Actual source code: fieldsplit.c
petsc-3.7.5 2017-01-01
2: #include <petsc/private/pcimpl.h> /*I "petscpc.h" I*/
3: #include <petsc/private/kspimpl.h>
4: #include <petscdm.h>
7: const char *const PCFieldSplitSchurPreTypes[] = {"SELF","SELFP","A11","USER","FULL","PCFieldSplitSchurPreType","PC_FIELDSPLIT_SCHUR_PRE_",0};
8: const char *const PCFieldSplitSchurFactTypes[] = {"DIAG","LOWER","UPPER","FULL","PCFieldSplitSchurFactType","PC_FIELDSPLIT_SCHUR_FACT_",0};
10: PetscLogEvent KSP_Solve_FS_0,KSP_Solve_FS_1,KSP_Solve_FS_S,KSP_Solve_FS_U,KSP_Solve_FS_L,KSP_Solve_FS_2,KSP_Solve_FS_3,KSP_Solve_FS_4;
12: typedef struct _PC_FieldSplitLink *PC_FieldSplitLink;
13: struct _PC_FieldSplitLink {
14: KSP ksp;
15: Vec x,y,z;
16: char *splitname;
17: PetscInt nfields;
18: PetscInt *fields,*fields_col;
19: VecScatter sctx;
20: IS is,is_col,is_orig;
21: PC_FieldSplitLink next,previous;
22: PetscLogEvent event;
23: };
25: typedef struct {
26: PCCompositeType type;
27: PetscBool defaultsplit; /* Flag for a system with a set of 'k' scalar fields with the same layout (and bs = k) */
28: PetscBool splitdefined; /* Flag is set after the splits have been defined, to prevent more splits from being added */
29: PetscInt bs; /* Block size for IS and Mat structures */
30: PetscInt nsplits; /* Number of field divisions defined */
31: Vec *x,*y,w1,w2;
32: Mat *mat; /* The diagonal block for each split */
33: Mat *pmat; /* The preconditioning diagonal block for each split */
34: Mat *Afield; /* The rows of the matrix associated with each split */
35: PetscBool issetup;
37: /* Only used when Schur complement preconditioning is used */
38: Mat B; /* The (0,1) block */
39: Mat C; /* The (1,0) block */
40: Mat schur; /* The Schur complement S = A11 - A10 A00^{-1} A01, the KSP here, kspinner, is H_1 in [El08] */
41: Mat schurp; /* Assembled approximation to S built by MatSchurComplement to be used as a preconditioning matrix when solving with S */
42: Mat schur_user; /* User-provided preconditioning matrix for the Schur complement */
43: PCFieldSplitSchurPreType schurpre; /* Determines which preconditioning matrix is used for the Schur complement */
44: PCFieldSplitSchurFactType schurfactorization;
45: KSP kspschur; /* The solver for S */
46: KSP kspupper; /* The solver for A in the upper diagonal part of the factorization (H_2 in [El08]) */
47: PC_FieldSplitLink head;
48: PetscBool reset; /* indicates PCReset() has been last called on this object, hack */
49: PetscBool isrestrict; /* indicates PCFieldSplitRestrictIS() has been last called on this object, hack */
50: PetscBool suboptionsset; /* Indicates that the KSPSetFromOptions() has been called on the sub-KSPs */
51: PetscBool dm_splits; /* Whether to use DMCreateFieldDecomposition() whenever possible */
52: PetscBool diag_use_amat; /* Whether to extract diagonal matrix blocks from Amat, rather than Pmat (weaker than -pc_use_amat) */
53: PetscBool offdiag_use_amat; /* Whether to extract off-diagonal matrix blocks from Amat, rather than Pmat (weaker than -pc_use_amat) */
54: } PC_FieldSplit;
56: /*
57: Notes: there is no particular reason that pmat, x, and y are stored as arrays in PC_FieldSplit instead of
58: inside PC_FieldSplitLink, just historical. If you want to be able to add new fields after already using the
59: PC you could change this.
60: */
62: /* This helper is so that setting a user-provided preconditioning matrix is orthogonal to choosing to use it. This way the
63: * application-provided FormJacobian can provide this matrix without interfering with the user's (command-line) choices. */
64: static Mat FieldSplitSchurPre(PC_FieldSplit *jac)
65: {
66: switch (jac->schurpre) {
67: case PC_FIELDSPLIT_SCHUR_PRE_SELF: return jac->schur;
68: case PC_FIELDSPLIT_SCHUR_PRE_SELFP: return jac->schurp;
69: case PC_FIELDSPLIT_SCHUR_PRE_A11: return jac->pmat[1];
70: case PC_FIELDSPLIT_SCHUR_PRE_FULL: /* We calculate this and store it in schur_user */
71: case PC_FIELDSPLIT_SCHUR_PRE_USER: /* Use a user-provided matrix if it is given, otherwise diagonal block */
72: default:
73: return jac->schur_user ? jac->schur_user : jac->pmat[1];
74: }
75: }
78: #include <petscdraw.h>
81: static PetscErrorCode PCView_FieldSplit(PC pc,PetscViewer viewer)
82: {
83: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
84: PetscErrorCode ierr;
85: PetscBool iascii,isdraw;
86: PetscInt i,j;
87: PC_FieldSplitLink ilink = jac->head;
90: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
91: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
92: if (iascii) {
93: if (jac->bs > 0) {
94: PetscViewerASCIIPrintf(viewer," FieldSplit with %s composition: total splits = %D, blocksize = %D\n",PCCompositeTypes[jac->type],jac->nsplits,jac->bs);
95: } else {
96: PetscViewerASCIIPrintf(viewer," FieldSplit with %s composition: total splits = %D\n",PCCompositeTypes[jac->type],jac->nsplits);
97: }
98: if (pc->useAmat) {
99: PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for blocks\n");
100: }
101: if (jac->diag_use_amat) {
102: PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for diagonal blocks\n");
103: }
104: if (jac->offdiag_use_amat) {
105: PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for off-diagonal blocks\n");
106: }
107: PetscViewerASCIIPrintf(viewer," Solver info for each split is in the following KSP objects:\n");
108: PetscViewerASCIIPushTab(viewer);
109: for (i=0; i<jac->nsplits; i++) {
110: if (ilink->fields) {
111: PetscViewerASCIIPrintf(viewer,"Split number %D Fields ",i);
112: PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);
113: for (j=0; j<ilink->nfields; j++) {
114: if (j > 0) {
115: PetscViewerASCIIPrintf(viewer,",");
116: }
117: PetscViewerASCIIPrintf(viewer," %D",ilink->fields[j]);
118: }
119: PetscViewerASCIIPrintf(viewer,"\n");
120: PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);
121: } else {
122: PetscViewerASCIIPrintf(viewer,"Split number %D Defined by IS\n",i);
123: }
124: KSPView(ilink->ksp,viewer);
125: ilink = ilink->next;
126: }
127: PetscViewerASCIIPopTab(viewer);
128: }
130: if (isdraw) {
131: PetscDraw draw;
132: PetscReal x,y,w,wd;
134: PetscViewerDrawGetDraw(viewer,0,&draw);
135: PetscDrawGetCurrentPoint(draw,&x,&y);
136: w = 2*PetscMin(1.0 - x,x);
137: wd = w/(jac->nsplits + 1);
138: x = x - wd*(jac->nsplits-1)/2.0;
139: for (i=0; i<jac->nsplits; i++) {
140: PetscDrawPushCurrentPoint(draw,x,y);
141: KSPView(ilink->ksp,viewer);
142: PetscDrawPopCurrentPoint(draw);
143: x += wd;
144: ilink = ilink->next;
145: }
146: }
147: return(0);
148: }
152: static PetscErrorCode PCView_FieldSplit_Schur(PC pc,PetscViewer viewer)
153: {
154: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
155: PetscErrorCode ierr;
156: PetscBool iascii,isdraw;
157: PetscInt i,j;
158: PC_FieldSplitLink ilink = jac->head;
161: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
162: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
163: if (iascii) {
164: if (jac->bs > 0) {
165: PetscViewerASCIIPrintf(viewer," FieldSplit with Schur preconditioner, blocksize = %D, factorization %s\n",jac->bs,PCFieldSplitSchurFactTypes[jac->schurfactorization]);
166: } else {
167: PetscViewerASCIIPrintf(viewer," FieldSplit with Schur preconditioner, factorization %s\n",PCFieldSplitSchurFactTypes[jac->schurfactorization]);
168: }
169: if (pc->useAmat) {
170: PetscViewerASCIIPrintf(viewer," using Amat (not Pmat) as operator for blocks\n");
171: }
172: switch (jac->schurpre) {
173: case PC_FIELDSPLIT_SCHUR_PRE_SELF:
174: PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from S itself\n");break;
175: case PC_FIELDSPLIT_SCHUR_PRE_SELFP:
176: PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from Sp, an assembled approximation to S, which uses (lumped, if requested) A00's diagonal's inverse\n");break;
177: case PC_FIELDSPLIT_SCHUR_PRE_A11:
178: PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from A11\n");break;
179: case PC_FIELDSPLIT_SCHUR_PRE_FULL:
180: PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from the exact Schur complement\n");break;
181: case PC_FIELDSPLIT_SCHUR_PRE_USER:
182: if (jac->schur_user) {
183: PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from user provided matrix\n");
184: } else {
185: PetscViewerASCIIPrintf(viewer," Preconditioner for the Schur complement formed from A11\n");
186: }
187: break;
188: default:
189: SETERRQ1(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_OUTOFRANGE, "Invalid Schur preconditioning type: %d", jac->schurpre);
190: }
191: PetscViewerASCIIPrintf(viewer," Split info:\n");
192: PetscViewerASCIIPushTab(viewer);
193: for (i=0; i<jac->nsplits; i++) {
194: if (ilink->fields) {
195: PetscViewerASCIIPrintf(viewer,"Split number %D Fields ",i);
196: PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);
197: for (j=0; j<ilink->nfields; j++) {
198: if (j > 0) {
199: PetscViewerASCIIPrintf(viewer,",");
200: }
201: PetscViewerASCIIPrintf(viewer," %D",ilink->fields[j]);
202: }
203: PetscViewerASCIIPrintf(viewer,"\n");
204: PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);
205: } else {
206: PetscViewerASCIIPrintf(viewer,"Split number %D Defined by IS\n",i);
207: }
208: ilink = ilink->next;
209: }
210: PetscViewerASCIIPrintf(viewer,"KSP solver for A00 block\n");
211: PetscViewerASCIIPushTab(viewer);
212: if (jac->head) {
213: KSPView(jac->head->ksp,viewer);
214: } else {PetscViewerASCIIPrintf(viewer," not yet available\n");}
215: PetscViewerASCIIPopTab(viewer);
216: if (jac->head && jac->kspupper != jac->head->ksp) {
217: PetscViewerASCIIPrintf(viewer,"KSP solver for upper A00 in upper triangular factor \n");
218: PetscViewerASCIIPushTab(viewer);
219: if (jac->kspupper) {KSPView(jac->kspupper,viewer);}
220: else {PetscViewerASCIIPrintf(viewer," not yet available\n");}
221: PetscViewerASCIIPopTab(viewer);
222: }
223: PetscViewerASCIIPrintf(viewer,"KSP solver for S = A11 - A10 inv(A00) A01 \n");
224: PetscViewerASCIIPushTab(viewer);
225: if (jac->kspschur) {
226: KSPView(jac->kspschur,viewer);
227: } else {
228: PetscViewerASCIIPrintf(viewer," not yet available\n");
229: }
230: PetscViewerASCIIPopTab(viewer);
231: PetscViewerASCIIPopTab(viewer);
232: } else if (isdraw && jac->head) {
233: PetscDraw draw;
234: PetscReal x,y,w,wd,h;
235: PetscInt cnt = 2;
236: char str[32];
238: PetscViewerDrawGetDraw(viewer,0,&draw);
239: PetscDrawGetCurrentPoint(draw,&x,&y);
240: if (jac->kspupper != jac->head->ksp) cnt++;
241: w = 2*PetscMin(1.0 - x,x);
242: wd = w/(cnt + 1);
244: PetscSNPrintf(str,32,"Schur fact. %s",PCFieldSplitSchurFactTypes[jac->schurfactorization]);
245: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);
246: y -= h;
247: if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_USER && !jac->schur_user) {
248: PetscSNPrintf(str,32,"Prec. for Schur from %s",PCFieldSplitSchurPreTypes[PC_FIELDSPLIT_SCHUR_PRE_A11]);
249: } else {
250: PetscSNPrintf(str,32,"Prec. for Schur from %s",PCFieldSplitSchurPreTypes[jac->schurpre]);
251: }
252: PetscDrawStringBoxed(draw,x+wd*(cnt-1)/2.0,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);
253: y -= h;
254: x = x - wd*(cnt-1)/2.0;
256: PetscDrawPushCurrentPoint(draw,x,y);
257: KSPView(jac->head->ksp,viewer);
258: PetscDrawPopCurrentPoint(draw);
259: if (jac->kspupper != jac->head->ksp) {
260: x += wd;
261: PetscDrawPushCurrentPoint(draw,x,y);
262: KSPView(jac->kspupper,viewer);
263: PetscDrawPopCurrentPoint(draw);
264: }
265: x += wd;
266: PetscDrawPushCurrentPoint(draw,x,y);
267: KSPView(jac->kspschur,viewer);
268: PetscDrawPopCurrentPoint(draw);
269: }
270: return(0);
271: }
275: /* Precondition: jac->bs is set to a meaningful value */
276: static PetscErrorCode PCFieldSplitSetRuntimeSplits_Private(PC pc)
277: {
279: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
280: PetscInt i,nfields,*ifields,nfields_col,*ifields_col;
281: PetscBool flg,flg_col;
282: char optionname[128],splitname[8],optionname_col[128];
285: PetscMalloc1(jac->bs,&ifields);
286: PetscMalloc1(jac->bs,&ifields_col);
287: for (i=0,flg=PETSC_TRUE;; i++) {
288: PetscSNPrintf(splitname,sizeof(splitname),"%D",i);
289: PetscSNPrintf(optionname,sizeof(optionname),"-pc_fieldsplit_%D_fields",i);
290: PetscSNPrintf(optionname_col,sizeof(optionname_col),"-pc_fieldsplit_%D_fields_col",i);
291: nfields = jac->bs;
292: nfields_col = jac->bs;
293: PetscOptionsGetIntArray(((PetscObject)pc)->options,((PetscObject)pc)->prefix,optionname,ifields,&nfields,&flg);
294: PetscOptionsGetIntArray(((PetscObject)pc)->options,((PetscObject)pc)->prefix,optionname_col,ifields_col,&nfields_col,&flg_col);
295: if (!flg) break;
296: else if (flg && !flg_col) {
297: if (!nfields) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Cannot list zero fields");
298: PCFieldSplitSetFields(pc,splitname,nfields,ifields,ifields);
299: } else {
300: if (!nfields || !nfields_col) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Cannot list zero fields");
301: if (nfields != nfields_col) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Number of row and column fields must match");
302: PCFieldSplitSetFields(pc,splitname,nfields,ifields,ifields_col);
303: }
304: }
305: if (i > 0) {
306: /* Makes command-line setting of splits take precedence over setting them in code.
