Actual source code: itcreate.c
petsc-3.4.5 2014-06-29
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_AMS)
74: #include <petscviewerams.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_AMS)
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_AMS)
125: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERAMS,&isams);
126: #endif
127: if (iascii) {
128: PetscObjectPrintClassNamePrefixType((PetscObject)ksp,viewer,"KSP Object");
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",ksp->rtol,ksp->abstol,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_AMS)
188: } else if (isams) {
189: if (((PetscObject)ksp)->amsmem == -1) {
190: PetscObjectViewAMS((PetscObject)ksp,viewer);
191: PetscStackCallAMS(AMS_Memory_take_access,(((PetscObject)ksp)->amsmem));
192: PetscStackCallAMS(AMS_Memory_add_field,(((PetscObject)ksp)->amsmem,"its",&ksp->its,1,AMS_INT,AMS_READ,AMS_COMMON,AMS_REDUCT_UNDEF));
193: if (!ksp->res_hist) {
194: KSPSetResidualHistory(ksp,NULL,PETSC_DECIDE,PETSC_FALSE);
195: }
196: PetscStackCallAMS(AMS_Memory_add_field,(((PetscObject)ksp)->amsmem,"res_hist",ksp->res_hist,10,AMS_DOUBLE,AMS_READ,AMS_COMMON,AMS_REDUCT_UNDEF));
197: PetscStackCallAMS(AMS_Memory_grant_access,(((PetscObject)ksp)->amsmem));
198: }
199: #endif
200: } else if (ksp->ops->view) {
201: (*ksp->ops->view)(ksp,viewer);
202: }
203: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
204: PCView(ksp->pc,viewer);
205: if (isdraw) {
206: PetscDraw draw;
207: PetscViewerDrawGetDraw(viewer,0,&draw);
208: PetscDrawPopCurrentPoint(draw);
209: }
210: return(0);
211: }
216: /*@
217: KSPSetNormType - Sets the norm that is used for convergence testing.
219: Logically Collective on KSP
221: Input Parameter:
222: + ksp - Krylov solver context
223: - normtype - one of
224: $ KSP_NORM_NONE - skips computing the norm, this should only be used if you are using
225: $ the Krylov method as a smoother with a fixed small number of iterations.
226: $ Implicitly sets KSPSkipConverged as KSP convergence test.
227: $ Supported only by CG, Richardson, Bi-CG-stab, CR, and CGS methods.
228: $ KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
229: $ of the preconditioned residual
230: $ KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual, supported only by
231: $ CG, CHEBYSHEV, and RICHARDSON, automatically true for right (see KSPSetPCSide())
232: $ preconditioning..
233: $ KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
236: Options Database Key:
237: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural>
239: Notes:
240: Currently only works with the CG, Richardson, Bi-CG-stab, CR, and CGS methods.
242: Level: advanced
244: .keywords: KSP, create, context, norms
246: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPSkipConverged(), KSPSetCheckNormIteration()
247: @*/
248: PetscErrorCode KSPSetNormType(KSP ksp,KSPNormType normtype)
249: {
255: ksp->normtype = normtype;
256: if (normtype == KSP_NORM_NONE) {
257: KSPSetConvergenceTest(ksp,KSPSkipConverged,0,0);
258: PetscInfo(ksp,"Warning: setting KSPNormType to skip computing the norm\n\
259: KSP convergence test is implicitly set to KSPSkipConverged\n");
260: }
261: return(0);
262: }
266: /*@
267: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
268: computed and used in the convergence test.
270: Logically Collective on KSP
272: Input Parameter:
273: + ksp - Krylov solver context
274: - it - use -1 to check at all iterations
276: Notes:
277: Currently only works with KSPCG, KSPBCGS and KSPIBCGS
279: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
281: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
282: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
283: Level: advanced
285: .keywords: KSP, create, context, norms
287: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPSkipConverged(), KSPSetNormType()
288: @*/
289: PetscErrorCode KSPSetCheckNormIteration(KSP ksp,PetscInt it)
290: {
294: ksp->chknorm = it;
295: return(0);
296: }
300: /*@
301: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() for
302: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
303: one additional iteration.
306: Logically Collective on KSP
308: Input Parameter:
309: + ksp - Krylov solver context
310: - flg - PETSC_TRUE or PETSC_FALSE
312: Options Database Keys:
313: . -ksp_lag_norm - lag the calculated residual norm
315: Notes:
316: Currently only works with KSPIBCGS.
