Actual source code: asm.c
petsc-3.13.6 2020-09-29
1: /*
2: This file defines an additive Schwarz preconditioner for any Mat implementation.
4: Note that each processor may have any number of subdomains. But in order to
5: deal easily with the VecScatter(), we treat each processor as if it has the
6: same number of subdomains.
8: n - total number of true subdomains on all processors
9: n_local_true - actual number of subdomains on this processor
10: n_local = maximum over all processors of n_local_true
11: */
13: #include <../src/ksp/pc/impls/asm/asm.h>
15: static PetscErrorCode PCView_ASM(PC pc,PetscViewer viewer)
16: {
17: PC_ASM *osm = (PC_ASM*)pc->data;
19: PetscMPIInt rank;
20: PetscInt i,bsz;
21: PetscBool iascii,isstring;
22: PetscViewer sviewer;
25: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
26: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
27: if (iascii) {
28: char overlaps[256] = "user-defined overlap",blocks[256] = "total subdomain blocks not yet set";
29: if (osm->overlap >= 0) {PetscSNPrintf(overlaps,sizeof(overlaps),"amount of overlap = %D",osm->overlap);}
30: if (osm->n > 0) {PetscSNPrintf(blocks,sizeof(blocks),"total subdomain blocks = %D",osm->n);}
31: PetscViewerASCIIPrintf(viewer," %s, %s\n",blocks,overlaps);
32: PetscViewerASCIIPrintf(viewer," restriction/interpolation type - %s\n",PCASMTypes[osm->type]);
33: if (osm->dm_subdomains) {PetscViewerASCIIPrintf(viewer," Additive Schwarz: using DM to define subdomains\n");}
34: if (osm->loctype != PC_COMPOSITE_ADDITIVE) {PetscViewerASCIIPrintf(viewer," Additive Schwarz: local solve composition type - %s\n",PCCompositeTypes[osm->loctype]);}
35: MPI_Comm_rank(PetscObjectComm((PetscObject)pc),&rank);
36: if (osm->same_local_solves) {
37: if (osm->ksp) {
38: PetscViewerASCIIPrintf(viewer," Local solve is same for all blocks, in the following KSP and PC objects:\n");
39: PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
40: if (!rank) {
41: PetscViewerASCIIPushTab(viewer);
42: KSPView(osm->ksp[0],sviewer);
43: PetscViewerASCIIPopTab(viewer);
44: }
45: PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
46: }
47: } else {
48: PetscViewerASCIIPushSynchronized(viewer);
49: PetscViewerASCIISynchronizedPrintf(viewer," [%d] number of local blocks = %D\n",(int)rank,osm->n_local_true);
50: PetscViewerFlush(viewer);
51: PetscViewerASCIIPrintf(viewer," Local solve info for each block is in the following KSP and PC objects:\n");
52: PetscViewerASCIIPushTab(viewer);
53: PetscViewerASCIIPrintf(viewer,"- - - - - - - - - - - - - - - - - -\n");
54: PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
55: for (i=0; i<osm->n_local_true; i++) {
56: ISGetLocalSize(osm->is[i],&bsz);
57: PetscViewerASCIISynchronizedPrintf(sviewer,"[%d] local block number %D, size = %D\n",(int)rank,i,bsz);
58: KSPView(osm->ksp[i],sviewer);
59: PetscViewerASCIISynchronizedPrintf(sviewer,"- - - - - - - - - - - - - - - - - -\n");
60: }
61: PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
62: PetscViewerASCIIPopTab(viewer);
63: PetscViewerFlush(viewer);
64: PetscViewerASCIIPopSynchronized(viewer);
65: }
66: } else if (isstring) {
67: PetscViewerStringSPrintf(viewer," blocks=%D, overlap=%D, type=%s",osm->n,osm->overlap,PCASMTypes[osm->type]);
68: PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
69: if (osm->ksp) {KSPView(osm->ksp[0],sviewer);}
70: PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer);
71: }
72: return(0);
73: }
75: static PetscErrorCode PCASMPrintSubdomains(PC pc)
76: {
77: PC_ASM *osm = (PC_ASM*)pc->data;
78: const char *prefix;
79: char fname[PETSC_MAX_PATH_LEN+1];
80: PetscViewer viewer, sviewer;
81: char *s;
82: PetscInt i,j,nidx;
83: const PetscInt *idx;
84: PetscMPIInt rank, size;
88: MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size);
89: MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank);
90: PCGetOptionsPrefix(pc,&prefix);
91: PetscOptionsGetString(NULL,prefix,"-pc_asm_print_subdomains",fname,PETSC_MAX_PATH_LEN,NULL);
92: if (fname[0] == 0) { PetscStrcpy(fname,"stdout"); };
93: PetscViewerASCIIOpen(PetscObjectComm((PetscObject)pc),fname,&viewer);
94: for (i=0; i<osm->n_local; i++) {
95: if (i < osm->n_local_true) {
96: ISGetLocalSize(osm->is[i],&nidx);
97: ISGetIndices(osm->is[i],&idx);
98: /* Print to a string viewer; no more than 15 characters per index plus 512 char for the header.*/
99: #define len 16*(nidx+1)+512
100: PetscMalloc1(len,&s);
101: PetscViewerStringOpen(PETSC_COMM_SELF, s, len, &sviewer);
102: #undef len
103: PetscViewerStringSPrintf(sviewer, "[%D:%D] Subdomain %D with overlap:\n", rank, size, i);
104: for (j=0; j<nidx; j++) {
105: PetscViewerStringSPrintf(sviewer,"%D ",idx[j]);
106: }
107: ISRestoreIndices(osm->is[i],&idx);
108: PetscViewerStringSPrintf(sviewer,"\n");
109: PetscViewerDestroy(&sviewer);
110: PetscViewerASCIIPushSynchronized(viewer);
111: PetscViewerASCIISynchronizedPrintf(viewer, s);
112: PetscViewerFlush(viewer);
113: PetscViewerASCIIPopSynchronized(viewer);
114: PetscFree(s);
115: if (osm->is_local) {
116: /* Print to a string viewer; no more than 15 characters per index plus 512 char for the header.*/
117: #define len 16*(nidx+1)+512
118: PetscMalloc1(len, &s);
119: PetscViewerStringOpen(PETSC_COMM_SELF, s, len, &sviewer);
120: #undef len
121: PetscViewerStringSPrintf(sviewer, "[%D:%D] Subdomain %D without overlap:\n", rank, size, i);
122: ISGetLocalSize(osm->is_local[i],&nidx);
123: ISGetIndices(osm->is_local[i],&idx);
124: for (j=0; j<nidx; j++) {
125: PetscViewerStringSPrintf(sviewer,"%D ",idx[j]);
126: }
127: ISRestoreIndices(osm->is_local[i],&idx);
128: PetscViewerStringSPrintf(sviewer,"\n");
129: PetscViewerDestroy(&sviewer);
130: PetscViewerASCIIPushSynchronized(viewer);
131: PetscViewerASCIISynchronizedPrintf(viewer, s);
132: PetscViewerFlush(viewer);
133: PetscViewerASCIIPopSynchronized(viewer);
134: PetscFree(s);
135: }
136: } else {
137: /* Participate in collective viewer calls. */
138: PetscViewerASCIIPushSynchronized(viewer);
139: PetscViewerFlush(viewer);
140: PetscViewerASCIIPopSynchronized(viewer);
141: /* Assume either all ranks have is_local or none do. */
142: if (osm->is_local) {
143: PetscViewerASCIIPushSynchronized(viewer);
144: PetscViewerFlush(viewer);
145: PetscViewerASCIIPopSynchronized(viewer);
146: }
147: }
148: }
149: PetscViewerFlush(viewer);
150: PetscViewerDestroy(&viewer);
151: return(0);
152: }
154: static PetscErrorCode PCSetUp_ASM(PC pc)
155: {
156: PC_ASM *osm = (PC_ASM*)pc->data;
158: PetscBool flg;
159: PetscInt i,m,m_local;
160: MatReuse scall = MAT_REUSE_MATRIX;
161: IS isl;
162: KSP ksp;
163: PC subpc;
164: const char *prefix,*pprefix;
165: Vec vec;
166: DM *domain_dm = NULL;
169: if (!pc->setupcalled) {
170: PetscInt m;
172: /* Note: if subdomains have been set either via PCASMSetTotalSubdomains() or via PCASMSetLocalSubdomains(), osm->n_local_true will not be PETSC_DECIDE */
173: if (osm->n_local_true == PETSC_DECIDE) {
174: /* no subdomains given */
175: /* try pc->dm first, if allowed */
176: if (osm->dm_subdomains && pc->dm) {
177: PetscInt num_domains, d;
178: char **domain_names;
179: IS *inner_domain_is, *outer_domain_is;
180: DMCreateDomainDecomposition(pc->dm, &num_domains, &domain_names, &inner_domain_is, &outer_domain_is, &domain_dm);
181: osm->overlap = -1; /* We do not want to increase the overlap of the IS.