307: Otherwise subsequent calls to PCFieldSplitSetIS() or PCFieldSplitSetFields() would
308: create new splits, which would probably not be what the user wanted. */
309: jac->splitdefined = PETSC_TRUE;
310: }
311: PetscFree(ifields);
312: PetscFree(ifields_col);
313: return(0);
314: }
318: static PetscErrorCode PCFieldSplitSetDefaults(PC pc)
319: {
320: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
321: PetscErrorCode ierr;
322: PC_FieldSplitLink ilink = jac->head;
323: PetscBool fieldsplit_default = PETSC_FALSE,stokes = PETSC_FALSE,coupling = PETSC_FALSE;
324: PetscInt i;
327: /*
328: Kinda messy, but at least this now uses DMCreateFieldDecomposition() even with jac->reset.
329: Should probably be rewritten.
330: */
331: if (!ilink || jac->reset) {
332: PetscOptionsGetBool(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_fieldsplit_detect_saddle_point",&stokes,NULL);
333: PetscOptionsGetBool(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_fieldsplit_detect_coupling",&coupling,NULL);
334: if (pc->dm && jac->dm_splits && !stokes && !coupling) {
335: PetscInt numFields, f, i, j;
336: char **fieldNames;
337: IS *fields;
338: DM *dms;
339: DM subdm[128];
340: PetscBool flg;
342: DMCreateFieldDecomposition(pc->dm, &numFields, &fieldNames, &fields, &dms);
343: /* Allow the user to prescribe the splits */
344: for (i = 0, flg = PETSC_TRUE;; i++) {
345: PetscInt ifields[128];
346: IS compField;
347: char optionname[128], splitname[8];
348: PetscInt nfields = numFields;
350: PetscSNPrintf(optionname, sizeof(optionname), "-pc_fieldsplit_%D_fields", i);
351: PetscOptionsGetIntArray(((PetscObject)pc)->options,((PetscObject)pc)->prefix, optionname, ifields, &nfields, &flg);
352: if (!flg) break;
353: if (numFields > 128) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot currently support %d > 128 fields", numFields);
354: DMCreateSubDM(pc->dm, nfields, ifields, &compField, &subdm[i]);
355: if (nfields == 1) {
356: PCFieldSplitSetIS(pc, fieldNames[ifields[0]], compField);
357: /* PetscPrintf(PetscObjectComm((PetscObject)pc), "%s Field Indices:", fieldNames[ifields[0]]);
358: ISView(compField, NULL); */
359: } else {
360: PetscSNPrintf(splitname, sizeof(splitname), "%D", i);
361: PCFieldSplitSetIS(pc, splitname, compField);
362: /* PetscPrintf(PetscObjectComm((PetscObject)pc), "%s Field Indices:", splitname);
363: ISView(compField, NULL); */
364: }
365: ISDestroy(&compField);
366: for (j = 0; j < nfields; ++j) {
367: f = ifields[j];
368: PetscFree(fieldNames[f]);
369: ISDestroy(&fields[f]);
370: }
371: }
372: if (i == 0) {
373: for (f = 0; f < numFields; ++f) {
374: PCFieldSplitSetIS(pc, fieldNames[f], fields[f]);
375: PetscFree(fieldNames[f]);
376: ISDestroy(&fields[f]);
377: }
378: } else {
379: for (j=0; j<numFields; j++) {
380: DMDestroy(dms+j);
381: }
382: PetscFree(dms);
383: PetscMalloc1(i, &dms);
384: for (j = 0; j < i; ++j) dms[j] = subdm[j];
385: }
386: PetscFree(fieldNames);
387: PetscFree(fields);
388: if (dms) {
389: PetscInfo(pc, "Setting up physics based fieldsplit preconditioner using the embedded DM\n");
390: for (ilink = jac->head, i = 0; ilink; ilink = ilink->next, ++i) {
391: const char *prefix;
392: PetscObjectGetOptionsPrefix((PetscObject)(ilink->ksp),&prefix);
393: PetscObjectSetOptionsPrefix((PetscObject)(dms[i]), prefix);
394: KSPSetDM(ilink->ksp, dms[i]);
395: KSPSetDMActive(ilink->ksp, PETSC_FALSE);
396: PetscObjectIncrementTabLevel((PetscObject)dms[i],(PetscObject)ilink->ksp,0);
397: DMDestroy(&dms[i]);
398: }
399: PetscFree(dms);
400: }
401: } else {
402: if (jac->bs <= 0) {
403: if (pc->pmat) {
404: MatGetBlockSize(pc->pmat,&jac->bs);
405: } else jac->bs = 1;
406: }
408: if (stokes) {
409: IS zerodiags,rest;
410: PetscInt nmin,nmax;
412: MatGetOwnershipRange(pc->mat,&nmin,&nmax);
413: MatFindZeroDiagonals(pc->mat,&zerodiags);
414: ISComplement(zerodiags,nmin,nmax,&rest);
415: if (jac->reset) {
416: jac->head->is = rest;
417: jac->head->next->is = zerodiags;
418: } else {
419: PCFieldSplitSetIS(pc,"0",rest);
420: PCFieldSplitSetIS(pc,"1",zerodiags);
421: }
422: ISDestroy(&zerodiags);
423: ISDestroy(&rest);
424: } else if (coupling) {
425: IS coupling,rest;
426: PetscInt nmin,nmax;
428: MatGetOwnershipRange(pc->mat,&nmin,&nmax);
429: MatFindOffBlockDiagonalEntries(pc->mat,&coupling);
430: ISCreateStride(PetscObjectComm((PetscObject)pc->mat),nmax-nmin,nmin,1,&rest);
431: ISSetIdentity(rest);
432: if (jac->reset) {
433: jac->head->is = rest;
434: jac->head->next->is = coupling;
435: } else {
436: PCFieldSplitSetIS(pc,"0",rest);
437: PCFieldSplitSetIS(pc,"1",coupling);
438: }
439: ISDestroy(&coupling);
440: ISDestroy(&rest);
441: } else {
442: if (jac->reset && !jac->isrestrict) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cases not yet handled when PCReset() was used");
443: PetscOptionsGetBool(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_fieldsplit_default",&fieldsplit_default,NULL);
444: if (!fieldsplit_default) {
445: /* Allow user to set fields from command line, if bs was known at the time of PCSetFromOptions_FieldSplit()
446: then it is set there. This is not ideal because we should only have options set in XXSetFromOptions(). */
447: PCFieldSplitSetRuntimeSplits_Private(pc);
448: if (jac->splitdefined) {PetscInfo(pc,"Splits defined using the options database\n");}
449: }
450: if ((fieldsplit_default || !jac->splitdefined) && !jac->isrestrict) {
451: PetscInfo(pc,"Using default splitting of fields\n");
452: for (i=0; i<jac->bs; i++) {
453: char splitname[8];
454: PetscSNPrintf(splitname,sizeof(splitname),"%D",i);
455: PCFieldSplitSetFields(pc,splitname,1,&i,&i);
456: }
457: jac->defaultsplit = PETSC_TRUE;
458: }
459: }
460: }
461: } else if (jac->nsplits == 1) {
462: if (ilink->is) {
463: IS is2;
464: PetscInt nmin,nmax;
466: MatGetOwnershipRange(pc->mat,&nmin,&nmax);
467: ISComplement(ilink->is,nmin,nmax,&is2);
468: PCFieldSplitSetIS(pc,"1",is2);
469: ISDestroy(&is2);
470: } else SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Must provide at least two sets of fields to PCFieldSplit()");
471: }
474: if (jac->nsplits < 2) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_PLIB,"Unhandled case, must have at least two fields, not %d", jac->nsplits);
475: return(0);
476: }
478: PETSC_EXTERN PetscErrorCode PetscOptionsFindPairPrefix_Private(PetscOptions,const char pre[], const char name[], char *value[], PetscBool *flg);
482: static PetscErrorCode PCSetUp_FieldSplit(PC pc)
483: {
484: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
485: PetscErrorCode ierr;
486: PC_FieldSplitLink ilink;
487: PetscInt i,nsplit;
488: PetscBool sorted, sorted_col;
491: PCFieldSplitSetDefaults(pc);
492: nsplit = jac->nsplits;
493: ilink = jac->head;
495: /* get the matrices for each split */
496: if (!jac->issetup) {
497: PetscInt rstart,rend,nslots,bs;
499: jac->issetup = PETSC_TRUE;
501: /* This is done here instead of in PCFieldSplitSetFields() because may not have matrix at that point */
502: if (jac->defaultsplit || !ilink->is) {
503: if (jac->bs <= 0) jac->bs = nsplit;
504: }
505: bs = jac->bs;
506: MatGetOwnershipRange(pc->pmat,&rstart,&rend);
507: nslots = (rend - rstart)/bs;
508: for (i=0; i<nsplit; i++) {
509: if (jac->defaultsplit) {
510: ISCreateStride(PetscObjectComm((PetscObject)pc),nslots,rstart+i,nsplit,&ilink->is);
511: ISDuplicate(ilink->is,&ilink->is_col);
512: } else if (!ilink->is) {
513: if (ilink->nfields > 1) {
514: PetscInt *ii,*jj,j,k,nfields = ilink->nfields,*fields = ilink->fields,*fields_col = ilink->fields_col;
515: PetscMalloc1(ilink->nfields*nslots,&ii);
516: PetscMalloc1(ilink->nfields*nslots,&jj);
517: for (j=0; j<nslots; j++) {
518: for (k=0; k<nfields; k++) {
519: ii[nfields*j + k] = rstart + bs*j + fields[k];
520: jj[nfields*j + k] = rstart + bs*j + fields_col[k];
521: }
522: }
523: ISCreateGeneral(PetscObjectComm((PetscObject)pc),nslots*nfields,ii,PETSC_OWN_POINTER,&ilink->is);
524: ISCreateGeneral(PetscObjectComm((PetscObject)pc),nslots*nfields,jj,PETSC_OWN_POINTER,&ilink->is_col);
525: ISSetBlockSize(ilink->is, nfields);
526: ISSetBlockSize(ilink->is_col, nfields);
527: } else {
528: ISCreateStride(PetscObjectComm((PetscObject)pc),nslots,rstart+ilink->fields[0],bs,&ilink->is);
529: ISCreateStride(PetscObjectComm((PetscObject)pc),nslots,rstart+ilink->fields_col[0],bs,&ilink->is_col);
530: }
531: }
532: ISSorted(ilink->is,&sorted);
533: if (ilink->is_col) { ISSorted(ilink->is_col,&sorted_col); }
534: if (!sorted || !sorted_col) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Fields must be sorted when creating split");
535: ilink = ilink->next;
536: }
537: }
539: ilink = jac->head;
540: if (!jac->pmat) {
541: Vec xtmp;
543: MatCreateVecs(pc->pmat,&xtmp,NULL);
544: PetscMalloc1(nsplit,&jac->pmat);
545: PetscMalloc2(nsplit,&jac->x,nsplit,&jac->y);
546: for (i=0; i<nsplit; i++) {
547: MatNullSpace sp;
549: /* Check for preconditioning matrix attached to IS */
550: PetscObjectQuery((PetscObject) ilink->is, "pmat", (PetscObject*) &jac->pmat[i]);
551: if (jac->pmat[i]) {
552: PetscObjectReference((PetscObject) jac->pmat[i]);
553: if (jac->type == PC_COMPOSITE_SCHUR) {
554: jac->schur_user = jac->pmat[i];
556: PetscObjectReference((PetscObject) jac->schur_user);
557: }
558: } else {
559: const char *prefix;
560: MatGetSubMatrix(pc->pmat,ilink->is,ilink->is_col,MAT_INITIAL_MATRIX,&jac->pmat[i]);
561: KSPGetOptionsPrefix(ilink->ksp,&prefix);
562: MatSetOptionsPrefix(jac->pmat[i],prefix);
563: MatViewFromOptions(jac->pmat[i],NULL,"-mat_view");
564: }
565: /* create work vectors for each split */
566: MatCreateVecs(jac->pmat[i],&jac->x[i],&jac->y[i]);
567: ilink->x = jac->x[i]; ilink->y = jac->y[i]; ilink->z = NULL;
568: /* compute scatter contexts needed by multiplicative versions and non-default splits */
569: VecScatterCreate(xtmp,ilink->is,jac->x[i],NULL,&ilink->sctx);
570: PetscObjectQuery((PetscObject) ilink->is, "nearnullspace", (PetscObject*) &sp);
571: if (sp) {
572: MatSetNearNullSpace(jac->pmat[i], sp);
573: }
574: ilink = ilink->next;
575: }
576: VecDestroy(&xtmp);
577: } else {
578: for (i=0; i<nsplit; i++) {
579: Mat pmat;
581: /* Check for preconditioning matrix attached to IS */
582: PetscObjectQuery((PetscObject) ilink->is, "pmat", (PetscObject*) &pmat);
583: if (!pmat) {
584: MatGetSubMatrix(pc->pmat,ilink->is,ilink->is_col,MAT_REUSE_MATRIX,&jac->pmat[i]);
585: }
586: ilink = ilink->next;
587: }
588: }
589: if (jac->diag_use_amat) {
590: ilink = jac->head;
591: if (!jac->mat) {
592: PetscMalloc1(nsplit,&jac->mat);
593: for (i=0; i<nsplit; i++) {
594: MatGetSubMatrix(pc->mat,ilink->is,ilink->is_col,MAT_INITIAL_MATRIX,&jac->mat[i]);
595: ilink = ilink->next;
596: }
597: } else {
598: for (i=0; i<nsplit; i++) {
599: if (jac->mat[i]) {MatGetSubMatrix(pc->mat,ilink->is,ilink->is_col,MAT_REUSE_MATRIX,&jac->mat[i]);}
600: ilink = ilink->next;
601: }
602: }
603: } else {
604: jac->mat = jac->pmat;
605: }
607: /* Check for null space attached to IS */
608: ilink = jac->head;
609: for (i=0; i<nsplit; i++) {
610: MatNullSpace sp;
612: PetscObjectQuery((PetscObject) ilink->is, "nullspace", (PetscObject*) &sp);
613: if (sp) {
614: MatSetNullSpace(jac->mat[i], sp);
615: }
616: ilink = ilink->next;
617: }
619: if (jac->type != PC_COMPOSITE_ADDITIVE && jac->type != PC_COMPOSITE_SCHUR) {
620: /* extract the rows of the matrix associated with each field: used for efficient computation of residual inside algorithm */
