Actual source code: itcreate.c

  1: /*
  2:      The basic KSP routines, Create, View etc. are here.
  3: */
  4: #include <petsc/private/kspimpl.h>

  6: /* Logging support */
  7: PetscClassId  KSP_CLASSID;
  8: PetscClassId  DMKSP_CLASSID;
  9: PetscClassId  KSPGUESS_CLASSID;
 10: PetscLogEvent KSP_GMRESOrthogonalization, KSP_SetUp, KSP_Solve, KSP_SolveTranspose, KSP_MatSolve;

 12: /*
 13:    Contains the list of registered KSP routines
 14: */
 15: PetscFunctionList KSPList              = NULL;
 16: PetscBool         KSPRegisterAllCalled = PETSC_FALSE;

 18: /*
 19:    Contains the list of registered KSP monitors
 20: */
 21: PetscFunctionList KSPMonitorList              = NULL;
 22: PetscFunctionList KSPMonitorCreateList        = NULL;
 23: PetscFunctionList KSPMonitorDestroyList       = NULL;
 24: PetscBool         KSPMonitorRegisterAllCalled = PETSC_FALSE;

 26: /*@C
 27:   KSPLoad - Loads a KSP that has been stored in binary  with KSPView().

 29:   Collective on viewer

 31:   Input Parameters:
 32: + newdm - the newly loaded KSP, this needs to have been created with KSPCreate() or
 33:            some related function before a call to KSPLoad().
 34: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()

 36:    Level: intermediate

 38:   Notes:
 39:    The type is determined by the data in the file, any type set into the KSP before this call is ignored.

 41:   Notes for advanced users:
 42:   Most users should not need to know the details of the binary storage
 43:   format, since KSPLoad() and KSPView() completely hide these details.
 44:   But for anyone who's interested, the standard binary matrix storage
 45:   format is
 46: .vb
 47:      has not yet been determined
 48: .ve

 50: .seealso: PetscViewerBinaryOpen(), KSPView(), MatLoad(), VecLoad()
 51: @*/
 52: PetscErrorCode  KSPLoad(KSP newdm, PetscViewer viewer)
 53: {
 55:   PetscBool      isbinary;
 56:   PetscInt       classid;
 57:   char           type[256];
 58:   PC             pc;

 63:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
 64:   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");

 66:   PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
 67:   if (classid != KSP_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)newdm),PETSC_ERR_ARG_WRONG,"Not KSP next in file");
 68:   PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
 69:   KSPSetType(newdm, type);
 70:   if (newdm->ops->load) {
 71:     (*newdm->ops->load)(newdm,viewer);
 72:   }
 73:   KSPGetPC(newdm,&pc);
 74:   PCLoad(pc,viewer);
 75:   return(0);
 76: }

 78: #include <petscdraw.h>
 79: #if defined(PETSC_HAVE_SAWS)
 80: #include <petscviewersaws.h>
 81: #endif
 82: /*@C
 83:    KSPView - Prints the KSP data structure.

 85:    Collective on ksp

 87:    Input Parameters:
 88: +  ksp - the Krylov space context
 89: -  viewer - visualization context

 91:    Options Database Keys:
 92: .  -ksp_view - print the KSP data structure at the end of a KSPSolve call

 94:    Note:
 95:    The available visualization contexts include
 96: +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
 97: -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
 98:          output where only the first processor opens
 99:          the file.  All other processors send their
100:          data to the first processor to print.

102:    The available formats include
103: +     PETSC_VIEWER_DEFAULT - standard output (default)
104: -     PETSC_VIEWER_ASCII_INFO_DETAIL - more verbose output for PCBJACOBI and PCASM

106:    The user can open an alternative visualization context with
107:    PetscViewerASCIIOpen() - output to a specified file.

109:   In the debugger you can do "call KSPView(ksp,0)" to display the KSP. (The same holds for any PETSc object viewer).

