Actual source code: itcreate.c
petsc-3.9.4 2018-09-11
2: /*
3: The basic KSP routines, Create, View etc. are here.
4: */
5: #include <petsc/private/kspimpl.h>
7: /* Logging support */
8: PetscClassId KSP_CLASSID;
9: PetscClassId DMKSP_CLASSID;
10: PetscClassId KSPGUESS_CLASSID;
11: PetscLogEvent KSP_GMRESOrthogonalization, KSP_SetUp, KSP_Solve;
13: /*
14: Contains the list of registered KSP routines
15: */
16: PetscFunctionList KSPList = 0;
17: PetscBool KSPRegisterAllCalled = PETSC_FALSE;
19: /*@C
20: KSPLoad - Loads a KSP that has been stored in binary with KSPView().
22: Collective on PetscViewer
24: Input Parameters:
25: + newdm - the newly loaded KSP, this needs to have been created with KSPCreate() or
26: some related function before a call to KSPLoad().
27: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
29: Level: intermediate
31: Notes:
32: The type is determined by the data in the file, any type set into the KSP before this call is ignored.
34: Notes for advanced users:
35: Most users should not need to know the details of the binary storage
36: format, since KSPLoad() and KSPView() completely hide these details.
37: But for anyone who's interested, the standard binary matrix storage
38: format is
39: .vb
40: has not yet been determined
41: .ve
43: .seealso: PetscViewerBinaryOpen(), KSPView(), MatLoad(), VecLoad()
44: @*/
45: PetscErrorCode KSPLoad(KSP newdm, PetscViewer viewer)
46: {
48: PetscBool isbinary;
49: PetscInt classid;
50: char type[256];
51: PC pc;
56: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
57: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
59: PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
60: if (classid != KSP_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)newdm),PETSC_ERR_ARG_WRONG,"Not KSP next in file");
61: PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
62: KSPSetType(newdm, type);
63: if (newdm->ops->load) {
64: (*newdm->ops->load)(newdm,viewer);
65: }
66: KSPGetPC(newdm,&pc);
67: PCLoad(pc,viewer);
68: return(0);
69: }
71: #include <petscdraw.h>
72: #if defined(PETSC_HAVE_SAWS)
73: #include <petscviewersaws.h>
74: #endif
75: /*@C
76: KSPView - Prints the KSP data structure.
78: Collective on KSP
80: Input Parameters:
81: + ksp - the Krylov space context
82: - viewer - visualization context
84: Options Database Keys:
85: . -ksp_view - print the ksp data structure at the end of a KSPSolve call
87: Note:
88: The available visualization contexts include
89: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
90: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
91: output where only the first processor opens
92: the file. All other processors send their
93: data to the first processor to print.
95: The user can open an alternative visualization context with
96: PetscViewerASCIIOpen() - output to a specified file.
98: Level: beginner
100: .keywords: KSP, view
102: .seealso: PCView(), PetscViewerASCIIOpen()
103: @*/
104: PetscErrorCode KSPView(KSP ksp,PetscViewer viewer)
105: {
107: PetscBool iascii,isbinary,isdraw;
108: #if defined(PETSC_HAVE_SAWS)
109: PetscBool issaws;
110: #endif
114: if (!viewer) {
115: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ksp),&viewer);
116: }
120: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
121: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
122: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
123: #if defined(PETSC_HAVE_SAWS)
124: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
125: #endif
126: if (iascii) {
127: PetscObjectPrintClassNamePrefixType((PetscObject)ksp,viewer);
128: if (ksp->ops->view) {
129: PetscViewerASCIIPushTab(viewer);
130: (*ksp->ops->view)(ksp,viewer);
131: PetscViewerASCIIPopTab(viewer);
132: }
133: if (ksp->guess_zero) {
134: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, initial guess is zero\n",ksp->max_it);
