Actual source code: composite.c
petsc-3.6.1 2015-08-06
2: /*
3: Defines a preconditioner that can consist of a collection of PCs
4: */
5: #include <petsc/private/pcimpl.h>
6: #include <petscksp.h> /*I "petscksp.h" I*/
8: typedef struct _PC_CompositeLink *PC_CompositeLink;
9: struct _PC_CompositeLink {
10: PC pc;
11: PC_CompositeLink next;
12: PC_CompositeLink previous;
13: };
15: typedef struct {
16: PC_CompositeLink head;
17: PCCompositeType type;
18: Vec work1;
19: Vec work2;
20: PetscScalar alpha;
21: } PC_Composite;
25: static PetscErrorCode PCApply_Composite_Multiplicative(PC pc,Vec x,Vec y)
26: {
27: PetscErrorCode ierr;
28: PC_Composite *jac = (PC_Composite*)pc->data;
29: PC_CompositeLink next = jac->head;
30: Mat mat = pc->pmat;
34: if (!next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"No composite preconditioners supplied via PCCompositeAddPC() or -pc_composite_pcs");
36: /* Set the reuse flag on children PCs */
37: while (next) {
38: PCSetReusePreconditioner(next->pc,pc->reusepreconditioner);
39: next = next->next;
40: }
41: next = jac->head;
43: if (next->next && !jac->work2) { /* allocate second work vector */
44: VecDuplicate(jac->work1,&jac->work2);
45: }
46: if (pc->useAmat) mat = pc->mat;
47: PCApply(next->pc,x,y); /* y <- B x */
48: while (next->next) {
49: next = next->next;
50: MatMult(mat,y,jac->work1); /* work1 <- A y */
51: VecWAXPY(jac->work2,-1.0,jac->work1,x); /* work2 <- x - work1 */
52: VecSet(jac->work1,0.0); /* zero since some PC's may not set all entries in the result */
53: PCApply(next->pc,jac->work2,jac->work1); /* work1 <- C work2 */
54: VecAXPY(y,1.0,jac->work1); /* y <- y + work1 = B x + C (x - A B x) = (B + C (1 - A B)) x */
55: }
56: if (jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) {
57: while (next->previous) {
58: next = next->previous;
59: MatMult(mat,y,jac->work1);
60: VecWAXPY(jac->work2,-1.0,jac->work1,x);
61: VecSet(jac->work1,0.0); /* zero since some PC's may not set all entries in the result */
62: PCApply(next->pc,jac->work2,jac->work1);
63: VecAXPY(y,1.0,jac->work1);
64: }
65: }
66: return(0);
67: }
71: static PetscErrorCode PCApplyTranspose_Composite_Multiplicative(PC pc,Vec x,Vec y)
72: {
73: PetscErrorCode ierr;
74: PC_Composite *jac = (PC_Composite*)pc->data;
75: PC_CompositeLink next = jac->head;
76: Mat mat = pc->pmat;
79: if (!next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"No composite preconditioners supplied via PCCompositeAddPC() or -pc_composite_pcs");
80: if (next->next && !jac->work2) { /* allocate second work vector */
81: VecDuplicate(jac->work1,&jac->work2);
82: }
83: if (pc->useAmat) mat = pc->mat;
84: /* locate last PC */
85: while (next->next) {
86: next = next->next;
87: }
88: PCApplyTranspose(next->pc,x,y);
89: while (next->previous) {
90: next = next->previous;
91: MatMultTranspose(mat,y,jac->work1);
92: VecWAXPY(jac->work2,-1.0,jac->work1,x);
93: VecSet(jac->work1,0.0); /* zero since some PC's may not set all entries in the result */
94: PCApplyTranspose(next->pc,jac->work2,jac->work1);
95: VecAXPY(y,1.0,jac->work1);
96: }
97: if (jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) {
98: next = jac->head;
99: while (next->next) {
100: next = next->next;
101: MatMultTranspose(mat,y,jac->work1);
102: VecWAXPY(jac->work2,-1.0,jac->work1,x);
103: VecSet(jac->work1,0.0); /* zero since some PC's may not set all entries in the result */
104: PCApplyTranspose(next->pc,jac->work2,jac->work1);
105: VecAXPY(y,1.0,jac->work1);
106: }
107: }
108: return(0);
109: }
111: /*
112: This is very special for a matrix of the form alpha I + R + S
113: where first preconditioner is built from alpha I + S and second from