111:    Level: beginner

113: .seealso: PCView(), PetscViewerASCIIOpen()
114: @*/
115: PetscErrorCode  KSPView(KSP ksp,PetscViewer viewer)
116: {
118:   PetscBool      iascii,isbinary,isdraw,isstring;
119: #if defined(PETSC_HAVE_SAWS)
120:   PetscBool      issaws;
121: #endif

125:   if (!viewer) {
126:     PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ksp),&viewer);
127:   }

131:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
132:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
133:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
134:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
135: #if defined(PETSC_HAVE_SAWS)
136:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
137: #endif
138:   if (iascii) {
139:     PetscObjectPrintClassNamePrefixType((PetscObject)ksp,viewer);
140:     if (ksp->ops->view) {
141:       PetscViewerASCIIPushTab(viewer);
142:       (*ksp->ops->view)(ksp,viewer);
143:       PetscViewerASCIIPopTab(viewer);
144:     }
145:     if (ksp->guess_zero) {
146:       PetscViewerASCIIPrintf(viewer,"  maximum iterations=%D, initial guess is zero\n",ksp->max_it);
147:     } else {
148:       PetscViewerASCIIPrintf(viewer,"  maximum iterations=%D, nonzero initial guess\n", ksp->max_it);
149:     }
150:     if (ksp->guess_knoll) {PetscViewerASCIIPrintf(viewer,"  using preconditioner applied to right hand side for initial guess\n");}
151:     PetscViewerASCIIPrintf(viewer,"  tolerances:  relative=%g, absolute=%g, divergence=%g\n",(double)ksp->rtol,(double)ksp->abstol,(double)ksp->divtol);
152:     if (ksp->pc_side == PC_RIGHT) {
153:       PetscViewerASCIIPrintf(viewer,"  right preconditioning\n");
154:     } else if (ksp->pc_side == PC_SYMMETRIC) {
155:       PetscViewerASCIIPrintf(viewer,"  symmetric preconditioning\n");
156:     } else {
157:       PetscViewerASCIIPrintf(viewer,"  left preconditioning\n");
158:     }
159:     if (ksp->guess) {
160:       PetscViewerASCIIPushTab(viewer);
161:       KSPGuessView(ksp->guess,viewer);
162:       PetscViewerASCIIPopTab(viewer);
163:     }
164:     if (ksp->dscale) {PetscViewerASCIIPrintf(viewer,"  diagonally scaled system\n");}
165:     PetscViewerASCIIPrintf(viewer,"  using %s norm type for convergence test\n",KSPNormTypes[ksp->normtype]);
166:   } else if (isbinary) {
167:     PetscInt    classid = KSP_FILE_CLASSID;
168:     MPI_Comm    comm;
169:     PetscMPIInt rank;
170:     char        type[256];

172:     PetscObjectGetComm((PetscObject)ksp,&comm);
173:     MPI_Comm_rank(comm,&rank);
174:     if (rank == 0) {
175:       PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT);
176:       PetscStrncpy(type,((PetscObject)ksp)->type_name,256);
177:       PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR);
178:     }
179:     if (ksp->ops->view) {
180:       (*ksp->ops->view)(ksp,viewer);
181:     }
182:   } else if (isstring) {
183:     const char *type;
184:     KSPGetType(ksp,&type);
185:     PetscViewerStringSPrintf(viewer," KSPType: %-7.7s",type);
186:     if (ksp->ops->view) {(*ksp->ops->view)(ksp,viewer);}
187:   } else if (isdraw) {
188:     PetscDraw draw;
189:     char      str[36];
190:     PetscReal x,y,bottom,h;
191:     PetscBool flg;

193:     PetscViewerDrawGetDraw(viewer,0,&draw);
194:     PetscDrawGetCurrentPoint(draw,&x,&y);
195:     PetscObjectTypeCompare((PetscObject)ksp,KSPPREONLY,&flg);
196:     if (!flg) {
197:       PetscStrncpy(str,"KSP: ",sizeof(str));
198:       PetscStrlcat(str,((PetscObject)ksp)->type_name,sizeof(str));
199:       PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_RED,PETSC_DRAW_BLACK,str,NULL,&h);
200:       bottom = y - h;
201:     } else {
202:       bottom = y;
203:     }
204:     PetscDrawPushCurrentPoint(draw,x,bottom);
205: #if defined(PETSC_HAVE_SAWS)
206:   } else if (issaws) {
207:     PetscMPIInt rank;
208:     const char  *name;

