Actual source code: snes.c
petsc-3.13.6 2020-09-29
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.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_Setup, 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: .seealso: SNESGetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes,PetscBool flg)
36: {
40: snes->errorifnotconverged = flg;
41: return(0);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Will SNESSolve() generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from SNESCreate()
52: Output Parameter:
53: . flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE
55: Level: intermediate
57: .seealso: SNESSetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes,PetscBool *flag)
60: {
64: *flag = snes->errorifnotconverged;
65: return(0);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
71: Logically Collective on SNES
73: Input Parameters:
74: + snes - the shell SNES
75: - flg - is the residual computed?
77: Level: advanced
79: .seealso: SNESGetAlwaysComputesFinalResidual()
80: @*/
81: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
82: {
85: snes->alwayscomputesfinalresidual = flg;
86: return(0);
87: }
89: /*@
90: SNESGetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
92: Logically Collective on SNES
94: Input Parameter:
95: . snes - the shell SNES
97: Output Parameter:
98: . flg - is the residual computed?
100: Level: advanced
102: .seealso: SNESSetAlwaysComputesFinalResidual()
103: @*/
104: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
105: {
108: *flg = snes->alwayscomputesfinalresidual;
109: return(0);
110: }
112: /*@
113: SNESSetFunctionDomainError - tells SNES that the input vector to your SNESFunction is not
114: in the functions domain. For example, negative pressure.
116: Logically Collective on SNES
118: Input Parameters:
119: . snes - the SNES context
121: Level: advanced
123: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction
124: @*/
125: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
126: {
129: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates input vector is not in the function domain");
130: snes->domainerror = PETSC_TRUE;
131: return(0);
132: }
134: /*@
135: SNESSetJacobianDomainError - tells SNES that computeJacobian does not make sense any more. For example there is a negative element transformation.
137: Logically Collective on SNES
139: Input Parameters:
140: . snes - the SNES context
142: Level: advanced
144: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError()
145: @*/
146: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
147: {
150: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates computeJacobian does not make sense");
151: snes->jacobiandomainerror = PETSC_TRUE;
152: return(0);
153: }
155: /*@
156: SNESSetCheckJacobianDomainError - if or not to check jacobian domain error after each Jacobian evaluation. By default, we check Jacobian domain error
157: in the debug mode, and do not check it in the optimized mode.
159: Logically Collective on SNES
161: Input Parameters:
162: + snes - the SNES context
163: - flg - indicates if or not to check jacobian domain error after each Jacobian evaluation
165: Level: advanced
167: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESGetCheckJacobianDomainError()
168: @*/
169: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
170: {
173: snes->checkjacdomainerror = flg;
174: return(0);
175: }
177: /*@
178: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
180: Logically Collective on SNES
182: Input Parameters:
183: . snes - the SNES context
185: Output Parameters:
186: . flg - PETSC_FALSE indicates that we don't check jacobian domain errors after each Jacobian evaluation
188: Level: advanced
190: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESSetCheckJacobianDomainError()
191: @*/
192: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
193: {
197: *flg = snes->checkjacdomainerror;
198: return(0);
199: }
201: /*@
202: SNESGetFunctionDomainError - Gets the status of the domain error after a call to SNESComputeFunction;
204: Logically Collective on SNES
206: Input Parameters:
207: . snes - the SNES context
209: Output Parameters:
210: . domainerror - Set to PETSC_TRUE if there's a domain error; PETSC_FALSE otherwise.
212: Level: advanced
214: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction()
215: @*/
216: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
217: {
221: *domainerror = snes->domainerror;
222: return(0);
223: }
225: /*@
226: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to SNESComputeJacobian;
228: Logically Collective on SNES
230: Input Parameters:
231: . snes - the SNES context
233: Output Parameters:
234: . domainerror - Set to PETSC_TRUE if there's a jacobian domain error; PETSC_FALSE otherwise.
236: Level: advanced
238: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction(),SNESGetFunctionDomainError()
239: @*/
240: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
241: {
245: *domainerror = snes->jacobiandomainerror;
246: return(0);
247: }
249: /*@C
250: SNESLoad - Loads a SNES that has been stored in binary with SNESView().
252: Collective on PetscViewer
254: Input Parameters:
255: + newdm - the newly loaded SNES, this needs to have been created with SNESCreate() or
256: some related function before a call to SNESLoad().
257: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
259: Level: intermediate
261: Notes:
262: The type is determined by the data in the file, any type set into the SNES before this call is ignored.
264: Notes for advanced users:
265: Most users should not need to know the details of the binary storage
266: format, since SNESLoad() and TSView() completely hide these details.
267: But for anyone who's interested, the standard binary matrix storage
268: format is
269: .vb
270: has not yet been determined
271: .ve
273: .seealso: PetscViewerBinaryOpen(), SNESView(), MatLoad(), VecLoad()
274: @*/
275: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
276: {
278: PetscBool isbinary;
279: PetscInt classid;
280: char type[256];
281: KSP ksp;
282: DM dm;
283: DMSNES dmsnes;
288: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
289: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
291: PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
292: if (classid != SNES_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONG,"Not SNES next in file");
293: PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
294: SNESSetType(snes, type);
295: if (snes->ops->load) {
296: (*snes->ops->load)(snes,viewer);
297: }
298: SNESGetDM(snes,&dm);
299: DMGetDMSNES(dm,&dmsnes);
300: DMSNESLoad(dmsnes,viewer);
301: SNESGetKSP(snes,&ksp);
302: KSPLoad(ksp,viewer);
303: return(0);
304: }
306: #include <petscdraw.h>
307: #if defined(PETSC_HAVE_SAWS)
308: #include <petscviewersaws.h>
309: #endif
311: /*@C
312: SNESViewFromOptions - View from Options
314: Collective on SNES
316: Input Parameters:
317: + A - the Section 1.5 Writing Application Codes with PETSc ordering context
318: . obj - Optional object
319: - name - command line option
321: Level: intermediate
322: .seealso: SNES, SNESView, PetscObjectViewFromOptions(), SNESCreate()
323: @*/
324: PetscErrorCode SNESViewFromOptions(SNES A,PetscObject obj,const char name[])
325: {
330: PetscObjectViewFromOptions((PetscObject)A,obj,name);
331: return(0);
332: }
334: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES,Vec,Mat,Mat,void*);
336: /*@C
337: SNESView - Prints the SNES data structure.
339: Collective on SNES
341: Input Parameters:
342: + SNES - the SNES context
343: - viewer - visualization context
345: Options Database Key:
346: . -snes_view - Calls SNESView() at end of SNESSolve()
348: Notes:
349: The available visualization contexts include
350: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
351: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
352: output where only the first processor opens
353: the file. All other processors send their
354: data to the first processor to print.
356: The user can open an alternative visualization context with
357: PetscViewerASCIIOpen() - output to a specified file.