621: /* FIXME: Can/should we reuse jac->mat whenever (jac->diag_use_amat) is true? */
622: ilink = jac->head;
623: if (nsplit == 2 && jac->type == PC_COMPOSITE_MULTIPLICATIVE) {
624: /* special case need where Afield[0] is not needed and only certain columns of Afield[1] are needed since update is only on those rows of the solution */
625: if (!jac->Afield) {
626: PetscCalloc1(nsplit,&jac->Afield);
627: MatGetSubMatrix(pc->mat,ilink->next->is,ilink->is,MAT_INITIAL_MATRIX,&jac->Afield[1]);
628: } else {
629: MatGetSubMatrix(pc->mat,ilink->next->is,ilink->is,MAT_REUSE_MATRIX,&jac->Afield[1]);
630: }
631: } else {
632: if (!jac->Afield) {
633: PetscMalloc1(nsplit,&jac->Afield);
634: for (i=0; i<nsplit; i++) {
635: MatGetSubMatrix(pc->mat,ilink->is,NULL,MAT_INITIAL_MATRIX,&jac->Afield[i]);
636: ilink = ilink->next;
637: }
638: } else {
639: for (i=0; i<nsplit; i++) {
640: MatGetSubMatrix(pc->mat,ilink->is,NULL,MAT_REUSE_MATRIX,&jac->Afield[i]);
641: ilink = ilink->next;
642: }
643: }
644: }
645: }
647: if (jac->type == PC_COMPOSITE_SCHUR) {
648: IS ccis;
649: PetscInt rstart,rend;
650: char lscname[256];
651: PetscObject LSC_L;
653: if (nsplit != 2) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_INCOMP,"To use Schur complement preconditioner you must have exactly 2 fields");
655: /* When extracting off-diagonal submatrices, we take complements from this range */
656: MatGetOwnershipRangeColumn(pc->mat,&rstart,&rend);
658: /* need to handle case when one is resetting up the preconditioner */
659: if (jac->schur) {
660: KSP kspA = jac->head->ksp, kspInner = NULL, kspUpper = jac->kspupper;
662: MatSchurComplementGetKSP(jac->schur, &kspInner);
663: ilink = jac->head;
664: ISComplement(ilink->is_col,rstart,rend,&ccis);
665: if (jac->offdiag_use_amat) {
666: MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->B);
667: } else {
668: MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->B);
669: }
670: ISDestroy(&ccis);
671: ilink = ilink->next;
672: ISComplement(ilink->is_col,rstart,rend,&ccis);
673: if (jac->offdiag_use_amat) {
674: MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->C);
675: } else {
676: MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_REUSE_MATRIX,&jac->C);
677: }
678: ISDestroy(&ccis);
679: MatSchurComplementUpdateSubMatrices(jac->schur,jac->mat[0],jac->pmat[0],jac->B,jac->C,jac->mat[1]);
680: if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_SELFP) {
681: MatDestroy(&jac->schurp);
682: MatSchurComplementGetPmat(jac->schur,MAT_INITIAL_MATRIX,&jac->schurp);
683: }
684: if (kspA != kspInner) {
685: KSPSetOperators(kspA,jac->mat[0],jac->pmat[0]);
686: }
687: if (kspUpper != kspA) {
688: KSPSetOperators(kspUpper,jac->mat[0],jac->pmat[0]);
689: }
690: KSPSetOperators(jac->kspschur,jac->schur,FieldSplitSchurPre(jac));
691: } else {
692: const char *Dprefix;
693: char schurprefix[256], schurmatprefix[256];
694: char schurtestoption[256];
695: MatNullSpace sp;
696: PetscBool flg;
698: /* extract the A01 and A10 matrices */
699: ilink = jac->head;
700: ISComplement(ilink->is_col,rstart,rend,&ccis);
701: if (jac->offdiag_use_amat) {
702: MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->B);
703: } else {
704: MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->B);
705: }
706: ISDestroy(&ccis);
707: ilink = ilink->next;
708: ISComplement(ilink->is_col,rstart,rend,&ccis);
709: if (jac->offdiag_use_amat) {
710: MatGetSubMatrix(pc->mat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->C);
711: } else {
712: MatGetSubMatrix(pc->pmat,ilink->is,ccis,MAT_INITIAL_MATRIX,&jac->C);
713: }
714: ISDestroy(&ccis);
716: /* Use mat[0] (diagonal block of Amat) preconditioned by pmat[0] to define Schur complement */
717: MatCreate(((PetscObject)jac->mat[0])->comm,&jac->schur);
718: MatSetType(jac->schur,MATSCHURCOMPLEMENT);
719: MatSchurComplementSetSubMatrices(jac->schur,jac->mat[0],jac->pmat[0],jac->B,jac->C,jac->mat[1]);
720: PetscSNPrintf(schurmatprefix, sizeof(schurmatprefix), "%sfieldsplit_%s_", ((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "", ilink->splitname);
721: /* Note that the inner KSP is NOT going to inherit this prefix, and if it did, it would be reset just below. Is that what we want? */
722: MatSetOptionsPrefix(jac->schur,schurmatprefix);
723: MatSetFromOptions(jac->schur);
724: MatGetNullSpace(jac->mat[1], &sp);
725: if (sp) {
726: MatSetNullSpace(jac->schur, sp);
727: }
729: PetscSNPrintf(schurtestoption, sizeof(schurtestoption), "-fieldsplit_%s_inner_", ilink->splitname);
730: PetscOptionsFindPairPrefix_Private(((PetscObject)pc)->options,((PetscObject)pc)->prefix, schurtestoption, NULL, &flg);
731: if (flg) {
732: DM dmInner;
733: KSP kspInner;
735: MatSchurComplementGetKSP(jac->schur, &kspInner);
736: PetscSNPrintf(schurprefix, sizeof(schurprefix), "%sfieldsplit_%s_inner_", ((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "", ilink->splitname);
737: /* Indent this deeper to emphasize the "inner" nature of this solver. */
738: PetscObjectIncrementTabLevel((PetscObject)kspInner, (PetscObject) pc, 2);
739: KSPSetOptionsPrefix(kspInner, schurprefix);
741: /* Set DM for new solver */
742: KSPGetDM(jac->head->ksp, &dmInner);
743: KSPSetDM(kspInner, dmInner);
744: KSPSetDMActive(kspInner, PETSC_FALSE);
745: } else {
746: /* Use the outer solver for the inner solve, but revert the KSPPREONLY from PCFieldSplitSetFields_FieldSplit or
747: * PCFieldSplitSetIS_FieldSplit. We don't want KSPPREONLY because it makes the Schur complement inexact,
748: * preventing Schur complement reduction to be an accurate solve. Usually when an iterative solver is used for
749: * S = D - C A_inner^{-1} B, we expect S to be defined using an accurate definition of A_inner^{-1}, so we make
750: * GMRES the default. Note that it is also common to use PREONLY for S, in which case S may not be used
751: * directly, and the user is responsible for setting an inexact method for fieldsplit's A^{-1}. */
752: KSPSetType(jac->head->ksp,KSPGMRES);
753: MatSchurComplementSetKSP(jac->schur,jac->head->ksp);
754: }
755: KSPSetOperators(jac->head->ksp,jac->mat[0],jac->pmat[0]);
756: KSPSetFromOptions(jac->head->ksp);
757: MatSetFromOptions(jac->schur);
759: PetscSNPrintf(schurtestoption, sizeof(schurtestoption), "-fieldsplit_%s_upper_", ilink->splitname);
760: PetscOptionsFindPairPrefix_Private(((PetscObject)pc)->options,((PetscObject)pc)->prefix, schurtestoption, NULL, &flg);
761: if (flg) {
762: DM dmInner;
764: PetscSNPrintf(schurprefix, sizeof(schurprefix), "%sfieldsplit_%s_upper_", ((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "", ilink->splitname);
765: KSPCreate(PetscObjectComm((PetscObject)pc), &jac->kspupper);
766: KSPSetErrorIfNotConverged(jac->kspupper,pc->erroriffailure);
767: KSPSetOptionsPrefix(jac->kspupper, schurprefix);
768: KSPGetDM(jac->head->ksp, &dmInner);
769: KSPSetDM(jac->kspupper, dmInner);
770: KSPSetDMActive(jac->kspupper, PETSC_FALSE);
771: KSPSetFromOptions(jac->kspupper);
772: KSPSetOperators(jac->kspupper,jac->mat[0],jac->pmat[0]);
773: VecDuplicate(jac->head->x, &jac->head->z);
774: } else {
775: jac->kspupper = jac->head->ksp;
776: PetscObjectReference((PetscObject) jac->head->ksp);
777: }
779: if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_SELFP) {
780: MatSchurComplementGetPmat(jac->schur,MAT_INITIAL_MATRIX,&jac->schurp);
781: }
782: KSPCreate(PetscObjectComm((PetscObject)pc),&jac->kspschur);
783: KSPSetErrorIfNotConverged(jac->kspschur,pc->erroriffailure);
784: PetscLogObjectParent((PetscObject)pc,(PetscObject)jac->kspschur);
785: PetscObjectIncrementTabLevel((PetscObject)jac->kspschur,(PetscObject)pc,1);
786: if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_SELF) {
787: PC pcschur;
788: KSPGetPC(jac->kspschur,&pcschur);
789: PCSetType(pcschur,PCNONE);
790: /* Note: This is bad if there exist preconditioners for MATSCHURCOMPLEMENT */
791: } else if (jac->schurpre == PC_FIELDSPLIT_SCHUR_PRE_FULL) {
792: MatSchurComplementComputeExplicitOperator(jac->schur, &jac->schur_user);
793: }
794: KSPSetOperators(jac->kspschur,jac->schur,FieldSplitSchurPre(jac));
795: KSPGetOptionsPrefix(jac->head->next->ksp, &Dprefix);
796: KSPSetOptionsPrefix(jac->kspschur, Dprefix);
797: /* propogate DM */
798: {
799: DM sdm;
800: KSPGetDM(jac->head->next->ksp, &sdm);
801: if (sdm) {
802: KSPSetDM(jac->kspschur, sdm);
803: KSPSetDMActive(jac->kspschur, PETSC_FALSE);
804: }
805: }
806: /* really want setfromoptions called in PCSetFromOptions_FieldSplit(), but it is not ready yet */
807: /* need to call this every time, since the jac->kspschur is freshly created, otherwise its options never get set */
808: KSPSetFromOptions(jac->kspschur);
809: }
811: /* HACK: special support to forward L and Lp matrices that might be used by PCLSC */
812: PetscSNPrintf(lscname,sizeof(lscname),"%s_LSC_L",ilink->splitname);
813: PetscObjectQuery((PetscObject)pc->mat,lscname,(PetscObject*)&LSC_L);
814: if (!LSC_L) {PetscObjectQuery((PetscObject)pc->pmat,lscname,(PetscObject*)&LSC_L);}
815: if (LSC_L) {PetscObjectCompose((PetscObject)jac->schur,"LSC_L",(PetscObject)LSC_L);}
816: PetscSNPrintf(lscname,sizeof(lscname),"%s_LSC_Lp",ilink->splitname);
817: PetscObjectQuery((PetscObject)pc->pmat,lscname,(PetscObject*)&LSC_L);
818: if (!LSC_L) {PetscObjectQuery((PetscObject)pc->mat,lscname,(PetscObject*)&LSC_L);}
819: if (LSC_L) {PetscObjectCompose((PetscObject)jac->schur,"LSC_Lp",(PetscObject)LSC_L);}
820: } else {
821: /* set up the individual splits' PCs */
822: i = 0;
823: ilink = jac->head;
824: while (ilink) {
825: KSPSetOperators(ilink->ksp,jac->mat[i],jac->pmat[i]);
826: /* really want setfromoptions called in PCSetFromOptions_FieldSplit(), but it is not ready yet */
827: if (!jac->suboptionsset) {KSPSetFromOptions(ilink->ksp);}
828: i++;
829: ilink = ilink->next;
830: }
831: }
833: jac->suboptionsset = PETSC_TRUE;
834: return(0);
835: }
837: #define FieldSplitSplitSolveAdd(ilink,xx,yy) \
838: (VecScatterBegin(ilink->sctx,xx,ilink->x,INSERT_VALUES,SCATTER_FORWARD) || \
839: VecScatterEnd(ilink->sctx,xx,ilink->x,INSERT_VALUES,SCATTER_FORWARD) || \
840: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL) ||\
841: KSPSolve(ilink->ksp,ilink->x,ilink->y) || \
842: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL) ||\
843: VecScatterBegin(ilink->sctx,ilink->y,yy,ADD_VALUES,SCATTER_REVERSE) || \
844: VecScatterEnd(ilink->sctx,ilink->y,yy,ADD_VALUES,SCATTER_REVERSE))
848: static PetscErrorCode PCApply_FieldSplit_Schur(PC pc,Vec x,Vec y)
849: {
850: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
851: PetscErrorCode ierr;
852: PC_FieldSplitLink ilinkA = jac->head, ilinkD = ilinkA->next;
853: KSP kspA = ilinkA->ksp, kspLower = kspA, kspUpper = jac->kspupper;
856: switch (jac->schurfactorization) {
857: case PC_FIELDSPLIT_SCHUR_FACT_DIAG:
858: /* [A00 0; 0 -S], positive definite, suitable for MINRES */
859: VecScatterBegin(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);
860: VecScatterBegin(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);
861: VecScatterEnd(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);
862: PetscLogEventBegin(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
863: KSPSolve(kspA,ilinkA->x,ilinkA->y);
864: PetscLogEventEnd(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