114: alpha I + R
115: */
118: static PetscErrorCode PCApply_Composite_Special(PC pc,Vec x,Vec y)
119: {
120: PetscErrorCode ierr;
121: PC_Composite *jac = (PC_Composite*)pc->data;
122: PC_CompositeLink next = jac->head;
125: if (!next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"No composite preconditioners supplied via PCCompositeAddPC() or -pc_composite_pcs");
126: if (!next->next || next->next->next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Special composite preconditioners requires exactly two PCs");
128: /* Set the reuse flag on children PCs */
129: PCSetReusePreconditioner(next->pc,pc->reusepreconditioner);
130: PCSetReusePreconditioner(next->next->pc,pc->reusepreconditioner);
132: PCApply(next->pc,x,jac->work1);
133: PCApply(next->next->pc,jac->work1,y);
134: return(0);
135: }
139: static PetscErrorCode PCApply_Composite_Additive(PC pc,Vec x,Vec y)
140: {
141: PetscErrorCode ierr;
142: PC_Composite *jac = (PC_Composite*)pc->data;
143: PC_CompositeLink next = jac->head;
146: if (!next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"No composite preconditioners supplied via PCCompositeAddPC() or -pc_composite_pcs");
148: /* Set the reuse flag on children PCs */
149: while (next) {
150: PCSetReusePreconditioner(next->pc,pc->reusepreconditioner);
151: next = next->next;
152: }
153: next = jac->head;
155: PCApply(next->pc,x,y);
156: while (next->next) {
157: next = next->next;
158: VecSet(jac->work1,0.0); /* zero since some PC's may not set all entries in the result */
159: PCApply(next->pc,x,jac->work1);
160: VecAXPY(y,1.0,jac->work1);
161: }
162: return(0);
163: }
167: static PetscErrorCode PCApplyTranspose_Composite_Additive(PC pc,Vec x,Vec y)
168: {
169: PetscErrorCode ierr;
170: PC_Composite *jac = (PC_Composite*)pc->data;
171: PC_CompositeLink next = jac->head;
174: if (!next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"No composite preconditioners supplied via PCCompositeAddPC() or -pc_composite_pcs");
175: PCApplyTranspose(next->pc,x,y);
176: while (next->next) {
177: next = next->next;
178: VecSet(jac->work1,0.0); /* zero since some PC's may not set all entries in the result */
179: PCApplyTranspose(next->pc,x,jac->work1);
180: VecAXPY(y,1.0,jac->work1);
181: }
182: return(0);
183: }
187: static PetscErrorCode PCSetUp_Composite(PC pc)
188: {
189: PetscErrorCode ierr;
190: PC_Composite *jac = (PC_Composite*)pc->data;
191: PC_CompositeLink next = jac->head;
194: if (!jac->work1) {
195: MatCreateVecs(pc->pmat,&jac->work1,0);
196: }
197: while (next) {
198: PCSetOperators(next->pc,pc->mat,pc->pmat);
199: next = next->next;
200: }
201: return(0);
202: }
206: static PetscErrorCode PCReset_Composite(PC pc)
207: {
208: PC_Composite *jac = (PC_Composite*)pc->data;
209: PetscErrorCode ierr;
210: PC_CompositeLink next = jac->head;
213: while (next) {
214: PCReset(next->pc);
215: next = next->next;
216: }
217: VecDestroy(&jac->work1);
218: VecDestroy(&jac->work2);
219: return(0);
220: }
224: static PetscErrorCode PCDestroy_Composite(PC pc)
225: {
226: PC_Composite *jac = (PC_Composite*)pc->data;
227: PetscErrorCode ierr;
228: PC_CompositeLink next = jac->head,next_tmp;
231: PCReset_Composite(pc);
232: while (next) {
233: PCDestroy(&next->pc);
234: next_tmp = next;
235: next = next->next;
236: PetscFree(next_tmp);
237: }
238: PetscFree(pc->data);
239: return(0);
240: }
244: static PetscErrorCode PCSetFromOptions_Composite(PetscOptions *PetscOptionsObject,PC pc)
245: {
246: PC_Composite *jac = (PC_Composite*)pc->data;
247: PetscErrorCode ierr;
248: PetscInt nmax = 8,i;
249: PC_CompositeLink next;
250: char *pcs[8];