135: } else {
136: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, nonzero initial guess\n", ksp->max_it);
137: }
138: if (ksp->guess_knoll) {PetscViewerASCIIPrintf(viewer," using preconditioner applied to right hand side for initial guess\n");}
139: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, divergence=%g\n",(double)ksp->rtol,(double)ksp->abstol,(double)ksp->divtol);
140: if (ksp->pc_side == PC_RIGHT) {
141: PetscViewerASCIIPrintf(viewer," right preconditioning\n");
142: } else if (ksp->pc_side == PC_SYMMETRIC) {
143: PetscViewerASCIIPrintf(viewer," symmetric preconditioning\n");
144: } else {
145: PetscViewerASCIIPrintf(viewer," left preconditioning\n");
146: }
147: if (ksp->guess) {
148: PetscViewerASCIIPushTab(viewer);
149: KSPGuessView(ksp->guess,viewer);
150: PetscViewerASCIIPopTab(viewer);
151: }
152: if (ksp->dscale) {PetscViewerASCIIPrintf(viewer," diagonally scaled system\n");}
153: PetscViewerASCIIPrintf(viewer," using %s norm type for convergence test\n",KSPNormTypes[ksp->normtype]);
154: } else if (isbinary) {
155: PetscInt classid = KSP_FILE_CLASSID;
156: MPI_Comm comm;
157: PetscMPIInt rank;
158: char type[256];
160: PetscObjectGetComm((PetscObject)ksp,&comm);
161: MPI_Comm_rank(comm,&rank);
162: if (!rank) {
163: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
164: PetscStrncpy(type,((PetscObject)ksp)->type_name,256);
165: PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);
166: }
167: if (ksp->ops->view) {
168: (*ksp->ops->view)(ksp,viewer);
169: }
170: } else if (isdraw) {
171: PetscDraw draw;
172: char str[36];
173: PetscReal x,y,bottom,h;
174: PetscBool flg;
176: PetscViewerDrawGetDraw(viewer,0,&draw);
177: PetscDrawGetCurrentPoint(draw,&x,&y);
178: PetscObjectTypeCompare((PetscObject)ksp,KSPPREONLY,&flg);
179: if (!flg) {
180: PetscStrncpy(str,"KSP: ",sizeof(str));
181: PetscStrlcat(str,((PetscObject)ksp)->type_name,sizeof(str));
182: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);
183: bottom = y - h;
184: } else {
185: bottom = y;
186: }
187: PetscDrawPushCurrentPoint(draw,x,bottom);
188: #if defined(PETSC_HAVE_SAWS)
189: } else if (issaws) {
190: PetscMPIInt rank;
191: const char *name;
193: PetscObjectGetName((PetscObject)ksp,&name);
194: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
195: if (!((PetscObject)ksp)->amsmem && !rank) {
196: char dir[1024];
198: PetscObjectViewSAWs((PetscObject)ksp,viewer);
199: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
200: PetscStackCallSAWs(SAWs_Register,(dir,&ksp->its,1,SAWs_READ,SAWs_INT));
201: if (!ksp->res_hist) {
202: KSPSetResidualHistory(ksp,NULL,PETSC_DECIDE,PETSC_TRUE);
203: }
204: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/res_hist",name);
205: PetscStackCallSAWs(SAWs_Register,(dir,ksp->res_hist,10,SAWs_READ,SAWs_DOUBLE));
206: }
207: #endif
208: } else if (ksp->ops->view) {
209: (*ksp->ops->view)(ksp,viewer);
210: }
211: if (!ksp->skippcsetfromoptions) {
212: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
213: PCView(ksp->pc,viewer);
214: }
215: if (isdraw) {
216: PetscDraw draw;
217: PetscViewerDrawGetDraw(viewer,0,&draw);
218: PetscDrawPopCurrentPoint(draw);
219: }
220: return(0);
221: }
224: /*@
225: KSPSetNormType - Sets the norm that is used for convergence testing.
227: Logically Collective on KSP
229: Input Parameter:
230: + ksp - Krylov solver context
231: - normtype - one of
232: $ KSP_NORM_NONE - skips computing the norm, this should only be used if you are using
233: $ the Krylov method as a smoother with a fixed small number of iterations.
234: $ Implicitly sets KSPConvergedSkip as KSP convergence test.
235: $ KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
236: $ of the preconditioned residual P^{-1}(b - A x)
237: $ KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual.