210:     PetscObjectGetName((PetscObject)ksp,&name);
211:     MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
212:     if (!((PetscObject)ksp)->amsmem && rank == 0) {
213:       char       dir[1024];

215:       PetscObjectViewSAWs((PetscObject)ksp,viewer);
216:       PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
217:       PetscStackCallSAWs(SAWs_Register,(dir,&ksp->its,1,SAWs_READ,SAWs_INT));
218:       if (!ksp->res_hist) {
219:         KSPSetResidualHistory(ksp,NULL,PETSC_DECIDE,PETSC_TRUE);
220:       }
221:       PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/res_hist",name);
222:       PetscStackCallSAWs(SAWs_Register,(dir,ksp->res_hist,10,SAWs_READ,SAWs_DOUBLE));
223:     }
224: #endif
225:   } else if (ksp->ops->view) {
226:     (*ksp->ops->view)(ksp,viewer);
227:   }
228:   if (ksp->pc) {
229:     PCView(ksp->pc,viewer);
230:   }
231:   if (isdraw) {
232:     PetscDraw draw;
233:     PetscViewerDrawGetDraw(viewer,0,&draw);
234:     PetscDrawPopCurrentPoint(draw);
235:   }
236:   return(0);
237: }

239: /*@C
240:    KSPViewFromOptions - View from Options

242:    Collective on KSP

244:    Input Parameters:
245: +  A - Krylov solver context
246: .  obj - Optional object
247: -  name - command line option

249:    Level: intermediate
250: .seealso:  KSP, KSPView, PetscObjectViewFromOptions(), KSPCreate()
251: @*/
252: PetscErrorCode  KSPViewFromOptions(KSP A,PetscObject obj,const char name[])
253: {

258:   PetscObjectViewFromOptions((PetscObject)A,obj,name);
259:   return(0);
260: }

262: /*@
263:    KSPSetNormType - Sets the norm that is used for convergence testing.

265:    Logically Collective on ksp

267:    Input Parameters:
268: +  ksp - Krylov solver context
269: -  normtype - one of
270: $   KSP_NORM_NONE - skips computing the norm, this should generally only be used if you are using
271: $                 the Krylov method as a smoother with a fixed small number of iterations.
272: $                 Implicitly sets KSPConvergedSkip() as KSP convergence test.
273: $                 Note that certain algorithms such as KSPGMRES ALWAYS require the norm calculation,
274: $                 for these methods the norms are still computed, they are just not used in
275: $                 the convergence test.
276: $   KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
277: $                 of the preconditioned residual P^{-1}(b - A x)
278: $   KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual.
279: $   KSP_NORM_NATURAL - supported  by KSPCG, KSPCR, KSPCGNE, KSPCGS

281:    Options Database Key:
282: .   -ksp_norm_type <none,preconditioned,unpreconditioned,natural>

284:    Notes:
285:    Not all combinations of preconditioner side (see KSPSetPCSide()) and norm type are supported by all Krylov methods.
286:    If only one is set, PETSc tries to automatically change the other to find a compatible pair.  If no such combination
287:    is supported, PETSc will generate an error.

289:    Developer Notes:
290:    Supported combinations of norm and preconditioner side are set using KSPSetSupportedNorm().

292:    Level: advanced

294: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetCheckNormIteration(), KSPSetPCSide(), KSPGetPCSide(), KSPNormType
295: @*/
296: PetscErrorCode  KSPSetNormType(KSP ksp,KSPNormType normtype)
297: {
301:   ksp->normtype = ksp->normtype_set = normtype;
302:   return(0);
303: }

305: /*@
306:    KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
307:      computed and used in the convergence test.