318: Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
320: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
321: Level: advanced
323: .keywords: KSP, create, context, norms
325: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPSkipConverged(), KSPSetNormType(), KSPSetCheckNormIteration()
326: @*/
327: PetscErrorCode KSPSetLagNorm(KSP ksp,PetscBool flg)
328: {
332: ksp->lagnorm = flg;
333: return(0);
334: }
338: /*@
339: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a KSP
341: Logically Collective
343: Input Arguments:
344: + ksp - Krylov method
345: . normtype - supported norm type
346: . pcside - preconditioner side that can be used with this norm
347: - preference - integer preference for this combination, larger values have higher priority
349: Level: developer
351: Notes:
352: This function should be called from the implementation files KSPCreate_XXX() to declare
353: which norms and preconditioner sides are supported. Users should not need to call this
354: function.
356: KSP_NORM_NONE is supported by default with all KSP methods and any PC side. If a KSP explicitly does not support
357: KSP_NORM_NONE, it should set this by setting priority=0.
359: .seealso: KSPSetNormType(), KSPSetPCSide()
360: @*/
361: PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType normtype,PCSide pcside,PetscInt priority)
362: {
366: ksp->normsupporttable[normtype][pcside] = priority;
367: return(0);
368: }
372: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
373: {
377: PetscMemzero(ksp->normsupporttable,sizeof(ksp->normsupporttable));
378: KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_LEFT,1);
379: KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_RIGHT,1);
380: return(0);
381: }
385: PetscErrorCode KSPSetUpNorms_Private(KSP ksp,KSPNormType *normtype,PCSide *pcside)
386: {
387: PetscInt i,j,best,ibest = 0,jbest = 0;
390: best = 0;
391: for (i=0; i<KSP_NORM_MAX; i++) {
392: for (j=0; j<PC_SIDE_MAX; j++) {
393: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i)
394: && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j)
395: && (ksp->normsupporttable[i][j] > best)) {
396: if (ksp->normtype == KSP_NORM_DEFAULT && i == KSP_NORM_NONE && ksp->normsupporttable[i][j] <= 1) {
397: continue; /* Skip because we don't want to default to no norms unless set by the KSP (preonly). */
398: }
399: best = ksp->normsupporttable[i][j];
400: ibest = i;
401: jbest = j;
402: }
403: }
404: }
405: if (best < 1) {
406: 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);
407: 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]);
408: 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]);
409: 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]);
410: }
411: *normtype = (KSPNormType)ibest;
412: *pcside = (PCSide)jbest;
413: return(0);
414: }
418: /*@
419: KSPGetNormType - Gets the norm that is used for convergence testing.
421: Not Collective
423: Input Parameter:
424: . ksp - Krylov solver context
426: Output Parameter:
427: . normtype - norm that is used for convergence testing
429: Level: advanced
431: .keywords: KSP, create, context, norms
433: .seealso: KSPNormType, KSPSetNormType(), KSPSkipConverged()
434: @*/
435: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
436: {
442: KSPSetUpNorms_Private(ksp,&ksp->normtype,&ksp->pc_side);
443: *normtype = ksp->normtype;
444: return(0);
445: }
447: #if defined(PETSC_HAVE_AMS)
448: #include <petscviewerams.h>
449: #endif
453: /*@
454: KSPSetOperators - Sets the matrix associated with the linear system
455: and a (possibly) different one associated with the preconditioner.
457: Collective on KSP and Mat
459: Input Parameters:
460: + ksp - the KSP context
461: . Amat - the matrix that defines the linear system
462: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
463: - flag - flag indicating information about the preconditioner matrix structure
464: during successive linear solves. This flag is ignored the first time a
465: linear system is solved, and thus is irrelevant when solving just one linear
466: system.
468: Notes:
469: The flag can be used to eliminate unnecessary work in the preconditioner
470: during the repeated solution of linear systems of the same size. The
471: available options are
472: $ SAME_PRECONDITIONER -
473: $ Pmat is identical during successive linear solves.
474: $ This option is intended for folks who are using
475: $ different Amat and Pmat matrices and want to reuse the
476: $ same preconditioner matrix. For example, this option
477: $ saves work by not recomputing incomplete factorization
478: $ for ILU/ICC preconditioners.
479: $ SAME_NONZERO_PATTERN -
480: $ Pmat has the same nonzero structure during
481: $ successive linear solves.
482: $ DIFFERENT_NONZERO_PATTERN -
483: $ Pmat does not have the same nonzero structure.
485: All future calls to KSPSetOperators() must use the same size matrices!
487: Passing a NULL for Amat or Pmat removes the matrix that is currently used.
489: If you wish to replace either Amat or Pmat but leave the other one untouched then
490: first call KSPGetOperators() to get the one you wish to keep, call PetscObjectReference()
491: on it and then pass it back in in your call to KSPSetOperators().
