Actual source code: matnest.c

  1: #include <../src/mat/impls/nest/matnestimpl.h>
  2: #include <../src/mat/impls/aij/seq/aij.h>
  3: #include <../src/mat/impls/shell/shell.h>
  4: #include <petscsf.h>

  6: static PetscErrorCode MatSetUp_NestIS_Private(Mat, PetscInt, const IS[], PetscInt, const IS[]);
  7: static PetscErrorCode MatCreateVecs_Nest(Mat, Vec *, Vec *);
  8: static PetscErrorCode MatReset_Nest(Mat);

 10: PETSC_INTERN PetscErrorCode MatConvert_Nest_IS(Mat, MatType, MatReuse, Mat *);

 12: /* private functions */
 13: static PetscErrorCode MatNestGetSizes_Private(Mat A, PetscInt *m, PetscInt *n, PetscInt *M, PetscInt *N)
 14: {
 15:   Mat_Nest *bA = (Mat_Nest *)A->data;
 16:   PetscInt  i, j;

 18:   PetscFunctionBegin;
 19:   *m = *n = *M = *N = 0;
 20:   for (i = 0; i < bA->nr; i++) { /* rows */
 21:     PetscInt sm, sM;
 22:     PetscCall(ISGetLocalSize(bA->isglobal.row[i], &sm));
 23:     PetscCall(ISGetSize(bA->isglobal.row[i], &sM));
 24:     *m += sm;
 25:     *M += sM;
 26:   }
 27:   for (j = 0; j < bA->nc; j++) { /* cols */
 28:     PetscInt sn, sN;
 29:     PetscCall(ISGetLocalSize(bA->isglobal.col[j], &sn));
 30:     PetscCall(ISGetSize(bA->isglobal.col[j], &sN));
 31:     *n += sn;
 32:     *N += sN;
 33:   }
 34:   PetscFunctionReturn(PETSC_SUCCESS);
 35: }

 37: /* operations */
 38: static PetscErrorCode MatMult_Nest(Mat A, Vec x, Vec y)
 39: {
 40:   Mat_Nest *bA = (Mat_Nest *)A->data;
 41:   Vec      *bx = bA->right, *by = bA->left;
 42:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;

 44:   PetscFunctionBegin;
 45:   for (i = 0; i < nr; i++) PetscCall(VecGetSubVector(y, bA->isglobal.row[i], &by[i]));
 46:   for (i = 0; i < nc; i++) PetscCall(VecGetSubVector(x, bA->isglobal.col[i], &bx[i]));
 47:   for (i = 0; i < nr; i++) {
 48:     PetscCall(VecZeroEntries(by[i]));
 49:     for (j = 0; j < nc; j++) {
 50:       if (!bA->m[i][j]) continue;
 51:       /* y[i] <- y[i] + A[i][j] * x[j] */
 52:       PetscCall(MatMultAdd(bA->m[i][j], bx[j], by[i], by[i]));
 53:     }
 54:   }
 55:   for (i = 0; i < nr; i++) PetscCall(VecRestoreSubVector(y, bA->isglobal.row[i], &by[i]));
 56:   for (i = 0; i < nc; i++) PetscCall(VecRestoreSubVector(x, bA->isglobal.col[i], &bx[i]));
 57:   PetscFunctionReturn(PETSC_SUCCESS);
 58: }

 60: static PetscErrorCode MatMultAdd_Nest(Mat A, Vec x, Vec y, Vec z)
 61: {
 62:   Mat_Nest *bA = (Mat_Nest *)A->data;
 63:   Vec      *bx = bA->right, *bz = bA->left;
 64:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;

 66:   PetscFunctionBegin;
 67:   for (i = 0; i < nr; i++) PetscCall(VecGetSubVector(z, bA->isglobal.row[i], &bz[i]));
 68:   for (i = 0; i < nc; i++) PetscCall(VecGetSubVector(x, bA->isglobal.col[i], &bx[i]));
 69:   for (i = 0; i < nr; i++) {
 70:     if (y != z) {
 71:       Vec by;
 72:       PetscCall(VecGetSubVector(y, bA->isglobal.row[i], &by));
 73:       PetscCall(VecCopy(by, bz[i]));
 74:       PetscCall(VecRestoreSubVector(y, bA->isglobal.row[i], &by));
 75:     }
 76:     for (j = 0; j < nc; j++) {
 77:       if (!bA->m[i][j]) continue;
 78:       /* y[i] <- y[i] + A[i][j] * x[j] */
 79:       PetscCall(MatMultAdd(bA->m[i][j], bx[j], bz[i], bz[i]));
 80:     }
 81:   }
 82:   for (i = 0; i < nr; i++) PetscCall(VecRestoreSubVector(z, bA->isglobal.row[i], &bz[i]));
 83:   for (i = 0; i < nc; i++) PetscCall(VecRestoreSubVector(x, bA->isglobal.col[i], &bx[i]));
 84:   PetscFunctionReturn(PETSC_SUCCESS);
 85: }

 87: typedef struct {
 88:   Mat         *workC;      /* array of Mat with specific containers depending on the underlying MatMatMult implementation */
 89:   PetscScalar *tarray;     /* buffer for storing all temporary products A[i][j] B[j] */
 90:   PetscInt    *dm, *dn, k; /* displacements and number of submatrices */
 91: } Nest_Dense;

 93: static PetscErrorCode MatProductNumeric_Nest_Dense(Mat C)
 94: {
 95:   Mat_Nest          *bA;
 96:   Nest_Dense        *contents;
 97:   Mat                viewB, viewC, productB, workC;
 98:   const PetscScalar *barray;
 99:   PetscScalar       *carray;
100:   PetscInt           i, j, M, N, nr, nc, ldb, ldc;
101:   Mat                A, B;

103:   PetscFunctionBegin;
104:   MatCheckProduct(C, 1);
105:   A = C->product->A;
106:   B = C->product->B;
107:   PetscCall(MatGetSize(B, NULL, &N));
108:   if (!N) {
109:     PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
110:     PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
111:     PetscFunctionReturn(PETSC_SUCCESS);
112:   }
113:   contents = (Nest_Dense *)C->product->data;
114:   PetscCheck(contents, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data empty");
115:   bA = (Mat_Nest *)A->data;
116:   nr = bA->nr;
117:   nc = bA->nc;
118:   PetscCall(MatDenseGetLDA(B, &ldb));
119:   PetscCall(MatDenseGetLDA(C, &ldc));
120:   PetscCall(MatZeroEntries(C));
121:   PetscCall(MatDenseGetArrayRead(B, &barray));
122:   PetscCall(MatDenseGetArray(C, &carray));
123:   for (i = 0; i < nr; i++) {
124:     PetscCall(ISGetSize(bA->isglobal.row[i], &M));
125:     PetscCall(MatCreateDense(PetscObjectComm((PetscObject)A), contents->dm[i + 1] - contents->dm[i], PETSC_DECIDE, M, N, PetscSafePointerPlusOffset(carray, contents->dm[i]), &viewC));
126:     PetscCall(MatDenseSetLDA(viewC, ldc));
127:     for (j = 0; j < nc; j++) {
128:       if (!bA->m[i][j]) continue;
129:       PetscCall(ISGetSize(bA->isglobal.col[j], &M));
130:       PetscCall(MatCreateDense(PetscObjectComm((PetscObject)A), contents->dn[j + 1] - contents->dn[j], PETSC_DECIDE, M, N, PetscSafePointerPlusOffset((PetscScalar *)barray, contents->dn[j]), &viewB));
131:       PetscCall(MatDenseSetLDA(viewB, ldb));

133:       /* MatMatMultNumeric(bA->m[i][j],viewB,contents->workC[i*nc + j]); */
134:       workC             = contents->workC[i * nc + j];
135:       productB          = workC->product->B;
136:       workC->product->B = viewB; /* use newly created dense matrix viewB */
137:       PetscCall(MatProductNumeric(workC));
138:       PetscCall(MatDestroy(&viewB));
139:       workC->product->B = productB; /* resume original B */

141:       /* C[i] <- workC + C[i] */
142:       PetscCall(MatAXPY(viewC, 1.0, contents->workC[i * nc + j], SAME_NONZERO_PATTERN));
143:     }
144:     PetscCall(MatDestroy(&viewC));
145:   }
146:   PetscCall(MatDenseRestoreArray(C, &carray));
147:   PetscCall(MatDenseRestoreArrayRead(B, &barray));

149:   PetscCall(MatSetOption(C, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
150:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
151:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
152:   PetscFunctionReturn(PETSC_SUCCESS);
153: }

155: static PetscErrorCode MatNest_DenseDestroy(void *ctx)
156: {
157:   Nest_Dense *contents = (Nest_Dense *)ctx;
158:   PetscInt    i;

160:   PetscFunctionBegin;
161:   PetscCall(PetscFree(contents->tarray));
162:   for (i = 0; i < contents->k; i++) PetscCall(MatDestroy(contents->workC + i));
163:   PetscCall(PetscFree3(contents->dm, contents->dn, contents->workC));
164:   PetscCall(PetscFree(contents));
165:   PetscFunctionReturn(PETSC_SUCCESS);
166: }

168: static PetscErrorCode MatProductSymbolic_Nest_Dense(Mat C)
169: {
170:   Mat_Nest          *bA;
171:   Mat                viewB, workC;
172:   const PetscScalar *barray;
173:   PetscInt           i, j, M, N, m, n, nr, nc, maxm = 0, ldb;
174:   Nest_Dense        *contents = NULL;
175:   PetscBool          cisdense;
176:   Mat                A, B;
177:   PetscReal          fill;

179:   PetscFunctionBegin;
180:   MatCheckProduct(C, 1);
181:   PetscCheck(!C->product->data, PetscObjectComm((PetscObject)C), PETSC_ERR_PLIB, "Product data not empty");
182:   A    = C->product->A;
183:   B    = C->product->B;
184:   fill = C->product->fill;
185:   bA   = (Mat_Nest *)A->data;
186:   nr   = bA->nr;
187:   nc   = bA->nc;
188:   PetscCall(MatGetLocalSize(C, &m, &n));
189:   PetscCall(MatGetSize(C, &M, &N));
190:   if (m == PETSC_DECIDE || n == PETSC_DECIDE || M == PETSC_DECIDE || N == PETSC_DECIDE) {
191:     PetscCall(MatGetLocalSize(B, NULL, &n));
192:     PetscCall(MatGetSize(B, NULL, &N));
193:     PetscCall(MatGetLocalSize(A, &m, NULL));
194:     PetscCall(MatGetSize(A, &M, NULL));
195:     PetscCall(MatSetSizes(C, m, n, M, N));
196:   }
197:   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &cisdense, MATSEQDENSE, MATMPIDENSE, MATSEQDENSECUDA, MATMPIDENSECUDA, ""));
198:   if (!cisdense) PetscCall(MatSetType(C, ((PetscObject)B)->type_name));
199:   PetscCall(MatSetUp(C));
200:   if (!N) {
201:     C->ops->productnumeric = MatProductNumeric_Nest_Dense;
202:     PetscFunctionReturn(PETSC_SUCCESS);
203:   }

205:   PetscCall(PetscNew(&contents));
206:   C->product->data    = contents;
207:   C->product->destroy = MatNest_DenseDestroy;
208:   PetscCall(PetscCalloc3(nr + 1, &contents->dm, nc + 1, &contents->dn, nr * nc, &contents->workC));
209:   contents->k = nr * nc;
210:   for (i = 0; i < nr; i++) {
211:     PetscCall(ISGetLocalSize(bA->isglobal.row[i], contents->dm + i + 1));
212:     maxm = PetscMax(maxm, contents->dm[i + 1]);
213:     contents->dm[i + 1] += contents->dm[i];
214:   }
215:   for (i = 0; i < nc; i++) {
216:     PetscCall(ISGetLocalSize(bA->isglobal.col[i], contents->dn + i + 1));
217:     contents->dn[i + 1] += contents->dn[i];
218:   }
219:   PetscCall(PetscMalloc1(maxm * N, &contents->tarray));
220:   PetscCall(MatDenseGetLDA(B, &ldb));
221:   PetscCall(MatGetSize(B, NULL, &N));
222:   PetscCall(MatDenseGetArrayRead(B, &barray));
223:   /* loops are permuted compared to MatMatMultNumeric so that viewB is created only once per column of A */
224:   for (j = 0; j < nc; j++) {
225:     PetscCall(ISGetSize(bA->isglobal.col[j], &M));
226:     PetscCall(MatCreateDense(PetscObjectComm((PetscObject)A), contents->dn[j + 1] - contents->dn[j], PETSC_DECIDE, M, N, PetscSafePointerPlusOffset((PetscScalar *)barray, contents->dn[j]), &viewB));
227:     PetscCall(MatDenseSetLDA(viewB, ldb));
228:     for (i = 0; i < nr; i++) {
229:       if (!bA->m[i][j]) continue;
230:       /* MatMatMultSymbolic may attach a specific container (depending on MatType of bA->m[i][j]) to workC[i][j] */

232:       PetscCall(MatProductCreate(bA->m[i][j], viewB, NULL, &contents->workC[i * nc + j]));
233:       workC = contents->workC[i * nc + j];
234:       PetscCall(MatProductSetType(workC, MATPRODUCT_AB));
235:       PetscCall(MatProductSetAlgorithm(workC, "default"));
236:       PetscCall(MatProductSetFill(workC, fill));
237:       PetscCall(MatProductSetFromOptions(workC));
238:       PetscCall(MatProductSymbolic(workC));

240:       /* since tarray will be shared by all Mat */
241:       PetscCall(MatSeqDenseSetPreallocation(workC, contents->tarray));
242:       PetscCall(MatMPIDenseSetPreallocation(workC, contents->tarray));
243:     }
244:     PetscCall(MatDestroy(&viewB));
245:   }
246:   PetscCall(MatDenseRestoreArrayRead(B, &barray));

248:   C->ops->productnumeric = MatProductNumeric_Nest_Dense;
249:   PetscFunctionReturn(PETSC_SUCCESS);
250: }

252: static PetscErrorCode MatProductSetFromOptions_Nest_Dense(Mat C)
253: {
254:   Mat_Product *product = C->product;

256:   PetscFunctionBegin;
257:   if (product->type == MATPRODUCT_AB) C->ops->productsymbolic = MatProductSymbolic_Nest_Dense;
258:   PetscFunctionReturn(PETSC_SUCCESS);
259: }

261: static PetscErrorCode MatMultTransposeKernel_Nest(Mat A, Vec x, Vec y, PetscBool herm)
262: {
263:   Mat_Nest *bA = (Mat_Nest *)A->data;
264:   Vec      *bx = bA->left, *by = bA->right;
265:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;

267:   PetscFunctionBegin;
268:   for (i = 0; i < nr; i++) PetscCall(VecGetSubVector(x, bA->isglobal.row[i], &bx[i]));
269:   for (i = 0; i < nc; i++) PetscCall(VecGetSubVector(y, bA->isglobal.col[i], &by[i]));
270:   for (j = 0; j < nc; j++) {
271:     PetscCall(VecZeroEntries(by[j]));
272:     for (i = 0; i < nr; i++) {
273:       if (!bA->m[i][j]) continue;
274:       if (herm) PetscCall(MatMultHermitianTransposeAdd(bA->m[i][j], bx[i], by[j], by[j])); /* y[j] <- y[j] + (A[i][j])^H * x[i] */
275:       else PetscCall(MatMultTransposeAdd(bA->m[i][j], bx[i], by[j], by[j]));               /* y[j] <- y[j] + (A[i][j])^T * x[i] */
276:     }
277:   }
278:   for (i = 0; i < nr; i++) PetscCall(VecRestoreSubVector(x, bA->isglobal.row[i], &bx[i]));
279:   for (i = 0; i < nc; i++) PetscCall(VecRestoreSubVector(y, bA->isglobal.col[i], &by[i]));
280:   PetscFunctionReturn(PETSC_SUCCESS);
281: }

