Actual source code: itcreate.c
petsc-dev 2014-02-02
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: $ Supported only by CG, Richardson, Bi-CG-stab, CR, and CGS methods.
235: $ KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
236: $ of the preconditioned residual
237: $ KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual, supported only by
238: $ CG, CHEBYSHEV, and RICHARDSON, automatically true for right (see KSPSetPCSide())
239: $ preconditioning..
240: $ KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
243: Options Database Key:
244: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural>
246: Notes:
247: Currently only works with the CG, Richardson, Bi-CG-stab, CR, and CGS methods.
249: Level: advanced
251: .keywords: KSP, create, context, norms
253: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetCheckNormIteration()
254: @*/
255: PetscErrorCode KSPSetNormType(KSP ksp,KSPNormType normtype)
256: {
262: ksp->normtype = normtype;
263: if (normtype == KSP_NORM_NONE) {
264: KSPSetConvergenceTest(ksp,KSPConvergedSkip,0,0);
265: PetscInfo(ksp,"Warning: setting KSPNormType to skip computing the norm\n\
266: KSP convergence test is implicitly set to KSPConvergedSkip\n");
267: }
268: return(0);
269: }
273: /*@
274: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
275: computed and used in the convergence test.
277: Logically Collective on KSP
279: Input Parameter:
280: + ksp - Krylov solver context
281: - it - use -1 to check at all iterations
283: Notes:
284: Currently only works with KSPCG, KSPBCGS and KSPIBCGS
286: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
288: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
289: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
290: Level: advanced
292: .keywords: KSP, create, context, norms
294: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
295: @*/
296: PetscErrorCode KSPSetCheckNormIteration(KSP ksp,PetscInt it)
297: {
301: ksp->chknorm = it;
302: return(0);
303: }
307: /*@
308: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() for
309: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
310: one additional iteration.
313: Logically Collective on KSP
315: Input Parameter:
316: + ksp - Krylov solver context
317: - flg - PETSC_TRUE or PETSC_FALSE
319: Options Database Keys:
320: . -ksp_lag_norm - lag the calculated residual norm
322: Notes:
323: Currently only works with KSPIBCGS.
325: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
327: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
328: Level: advanced
330: .keywords: KSP, create, context, norms
332: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetCheckNormIteration()
333: @*/
334: PetscErrorCode KSPSetLagNorm(KSP ksp,PetscBool flg)
335: {
339: ksp->lagnorm = flg;
340: return(0);
341: }
345: /*@
346: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a KSP
348: Logically Collective
350: Input Arguments:
351: + ksp - Krylov method
352: . normtype - supported norm type
353: . pcside - preconditioner side that can be used with this norm
354: - preference - integer preference for this combination, larger values have higher priority
356: Level: developer
358: Notes:
359: This function should be called from the implementation files KSPCreate_XXX() to declare
360: which norms and preconditioner sides are supported. Users should not need to call this
361: function.
363: KSP_NORM_NONE is supported by default with all KSP methods and any PC side. If a KSP explicitly does not support
364: KSP_NORM_NONE, it should set this by setting priority=0.
366: .seealso: KSPSetNormType(), KSPSetPCSide()
367: @*/
368: PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType normtype,PCSide pcside,PetscInt priority)
369: {
373: ksp->normsupporttable[normtype][pcside] = priority;
374: return(0);
375: }
379: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
380: {
384: PetscMemzero(ksp->normsupporttable,sizeof(ksp->normsupporttable));
385: KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_LEFT,1);
386: KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_RIGHT,1);
387: return(0);
388: }
392: PetscErrorCode KSPSetUpNorms_Private(KSP ksp,KSPNormType *normtype,PCSide *pcside)
393: {
394: PetscInt i,j,best,ibest = 0,jbest = 0;
397: best = 0;
398: for (i=0; i<KSP_NORM_MAX; i++) {
399: for (j=0; j<PC_SIDE_MAX; j++) {
400: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i)
401: && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j)
402: && (ksp->normsupporttable[i][j] > best)) {
403: if (ksp->normtype == KSP_NORM_DEFAULT && i == KSP_NORM_NONE && ksp->normsupporttable[i][j] <= 1) {
404: continue; /* Skip because we don't want to default to no norms unless set by the KSP (preonly). */
405: }
406: best = ksp->normsupporttable[i][j];
407: ibest = i;
408: jbest = j;
409: }
410: }
411: }
412: if (best < 1) {
413: 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);
414: 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]);
415: 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]);
416: 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]);
417: }
418: *normtype = (KSPNormType)ibest;
419: *pcside = (PCSide)jbest;
420: return(0);
421: }
425: /*@
426: KSPGetNormType - Gets the norm that is used for convergence testing.