309:    Logically Collective on ksp

311:    Input Parameters:
312: +  ksp - Krylov solver context
313: -  it  - use -1 to check at all iterations

315:    Notes:
316:    Currently only works with KSPCG, KSPBCGS and KSPIBCGS

318:    Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm

320:    On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
321:     -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
322:    Level: advanced

324: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
325: @*/
326: PetscErrorCode  KSPSetCheckNormIteration(KSP ksp,PetscInt it)
327: {
331:   ksp->chknorm = it;
332:   return(0);
333: }

335: /*@
336:    KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() for
337:    computing the inner products for the next iteration.  This can reduce communication costs at the expense of doing
338:    one additional iteration.

340:    Logically Collective on ksp

342:    Input Parameters:
343: +  ksp - Krylov solver context
344: -  flg - PETSC_TRUE or PETSC_FALSE

346:    Options Database Keys:
347: .  -ksp_lag_norm - lag the calculated residual norm

349:    Notes:
350:    Currently only works with KSPIBCGS.

352:    Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm

354:    If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
355:    Level: advanced

357: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetCheckNormIteration()
358: @*/
359: PetscErrorCode  KSPSetLagNorm(KSP ksp,PetscBool flg)
360: {
364:   ksp->lagnorm = flg;
365:   return(0);
366: }

368: /*@
369:    KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a KSP

371:    Logically Collective

373:    Input Parameters:
374: +  ksp - Krylov method
375: .  normtype - supported norm type
376: .  pcside - preconditioner side that can be used with this norm
377: -  priority - positive integer preference for this combination; larger values have higher priority

379:    Level: developer

381:    Notes:
382:    This function should be called from the implementation files KSPCreate_XXX() to declare
383:    which norms and preconditioner sides are supported. Users should not need to call this
384:    function.

386: .seealso: KSPSetNormType(), KSPSetPCSide()
387: @*/
388: PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType normtype,PCSide pcside,PetscInt priority)
389: {

393:   ksp->normsupporttable[normtype][pcside] = priority;
394:   return(0);
395: }

397: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
398: {

402:   PetscMemzero(ksp->normsupporttable,sizeof(ksp->normsupporttable));
403:   ksp->pc_side  = ksp->pc_side_set;
404:   ksp->normtype = ksp->normtype_set;
405:   return(0);
406: }

408: PetscErrorCode KSPSetUpNorms_Private(KSP ksp,PetscBool errorifnotsupported,KSPNormType *normtype,PCSide *pcside)
409: {
410:   PetscInt i,j,best,ibest = 0,jbest = 0;

413:   best = 0;
414:   for (i=0; i<KSP_NORM_MAX; i++) {
415:     for (j=0; j<PC_SIDE_MAX; j++) {
416:       if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i) && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j) && (ksp->normsupporttable[i][j] > best)) {
417:         best  = ksp->normsupporttable[i][j];
418:         ibest = i;
419:         jbest = j;
420:       }
421:     }
422:   }
423:   if (best < 1 && errorifnotsupported) {
424:     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);
425:     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]);
426:     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]);
427:     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]);
428:   }
429:   if (normtype) *normtype = (KSPNormType)ibest;
430:   if (pcside)   *pcside   = (PCSide)jbest;
431:   return(0);
432: }

434: /*@
435:    KSPGetNormType - Gets the norm that is used for convergence testing.

437:    Not Collective

439:    Input Parameter:
440: .  ksp - Krylov solver context

442:    Output Parameter:
443: .  normtype - norm that is used for convergence testing

445:    Level: advanced

447: .seealso: KSPNormType, KSPSetNormType(), KSPConvergedSkip()
448: @*/
449: PetscErrorCode  KSPGetNormType(KSP ksp, KSPNormType *normtype)
450: {

456:   KSPSetUpNorms_Private(ksp,PETSC_TRUE,&ksp->normtype,&ksp->pc_side);
457:   *normtype = ksp->normtype;
458:   return(0);
459: }

461: #if defined(PETSC_HAVE_SAWS)
462: #include <petscviewersaws.h>
463: #endif

465: /*@
466:    KSPSetOperators - Sets the matrix associated with the linear system
467:    and a (possibly) different one associated with the preconditioner.

