Actual source code: itcreate.c
petsc-3.12.5 2020-03-29
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, KSP_SolveTranspose;
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 viewer
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: .seealso: PCView(), PetscViewerASCIIOpen()
101: @*/
102: PetscErrorCode KSPView(KSP ksp,PetscViewer viewer)
103: {
105: PetscBool iascii,isbinary,isdraw,isstring;
106: #if defined(PETSC_HAVE_SAWS)
107: PetscBool issaws;
108: #endif
112: if (!viewer) {
113: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ksp),&viewer);
114: }
118: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
119: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
120: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
121: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
122: #if defined(PETSC_HAVE_SAWS)
123: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
124: #endif
125: if (iascii) {
126: PetscObjectPrintClassNamePrefixType((PetscObject)ksp,viewer);
127: if (ksp->ops->view) {
128: PetscViewerASCIIPushTab(viewer);
129: (*ksp->ops->view)(ksp,viewer);
130: PetscViewerASCIIPopTab(viewer);
131: }
132: if (ksp->guess_zero) {
133: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, initial guess is zero\n",ksp->max_it);
134: } else {
135: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, nonzero initial guess\n", ksp->max_it);
136: }
137: if (ksp->guess_knoll) {PetscViewerASCIIPrintf(viewer," using preconditioner applied to right hand side for initial guess\n");}
138: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, divergence=%g\n",(double)ksp->rtol,(double)ksp->abstol,(double)ksp->divtol);
139: if (ksp->pc_side == PC_RIGHT) {
140: PetscViewerASCIIPrintf(viewer," right preconditioning\n");
141: } else if (ksp->pc_side == PC_SYMMETRIC) {
142: PetscViewerASCIIPrintf(viewer," symmetric preconditioning\n");
143: } else {
144: PetscViewerASCIIPrintf(viewer," left preconditioning\n");
145: }
146: if (ksp->guess) {
147: PetscViewerASCIIPushTab(viewer);
148: KSPGuessView(ksp->guess,viewer);
149: PetscViewerASCIIPopTab(viewer);
150: }
151: if (ksp->dscale) {PetscViewerASCIIPrintf(viewer," diagonally scaled system\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 (isstring) {
170: const char *type;
171: KSPGetType(ksp,&type);
172: PetscViewerStringSPrintf(viewer," KSPType: %-7.7s",type);
173: if (ksp->ops->view) {(*ksp->ops->view)(ksp,viewer);}
174: } else if (isdraw) {
175: PetscDraw draw;
176: char str[36];
177: PetscReal x,y,bottom,h;
178: PetscBool flg;
180: PetscViewerDrawGetDraw(viewer,0,&draw);
181: PetscDrawGetCurrentPoint(draw,&x,&y);
182: PetscObjectTypeCompare((PetscObject)ksp,KSPPREONLY,&flg);
183: if (!flg) {
184: PetscStrncpy(str,"KSP: ",sizeof(str));
185: PetscStrlcat(str,((PetscObject)ksp)->type_name,sizeof(str));
186: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);
187: bottom = y - h;
188: } else {
189: bottom = y;
190: }
191: PetscDrawPushCurrentPoint(draw,x,bottom);
192: #if defined(PETSC_HAVE_SAWS)
193: } else if (issaws) {
194: PetscMPIInt rank;
195: const char *name;
197: PetscObjectGetName((PetscObject)ksp,&name);
198: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
199: if (!((PetscObject)ksp)->amsmem && !rank) {
200: char dir[1024];
202: PetscObjectViewSAWs((PetscObject)ksp,viewer);
203: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
204: PetscStackCallSAWs(SAWs_Register,(dir,&ksp->its,1,SAWs_READ,SAWs_INT));
205: if (!ksp->res_hist) {
206: KSPSetResidualHistory(ksp,NULL,PETSC_DECIDE,PETSC_TRUE);
207: }
208: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/res_hist",name);
209: PetscStackCallSAWs(SAWs_Register,(dir,ksp->res_hist,10,SAWs_READ,SAWs_DOUBLE));
210: }
211: #endif
212: } else if (ksp->ops->view) {
213: (*ksp->ops->view)(ksp,viewer);
214: }
215: if (!ksp->skippcsetfromoptions) {
216: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
217: PCView(ksp->pc,viewer);
218: }
219: if (isdraw) {
220: PetscDraw draw;
221: PetscViewerDrawGetDraw(viewer,0,&draw);
222: PetscDrawPopCurrentPoint(draw);
223: }
224: return(0);
225: }
228: /*@
229: KSPSetNormType - Sets the norm that is used for convergence testing.