865: VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
866: VecScatterEnd(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);
867: PetscLogEventBegin(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
868: KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);
869: PetscLogEventEnd(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
870: VecScale(ilinkD->y,-1.);
871: VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
872: VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
873: VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
874: break;
875: case PC_FIELDSPLIT_SCHUR_FACT_LOWER:
876: /* [A00 0; A10 S], suitable for left preconditioning */
877: VecScatterBegin(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);
878: VecScatterEnd(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);
879: PetscLogEventBegin(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
880: KSPSolve(kspA,ilinkA->x,ilinkA->y);
881: PetscLogEventEnd(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
882: MatMult(jac->C,ilinkA->y,ilinkD->x);
883: VecScale(ilinkD->x,-1.);
884: VecScatterBegin(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);
885: VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
886: VecScatterEnd(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);
887: PetscLogEventBegin(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
888: KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);
889: PetscLogEventEnd(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
890: VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
891: VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
892: VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
893: break;
894: case PC_FIELDSPLIT_SCHUR_FACT_UPPER:
895: /* [A00 A01; 0 S], suitable for right preconditioning */
896: VecScatterBegin(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);
897: VecScatterEnd(ilinkD->sctx,x,ilinkD->x,INSERT_VALUES,SCATTER_FORWARD);
898: PetscLogEventBegin(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
899: KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);
900: PetscLogEventEnd(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL); MatMult(jac->B,ilinkD->y,ilinkA->x);
901: VecScale(ilinkA->x,-1.);
902: VecScatterBegin(ilinkA->sctx,x,ilinkA->x,ADD_VALUES,SCATTER_FORWARD);
903: VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
904: VecScatterEnd(ilinkA->sctx,x,ilinkA->x,ADD_VALUES,SCATTER_FORWARD);
905: PetscLogEventBegin(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
906: KSPSolve(kspA,ilinkA->x,ilinkA->y);
907: PetscLogEventEnd(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
908: VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
909: VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
910: VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
911: break;
912: case PC_FIELDSPLIT_SCHUR_FACT_FULL:
913: /* [1 0; A10 A00^{-1} 1] [A00 0; 0 S] [1 A00^{-1}A01; 0 1], an exact solve if applied exactly, needs one extra solve with A */
914: VecScatterBegin(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);
915: VecScatterEnd(ilinkA->sctx,x,ilinkA->x,INSERT_VALUES,SCATTER_FORWARD);
916: PetscLogEventBegin(KSP_Solve_FS_L,kspLower,ilinkA->x,ilinkA->y,NULL);
917: KSPSolve(kspLower,ilinkA->x,ilinkA->y);
918: PetscLogEventEnd(KSP_Solve_FS_L,kspLower,ilinkA->x,ilinkA->y,NULL);
919: MatMult(jac->C,ilinkA->y,ilinkD->x);
920: VecScale(ilinkD->x,-1.0);
921: VecScatterBegin(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);
922: VecScatterEnd(ilinkD->sctx,x,ilinkD->x,ADD_VALUES,SCATTER_FORWARD);
924: PetscLogEventBegin(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
925: KSPSolve(jac->kspschur,ilinkD->x,ilinkD->y);
926: PetscLogEventEnd(KSP_Solve_FS_S,jac->kspschur,ilinkD->x,ilinkD->y,NULL);
927: VecScatterBegin(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
928: VecScatterEnd(ilinkD->sctx,ilinkD->y,y,INSERT_VALUES,SCATTER_REVERSE);
930: if (kspUpper == kspA) {
931: MatMult(jac->B,ilinkD->y,ilinkA->y);
932: VecAXPY(ilinkA->x,-1.0,ilinkA->y);
933: PetscLogEventBegin(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
934: KSPSolve(kspA,ilinkA->x,ilinkA->y);
935: PetscLogEventEnd(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
936: } else {
937: PetscLogEventBegin(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
938: KSPSolve(kspA,ilinkA->x,ilinkA->y);
939: PetscLogEventEnd(ilinkA->event,kspA,ilinkA->x,ilinkA->y,NULL);
940: MatMult(jac->B,ilinkD->y,ilinkA->x);
941: PetscLogEventBegin(KSP_Solve_FS_U,kspUpper,ilinkA->x,ilinkA->z,NULL);
942: KSPSolve(kspUpper,ilinkA->x,ilinkA->z);
943: PetscLogEventEnd(KSP_Solve_FS_U,kspUpper,ilinkA->x,ilinkA->z,NULL);
944: VecAXPY(ilinkA->y,-1.0,ilinkA->z);
945: }
946: VecScatterBegin(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
947: VecScatterEnd(ilinkA->sctx,ilinkA->y,y,INSERT_VALUES,SCATTER_REVERSE);
948: }
949: return(0);
950: }
954: static PetscErrorCode PCApply_FieldSplit(PC pc,Vec x,Vec y)
955: {
956: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
957: PetscErrorCode ierr;
958: PC_FieldSplitLink ilink = jac->head;
959: PetscInt cnt,bs;
960: KSPConvergedReason reason;
963: if (jac->type == PC_COMPOSITE_ADDITIVE) {
964: if (jac->defaultsplit) {
965: VecGetBlockSize(x,&bs);
966: if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of x vector %D does not match fieldsplit blocksize %D",bs,jac->bs);
967: VecGetBlockSize(y,&bs);
968: if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of y vector %D does not match fieldsplit blocksize %D",bs,jac->bs);
969: VecStrideGatherAll(x,jac->x,INSERT_VALUES);
970: while (ilink) {
971: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
972: KSPSolve(ilink->ksp,ilink->x,ilink->y);
973: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
974: KSPGetConvergedReason(ilink->ksp,&reason);
975: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
976: pc->failedreason = PC_SUBPC_ERROR;
977: }
978: ilink = ilink->next;
979: }
980: VecStrideScatterAll(jac->y,y,INSERT_VALUES);
981: } else {
982: VecSet(y,0.0);
983: while (ilink) {
984: FieldSplitSplitSolveAdd(ilink,x,y);
985: KSPGetConvergedReason(ilink->ksp,&reason);
986: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
987: pc->failedreason = PC_SUBPC_ERROR;
988: }
989: ilink = ilink->next;
990: }
991: }
992: } else if (jac->type == PC_COMPOSITE_MULTIPLICATIVE && jac->nsplits == 2) {
993: VecSet(y,0.0);
994: /* solve on first block for first block variables */
995: VecScatterBegin(ilink->sctx,x,ilink->x,INSERT_VALUES,SCATTER_FORWARD);
996: VecScatterEnd(ilink->sctx,x,ilink->x,INSERT_VALUES,SCATTER_FORWARD);
997: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
998: KSPSolve(ilink->ksp,ilink->x,ilink->y);
999: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1000: KSPGetConvergedReason(ilink->ksp,&reason);
1001: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1002: pc->failedreason = PC_SUBPC_ERROR;
1003: }
1004: VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1005: VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1007: /* compute the residual only onto second block variables using first block variables */
1008: MatMult(jac->Afield[1],ilink->y,ilink->next->x);
1009: ilink = ilink->next;
1010: VecScale(ilink->x,-1.0);
1011: VecScatterBegin(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);
1012: VecScatterEnd(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);
1014: /* solve on second block variables */
1015: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1016: KSPSolve(ilink->ksp,ilink->x,ilink->y);
1017: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1018: KSPGetConvergedReason(ilink->ksp,&reason);
1019: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1020: pc->failedreason = PC_SUBPC_ERROR;
1021: }
1022: VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1023: VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1024: } else if (jac->type == PC_COMPOSITE_MULTIPLICATIVE || jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) {
1025: if (!jac->w1) {
1026: VecDuplicate(x,&jac->w1);
1027: VecDuplicate(x,&jac->w2);
1028: }
1029: VecSet(y,0.0);
1030: FieldSplitSplitSolveAdd(ilink,x,y);
1031: KSPGetConvergedReason(ilink->ksp,&reason);
1032: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1033: pc->failedreason = PC_SUBPC_ERROR;
1034: }
1035: cnt = 1;
1036: while (ilink->next) {
1037: ilink = ilink->next;
1038: /* compute the residual only over the part of the vector needed */
1039: MatMult(jac->Afield[cnt++],y,ilink->x);
1040: VecScale(ilink->x,-1.0);
1041: VecScatterBegin(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);
1042: VecScatterEnd(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);
1043: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1044: KSPSolve(ilink->ksp,ilink->x,ilink->y);
1045: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1046: KSPGetConvergedReason(ilink->ksp,&reason);
1047: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1048: pc->failedreason = PC_SUBPC_ERROR;
1049: }
1050: VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1051: VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1052: }
1053: if (jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) {
1054: cnt -= 2;
1055: while (ilink->previous) {
1056: ilink = ilink->previous;
1057: /* compute the residual only over the part of the vector needed */
1058: MatMult(jac->Afield[cnt--],y,ilink->x);
1059: VecScale(ilink->x,-1.0);
1060: VecScatterBegin(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);
1061: VecScatterEnd(ilink->sctx,x,ilink->x,ADD_VALUES,SCATTER_FORWARD);
1062: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1063: KSPSolve(ilink->ksp,ilink->x,ilink->y);
1064: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1065: KSPGetConvergedReason(ilink->ksp,&reason);
1066: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1067: pc->failedreason = PC_SUBPC_ERROR;
1068: }
1069: VecScatterBegin(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1070: VecScatterEnd(ilink->sctx,ilink->y,y,ADD_VALUES,SCATTER_REVERSE);
1071: }
1072: }
1073: } else SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Unsupported or unknown composition",(int) jac->type);
1074: return(0);
1075: }
1077: #define FieldSplitSplitSolveAddTranspose(ilink,xx,yy) \
1078: (VecScatterBegin(ilink->sctx,xx,ilink->y,INSERT_VALUES,SCATTER_FORWARD) || \
1079: VecScatterEnd(ilink->sctx,xx,ilink->y,INSERT_VALUES,SCATTER_FORWARD) || \
1080: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->y,ilink->x,NULL) || \
1081: KSPSolveTranspose(ilink->ksp,ilink->y,ilink->x) || \
1082: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->y,ilink->x,NULL) || \
1083: VecScatterBegin(ilink->sctx,ilink->x,yy,ADD_VALUES,SCATTER_REVERSE) || \
1084: VecScatterEnd(ilink->sctx,ilink->x,yy,ADD_VALUES,SCATTER_REVERSE))
1088: static PetscErrorCode PCApplyTranspose_FieldSplit(PC pc,Vec x,Vec y)
1089: {
1090: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1091: PetscErrorCode ierr;
1092: PC_FieldSplitLink ilink = jac->head;
1093: PetscInt bs;
1094: KSPConvergedReason reason;
1097: if (jac->type == PC_COMPOSITE_ADDITIVE) {
1098: if (jac->defaultsplit) {
1099: VecGetBlockSize(x,&bs);
1100: if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of x vector %D does not match fieldsplit blocksize %D",bs,jac->bs);
1101: VecGetBlockSize(y,&bs);
