Actual source code: snes.c

petsc-3.8.3 2017-12-09
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  2:  #include <petsc/private/snesimpl.h>
  3:  #include <petscdmshell.h>
  4:  #include <petscdraw.h>
  5:  #include <petscds.h>
  6:  #include <petscconvest.h>

  8: PetscBool         SNESRegisterAllCalled = PETSC_FALSE;
  9: PetscFunctionList SNESList              = NULL;

 11: /* Logging support */
 12: PetscClassId  SNES_CLASSID, DMSNES_CLASSID;
 13: PetscLogEvent SNES_Solve, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;

 15: /*@
 16:    SNESSetErrorIfNotConverged - Causes SNESSolve() to generate an error if the solver has not converged.

 18:    Logically Collective on SNES

 20:    Input Parameters:
 21: +  snes - iterative context obtained from SNESCreate()
 22: -  flg - PETSC_TRUE indicates you want the error generated

 24:    Options database keys:
 25: .  -snes_error_if_not_converged : this takes an optional truth value (0/1/no/yes/true/false)

 27:    Level: intermediate

 29:    Notes:
 30:     Normally PETSc continues if a linear solver fails to converge, you can call SNESGetConvergedReason() after a SNESSolve()
 31:     to determine if it has converged.

 33: .keywords: SNES, set, initial guess, nonzero

 35: .seealso: SNESGetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
 36: @*/
 37: PetscErrorCode  SNESSetErrorIfNotConverged(SNES snes,PetscBool flg)
 38: {
 42:   snes->errorifnotconverged = flg;
 43:   return(0);
 44: }

 46: /*@
 47:    SNESGetErrorIfNotConverged - Will SNESSolve() generate an error if the solver does not converge?

 49:    Not Collective

 51:    Input Parameter:
 52: .  snes - iterative context obtained from SNESCreate()

 54:    Output Parameter:
 55: .  flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE

 57:    Level: intermediate

 59: .keywords: SNES, set, initial guess, nonzero

 61: .seealso:  SNESSetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
 62: @*/
 63: PetscErrorCode  SNESGetErrorIfNotConverged(SNES snes,PetscBool  *flag)
 64: {
 68:   *flag = snes->errorifnotconverged;
 69:   return(0);
 70: }

 72: /*@
 73:     SNESSetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?

 75:    Logically Collective on SNES

 77:     Input Parameters:
 78: +   snes - the shell SNES
 79: -   flg - is the residual computed?

 81:    Level: advanced

 83: .seealso: SNESGetAlwaysComputesFinalResidual()
 84: @*/
 85: PetscErrorCode  SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
 86: {
 89:   snes->alwayscomputesfinalresidual = flg;
 90:   return(0);
 91: }

 93: /*@
 94:     SNESGetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?

 96:    Logically Collective on SNES

 98:     Input Parameter:
 99: .   snes - the shell SNES

101:     Output Parameter:
102: .   flg - is the residual computed?

104:    Level: advanced

106: .seealso: SNESSetAlwaysComputesFinalResidual()
107: @*/
108: PetscErrorCode  SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
109: {
112:   *flg = snes->alwayscomputesfinalresidual;
113:   return(0);
114: }

116: /*@
117:    SNESSetFunctionDomainError - tells SNES that the input vector to your SNESFunction is not
118:      in the functions domain. For example, negative pressure.

120:    Logically Collective on SNES

122:    Input Parameters:
123: .  snes - the SNES context

125:    Level: advanced

127: .keywords: SNES, view

129: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction
130: @*/
131: PetscErrorCode  SNESSetFunctionDomainError(SNES snes)
132: {
135:   if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates input vector is not in the function domain");
136:   snes->domainerror = PETSC_TRUE;
137:   return(0);
138: }

140: /*@
141:    SNESGetFunctionDomainError - Gets the status of the domain error after a call to SNESComputeFunction;

143:    Logically Collective on SNES

145:    Input Parameters:
146: .  snes - the SNES context

148:    Output Parameters:
149: .  domainerror - Set to PETSC_TRUE if there's a domain error; PETSC_FALSE otherwise.

151:    Level: advanced

153: .keywords: SNES, view

155: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction()
156: @*/
157: PetscErrorCode  SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
158: {
162:   *domainerror = snes->domainerror;
163:   return(0);
164: }

166: /*@C
167:   SNESLoad - Loads a SNES that has been stored in binary  with SNESView().

169:   Collective on PetscViewer

171:   Input Parameters:
172: + newdm - the newly loaded SNES, this needs to have been created with SNESCreate() or
173:            some related function before a call to SNESLoad().
174: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()

176:    Level: intermediate

178:   Notes:
179:    The type is determined by the data in the file, any type set into the SNES before this call is ignored.

181:   Notes for advanced users:
182:   Most users should not need to know the details of the binary storage
183:   format, since SNESLoad() and TSView() completely hide these details.
184:   But for anyone who's interested, the standard binary matrix storage
185:   format is
186: .vb
187:      has not yet been determined
188: .ve

190: .seealso: PetscViewerBinaryOpen(), SNESView(), MatLoad(), VecLoad()
191: @*/
192: PetscErrorCode  SNESLoad(SNES snes, PetscViewer viewer)
193: {
195:   PetscBool      isbinary;
196:   PetscInt       classid;
197:   char           type[256];
198:   KSP            ksp;
199:   DM             dm;
200:   DMSNES         dmsnes;

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

208:   PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
209:   if (classid != SNES_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONG,"Not SNES next in file");
210:   PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
211:   SNESSetType(snes, type);
212:   if (snes->ops->load) {
213:     (*snes->ops->load)(snes,viewer);
214:   }
215:   SNESGetDM(snes,&dm);
216:   DMGetDMSNES(dm,&dmsnes);
217:   DMSNESLoad(dmsnes,viewer);
218:   SNESGetKSP(snes,&ksp);
219:   KSPLoad(ksp,viewer);
220:   return(0);
221: }

223:  #include <petscdraw.h>
224: #if defined(PETSC_HAVE_SAWS)
225:  #include <petscviewersaws.h>
226: #endif
227: /*@C
228:    SNESView - Prints the SNES data structure.

230:    Collective on SNES

232:    Input Parameters:
233: +  SNES - the SNES context
234: -  viewer - visualization context

236:    Options Database Key:
237: .  -snes_view - Calls SNESView() at end of SNESSolve()

239:    Notes:
240:    The available visualization contexts include
241: +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
242: -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
243:          output where only the first processor opens
244:          the file.  All other processors send their
245:          data to the first processor to print.

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

250:    Level: beginner

252: .keywords: SNES, view

254: .seealso: PetscViewerASCIIOpen()
255: @*/
256: PetscErrorCode  SNESView(SNES snes,PetscViewer viewer)
257: {
258:   SNESKSPEW      *kctx;
260:   KSP            ksp;
261:   SNESLineSearch linesearch;
262:   PetscBool      iascii,isstring,isbinary,isdraw;
263:   DMSNES         dmsnes;
264: #if defined(PETSC_HAVE_SAWS)
265:   PetscBool      issaws;
266: #endif

270:   if (!viewer) {
271:     PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
272:   }

276:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
277:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
278:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
279:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
280: #if defined(PETSC_HAVE_SAWS)
281:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
282: #endif
283:   if (iascii) {
284:     SNESNormSchedule normschedule;

286:     PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
287:     if (!snes->setupcalled) {
288:       PetscViewerASCIIPrintf(viewer,"  SNES has not been set up so information may be incomplete\n");
289:     }
290:     if (snes->ops->view) {
291:       PetscViewerASCIIPushTab(viewer);
292:       (*snes->ops->view)(snes,viewer);
293:       PetscViewerASCIIPopTab(viewer);
294:     }
295:     PetscViewerASCIIPrintf(viewer,"  maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
296:     PetscViewerASCIIPrintf(viewer,"  tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
297:     if (snes->usesksp) {
298:       PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",snes->linear_its);
299:     }
300:     PetscViewerASCIIPrintf(viewer,"  total number of function evaluations=%D\n",snes->nfuncs);
301:     SNESGetNormSchedule(snes, &normschedule);
302:     if (normschedule > 0) {PetscViewerASCIIPrintf(viewer,"  norm schedule %s\n",SNESNormSchedules[normschedule]);}
303:     if (snes->gridsequence) {
304:       PetscViewerASCIIPrintf(viewer,"  total number of grid sequence refinements=%D\n",snes->gridsequence);
305:     }
306:     if (snes->ksp_ewconv) {
307:       kctx = (SNESKSPEW*)snes->kspconvctx;
308:       if (kctx) {
309:         PetscViewerASCIIPrintf(viewer,"  Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
310:         PetscViewerASCIIPrintf(viewer,"    rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
311:         PetscViewerASCIIPrintf(viewer,"    gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
312:       }
313:     }
314:     if (snes->lagpreconditioner == -1) {
315:       PetscViewerASCIIPrintf(viewer,"  Preconditioned is never rebuilt\n");
316:     } else if (snes->lagpreconditioner > 1) {
317:       PetscViewerASCIIPrintf(viewer,"  Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
318:     }
319:     if (snes->lagjacobian == -1) {
320:       PetscViewerASCIIPrintf(viewer,"  Jacobian is never rebuilt\n");
321:     } else if (snes->lagjacobian > 1) {
322:       PetscViewerASCIIPrintf(viewer,"  Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
323:     }
324:   } else if (isstring) {
325:     const char *type;
326:     SNESGetType(snes,&type);
327:     PetscViewerStringSPrintf(viewer," %-3.3s",type);
328:   } else if (isbinary) {
329:     PetscInt    classid = SNES_FILE_CLASSID;
330:     MPI_Comm    comm;
331:     PetscMPIInt rank;
332:     char        type[256];

334:     PetscObjectGetComm((PetscObject)snes,&comm);
335:     MPI_Comm_rank(comm,&rank);
336:     if (!rank) {
337:       PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
338:       PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
339:       PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR,PETSC_FALSE);
340:     }
341:     if (snes->ops->view) {
342:       (*snes->ops->view)(snes,viewer);
343:     }
344:   } else if (isdraw) {
345:     PetscDraw draw;
346:     char      str[36];
347:     PetscReal x,y,bottom,h;

349:     PetscViewerDrawGetDraw(viewer,0,&draw);
350:     PetscDrawGetCurrentPoint(draw,&x,&y);
351:     PetscStrcpy(str,"SNES: ");
352:     PetscStrcat(str,((PetscObject)snes)->type_name);
353:     PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
354:     bottom = y - h;
355:     PetscDrawPushCurrentPoint(draw,x,bottom);
356:     if (snes->ops->view) {
357:       (*snes->ops->view)(snes,viewer);
358:     }
359: #if defined(PETSC_HAVE_SAWS)
360:   } else if (issaws) {
361:     PetscMPIInt rank;
362:     const char *name;

364:     PetscObjectGetName((PetscObject)snes,&name);
365:     MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
366:     if (!((PetscObject)snes)->amsmem && !rank) {
367:       char       dir[1024];

369:       PetscObjectViewSAWs((PetscObject)snes,viewer);
370:       PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
371:       PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
372:       if (!snes->conv_hist) {
373:         SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
374:       }
375:       PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
376:       PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
377:     }
378: #endif
379:   }
380:   if (snes->linesearch) {
381:     PetscViewerASCIIPushTab(viewer);
382:     SNESGetLineSearch(snes, &linesearch);
383:     SNESLineSearchView(linesearch, viewer);
384:     PetscViewerASCIIPopTab(viewer);
385:   }
386:   if (snes->npc && snes->usesnpc) {
387:     PetscViewerASCIIPushTab(viewer);
388:     SNESView(snes->npc, viewer);
389:     PetscViewerASCIIPopTab(viewer);
390:   }
391:   PetscViewerASCIIPushTab(viewer);
392:   DMGetDMSNES(snes->dm,&dmsnes);
393:   DMSNESView(dmsnes, viewer);
394:   PetscViewerASCIIPopTab(viewer);
395:   if (snes->usesksp) {
396:     SNESGetKSP(snes,&ksp);
397:     PetscViewerASCIIPushTab(viewer);
398:     KSPView(ksp,viewer);
399:     PetscViewerASCIIPopTab(viewer);
400:   }
401:   if (isdraw) {
402:     PetscDraw draw;
403:     PetscViewerDrawGetDraw(viewer,0,&draw);
404:     PetscDrawPopCurrentPoint(draw);
405:   }
406:   return(0);
407: }

409: /*
410:   We retain a list of functions that also take SNES command
411:   line options. These are called at the end SNESSetFromOptions()
412: */
413: #define MAXSETFROMOPTIONS 5
414: static PetscInt numberofsetfromoptions;
415: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);

417: /*@C
418:   SNESAddOptionsChecker - Adds an additional function to check for SNES options.

420:   Not Collective

422:   Input Parameter:
423: . snescheck - function that checks for options

425:   Level: developer

427: .seealso: SNESSetFromOptions()
428: @*/
429: PetscErrorCode  SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
430: {
432:   if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
433:   othersetfromoptions[numberofsetfromoptions++] = snescheck;
434:   return(0);
435: }

437: extern PetscErrorCode  SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);

439: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
440: {
441:   Mat            J;
442:   KSP            ksp;
443:   PC             pc;
444:   PetscBool      match;
446:   MatNullSpace   nullsp;


451:   if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
452:     Mat A = snes->jacobian, B = snes->jacobian_pre;
453:     MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
454:   }

456:   if (version == 1) {
457:     MatCreateSNESMF(snes,&J);
458:     MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
459:     MatSetFromOptions(J);
460:   } else if (version == 2) {
461:     if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
462: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
463:     SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
464: #else
465:     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
466: #endif
467:   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");

469:   /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
470:   if (snes->jacobian) {
471:     MatGetNullSpace(snes->jacobian,&nullsp);
472:     if (nullsp) {
473:       MatSetNullSpace(J,nullsp);
474:     }
475:   }

477:   PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
478:   if (hasOperator) {

480:     /* This version replaces the user provided Jacobian matrix with a
481:        matrix-free version but still employs the user-provided preconditioner matrix. */
482:     SNESSetJacobian(snes,J,0,0,0);
483:   } else {
484:     /* This version replaces both the user-provided Jacobian and the user-
485:      provided preconditioner Jacobian with the default matrix free version. */
486:     if ((snes->npcside== PC_LEFT) && snes->npc) {
487:       if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
488:     } else {
489:       SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
490:     }
491:     /* Force no preconditioner */
492:     SNESGetKSP(snes,&ksp);
493:     KSPGetPC(ksp,&pc);
494:     PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
495:     if (!match) {
496:       PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
497:       PCSetType(pc,PCNONE);
498:     }
499:   }
500:   MatDestroy(&J);
501:   return(0);
502: }

504: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
505: {
506:   SNES           snes = (SNES)ctx;
508:   Vec            Xfine,Xfine_named = NULL,Xcoarse;

511:   if (PetscLogPrintInfo) {
512:     PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
513:     DMGetRefineLevel(dmfine,&finelevel);
514:     DMGetCoarsenLevel(dmfine,&fineclevel);
515:     DMGetRefineLevel(dmcoarse,&coarselevel);
516:     DMGetCoarsenLevel(dmcoarse,&coarseclevel);
517:     PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
518:   }
519:   if (dmfine == snes->dm) Xfine = snes->vec_sol;
520:   else {
521:     DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
522:     Xfine = Xfine_named;
523:   }
524:   DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
525:   if (Inject) {
526:     MatRestrict(Inject,Xfine,Xcoarse);
527:   } else {
528:     MatRestrict(Restrict,Xfine,Xcoarse);
529:     VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
530:   }
531:   DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
532:   if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
533:   return(0);
534: }

536: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
537: {

541:   DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
542:   return(0);
543: }

545: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
546:  * safely call SNESGetDM() in their residual evaluation routine. */
547: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
548: {
549:   SNES           snes = (SNES)ctx;
551:   Mat            Asave = A,Bsave = B;
552:   Vec            X,Xnamed = NULL;
553:   DM             dmsave;
554:   void           *ctxsave;
555:   PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);

558:   dmsave = snes->dm;
559:   KSPGetDM(ksp,&snes->dm);
560:   if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
561:   else {                                     /* We are on a coarser level, this vec was initialized using a DM restrict hook */
562:     DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
563:     X    = Xnamed;
564:     SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
565:     /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
566:     if (jac == SNESComputeJacobianDefaultColor) {
567:       SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
568:     }
569:   }
570:   /* put the previous context back */

572:   SNESComputeJacobian(snes,X,A,B);
573:   if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
574:     SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
575:   }

577:   if (A != Asave || B != Bsave) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_SUP,"No support for changing matrices at this time");
578:   if (Xnamed) {
579:     DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
580:   }
581:   snes->dm = dmsave;
582:   return(0);
583: }

585: /*@
586:    SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()

588:    Collective

590:    Input Arguments:
591: .  snes - snes to configure

593:    Level: developer

595: .seealso: SNESSetUp()
596: @*/
597: PetscErrorCode SNESSetUpMatrices(SNES snes)
598: {
600:   DM             dm;
601:   DMSNES         sdm;

604:   SNESGetDM(snes,&dm);
605:   DMGetDMSNES(dm,&sdm);
606:   if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
607:   else if (!snes->jacobian && snes->mf) {
608:     Mat  J;
609:     void *functx;
610:     MatCreateSNESMF(snes,&J);
611:     MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
612:     MatSetFromOptions(J);
613:     SNESGetFunction(snes,NULL,NULL,&functx);
614:     SNESSetJacobian(snes,J,J,0,0);
615:     MatDestroy(&J);
616:   } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
617:     Mat J,B;
618:     MatCreateSNESMF(snes,&J);
619:     MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
620:     MatSetFromOptions(J);
621:     DMCreateMatrix(snes->dm,&B);
622:     /* sdm->computejacobian was already set to reach here */
623:     SNESSetJacobian(snes,J,B,NULL,NULL);
624:     MatDestroy(&J);
625:     MatDestroy(&B);
626:   } else if (!snes->jacobian_pre) {
627:     PetscDS   prob;
628:     Mat       J, B;
629:     PetscBool hasPrec = PETSC_FALSE;

631:     J    = snes->jacobian;
632:     DMGetDS(dm, &prob);
633:     if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
634:     if (J)            {PetscObjectReference((PetscObject) J);}
635:     else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
636:     DMCreateMatrix(snes->dm, &B);
637:     SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
638:     MatDestroy(&J);
639:     MatDestroy(&B);
640:   }
641:   {
642:     KSP ksp;
643:     SNESGetKSP(snes,&ksp);
644:     KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
645:     DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
646:   }
647:   return(0);
648: }

650: /*@C
651:    SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user

653:    Collective on SNES

655:    Input Parameters:
656: +  snes - SNES object you wish to monitor
657: .  name - the monitor type one is seeking
658: .  help - message indicating what monitoring is done
659: .  manual - manual page for the monitor
660: .  monitor - the monitor function
661: -  monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the SNES or PetscViewer objects

663:    Level: developer

665: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
666:           PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
667:           PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
668:           PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
669:           PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
670:           PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
671:           PetscOptionsFList(), PetscOptionsEList()
672: @*/
673: PetscErrorCode  SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
674: {
675:   PetscErrorCode    ierr;
676:   PetscViewer       viewer;
677:   PetscViewerFormat format;
678:   PetscBool         flg;

681:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
682:   if (flg) {
683:     PetscViewerAndFormat *vf;
684:     PetscViewerAndFormatCreate(viewer,format,&vf);
685:     PetscObjectDereference((PetscObject)viewer);
686:     if (monitorsetup) {
687:       (*monitorsetup)(snes,vf);
688:     }
689:     SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
690:   }
691:   return(0);
692: }

694: /*@
695:    SNESSetFromOptions - Sets various SNES and KSP parameters from user options.