182: A future improvement of this code might allow one to use
183: DM-defined subdomains and also increase the overlap,
184: but that is not currently supported */
185: if (num_domains) {
186: PCASMSetLocalSubdomains(pc, num_domains, outer_domain_is, inner_domain_is);
187: }
188: for (d = 0; d < num_domains; ++d) {
189: if (domain_names) {PetscFree(domain_names[d]);}
190: if (inner_domain_is) {ISDestroy(&inner_domain_is[d]);}
191: if (outer_domain_is) {ISDestroy(&outer_domain_is[d]);}
192: }
193: PetscFree(domain_names);
194: PetscFree(inner_domain_is);
195: PetscFree(outer_domain_is);
196: }
197: if (osm->n_local_true == PETSC_DECIDE) {
198: /* still no subdomains; use one subdomain per processor */
199: osm->n_local_true = 1;
200: }
201: }
202: { /* determine the global and max number of subdomains */
203: struct {PetscInt max,sum;} inwork,outwork;
204: PetscMPIInt size;
206: inwork.max = osm->n_local_true;
207: inwork.sum = osm->n_local_true;
208: MPIU_Allreduce(&inwork,&outwork,1,MPIU_2INT,MPIU_MAXSUM_OP,PetscObjectComm((PetscObject)pc));
209: osm->n_local = outwork.max;
210: osm->n = outwork.sum;
212: MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);
213: if (outwork.max == 1 && outwork.sum == size) {
214: /* osm->n_local_true = 1 on all processes, set this option may enable use of optimized MatCreateSubMatrices() implementation */
215: MatSetOption(pc->pmat,MAT_SUBMAT_SINGLEIS,PETSC_TRUE);
216: }
217: }
218: if (!osm->is) { /* create the index sets */
219: PCASMCreateSubdomains(pc->pmat,osm->n_local_true,&osm->is);
220: }
221: if (osm->n_local_true > 1 && !osm->is_local) {
222: PetscMalloc1(osm->n_local_true,&osm->is_local);
223: for (i=0; i<osm->n_local_true; i++) {
224: if (osm->overlap > 0) { /* With positive overlap, osm->is[i] will be modified */
225: ISDuplicate(osm->is[i],&osm->is_local[i]);
226: ISCopy(osm->is[i],osm->is_local[i]);
227: } else {
228: PetscObjectReference((PetscObject)osm->is[i]);
229: osm->is_local[i] = osm->is[i];
230: }
231: }
232: }
233: PCGetOptionsPrefix(pc,&prefix);
234: flg = PETSC_FALSE;
235: PetscOptionsGetBool(NULL,prefix,"-pc_asm_print_subdomains",&flg,NULL);
236: if (flg) { PCASMPrintSubdomains(pc); }
238: if (osm->overlap > 0) {
239: /* Extend the "overlapping" regions by a number of steps */
240: MatIncreaseOverlap(pc->pmat,osm->n_local_true,osm->is,osm->overlap);
241: }
242: if (osm->sort_indices) {
243: for (i=0; i<osm->n_local_true; i++) {
244: ISSort(osm->is[i]);
245: if (osm->is_local) {
246: ISSort(osm->is_local[i]);
247: }
248: }
249: }
251: if (!osm->ksp) {
252: /* Create the local solvers */
253: PetscMalloc1(osm->n_local_true,&osm->ksp);
254: if (domain_dm) {
255: PetscInfo(pc,"Setting up ASM subproblems using the embedded DM\n");
256: }
257: for (i=0; i<osm->n_local_true; i++) {
258: KSPCreate(PETSC_COMM_SELF,&ksp);
259: KSPSetErrorIfNotConverged(ksp,pc->erroriffailure);
260: PetscLogObjectParent((PetscObject)pc,(PetscObject)ksp);
261: PetscObjectIncrementTabLevel((PetscObject)ksp,(PetscObject)pc,1);
262: KSPSetType(ksp,KSPPREONLY);
263: KSPGetPC(ksp,&subpc);
264: PCGetOptionsPrefix(pc,&prefix);
265: KSPSetOptionsPrefix(ksp,prefix);
266: KSPAppendOptionsPrefix(ksp,"sub_");
267: if (domain_dm) {
268: KSPSetDM(ksp, domain_dm[i]);
269: KSPSetDMActive(ksp, PETSC_FALSE);
270: DMDestroy(&domain_dm[i]);
271: }
272: osm->ksp[i] = ksp;
273: }
274: if (domain_dm) {
275: PetscFree(domain_dm);
276: }
277: }
279: ISConcatenate(PETSC_COMM_SELF, osm->n_local_true, osm->is, &osm->lis);
280: ISSortRemoveDups(osm->lis);
281: ISGetLocalSize(osm->lis, &m);
282: VecCreateSeq(PETSC_COMM_SELF, m, &osm->lx);
283: VecDuplicate(osm->lx, &osm->ly);
285: scall = MAT_INITIAL_MATRIX;
286: } else {
287: /*
288: Destroy the blocks from the previous iteration
289: */
290: if (pc->flag == DIFFERENT_NONZERO_PATTERN) {
291: MatDestroyMatrices(osm->n_local_true,&osm->pmat);
292: scall = MAT_INITIAL_MATRIX;
293: }
294: }
296: /*
297: Extract out the submatrices
298: */
299: MatCreateSubMatrices(pc->pmat,osm->n_local_true,osm->is,osm->is,scall,&osm->pmat);
300: if (scall == MAT_INITIAL_MATRIX) {
301: PetscObjectGetOptionsPrefix((PetscObject)pc->pmat,&pprefix);
302: for (i=0; i<osm->n_local_true; i++) {
303: PetscLogObjectParent((PetscObject)pc,(PetscObject)osm->pmat[i]);
304: PetscObjectSetOptionsPrefix((PetscObject)osm->pmat[i],pprefix);
305: }
306: }
308: /* Convert the types of the submatrices (if needbe) */
309: if (osm->sub_mat_type) {
310: for (i=0; i<osm->n_local_true; i++) {
311: MatConvert(osm->pmat[i],osm->sub_mat_type,MAT_INPLACE_MATRIX,&(osm->pmat[i]));
312: }
313: }
315: if (!pc->setupcalled) {
316: /* Create the local work vectors (from the local matrices) and scatter contexts */
317: MatCreateVecs(pc->pmat,&vec,0);
319: if (osm->is_local && (osm->type == PC_ASM_INTERPOLATE || osm->type == PC_ASM_NONE )) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot use interpolate or none PCASMType if is_local was provided to PCASMSetLocalSubdomains()");
320: if (osm->is_local && osm->type == PC_ASM_RESTRICT && osm->loctype == PC_COMPOSITE_ADDITIVE) {
321: PetscMalloc1(osm->n_local_true,&osm->lprolongation);
322: }
323: PetscMalloc1(osm->n_local_true,&osm->lrestriction);
324: PetscMalloc1(osm->n_local_true,&osm->x);
325: PetscMalloc1(osm->n_local_true,&osm->y);
327: ISGetLocalSize(osm->lis,&m);
328: ISCreateStride(PETSC_COMM_SELF,m,0,1,&isl);
329: VecScatterCreate(vec,osm->lis,osm->lx,isl,&osm->restriction);
330: ISDestroy(&isl);
333: for (i=0; i<osm->n_local_true; ++i) {
334: ISLocalToGlobalMapping ltog;
335: IS isll;
336: const PetscInt *idx_is;
337: PetscInt *idx_lis,nout;
339: ISGetLocalSize(osm->is[i],&m);
340: MatCreateVecs(osm->pmat[i],&osm->x[i],NULL);
341: VecDuplicate(osm->x[i],&osm->y[i]);
343: /* generate a scatter from ly to y[i] picking all the overlapping is[i] entries */
344: ISLocalToGlobalMappingCreateIS(osm->lis,<og);
345: ISGetLocalSize(osm->is[i],&m);
346: ISGetIndices(osm->is[i], &idx_is);
347: PetscMalloc1(m,&idx_lis);
348: ISGlobalToLocalMappingApply(ltog,IS_GTOLM_DROP,m,idx_is,&nout,idx_lis);
349: if (nout != m) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"is not a subset of lis");
350: ISRestoreIndices(osm->is[i], &idx_is);
351: ISCreateGeneral(PETSC_COMM_SELF,m,idx_lis,PETSC_OWN_POINTER,&isll);
352: ISLocalToGlobalMappingDestroy(<og);
353: ISCreateStride(PETSC_COMM_SELF,m,0,1,&isl);
354: VecScatterCreate(osm->ly,isll,osm->y[i],isl,&osm->lrestriction[i]);
355: ISDestroy(&isll);
356: ISDestroy(&isl);
357: if (osm->lprolongation) { /* generate a scatter from y[i] to ly picking only the the non-overlapping is_local[i] entries */
358: ISLocalToGlobalMapping ltog;
359: IS isll,isll_local;
360: const PetscInt *idx_local;
361: PetscInt *idx1, *idx2, nout;
363: ISGetLocalSize(osm->is_local[i],&m_local);
364: ISGetIndices(osm->is_local[i], &idx_local);
366: ISLocalToGlobalMappingCreateIS(osm->is[i],<og);
367: PetscMalloc1(m_local,&idx1);
368: ISGlobalToLocalMappingApply(ltog,IS_GTOLM_DROP,m_local,idx_local,&nout,idx1);
369: ISLocalToGlobalMappingDestroy(<og);
370: if (nout != m_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"is_local not a subset of is");
371: ISCreateGeneral(PETSC_COMM_SELF,m_local,idx1,PETSC_OWN_POINTER,&isll);
373: ISLocalToGlobalMappingCreateIS(osm->lis,<og);
374: PetscMalloc1(m_local,&idx2);
375: ISGlobalToLocalMappingApply(ltog,IS_GTOLM_DROP,m_local,idx_local,&nout,idx2);
376: ISLocalToGlobalMappingDestroy(<og);
377: if (nout != m_local) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"is_local not a subset of lis");
378: ISCreateGeneral(PETSC_COMM_SELF,m_local,idx2,PETSC_OWN_POINTER,&isll_local);
380: ISRestoreIndices(osm->is_local[i], &idx_local);
381: VecScatterCreate(osm->y[i],isll,osm->ly,isll_local,&osm->lprolongation[i]);
383: ISDestroy(&isll);
384: ISDestroy(&isll_local);
385: }
386: }
387: VecDestroy(&vec);
388: }
390: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) {
391: IS *cis;
392: PetscInt c;
394: PetscMalloc1(osm->n_local_true, &cis);
395: for (c = 0; c < osm->n_local_true; ++c) cis[c] = osm->lis;
396: MatCreateSubMatrices(pc->pmat, osm->n_local_true, osm->is, cis, scall, &osm->lmats);
397: PetscFree(cis);
398: }
400: /* Return control to the user so that the submatrices can be modified (e.g., to apply
401: different boundary conditions for the submatrices than for the global problem) */
402: PCModifySubMatrices(pc,osm->n_local_true,osm->is,osm->is,osm->pmat,pc->modifysubmatricesP);
404: /*
405: Loop over subdomains putting them into local ksp
406: */
407: for (i=0; i<osm->n_local_true; i++) {
408: KSPSetOperators(osm->ksp[i],osm->pmat[i],osm->pmat[i]);
409: if (!pc->setupcalled) {
410: KSPSetFromOptions(osm->ksp[i]);
411: }
412: }
413: return(0);
414: }
416: static PetscErrorCode PCSetUpOnBlocks_ASM(PC pc)
417: {
418: PC_ASM *osm = (PC_ASM*)pc->data;
419: PetscErrorCode ierr;
420: PetscInt i;
421: KSPConvergedReason reason;
424: for (i=0; i<osm->n_local_true; i++) {
425: KSPSetUp(osm->ksp[i]);
426: KSPGetConvergedReason(osm->ksp[i],&reason);
427: if (reason == KSP_DIVERGED_PC_FAILED) {
428: pc->failedreason = PC_SUBPC_ERROR;
429: }
430: }
431: return(0);
432: }
434: static PetscErrorCode PCApply_ASM(PC pc,Vec x,Vec y)
435: {
436: PC_ASM *osm = (PC_ASM*)pc->data;
438: PetscInt i,n_local_true = osm->n_local_true;
439: ScatterMode forward = SCATTER_FORWARD,reverse = SCATTER_REVERSE;
442: /*
443: Support for limiting the restriction or interpolation to only local
444: subdomain values (leaving the other values 0).
