n, P->cmap->N, P->cmap->N));
478:   PetscCall(MatSetType(C, MATDIAGONAL));
479:   /* Duplicate A's diagonal Vec so C inherits the correct VecType (e.g., Kokkos, CUDA, HIP) */
480:   PetscCall(MatDiagonalGetDiagonal(A, &adiag));
481:   PetscCall(VecDuplicate(adiag, &cdiag));
482:   PetscCall(MatDiagonalSetDiagonal(C, cdiag));
483:   PetscCall(VecDestroy(&cdiag));
484:   PetscCall(MatDiagonalRestoreDiagonal(A, &adiag));
485:   C->assembled           = PETSC_TRUE;
486:   C->ops->productnumeric = MatProductNumeric_PtAP_Diagonal_ConstDiag;
487:   PetscFunctionReturn(PETSC_SUCCESS);
488: }

490: /* PtAP for any (non-diagonal) A and constantdiagonal P: C = beta^2 * A */
491: static PetscErrorCode MatProductNumeric_PtAP_Anytype_ConstDiag(Mat C)
492: {
493:   Mat                   A = C->product->A, P = C->product->B;
494:   Mat_ConstantDiagonal *p = (Mat_ConstantDiagonal *)P->data;

496:   PetscFunctionBegin;
497:   MatCheckProduct(C, 1);
498:   PetscCall(MatCopy(A, C, SAME_NONZERO_PATTERN));
499:   PetscCall(MatScale(C, p->diag * p->diag));
500:   PetscFunctionReturn(PETSC_SUCCESS);
501: }

503: static PetscErrorCode MatProductSymbolic_PtAP_Anytype_ConstDiag(Mat C)
504: {
505:   Mat          A       = C->product->A;
506:   Mat_Product *product = C->product;
507:   Mat          Cwork;

509:   PetscFunctionBegin;
510:   MatCheckProduct(C, 1);
511:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
512:   PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &Cwork));
513:   C->product = NULL;
514:   PetscCall(MatHeaderReplace(C, &Cwork));
515:   C->product             = product;
516:   C->ops->productnumeric = MatProductNumeric_PtAP_Anytype_ConstDiag;
517:   PetscFunctionReturn(PETSC_SUCCESS);
518: }

520: /* PtAP for constantdiagonal A and any non-diagonal P: C = alpha * P^T * P */
521: typedef struct {
522:   Mat              PtP;       /* P^T * P result via MatProduct AtB */
523:   PetscObjectState pnnzstate; /* P's nonzero state when inner symbolic was last built */
524: } MatProductCtx_PtAP_ConstDiag_Anytype;

526: static PetscErrorCode MatProductCtxDestroy_PtAP_ConstDiag_Anytype(PetscCtxRt data)
527: {
528:   MatProductCtx_PtAP_ConstDiag_Anytype *ctx = *(MatProductCtx_PtAP_ConstDiag_Anytype **)data;

530:   PetscFunctionBegin;
531:   PetscCall(MatDestroy(&ctx->PtP));
532:   PetscCall(PetscFree(ctx));
533:   PetscFunctionReturn(PETSC_SUCCESS);
534: }

536: static PetscErrorCode MatProductNumeric_PtAP_ConstDiag_Anytype(Mat C)
537: {
538:   Mat_Product                          *product = C->product;
539:   Mat                                   A = product->A, P = product->B;
540:   MatProductCtx_PtAP_ConstDiag_Anytype *ctx = (MatProductCtx_PtAP_ConstDiag_Anytype *)product->data;
541:   Mat_ConstantDiagonal                 *a   = (Mat_ConstantDiagonal *)A->data;
542:   PetscObjectState                      pnnzstate;

544:   PetscFunctionBegin;
545:   MatCheckProduct(C, 1);
546:   /* Rebuild inner symbolic if P's nonzero structure has changed */
547:   PetscCall(MatGetNonzeroState(P, &pnnzstate));
548:   if (pnnzstate != ctx->pnnzstate) {
549:     PetscCall(MatDestroy(&ctx->PtP));
550:     PetscCall(MatProductCreate(P, P, NULL, &ctx->PtP));
551:     PetscCall(MatProductSetType(ctx->PtP, MATPRODUCT_AtB));
552:     PetscCall(MatProductSetFill(ctx->PtP, product->fill));
553:     PetscCall(MatProductSetFromOptions(ctx->PtP));
554:     PetscCall(MatProductSymbolic(ctx->PtP));
555:     ctx->pnnzstate = pnnzstate;
556:   }
557:   /* Compute P^T * P */
558:   PetscCall(MatProductNumeric(ctx->PtP));
559:   PetscCall(MatCopy(ctx->PtP, C, SAME_NONZERO_PATTERN));
560:   PetscCall(MatScale(C, a->diag));
561:   PetscFunctionReturn(PETSC_SUCCESS);
562: }