231: Logically Collective on ksp
233: Input Parameter:
234: + ksp - Krylov solver context
235: - normtype - one of
236: $ KSP_NORM_NONE - skips computing the norm, this should generally only be used if you are using
237: $ the Krylov method as a smoother with a fixed small number of iterations.
238: $ Implicitly sets KSPConvergedSkip() as KSP convergence test.
239: $ Note that certain algorithms such as KSPGMRES ALWAYS require the norm calculation,
240: $ for these methods the norms are still computed, they are just not used in
241: $ the convergence test.
242: $ KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
243: $ of the preconditioned residual P^{-1}(b - A x)
244: $ KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual.
245: $ KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
248: Options Database Key:
249: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural>
251: Notes:
252: Not all combinations of preconditioner side (see KSPSetPCSide()) and norm type are supported by all Krylov methods.
253: If only one is set, PETSc tries to automatically change the other to find a compatible pair. If no such combination
254: is supported, PETSc will generate an error.
256: Developer Notes:
257: Supported combinations of norm and preconditioner side are set using KSPSetSupportedNorm().
259: Level: advanced
261: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetCheckNormIteration(), KSPSetPCSide(), KSPGetPCSide(), KSPNormType
262: @*/
263: PetscErrorCode KSPSetNormType(KSP ksp,KSPNormType normtype)
264: {
268: ksp->normtype = ksp->normtype_set = normtype;
269: return(0);
270: }
272: /*@
273: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
274: computed and used in the convergence test.
276: Logically Collective on ksp
278: Input Parameter:
279: + ksp - Krylov solver context
280: - it - use -1 to check at all iterations
282: Notes:
283: Currently only works with KSPCG, KSPBCGS and KSPIBCGS
285: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
287: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
288: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
289: Level: advanced
291: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
292: @*/
293: PetscErrorCode KSPSetCheckNormIteration(KSP ksp,PetscInt it)
294: {
298: ksp->chknorm = it;
299: return(0);
300: }
302: /*@
303: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() for
304: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
305: one additional iteration.
308: Logically Collective on ksp
310: Input Parameter:
311: + ksp - Krylov solver context
312: - flg - PETSC_TRUE or PETSC_FALSE
314: Options Database Keys:
315: . -ksp_lag_norm - lag the calculated residual norm
317: Notes:
318: Currently only works with KSPIBCGS.
320: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
322: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
323: Level: advanced
325: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetCheckNormIteration()
326: @*/
327: PetscErrorCode KSPSetLagNorm(KSP ksp,PetscBool flg)
328: {
332: ksp->lagnorm = flg;
333: return(0);
334: }
336: /*@
337: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a KSP
339: Logically Collective
341: Input Arguments:
342: + ksp - Krylov method
343: . normtype - supported norm type
344: . pcside - preconditioner side that can be used with this norm
345: - priority - positive integer preference for this combination; larger values have higher priority
347: Level: developer
349: Notes:
350: This function should be called from the implementation files KSPCreate_XXX() to declare
351: which norms and preconditioner sides are supported. Users should not need to call this
352: function.
354: .seealso: KSPSetNormType(), KSPSetPCSide()
355: @*/
356: PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType normtype,PCSide pcside,PetscInt priority)
357: {
361: ksp->normsupporttable[normtype][pcside] = priority;
362: return(0);
363: }
365: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
366: {
370: PetscMemzero(ksp->normsupporttable,sizeof(ksp->normsupporttable));
371: ksp->pc_side = ksp->pc_side_set;
372: ksp->normtype = ksp->normtype_set;
373: return(0);
374: }
376: PetscErrorCode KSPSetUpNorms_Private(KSP ksp,PetscBool errorifnotsupported,KSPNormType *normtype,PCSide *pcside)
377: {
378: PetscInt i,j,best,ibest = 0,jbest = 0;
381: best = 0;
382: for (i=0; i<KSP_NORM_MAX; i++) {
383: for (j=0; j<PC_SIDE_MAX; j++) {
384: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i) && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j) && (ksp->normsupporttable[i][j] > best)) {
385: best = ksp->normsupporttable[i][j];
386: ibest = i;
387: jbest = j;
388: }
389: }
390: }
391: if (best < 1 && errorifnotsupported) {
392: 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);
393: 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]);
394: 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]);
395: 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]);
396: }
397: if (normtype) *normtype = (KSPNormType)ibest;
398: if (pcside) *pcside = (PCSide)jbest;
399: return(0);
400: }
402: /*@
403: KSPGetNormType - Gets the norm that is used for convergence testing.