493: Caution:
494: If you specify SAME_NONZERO_PATTERN, PETSc believes your assertion
495: and does not check the structure of the matrix. If you erroneously
496: claim that the structure is the same when it actually is not, the new
497: preconditioner will not function correctly. Thus, use this optimization
498: feature carefully!
500: If in doubt about whether your preconditioner matrix has changed
501: structure or not, use the flag DIFFERENT_NONZERO_PATTERN.
503: Level: beginner
505: Alternative usage: If the operators have NOT been set with KSP/PCSetOperators() then the operators
506: are created in PC and returned to the user. In this case, if both operators
507: mat and pmat are requested, two DIFFERENT operators will be returned. If
508: only one is requested both operators in the PC will be the same (i.e. as
509: if one had called KSP/PCSetOperators() with the same argument for both Mats).
510: The user must set the sizes of the returned matrices and their type etc just
511: as if the user created them with MatCreate(). For example,
513: $ KSP/PCGetOperators(ksp/pc,&mat,NULL,NULL); is equivalent to
514: $ set size, type, etc of mat
516: $ MatCreate(comm,&mat);
517: $ KSP/PCSetOperators(ksp/pc,mat,mat,SAME_NONZERO_PATTERN);
518: $ PetscObjectDereference((PetscObject)mat);
519: $ set size, type, etc of mat
521: and
523: $ KSP/PCGetOperators(ksp/pc,&mat,&pmat,NULL); is equivalent to
524: $ set size, type, etc of mat and pmat
526: $ MatCreate(comm,&mat);
527: $ MatCreate(comm,&pmat);
528: $ KSP/PCSetOperators(ksp/pc,mat,pmat,SAME_NONZERO_PATTERN);
529: $ PetscObjectDereference((PetscObject)mat);
530: $ PetscObjectDereference((PetscObject)pmat);
531: $ set size, type, etc of mat and pmat
533: The rational for this support is so that when creating a TS, SNES, or KSP the hierarchy
534: of underlying objects (i.e. SNES, KSP, PC, Mat) and their livespans can be completely
535: managed by the top most level object (i.e. the TS, SNES, or KSP). Another way to look
536: at this is when you create a SNES you do not NEED to create a KSP and attach it to
537: the SNES object (the SNES object manages it for you). Similarly when you create a KSP
538: you do not need to attach a PC to it (the KSP object manages the PC object for you).
539: Thus, why should YOU have to create the Mat and attach it to the SNES/KSP/PC, when
540: it can be created for you?
542: .keywords: KSP, set, operators, matrix, preconditioner, linear system
544: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators()
545: @*/
546: PetscErrorCode KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat,MatStructure flag)
547: {
548: MatNullSpace nullsp;
557: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
558: PCSetOperators(ksp->pc,Amat,Pmat,flag);
559: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
560: if (ksp->guess) {
561: KSPFischerGuessReset(ksp->guess);
562: }
563: if (Pmat) {
564: MatGetNullSpace(Pmat, &nullsp);
565: if (nullsp) {
566: KSPSetNullSpace(ksp, nullsp);
567: }
568: }
569: return(0);
570: }
574: /*@
575: KSPGetOperators - Gets the matrix associated with the linear system
576: and a (possibly) different one associated with the preconditioner.
578: Collective on KSP and Mat
580: Input Parameter:
581: . ksp - the KSP context
583: Output Parameters:
584: + Amat - the matrix that defines the linear system
585: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
586: - flag - flag indicating information about the preconditioner matrix structure
587: during successive linear solves. This flag is ignored the first time a
588: linear system is solved, and thus is irrelevant when solving just one linear
589: system.
591: Level: intermediate
593: Notes: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
595: .keywords: KSP, set, get, operators, matrix, preconditioner, linear system
597: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()
598: @*/
599: PetscErrorCode KSPGetOperators(KSP ksp,Mat *Amat,Mat *Pmat,MatStructure *flag)
600: {
605: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
606: PCGetOperators(ksp->pc,Amat,Pmat,flag);
607: return(0);
608: }
612: /*@C
613: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
614: possibly a different one associated with the preconditioner have been set in the KSP.