283: static PetscErrorCode MatMultTranspose_Nest(Mat A, Vec x, Vec y)
284: {
285:   PetscFunctionBegin;
286:   PetscCall(MatMultTransposeKernel_Nest(A, x, y, PETSC_FALSE));
287:   PetscFunctionReturn(PETSC_SUCCESS);
288: }

290: static PetscErrorCode MatMultHermitianTranspose_Nest(Mat A, Vec x, Vec y)
291: {
292:   PetscFunctionBegin;
293:   PetscCall(MatMultTransposeKernel_Nest(A, x, y, PETSC_TRUE));
294:   PetscFunctionReturn(PETSC_SUCCESS);
295: }

297: static PetscErrorCode MatMultTransposeAddKernel_Nest(Mat A, Vec x, Vec y, Vec z, PetscBool herm)
298: {
299:   Mat_Nest *bA = (Mat_Nest *)A->data;
300:   Vec      *bx = bA->left, *bz = bA->right;
301:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;

303:   PetscFunctionBegin;
304:   for (i = 0; i < nr; i++) PetscCall(VecGetSubVector(x, bA->isglobal.row[i], &bx[i]));
305:   for (i = 0; i < nc; i++) PetscCall(VecGetSubVector(z, bA->isglobal.col[i], &bz[i]));
306:   for (j = 0; j < nc; j++) {
307:     if (y != z) {
308:       Vec by;
309:       PetscCall(VecGetSubVector(y, bA->isglobal.col[j], &by));
310:       PetscCall(VecCopy(by, bz[j]));
311:       PetscCall(VecRestoreSubVector(y, bA->isglobal.col[j], &by));
312:     }
313:     for (i = 0; i < nr; i++) {
314:       if (!bA->m[i][j]) continue;
315:       if (herm) PetscCall(MatMultHermitianTransposeAdd(bA->m[i][j], bx[i], bz[j], bz[j])); /* z[j] <- y[j] + (A[i][j])^H * x[i] */
316:       else PetscCall(MatMultTransposeAdd(bA->m[i][j], bx[i], bz[j], bz[j]));               /* z[j] <- y[j] + (A[i][j])^T * x[i] */
317:     }
318:   }
319:   for (i = 0; i < nr; i++) PetscCall(VecRestoreSubVector(x, bA->isglobal.row[i], &bx[i]));
320:   for (i = 0; i < nc; i++) PetscCall(VecRestoreSubVector(z, bA->isglobal.col[i], &bz[i]));
321:   PetscFunctionReturn(PETSC_SUCCESS);
322: }

324: static PetscErrorCode MatMultTransposeAdd_Nest(Mat A, Vec x, Vec y, Vec z)
325: {
326:   PetscFunctionBegin;
327:   PetscCall(MatMultTransposeAddKernel_Nest(A, x, y, z, PETSC_FALSE));
328:   PetscFunctionReturn(PETSC_SUCCESS);
329: }

331: static PetscErrorCode MatMultHermitianTransposeAdd_Nest(Mat A, Vec x, Vec y, Vec z)
332: {
333:   PetscFunctionBegin;
334:   PetscCall(MatMultTransposeAddKernel_Nest(A, x, y, z, PETSC_TRUE));
335:   PetscFunctionReturn(PETSC_SUCCESS);
336: }

338: static PetscErrorCode MatTranspose_Nest(Mat A, MatReuse reuse, Mat *B)
339: {
340:   Mat_Nest *bA = (Mat_Nest *)A->data, *bC;
341:   Mat       C;
342:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;

344:   PetscFunctionBegin;
345:   if (reuse == MAT_REUSE_MATRIX) PetscCall(MatTransposeCheckNonzeroState_Private(A, *B));
346:   PetscCheck(reuse != MAT_INPLACE_MATRIX || nr == nc, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_SIZ, "Square nested matrix only for in-place");

348:   if (reuse == MAT_INITIAL_MATRIX || reuse == MAT_INPLACE_MATRIX) {
349:     Mat *subs;
350:     IS  *is_row, *is_col;

352:     PetscCall(PetscCalloc1(nr * nc, &subs));
353:     PetscCall(PetscMalloc2(nr, &is_row, nc, &is_col));
354:     PetscCall(MatNestGetISs(A, is_row, is_col));
355:     if (reuse == MAT_INPLACE_MATRIX) {
356:       for (i = 0; i < nr; i++) {
357:         for (j = 0; j < nc; j++) subs[i + nr * j] = bA->m[i][j];
358:       }
359:     }

361:     PetscCall(MatCreateNest(PetscObjectComm((PetscObject)A), nc, is_col, nr, is_row, subs, &C));
362:     PetscCall(PetscFree(subs));
363:     PetscCall(PetscFree2(is_row, is_col));
364:   } else {
365:     C = *B;
366:   }

368:   bC = (Mat_Nest *)C->data;
369:   for (i = 0; i < nr; i++) {
370:     for (j = 0; j < nc; j++) {
371:       if (bA->m[i][j]) {
372:         PetscCall(MatTranspose(bA->m[i][j], reuse, &bC->m[j][i]));
373:       } else {
374:         bC->m[j][i] = NULL;
375:       }
376:     }
377:   }

379:   if (reuse == MAT_INITIAL_MATRIX || reuse == MAT_REUSE_MATRIX) {
380:     *B = C;
381:   } else {
382:     PetscCall(MatHeaderMerge(A, &C));
383:   }
384:   PetscFunctionReturn(PETSC_SUCCESS);
385: }

387: static PetscErrorCode MatNestDestroyISList(PetscInt n, IS **list)
388: {
389:   IS      *lst = *list;
390:   PetscInt i;

392:   PetscFunctionBegin;
393:   if (!lst) PetscFunctionReturn(PETSC_SUCCESS);
394:   for (i = 0; i < n; i++)
395:     if (lst[i]) PetscCall(ISDestroy(&lst[i]));
396:   PetscCall(PetscFree(lst));
397:   *list = NULL;
398:   PetscFunctionReturn(PETSC_SUCCESS);
399: }

401: static PetscErrorCode MatReset_Nest(Mat A)
402: {
403:   Mat_Nest *vs = (Mat_Nest *)A->data;
404:   PetscInt  i, j;

406:   PetscFunctionBegin;
407:   /* release the matrices and the place holders */
408:   PetscCall(MatNestDestroyISList(vs->nr, &vs->isglobal.row));
409:   PetscCall(MatNestDestroyISList(vs->nc, &vs->isglobal.col));
410:   PetscCall(MatNestDestroyISList(vs->nr, &vs->islocal.row));
411:   PetscCall(MatNestDestroyISList(vs->nc, &vs->islocal.col));

413:   PetscCall(PetscFree(vs->row_len));
414:   PetscCall(PetscFree(vs->col_len));
415:   PetscCall(PetscFree(vs->nnzstate));

417:   PetscCall(PetscFree2(vs->left, vs->right));

419:   /* release the matrices and the place holders */
420:   if (vs->m) {
421:     for (i = 0; i < vs->nr; i++) {
422:       for (j = 0; j < vs->nc; j++) PetscCall(MatDestroy(&vs->m[i][j]));
423:     }
424:     PetscCall(PetscFree(vs->m[0]));
425:     PetscCall(PetscFree(vs->m));
426:   }

428:   /* restore defaults */
429:   vs->nr            = 0;
430:   vs->nc            = 0;
431:   vs->splitassembly = PETSC_FALSE;
432:   PetscFunctionReturn(PETSC_SUCCESS);
433: }

435: static PetscErrorCode MatDestroy_Nest(Mat A)
436: {
437:   PetscFunctionBegin;
438:   PetscCall(MatReset_Nest(A));
439:   PetscCall(PetscFree(A->data));
440:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetSubMat_C", NULL));
441:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestSetSubMat_C", NULL));
442:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetSubMats_C", NULL));
443:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetSize_C", NULL));
444:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetISs_C", NULL));
445:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetLocalISs_C", NULL));
446:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestSetVecType_C", NULL));
447:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestSetSubMats_C", NULL));
448:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_mpiaij_C", NULL));
449:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_seqaij_C", NULL));
450:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_aij_C", NULL));
451:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_is_C", NULL));
452:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_mpidense_C", NULL));
453:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_seqdense_C", NULL));
454:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_nest_seqdense_C", NULL));
455:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_nest_mpidense_C", NULL));
456:   PetscFunctionReturn(PETSC_SUCCESS);
457: }

459: static PetscErrorCode MatMissingDiagonal_Nest(Mat mat, PetscBool *missing, PetscInt *dd)
460: {
461:   Mat_Nest *vs = (Mat_Nest *)mat->data;
462:   PetscInt  i;

464:   PetscFunctionBegin;
465:   if (dd) *dd = 0;
466:   if (!vs->nr) {
467:     *missing = PETSC_TRUE;
468:     PetscFunctionReturn(PETSC_SUCCESS);
469:   }
470:   *missing = PETSC_FALSE;
471:   for (i = 0; i < vs->nr && !*missing; i++) {
472:     *missing = PETSC_TRUE;
473:     if (vs->m[i][i]) {
474:       PetscCall(MatMissingDiagonal(vs->m[i][i], missing, NULL));
475:       PetscCheck(!*missing || !dd, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "First missing entry not yet implemented");
476:     }
477:   }
478:   PetscFunctionReturn(PETSC_SUCCESS);
479: }

481: static PetscErrorCode MatAssemblyBegin_Nest(Mat A, MatAssemblyType type)
482: {
483:   Mat_Nest *vs = (Mat_Nest *)A->data;
484:   PetscInt  i, j;
485:   PetscBool nnzstate = PETSC_FALSE;

487:   PetscFunctionBegin;
488:   for (i = 0; i < vs->nr; i++) {
489:     for (j = 0; j < vs->nc; j++) {
490:       PetscObjectState subnnzstate = 0;
491:       if (vs->m[i][j]) {
492:         PetscCall(MatAssemblyBegin(vs->m[i][j], type));
493:         if (!vs->splitassembly) {
494:           /* Note: split assembly will fail if the same block appears more than once (even indirectly through a nested
495:            * sub-block). This could be fixed by adding a flag to Mat so that there was a way to check if a Mat was
496:            * already performing an assembly, but the result would by more complicated and appears to offer less
497:            * potential for diagnostics and correctness checking. Split assembly should be fixed once there is an
498:            * interface for libraries to make asynchronous progress in "user-defined non-blocking collectives".
499:            */
500:           PetscCall(MatAssemblyEnd(vs->m[i][j], type));
501:           PetscCall(MatGetNonzeroState(vs->m[i][j], &subnnzstate));
502:         }
503:       }
504:       nnzstate                     = (PetscBool)(nnzstate || vs->nnzstate[i * vs->nc + j] != subnnzstate);
505:       vs->nnzstate[i * vs->nc + j] = subnnzstate;
506:     }
507:   }
508:   if (nnzstate) A->nonzerostate++;
509:   PetscFunctionReturn(PETSC_SUCCESS);
510: }

512: static PetscErrorCode MatAssemblyEnd_Nest(Mat A, MatAssemblyType type)
513: {
514:   Mat_Nest *vs = (Mat_Nest *)A->data;
515:   PetscInt  i, j;

517:   PetscFunctionBegin;
518:   for (i = 0; i < vs->nr; i++) {
519:     for (j = 0; j < vs->nc; j++) {
520:       if (vs->m[i][j]) {
521:         if (vs->splitassembly) PetscCall(MatAssemblyEnd(vs->m[i][j], type));
522:       }
523:     }
524:   }
525:   PetscFunctionReturn(PETSC_SUCCESS);
526: }

528: static PetscErrorCode MatNestFindNonzeroSubMatRow(Mat A, PetscInt row, Mat *B)
529: {
530:   Mat_Nest *vs = (Mat_Nest *)A->data;
531:   PetscInt  j;
532:   Mat       sub;

534:   PetscFunctionBegin;
535:   sub = (row < vs->nc) ? vs->m[row][row] : (Mat)NULL; /* Prefer to find on the diagonal */
536:   for (j = 0; !sub && j < vs->nc; j++) sub = vs->m[row][j];
537:   if (sub) PetscCall(MatSetUp(sub)); /* Ensure that the sizes are available */
538:   *B = sub;
539:   PetscFunctionReturn(PETSC_SUCCESS);
540: }

542: static PetscErrorCode MatNestFindNonzeroSubMatCol(Mat A, PetscInt col, Mat *B)
543: {
544:   Mat_Nest *vs = (Mat_Nest *)A->data;
545:   PetscInt  i;
546:   Mat       sub;

548:   PetscFunctionBegin;
549:   sub = (col < vs->nr) ? vs->m[col][col] : (Mat)NULL; /* Prefer to find on the diagonal */
550:   for (i = 0; !sub && i < vs->nr; i++) sub = vs->m[i][col];
551:   if (sub) PetscCall(MatSetUp(sub)); /* Ensure that the sizes are available */
552:   *B = sub;
553:   PetscFunctionReturn(PETSC_SUCCESS);
554: }

556: static PetscErrorCode MatNestFindISRange(Mat A, PetscInt n, const IS list[], IS is, PetscInt *begin, PetscInt *end)
557: {
558:   PetscInt  i, j, size, m;
559:   PetscBool flg;
560:   IS        out, concatenate[2];

562:   PetscFunctionBegin;
563:   PetscAssertPointer(list, 3);
565:   if (begin) {
566:     PetscAssertPointer(begin, 5);
567:     *begin = -1;
568:   }
569:   if (end) {
570:     PetscAssertPointer(end, 6);
571:     *end = -1;
572:   }
573:   for (i = 0; i < n; i++) {
574:     if (!list[i]) continue;
575:     PetscCall(ISEqualUnsorted(list[i], is, &flg));
576:     if (flg) {
577:       if (begin) *begin = i;
578:       if (end) *end = i + 1;
579:       PetscFunctionReturn(PETSC_SUCCESS);
580:     }
581:   }
582:   PetscCall(ISGetSize(is, &size));
583:   for (i = 0; i < n - 1; i++) {
584:     if (!list[i]) continue;
585:     m = 0;
586:     PetscCall(ISConcatenate(PetscObjectComm((PetscObject)A), 2, list + i, &out));
587:     PetscCall(ISGetSize(out, &m));
588:     for (j = i + 2; j < n && m < size; j++) {
589:       if (list[j]) {
590:         concatenate[0] = out;
591:         concatenate[1] = list[j];
592:         PetscCall(ISConcatenate(PetscObjectComm((PetscObject)A), 2, concatenate, &out));
593:         PetscCall(ISDestroy(concatenate));
594:         PetscCall(ISGetSize(out, &m));
595:       }
596:     }
597:     if (m == size) {
598:       PetscCall(ISEqualUnsorted(out, is, &flg));
599:       if (flg) {
600:         if (begin) *begin = i;
601:         if (end) *end = j;
602:         PetscCall(ISDestroy(&out));
603:         PetscFunctionReturn(PETSC_SUCCESS);
604:       }
605:     }
606:     PetscCall(ISDestroy(&out));
607:   }
608:   PetscFunctionReturn(PETSC_SUCCESS);
609: }

611: static PetscErrorCode MatNestFillEmptyMat_Private(Mat A, PetscInt i, PetscInt j, Mat *B)
612: {
613:   Mat_Nest *vs = (Mat_Nest *)A->data;
614:   PetscInt  lr, lc;