1102: if (jac->bs > 0 && bs != jac->bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Blocksize of y vector %D does not match fieldsplit blocksize %D",bs,jac->bs);
1103: VecStrideGatherAll(x,jac->x,INSERT_VALUES);
1104: while (ilink) {
1105: PetscLogEventBegin(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1106: KSPSolveTranspose(ilink->ksp,ilink->x,ilink->y);
1107: PetscLogEventEnd(ilink->event,ilink->ksp,ilink->x,ilink->y,NULL);
1108: KSPGetConvergedReason(ilink->ksp,&reason);
1109: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1110: pc->failedreason = PC_SUBPC_ERROR;
1111: }
1112: ilink = ilink->next;
1113: }
1114: VecStrideScatterAll(jac->y,y,INSERT_VALUES);
1115: } else {
1116: VecSet(y,0.0);
1117: while (ilink) {
1118: FieldSplitSplitSolveAddTranspose(ilink,x,y);
1119: KSPGetConvergedReason(ilink->ksp,&reason);
1120: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1121: pc->failedreason = PC_SUBPC_ERROR;
1122: }
1123: ilink = ilink->next;
1124: }
1125: }
1126: } else {
1127: if (!jac->w1) {
1128: VecDuplicate(x,&jac->w1);
1129: VecDuplicate(x,&jac->w2);
1130: }
1131: VecSet(y,0.0);
1132: if (jac->type == PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE) {
1133: FieldSplitSplitSolveAddTranspose(ilink,x,y);
1134: KSPGetConvergedReason(ilink->ksp,&reason);
1135: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1136: pc->failedreason = PC_SUBPC_ERROR;
1137: }
1138: while (ilink->next) {
1139: ilink = ilink->next;
1140: MatMultTranspose(pc->mat,y,jac->w1);
1141: VecWAXPY(jac->w2,-1.0,jac->w1,x);
1142: FieldSplitSplitSolveAddTranspose(ilink,jac->w2,y);
1143: }
1144: while (ilink->previous) {
1145: ilink = ilink->previous;
1146: MatMultTranspose(pc->mat,y,jac->w1);
1147: VecWAXPY(jac->w2,-1.0,jac->w1,x);
1148: FieldSplitSplitSolveAddTranspose(ilink,jac->w2,y);
1149: }
1150: } else {
1151: while (ilink->next) { /* get to last entry in linked list */
1152: ilink = ilink->next;
1153: }
1154: FieldSplitSplitSolveAddTranspose(ilink,x,y);
1155: KSPGetConvergedReason(ilink->ksp,&reason);
1156: if (reason == KSP_DIVERGED_PCSETUP_FAILED) {
1157: pc->failedreason = PC_SUBPC_ERROR;
1158: }
1159: while (ilink->previous) {
1160: ilink = ilink->previous;
1161: MatMultTranspose(pc->mat,y,jac->w1);
1162: VecWAXPY(jac->w2,-1.0,jac->w1,x);
1163: FieldSplitSplitSolveAddTranspose(ilink,jac->w2,y);
1164: }
1165: }
1166: }
1167: return(0);
1168: }
1172: static PetscErrorCode PCReset_FieldSplit(PC pc)
1173: {
1174: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1175: PetscErrorCode ierr;
1176: PC_FieldSplitLink ilink = jac->head,next;
1179: while (ilink) {
1180: KSPReset(ilink->ksp);
1181: VecDestroy(&ilink->x);
1182: VecDestroy(&ilink->y);
1183: VecDestroy(&ilink->z);
1184: VecScatterDestroy(&ilink->sctx);
1185: if (!ilink->is_orig) { /* save the original IS */
1186: PetscObjectReference((PetscObject)ilink->is);
1187: ilink->is_orig = ilink->is;
1188: }
1189: ISDestroy(&ilink->is);
1190: ISDestroy(&ilink->is_col);
1191: next = ilink->next;
1192: ilink = next;
1193: }
1194: PetscFree2(jac->x,jac->y);
1195: if (jac->mat && jac->mat != jac->pmat) {
1196: MatDestroyMatrices(jac->nsplits,&jac->mat);
1197: } else if (jac->mat) {
1198: jac->mat = NULL;
1199: }
1200: if (jac->pmat) {MatDestroyMatrices(jac->nsplits,&jac->pmat);}
1201: if (jac->Afield) {MatDestroyMatrices(jac->nsplits,&jac->Afield);}
1202: VecDestroy(&jac->w1);
1203: VecDestroy(&jac->w2);
1204: MatDestroy(&jac->schur);
1205: MatDestroy(&jac->schurp);
1206: MatDestroy(&jac->schur_user);
1207: KSPDestroy(&jac->kspschur);
1208: KSPDestroy(&jac->kspupper);
1209: MatDestroy(&jac->B);
1210: MatDestroy(&jac->C);
1211: jac->reset = PETSC_TRUE;
1212: jac->isrestrict = PETSC_FALSE;
1213: return(0);
1214: }
1218: static PetscErrorCode PCDestroy_FieldSplit(PC pc)
1219: {
1220: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1221: PetscErrorCode ierr;
1222: PC_FieldSplitLink ilink = jac->head,next;
1225: PCReset_FieldSplit(pc);
1226: while (ilink) {
1227: KSPDestroy(&ilink->ksp);
1228: ISDestroy(&ilink->is_orig);
1229: next = ilink->next;
1230: PetscFree(ilink->splitname);
1231: PetscFree(ilink->fields);
1232: PetscFree(ilink->fields_col);
1233: PetscFree(ilink);
1234: ilink = next;
1235: }
1236: PetscFree2(jac->x,jac->y);
1237: PetscFree(pc->data);
1238: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",NULL);
1239: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetFields_C",NULL);
1240: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetIS_C",NULL);
1241: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetType_C",NULL);
1242: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetBlockSize_C",NULL);
1243: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurPre_C",NULL);
1244: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSchurPre_C",NULL);
1245: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurFactType_C",NULL);
1246: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitRestrictIS_C",NULL);
1247: return(0);
1248: }
1252: static PetscErrorCode PCSetFromOptions_FieldSplit(PetscOptionItems *PetscOptionsObject,PC pc)
1253: {
1254: PetscErrorCode ierr;
1255: PetscInt bs;
1256: PetscBool flg,stokes = PETSC_FALSE;
1257: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1258: PCCompositeType ctype;
1261: PetscOptionsHead(PetscOptionsObject,"FieldSplit options");
1262: PetscOptionsBool("-pc_fieldsplit_dm_splits","Whether to use DMCreateFieldDecomposition() for splits","PCFieldSplitSetDMSplits",jac->dm_splits,&jac->dm_splits,NULL);
1263: PetscOptionsInt("-pc_fieldsplit_block_size","Blocksize that defines number of fields","PCFieldSplitSetBlockSize",jac->bs,&bs,&flg);
1264: if (flg) {
1265: PCFieldSplitSetBlockSize(pc,bs);
1266: }
1267: jac->diag_use_amat = pc->useAmat;
1268: PetscOptionsBool("-pc_fieldsplit_diag_use_amat","Use Amat (not Pmat) to extract diagonal fieldsplit blocks", "PCFieldSplitSetDiagUseAmat",jac->diag_use_amat,&jac->diag_use_amat,NULL);
1269: jac->offdiag_use_amat = pc->useAmat;
1270: PetscOptionsBool("-pc_fieldsplit_off_diag_use_amat","Use Amat (not Pmat) to extract off-diagonal fieldsplit blocks", "PCFieldSplitSetOffDiagUseAmat",jac->offdiag_use_amat,&jac->offdiag_use_amat,NULL);
1271: /* FIXME: No programmatic equivalent to the following. */
1272: PetscOptionsGetBool(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_fieldsplit_detect_saddle_point",&stokes,NULL);
1273: if (stokes) {
1274: PCFieldSplitSetType(pc,PC_COMPOSITE_SCHUR);
1275: jac->schurpre = PC_FIELDSPLIT_SCHUR_PRE_SELF;
1276: }
1278: PetscOptionsEnum("-pc_fieldsplit_type","Type of composition","PCFieldSplitSetType",PCCompositeTypes,(PetscEnum)jac->type,(PetscEnum*)&ctype,&flg);
1279: if (flg) {
1280: PCFieldSplitSetType(pc,ctype);
1281: }
1282: /* Only setup fields once */
1283: if ((jac->bs > 0) && (jac->nsplits == 0)) {
1284: /* only allow user to set fields from command line if bs is already known.
1285: otherwise user can set them in PCFieldSplitSetDefaults() */
1286: PCFieldSplitSetRuntimeSplits_Private(pc);
1287: if (jac->splitdefined) {PetscInfo(pc,"Splits defined using the options database\n");}
1288: }
1289: if (jac->type == PC_COMPOSITE_SCHUR) {
1290: PetscOptionsGetEnum(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_fieldsplit_schur_factorization_type",PCFieldSplitSchurFactTypes,(PetscEnum*)&jac->schurfactorization,&flg);
1291: if (flg) {PetscInfo(pc,"Deprecated use of -pc_fieldsplit_schur_factorization_type\n");}
1292: PetscOptionsEnum("-pc_fieldsplit_schur_fact_type","Which off-diagonal parts of the block factorization to use","PCFieldSplitSetSchurFactType",PCFieldSplitSchurFactTypes,(PetscEnum)jac->schurfactorization,(PetscEnum*)&jac->schurfactorization,NULL);
1293: PetscOptionsEnum("-pc_fieldsplit_schur_precondition","How to build preconditioner for Schur complement","PCFieldSplitSetSchurPre",PCFieldSplitSchurPreTypes,(PetscEnum)jac->schurpre,(PetscEnum*)&jac->schurpre,NULL);
1294: }
1295: PetscOptionsTail();
1296: return(0);
1297: }
1299: /*------------------------------------------------------------------------------------*/
1303: static PetscErrorCode PCFieldSplitSetFields_FieldSplit(PC pc,const char splitname[],PetscInt n,const PetscInt *fields,const PetscInt *fields_col)
1304: {
1305: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1306: PetscErrorCode ierr;
1307: PC_FieldSplitLink ilink,next = jac->head;
1308: char prefix[128];
1309: PetscInt i;
1312: if (jac->splitdefined) {
1313: PetscInfo1(pc,"Ignoring new split \"%s\" because the splits have already been defined\n",splitname);
1314: return(0);
1315: }
1316: for (i=0; i<n; i++) {
1317: if (fields[i] >= jac->bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Field %D requested but only %D exist",fields[i],jac->bs);
1318: if (fields[i] < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative field %D requested",fields[i]);
1319: }
1320: PetscNew(&ilink);
1321: if (splitname) {
1322: PetscStrallocpy(splitname,&ilink->splitname);
1323: } else {
1324: PetscMalloc1(3,&ilink->splitname);
1325: PetscSNPrintf(ilink->splitname,2,"%s",jac->nsplits);
1326: }
1327: ilink->event = jac->nsplits < 5 ? KSP_Solve_FS_0 + jac->nsplits : KSP_Solve_FS_0 + 4; /* Any split great than 4 gets logged in the 4th split */
1328: PetscMalloc1(n,&ilink->fields);
1329: PetscMemcpy(ilink->fields,fields,n*sizeof(PetscInt));
1330: PetscMalloc1(n,&ilink->fields_col);
1331: PetscMemcpy(ilink->fields_col,fields_col,n*sizeof(PetscInt));
1333: ilink->nfields = n;
1334: ilink->next = NULL;
1335: KSPCreate(PetscObjectComm((PetscObject)pc),&ilink->ksp);
1336: KSPSetErrorIfNotConverged(ilink->ksp,pc->erroriffailure);
1337: PetscObjectIncrementTabLevel((PetscObject)ilink->ksp,(PetscObject)pc,1);
1338: KSPSetType(ilink->ksp,KSPPREONLY);
1339: PetscLogObjectParent((PetscObject)pc,(PetscObject)ilink->ksp);
1341: PetscSNPrintf(prefix,sizeof(prefix),"%sfieldsplit_%s_",((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "",ilink->splitname);
1342: KSPSetOptionsPrefix(ilink->ksp,prefix);
1344: if (!next) {
1345: jac->head = ilink;
1346: ilink->previous = NULL;
1347: } else {
1348: while (next->next) {
1349: next = next->next;
1350: }
1351: next->next = ilink;
1352: ilink->previous = next;
1353: }
1354: jac->nsplits++;
1355: return(0);
1356: }
1360: static PetscErrorCode PCFieldSplitGetSubKSP_FieldSplit_Schur(PC pc,PetscInt *n,KSP **subksp)
1361: {
1362: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1366: PetscMalloc1(jac->nsplits,subksp);
1367: MatSchurComplementGetKSP(jac->schur,*subksp);
1369: (*subksp)[1] = jac->kspschur;
1370: if (n) *n = jac->nsplits;
1371: return(0);
1372: }
1376: static PetscErrorCode PCFieldSplitGetSubKSP_FieldSplit(PC pc,PetscInt *n,KSP **subksp)
1377: {
1378: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1379: PetscErrorCode ierr;
1380: PetscInt cnt = 0;
1381: PC_FieldSplitLink ilink = jac->head;
1384: PetscMalloc1(jac->nsplits,subksp);
1385: while (ilink) {
1386: (*subksp)[cnt++] = ilink->ksp;
1387: ilink = ilink->next;
1388: }
1389: if (cnt != jac->nsplits) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Corrupt PCFIELDSPLIT object: number of splits in linked list %D does not match number in object %D",cnt,jac->nsplits);
1390: if (n) *n = jac->nsplits;
1391: return(0);
1392: }
1396: /*@C
1397: PCFieldSplitRestrictIS - Restricts the fieldsplit ISs to be within a given IS.