564: static PetscErrorCode MatProductSymbolic_PtAP_ConstDiag_Anytype(Mat C)
565: {
566:   Mat_Product                          *product = C->product;
567:   Mat                                   P       = product->B;
568:   MatProductCtx_PtAP_ConstDiag_Anytype *ctx;
569:   Mat                                   Cwork;

571:   PetscFunctionBegin;
572:   MatCheckProduct(C, 1);
573:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
574:   PetscCall(PetscNew(&ctx));

576:   /* PtP = P^T * P (symbolic) */
577:   PetscCall(MatProductCreate(P, P, NULL, &ctx->PtP));
578:   PetscCall(MatProductSetType(ctx->PtP, MATPRODUCT_AtB));
579:   PetscCall(MatProductSetFill(ctx->PtP, product->fill));
580:   PetscCall(MatProductSetFromOptions(ctx->PtP));
581:   PetscCall(MatProductSymbolic(ctx->PtP));

583:   /* Record P's nonzero state so numeric phase can detect structural changes */
584:   PetscCall(MatGetNonzeroState(P, &ctx->pnnzstate));

586:   /* Set up C with the same structure as PtP */
587:   PetscCall(MatDuplicate(ctx->PtP, MAT_DO_NOT_COPY_VALUES, &Cwork));
588:   C->product = NULL;
589:   PetscCall(MatHeaderReplace(C, &Cwork));
590:   C->product = product;
591:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
592:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
593:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
594:   product->data          = ctx;
595:   product->destroy       = MatProductCtxDestroy_PtAP_ConstDiag_Anytype;
596:   C->ops->productnumeric = MatProductNumeric_PtAP_ConstDiag_Anytype;
597:   PetscFunctionReturn(PETSC_SUCCESS);
598: }

600: /* AB for MATCONSTANTDIAGONAL A and any non-diagonal B: C = alpha * B */
601: static PetscErrorCode MatProductNumeric_AB_ConstDiag_Anytype(Mat C)
602: {
603:   Mat                   A = C->product->A, B = C->product->B;
604:   Mat_ConstantDiagonal *a = (Mat_ConstantDiagonal *)A->data;

606:   PetscFunctionBegin;
607:   MatCheckProduct(C, 1);
608:   PetscCall(MatCopy(B, C, SAME_NONZERO_PATTERN));
609:   PetscCall(MatScale(C, a->diag));
610:   PetscFunctionReturn(PETSC_SUCCESS);
611: }

613: static PetscErrorCode MatProductSymbolic_AB_ConstDiag_Anytype(Mat C)
614: {
615:   Mat          B       = C->product->B;
616:   Mat_Product *product = C->product;
617:   Mat          Cwork;

619:   PetscFunctionBegin;
620:   MatCheckProduct(C, 1);
621:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
622:   PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Cwork));
623:   C->product = NULL;
624:   PetscCall(MatHeaderReplace(C, &Cwork));
625:   C->product             = product;
626:   C->ops->productnumeric = MatProductNumeric_AB_ConstDiag_Anytype;
627:   PetscFunctionReturn(PETSC_SUCCESS);
628: }

630: /* AB for any non-diagonal A and MATCONSTANTDIAGONAL B: C = beta * A */
631: static PetscErrorCode MatProductNumeric_AB_Anytype_ConstDiag(Mat C)
632: {
633:   Mat                   A = C->product->A, B = C->product->B;
634:   Mat_ConstantDiagonal *b = (Mat_ConstantDiagonal *)B->data;

636:   PetscFunctionBegin;
637:   MatCheckProduct(C, 1);
638:   PetscCall(MatCopy(A, C, SAME_NONZERO_PATTERN));
639:   PetscCall(MatScale(C, b->diag));
640:   PetscFunctionReturn(PETSC_SUCCESS);
641: }

643: static PetscErrorCode MatProductSymbolic_AB_Anytype_ConstDiag(Mat C)
644: {
645:   Mat          A       = C->product->A;
646:   Mat_Product *product = C->product;
647:   Mat          Cwork;