616:   PetscFunctionBegin;
617:   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
618:   PetscCall(ISGetLocalSize(vs->isglobal.row[i], &lr));
619:   PetscCall(ISGetLocalSize(vs->isglobal.col[j], &lc));
620:   PetscCall(MatSetSizes(*B, lr, lc, PETSC_DECIDE, PETSC_DECIDE));
621:   PetscCall(MatSetType(*B, MATAIJ));
622:   PetscCall(MatSeqAIJSetPreallocation(*B, 0, NULL));
623:   PetscCall(MatMPIAIJSetPreallocation(*B, 0, NULL, 0, NULL));
624:   PetscCall(MatSetUp(*B));
625:   PetscCall(MatSetOption(*B, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
626:   PetscCall(MatAssemblyBegin(*B, MAT_FINAL_ASSEMBLY));
627:   PetscCall(MatAssemblyEnd(*B, MAT_FINAL_ASSEMBLY));
628:   PetscFunctionReturn(PETSC_SUCCESS);
629: }

631: static PetscErrorCode MatNestGetBlock_Private(Mat A, PetscInt rbegin, PetscInt rend, PetscInt cbegin, PetscInt cend, Mat *B)
632: {
633:   Mat_Nest  *vs = (Mat_Nest *)A->data;
634:   Mat       *a;
635:   PetscInt   i, j, k, l, nr = rend - rbegin, nc = cend - cbegin;
636:   char       keyname[256];
637:   PetscBool *b;
638:   PetscBool  flg;

640:   PetscFunctionBegin;
641:   *B = NULL;
642:   PetscCall(PetscSNPrintf(keyname, sizeof(keyname), "NestBlock_%" PetscInt_FMT "-%" PetscInt_FMT "x%" PetscInt_FMT "-%" PetscInt_FMT, rbegin, rend, cbegin, cend));
643:   PetscCall(PetscObjectQuery((PetscObject)A, keyname, (PetscObject *)B));
644:   if (*B) PetscFunctionReturn(PETSC_SUCCESS);

646:   PetscCall(PetscMalloc2(nr * nc, &a, nr * nc, &b));
647:   for (i = 0; i < nr; i++) {
648:     for (j = 0; j < nc; j++) {
649:       a[i * nc + j] = vs->m[rbegin + i][cbegin + j];
650:       b[i * nc + j] = PETSC_FALSE;
651:     }
652:   }
653:   if (nc != vs->nc && nr != vs->nr) {
654:     for (i = 0; i < nr; i++) {
655:       for (j = 0; j < nc; j++) {
656:         flg = PETSC_FALSE;
657:         for (k = 0; (k < nr && !flg); k++) {
658:           if (a[j + k * nc]) flg = PETSC_TRUE;
659:         }
660:         if (flg) {
661:           flg = PETSC_FALSE;
662:           for (l = 0; (l < nc && !flg); l++) {
663:             if (a[i * nc + l]) flg = PETSC_TRUE;
664:           }
665:         }
666:         if (!flg) {
667:           b[i * nc + j] = PETSC_TRUE;
668:           PetscCall(MatNestFillEmptyMat_Private(A, rbegin + i, cbegin + j, a + i * nc + j));
669:         }
670:       }
671:     }
672:   }
673:   PetscCall(MatCreateNest(PetscObjectComm((PetscObject)A), nr, nr != vs->nr ? NULL : vs->isglobal.row, nc, nc != vs->nc ? NULL : vs->isglobal.col, a, B));
674:   for (i = 0; i < nr; i++) {
675:     for (j = 0; j < nc; j++) {
676:       if (b[i * nc + j]) PetscCall(MatDestroy(a + i * nc + j));
677:     }
678:   }
679:   PetscCall(PetscFree2(a, b));
680:   (*B)->assembled = A->assembled;
681:   PetscCall(PetscObjectCompose((PetscObject)A, keyname, (PetscObject)*B));
682:   PetscCall(PetscObjectDereference((PetscObject)*B)); /* Leave the only remaining reference in the composition */
683:   PetscFunctionReturn(PETSC_SUCCESS);
684: }

686: static PetscErrorCode MatNestFindSubMat(Mat A, struct MatNestISPair *is, IS isrow, IS iscol, Mat *B)
687: {
688:   Mat_Nest *vs = (Mat_Nest *)A->data;
689:   PetscInt  rbegin, rend, cbegin, cend;

691:   PetscFunctionBegin;
692:   PetscCall(MatNestFindISRange(A, vs->nr, is->row, isrow, &rbegin, &rend));
693:   PetscCall(MatNestFindISRange(A, vs->nc, is->col, iscol, &cbegin, &cend));
694:   if (rend == rbegin + 1 && cend == cbegin + 1) {
695:     if (!vs->m[rbegin][cbegin]) PetscCall(MatNestFillEmptyMat_Private(A, rbegin, cbegin, vs->m[rbegin] + cbegin));
696:     *B = vs->m[rbegin][cbegin];
697:   } else if (rbegin != -1 && cbegin != -1) {
698:     PetscCall(MatNestGetBlock_Private(A, rbegin, rend, cbegin, cend, B));
699:   } else SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_INCOMP, "Could not find index set");
700:   PetscFunctionReturn(PETSC_SUCCESS);
701: }

703: /*
704:    TODO: This does not actually returns a submatrix we can modify
705: */
706: static PetscErrorCode MatCreateSubMatrix_Nest(Mat A, IS isrow, IS iscol, MatReuse reuse, Mat *B)
707: {
708:   Mat_Nest *vs = (Mat_Nest *)A->data;
709:   Mat       sub;

711:   PetscFunctionBegin;
712:   PetscCall(MatNestFindSubMat(A, &vs->isglobal, isrow, iscol, &sub));
713:   switch (reuse) {
714:   case MAT_INITIAL_MATRIX:
715:     if (sub) PetscCall(PetscObjectReference((PetscObject)sub));
716:     *B = sub;
717:     break;
718:   case MAT_REUSE_MATRIX:
719:     PetscCheck(sub == *B, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Submatrix was not used before in this call");
720:     break;
721:   case MAT_IGNORE_MATRIX: /* Nothing to do */
722:     break;
723:   case MAT_INPLACE_MATRIX: /* Nothing to do */
724:     SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "MAT_INPLACE_MATRIX is not supported yet");
725:   }
726:   PetscFunctionReturn(PETSC_SUCCESS);
727: }

729: static PetscErrorCode MatGetLocalSubMatrix_Nest(Mat A, IS isrow, IS iscol, Mat *B)
730: {
731:   Mat_Nest *vs = (Mat_Nest *)A->data;
732:   Mat       sub;

734:   PetscFunctionBegin;
735:   PetscCall(MatNestFindSubMat(A, &vs->islocal, isrow, iscol, &sub));
736:   /* We allow the submatrix to be NULL, perhaps it would be better for the user to return an empty matrix instead */
737:   if (sub) PetscCall(PetscObjectReference((PetscObject)sub));
738:   *B = sub;
739:   PetscFunctionReturn(PETSC_SUCCESS);
740: }

742: static PetscErrorCode MatRestoreLocalSubMatrix_Nest(Mat A, IS isrow, IS iscol, Mat *B)
743: {
744:   Mat_Nest *vs = (Mat_Nest *)A->data;
745:   Mat       sub;

747:   PetscFunctionBegin;
748:   PetscCall(MatNestFindSubMat(A, &vs->islocal, isrow, iscol, &sub));
749:   PetscCheck(*B == sub, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Local submatrix has not been gotten");
750:   if (sub) {
751:     PetscCheck(((PetscObject)sub)->refct > 1, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Local submatrix has had reference count decremented too many times");
752:     PetscCall(MatDestroy(B));
753:   }
754:   PetscFunctionReturn(PETSC_SUCCESS);
755: }

757: static PetscErrorCode MatGetDiagonal_Nest(Mat A, Vec v)
758: {
759:   Mat_Nest *bA = (Mat_Nest *)A->data;
760:   PetscInt  i;

762:   PetscFunctionBegin;
763:   for (i = 0; i < bA->nr; i++) {
764:     Vec bv;
765:     PetscCall(VecGetSubVector(v, bA->isglobal.row[i], &bv));
766:     if (bA->m[i][i]) {
767:       PetscCall(MatGetDiagonal(bA->m[i][i], bv));
768:     } else {
769:       PetscCall(VecSet(bv, 0.0));
770:     }
771:     PetscCall(VecRestoreSubVector(v, bA->isglobal.row[i], &bv));
772:   }
773:   PetscFunctionReturn(PETSC_SUCCESS);
774: }

776: static PetscErrorCode MatDiagonalScale_Nest(Mat A, Vec l, Vec r)
777: {
778:   Mat_Nest *bA = (Mat_Nest *)A->data;
779:   Vec       bl, *br;
780:   PetscInt  i, j;

782:   PetscFunctionBegin;
783:   PetscCall(PetscCalloc1(bA->nc, &br));
784:   if (r) {
785:     for (j = 0; j < bA->nc; j++) PetscCall(VecGetSubVector(r, bA->isglobal.col[j], &br[j]));
786:   }
787:   bl = NULL;
788:   for (i = 0; i < bA->nr; i++) {
789:     if (l) PetscCall(VecGetSubVector(l, bA->isglobal.row[i], &bl));
790:     for (j = 0; j < bA->nc; j++) {
791:       if (bA->m[i][j]) PetscCall(MatDiagonalScale(bA->m[i][j], bl, br[j]));
792:     }
793:     if (l) PetscCall(VecRestoreSubVector(l, bA->isglobal.row[i], &bl));
794:   }
795:   if (r) {
796:     for (j = 0; j < bA->nc; j++) PetscCall(VecRestoreSubVector(r, bA->isglobal.col[j], &br[j]));
797:   }
798:   PetscCall(PetscFree(br));
799:   PetscFunctionReturn(PETSC_SUCCESS);
800: }

802: static PetscErrorCode MatScale_Nest(Mat A, PetscScalar a)
803: {
804:   Mat_Nest *bA = (Mat_Nest *)A->data;
805:   PetscInt  i, j;

807:   PetscFunctionBegin;
808:   for (i = 0; i < bA->nr; i++) {
809:     for (j = 0; j < bA->nc; j++) {
810:       if (bA->m[i][j]) PetscCall(MatScale(bA->m[i][j], a));
811:     }
812:   }
813:   PetscFunctionReturn(PETSC_SUCCESS);
814: }

816: static PetscErrorCode MatShift_Nest(Mat A, PetscScalar a)
817: {
818:   Mat_Nest *bA = (Mat_Nest *)A->data;
819:   PetscInt  i;
820:   PetscBool nnzstate = PETSC_FALSE;

822:   PetscFunctionBegin;
823:   for (i = 0; i < bA->nr; i++) {
824:     PetscObjectState subnnzstate = 0;
825:     PetscCheck(bA->m[i][i], PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "No support for shifting an empty diagonal block, insert a matrix in block (%" PetscInt_FMT ",%" PetscInt_FMT ")", i, i);
826:     PetscCall(MatShift(bA->m[i][i], a));
827:     PetscCall(MatGetNonzeroState(bA->m[i][i], &subnnzstate));
828:     nnzstate                     = (PetscBool)(nnzstate || bA->nnzstate[i * bA->nc + i] != subnnzstate);
829:     bA->nnzstate[i * bA->nc + i] = subnnzstate;
830:   }
831:   if (nnzstate) A->nonzerostate++;
832:   PetscFunctionReturn(PETSC_SUCCESS);
833: }

835: static PetscErrorCode MatDiagonalSet_Nest(Mat A, Vec D, InsertMode is)
836: {
837:   Mat_Nest *bA = (Mat_Nest *)A->data;
838:   PetscInt  i;
839:   PetscBool nnzstate = PETSC_FALSE;

841:   PetscFunctionBegin;
842:   for (i = 0; i < bA->nr; i++) {
843:     PetscObjectState subnnzstate = 0;
844:     Vec              bv;
845:     PetscCall(VecGetSubVector(D, bA->isglobal.row[i], &bv));
846:     if (bA->m[i][i]) {
847:       PetscCall(MatDiagonalSet(bA->m[i][i], bv, is));
848:       PetscCall(MatGetNonzeroState(bA->m[i][i], &subnnzstate));
849:     }
850:     PetscCall(VecRestoreSubVector(D, bA->isglobal.row[i], &bv));
851:     nnzstate                     = (PetscBool)(nnzstate || bA->nnzstate[i * bA->nc + i] != subnnzstate);
852:     bA->nnzstate[i * bA->nc + i] = subnnzstate;
853:   }
854:   if (nnzstate) A->nonzerostate++;
855:   PetscFunctionReturn(PETSC_SUCCESS);
856: }

858: static PetscErrorCode MatSetRandom_Nest(Mat A, PetscRandom rctx)
859: {
860:   Mat_Nest *bA = (Mat_Nest *)A->data;
861:   PetscInt  i, j;

863:   PetscFunctionBegin;
864:   for (i = 0; i < bA->nr; i++) {
865:     for (j = 0; j < bA->nc; j++) {
866:       if (bA->m[i][j]) PetscCall(MatSetRandom(bA->m[i][j], rctx));
867:     }
868:   }
869:   PetscFunctionReturn(PETSC_SUCCESS);
870: }

872: static PetscErrorCode MatCreateVecs_Nest(Mat A, Vec *right, Vec *left)
873: {
874:   Mat_Nest *bA = (Mat_Nest *)A->data;
875:   Vec      *L, *R;
876:   MPI_Comm  comm;
877:   PetscInt  i, j;

879:   PetscFunctionBegin;
880:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
881:   if (right) {
882:     /* allocate R */
883:     PetscCall(PetscMalloc1(bA->nc, &R));
884:     /* Create the right vectors */
885:     for (j = 0; j < bA->nc; j++) {
886:       for (i = 0; i < bA->nr; i++) {
887:         if (bA->m[i][j]) {
888:           PetscCall(MatCreateVecs(bA->m[i][j], &R[j], NULL));
889:           break;
890:         }
891:       }
892:       PetscCheck(i != bA->nr, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Mat(Nest) contains a null column.");
893:     }
894:     PetscCall(VecCreateNest(comm, bA->nc, bA->isglobal.col, R, right));
895:     /* hand back control to the nest vector */
896:     for (j = 0; j < bA->nc; j++) PetscCall(VecDestroy(&R[j]));
897:     PetscCall(PetscFree(R));
898:   }

900:   if (left) {
901:     /* allocate L */
902:     PetscCall(PetscMalloc1(bA->nr, &L));
903:     /* Create the left vectors */
904:     for (i = 0; i < bA->nr; i++) {
905:       for (j = 0; j < bA->nc; j++) {
906:         if (bA->m[i][j]) {
907:           PetscCall(MatCreateVecs(bA->m[i][j], NULL, &L[i]));
908:           break;
909:         }
910:       }
911:       PetscCheck(j != bA->nc, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Mat(Nest) contains a null row.");
912:     }

914:     PetscCall(VecCreateNest(comm, bA->nr, bA->isglobal.row, L, left));
915:     for (i = 0; i < bA->nr; i++) PetscCall(VecDestroy(&L[i]));

917:     PetscCall(PetscFree(L));
918:   }
919:   PetscFunctionReturn(PETSC_SUCCESS);
920: }

922: static PetscErrorCode MatView_Nest(Mat A, PetscViewer viewer)
923: {
924:   Mat_Nest *bA = (Mat_Nest *)A->data;
925:   PetscBool isascii, viewSub = PETSC_FALSE;
926:   PetscInt  i, j;