469:    Collective on ksp

471:    Input Parameters:
472: +  ksp - the KSP context
473: .  Amat - the matrix that defines the linear system
474: -  Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.

476:    Notes:

478:     If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
479:     space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.

481:     All future calls to KSPSetOperators() must use the same size matrices!

483:     Passing a NULL for Amat or Pmat removes the matrix that is currently used.

485:     If you wish to replace either Amat or Pmat but leave the other one untouched then
486:     first call KSPGetOperators() to get the one you wish to keep, call PetscObjectReference()
487:     on it and then pass it back in in your call to KSPSetOperators().

489:     Level: beginner

491:    Alternative usage: If the operators have NOT been set with KSP/PCSetOperators() then the operators
492:       are created in PC and returned to the user. In this case, if both operators
493:       mat and pmat are requested, two DIFFERENT operators will be returned. If
494:       only one is requested both operators in the PC will be the same (i.e. as
495:       if one had called KSP/PCSetOperators() with the same argument for both Mats).
496:       The user must set the sizes of the returned matrices and their type etc just
497:       as if the user created them with MatCreate(). For example,

499: $         KSP/PCGetOperators(ksp/pc,&mat,NULL); is equivalent to
500: $           set size, type, etc of mat

502: $         MatCreate(comm,&mat);
503: $         KSP/PCSetOperators(ksp/pc,mat,mat);
504: $         PetscObjectDereference((PetscObject)mat);
505: $           set size, type, etc of mat

507:      and

509: $         KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
510: $           set size, type, etc of mat and pmat

512: $         MatCreate(comm,&mat);
513: $         MatCreate(comm,&pmat);
514: $         KSP/PCSetOperators(ksp/pc,mat,pmat);
515: $         PetscObjectDereference((PetscObject)mat);
516: $         PetscObjectDereference((PetscObject)pmat);
517: $           set size, type, etc of mat and pmat

519:     The rational for this support is so that when creating a TS, SNES, or KSP the hierarchy
520:     of underlying objects (i.e. SNES, KSP, PC, Mat) and their livespans can be completely
521:     managed by the top most level object (i.e. the TS, SNES, or KSP). Another way to look
522:     at this is when you create a SNES you do not NEED to create a KSP and attach it to
523:     the SNES object (the SNES object manages it for you). Similarly when you create a KSP
524:     you do not need to attach a PC to it (the KSP object manages the PC object for you).
525:     Thus, why should YOU have to create the Mat and attach it to the SNES/KSP/PC, when
526:     it can be created for you?

528: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators(), KSPSetComputeOperators(), KSPSetComputeInitialGuess(), KSPSetComputeRHS()
529: @*/
530: PetscErrorCode  KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat)
531: {

540:   if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
541:   PCSetOperators(ksp->pc,Amat,Pmat);
542:   if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX;  /* so that next solve call will call PCSetUp() on new matrix */
543:   return(0);
544: }

546: /*@
547:    KSPGetOperators - Gets the matrix associated with the linear system
548:    and a (possibly) different one associated with the preconditioner.

550:    Collective on ksp

552:    Input Parameter:
553: .  ksp - the KSP context

555:    Output Parameters:
556: +  Amat - the matrix that defines the linear system
557: -  Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.

559:     Level: intermediate

561:    Notes:
562:     DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.

564: .seealso: KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()
565: @*/
566: PetscErrorCode  KSPGetOperators(KSP ksp,Mat *Amat,Mat *Pmat)
567: {

572:   if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
573:   PCGetOperators(ksp->pc,Amat,Pmat);
574:   return(0);
575: }

577: /*@C
578:    KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
579:    possibly a different one associated with the preconditioner have been set in the KSP.