238: $ KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
241: Options Database Key:
242: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural>
244: Notes:
245: Not all combinations of preconditioner side (see KSPSetPCSide()) and norm type are supported by all Krylov methods.
246: If only one is set, PETSc tries to automatically change the other to find a compatible pair. If no such combination
247: is supported, PETSc will generate an error.
249: Developer Notes:
250: Supported combinations of norm and preconditioner side are set using KSPSetSupportedNorm().
252: Level: advanced
254: .keywords: KSP, create, context, norms
256: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetCheckNormIteration(), KSPSetPCSide(), KSPGetPCSide(), KSPNormType
257: @*/
258: PetscErrorCode KSPSetNormType(KSP ksp,KSPNormType normtype)
259: {
263: ksp->normtype = ksp->normtype_set = normtype;
264: return(0);
265: }
267: /*@
268: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
269: computed and used in the convergence test.
271: Logically Collective on KSP
273: Input Parameter:
274: + ksp - Krylov solver context
275: - it - use -1 to check at all iterations
277: Notes:
278: Currently only works with KSPCG, KSPBCGS and KSPIBCGS
280: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
282: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
283: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
284: Level: advanced
286: .keywords: KSP, create, context, norms
288: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
289: @*/
290: PetscErrorCode KSPSetCheckNormIteration(KSP ksp,PetscInt it)
291: {
295: ksp->chknorm = it;
296: return(0);
297: }
299: /*@
300: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() for
301: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
302: one additional iteration.
305: Logically Collective on KSP
307: Input Parameter:
308: + ksp - Krylov solver context
309: - flg - PETSC_TRUE or PETSC_FALSE
311: Options Database Keys:
312: . -ksp_lag_norm - lag the calculated residual norm
314: Notes:
315: Currently only works with KSPIBCGS.
317: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
319: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
320: Level: advanced
322: .keywords: KSP, create, context, norms
324: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetCheckNormIteration()
325: @*/
326: PetscErrorCode KSPSetLagNorm(KSP ksp,PetscBool flg)
327: {
331: ksp->lagnorm = flg;
332: return(0);
333: }
335: /*@
336: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a KSP
338: Logically Collective
340: Input Arguments:
341: + ksp - Krylov method
342: . normtype - supported norm type
343: . pcside - preconditioner side that can be used with this norm
344: - priority - positive integer preference for this combination; larger values have higher priority
346: Level: developer
348: Notes:
349: This function should be called from the implementation files KSPCreate_XXX() to declare
350: which norms and preconditioner sides are supported. Users should not need to call this
351: function.
353: .seealso: KSPSetNormType(), KSPSetPCSide()
354: @*/
355: PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType normtype,PCSide pcside,PetscInt priority)
356: {
360: ksp->normsupporttable[normtype][pcside] = priority;
361: return(0);
362: }
364: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
365: {
369: PetscMemzero(ksp->normsupporttable,sizeof(ksp->normsupporttable));
370: ksp->pc_side = ksp->pc_side_set;
371: ksp->normtype = ksp->normtype_set;
372: return(0);
373: }
375: PetscErrorCode KSPSetUpNorms_Private(KSP ksp,PetscBool errorifnotsupported,KSPNormType *normtype,PCSide *pcside)
376: {
377: PetscInt i,j,best,ibest = 0,jbest = 0;
380: best = 0;
381: for (i=0; i<KSP_NORM_MAX; i++) {
382: for (j=0; j<PC_SIDE_MAX; j++) {
383: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i) && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j) && (ksp->normsupporttable[i][j] > best)) {
384: best = ksp->normsupporttable[i][j];
385: ibest = i;
386: jbest = j;
387: }
388: }
389: }
390: if (best < 1 && errorifnotsupported) {
391: 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);
392: 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]);
393: 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]);
394: 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]);
395: }
396: if (normtype) *normtype = (KSPNormType)ibest;
397: if (pcside) *pcside = (PCSide)jbest;
398: return(0);
399: }
401: /*@
402: KSPGetNormType - Gets the norm that is used for convergence testing.