649:   PetscFunctionBegin;
650:   MatCheckProduct(C, 1);
651:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
652:   PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &Cwork));
653:   C->product = NULL;
654:   PetscCall(MatHeaderReplace(C, &Cwork));
655:   C->product             = product;
656:   C->ops->productnumeric = MatProductNumeric_AB_Anytype_ConstDiag;
657:   PetscFunctionReturn(PETSC_SUCCESS);
658: }

660: /* AB for MATCONSTANTDIAGONAL * MATCONSTANTDIAGONAL: C = alpha * beta * I */
661: static PetscErrorCode MatProductNumeric_AB_ConstDiag_ConstDiag(Mat C)
662: {
663:   Mat                   A = C->product->A, B = C->product->B;
664:   Mat_ConstantDiagonal *a = (Mat_ConstantDiagonal *)A->data, *b = (Mat_ConstantDiagonal *)B->data, *c = (Mat_ConstantDiagonal *)C->data;

666:   PetscFunctionBegin;
667:   MatCheckProduct(C, 1);
668:   c->diag = a->diag * b->diag;
669:   PetscFunctionReturn(PETSC_SUCCESS);
670: }

672: static PetscErrorCode MatProductSymbolic_AB_ConstDiag_ConstDiag(Mat C)
673: {
674:   Mat A = C->product->A, B = C->product->B;

676:   PetscFunctionBegin;
677:   MatCheckProduct(C, 1);
678:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
679:   PetscCall(MatSetSizes(C, A->rmap->n, B->cmap->n, A->rmap->N, B->cmap->N));
680:   PetscCall(MatSetType(C, MATCONSTANTDIAGONAL));
681:   C->assembled           = PETSC_TRUE;
682:   C->ops->productnumeric = MatProductNumeric_AB_ConstDiag_ConstDiag;
683:   PetscFunctionReturn(PETSC_SUCCESS);
684: }

686: /* AB for MATCONSTANTDIAGONAL A and MATDIAGONAL B: C_i = alpha * b_i */
687: static PetscErrorCode MatProductNumeric_AB_ConstDiag_Diagonal(Mat C)
688: {
689:   Mat                   A = C->product->A, B = C->product->B;
690:   Mat_ConstantDiagonal *a = (Mat_ConstantDiagonal *)A->data;
691:   Vec                   bdiag, cdiag;

693:   PetscFunctionBegin;
694:   MatCheckProduct(C, 1);
695:   PetscCall(MatDiagonalGetDiagonal(B, &bdiag));
696:   PetscCall(MatDiagonalGetDiagonal(C, &cdiag));
697:   PetscCall(VecCopy(bdiag, cdiag));
698:   PetscCall(VecScale(cdiag, a->diag));
699:   PetscCall(MatDiagonalRestoreDiagonal(C, &cdiag));
700:   PetscCall(MatDiagonalRestoreDiagonal(B, &bdiag));
701:   PetscFunctionReturn(PETSC_SUCCESS);
702: }

704: static PetscErrorCode MatProductSymbolic_AB_ConstDiag_Diagonal(Mat C)
705: {
706:   Mat A = C->product->A, B = C->product->B;
707:   Vec bdiag, cdiag;

709:   PetscFunctionBegin;
710:   MatCheckProduct(C, 1);
711:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
712:   PetscCall(MatSetSizes(C, A->rmap->n, B->cmap->n, A->rmap->N, B->cmap->N));
713:   PetscCall(MatSetType(C, MATDIAGONAL));
714:   /* Duplicate B's diagonal Vec so C inherits the correct VecType (e.g., Kokkos, CUDA, HIP) */
715:   PetscCall(MatDiagonalGetDiagonal(B, &bdiag));
716:   PetscCall(VecDuplicate(bdiag, &cdiag));
717:   PetscCall(MatDiagonalSetDiagonal(C, cdiag));
718:   PetscCall(VecDestroy(&cdiag));
719:   PetscCall(MatDiagonalRestoreDiagonal(B, &bdiag));
720:   C->assembled           = PETSC_TRUE;
721:   C->ops->productnumeric = MatProductNumeric_AB_ConstDiag_Diagonal;
722:   PetscFunctionReturn(PETSC_SUCCESS);
723: }

