Actual source code: itcreate.c
petsc-3.5.4 2015-05-23
2: /*
3: The basic KSP routines, Create, View etc. are here.
4: */
5: #include <petsc-private/kspimpl.h> /*I "petscksp.h" I*/
7: /* Logging support */
8: PetscClassId KSP_CLASSID;
9: PetscClassId DMKSP_CLASSID;
10: PetscLogEvent KSP_GMRESOrthogonalization, KSP_SetUp, KSP_Solve;
12: /*
13: Contains the list of registered KSP routines
14: */
15: PetscFunctionList KSPList = 0;
16: PetscBool KSPRegisterAllCalled = PETSC_FALSE;
20: /*@C
21: KSPLoad - Loads a KSP that has been stored in binary with KSPView().
23: Collective on PetscViewer
25: Input Parameters:
26: + newdm - the newly loaded KSP, this needs to have been created with KSPCreate() or
27: some related function before a call to KSPLoad().
28: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
30: Level: intermediate
32: Notes:
33: The type is determined by the data in the file, any type set into the KSP before this call is ignored.
35: Notes for advanced users:
36: Most users should not need to know the details of the binary storage
37: format, since KSPLoad() and KSPView() completely hide these details.
38: But for anyone who's interested, the standard binary matrix storage
39: format is
40: .vb
41: has not yet been determined
42: .ve
44: .seealso: PetscViewerBinaryOpen(), KSPView(), MatLoad(), VecLoad()
45: @*/
46: PetscErrorCode KSPLoad(KSP newdm, PetscViewer viewer)
47: {
49: PetscBool isbinary;
50: PetscInt classid;
51: char type[256];
52: PC pc;
57: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
58: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
60: PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);
61: if (classid != KSP_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)newdm),PETSC_ERR_ARG_WRONG,"Not KSP next in file");
62: PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);
63: KSPSetType(newdm, type);
64: if (newdm->ops->load) {
65: (*newdm->ops->load)(newdm,viewer);
66: }
67: KSPGetPC(newdm,&pc);
68: PCLoad(pc,viewer);
69: return(0);
70: }
72: #include <petscdraw.h>
73: #if defined(PETSC_HAVE_SAWS)
74: #include <petscviewersaws.h>
75: #endif
78: /*@C
79: KSPView - Prints the KSP data structure.
81: Collective on KSP
83: Input Parameters:
84: + ksp - the Krylov space context
85: - viewer - visualization context
87: Options Database Keys:
88: . -ksp_view - print the ksp data structure at the end of a KSPSolve call
90: Note:
91: The available visualization contexts include
92: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
93: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
94: output where only the first processor opens
95: the file. All other processors send their
96: data to the first processor to print.
98: The user can open an alternative visualization context with
99: PetscViewerASCIIOpen() - output to a specified file.
101: Level: beginner
103: .keywords: KSP, view
105: .seealso: PCView(), PetscViewerASCIIOpen()
106: @*/
107: PetscErrorCode KSPView(KSP ksp,PetscViewer viewer)
108: {
110: PetscBool iascii,isbinary,isdraw;
111: #if defined(PETSC_HAVE_SAWS)
112: PetscBool isams;
113: #endif
117: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ksp));
121: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
122: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
123: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
124: #if defined(PETSC_HAVE_SAWS)
125: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);
126: #endif
127: if (iascii) {
128: PetscObjectPrintClassNamePrefixType((PetscObject)ksp,viewer);
129: if (ksp->ops->view) {
130: PetscViewerASCIIPushTab(viewer);
131: (*ksp->ops->view)(ksp,viewer);
132: PetscViewerASCIIPopTab(viewer);
133: }
134: if (ksp->guess_zero) {