445: */
446: if (!(osm->type & PC_ASM_RESTRICT)) {
447: forward = SCATTER_FORWARD_LOCAL;
448: /* have to zero the work RHS since scatter may leave some slots empty */
449: VecSet(osm->lx, 0.0);
450: }
451: if (!(osm->type & PC_ASM_INTERPOLATE)) {
452: reverse = SCATTER_REVERSE_LOCAL;
453: }
455: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE || osm->loctype == PC_COMPOSITE_ADDITIVE) {
456: /* zero the global and the local solutions */
457: VecSet(y, 0.0);
458: VecSet(osm->ly, 0.0);
460: /* Copy the global RHS to local RHS including the ghost nodes */
461: VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward);
462: VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward);
464: /* Restrict local RHS to the overlapping 0-block RHS */
465: VecScatterBegin(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward);
466: VecScatterEnd(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward);
468: /* do the local solves */
469: for (i = 0; i < n_local_true; ++i) {
471: /* solve the overlapping i-block */
472: PetscLogEventBegin(PC_ApplyOnBlocks,osm->ksp[i],osm->x[i],osm->y[i],0);
473: KSPSolve(osm->ksp[i], osm->x[i], osm->y[i]);
474: KSPCheckSolve(osm->ksp[i],pc,osm->y[i]);
475: PetscLogEventEnd(PC_ApplyOnBlocks,osm->ksp[i],osm->x[i],osm->y[i],0);
477: if (osm->lprolongation) { /* interpolate the non-overlapping i-block solution to the local solution (only for restrictive additive) */
478: VecScatterBegin(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward);
479: VecScatterEnd(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward);
480: }
481: else { /* interpolate the overlapping i-block solution to the local solution */
482: VecScatterBegin(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse);
483: VecScatterEnd(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse);
484: }
486: if (i < n_local_true-1) {
487: /* Restrict local RHS to the overlapping (i+1)-block RHS */
488: VecScatterBegin(osm->lrestriction[i+1], osm->lx, osm->x[i+1], INSERT_VALUES, forward);
489: VecScatterEnd(osm->lrestriction[i+1], osm->lx, osm->x[i+1], INSERT_VALUES, forward);
491: if ( osm->loctype == PC_COMPOSITE_MULTIPLICATIVE){
492: /* update the overlapping (i+1)-block RHS using the current local solution */
493: MatMult(osm->lmats[i+1], osm->ly, osm->y[i+1]);
494: VecAXPBY(osm->x[i+1],-1.,1., osm->y[i+1]);
495: }
496: }
497: }
498: /* Add the local solution to the global solution including the ghost nodes */
499: VecScatterBegin(osm->restriction, osm->ly, y, ADD_VALUES, reverse);
500: VecScatterEnd(osm->restriction, osm->ly, y, ADD_VALUES, reverse);
501: } else {
502: SETERRQ1(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Invalid local composition type: %s", PCCompositeTypes[osm->loctype]);
503: }
504: return(0);
505: }
507: static PetscErrorCode PCApplyTranspose_ASM(PC pc,Vec x,Vec y)
508: {
509: PC_ASM *osm = (PC_ASM*)pc->data;
511: PetscInt i,n_local_true = osm->n_local_true;
512: ScatterMode forward = SCATTER_FORWARD,reverse = SCATTER_REVERSE;
515: /*
516: Support for limiting the restriction or interpolation to only local
517: subdomain values (leaving the other values 0).
519: Note: these are reversed from the PCApply_ASM() because we are applying the
520: transpose of the three terms
521: */
523: if (!(osm->type & PC_ASM_INTERPOLATE)) {
524: forward = SCATTER_FORWARD_LOCAL;
525: /* have to zero the work RHS since scatter may leave some slots empty */
526: VecSet(osm->lx, 0.0);
527: }
528: if (!(osm->type & PC_ASM_RESTRICT)) reverse = SCATTER_REVERSE_LOCAL;
530: /* zero the global and the local solutions */
531: VecSet(y, 0.0);
532: VecSet(osm->ly, 0.0);
534: /* Copy the global RHS to local RHS including the ghost nodes */
535: VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward);
536: VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward);
538: /* Restrict local RHS to the overlapping 0-block RHS */
539: VecScatterBegin(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward);
540: VecScatterEnd(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward);
542: /* do the local solves */
543: for (i = 0; i < n_local_true; ++i) {
545: /* solve the overlapping i-block */
546: PetscLogEventBegin(PC_ApplyOnBlocks,osm->ksp[i],osm->x[i],osm->y[i],0);
547: KSPSolveTranspose(osm->ksp[i], osm->x[i], osm->y[i]);
548: KSPCheckSolve(osm->ksp[i],pc,osm->y[i]);
549: PetscLogEventEnd(PC_ApplyOnBlocks,osm->ksp[i],osm->x[i],osm->y[i],0);
551: if (osm->lprolongation) { /* interpolate the non-overlapping i-block solution to the local solution */
552: VecScatterBegin(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward);
553: VecScatterEnd(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward);
554: } else { /* interpolate the overlapping i-block solution to the local solution */
555: VecScatterBegin(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse);
556: VecScatterEnd(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse);
557: }
559: if (i < n_local_true-1) {
560: /* Restrict local RHS to the overlapping (i+1)-block RHS */
561: VecScatterBegin(osm->lrestriction[i+1], osm->lx, osm->x[i+1], INSERT_VALUES, forward);
562: VecScatterEnd(osm->lrestriction[i+1], osm->lx, osm->x[i+1], INSERT_VALUES, forward);
563: }
564: }
565: /* Add the local solution to the global solution including the ghost nodes */
566: VecScatterBegin(osm->restriction, osm->ly, y, ADD_VALUES, reverse);
567: VecScatterEnd(osm->restriction, osm->ly, y, ADD_VALUES, reverse);
569: return(0);
571: }
573: static PetscErrorCode PCReset_ASM(PC pc)
574: {
575: PC_ASM *osm = (PC_ASM*)pc->data;
577: PetscInt i;
580: if (osm->ksp) {
581: for (i=0; i<osm->n_local_true; i++) {
582: KSPReset(osm->ksp[i]);
583: }
584: }
585: if (osm->pmat) {
586: if (osm->n_local_true > 0) {
587: MatDestroySubMatrices(osm->n_local_true,&osm->pmat);
588: }
589: }
590: if (osm->lrestriction) {
591: VecScatterDestroy(&osm->restriction);
592: for (i=0; i<osm->n_local_true; i++) {
593: VecScatterDestroy(&osm->lrestriction[i]);
594: if (osm->lprolongation) {VecScatterDestroy(&osm->lprolongation[i]);}
595: VecDestroy(&osm->x[i]);
596: VecDestroy(&osm->y[i]);
597: }
598: PetscFree(osm->lrestriction);
599: if (osm->lprolongation) {PetscFree(osm->lprolongation);}
600: PetscFree(osm->x);
601: PetscFree(osm->y);
603: }
604: PCASMDestroySubdomains(osm->n_local_true,osm->is,osm->is_local);
605: ISDestroy(&osm->lis);
606: VecDestroy(&osm->lx);
607: VecDestroy(&osm->ly);
608: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) {
609: MatDestroyMatrices(osm->n_local_true, &osm->lmats);
610: }
612: PetscFree(osm->sub_mat_type);
614: osm->is = 0;
615: osm->is_local = 0;
616: return(0);
617: }
619: static PetscErrorCode PCDestroy_ASM(PC pc)
620: {
621: PC_ASM *osm = (PC_ASM*)pc->data;
623: PetscInt i;
626: PCReset_ASM(pc);
627: if (osm->ksp) {
628: for (i=0; i<osm->n_local_true; i++) {
629: KSPDestroy(&osm->ksp[i]);
630: }
631: PetscFree(osm->ksp);
632: }
633: PetscFree(pc->data);
634: return(0);
635: }
637: static PetscErrorCode PCSetFromOptions_ASM(PetscOptionItems *PetscOptionsObject,PC pc)
638: {
639: PC_ASM *osm = (PC_ASM*)pc->data;
641: PetscInt blocks,ovl;
642: PetscBool flg;
643: PCASMType asmtype;
644: PCCompositeType loctype;
645: char sub_mat_type[256];
648: PetscOptionsHead(PetscOptionsObject,"Additive Schwarz options");