928:   PetscFunctionBegin;
929:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
930:   if (isascii) {
931:     PetscCall(PetscOptionsGetBool(((PetscObject)A)->options, ((PetscObject)A)->prefix, "-mat_view_nest_sub", &viewSub, NULL));
932:     PetscCall(PetscViewerASCIIPrintf(viewer, "Matrix object:\n"));
933:     PetscCall(PetscViewerASCIIPushTab(viewer));
934:     PetscCall(PetscViewerASCIIPrintf(viewer, "type=nest, rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", bA->nr, bA->nc));

936:     PetscCall(PetscViewerASCIIPrintf(viewer, "MatNest structure:\n"));
937:     for (i = 0; i < bA->nr; i++) {
938:       for (j = 0; j < bA->nc; j++) {
939:         MatType   type;
940:         char      name[256] = "", prefix[256] = "";
941:         PetscInt  NR, NC;
942:         PetscBool isNest = PETSC_FALSE;

944:         if (!bA->m[i][j]) {
945:           PetscCall(PetscViewerASCIIPrintf(viewer, "(%" PetscInt_FMT ",%" PetscInt_FMT ") : NULL\n", i, j));
946:           continue;
947:         }
948:         PetscCall(MatGetSize(bA->m[i][j], &NR, &NC));
949:         PetscCall(MatGetType(bA->m[i][j], &type));
950:         if (((PetscObject)bA->m[i][j])->name) PetscCall(PetscSNPrintf(name, sizeof(name), "name=\"%s\", ", ((PetscObject)bA->m[i][j])->name));
951:         if (((PetscObject)bA->m[i][j])->prefix) PetscCall(PetscSNPrintf(prefix, sizeof(prefix), "prefix=\"%s\", ", ((PetscObject)bA->m[i][j])->prefix));
952:         PetscCall(PetscObjectTypeCompare((PetscObject)bA->m[i][j], MATNEST, &isNest));

954:         PetscCall(PetscViewerASCIIPrintf(viewer, "(%" PetscInt_FMT ",%" PetscInt_FMT ") : %s%stype=%s, rows=%" PetscInt_FMT ", cols=%" PetscInt_FMT "\n", i, j, name, prefix, type, NR, NC));

956:         if (isNest || viewSub) {
957:           PetscCall(PetscViewerASCIIPushTab(viewer)); /* push1 */
958:           PetscCall(MatView(bA->m[i][j], viewer));
959:           PetscCall(PetscViewerASCIIPopTab(viewer)); /* pop1 */
960:         }
961:       }
962:     }
963:     PetscCall(PetscViewerASCIIPopTab(viewer)); /* pop0 */
964:   }
965:   PetscFunctionReturn(PETSC_SUCCESS);
966: }

968: static PetscErrorCode MatZeroEntries_Nest(Mat A)
969: {
970:   Mat_Nest *bA = (Mat_Nest *)A->data;
971:   PetscInt  i, j;

973:   PetscFunctionBegin;
974:   for (i = 0; i < bA->nr; i++) {
975:     for (j = 0; j < bA->nc; j++) {
976:       if (!bA->m[i][j]) continue;
977:       PetscCall(MatZeroEntries(bA->m[i][j]));
978:     }
979:   }
980:   PetscFunctionReturn(PETSC_SUCCESS);
981: }

983: static PetscErrorCode MatCopy_Nest(Mat A, Mat B, MatStructure str)
984: {
985:   Mat_Nest *bA = (Mat_Nest *)A->data, *bB = (Mat_Nest *)B->data;
986:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;
987:   PetscBool nnzstate = PETSC_FALSE;

989:   PetscFunctionBegin;
990:   PetscCheck(nr == bB->nr && nc == bB->nc, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_INCOMP, "Cannot copy a Mat_Nest of block size (%" PetscInt_FMT ",%" PetscInt_FMT ") to a Mat_Nest of block size (%" PetscInt_FMT ",%" PetscInt_FMT ")", bB->nr, bB->nc, nr, nc);
991:   for (i = 0; i < nr; i++) {
992:     for (j = 0; j < nc; j++) {
993:       PetscObjectState subnnzstate = 0;
994:       if (bA->m[i][j] && bB->m[i][j]) {
995:         PetscCall(MatCopy(bA->m[i][j], bB->m[i][j], str));
996:         PetscCall(MatGetNonzeroState(bB->m[i][j], &subnnzstate));
997:         nnzstate                 = (PetscBool)(nnzstate || bB->nnzstate[i * nc + j] != subnnzstate);
998:         bB->nnzstate[i * nc + j] = subnnzstate;
999:       } else if (bA->m[i][j]) { // bB->m[i][j] is NULL
1000:         Mat M;

1002:         PetscCheck(str == DIFFERENT_NONZERO_PATTERN || str == UNKNOWN_NONZERO_PATTERN, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_INCOMP, "Matrix block does not exist at %" PetscInt_FMT ",%" PetscInt_FMT ". Use DIFFERENT_NONZERO_PATTERN or UNKNOWN_NONZERO_PATTERN", i, j);
1003:         PetscCall(MatDuplicate(bA->m[i][j], MAT_COPY_VALUES, &M));
1004:         PetscCall(MatNestSetSubMat(B, i, j, M));
1005:         PetscCall(MatDestroy(&M));
1006:       } else if (bB->m[i][j]) { // bA->m[i][j] is NULL
1007:         PetscCheck(str == DIFFERENT_NONZERO_PATTERN || str == SUBSET_NONZERO_PATTERN || str == UNKNOWN_NONZERO_PATTERN, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_INCOMP, "Matrix block does not exist at %" PetscInt_FMT ",%" PetscInt_FMT ". Use DIFFERENT_NONZERO_PATTERN, SUBSET_NONZERO_PATTERN or UNKNOWN_NONZERO_PATTERN", i, j);
1008:         PetscCall(MatNestSetSubMat(B, i, j, NULL));
1009:       }
1010:     }
1011:   }
1012:   if (nnzstate) B->nonzerostate++;
1013:   PetscFunctionReturn(PETSC_SUCCESS);
1014: }

1016: static PetscErrorCode MatAXPY_Nest(Mat Y, PetscScalar a, Mat X, MatStructure str)
1017: {
1018:   Mat_Nest *bY = (Mat_Nest *)Y->data, *bX = (Mat_Nest *)X->data;
1019:   PetscInt  i, j, nr = bY->nr, nc = bY->nc;
1020:   PetscBool nnzstate = PETSC_FALSE;

1022:   PetscFunctionBegin;
1023:   PetscCheck(nr == bX->nr && nc == bX->nc, PetscObjectComm((PetscObject)Y), PETSC_ERR_ARG_INCOMP, "Cannot AXPY a MatNest of block size (%" PetscInt_FMT ",%" PetscInt_FMT ") with a MatNest of block size (%" PetscInt_FMT ",%" PetscInt_FMT ")", bX->nr, bX->nc, nr, nc);
1024:   for (i = 0; i < nr; i++) {
1025:     for (j = 0; j < nc; j++) {
1026:       PetscObjectState subnnzstate = 0;
1027:       if (bY->m[i][j] && bX->m[i][j]) {
1028:         PetscCall(MatAXPY(bY->m[i][j], a, bX->m[i][j], str));
1029:       } else if (bX->m[i][j]) {
1030:         Mat M;

1032:         PetscCheck(str == DIFFERENT_NONZERO_PATTERN || str == UNKNOWN_NONZERO_PATTERN, PetscObjectComm((PetscObject)Y), PETSC_ERR_ARG_INCOMP, "Matrix block does not exist at %" PetscInt_FMT ",%" PetscInt_FMT ". Use DIFFERENT_NONZERO_PATTERN or UNKNOWN_NONZERO_PATTERN", i, j);
1033:         PetscCall(MatDuplicate(bX->m[i][j], MAT_COPY_VALUES, &M));
1034:         PetscCall(MatNestSetSubMat(Y, i, j, M));
1035:         PetscCall(MatDestroy(&M));
1036:       }
1037:       if (bY->m[i][j]) PetscCall(MatGetNonzeroState(bY->m[i][j], &subnnzstate));
1038:       nnzstate                 = (PetscBool)(nnzstate || bY->nnzstate[i * nc + j] != subnnzstate);
1039:       bY->nnzstate[i * nc + j] = subnnzstate;
1040:     }
1041:   }
1042:   if (nnzstate) Y->nonzerostate++;
1043:   PetscFunctionReturn(PETSC_SUCCESS);
1044: }

1046: static PetscErrorCode MatDuplicate_Nest(Mat A, MatDuplicateOption op, Mat *B)
1047: {
1048:   Mat_Nest *bA = (Mat_Nest *)A->data;
1049:   Mat      *b;
1050:   PetscInt  i, j, nr = bA->nr, nc = bA->nc;

1052:   PetscFunctionBegin;
1053:   PetscCall(PetscMalloc1(nr * nc, &b));
1054:   for (i = 0; i < nr; i++) {
1055:     for (j = 0; j < nc; j++) {
1056:       if (bA->m[i][j]) {
1057:         PetscCall(MatDuplicate(bA->m[i][j], op, &b[i * nc + j]));
1058:       } else {
1059:         b[i * nc + j] = NULL;
1060:       }
1061:     }
1062:   }
1063:   PetscCall(MatCreateNest(PetscObjectComm((PetscObject)A), nr, bA->isglobal.row, nc, bA->isglobal.col, b, B));
1064:   /* Give the new MatNest exclusive ownership */
1065:   for (i = 0; i < nr * nc; i++) PetscCall(MatDestroy(&b[i]));
1066:   PetscCall(PetscFree(b));

1068:   PetscCall(MatAssemblyBegin(*B, MAT_FINAL_ASSEMBLY));
1069:   PetscCall(MatAssemblyEnd(*B, MAT_FINAL_ASSEMBLY));
1070:   PetscFunctionReturn(PETSC_SUCCESS);
1071: }

1073: /* nest api */
1074: static PetscErrorCode MatNestGetSubMat_Nest(Mat A, PetscInt idxm, PetscInt jdxm, Mat *mat)
1075: {
1076:   Mat_Nest *bA = (Mat_Nest *)A->data;

1078:   PetscFunctionBegin;
1079:   PetscCheck(idxm < bA->nr, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, idxm, bA->nr - 1);
1080:   PetscCheck(jdxm < bA->nc, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Col too large: row %" PetscInt_FMT " max %" PetscInt_FMT, jdxm, bA->nc - 1);
1081:   *mat = bA->m[idxm][jdxm];
1082:   PetscFunctionReturn(PETSC_SUCCESS);
1083: }

1085: /*@
1086:   MatNestGetSubMat - Returns a single, sub-matrix from a `MATNEST`

1088:   Not Collective

1090:   Input Parameters:
1091: + A    - `MATNEST` matrix
1092: . idxm - index of the matrix within the nest matrix
1093: - jdxm - index of the matrix within the nest matrix

1095:   Output Parameter:
1096: . sub - matrix at index `idxm`, `jdxm` within the nest matrix

1098:   Level: developer

1100: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatNestGetSize()`, `MatNestGetSubMats()`, `MatCreateNest()`, `MatNestSetSubMat()`,
1101:           `MatNestGetLocalISs()`, `MatNestGetISs()`
1102: @*/
1103: PetscErrorCode MatNestGetSubMat(Mat A, PetscInt idxm, PetscInt jdxm, Mat *sub)
1104: {
1105:   PetscFunctionBegin;
1109:   PetscAssertPointer(sub, 4);
1110:   PetscUseMethod(A, "MatNestGetSubMat_C", (Mat, PetscInt, PetscInt, Mat *), (A, idxm, jdxm, sub));
1111:   PetscFunctionReturn(PETSC_SUCCESS);
1112: }

1114: static PetscErrorCode MatNestSetSubMat_Nest(Mat A, PetscInt idxm, PetscInt jdxm, Mat mat)
1115: {
1116:   Mat_Nest *bA = (Mat_Nest *)A->data;
1117:   PetscInt  m, n, M, N, mi, ni, Mi, Ni;

1119:   PetscFunctionBegin;
1120:   PetscCheck(idxm < bA->nr, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, idxm, bA->nr - 1);
1121:   PetscCheck(jdxm < bA->nc, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Col too large: row %" PetscInt_FMT " max %" PetscInt_FMT, jdxm, bA->nc - 1);
1122:   if (mat) {
1123:     PetscCall(MatGetLocalSize(mat, &m, &n));
1124:     PetscCall(MatGetSize(mat, &M, &N));
1125:     PetscCall(ISGetLocalSize(bA->isglobal.row[idxm], &mi));
1126:     PetscCall(ISGetSize(bA->isglobal.row[idxm], &Mi));
1127:     PetscCall(ISGetLocalSize(bA->isglobal.col[jdxm], &ni));
1128:     PetscCall(ISGetSize(bA->isglobal.col[jdxm], &Ni));
1129:     PetscCheck(M == Mi && N == Ni, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_INCOMP, "Submatrix dimension (%" PetscInt_FMT ",%" PetscInt_FMT ") incompatible with nest block (%" PetscInt_FMT ",%" PetscInt_FMT ")", M, N, Mi, Ni);
1130:     PetscCheck(m == mi && n == ni, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_INCOMP, "Submatrix local dimension (%" PetscInt_FMT ",%" PetscInt_FMT ") incompatible with nest block (%" PetscInt_FMT ",%" PetscInt_FMT ")", m, n, mi, ni);
1131:   }

1133:   /* do not increase object state */
1134:   if (mat == bA->m[idxm][jdxm]) PetscFunctionReturn(PETSC_SUCCESS);

1136:   PetscCall(PetscObjectReference((PetscObject)mat));
1137:   PetscCall(MatDestroy(&bA->m[idxm][jdxm]));
1138:   bA->m[idxm][jdxm] = mat;
1139:   PetscCall(PetscObjectStateIncrease((PetscObject)A));
1140:   if (mat) PetscCall(MatGetNonzeroState(mat, &bA->nnzstate[idxm * bA->nc + jdxm]));
1141:   else bA->nnzstate[idxm * bA->nc + jdxm] = 0;
1142:   A->nonzerostate++;
1143:   PetscFunctionReturn(PETSC_SUCCESS);
1144: }

1146: /*@
1147:   MatNestSetSubMat - Set a single submatrix in the `MATNEST`

1149:   Logically Collective

1151:   Input Parameters:
1152: + A    - `MATNEST` matrix
1153: . idxm - index of the matrix within the nest matrix
1154: . jdxm - index of the matrix within the nest matrix
1155: - sub  - matrix at index `idxm`, `jdxm` within the nest matrix

1157:   Level: developer

1159:   Notes:
1160:   The new submatrix must have the same size and communicator as that block of the nest.

1162:   This increments the reference count of the submatrix.

1164: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatNestSetSubMats()`, `MatNestGetSubMats()`, `MatNestGetLocalISs()`, `MatCreateNest()`,
1165:           `MatNestGetSubMat()`, `MatNestGetISs()`, `MatNestGetSize()`
1166: @*/
1167: PetscErrorCode MatNestSetSubMat(Mat A, PetscInt idxm, PetscInt jdxm, Mat sub)
1168: {
1169:   PetscFunctionBegin;
1174:   PetscTryMethod(A, "MatNestSetSubMat_C", (Mat, PetscInt, PetscInt, Mat), (A, idxm, jdxm, sub));
1175:   PetscFunctionReturn(PETSC_SUCCESS);
1176: }

1178: static PetscErrorCode MatNestGetSubMats_Nest(Mat A, PetscInt *M, PetscInt *N, Mat ***mat)
1179: {
1180:   Mat_Nest *bA = (Mat_Nest *)A->data;

1182:   PetscFunctionBegin;
1183:   if (M) *M = bA->nr;
1184:   if (N) *N = bA->nc;
1185:   if (mat) *mat = bA->m;
1186:   PetscFunctionReturn(PETSC_SUCCESS);
1187: }

1189: /*@C
1190:   MatNestGetSubMats - Returns the entire two dimensional array of matrices defining a `MATNEST` matrix.