135: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, initial guess is zero\n",ksp->max_it);
136: } else {
137: PetscViewerASCIIPrintf(viewer," maximum iterations=%D\n", ksp->max_it);
138: }
139: if (ksp->guess_knoll) {PetscViewerASCIIPrintf(viewer," using preconditioner applied to right hand side for initial guess\n");}
140: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, divergence=%g\n",(double)ksp->rtol,(double)ksp->abstol,(double)ksp->divtol);
141: if (ksp->pc_side == PC_RIGHT) {
142: PetscViewerASCIIPrintf(viewer," right preconditioning\n");
143: } else if (ksp->pc_side == PC_SYMMETRIC) {
144: PetscViewerASCIIPrintf(viewer," symmetric preconditioning\n");
145: } else {
146: PetscViewerASCIIPrintf(viewer," left preconditioning\n");
147: }
148: if (ksp->guess) {PetscViewerASCIIPrintf(viewer," using Fischers initial guess method %D with size %D\n",ksp->guess->method,ksp->guess->maxl);}
149: if (ksp->dscale) {PetscViewerASCIIPrintf(viewer," diagonally scaled system\n");}
150: if (ksp->nullsp) {PetscViewerASCIIPrintf(viewer," has attached null space\n");}
151: if (!ksp->guess_zero) {PetscViewerASCIIPrintf(viewer," using nonzero initial guess\n");}
152: PetscViewerASCIIPrintf(viewer," using %s norm type for convergence test\n",KSPNormTypes[ksp->normtype]);
153: } else if (isbinary) {
154: PetscInt classid = KSP_FILE_CLASSID;
155: MPI_Comm comm;
156: PetscMPIInt rank;
157: char type[256];
159: PetscObjectGetComm((PetscObject)ksp,&comm);
160: MPI_Comm_rank(comm,&rank);
161: if (!rank) {
162: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
163: PetscStrncpy(type,((PetscObject)ksp)->type_name,256);
164: PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);
165: }
166: if (ksp->ops->view) {
167: (*ksp->ops->view)(ksp,viewer);
168: }
169: } else if (isdraw) {
170: PetscDraw draw;
171: char str[36];
172: PetscReal x,y,bottom,h;
173: PetscBool flg;
175: PetscViewerDrawGetDraw(viewer,0,&draw);
176: PetscDrawGetCurrentPoint(draw,&x,&y);
177: PetscObjectTypeCompare((PetscObject)ksp,KSPPREONLY,&flg);
178: if (!flg) {
179: PetscStrcpy(str,"KSP: ");
180: PetscStrcat(str,((PetscObject)ksp)->type_name);
181: PetscDrawBoxedString(draw,x,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);
182: bottom = y - h;
183: } else {
184: bottom = y;
185: }
186: PetscDrawPushCurrentPoint(draw,x,bottom);
187: #if defined(PETSC_HAVE_SAWS)
188: } else if (isams) {
189: PetscMPIInt rank;
190: const char *name;
192: PetscObjectGetName((PetscObject)ksp,&name);
193: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
194: if (!((PetscObject)ksp)->amsmem && !rank) {
195: char dir[1024];
197: PetscObjectViewSAWs((PetscObject)ksp,viewer);
198: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
199: PetscStackCallSAWs(SAWs_Register,(dir,&ksp->its,1,SAWs_READ,SAWs_INT));
200: if (!ksp->res_hist) {
201: KSPSetResidualHistory(ksp,NULL,PETSC_DECIDE,PETSC_TRUE);
202: }
203: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/res_hist",name);
204: PetscStackCallSAWs(SAWs_Register,(dir,ksp->res_hist,10,SAWs_READ,SAWs_DOUBLE));
205: }
206: #endif
207: } else if (ksp->ops->view) {
208: (*ksp->ops->view)(ksp,viewer);
209: }
210: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
211: PCView(ksp->pc,viewer);
212: if (isdraw) {
213: PetscDraw draw;
214: PetscViewerDrawGetDraw(viewer,0,&draw);
215: PetscDrawPopCurrentPoint(draw);
216: }
217: return(0);
218: }
223: /*@
224: KSPSetNormType - Sets the norm that is used for convergence testing.
226: Logically Collective on KSP
228: Input Parameter:
229: + ksp - Krylov solver context
230: - normtype - one of
231: $ KSP_NORM_NONE - skips computing the norm, this should only be used if you are using
232: $ the Krylov method as a smoother with a fixed small number of iterations.