697:    Collective on SNES

699:    Input Parameter:
700: .  snes - the SNES context

702:    Options Database Keys:
703: +  -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
704: .  -snes_stol - convergence tolerance in terms of the norm
705:                 of the change in the solution between steps
706: .  -snes_atol <abstol> - absolute tolerance of residual norm
707: .  -snes_rtol <rtol> - relative decrease in tolerance norm from initial
708: .  -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
709: .  -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
710: .  -snes_max_it <max_it> - maximum number of iterations
711: .  -snes_max_funcs <max_funcs> - maximum number of function evaluations
712: .  -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
713: .  -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
714: .  -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
715: .  -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
716: .  -snes_trtol <trtol> - trust region tolerance
717: .  -snes_no_convergence_test - skip convergence test in nonlinear
718:                                solver; hence iterations will continue until max_it
719:                                or some other criterion is reached. Saves expense
720:                                of convergence test
721: .  -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
722: .  -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
723: .  -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
724: .  -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
725: .  -snes_monitor_lg_residualnorm - plots residual norm at each iteration
726: .  -snes_monitor_lg_range - plots residual norm at each iteration
727: .  -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
728: .  -snes_fd_color - use finite differences with coloring to compute Jacobian
729: .  -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
730: -  -snes_converged_reason - print the reason for convergence/divergence after each solve

732:     Options Database for Eisenstat-Walker method:
733: +  -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
734: .  -snes_ksp_ew_version ver - version of  Eisenstat-Walker method
735: .  -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
736: .  -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
737: .  -snes_ksp_ew_gamma <gamma> - Sets gamma
738: .  -snes_ksp_ew_alpha <alpha> - Sets alpha
739: .  -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
740: -  -snes_ksp_ew_threshold <threshold> - Sets threshold

742:    Notes:
743:    To see all options, run your program with the -help option or consult
744:    Users-Manual: ch_snes

746:    Level: beginner

748: .keywords: SNES, nonlinear, set, options, database

750: .seealso: SNESSetOptionsPrefix()
751: @*/
752: PetscErrorCode  SNESSetFromOptions(SNES snes)
753: {
754:   PetscBool      flg,pcset,persist,set;
755:   PetscInt       i,indx,lag,grids;
756:   const char     *deft        = SNESNEWTONLS;
757:   const char     *convtests[] = {"default","skip"};
758:   SNESKSPEW      *kctx        = NULL;
759:   char           type[256], monfilename[PETSC_MAX_PATH_LEN];
761:   PCSide         pcside;
762:   const char     *optionsprefix;

766:   SNESRegisterAll();
767:   PetscObjectOptionsBegin((PetscObject)snes);
768:   if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
769:   PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
770:   if (flg) {
771:     SNESSetType(snes,type);
772:   } else if (!((PetscObject)snes)->type_name) {
773:     SNESSetType(snes,deft);
774:   }
775:   PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
776:   PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);

778:   PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
779:   PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
780:   PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
781:   PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
782:   PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
783:   PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
784:   PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
785:   PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESForceIteration",snes->forceiteration,&snes->forceiteration,NULL);

787:   PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
788:   if (flg) {
789:     SNESSetLagPreconditioner(snes,lag);
790:   }
791:   PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
792:   if (flg) {
793:     SNESSetLagPreconditionerPersists(snes,persist);
794:   }
795:   PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
796:   if (flg) {
797:     SNESSetLagJacobian(snes,lag);
798:   }
799:   PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
800:   if (flg) {
801:     SNESSetLagJacobianPersists(snes,persist);
802:   }

804:   PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
805:   if (flg) {
806:     SNESSetGridSequence(snes,grids);
807:   }

809:   PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
810:   if (flg) {
811:     switch (indx) {
812:     case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
813:     case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL);    break;
814:     }
815:   }

817:   PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
818:   if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }

820:   PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
821:   if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }

823:   kctx = (SNESKSPEW*)snes->kspconvctx;

825:   PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);

827:   PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
828:   PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
829:   PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
830:   PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
831:   PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
832:   PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
833:   PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);

835:   flg  = PETSC_FALSE;
836:   PetscOptionsBool("-snes_check_jacobian","Check each Jacobian with a differenced one","SNESUpdateCheckJacobian",flg,&flg,&set);
837:   if (set && flg) {
838:     SNESSetUpdate(snes,SNESUpdateCheckJacobian);
839:   }

841:   flg  = PETSC_FALSE;
842:   PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
843:   if (set && flg) {SNESMonitorCancel(snes);}

845:   SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
846:   SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
847:   SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);

849:   SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
850:   SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
851:   SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
852:   SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
853:   SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
854:   SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
855:   SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);

857:   PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
858:   if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}


861:   flg  = PETSC_FALSE;
862:   PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
863:   if (flg) {
864:     PetscDrawLG ctx;

866:     SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
867:     SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
868:   }
869:   flg  = PETSC_FALSE;
870:   PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
871:   if (flg) {
872:     PetscViewer ctx;

874:     PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
875:     SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
876:   }



880:   flg  = PETSC_FALSE;
881:   PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
882:   if (flg) {
883:     void    *functx;
884:     DM      dm;
885:     DMSNES  sdm;
886:     SNESGetDM(snes,&dm);
887:     DMGetDMSNES(dm,&sdm);
888:     sdm->jacobianctx = NULL;
889:     SNESGetFunction(snes,NULL,NULL,&functx);
890:     SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
891:     PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
892:   }

894:   flg  = PETSC_FALSE;
895:   PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
896:   if (flg) {
897:     SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
898:   }

900:   flg  = PETSC_FALSE;
901:   PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
902:   if (flg) {
903:     DM             dm;
904:     DMSNES         sdm;
905:     SNESGetDM(snes,&dm);
906:     DMGetDMSNES(dm,&sdm);
907:     sdm->jacobianctx = NULL;
908:     SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
909:     PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
910:   }

912:   flg  = PETSC_FALSE;
913:   PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
914:   if (flg && snes->mf_operator) {
915:     snes->mf_operator = PETSC_TRUE;
916:     snes->mf          = PETSC_TRUE;
917:   }
918:   flg  = PETSC_FALSE;
919:   PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
920:   if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
921:   PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);

923:   flg  = PETSC_FALSE;
924:   SNESGetNPCSide(snes,&pcside);
925:   PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
926:   if (flg) {SNESSetNPCSide(snes,pcside);}

928: #if defined(PETSC_HAVE_SAWS)
929:   /*
930:     Publish convergence information using SAWs
931:   */
932:   flg  = PETSC_FALSE;
933:   PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
934:   if (flg) {
935:     void *ctx;
936:     SNESMonitorSAWsCreate(snes,&ctx);
937:     SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
938:   }
939: #endif
940: #if defined(PETSC_HAVE_SAWS)
941:   {
942:   PetscBool set;
943:   flg  = PETSC_FALSE;
944:   PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
945:   if (set) {
946:     PetscObjectSAWsSetBlock((PetscObject)snes,flg);
947:   }
948:   }
949: #endif

951:   for (i = 0; i < numberofsetfromoptions; i++) {
952:     (*othersetfromoptions[i])(snes);
953:   }

955:   if (snes->ops->setfromoptions) {
956:     (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
957:   }

959:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
960:   PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
961:   PetscOptionsEnd();

963:   if (!snes->linesearch) {
964:     SNESGetLineSearch(snes, &snes->linesearch);
965:   }
966:   SNESLineSearchSetFromOptions(snes->linesearch);

968:   if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
969:   KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
970:   KSPSetFromOptions(snes->ksp);

972:   /* if someone has set the SNES NPC type, create it. */
973:   SNESGetOptionsPrefix(snes, &optionsprefix);
974:   PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
975:   if (pcset && (!snes->npc)) {
976:     SNESGetNPC(snes, &snes->npc);
977:   }
978:   return(0);
979: }

981: /*@C
982:    SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
983:    the nonlinear solvers.

985:    Logically Collective on SNES

987:    Input Parameters:
988: +  snes - the SNES context
989: .  compute - function to compute the context
990: -  destroy - function to destroy the context

992:    Level: intermediate

994:    Notes:
995:    This function is currently not available from Fortran.

997: .keywords: SNES, nonlinear, set, application, context

999: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1000: @*/
1001: PetscErrorCode  SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1002: {
1005:   snes->ops->usercompute = compute;
1006:   snes->ops->userdestroy = destroy;
1007:   return(0);
1008: }

1010: /*@
1011:    SNESSetApplicationContext - Sets the optional user-defined context for
1012:    the nonlinear solvers.

1014:    Logically Collective on SNES

1016:    Input Parameters:
1017: +  snes - the SNES context
1018: -  usrP - optional user context

1020:    Level: intermediate

1022:    Fortran Notes: To use this from Fortran you must write a Fortran interface definition for this
1023:     function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.

1025: .keywords: SNES, nonlinear, set, application, context

1027: .seealso: SNESGetApplicationContext()
1028: @*/
1029: PetscErrorCode  SNESSetApplicationContext(SNES snes,void *usrP)
1030: {
1032:   KSP            ksp;

1036:   SNESGetKSP(snes,&ksp);
1037:   KSPSetApplicationContext(ksp,usrP);
1038:   snes->user = usrP;
1039:   return(0);
1040: }

1042: /*@
1043:    SNESGetApplicationContext - Gets the user-defined context for the
1044:    nonlinear solvers.

1046:    Not Collective

1048:    Input Parameter:
1049: .  snes - SNES context

1051:    Output Parameter:
1052: .  usrP - user context

1054:    Fortran Notes: To use this from Fortran you must write a Fortran interface definition for this
1055:     function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.

1057:    Level: intermediate

1059: .keywords: SNES, nonlinear, get, application, context

1061: .seealso: SNESSetApplicationContext()
1062: @*/
1063: PetscErrorCode  SNESGetApplicationContext(SNES snes,void *usrP)
1064: {
1067:   *(void**)usrP = snes->user;
1068:   return(0);
1069: }

1071: /*@
1072:    SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply
1073:                           the Jacobian.

1075:    Collective on SNES

1077:    Input Parameters:
1078: +  snes - SNES context
1079: .  mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1080: -  mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used

1082:    Options Database:
1083: + -snes_mf - use matrix free for both the mat and pmat operator
1084: - -snes_mf_operator - use matrix free only for the mat operator

1086:    Level: intermediate

1088: .keywords: SNES, nonlinear, get, iteration, number,

1090: .seealso:   SNESGetUseMatrixFree(), MatCreateSNESMF()
1091: @*/
1092: PetscErrorCode  SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1093: {
1098:   if (mf && !mf_operator) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"If using mf must also use mf_operator");
1099:   snes->mf          = mf;
1100:   snes->mf_operator = mf_operator;
1101:   return(0);
1102: }

1104: /*@
1105:    SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply
1106:                           the Jacobian.

1108:    Collective on SNES

1110:    Input Parameter:
1111: .  snes - SNES context

1113:    Output Parameters:
1114: +  mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1115: -  mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used

1117:    Options Database:
1118: + -snes_mf - use matrix free for both the mat and pmat operator
1119: - -snes_mf_operator - use matrix free only for the mat operator

1121:    Level: intermediate

1123: .keywords: SNES, nonlinear, get, iteration, number,

1125: .seealso:   SNESSetUseMatrixFree(), MatCreateSNESMF()
1126: @*/
1127: PetscErrorCode  SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1128: {
1131:   if (mf)          *mf          = snes->mf;
1132:   if (mf_operator) *mf_operator = snes->mf_operator;
1133:   return(0);
1134: }

1136: /*@
1137:    SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1138:    at this time.

1140:    Not Collective

1142:    Input Parameter:
1143: .  snes - SNES context

1145:    Output Parameter:
1146: .  iter - iteration number

1148:    Notes:
1149:    For example, during the computation of iteration 2 this would return 1.

1151:    This is useful for using lagged Jacobians (where one does not recompute the
1152:    Jacobian at each SNES iteration). For example, the code
1153: .vb
1154:       SNESGetIterationNumber(snes,&it);
1155:       if (!(it % 2)) {
1156:         [compute Jacobian here]
1157:       }
1158: .ve
1159:    can be used in your ComputeJacobian() function to cause the Jacobian to be
1160:    recomputed every second SNES iteration.

1162:    Level: intermediate

1164: .keywords: SNES, nonlinear, get, iteration, number,

1166: .seealso:   SNESGetLinearSolveIterations()
1167: @*/
1168: PetscErrorCode  SNESGetIterationNumber(SNES snes,PetscInt *iter)
1169: {
1173:   *iter = snes->iter;
1174:   return(0);
1175: }

1177: /*@
1178:    SNESSetIterationNumber - Sets the current iteration number.

1180:    Not Collective

1182:    Input Parameter:
1183: .  snes - SNES context
1184: .  iter - iteration number

1186:    Level: developer

1188: .keywords: SNES, nonlinear, set, iteration, number,

1190: .seealso:   SNESGetLinearSolveIterations()
1191: @*/
1192: PetscErrorCode  SNESSetIterationNumber(SNES snes,PetscInt iter)
1193: {

1198:   PetscObjectSAWsTakeAccess((PetscObject)snes);
1199:   snes->iter = iter;
1200:   PetscObjectSAWsGrantAccess((PetscObject)snes);
1201:   return(0);
1202: }

1204: /*@
1205:    SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1206:    attempted by the nonlinear solver.

1208:    Not Collective

1210:    Input Parameter:
1211: .  snes - SNES context

1213:    Output Parameter:
1214: .  nfails - number of unsuccessful steps attempted

1216:    Notes:
1217:    This counter is reset to zero for each successive call to SNESSolve().

1219:    Level: intermediate

1221: .keywords: SNES, nonlinear, get, number, unsuccessful, steps

1223: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1224:           SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1225: @*/
1226: PetscErrorCode  SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1227: {
1231:   *nfails = snes->numFailures;
1232:   return(0);
1233: }

1235: /*@
1236:    SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1237:    attempted by the nonlinear solver before it gives up.

1239:    Not Collective

1241:    Input Parameters:
1242: +  snes     - SNES context
1243: -  maxFails - maximum of unsuccessful steps

1245:    Level: intermediate

1247: .keywords: SNES, nonlinear, set, maximum, unsuccessful, steps

1249: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1250:           SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1251: @*/
1252: PetscErrorCode  SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1253: {
1256:   snes->maxFailures = maxFails;
1257:   return(0);
1258: }

1260: /*@
1261:    SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1262:    attempted by the nonlinear solver before it gives up.

1264:    Not Collective

1266:    Input Parameter:
1267: .  snes     - SNES context

1269:    Output Parameter:
1270: .  maxFails - maximum of unsuccessful steps

1272:    Level: intermediate

1274: .keywords: SNES, nonlinear, get, maximum, unsuccessful, steps

1276: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1277:           SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()

1279: @*/
1280: PetscErrorCode  SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1281: {
1285:   *maxFails = snes->maxFailures;
1286:   return(0);
1287: }

1289: /*@
1290:    SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1291:      done by SNES.

1293:    Not Collective

1295:    Input Parameter:
1296: .  snes     - SNES context

1298:    Output Parameter:
1299: .  nfuncs - number of evaluations

1301:    Level: intermediate

1303:    Notes: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.

1305: .keywords: SNES, nonlinear, get, maximum, unsuccessful, steps

1307: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1308: @*/
1309: PetscErrorCode  SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1310: {
1314:   *nfuncs = snes->nfuncs;
1315:   return(0);
1316: }

1318: /*@
1319:    SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1320:    linear solvers.

1322:    Not Collective

1324:    Input Parameter:
1325: .  snes - SNES context

1327:    Output Parameter:
1328: .  nfails - number of failed solves

1330:    Level: intermediate

1332:    Options Database Keys:
1333: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated

1335:    Notes:
1336:    This counter is reset to zero for each successive call to SNESSolve().

1338: .keywords: SNES, nonlinear, get, number, unsuccessful, steps

1340: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1341: @*/
1342: PetscErrorCode  SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1343: {
1347:   *nfails = snes->numLinearSolveFailures;
1348:   return(0);
1349: }

1351: /*@
1352:    SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1353:    allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE

1355:    Logically Collective on SNES

1357:    Input Parameters:
1358: +  snes     - SNES context
1359: -  maxFails - maximum allowed linear solve failures

1361:    Level: intermediate

1363:    Options Database Keys:
1364: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated

1366:    Notes: By default this is 0; that is SNES returns on the first failed linear solve

1368: .keywords: SNES, nonlinear, set, maximum, unsuccessful, steps

1370: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1371: @*/
1372: PetscErrorCode  SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1373: {
1377:   snes->maxLinearSolveFailures = maxFails;
1378:   return(0);
1379: }

1381: /*@
1382:    SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1383:      are allowed before SNES terminates

1385:    Not Collective

1387:    Input Parameter:
1388: .  snes     - SNES context

1390:    Output Parameter:
1391: .  maxFails - maximum of unsuccessful solves allowed

1393:    Level: intermediate

1395:    Notes: By default this is 1; that is SNES returns on the first failed linear solve

1397: .keywords: SNES, nonlinear, get, maximum, unsuccessful, steps

1399: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1400: @*/
1401: PetscErrorCode  SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1402: {
1406:   *maxFails = snes->maxLinearSolveFailures;
1407:   return(0);
1408: }

1410: /*@
1411:    SNESGetLinearSolveIterations - Gets the total number of linear iterations
1412:    used by the nonlinear solver.

1414:    Not Collective

1416:    Input Parameter:
1417: .  snes - SNES context

1419:    Output Parameter:
1420: .  lits - number of linear iterations

1422:    Notes:
1423:    This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.

1425:    If the linear solver fails inside the SNESSolve() the iterations for that call to the linear solver are not included. If you wish to count them 
1426:    then call KSPGetIterationNumber() after the failed solve.

1428:    Level: intermediate

1430: .keywords: SNES, nonlinear, get, number, linear, iterations

1432: .seealso:  SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1433: @*/
1434: PetscErrorCode  SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1435: {
1439:   *lits = snes->linear_its;
1440:   return(0);
1441: }

1443: /*@
1444:    SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1445:    are reset every time SNESSolve() is called.