1192:   Not Collective

1194:   Input Parameter:
1195: . A - nest matrix

1197:   Output Parameters:
1198: + M   - number of submatrix rows in the nest matrix
1199: . N   - number of submatrix columns in the nest matrix
1200: - mat - array of matrices

1202:   Level: developer

1204:   Note:
1205:   The user should not free the array `mat`.

1207:   Fortran Notes:
1208:   This routine has a calling sequence `call MatNestGetSubMats(A, M, N, mat, ierr)`
1209:   where the space allocated for the optional argument `mat` is assumed large enough (if provided).
1210:   Matrices in `mat` are returned in row-major order, see `MatCreateNest()` for an example.

1212: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatNestGetSize()`, `MatNestGetSubMat()`, `MatNestGetLocalISs()`, `MatCreateNest()`,
1213:           `MatNestSetSubMats()`, `MatNestGetISs()`, `MatNestSetSubMat()`
1214: @*/
1215: PetscErrorCode MatNestGetSubMats(Mat A, PetscInt *M, PetscInt *N, Mat ***mat)
1216: {
1217:   PetscFunctionBegin;
1219:   PetscUseMethod(A, "MatNestGetSubMats_C", (Mat, PetscInt *, PetscInt *, Mat ***), (A, M, N, mat));
1220:   PetscFunctionReturn(PETSC_SUCCESS);
1221: }

1223: static PetscErrorCode MatNestGetSize_Nest(Mat A, PetscInt *M, PetscInt *N)
1224: {
1225:   Mat_Nest *bA = (Mat_Nest *)A->data;

1227:   PetscFunctionBegin;
1228:   if (M) *M = bA->nr;
1229:   if (N) *N = bA->nc;
1230:   PetscFunctionReturn(PETSC_SUCCESS);
1231: }

1233: /*@
1234:   MatNestGetSize - Returns the size of the `MATNEST` matrix.

1236:   Not Collective

1238:   Input Parameter:
1239: . A - `MATNEST` matrix

1241:   Output Parameters:
1242: + M - number of rows in the nested mat
1243: - N - number of cols in the nested mat

1245:   Level: developer

1247:   Note:
1248:   `size` refers to the number of submatrices in the row and column directions of the nested matrix

1250: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatNestGetSubMat()`, `MatNestGetSubMats()`, `MatCreateNest()`, `MatNestGetLocalISs()`,
1251:           `MatNestGetISs()`
1252: @*/
1253: PetscErrorCode MatNestGetSize(Mat A, PetscInt *M, PetscInt *N)
1254: {
1255:   PetscFunctionBegin;
1257:   PetscUseMethod(A, "MatNestGetSize_C", (Mat, PetscInt *, PetscInt *), (A, M, N));
1258:   PetscFunctionReturn(PETSC_SUCCESS);
1259: }

1261: static PetscErrorCode MatNestGetISs_Nest(Mat A, IS rows[], IS cols[])
1262: {
1263:   Mat_Nest *vs = (Mat_Nest *)A->data;
1264:   PetscInt  i;

1266:   PetscFunctionBegin;
1267:   if (rows)
1268:     for (i = 0; i < vs->nr; i++) rows[i] = vs->isglobal.row[i];
1269:   if (cols)
1270:     for (i = 0; i < vs->nc; i++) cols[i] = vs->isglobal.col[i];
1271:   PetscFunctionReturn(PETSC_SUCCESS);
1272: }

1274: /*@
1275:   MatNestGetISs - Returns the index sets partitioning the row and column spaces of a `MATNEST`

1277:   Not Collective

1279:   Input Parameter:
1280: . A - `MATNEST` matrix

1282:   Output Parameters:
1283: + rows - array of row index sets (pass `NULL` to ignore)
1284: - cols - array of column index sets (pass `NULL` to ignore)

1286:   Level: advanced

1288:   Note:
1289:   The user must have allocated arrays of the correct size. The reference count is not increased on the returned `IS`s.

1291: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatNestGetSubMat()`, `MatNestGetSubMats()`, `MatNestGetSize()`, `MatNestGetLocalISs()`,
1292:           `MatCreateNest()`, `MatNestSetSubMats()`
1293: @*/
1294: PetscErrorCode MatNestGetISs(Mat A, IS rows[], IS cols[])
1295: {
1296:   PetscFunctionBegin;
1298:   PetscUseMethod(A, "MatNestGetISs_C", (Mat, IS[], IS[]), (A, rows, cols));
1299:   PetscFunctionReturn(PETSC_SUCCESS);
1300: }

1302: static PetscErrorCode MatNestGetLocalISs_Nest(Mat A, IS rows[], IS cols[])
1303: {
1304:   Mat_Nest *vs = (Mat_Nest *)A->data;
1305:   PetscInt  i;

1307:   PetscFunctionBegin;
1308:   if (rows)
1309:     for (i = 0; i < vs->nr; i++) rows[i] = vs->islocal.row[i];
1310:   if (cols)
1311:     for (i = 0; i < vs->nc; i++) cols[i] = vs->islocal.col[i];
1312:   PetscFunctionReturn(PETSC_SUCCESS);
1313: }

1315: /*@
1316:   MatNestGetLocalISs - Returns the index sets partitioning the row and column spaces of a `MATNEST`

1318:   Not Collective

1320:   Input Parameter:
1321: . A - `MATNEST` matrix

1323:   Output Parameters:
1324: + rows - array of row index sets (pass `NULL` to ignore)
1325: - cols - array of column index sets (pass `NULL` to ignore)

1327:   Level: advanced

1329:   Note:
1330:   The user must have allocated arrays of the correct size. The reference count is not increased on the returned `IS`s.

1332: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatNestGetSubMat()`, `MatNestGetSubMats()`, `MatNestGetSize()`, `MatNestGetISs()`, `MatCreateNest()`,
1333:           `MatNestSetSubMats()`, `MatNestSetSubMat()`
1334: @*/
1335: PetscErrorCode MatNestGetLocalISs(Mat A, IS rows[], IS cols[])
1336: {
1337:   PetscFunctionBegin;
1339:   PetscUseMethod(A, "MatNestGetLocalISs_C", (Mat, IS[], IS[]), (A, rows, cols));
1340:   PetscFunctionReturn(PETSC_SUCCESS);
1341: }

1343: static PetscErrorCode MatNestSetVecType_Nest(Mat A, VecType vtype)
1344: {
1345:   PetscBool flg;

1347:   PetscFunctionBegin;
1348:   PetscCall(PetscStrcmp(vtype, VECNEST, &flg));
1349:   /* In reality, this only distinguishes VECNEST and "other" */
1350:   if (flg) A->ops->getvecs = MatCreateVecs_Nest;
1351:   else A->ops->getvecs = NULL;
1352:   PetscFunctionReturn(PETSC_SUCCESS);
1353: }

1355: /*@
1356:   MatNestSetVecType - Sets the type of `Vec` returned by `MatCreateVecs()`

1358:   Not Collective

1360:   Input Parameters:
1361: + A     - `MATNEST` matrix
1362: - vtype - `VecType` to use for creating vectors

1364:   Level: developer

1366: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatCreateVecs()`, `MatCreateNest()`, `VecType`
1367: @*/
1368: PetscErrorCode MatNestSetVecType(Mat A, VecType vtype)
1369: {
1370:   PetscFunctionBegin;
1372:   PetscTryMethod(A, "MatNestSetVecType_C", (Mat, VecType), (A, vtype));
1373:   PetscFunctionReturn(PETSC_SUCCESS);
1374: }

1376: static PetscErrorCode MatNestSetSubMats_Nest(Mat A, PetscInt nr, const IS is_row[], PetscInt nc, const IS is_col[], const Mat a[])
1377: {
1378:   Mat_Nest *s = (Mat_Nest *)A->data;
1379:   PetscInt  i, j, m, n, M, N;
1380:   PetscBool cong, isstd, sametype = PETSC_FALSE;
1381:   VecType   vtype, type;

1383:   PetscFunctionBegin;
1384:   PetscCall(MatReset_Nest(A));

1386:   s->nr = nr;
1387:   s->nc = nc;

1389:   /* Create space for submatrices */
1390:   PetscCall(PetscMalloc1(nr, &s->m));
1391:   PetscCall(PetscMalloc1(nr * nc, &s->m[0]));
1392:   for (i = 0; i < nr; i++) {
1393:     s->m[i] = s->m[0] + i * nc;
1394:     for (j = 0; j < nc; j++) {
1395:       s->m[i][j] = a ? a[i * nc + j] : NULL;
1396:       PetscCall(PetscObjectReference((PetscObject)s->m[i][j]));
1397:     }
1398:   }
1399:   PetscCall(MatGetVecType(A, &vtype));
1400:   PetscCall(PetscStrcmp(vtype, VECSTANDARD, &isstd));
1401:   if (isstd) {
1402:     /* check if all blocks have the same vectype */
1403:     vtype = NULL;
1404:     for (i = 0; i < nr; i++) {
1405:       for (j = 0; j < nc; j++) {
1406:         if (s->m[i][j]) {
1407:           if (!vtype) { /* first visited block */
1408:             PetscCall(MatGetVecType(s->m[i][j], &vtype));
1409:             sametype = PETSC_TRUE;
1410:           } else if (sametype) {
1411:             PetscCall(MatGetVecType(s->m[i][j], &type));
1412:             PetscCall(PetscStrcmp(vtype, type, &sametype));
1413:           }
1414:         }
1415:       }
1416:     }
1417:     if (sametype) { /* propagate vectype */
1418:       PetscCall(MatSetVecType(A, vtype));
1419:     }
1420:   }

1422:   PetscCall(MatSetUp_NestIS_Private(A, nr, is_row, nc, is_col));

1424:   PetscCall(PetscMalloc1(nr, &s->row_len));
1425:   PetscCall(PetscMalloc1(nc, &s->col_len));
1426:   for (i = 0; i < nr; i++) s->row_len[i] = -1;
1427:   for (j = 0; j < nc; j++) s->col_len[j] = -1;

1429:   PetscCall(PetscCalloc1(nr * nc, &s->nnzstate));
1430:   for (i = 0; i < nr; i++) {
1431:     for (j = 0; j < nc; j++) {
1432:       if (s->m[i][j]) PetscCall(MatGetNonzeroState(s->m[i][j], &s->nnzstate[i * nc + j]));
1433:     }
1434:   }

1436:   PetscCall(MatNestGetSizes_Private(A, &m, &n, &M, &N));

1438:   PetscCall(PetscLayoutSetSize(A->rmap, M));
1439:   PetscCall(PetscLayoutSetLocalSize(A->rmap, m));
1440:   PetscCall(PetscLayoutSetSize(A->cmap, N));
1441:   PetscCall(PetscLayoutSetLocalSize(A->cmap, n));

1443:   PetscCall(PetscLayoutSetUp(A->rmap));
1444:   PetscCall(PetscLayoutSetUp(A->cmap));

1446:   /* disable operations that are not supported for non-square matrices,
1447:      or matrices for which is_row != is_col  */
1448:   PetscCall(MatHasCongruentLayouts(A, &cong));
1449:   if (cong && nr != nc) cong = PETSC_FALSE;
1450:   if (cong) {
1451:     for (i = 0; cong && i < nr; i++) PetscCall(ISEqualUnsorted(s->isglobal.row[i], s->isglobal.col[i], &cong));
1452:   }
1453:   if (!cong) {
1454:     A->ops->missingdiagonal = NULL;
1455:     A->ops->getdiagonal     = NULL;
1456:     A->ops->shift           = NULL;
1457:     A->ops->diagonalset     = NULL;
1458:   }

1460:   PetscCall(PetscCalloc2(nr, &s->left, nc, &s->right));
1461:   PetscCall(PetscObjectStateIncrease((PetscObject)A));
1462:   A->nonzerostate++;
1463:   PetscFunctionReturn(PETSC_SUCCESS);
1464: }

1466: /*@
1467:   MatNestSetSubMats - Sets the nested submatrices in a `MATNEST`

1469:   Collective

1471:   Input Parameters:
1472: + A      - `MATNEST` matrix
1473: . nr     - number of nested row blocks
1474: . is_row - index sets for each nested row block, or `NULL` to make contiguous
1475: . nc     - number of nested column blocks
1476: . is_col - index sets for each nested column block, or `NULL` to make contiguous
1477: - a      - array of nr*nc submatrices, or `NULL`

1479:   Level: advanced

1481:   Notes:
1482:   This always resets any block matrix information previously set.

1484:   Pass `NULL` in the corresponding entry of `a` for an empty block.

1486:   In both C and Fortran, `a` must be a row-major order array containing the matrices. See
1487:   `MatCreateNest()` for an example.

1489: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatCreateNest()`, `MatNestSetSubMat()`, `MatNestGetSubMat()`, `MatNestGetSubMats()`
1490: @*/
1491: PetscErrorCode MatNestSetSubMats(Mat A, PetscInt nr, const IS is_row[], PetscInt nc, const IS is_col[], const Mat a[])
1492: {
1493:   PetscFunctionBegin;
1496:   PetscCheck(nr >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Number of rows cannot be negative");
1497:   if (nr && is_row) {
1498:     PetscAssertPointer(is_row, 3);
1500:   }
1502:   PetscCheck(nc >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Number of columns cannot be negative");
1503:   if (nc && is_col) {
1504:     PetscAssertPointer(is_col, 5);
1506:   }
1507:   PetscTryMethod(A, "MatNestSetSubMats_C", (Mat, PetscInt, const IS[], PetscInt, const IS[], const Mat[]), (A, nr, is_row, nc, is_col, a));
1508:   PetscFunctionReturn(PETSC_SUCCESS);
1509: }

1511: static PetscErrorCode MatNestCreateAggregateL2G_Private(Mat A, PetscInt n, const IS islocal[], const IS isglobal[], PetscBool colflg, ISLocalToGlobalMapping *ltog)
1512: {
1513:   PetscBool flg;
1514:   PetscInt  i, j, m, mi, *ix;

1516:   PetscFunctionBegin;
1517:   *ltog = NULL;
1518:   for (i = 0, m = 0, flg = PETSC_FALSE; i < n; i++) {
1519:     if (islocal[i]) {
1520:       PetscCall(ISGetLocalSize(islocal[i], &mi));
1521:       flg = PETSC_TRUE; /* We found a non-trivial entry */
1522:     } else {
1523:       PetscCall(ISGetLocalSize(isglobal[i], &mi));
1524:     }
1525:     m += mi;
1526:   }
1527:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

1529:   PetscCall(PetscMalloc1(m, &ix));
1530:   for (i = 0, m = 0; i < n; i++) {
1531:     ISLocalToGlobalMapping smap = NULL;
1532:     Mat                    sub  = NULL;
1533:     PetscSF                sf;
1534:     PetscLayout            map;
1535:     const PetscInt        *ix2;