233: $ Implicitly sets KSPConvergedSkip as KSP convergence test.
234: $ KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
235: $ of the preconditioned residual P^{-1}(b - A x)
236: $ KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual.
237: $ KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
240: Options Database Key:
241: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural>
243: Notes:
244: Not all combinations of preconditioner side (see KSPSetPCSide()) and norm type are supported by all Krylov methods.
245: If only one is set, PETSc tries to automatically change the other to find a compatible pair. If no such combination
246: is supported, PETSc will generate an error.
248: Developer Notes:
249: Supported combinations of norm and preconditioner side are set using KSPSetSupportedNorm().
251: Level: advanced
253: .keywords: KSP, create, context, norms
255: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetCheckNormIteration()
256: @*/
257: PetscErrorCode KSPSetNormType(KSP ksp,KSPNormType normtype)
258: {
264: ksp->normtype = ksp->normtype_set = normtype;
265: if (normtype == KSP_NORM_NONE) {
266: KSPSetConvergenceTest(ksp,KSPConvergedSkip,0,0);
267: PetscInfo(ksp,"Warning: setting KSPNormType to skip computing the norm\n\
268: KSP convergence test is implicitly set to KSPConvergedSkip\n");
269: }
270: return(0);
271: }
275: /*@
276: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
277: computed and used in the convergence test.
279: Logically Collective on KSP
281: Input Parameter:
282: + ksp - Krylov solver context
283: - it - use -1 to check at all iterations
285: Notes:
286: Currently only works with KSPCG, KSPBCGS and KSPIBCGS
288: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
290: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
291: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
292: Level: advanced
294: .keywords: KSP, create, context, norms
296: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
297: @*/
298: PetscErrorCode KSPSetCheckNormIteration(KSP ksp,PetscInt it)
299: {
303: ksp->chknorm = it;
304: return(0);
305: }
309: /*@
310: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() for
311: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
312: one additional iteration.
315: Logically Collective on KSP
317: Input Parameter:
318: + ksp - Krylov solver context
319: - flg - PETSC_TRUE or PETSC_FALSE
321: Options Database Keys:
322: . -ksp_lag_norm - lag the calculated residual norm
324: Notes:
325: Currently only works with KSPIBCGS.
327: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
329: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
330: Level: advanced
332: .keywords: KSP, create, context, norms
334: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetCheckNormIteration()
335: @*/
336: PetscErrorCode KSPSetLagNorm(KSP ksp,PetscBool flg)
337: {
341: ksp->lagnorm = flg;
342: return(0);
343: }
347: /*@
348: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a KSP
350: Logically Collective
352: Input Arguments:
353: + ksp - Krylov method
354: . normtype - supported norm type
355: . pcside - preconditioner side that can be used with this norm
356: - preference - integer preference for this combination, larger values have higher priority
358: Level: developer
360: Notes:
361: This function should be called from the implementation files KSPCreate_XXX() to declare
362: which norms and preconditioner sides are supported. Users should not need to call this
363: function.
365: KSP_NORM_NONE is supported by default with all KSP methods and any PC side at priority 1. If a KSP explicitly does
366: not support KSP_NORM_NONE, it should set this by setting priority=0. Since defaulting to KSP_NORM_NONE is usually
367: undesirable, more desirable norms should usually have priority 2 or higher.