649: PetscOptionsBool("-pc_asm_dm_subdomains","Use DMCreateDomainDecomposition() to define subdomains","PCASMSetDMSubdomains",osm->dm_subdomains,&osm->dm_subdomains,&flg);
650: PetscOptionsInt("-pc_asm_blocks","Number of subdomains","PCASMSetTotalSubdomains",osm->n,&blocks,&flg);
651: if (flg) {
652: PCASMSetTotalSubdomains(pc,blocks,NULL,NULL);
653: osm->dm_subdomains = PETSC_FALSE;
654: }
655: PetscOptionsInt("-pc_asm_local_blocks","Number of local subdomains","PCASMSetLocalSubdomains",osm->n_local_true,&blocks,&flg);
656: if (flg) {
657: PCASMSetLocalSubdomains(pc,blocks,NULL,NULL);
658: osm->dm_subdomains = PETSC_FALSE;
659: }
660: PetscOptionsInt("-pc_asm_overlap","Number of grid points overlap","PCASMSetOverlap",osm->overlap,&ovl,&flg);
661: if (flg) {
662: PCASMSetOverlap(pc,ovl);
663: osm->dm_subdomains = PETSC_FALSE;
664: }
665: flg = PETSC_FALSE;
666: PetscOptionsEnum("-pc_asm_type","Type of restriction/extension","PCASMSetType",PCASMTypes,(PetscEnum)osm->type,(PetscEnum*)&asmtype,&flg);
667: if (flg) {PCASMSetType(pc,asmtype); }
668: flg = PETSC_FALSE;
669: PetscOptionsEnum("-pc_asm_local_type","Type of local solver composition","PCASMSetLocalType",PCCompositeTypes,(PetscEnum)osm->loctype,(PetscEnum*)&loctype,&flg);
670: if (flg) {PCASMSetLocalType(pc,loctype); }
671: PetscOptionsFList("-pc_asm_sub_mat_type","Subsolve Matrix Type","PCASMSetSubMatType",MatList,NULL,sub_mat_type,256,&flg);
672: if (flg) {
673: PCASMSetSubMatType(pc,sub_mat_type);
674: }
675: PetscOptionsTail();
676: return(0);
677: }
679: /*------------------------------------------------------------------------------------*/
681: static PetscErrorCode PCASMSetLocalSubdomains_ASM(PC pc,PetscInt n,IS is[],IS is_local[])
682: {
683: PC_ASM *osm = (PC_ASM*)pc->data;
685: PetscInt i;
688: if (n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Each process must have 1 or more blocks, n = %D",n);
689: if (pc->setupcalled && (n != osm->n_local_true || is)) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"PCASMSetLocalSubdomains() should be called before calling PCSetUp().");
691: if (!pc->setupcalled) {
692: if (is) {
693: for (i=0; i<n; i++) {PetscObjectReference((PetscObject)is[i]);}
694: }
695: if (is_local) {
696: for (i=0; i<n; i++) {PetscObjectReference((PetscObject)is_local[i]);}
697: }
698: PCASMDestroySubdomains(osm->n_local_true,osm->is,osm->is_local);
700: osm->n_local_true = n;
701: osm->is = 0;
702: osm->is_local = 0;
703: if (is) {
704: PetscMalloc1(n,&osm->is);
705: for (i=0; i<n; i++) osm->is[i] = is[i];
706: /* Flag indicating that the user has set overlapping subdomains so PCASM should not increase their size. */
707: osm->overlap = -1;
708: }
709: if (is_local) {
710: PetscMalloc1(n,&osm->is_local);
711: for (i=0; i<n; i++) osm->is_local[i] = is_local[i];
712: if (!is) {
713: PetscMalloc1(osm->n_local_true,&osm->is);
714: for (i=0; i<osm->n_local_true; i++) {
715: if (osm->overlap > 0) { /* With positive overlap, osm->is[i] will be modified */
716: ISDuplicate(osm->is_local[i],&osm->is[i]);
717: ISCopy(osm->is_local[i],osm->is[i]);
718: } else {
719: PetscObjectReference((PetscObject)osm->is_local[i]);
720: osm->is[i] = osm->is_local[i];
721: }
722: }
723: }
724: }
725: }
726: return(0);
727: }
729: static PetscErrorCode PCASMSetTotalSubdomains_ASM(PC pc,PetscInt N,IS *is,IS *is_local)
730: {
731: PC_ASM *osm = (PC_ASM*)pc->data;
733: PetscMPIInt rank,size;
734: PetscInt n;
737: if (N < 1) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Number of total blocks must be > 0, N = %D",N);
738: if (is || is_local) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Use PCASMSetLocalSubdomains() to set specific index sets\n\they cannot be set globally yet.");
740: /*
741: Split the subdomains equally among all processors
742: */
743: MPI_Comm_rank(PetscObjectComm((PetscObject)pc),&rank);
744: MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);
745: n = N/size + ((N % size) > rank);
746: if (!n) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Process %d must have at least one block: total processors %d total blocks %D",(int)rank,(int)size,N);
747: if (pc->setupcalled && n != osm->n_local_true) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"PCASMSetTotalSubdomains() should be called before PCSetUp().");
748: if (!pc->setupcalled) {
749: PCASMDestroySubdomains(osm->n_local_true,osm->is,osm->is_local);
751: osm->n_local_true = n;
752: osm->is = 0;
753: osm->is_local = 0;
754: }
755: return(0);
756: }
758: static PetscErrorCode PCASMSetOverlap_ASM(PC pc,PetscInt ovl)
759: {
760: PC_ASM *osm = (PC_ASM*)pc->data;
763: if (ovl < 0) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Negative overlap value requested");
764: if (pc->setupcalled && ovl != osm->overlap) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"PCASMSetOverlap() should be called before PCSetUp().");
765: if (!pc->setupcalled) osm->overlap = ovl;
766: return(0);
767: }
769: static PetscErrorCode PCASMSetType_ASM(PC pc,PCASMType type)
770: {
771: PC_ASM *osm = (PC_ASM*)pc->data;
774: osm->type = type;
775: osm->type_set = PETSC_TRUE;
776: return(0);
777: }
779: static PetscErrorCode PCASMGetType_ASM(PC pc,PCASMType *type)
780: {
781: PC_ASM *osm = (PC_ASM*)pc->data;
784: *type = osm->type;
785: return(0);
786: }
788: static PetscErrorCode PCASMSetLocalType_ASM(PC pc, PCCompositeType type)
789: {
790: PC_ASM *osm = (PC_ASM *) pc->data;
793: if (type != PC_COMPOSITE_ADDITIVE && type != PC_COMPOSITE_MULTIPLICATIVE) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Only supports additive or multiplicative as the local type");
794: osm->loctype = type;
795: return(0);
796: }
798: static PetscErrorCode PCASMGetLocalType_ASM(PC pc, PCCompositeType *type)
799: {
800: PC_ASM *osm = (PC_ASM *) pc->data;
803: *type = osm->loctype;
804: return(0);
805: }
807: static PetscErrorCode PCASMSetSortIndices_ASM(PC pc,PetscBool doSort)
808: {
809: PC_ASM *osm = (PC_ASM*)pc->data;
812: osm->sort_indices = doSort;
813: return(0);
814: }
816: static PetscErrorCode PCASMGetSubKSP_ASM(PC pc,PetscInt *n_local,PetscInt *first_local,KSP **ksp)
817: {
818: PC_ASM *osm = (PC_ASM*)pc->data;
822: if (osm->n_local_true < 1) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ORDER,"Need to call PCSetUp() on PC (or KSPSetUp() on the outer KSP object) before calling here");
824: if (n_local) *n_local = osm->n_local_true;
825: if (first_local) {
826: MPI_Scan(&osm->n_local_true,first_local,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)pc));
827: *first_local -= osm->n_local_true;
828: }
829: if (ksp) {
830: /* Assume that local solves are now different; not necessarily
831: true though! This flag is used only for PCView_ASM() */
832: *ksp = osm->ksp;
833: osm->same_local_solves = PETSC_FALSE;
834: }
835: return(0);
836: }
838: static PetscErrorCode PCASMGetSubMatType_ASM(PC pc,MatType *sub_mat_type)
839: {
840: PC_ASM *osm = (PC_ASM*)pc->data;
845: *sub_mat_type = osm->sub_mat_type;
846: return(0);
847: }
849: static PetscErrorCode PCASMSetSubMatType_ASM(PC pc,MatType sub_mat_type)
850: {
851: PetscErrorCode ierr;
852: PC_ASM *osm = (PC_ASM*)pc->data;
856: PetscFree(osm->sub_mat_type);
857: PetscStrallocpy(sub_mat_type,(char**)&osm->sub_mat_type);
858: return(0);
859: }
861: /*@C
862: PCASMSetLocalSubdomains - Sets the local subdomains (for this processor only) for the additive Schwarz preconditioner.