1537:     if (!colflg) {
1538:       PetscCall(MatNestFindNonzeroSubMatRow(A, i, &sub));
1539:     } else {
1540:       PetscCall(MatNestFindNonzeroSubMatCol(A, i, &sub));
1541:     }
1542:     if (sub) {
1543:       if (!colflg) {
1544:         PetscCall(MatGetLocalToGlobalMapping(sub, &smap, NULL));
1545:       } else {
1546:         PetscCall(MatGetLocalToGlobalMapping(sub, NULL, &smap));
1547:       }
1548:     }
1549:     /*
1550:        Now we need to extract the monolithic global indices that correspond to the given split global indices.
1551:        In many/most cases, we only want MatGetLocalSubMatrix() to work, in which case we only need to know the size of the local spaces.
1552:     */
1553:     PetscCall(ISGetIndices(isglobal[i], &ix2));
1554:     if (islocal[i]) {
1555:       PetscInt *ilocal, *iremote;
1556:       PetscInt  mil, nleaves;

1558:       PetscCall(ISGetLocalSize(islocal[i], &mi));
1559:       PetscCheck(smap, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Missing local to global map");
1560:       for (j = 0; j < mi; j++) ix[m + j] = j;
1561:       PetscCall(ISLocalToGlobalMappingApply(smap, mi, ix + m, ix + m));

1563:       /* PetscSFSetGraphLayout does not like negative indices */
1564:       PetscCall(PetscMalloc2(mi, &ilocal, mi, &iremote));
1565:       for (j = 0, nleaves = 0; j < mi; j++) {
1566:         if (ix[m + j] < 0) continue;
1567:         ilocal[nleaves]  = j;
1568:         iremote[nleaves] = ix[m + j];
1569:         nleaves++;
1570:       }
1571:       PetscCall(ISGetLocalSize(isglobal[i], &mil));
1572:       PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &sf));
1573:       PetscCall(PetscLayoutCreate(PetscObjectComm((PetscObject)A), &map));
1574:       PetscCall(PetscLayoutSetLocalSize(map, mil));
1575:       PetscCall(PetscLayoutSetUp(map));
1576:       PetscCall(PetscSFSetGraphLayout(sf, map, nleaves, ilocal, PETSC_USE_POINTER, iremote));
1577:       PetscCall(PetscLayoutDestroy(&map));
1578:       PetscCall(PetscSFBcastBegin(sf, MPIU_INT, ix2, ix + m, MPI_REPLACE));
1579:       PetscCall(PetscSFBcastEnd(sf, MPIU_INT, ix2, ix + m, MPI_REPLACE));
1580:       PetscCall(PetscSFDestroy(&sf));
1581:       PetscCall(PetscFree2(ilocal, iremote));
1582:     } else {
1583:       PetscCall(ISGetLocalSize(isglobal[i], &mi));
1584:       for (j = 0; j < mi; j++) ix[m + j] = ix2[i];
1585:     }
1586:     PetscCall(ISRestoreIndices(isglobal[i], &ix2));
1587:     m += mi;
1588:   }
1589:   PetscCall(ISLocalToGlobalMappingCreate(PetscObjectComm((PetscObject)A), 1, m, ix, PETSC_OWN_POINTER, ltog));
1590:   PetscFunctionReturn(PETSC_SUCCESS);
1591: }

1593: /* If an IS was provided, there is nothing Nest needs to do, otherwise Nest will build a strided IS */
1594: /*
1595:   nprocessors = NP
1596:   Nest x^T = ((g_0,g_1,...g_nprocs-1), (h_0,h_1,...h_NP-1))
1597:        proc 0: => (g_0,h_0,)
1598:        proc 1: => (g_1,h_1,)
1599:        ...
1600:        proc nprocs-1: => (g_NP-1,h_NP-1,)

1602:             proc 0:                      proc 1:                    proc nprocs-1:
1603:     is[0] = (0,1,2,...,nlocal(g_0)-1)  (0,1,...,nlocal(g_1)-1)  (0,1,...,nlocal(g_NP-1))

1605:             proc 0:
1606:     is[1] = (nlocal(g_0),nlocal(g_0)+1,...,nlocal(g_0)+nlocal(h_0)-1)
1607:             proc 1:
1608:     is[1] = (nlocal(g_1),nlocal(g_1)+1,...,nlocal(g_1)+nlocal(h_1)-1)

1610:             proc NP-1:
1611:     is[1] = (nlocal(g_NP-1),nlocal(g_NP-1)+1,...,nlocal(g_NP-1)+nlocal(h_NP-1)-1)
1612: */
1613: static PetscErrorCode MatSetUp_NestIS_Private(Mat A, PetscInt nr, const IS is_row[], PetscInt nc, const IS is_col[])
1614: {
1615:   Mat_Nest *vs = (Mat_Nest *)A->data;
1616:   PetscInt  i, j, offset, n, nsum, bs;
1617:   Mat       sub = NULL;

1619:   PetscFunctionBegin;
1620:   PetscCall(PetscMalloc1(nr, &vs->isglobal.row));
1621:   PetscCall(PetscMalloc1(nc, &vs->isglobal.col));
1622:   if (is_row) { /* valid IS is passed in */
1623:     /* refs on is[] are incremented */
1624:     for (i = 0; i < vs->nr; i++) {
1625:       PetscCall(PetscObjectReference((PetscObject)is_row[i]));
1626:       vs->isglobal.row[i] = is_row[i];
1627:     }
1628:   } else { /* Create the ISs by inspecting sizes of a submatrix in each row */
1629:     nsum = 0;
1630:     for (i = 0; i < vs->nr; i++) { /* Add up the local sizes to compute the aggregate offset */
1631:       PetscCall(MatNestFindNonzeroSubMatRow(A, i, &sub));
1632:       PetscCheck(sub, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "No nonzero submatrix in row %" PetscInt_FMT, i);
1633:       PetscCall(MatGetLocalSize(sub, &n, NULL));
1634:       PetscCheck(n >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Sizes have not yet been set for submatrix");
1635:       nsum += n;
1636:     }
1637:     PetscCallMPI(MPI_Scan(&nsum, &offset, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)A)));
1638:     offset -= nsum;
1639:     for (i = 0; i < vs->nr; i++) {
1640:       PetscCall(MatNestFindNonzeroSubMatRow(A, i, &sub));
1641:       PetscCall(MatGetLocalSize(sub, &n, NULL));
1642:       PetscCall(MatGetBlockSizes(sub, &bs, NULL));
1643:       PetscCall(ISCreateStride(PetscObjectComm((PetscObject)sub), n, offset, 1, &vs->isglobal.row[i]));
1644:       PetscCall(ISSetBlockSize(vs->isglobal.row[i], bs));
1645:       offset += n;
1646:     }
1647:   }

1649:   if (is_col) { /* valid IS is passed in */
1650:     /* refs on is[] are incremented */
1651:     for (j = 0; j < vs->nc; j++) {
1652:       PetscCall(PetscObjectReference((PetscObject)is_col[j]));
1653:       vs->isglobal.col[j] = is_col[j];
1654:     }
1655:   } else { /* Create the ISs by inspecting sizes of a submatrix in each column */
1656:     offset = A->cmap->rstart;
1657:     nsum   = 0;
1658:     for (j = 0; j < vs->nc; j++) {
1659:       PetscCall(MatNestFindNonzeroSubMatCol(A, j, &sub));
1660:       PetscCheck(sub, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "No nonzero submatrix in column %" PetscInt_FMT, i);
1661:       PetscCall(MatGetLocalSize(sub, NULL, &n));
1662:       PetscCheck(n >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Sizes have not yet been set for submatrix");
1663:       nsum += n;
1664:     }
1665:     PetscCallMPI(MPI_Scan(&nsum, &offset, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)A)));
1666:     offset -= nsum;
1667:     for (j = 0; j < vs->nc; j++) {
1668:       PetscCall(MatNestFindNonzeroSubMatCol(A, j, &sub));
1669:       PetscCall(MatGetLocalSize(sub, NULL, &n));
1670:       PetscCall(MatGetBlockSizes(sub, NULL, &bs));
1671:       PetscCall(ISCreateStride(PetscObjectComm((PetscObject)sub), n, offset, 1, &vs->isglobal.col[j]));
1672:       PetscCall(ISSetBlockSize(vs->isglobal.col[j], bs));
1673:       offset += n;
1674:     }
1675:   }

1677:   /* Set up the local ISs */
1678:   PetscCall(PetscMalloc1(vs->nr, &vs->islocal.row));
1679:   PetscCall(PetscMalloc1(vs->nc, &vs->islocal.col));
1680:   for (i = 0, offset = 0; i < vs->nr; i++) {
1681:     IS                     isloc;
1682:     ISLocalToGlobalMapping rmap = NULL;
1683:     PetscInt               nlocal, bs;
1684:     PetscCall(MatNestFindNonzeroSubMatRow(A, i, &sub));
1685:     if (sub) PetscCall(MatGetLocalToGlobalMapping(sub, &rmap, NULL));
1686:     if (rmap) {
1687:       PetscCall(MatGetBlockSizes(sub, &bs, NULL));
1688:       PetscCall(ISLocalToGlobalMappingGetSize(rmap, &nlocal));
1689:       PetscCall(ISCreateStride(PETSC_COMM_SELF, nlocal, offset, 1, &isloc));
1690:       PetscCall(ISSetBlockSize(isloc, bs));
1691:     } else {
1692:       nlocal = 0;
1693:       isloc  = NULL;
1694:     }
1695:     vs->islocal.row[i] = isloc;
1696:     offset += nlocal;
1697:   }
1698:   for (i = 0, offset = 0; i < vs->nc; i++) {
1699:     IS                     isloc;
1700:     ISLocalToGlobalMapping cmap = NULL;
1701:     PetscInt               nlocal, bs;
1702:     PetscCall(MatNestFindNonzeroSubMatCol(A, i, &sub));
1703:     if (sub) PetscCall(MatGetLocalToGlobalMapping(sub, NULL, &cmap));
1704:     if (cmap) {
1705:       PetscCall(MatGetBlockSizes(sub, NULL, &bs));
1706:       PetscCall(ISLocalToGlobalMappingGetSize(cmap, &nlocal));
1707:       PetscCall(ISCreateStride(PETSC_COMM_SELF, nlocal, offset, 1, &isloc));
1708:       PetscCall(ISSetBlockSize(isloc, bs));
1709:     } else {
1710:       nlocal = 0;
1711:       isloc  = NULL;
1712:     }
1713:     vs->islocal.col[i] = isloc;
1714:     offset += nlocal;
1715:   }

1717:   /* Set up the aggregate ISLocalToGlobalMapping */
1718:   {
1719:     ISLocalToGlobalMapping rmap, cmap;
1720:     PetscCall(MatNestCreateAggregateL2G_Private(A, vs->nr, vs->islocal.row, vs->isglobal.row, PETSC_FALSE, &rmap));
1721:     PetscCall(MatNestCreateAggregateL2G_Private(A, vs->nc, vs->islocal.col, vs->isglobal.col, PETSC_TRUE, &cmap));
1722:     if (rmap && cmap) PetscCall(MatSetLocalToGlobalMapping(A, rmap, cmap));
1723:     PetscCall(ISLocalToGlobalMappingDestroy(&rmap));
1724:     PetscCall(ISLocalToGlobalMappingDestroy(&cmap));
1725:   }

1727:   if (PetscDefined(USE_DEBUG)) {
1728:     for (i = 0; i < vs->nr; i++) {
1729:       for (j = 0; j < vs->nc; j++) {
1730:         PetscInt m, n, M, N, mi, ni, Mi, Ni;
1731:         Mat      B = vs->m[i][j];
1732:         if (!B) continue;
1733:         PetscCall(MatGetSize(B, &M, &N));
1734:         PetscCall(MatGetLocalSize(B, &m, &n));
1735:         PetscCall(ISGetSize(vs->isglobal.row[i], &Mi));
1736:         PetscCall(ISGetSize(vs->isglobal.col[j], &Ni));
1737:         PetscCall(ISGetLocalSize(vs->isglobal.row[i], &mi));
1738:         PetscCall(ISGetLocalSize(vs->isglobal.col[j], &ni));
1739:         PetscCheck(M == Mi && N == Ni, PetscObjectComm((PetscObject)sub), PETSC_ERR_ARG_INCOMP, "Global sizes (%" PetscInt_FMT ",%" PetscInt_FMT ") of nested submatrix (%" PetscInt_FMT ",%" PetscInt_FMT ") do not agree with space defined by index sets (%" PetscInt_FMT ",%" PetscInt_FMT ")", M, N, i, j, Mi, Ni);
1740:         PetscCheck(m == mi && n == ni, PetscObjectComm((PetscObject)sub), PETSC_ERR_ARG_INCOMP, "Local sizes (%" PetscInt_FMT ",%" PetscInt_FMT ") of nested submatrix (%" PetscInt_FMT ",%" PetscInt_FMT ") do not agree with space defined by index sets (%" PetscInt_FMT ",%" PetscInt_FMT ")", m, n, i, j, mi, ni);
1741:       }
1742:     }
1743:   }

1745:   /* Set A->assembled if all non-null blocks are currently assembled */
1746:   for (i = 0; i < vs->nr; i++) {
1747:     for (j = 0; j < vs->nc; j++) {
1748:       if (vs->m[i][j] && !vs->m[i][j]->assembled) PetscFunctionReturn(PETSC_SUCCESS);
1749:     }
1750:   }
1751:   A->assembled = PETSC_TRUE;
1752:   PetscFunctionReturn(PETSC_SUCCESS);
1753: }

1755: /*@C
1756:   MatCreateNest - Creates a new `MATNEST` matrix containing several nested submatrices, each stored separately

1758:   Collective

1760:   Input Parameters:
1761: + comm   - Communicator for the new `MATNEST`
1762: . nr     - number of nested row blocks
1763: . is_row - index sets for each nested row block, or `NULL` to make contiguous
1764: . nc     - number of nested column blocks
1765: . is_col - index sets for each nested column block, or `NULL` to make contiguous
1766: - a      - array of nr*nc submatrices, empty submatrices can be passed using `NULL`

1768:   Output Parameter:
1769: . B - new matrix

1771:   Note:
1772:   In both C and Fortran, `a` must be a row-major order array holding references to the matrices.
1773:   For instance, to represent the matrix
1774:   $\begin{bmatrix} A_{11} & A_{12} \\ A_{21} & A_{22}\end{bmatrix}$
1775:   one should use `Mat a[4]={A11,A12,A21,A22}`.