428: Not Collective
430: Input Parameter:
431: . ksp - Krylov solver context
433: Output Parameter:
434: . normtype - norm that is used for convergence testing
436: Level: advanced
438: .keywords: KSP, create, context, norms
440: .seealso: KSPNormType, KSPSetNormType(), KSPConvergedSkip()
441: @*/
442: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
443: {
449: KSPSetUpNorms_Private(ksp,&ksp->normtype,&ksp->pc_side);
450: *normtype = ksp->normtype;
451: return(0);
452: }
454: #if defined(PETSC_HAVE_SAWS)
455: #include <petscviewersaws.h>
456: #endif
460: /*@
461: KSPSetOperators - Sets the matrix associated with the linear system
462: and a (possibly) different one associated with the preconditioner.
464: Collective on KSP and Mat
466: Input Parameters:
467: + ksp - the KSP context
468: . Amat - the matrix that defines the linear system
469: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
470: - flag - flag indicating information about the preconditioner matrix structure
471: during successive linear solves. This flag is ignored the first time a
472: linear system is solved, and thus is irrelevant when solving just one linear
473: system.
475: Notes:
476: The flag can be used to eliminate unnecessary work in the preconditioner
477: during the repeated solution of linear systems of the same size. The
478: available options are
479: $ SAME_PRECONDITIONER -
480: $ Pmat is identical during successive linear solves.
481: $ This option is intended for folks who are using
482: $ different Amat and Pmat matrices and want to reuse the
483: $ same preconditioner matrix. For example, this option
484: $ saves work by not recomputing incomplete factorization
485: $ for ILU/ICC preconditioners.
486: $ SAME_NONZERO_PATTERN -
487: $ Pmat has the same nonzero structure during
488: $ successive linear solves.
489: $ DIFFERENT_NONZERO_PATTERN -
490: $ Pmat does not have the same nonzero structure.
492: All future calls to KSPSetOperators() must use the same size matrices!
494: Passing a NULL for Amat or Pmat removes the matrix that is currently used.
496: If you wish to replace either Amat or Pmat but leave the other one untouched then
497: first call KSPGetOperators() to get the one you wish to keep, call PetscObjectReference()
498: on it and then pass it back in in your call to KSPSetOperators().
500: Caution:
501: If you specify SAME_NONZERO_PATTERN, PETSc believes your assertion
502: and does not check the structure of the matrix. If you erroneously
503: claim that the structure is the same when it actually is not, the new
504: preconditioner will not function correctly. Thus, use this optimization
505: feature carefully!
507: If in doubt about whether your preconditioner matrix has changed
508: structure or not, use the flag DIFFERENT_NONZERO_PATTERN.
510: Level: beginner
512: Alternative usage: If the operators have NOT been set with KSP/PCSetOperators() then the operators
513: are created in PC and returned to the user. In this case, if both operators
514: mat and pmat are requested, two DIFFERENT operators will be returned. If
515: only one is requested both operators in the PC will be the same (i.e. as
516: if one had called KSP/PCSetOperators() with the same argument for both Mats).