369: .seealso: KSPSetNormType(), KSPSetPCSide()
370: @*/
371: PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType normtype,PCSide pcside,PetscInt priority)
372: {
376: ksp->normsupporttable[normtype][pcside] = priority;
377: return(0);
378: }
382: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
383: {
387: PetscMemzero(ksp->normsupporttable,sizeof(ksp->normsupporttable));
388: KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_LEFT,1);
389: KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_RIGHT,1);
390: ksp->pc_side = ksp->pc_side_set;
391: ksp->normtype = ksp->normtype_set;
392: return(0);
393: }
397: PetscErrorCode KSPSetUpNorms_Private(KSP ksp,KSPNormType *normtype,PCSide *pcside)
398: {
399: PetscInt i,j,best,ibest = 0,jbest = 0;
402: best = 0;
403: for (i=0; i<KSP_NORM_MAX; i++) {
404: for (j=0; j<PC_SIDE_MAX; j++) {
405: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i)
406: && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j)
407: && (ksp->normsupporttable[i][j] > best)) {
408: best = ksp->normsupporttable[i][j];
409: ibest = i;
410: jbest = j;
411: }
412: }
413: }
414: if (best < 1) {
415: if (ksp->normtype == KSP_NORM_DEFAULT && ksp->pc_side == PC_SIDE_DEFAULT) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_PLIB,"The %s KSP implementation did not call KSPSetSupportedNorm()",((PetscObject)ksp)->type_name);
416: if (ksp->normtype == KSP_NORM_DEFAULT) SETERRQ2(PetscObjectComm((PetscObject)ksp),PETSC_ERR_SUP,"KSP %s does not support %s",((PetscObject)ksp)->type_name,PCSides[ksp->pc_side]);
417: if (ksp->pc_side == PC_SIDE_DEFAULT) SETERRQ2(PetscObjectComm((PetscObject)ksp),PETSC_ERR_SUP,"KSP %s does not support %s",((PetscObject)ksp)->type_name,KSPNormTypes[ksp->normtype]);
418: SETERRQ3(PetscObjectComm((PetscObject)ksp),PETSC_ERR_SUP,"KSP %s does not support %s with %s",((PetscObject)ksp)->type_name,KSPNormTypes[ksp->normtype],PCSides[ksp->pc_side]);
419: }
420: *normtype = (KSPNormType)ibest;
421: *pcside = (PCSide)jbest;
422: return(0);
423: }
427: /*@
428: KSPGetNormType - Gets the norm that is used for convergence testing.
430: Not Collective
432: Input Parameter:
433: . ksp - Krylov solver context
435: Output Parameter:
436: . normtype - norm that is used for convergence testing
438: Level: advanced
440: .keywords: KSP, create, context, norms
442: .seealso: KSPNormType, KSPSetNormType(), KSPConvergedSkip()
443: @*/
444: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
445: {
451: KSPSetUpNorms_Private(ksp,&ksp->normtype,&ksp->pc_side);
452: *normtype = ksp->normtype;
453: return(0);
454: }
456: #if defined(PETSC_HAVE_SAWS)
457: #include <petscviewersaws.h>
458: #endif
462: /*@
463: KSPSetOperators - Sets the matrix associated with the linear system
464: and a (possibly) different one associated with the preconditioner.
466: Collective on KSP and Mat
468: Input Parameters:
469: + ksp - the KSP context
470: . Amat - the matrix that defines the linear system
471: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
473: Notes:
475: All future calls to KSPSetOperators() must use the same size matrices!
477: Passing a NULL for Amat or Pmat removes the matrix that is currently used.
479: If you wish to replace either Amat or Pmat but leave the other one untouched then
480: first call KSPGetOperators() to get the one you wish to keep, call PetscObjectReference()
481: on it and then pass it back in in your call to KSPSetOperators().
483: Level: beginner
485: Alternative usage: If the operators have NOT been set with KSP/PCSetOperators() then the operators
486: are created in PC and returned to the user. In this case, if both operators
487: mat and pmat are requested, two DIFFERENT operators will be returned. If
488: only one is requested both operators in the PC will be the same (i.e. as
489: if one had called KSP/PCSetOperators() with the same argument for both Mats).