1399: Input Parameters:
1400: + pc - the preconditioner context
1401: + is - the index set that defines the indices to which the fieldsplit is to be restricted
1403: Level: advanced
1405: @*/
1406: PetscErrorCode PCFieldSplitRestrictIS(PC pc,IS isy)
1407: {
1413: PetscTryMethod(pc,"PCFieldSplitRestrictIS_C",(PC,IS),(pc,isy));
1414: return(0);
1415: }
1420: static PetscErrorCode PCFieldSplitRestrictIS_FieldSplit(PC pc, IS isy)
1421: {
1422: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1423: PetscErrorCode ierr;
1424: PC_FieldSplitLink ilink = jac->head, next;
1425: PetscInt localsize,size,sizez,i;
1426: const PetscInt *ind, *indz;
1427: PetscInt *indc, *indcz;
1428: PetscBool flg;
1431: ISGetLocalSize(isy,&localsize);
1432: MPI_Scan(&localsize,&size,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)isy));
1433: size -= localsize;
1434: while(ilink) {
1435: IS isrl,isr;
1436: PC subpc;
1437: if (jac->reset) {
1438: ISEmbed(ilink->is_orig, isy, PETSC_TRUE, &isrl);
1439: } else {
1440: ISEmbed(ilink->is, isy, PETSC_TRUE, &isrl);
1441: }
1442: ISGetLocalSize(isrl,&localsize);
1443: PetscMalloc1(localsize,&indc);
1444: ISGetIndices(isrl,&ind);
1445: PetscMemcpy(indc,ind,localsize*sizeof(PetscInt));
1446: ISRestoreIndices(isrl,&ind);
1447: ISDestroy(&isrl);
1448: for (i=0; i<localsize; i++) *(indc+i) += size;
1449: ISCreateGeneral(PetscObjectComm((PetscObject)isy),localsize,indc,PETSC_OWN_POINTER,&isr);
1450: PetscObjectReference((PetscObject)isr);
1451: ISDestroy(&ilink->is);
1452: ilink->is = isr;
1453: PetscObjectReference((PetscObject)isr);
1454: ISDestroy(&ilink->is_col);
1455: ilink->is_col = isr;
1456: ISDestroy(&isr);
1457: KSPGetPC(ilink->ksp, &subpc);
1458: PetscObjectTypeCompare((PetscObject)subpc,PCFIELDSPLIT,&flg);
1459: if(flg) {
1460: IS iszl,isz;
1461: MPI_Comm comm;
1462: if (jac->reset) {
1463: ISGetLocalSize(ilink->is_orig,&localsize);
1464: comm = PetscObjectComm((PetscObject)ilink->is_orig);
1465: ISEmbed(isy, ilink->is_orig, PETSC_TRUE, &iszl);
1466: } else {
1467: ISGetLocalSize(ilink->is,&localsize);
1468: comm = PetscObjectComm((PetscObject)ilink->is);
1469: ISEmbed(isy, ilink->is, PETSC_TRUE, &iszl);
1470: }
1471: MPI_Scan(&localsize,&sizez,1,MPIU_INT,MPI_SUM,comm);
1472: sizez -= localsize;
1473: ISGetLocalSize(iszl,&localsize);
1474: PetscMalloc1(localsize,&indcz);
1475: ISGetIndices(iszl,&indz);
1476: PetscMemcpy(indcz,indz,localsize*sizeof(PetscInt));
1477: ISRestoreIndices(iszl,&indz);
1478: ISDestroy(&iszl);
1479: for (i=0; i<localsize; i++) *(indcz+i) += sizez;
1480: ISCreateGeneral(comm,localsize,indcz,PETSC_OWN_POINTER,&isz);
1481: PCFieldSplitRestrictIS(subpc,isz);
1482: ISDestroy(&isz);
1483: }
1484: next = ilink->next;
1485: ilink = next;
1486: }
1487: jac->isrestrict = PETSC_TRUE;
1488: return(0);
1489: }
1493: static PetscErrorCode PCFieldSplitSetIS_FieldSplit(PC pc,const char splitname[],IS is)
1494: {
1495: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1496: PetscErrorCode ierr;
1497: PC_FieldSplitLink ilink, next = jac->head;
1498: char prefix[128];
1501: if (jac->splitdefined) {
1502: PetscInfo1(pc,"Ignoring new split \"%s\" because the splits have already been defined\n",splitname);
1503: return(0);
1504: }
1505: PetscNew(&ilink);
1506: if (splitname) {
1507: PetscStrallocpy(splitname,&ilink->splitname);
1508: } else {
1509: PetscMalloc1(8,&ilink->splitname);
1510: PetscSNPrintf(ilink->splitname,7,"%D",jac->nsplits);
1511: }
1512: ilink->event = jac->nsplits < 5 ? KSP_Solve_FS_0 + jac->nsplits : KSP_Solve_FS_0 + 4; /* Any split great than 4 gets logged in the 4th split */
1513: PetscObjectReference((PetscObject)is);
1514: ISDestroy(&ilink->is);
1515: ilink->is = is;
1516: PetscObjectReference((PetscObject)is);
1517: ISDestroy(&ilink->is_col);
1518: ilink->is_col = is;
1519: ilink->next = NULL;
1520: KSPCreate(PetscObjectComm((PetscObject)pc),&ilink->ksp);
1521: KSPSetErrorIfNotConverged(ilink->ksp,pc->erroriffailure);
1522: PetscObjectIncrementTabLevel((PetscObject)ilink->ksp,(PetscObject)pc,1);
1523: KSPSetType(ilink->ksp,KSPPREONLY);
1524: PetscLogObjectParent((PetscObject)pc,(PetscObject)ilink->ksp);
1526: PetscSNPrintf(prefix,sizeof(prefix),"%sfieldsplit_%s_",((PetscObject)pc)->prefix ? ((PetscObject)pc)->prefix : "",ilink->splitname);
1527: KSPSetOptionsPrefix(ilink->ksp,prefix);
1529: if (!next) {
1530: jac->head = ilink;
1531: ilink->previous = NULL;
1532: } else {
1533: while (next->next) {
1534: next = next->next;
1535: }
1536: next->next = ilink;
1537: ilink->previous = next;
1538: }
1539: jac->nsplits++;
1540: return(0);
1541: }
1545: /*@
1546: PCFieldSplitSetFields - Sets the fields for one particular split in the field split preconditioner
1548: Logically Collective on PC
1550: Input Parameters:
1551: + pc - the preconditioner context
1552: . splitname - name of this split, if NULL the number of the split is used
1553: . n - the number of fields in this split
1554: - fields - the fields in this split
1556: Level: intermediate
1558: Notes: Use PCFieldSplitSetIS() to set a completely general set of indices as a field.
1560: The PCFieldSplitSetFields() is for defining fields as strided blocks. For example, if the block
1561: size is three then one can define a field as 0, or 1 or 2 or 0,1 or 0,2 or 1,2 which mean
1562: 0xx3xx6xx9xx12 ... x1xx4xx7xx ... xx2xx5xx8xx.. 01x34x67x... 0x1x3x5x7.. x12x45x78x....
1563: where the numbered entries indicate what is in the field.
1565: This function is called once per split (it creates a new split each time). Solve options
1566: for this split will be available under the prefix -fieldsplit_SPLITNAME_.
1568: Developer Note: This routine does not actually create the IS representing the split, that is delayed
1569: until PCSetUp_FieldSplit(), because information about the vector/matrix layouts may not be
1570: available when this routine is called.
1572: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetBlockSize(), PCFieldSplitSetIS()
1574: @*/
1575: PetscErrorCode PCFieldSplitSetFields(PC pc,const char splitname[],PetscInt n,const PetscInt *fields,const PetscInt *fields_col)
1576: {
1582: if (n < 1) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Provided number of fields %D in split \"%s\" not positive",n,splitname);
1584: PetscTryMethod(pc,"PCFieldSplitSetFields_C",(PC,const char[],PetscInt,const PetscInt*,const PetscInt*),(pc,splitname,n,fields,fields_col));
1585: return(0);
1586: }
1590: /*@
1591: PCFieldSplitSetDiagUseAmat - set flag indicating whether to extract diagonal blocks from Amat (rather than Pmat)
1593: Logically Collective on PC
1595: Input Parameters:
1596: + pc - the preconditioner object
1597: - flg - boolean flag indicating whether or not to use Amat to extract the diagonal blocks from
1599: Options Database:
1600: . -pc_fieldsplit_diag_use_amat
1602: Level: intermediate
1604: .seealso: PCFieldSplitGetDiagUseAmat(), PCFieldSplitSetOffDiagUseAmat(), PCFIELDSPLIT
1606: @*/
1607: PetscErrorCode PCFieldSplitSetDiagUseAmat(PC pc,PetscBool flg)
1608: {
1609: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1610: PetscBool isfs;
1615: PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);
1616: if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT);
1617: jac->diag_use_amat = flg;
1618: return(0);
1619: }
1623: /*@
1624: PCFieldSplitGetDiagUseAmat - get the flag indicating whether to extract diagonal blocks from Amat (rather than Pmat)
1626: Logically Collective on PC
1628: Input Parameters:
1629: . pc - the preconditioner object
1631: Output Parameters:
1632: . flg - boolean flag indicating whether or not to use Amat to extract the diagonal blocks from
1635: Level: intermediate
1637: .seealso: PCFieldSplitSetDiagUseAmat(), PCFieldSplitGetOffDiagUseAmat(), PCFIELDSPLIT
1639: @*/
1640: PetscErrorCode PCFieldSplitGetDiagUseAmat(PC pc,PetscBool *flg)
1641: {
1642: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1643: PetscBool isfs;
1649: PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);
1650: if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT);
1651: *flg = jac->diag_use_amat;
1652: return(0);
1653: }
1657: /*@
1658: PCFieldSplitSetOffDiagUseAmat - set flag indicating whether to extract off-diagonal blocks from Amat (rather than Pmat)
1660: Logically Collective on PC
1662: Input Parameters:
1663: + pc - the preconditioner object
1664: - flg - boolean flag indicating whether or not to use Amat to extract the off-diagonal blocks from
1666: Options Database:
1667: . -pc_fieldsplit_off_diag_use_amat
1669: Level: intermediate
1671: .seealso: PCFieldSplitGetOffDiagUseAmat(), PCFieldSplitSetDiagUseAmat(), PCFIELDSPLIT
1673: @*/
1674: PetscErrorCode PCFieldSplitSetOffDiagUseAmat(PC pc,PetscBool flg)
1675: {
1676: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1677: PetscBool isfs;
1682: PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);
1683: if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT);
1684: jac->offdiag_use_amat = flg;
1685: return(0);
1686: }
1690: /*@
1691: PCFieldSplitGetOffDiagUseAmat - get the flag indicating whether to extract off-diagonal blocks from Amat (rather than Pmat)
1693: Logically Collective on PC
1695: Input Parameters:
1696: . pc - the preconditioner object
1698: Output Parameters:
1699: . flg - boolean flag indicating whether or not to use Amat to extract the off-diagonal blocks from
1702: Level: intermediate
1704: .seealso: PCFieldSplitSetOffDiagUseAmat(), PCFieldSplitGetDiagUseAmat(), PCFIELDSPLIT
1706: @*/
1707: PetscErrorCode PCFieldSplitGetOffDiagUseAmat(PC pc,PetscBool *flg)
1708: {
1709: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
1710: PetscBool isfs;
1716: PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);
1717: if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"PC not of type %s",PCFIELDSPLIT);
1718: *flg = jac->offdiag_use_amat;
1719: return(0);
1720: }
1726: /*@C
1727: PCFieldSplitSetIS - Sets the exact elements for field
1729: Logically Collective on PC
1731: Input Parameters:
1732: + pc - the preconditioner context
1733: . splitname - name of this split, if NULL the number of the split is used
1734: - is - the index set that defines the vector elements in this field
1737: Notes:
1738: Use PCFieldSplitSetFields(), for fields defined by strided types.
1740: This function is called once per split (it creates a new split each time). Solve options
1741: for this split will be available under the prefix -fieldsplit_SPLITNAME_.