517: The user must set the sizes of the returned matrices and their type etc just
518: as if the user created them with MatCreate(). For example,
520: $ KSP/PCGetOperators(ksp/pc,&mat,NULL,NULL); is equivalent to
521: $ set size, type, etc of mat
523: $ MatCreate(comm,&mat);
524: $ KSP/PCSetOperators(ksp/pc,mat,mat,SAME_NONZERO_PATTERN);
525: $ PetscObjectDereference((PetscObject)mat);
526: $ set size, type, etc of mat
528: and
530: $ KSP/PCGetOperators(ksp/pc,&mat,&pmat,NULL); is equivalent to
531: $ set size, type, etc of mat and pmat
533: $ MatCreate(comm,&mat);
534: $ MatCreate(comm,&pmat);
535: $ KSP/PCSetOperators(ksp/pc,mat,pmat,SAME_NONZERO_PATTERN);
536: $ PetscObjectDereference((PetscObject)mat);
537: $ PetscObjectDereference((PetscObject)pmat);
538: $ set size, type, etc of mat and pmat
540: The rational for this support is so that when creating a TS, SNES, or KSP the hierarchy
541: of underlying objects (i.e. SNES, KSP, PC, Mat) and their livespans can be completely
542: managed by the top most level object (i.e. the TS, SNES, or KSP). Another way to look
543: at this is when you create a SNES you do not NEED to create a KSP and attach it to
544: the SNES object (the SNES object manages it for you). Similarly when you create a KSP
545: you do not need to attach a PC to it (the KSP object manages the PC object for you).
546: Thus, why should YOU have to create the Mat and attach it to the SNES/KSP/PC, when
547: it can be created for you?
549: .keywords: KSP, set, operators, matrix, preconditioner, linear system
551: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators()
552: @*/
553: PetscErrorCode KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat,MatStructure flag)
554: {
555: MatNullSpace nullsp;
564: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
565: PCSetOperators(ksp->pc,Amat,Pmat,flag);
566: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
567: if (ksp->guess) {
568: KSPFischerGuessReset(ksp->guess);
569: }
570: if (Pmat) {
571: MatGetNullSpace(Pmat, &nullsp);
572: if (nullsp) {
573: KSPSetNullSpace(ksp, nullsp);
574: }
575: }
576: return(0);
577: }
581: /*@
582: KSPGetOperators - Gets the matrix associated with the linear system
583: and a (possibly) different one associated with the preconditioner.
585: Collective on KSP and Mat
587: Input Parameter:
588: . ksp - the KSP context
590: Output Parameters:
591: + Amat - the matrix that defines the linear system
592: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
593: - flag - flag indicating information about the preconditioner matrix structure
594: during successive linear solves. This flag is ignored the first time a
595: linear system is solved, and thus is irrelevant when solving just one linear
596: system.
598: Level: intermediate
600: Notes: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
602: .keywords: KSP, set, get, operators, matrix, preconditioner, linear system
604: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()
605: @*/
606: PetscErrorCode KSPGetOperators(KSP ksp,Mat *Amat,Mat *Pmat,MatStructure *flag)
607: {
612: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
613: PCGetOperators(ksp->pc,Amat,Pmat,flag);
614: return(0);
615: }
619: /*@C
620: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
621: possibly a different one associated with the preconditioner have been set in the KSP.
623: Not collective, though the results on all processes should be the same
625: Input Parameter:
626: . pc - the KSP context
628: Output Parameters:
629: + mat - the matrix associated with the linear system was set
630: - pmat - matrix associated with the preconditioner was set, usually the same
632: Level: intermediate
634: .keywords: KSP, get, operators, matrix, linear system
636: .seealso: PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()
637: @*/
638: PetscErrorCode KSPGetOperatorsSet(KSP ksp,PetscBool *mat,PetscBool *pmat)
639: {
644: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
645: PCGetOperatorsSet(ksp->pc,mat,pmat);
646: return(0);
647: }
651: /*@C
652: KSPSetPreSolve - Sets a function that is called before every KSPSolve() is started
654: Logically Collective on KSP
656: Input Parameters:
657: + ksp - the solver object
658: . presolve - the function to call before the solve
659: - prectx - any context needed by the function
661: Level: developer
663: .keywords: KSP, create, context
665: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPostSolve()
666: @*/
667: PetscErrorCode KSPSetPreSolve(KSP ksp,PetscErrorCode (*presolve)(KSP,Vec,Vec,void*),void *prectx)
668: {
671: ksp->presolve = presolve;
672: ksp->prectx = prectx;
673: return(0);
674: }
678: /*@C
679: KSPSetPostSolve - Sets a function that is called after every KSPSolve() completes (whether it converges or not)
681: Logically Collective on KSP
683: Input Parameters:
684: + ksp - the solver object
685: . postsolve - the function to call after the solve
686: - postctx - any context needed by the function
688: Level: developer
690: .keywords: KSP, create, context
692: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve()
693: @*/
694: PetscErrorCode KSPSetPostSolve(KSP ksp,PetscErrorCode (*postsolve)(KSP,Vec,Vec,void*),void *postctx)
695: {
698: ksp->postsolve = postsolve;
699: ksp->postctx = postctx;
700: return(0);
701: }
705: /*@
706: KSPCreate - Creates the default KSP context.