1447:    Logically Collective on SNES

1449:    Input Parameter:
1450: +  snes - SNES context
1451: -  reset - whether to reset the counters or not

1453:    Notes:
1454:    This defaults to PETSC_TRUE

1456:    Level: developer

1458: .keywords: SNES, nonlinear, set, reset, number, linear, iterations

1460: .seealso:  SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1461: @*/
1462: PetscErrorCode  SNESSetCountersReset(SNES snes,PetscBool reset)
1463: {
1467:   snes->counters_reset = reset;
1468:   return(0);
1469: }


1472: /*@
1473:    SNESSetKSP - Sets a KSP context for the SNES object to use

1475:    Not Collective, but the SNES and KSP objects must live on the same MPI_Comm

1477:    Input Parameters:
1478: +  snes - the SNES context
1479: -  ksp - the KSP context

1481:    Notes:
1482:    The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1483:    so this routine is rarely needed.

1485:    The KSP object that is already in the SNES object has its reference count
1486:    decreased by one.

1488:    Level: developer

1490: .keywords: SNES, nonlinear, get, KSP, context

1492: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1493: @*/
1494: PetscErrorCode  SNESSetKSP(SNES snes,KSP ksp)
1495: {

1502:   PetscObjectReference((PetscObject)ksp);
1503:   if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1504:   snes->ksp = ksp;
1505:   return(0);
1506: }

1508: /* -----------------------------------------------------------*/
1509: /*@
1510:    SNESCreate - Creates a nonlinear solver context.

1512:    Collective on MPI_Comm

1514:    Input Parameters:
1515: .  comm - MPI communicator

1517:    Output Parameter:
1518: .  outsnes - the new SNES context

1520:    Options Database Keys:
1521: +   -snes_mf - Activates default matrix-free Jacobian-vector products,
1522:                and no preconditioning matrix
1523: .   -snes_mf_operator - Activates default matrix-free Jacobian-vector
1524:                products, and a user-provided preconditioning matrix
1525:                as set by SNESSetJacobian()
1526: -   -snes_fd - Uses (slow!) finite differences to compute Jacobian

1528:    Level: beginner

1530:    Developer Notes: SNES always creates a KSP object even though many SNES methods do not use it. This is
1531:                     unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1532:                     particular method does use KSP and regulates if the information about the KSP is printed
1533:                     in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1534:                     by help messages about meaningless SNES options.

1536:                     SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1537:                     be fixed.

1539: .keywords: SNES, nonlinear, create, context

1541: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()

1543: @*/
1544: PetscErrorCode  SNESCreate(MPI_Comm comm,SNES *outsnes)
1545: {
1547:   SNES           snes;
1548:   SNESKSPEW      *kctx;

1552:   *outsnes = NULL;
1553:   SNESInitializePackage();

1555:   PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);

1557:   snes->ops->converged    = SNESConvergedDefault;
1558:   snes->usesksp           = PETSC_TRUE;
1559:   snes->tolerancesset     = PETSC_FALSE;
1560:   snes->max_its           = 50;
1561:   snes->max_funcs         = 10000;
1562:   snes->norm              = 0.0;
1563:   snes->normschedule      = SNES_NORM_ALWAYS;
1564:   snes->functype          = SNES_FUNCTION_DEFAULT;
1565: #if defined(PETSC_USE_REAL_SINGLE)
1566:   snes->rtol              = 1.e-5;
1567: #else
1568:   snes->rtol              = 1.e-8;
1569: #endif
1570:   snes->ttol              = 0.0;
1571: #if defined(PETSC_USE_REAL_SINGLE)
1572:   snes->abstol            = 1.e-25;
1573: #else
1574:   snes->abstol            = 1.e-50;
1575: #endif
1576: #if defined(PETSC_USE_REAL_SINGLE)
1577:   snes->stol              = 1.e-5;
1578: #else
1579:   snes->stol              = 1.e-8;
1580: #endif
1581: #if defined(PETSC_USE_REAL_SINGLE)
1582:   snes->deltatol          = 1.e-6;
1583: #else
1584:   snes->deltatol          = 1.e-12;
1585: #endif
1586:   snes->divtol            = 1.e4;
1587:   snes->rnorm0            = 0;
1588:   snes->nfuncs            = 0;
1589:   snes->numFailures       = 0;
1590:   snes->maxFailures       = 1;
1591:   snes->linear_its        = 0;
1592:   snes->lagjacobian       = 1;
1593:   snes->jac_iter          = 0;
1594:   snes->lagjac_persist    = PETSC_FALSE;
1595:   snes->lagpreconditioner = 1;
1596:   snes->pre_iter          = 0;
1597:   snes->lagpre_persist    = PETSC_FALSE;
1598:   snes->numbermonitors    = 0;
1599:   snes->data              = 0;
1600:   snes->setupcalled       = PETSC_FALSE;
1601:   snes->ksp_ewconv        = PETSC_FALSE;
1602:   snes->nwork             = 0;
1603:   snes->work              = 0;
1604:   snes->nvwork            = 0;
1605:   snes->vwork             = 0;
1606:   snes->conv_hist_len     = 0;
1607:   snes->conv_hist_max     = 0;
1608:   snes->conv_hist         = NULL;
1609:   snes->conv_hist_its     = NULL;
1610:   snes->conv_hist_reset   = PETSC_TRUE;
1611:   snes->counters_reset    = PETSC_TRUE;
1612:   snes->vec_func_init_set = PETSC_FALSE;
1613:   snes->reason            = SNES_CONVERGED_ITERATING;
1614:   snes->npcside           = PC_RIGHT;

1616:   snes->mf          = PETSC_FALSE;
1617:   snes->mf_operator = PETSC_FALSE;
1618:   snes->mf_version  = 1;

1620:   snes->numLinearSolveFailures = 0;
1621:   snes->maxLinearSolveFailures = 1;

1623:   snes->vizerotolerance = 1.e-8;

1625:   /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1626:   snes->alwayscomputesfinalresidual = PETSC_FALSE;

1628:   /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1629:   PetscNewLog(snes,&kctx);

1631:   snes->kspconvctx  = (void*)kctx;
1632:   kctx->version     = 2;
1633:   kctx->rtol_0      = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1634:                              this was too large for some test cases */
1635:   kctx->rtol_last   = 0.0;
1636:   kctx->rtol_max    = .9;
1637:   kctx->gamma       = 1.0;
1638:   kctx->alpha       = .5*(1.0 + PetscSqrtReal(5.0));
1639:   kctx->alpha2      = kctx->alpha;
1640:   kctx->threshold   = .1;
1641:   kctx->lresid_last = 0.0;
1642:   kctx->norm_last   = 0.0;

1644:   *outsnes = snes;
1645:   return(0);
1646: }

1648: /*MC
1649:     SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES

1651:      Synopsis:
1652:      #include "petscsnes.h"
1653:      PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);

1655:      Input Parameters:
1656: +     snes - the SNES context
1657: .     x    - state at which to evaluate residual
1658: -     ctx     - optional user-defined function context, passed in with SNESSetFunction()

1660:      Output Parameter:
1661: .     f  - vector to put residual (function value)

1663:    Level: intermediate

1665: .seealso:   SNESSetFunction(), SNESGetFunction()
1666: M*/

1668: /*@C
1669:    SNESSetFunction - Sets the function evaluation routine and function
1670:    vector for use by the SNES routines in solving systems of nonlinear
1671:    equations.

1673:    Logically Collective on SNES

1675:    Input Parameters:
1676: +  snes - the SNES context
1677: .  r - vector to store function value
1678: .  f - function evaluation routine; see SNESFunction for calling sequence details
1679: -  ctx - [optional] user-defined context for private data for the
1680:          function evaluation routine (may be NULL)

1682:    Notes:
1683:    The Newton-like methods typically solve linear systems of the form
1684: $      f'(x) x = -f(x),
1685:    where f'(x) denotes the Jacobian matrix and f(x) is the function.

1687:    Level: beginner

1689: .keywords: SNES, nonlinear, set, function

1691: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1692: @*/
1693: PetscErrorCode  SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1694: {
1696:   DM             dm;

1700:   if (r) {
1703:     PetscObjectReference((PetscObject)r);
1704:     VecDestroy(&snes->vec_func);

1706:     snes->vec_func = r;
1707:   }
1708:   SNESGetDM(snes,&dm);
1709:   DMSNESSetFunction(dm,f,ctx);
1710:   return(0);
1711: }


1714: /*@C
1715:    SNESSetInitialFunction - Sets the function vector to be used as the
1716:    function norm at the initialization of the method.  In some
1717:    instances, the user has precomputed the function before calling
1718:    SNESSolve.  This function allows one to avoid a redundant call
1719:    to SNESComputeFunction in that case.

1721:    Logically Collective on SNES

1723:    Input Parameters:
1724: +  snes - the SNES context
1725: -  f - vector to store function value

1727:    Notes:
1728:    This should not be modified during the solution procedure.

1730:    This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.

1732:    Level: developer

1734: .keywords: SNES, nonlinear, set, function

1736: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1737: @*/
1738: PetscErrorCode  SNESSetInitialFunction(SNES snes, Vec f)
1739: {
1741:   Vec            vec_func;

1747:   if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1748:     snes->vec_func_init_set = PETSC_FALSE;
1749:     return(0);
1750:   }
1751:   SNESGetFunction(snes,&vec_func,NULL,NULL);
1752:   VecCopy(f, vec_func);

1754:   snes->vec_func_init_set = PETSC_TRUE;
1755:   return(0);
1756: }

1758: /*@
1759:    SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1760:    of the SNES method.

1762:    Logically Collective on SNES

1764:    Input Parameters:
1765: +  snes - the SNES context
1766: -  normschedule - the frequency of norm computation

1768:    Options Database Key:
1769: .  -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>

1771:    Notes:
1772:    Only certain SNES methods support certain SNESNormSchedules.  Most require evaluation
1773:    of the nonlinear function and the taking of its norm at every iteration to
1774:    even ensure convergence at all.  However, methods such as custom Gauss-Seidel methods
1775:    (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1776:    may either be monitored for convergence or not.  As these are often used as nonlinear
1777:    preconditioners, monitoring the norm of their error is not a useful enterprise within
1778:    their solution.

1780:    Level: developer

1782: .keywords: SNES, nonlinear, set, function, norm, type

1784: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1785: @*/
1786: PetscErrorCode  SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1787: {
1790:   snes->normschedule = normschedule;
1791:   return(0);
1792: }


1795: /*@
1796:    SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1797:    of the SNES method.

1799:    Logically Collective on SNES

1801:    Input Parameters:
1802: +  snes - the SNES context
1803: -  normschedule - the type of the norm used

1805:    Level: advanced

1807: .keywords: SNES, nonlinear, set, function, norm, type

1809: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1810: @*/
1811: PetscErrorCode  SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1812: {
1815:   *normschedule = snes->normschedule;
1816:   return(0);
1817: }


1820: /*@
1821:   SNESSetFunctionNorm - Sets the last computed residual norm.

1823:   Logically Collective on SNES

1825:   Input Parameters:
1826: + snes - the SNES context

1828: - normschedule - the frequency of norm computation

1830:   Level: developer

1832: .keywords: SNES, nonlinear, set, function, norm, type
1833: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1834: @*/
1835: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1836: {
1839:   snes->norm = norm;
1840:   return(0);
1841: }

1843: /*@
1844:   SNESGetFunctionNorm - Gets the last computed norm of the residual

1846:   Not Collective

1848:   Input Parameter:
1849: . snes - the SNES context

1851:   Output Parameter:
1852: . norm - the last computed residual norm

1854:   Level: developer

1856: .keywords: SNES, nonlinear, set, function, norm, type
1857: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1858: @*/
1859: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1860: {
1864:   *norm = snes->norm;
1865:   return(0);
1866: }

1868: /*@C
1869:    SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
1870:    of the SNES method.

1872:    Logically Collective on SNES

1874:    Input Parameters:
1875: +  snes - the SNES context
1876: -  normschedule - the frequency of norm computation

1878:    Notes:
1879:    Only certain SNES methods support certain SNESNormSchedules.  Most require evaluation
1880:    of the nonlinear function and the taking of its norm at every iteration to
1881:    even ensure convergence at all.  However, methods such as custom Gauss-Seidel methods
1882:    (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1883:    may either be monitored for convergence or not.  As these are often used as nonlinear
1884:    preconditioners, monitoring the norm of their error is not a useful enterprise within
1885:    their solution.

1887:    Level: developer

1889: .keywords: SNES, nonlinear, set, function, norm, type

1891: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1892: @*/
1893: PetscErrorCode  SNESSetFunctionType(SNES snes, SNESFunctionType type)
1894: {
1897:   snes->functype = type;
1898:   return(0);
1899: }


1902: /*@C
1903:    SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
1904:    of the SNES method.

1906:    Logically Collective on SNES

1908:    Input Parameters:
1909: +  snes - the SNES context
1910: -  normschedule - the type of the norm used

1912:    Level: advanced

1914: .keywords: SNES, nonlinear, set, function, norm, type

1916: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1917: @*/
1918: PetscErrorCode  SNESGetFunctionType(SNES snes, SNESFunctionType *type)
1919: {
1922:   *type = snes->functype;
1923:   return(0);
1924: }

1926: /*MC
1927:     SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function

1929:      Synopsis:
1930:      #include <petscsnes.h>
1931: $    SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);

1933: +  X   - solution vector
1934: .  B   - RHS vector
1935: -  ctx - optional user-defined Gauss-Seidel context

1937:    Level: intermediate

1939: .seealso:   SNESSetNGS(), SNESGetNGS()
1940: M*/

1942: /*@C
1943:    SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
1944:    use with composed nonlinear solvers.

1946:    Input Parameters:
1947: +  snes   - the SNES context
1948: .  f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
1949: -  ctx    - [optional] user-defined context for private data for the
1950:             smoother evaluation routine (may be NULL)

1952:    Notes:
1953:    The NGS routines are used by the composed nonlinear solver to generate
1954:     a problem appropriate update to the solution, particularly FAS.

1956:    Level: intermediate

1958: .keywords: SNES, nonlinear, set, Gauss-Seidel

1960: .seealso: SNESGetFunction(), SNESComputeNGS()
1961: @*/
1962: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1963: {
1965:   DM             dm;

1969:   SNESGetDM(snes,&dm);
1970:   DMSNESSetNGS(dm,f,ctx);
1971:   return(0);
1972: }

1974: PETSC_EXTERN PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
1975: {
1977:   DM             dm;
1978:   DMSNES         sdm;

1981:   SNESGetDM(snes,&dm);
1982:   DMGetDMSNES(dm,&sdm);
1983:   /*  A(x)*x - b(x) */
1984:   if (sdm->ops->computepfunction) {
1985:     (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
1986:   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");

1988:   if (sdm->ops->computepjacobian) {
1989:     (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
1990:   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard matrix.");
1991:   VecScale(f,-1.0);
1992:   MatMultAdd(snes->jacobian,x,f,f);
1993:   return(0);
1994: }

1996: PETSC_EXTERN PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
1997: {
1999:   /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2000:   return(0);
2001: }

2003: /*@C
2004:    SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)

2006:    Logically Collective on SNES

2008:    Input Parameters:
2009: +  snes - the SNES context
2010: .  r - vector to store function value
2011: .  b - function evaluation routine
2012: .  Amat - matrix with which A(x) x - b(x) is to be computed
2013: .  Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2014: .  J  - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2015: -  ctx - [optional] user-defined context for private data for the
2016:          function evaluation routine (may be NULL)

2018:    Notes:
2019:     We do not recomemend using this routine. It is far better to provide the nonlinear function F() and some approximation to the Jacobian and use
2020:     an approximate Newton solver. This interface is provided to allow porting/testing a previous Picard based code in PETSc before converting it to approximate Newton.

2022:     One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both

2024: $     Solves the equation A(x) x = b(x) via the defect correction algorithm A(x^{n}) (x^{n+1} - x^{n}) = b(x^{n}) - A(x^{n})x^{n}
2025: $     Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.

2027:      Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.

2029:    We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2030:    the direct Picard iteration A(x^n) x^{n+1} = b(x^n)

2032:    There is some controversity over the definition of a Picard iteration for nonlinear systems but almost everyone agrees that it involves a linear solve and some
2033:    believe it is the iteration  A(x^{n}) x^{n+1} = b(x^{n}) hence we use the name Picard. If anyone has an authoritative  reference that defines the Picard iteration
2034:    different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).

2036:    Level: intermediate

2038: .keywords: SNES, nonlinear, set, function

2040: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2041: @*/
2042: PetscErrorCode  SNESSetPicard(SNES snes,Vec r,PetscErrorCode (*b)(SNES,Vec,Vec,void*),Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2043: {
2045:   DM             dm;

2049:   SNESGetDM(snes, &dm);
2050:   DMSNESSetPicard(dm,b,J,ctx);
2051:   SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2052:   SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2053:   return(0);
2054: }

2056: /*@C
2057:    SNESGetPicard - Returns the context for the Picard iteration

2059:    Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.

2061:    Input Parameter:
2062: .  snes - the SNES context

2064:    Output Parameter:
2065: +  r - the function (or NULL)
2066: .  f - the function (or NULL); see SNESFunction for calling sequence details
2067: .  Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2068: .  Pmat  - the matrix from which the preconditioner will be constructed (or NULL)
2069: .  J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2070: -  ctx - the function context (or NULL)

2072:    Level: advanced

2074: .keywords: SNES, nonlinear, get, function

2076: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2077: @*/
2078: PetscErrorCode  SNESGetPicard(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2079: {
2081:   DM             dm;

2085:   SNESGetFunction(snes,r,NULL,NULL);
2086:   SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2087:   SNESGetDM(snes,&dm);
2088:   DMSNESGetPicard(dm,f,J,ctx);
2089:   return(0);
2090: }

2092: /*@C
2093:    SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem

2095:    Logically Collective on SNES

2097:    Input Parameters:
2098: +  snes - the SNES context
2099: .  func - function evaluation routine
2100: -  ctx - [optional] user-defined context for private data for the
2101:          function evaluation routine (may be NULL)

2103:    Calling sequence of func:
2104: $    func (SNES snes,Vec x,void *ctx);

2106: .  f - function vector
2107: -  ctx - optional user-defined function context

2109:    Level: intermediate

2111: .keywords: SNES, nonlinear, set, function

2113: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2114: @*/
2115: PetscErrorCode  SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2116: {
2119:   if (func) snes->ops->computeinitialguess = func;
2120:   if (ctx)  snes->initialguessP            = ctx;
2121:   return(0);
2122: }

2124: /* --------------------------------------------------------------- */
2125: /*@C
2126:    SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2127:    it assumes a zero right hand side.