405: Not Collective
407: Input Parameter:
408: . ksp - Krylov solver context
410: Output Parameter:
411: . normtype - norm that is used for convergence testing
413: Level: advanced
415: .seealso: KSPNormType, KSPSetNormType(), KSPConvergedSkip()
416: @*/
417: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
418: {
424: KSPSetUpNorms_Private(ksp,PETSC_TRUE,&ksp->normtype,&ksp->pc_side);
425: *normtype = ksp->normtype;
426: return(0);
427: }
429: #if defined(PETSC_HAVE_SAWS)
430: #include <petscviewersaws.h>
431: #endif
433: /*@
434: KSPSetOperators - Sets the matrix associated with the linear system
435: and a (possibly) different one associated with the preconditioner.
437: Collective on ksp
439: Input Parameters:
440: + ksp - the KSP context
441: . Amat - the matrix that defines the linear system
442: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
444: Notes:
446: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
447: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
449: All future calls to KSPSetOperators() must use the same size matrices!
451: Passing a NULL for Amat or Pmat removes the matrix that is currently used.
453: If you wish to replace either Amat or Pmat but leave the other one untouched then
454: first call KSPGetOperators() to get the one you wish to keep, call PetscObjectReference()
455: on it and then pass it back in in your call to KSPSetOperators().
457: Level: beginner
459: Alternative usage: If the operators have NOT been set with KSP/PCSetOperators() then the operators
460: are created in PC and returned to the user. In this case, if both operators
461: mat and pmat are requested, two DIFFERENT operators will be returned. If
462: only one is requested both operators in the PC will be the same (i.e. as
463: if one had called KSP/PCSetOperators() with the same argument for both Mats).
464: The user must set the sizes of the returned matrices and their type etc just
465: as if the user created them with MatCreate(). For example,
467: $ KSP/PCGetOperators(ksp/pc,&mat,NULL); is equivalent to
468: $ set size, type, etc of mat
470: $ MatCreate(comm,&mat);
471: $ KSP/PCSetOperators(ksp/pc,mat,mat);
472: $ PetscObjectDereference((PetscObject)mat);
473: $ set size, type, etc of mat
475: and
477: $ KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
478: $ set size, type, etc of mat and pmat
480: $ MatCreate(comm,&mat);
481: $ MatCreate(comm,&pmat);
482: $ KSP/PCSetOperators(ksp/pc,mat,pmat);
483: $ PetscObjectDereference((PetscObject)mat);
484: $ PetscObjectDereference((PetscObject)pmat);
485: $ set size, type, etc of mat and pmat
487: The rational for this support is so that when creating a TS, SNES, or KSP the hierarchy
488: of underlying objects (i.e. SNES, KSP, PC, Mat) and their livespans can be completely
489: managed by the top most level object (i.e. the TS, SNES, or KSP). Another way to look
490: at this is when you create a SNES you do not NEED to create a KSP and attach it to
491: the SNES object (the SNES object manages it for you). Similarly when you create a KSP
492: you do not need to attach a PC to it (the KSP object manages the PC object for you).
493: Thus, why should YOU have to create the Mat and attach it to the SNES/KSP/PC, when
494: it can be created for you?
496: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators(), KSPSetComputeOperators(), KSPSetComputeInitialGuess(), KSPSetComputeRHS()
497: @*/
498: PetscErrorCode KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat)
499: {
508: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
509: PCSetOperators(ksp->pc,Amat,Pmat);
510: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
511: return(0);
512: }
514: /*@
515: KSPGetOperators - Gets the matrix associated with the linear system
516: and a (possibly) different one associated with the preconditioner.