404: Not Collective
406: Input Parameter:
407: . ksp - Krylov solver context
409: Output Parameter:
410: . normtype - norm that is used for convergence testing
412: Level: advanced
414: .keywords: KSP, create, context, norms
416: .seealso: KSPNormType, KSPSetNormType(), KSPConvergedSkip()
417: @*/
418: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
419: {
425: KSPSetUpNorms_Private(ksp,PETSC_TRUE,&ksp->normtype,&ksp->pc_side);
426: *normtype = ksp->normtype;
427: return(0);
428: }
430: #if defined(PETSC_HAVE_SAWS)
431: #include <petscviewersaws.h>
432: #endif
434: /*@
435: KSPSetOperators - Sets the matrix associated with the linear system
436: and a (possibly) different one associated with the preconditioner.
438: Collective on KSP and Mat
440: Input Parameters:
441: + ksp - the KSP context
442: . Amat - the matrix that defines the linear system
443: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
445: Notes:
447: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
448: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
450: All future calls to KSPSetOperators() must use the same size matrices!
452: Passing a NULL for Amat or Pmat removes the matrix that is currently used.
454: If you wish to replace either Amat or Pmat but leave the other one untouched then
455: first call KSPGetOperators() to get the one you wish to keep, call PetscObjectReference()
456: on it and then pass it back in in your call to KSPSetOperators().
458: Level: beginner
460: Alternative usage: If the operators have NOT been set with KSP/PCSetOperators() then the operators
461: are created in PC and returned to the user. In this case, if both operators
462: mat and pmat are requested, two DIFFERENT operators will be returned. If
463: only one is requested both operators in the PC will be the same (i.e. as
464: if one had called KSP/PCSetOperators() with the same argument for both Mats).
465: The user must set the sizes of the returned matrices and their type etc just
466: as if the user created them with MatCreate(). For example,
468: $ KSP/PCGetOperators(ksp/pc,&mat,NULL); is equivalent to
469: $ set size, type, etc of mat
471: $ MatCreate(comm,&mat);
472: $ KSP/PCSetOperators(ksp/pc,mat,mat);
473: $ PetscObjectDereference((PetscObject)mat);
474: $ set size, type, etc of mat
476: and
478: $ KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
479: $ set size, type, etc of mat and pmat
481: $ MatCreate(comm,&mat);
482: $ MatCreate(comm,&pmat);
483: $ KSP/PCSetOperators(ksp/pc,mat,pmat);
484: $ PetscObjectDereference((PetscObject)mat);
485: $ PetscObjectDereference((PetscObject)pmat);
486: $ set size, type, etc of mat and pmat
488: The rational for this support is so that when creating a TS, SNES, or KSP the hierarchy
489: of underlying objects (i.e. SNES, KSP, PC, Mat) and their livespans can be completely
490: managed by the top most level object (i.e. the TS, SNES, or KSP). Another way to look
491: at this is when you create a SNES you do not NEED to create a KSP and attach it to
492: the SNES object (the SNES object manages it for you). Similarly when you create a KSP
493: you do not need to attach a PC to it (the KSP object manages the PC object for you).
494: Thus, why should YOU have to create the Mat and attach it to the SNES/KSP/PC, when
495: it can be created for you?
497: .keywords: KSP, set, operators, matrix, preconditioner, linear system
499: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators(), KSPSetComputeOperators(), KSPSetComputeInitialGuess(), KSPSetComputeRHS()
500: @*/
501: PetscErrorCode KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat)
502: {
511: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
512: PCSetOperators(ksp->pc,Amat,Pmat);
513: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
514: return(0);
515: }
517: /*@
518: KSPGetOperators - Gets the matrix associated with the linear system
519: and a (possibly) different one associated with the preconditioner.
521: Collective on KSP and Mat
523: Input Parameter:
524: . ksp - the KSP context
526: Output Parameters:
527: + Amat - the matrix that defines the linear system
528: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
530: Level: intermediate
532: Notes: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
534: .keywords: KSP, set, get, operators, matrix, preconditioner, linear system
536: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()
537: @*/
538: PetscErrorCode KSPGetOperators(KSP ksp,Mat *Amat,Mat *Pmat)
539: {
544: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
545: PCGetOperators(ksp->pc,Amat,Pmat);
546: return(0);
547: }
549: /*@C
550: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
551: possibly a different one associated with the preconditioner have been set in the KSP.