616: Not collective, though the results on all processes should be the same
618: Input Parameter:
619: . pc - the KSP context
621: Output Parameters:
622: + mat - the matrix associated with the linear system was set
623: - pmat - matrix associated with the preconditioner was set, usually the same
625: Level: intermediate
627: .keywords: KSP, get, operators, matrix, linear system
629: .seealso: PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()
630: @*/
631: PetscErrorCode KSPGetOperatorsSet(KSP ksp,PetscBool *mat,PetscBool *pmat)
632: {
637: if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
638: PCGetOperatorsSet(ksp->pc,mat,pmat);
639: return(0);
640: }
644: /*@C
645: KSPSetPreSolve - Sets a function that is called before every KSPSolve() is started
647: Logically Collective on KSP
649: Input Parameters:
650: + ksp - the solver object
651: . presolve - the function to call before the solve
652: - prectx - any context needed by the function
654: Level: developer
656: .keywords: KSP, create, context
658: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPostSolve()
659: @*/
660: PetscErrorCode KSPSetPreSolve(KSP ksp,PetscErrorCode (*presolve)(KSP,Vec,Vec,void*),void *prectx)
661: {
664: ksp->presolve = presolve;
665: ksp->prectx = prectx;
666: return(0);
667: }
671: /*@C
672: KSPSetPostSolve - Sets a function that is called after every KSPSolve() completes (whether it converges or not)
674: Logically Collective on KSP
676: Input Parameters:
677: + ksp - the solver object
678: . postsolve - the function to call after the solve
679: - postctx - any context needed by the function
681: Level: developer
683: .keywords: KSP, create, context
685: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve()
686: @*/
687: PetscErrorCode KSPSetPostSolve(KSP ksp,PetscErrorCode (*postsolve)(KSP,Vec,Vec,void*),void *postctx)
688: {
691: ksp->postsolve = postsolve;
692: ksp->postctx = postctx;
693: return(0);
694: }
698: /*@
699: KSPCreate - Creates the default KSP context.
701: Collective on MPI_Comm
703: Input Parameter:
704: . comm - MPI communicator
706: Output Parameter:
707: . ksp - location to put the KSP context
709: Notes:
710: The default KSP type is GMRES with a restart of 30, using modified Gram-Schmidt
711: orthogonalization.
713: Level: beginner
715: .keywords: KSP, create, context
717: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP
718: @*/
719: PetscErrorCode KSPCreate(MPI_Comm comm,KSP *inksp)
720: {
721: KSP ksp;
723: void *ctx;
727: *inksp = 0;
728: #if !defined(PETSC_USE_DYNAMIC_LIBRARIES)
729: KSPInitializePackage();
730: #endif
732: PetscHeaderCreate(ksp,_p_KSP,struct _KSPOps,KSP_CLASSID,"KSP","Krylov Method","KSP",comm,KSPDestroy,KSPView);
734: ksp->max_it = 10000;
735: ksp->pc_side = PC_SIDE_DEFAULT;
736: ksp->rtol = 1.e-5;
737: ksp->abstol = 1.e-50;
738: ksp->divtol = 1.e4;
740: ksp->chknorm = -1;
741: ksp->normtype = KSP_NORM_DEFAULT;
742: ksp->rnorm = 0.0;
743: ksp->its = 0;
744: ksp->guess_zero = PETSC_TRUE;
745: ksp->calc_sings = PETSC_FALSE;
746: ksp->res_hist = NULL;
747: ksp->res_hist_alloc = NULL;
748: ksp->res_hist_len = 0;
749: ksp->res_hist_max = 0;
750: ksp->res_hist_reset = PETSC_TRUE;
751: ksp->numbermonitors = 0;
753: KSPDefaultConvergedCreate(&ctx);
754: KSPSetConvergenceTest(ksp,KSPDefaultConverged,ctx,KSPDefaultConvergedDestroy);
755: ksp->ops->buildsolution = KSPBuildSolutionDefault;
756: ksp->ops->buildresidual = KSPBuildResidualDefault;
758: ksp->vec_sol = 0;
759: ksp->vec_rhs = 0;
760: ksp->pc = 0;
761: ksp->data = 0;
762: ksp->nwork = 0;
763: ksp->work = 0;
764: ksp->reason = KSP_CONVERGED_ITERATING;
765: ksp->setupstage = KSP_SETUP_NEW;
767: KSPNormSupportTableReset_Private(ksp);
769: *inksp = ksp;
770: return(0);
771: }
775: /*@C
776: KSPSetType - Builds KSP for a particular solver.
778: Logically Collective on KSP
780: Input Parameters:
781: + ksp - the Krylov space context
782: - type - a known method
784: Options Database Key:
785: . -ksp_type <method> - Sets the method; use -help for a list
786: of available methods (for instance, cg or gmres)
788: Notes:
789: See "petsc/include/petscksp.h" for available methods (for instance,
790: KSPCG or KSPGMRES).
792: Normally, it is best to use the KSPSetFromOptions() command and
793: then set the KSP type from the options database rather than by using
794: this routine. Using the options database provides the user with
795: maximum flexibility in evaluating the many different Krylov methods.