864: Collective on pc
866: Input Parameters:
867: + pc - the preconditioner context
868: . n - the number of subdomains for this processor (default value = 1)
869: . is - the index set that defines the subdomains for this processor
870: (or NULL for PETSc to determine subdomains)
871: - is_local - the index sets that define the local part of the subdomains for this processor, not used unless PCASMType is PC_ASM_RESTRICT
872: (or NULL to not provide these)
874: Options Database Key:
875: To set the total number of subdomain blocks rather than specify the
876: index sets, use the option
877: . -pc_asm_local_blocks <blks> - Sets local blocks
879: Notes:
880: The IS numbering is in the parallel, global numbering of the vector for both is and is_local
882: By default the ASM preconditioner uses 1 block per processor.
884: Use PCASMSetTotalSubdomains() to set the subdomains for all processors.
886: If is_local is provided and PCASMType is PC_ASM_RESTRICT then the solution only over the is_local region is interpolated
887: back to form the global solution (this is the standard restricted additive Schwarz method)
889: If the is_local is provided and PCASMType is PC_ASM_INTERPOLATE or PC_ASM_NONE then an error is generated since there is
890: no code to handle that case.
892: Level: advanced
894: .seealso: PCASMSetTotalSubdomains(), PCASMSetOverlap(), PCASMGetSubKSP(),
895: PCASMCreateSubdomains2D(), PCASMGetLocalSubdomains(), PCASMType, PCASMSetType()
896: @*/
897: PetscErrorCode PCASMSetLocalSubdomains(PC pc,PetscInt n,IS is[],IS is_local[])
898: {
903: PetscTryMethod(pc,"PCASMSetLocalSubdomains_C",(PC,PetscInt,IS[],IS[]),(pc,n,is,is_local));
904: return(0);
905: }
907: /*@C
908: PCASMSetTotalSubdomains - Sets the subdomains for all processors for the
909: additive Schwarz preconditioner. Either all or no processors in the
910: PC communicator must call this routine, with the same index sets.
912: Collective on pc
914: Input Parameters:
915: + pc - the preconditioner context
916: . N - the number of subdomains for all processors
917: . is - the index sets that define the subdomains for all processors
918: (or NULL to ask PETSc to determine the subdomains)
919: - is_local - the index sets that define the local part of the subdomains for this processor
920: (or NULL to not provide this information)
922: Options Database Key:
923: To set the total number of subdomain blocks rather than specify the
924: index sets, use the option
925: . -pc_asm_blocks <blks> - Sets total blocks
927: Notes:
928: Currently you cannot use this to set the actual subdomains with the argument is or is_local.
930: By default the ASM preconditioner uses 1 block per processor.
932: These index sets cannot be destroyed until after completion of the
933: linear solves for which the ASM preconditioner is being used.
935: Use PCASMSetLocalSubdomains() to set local subdomains.
937: The IS numbering is in the parallel, global numbering of the vector for both is and is_local
939: Level: advanced
941: .seealso: PCASMSetLocalSubdomains(), PCASMSetOverlap(), PCASMGetSubKSP(),
942: PCASMCreateSubdomains2D()
943: @*/
944: PetscErrorCode PCASMSetTotalSubdomains(PC pc,PetscInt N,IS is[],IS is_local[])
945: {
950: PetscTryMethod(pc,"PCASMSetTotalSubdomains_C",(PC,PetscInt,IS[],IS[]),(pc,N,is,is_local));
951: return(0);
952: }
954: /*@
955: PCASMSetOverlap - Sets the overlap between a pair of subdomains for the
956: additive Schwarz preconditioner. Either all or no processors in the
957: PC communicator must call this routine.
959: Logically Collective on pc
961: Input Parameters:
962: + pc - the preconditioner context
963: - ovl - the amount of overlap between subdomains (ovl >= 0, default value = 1)
965: Options Database Key:
966: . -pc_asm_overlap <ovl> - Sets overlap
968: Notes:
969: By default the ASM preconditioner uses 1 block per processor. To use
970: multiple blocks per perocessor, see PCASMSetTotalSubdomains() and
971: PCASMSetLocalSubdomains() (and the option -pc_asm_blocks <blks>).
973: The overlap defaults to 1, so if one desires that no additional
974: overlap be computed beyond what may have been set with a call to
975: PCASMSetTotalSubdomains() or PCASMSetLocalSubdomains(), then ovl
976: must be set to be 0. In particular, if one does not explicitly set
977: the subdomains an Section 1.5 Writing Application Codes with PETSc code, then all overlap would be computed
978: internally by PETSc, and using an overlap of 0 would result in an ASM
979: variant that is equivalent to the block Jacobi preconditioner.
981: The default algorithm used by PETSc to increase overlap is fast, but not scalable,
982: use the option -mat_increase_overlap_scalable when the problem and number of processes is large.
984: Note that one can define initial index sets with any overlap via
985: PCASMSetLocalSubdomains(); the routine
986: PCASMSetOverlap() merely allows PETSc to extend that overlap further
987: if desired.
989: Level: intermediate
991: .seealso: PCASMSetTotalSubdomains(), PCASMSetLocalSubdomains(), PCASMGetSubKSP(),
992: PCASMCreateSubdomains2D(), PCASMGetLocalSubdomains(), MatIncreaseOverlap()
993: @*/
994: PetscErrorCode PCASMSetOverlap(PC pc,PetscInt ovl)
995: {
1001: PetscTryMethod(pc,"PCASMSetOverlap_C",(PC,PetscInt),(pc,ovl));
1002: return(0);
1003: }
1005: /*@
1006: PCASMSetType - Sets the type of restriction and interpolation used
1007: for local problems in the additive Schwarz method.
1009: Logically Collective on pc
1011: Input Parameters:
1012: + pc - the preconditioner context
1013: - type - variant of ASM, one of
1014: .vb
1015: PC_ASM_BASIC - full interpolation and restriction
1016: PC_ASM_RESTRICT - full restriction, local processor interpolation
1017: PC_ASM_INTERPOLATE - full interpolation, local processor restriction
1018: PC_ASM_NONE - local processor restriction and interpolation
1019: .ve
1021: Options Database Key:
1022: . -pc_asm_type [basic,restrict,interpolate,none] - Sets ASM type
1024: Notes:
1025: if the is_local arguments are passed to PCASMSetLocalSubdomains() then they are used when PC_ASM_RESTRICT has been selected
1026: to limit the local processor interpolation
1028: Level: intermediate
1030: .seealso: PCASMSetTotalSubdomains(), PCASMSetTotalSubdomains(), PCASMGetSubKSP(),
1031: PCASMCreateSubdomains2D(), PCASMType, PCASMSetLocalType(), PCASMGetLocalType()
1032: @*/
1033: PetscErrorCode PCASMSetType(PC pc,PCASMType type)
1034: {
1040: PetscTryMethod(pc,"PCASMSetType_C",(PC,PCASMType),(pc,type));
1041: return(0);
1042: }
1044: /*@
1045: PCASMGetType - Gets the type of restriction and interpolation used
1046: for local problems in the additive Schwarz method.
1048: Logically Collective on pc
1050: Input Parameter:
1051: . pc - the preconditioner context
1053: Output Parameter:
1054: . type - variant of ASM, one of
1056: .vb
1057: PC_ASM_BASIC - full interpolation and restriction
1058: PC_ASM_RESTRICT - full restriction, local processor interpolation
1059: PC_ASM_INTERPOLATE - full interpolation, local processor restriction
1060: PC_ASM_NONE - local processor restriction and interpolation
1061: .ve
1063: Options Database Key:
1064: . -pc_asm_type [basic,restrict,interpolate,none] - Sets ASM type
1066: Level: intermediate
1068: .seealso: PCASMSetTotalSubdomains(), PCASMSetTotalSubdomains(), PCASMGetSubKSP(),
1069: PCASMCreateSubdomains2D(), PCASMType, PCASMSetType(), PCASMSetLocalType(), PCASMGetLocalType()
1070: @*/
1071: PetscErrorCode PCASMGetType(PC pc,PCASMType *type)
1072: {
1077: PetscUseMethod(pc,"PCASMGetType_C",(PC,PCASMType*),(pc,type));
1078: return(0);
1079: }
1081: /*@
1082: PCASMSetLocalType - Sets the type of composition used for local problems in the additive Schwarz method.