1743: Level: intermediate
1745: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetBlockSize()
1747: @*/
1748: PetscErrorCode PCFieldSplitSetIS(PC pc,const char splitname[],IS is)
1749: {
1756: PetscUseMethod(pc,"PCFieldSplitSetIS_C",(PC,const char[],IS),(pc,splitname,is));
1757: return(0);
1758: }
1762: /*@
1763: PCFieldSplitGetIS - Retrieves the elements for a field as an IS
1765: Logically Collective on PC
1767: Input Parameters:
1768: + pc - the preconditioner context
1769: - splitname - name of this split
1771: Output Parameter:
1772: - is - the index set that defines the vector elements in this field, or NULL if the field is not found
1774: Level: intermediate
1776: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetIS()
1778: @*/
1779: PetscErrorCode PCFieldSplitGetIS(PC pc,const char splitname[],IS *is)
1780: {
1787: {
1788: PC_FieldSplit *jac = (PC_FieldSplit*) pc->data;
1789: PC_FieldSplitLink ilink = jac->head;
1790: PetscBool found;
1792: *is = NULL;
1793: while (ilink) {
1794: PetscStrcmp(ilink->splitname, splitname, &found);
1795: if (found) {
1796: *is = ilink->is;
1797: break;
1798: }
1799: ilink = ilink->next;
1800: }
1801: }
1802: return(0);
1803: }
1807: /*@
1808: PCFieldSplitSetBlockSize - Sets the block size for defining where fields start in the
1809: fieldsplit preconditioner. If not set the matrix block size is used.
1811: Logically Collective on PC
1813: Input Parameters:
1814: + pc - the preconditioner context
1815: - bs - the block size
1817: Level: intermediate
1819: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields()
1821: @*/
1822: PetscErrorCode PCFieldSplitSetBlockSize(PC pc,PetscInt bs)
1823: {
1829: PetscTryMethod(pc,"PCFieldSplitSetBlockSize_C",(PC,PetscInt),(pc,bs));
1830: return(0);
1831: }
1835: /*@C
1836: PCFieldSplitGetSubKSP - Gets the KSP contexts for all splits
1838: Collective on KSP
1840: Input Parameter:
1841: . pc - the preconditioner context
1843: Output Parameters:
1844: + n - the number of splits
1845: - pc - the array of KSP contexts
1847: Note:
1848: After PCFieldSplitGetSubKSP() the array of KSPs IS to be freed by the user
1849: (not the KSP just the array that contains them).
1851: You must call KSPSetUp() before calling PCFieldSplitGetSubKSP().
1853: Fortran Usage: You must pass in a KSP array that is large enough to contain all the local KSPs.
1854: You can call PCFieldSplitGetSubKSP(pc,n,NULL_OBJECT,ierr) to determine how large the
1855: KSP array must be.
1858: Level: advanced
1860: .seealso: PCFIELDSPLIT
1861: @*/
1862: PetscErrorCode PCFieldSplitGetSubKSP(PC pc,PetscInt *n,KSP *subksp[])
1863: {
1869: PetscUseMethod(pc,"PCFieldSplitGetSubKSP_C",(PC,PetscInt*,KSP **),(pc,n,subksp));
1870: return(0);
1871: }
1875: /*@
1876: PCFieldSplitSetSchurPre - Indicates if the Schur complement is preconditioned by a preconditioner constructed by the
1877: A11 matrix. Otherwise no preconditioner is used.
1879: Collective on PC
1881: Input Parameters:
1882: + pc - the preconditioner context
1883: . ptype - which matrix to use for preconditioning the Schur complement: PC_FIELDSPLIT_SCHUR_PRE_A11 (default), PC_FIELDSPLIT_SCHUR_PRE_SELF, PC_FIELDSPLIT_SCHUR_PRE_USER
1884: PC_FIELDSPLIT_SCHUR_PRE_SELFP, and PC_FIELDSPLIT_SCHUR_PRE_FULL
1885: - userpre - matrix to use for preconditioning, or NULL
1887: Options Database:
1888: . -pc_fieldsplit_schur_precondition <self,selfp,user,a11,full> - default is a11. See notes for meaning of various arguments
1890: Notes:
1891: $ If ptype is
1892: $ a11 then the preconditioner for the Schur complement is generated from the block diagonal part of the preconditioner
1893: $ matrix associated with the Schur complement (i.e. A11), not he Schur complement matrix
1894: $ self the preconditioner for the Schur complement is generated from the symbolic representation of the Schur complement matrix:
1895: $ The only preconditioner that currently works with this symbolic respresentation matrix object is the PCLSC
1896: $ preconditioner
1897: $ user then the preconditioner for the Schur complement is generated from the user provided matrix (pre argument
1898: $ to this function).
1899: $ selfp then the preconditioning for the Schur complement is generated from an explicitly-assembled approximation Sp = A11 - A10 inv(diag(A00)) A01
1900: $ This is only a good preconditioner when diag(A00) is a good preconditioner for A00. Optionally, A00 can be
1901: $ lumped before extracting the diagonal using the additional option -fieldsplit_1_mat_schur_complement_ainv_type lump
1902: $ full then the preconditioner for the Schur complement is generated from the exact Schur complement matrix representation computed internally by PFIELDSPLIT (this is expensive)
1903: $ useful mostly as a test that the Schur complement approach can work for your problem
1905: When solving a saddle point problem, where the A11 block is identically zero, using a11 as the ptype only makes sense
1906: with the additional option -fieldsplit_1_pc_type none. Usually for saddle point problems one would use a ptype of self and
1907: -fieldsplit_1_pc_type lsc which uses the least squares commutator to compute a preconditioner for the Schur complement.
1909: Level: intermediate
1911: .seealso: PCFieldSplitGetSchurPre(), PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType,
1912: MatSchurComplementSetAinvType(), PCLSC
1914: @*/
1915: PetscErrorCode PCFieldSplitSetSchurPre(PC pc,PCFieldSplitSchurPreType ptype,Mat pre)
1916: {
1921: PetscTryMethod(pc,"PCFieldSplitSetSchurPre_C",(PC,PCFieldSplitSchurPreType,Mat),(pc,ptype,pre));
1922: return(0);
1923: }
1924: PetscErrorCode PCFieldSplitSchurPrecondition(PC pc,PCFieldSplitSchurPreType ptype,Mat pre) {return PCFieldSplitSetSchurPre(pc,ptype,pre);} /* Deprecated name */
1928: /*@
1929: PCFieldSplitGetSchurPre - For Schur complement fieldsplit, determine how the Schur complement will be
1930: preconditioned. See PCFieldSplitSetSchurPre() for details.
1932: Logically Collective on PC
1934: Input Parameters:
1935: . pc - the preconditioner context
1937: Output Parameters:
1938: + ptype - which matrix to use for preconditioning the Schur complement: PC_FIELDSPLIT_SCHUR_PRE_A11, PC_FIELDSPLIT_SCHUR_PRE_SELF, PC_FIELDSPLIT_PRE_USER
1939: - userpre - matrix to use for preconditioning (with PC_FIELDSPLIT_PRE_USER), or NULL
1941: Level: intermediate
1943: .seealso: PCFieldSplitSetSchurPre(), PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType, PCLSC
1945: @*/
1946: PetscErrorCode PCFieldSplitGetSchurPre(PC pc,PCFieldSplitSchurPreType *ptype,Mat *pre)
1947: {
1952: PetscUseMethod(pc,"PCFieldSplitGetSchurPre_C",(PC,PCFieldSplitSchurPreType*,Mat*),(pc,ptype,pre));
1953: return(0);
1954: }
1958: /*@
1959: PCFieldSplitSchurGetS - extract the MatSchurComplement object used by this PC in case it needs to be configured separately
1961: Not collective
1963: Input Parameter:
1964: . pc - the preconditioner context
1966: Output Parameter:
1967: . S - the Schur complement matrix
1969: Notes:
1970: This matrix should not be destroyed using MatDestroy(); rather, use PCFieldSplitSchurRestoreS().
1972: Level: advanced
1974: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSchurPreType, PCFieldSplitSetSchurPre(), MatSchurComplement, PCFieldSplitSchurRestoreS()
1976: @*/
1977: PetscErrorCode PCFieldSplitSchurGetS(PC pc,Mat *S)
1978: {
1980: const char* t;
1981: PetscBool isfs;
1982: PC_FieldSplit *jac;
1986: PetscObjectGetType((PetscObject)pc,&t);
1987: PetscStrcmp(t,PCFIELDSPLIT,&isfs);
1988: if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PC of type PCFIELDSPLIT, got %s instead",t);
1989: jac = (PC_FieldSplit*)pc->data;
1990: if (jac->type != PC_COMPOSITE_SCHUR) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PCFIELDSPLIT of type SCHUR, got %D instead",jac->type);
1991: if (S) *S = jac->schur;
1992: return(0);
1993: }
1997: /*@
1998: PCFieldSplitSchurRestoreS - restores the MatSchurComplement object used by this PC
2000: Not collective
2002: Input Parameters:
2003: + pc - the preconditioner context
2004: . S - the Schur complement matrix
2006: Level: advanced
2008: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSchurPreType, PCFieldSplitSetSchurPre(), MatSchurComplement, PCFieldSplitSchurGetS()
2010: @*/
2011: PetscErrorCode PCFieldSplitSchurRestoreS(PC pc,Mat *S)
2012: {
2014: const char* t;
2015: PetscBool isfs;
2016: PC_FieldSplit *jac;
2020: PetscObjectGetType((PetscObject)pc,&t);
2021: PetscStrcmp(t,PCFIELDSPLIT,&isfs);
2022: if (!isfs) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PC of type PCFIELDSPLIT, got %s instead",t);
2023: jac = (PC_FieldSplit*)pc->data;
2024: if (jac->type != PC_COMPOSITE_SCHUR) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected PCFIELDSPLIT of type SCHUR, got %D instead",jac->type);
2025: if (!S || *S != jac->schur) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"MatSchurComplement restored is not the same as gotten");
2026: return(0);
2027: }
2032: static PetscErrorCode PCFieldSplitSetSchurPre_FieldSplit(PC pc,PCFieldSplitSchurPreType ptype,Mat pre)
2033: {
2034: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2038: jac->schurpre = ptype;
2039: if (ptype == PC_FIELDSPLIT_SCHUR_PRE_USER && pre) {
2040: MatDestroy(&jac->schur_user);
2041: jac->schur_user = pre;
2042: PetscObjectReference((PetscObject)jac->schur_user);
2043: }
2044: return(0);
2045: }
2049: static PetscErrorCode PCFieldSplitGetSchurPre_FieldSplit(PC pc,PCFieldSplitSchurPreType *ptype,Mat *pre)
2050: {
2051: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2054: *ptype = jac->schurpre;
2055: *pre = jac->schur_user;
2056: return(0);
2057: }
2061: /*@
2062: PCFieldSplitSetSchurFactType - sets which blocks of the approximate block factorization to retain
2064: Collective on PC
2066: Input Parameters:
2067: + pc - the preconditioner context
2068: - ftype - which blocks of factorization to retain, PC_FIELDSPLIT_SCHUR_FACT_FULL is default
2070: Options Database:
2071: . -pc_fieldsplit_schur_fact_type <diag,lower,upper,full> default is full
2074: Level: intermediate
2076: Notes:
2077: The FULL factorization is
2079: $ (A B) = (1 0) (A 0) (1 Ainv*B)
2080: $ (C D) (C*Ainv 1) (0 S) (0 1 )
2082: where S = D - C*Ainv*B. In practice, the full factorization is applied via block triangular solves with the grouping L*(D*U). UPPER uses D*U, LOWER uses L*D,
2083: and DIAG is the diagonal part with the sign of S flipped (because this makes the preconditioner positive definite for many formulations, thus allowing the use of KSPMINRES).
2085: If applied exactly, FULL factorization is a direct solver. The preconditioned operator with LOWER or UPPER has all eigenvalues equal to 1 and minimal polynomial
2086: of degree 2, so KSPGMRES converges in 2 iterations. If the iteration count is very low, consider using KSPFGMRES or KSPGCR which can use one less preconditioner
2087: application in this case. Note that the preconditioned operator may be highly non-normal, so such fast convergence may not be observed in practice. With DIAG,
2088: the preconditioned operator has three distinct nonzero eigenvalues and minimal polynomial of degree at most 4, so KSPGMRES converges in at most 4 iterations.
2090: For symmetric problems in which A is positive definite and S is negative definite, DIAG can be used with KSPMINRES. Note that a flexible method like KSPFGMRES
2091: or KSPGCR must be used if the fieldsplit preconditioner is nonlinear (e.g. a few iterations of a Krylov method is used inside a split).
2093: References:
2094: + 1. - Murphy, Golub, and Wathen, A note on preconditioning indefinite linear systems, SIAM J. Sci. Comput., 21 (2000).
2095: - 2. - Ipsen, A note on preconditioning nonsymmetric matrices, SIAM J. Sci. Comput., 23 (2001).