553: Not collective, though the results on all processes should be the same
555: Input Parameter:
556: . pc - the KSP context
558: Output Parameters:
559: + mat - the matrix associated with the linear system was set
560: - pmat - matrix associated with the preconditioner was set, usually the same
562: Level: intermediate
564: .keywords: KSP, get, operators, matrix, linear system
566: .seealso: PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()
567: @*/
568: PetscErrorCode KSPGetOperatorsSet(KSP ksp,PetscBool *mat,PetscBool *pmat)
569: {
574: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
575: PCGetOperatorsSet(ksp->pc,mat,pmat);
576: return(0);
577: }
579: /*@C
580: KSPSetPreSolve - Sets a function that is called before every KSPSolve() is started
582: Logically Collective on KSP
584: Input Parameters:
585: + ksp - the solver object
586: . presolve - the function to call before the solve
587: - prectx - any context needed by the function
589: Level: developer
591: .keywords: KSP, create, context
593: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPostSolve()
594: @*/
595: PetscErrorCode KSPSetPreSolve(KSP ksp,PetscErrorCode (*presolve)(KSP,Vec,Vec,void*),void *prectx)
596: {
599: ksp->presolve = presolve;
600: ksp->prectx = prectx;
601: return(0);
602: }
604: /*@C
605: KSPSetPostSolve - Sets a function that is called after every KSPSolve() completes (whether it converges or not)
607: Logically Collective on KSP
609: Input Parameters:
610: + ksp - the solver object
611: . postsolve - the function to call after the solve
612: - postctx - any context needed by the function
614: Level: developer
616: .keywords: KSP, create, context
618: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve()
619: @*/
620: PetscErrorCode KSPSetPostSolve(KSP ksp,PetscErrorCode (*postsolve)(KSP,Vec,Vec,void*),void *postctx)
621: {
624: ksp->postsolve = postsolve;
625: ksp->postctx = postctx;
626: return(0);
627: }
629: /*@
630: KSPCreate - Creates the default KSP context.
632: Collective on MPI_Comm
634: Input Parameter:
635: . comm - MPI communicator
637: Output Parameter:
638: . ksp - location to put the KSP context
640: Notes:
641: The default KSP type is GMRES with a restart of 30, using modified Gram-Schmidt
642: orthogonalization.
644: Level: beginner
646: .keywords: KSP, create, context
648: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP
649: @*/
650: PetscErrorCode KSPCreate(MPI_Comm comm,KSP *inksp)
651: {
652: KSP ksp;
654: void *ctx;
658: *inksp = 0;
659: KSPInitializePackage();
661: PetscHeaderCreate(ksp,KSP_CLASSID,"KSP","Krylov Method","KSP",comm,KSPDestroy,KSPView);
663: ksp->max_it = 10000;
664: ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
665: ksp->rtol = 1.e-5;
666: #if defined(PETSC_USE_REAL_SINGLE)
667: ksp->abstol = 1.e-25;
668: #else
669: ksp->abstol = 1.e-50;
670: #endif
671: ksp->divtol = 1.e4;
673: ksp->chknorm = -1;
674: ksp->normtype = ksp->normtype_set = KSP_NORM_DEFAULT;
675: ksp->rnorm = 0.0;
676: ksp->its = 0;
677: ksp->guess_zero = PETSC_TRUE;
678: ksp->calc_sings = PETSC_FALSE;
679: ksp->res_hist = NULL;
680: ksp->res_hist_alloc = NULL;
681: ksp->res_hist_len = 0;
682: ksp->res_hist_max = 0;
683: ksp->res_hist_reset = PETSC_TRUE;
684: ksp->numbermonitors = 0;
686: KSPConvergedDefaultCreate(&ctx);
687: KSPSetConvergenceTest(ksp,KSPConvergedDefault,ctx,KSPConvergedDefaultDestroy);
688: ksp->ops->buildsolution = KSPBuildSolutionDefault;
689: ksp->ops->buildresidual = KSPBuildResidualDefault;
691: ksp->vec_sol = 0;
692: ksp->vec_rhs = 0;
693: ksp->pc = 0;
694: ksp->data = 0;
695: ksp->nwork = 0;
696: ksp->work = 0;
697: ksp->reason = KSP_CONVERGED_ITERATING;
698: ksp->setupstage = KSP_SETUP_NEW;
700: KSPNormSupportTableReset_Private(ksp);
702: *inksp = ksp;
703: return(0);
704: }
706: /*@C
707: KSPSetType - Builds KSP for a particular solver.