2129:    Logically Collective on SNES

2131:    Input Parameter:
2132: .  snes - the SNES context

2134:    Output Parameter:
2135: .  rhs - the right hand side vector or NULL if the right hand side vector is null

2137:    Level: intermediate

2139: .keywords: SNES, nonlinear, get, function, right hand side

2141: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2142: @*/
2143: PetscErrorCode  SNESGetRhs(SNES snes,Vec *rhs)
2144: {
2148:   *rhs = snes->vec_rhs;
2149:   return(0);
2150: }

2152: /*@
2153:    SNESComputeFunction - Calls the function that has been set with SNESSetFunction().

2155:    Collective on SNES

2157:    Input Parameters:
2158: +  snes - the SNES context
2159: -  x - input vector

2161:    Output Parameter:
2162: .  y - function vector, as set by SNESSetFunction()

2164:    Notes:
2165:    SNESComputeFunction() is typically used within nonlinear solvers
2166:    implementations, so most users would not generally call this routine
2167:    themselves.

2169:    Level: developer

2171: .keywords: SNES, nonlinear, compute, function

2173: .seealso: SNESSetFunction(), SNESGetFunction()
2174: @*/
2175: PetscErrorCode  SNESComputeFunction(SNES snes,Vec x,Vec y)
2176: {
2178:   DM             dm;
2179:   DMSNES         sdm;

2187:   VecValidValues(x,2,PETSC_TRUE);

2189:   SNESGetDM(snes,&dm);
2190:   DMGetDMSNES(dm,&sdm);
2191:   if (sdm->ops->computefunction) {
2192:     if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2193:       PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2194:     }
2195:     VecLockPush(x);
2196:     PetscStackPush("SNES user function");
2197:     (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2198:     PetscStackPop;
2199:     VecLockPop(x);
2200:     if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2201:       PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2202:     }
2203:   } else if (snes->vec_rhs) {
2204:     MatMult(snes->jacobian, x, y);
2205:   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2206:   if (snes->vec_rhs) {
2207:     VecAXPY(y,-1.0,snes->vec_rhs);
2208:   }
2209:   snes->nfuncs++;
2210:   /*
2211:      domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2212:      propagate the value to all processes
2213:   */
2214:   if (snes->domainerror) {
2215:     VecSetInf(y);
2216:   }
2217:   return(0);
2218: }

2220: /*@
2221:    SNESComputeNGS - Calls the Gauss-Seidel function that has been set with  SNESSetNGS().

2223:    Collective on SNES

2225:    Input Parameters:
2226: +  snes - the SNES context
2227: .  x - input vector
2228: -  b - rhs vector

2230:    Output Parameter:
2231: .  x - new solution vector

2233:    Notes:
2234:    SNESComputeNGS() is typically used within composed nonlinear solver
2235:    implementations, so most users would not generally call this routine
2236:    themselves.

2238:    Level: developer

2240: .keywords: SNES, nonlinear, compute, function

2242: .seealso: SNESSetNGS(), SNESComputeFunction()
2243: @*/
2244: PetscErrorCode  SNESComputeNGS(SNES snes,Vec b,Vec x)
2245: {
2247:   DM             dm;
2248:   DMSNES         sdm;

2256:   if (b) {VecValidValues(b,2,PETSC_TRUE);}
2257:   PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2258:   SNESGetDM(snes,&dm);
2259:   DMGetDMSNES(dm,&sdm);
2260:   if (sdm->ops->computegs) {
2261:     if (b) {VecLockPush(b);}
2262:     PetscStackPush("SNES user NGS");
2263:     (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2264:     PetscStackPop;
2265:     if (b) {VecLockPop(b);}
2266:   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2267:   PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2268:   return(0);
2269: }

2271: /*@
2272:    SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().

2274:    Collective on SNES and Mat

2276:    Input Parameters:
2277: +  snes - the SNES context
2278: -  x - input vector

2280:    Output Parameters:
2281: +  A - Jacobian matrix
2282: -  B - optional preconditioning matrix

2284:   Options Database Keys:
2285: +    -snes_lag_preconditioner <lag>
2286: .    -snes_lag_jacobian <lag>
2287: .    -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2288: .    -snes_compare_explicit_draw  - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2289: .    -snes_compare_explicit_contour  - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2290: .    -snes_compare_operator  - Make the comparison options above use the operator instead of the preconditioning matrix
2291: .    -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2292: .    -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2293: .    -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2294: .    -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2295: .    -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2296: .    -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2297: -    -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences


2300:    Notes:
2301:    Most users should not need to explicitly call this routine, as it
2302:    is used internally within the nonlinear solvers.

2304:    Level: developer

2306: .keywords: SNES, compute, Jacobian, matrix

2308: .seealso:  SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2309: @*/
2310: PetscErrorCode  SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2311: {
2313:   PetscBool      flag;
2314:   DM             dm;
2315:   DMSNES         sdm;
2316:   KSP            ksp;

2322:   VecValidValues(X,2,PETSC_TRUE);
2323:   SNESGetDM(snes,&dm);
2324:   DMGetDMSNES(dm,&sdm);

2326:   if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");

2328:   /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */

2330:   if (snes->lagjacobian == -2) {
2331:     snes->lagjacobian = -1;

2333:     PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2334:   } else if (snes->lagjacobian == -1) {
2335:     PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2336:     PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2337:     if (flag) {
2338:       MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2339:       MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2340:     }
2341:     return(0);
2342:   } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2343:     PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2344:     PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2345:     if (flag) {
2346:       MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2347:       MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2348:     }
2349:     return(0);
2350:   }
2351:   if (snes->npc && snes->npcside== PC_LEFT) {
2352:       MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2353:       MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2354:       return(0);
2355:   }

2357:   PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2358:   VecLockPush(X);
2359:   PetscStackPush("SNES user Jacobian function");
2360:   (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2361:   PetscStackPop;
2362:   VecLockPop(X);
2363:   PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);

2365:   /* the next line ensures that snes->ksp exists */
2366:   SNESGetKSP(snes,&ksp);
2367:   if (snes->lagpreconditioner == -2) {
2368:     PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2369:     KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2370:     snes->lagpreconditioner = -1;
2371:   } else if (snes->lagpreconditioner == -1) {
2372:     PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2373:     KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2374:   } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2375:     PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2376:     KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2377:   } else {
2378:     PetscInfo(snes,"Rebuilding preconditioner\n");
2379:     KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2380:   }

2382:   /* make sure user returned a correct Jacobian and preconditioner */
2385:   {
2386:     PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2387:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2388:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2389:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2390:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2391:     if (flag || flag_draw || flag_contour) {
2392:       Mat          Bexp_mine = NULL,Bexp,FDexp;
2393:       PetscViewer  vdraw,vstdout;
2394:       PetscBool    flg;
2395:       if (flag_operator) {
2396:         MatComputeExplicitOperator(A,&Bexp_mine);
2397:         Bexp = Bexp_mine;
2398:       } else {
2399:         /* See if the preconditioning matrix can be viewed and added directly */
2400:         PetscObjectTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2401:         if (flg) Bexp = B;
2402:         else {
2403:           /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2404:           MatComputeExplicitOperator(B,&Bexp_mine);
2405:           Bexp = Bexp_mine;
2406:         }
2407:       }
2408:       MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2409:       SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2410:       PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2411:       if (flag_draw || flag_contour) {
2412:         PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2413:         if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2414:       } else vdraw = NULL;
2415:       PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2416:       if (flag) {MatView(Bexp,vstdout);}
2417:       if (vdraw) {MatView(Bexp,vdraw);}
2418:       PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2419:       if (flag) {MatView(FDexp,vstdout);}
2420:       if (vdraw) {MatView(FDexp,vdraw);}
2421:       MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2422:       PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2423:       if (flag) {MatView(FDexp,vstdout);}
2424:       if (vdraw) {              /* Always use contour for the difference */
2425:         PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2426:         MatView(FDexp,vdraw);
2427:         PetscViewerPopFormat(vdraw);
2428:       }
2429:       if (flag_contour) {PetscViewerPopFormat(vdraw);}
2430:       PetscViewerDestroy(&vdraw);
2431:       MatDestroy(&Bexp_mine);
2432:       MatDestroy(&FDexp);
2433:     }
2434:   }
2435:   {
2436:     PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2437:     PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2438:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2439:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2440:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2441:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2442:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2443:     if (flag_threshold) {
2444:       PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2445:       PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2446:     }
2447:     if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2448:       Mat            Bfd;
2449:       PetscViewer    vdraw,vstdout;
2450:       MatColoring    coloring;
2451:       ISColoring     iscoloring;
2452:       MatFDColoring  matfdcoloring;
2453:       PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2454:       void           *funcctx;
2455:       PetscReal      norm1,norm2,normmax;

2457:       MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2458:       MatColoringCreate(Bfd,&coloring);
2459:       MatColoringSetType(coloring,MATCOLORINGSL);
2460:       MatColoringSetFromOptions(coloring);
2461:       MatColoringApply(coloring,&iscoloring);
2462:       MatColoringDestroy(&coloring);
2463:       MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2464:       MatFDColoringSetFromOptions(matfdcoloring);
2465:       MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2466:       ISColoringDestroy(&iscoloring);

2468:       /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2469:       SNESGetFunction(snes,NULL,&func,&funcctx);
2470:       MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2471:       PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2472:       PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2473:       MatFDColoringSetFromOptions(matfdcoloring);
2474:       MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2475:       MatFDColoringDestroy(&matfdcoloring);

2477:       PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2478:       if (flag_draw || flag_contour) {
2479:         PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2480:         if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2481:       } else vdraw = NULL;
2482:       PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2483:       if (flag_display) {MatView(B,vstdout);}
2484:       if (vdraw) {MatView(B,vdraw);}
2485:       PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2486:       if (flag_display) {MatView(Bfd,vstdout);}
2487:       if (vdraw) {MatView(Bfd,vdraw);}
2488:       MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2489:       MatNorm(Bfd,NORM_1,&norm1);
2490:       MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2491:       MatNorm(Bfd,NORM_MAX,&normmax);
2492:       PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2493:       if (flag_display) {MatView(Bfd,vstdout);}
2494:       if (vdraw) {              /* Always use contour for the difference */
2495:         PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2496:         MatView(Bfd,vdraw);
2497:         PetscViewerPopFormat(vdraw);
2498:       }
2499:       if (flag_contour) {PetscViewerPopFormat(vdraw);}

2501:       if (flag_threshold) {
2502:         PetscInt bs,rstart,rend,i;
2503:         MatGetBlockSize(B,&bs);
2504:         MatGetOwnershipRange(B,&rstart,&rend);
2505:         for (i=rstart; i<rend; i++) {
2506:           const PetscScalar *ba,*ca;
2507:           const PetscInt    *bj,*cj;
2508:           PetscInt          bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2509:           PetscReal         maxentry = 0,maxdiff = 0,maxrdiff = 0;
2510:           MatGetRow(B,i,&bn,&bj,&ba);
2511:           MatGetRow(Bfd,i,&cn,&cj,&ca);
2512:           if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2513:           for (j=0; j<bn; j++) {
2514:             PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2515:             if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2516:               maxentrycol = bj[j];
2517:               maxentry    = PetscRealPart(ba[j]);
2518:             }
2519:             if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2520:               maxdiffcol = bj[j];
2521:               maxdiff    = PetscRealPart(ca[j]);
2522:             }
2523:             if (rdiff > maxrdiff) {
2524:               maxrdiffcol = bj[j];
2525:               maxrdiff    = rdiff;
2526:             }
2527:           }
2528:           if (maxrdiff > 1) {
2529:             PetscViewerASCIIPrintf(vstdout,"row %D (maxentry=%g at %D, maxdiff=%g at %D, maxrdiff=%g at %D):",i,(double)maxentry,maxentrycol,(double)maxdiff,maxdiffcol,(double)maxrdiff,maxrdiffcol);
2530:             for (j=0; j<bn; j++) {
2531:               PetscReal rdiff;
2532:               rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2533:               if (rdiff > 1) {
2534:                 PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2535:               }
2536:             }
2537:             PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2538:           }
2539:           MatRestoreRow(B,i,&bn,&bj,&ba);
2540:           MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2541:         }
2542:       }
2543:       PetscViewerDestroy(&vdraw);
2544:       MatDestroy(&Bfd);
2545:     }
2546:   }
2547:   return(0);
2548: }

2550: /*MC
2551:     SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES

2553:      Synopsis:
2554:      #include "petscsnes.h"
2555:      PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);

2557: +  x - input vector
2558: .  Amat - the matrix that defines the (approximate) Jacobian
2559: .  Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2560: -  ctx - [optional] user-defined Jacobian context

2562:    Level: intermediate

2564: .seealso:   SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2565: M*/

2567: /*@C
2568:    SNESSetJacobian - Sets the function to compute Jacobian as well as the
2569:    location to store the matrix.

2571:    Logically Collective on SNES and Mat

2573:    Input Parameters:
2574: +  snes - the SNES context
2575: .  Amat - the matrix that defines the (approximate) Jacobian
2576: .  Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2577: .  J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2578: -  ctx - [optional] user-defined context for private data for the
2579:          Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)

2581:    Notes:
2582:    If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2583:    each matrix.

2585:    If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2586:    space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.

2588:    If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2589:    must be a MatFDColoring.

2591:    Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian.  One common
2592:    example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.

2594:    Level: beginner

2596: .keywords: SNES, nonlinear, set, Jacobian, matrix

2598: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J, 
2599:           SNESSetPicard(), SNESJacobianFunction
2600: @*/
2601: PetscErrorCode  SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2602: {
2604:   DM             dm;

2612:   SNESGetDM(snes,&dm);
2613:   DMSNESSetJacobian(dm,J,ctx);
2614:   if (Amat) {
2615:     PetscObjectReference((PetscObject)Amat);
2616:     MatDestroy(&snes->jacobian);

2618:     snes->jacobian = Amat;
2619:   }
2620:   if (Pmat) {
2621:     PetscObjectReference((PetscObject)Pmat);
2622:     MatDestroy(&snes->jacobian_pre);

2624:     snes->jacobian_pre = Pmat;
2625:   }
2626:   return(0);
2627: }

2629: /*@C
2630:    SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2631:    provided context for evaluating the Jacobian.

2633:    Not Collective, but Mat object will be parallel if SNES object is

2635:    Input Parameter:
2636: .  snes - the nonlinear solver context

2638:    Output Parameters:
2639: +  Amat - location to stash (approximate) Jacobian matrix (or NULL)
2640: .  Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2641: .  J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2642: -  ctx - location to stash Jacobian ctx (or NULL)

2644:    Level: advanced

2646: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2647: @*/
2648: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2649: {
2651:   DM             dm;
2652:   DMSNES         sdm;

2656:   if (Amat) *Amat = snes->jacobian;
2657:   if (Pmat) *Pmat = snes->jacobian_pre;
2658:   SNESGetDM(snes,&dm);
2659:   DMGetDMSNES(dm,&sdm);
2660:   if (J) *J = sdm->ops->computejacobian;
2661:   if (ctx) *ctx = sdm->jacobianctx;
2662:   return(0);
2663: }

2665: /*@
2666:    SNESSetUp - Sets up the internal data structures for the later use
2667:    of a nonlinear solver.

2669:    Collective on SNES

2671:    Input Parameters:
2672: .  snes - the SNES context

2674:    Notes:
2675:    For basic use of the SNES solvers the user need not explicitly call
2676:    SNESSetUp(), since these actions will automatically occur during
2677:    the call to SNESSolve().  However, if one wishes to control this
2678:    phase separately, SNESSetUp() should be called after SNESCreate()
2679:    and optional routines of the form SNESSetXXX(), but before SNESSolve().

2681:    Level: advanced

2683: .keywords: SNES, nonlinear, setup

2685: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
2686: @*/
2687: PetscErrorCode  SNESSetUp(SNES snes)
2688: {
2690:   DM             dm;
2691:   DMSNES         sdm;
2692:   SNESLineSearch linesearch, pclinesearch;
2693:   void           *lsprectx,*lspostctx;
2694:   PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
2695:   PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
2696:   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2697:   Vec            f,fpc;
2698:   void           *funcctx;
2699:   PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
2700:   void           *jacctx,*appctx;
2701:   Mat            j,jpre;

2705:   if (snes->setupcalled) return(0);

2707:   if (!((PetscObject)snes)->type_name) {
2708:     SNESSetType(snes,SNESNEWTONLS);
2709:   }

2711:   SNESGetFunction(snes,&snes->vec_func,NULL,NULL);

2713:   SNESGetDM(snes,&dm);
2714:   DMGetDMSNES(dm,&sdm);
2715:   if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
2716:   if (!sdm->ops->computejacobian) {
2717:     DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
2718:   }
2719:   if (!snes->vec_func) {
2720:     DMCreateGlobalVector(dm,&snes->vec_func);
2721:   }

2723:   if (!snes->ksp) {
2724:     SNESGetKSP(snes, &snes->ksp);
2725:   }

2727:   if (!snes->linesearch) {
2728:     SNESGetLineSearch(snes, &snes->linesearch);
2729:   }
2730:   SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);

2732:   if (snes->npc && (snes->npcside== PC_LEFT)) {
2733:     snes->mf          = PETSC_TRUE;
2734:     snes->mf_operator = PETSC_FALSE;
2735:   }

2737:   if (snes->npc) {
2738:     /* copy the DM over */
2739:     SNESGetDM(snes,&dm);
2740:     SNESSetDM(snes->npc,dm);

2742:     SNESGetFunction(snes,&f,&func,&funcctx);
2743:     VecDuplicate(f,&fpc);
2744:     SNESSetFunction(snes->npc,fpc,func,funcctx);
2745:     SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
2746:     SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
2747:     SNESGetApplicationContext(snes,&appctx);
2748:     SNESSetApplicationContext(snes->npc,appctx);
2749:     VecDestroy(&fpc);

2751:     /* copy the function pointers over */
2752:     PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);

2754:     /* default to 1 iteration */
2755:     SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
2756:     if (snes->npcside==PC_RIGHT) {
2757:       SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
2758:     } else {
2759:       SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
2760:     }
2761:     SNESSetFromOptions(snes->npc);

2763:     /* copy the line search context over */
2764:     SNESGetLineSearch(snes,&linesearch);
2765:     SNESGetLineSearch(snes->npc,&pclinesearch);
2766:     SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
2767:     SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
2768:     SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
2769:     SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
2770:     PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
2771:   }
2772:   if (snes->mf) {
2773:     SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
2774:   }
2775:   if (snes->ops->usercompute && !snes->user) {
2776:     (*snes->ops->usercompute)(snes,(void**)&snes->user);
2777:   }

2779:   snes->jac_iter = 0;
2780:   snes->pre_iter = 0;

2782:   if (snes->ops->setup) {
2783:     (*snes->ops->setup)(snes);
2784:   }

2786:   if (snes->npc && (snes->npcside== PC_LEFT)) {
2787:     if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
2788:       SNESGetLineSearch(snes,&linesearch);
2789:       SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
2790:     }
2791:   }

2793:   snes->setupcalled = PETSC_TRUE;
2794:   return(0);
2795: }

2797: /*@
2798:    SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats

2800:    Collective on SNES

2802:    Input Parameter:
2803: .  snes - iterative context obtained from SNESCreate()

2805:    Level: intermediate

2807:    Notes: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()

2809: .keywords: SNES, destroy

2811: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
2812: @*/
2813: PetscErrorCode  SNESReset(SNES snes)
2814: {

2819:   if (snes->ops->userdestroy && snes->user) {
2820:     (*snes->ops->userdestroy)((void**)&snes->user);
2821:     snes->user = NULL;
2822:   }
2823:   if (snes->npc) {
2824:     SNESReset(snes->npc);
2825:   }

2827:   if (snes->ops->reset) {
2828:     (*snes->ops->reset)(snes);
2829:   }
2830:   if (snes->ksp) {
2831:     KSPReset(snes->ksp);
2832:   }

2834:   if (snes->linesearch) {
2835:     SNESLineSearchReset(snes->linesearch);
2836:   }

2838:   VecDestroy(&snes->vec_rhs);
2839:   VecDestroy(&snes->vec_sol);
2840:   VecDestroy(&snes->vec_sol_update);
2841:   VecDestroy(&snes->vec_func);
2842:   MatDestroy(&snes->jacobian);
2843:   MatDestroy(&snes->jacobian_pre);
2844:   VecDestroyVecs(snes->nwork,&snes->work);
2845:   VecDestroyVecs(snes->nvwork,&snes->vwork);

2847:   snes->alwayscomputesfinalresidual = PETSC_FALSE;

2849:   snes->nwork       = snes->nvwork = 0;
2850:   snes->setupcalled = PETSC_FALSE;
2851:   return(0);
2852: }

2854: /*@
2855:    SNESDestroy - Destroys the nonlinear solver context that was created
2856:    with SNESCreate().