490: The user must set the sizes of the returned matrices and their type etc just
491: as if the user created them with MatCreate(). For example,
493: $ KSP/PCGetOperators(ksp/pc,&mat,NULL); is equivalent to
494: $ set size, type, etc of mat
496: $ MatCreate(comm,&mat);
497: $ KSP/PCSetOperators(ksp/pc,mat,mat);
498: $ PetscObjectDereference((PetscObject)mat);
499: $ set size, type, etc of mat
501: and
503: $ KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
504: $ set size, type, etc of mat and pmat
506: $ MatCreate(comm,&mat);
507: $ MatCreate(comm,&pmat);
508: $ KSP/PCSetOperators(ksp/pc,mat,pmat);
509: $ PetscObjectDereference((PetscObject)mat);
510: $ PetscObjectDereference((PetscObject)pmat);
511: $ set size, type, etc of mat and pmat
513: The rational for this support is so that when creating a TS, SNES, or KSP the hierarchy
514: of underlying objects (i.e. SNES, KSP, PC, Mat) and their livespans can be completely
515: managed by the top most level object (i.e. the TS, SNES, or KSP). Another way to look
516: at this is when you create a SNES you do not NEED to create a KSP and attach it to
517: the SNES object (the SNES object manages it for you). Similarly when you create a KSP
518: you do not need to attach a PC to it (the KSP object manages the PC object for you).
519: Thus, why should YOU have to create the Mat and attach it to the SNES/KSP/PC, when
520: it can be created for you?
522: .keywords: KSP, set, operators, matrix, preconditioner, linear system
524: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators(), KSPSetComputeOperators(), KSPSetComputeInitialGuess(), KSPSetComputeRHS()
525: @*/
526: PetscErrorCode KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat)
527: {
528: MatNullSpace nullsp;
537: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
538: PCSetOperators(ksp->pc,Amat,Pmat);
539: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
540: if (ksp->guess) {
541: KSPFischerGuessReset(ksp->guess);
542: }
543: if (Pmat) {
544: MatGetNullSpace(Pmat, &nullsp);
545: if (nullsp) {
546: KSPSetNullSpace(ksp, nullsp);
547: }
548: }
549: return(0);
550: }
554: /*@
555: KSPGetOperators - Gets the matrix associated with the linear system
556: and a (possibly) different one associated with the preconditioner.
558: Collective on KSP and Mat
560: Input Parameter:
561: . ksp - the KSP context
563: Output Parameters:
564: + Amat - the matrix that defines the linear system
565: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
567: Level: intermediate
569: Notes: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
571: .keywords: KSP, set, get, operators, matrix, preconditioner, linear system
573: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()
574: @*/
575: PetscErrorCode KSPGetOperators(KSP ksp,Mat *Amat,Mat *Pmat)
576: {
581: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
582: PCGetOperators(ksp->pc,Amat,Pmat);
583: return(0);
584: }
588: /*@C
589: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
590: possibly a different one associated with the preconditioner have been set in the KSP.
592: Not collective, though the results on all processes should be the same
594: Input Parameter:
595: . pc - the KSP context
597: Output Parameters:
598: + mat - the matrix associated with the linear system was set
599: - pmat - matrix associated with the preconditioner was set, usually the same
601: Level: intermediate
603: .keywords: KSP, get, operators, matrix, linear system
605: .seealso: PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()
606: @*/
607: PetscErrorCode KSPGetOperatorsSet(KSP ksp,PetscBool *mat,PetscBool *pmat)
608: {
613: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
614: PCGetOperatorsSet(ksp->pc,mat,pmat);
615: return(0);
616: }
620: /*@C
621: KSPSetPreSolve - Sets a function that is called before every KSPSolve() is started
623: Logically Collective on KSP
625: Input Parameters:
626: + ksp - the solver object
627: . presolve - the function to call before the solve
628: - prectx - any context needed by the function
630: Level: developer
632: .keywords: KSP, create, context
634: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPostSolve()
635: @*/
636: PetscErrorCode KSPSetPreSolve(KSP ksp,PetscErrorCode (*presolve)(KSP,Vec,Vec,void*),void *prectx)
637: {
640: ksp->presolve = presolve;
641: ksp->prectx = prectx;
642: return(0);
643: }
647: /*@C
648: KSPSetPostSolve - Sets a function that is called after every KSPSolve() completes (whether it converges or not)
650: Logically Collective on KSP
652: Input Parameters:
653: + ksp - the solver object
654: . postsolve - the function to call after the solve
655: - postctx - any context needed by the function
657: Level: developer
659: .keywords: KSP, create, context
661: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve()
662: @*/
663: PetscErrorCode KSPSetPostSolve(KSP ksp,PetscErrorCode (*postsolve)(KSP,Vec,Vec,void*),void *postctx)
664: {
667: ksp->postsolve = postsolve;
668: ksp->postctx = postctx;
669: return(0);
670: }
674: /*@
675: KSPCreate - Creates the default KSP context.