796: The KSPSetType() routine is provided for those situations where it
797: is necessary to set the iterative solver independently of the command
798: line or options database. This might be the case, for example, when
799: the choice of iterative solver changes during the execution of the
800: program, and the user's application is taking responsibility for
801: choosing the appropriate method. In other words, this routine is
802: not for beginners.
804: Level: intermediate
806: Developer Note: KSPRegister() is used to add Krylov types to KSPList from which they
807: are accessed by KSPSetType().
809: .keywords: KSP, set, method
811: .seealso: PCSetType(), KSPType, KSPRegister(), KSPCreate()
813: @*/
814: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
815: {
816: PetscErrorCode ierr,(*r)(KSP);
817: PetscBool match;
823: PetscObjectTypeCompare((PetscObject)ksp,type,&match);
824: if (match) return(0);
826: PetscFunctionListFind(KSPList,type,&r);
827: if (!r) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested KSP type %s",type);
828: /* Destroy the previous private KSP context */
829: if (ksp->ops->destroy) {
830: (*ksp->ops->destroy)(ksp);
831: ksp->ops->destroy = NULL;
832: }
833: /* Reinitialize function pointers in KSPOps structure */
834: PetscMemzero(ksp->ops,sizeof(struct _KSPOps));
835: ksp->ops->buildsolution = KSPBuildSolutionDefault;
836: ksp->ops->buildresidual = KSPBuildResidualDefault;
837: KSPNormSupportTableReset_Private(ksp);
838: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
839: ksp->setupstage = KSP_SETUP_NEW;
840: PetscObjectChangeTypeName((PetscObject)ksp,type);
841: (*r)(ksp);
842: return(0);
843: }
847: /*@C
848: KSPGetType - Gets the KSP type as a string from the KSP object.
850: Not Collective
852: Input Parameter:
853: . ksp - Krylov context
855: Output Parameter:
856: . name - name of KSP method
858: Level: intermediate
860: .keywords: KSP, get, method, name
862: .seealso: KSPSetType()
863: @*/
864: PetscErrorCode KSPGetType(KSP ksp,KSPType *type)
865: {
869: *type = ((PetscObject)ksp)->type_name;
870: return(0);
871: }
875: /*@C
876: KSPRegister - Adds a method to the Krylov subspace solver package.
878: Not Collective
880: Input Parameters:
881: + name_solver - name of a new user-defined solver
882: - routine_create - routine to create method context
884: Notes:
885: KSPRegister() may be called multiple times to add several user-defined solvers.
887: Sample usage:
888: .vb
889: KSPRegister("my_solver",MySolverCreate);
890: .ve
892: Then, your solver can be chosen with the procedural interface via
893: $ KSPSetType(ksp,"my_solver")
894: or at runtime via the option
895: $ -ksp_type my_solver
897: Level: advanced
899: .keywords: KSP, register
901: .seealso: KSPRegisterAll(), KSPRegisterDestroy()
903: @*/
904: PetscErrorCode KSPRegister(const char sname[],PetscErrorCode (*function)(KSP))
905: {
909: PetscFunctionListAdd(&KSPList,sname,function);
910: return(0);
911: }
915: /*@
916: KSPSetNullSpace - Sets the null space of the operator
918: Logically Collective on KSP
920: Input Parameters:
921: + ksp - the Krylov space object
922: - nullsp - the null space of the operator
924: Notes: If the Mat provided to KSP has a nullspace added to it with MatSetNullSpace() then
925: KSP will automatically use the MatNullSpace and you don't need to call KSPSetNullSpace().
927: Level: advanced
929: .seealso: KSPSetOperators(), MatNullSpaceCreate(), KSPGetNullSpace(), MatSetNullSpace()
930: @*/
931: PetscErrorCode KSPSetNullSpace(KSP ksp,MatNullSpace nullsp)
932: {
938: PetscObjectReference((PetscObject)nullsp);
939: if (ksp->nullsp) { MatNullSpaceDestroy(&ksp->nullsp); }
940: ksp->nullsp = nullsp;
941: return(0);
942: }
946: /*@
947: KSPGetNullSpace - Gets the null space of the operator
949: Not Collective
951: Input Parameters:
952: + ksp - the Krylov space object
953: - nullsp - the null space of the operator
955: Level: advanced
957: .seealso: KSPSetOperators(), MatNullSpaceCreate(), KSPSetNullSpace()
958: @*/
959: PetscErrorCode KSPGetNullSpace(KSP ksp,MatNullSpace *nullsp)
960: {
964: *nullsp = ksp->nullsp;
965: return(0);
966: }