581:    Not collective, though the results on all processes should be the same

583:    Input Parameter:
584: .  pc - the KSP context

586:    Output Parameters:
587: +  mat - the matrix associated with the linear system was set
588: -  pmat - matrix associated with the preconditioner was set, usually the same

590:    Level: intermediate

592: .seealso: PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()
593: @*/
594: PetscErrorCode  KSPGetOperatorsSet(KSP ksp,PetscBool  *mat,PetscBool  *pmat)
595: {

600:   if (!ksp->pc) {KSPGetPC(ksp,&ksp->pc);}
601:   PCGetOperatorsSet(ksp->pc,mat,pmat);
602:   return(0);
603: }

605: /*@C
606:    KSPSetPreSolve - Sets a function that is called before every KSPSolve() is started

608:    Logically Collective on ksp

610:    Input Parameters:
611: +   ksp - the solver object
612: .   presolve - the function to call before the solve
613: -   prectx - any context needed by the function

615:    Calling sequence of presolve:
616: $  func(KSP ksp,Vec rhs,Vec x,void *ctx)

618: +  ksp - the KSP context
619: .  rhs - the right-hand side vector
620: .  x - the solution vector
621: -  ctx - optional user-provided context

623:    Level: developer

625: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPostSolve()
626: @*/
627: PetscErrorCode  KSPSetPreSolve(KSP ksp,PetscErrorCode (*presolve)(KSP,Vec,Vec,void*),void *prectx)
628: {
631:   ksp->presolve = presolve;
632:   ksp->prectx   = prectx;
633:   return(0);
634: }

636: /*@C
637:    KSPSetPostSolve - Sets a function that is called after every KSPSolve() completes (whether it converges or not)

639:    Logically Collective on ksp

641:    Input Parameters:
642: +   ksp - the solver object
643: .   postsolve - the function to call after the solve
644: -   postctx - any context needed by the function

646:    Level: developer

648:    Calling sequence of postsolve:
649: $  func(KSP ksp,Vec rhs,Vec x,void *ctx)

651: +  ksp - the KSP context
652: .  rhs - the right-hand side vector
653: .  x - the solution vector
654: -  ctx - optional user-provided context

656: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve()
657: @*/
658: PetscErrorCode  KSPSetPostSolve(KSP ksp,PetscErrorCode (*postsolve)(KSP,Vec,Vec,void*),void *postctx)
659: {
662:   ksp->postsolve = postsolve;
663:   ksp->postctx   = postctx;
664:   return(0);
665: }

667: /*@
668:    KSPCreate - Creates the default KSP context.

670:    Collective

672:    Input Parameter:
673: .  comm - MPI communicator

675:    Output Parameter:
676: .  ksp - location to put the KSP context

678:    Notes:
679:    The default KSP type is GMRES with a restart of 30, using modified Gram-Schmidt
680:    orthogonalization.

682:    Level: beginner

684: .seealso: KSPSetUp(), KSPSolve(), KSPDestroy(), KSP
685: @*/
686: PetscErrorCode  KSPCreate(MPI_Comm comm,KSP *inksp)
687: {
688:   KSP            ksp;
690:   void           *ctx;

694:   *inksp = NULL;
695:   KSPInitializePackage();

697:   PetscHeaderCreate(ksp,KSP_CLASSID,"KSP","Krylov Method","KSP",comm,KSPDestroy,KSPView);

699:   ksp->max_it  = 10000;
700:   ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
701:   ksp->rtol    = 1.e-5;
702: #if defined(PETSC_USE_REAL_SINGLE)
703:   ksp->abstol  = 1.e-25;
704: #else
705:   ksp->abstol  = 1.e-50;
706: #endif
707:   ksp->divtol  = 1.e4;

709:   ksp->chknorm        = -1;
710:   ksp->normtype       = ksp->normtype_set = KSP_NORM_DEFAULT;
711:   ksp->rnorm          = 0.0;
712:   ksp->its            = 0;
713:   ksp->guess_zero     = PETSC_TRUE;
714:   ksp->calc_sings     = PETSC_FALSE;
715:   ksp->res_hist       = NULL;
716:   ksp->res_hist_alloc = NULL;
717:   ksp->res_hist_len   = 0;
718:   ksp->res_hist_max   = 0;
719:   ksp->res_hist_reset = PETSC_TRUE;
720:   ksp->err_hist       = NULL;
721:   ksp->err_hist_alloc = NULL;
722:   ksp->err_hist_len   = 0;
723:   ksp->err_hist_max   = 0;
724:   ksp->err_hist_reset = PETSC_TRUE;
725:   ksp->numbermonitors = 0;
726:   ksp->numberreasonviews = 0;
727:   ksp->setfromoptionscalled = 0;
728:   ksp->nmax = PETSC_DECIDE;