359: Level: beginner
361: .seealso: PetscViewerASCIIOpen()
362: @*/
363: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
364: {
365: SNESKSPEW *kctx;
367: KSP ksp;
368: SNESLineSearch linesearch;
369: PetscBool iascii,isstring,isbinary,isdraw;
370: DMSNES dmsnes;
371: #if defined(PETSC_HAVE_SAWS)
372: PetscBool issaws;
373: #endif
377: if (!viewer) {
378: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
379: }
383: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
384: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
385: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
386: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
387: #if defined(PETSC_HAVE_SAWS)
388: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
389: #endif
390: if (iascii) {
391: SNESNormSchedule normschedule;
392: DM dm;
393: PetscErrorCode (*cJ)(SNES,Vec,Mat,Mat,void*);
394: void *ctx;
395: const char *pre = "";
397: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
398: if (!snes->setupcalled) {
399: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
400: }
401: if (snes->ops->view) {
402: PetscViewerASCIIPushTab(viewer);
403: (*snes->ops->view)(snes,viewer);
404: PetscViewerASCIIPopTab(viewer);
405: }
406: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
407: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
408: if (snes->usesksp) {
409: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
410: }
411: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
412: SNESGetNormSchedule(snes, &normschedule);
413: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
414: if (snes->gridsequence) {
415: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
416: }
417: if (snes->ksp_ewconv) {
418: kctx = (SNESKSPEW*)snes->kspconvctx;
419: if (kctx) {
420: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
421: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
422: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
423: }
424: }
425: if (snes->lagpreconditioner == -1) {
426: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
427: } else if (snes->lagpreconditioner > 1) {
428: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
429: }
430: if (snes->lagjacobian == -1) {
431: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
432: } else if (snes->lagjacobian > 1) {
433: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
434: }
435: SNESGetDM(snes,&dm);
436: DMSNESGetJacobian(dm,&cJ,&ctx);
437: if (snes->mf_operator) {
438: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing\n");
439: pre = "Preconditioning ";
440: }
441: if (cJ == SNESComputeJacobianDefault) {
442: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences one column at a time\n",pre);
443: } else if (cJ == SNESComputeJacobianDefaultColor) {
444: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences with coloring\n",pre);
445: /* it slightly breaks data encapsulation for access the DMDA information directly */
446: } else if (cJ == SNESComputeJacobian_DMDA) {
447: MatFDColoring fdcoloring;
448: PetscObjectQuery((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject*)&fdcoloring);
449: if (fdcoloring) {
450: PetscViewerASCIIPrintf(viewer," %sJacobian is built using colored finite differences on a DMDA\n",pre);
451: } else {
452: PetscViewerASCIIPrintf(viewer," %sJacobian is built using a DMDA local Jacobian\n",pre);
453: }
454: } else if (snes->mf) {
455: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing, no explict Jacobian\n");
456: }
457: } else if (isstring) {
458: const char *type;
459: SNESGetType(snes,&type);
460: PetscViewerStringSPrintf(viewer," SNESType: %-7.7s",type);
461: if (snes->ops->view) {(*snes->ops->view)(snes,viewer);}
462: } else if (isbinary) {
463: PetscInt classid = SNES_FILE_CLASSID;
464: MPI_Comm comm;
465: PetscMPIInt rank;
466: char type[256];
468: PetscObjectGetComm((PetscObject)snes,&comm);
469: MPI_Comm_rank(comm,&rank);
470: if (!rank) {
471: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT);
472: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
473: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR);
474: }
475: if (snes->ops->view) {
476: (*snes->ops->view)(snes,viewer);
477: }
478: } else if (isdraw) {
479: PetscDraw draw;
480: char str[36];
481: PetscReal x,y,bottom,h;
483: PetscViewerDrawGetDraw(viewer,0,&draw);
484: PetscDrawGetCurrentPoint(draw,&x,&y);
485: PetscStrncpy(str,"SNES: ",sizeof(str));
486: PetscStrlcat(str,((PetscObject)snes)->type_name,sizeof(str));
487: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
488: bottom = y - h;
489: PetscDrawPushCurrentPoint(draw,x,bottom);
490: if (snes->ops->view) {
491: (*snes->ops->view)(snes,viewer);
492: }
493: #if defined(PETSC_HAVE_SAWS)
494: } else if (issaws) {
495: PetscMPIInt rank;
496: const char *name;
498: PetscObjectGetName((PetscObject)snes,&name);
499: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
500: if (!((PetscObject)snes)->amsmem && !rank) {
501: char dir[1024];
503: PetscObjectViewSAWs((PetscObject)snes,viewer);
504: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
505: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
506: if (!snes->conv_hist) {
507: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
508: }
509: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
510: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
511: }
512: #endif
513: }
514: if (snes->linesearch) {
515: SNESGetLineSearch(snes, &linesearch);
516: PetscViewerASCIIPushTab(viewer);
517: SNESLineSearchView(linesearch, viewer);
518: PetscViewerASCIIPopTab(viewer);
519: }
520: if (snes->npc && snes->usesnpc) {
521: PetscViewerASCIIPushTab(viewer);
522: SNESView(snes->npc, viewer);
523: PetscViewerASCIIPopTab(viewer);
524: }
525: PetscViewerASCIIPushTab(viewer);
526: DMGetDMSNES(snes->dm,&dmsnes);
527: DMSNESView(dmsnes, viewer);
528: PetscViewerASCIIPopTab(viewer);
529: if (snes->usesksp) {
530: SNESGetKSP(snes,&ksp);
531: PetscViewerASCIIPushTab(viewer);
532: KSPView(ksp,viewer);
533: PetscViewerASCIIPopTab(viewer);
534: }
535: if (isdraw) {
536: PetscDraw draw;
537: PetscViewerDrawGetDraw(viewer,0,&draw);
538: PetscDrawPopCurrentPoint(draw);
539: }
540: return(0);
541: }
543: /*
544: We retain a list of functions that also take SNES command
545: line options. These are called at the end SNESSetFromOptions()
546: */
547: #define MAXSETFROMOPTIONS 5
548: static PetscInt numberofsetfromoptions;
549: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
551: /*@C
552: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
554: Not Collective
556: Input Parameter:
557: . snescheck - function that checks for options
559: Level: developer
561: .seealso: SNESSetFromOptions()
562: @*/
563: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
564: {
566: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
567: othersetfromoptions[numberofsetfromoptions++] = snescheck;
568: return(0);
569: }
571: PETSC_INTERN PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
573: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
574: {
575: Mat J;
577: MatNullSpace nullsp;
582: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
583: Mat A = snes->jacobian, B = snes->jacobian_pre;
584: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
585: }
587: if (version == 1) {
588: MatCreateSNESMF(snes,&J);
589: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
590: MatSetFromOptions(J);
591: } else if (version == 2) {
592: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
593: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
594: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
595: #else
596: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
597: #endif
598: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");
600: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
601: if (snes->jacobian) {
602: MatGetNullSpace(snes->jacobian,&nullsp);
603: if (nullsp) {
604: MatSetNullSpace(J,nullsp);
605: }
606: }
608: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
609: if (hasOperator) {
611: /* This version replaces the user provided Jacobian matrix with a
612: matrix-free version but still employs the user-provided preconditioner matrix. */
613: SNESSetJacobian(snes,J,0,0,0);
614: } else {
615: /* This version replaces both the user-provided Jacobian and the user-
616: provided preconditioner Jacobian with the default matrix free version. */
617: if ((snes->npcside== PC_LEFT) && snes->npc) {
618: if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
619: } else {
620: KSP ksp;
621: PC pc;
622: PetscBool match;
624: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
625: /* Force no preconditioner */
626: SNESGetKSP(snes,&ksp);
627: KSPGetPC(ksp,&pc);
628: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
629: if (!match) {
630: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
631: PCSetType(pc,PCNONE);
632: }
633: }
634: }
635: MatDestroy(&J);
636: return(0);
637: }
639: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
640: {
641: SNES snes = (SNES)ctx;
643: Vec Xfine,Xfine_named = NULL,Xcoarse;
646: if (PetscLogPrintInfo) {
647: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
648: DMGetRefineLevel(dmfine,&finelevel);
649: DMGetCoarsenLevel(dmfine,&fineclevel);
650: DMGetRefineLevel(dmcoarse,&coarselevel);
651: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
652: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
653: }
654: if (dmfine == snes->dm) Xfine = snes->vec_sol;
655: else {
656: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
657: Xfine = Xfine_named;
658: }
659: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
660: if (Inject) {
661: MatRestrict(Inject,Xfine,Xcoarse);
662: } else {
663: MatRestrict(Restrict,Xfine,Xcoarse);
664: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
665: }
666: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
667: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
668: return(0);
669: }
671: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
672: {
676: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
677: return(0);
678: }
680: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
681: * safely call SNESGetDM() in their residual evaluation routine. */
682: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
683: {
684: SNES snes = (SNES)ctx;
686: Vec X,Xnamed = NULL;
687: DM dmsave;
688: void *ctxsave;
689: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*) = NULL;
692: dmsave = snes->dm;
693: KSPGetDM(ksp,&snes->dm);
694: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
695: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
696: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
697: X = Xnamed;
698: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
699: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
700: if (jac == SNESComputeJacobianDefaultColor) {
701: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
702: }
703: }
704: /* Make sure KSP DM has the Jacobian computation routine */
705: {
706: DMSNES sdm;
708: DMGetDMSNES(snes->dm, &sdm);
709: if (!sdm->ops->computejacobian) {
710: DMCopyDMSNES(dmsave, snes->dm);
711: }
712: }
713: /* Compute the operators */
714: SNESComputeJacobian(snes,X,A,B);
715: /* Put the previous context back */
716: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
717: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
718: }
720: if (Xnamed) {DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);}
721: snes->dm = dmsave;
722: return(0);
723: }
725: /*@
726: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
728: Collective
730: Input Arguments:
731: . snes - snes to configure
733: Level: developer
735: .seealso: SNESSetUp()
736: @*/
737: PetscErrorCode SNESSetUpMatrices(SNES snes)
738: {
740: DM dm;
741: DMSNES sdm;
744: SNESGetDM(snes,&dm);
745: DMGetDMSNES(dm,&sdm);
746: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
747: else if (!snes->jacobian && snes->mf) {
748: Mat J;
749: void *functx;
750: MatCreateSNESMF(snes,&J);
751: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
752: MatSetFromOptions(J);
753: SNESGetFunction(snes,NULL,NULL,&functx);
754: SNESSetJacobian(snes,J,J,0,0);
755: MatDestroy(&J);
756: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
757: Mat J,B;
758: MatCreateSNESMF(snes,&J);
759: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
760: MatSetFromOptions(J);
761: DMCreateMatrix(snes->dm,&B);
762: /* sdm->computejacobian was already set to reach here */
763: SNESSetJacobian(snes,J,B,NULL,NULL);
764: MatDestroy(&J);
765: MatDestroy(&B);
766: } else if (!snes->jacobian_pre) {
767: PetscErrorCode (*nspconstr)(DM, PetscInt, MatNullSpace *);
768: PetscDS prob;
769: Mat J, B;
770: MatNullSpace nullspace = NULL;
771: PetscBool hasPrec = PETSC_FALSE;
772: PetscInt Nf;
774: J = snes->jacobian;
775: DMGetDS(dm, &prob);
776: if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
777: if (J) {PetscObjectReference((PetscObject) J);}
778: else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
779: DMCreateMatrix(snes->dm, &B);
780: PetscDSGetNumFields(prob, &Nf);
781: DMGetNullSpaceConstructor(snes->dm, Nf, &nspconstr);
782: if (nspconstr) (*nspconstr)(snes->dm, -1, &nullspace);
783: MatSetNullSpace(B, nullspace);
784: MatNullSpaceDestroy(&nullspace);
785: SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
786: MatDestroy(&J);
787: MatDestroy(&B);
788: }
789: {
790: KSP ksp;
791: SNESGetKSP(snes,&ksp);
792: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
793: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
794: }
795: return(0);
796: }
798: /*@C
799: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
801: Collective on SNES
803: Input Parameters:
804: + snes - SNES object you wish to monitor
805: . name - the monitor type one is seeking
806: . help - message indicating what monitoring is done