2097: .seealso: PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType
2098: @*/
2099: PetscErrorCode PCFieldSplitSetSchurFactType(PC pc,PCFieldSplitSchurFactType ftype)
2100: {
2105: PetscTryMethod(pc,"PCFieldSplitSetSchurFactType_C",(PC,PCFieldSplitSchurFactType),(pc,ftype));
2106: return(0);
2107: }
2111: static PetscErrorCode PCFieldSplitSetSchurFactType_FieldSplit(PC pc,PCFieldSplitSchurFactType ftype)
2112: {
2113: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2116: jac->schurfactorization = ftype;
2117: return(0);
2118: }
2122: /*@C
2123: PCFieldSplitGetSchurBlocks - Gets all matrix blocks for the Schur complement
2125: Collective on KSP
2127: Input Parameter:
2128: . pc - the preconditioner context
2130: Output Parameters:
2131: + A00 - the (0,0) block
2132: . A01 - the (0,1) block
2133: . A10 - the (1,0) block
2134: - A11 - the (1,1) block
2136: Level: advanced
2138: .seealso: PCFIELDSPLIT
2139: @*/
2140: PetscErrorCode PCFieldSplitGetSchurBlocks(PC pc,Mat *A00,Mat *A01,Mat *A10, Mat *A11)
2141: {
2142: PC_FieldSplit *jac = (PC_FieldSplit*) pc->data;
2146: if (jac->type != PC_COMPOSITE_SCHUR) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONG, "FieldSplit is not using a Schur complement approach.");
2147: if (A00) *A00 = jac->pmat[0];
2148: if (A01) *A01 = jac->B;
2149: if (A10) *A10 = jac->C;
2150: if (A11) *A11 = jac->pmat[1];
2151: return(0);
2152: }
2156: static PetscErrorCode PCFieldSplitSetType_FieldSplit(PC pc,PCCompositeType type)
2157: {
2158: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2162: jac->type = type;
2163: if (type == PC_COMPOSITE_SCHUR) {
2164: pc->ops->apply = PCApply_FieldSplit_Schur;
2165: pc->ops->view = PCView_FieldSplit_Schur;
2167: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",PCFieldSplitGetSubKSP_FieldSplit_Schur);
2168: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurPre_C",PCFieldSplitSetSchurPre_FieldSplit);
2169: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSchurPre_C",PCFieldSplitGetSchurPre_FieldSplit);
2170: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurFactType_C",PCFieldSplitSetSchurFactType_FieldSplit);
2172: } else {
2173: pc->ops->apply = PCApply_FieldSplit;
2174: pc->ops->view = PCView_FieldSplit;
2176: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",PCFieldSplitGetSubKSP_FieldSplit);
2177: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurPre_C",0);
2178: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSchurPre_C",0);
2179: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetSchurFactType_C",0);
2180: }
2181: return(0);
2182: }
2186: static PetscErrorCode PCFieldSplitSetBlockSize_FieldSplit(PC pc,PetscInt bs)
2187: {
2188: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2191: if (bs < 1) SETERRQ1(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Blocksize must be positive, you gave %D",bs);
2192: if (jac->bs > 0 && jac->bs != bs) SETERRQ2(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Cannot change fieldsplit blocksize from %D to %D after it has been set",jac->bs,bs);
2193: jac->bs = bs;
2194: return(0);
2195: }
2199: /*@
2200: PCFieldSplitSetType - Sets the type of fieldsplit preconditioner.
2202: Collective on PC
2204: Input Parameter:
2205: . pc - the preconditioner context
2206: . type - PC_COMPOSITE_ADDITIVE, PC_COMPOSITE_MULTIPLICATIVE (default), PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE, PC_COMPOSITE_SPECIAL, PC_COMPOSITE_SCHUR
2208: Options Database Key:
2209: . -pc_fieldsplit_type <type: one of multiplicative, additive, symmetric_multiplicative, special, schur> - Sets fieldsplit preconditioner type
2211: Level: Intermediate
2213: .keywords: PC, set, type, composite preconditioner, additive, multiplicative
2215: .seealso: PCCompositeSetType()
2217: @*/
2218: PetscErrorCode PCFieldSplitSetType(PC pc,PCCompositeType type)
2219: {
2224: PetscTryMethod(pc,"PCFieldSplitSetType_C",(PC,PCCompositeType),(pc,type));
2225: return(0);
2226: }
2230: /*@
2231: PCFieldSplitGetType - Gets the type of fieldsplit preconditioner.
2233: Not collective
2235: Input Parameter:
2236: . pc - the preconditioner context
2238: Output Parameter:
2239: . type - PC_COMPOSITE_ADDITIVE, PC_COMPOSITE_MULTIPLICATIVE (default), PC_COMPOSITE_SYMMETRIC_MULTIPLICATIVE, PC_COMPOSITE_SPECIAL, PC_COMPOSITE_SCHUR
2241: Level: Intermediate
2243: .keywords: PC, set, type, composite preconditioner, additive, multiplicative
2244: .seealso: PCCompositeSetType()
2245: @*/
2246: PetscErrorCode PCFieldSplitGetType(PC pc, PCCompositeType *type)
2247: {
2248: PC_FieldSplit *jac = (PC_FieldSplit*) pc->data;
2253: *type = jac->type;
2254: return(0);
2255: }
2259: /*@
2260: PCFieldSplitSetDMSplits - Flags whether DMCreateFieldDecomposition() should be used to define the splits, whenever possible.
2262: Logically Collective
2264: Input Parameters:
2265: + pc - the preconditioner context
2266: - flg - boolean indicating whether to use field splits defined by the DM
2268: Options Database Key:
2269: . -pc_fieldsplit_dm_splits
2271: Level: Intermediate
2273: .keywords: PC, DM, composite preconditioner, additive, multiplicative
2275: .seealso: PCFieldSplitGetDMSplits()
2277: @*/
2278: PetscErrorCode PCFieldSplitSetDMSplits(PC pc,PetscBool flg)
2279: {
2280: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2281: PetscBool isfs;
2287: PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);
2288: if (isfs) {
2289: jac->dm_splits = flg;
2290: }
2291: return(0);
2292: }
2297: /*@
2298: PCFieldSplitGetDMSplits - Returns flag indicating whether DMCreateFieldDecomposition() should be used to define the splits, whenever possible.
2300: Logically Collective
2302: Input Parameter:
2303: . pc - the preconditioner context
2305: Output Parameter:
2306: . flg - boolean indicating whether to use field splits defined by the DM
2308: Level: Intermediate
2310: .keywords: PC, DM, composite preconditioner, additive, multiplicative
2312: .seealso: PCFieldSplitSetDMSplits()
2314: @*/
2315: PetscErrorCode PCFieldSplitGetDMSplits(PC pc,PetscBool* flg)
2316: {
2317: PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
2318: PetscBool isfs;
2324: PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&isfs);
2325: if (isfs) {
2326: if(flg) *flg = jac->dm_splits;
2327: }
2328: return(0);
2329: }
2331: /* -------------------------------------------------------------------------------------*/
2332: /*MC
2333: PCFIELDSPLIT - Preconditioner created by combining separate preconditioners for individual
2334: fields or groups of fields. See the users manual section "Solving Block Matrices" for more details.
2336: To set options on the solvers for each block append -fieldsplit_ to all the PC
2337: options database keys. For example, -fieldsplit_pc_type ilu -fieldsplit_pc_factor_levels 1
2339: To set the options on the solvers separate for each block call PCFieldSplitGetSubKSP()
2340: and set the options directly on the resulting KSP object
2342: Level: intermediate
2344: Options Database Keys:
2345: + -pc_fieldsplit_%d_fields <a,b,..> - indicates the fields to be used in the %d'th split
2346: . -pc_fieldsplit_default - automatically add any fields to additional splits that have not
2347: been supplied explicitly by -pc_fieldsplit_%d_fields
2348: . -pc_fieldsplit_block_size <bs> - size of block that defines fields (i.e. there are bs fields)
2349: . -pc_fieldsplit_type <additive,multiplicative,symmetric_multiplicative,schur> - type of relaxation or factorization splitting
2350: . -pc_fieldsplit_schur_precondition <self,selfp,user,a11,full> - default is a11; see PCFieldSplitSetSchurPre()
2351: . -pc_fieldsplit_detect_saddle_point - automatically finds rows with zero or negative diagonal and uses Schur complement with no preconditioner as the solver
2353: - Options prefix for inner solvers when using Schur complement preconditioner are -fieldsplit_0_ and -fieldsplit_1_
2354: for all other solvers they are -fieldsplit_%d_ for the dth field, use -fieldsplit_ for all fields
2356: Notes:
2357: Use PCFieldSplitSetFields() to set fields defined by "strided" entries and PCFieldSplitSetIS()
2358: to define a field by an arbitrary collection of entries.
2360: If no fields are set the default is used. The fields are defined by entries strided by bs,
2361: beginning at 0 then 1, etc to bs-1. The block size can be set with PCFieldSplitSetBlockSize(),
2362: if this is not called the block size defaults to the blocksize of the second matrix passed
2363: to KSPSetOperators()/PCSetOperators().
2365: $ For the Schur complement preconditioner if J = ( A00 A01 )
2366: $ ( A10 A11 )
2367: $ the preconditioner using full factorization is
2368: $ ( I -ksp(A00) A01 ) ( inv(A00) 0 ) ( I 0 )
2369: $ ( 0 I ) ( 0 ksp(S) ) ( -A10 ksp(A00) I )
2370: where the action of inv(A00) is applied using the KSP solver with prefix -fieldsplit_0_. S is the Schur complement
2371: $ S = A11 - A10 ksp(A00) A01
2372: which is usually dense and not stored explicitly. The action of ksp(S) is computed using the KSP solver with prefix -fieldsplit_splitname_ (where splitname was given
2373: in providing the SECOND split or 1 if not give). For PCFieldSplitGetKSP() when field number is 0,
2374: it returns the KSP associated with -fieldsplit_0_ while field number 1 gives -fieldsplit_1_ KSP. By default
2375: A11 is used to construct a preconditioner for S, use PCFieldSplitSetSchurPre() for all the possible ways to construct the preconditioner for S.
2377: The factorization type is set using -pc_fieldsplit_schur_fact_type <diag, lower, upper, full>. The full is shown above,
2378: diag gives
2379: $ ( inv(A00) 0 )
2380: $ ( 0 -ksp(S) )
2381: note that slightly counter intuitively there is a negative in front of the ksp(S) so that the preconditioner is positive definite. The lower factorization is the inverse of
2382: $ ( A00 0 )
2383: $ ( A10 S )
2384: where the inverses of A00 and S are applied using KSPs. The upper factorization is the inverse of
2385: $ ( A00 A01 )
2386: $ ( 0 S )
2387: where again the inverses of A00 and S are applied using KSPs.
2389: If only one set of indices (one IS) is provided with PCFieldSplitSetIS() then the complement of that IS
2390: is used automatically for a second block.
2392: The fieldsplit preconditioner cannot currently be used with the BAIJ or SBAIJ data formats if the blocksize is larger than 1.
2393: Generally it should be used with the AIJ format.
2395: The forms of these preconditioners are closely related if not identical to forms derived as "Distributive Iterations", see,
2396: for example, page 294 in "Principles of Computational Fluid Dynamics" by Pieter Wesseling. Note that one can also use PCFIELDSPLIT
2397: inside a smoother resulting in "Distributive Smoothers".
2399: Concepts: physics based preconditioners, block preconditioners
2401: There is a nice discussion of block preconditioners in
2403: [El08] A taxonomy and comparison of parallel block multi-level preconditioners for the incompressible Navier-Stokes equations
2404: Howard Elman, V.E. Howle, John Shadid, Robert Shuttleworth, Ray Tuminaro, Journal of Computational Physics 227 (2008) 1790--1808
2405: http://chess.cs.umd.edu/~elman/papers/tax.pdf
2407: The Constrained Pressure Preconditioner (CPR) does not appear to be currently implementable directly with PCFIELDSPLIT. CPR solves first the Schur complemented pressure equation, updates the
2408: residual on all variables and then applies a simple ILU like preconditioner on all the variables. So it is very much like the full Schur complement with selfp representing the Schur complement but instead
2409: of backsolving for the saturations in the last step it solves a full coupled (ILU) system for updates to all the variables.
2411: .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, Block_Preconditioners, PCLSC,
2412: PCFieldSplitGetSubKSP(), PCFieldSplitSetFields(), PCFieldSplitSetType(), PCFieldSplitSetIS(), PCFieldSplitSetSchurPre(),
2413: MatSchurComplementSetAinvType()
2414: M*/
2418: PETSC_EXTERN PetscErrorCode PCCreate_FieldSplit(PC pc)
2419: {
2421: PC_FieldSplit *jac;
2424: PetscNewLog(pc,&jac);
2426: jac->bs = -1;
2427: jac->nsplits = 0;
2428: jac->type = PC_COMPOSITE_MULTIPLICATIVE;
2429: jac->schurpre = PC_FIELDSPLIT_SCHUR_PRE_USER; /* Try user preconditioner first, fall back on diagonal */
2430: jac->schurfactorization = PC_FIELDSPLIT_SCHUR_FACT_FULL;
2431: jac->dm_splits = PETSC_TRUE;
2433: pc->data = (void*)jac;
2435: pc->ops->apply = PCApply_FieldSplit;
2436: pc->ops->applytranspose = PCApplyTranspose_FieldSplit;
2437: pc->ops->setup = PCSetUp_FieldSplit;
2438: pc->ops->reset = PCReset_FieldSplit;
2439: pc->ops->destroy = PCDestroy_FieldSplit;
2440: pc->ops->setfromoptions = PCSetFromOptions_FieldSplit;
2441: pc->ops->view = PCView_FieldSplit;
2442: pc->ops->applyrichardson = 0;
2444: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitGetSubKSP_C",PCFieldSplitGetSubKSP_FieldSplit);
2445: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetFields_C",PCFieldSplitSetFields_FieldSplit);
2446: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetIS_C",PCFieldSplitSetIS_FieldSplit);
2447: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetType_C",PCFieldSplitSetType_FieldSplit);
2448: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitSetBlockSize_C",PCFieldSplitSetBlockSize_FieldSplit);
2449: PetscObjectComposeFunction((PetscObject)pc,"PCFieldSplitRestrictIS_C",PCFieldSplitRestrictIS_FieldSplit);
2450: return(0);
2451: }