730:   KSPConvergedDefaultCreate(&ctx);
731:   KSPSetConvergenceTest(ksp,KSPConvergedDefault,ctx,KSPConvergedDefaultDestroy);
732:   ksp->ops->buildsolution = KSPBuildSolutionDefault;
733:   ksp->ops->buildresidual = KSPBuildResidualDefault;

735:   ksp->vec_sol    = NULL;
736:   ksp->vec_rhs    = NULL;
737:   ksp->pc         = NULL;
738:   ksp->data       = NULL;
739:   ksp->nwork      = 0;
740:   ksp->work       = NULL;
741:   ksp->reason     = KSP_CONVERGED_ITERATING;
742:   ksp->setupstage = KSP_SETUP_NEW;

744:   KSPNormSupportTableReset_Private(ksp);

746:   *inksp = ksp;
747:   return(0);
748: }

750: /*@C
751:    KSPSetType - Builds KSP for a particular solver.

753:    Logically Collective on ksp

755:    Input Parameters:
756: +  ksp      - the Krylov space context
757: -  type - a known method

759:    Options Database Key:
760: .  -ksp_type  <method> - Sets the method; use -help for a list
761:     of available methods (for instance, cg or gmres)

763:    Notes:
764:    See "petsc/include/petscksp.h" for available methods (for instance,
765:    KSPCG or KSPGMRES).

767:   Normally, it is best to use the KSPSetFromOptions() command and
768:   then set the KSP type from the options database rather than by using
769:   this routine.  Using the options database provides the user with
770:   maximum flexibility in evaluating the many different Krylov methods.
771:   The KSPSetType() routine is provided for those situations where it
772:   is necessary to set the iterative solver independently of the command
773:   line or options database.  This might be the case, for example, when
774:   the choice of iterative solver changes during the execution of the
775:   program, and the user's application is taking responsibility for
776:   choosing the appropriate method.  In other words, this routine is
777:   not for beginners.

779:   Level: intermediate

781:   Developer Note: KSPRegister() is used to add Krylov types to KSPList from which they
782:   are accessed by KSPSetType().

784: .seealso: PCSetType(), KSPType, KSPRegister(), KSPCreate()

786: @*/
787: PetscErrorCode  KSPSetType(KSP ksp, KSPType type)
788: {
789:   PetscErrorCode ierr,(*r)(KSP);
790:   PetscBool      match;


796:   PetscObjectTypeCompare((PetscObject)ksp,type,&match);
797:   if (match) return(0);

799:   PetscFunctionListFind(KSPList,type,&r);
800:   if (!r) SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested KSP type %s",type);
801:   /* Destroy the previous private KSP context */
802:   if (ksp->ops->destroy) {
803:     (*ksp->ops->destroy)(ksp);
804:     ksp->ops->destroy = NULL;
805:   }
806:   /* Reinitialize function pointers in KSPOps structure */
807:   PetscMemzero(ksp->ops,sizeof(struct _KSPOps));
808:   ksp->ops->buildsolution = KSPBuildSolutionDefault;
809:   ksp->ops->buildresidual = KSPBuildResidualDefault;
810:   KSPNormSupportTableReset_Private(ksp);
811:   ksp->setupnewmatrix     = PETSC_FALSE; // restore default (setup not called in case of new matrix)
812:   /* Call the KSPCreate_XXX routine for this particular Krylov solver */
813:   ksp->setupstage = KSP_SETUP_NEW;
814:   (*r)(ksp);
815:   PetscObjectChangeTypeName((PetscObject)ksp,type);
816:   return(0);
817: }

819: /*@C
820:    KSPGetType - Gets the KSP type as a string from the KSP object.