807: . manual - manual page for the monitor
808: . monitor - the monitor function
809: - 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
811: Level: developer
813: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
814: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
815: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
816: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
817: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
818: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
819: PetscOptionsFList(), PetscOptionsEList()
820: @*/
821: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
822: {
823: PetscErrorCode ierr;
824: PetscViewer viewer;
825: PetscViewerFormat format;
826: PetscBool flg;
829: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
830: if (flg) {
831: PetscViewerAndFormat *vf;
832: PetscViewerAndFormatCreate(viewer,format,&vf);
833: PetscObjectDereference((PetscObject)viewer);
834: if (monitorsetup) {
835: (*monitorsetup)(snes,vf);
836: }
837: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
838: }
839: return(0);
840: }
842: /*@
843: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
845: Collective on SNES
847: Input Parameter:
848: . snes - the SNES context
850: Options Database Keys:
851: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
852: . -snes_stol - convergence tolerance in terms of the norm
853: of the change in the solution between steps
854: . -snes_atol <abstol> - absolute tolerance of residual norm
855: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
856: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
857: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
858: . -snes_max_it <max_it> - maximum number of iterations
859: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
860: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
861: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
862: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
863: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
864: . -snes_trtol <trtol> - trust region tolerance
865: . -snes_no_convergence_test - skip convergence test in nonlinear
866: solver; hence iterations will continue until max_it
867: or some other criterion is reached. Saves expense
868: of convergence test
869: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
870: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
871: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
872: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
873: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
874: . -snes_monitor_lg_range - plots residual norm at each iteration
875: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
876: . -snes_fd_color - use finite differences with coloring to compute Jacobian
877: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
878: . -snes_converged_reason - print the reason for convergence/divergence after each solve
879: - -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
881: Options Database for Eisenstat-Walker method:
882: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
883: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
884: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
885: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
886: . -snes_ksp_ew_gamma <gamma> - Sets gamma
887: . -snes_ksp_ew_alpha <alpha> - Sets alpha
888: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
889: - -snes_ksp_ew_threshold <threshold> - Sets threshold
891: Notes:
892: To see all options, run your program with the -help option or consult the users manual
894: Notes:
895: SNES supports three approaches for computing (approximate) Jacobians: user provided via SNESSetJacobian(), matrix free, and computing explictly with
896: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
898: Level: beginner
900: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions(), SNES, SNESCreate()
901: @*/
902: PetscErrorCode SNESSetFromOptions(SNES snes)
903: {
904: PetscBool flg,pcset,persist,set;
905: PetscInt i,indx,lag,grids;
906: const char *deft = SNESNEWTONLS;
907: const char *convtests[] = {"default","skip"};
908: SNESKSPEW *kctx = NULL;
909: char type[256], monfilename[PETSC_MAX_PATH_LEN];
911: PCSide pcside;
912: const char *optionsprefix;
916: SNESRegisterAll();
917: PetscObjectOptionsBegin((PetscObject)snes);
918: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
919: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
920: if (flg) {
921: SNESSetType(snes,type);
922: } else if (!((PetscObject)snes)->type_name) {
923: SNESSetType(snes,deft);
924: }
925: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
926: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
928: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
929: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
930: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
931: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
932: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
933: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
934: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
935: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
936: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
938: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
939: if (flg) {
940: SNESSetLagPreconditioner(snes,lag);
941: }
942: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple SNES solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
943: if (flg) {
944: SNESSetLagPreconditionerPersists(snes,persist);
945: }
946: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
947: if (flg) {
948: SNESSetLagJacobian(snes,lag);
949: }
950: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple SNES solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
951: if (flg) {
952: SNESSetLagJacobianPersists(snes,persist);
953: }
955: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
956: if (flg) {
957: SNESSetGridSequence(snes,grids);
958: }
960: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
961: if (flg) {
962: switch (indx) {
963: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
964: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
965: }
966: }
968: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
969: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
971: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
972: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
974: kctx = (SNESKSPEW*)snes->kspconvctx;
976: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
978: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
979: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
980: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
981: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
982: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
983: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
984: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
986: flg = PETSC_FALSE;
987: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
988: if (set && flg) {SNESMonitorCancel(snes);}
990: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
991: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
992: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
994: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
995: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
996: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
997: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
998: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
999: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
1000: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
1002: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
1003: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
1005: flg = PETSC_FALSE;
1006: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
1007: if (flg) {
1008: PetscDrawLG ctx;
1010: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1011: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
1012: }
1013: flg = PETSC_FALSE;
1014: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
1015: if (flg) {
1016: PetscViewer ctx;
1018: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1019: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
1020: }
1022: flg = PETSC_FALSE;
1023: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
1024: if (flg) {
1025: void *functx;
1026: DM dm;
1027: DMSNES sdm;
1028: SNESGetDM(snes,&dm);
1029: DMGetDMSNES(dm,&sdm);
1030: sdm->jacobianctx = NULL;
1031: SNESGetFunction(snes,NULL,NULL,&functx);
1032: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
1033: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
1034: }
1036: flg = PETSC_FALSE;
1037: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
1038: if (flg) {
1039: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
1040: }
1042: flg = PETSC_FALSE;
1043: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1044: if (flg) {
1045: DM dm;
1046: DMSNES sdm;
1047: SNESGetDM(snes,&dm);
1048: DMGetDMSNES(dm,&sdm);
1049: sdm->jacobianctx = NULL;
1050: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
1051: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1052: }
1054: flg = PETSC_FALSE;
1055: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1056: if (flg && snes->mf_operator) {
1057: snes->mf_operator = PETSC_TRUE;
1058: snes->mf = PETSC_TRUE;
1059: }
1060: flg = PETSC_FALSE;
1061: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1062: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1063: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
1065: flg = PETSC_FALSE;
1066: SNESGetNPCSide(snes,&pcside);
1067: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1068: if (flg) {SNESSetNPCSide(snes,pcside);}
1070: #if defined(PETSC_HAVE_SAWS)
1071: /*
1072: Publish convergence information using SAWs
1073: */
1074: flg = PETSC_FALSE;
1075: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1076: if (flg) {
1077: void *ctx;
1078: SNESMonitorSAWsCreate(snes,&ctx);
1079: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1080: }
1081: #endif
1082: #if defined(PETSC_HAVE_SAWS)
1083: {
1084: PetscBool set;
1085: flg = PETSC_FALSE;
1086: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1087: if (set) {
1088: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1089: }
1090: }
1091: #endif
1093: for (i = 0; i < numberofsetfromoptions; i++) {
1094: (*othersetfromoptions[i])(snes);
1095: }
1097: if (snes->ops->setfromoptions) {
1098: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1099: }
1101: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1102: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1103: PetscOptionsEnd();
1105: if (snes->linesearch) {
1106: SNESGetLineSearch(snes, &snes->linesearch);
1107: SNESLineSearchSetFromOptions(snes->linesearch);
1108: }
1110: if (snes->usesksp) {
1111: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1112: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1113: KSPSetFromOptions(snes->ksp);
1114: }
1116: /* if user has set the SNES NPC type via options database, create it. */
1117: SNESGetOptionsPrefix(snes, &optionsprefix);
1118: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1119: if (pcset && (!snes->npc)) {
1120: SNESGetNPC(snes, &snes->npc);
1121: }
1122: if (snes->npc) {
1123: SNESSetFromOptions(snes->npc);
1124: }
1125: snes->setfromoptionscalled++;
1126: return(0);
1127: }
1129: /*@
1130: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1132: Collective on SNES
1134: Input Parameter:
1135: . snes - the SNES context
1137: Level: beginner
1139: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1140: @*/
1141: PetscErrorCode SNESResetFromOptions(SNES snes)
1142: {
1146: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1147: return(0);
1148: }
1150: /*@C
1151: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1152: the nonlinear solvers.
1154: Logically Collective on SNES
1156: Input Parameters:
1157: + snes - the SNES context
1158: . compute - function to compute the context
1159: - destroy - function to destroy the context
1161: Level: intermediate
1163: Notes:
1164: This function is currently not available from Fortran.
1166: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1167: @*/
1168: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1169: {
1172: snes->ops->usercompute = compute;
1173: snes->ops->userdestroy = destroy;
1174: return(0);
1175: }
1177: /*@
1178: SNESSetApplicationContext - Sets the optional user-defined context for
1179: the nonlinear solvers.
1181: Logically Collective on SNES
1183: Input Parameters:
1184: + snes - the SNES context
1185: - usrP - optional user context
1187: Level: intermediate
1189: Fortran Notes:
1190: To use this from Fortran you must write a Fortran interface definition for this
1191: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1193: .seealso: SNESGetApplicationContext()
1194: @*/
1195: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1196: {
1198: KSP ksp;
1202: SNESGetKSP(snes,&ksp);
1203: KSPSetApplicationContext(ksp,usrP);
1204: snes->user = usrP;
1205: return(0);
1206: }
1208: /*@
1209: SNESGetApplicationContext - Gets the user-defined context for the
1210: nonlinear solvers.
1212: Not Collective
1214: Input Parameter:
1215: . snes - SNES context
1217: Output Parameter:
1218: . usrP - user context
1220: Fortran Notes:
1221: To use this from Fortran you must write a Fortran interface definition for this
1222: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1224: Level: intermediate
1226: .seealso: SNESSetApplicationContext()
1227: @*/
1228: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1229: {
1232: *(void**)usrP = snes->user;
1233: return(0);
1234: }
1236: /*@
1237: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply the Jacobian.