708: Collective on MPI_Comm
710: Input Parameter:
711: . comm - MPI communicator
713: Output Parameter:
714: . ksp - location to put the KSP context
716: Notes:
717: The default KSP type is GMRES with a restart of 30, using modified Gram-Schmidt
718: orthogonalization.
720: Level: beginner
722: .keywords: KSP, create, context
724: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP
725: @*/
726: PetscErrorCode KSPCreate(MPI_Comm comm,KSP *inksp)
727: {
728: KSP ksp;
730: void *ctx;
734: *inksp = 0;
735: KSPInitializePackage();
737: PetscHeaderCreate(ksp,_p_KSP,struct _KSPOps,KSP_CLASSID,"KSP","Krylov Method","KSP",comm,KSPDestroy,KSPView);
739: ksp->max_it = 10000;
740: ksp->pc_side = PC_SIDE_DEFAULT;
741: ksp->rtol = 1.e-5;
742: #if defined(PETSC_USE_REAL_SINGLE)
743: ksp->abstol = 1.e-25;
744: #else
745: ksp->abstol = 1.e-50;
746: #endif
747: ksp->divtol = 1.e4;
749: ksp->chknorm = -1;
750: ksp->normtype = KSP_NORM_DEFAULT;
751: ksp->rnorm = 0.0;
752: ksp->its = 0;
753: ksp->guess_zero = PETSC_TRUE;
754: ksp->calc_sings = PETSC_FALSE;
755: ksp->res_hist = NULL;
756: ksp->res_hist_alloc = NULL;
757: ksp->res_hist_len = 0;
758: ksp->res_hist_max = 0;
759: ksp->res_hist_reset = PETSC_TRUE;
760: ksp->numbermonitors = 0;
762: KSPConvergedDefaultCreate(&ctx);
763: KSPSetConvergenceTest(ksp,KSPConvergedDefault,ctx,KSPConvergedDefaultDestroy);
764: ksp->ops->buildsolution = KSPBuildSolutionDefault;
765: ksp->ops->buildresidual = KSPBuildResidualDefault;
767: ksp->vec_sol = 0;
768: ksp->vec_rhs = 0;
769: ksp->pc = 0;
770: ksp->data = 0;
771: ksp->nwork = 0;
772: ksp->work = 0;
773: ksp->reason = KSP_CONVERGED_ITERATING;
774: ksp->setupstage = KSP_SETUP_NEW;
776: KSPNormSupportTableReset_Private(ksp);
778: *inksp = ksp;
779: return(0);
780: }
784: /*@C
785: KSPSetType - Builds KSP for a particular solver.
787: Logically Collective on KSP
789: Input Parameters:
790: + ksp - the Krylov space context
791: - type - a known method
793: Options Database Key:
794: . -ksp_type <method> - Sets the method; use -help for a list
795: of available methods (for instance, cg or gmres)
797: Notes:
798: See "petsc/include/petscksp.h" for available methods (for instance,
799: KSPCG or KSPGMRES).
801: Normally, it is best to use the KSPSetFromOptions() command and
802: then set the KSP type from the options database rather than by using
803: this routine. Using the options database provides the user with
804: maximum flexibility in evaluating the many different Krylov methods.
805: The KSPSetType() routine is provided for those situations where it
806: is necessary to set the iterative solver independently of the command
807: line or options database. This might be the case, for example, when
808: the choice of iterative solver changes during the execution of the
809: program, and the user's application is taking responsibility for
810: choosing the appropriate method. In other words, this routine is
811: not for beginners.
813: Level: intermediate
815: Developer Note: KSPRegister() is used to add Krylov types to KSPList from which they
816: are accessed by KSPSetType().