1084: Logically Collective on pc
1086: Input Parameters:
1087: + pc - the preconditioner context
1088: - type - type of composition, one of
1089: .vb
1090: PC_COMPOSITE_ADDITIVE - local additive combination
1091: PC_COMPOSITE_MULTIPLICATIVE - local multiplicative combination
1092: .ve
1094: Options Database Key:
1095: . -pc_asm_local_type [additive,multiplicative] - Sets local solver composition type
1097: Level: intermediate
1099: .seealso: PCASMSetType(), PCASMGetType(), PCASMGetLocalType(), PCASM, PCASMType, PCASMSetType(), PCASMGetType(), PCCompositeType
1100: @*/
1101: PetscErrorCode PCASMSetLocalType(PC pc, PCCompositeType type)
1102: {
1108: PetscTryMethod(pc, "PCASMSetLocalType_C", (PC, PCCompositeType), (pc, type));
1109: return(0);
1110: }
1112: /*@
1113: PCASMGetLocalType - Gets the type of composition used for local problems in the additive Schwarz method.
1115: Logically Collective on pc
1117: Input Parameter:
1118: . pc - the preconditioner context
1120: Output Parameter:
1121: . type - type of composition, one of
1122: .vb
1123: PC_COMPOSITE_ADDITIVE - local additive combination
1124: PC_COMPOSITE_MULTIPLICATIVE - local multiplicative combination
1125: .ve
1127: Options Database Key:
1128: . -pc_asm_local_type [additive,multiplicative] - Sets local solver composition type
1130: Level: intermediate
1132: .seealso: PCASMSetType(), PCASMGetType(), PCASMSetLocalType(), PCASMCreate(), PCASMType, PCASMSetType(), PCASMGetType(), PCCompositeType
1133: @*/
1134: PetscErrorCode PCASMGetLocalType(PC pc, PCCompositeType *type)
1135: {
1141: PetscUseMethod(pc, "PCASMGetLocalType_C", (PC, PCCompositeType *), (pc, type));
1142: return(0);
1143: }
1145: /*@
1146: PCASMSetSortIndices - Determines whether subdomain indices are sorted.
1148: Logically Collective on pc
1150: Input Parameters:
1151: + pc - the preconditioner context
1152: - doSort - sort the subdomain indices
1154: Level: intermediate
1156: .seealso: PCASMSetLocalSubdomains(), PCASMSetTotalSubdomains(), PCASMGetSubKSP(),
1157: PCASMCreateSubdomains2D()
1158: @*/
1159: PetscErrorCode PCASMSetSortIndices(PC pc,PetscBool doSort)
1160: {
1166: PetscTryMethod(pc,"PCASMSetSortIndices_C",(PC,PetscBool),(pc,doSort));
1167: return(0);
1168: }
1170: /*@C
1171: PCASMGetSubKSP - Gets the local KSP contexts for all blocks on
1172: this processor.
1174: Collective on pc iff first_local is requested
1176: Input Parameter:
1177: . pc - the preconditioner context
1179: Output Parameters:
1180: + n_local - the number of blocks on this processor or NULL
1181: . first_local - the global number of the first block on this processor or NULL,
1182: all processors must request or all must pass NULL
1183: - ksp - the array of KSP contexts
1185: Note:
1186: After PCASMGetSubKSP() the array of KSPes is not to be freed.
1188: You must call KSPSetUp() before calling PCASMGetSubKSP().
1190: Fortran note:
1191: The output argument 'ksp' must be an array of sufficient length or PETSC_NULL_KSP. The latter can be used to learn the necessary length.
1193: Level: advanced
1195: .seealso: PCASMSetTotalSubdomains(), PCASMSetTotalSubdomains(), PCASMSetOverlap(),
1196: PCASMCreateSubdomains2D(),
1197: @*/
1198: PetscErrorCode PCASMGetSubKSP(PC pc,PetscInt *n_local,PetscInt *first_local,KSP *ksp[])
1199: {
1204: PetscUseMethod(pc,"PCASMGetSubKSP_C",(PC,PetscInt*,PetscInt*,KSP **),(pc,n_local,first_local,ksp));
1205: return(0);
1206: }
1208: /* -------------------------------------------------------------------------------------*/
1209: /*MC
1210: PCASM - Use the (restricted) additive Schwarz method, each block is (approximately) solved with
1211: its own KSP object.
1213: Options Database Keys:
1214: + -pc_asm_blocks <blks> - Sets total blocks
1215: . -pc_asm_overlap <ovl> - Sets overlap
1216: . -pc_asm_type [basic,restrict,interpolate,none] - Sets ASM type, default is restrict
1217: - -pc_asm_local_type [additive, multiplicative] - Sets ASM type, default is additive
1219: IMPORTANT: If you run with, for example, 3 blocks on 1 processor or 3 blocks on 3 processors you
1220: will get a different convergence rate due to the default option of -pc_asm_type restrict. Use
1221: -pc_asm_type basic to use the standard ASM.
1223: Notes:
1224: Each processor can have one or more blocks, but a block cannot be shared by more
1225: than one processor. Use PCGASM for subdomains shared by multiple processes. Defaults to one block per processor.
1227: To set options on the solvers for each block append -sub_ to all the KSP, and PC
1228: options database keys. For example, -sub_pc_type ilu -sub_pc_factor_levels 1 -sub_ksp_type preonly
1230: To set the options on the solvers separate for each block call PCASMGetSubKSP()
1231: and set the options directly on the resulting KSP object (you can access its PC
1232: with KSPGetPC())
1234: Level: beginner
1236: References:
1237: + 1. - M Dryja, OB Widlund, An additive variant of the Schwarz alternating method for the case of many subregions
1238: Courant Institute, New York University Technical report
1239: - 2. - Barry Smith, Petter Bjorstad, and William Gropp, Domain Decompositions: Parallel Multilevel Methods for Elliptic Partial Differential Equations,
1240: Cambridge University Press.
1242: .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC,
1243: PCBJACOBI, PCASMGetSubKSP(), PCASMSetLocalSubdomains(), PCASMType, PCASMGetType(), PCASMSetLocalType(), PCASMGetLocalType()
1244: PCASMSetTotalSubdomains(), PCSetModifySubMatrices(), PCASMSetOverlap(), PCASMSetType(), PCCompositeType
1246: M*/
1248: PETSC_EXTERN PetscErrorCode PCCreate_ASM(PC pc)
1249: {
1251: PC_ASM *osm;
1254: PetscNewLog(pc,&osm);
1256: osm->n = PETSC_DECIDE;
1257: osm->n_local = 0;
1258: osm->n_local_true = PETSC_DECIDE;
1259: osm->overlap = 1;
1260: osm->ksp = 0;
1261: osm->restriction = 0;
1262: osm->lprolongation = 0;
1263: osm->lrestriction = 0;
1264: osm->x = 0;
1265: osm->y = 0;
1266: osm->is = 0;
1267: osm->is_local = 0;
1268: osm->mat = 0;
1269: osm->pmat = 0;
1270: osm->type = PC_ASM_RESTRICT;
1271: osm->loctype = PC_COMPOSITE_ADDITIVE;
1272: osm->same_local_solves = PETSC_TRUE;
1273: osm->sort_indices = PETSC_TRUE;
1274: osm->dm_subdomains = PETSC_FALSE;
1275: osm->sub_mat_type = NULL;
1277: pc->data = (void*)osm;
1278: pc->ops->apply = PCApply_ASM;
1279: pc->ops->applytranspose = PCApplyTranspose_ASM;
1280: pc->ops->setup = PCSetUp_ASM;
1281: pc->ops->reset = PCReset_ASM;
1282: pc->ops->destroy = PCDestroy_ASM;
1283: pc->ops->setfromoptions = PCSetFromOptions_ASM;
1284: pc->ops->setuponblocks = PCSetUpOnBlocks_ASM;
1285: pc->ops->view = PCView_ASM;
1286: pc->ops->applyrichardson = 0;
1288: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetLocalSubdomains_C",PCASMSetLocalSubdomains_ASM);
1289: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetTotalSubdomains_C",PCASMSetTotalSubdomains_ASM);
1290: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetOverlap_C",PCASMSetOverlap_ASM);
1291: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetType_C",PCASMSetType_ASM);
1292: PetscObjectComposeFunction((PetscObject)pc,"PCASMGetType_C",PCASMGetType_ASM);
1293: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetLocalType_C",PCASMSetLocalType_ASM);
1294: PetscObjectComposeFunction((PetscObject)pc,"PCASMGetLocalType_C",PCASMGetLocalType_ASM);
1295: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetSortIndices_C",PCASMSetSortIndices_ASM);
1296: PetscObjectComposeFunction((PetscObject)pc,"PCASMGetSubKSP_C",PCASMGetSubKSP_ASM);
1297: PetscObjectComposeFunction((PetscObject)pc,"PCASMGetSubMatType_C",PCASMGetSubMatType_ASM);
1298: PetscObjectComposeFunction((PetscObject)pc,"PCASMSetSubMatType_C",PCASMSetSubMatType_ASM);
1299: return(0);
1300: }
1302: /*@C
1303: PCASMCreateSubdomains - Creates the index sets for the overlapping Schwarz
1304: preconditioner for a any problem on a general grid.