677: Collective on MPI_Comm
679: Input Parameter:
680: . comm - MPI communicator
682: Output Parameter:
683: . ksp - location to put the KSP context
685: Notes:
686: The default KSP type is GMRES with a restart of 30, using modified Gram-Schmidt
687: orthogonalization.
689: Level: beginner
691: .keywords: KSP, create, context
693: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP
694: @*/
695: PetscErrorCode KSPCreate(MPI_Comm comm,KSP *inksp)
696: {
697: KSP ksp;
699: void *ctx;
703: *inksp = 0;
704: KSPInitializePackage();
706: PetscHeaderCreate(ksp,_p_KSP,struct _KSPOps,KSP_CLASSID,"KSP","Krylov Method","KSP",comm,KSPDestroy,KSPView);
708: ksp->max_it = 10000;
709: ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
710: ksp->rtol = 1.e-5;
711: #if defined(PETSC_USE_REAL_SINGLE)
712: ksp->abstol = 1.e-25;
713: #else
714: ksp->abstol = 1.e-50;
715: #endif
716: ksp->divtol = 1.e4;
718: ksp->chknorm = -1;
719: ksp->normtype = ksp->normtype_set = KSP_NORM_DEFAULT;
720: ksp->rnorm = 0.0;
721: ksp->its = 0;
722: ksp->guess_zero = PETSC_TRUE;
723: ksp->calc_sings = PETSC_FALSE;
724: ksp->res_hist = NULL;
725: ksp->res_hist_alloc = NULL;
726: ksp->res_hist_len = 0;
727: ksp->res_hist_max = 0;
728: ksp->res_hist_reset = PETSC_TRUE;
729: ksp->numbermonitors = 0;
731: KSPConvergedDefaultCreate(&ctx);
732: KSPSetConvergenceTest(ksp,KSPConvergedDefault,ctx,KSPConvergedDefaultDestroy);
733: ksp->ops->buildsolution = KSPBuildSolutionDefault;
734: ksp->ops->buildresidual = KSPBuildResidualDefault;
736: ksp->vec_sol = 0;
737: ksp->vec_rhs = 0;
738: ksp->pc = 0;
739: ksp->data = 0;
740: ksp->nwork = 0;
741: ksp->work = 0;
742: ksp->reason = KSP_CONVERGED_ITERATING;
743: ksp->setupstage = KSP_SETUP_NEW;
745: KSPNormSupportTableReset_Private(ksp);
747: *inksp = ksp;
748: return(0);
749: }
753: /*@C
754: KSPSetType - Builds KSP for a particular solver.
756: Logically Collective on KSP
758: Input Parameters:
759: + ksp - the Krylov space context
760: - type - a known method
762: Options Database Key:
763: . -ksp_type <method> - Sets the method; use -help for a list
764: of available methods (for instance, cg or gmres)
766: Notes:
767: See "petsc/include/petscksp.h" for available methods (for instance,
768: KSPCG or KSPGMRES).
770: Normally, it is best to use the KSPSetFromOptions() command and
771: then set the KSP type from the options database rather than by using
772: this routine. Using the options database provides the user with
773: maximum flexibility in evaluating the many different Krylov methods.
774: The KSPSetType() routine is provided for those situations where it
775: is necessary to set the iterative solver independently of the command
776: line or options database. This might be the case, for example, when
777: the choice of iterative solver changes during the execution of the
778: program, and the user's application is taking responsibility for
779: choosing the appropriate method. In other words, this routine is
780: not for beginners.
782: Level: intermediate
784: Developer Note: KSPRegister() is used to add Krylov types to KSPList from which they
785: are accessed by KSPSetType().