725: /* AB for MATDIAGONAL A and MATCONSTANTDIAGONAL B: C_i = beta * a_i */
726: static PetscErrorCode MatProductNumeric_AB_Diagonal_ConstDiag(Mat C)
727: {
728:   Mat                   A = C->product->A, B = C->product->B;
729:   Mat_ConstantDiagonal *b = (Mat_ConstantDiagonal *)B->data;
730:   Vec                   adiag, cdiag;

732:   PetscFunctionBegin;
733:   MatCheckProduct(C, 1);
734:   PetscCall(MatDiagonalGetDiagonal(A, &adiag));
735:   PetscCall(MatDiagonalGetDiagonal(C, &cdiag));
736:   PetscCall(VecCopy(adiag, cdiag));
737:   PetscCall(VecScale(cdiag, b->diag));
738:   PetscCall(MatDiagonalRestoreDiagonal(C, &cdiag));
739:   PetscCall(MatDiagonalRestoreDiagonal(A, &adiag));
740:   PetscFunctionReturn(PETSC_SUCCESS);
741: }

743: static PetscErrorCode MatProductSymbolic_AB_Diagonal_ConstDiag(Mat C)
744: {
745:   Mat A = C->product->A, B = C->product->B;
746:   Vec adiag, cdiag;

748:   PetscFunctionBegin;
749:   MatCheckProduct(C, 1);
750:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
751:   PetscCall(MatSetSizes(C, A->rmap->n, B->cmap->n, A->rmap->N, B->cmap->N));
752:   PetscCall(MatSetType(C, MATDIAGONAL));
753:   /* Duplicate A's diagonal Vec so C inherits the correct VecType (e.g., Kokkos, CUDA, HIP) */
754:   PetscCall(MatDiagonalGetDiagonal(A, &adiag));
755:   PetscCall(VecDuplicate(adiag, &cdiag));
756:   PetscCall(MatDiagonalSetDiagonal(C, cdiag));
757:   PetscCall(VecDestroy(&cdiag));
758:   PetscCall(MatDiagonalRestoreDiagonal(A, &adiag));
759:   C->assembled           = PETSC_TRUE;
760:   C->ops->productnumeric = MatProductNumeric_AB_Diagonal_ConstDiag;
761:   PetscFunctionReturn(PETSC_SUCCESS);
762: }

764: static PetscErrorCode MatProductSetFromOptions_ConstDiag_ConstDiag(Mat C)
765: {
766:   Mat_Product *product = C->product;

768:   PetscFunctionBegin;
769:   if (product->type == MATPRODUCT_PtAP) C->ops->productsymbolic = MatProductSymbolic_PtAP_ConstDiag_ConstDiag;
770:   else if (product->type == MATPRODUCT_AB) C->ops->productsymbolic = MatProductSymbolic_AB_ConstDiag_ConstDiag;
771:   PetscFunctionReturn(PETSC_SUCCESS);
772: }

774: static PetscErrorCode MatProductSetFromOptions_ConstDiag_Diagonal(Mat C)
775: {
776:   Mat_Product *product = C->product;

778:   PetscFunctionBegin;
779:   if (product->type == MATPRODUCT_PtAP) C->ops->productsymbolic = MatProductSymbolic_PtAP_ConstDiag_Diagonal;
780:   else if (product->type == MATPRODUCT_AB) C->ops->productsymbolic = MatProductSymbolic_AB_ConstDiag_Diagonal;
781:   PetscFunctionReturn(PETSC_SUCCESS);
782: }

784: static PetscErrorCode MatProductSetFromOptions_Diagonal_ConstDiag(Mat C)
785: {
786:   Mat_Product *product = C->product;

788:   PetscFunctionBegin;
789:   if (product->type == MATPRODUCT_PtAP) C->ops->productsymbolic = MatProductSymbolic_PtAP_Diagonal_ConstDiag;
790:   else if (product->type == MATPRODUCT_AB) C->ops->productsymbolic = MatProductSymbolic_AB_Diagonal_ConstDiag;
791:   PetscFunctionReturn(PETSC_SUCCESS);
792: }

794: static PetscErrorCode MatProductSetFromOptions_ConstDiag_Dense_AB(Mat C)
795: {
796:   PetscFunctionBegin;
797:   C->ops->productsymbolic = MatProductSymbolic_ConstDiag_Dense;
798:   PetscFunctionReturn(PETSC_SUCCESS);
799: }

801: static PetscErrorCode MatProductSetFromOptions_ConstDiag_Dense(Mat C)
802: {
803:   Mat_Product *product = C->product;