1239: Collective on SNES
1241: Input Parameters:
1242: + snes - SNES context
1243: . mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1244: - mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1246: Options Database:
1247: + -snes_mf - use matrix free for both the mat and pmat operator
1248: . -snes_mf_operator - use matrix free only for the mat operator
1249: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1250: - -snes_fd - compute the Jacobian via finite differences (slow)
1252: Level: intermediate
1254: Notes:
1255: SNES supports three approaches for computing (approximate) Jacobians: user provided via SNESSetJacobian(), matrix free, and computing explictly with
1256: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
1258: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF(), SNESComputeJacobianDefaultColor()
1259: @*/
1260: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1261: {
1266: snes->mf = mf_operator ? PETSC_TRUE : mf;
1267: snes->mf_operator = mf_operator;
1268: return(0);
1269: }
1271: /*@
1272: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply the Jacobian.
1274: Collective on SNES
1276: Input Parameter:
1277: . snes - SNES context
1279: Output Parameters:
1280: + mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1281: - mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1283: Options Database:
1284: + -snes_mf - use matrix free for both the mat and pmat operator
1285: - -snes_mf_operator - use matrix free only for the mat operator
1287: Level: intermediate
1289: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1290: @*/
1291: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1292: {
1295: if (mf) *mf = snes->mf;
1296: if (mf_operator) *mf_operator = snes->mf_operator;
1297: return(0);
1298: }
1300: /*@
1301: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1302: at this time.
1304: Not Collective
1306: Input Parameter:
1307: . snes - SNES context
1309: Output Parameter:
1310: . iter - iteration number
1312: Notes:
1313: For example, during the computation of iteration 2 this would return 1.
1315: This is useful for using lagged Jacobians (where one does not recompute the
1316: Jacobian at each SNES iteration). For example, the code
1317: .vb
1318: SNESGetIterationNumber(snes,&it);
1319: if (!(it % 2)) {
1320: [compute Jacobian here]
1321: }
1322: .ve
1323: can be used in your ComputeJacobian() function to cause the Jacobian to be
1324: recomputed every second SNES iteration.
1326: After the SNES solve is complete this will return the number of nonlinear iterations used.
1328: Level: intermediate
1330: .seealso: SNESGetLinearSolveIterations()
1331: @*/
1332: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1333: {
1337: *iter = snes->iter;
1338: return(0);
1339: }
1341: /*@
1342: SNESSetIterationNumber - Sets the current iteration number.
1344: Not Collective
1346: Input Parameter:
1347: + snes - SNES context
1348: - iter - iteration number
1350: Level: developer
1352: .seealso: SNESGetLinearSolveIterations()
1353: @*/
1354: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1355: {
1360: PetscObjectSAWsTakeAccess((PetscObject)snes);
1361: snes->iter = iter;
1362: PetscObjectSAWsGrantAccess((PetscObject)snes);
1363: return(0);
1364: }
1366: /*@
1367: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1368: attempted by the nonlinear solver.
1370: Not Collective
1372: Input Parameter:
1373: . snes - SNES context
1375: Output Parameter:
1376: . nfails - number of unsuccessful steps attempted
1378: Notes:
1379: This counter is reset to zero for each successive call to SNESSolve().
1381: Level: intermediate
1383: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1384: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1385: @*/
1386: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1387: {
1391: *nfails = snes->numFailures;
1392: return(0);
1393: }
1395: /*@
1396: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1397: attempted by the nonlinear solver before it gives up.
1399: Not Collective
1401: Input Parameters:
1402: + snes - SNES context
1403: - maxFails - maximum of unsuccessful steps
1405: Level: intermediate
1407: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1408: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1409: @*/
1410: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1411: {
1414: snes->maxFailures = maxFails;
1415: return(0);
1416: }
1418: /*@
1419: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1420: attempted by the nonlinear solver before it gives up.
1422: Not Collective
1424: Input Parameter:
1425: . snes - SNES context
1427: Output Parameter:
1428: . maxFails - maximum of unsuccessful steps
1430: Level: intermediate
1432: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1433: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1435: @*/
1436: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1437: {
1441: *maxFails = snes->maxFailures;
1442: return(0);
1443: }
1445: /*@
1446: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1447: done by SNES.
1449: Not Collective
1451: Input Parameter:
1452: . snes - SNES context
1454: Output Parameter:
1455: . nfuncs - number of evaluations
1457: Level: intermediate
1459: Notes:
1460: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1462: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1463: @*/
1464: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1465: {
1469: *nfuncs = snes->nfuncs;
1470: return(0);
1471: }
1473: /*@
1474: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1475: linear solvers.
1477: Not Collective
1479: Input Parameter:
1480: . snes - SNES context
1482: Output Parameter:
1483: . nfails - number of failed solves
1485: Level: intermediate
1487: Options Database Keys:
1488: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1490: Notes:
1491: This counter is reset to zero for each successive call to SNESSolve().
1493: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1494: @*/
1495: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1496: {
1500: *nfails = snes->numLinearSolveFailures;
1501: return(0);
1502: }
1504: /*@
1505: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1506: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1508: Logically Collective on SNES
1510: Input Parameters:
1511: + snes - SNES context
1512: - maxFails - maximum allowed linear solve failures
1514: Level: intermediate
1516: Options Database Keys:
1517: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1519: Notes:
1520: By default this is 0; that is SNES returns on the first failed linear solve
1522: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1523: @*/
1524: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1525: {
1529: snes->maxLinearSolveFailures = maxFails;
1530: return(0);
1531: }
1533: /*@
1534: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1535: are allowed before SNES terminates
1537: Not Collective
1539: Input Parameter:
1540: . snes - SNES context
1542: Output Parameter:
1543: . maxFails - maximum of unsuccessful solves allowed
1545: Level: intermediate
1547: Notes:
1548: By default this is 1; that is SNES returns on the first failed linear solve
1550: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1551: @*/
1552: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1553: {
1557: *maxFails = snes->maxLinearSolveFailures;
1558: return(0);
1559: }
1561: /*@
1562: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1563: used by the nonlinear solver.
1565: Not Collective
1567: Input Parameter:
1568: . snes - SNES context
1570: Output Parameter:
1571: . lits - number of linear iterations
1573: Notes:
1574: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1576: 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
1577: then call KSPGetIterationNumber() after the failed solve.
1579: Level: intermediate
1581: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1582: @*/
1583: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1584: {
1588: *lits = snes->linear_its;
1589: return(0);
1590: }
1592: /*@
1593: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1594: are reset every time SNESSolve() is called.
1596: Logically Collective on SNES
1598: Input Parameter:
1599: + snes - SNES context
1600: - reset - whether to reset the counters or not
1602: Notes:
1603: This defaults to PETSC_TRUE
1605: Level: developer
1607: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1608: @*/
1609: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1610: {
1614: snes->counters_reset = reset;
1615: return(0);
1616: }
1619: /*@
1620: SNESSetKSP - Sets a KSP context for the SNES object to use
1622: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1624: Input Parameters:
1625: + snes - the SNES context
1626: - ksp - the KSP context
1628: Notes:
1629: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1630: so this routine is rarely needed.
1632: The KSP object that is already in the SNES object has its reference count
1633: decreased by one.
1635: Level: developer
1637: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1638: @*/
1639: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1640: {
1647: PetscObjectReference((PetscObject)ksp);
1648: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1649: snes->ksp = ksp;
1650: return(0);
1651: }
1653: /* -----------------------------------------------------------*/
1654: /*@
1655: SNESCreate - Creates a nonlinear solver context.
1657: Collective
1659: Input Parameters:
1660: . comm - MPI communicator
1662: Output Parameter:
1663: . outsnes - the new SNES context
1665: Options Database Keys:
1666: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1667: and no preconditioning matrix
1668: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1669: products, and a user-provided preconditioning matrix
1670: as set by SNESSetJacobian()
1671: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1673: Level: beginner
1675: Developer Notes:
1676: SNES always creates a KSP object even though many SNES methods do not use it. This is
1677: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1678: particular method does use KSP and regulates if the information about the KSP is printed
1679: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1680: by help messages about meaningless SNES options.
1682: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1683: be fixed.