709: Logically Collective on KSP
711: Input Parameters:
712: + ksp - the Krylov space context
713: - type - a known method
715: Options Database Key:
716: . -ksp_type <method> - Sets the method; use -help for a list
717: of available methods (for instance, cg or gmres)
719: Notes:
720: See "petsc/include/petscksp.h" for available methods (for instance,
721: KSPCG or KSPGMRES).
723: Normally, it is best to use the KSPSetFromOptions() command and
724: then set the KSP type from the options database rather than by using
725: this routine. Using the options database provides the user with
726: maximum flexibility in evaluating the many different Krylov methods.
727: The KSPSetType() routine is provided for those situations where it
728: is necessary to set the iterative solver independently of the command
729: line or options database. This might be the case, for example, when
730: the choice of iterative solver changes during the execution of the
731: program, and the user's application is taking responsibility for
732: choosing the appropriate method. In other words, this routine is
733: not for beginners.
735: Level: intermediate
737: Developer Note: KSPRegister() is used to add Krylov types to KSPList from which they
738: are accessed by KSPSetType().
740: .keywords: KSP, set, method
742: .seealso: PCSetType(), KSPType, KSPRegister(), KSPCreate()
744: @*/
745: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
746: {
747: PetscErrorCode ierr,(*r)(KSP);
748: PetscBool match;
754: PetscObjectTypeCompare((PetscObject)ksp,type,&match);
755: if (match) return(0);
757: PetscFunctionListFind(KSPList,type,&r);
758: if (!r) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested KSP type %s",type);
759: /* Destroy the previous private KSP context */
760: if (ksp->ops->destroy) {
761: (*ksp->ops->destroy)(ksp);
762: ksp->ops->destroy = NULL;
763: }
764: /* Reinitialize function pointers in KSPOps structure */
765: PetscMemzero(ksp->ops,sizeof(struct _KSPOps));
766: ksp->ops->buildsolution = KSPBuildSolutionDefault;
767: ksp->ops->buildresidual = KSPBuildResidualDefault;
768: KSPNormSupportTableReset_Private(ksp);
769: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
770: ksp->setupstage = KSP_SETUP_NEW;
771: PetscObjectChangeTypeName((PetscObject)ksp,type);
772: (*r)(ksp);
773: return(0);
774: }
776: /*@C
777: KSPGetType - Gets the KSP type as a string from the KSP object.
779: Not Collective
781: Input Parameter:
782: . ksp - Krylov context
784: Output Parameter:
785: . name - name of KSP method
787: Level: intermediate
789: .keywords: KSP, get, method, name
791: .seealso: KSPSetType()
792: @*/
793: PetscErrorCode KSPGetType(KSP ksp,KSPType *type)
794: {
798: *type = ((PetscObject)ksp)->type_name;
799: return(0);
800: }
802: /*@C
803: KSPRegister - Adds a method to the Krylov subspace solver package.
805: Not Collective
807: Input Parameters:
808: + name_solver - name of a new user-defined solver
809: - routine_create - routine to create method context
811: Notes:
812: KSPRegister() may be called multiple times to add several user-defined solvers.
814: Sample usage:
815: .vb
816: KSPRegister("my_solver",MySolverCreate);
817: .ve
819: Then, your solver can be chosen with the procedural interface via
820: $ KSPSetType(ksp,"my_solver")
821: or at runtime via the option
822: $ -ksp_type my_solver
824: Level: advanced
826: .keywords: KSP, register
828: .seealso: KSPRegisterAll(), KSPRegisterDestroy()
830: @*/
831: PetscErrorCode KSPRegister(const char sname[],PetscErrorCode (*function)(KSP))
832: {
836: PetscFunctionListAdd(&KSPList,sname,function);
837: return(0);
838: }