1306: Collective
1308: Input Parameters:
1309: + A - The global matrix operator
1310: - n - the number of local blocks
1312: Output Parameters:
1313: . outis - the array of index sets defining the subdomains
1315: Level: advanced
1317: Note: this generates nonoverlapping subdomains; the PCASM will generate the overlap
1318: from these if you use PCASMSetLocalSubdomains()
1320: In the Fortran version you must provide the array outis[] already allocated of length n.
1322: .seealso: PCASMSetLocalSubdomains(), PCASMDestroySubdomains()
1323: @*/
1324: PetscErrorCode PCASMCreateSubdomains(Mat A, PetscInt n, IS* outis[])
1325: {
1326: MatPartitioning mpart;
1327: const char *prefix;
1328: PetscInt i,j,rstart,rend,bs;
1329: PetscBool hasop, isbaij = PETSC_FALSE,foundpart = PETSC_FALSE;
1330: Mat Ad = NULL, adj;
1331: IS ispart,isnumb,*is;
1332: PetscErrorCode ierr;
1337: if (n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of local blocks must be > 0, n = %D",n);
1339: /* Get prefix, row distribution, and block size */
1340: MatGetOptionsPrefix(A,&prefix);
1341: MatGetOwnershipRange(A,&rstart,&rend);
1342: MatGetBlockSize(A,&bs);
1343: if (rstart/bs*bs != rstart || rend/bs*bs != rend) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"bad row distribution [%D,%D) for matrix block size %D",rstart,rend,bs);
1345: /* Get diagonal block from matrix if possible */
1346: MatHasOperation(A,MATOP_GET_DIAGONAL_BLOCK,&hasop);
1347: if (hasop) {
1348: MatGetDiagonalBlock(A,&Ad);
1349: }
1350: if (Ad) {
1351: PetscObjectBaseTypeCompare((PetscObject)Ad,MATSEQBAIJ,&isbaij);
1352: if (!isbaij) {PetscObjectBaseTypeCompare((PetscObject)Ad,MATSEQSBAIJ,&isbaij);}
1353: }
1354: if (Ad && n > 1) {
1355: PetscBool match,done;
1356: /* Try to setup a good matrix partitioning if available */
1357: MatPartitioningCreate(PETSC_COMM_SELF,&mpart);
1358: PetscObjectSetOptionsPrefix((PetscObject)mpart,prefix);
1359: MatPartitioningSetFromOptions(mpart);
1360: PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGCURRENT,&match);
1361: if (!match) {
1362: PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGSQUARE,&match);
1363: }
1364: if (!match) { /* assume a "good" partitioner is available */
1365: PetscInt na;
1366: const PetscInt *ia,*ja;
1367: MatGetRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);
1368: if (done) {
1369: /* Build adjacency matrix by hand. Unfortunately a call to
1370: MatConvert(Ad,MATMPIADJ,MAT_INITIAL_MATRIX,&adj) will
1371: remove the block-aij structure and we cannot expect
1372: MatPartitioning to split vertices as we need */
1373: PetscInt i,j,len,nnz,cnt,*iia=0,*jja=0;
1374: const PetscInt *row;
1375: nnz = 0;
1376: for (i=0; i<na; i++) { /* count number of nonzeros */
1377: len = ia[i+1] - ia[i];
1378: row = ja + ia[i];
1379: for (j=0; j<len; j++) {
1380: if (row[j] == i) { /* don't count diagonal */
1381: len--; break;
1382: }
1383: }
1384: nnz += len;
1385: }
1386: PetscMalloc1(na+1,&iia);
1387: PetscMalloc1(nnz,&jja);
1388: nnz = 0;
1389: iia[0] = 0;
1390: for (i=0; i<na; i++) { /* fill adjacency */
1391: cnt = 0;
1392: len = ia[i+1] - ia[i];
1393: row = ja + ia[i];
1394: for (j=0; j<len; j++) {
1395: if (row[j] != i) { /* if not diagonal */
1396: jja[nnz+cnt++] = row[j];
1397: }
1398: }
1399: nnz += cnt;
1400: iia[i+1] = nnz;
1401: }
1402: /* Partitioning of the adjacency matrix */
1403: MatCreateMPIAdj(PETSC_COMM_SELF,na,na,iia,jja,NULL,&adj);
1404: MatPartitioningSetAdjacency(mpart,adj);
1405: MatPartitioningSetNParts(mpart,n);
1406: MatPartitioningApply(mpart,&ispart);
1407: ISPartitioningToNumbering(ispart,&isnumb);
1408: MatDestroy(&adj);
1409: foundpart = PETSC_TRUE;
1410: }
1411: MatRestoreRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);
1412: }
1413: MatPartitioningDestroy(&mpart);
1414: }
1416: PetscMalloc1(n,&is);
1417: *outis = is;
1419: if (!foundpart) {
1421: /* Partitioning by contiguous chunks of rows */
1423: PetscInt mbs = (rend-rstart)/bs;
1424: PetscInt start = rstart;
1425: for (i=0; i<n; i++) {
1426: PetscInt count = (mbs/n + ((mbs % n) > i)) * bs;
1427: ISCreateStride(PETSC_COMM_SELF,count,start,1,&is[i]);
1428: start += count;
1429: }
1431: } else {
1433: /* Partitioning by adjacency of diagonal block */
1435: const PetscInt *numbering;
1436: PetscInt *count,nidx,*indices,*newidx,start=0;
1437: /* Get node count in each partition */
1438: PetscMalloc1(n,&count);
1439: ISPartitioningCount(ispart,n,count);
1440: if (isbaij && bs > 1) { /* adjust for the block-aij case */
1441: for (i=0; i<n; i++) count[i] *= bs;
1442: }
1443: /* Build indices from node numbering */
1444: ISGetLocalSize(isnumb,&nidx);
1445: PetscMalloc1(nidx,&indices);
1446: for (i=0; i<nidx; i++) indices[i] = i; /* needs to be initialized */
1447: ISGetIndices(isnumb,&numbering);
1448: PetscSortIntWithPermutation(nidx,numbering,indices);
1449: ISRestoreIndices(isnumb,&numbering);
1450: if (isbaij && bs > 1) { /* adjust for the block-aij case */
1451: PetscMalloc1(nidx*bs,&newidx);
1452: for (i=0; i<nidx; i++) {
1453: for (j=0; j<bs; j++) newidx[i*bs+j] = indices[i]*bs + j;
1454: }
1455: PetscFree(indices);
1456: nidx *= bs;
1457: indices = newidx;
1458: }
1459: /* Shift to get global indices */
1460: for (i=0; i<nidx; i++) indices[i] += rstart;
1462: /* Build the index sets for each block */
1463: for (i=0; i<n; i++) {
1464: ISCreateGeneral(PETSC_COMM_SELF,count[i],&indices[start],PETSC_COPY_VALUES,&is[i]);
1465: ISSort(is[i]);
1466: start += count[i];
1467: }
1469: PetscFree(count);
1470: PetscFree(indices);
1471: ISDestroy(&isnumb);
1472: ISDestroy(&ispart);
1474: }
1475: return(0);
1476: }
1478: /*@C
1479: PCASMDestroySubdomains - Destroys the index sets created with
1480: PCASMCreateSubdomains(). Should be called after setting subdomains
1481: with PCASMSetLocalSubdomains().
1483: Collective
1485: Input Parameters:
1486: + n - the number of index sets
1487: . is - the array of index sets
1488: - is_local - the array of local index sets, can be NULL
1490: Level: advanced
1492: .seealso: PCASMCreateSubdomains(), PCASMSetLocalSubdomains()
1493: @*/
1494: PetscErrorCode PCASMDestroySubdomains(PetscInt n, IS is[], IS is_local[])
1495: {
1496: PetscInt i;
1500: if (n <= 0) return(0);
1501: if (is) {
1503: for (i=0; i<n; i++) { ISDestroy(&is[i]); }
1504: PetscFree(is);
1505: }
1506: if (is_local) {
1508: for (i=0; i<n; i++) { ISDestroy(&is_local[i]); }
1509: PetscFree(is_local);
1510: }
1511: return(0);
1512: }
1514: /*@
1515: PCASMCreateSubdomains2D - Creates the index sets for the overlapping Schwarz
1516: preconditioner for a two-dimensional problem on a regular grid.
1518: Not Collective
1520: Input Parameters:
1521: + m, n - the number of mesh points in the x and y directions
1522: . M, N - the number of subdomains in the x and y directions
1523: . dof - degrees of freedom per node
1524: - overlap - overlap in mesh lines
1526: Output Parameters:
1527: + Nsub - the number of subdomains created
1528: . is - array of index sets defining overlapping (if overlap > 0) subdomains
1529: - is_local - array of index sets defining non-overlapping subdomains
1531: Note:
1532: Presently PCAMSCreateSubdomains2d() is valid only for sequential
1533: preconditioners. More general related routines are
1534: PCASMSetTotalSubdomains() and PCASMSetLocalSubdomains().