1685: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1687: @*/
1688: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1689: {
1691: SNES snes;
1692: SNESKSPEW *kctx;
1696: *outsnes = NULL;
1697: SNESInitializePackage();
1699: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1701: snes->ops->converged = SNESConvergedDefault;
1702: snes->usesksp = PETSC_TRUE;
1703: snes->tolerancesset = PETSC_FALSE;
1704: snes->max_its = 50;
1705: snes->max_funcs = 10000;
1706: snes->norm = 0.0;
1707: snes->xnorm = 0.0;
1708: snes->ynorm = 0.0;
1709: snes->normschedule = SNES_NORM_ALWAYS;
1710: snes->functype = SNES_FUNCTION_DEFAULT;
1711: #if defined(PETSC_USE_REAL_SINGLE)
1712: snes->rtol = 1.e-5;
1713: #else
1714: snes->rtol = 1.e-8;
1715: #endif
1716: snes->ttol = 0.0;
1717: #if defined(PETSC_USE_REAL_SINGLE)
1718: snes->abstol = 1.e-25;
1719: #else
1720: snes->abstol = 1.e-50;
1721: #endif
1722: #if defined(PETSC_USE_REAL_SINGLE)
1723: snes->stol = 1.e-5;
1724: #else
1725: snes->stol = 1.e-8;
1726: #endif
1727: #if defined(PETSC_USE_REAL_SINGLE)
1728: snes->deltatol = 1.e-6;
1729: #else
1730: snes->deltatol = 1.e-12;
1731: #endif
1732: snes->divtol = 1.e4;
1733: snes->rnorm0 = 0;
1734: snes->nfuncs = 0;
1735: snes->numFailures = 0;
1736: snes->maxFailures = 1;
1737: snes->linear_its = 0;
1738: snes->lagjacobian = 1;
1739: snes->jac_iter = 0;
1740: snes->lagjac_persist = PETSC_FALSE;
1741: snes->lagpreconditioner = 1;
1742: snes->pre_iter = 0;
1743: snes->lagpre_persist = PETSC_FALSE;
1744: snes->numbermonitors = 0;
1745: snes->data = 0;
1746: snes->setupcalled = PETSC_FALSE;
1747: snes->ksp_ewconv = PETSC_FALSE;
1748: snes->nwork = 0;
1749: snes->work = 0;
1750: snes->nvwork = 0;
1751: snes->vwork = 0;
1752: snes->conv_hist_len = 0;
1753: snes->conv_hist_max = 0;
1754: snes->conv_hist = NULL;
1755: snes->conv_hist_its = NULL;
1756: snes->conv_hist_reset = PETSC_TRUE;
1757: snes->counters_reset = PETSC_TRUE;
1758: snes->vec_func_init_set = PETSC_FALSE;
1759: snes->reason = SNES_CONVERGED_ITERATING;
1760: snes->npcside = PC_RIGHT;
1761: snes->setfromoptionscalled = 0;
1763: snes->mf = PETSC_FALSE;
1764: snes->mf_operator = PETSC_FALSE;
1765: snes->mf_version = 1;
1767: snes->numLinearSolveFailures = 0;
1768: snes->maxLinearSolveFailures = 1;
1770: snes->vizerotolerance = 1.e-8;
1771: #if defined(PETSC_USE_DEBUG)
1772: snes->checkjacdomainerror = PETSC_TRUE;
1773: #else
1774: snes->checkjacdomainerror = PETSC_FALSE;
1775: #endif
1777: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1778: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1780: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1781: PetscNewLog(snes,&kctx);
1783: snes->kspconvctx = (void*)kctx;
1784: kctx->version = 2;
1785: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1786: this was too large for some test cases */
1787: kctx->rtol_last = 0.0;
1788: kctx->rtol_max = .9;
1789: kctx->gamma = 1.0;
1790: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1791: kctx->alpha2 = kctx->alpha;
1792: kctx->threshold = .1;
1793: kctx->lresid_last = 0.0;
1794: kctx->norm_last = 0.0;
1796: *outsnes = snes;
1797: return(0);
1798: }
1800: /*MC
1801: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1803: Synopsis:
1804: #include "petscsnes.h"
1805: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1807: Collective on snes
1809: Input Parameters:
1810: + snes - the SNES context
1811: . x - state at which to evaluate residual
1812: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1814: Output Parameter:
1815: . f - vector to put residual (function value)
1817: Level: intermediate
1819: .seealso: SNESSetFunction(), SNESGetFunction()
1820: M*/
1822: /*@C
1823: SNESSetFunction - Sets the function evaluation routine and function
1824: vector for use by the SNES routines in solving systems of nonlinear
1825: equations.
1827: Logically Collective on SNES
1829: Input Parameters:
1830: + snes - the SNES context
1831: . r - vector to store function value
1832: . f - function evaluation routine; see SNESFunction for calling sequence details
1833: - ctx - [optional] user-defined context for private data for the
1834: function evaluation routine (may be NULL)
1836: Notes:
1837: The Newton-like methods typically solve linear systems of the form
1838: $ f'(x) x = -f(x),
1839: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1841: Level: beginner
1843: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1844: @*/
1845: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1846: {
1848: DM dm;
1852: if (r) {
1855: PetscObjectReference((PetscObject)r);
1856: VecDestroy(&snes->vec_func);
1858: snes->vec_func = r;
1859: }
1860: SNESGetDM(snes,&dm);
1861: DMSNESSetFunction(dm,f,ctx);
1862: return(0);
1863: }
1866: /*@C
1867: SNESSetInitialFunction - Sets the function vector to be used as the
1868: function norm at the initialization of the method. In some
1869: instances, the user has precomputed the function before calling
1870: SNESSolve. This function allows one to avoid a redundant call
1871: to SNESComputeFunction in that case.
1873: Logically Collective on SNES
1875: Input Parameters:
1876: + snes - the SNES context
1877: - f - vector to store function value
1879: Notes:
1880: This should not be modified during the solution procedure.
1882: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1884: Level: developer
1886: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1887: @*/
1888: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1889: {
1891: Vec vec_func;
1897: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1898: snes->vec_func_init_set = PETSC_FALSE;
1899: return(0);
1900: }
1901: SNESGetFunction(snes,&vec_func,NULL,NULL);
1902: VecCopy(f, vec_func);
1904: snes->vec_func_init_set = PETSC_TRUE;
1905: return(0);
1906: }
1908: /*@
1909: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1910: of the SNES method.
1912: Logically Collective on SNES
1914: Input Parameters:
1915: + snes - the SNES context
1916: - normschedule - the frequency of norm computation
1918: Options Database Key:
1919: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1921: Notes:
1922: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1923: of the nonlinear function and the taking of its norm at every iteration to
1924: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1925: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1926: may either be monitored for convergence or not. As these are often used as nonlinear
1927: preconditioners, monitoring the norm of their error is not a useful enterprise within
1928: their solution.
1930: Level: developer
1932: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1933: @*/
1934: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1935: {
1938: snes->normschedule = normschedule;
1939: return(0);
1940: }
1943: /*@
1944: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1945: of the SNES method.
1947: Logically Collective on SNES
1949: Input Parameters:
1950: + snes - the SNES context
1951: - normschedule - the type of the norm used
1953: Level: advanced
1955: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1956: @*/
1957: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1958: {
1961: *normschedule = snes->normschedule;
1962: return(0);
1963: }
1966: /*@
1967: SNESSetFunctionNorm - Sets the last computed residual norm.
1969: Logically Collective on SNES
1971: Input Parameters:
1972: + snes - the SNES context
1974: - normschedule - the frequency of norm computation
1976: Level: developer
1978: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1979: @*/
1980: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1981: {
1984: snes->norm = norm;
1985: return(0);
1986: }
1988: /*@
1989: SNESGetFunctionNorm - Gets the last computed norm of the residual
1991: Not Collective
1993: Input Parameter:
1994: . snes - the SNES context
1996: Output Parameter:
1997: . norm - the last computed residual norm
1999: Level: developer
2001: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2002: @*/
2003: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2004: {
2008: *norm = snes->norm;
2009: return(0);
2010: }
2012: /*@
2013: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
2015: Not Collective
2017: Input Parameter:
2018: . snes - the SNES context
2020: Output Parameter:
2021: . ynorm - the last computed update norm
2023: Level: developer
2025: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
2026: @*/
2027: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2028: {
2032: *ynorm = snes->ynorm;
2033: return(0);
2034: }
2036: /*@
2037: SNESGetSolutionNorm - Gets the last computed norm of the solution
2039: Not Collective
2041: Input Parameter:
2042: . snes - the SNES context
2044: Output Parameter:
2045: . xnorm - the last computed solution norm
2047: Level: developer
2049: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2050: @*/
2051: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2052: {
2056: *xnorm = snes->xnorm;
2057: return(0);
2058: }
2060: /*@C
2061: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2062: of the SNES method.
2064: Logically Collective on SNES
2066: Input Parameters:
2067: + snes - the SNES context
2068: - normschedule - the frequency of norm computation
2070: Notes:
2071: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2072: of the nonlinear function and the taking of its norm at every iteration to
2073: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2074: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2075: may either be monitored for convergence or not. As these are often used as nonlinear
2076: preconditioners, monitoring the norm of their error is not a useful enterprise within
2077: their solution.
2079: Level: developer
2081: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2082: @*/
2083: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2084: {
2087: snes->functype = type;
2088: return(0);
2089: }
2092: /*@C
2093: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2094: of the SNES method.
2096: Logically Collective on SNES
2098: Input Parameters:
2099: + snes - the SNES context
2100: - normschedule - the type of the norm used
2102: Level: advanced
2104: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2105: @*/
2106: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2107: {
2110: *type = snes->functype;
2111: return(0);
2112: }
2114: /*MC
2115: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2117: Synopsis:
2118: #include <petscsnes.h>
2119: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2121: Collective on snes
2123: Input Parameters:
2124: + X - solution vector
2125: . B - RHS vector
2126: - ctx - optional user-defined Gauss-Seidel context
2128: Output Parameter:
2129: . X - solution vector
2131: Level: intermediate
2133: .seealso: SNESSetNGS(), SNESGetNGS()
2134: M*/
2136: /*@C
2137: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2138: use with composed nonlinear solvers.
2140: Input Parameters:
2141: + snes - the SNES context
2142: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2143: - ctx - [optional] user-defined context for private data for the
2144: smoother evaluation routine (may be NULL)
2146: Notes:
2147: The NGS routines are used by the composed nonlinear solver to generate
2148: a problem appropriate update to the solution, particularly FAS.
2150: Level: intermediate
2152: .seealso: SNESGetFunction(), SNESComputeNGS()
2153: @*/
2154: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2155: {
2157: DM dm;
2161: SNESGetDM(snes,&dm);
2162: DMSNESSetNGS(dm,f,ctx);
2163: return(0);
2164: }
2166: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2167: {
2169: DM dm;
2170: DMSNES sdm;
2173: SNESGetDM(snes,&dm);
2174: DMGetDMSNES(dm,&sdm);
2175: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2176: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2177: /* A(x)*x - b(x) */
2178: PetscStackPush("SNES Picard user function");
2179: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2180: PetscStackPop;
2181: PetscStackPush("SNES Picard user Jacobian");
2182: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2183: PetscStackPop;
2184: VecScale(f,-1.0);
2185: MatMultAdd(snes->jacobian,x,f,f);
2186: return(0);
2187: }
2189: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2190: {
2192: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2193: return(0);
2194: }
2196: /*@C
2197: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2199: Logically Collective on SNES
2201: Input Parameters:
2202: + snes - the SNES context
2203: . r - vector to store function value
2204: . b - function evaluation routine
2205: . Amat - matrix with which A(x) x - b(x) is to be computed
2206: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2207: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2208: - ctx - [optional] user-defined context for private data for the
2209: function evaluation routine (may be NULL)
2211: Notes:
2212: 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
2213: 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.