805:   PetscFunctionBegin;
806:   if (product->type == MATPRODUCT_AB || product->type == MATPRODUCT_AtB) PetscCall(MatProductSetFromOptions_ConstDiag_Dense_AB(C));
807:   else if (product->type == MATPRODUCT_PtAP) C->ops->productsymbolic = MatProductSymbolic_PtAP_ConstDiag_Anytype;
808:   PetscFunctionReturn(PETSC_SUCCESS);
809: }

811: static PetscErrorCode MatProductSetFromOptions_ConstDiag_Anytype(Mat C)
812: {
813:   Mat_Product *product = C->product;
814:   PetscBool    Acdiag, Bcdiag;

816:   PetscFunctionBegin;
817:   PetscCall(PetscObjectTypeCompare((PetscObject)product->A, MATCONSTANTDIAGONAL, &Acdiag));
818:   PetscCall(PetscObjectTypeCompare((PetscObject)product->B, MATCONSTANTDIAGONAL, &Bcdiag));
819:   if (Acdiag && !Bcdiag && (product->type == MATPRODUCT_PtAP)) C->ops->productsymbolic = MatProductSymbolic_PtAP_ConstDiag_Anytype;
820:   else if (Bcdiag && !Acdiag && (product->type == MATPRODUCT_PtAP)) C->ops->productsymbolic = MatProductSymbolic_PtAP_Anytype_ConstDiag;
821:   else if (Acdiag && !Bcdiag && (product->type == MATPRODUCT_AB)) C->ops->productsymbolic = MatProductSymbolic_AB_ConstDiag_Anytype;
822:   else if (Bcdiag && !Acdiag && (product->type == MATPRODUCT_AB)) C->ops->productsymbolic = MatProductSymbolic_AB_Anytype_ConstDiag;
823:   PetscFunctionReturn(PETSC_SUCCESS);
824: }

826: /*MC
827:    MATCONSTANTDIAGONAL - "constant-diagonal" - A diagonal matrix type with a uniform value
828:    along the diagonal.

830:   Level: advanced

832: .seealso: [](ch_matrices), `Mat`, `MatCreateConstantDiagonal()`
833: M*/
834: PETSC_EXTERN PetscErrorCode MatCreate_ConstantDiagonal(Mat A)
835: {
836:   Mat_ConstantDiagonal *ctx;

838:   PetscFunctionBegin;
839:   PetscCall(PetscNew(&ctx));
840:   ctx->diag = 0.0;
841:   A->data   = (void *)ctx;

843:   A->assembled                   = PETSC_TRUE;
844:   A->preallocated                = PETSC_TRUE;
845:   A->structurally_symmetric      = PETSC_BOOL3_TRUE;
846:   A->structural_symmetry_eternal = PETSC_TRUE;
847:   A->symmetric                   = PETSC_BOOL3_TRUE;
848:   if (!PetscDefined(USE_COMPLEX)) A->hermitian = PETSC_BOOL3_TRUE;
849:   A->symmetry_eternal = PETSC_TRUE;

851:   A->ops->mult                      = MatMult_ConstantDiagonal;
852:   A->ops->multadd                   = MatMultAdd_ConstantDiagonal;
853:   A->ops->multtranspose             = MatMult_ConstantDiagonal;
854:   A->ops->multtransposeadd          = MatMultAdd_ConstantDiagonal;
855:   A->ops->multhermitiantranspose    = MatMultHermitianTranspose_ConstantDiagonal;
856:   A->ops->multhermitiantransposeadd = MatMultHermitianTransposeAdd_ConstantDiagonal;
857:   A->ops->solve                     = MatSolve_ConstantDiagonal;
858:   A->ops->solvetranspose            = MatSolve_ConstantDiagonal;
859:   A->ops->norm                      = MatNorm_ConstantDiagonal;
860:   A->ops->createsubmatrices         = MatCreateSubMatrices_ConstantDiagonal;
861:   A->ops->duplicate                 = MatDuplicate_ConstantDiagonal;
862:   A->ops->getrow                    = MatGetRow_ConstantDiagonal;
863:   A->ops->restorerow                = MatRestoreRow_ConstantDiagonal;
864:   A->ops->sor                       = MatSOR_ConstantDiagonal;
865:   A->ops->shift                     = MatShift_ConstantDiagonal;
866:   A->ops->scale                     = MatScale_ConstantDiagonal;
867:   A->ops->getdiagonal               = MatGetDiagonal_ConstantDiagonal;
868:   A->ops->view                      = MatView_ConstantDiagonal;
869:   A->ops->zeroentries               = MatZeroEntries_ConstantDiagonal;
870:   A->ops->destroy                   = MatDestroy_ConstantDiagonal;
871:   A->ops->getinfo                   = MatGetInfo_ConstantDiagonal;
872:   A->ops->equal                     = MatEqual_ConstantDiagonal;
873:   A->ops->axpy                      = MatAXPY_ConstantDiagonal;
874:   A->ops->setrandom                 = MatSetRandom_ConstantDiagonal;
875:   A->ops->conjugate                 = MatConjugate_ConstantDiagonal;
876:   A->ops->transpose                 = MatTranspose_ConstantDiagonal;

878:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATCONSTANTDIAGONAL));
879:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConstantDiagonalGetConstant_C", MatConstantDiagonalGetConstant_ConstantDiagonal));
880:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_constantdiagonal_constantdiagonal_C", MatProductSetFromOptions_ConstDiag_ConstDiag));
881:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_constantdiagonal_diagonal_C", MatProductSetFromOptions_ConstDiag_Diagonal));
882:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_diagonal_constantdiagonal_C", MatProductSetFromOptions_Diagonal_ConstDiag));
883:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_constantdiagonal_seqdense_C", MatProductSetFromOptions_ConstDiag_Dense));
884:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_constantdiagonal_mpidense_C", MatProductSetFromOptions_ConstDiag_Dense));
885:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_anytype_C", MatProductSetFromOptions_ConstDiag_Anytype));
886:   PetscFunctionReturn(PETSC_SUCCESS);
887: }

889: static PetscErrorCode MatFactorNumeric_ConstantDiagonal(Mat fact, Mat A, const MatFactorInfo *info)
890: {
891:   Mat_ConstantDiagonal *actx = (Mat_ConstantDiagonal *)A->data, *fctx = (Mat_ConstantDiagonal *)fact->data;

893:   PetscFunctionBegin;
894:   if (actx->diag == 0.0) fact->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
895:   else fact->factorerrortype = MAT_FACTOR_NOERROR;
896:   fctx->diag       = 1.0 / actx->diag;
897:   fact->ops->solve = MatMult_ConstantDiagonal;
898:   PetscFunctionReturn(PETSC_SUCCESS);
899: }

901: static PetscErrorCode MatFactorSymbolic_LU_ConstantDiagonal(Mat fact, Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
902: {
903:   PetscFunctionBegin;
904:   fact->ops->lufactornumeric = MatFactorNumeric_ConstantDiagonal;
905:   PetscFunctionReturn(PETSC_SUCCESS);
906: }

908: static PetscErrorCode MatFactorSymbolic_Cholesky_ConstantDiagonal(Mat fact, Mat A, IS isrow, const MatFactorInfo *info)
909: {
910:   PetscFunctionBegin;
911:   fact->ops->choleskyfactornumeric = MatFactorNumeric_ConstantDiagonal;
912:   PetscFunctionReturn(PETSC_SUCCESS);
913: }

915: PETSC_INTERN PetscErrorCode MatGetFactor_constantdiagonal_petsc(Mat A, MatFactorType ftype, Mat *B)
916: {
917:   PetscInt n = A->rmap->n, N = A->rmap->N;

919:   PetscFunctionBegin;
920:   PetscCall(MatCreateConstantDiagonal(PetscObjectComm((PetscObject)A), n, n, N, N, 0, B));

922:   (*B)->factortype                  = ftype;
923:   (*B)->ops->ilufactorsymbolic      = MatFactorSymbolic_LU_ConstantDiagonal;
924:   (*B)->ops->lufactorsymbolic       = MatFactorSymbolic_LU_ConstantDiagonal;
925:   (*B)->ops->iccfactorsymbolic      = MatFactorSymbolic_Cholesky_ConstantDiagonal;
926:   (*B)->ops->choleskyfactorsymbolic = MatFactorSymbolic_Cholesky_ConstantDiagonal;

928:   (*B)->ops->shift       = NULL;
929:   (*B)->ops->scale       = NULL;
930:   (*B)->ops->mult        = NULL;
931:   (*B)->ops->sor         = NULL;
932:   (*B)->ops->zeroentries = NULL;

934:   PetscCall(PetscFree((*B)->solvertype));
935:   PetscCall(PetscStrallocpy(MATSOLVERPETSC, &(*B)->solvertype));
936:   PetscFunctionReturn(PETSC_SUCCESS);
937: }