2858:    Collective on SNES

2860:    Input Parameter:
2861: .  snes - the SNES context

2863:    Level: beginner

2865: .keywords: SNES, nonlinear, destroy

2867: .seealso: SNESCreate(), SNESSolve()
2868: @*/
2869: PetscErrorCode  SNESDestroy(SNES *snes)
2870: {

2874:   if (!*snes) return(0);
2876:   if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}

2878:   SNESReset((*snes));
2879:   SNESDestroy(&(*snes)->npc);

2881:   /* if memory was published with SAWs then destroy it */
2882:   PetscObjectSAWsViewOff((PetscObject)*snes);
2883:   if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}

2885:   if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
2886:   DMDestroy(&(*snes)->dm);
2887:   KSPDestroy(&(*snes)->ksp);
2888:   SNESLineSearchDestroy(&(*snes)->linesearch);

2890:   PetscFree((*snes)->kspconvctx);
2891:   if ((*snes)->ops->convergeddestroy) {
2892:     (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
2893:   }
2894:   if ((*snes)->conv_malloc) {
2895:     PetscFree((*snes)->conv_hist);
2896:     PetscFree((*snes)->conv_hist_its);
2897:   }
2898:   SNESMonitorCancel((*snes));
2899:   PetscHeaderDestroy(snes);
2900:   return(0);
2901: }

2903: /* ----------- Routines to set solver parameters ---------- */

2905: /*@
2906:    SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.

2908:    Logically Collective on SNES

2910:    Input Parameters:
2911: +  snes - the SNES context
2912: -  lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
2913:          the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that

2915:    Options Database Keys:
2916: .    -snes_lag_preconditioner <lag>

2918:    Notes:
2919:    The default is 1
2920:    The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
2921:    If  -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use

2923:    Level: intermediate

2925: .keywords: SNES, nonlinear, set, convergence, tolerances

2927: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()

2929: @*/
2930: PetscErrorCode  SNESSetLagPreconditioner(SNES snes,PetscInt lag)
2931: {
2934:   if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
2935:   if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
2937:   snes->lagpreconditioner = lag;
2938:   return(0);
2939: }

2941: /*@
2942:    SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does

2944:    Logically Collective on SNES

2946:    Input Parameters:
2947: +  snes - the SNES context
2948: -  steps - the number of refinements to do, defaults to 0

2950:    Options Database Keys:
2951: .    -snes_grid_sequence <steps>

2953:    Level: intermediate

2955:    Notes:
2956:    Use SNESGetSolution() to extract the fine grid solution after grid sequencing.

2958: .keywords: SNES, nonlinear, set, convergence, tolerances

2960: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()

2962: @*/
2963: PetscErrorCode  SNESSetGridSequence(SNES snes,PetscInt steps)
2964: {
2968:   snes->gridsequence = steps;
2969:   return(0);
2970: }

2972: /*@
2973:    SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does

2975:    Logically Collective on SNES

2977:    Input Parameter:
2978: .  snes - the SNES context

2980:    Output Parameter:
2981: .  steps - the number of refinements to do, defaults to 0

2983:    Options Database Keys:
2984: .    -snes_grid_sequence <steps>

2986:    Level: intermediate

2988:    Notes:
2989:    Use SNESGetSolution() to extract the fine grid solution after grid sequencing.

2991: .keywords: SNES, nonlinear, set, convergence, tolerances

2993: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()

2995: @*/
2996: PetscErrorCode  SNESGetGridSequence(SNES snes,PetscInt *steps)
2997: {
3000:   *steps = snes->gridsequence;
3001:   return(0);
3002: }

3004: /*@
3005:    SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt

3007:    Not Collective

3009:    Input Parameter:
3010: .  snes - the SNES context

3012:    Output Parameter:
3013: .   lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3014:          the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that

3016:    Options Database Keys:
3017: .    -snes_lag_preconditioner <lag>

3019:    Notes:
3020:    The default is 1
3021:    The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1

3023:    Level: intermediate

3025: .keywords: SNES, nonlinear, set, convergence, tolerances

3027: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()

3029: @*/
3030: PetscErrorCode  SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3031: {
3034:   *lag = snes->lagpreconditioner;
3035:   return(0);
3036: }

3038: /*@
3039:    SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3040:      often the preconditioner is rebuilt.

3042:    Logically Collective on SNES

3044:    Input Parameters:
3045: +  snes - the SNES context
3046: -  lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3047:          the Jacobian is built etc. -2 means rebuild at next chance but then never again

3049:    Options Database Keys:
3050: .    -snes_lag_jacobian <lag>

3052:    Notes:
3053:    The default is 1
3054:    The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3055:    If  -1 is used before the very first nonlinear solve the CODE WILL FAIL! because no Jacobian is used, use -2 to indicate you want it recomputed
3056:    at the next Newton step but never again (unless it is reset to another value)

3058:    Level: intermediate

3060: .keywords: SNES, nonlinear, set, convergence, tolerances

3062: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()

3064: @*/
3065: PetscErrorCode  SNESSetLagJacobian(SNES snes,PetscInt lag)
3066: {
3069:   if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3070:   if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3072:   snes->lagjacobian = lag;
3073:   return(0);
3074: }

3076: /*@
3077:    SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt

3079:    Not Collective

3081:    Input Parameter:
3082: .  snes - the SNES context

3084:    Output Parameter:
3085: .   lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3086:          the Jacobian is built etc.

3088:    Options Database Keys:
3089: .    -snes_lag_jacobian <lag>

3091:    Notes:
3092:    The default is 1
3093:    The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1

3095:    Level: intermediate

3097: .keywords: SNES, nonlinear, set, convergence, tolerances

3099: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()

3101: @*/
3102: PetscErrorCode  SNESGetLagJacobian(SNES snes,PetscInt *lag)
3103: {
3106:   *lag = snes->lagjacobian;
3107:   return(0);
3108: }

3110: /*@
3111:    SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves

3113:    Logically collective on SNES

3115:    Input Parameter:
3116: +  snes - the SNES context
3117: -   flg - jacobian lagging persists if true

3119:    Options Database Keys:
3120: .    -snes_lag_jacobian_persists <flg>

3122:    Notes: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3123:    several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3124:    timesteps may present huge efficiency gains.

3126:    Level: developer

3128: .keywords: SNES, nonlinear, lag

3130: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()

3132: @*/
3133: PetscErrorCode  SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3134: {
3138:   snes->lagjac_persist = flg;
3139:   return(0);
3140: }

3142: /*@
3143:    SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves

3145:    Logically Collective on SNES

3147:    Input Parameter:
3148: +  snes - the SNES context
3149: -   flg - preconditioner lagging persists if true

3151:    Options Database Keys:
3152: .    -snes_lag_jacobian_persists <flg>

3154:    Notes: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3155:    by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3156:    several timesteps may present huge efficiency gains.

3158:    Level: developer

3160: .keywords: SNES, nonlinear, lag

3162: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()

3164: @*/
3165: PetscErrorCode  SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3166: {
3170:   snes->lagpre_persist = flg;
3171:   return(0);
3172: }

3174: /*@
3175:    SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm

3177:    Logically Collective on SNES

3179:    Input Parameters:
3180: +  snes - the SNES context
3181: -  force - PETSC_TRUE require at least one iteration

3183:    Options Database Keys:
3184: .    -snes_force_iteration <force> - Sets forcing an iteration

3186:    Notes:
3187:    This is used sometimes with TS to prevent TS from detecting a false steady state solution

3189:    Level: intermediate

3191: .keywords: SNES, nonlinear, set, convergence, tolerances

3193: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3194: @*/
3195: PetscErrorCode  SNESSetForceIteration(SNES snes,PetscBool force)
3196: {
3199:   snes->forceiteration = force;
3200:   return(0);
3201: }


3204: /*@
3205:    SNESSetTolerances - Sets various parameters used in convergence tests.

3207:    Logically Collective on SNES

3209:    Input Parameters:
3210: +  snes - the SNES context
3211: .  abstol - absolute convergence tolerance
3212: .  rtol - relative convergence tolerance
3213: .  stol -  convergence tolerance in terms of the norm of the change in the solution between steps,  || delta x || < stol*|| x ||
3214: .  maxit - maximum number of iterations
3215: -  maxf - maximum number of function evaluations

3217:    Options Database Keys:
3218: +    -snes_atol <abstol> - Sets abstol
3219: .    -snes_rtol <rtol> - Sets rtol
3220: .    -snes_stol <stol> - Sets stol
3221: .    -snes_max_it <maxit> - Sets maxit
3222: -    -snes_max_funcs <maxf> - Sets maxf

3224:    Notes:
3225:    The default maximum number of iterations is 50.
3226:    The default maximum number of function evaluations is 1000.

3228:    Level: intermediate

3230: .keywords: SNES, nonlinear, set, convergence, tolerances

3232: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3233: @*/
3234: PetscErrorCode  SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3235: {

3244:   if (abstol != PETSC_DEFAULT) {
3245:     if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3246:     snes->abstol = abstol;
3247:   }
3248:   if (rtol != PETSC_DEFAULT) {
3249:     if (rtol < 0.0 || 1.0 <= rtol) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Relative tolerance %g must be non-negative and less than 1.0",(double)rtol);
3250:     snes->rtol = rtol;
3251:   }
3252:   if (stol != PETSC_DEFAULT) {
3253:     if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3254:     snes->stol = stol;
3255:   }
3256:   if (maxit != PETSC_DEFAULT) {
3257:     if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3258:     snes->max_its = maxit;
3259:   }
3260:   if (maxf != PETSC_DEFAULT) {
3261:     if (maxf < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be non-negative",maxf);
3262:     snes->max_funcs = maxf;
3263:   }
3264:   snes->tolerancesset = PETSC_TRUE;
3265:   return(0);
3266: }

3268: /*@
3269:    SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.

3271:    Logically Collective on SNES

3273:    Input Parameters:
3274: +  snes - the SNES context
3275: -  divtol - the divergence tolerance. Use -1 to deactivate the test.

3277:    Options Database Keys:
3278: +    -snes_divergence_tolerance <divtol> - Sets divtol

3280:    Notes:
3281:    The default divergence tolerance is 1e4.

3283:    Level: intermediate

3285: .keywords: SNES, nonlinear, set, divergence, tolerance

3287: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3288: @*/
3289: PetscErrorCode  SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3290: {

3295:   if (divtol != PETSC_DEFAULT) {
3296:     snes->divtol = divtol;
3297:   }
3298:   else {
3299:     snes->divtol = 1.0e4;
3300:   }
3301:   return(0);
3302: }

3304: /*@
3305:    SNESGetTolerances - Gets various parameters used in convergence tests.

3307:    Not Collective

3309:    Input Parameters:
3310: +  snes - the SNES context
3311: .  atol - absolute convergence tolerance
3312: .  rtol - relative convergence tolerance
3313: .  stol -  convergence tolerance in terms of the norm
3314:            of the change in the solution between steps
3315: .  maxit - maximum number of iterations
3316: -  maxf - maximum number of function evaluations

3318:    Notes:
3319:    The user can specify NULL for any parameter that is not needed.

3321:    Level: intermediate

3323: .keywords: SNES, nonlinear, get, convergence, tolerances

3325: .seealso: SNESSetTolerances()
3326: @*/
3327: PetscErrorCode  SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3328: {
3331:   if (atol)  *atol  = snes->abstol;
3332:   if (rtol)  *rtol  = snes->rtol;
3333:   if (stol)  *stol  = snes->stol;
3334:   if (maxit) *maxit = snes->max_its;
3335:   if (maxf)  *maxf  = snes->max_funcs;
3336:   return(0);
3337: }

3339: /*@
3340:    SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.

3342:    Not Collective

3344:    Input Parameters:
3345: +  snes - the SNES context
3346: -  divtol - divergence tolerance

3348:    Level: intermediate

3350: .keywords: SNES, nonlinear, get, divergence, tolerance

3352: .seealso: SNESSetDivergenceTolerance()
3353: @*/
3354: PetscErrorCode  SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3355: {
3358:   if (divtol) *divtol = snes->divtol;
3359:   return(0);
3360: }

3362: /*@
3363:    SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.

3365:    Logically Collective on SNES

3367:    Input Parameters:
3368: +  snes - the SNES context
3369: -  tol - tolerance

3371:    Options Database Key:
3372: .  -snes_trtol <tol> - Sets tol

3374:    Level: intermediate

3376: .keywords: SNES, nonlinear, set, trust region, tolerance

3378: .seealso: SNESSetTolerances()
3379: @*/
3380: PetscErrorCode  SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3381: {
3385:   snes->deltatol = tol;
3386:   return(0);
3387: }

3389: /*
3390:    Duplicate the lg monitors for SNES from KSP; for some reason with
3391:    dynamic libraries things don't work under Sun4 if we just use
3392:    macros instead of functions
3393: */
3394: PetscErrorCode  SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3395: {

3400:   KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3401:   return(0);
3402: }

3404: PetscErrorCode  SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3405: {

3409:   KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3410:   return(0);
3411: }

3413: PETSC_INTERN PetscErrorCode  SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);

3415: PetscErrorCode  SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3416: {
3417:   PetscDrawLG      lg;
3418:   PetscErrorCode   ierr;
3419:   PetscReal        x,y,per;
3420:   PetscViewer      v = (PetscViewer)monctx;
3421:   static PetscReal prev; /* should be in the context */
3422:   PetscDraw        draw;

3426:   PetscViewerDrawGetDrawLG(v,0,&lg);
3427:   if (!n) {PetscDrawLGReset(lg);}
3428:   PetscDrawLGGetDraw(lg,&draw);
3429:   PetscDrawSetTitle(draw,"Residual norm");
3430:   x    = (PetscReal)n;
3431:   if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3432:   else y = -15.0;
3433:   PetscDrawLGAddPoint(lg,&x,&y);
3434:   if (n < 20 || !(n % 5) || snes->reason) {
3435:     PetscDrawLGDraw(lg);
3436:     PetscDrawLGSave(lg);
3437:   }

3439:   PetscViewerDrawGetDrawLG(v,1,&lg);
3440:   if (!n) {PetscDrawLGReset(lg);}
3441:   PetscDrawLGGetDraw(lg,&draw);
3442:   PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3443:    SNESMonitorRange_Private(snes,n,&per);
3444:   x    = (PetscReal)n;
3445:   y    = 100.0*per;
3446:   PetscDrawLGAddPoint(lg,&x,&y);
3447:   if (n < 20 || !(n % 5) || snes->reason) {
3448:     PetscDrawLGDraw(lg);
3449:     PetscDrawLGSave(lg);
3450:   }

3452:   PetscViewerDrawGetDrawLG(v,2,&lg);
3453:   if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3454:   PetscDrawLGGetDraw(lg,&draw);
3455:   PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3456:   x    = (PetscReal)n;
3457:   y    = (prev - rnorm)/prev;
3458:   PetscDrawLGAddPoint(lg,&x,&y);
3459:   if (n < 20 || !(n % 5) || snes->reason) {
3460:     PetscDrawLGDraw(lg);
3461:     PetscDrawLGSave(lg);
3462:   }

3464:   PetscViewerDrawGetDrawLG(v,3,&lg);
3465:   if (!n) {PetscDrawLGReset(lg);}
3466:   PetscDrawLGGetDraw(lg,&draw);
3467:   PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3468:   x    = (PetscReal)n;
3469:   y    = (prev - rnorm)/(prev*per);
3470:   if (n > 2) { /*skip initial crazy value */
3471:     PetscDrawLGAddPoint(lg,&x,&y);
3472:   }
3473:   if (n < 20 || !(n % 5) || snes->reason) {
3474:     PetscDrawLGDraw(lg);
3475:     PetscDrawLGSave(lg);
3476:   }
3477:   prev = rnorm;
3478:   return(0);
3479: }

3481: /*@
3482:    SNESMonitor - runs the user provided monitor routines, if they exist

3484:    Collective on SNES

3486:    Input Parameters:
3487: +  snes - nonlinear solver context obtained from SNESCreate()
3488: .  iter - iteration number
3489: -  rnorm - relative norm of the residual

3491:    Notes:
3492:    This routine is called by the SNES implementations.
3493:    It does not typically need to be called by the user.

3495:    Level: developer

3497: .seealso: SNESMonitorSet()
3498: @*/
3499: PetscErrorCode  SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3500: {
3502:   PetscInt       i,n = snes->numbermonitors;

3505:   VecLockPush(snes->vec_sol);
3506:   for (i=0; i<n; i++) {
3507:     (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3508:   }
3509:   VecLockPop(snes->vec_sol);
3510:   return(0);
3511: }

3513: /* ------------ Routines to set performance monitoring options ----------- */

3515: /*MC
3516:     SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver

3518:      Synopsis:
3519:      #include <petscsnes.h>
3520: $    PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)

3522: +    snes - the SNES context
3523: .    its - iteration number
3524: .    norm - 2-norm function value (may be estimated)
3525: -    mctx - [optional] monitoring context

3527:    Level: advanced

3529: .seealso:   SNESMonitorSet(), SNESMonitorGet()
3530: M*/

3532: /*@C
3533:    SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3534:    iteration of the nonlinear solver to display the iteration's
3535:    progress.