2215: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2217: $ 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}
2218: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2220: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2222: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2223: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2225: 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
2226: 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
2227: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2229: Level: intermediate
2231: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2232: @*/
2233: 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)
2234: {
2236: DM dm;
2240: SNESGetDM(snes, &dm);
2241: DMSNESSetPicard(dm,b,J,ctx);
2242: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2243: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2244: return(0);
2245: }
2247: /*@C
2248: SNESGetPicard - Returns the context for the Picard iteration
2250: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2252: Input Parameter:
2253: . snes - the SNES context
2255: Output Parameter:
2256: + r - the function (or NULL)
2257: . f - the function (or NULL); see SNESFunction for calling sequence details
2258: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2259: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2260: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2261: - ctx - the function context (or NULL)
2263: Level: advanced
2265: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2266: @*/
2267: 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)
2268: {
2270: DM dm;
2274: SNESGetFunction(snes,r,NULL,NULL);
2275: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2276: SNESGetDM(snes,&dm);
2277: DMSNESGetPicard(dm,f,J,ctx);
2278: return(0);
2279: }
2281: /*@C
2282: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2284: Logically Collective on SNES
2286: Input Parameters:
2287: + snes - the SNES context
2288: . func - function evaluation routine
2289: - ctx - [optional] user-defined context for private data for the
2290: function evaluation routine (may be NULL)
2292: Calling sequence of func:
2293: $ func (SNES snes,Vec x,void *ctx);
2295: . f - function vector
2296: - ctx - optional user-defined function context
2298: Level: intermediate
2300: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2301: @*/
2302: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2303: {
2306: if (func) snes->ops->computeinitialguess = func;
2307: if (ctx) snes->initialguessP = ctx;
2308: return(0);
2309: }
2311: /* --------------------------------------------------------------- */
2312: /*@C
2313: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2314: it assumes a zero right hand side.
2316: Logically Collective on SNES
2318: Input Parameter:
2319: . snes - the SNES context
2321: Output Parameter:
2322: . rhs - the right hand side vector or NULL if the right hand side vector is null
2324: Level: intermediate
2326: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2327: @*/
2328: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2329: {
2333: *rhs = snes->vec_rhs;
2334: return(0);
2335: }
2337: /*@
2338: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2340: Collective on SNES
2342: Input Parameters:
2343: + snes - the SNES context
2344: - x - input vector
2346: Output Parameter:
2347: . y - function vector, as set by SNESSetFunction()
2349: Notes:
2350: SNESComputeFunction() is typically used within nonlinear solvers
2351: implementations, so most users would not generally call this routine
2352: themselves.
2354: Level: developer
2356: .seealso: SNESSetFunction(), SNESGetFunction()
2357: @*/
2358: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2359: {
2361: DM dm;
2362: DMSNES sdm;
2370: VecValidValues(x,2,PETSC_TRUE);
2372: SNESGetDM(snes,&dm);
2373: DMGetDMSNES(dm,&sdm);
2374: if (sdm->ops->computefunction) {
2375: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2376: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2377: }
2378: VecLockReadPush(x);
2379: PetscStackPush("SNES user function");
2380: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2381: snes->domainerror = PETSC_FALSE;
2382: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2383: PetscStackPop;
2384: VecLockReadPop(x);
2385: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2386: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2387: }
2388: } else if (snes->vec_rhs) {
2389: MatMult(snes->jacobian, x, y);
2390: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2391: if (snes->vec_rhs) {
2392: VecAXPY(y,-1.0,snes->vec_rhs);
2393: }
2394: snes->nfuncs++;
2395: /*
2396: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2397: propagate the value to all processes
2398: */
2399: if (snes->domainerror) {
2400: VecSetInf(y);
2401: }
2402: return(0);
2403: }
2405: /*@
2406: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2408: Collective on SNES
2410: Input Parameters:
2411: + snes - the SNES context
2412: . x - input vector
2413: - b - rhs vector
2415: Output Parameter:
2416: . x - new solution vector
2418: Notes:
2419: SNESComputeNGS() is typically used within composed nonlinear solver
2420: implementations, so most users would not generally call this routine
2421: themselves.
2423: Level: developer
2425: .seealso: SNESSetNGS(), SNESComputeFunction()
2426: @*/
2427: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2428: {
2430: DM dm;
2431: DMSNES sdm;
2439: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2440: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2441: SNESGetDM(snes,&dm);
2442: DMGetDMSNES(dm,&sdm);
2443: if (sdm->ops->computegs) {
2444: if (b) {VecLockReadPush(b);}
2445: PetscStackPush("SNES user NGS");
2446: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2447: PetscStackPop;
2448: if (b) {VecLockReadPop(b);}
2449: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2450: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2451: return(0);
2452: }
2454: PetscErrorCode SNESTestJacobian(SNES snes)
2455: {
2456: Mat A,B,C,D,jacobian;
2457: Vec x = snes->vec_sol,f = snes->vec_func;
2458: PetscErrorCode ierr;
2459: PetscReal nrm,gnorm;
2460: PetscReal threshold = 1.e-5;
2461: MatType mattype;
2462: PetscInt m,n,M,N;
2463: void *functx;
2464: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg,istranspose;
2465: PetscViewer viewer,mviewer;
2466: MPI_Comm comm;
2467: PetscInt tabs;
2468: static PetscBool directionsprinted = PETSC_FALSE;
2469: PetscViewerFormat format;
2472: PetscObjectOptionsBegin((PetscObject)snes);
2473: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2474: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2475: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2476: if (!complete_print) {
2477: PetscOptionsDeprecated("-snes_test_jacobian_display","-snes_test_jacobian_view","3.13",NULL);
2478: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2479: }
2480: /* for compatibility with PETSc 3.9 and older. */
2481: PetscOptionsDeprecated("-snes_test_jacobian_display_threshold","-snes_test_jacobian","3.13","-snes_test_jacobian accepts an optional threshold (since v3.10)");
2482: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2483: PetscOptionsEnd();
2484: if (!test) return(0);
2486: PetscObjectGetComm((PetscObject)snes,&comm);
2487: PetscViewerASCIIGetStdout(comm,&viewer);
2488: PetscViewerASCIIGetTab(viewer, &tabs);
2489: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2490: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2491: if (!complete_print && !directionsprinted) {
2492: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2493: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2494: }
2495: if (!directionsprinted) {
2496: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2497: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2498: directionsprinted = PETSC_TRUE;
2499: }
2500: if (complete_print) {
2501: PetscViewerPushFormat(mviewer,format);
2502: }
2504: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2505: if (!flg) jacobian = snes->jacobian;
2506: else jacobian = snes->jacobian_pre;
2508: if (!x) {
2509: MatCreateVecs(jacobian, &x, NULL);
2510: } else {
2511: PetscObjectReference((PetscObject) x);
2512: }
2513: if (!f) {
2514: VecDuplicate(x, &f);
2515: } else {
2516: PetscObjectReference((PetscObject) f);
2517: }
2518: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2519: SNESComputeFunction(snes,x,f);
2520: VecDestroy(&f);
2521: PetscObjectTypeCompare((PetscObject)snes,SNESKSPTRANSPOSEONLY,&istranspose);
2522: while (jacobian) {
2523: Mat JT = NULL, Jsave = NULL;
2525: if (istranspose) {
2526: MatCreateTranspose(jacobian,&JT);
2527: Jsave = jacobian;
2528: jacobian = JT;
2529: }
2530: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2531: if (flg) {
2532: A = jacobian;
2533: PetscObjectReference((PetscObject)A);
2534: } else {
2535: MatComputeOperator(jacobian,MATAIJ,&A);
2536: }
2538: MatGetType(A,&mattype);
2539: MatGetSize(A,&M,&N);
2540: MatGetLocalSize(A,&m,&n);
2541: MatCreate(PetscObjectComm((PetscObject)A),&B);
2542: MatSetType(B,mattype);
2543: MatSetSizes(B,m,n,M,N);
2544: MatSetBlockSizesFromMats(B,A,A);
2545: MatSetUp(B);
2546: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2548: SNESGetFunction(snes,NULL,NULL,&functx);
2549: SNESComputeJacobianDefault(snes,x,B,B,functx);
2551: MatDuplicate(B,MAT_COPY_VALUES,&D);
2552: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2553: MatNorm(D,NORM_FROBENIUS,&nrm);
2554: MatNorm(A,NORM_FROBENIUS,&gnorm);
2555: MatDestroy(&D);
2556: if (!gnorm) gnorm = 1; /* just in case */
2557: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2559: if (complete_print) {
2560: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2561: MatView(A,mviewer);
2562: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2563: MatView(B,mviewer);
2564: }
2566: if (threshold_print || complete_print) {
2567: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2568: PetscScalar *cvals;
2569: const PetscInt *bcols;
2570: const PetscScalar *bvals;
2572: MatCreate(PetscObjectComm((PetscObject)A),&C);
2573: MatSetType(C,mattype);
2574: MatSetSizes(C,m,n,M,N);
2575: MatSetBlockSizesFromMats(C,A,A);
2576: MatSetUp(C);
2577: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2579: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2580: MatGetOwnershipRange(B,&Istart,&Iend);
2582: for (row = Istart; row < Iend; row++) {
2583: MatGetRow(B,row,&bncols,&bcols,&bvals);
2584: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2585: for (j = 0, cncols = 0; j < bncols; j++) {
2586: if (PetscAbsScalar(bvals[j]) > threshold) {
2587: ccols[cncols] = bcols[j];
2588: cvals[cncols] = bvals[j];
2589: cncols += 1;
2590: }
2591: }
2592: if (cncols) {
2593: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2594: }
2595: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2596: PetscFree2(ccols,cvals);
2597: }
2598: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2599: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2600: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2601: MatView(C,complete_print ? mviewer : viewer);
2602: MatDestroy(&C);
2603: }
2604: MatDestroy(&A);
2605: MatDestroy(&B);
2606: MatDestroy(&JT);
2607: if (Jsave) jacobian = Jsave;
2608: if (jacobian != snes->jacobian_pre) {
2609: jacobian = snes->jacobian_pre;
2610: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2611: }
2612: else jacobian = NULL;
2613: }
2614: VecDestroy(&x);
2615: if (complete_print) {
2616: PetscViewerPopFormat(mviewer);
2617: }
2618: if (mviewer) { PetscViewerDestroy(&mviewer); }
2619: PetscViewerASCIISetTab(viewer,tabs);
2620: return(0);
2621: }
2623: /*@
2624: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2626: Collective on SNES
2628: Input Parameters:
2629: + snes - the SNES context
2630: - x - input vector
2632: Output Parameters:
2633: + A - Jacobian matrix
2634: - B - optional preconditioning matrix
2636: Options Database Keys:
2637: + -snes_lag_preconditioner <lag>
2638: . -snes_lag_jacobian <lag>
2639: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one compute via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
2640: . -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2641: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2642: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2643: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2644: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2645: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2646: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2647: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2648: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2649: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2650: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2651: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2654: Notes:
2655: Most users should not need to explicitly call this routine, as it
2656: is used internally within the nonlinear solvers.