518: Collective on ksp
520: Input Parameter:
521: . ksp - the KSP context
523: Output Parameters:
524: + Amat - the matrix that defines the linear system
525: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
527: Level: intermediate
529: Notes:
530: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
532: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()
533: @*/
534: PetscErrorCode KSPGetOperators(KSP ksp,Mat *Amat,Mat *Pmat)
535: {
540: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
541: PCGetOperators(ksp->pc,Amat,Pmat);
542: return(0);
543: }
545: /*@C
546: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
547: possibly a different one associated with the preconditioner have been set in the KSP.
549: Not collective, though the results on all processes should be the same
551: Input Parameter:
552: . pc - the KSP context
554: Output Parameters:
555: + mat - the matrix associated with the linear system was set
556: - pmat - matrix associated with the preconditioner was set, usually the same
558: Level: intermediate
560: .seealso: PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()
561: @*/
562: PetscErrorCode KSPGetOperatorsSet(KSP ksp,PetscBool *mat,PetscBool *pmat)
563: {
568: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
569: PCGetOperatorsSet(ksp->pc,mat,pmat);
570: return(0);
571: }
573: /*@C
574: KSPSetPreSolve - Sets a function that is called before every KSPSolve() is started
576: Logically Collective on ksp
578: Input Parameters:
579: + ksp - the solver object
580: . presolve - the function to call before the solve
581: - prectx - any context needed by the function
583: Calling sequence of presolve:
584: $ func(KSP ksp,Vec rhs,Vec x,void *ctx)
586: + ksp - the KSP context
587: . rhs - the right-hand side vector
588: . x - the solution vector
589: - ctx - optional user-provided context
591: Level: developer
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: Calling sequence of postsolve:
617: $ func(KSP ksp,Vec rhs,Vec x,void *ctx)
619: + ksp - the KSP context
620: . rhs - the right-hand side vector
621: . x - the solution vector
622: - ctx - optional user-provided context
624: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve()
625: @*/
626: PetscErrorCode KSPSetPostSolve(KSP ksp,PetscErrorCode (*postsolve)(KSP,Vec,Vec,void*),void *postctx)
627: {
630: ksp->postsolve = postsolve;
631: ksp->postctx = postctx;
632: return(0);
633: }
635: /*@
636: KSPCreate - Creates the default KSP context.
638: Collective
640: Input Parameter:
641: . comm - MPI communicator
643: Output Parameter:
644: . ksp - location to put the KSP context
646: Notes:
647: The default KSP type is GMRES with a restart of 30, using modified Gram-Schmidt
648: orthogonalization.
650: Level: beginner
652: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP
653: @*/
654: PetscErrorCode KSPCreate(MPI_Comm comm,KSP *inksp)
655: {
656: KSP ksp;
658: void *ctx;
662: *inksp = 0;
663: KSPInitializePackage();
665: PetscHeaderCreate(ksp,KSP_CLASSID,"KSP","Krylov Method","KSP",comm,KSPDestroy,KSPView);
667: ksp->max_it = 10000;
668: ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
669: ksp->rtol = 1.e-5;
670: #if defined(PETSC_USE_REAL_SINGLE)
671: ksp->abstol = 1.e-25;
672: #else
673: ksp->abstol = 1.e-50;
674: #endif
675: ksp->divtol = 1.e4;
677: ksp->chknorm = -1;
678: ksp->normtype = ksp->normtype_set = KSP_NORM_DEFAULT;
679: ksp->rnorm = 0.0;
680: ksp->its = 0;
681: ksp->guess_zero = PETSC_TRUE;
682: ksp->calc_sings = PETSC_FALSE;
683: ksp->res_hist = NULL;
684: ksp->res_hist_alloc = NULL;
685: ksp->res_hist_len = 0;
686: ksp->res_hist_max = 0;
687: ksp->res_hist_reset = PETSC_TRUE;
688: ksp->numbermonitors = 0;
689: ksp->setfromoptionscalled = 0;
691: KSPConvergedDefaultCreate(&ctx);
692: KSPSetConvergenceTest(ksp,KSPConvergedDefault,ctx,KSPConvergedDefaultDestroy);
693: ksp->ops->buildsolution = KSPBuildSolutionDefault;
694: ksp->ops->buildresidual = KSPBuildResidualDefault;
696: ksp->vec_sol = 0;
697: ksp->vec_rhs = 0;
698: ksp->pc = 0;
699: ksp->data = 0;
700: ksp->nwork = 0;
701: ksp->work = 0;
702: ksp->reason = KSP_CONVERGED_ITERATING;
703: ksp->setupstage = KSP_SETUP_NEW;
705: KSPNormSupportTableReset_Private(ksp);
707: *inksp = ksp;
708: return(0);
709: }
711: /*@C
712: KSPSetType - Builds KSP for a particular solver.