1777:   Level: advanced

1779: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatCreate()`, `VecCreateNest()`, `DMCreateMatrix()`, `MatNestSetSubMat()`,
1780:           `MatNestGetSubMat()`, `MatNestGetLocalISs()`, `MatNestGetSize()`,
1781:           `MatNestGetISs()`, `MatNestSetSubMats()`, `MatNestGetSubMats()`
1782: @*/
1783: PetscErrorCode MatCreateNest(MPI_Comm comm, PetscInt nr, const IS is_row[], PetscInt nc, const IS is_col[], const Mat a[], Mat *B) PeNSS
1784: {
1785:   PetscFunctionBegin;
1786:   PetscCall(MatCreate(comm, B));
1787:   PetscCall(MatSetType(*B, MATNEST));
1788:   (*B)->preallocated = PETSC_TRUE;
1789:   PetscCall(MatNestSetSubMats(*B, nr, is_row, nc, is_col, a));
1790:   PetscFunctionReturn(PETSC_SUCCESS);
1791: }

1793: static PetscErrorCode MatConvert_Nest_SeqAIJ_fast(Mat A, MatType newtype, MatReuse reuse, Mat *newmat)
1794: {
1795:   Mat_Nest     *nest = (Mat_Nest *)A->data;
1796:   Mat          *trans;
1797:   PetscScalar **avv;
1798:   PetscScalar  *vv;
1799:   PetscInt    **aii, **ajj;
1800:   PetscInt     *ii, *jj, *ci;
1801:   PetscInt      nr, nc, nnz, i, j;
1802:   PetscBool     done;

1804:   PetscFunctionBegin;
1805:   PetscCall(MatGetSize(A, &nr, &nc));
1806:   if (reuse == MAT_REUSE_MATRIX) {
1807:     PetscInt rnr;

1809:     PetscCall(MatGetRowIJ(*newmat, 0, PETSC_FALSE, PETSC_FALSE, &rnr, (const PetscInt **)&ii, (const PetscInt **)&jj, &done));
1810:     PetscCheck(done, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "MatGetRowIJ");
1811:     PetscCheck(rnr == nr, PetscObjectComm((PetscObject)A), PETSC_ERR_USER, "Cannot reuse matrix, wrong number of rows");
1812:     PetscCall(MatSeqAIJGetArray(*newmat, &vv));
1813:   }
1814:   /* extract CSR for nested SeqAIJ matrices */
1815:   nnz = 0;
1816:   PetscCall(PetscCalloc4(nest->nr * nest->nc, &aii, nest->nr * nest->nc, &ajj, nest->nr * nest->nc, &avv, nest->nr * nest->nc, &trans));
1817:   for (i = 0; i < nest->nr; ++i) {
1818:     for (j = 0; j < nest->nc; ++j) {
1819:       Mat B = nest->m[i][j];
1820:       if (B) {
1821:         PetscScalar *naa;
1822:         PetscInt    *nii, *njj, nnr;
1823:         PetscBool    istrans;

1825:         PetscCall(PetscObjectTypeCompare((PetscObject)B, MATTRANSPOSEVIRTUAL, &istrans));
1826:         if (istrans) {
1827:           Mat Bt;

1829:           PetscCall(MatTransposeGetMat(B, &Bt));
1830:           PetscCall(MatTranspose(Bt, MAT_INITIAL_MATRIX, &trans[i * nest->nc + j]));
1831:           B = trans[i * nest->nc + j];
1832:         } else {
1833:           PetscCall(PetscObjectTypeCompare((PetscObject)B, MATHERMITIANTRANSPOSEVIRTUAL, &istrans));
1834:           if (istrans) {
1835:             Mat Bt;

1837:             PetscCall(MatHermitianTransposeGetMat(B, &Bt));
1838:             PetscCall(MatHermitianTranspose(Bt, MAT_INITIAL_MATRIX, &trans[i * nest->nc + j]));
1839:             B = trans[i * nest->nc + j];
1840:           }
1841:         }
1842:         PetscCall(MatGetRowIJ(B, 0, PETSC_FALSE, PETSC_FALSE, &nnr, (const PetscInt **)&nii, (const PetscInt **)&njj, &done));
1843:         PetscCheck(done, PetscObjectComm((PetscObject)B), PETSC_ERR_PLIB, "MatGetRowIJ");
1844:         PetscCall(MatSeqAIJGetArray(B, &naa));
1845:         nnz += nii[nnr];

1847:         aii[i * nest->nc + j] = nii;
1848:         ajj[i * nest->nc + j] = njj;
1849:         avv[i * nest->nc + j] = naa;
1850:       }
1851:     }
1852:   }
1853:   if (reuse != MAT_REUSE_MATRIX) {
1854:     PetscCall(PetscMalloc1(nr + 1, &ii));
1855:     PetscCall(PetscMalloc1(nnz, &jj));
1856:     PetscCall(PetscMalloc1(nnz, &vv));
1857:   } else {
1858:     PetscCheck(nnz == ii[nr], PetscObjectComm((PetscObject)A), PETSC_ERR_USER, "Cannot reuse matrix, wrong number of nonzeros");
1859:   }

1861:   /* new row pointer */
1862:   PetscCall(PetscArrayzero(ii, nr + 1));
1863:   for (i = 0; i < nest->nr; ++i) {
1864:     PetscInt ncr, rst;

1866:     PetscCall(ISStrideGetInfo(nest->isglobal.row[i], &rst, NULL));
1867:     PetscCall(ISGetLocalSize(nest->isglobal.row[i], &ncr));
1868:     for (j = 0; j < nest->nc; ++j) {
1869:       if (aii[i * nest->nc + j]) {
1870:         PetscInt *nii = aii[i * nest->nc + j];
1871:         PetscInt  ir;

1873:         for (ir = rst; ir < ncr + rst; ++ir) {
1874:           ii[ir + 1] += nii[1] - nii[0];
1875:           nii++;
1876:         }
1877:       }
1878:     }
1879:   }
1880:   for (i = 0; i < nr; i++) ii[i + 1] += ii[i];

1882:   /* construct CSR for the new matrix */
1883:   PetscCall(PetscCalloc1(nr, &ci));
1884:   for (i = 0; i < nest->nr; ++i) {
1885:     PetscInt ncr, rst;

1887:     PetscCall(ISStrideGetInfo(nest->isglobal.row[i], &rst, NULL));
1888:     PetscCall(ISGetLocalSize(nest->isglobal.row[i], &ncr));
1889:     for (j = 0; j < nest->nc; ++j) {
1890:       if (aii[i * nest->nc + j]) {
1891:         PetscScalar *nvv = avv[i * nest->nc + j], vscale = 1.0, vshift = 0.0;
1892:         PetscInt    *nii = aii[i * nest->nc + j];
1893:         PetscInt    *njj = ajj[i * nest->nc + j];
1894:         PetscInt     ir, cst;

1896:         if (trans[i * nest->nc + j]) {
1897:           vscale = ((Mat_Shell *)nest->m[i][j]->data)->vscale;
1898:           vshift = ((Mat_Shell *)nest->m[i][j]->data)->vshift;
1899:         }
1900:         PetscCall(ISStrideGetInfo(nest->isglobal.col[j], &cst, NULL));
1901:         for (ir = rst; ir < ncr + rst; ++ir) {
1902:           PetscInt ij, rsize = nii[1] - nii[0], ist = ii[ir] + ci[ir];

1904:           for (ij = 0; ij < rsize; ij++) {
1905:             jj[ist + ij] = *njj + cst;
1906:             vv[ist + ij] = vscale * *nvv;
1907:             if (PetscUnlikely(vshift != 0.0 && *njj == ir - rst)) vv[ist + ij] += vshift;
1908:             njj++;
1909:             nvv++;
1910:           }
1911:           ci[ir] += rsize;
1912:           nii++;
1913:         }
1914:       }
1915:     }
1916:   }
1917:   PetscCall(PetscFree(ci));

1919:   /* restore info */
1920:   for (i = 0; i < nest->nr; ++i) {
1921:     for (j = 0; j < nest->nc; ++j) {
1922:       Mat B = nest->m[i][j];
1923:       if (B) {
1924:         PetscInt nnr = 0, k = i * nest->nc + j;

1926:         B = (trans[k] ? trans[k] : B);
1927:         PetscCall(MatRestoreRowIJ(B, 0, PETSC_FALSE, PETSC_FALSE, &nnr, (const PetscInt **)&aii[k], (const PetscInt **)&ajj[k], &done));
1928:         PetscCheck(done, PetscObjectComm((PetscObject)B), PETSC_ERR_PLIB, "MatRestoreRowIJ");
1929:         PetscCall(MatSeqAIJRestoreArray(B, &avv[k]));
1930:         PetscCall(MatDestroy(&trans[k]));
1931:       }
1932:     }
1933:   }
1934:   PetscCall(PetscFree4(aii, ajj, avv, trans));

1936:   /* finalize newmat */
1937:   if (reuse == MAT_INITIAL_MATRIX) {
1938:     PetscCall(MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A), nr, nc, ii, jj, vv, newmat));
1939:   } else if (reuse == MAT_INPLACE_MATRIX) {
1940:     Mat B;

1942:     PetscCall(MatCreateSeqAIJWithArrays(PetscObjectComm((PetscObject)A), nr, nc, ii, jj, vv, &B));
1943:     PetscCall(MatHeaderReplace(A, &B));
1944:   }
1945:   PetscCall(MatAssemblyBegin(*newmat, MAT_FINAL_ASSEMBLY));
1946:   PetscCall(MatAssemblyEnd(*newmat, MAT_FINAL_ASSEMBLY));
1947:   {
1948:     Mat_SeqAIJ *a = (Mat_SeqAIJ *)((*newmat)->data);
1949:     a->free_a     = PETSC_TRUE;
1950:     a->free_ij    = PETSC_TRUE;
1951:   }
1952:   PetscFunctionReturn(PETSC_SUCCESS);
1953: }

1955: PETSC_INTERN PetscErrorCode MatAXPY_Dense_Nest(Mat Y, PetscScalar a, Mat X)
1956: {
1957:   Mat_Nest *nest = (Mat_Nest *)X->data;
1958:   PetscInt  i, j, k, rstart;
1959:   PetscBool flg;

1961:   PetscFunctionBegin;
1962:   /* Fill by row */
1963:   for (j = 0; j < nest->nc; ++j) {
1964:     /* Using global column indices and ISAllGather() is not scalable. */
1965:     IS              bNis;
1966:     PetscInt        bN;
1967:     const PetscInt *bNindices;
1968:     PetscCall(ISAllGather(nest->isglobal.col[j], &bNis));
1969:     PetscCall(ISGetSize(bNis, &bN));
1970:     PetscCall(ISGetIndices(bNis, &bNindices));
1971:     for (i = 0; i < nest->nr; ++i) {
1972:       Mat             B = nest->m[i][j], D = NULL;
1973:       PetscInt        bm, br;
1974:       const PetscInt *bmindices;
1975:       if (!B) continue;
1976:       PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &flg, MATTRANSPOSEVIRTUAL, MATHERMITIANTRANSPOSEVIRTUAL, ""));
1977:       if (flg) {
1978:         PetscTryMethod(B, "MatTransposeGetMat_C", (Mat, Mat *), (B, &D));
1979:         PetscTryMethod(B, "MatHermitianTransposeGetMat_C", (Mat, Mat *), (B, &D));
1980:         PetscCall(MatConvert(B, ((PetscObject)D)->type_name, MAT_INITIAL_MATRIX, &D));
1981:         B = D;
1982:       }
1983:       PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
1984:       if (flg) {
1985:         if (D) PetscCall(MatConvert(D, MATBAIJ, MAT_INPLACE_MATRIX, &D));
1986:         else PetscCall(MatConvert(B, MATBAIJ, MAT_INITIAL_MATRIX, &D));
1987:         B = D;
1988:       }
1989:       PetscCall(ISGetLocalSize(nest->isglobal.row[i], &bm));
1990:       PetscCall(ISGetIndices(nest->isglobal.row[i], &bmindices));
1991:       PetscCall(MatGetOwnershipRange(B, &rstart, NULL));
1992:       for (br = 0; br < bm; ++br) {
1993:         PetscInt           row = bmindices[br], brncols, *cols;
1994:         const PetscInt    *brcols;
1995:         const PetscScalar *brcoldata;
1996:         PetscScalar       *vals = NULL;
1997:         PetscCall(MatGetRow(B, br + rstart, &brncols, &brcols, &brcoldata));
1998:         PetscCall(PetscMalloc1(brncols, &cols));
1999:         for (k = 0; k < brncols; k++) cols[k] = bNindices[brcols[k]];
2000:         /*
2001:           Nest blocks are required to be nonoverlapping -- otherwise nest and monolithic index layouts wouldn't match.
2002:           Thus, we could use INSERT_VALUES, but I prefer ADD_VALUES.
2003:          */
2004:         if (a != 1.0) {
2005:           PetscCall(PetscMalloc1(brncols, &vals));
2006:           for (k = 0; k < brncols; k++) vals[k] = a * brcoldata[k];
2007:           PetscCall(MatSetValues(Y, 1, &row, brncols, cols, vals, ADD_VALUES));
2008:           PetscCall(PetscFree(vals));
2009:         } else {
2010:           PetscCall(MatSetValues(Y, 1, &row, brncols, cols, brcoldata, ADD_VALUES));
2011:         }
2012:         PetscCall(MatRestoreRow(B, br + rstart, &brncols, &brcols, &brcoldata));
2013:         PetscCall(PetscFree(cols));
2014:       }
2015:       if (D) PetscCall(MatDestroy(&D));
2016:       PetscCall(ISRestoreIndices(nest->isglobal.row[i], &bmindices));
2017:     }
2018:     PetscCall(ISRestoreIndices(bNis, &bNindices));
2019:     PetscCall(ISDestroy(&bNis));
2020:   }
2021:   PetscCall(MatAssemblyBegin(Y, MAT_FINAL_ASSEMBLY));
2022:   PetscCall(MatAssemblyEnd(Y, MAT_FINAL_ASSEMBLY));
2023:   PetscFunctionReturn(PETSC_SUCCESS);
2024: }

2026: static PetscErrorCode MatConvert_Nest_AIJ(Mat A, MatType newtype, MatReuse reuse, Mat *newmat)
2027: {
2028:   Mat_Nest   *nest = (Mat_Nest *)A->data;
2029:   PetscInt    m, n, M, N, i, j, k, *dnnz, *onnz = NULL, rstart, cstart, cend;
2030:   PetscMPIInt size;
2031:   Mat         C;

2033:   PetscFunctionBegin;
2034:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)A), &size));
2035:   if (size == 1) { /* look for a special case with SeqAIJ matrices and strided-1, contiguous, blocks */
2036:     PetscInt  nf;
2037:     PetscBool fast;

2039:     PetscCall(PetscStrcmp(newtype, MATAIJ, &fast));
2040:     if (!fast) PetscCall(PetscStrcmp(newtype, MATSEQAIJ, &fast));
2041:     for (i = 0; i < nest->nr && fast; ++i) {
2042:       for (j = 0; j < nest->nc && fast; ++j) {
2043:         Mat B = nest->m[i][j];
2044:         if (B) {
2045:           PetscCall(PetscObjectTypeCompare((PetscObject)B, MATSEQAIJ, &fast));
2046:           if (!fast) {
2047:             PetscBool istrans;

2049:             PetscCall(PetscObjectTypeCompare((PetscObject)B, MATTRANSPOSEVIRTUAL, &istrans));
2050:             if (istrans) {
2051:               Mat Bt;

2053:               PetscCall(MatTransposeGetMat(B, &Bt));
2054:               PetscCall(PetscObjectTypeCompare((PetscObject)Bt, MATSEQAIJ, &fast));
2055:             } else {
2056:               PetscCall(PetscObjectTypeCompare((PetscObject)B, MATHERMITIANTRANSPOSEVIRTUAL, &istrans));
2057:               if (istrans) {
2058:                 Mat Bt;

2060:                 PetscCall(MatHermitianTransposeGetMat(B, &Bt));
2061:                 PetscCall(PetscObjectTypeCompare((PetscObject)Bt, MATSEQAIJ, &fast));
2062:               }
2063:             }
2064:             if (fast) fast = (PetscBool)(!((Mat_Shell *)B->data)->zrows && !((Mat_Shell *)B->data)->zcols && !((Mat_Shell *)B->data)->axpy && !((Mat_Shell *)B->data)->left && !((Mat_Shell *)B->data)->right && !((Mat_Shell *)B->data)->dshift);
2065:           }
2066:         }
2067:       }
2068:     }
2069:     for (i = 0, nf = 0; i < nest->nr && fast; ++i) {
2070:       PetscCall(PetscObjectTypeCompare((PetscObject)nest->isglobal.row[i], ISSTRIDE, &fast));
2071:       if (fast) {
2072:         PetscInt f, s;