251: PetscBool flg;
254: PetscOptionsHead(PetscOptionsObject,"Composite preconditioner options");
255: PetscOptionsEnum("-pc_composite_type","Type of composition","PCCompositeSetType",PCCompositeTypes,(PetscEnum)jac->type,(PetscEnum*)&jac->type,&flg);
256: if (flg) {
257: PCCompositeSetType(pc,jac->type);
258: }
259: PetscOptionsStringArray("-pc_composite_pcs","List of composite solvers","PCCompositeAddPC",pcs,&nmax,&flg);
260: if (flg) {
261: for (i=0; i<nmax; i++) {
262: PCCompositeAddPC(pc,pcs[i]);
263: PetscFree(pcs[i]); /* deallocate string pcs[i], which is allocated in PetscOptionsStringArray() */
264: }
265: }
266: PetscOptionsTail();
268: next = jac->head;
269: while (next) {
270: PCSetFromOptions(next->pc);
271: next = next->next;
272: }
273: return(0);
274: }
278: static PetscErrorCode PCView_Composite(PC pc,PetscViewer viewer)
279: {
280: PC_Composite *jac = (PC_Composite*)pc->data;
281: PetscErrorCode ierr;
282: PC_CompositeLink next = jac->head;
283: PetscBool iascii;
286: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
287: if (iascii) {
288: PetscViewerASCIIPrintf(viewer,"Composite PC type - %s\n",PCCompositeTypes[jac->type]);
289: PetscViewerASCIIPrintf(viewer,"PCs on composite preconditioner follow\n");
290: PetscViewerASCIIPrintf(viewer,"---------------------------------\n");
291: }
292: if (iascii) {
293: PetscViewerASCIIPushTab(viewer);
294: }
295: while (next) {
296: PCView(next->pc,viewer);
297: next = next->next;
298: }
299: if (iascii) {
300: PetscViewerASCIIPopTab(viewer);
301: PetscViewerASCIIPrintf(viewer,"---------------------------------\n");
302: }
303: return(0);
304: }
306: /* ------------------------------------------------------------------------------*/
310: static PetscErrorCode PCCompositeSpecialSetAlpha_Composite(PC pc,PetscScalar alpha)
311: {
312: PC_Composite *jac = (PC_Composite*)pc->data;
315: jac->alpha = alpha;
316: return(0);
317: }
321: static PetscErrorCode PCCompositeSetType_Composite(PC pc,PCCompositeType type)
322: {
323: PC_Composite *jac = (PC_Composite*)pc->data;
326: if (type == PC_COMPOSITE_ADDITIVE) {
327: pc->ops->apply = PCApply_Composite_Additive;
328: pc->ops->applytranspose = PCApplyTranspose_Composite_Additive;
329: } else if (type == PC_COMPOSITE_MULTIPLICATIVE || type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) {
330: pc->ops->apply = PCApply_Composite_Multiplicative;
331: pc->ops->applytranspose = PCApplyTranspose_Composite_Multiplicative;
332: } else if (type == PC_COMPOSITE_SPECIAL) {
333: pc->ops->apply = PCApply_Composite_Special;
334: pc->ops->applytranspose = NULL;
335: } else SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONG,"Unkown composite preconditioner type");
336: jac->type = type;
337: return(0);
338: }
342: static PetscErrorCode PCCompositeGetType_Composite(PC pc,PCCompositeType *type)
343: {
344: PC_Composite *jac = (PC_Composite*)pc->data;
347: *type = jac->type;
348: return(0);
349: }
353: static PetscErrorCode PCCompositeAddPC_Composite(PC pc,PCType type)
354: {
355: PC_Composite *jac;
356: PC_CompositeLink next,ilink;
357: PetscErrorCode ierr;
358: PetscInt cnt = 0;
359: const char *prefix;
360: char newprefix[8];
363: PetscNewLog(pc,&ilink);
364: ilink->next = 0;
365: PCCreate(PetscObjectComm((PetscObject)pc),&ilink->pc);
366: PetscLogObjectParent((PetscObject)pc,(PetscObject)ilink->pc);
368: jac = (PC_Composite*)pc->data;
369: next = jac->head;
370: if (!next) {
371: jac->head = ilink;
372: ilink->previous = NULL;
373: } else {
374: cnt++;
375: while (next->next) {
376: next = next->next;
377: cnt++;
378: }
379: next->next = ilink;
380: ilink->previous = next;
381: }