714: Logically Collective on ksp
716: Input Parameters:
717: + ksp - the Krylov space context
718: - type - a known method
720: Options Database Key:
721: . -ksp_type <method> - Sets the method; use -help for a list
722: of available methods (for instance, cg or gmres)
724: Notes:
725: See "petsc/include/petscksp.h" for available methods (for instance,
726: KSPCG or KSPGMRES).
728: Normally, it is best to use the KSPSetFromOptions() command and
729: then set the KSP type from the options database rather than by using
730: this routine. Using the options database provides the user with
731: maximum flexibility in evaluating the many different Krylov methods.
732: The KSPSetType() routine is provided for those situations where it
733: is necessary to set the iterative solver independently of the command
734: line or options database. This might be the case, for example, when
735: the choice of iterative solver changes during the execution of the
736: program, and the user's application is taking responsibility for
737: choosing the appropriate method. In other words, this routine is
738: not for beginners.
740: Level: intermediate
742: Developer Note: KSPRegister() is used to add Krylov types to KSPList from which they
743: are accessed by KSPSetType().
745: .seealso: PCSetType(), KSPType, KSPRegister(), KSPCreate()
747: @*/
748: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
749: {
750: PetscErrorCode ierr,(*r)(KSP);
751: PetscBool match;
757: PetscObjectTypeCompare((PetscObject)ksp,type,&match);
758: if (match) return(0);
760: PetscFunctionListFind(KSPList,type,&r);
761: if (!r) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested KSP type %s",type);
762: /* Destroy the previous private KSP context */
763: if (ksp->ops->destroy) {
764: (*ksp->ops->destroy)(ksp);
765: ksp->ops->destroy = NULL;
766: }
767: /* Reinitialize function pointers in KSPOps structure */
768: PetscMemzero(ksp->ops,sizeof(struct _KSPOps));
769: ksp->ops->buildsolution = KSPBuildSolutionDefault;
770: ksp->ops->buildresidual = KSPBuildResidualDefault;
771: KSPNormSupportTableReset_Private(ksp);
772: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
773: ksp->setupstage = KSP_SETUP_NEW;
774: PetscObjectChangeTypeName((PetscObject)ksp,type);
775: (*r)(ksp);
776: return(0);
777: }
779: /*@C
780: KSPGetType - Gets the KSP type as a string from the KSP object.
782: Not Collective
784: Input Parameter:
785: . ksp - Krylov context
787: Output Parameter:
788: . name - name of KSP method
790: Level: intermediate
792: .seealso: KSPSetType()
793: @*/
794: PetscErrorCode KSPGetType(KSP ksp,KSPType *type)
795: {
799: *type = ((PetscObject)ksp)->type_name;
800: return(0);
801: }
803: /*@C
804: KSPRegister - Adds a method to the Krylov subspace solver package.
806: Not Collective
808: Input Parameters:
809: + name_solver - name of a new user-defined solver
810: - routine_create - routine to create method context
812: Notes:
813: KSPRegister() may be called multiple times to add several user-defined solvers.
815: Sample usage:
816: .vb
817: KSPRegister("my_solver",MySolverCreate);
818: .ve
820: Then, your solver can be chosen with the procedural interface via
821: $ KSPSetType(ksp,"my_solver")
822: or at runtime via the option
823: $ -ksp_type my_solver
825: Level: advanced
827: .seealso: KSPRegisterAll()
828: @*/
829: PetscErrorCode KSPRegister(const char sname[],PetscErrorCode (*function)(KSP))
830: {
834: KSPInitializePackage();
835: PetscFunctionListAdd(&KSPList,sname,function);
836: return(0);
837: }