2074:         PetscCall(ISStrideGetInfo(nest->isglobal.row[i], &f, &s));
2075:         if (f != nf || s != 1) {
2076:           fast = PETSC_FALSE;
2077:         } else {
2078:           PetscCall(ISGetSize(nest->isglobal.row[i], &f));
2079:           nf += f;
2080:         }
2081:       }
2082:     }
2083:     for (i = 0, nf = 0; i < nest->nc && fast; ++i) {
2084:       PetscCall(PetscObjectTypeCompare((PetscObject)nest->isglobal.col[i], ISSTRIDE, &fast));
2085:       if (fast) {
2086:         PetscInt f, s;

2088:         PetscCall(ISStrideGetInfo(nest->isglobal.col[i], &f, &s));
2089:         if (f != nf || s != 1) {
2090:           fast = PETSC_FALSE;
2091:         } else {
2092:           PetscCall(ISGetSize(nest->isglobal.col[i], &f));
2093:           nf += f;
2094:         }
2095:       }
2096:     }
2097:     if (fast) {
2098:       PetscCall(MatConvert_Nest_SeqAIJ_fast(A, newtype, reuse, newmat));
2099:       PetscFunctionReturn(PETSC_SUCCESS);
2100:     }
2101:   }
2102:   PetscCall(MatGetSize(A, &M, &N));
2103:   PetscCall(MatGetLocalSize(A, &m, &n));
2104:   PetscCall(MatGetOwnershipRangeColumn(A, &cstart, &cend));
2105:   if (reuse == MAT_REUSE_MATRIX) C = *newmat;
2106:   else {
2107:     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2108:     PetscCall(MatSetType(C, newtype));
2109:     PetscCall(MatSetSizes(C, m, n, M, N));
2110:   }
2111:   PetscCall(PetscMalloc1(2 * m, &dnnz));
2112:   if (m) {
2113:     onnz = dnnz + m;
2114:     for (k = 0; k < m; k++) {
2115:       dnnz[k] = 0;
2116:       onnz[k] = 0;
2117:     }
2118:   }
2119:   for (j = 0; j < nest->nc; ++j) {
2120:     IS              bNis;
2121:     PetscInt        bN;
2122:     const PetscInt *bNindices;
2123:     PetscBool       flg;
2124:     /* Using global column indices and ISAllGather() is not scalable. */
2125:     PetscCall(ISAllGather(nest->isglobal.col[j], &bNis));
2126:     PetscCall(ISGetSize(bNis, &bN));
2127:     PetscCall(ISGetIndices(bNis, &bNindices));
2128:     for (i = 0; i < nest->nr; ++i) {
2129:       PetscSF         bmsf;
2130:       PetscSFNode    *iremote;
2131:       Mat             B = nest->m[i][j], D = NULL;
2132:       PetscInt        bm, *sub_dnnz, *sub_onnz, br;
2133:       const PetscInt *bmindices;
2134:       if (!B) continue;
2135:       PetscCall(ISGetLocalSize(nest->isglobal.row[i], &bm));
2136:       PetscCall(ISGetIndices(nest->isglobal.row[i], &bmindices));
2137:       PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)A), &bmsf));
2138:       PetscCall(PetscMalloc1(bm, &iremote));
2139:       PetscCall(PetscMalloc1(bm, &sub_dnnz));
2140:       PetscCall(PetscMalloc1(bm, &sub_onnz));
2141:       for (k = 0; k < bm; ++k) {
2142:         sub_dnnz[k] = 0;
2143:         sub_onnz[k] = 0;
2144:       }
2145:       PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &flg, MATTRANSPOSEVIRTUAL, MATHERMITIANTRANSPOSEVIRTUAL, ""));
2146:       if (flg) {
2147:         PetscTryMethod(B, "MatTransposeGetMat_C", (Mat, Mat *), (B, &D));
2148:         PetscTryMethod(B, "MatHermitianTransposeGetMat_C", (Mat, Mat *), (B, &D));
2149:         PetscCall(MatConvert(B, ((PetscObject)D)->type_name, MAT_INITIAL_MATRIX, &D));
2150:         B = D;
2151:       }
2152:       PetscCall(PetscObjectTypeCompareAny((PetscObject)B, &flg, MATSEQSBAIJ, MATMPISBAIJ, ""));
2153:       if (flg) {
2154:         if (D) PetscCall(MatConvert(D, MATBAIJ, MAT_INPLACE_MATRIX, &D));
2155:         else PetscCall(MatConvert(B, MATBAIJ, MAT_INITIAL_MATRIX, &D));
2156:         B = D;
2157:       }
2158:       /*
2159:        Locate the owners for all of the locally-owned global row indices for this row block.
2160:        These determine the roots of PetscSF used to communicate preallocation data to row owners.
2161:        The roots correspond to the dnnz and onnz entries; thus, there are two roots per row.
2162:        */
2163:       PetscCall(MatGetOwnershipRange(B, &rstart, NULL));
2164:       for (br = 0; br < bm; ++br) {
2165:         PetscInt        row = bmindices[br], brncols, col;
2166:         const PetscInt *brcols;
2167:         PetscInt        rowrel   = 0; /* row's relative index on its owner rank */
2168:         PetscMPIInt     rowowner = 0;
2169:         PetscCall(PetscLayoutFindOwnerIndex(A->rmap, row, &rowowner, &rowrel));
2170:         /* how many roots  */
2171:         iremote[br].rank  = rowowner;
2172:         iremote[br].index = rowrel; /* edge from bmdnnz to dnnz */
2173:         /* get nonzero pattern */
2174:         PetscCall(MatGetRow(B, br + rstart, &brncols, &brcols, NULL));
2175:         for (k = 0; k < brncols; k++) {
2176:           col = bNindices[brcols[k]];
2177:           if (col >= A->cmap->range[rowowner] && col < A->cmap->range[rowowner + 1]) {
2178:             sub_dnnz[br]++;
2179:           } else {
2180:             sub_onnz[br]++;
2181:           }
2182:         }
2183:         PetscCall(MatRestoreRow(B, br + rstart, &brncols, &brcols, NULL));
2184:       }
2185:       if (D) PetscCall(MatDestroy(&D));
2186:       PetscCall(ISRestoreIndices(nest->isglobal.row[i], &bmindices));
2187:       /* bsf will have to take care of disposing of bedges. */
2188:       PetscCall(PetscSFSetGraph(bmsf, m, bm, NULL, PETSC_OWN_POINTER, iremote, PETSC_OWN_POINTER));
2189:       PetscCall(PetscSFReduceBegin(bmsf, MPIU_INT, sub_dnnz, dnnz, MPI_SUM));
2190:       PetscCall(PetscSFReduceEnd(bmsf, MPIU_INT, sub_dnnz, dnnz, MPI_SUM));
2191:       PetscCall(PetscSFReduceBegin(bmsf, MPIU_INT, sub_onnz, onnz, MPI_SUM));
2192:       PetscCall(PetscSFReduceEnd(bmsf, MPIU_INT, sub_onnz, onnz, MPI_SUM));
2193:       PetscCall(PetscFree(sub_dnnz));
2194:       PetscCall(PetscFree(sub_onnz));
2195:       PetscCall(PetscSFDestroy(&bmsf));
2196:     }
2197:     PetscCall(ISRestoreIndices(bNis, &bNindices));
2198:     PetscCall(ISDestroy(&bNis));
2199:   }
2200:   /* Resize preallocation if overestimated */
2201:   for (i = 0; i < m; i++) {
2202:     dnnz[i] = PetscMin(dnnz[i], A->cmap->n);
2203:     onnz[i] = PetscMin(onnz[i], A->cmap->N - A->cmap->n);
2204:   }
2205:   PetscCall(MatSeqAIJSetPreallocation(C, 0, dnnz));
2206:   PetscCall(MatMPIAIJSetPreallocation(C, 0, dnnz, 0, onnz));
2207:   PetscCall(PetscFree(dnnz));
2208:   PetscCall(MatAXPY_Dense_Nest(C, 1.0, A));
2209:   if (reuse == MAT_INPLACE_MATRIX) {
2210:     PetscCall(MatHeaderReplace(A, &C));
2211:   } else *newmat = C;
2212:   PetscFunctionReturn(PETSC_SUCCESS);
2213: }

2215: static PetscErrorCode MatConvert_Nest_Dense(Mat A, MatType newtype, MatReuse reuse, Mat *newmat)
2216: {
2217:   Mat      B;
2218:   PetscInt m, n, M, N;

2220:   PetscFunctionBegin;
2221:   PetscCall(MatGetSize(A, &M, &N));
2222:   PetscCall(MatGetLocalSize(A, &m, &n));
2223:   if (reuse == MAT_REUSE_MATRIX) {
2224:     B = *newmat;
2225:     PetscCall(MatZeroEntries(B));
2226:   } else {
2227:     PetscCall(MatCreateDense(PetscObjectComm((PetscObject)A), m, PETSC_DECIDE, M, N, NULL, &B));
2228:   }
2229:   PetscCall(MatAXPY_Dense_Nest(B, 1.0, A));
2230:   if (reuse == MAT_INPLACE_MATRIX) {
2231:     PetscCall(MatHeaderReplace(A, &B));
2232:   } else if (reuse == MAT_INITIAL_MATRIX) *newmat = B;
2233:   PetscFunctionReturn(PETSC_SUCCESS);
2234: }

2236: static PetscErrorCode MatHasOperation_Nest(Mat mat, MatOperation op, PetscBool *has)
2237: {
2238:   Mat_Nest    *bA = (Mat_Nest *)mat->data;
2239:   MatOperation opAdd;
2240:   PetscInt     i, j, nr = bA->nr, nc = bA->nc;
2241:   PetscBool    flg;

2243:   PetscFunctionBegin;
2244:   *has = PETSC_FALSE;
2245:   if (op == MATOP_MULT || op == MATOP_MULT_ADD || op == MATOP_MULT_TRANSPOSE || op == MATOP_MULT_TRANSPOSE_ADD) {
2246:     opAdd = (op == MATOP_MULT || op == MATOP_MULT_ADD ? MATOP_MULT_ADD : MATOP_MULT_TRANSPOSE_ADD);
2247:     for (j = 0; j < nc; j++) {
2248:       for (i = 0; i < nr; i++) {
2249:         if (!bA->m[i][j]) continue;
2250:         PetscCall(MatHasOperation(bA->m[i][j], opAdd, &flg));
2251:         if (!flg) PetscFunctionReturn(PETSC_SUCCESS);
2252:       }
2253:     }
2254:   }
2255:   if (((void **)mat->ops)[op]) *has = PETSC_TRUE;
2256:   PetscFunctionReturn(PETSC_SUCCESS);
2257: }

2259: /*MC
2260:   MATNEST -  "nest" - Matrix type consisting of nested submatrices, each stored separately.

2262:   Level: intermediate

2264:   Notes:
2265:   This matrix type permits scalable use of `PCFIELDSPLIT` and avoids the large memory costs of extracting submatrices.
2266:   It allows the use of symmetric and block formats for parts of multi-physics simulations.
2267:   It is usually used with `DMCOMPOSITE` and `DMCreateMatrix()`

2269:   Each of the submatrices lives on the same MPI communicator as the original nest matrix (though they can have zero
2270:   rows/columns on some processes.) Thus this is not meant for cases where the submatrices live on far fewer processes
2271:   than the nest matrix.

2273: .seealso: [](ch_matrices), `Mat`, `MATNEST`, `MatCreate()`, `MatType`, `MatCreateNest()`, `MatNestSetSubMat()`, `MatNestGetSubMat()`,
2274:           `VecCreateNest()`, `DMCreateMatrix()`, `DMCOMPOSITE`, `MatNestSetVecType()`, `MatNestGetLocalISs()`,
2275:           `MatNestGetISs()`, `MatNestSetSubMats()`, `MatNestGetSubMats()`
2276: M*/
2277: PETSC_EXTERN PetscErrorCode MatCreate_Nest(Mat A)
2278: {
2279:   Mat_Nest *s;

2281:   PetscFunctionBegin;
2282:   PetscCall(PetscNew(&s));
2283:   A->data = (void *)s;

2285:   s->nr            = -1;
2286:   s->nc            = -1;
2287:   s->m             = NULL;
2288:   s->splitassembly = PETSC_FALSE;

2290:   PetscCall(PetscMemzero(A->ops, sizeof(*A->ops)));

2292:   A->ops->mult                      = MatMult_Nest;
2293:   A->ops->multadd                   = MatMultAdd_Nest;
2294:   A->ops->multtranspose             = MatMultTranspose_Nest;
2295:   A->ops->multtransposeadd          = MatMultTransposeAdd_Nest;
2296:   A->ops->transpose                 = MatTranspose_Nest;
2297:   A->ops->multhermitiantranspose    = MatMultHermitianTranspose_Nest;
2298:   A->ops->multhermitiantransposeadd = MatMultHermitianTransposeAdd_Nest;
2299:   A->ops->assemblybegin             = MatAssemblyBegin_Nest;
2300:   A->ops->assemblyend               = MatAssemblyEnd_Nest;
2301:   A->ops->zeroentries               = MatZeroEntries_Nest;
2302:   A->ops->copy                      = MatCopy_Nest;
2303:   A->ops->axpy                      = MatAXPY_Nest;
2304:   A->ops->duplicate                 = MatDuplicate_Nest;
2305:   A->ops->createsubmatrix           = MatCreateSubMatrix_Nest;
2306:   A->ops->destroy                   = MatDestroy_Nest;
2307:   A->ops->view                      = MatView_Nest;
2308:   A->ops->getvecs                   = NULL; /* Use VECNEST by calling MatNestSetVecType(A,VECNEST) */
2309:   A->ops->getlocalsubmatrix         = MatGetLocalSubMatrix_Nest;
2310:   A->ops->restorelocalsubmatrix     = MatRestoreLocalSubMatrix_Nest;
2311:   A->ops->getdiagonal               = MatGetDiagonal_Nest;
2312:   A->ops->diagonalscale             = MatDiagonalScale_Nest;
2313:   A->ops->scale                     = MatScale_Nest;
2314:   A->ops->shift                     = MatShift_Nest;
2315:   A->ops->diagonalset               = MatDiagonalSet_Nest;
2316:   A->ops->setrandom                 = MatSetRandom_Nest;
2317:   A->ops->hasoperation              = MatHasOperation_Nest;
2318:   A->ops->missingdiagonal           = MatMissingDiagonal_Nest;

2320:   A->spptr     = NULL;
2321:   A->assembled = PETSC_FALSE;

2323:   /* expose Nest api's */
2324:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetSubMat_C", MatNestGetSubMat_Nest));
2325:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestSetSubMat_C", MatNestSetSubMat_Nest));
2326:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetSubMats_C", MatNestGetSubMats_Nest));
2327:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetSize_C", MatNestGetSize_Nest));
2328:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetISs_C", MatNestGetISs_Nest));
2329:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestGetLocalISs_C", MatNestGetLocalISs_Nest));
2330:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestSetVecType_C", MatNestSetVecType_Nest));
2331:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatNestSetSubMats_C", MatNestSetSubMats_Nest));
2332:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_mpiaij_C", MatConvert_Nest_AIJ));
2333:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_seqaij_C", MatConvert_Nest_AIJ));
2334:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_aij_C", MatConvert_Nest_AIJ));
2335:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_is_C", MatConvert_Nest_IS));
2336:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_mpidense_C", MatConvert_Nest_Dense));
2337:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_nest_seqdense_C", MatConvert_Nest_Dense));
2338:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_nest_seqdense_C", MatProductSetFromOptions_Nest_Dense));
2339:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_nest_mpidense_C", MatProductSetFromOptions_Nest_Dense));

2341:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATNEST));
2342:   PetscFunctionReturn(PETSC_SUCCESS);
2343: }