3537:    Logically Collective on SNES

3539:    Input Parameters:
3540: +  snes - the SNES context
3541: .  f - the monitor function, see SNESMonitorFunction for the calling sequence
3542: .  mctx - [optional] user-defined context for private data for the
3543:           monitor routine (use NULL if no context is desired)
3544: -  monitordestroy - [optional] routine that frees monitor context
3545:           (may be NULL)

3547:    Options Database Keys:
3548: +    -snes_monitor        - sets SNESMonitorDefault()
3549: .    -snes_monitor_lg_residualnorm    - sets line graph monitor,
3550:                             uses SNESMonitorLGCreate()
3551: -    -snes_monitor_cancel - cancels all monitors that have
3552:                             been hardwired into a code by
3553:                             calls to SNESMonitorSet(), but
3554:                             does not cancel those set via
3555:                             the options database.

3557:    Notes:
3558:    Several different monitoring routines may be set by calling
3559:    SNESMonitorSet() multiple times; all will be called in the
3560:    order in which they were set.

3562:    Fortran notes: Only a single monitor function can be set for each SNES object

3564:    Level: intermediate

3566: .keywords: SNES, nonlinear, set, monitor

3568: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3569: @*/
3570: PetscErrorCode  SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3571: {
3572:   PetscInt       i;
3574:   PetscBool      identical;

3578:   for (i=0; i<snes->numbermonitors;i++) {
3579:     PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3580:     if (identical) return(0);
3581:   }
3582:   if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3583:   snes->monitor[snes->numbermonitors]          = f;
3584:   snes->monitordestroy[snes->numbermonitors]   = monitordestroy;
3585:   snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3586:   return(0);
3587: }

3589: /*@
3590:    SNESMonitorCancel - Clears all the monitor functions for a SNES object.

3592:    Logically Collective on SNES

3594:    Input Parameters:
3595: .  snes - the SNES context

3597:    Options Database Key:
3598: .  -snes_monitor_cancel - cancels all monitors that have been hardwired
3599:     into a code by calls to SNESMonitorSet(), but does not cancel those
3600:     set via the options database

3602:    Notes:
3603:    There is no way to clear one specific monitor from a SNES object.

3605:    Level: intermediate

3607: .keywords: SNES, nonlinear, set, monitor

3609: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3610: @*/
3611: PetscErrorCode  SNESMonitorCancel(SNES snes)
3612: {
3614:   PetscInt       i;

3618:   for (i=0; i<snes->numbermonitors; i++) {
3619:     if (snes->monitordestroy[i]) {
3620:       (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3621:     }
3622:   }
3623:   snes->numbermonitors = 0;
3624:   return(0);
3625: }

3627: /*MC
3628:     SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver

3630:      Synopsis:
3631:      #include <petscsnes.h>
3632: $     PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)

3634: +    snes - the SNES context
3635: .    it - current iteration (0 is the first and is before any Newton step)
3636: .    cctx - [optional] convergence context
3637: .    reason - reason for convergence/divergence
3638: .    xnorm - 2-norm of current iterate
3639: .    gnorm - 2-norm of current step
3640: -    f - 2-norm of function

3642:    Level: intermediate

3644: .seealso:   SNESSetConvergenceTest(), SNESGetConvergenceTest()
3645: M*/

3647: /*@C
3648:    SNESSetConvergenceTest - Sets the function that is to be used
3649:    to test for convergence of the nonlinear iterative solution.

3651:    Logically Collective on SNES

3653:    Input Parameters:
3654: +  snes - the SNES context
3655: .  SNESConvergenceTestFunction - routine to test for convergence
3656: .  cctx - [optional] context for private data for the convergence routine  (may be NULL)
3657: -  destroy - [optional] destructor for the context (may be NULL; NULL_FUNCTION in Fortran)

3659:    Level: advanced

3661: .keywords: SNES, nonlinear, set, convergence, test

3663: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3664: @*/
3665: PetscErrorCode  SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3666: {

3671:   if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3672:   if (snes->ops->convergeddestroy) {
3673:     (*snes->ops->convergeddestroy)(snes->cnvP);
3674:   }
3675:   snes->ops->converged        = SNESConvergenceTestFunction;
3676:   snes->ops->convergeddestroy = destroy;
3677:   snes->cnvP                  = cctx;
3678:   return(0);
3679: }

3681: /*@
3682:    SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.

3684:    Not Collective

3686:    Input Parameter:
3687: .  snes - the SNES context

3689:    Output Parameter:
3690: .  reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3691:             manual pages for the individual convergence tests for complete lists

3693:    Options Database:
3694: .   -snes_converged_reason - prints the reason to standard out

3696:    Level: intermediate

3698:    Notes: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.

3700: .keywords: SNES, nonlinear, set, convergence, test

3702: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
3703: @*/
3704: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
3705: {
3709:   *reason = snes->reason;
3710:   return(0);
3711: }

3713: /*@
3714:    SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.

3716:    Not Collective

3718:    Input Parameters:
3719: +  snes - the SNES context
3720: -  reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3721:             manual pages for the individual convergence tests for complete lists

3723:    Level: intermediate

3725: .keywords: SNES, nonlinear, set, convergence, test
3726: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
3727: @*/
3728: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
3729: {
3732:   snes->reason = reason;
3733:   return(0);
3734: }

3736: /*@
3737:    SNESSetConvergenceHistory - Sets the array used to hold the convergence history.

3739:    Logically Collective on SNES

3741:    Input Parameters:
3742: +  snes - iterative context obtained from SNESCreate()
3743: .  a   - array to hold history, this array will contain the function norms computed at each step
3744: .  its - integer array holds the number of linear iterations for each solve.
3745: .  na  - size of a and its
3746: -  reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
3747:            else it continues storing new values for new nonlinear solves after the old ones

3749:    Notes:
3750:    If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
3751:    default array of length 10000 is allocated.

3753:    This routine is useful, e.g., when running a code for purposes
3754:    of accurate performance monitoring, when no I/O should be done
3755:    during the section of code that is being timed.

3757:    Level: intermediate

3759: .keywords: SNES, set, convergence, history

3761: .seealso: SNESGetConvergenceHistory()

3763: @*/
3764: PetscErrorCode  SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
3765: {

3772:   if (!a) {
3773:     if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
3774:     PetscCalloc1(na,&a);
3775:     PetscCalloc1(na,&its);

3777:     snes->conv_malloc = PETSC_TRUE;
3778:   }
3779:   snes->conv_hist       = a;
3780:   snes->conv_hist_its   = its;
3781:   snes->conv_hist_max   = na;
3782:   snes->conv_hist_len   = 0;
3783:   snes->conv_hist_reset = reset;
3784:   return(0);
3785: }

3787: #if defined(PETSC_HAVE_MATLAB_ENGINE)
3788: #include <engine.h>   /* MATLAB include file */
3789: #include <mex.h>      /* MATLAB include file */

3791: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
3792: {
3793:   mxArray   *mat;
3794:   PetscInt  i;
3795:   PetscReal *ar;

3798:   mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
3799:   ar  = (PetscReal*) mxGetData(mat);
3800:   for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
3801:   PetscFunctionReturn(mat);
3802: }
3803: #endif

3805: /*@C
3806:    SNESGetConvergenceHistory - Gets the array used to hold the convergence history.

3808:    Not Collective

3810:    Input Parameter:
3811: .  snes - iterative context obtained from SNESCreate()

3813:    Output Parameters:
3814: .  a   - array to hold history
3815: .  its - integer array holds the number of linear iterations (or
3816:          negative if not converged) for each solve.
3817: -  na  - size of a and its

3819:    Notes:
3820:     The calling sequence for this routine in Fortran is
3821: $   call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)

3823:    This routine is useful, e.g., when running a code for purposes
3824:    of accurate performance monitoring, when no I/O should be done
3825:    during the section of code that is being timed.

3827:    Level: intermediate

3829: .keywords: SNES, get, convergence, history

3831: .seealso: SNESSetConvergencHistory()

3833: @*/
3834: PetscErrorCode  SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
3835: {
3838:   if (a)   *a   = snes->conv_hist;
3839:   if (its) *its = snes->conv_hist_its;
3840:   if (na)  *na  = snes->conv_hist_len;
3841:   return(0);
3842: }

3844: /*@C
3845:   SNESSetUpdate - Sets the general-purpose update function called
3846:   at the beginning of every iteration of the nonlinear solve. Specifically
3847:   it is called just before the Jacobian is "evaluated".

3849:   Logically Collective on SNES

3851:   Input Parameters:
3852: . snes - The nonlinear solver context
3853: . func - The function

3855:   Calling sequence of func:
3856: . func (SNES snes, PetscInt step);

3858: . step - The current step of the iteration

3860:   Level: advanced

3862:   Note: This is NOT what one uses to update the ghost points before a function evaluation, that should be done at the beginning of your FormFunction()
3863:         This is not used by most users.

3865: .keywords: SNES, update

3867: .seealso SNESSetJacobian(), SNESSolve()
3868: @*/
3869: PetscErrorCode  SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
3870: {
3873:   snes->ops->update = func;
3874:   return(0);
3875: }

3877: /*
3878:    SNESScaleStep_Private - Scales a step so that its length is less than the
3879:    positive parameter delta.

3881:     Input Parameters:
3882: +   snes - the SNES context
3883: .   y - approximate solution of linear system
3884: .   fnorm - 2-norm of current function
3885: -   delta - trust region size

3887:     Output Parameters:
3888: +   gpnorm - predicted function norm at the new point, assuming local
3889:     linearization.  The value is zero if the step lies within the trust
3890:     region, and exceeds zero otherwise.
3891: -   ynorm - 2-norm of the step

3893:     Note:
3894:     For non-trust region methods such as SNESNEWTONLS, the parameter delta
3895:     is set to be the maximum allowable step size.

3897: .keywords: SNES, nonlinear, scale, step
3898: */
3899: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
3900: {
3901:   PetscReal      nrm;
3902:   PetscScalar    cnorm;


3910:   VecNorm(y,NORM_2,&nrm);
3911:   if (nrm > *delta) {
3912:     nrm     = *delta/nrm;
3913:     *gpnorm = (1.0 - nrm)*(*fnorm);
3914:     cnorm   = nrm;
3915:     VecScale(y,cnorm);
3916:     *ynorm  = *delta;
3917:   } else {
3918:     *gpnorm = 0.0;
3919:     *ynorm  = nrm;
3920:   }
3921:   return(0);
3922: }

3924: /*@
3925:    SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer

3927:    Collective on SNES

3929:    Parameter:
3930: +  snes - iterative context obtained from SNESCreate()
3931: -  viewer - the viewer to display the reason


3934:    Options Database Keys:
3935: .  -snes_converged_reason - print reason for converged or diverged, also prints number of iterations

3937:    Level: beginner

3939: .keywords: SNES, solve, linear system

3941: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()

3943: @*/
3944: PetscErrorCode  SNESReasonView(SNES snes,PetscViewer viewer)
3945: {
3947:   PetscBool      isAscii;

3950:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
3951:   if (isAscii) {
3952:     PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
3953:     if (snes->reason > 0) {
3954:       if (((PetscObject) snes)->prefix) {
3955:         PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
3956:       } else {
3957:         PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
3958:       }
3959:     } else {
3960:       if (((PetscObject) snes)->prefix) {
3961:         PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
3962:       } else {
3963:         PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
3964:       }
3965:     }
3966:     PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
3967:   }
3968:   return(0);
3969: }

3971: /*@C
3972:   SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.

3974:   Collective on SNES

3976:   Input Parameters:
3977: . snes   - the SNES object

3979:   Level: intermediate

3981: @*/
3982: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
3983: {
3984:   PetscErrorCode    ierr;
3985:   PetscViewer       viewer;
3986:   PetscBool         flg;
3987:   static PetscBool  incall = PETSC_FALSE;
3988:   PetscViewerFormat format;

3991:   if (incall) return(0);
3992:   incall = PETSC_TRUE;
3993:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
3994:   if (flg) {
3995:     PetscViewerPushFormat(viewer,format);
3996:     SNESReasonView(snes,viewer);
3997:     PetscViewerPopFormat(viewer);
3998:     PetscViewerDestroy(&viewer);
3999:   }
4000:   incall = PETSC_FALSE;
4001:   return(0);
4002: }

4004: /*@C
4005:    SNESSolve - Solves a nonlinear system F(x) = b.
4006:    Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().

4008:    Collective on SNES

4010:    Input Parameters:
4011: +  snes - the SNES context
4012: .  b - the constant part of the equation F(x) = b, or NULL to use zero.
4013: -  x - the solution vector.

4015:    Notes:
4016:    The user should initialize the vector,x, with the initial guess
4017:    for the nonlinear solve prior to calling SNESSolve.  In particular,
4018:    to employ an initial guess of zero, the user should explicitly set
4019:    this vector to zero by calling VecSet().

4021:    Level: beginner

4023: .keywords: SNES, nonlinear, solve

4025: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4026: @*/
4027: PetscErrorCode  SNESSolve(SNES snes,Vec b,Vec x)
4028: {
4029:   PetscErrorCode    ierr;
4030:   PetscBool         flg;
4031:   PetscInt          grid;
4032:   Vec               xcreated = NULL;
4033:   DM                dm;


4042:   {
4043:     PetscViewer       viewer;
4044:     PetscViewerFormat format;
4045:     PetscBool         flg;
4046:     static PetscBool  incall = PETSC_FALSE;

4048:     if (!incall) {
4049:       PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes), ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4050:       if (flg) {
4051:         PetscConvEst conv;
4052:         PetscReal    alpha; /* Convergence rate of the solution error in the L_2 norm */

4054:         incall = PETSC_TRUE;
4055:         PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4056:         PetscConvEstSetSolver(conv, snes);
4057:         PetscConvEstSetFromOptions(conv);
4058:         PetscConvEstSetUp(conv);
4059:         PetscConvEstGetConvRate(conv, &alpha);
4060:         PetscViewerPushFormat(viewer, format);
4061:         PetscConvEstRateView(conv, alpha, viewer);
4062:         PetscViewerPopFormat(viewer);
4063:         PetscViewerDestroy(&viewer);
4064:         PetscConvEstDestroy(&conv);
4065:         incall = PETSC_FALSE;
4066:       }
4067:     }
4068:   }
4069:   if (!x) {
4070:     SNESGetDM(snes,&dm);
4071:     DMCreateGlobalVector(dm,&xcreated);
4072:     x    = xcreated;
4073:   }
4074:   SNESViewFromOptions(snes,NULL,"-snes_view_pre");

4076:   for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4077:   for (grid=0; grid<snes->gridsequence+1; grid++) {

4079:     /* set solution vector */
4080:     if (!grid) {PetscObjectReference((PetscObject)x);}
4081:     VecDestroy(&snes->vec_sol);
4082:     snes->vec_sol = x;
4083:     SNESGetDM(snes,&dm);

4085:     /* set affine vector if provided */
4086:     if (b) { PetscObjectReference((PetscObject)b); }
4087:     VecDestroy(&snes->vec_rhs);
4088:     snes->vec_rhs = b;

4090:     if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4091:     if (snes->vec_rhs  == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4092:     if (!snes->vec_sol_update /* && snes->vec_sol */) {
4093:       VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4094:       PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4095:     }
4096:     DMShellSetGlobalVector(dm,snes->vec_sol);
4097:     SNESSetUp(snes);

4099:     if (!grid) {
4100:       if (snes->ops->computeinitialguess) {
4101:         (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4102:       }
4103:     }

4105:     if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4106:     if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}

4108:     PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4109:     (*snes->ops->solve)(snes);
4110:     PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4111:     if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4112:     snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */

4114:     if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4115:     if (snes->lagpre_persist) snes->pre_iter += snes->iter;

4117:     PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4118:     if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4119:     SNESReasonViewFromOptions(snes);

4121:     if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4122:     if (snes->reason < 0) break;
4123:     if (grid <  snes->gridsequence) {
4124:       DM  fine;
4125:       Vec xnew;
4126:       Mat interp;

4128:       DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4129:       if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4130:       DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4131:       DMCreateGlobalVector(fine,&xnew);
4132:       MatInterpolate(interp,x,xnew);
4133:       DMInterpolate(snes->dm,interp,fine);
4134:       MatDestroy(&interp);
4135:       x    = xnew;

4137:       SNESReset(snes);
4138:       SNESSetDM(snes,fine);
4139:       DMDestroy(&fine);
4140:       PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4141:     }
4142:   }
4143:   SNESViewFromOptions(snes,NULL,"-snes_view");
4144:   VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");

4146:   VecDestroy(&xcreated);
4147:   PetscObjectSAWsBlock((PetscObject)snes);
4148:   return(0);
4149: }

4151: /* --------- Internal routines for SNES Package --------- */

4153: /*@C
4154:    SNESSetType - Sets the method for the nonlinear solver.

4156:    Collective on SNES

4158:    Input Parameters:
4159: +  snes - the SNES context
4160: -  type - a known method

4162:    Options Database Key:
4163: .  -snes_type <type> - Sets the method; use -help for a list
4164:    of available methods (for instance, newtonls or newtontr)

4166:    Notes:
4167:    See "petsc/include/petscsnes.h" for available methods (for instance)
4168: +    SNESNEWTONLS - Newton's method with line search
4169:      (systems of nonlinear equations)
4170: .    SNESNEWTONTR - Newton's method with trust region
4171:      (systems of nonlinear equations)

4173:   Normally, it is best to use the SNESSetFromOptions() command and then
4174:   set the SNES solver type from the options database rather than by using
4175:   this routine.  Using the options database provides the user with
4176:   maximum flexibility in evaluating the many nonlinear solvers.
4177:   The SNESSetType() routine is provided for those situations where it
4178:   is necessary to set the nonlinear solver independently of the command
4179:   line or options database.  This might be the case, for example, when
4180:   the choice of solver changes during the execution of the program,
4181:   and the user's application is taking responsibility for choosing the
4182:   appropriate method.

4184:     Developer Notes: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4185:     the constructor in that list and calls it to create the spexific object.

4187:   Level: intermediate

4189: .keywords: SNES, set, type

4191: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()

4193: @*/
4194: PetscErrorCode  SNESSetType(SNES snes,SNESType type)
4195: {
4196:   PetscErrorCode ierr,(*r)(SNES);
4197:   PetscBool      match;


4203:   PetscObjectTypeCompare((PetscObject)snes,type,&match);
4204:   if (match) return(0);

4206:    PetscFunctionListFind(SNESList,type,&r);
4207:   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4208:   /* Destroy the previous private SNES context */
4209:   if (snes->ops->destroy) {
4210:     (*(snes)->ops->destroy)(snes);
4211:     snes->ops->destroy = NULL;
4212:   }
4213:   /* Reinitialize function pointers in SNESOps structure */
4214:   snes->ops->setup          = 0;
4215:   snes->ops->solve          = 0;
4216:   snes->ops->view           = 0;
4217:   snes->ops->setfromoptions = 0;
4218:   snes->ops->destroy        = 0;
4219:   /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4220:   snes->setupcalled = PETSC_FALSE;

4222:   PetscObjectChangeTypeName((PetscObject)snes,type);
4223:   (*r)(snes);
4224:   return(0);
4225: }

4227: /*@C
4228:    SNESGetType - Gets the SNES method type and name (as a string).