382: PCGetOptionsPrefix(pc,&prefix);
383: PCSetOptionsPrefix(ilink->pc,prefix);
384: sprintf(newprefix,"sub_%d_",(int)cnt);
385: PCAppendOptionsPrefix(ilink->pc,newprefix);
386: /* type is set after prefix, because some methods may modify prefix, e.g. pcksp */
387: PCSetType(ilink->pc,type);
388: return(0);
389: }
393: static PetscErrorCode PCCompositeGetNumberPC_Composite(PC pc,PetscInt *n)
394: {
395: PC_Composite *jac;
396: PC_CompositeLink next;
399: jac = (PC_Composite*)pc->data;
400: next = jac->head;
401: *n = 0;
402: while (next) {
403: next = next->next;
404: (*n) ++;
405: }
406: return(0);
407: }
411: static PetscErrorCode PCCompositeGetPC_Composite(PC pc,PetscInt n,PC *subpc)
412: {
413: PC_Composite *jac;
414: PC_CompositeLink next;
415: PetscInt i;
418: jac = (PC_Composite*)pc->data;
419: next = jac->head;
420: for (i=0; i<n; i++) {
421: if (!next->next) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_INCOMP,"Not enough PCs in composite preconditioner");
422: next = next->next;
423: }
424: *subpc = next->pc;
425: return(0);
426: }
428: /* -------------------------------------------------------------------------------- */
431: /*@
432: PCCompositeSetType - Sets the type of composite preconditioner.
434: Logically Collective on PC
436: Input Parameters:
437: + pc - the preconditioner context
438: - type - PC_COMPOSITE_ADDITIVE (default), PC_COMPOSITE_MULTIPLICATIVE, PC_COMPOSITE_SPECIAL
440: Options Database Key:
441: . -pc_composite_type <type: one of multiplicative, additive, special> - Sets composite preconditioner type
443: Level: Developer
445: .keywords: PC, set, type, composite preconditioner, additive, multiplicative
446: @*/
447: PetscErrorCode PCCompositeSetType(PC pc,PCCompositeType type)
448: {
454: PetscTryMethod(pc,"PCCompositeSetType_C",(PC,PCCompositeType),(pc,type));
455: return(0);
456: }
460: /*@
461: PCCompositeGetType - Gets the type of composite preconditioner.
463: Logically Collective on PC
465: Input Parameter:
466: . pc - the preconditioner context
468: Output Parameter:
469: . type - PC_COMPOSITE_ADDITIVE (default), PC_COMPOSITE_MULTIPLICATIVE, PC_COMPOSITE_SPECIAL
471: Options Database Key:
472: . -pc_composite_type <type: one of multiplicative, additive, special> - Sets composite preconditioner type
474: Level: Developer
476: .keywords: PC, set, type, composite preconditioner, additive, multiplicative
477: @*/
478: PetscErrorCode PCCompositeGetType(PC pc,PCCompositeType *type)
479: {
484: PetscUseMethod(pc,"PCCompositeGetType_C",(PC,PCCompositeType*),(pc,type));
485: return(0);
486: }
490: /*@
491: PCCompositeSpecialSetAlpha - Sets alpha for the special composite preconditioner
492: for alphaI + R + S
494: Logically Collective on PC
496: Input Parameter:
497: + pc - the preconditioner context
498: - alpha - scale on identity
500: Level: Developer
502: .keywords: PC, set, type, composite preconditioner, additive, multiplicative
503: @*/
504: PetscErrorCode PCCompositeSpecialSetAlpha(PC pc,PetscScalar alpha)
505: {
511: PetscTryMethod(pc,"PCCompositeSpecialSetAlpha_C",(PC,PetscScalar),(pc,alpha));
512: return(0);
513: }
517: /*@C
518: PCCompositeAddPC - Adds another PC to the composite PC.
520: Collective on PC
522: Input Parameters:
523: + pc - the preconditioner context
524: - type - the type of the new preconditioner
526: Level: Developer
528: .keywords: PC, composite preconditioner, add
529: @*/
530: PetscErrorCode PCCompositeAddPC(PC pc,PCType type)
531: {
536: PetscTryMethod(pc,"PCCompositeAddPC_C",(PC,PCType),(pc,type));
537: return(0);
538: }
542: /*@
543: PCCompositeGetNumberPC - Gets the number of PC objects in the composite PC.