2658: Developer Notes:
2659: This has duplicative ways of checking the accuracy of the user provided Jacobian (see the options above). This is for historical reasons, the routine SNESTestJacobian() use to used
2660: for with the SNESType of test that has been removed.
2662: Level: developer
2664: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2665: @*/
2666: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2667: {
2669: PetscBool flag;
2670: DM dm;
2671: DMSNES sdm;
2672: KSP ksp;
2678: VecValidValues(X,2,PETSC_TRUE);
2679: SNESGetDM(snes,&dm);
2680: DMGetDMSNES(dm,&sdm);
2682: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2684: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2686: if (snes->lagjacobian == -2) {
2687: snes->lagjacobian = -1;
2689: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2690: } else if (snes->lagjacobian == -1) {
2691: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2692: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2693: if (flag) {
2694: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2695: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2696: }
2697: return(0);
2698: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2699: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2700: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2701: if (flag) {
2702: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2703: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2704: }
2705: return(0);
2706: }
2707: if (snes->npc && snes->npcside== PC_LEFT) {
2708: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2709: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2710: return(0);
2711: }
2713: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2714: VecLockReadPush(X);
2715: PetscStackPush("SNES user Jacobian function");
2716: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2717: PetscStackPop;
2718: VecLockReadPop(X);
2719: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2721: /* attach latest linearization point to the preconditioning matrix */
2722: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2724: /* the next line ensures that snes->ksp exists */
2725: SNESGetKSP(snes,&ksp);
2726: if (snes->lagpreconditioner == -2) {
2727: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2728: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2729: snes->lagpreconditioner = -1;
2730: } else if (snes->lagpreconditioner == -1) {
2731: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2732: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2733: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2734: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2735: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2736: } else {
2737: PetscInfo(snes,"Rebuilding preconditioner\n");
2738: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2739: }
2741: SNESTestJacobian(snes);
2742: /* make sure user returned a correct Jacobian and preconditioner */
2745: {
2746: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2747: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2748: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2749: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2750: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2751: if (flag || flag_draw || flag_contour) {
2752: Mat Bexp_mine = NULL,Bexp,FDexp;
2753: PetscViewer vdraw,vstdout;
2754: PetscBool flg;
2755: if (flag_operator) {
2756: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2757: Bexp = Bexp_mine;
2758: } else {
2759: /* See if the preconditioning matrix can be viewed and added directly */
2760: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2761: if (flg) Bexp = B;
2762: else {
2763: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2764: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2765: Bexp = Bexp_mine;
2766: }
2767: }
2768: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2769: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2770: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2771: if (flag_draw || flag_contour) {
2772: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2773: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2774: } else vdraw = NULL;
2775: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2776: if (flag) {MatView(Bexp,vstdout);}
2777: if (vdraw) {MatView(Bexp,vdraw);}
2778: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2779: if (flag) {MatView(FDexp,vstdout);}
2780: if (vdraw) {MatView(FDexp,vdraw);}
2781: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2782: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2783: if (flag) {MatView(FDexp,vstdout);}
2784: if (vdraw) { /* Always use contour for the difference */
2785: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2786: MatView(FDexp,vdraw);
2787: PetscViewerPopFormat(vdraw);
2788: }
2789: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2790: PetscViewerDestroy(&vdraw);
2791: MatDestroy(&Bexp_mine);
2792: MatDestroy(&FDexp);
2793: }
2794: }
2795: {
2796: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2797: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2798: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2799: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2800: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2801: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2802: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2803: if (flag_threshold) {
2804: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2805: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2806: }
2807: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2808: Mat Bfd;
2809: PetscViewer vdraw,vstdout;
2810: MatColoring coloring;
2811: ISColoring iscoloring;
2812: MatFDColoring matfdcoloring;
2813: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2814: void *funcctx;
2815: PetscReal norm1,norm2,normmax;
2817: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2818: MatColoringCreate(Bfd,&coloring);
2819: MatColoringSetType(coloring,MATCOLORINGSL);
2820: MatColoringSetFromOptions(coloring);
2821: MatColoringApply(coloring,&iscoloring);
2822: MatColoringDestroy(&coloring);
2823: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2824: MatFDColoringSetFromOptions(matfdcoloring);
2825: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2826: ISColoringDestroy(&iscoloring);
2828: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2829: SNESGetFunction(snes,NULL,&func,&funcctx);
2830: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2831: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2832: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2833: MatFDColoringSetFromOptions(matfdcoloring);
2834: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2835: MatFDColoringDestroy(&matfdcoloring);
2837: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2838: if (flag_draw || flag_contour) {
2839: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2840: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2841: } else vdraw = NULL;
2842: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2843: if (flag_display) {MatView(B,vstdout);}
2844: if (vdraw) {MatView(B,vdraw);}
2845: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2846: if (flag_display) {MatView(Bfd,vstdout);}
2847: if (vdraw) {MatView(Bfd,vdraw);}
2848: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2849: MatNorm(Bfd,NORM_1,&norm1);
2850: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2851: MatNorm(Bfd,NORM_MAX,&normmax);
2852: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2853: if (flag_display) {MatView(Bfd,vstdout);}
2854: if (vdraw) { /* Always use contour for the difference */
2855: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2856: MatView(Bfd,vdraw);
2857: PetscViewerPopFormat(vdraw);
2858: }
2859: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2861: if (flag_threshold) {
2862: PetscInt bs,rstart,rend,i;
2863: MatGetBlockSize(B,&bs);
2864: MatGetOwnershipRange(B,&rstart,&rend);
2865: for (i=rstart; i<rend; i++) {
2866: const PetscScalar *ba,*ca;
2867: const PetscInt *bj,*cj;
2868: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2869: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2870: MatGetRow(B,i,&bn,&bj,&ba);
2871: MatGetRow(Bfd,i,&cn,&cj,&ca);
2872: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2873: for (j=0; j<bn; j++) {
2874: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2875: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2876: maxentrycol = bj[j];
2877: maxentry = PetscRealPart(ba[j]);
2878: }
2879: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2880: maxdiffcol = bj[j];
2881: maxdiff = PetscRealPart(ca[j]);
2882: }
2883: if (rdiff > maxrdiff) {
2884: maxrdiffcol = bj[j];
2885: maxrdiff = rdiff;
2886: }
2887: }
2888: if (maxrdiff > 1) {
2889: 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);
2890: for (j=0; j<bn; j++) {
2891: PetscReal rdiff;
2892: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2893: if (rdiff > 1) {
2894: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2895: }
2896: }
2897: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2898: }
2899: MatRestoreRow(B,i,&bn,&bj,&ba);
2900: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2901: }
2902: }
2903: PetscViewerDestroy(&vdraw);
2904: MatDestroy(&Bfd);
2905: }
2906: }
2907: return(0);
2908: }
2910: /*MC
2911: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2913: Synopsis:
2914: #include "petscsnes.h"
2915: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2917: Collective on snes
2919: Input Parameters:
2920: + x - input vector, the Jacobian is to be computed at this value
2921: - ctx - [optional] user-defined Jacobian context
2923: Output Parameters:
2924: + Amat - the matrix that defines the (approximate) Jacobian
2925: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2927: Level: intermediate
2929: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2930: M*/
2932: /*@C
2933: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2934: location to store the matrix.
2936: Logically Collective on SNES
2938: Input Parameters:
2939: + snes - the SNES context
2940: . Amat - the matrix that defines the (approximate) Jacobian
2941: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2942: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2943: - ctx - [optional] user-defined context for private data for the
2944: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2946: Notes:
2947: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2948: each matrix.