4230:    Not Collective

4232:    Input Parameter:
4233: .  snes - nonlinear solver context

4235:    Output Parameter:
4236: .  type - SNES method (a character string)

4238:    Level: intermediate

4240: .keywords: SNES, nonlinear, get, type, name
4241: @*/
4242: PetscErrorCode  SNESGetType(SNES snes,SNESType *type)
4243: {
4247:   *type = ((PetscObject)snes)->type_name;
4248:   return(0);
4249: }

4251: /*@
4252:   SNESSetSolution - Sets the solution vector for use by the SNES routines.

4254:   Logically Collective on SNES and Vec

4256:   Input Parameters:
4257: + snes - the SNES context obtained from SNESCreate()
4258: - u    - the solution vector

4260:   Level: beginner

4262: .keywords: SNES, set, solution
4263: @*/
4264: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4265: {
4266:   DM             dm;

4272:   PetscObjectReference((PetscObject) u);
4273:   VecDestroy(&snes->vec_sol);

4275:   snes->vec_sol = u;

4277:   SNESGetDM(snes, &dm);
4278:   DMShellSetGlobalVector(dm, u);
4279:   return(0);
4280: }

4282: /*@
4283:    SNESGetSolution - Returns the vector where the approximate solution is
4284:    stored. This is the fine grid solution when using SNESSetGridSequence().

4286:    Not Collective, but Vec is parallel if SNES is parallel

4288:    Input Parameter:
4289: .  snes - the SNES context

4291:    Output Parameter:
4292: .  x - the solution

4294:    Level: intermediate

4296: .keywords: SNES, nonlinear, get, solution

4298: .seealso:  SNESGetSolutionUpdate(), SNESGetFunction()
4299: @*/
4300: PetscErrorCode  SNESGetSolution(SNES snes,Vec *x)
4301: {
4305:   *x = snes->vec_sol;
4306:   return(0);
4307: }

4309: /*@
4310:    SNESGetSolutionUpdate - Returns the vector where the solution update is
4311:    stored.

4313:    Not Collective, but Vec is parallel if SNES is parallel

4315:    Input Parameter:
4316: .  snes - the SNES context

4318:    Output Parameter:
4319: .  x - the solution update

4321:    Level: advanced

4323: .keywords: SNES, nonlinear, get, solution, update

4325: .seealso: SNESGetSolution(), SNESGetFunction()
4326: @*/
4327: PetscErrorCode  SNESGetSolutionUpdate(SNES snes,Vec *x)
4328: {
4332:   *x = snes->vec_sol_update;
4333:   return(0);
4334: }

4336: /*@C
4337:    SNESGetFunction - Returns the vector where the function is stored.

4339:    Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.

4341:    Input Parameter:
4342: .  snes - the SNES context

4344:    Output Parameter:
4345: +  r - the vector that is used to store residuals (or NULL if you don't want it)
4346: .  f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4347: -  ctx - the function context (or NULL if you don't want it)

4349:    Level: advanced

4351: .keywords: SNES, nonlinear, get, function

4353: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4354: @*/
4355: PetscErrorCode  SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4356: {
4358:   DM             dm;

4362:   if (r) {
4363:     if (!snes->vec_func) {
4364:       if (snes->vec_rhs) {
4365:         VecDuplicate(snes->vec_rhs,&snes->vec_func);
4366:       } else if (snes->vec_sol) {
4367:         VecDuplicate(snes->vec_sol,&snes->vec_func);
4368:       } else if (snes->dm) {
4369:         DMCreateGlobalVector(snes->dm,&snes->vec_func);
4370:       }
4371:     }
4372:     *r = snes->vec_func;
4373:   }
4374:   SNESGetDM(snes,&dm);
4375:   DMSNESGetFunction(dm,f,ctx);
4376:   return(0);
4377: }

4379: /*@C
4380:    SNESGetNGS - Returns the NGS function and context.

4382:    Input Parameter:
4383: .  snes - the SNES context

4385:    Output Parameter:
4386: +  f - the function (or NULL) see SNESNGSFunction for details
4387: -  ctx    - the function context (or NULL)

4389:    Level: advanced

4391: .keywords: SNES, nonlinear, get, function

4393: .seealso: SNESSetNGS(), SNESGetFunction()
4394: @*/

4396: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4397: {
4399:   DM             dm;

4403:   SNESGetDM(snes,&dm);
4404:   DMSNESGetNGS(dm,f,ctx);
4405:   return(0);
4406: }

4408: /*@C
4409:    SNESSetOptionsPrefix - Sets the prefix used for searching for all
4410:    SNES options in the database.

4412:    Logically Collective on SNES

4414:    Input Parameter:
4415: +  snes - the SNES context
4416: -  prefix - the prefix to prepend to all option names

4418:    Notes:
4419:    A hyphen (-) must NOT be given at the beginning of the prefix name.
4420:    The first character of all runtime options is AUTOMATICALLY the hyphen.

4422:    Level: advanced

4424: .keywords: SNES, set, options, prefix, database

4426: .seealso: SNESSetFromOptions()
4427: @*/
4428: PetscErrorCode  SNESSetOptionsPrefix(SNES snes,const char prefix[])
4429: {

4434:   PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4435:   if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4436:   if (snes->linesearch) {
4437:     SNESGetLineSearch(snes,&snes->linesearch);
4438:     PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4439:   }
4440:   KSPSetOptionsPrefix(snes->ksp,prefix);
4441:   return(0);
4442: }

4444: /*@C
4445:    SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4446:    SNES options in the database.

4448:    Logically Collective on SNES

4450:    Input Parameters:
4451: +  snes - the SNES context
4452: -  prefix - the prefix to prepend to all option names

4454:    Notes:
4455:    A hyphen (-) must NOT be given at the beginning of the prefix name.
4456:    The first character of all runtime options is AUTOMATICALLY the hyphen.

4458:    Level: advanced

4460: .keywords: SNES, append, options, prefix, database

4462: .seealso: SNESGetOptionsPrefix()
4463: @*/
4464: PetscErrorCode  SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4465: {

4470:   PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4471:   if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4472:   if (snes->linesearch) {
4473:     SNESGetLineSearch(snes,&snes->linesearch);
4474:     PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4475:   }
4476:   KSPAppendOptionsPrefix(snes->ksp,prefix);
4477:   return(0);
4478: }

4480: /*@C
4481:    SNESGetOptionsPrefix - Sets the prefix used for searching for all
4482:    SNES options in the database.

4484:    Not Collective

4486:    Input Parameter:
4487: .  snes - the SNES context

4489:    Output Parameter:
4490: .  prefix - pointer to the prefix string used

4492:    Notes: On the fortran side, the user should pass in a string 'prefix' of
4493:    sufficient length to hold the prefix.

4495:    Level: advanced

4497: .keywords: SNES, get, options, prefix, database

4499: .seealso: SNESAppendOptionsPrefix()
4500: @*/
4501: PetscErrorCode  SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4502: {

4507:   PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4508:   return(0);
4509: }


4512: /*@C
4513:   SNESRegister - Adds a method to the nonlinear solver package.

4515:    Not collective

4517:    Input Parameters:
4518: +  name_solver - name of a new user-defined solver
4519: -  routine_create - routine to create method context

4521:    Notes:
4522:    SNESRegister() may be called multiple times to add several user-defined solvers.

4524:    Sample usage:
4525: .vb
4526:    SNESRegister("my_solver",MySolverCreate);
4527: .ve

4529:    Then, your solver can be chosen with the procedural interface via
4530: $     SNESSetType(snes,"my_solver")
4531:    or at runtime via the option
4532: $     -snes_type my_solver

4534:    Level: advanced

4536:     Note: If your function is not being put into a shared library then use SNESRegister() instead

4538: .keywords: SNES, nonlinear, register

4540: .seealso: SNESRegisterAll(), SNESRegisterDestroy()

4542:   Level: advanced
4543: @*/
4544: PetscErrorCode  SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4545: {

4549:   PetscFunctionListAdd(&SNESList,sname,function);
4550:   return(0);
4551: }

4553: PetscErrorCode  SNESTestLocalMin(SNES snes)
4554: {
4556:   PetscInt       N,i,j;
4557:   Vec            u,uh,fh;
4558:   PetscScalar    value;
4559:   PetscReal      norm;

4562:   SNESGetSolution(snes,&u);
4563:   VecDuplicate(u,&uh);
4564:   VecDuplicate(u,&fh);

4566:   /* currently only works for sequential */
4567:   PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4568:   VecGetSize(u,&N);
4569:   for (i=0; i<N; i++) {
4570:     VecCopy(u,uh);
4571:     PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4572:     for (j=-10; j<11; j++) {
4573:       value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4574:       VecSetValue(uh,i,value,ADD_VALUES);
4575:       SNESComputeFunction(snes,uh,fh);
4576:       VecNorm(fh,NORM_2,&norm);
4577:       PetscPrintf(PETSC_COMM_WORLD,"       j norm %D %18.16e\n",j,norm);
4578:       value = -value;
4579:       VecSetValue(uh,i,value,ADD_VALUES);
4580:     }
4581:   }
4582:   VecDestroy(&uh);
4583:   VecDestroy(&fh);
4584:   return(0);
4585: }

4587: /*@
4588:    SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4589:    computing relative tolerance for linear solvers within an inexact
4590:    Newton method.

4592:    Logically Collective on SNES

4594:    Input Parameters:
4595: +  snes - SNES context
4596: -  flag - PETSC_TRUE or PETSC_FALSE

4598:     Options Database:
4599: +  -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4600: .  -snes_ksp_ew_version ver - version of  Eisenstat-Walker method
4601: .  -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4602: .  -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4603: .  -snes_ksp_ew_gamma <gamma> - Sets gamma
4604: .  -snes_ksp_ew_alpha <alpha> - Sets alpha
4605: .  -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4606: -  -snes_ksp_ew_threshold <threshold> - Sets threshold

4608:    Notes:
4609:    Currently, the default is to use a constant relative tolerance for
4610:    the inner linear solvers.  Alternatively, one can use the
4611:    Eisenstat-Walker method, where the relative convergence tolerance
4612:    is reset at each Newton iteration according progress of the nonlinear
4613:    solver.

4615:    Level: advanced

4617:    Reference:
4618:    S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4619:    inexact Newton method", SISC 17 (1), pp.16-32, 1996.

4621: .keywords: SNES, KSP, Eisenstat, Walker, convergence, test, inexact, Newton

4623: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4624: @*/
4625: PetscErrorCode  SNESKSPSetUseEW(SNES snes,PetscBool flag)
4626: {
4630:   snes->ksp_ewconv = flag;
4631:   return(0);
4632: }

4634: /*@
4635:    SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
4636:    for computing relative tolerance for linear solvers within an
4637:    inexact Newton method.

4639:    Not Collective

4641:    Input Parameter:
4642: .  snes - SNES context

4644:    Output Parameter:
4645: .  flag - PETSC_TRUE or PETSC_FALSE

4647:    Notes:
4648:    Currently, the default is to use a constant relative tolerance for
4649:    the inner linear solvers.  Alternatively, one can use the
4650:    Eisenstat-Walker method, where the relative convergence tolerance
4651:    is reset at each Newton iteration according progress of the nonlinear
4652:    solver.

4654:    Level: advanced

4656:    Reference:
4657:    S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4658:    inexact Newton method", SISC 17 (1), pp.16-32, 1996.

4660: .keywords: SNES, KSP, Eisenstat, Walker, convergence, test, inexact, Newton

4662: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4663: @*/
4664: PetscErrorCode  SNESKSPGetUseEW(SNES snes, PetscBool  *flag)
4665: {
4669:   *flag = snes->ksp_ewconv;
4670:   return(0);
4671: }

4673: /*@
4674:    SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
4675:    convergence criteria for the linear solvers within an inexact
4676:    Newton method.

4678:    Logically Collective on SNES

4680:    Input Parameters:
4681: +    snes - SNES context
4682: .    version - version 1, 2 (default is 2) or 3
4683: .    rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
4684: .    rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
4685: .    gamma - multiplicative factor for version 2 rtol computation
4686:              (0 <= gamma2 <= 1)
4687: .    alpha - power for version 2 rtol computation (1 < alpha <= 2)
4688: .    alpha2 - power for safeguard
4689: -    threshold - threshold for imposing safeguard (0 < threshold < 1)

4691:    Note:
4692:    Version 3 was contributed by Luis Chacon, June 2006.

4694:    Use PETSC_DEFAULT to retain the default for any of the parameters.

4696:    Level: advanced

4698:    Reference:
4699:    S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4700:    inexact Newton method", Utah State University Math. Stat. Dept. Res.
4701:    Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.

4703: .keywords: SNES, KSP, Eisenstat, Walker, set, parameters

4705: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
4706: @*/
4707: PetscErrorCode  SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
4708: {
4709:   SNESKSPEW *kctx;

4713:   kctx = (SNESKSPEW*)snes->kspconvctx;
4714:   if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");

4723:   if (version != PETSC_DEFAULT)   kctx->version   = version;
4724:   if (rtol_0 != PETSC_DEFAULT)    kctx->rtol_0    = rtol_0;
4725:   if (rtol_max != PETSC_DEFAULT)  kctx->rtol_max  = rtol_max;
4726:   if (gamma != PETSC_DEFAULT)     kctx->gamma     = gamma;
4727:   if (alpha != PETSC_DEFAULT)     kctx->alpha     = alpha;
4728:   if (alpha2 != PETSC_DEFAULT)    kctx->alpha2    = alpha2;
4729:   if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;

4731:   if (kctx->version < 1 || kctx->version > 3) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 and 3 are supported: %D",kctx->version);
4732:   if (kctx->rtol_0 < 0.0 || kctx->rtol_0 >= 1.0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"0.0 <= rtol_0 < 1.0: %g",(double)kctx->rtol_0);
4733:   if (kctx->rtol_max < 0.0 || kctx->rtol_max >= 1.0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"0.0 <= rtol_max (%g) < 1.0\n",(double)kctx->rtol_max);
4734:   if (kctx->gamma < 0.0 || kctx->gamma > 1.0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"0.0 <= gamma (%g) <= 1.0\n",(double)kctx->gamma);
4735:   if (kctx->alpha <= 1.0 || kctx->alpha > 2.0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"1.0 < alpha (%g) <= 2.0\n",(double)kctx->alpha);
4736:   if (kctx->threshold <= 0.0 || kctx->threshold >= 1.0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"0.0 < threshold (%g) < 1.0\n",(double)kctx->threshold);
4737:   return(0);
4738: }

4740: /*@
4741:    SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
4742:    convergence criteria for the linear solvers within an inexact
4743:    Newton method.

4745:    Not Collective

4747:    Input Parameters:
4748:      snes - SNES context

4750:    Output Parameters:
4751: +    version - version 1, 2 (default is 2) or 3
4752: .    rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
4753: .    rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
4754: .    gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
4755: .    alpha - power for version 2 rtol computation (1 < alpha <= 2)
4756: .    alpha2 - power for safeguard
4757: -    threshold - threshold for imposing safeguard (0 < threshold < 1)

4759:    Level: advanced

4761: .keywords: SNES, KSP, Eisenstat, Walker, get, parameters

4763: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
4764: @*/
4765: PetscErrorCode  SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
4766: {
4767:   SNESKSPEW *kctx;

4771:   kctx = (SNESKSPEW*)snes->kspconvctx;
4772:   if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
4773:   if (version)   *version   = kctx->version;
4774:   if (rtol_0)    *rtol_0    = kctx->rtol_0;
4775:   if (rtol_max)  *rtol_max  = kctx->rtol_max;
4776:   if (gamma)     *gamma     = kctx->gamma;
4777:   if (alpha)     *alpha     = kctx->alpha;
4778:   if (alpha2)    *alpha2    = kctx->alpha2;
4779:   if (threshold) *threshold = kctx->threshold;
4780:   return(0);
4781: }

4783:  PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
4784: {
4786:   SNESKSPEW      *kctx = (SNESKSPEW*)snes->kspconvctx;
4787:   PetscReal      rtol  = PETSC_DEFAULT,stol;

4790:   if (!snes->ksp_ewconv) return(0);
4791:   if (!snes->iter) {
4792:     rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
4793:     VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
4794:   }
4795:   else {
4796:     if (kctx->version == 1) {
4797:       rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
4798:       if (rtol < 0.0) rtol = -rtol;
4799:       stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
4800:       if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
4801:     } else if (kctx->version == 2) {
4802:       rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
4803:       stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
4804:       if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
4805:     } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
4806:       rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
4807:       /* safeguard: avoid sharp decrease of rtol */
4808:       stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
4809:       stol = PetscMax(rtol,stol);
4810:       rtol = PetscMin(kctx->rtol_0,stol);
4811:       /* safeguard: avoid oversolving */
4812:       stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
4813:       stol = PetscMax(rtol,stol);
4814:       rtol = PetscMin(kctx->rtol_0,stol);
4815:     } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
4816:   }
4817:   /* safeguard: avoid rtol greater than one */
4818:   rtol = PetscMin(rtol,kctx->rtol_max);
4819:   KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
4820:   PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
4821:   return(0);
4822: }

4824: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
4825: {
4827:   SNESKSPEW      *kctx = (SNESKSPEW*)snes->kspconvctx;
4828:   PCSide         pcside;
4829:   Vec            lres;

4832:   if (!snes->ksp_ewconv) return(0);
4833:   KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
4834:   kctx->norm_last = snes->norm;
4835:   if (kctx->version == 1) {
4836:     PC        pc;
4837:     PetscBool isNone;

4839:     KSPGetPC(ksp, &pc);
4840:     PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
4841:     KSPGetPCSide(ksp,&pcside);
4842:      if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
4843:       /* KSP residual is true linear residual */
4844:       KSPGetResidualNorm(ksp,&kctx->lresid_last);
4845:     } else {
4846:       /* KSP residual is preconditioned residual */
4847:       /* compute true linear residual norm */
4848:       VecDuplicate(b,&lres);
4849:       MatMult(snes->jacobian,x,lres);
4850:       VecAYPX(lres,-1.0,b);
4851:       VecNorm(lres,NORM_2,&kctx->lresid_last);
4852:       VecDestroy(&lres);
4853:     }
4854:   }
4855:   return(0);
4856: }

4858: /*@
4859:    SNESGetKSP - Returns the KSP context for a SNES solver.

4861:    Not Collective, but if SNES object is parallel, then KSP object is parallel

4863:    Input Parameter:
4864: .  snes - the SNES context

4866:    Output Parameter:
4867: .  ksp - the KSP context

4869:    Notes:
4870:    The user can then directly manipulate the KSP context to set various
4871:    options, etc.  Likewise, the user can then extract and manipulate the
4872:    PC contexts as well.