818: .keywords: KSP, set, method
820: .seealso: PCSetType(), KSPType, KSPRegister(), KSPCreate()
822: @*/
823: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
824: {
825: PetscErrorCode ierr,(*r)(KSP);
826: PetscBool match;
832: PetscObjectTypeCompare((PetscObject)ksp,type,&match);
833: if (match) return(0);
835: PetscFunctionListFind(KSPList,type,&r);
836: if (!r) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested KSP type %s",type);
837: /* Destroy the previous private KSP context */
838: if (ksp->ops->destroy) {
839: (*ksp->ops->destroy)(ksp);
840: ksp->ops->destroy = NULL;
841: }
842: /* Reinitialize function pointers in KSPOps structure */
843: PetscMemzero(ksp->ops,sizeof(struct _KSPOps));
844: ksp->ops->buildsolution = KSPBuildSolutionDefault;
845: ksp->ops->buildresidual = KSPBuildResidualDefault;
846: KSPNormSupportTableReset_Private(ksp);
847: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
848: ksp->setupstage = KSP_SETUP_NEW;
849: PetscObjectChangeTypeName((PetscObject)ksp,type);
850: (*r)(ksp);
851: return(0);
852: }
856: /*@C
857: KSPGetType - Gets the KSP type as a string from the KSP object.
859: Not Collective
861: Input Parameter:
862: . ksp - Krylov context
864: Output Parameter:
865: . name - name of KSP method
867: Level: intermediate
869: .keywords: KSP, get, method, name
871: .seealso: KSPSetType()
872: @*/
873: PetscErrorCode KSPGetType(KSP ksp,KSPType *type)
874: {
878: *type = ((PetscObject)ksp)->type_name;
879: return(0);
880: }
884: /*@C
885: KSPRegister - Adds a method to the Krylov subspace solver package.
887: Not Collective
889: Input Parameters:
890: + name_solver - name of a new user-defined solver
891: - routine_create - routine to create method context
893: Notes:
894: KSPRegister() may be called multiple times to add several user-defined solvers.
896: Sample usage:
897: .vb
898: KSPRegister("my_solver",MySolverCreate);
899: .ve
901: Then, your solver can be chosen with the procedural interface via
902: $ KSPSetType(ksp,"my_solver")
903: or at runtime via the option
904: $ -ksp_type my_solver
906: Level: advanced
908: .keywords: KSP, register
910: .seealso: KSPRegisterAll(), KSPRegisterDestroy()
912: @*/
913: PetscErrorCode KSPRegister(const char sname[],PetscErrorCode (*function)(KSP))
914: {
918: PetscFunctionListAdd(&KSPList,sname,function);
919: return(0);
920: }
924: /*@
925: KSPSetNullSpace - Sets the null space of the operator
927: Logically Collective on KSP
929: Input Parameters:
930: + ksp - the Krylov space object
931: - nullsp - the null space of the operator
933: Notes: If the Mat provided to KSP has a nullspace added to it with MatSetNullSpace() then
934: KSP will automatically use the MatNullSpace and you don't need to call KSPSetNullSpace().
936: Level: advanced
938: .seealso: KSPSetOperators(), MatNullSpaceCreate(), KSPGetNullSpace(), MatSetNullSpace()
939: @*/
940: PetscErrorCode KSPSetNullSpace(KSP ksp,MatNullSpace nullsp)
941: {
947: PetscObjectReference((PetscObject)nullsp);
948: if (ksp->nullsp) { MatNullSpaceDestroy(&ksp->nullsp); }
949: ksp->nullsp = nullsp;
950: return(0);
951: }
955: /*@
956: KSPGetNullSpace - Gets the null space of the operator
958: Not Collective
960: Input Parameters:
961: + ksp - the Krylov space object
962: - nullsp - the null space of the operator
964: Level: advanced
966: .seealso: KSPSetOperators(), MatNullSpaceCreate(), KSPSetNullSpace()
967: @*/
968: PetscErrorCode KSPGetNullSpace(KSP ksp,MatNullSpace *nullsp)
969: {
973: *nullsp = ksp->nullsp;
974: return(0);
975: }