1536: Level: advanced
1538: .seealso: PCASMSetTotalSubdomains(), PCASMSetLocalSubdomains(), PCASMGetSubKSP(),
1539: PCASMSetOverlap()
1540: @*/
1541: PetscErrorCode PCASMCreateSubdomains2D(PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt dof,PetscInt overlap,PetscInt *Nsub,IS **is,IS **is_local)
1542: {
1543: PetscInt i,j,height,width,ystart,xstart,yleft,yright,xleft,xright,loc_outer;
1545: PetscInt nidx,*idx,loc,ii,jj,count;
1548: if (dof != 1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP," ");
1550: *Nsub = N*M;
1551: PetscMalloc1(*Nsub,is);
1552: PetscMalloc1(*Nsub,is_local);
1553: ystart = 0;
1554: loc_outer = 0;
1555: for (i=0; i<N; i++) {
1556: height = n/N + ((n % N) > i); /* height of subdomain */
1557: if (height < 2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many N subdomains for mesh dimension n");
1558: yleft = ystart - overlap; if (yleft < 0) yleft = 0;
1559: yright = ystart + height + overlap; if (yright > n) yright = n;
1560: xstart = 0;
1561: for (j=0; j<M; j++) {
1562: width = m/M + ((m % M) > j); /* width of subdomain */
1563: if (width < 2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many M subdomains for mesh dimension m");
1564: xleft = xstart - overlap; if (xleft < 0) xleft = 0;
1565: xright = xstart + width + overlap; if (xright > m) xright = m;
1566: nidx = (xright - xleft)*(yright - yleft);
1567: PetscMalloc1(nidx,&idx);
1568: loc = 0;
1569: for (ii=yleft; ii<yright; ii++) {
1570: count = m*ii + xleft;
1571: for (jj=xleft; jj<xright; jj++) idx[loc++] = count++;
1572: }
1573: ISCreateGeneral(PETSC_COMM_SELF,nidx,idx,PETSC_COPY_VALUES,(*is)+loc_outer);
1574: if (overlap == 0) {
1575: PetscObjectReference((PetscObject)(*is)[loc_outer]);
1577: (*is_local)[loc_outer] = (*is)[loc_outer];
1578: } else {
1579: for (loc=0,ii=ystart; ii<ystart+height; ii++) {
1580: for (jj=xstart; jj<xstart+width; jj++) {
1581: idx[loc++] = m*ii + jj;
1582: }
1583: }
1584: ISCreateGeneral(PETSC_COMM_SELF,loc,idx,PETSC_COPY_VALUES,*is_local+loc_outer);
1585: }
1586: PetscFree(idx);
1587: xstart += width;
1588: loc_outer++;
1589: }
1590: ystart += height;
1591: }
1592: for (i=0; i<*Nsub; i++) { ISSort((*is)[i]); }
1593: return(0);
1594: }
1596: /*@C
1597: PCASMGetLocalSubdomains - Gets the local subdomains (for this processor
1598: only) for the additive Schwarz preconditioner.
1600: Not Collective
1602: Input Parameter:
1603: . pc - the preconditioner context
1605: Output Parameters:
1606: + n - the number of subdomains for this processor (default value = 1)
1607: . is - the index sets that define the subdomains for this processor
1608: - is_local - the index sets that define the local part of the subdomains for this processor (can be NULL)
1611: Notes:
1612: The IS numbering is in the parallel, global numbering of the vector.
1614: Level: advanced
1616: .seealso: PCASMSetTotalSubdomains(), PCASMSetOverlap(), PCASMGetSubKSP(),
1617: PCASMCreateSubdomains2D(), PCASMSetLocalSubdomains(), PCASMGetLocalSubmatrices()
1618: @*/
1619: PetscErrorCode PCASMGetLocalSubdomains(PC pc,PetscInt *n,IS *is[],IS *is_local[])
1620: {
1621: PC_ASM *osm = (PC_ASM*)pc->data;
1623: PetscBool match;
1629: PetscObjectTypeCompare((PetscObject)pc,PCASM,&match);
1630: if (!match) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONG,"PC is not a PCASM");
1631: if (n) *n = osm->n_local_true;
1632: if (is) *is = osm->is;
1633: if (is_local) *is_local = osm->is_local;
1634: return(0);
1635: }
1637: /*@C
1638: PCASMGetLocalSubmatrices - Gets the local submatrices (for this processor
1639: only) for the additive Schwarz preconditioner.
1641: Not Collective
1643: Input Parameter:
1644: . pc - the preconditioner context
1646: Output Parameters:
1647: + n - the number of matrices for this processor (default value = 1)
1648: - mat - the matrices
1650: Level: advanced
1652: Notes:
1653: Call after PCSetUp() (or KSPSetUp()) but before PCApply() and before PCSetUpOnBlocks())
1655: Usually one would use PCSetModifySubMatrices() to change the submatrices in building the preconditioner.
1657: .seealso: PCASMSetTotalSubdomains(), PCASMSetOverlap(), PCASMGetSubKSP(),
1658: PCASMCreateSubdomains2D(), PCASMSetLocalSubdomains(), PCASMGetLocalSubdomains(), PCSetModifySubMatrices()
1659: @*/
1660: PetscErrorCode PCASMGetLocalSubmatrices(PC pc,PetscInt *n,Mat *mat[])
1661: {
1662: PC_ASM *osm;
1664: PetscBool match;
1670: if (!pc->setupcalled) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must call after KSPSetUp() or PCSetUp().");
1671: PetscObjectTypeCompare((PetscObject)pc,PCASM,&match);
1672: if (!match) {
1673: if (n) *n = 0;
1674: if (mat) *mat = NULL;
1675: } else {
1676: osm = (PC_ASM*)pc->data;
1677: if (n) *n = osm->n_local_true;
1678: if (mat) *mat = osm->pmat;
1679: }
1680: return(0);
1681: }
1683: /*@
1684: PCASMSetDMSubdomains - Indicates whether to use DMCreateDomainDecomposition() to define the subdomains, whenever possible.
1686: Logically Collective
1688: Input Parameter:
1689: + pc - the preconditioner
1690: - flg - boolean indicating whether to use subdomains defined by the DM
1692: Options Database Key:
1693: . -pc_asm_dm_subdomains
1695: Level: intermediate
1697: Notes:
1698: PCASMSetTotalSubdomains() and PCASMSetOverlap() take precedence over PCASMSetDMSubdomains(),
1699: so setting either of the first two effectively turns the latter off.
1701: .seealso: PCASMGetDMSubdomains(), PCASMSetTotalSubdomains(), PCASMSetOverlap()
1702: PCASMCreateSubdomains2D(), PCASMSetLocalSubdomains(), PCASMGetLocalSubdomains()
1703: @*/
1704: PetscErrorCode PCASMSetDMSubdomains(PC pc,PetscBool flg)
1705: {
1706: PC_ASM *osm = (PC_ASM*)pc->data;
1708: PetscBool match;
1713: if (pc->setupcalled) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for a setup PC.");
1714: PetscObjectTypeCompare((PetscObject)pc,PCASM,&match);
1715: if (match) {
1716: osm->dm_subdomains = flg;
1717: }
1718: return(0);
1719: }
1721: /*@
1722: PCASMGetDMSubdomains - Returns flag indicating whether to use DMCreateDomainDecomposition() to define the subdomains, whenever possible.
1723: Not Collective
1725: Input Parameter:
1726: . pc - the preconditioner
1728: Output Parameter:
1729: . flg - boolean indicating whether to use subdomains defined by the DM
1731: Level: intermediate
1733: .seealso: PCASMSetDMSubdomains(), PCASMSetTotalSubdomains(), PCASMSetOverlap()
1734: PCASMCreateSubdomains2D(), PCASMSetLocalSubdomains(), PCASMGetLocalSubdomains()
1735: @*/
1736: PetscErrorCode PCASMGetDMSubdomains(PC pc,PetscBool* flg)
1737: {
1738: PC_ASM *osm = (PC_ASM*)pc->data;
1740: PetscBool match;
1745: PetscObjectTypeCompare((PetscObject)pc,PCASM,&match);
1746: if (match) {
1747: if (flg) *flg = osm->dm_subdomains;
1748: }
1749: return(0);
1750: }
1752: /*@
1753: PCASMGetSubMatType - Gets the matrix type used for ASM subsolves, as a string.
1755: Not Collective
1757: Input Parameter:
1758: . pc - the PC
1760: Output Parameter:
1761: . -pc_asm_sub_mat_type - name of matrix type
1763: Level: advanced
1765: .seealso: PCASMSetSubMatType(), PCASM, PCSetType(), VecSetType(), MatType, Mat
1766: @*/
1767: PetscErrorCode PCASMGetSubMatType(PC pc,MatType *sub_mat_type){
1770: PetscTryMethod(pc,"PCASMGetSubMatType_C",(PC,MatType*),(pc,sub_mat_type));
1771: return(0);
1772: }
1774: /*@
1775: PCASMSetSubMatType - Set the type of matrix used for ASM subsolves
1777: Collective on Mat
1779: Input Parameters:
1780: + pc - the PC object
1781: - sub_mat_type - matrix type
1783: Options Database Key:
1784: . -pc_asm_sub_mat_type <sub_mat_type> - Sets the matrix type used for subsolves, for example, seqaijviennacl. If you specify a base name like aijviennacl, the corresponding sequential type is assumed.
1786: Notes:
1787: See "${PETSC_DIR}/include/petscmat.h" for available types
1789: Level: advanced
1791: .seealso: PCASMGetSubMatType(), PCASM, PCSetType(), VecSetType(), MatType, Mat
1792: @*/
1793: PetscErrorCode PCASMSetSubMatType(PC pc,MatType sub_mat_type)
1794: {
1797: PetscTryMethod(pc,"PCASMSetSubMatType_C",(PC,MatType),(pc,sub_mat_type));
1798: return(0);
1799: }