822:    Not Collective

824:    Input Parameter:
825: .  ksp - Krylov context

827:    Output Parameter:
828: .  name - name of KSP method

830:    Level: intermediate

832: .seealso: KSPSetType()
833: @*/
834: PetscErrorCode  KSPGetType(KSP ksp,KSPType *type)
835: {
839:   *type = ((PetscObject)ksp)->type_name;
840:   return(0);
841: }

843: /*@C
844:   KSPRegister -  Adds a method to the Krylov subspace solver package.

846:    Not Collective

848:    Input Parameters:
849: +  name_solver - name of a new user-defined solver
850: -  routine_create - routine to create method context

852:    Notes:
853:    KSPRegister() may be called multiple times to add several user-defined solvers.

855:    Sample usage:
856: .vb
857:    KSPRegister("my_solver",MySolverCreate);
858: .ve

860:    Then, your solver can be chosen with the procedural interface via
861: $     KSPSetType(ksp,"my_solver")
862:    or at runtime via the option
863: $     -ksp_type my_solver

865:    Level: advanced

867: .seealso: KSPRegisterAll()
868: @*/
869: PetscErrorCode  KSPRegister(const char sname[],PetscErrorCode (*function)(KSP))
870: {

874:   KSPInitializePackage();
875:   PetscFunctionListAdd(&KSPList,sname,function);
876:   return(0);
877: }

879: PetscErrorCode KSPMonitorMakeKey_Internal(const char name[], PetscViewerType vtype, PetscViewerFormat format, char key[])
880: {

884:   PetscStrncpy(key, name, PETSC_MAX_PATH_LEN);
885:   PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN);
886:   PetscStrlcat(key, vtype, PETSC_MAX_PATH_LEN);
887:   PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN);
888:   PetscStrlcat(key, PetscViewerFormats[format], PETSC_MAX_PATH_LEN);
889:   return(0);
890: }

892: /*@C
893:   KSPMonitorRegister -  Adds Krylov subspace solver monitor routine.

895:   Not Collective

897:   Input Parameters:
898: + name    - name of a new monitor routine
899: . vtype   - A PetscViewerType for the output
900: . format  - A PetscViewerFormat for the output
901: . monitor - Monitor routine
902: . create  - Creation routine, or NULL
903: - destroy - Destruction routine, or NULL

905:   Notes:
906:   KSPMonitorRegister() may be called multiple times to add several user-defined monitors.

908:   Sample usage:
909: .vb
910:   KSPMonitorRegister("my_monitor",PETSCVIEWERASCII,PETSC_VIEWER_ASCII_INFO_DETAIL,MyMonitor,NULL,NULL);
911: .ve

913:   Then, your monitor can be chosen with the procedural interface via
914: $     KSPMonitorSetFromOptions(ksp,"-ksp_monitor_my_monitor","my_monitor",NULL)
915:   or at runtime via the option
916: $     -ksp_monitor_my_monitor

918:    Level: advanced

920: .seealso: KSPMonitorRegisterAll()
921: @*/
922: PetscErrorCode KSPMonitorRegister(const char name[], PetscViewerType vtype, PetscViewerFormat format,
923:                                   PetscErrorCode (*monitor)(KSP, PetscInt, PetscReal, PetscViewerAndFormat *),
924:                                   PetscErrorCode (*create)(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **),
925:                                   PetscErrorCode (*destroy)(PetscViewerAndFormat **))
926: {
927:   char           key[PETSC_MAX_PATH_LEN];

931:   KSPInitializePackage();
932:   KSPMonitorMakeKey_Internal(name, vtype, format, key);
933:   PetscFunctionListAdd(&KSPMonitorList, key, monitor);
934:   if (create)  {PetscFunctionListAdd(&KSPMonitorCreateList,  key, create);}
935:   if (destroy) {PetscFunctionListAdd(&KSPMonitorDestroyList, key, destroy);}
936:   return(0);
937: }