787: .keywords: KSP, set, method
789: .seealso: PCSetType(), KSPType, KSPRegister(), KSPCreate()
791: @*/
792: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
793: {
794: PetscErrorCode ierr,(*r)(KSP);
795: PetscBool match;
801: PetscObjectTypeCompare((PetscObject)ksp,type,&match);
802: if (match) return(0);
804: PetscFunctionListFind(KSPList,type,&r);
805: if (!r) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested KSP type %s",type);
806: /* Destroy the previous private KSP context */
807: if (ksp->ops->destroy) {
808: (*ksp->ops->destroy)(ksp);
809: ksp->ops->destroy = NULL;
810: }
811: /* Reinitialize function pointers in KSPOps structure */
812: PetscMemzero(ksp->ops,sizeof(struct _KSPOps));
813: ksp->ops->buildsolution = KSPBuildSolutionDefault;
814: ksp->ops->buildresidual = KSPBuildResidualDefault;
815: KSPNormSupportTableReset_Private(ksp);
816: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
817: ksp->setupstage = KSP_SETUP_NEW;
818: PetscObjectChangeTypeName((PetscObject)ksp,type);
819: (*r)(ksp);
820: return(0);
821: }
825: /*@C
826: KSPGetType - Gets the KSP type as a string from the KSP object.
828: Not Collective
830: Input Parameter:
831: . ksp - Krylov context
833: Output Parameter:
834: . name - name of KSP method
836: Level: intermediate
838: .keywords: KSP, get, method, name
840: .seealso: KSPSetType()
841: @*/
842: PetscErrorCode KSPGetType(KSP ksp,KSPType *type)
843: {
847: *type = ((PetscObject)ksp)->type_name;
848: return(0);
849: }
853: /*@C
854: KSPRegister - Adds a method to the Krylov subspace solver package.
856: Not Collective
858: Input Parameters:
859: + name_solver - name of a new user-defined solver
860: - routine_create - routine to create method context
862: Notes:
863: KSPRegister() may be called multiple times to add several user-defined solvers.
865: Sample usage:
866: .vb
867: KSPRegister("my_solver",MySolverCreate);
868: .ve
870: Then, your solver can be chosen with the procedural interface via
871: $ KSPSetType(ksp,"my_solver")
872: or at runtime via the option
873: $ -ksp_type my_solver
875: Level: advanced
877: .keywords: KSP, register
879: .seealso: KSPRegisterAll(), KSPRegisterDestroy()
881: @*/
882: PetscErrorCode KSPRegister(const char sname[],PetscErrorCode (*function)(KSP))
883: {
887: PetscFunctionListAdd(&KSPList,sname,function);
888: return(0);
889: }
893: /*@
894: KSPSetNullSpace - Sets the null space of the operator
896: Logically Collective on KSP
898: Input Parameters:
899: + ksp - the Krylov space object
900: - nullsp - the null space of the operator
902: Notes: If the Mat provided to KSP has a nullspace added to it with MatSetNullSpace() then
903: KSP will automatically use the MatNullSpace and you don't need to call KSPSetNullSpace().
905: Level: advanced
907: .seealso: KSPSetOperators(), MatNullSpaceCreate(), KSPGetNullSpace(), MatSetNullSpace()
908: @*/
909: PetscErrorCode KSPSetNullSpace(KSP ksp,MatNullSpace nullsp)
910: {
916: PetscObjectReference((PetscObject)nullsp);
917: if (ksp->nullsp) { MatNullSpaceDestroy(&ksp->nullsp); }
918: ksp->nullsp = nullsp;
919: return(0);
920: }
924: /*@
925: KSPGetNullSpace - Gets the null space of the operator
927: Not Collective
929: Input Parameters:
930: + ksp - the Krylov space object
931: - nullsp - the null space of the operator
933: Level: advanced
935: .seealso: KSPSetOperators(), MatNullSpaceCreate(), KSPSetNullSpace()
936: @*/
937: PetscErrorCode KSPGetNullSpace(KSP ksp,MatNullSpace *nullsp)
938: {
942: *nullsp = ksp->nullsp;
943: return(0);
944: }