545: Not Collective
547: Input Parameter:
548: . pc - the preconditioner context
550: Output Parameter:
551: . num - the number of sub pcs
553: Level: Developer
555: .keywords: PC, get, composite preconditioner, sub preconditioner
557: .seealso: PCCompositeGetPC()
558: @*/
559: PetscErrorCode PCCompositeGetNumberPC(PC pc,PetscInt *num)
560: {
566: PetscUseMethod(pc,"PCCompositeGetNumberPC_C",(PC,PetscInt*),(pc,num));
567: return(0);
568: }
572: /*@
573: PCCompositeGetPC - Gets one of the PC objects in the composite PC.
575: Not Collective
577: Input Parameter:
578: + pc - the preconditioner context
579: - n - the number of the pc requested
581: Output Parameters:
582: . subpc - the PC requested
584: Level: Developer
586: .keywords: PC, get, composite preconditioner, sub preconditioner
588: .seealso: PCCompositeAddPC(), PCCompositeGetNumberPC()
589: @*/
590: PetscErrorCode PCCompositeGetPC(PC pc,PetscInt n,PC *subpc)
591: {
597: PetscUseMethod(pc,"PCCompositeGetPC_C",(PC,PetscInt,PC*),(pc,n,subpc));
598: return(0);
599: }
601: /* -------------------------------------------------------------------------------------------*/
603: /*MC
604: PCCOMPOSITE - Build a preconditioner by composing together several preconditioners
606: Options Database Keys:
607: + -pc_composite_type <type: one of multiplicative, additive, symmetric_multiplicative, special> - Sets composite preconditioner type
608: . -pc_use_amat - Activates PCSetUseAmat()
609: - -pc_composite_pcs - <pc0,pc1,...> list of PCs to compose
611: Level: intermediate
613: Concepts: composing solvers
615: Notes: To use a Krylov method inside the composite preconditioner, set the PCType of one or more
616: inner PCs to be PCKSP.
617: Using a Krylov method inside another Krylov method can be dangerous (you get divergence or
618: the incorrect answer) unless you use KSPFGMRES as the outer Krylov method
621: .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC,
622: PCSHELL, PCKSP, PCCompositeSetType(), PCCompositeSpecialSetAlpha(), PCCompositeAddPC(),
623: PCCompositeGetPC(), PCSetUseAmat()
625: M*/
629: PETSC_EXTERN PetscErrorCode PCCreate_Composite(PC pc)
630: {
632: PC_Composite *jac;
635: PetscNewLog(pc,&jac);
637: pc->ops->apply = PCApply_Composite_Additive;
638: pc->ops->applytranspose = PCApplyTranspose_Composite_Additive;
639: pc->ops->setup = PCSetUp_Composite;
640: pc->ops->reset = PCReset_Composite;
641: pc->ops->destroy = PCDestroy_Composite;
642: pc->ops->setfromoptions = PCSetFromOptions_Composite;
643: pc->ops->view = PCView_Composite;
644: pc->ops->applyrichardson = 0;
646: pc->data = (void*)jac;
647: jac->type = PC_COMPOSITE_ADDITIVE;
648: jac->work1 = 0;
649: jac->work2 = 0;
650: jac->head = 0;
652: PetscObjectComposeFunction((PetscObject)pc,"PCCompositeSetType_C",PCCompositeSetType_Composite);
653: PetscObjectComposeFunction((PetscObject)pc,"PCCompositeGetType_C",PCCompositeGetType_Composite);
654: PetscObjectComposeFunction((PetscObject)pc,"PCCompositeAddPC_C",PCCompositeAddPC_Composite);
655: PetscObjectComposeFunction((PetscObject)pc,"PCCompositeGetNumberPC_C",PCCompositeGetNumberPC_Composite);
656: PetscObjectComposeFunction((PetscObject)pc,"PCCompositeGetPC_C",PCCompositeGetPC_Composite);
657: PetscObjectComposeFunction((PetscObject)pc,"PCCompositeSpecialSetAlpha_C",PCCompositeSpecialSetAlpha_Composite);
658: return(0);
659: }