4874:    Level: beginner

4876: .keywords: SNES, nonlinear, get, KSP, context

4878: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
4879: @*/
4880: PetscErrorCode  SNESGetKSP(SNES snes,KSP *ksp)
4881: {


4888:   if (!snes->ksp) {
4889:     PetscBool monitor = PETSC_FALSE;

4891:     KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
4892:     PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
4893:     PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);

4895:     KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
4896:     KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);

4898:     PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
4899:     if (monitor) {
4900:       KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
4901:     }
4902:     monitor = PETSC_FALSE;
4903:     PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
4904:     if (monitor) {
4905:       PetscObject *objs;
4906:       KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
4907:       objs[0] = (PetscObject) snes;
4908:       KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
4909:     }
4910:   }
4911:   *ksp = snes->ksp;
4912:   return(0);
4913: }


4916:  #include <petsc/private/dmimpl.h>
4917: /*@
4918:    SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners

4920:    Logically Collective on SNES

4922:    Input Parameters:
4923: +  snes - the nonlinear solver context
4924: -  dm - the dm, cannot be NULL

4926:    Level: intermediate

4928: .seealso: SNESGetDM(), SNESHasDM(), KSPSetDM(), KSPGetDM()
4929: @*/
4930: PetscErrorCode  SNESSetDM(SNES snes,DM dm)
4931: {
4933:   KSP            ksp;
4934:   DMSNES         sdm;

4939:   PetscObjectReference((PetscObject)dm);
4940:   if (snes->dm) {               /* Move the DMSNES context over to the new DM unless the new DM already has one */
4941:     if (snes->dm->dmsnes && !dm->dmsnes) {
4942:       DMCopyDMSNES(snes->dm,dm);
4943:       DMGetDMSNES(snes->dm,&sdm);
4944:       if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
4945:     }
4946:     DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
4947:     DMDestroy(&snes->dm);
4948:   }
4949:   snes->dm     = dm;
4950:   snes->dmAuto = PETSC_FALSE;

4952:   SNESGetKSP(snes,&ksp);
4953:   KSPSetDM(ksp,dm);
4954:   KSPSetDMActive(ksp,PETSC_FALSE);
4955:   if (snes->npc) {
4956:     SNESSetDM(snes->npc, snes->dm);
4957:     SNESSetNPCSide(snes,snes->npcside);
4958:   }
4959:   return(0);
4960: }

4962: /*@
4963:    SNESGetDM - Gets the DM that may be used by some preconditioners

4965:    Not Collective but DM obtained is parallel on SNES

4967:    Input Parameter:
4968: . snes - the preconditioner context

4970:    Output Parameter:
4971: .  dm - the dm

4973:    Level: intermediate

4975: .seealso: SNESSetDM(), SNESHasDM(), KSPSetDM(), KSPGetDM()
4976: @*/
4977: PetscErrorCode  SNESGetDM(SNES snes,DM *dm)
4978: {

4983:   if (!snes->dm) {
4984:     DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
4985:     snes->dmAuto = PETSC_TRUE;
4986:   }
4987:   *dm = snes->dm;
4988:   return(0);
4989: }


4992: /*@
4993:    SNESHasDM - Whether snes has dm

4995:    Not collective but all processes must return the same value

4997:    Input Parameter:
4998: . snes - the nonlinear solver object

5000:    Output Parameter:
5001: .  hasdm - a flag indicates whether there is dm in snes

5003:    Level: intermediate

5005: .seealso: SNESGetDM(), SNESSetDM(), KSPSetDM(), KSPGetDM()
5006: @*/
5007: PetscErrorCode  SNESHasDM(SNES snes,PetscBool *hasdm)
5008: {
5012:   if (snes->dm) *hasdm = PETSC_TRUE;
5013:   else *hasdm = PETSC_FALSE;
5014:   return(0);
5015: }

5017: /*@
5018:   SNESSetNPC - Sets the nonlinear preconditioner to be used.

5020:   Collective on SNES

5022:   Input Parameters:
5023: + snes - iterative context obtained from SNESCreate()
5024: - pc   - the preconditioner object

5026:   Notes:
5027:   Use SNESGetNPC() to retrieve the preconditioner context (for example,
5028:   to configure it using the API).

5030:   Level: developer

5032: .keywords: SNES, set, precondition
5033: .seealso: SNESGetNPC(), SNESHasNPC()
5034: @*/
5035: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5036: {

5043:   PetscObjectReference((PetscObject) pc);
5044:   SNESDestroy(&snes->npc);
5045:   snes->npc = pc;
5046:   PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5047:   return(0);
5048: }

5050: /*@
5051:   SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.

5053:   Not Collective

5055:   Input Parameter:
5056: . snes - iterative context obtained from SNESCreate()

5058:   Output Parameter:
5059: . pc - preconditioner context

5061:   Notes: If a SNES was previously set with SNESSetNPC() then that SNES is returned.

5063:   Level: developer

5065: .keywords: SNES, get, preconditioner
5066: .seealso: SNESSetNPC(), SNESHasNPC()
5067: @*/
5068: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5069: {
5071:   const char     *optionsprefix;

5076:   if (!snes->npc) {
5077:     SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5078:     PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5079:     PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5080:     SNESGetOptionsPrefix(snes,&optionsprefix);
5081:     SNESSetOptionsPrefix(snes->npc,optionsprefix);
5082:     SNESAppendOptionsPrefix(snes->npc,"npc_");
5083:     SNESSetCountersReset(snes->npc,PETSC_FALSE);
5084:   }
5085:   *pc = snes->npc;
5086:   return(0);
5087: }

5089: /*@
5090:   SNESHasNPC - Returns whether a nonlinear preconditioner exists

5092:   Not Collective

5094:   Input Parameter:
5095: . snes - iterative context obtained from SNESCreate()

5097:   Output Parameter:
5098: . has_npc - whether the SNES has an NPC or not

5100:   Level: developer

5102: .keywords: SNES, has, preconditioner
5103: .seealso: SNESSetNPC(), SNESGetNPC()
5104: @*/
5105: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5106: {
5109:   *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5110:   return(0);
5111: }

5113: /*@
5114:     SNESSetNPCSide - Sets the preconditioning side.

5116:     Logically Collective on SNES

5118:     Input Parameter:
5119: .   snes - iterative context obtained from SNESCreate()

5121:     Output Parameter:
5122: .   side - the preconditioning side, where side is one of
5123: .vb
5124:       PC_LEFT - left preconditioning
5125:       PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5126: .ve

5128:     Options Database Keys:
5129: .   -snes_pc_side <right,left>

5131:     Notes: SNESNRICHARDSON and SNESNCG only support left preconditioning.

5133:     Level: intermediate

5135: .keywords: SNES, set, right, left, side, preconditioner, flag

5137: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5138: @*/
5139: PetscErrorCode  SNESSetNPCSide(SNES snes,PCSide side)
5140: {
5144:   snes->npcside= side;
5145:   return(0);
5146: }

5148: /*@
5149:     SNESGetNPCSide - Gets the preconditioning side.

5151:     Not Collective

5153:     Input Parameter:
5154: .   snes - iterative context obtained from SNESCreate()

5156:     Output Parameter:
5157: .   side - the preconditioning side, where side is one of
5158: .vb
5159:       PC_LEFT - left preconditioning
5160:       PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5161: .ve

5163:     Level: intermediate

5165: .keywords: SNES, get, right, left, side, preconditioner, flag

5167: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5168: @*/
5169: PetscErrorCode  SNESGetNPCSide(SNES snes,PCSide *side)
5170: {
5174:   *side = snes->npcside;
5175:   return(0);
5176: }

5178: /*@
5179:   SNESSetLineSearch - Sets the linesearch on the SNES instance.

5181:   Collective on SNES

5183:   Input Parameters:
5184: + snes - iterative context obtained from SNESCreate()
5185: - linesearch   - the linesearch object

5187:   Notes:
5188:   Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5189:   to configure it using the API).

5191:   Level: developer

5193: .keywords: SNES, set, linesearch
5194: .seealso: SNESGetLineSearch()
5195: @*/
5196: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5197: {

5204:   PetscObjectReference((PetscObject) linesearch);
5205:   SNESLineSearchDestroy(&snes->linesearch);

5207:   snes->linesearch = linesearch;

5209:   PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5210:   return(0);
5211: }

5213: /*@
5214:   SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5215:   or creates a default line search instance associated with the SNES and returns it.

5217:   Not Collective

5219:   Input Parameter:
5220: . snes - iterative context obtained from SNESCreate()

5222:   Output Parameter:
5223: . linesearch - linesearch context

5225:   Level: beginner

5227: .keywords: SNES, get, linesearch
5228: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5229: @*/
5230: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5231: {
5233:   const char     *optionsprefix;

5238:   if (!snes->linesearch) {
5239:     SNESGetOptionsPrefix(snes, &optionsprefix);
5240:     SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5241:     SNESLineSearchSetSNES(snes->linesearch, snes);
5242:     SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5243:     PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5244:     PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5245:   }
5246:   *linesearch = snes->linesearch;
5247:   return(0);
5248: }

5250: #if defined(PETSC_HAVE_MATLAB_ENGINE)
5251: #include <mex.h>

5253: typedef struct {char *funcname; mxArray *ctx;} SNESMatlabContext;

5255: /*
5256:    SNESComputeFunction_Matlab - Calls the function that has been set with SNESSetFunctionMatlab().

5258:    Collective on SNES

5260:    Input Parameters:
5261: +  snes - the SNES context
5262: -  x - input vector

5264:    Output Parameter:
5265: .  y - function vector, as set by SNESSetFunction()

5267:    Notes:
5268:    SNESComputeFunction() is typically used within nonlinear solvers
5269:    implementations, so most users would not generally call this routine
5270:    themselves.

5272:    Level: developer

5274: .keywords: SNES, nonlinear, compute, function

5276: .seealso: SNESSetFunction(), SNESGetFunction()
5277: */
5278: PetscErrorCode  SNESComputeFunction_Matlab(SNES snes,Vec x,Vec y, void *ctx)
5279: {
5280:   PetscErrorCode    ierr;
5281:   SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
5282:   int               nlhs  = 1,nrhs = 5;
5283:   mxArray           *plhs[1],*prhs[5];
5284:   long long int     lx = 0,ly = 0,ls = 0;


5293:   /* call Matlab function in ctx with arguments x and y */

5295:   PetscMemcpy(&ls,&snes,sizeof(snes));
5296:   PetscMemcpy(&lx,&x,sizeof(x));
5297:   PetscMemcpy(&ly,&y,sizeof(x));
5298:   prhs[0] = mxCreateDoubleScalar((double)ls);
5299:   prhs[1] = mxCreateDoubleScalar((double)lx);
5300:   prhs[2] = mxCreateDoubleScalar((double)ly);
5301:   prhs[3] = mxCreateString(sctx->funcname);
5302:   prhs[4] = sctx->ctx;
5303:   mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESComputeFunctionInternal");
5304:   mxGetScalar(plhs[0]);
5305:   mxDestroyArray(prhs[0]);
5306:   mxDestroyArray(prhs[1]);
5307:   mxDestroyArray(prhs[2]);
5308:   mxDestroyArray(prhs[3]);
5309:   mxDestroyArray(plhs[0]);
5310:   return(0);
5311: }

5313: /*
5314:    SNESSetFunctionMatlab - Sets the function evaluation routine and function
5315:    vector for use by the SNES routines in solving systems of nonlinear
5316:    equations from MATLAB. Here the function is a string containing the name of a MATLAB function

5318:    Logically Collective on SNES

5320:    Input Parameters:
5321: +  snes - the SNES context
5322: .  r - vector to store function value
5323: -  f - function evaluation routine

5325:    Notes:
5326:    The Newton-like methods typically solve linear systems of the form
5327: $      f'(x) x = -f(x),
5328:    where f'(x) denotes the Jacobian matrix and f(x) is the function.

5330:    Level: beginner

5332:    Developer Note:  This bleeds the allocated memory SNESMatlabContext *sctx;

5334: .keywords: SNES, nonlinear, set, function

5336: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
5337: */
5338: PetscErrorCode  SNESSetFunctionMatlab(SNES snes,Vec r,const char *f,mxArray *ctx)
5339: {
5340:   PetscErrorCode    ierr;
5341:   SNESMatlabContext *sctx;

5344:   /* currently sctx is memory bleed */
5345:   PetscNew(&sctx);
5346:   PetscStrallocpy(f,&sctx->funcname);
5347:   /*
5348:      This should work, but it doesn't
5349:   sctx->ctx = ctx;
5350:   mexMakeArrayPersistent(sctx->ctx);
5351:   */
5352:   sctx->ctx = mxDuplicateArray(ctx);
5353:   SNESSetFunction(snes,r,SNESComputeFunction_Matlab,sctx);
5354:   return(0);
5355: }

5357: /*
5358:    SNESComputeJacobian_Matlab - Calls the function that has been set with SNESSetJacobianMatlab().

5360:    Collective on SNES

5362:    Input Parameters:
5363: +  snes - the SNES context
5364: .  x - input vector
5365: .  A, B - the matrices
5366: -  ctx - user context

5368:    Level: developer

5370: .keywords: SNES, nonlinear, compute, function

5372: .seealso: SNESSetFunction(), SNESGetFunction()
5373: @*/
5374: PetscErrorCode  SNESComputeJacobian_Matlab(SNES snes,Vec x,Mat A,Mat B,void *ctx)
5375: {
5376:   PetscErrorCode    ierr;
5377:   SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
5378:   int               nlhs  = 2,nrhs = 6;
5379:   mxArray           *plhs[2],*prhs[6];
5380:   long long int     lx = 0,lA = 0,ls = 0, lB = 0;


5386:   /* call Matlab function in ctx with arguments x and y */

5388:   PetscMemcpy(&ls,&snes,sizeof(snes));
5389:   PetscMemcpy(&lx,&x,sizeof(x));
5390:   PetscMemcpy(&lA,A,sizeof(x));
5391:   PetscMemcpy(&lB,B,sizeof(x));
5392:   prhs[0] = mxCreateDoubleScalar((double)ls);
5393:   prhs[1] = mxCreateDoubleScalar((double)lx);
5394:   prhs[2] = mxCreateDoubleScalar((double)lA);
5395:   prhs[3] = mxCreateDoubleScalar((double)lB);
5396:   prhs[4] = mxCreateString(sctx->funcname);
5397:   prhs[5] = sctx->ctx;
5398:   mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESComputeJacobianInternal");
5399:   mxGetScalar(plhs[0]);
5400:   mxDestroyArray(prhs[0]);
5401:   mxDestroyArray(prhs[1]);
5402:   mxDestroyArray(prhs[2]);
5403:   mxDestroyArray(prhs[3]);
5404:   mxDestroyArray(prhs[4]);
5405:   mxDestroyArray(plhs[0]);
5406:   mxDestroyArray(plhs[1]);
5407:   return(0);
5408: }

5410: /*
5411:    SNESSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
5412:    vector for use by the SNES routines in solving systems of nonlinear
5413:    equations from MATLAB. Here the function is a string containing the name of a MATLAB function

5415:    Logically Collective on SNES

5417:    Input Parameters:
5418: +  snes - the SNES context
5419: .  A,B - Jacobian matrices
5420: .  J - function evaluation routine
5421: -  ctx - user context

5423:    Level: developer

5425:    Developer Note:  This bleeds the allocated memory SNESMatlabContext *sctx;

5427: .keywords: SNES, nonlinear, set, function

5429: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction(), J
5430: */
5431: PetscErrorCode  SNESSetJacobianMatlab(SNES snes,Mat A,Mat B,const char *J,mxArray *ctx)
5432: {
5433:   PetscErrorCode    ierr;
5434:   SNESMatlabContext *sctx;

5437:   /* currently sctx is memory bleed */
5438:   PetscNew(&sctx);
5439:   PetscStrallocpy(J,&sctx->funcname);
5440:   /*
5441:      This should work, but it doesn't
5442:   sctx->ctx = ctx;
5443:   mexMakeArrayPersistent(sctx->ctx);
5444:   */
5445:   sctx->ctx = mxDuplicateArray(ctx);
5446:   SNESSetJacobian(snes,A,B,SNESComputeJacobian_Matlab,sctx);
5447:   return(0);
5448: }

5450: /*
5451:    SNESMonitor_Matlab - Calls the function that has been set with SNESMonitorSetMatlab().

5453:    Collective on SNES

5455: .seealso: SNESSetFunction(), SNESGetFunction()
5456: @*/
5457: PetscErrorCode  SNESMonitor_Matlab(SNES snes,PetscInt it, PetscReal fnorm, void *ctx)
5458: {
5459:   PetscErrorCode    ierr;
5460:   SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
5461:   int               nlhs  = 1,nrhs = 6;
5462:   mxArray           *plhs[1],*prhs[6];
5463:   long long int     lx = 0,ls = 0;
5464:   Vec               x  = snes->vec_sol;


5469:   PetscMemcpy(&ls,&snes,sizeof(snes));
5470:   PetscMemcpy(&lx,&x,sizeof(x));
5471:   prhs[0] = mxCreateDoubleScalar((double)ls);
5472:   prhs[1] = mxCreateDoubleScalar((double)it);
5473:   prhs[2] = mxCreateDoubleScalar((double)fnorm);
5474:   prhs[3] = mxCreateDoubleScalar((double)lx);
5475:   prhs[4] = mxCreateString(sctx->funcname);
5476:   prhs[5] = sctx->ctx;
5477:   mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESMonitorInternal");
5478:   mxGetScalar(plhs[0]);
5479:   mxDestroyArray(prhs[0]);
5480:   mxDestroyArray(prhs[1]);
5481:   mxDestroyArray(prhs[2]);
5482:   mxDestroyArray(prhs[3]);
5483:   mxDestroyArray(prhs[4]);
5484:   mxDestroyArray(plhs[0]);
5485:   return(0);
5486: }

5488: /*
5489:    SNESMonitorSetMatlab - Sets the monitor function from MATLAB

5491:    Level: developer

5493:    Developer Note:  This bleeds the allocated memory SNESMatlabContext *sctx;

5495: .keywords: SNES, nonlinear, set, function

5497: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
5498: */
5499: PetscErrorCode  SNESMonitorSetMatlab(SNES snes,const char *f,mxArray *ctx)
5500: {
5501:   PetscErrorCode    ierr;
5502:   SNESMatlabContext *sctx;

5505:   /* currently sctx is memory bleed */
5506:   PetscNew(&sctx);
5507:   PetscStrallocpy(f,&sctx->funcname);
5508:   /*
5509:      This should work, but it doesn't
5510:   sctx->ctx = ctx;
5511:   mexMakeArrayPersistent(sctx->ctx);
5512:   */
5513:   sctx->ctx = mxDuplicateArray(ctx);
5514:   SNESMonitorSet(snes,SNESMonitor_Matlab,sctx,NULL);
5515:   return(0);
5516: }

5518: #endif