2950: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2951: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2953: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2954: must be a MatFDColoring.
2956: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2957: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2959: Level: beginner
2961: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2962: SNESSetPicard(), SNESJacobianFunction
2963: @*/
2964: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2965: {
2967: DM dm;
2975: SNESGetDM(snes,&dm);
2976: DMSNESSetJacobian(dm,J,ctx);
2977: if (Amat) {
2978: PetscObjectReference((PetscObject)Amat);
2979: MatDestroy(&snes->jacobian);
2981: snes->jacobian = Amat;
2982: }
2983: if (Pmat) {
2984: PetscObjectReference((PetscObject)Pmat);
2985: MatDestroy(&snes->jacobian_pre);
2987: snes->jacobian_pre = Pmat;
2988: }
2989: return(0);
2990: }
2992: /*@C
2993: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2994: provided context for evaluating the Jacobian.
2996: Not Collective, but Mat object will be parallel if SNES object is
2998: Input Parameter:
2999: . snes - the nonlinear solver context
3001: Output Parameters:
3002: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
3003: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
3004: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
3005: - ctx - location to stash Jacobian ctx (or NULL)
3007: Level: advanced
3009: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
3010: @*/
3011: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
3012: {
3014: DM dm;
3015: DMSNES sdm;
3019: if (Amat) *Amat = snes->jacobian;
3020: if (Pmat) *Pmat = snes->jacobian_pre;
3021: SNESGetDM(snes,&dm);
3022: DMGetDMSNES(dm,&sdm);
3023: if (J) *J = sdm->ops->computejacobian;
3024: if (ctx) *ctx = sdm->jacobianctx;
3025: return(0);
3026: }
3028: /*@
3029: SNESSetUp - Sets up the internal data structures for the later use
3030: of a nonlinear solver.
3032: Collective on SNES
3034: Input Parameters:
3035: . snes - the SNES context
3037: Notes:
3038: For basic use of the SNES solvers the user need not explicitly call
3039: SNESSetUp(), since these actions will automatically occur during
3040: the call to SNESSolve(). However, if one wishes to control this
3041: phase separately, SNESSetUp() should be called after SNESCreate()
3042: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3044: Level: advanced
3046: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3047: @*/
3048: PetscErrorCode SNESSetUp(SNES snes)
3049: {
3051: DM dm;
3052: DMSNES sdm;
3053: SNESLineSearch linesearch, pclinesearch;
3054: void *lsprectx,*lspostctx;
3055: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3056: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3057: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3058: Vec f,fpc;
3059: void *funcctx;
3060: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3061: void *jacctx,*appctx;
3062: Mat j,jpre;
3066: if (snes->setupcalled) return(0);
3067: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3069: if (!((PetscObject)snes)->type_name) {
3070: SNESSetType(snes,SNESNEWTONLS);
3071: }
3073: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3075: SNESGetDM(snes,&dm);
3076: DMGetDMSNES(dm,&sdm);
3077: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3078: if (!sdm->ops->computejacobian) {
3079: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3080: }
3081: if (!snes->vec_func) {
3082: DMCreateGlobalVector(dm,&snes->vec_func);
3083: }
3085: if (!snes->ksp) {
3086: SNESGetKSP(snes, &snes->ksp);
3087: }
3089: if (snes->linesearch) {
3090: SNESGetLineSearch(snes, &snes->linesearch);
3091: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3092: }
3094: if (snes->npc && (snes->npcside== PC_LEFT)) {
3095: snes->mf = PETSC_TRUE;
3096: snes->mf_operator = PETSC_FALSE;
3097: }
3099: if (snes->npc) {
3100: /* copy the DM over */
3101: SNESGetDM(snes,&dm);
3102: SNESSetDM(snes->npc,dm);
3104: SNESGetFunction(snes,&f,&func,&funcctx);
3105: VecDuplicate(f,&fpc);
3106: SNESSetFunction(snes->npc,fpc,func,funcctx);
3107: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3108: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3109: SNESGetApplicationContext(snes,&appctx);
3110: SNESSetApplicationContext(snes->npc,appctx);
3111: VecDestroy(&fpc);
3113: /* copy the function pointers over */
3114: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3116: /* default to 1 iteration */
3117: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3118: if (snes->npcside==PC_RIGHT) {
3119: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3120: } else {
3121: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3122: }
3123: SNESSetFromOptions(snes->npc);
3125: /* copy the line search context over */
3126: if (snes->linesearch && snes->npc->linesearch) {
3127: SNESGetLineSearch(snes,&linesearch);
3128: SNESGetLineSearch(snes->npc,&pclinesearch);
3129: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3130: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3131: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3132: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3133: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3134: }
3135: }
3136: if (snes->mf) {
3137: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3138: }
3139: if (snes->ops->usercompute && !snes->user) {
3140: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3141: }
3143: snes->jac_iter = 0;
3144: snes->pre_iter = 0;
3146: if (snes->ops->setup) {
3147: (*snes->ops->setup)(snes);
3148: }
3150: if (snes->npc && (snes->npcside== PC_LEFT)) {
3151: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3152: if (snes->linesearch){
3153: SNESGetLineSearch(snes,&linesearch);
3154: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3155: }
3156: }
3157: }
3158: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3159: snes->setupcalled = PETSC_TRUE;
3160: return(0);
3161: }
3163: /*@
3164: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3166: Collective on SNES
3168: Input Parameter:
3169: . snes - iterative context obtained from SNESCreate()
3171: Level: intermediate
3173: Notes:
3174: Also calls the Section 1.5 Writing Application Codes with PETSc context destroy routine set with SNESSetComputeApplicationContext()
3176: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3177: @*/
3178: PetscErrorCode SNESReset(SNES snes)
3179: {
3184: if (snes->ops->userdestroy && snes->user) {
3185: (*snes->ops->userdestroy)((void**)&snes->user);
3186: snes->user = NULL;
3187: }
3188: if (snes->npc) {
3189: SNESReset(snes->npc);
3190: }
3192: if (snes->ops->reset) {
3193: (*snes->ops->reset)(snes);
3194: }
3195: if (snes->ksp) {
3196: KSPReset(snes->ksp);
3197: }
3199: if (snes->linesearch) {
3200: SNESLineSearchReset(snes->linesearch);
3201: }
3203: VecDestroy(&snes->vec_rhs);
3204: VecDestroy(&snes->vec_sol);
3205: VecDestroy(&snes->vec_sol_update);
3206: VecDestroy(&snes->vec_func);
3207: MatDestroy(&snes->jacobian);
3208: MatDestroy(&snes->jacobian_pre);
3209: VecDestroyVecs(snes->nwork,&snes->work);
3210: VecDestroyVecs(snes->nvwork,&snes->vwork);
3212: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3214: snes->nwork = snes->nvwork = 0;
3215: snes->setupcalled = PETSC_FALSE;
3216: return(0);
3217: }
3219: /*@
3220: SNESDestroy - Destroys the nonlinear solver context that was created
3221: with SNESCreate().
3223: Collective on SNES
3225: Input Parameter:
3226: . snes - the SNES context
3228: Level: beginner
3230: .seealso: SNESCreate(), SNESSolve()
3231: @*/
3232: PetscErrorCode SNESDestroy(SNES *snes)
3233: {
3237: if (!*snes) return(0);
3239: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3241: SNESReset((*snes));
3242: SNESDestroy(&(*snes)->npc);
3244: /* if memory was published with SAWs then destroy it */
3245: PetscObjectSAWsViewOff((PetscObject)*snes);
3246: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3248: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3249: DMDestroy(&(*snes)->dm);
3250: KSPDestroy(&(*snes)->ksp);
3251: SNESLineSearchDestroy(&(*snes)->linesearch);
3253: PetscFree((*snes)->kspconvctx);
3254: if ((*snes)->ops->convergeddestroy) {
3255: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3256: }
3257: if ((*snes)->conv_hist_alloc) {
3258: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3259: }
3260: SNESMonitorCancel((*snes));
3261: PetscHeaderDestroy(snes);
3262: return(0);
3263: }
3265: /* ----------- Routines to set solver parameters ---------- */
3267: /*@
3268: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3270: Logically Collective on SNES
3272: Input Parameters:
3273: + snes - the SNES context
3274: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3275: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3277: Options Database Keys:
3278: . -snes_lag_preconditioner <lag>
3280: Notes:
3281: The default is 1
3282: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3283: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3285: Level: intermediate
3287: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3289: @*/
3290: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3291: {
3294: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3295: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3297: snes->lagpreconditioner = lag;
3298: return(0);
3299: }
3301: /*@
3302: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3304: Logically Collective on SNES
3306: Input Parameters:
3307: + snes - the SNES context
3308: - steps - the number of refinements to do, defaults to 0
3310: Options Database Keys:
3311: . -snes_grid_sequence <steps>
3313: Level: intermediate
3315: Notes:
3316: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3318: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3320: @*/
3321: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3322: {
3326: snes->gridsequence = steps;
3327: return(0);
3328: }
3330: /*@
3331: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3333: Logically Collective on SNES
3335: Input Parameter:
3336: . snes - the SNES context
3338: Output Parameter:
3339: . steps - the number of refinements to do, defaults to 0
3341: Options Database Keys:
3342: . -snes_grid_sequence <steps>
3344: Level: intermediate
3346: Notes:
3347: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3349: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3351: @*/
3352: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3353: {
3356: *steps = snes->gridsequence;
3357: return(0);
3358: }
3360: /*@
3361: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3363: Not Collective
3365: Input Parameter:
3366: . snes - the SNES context
3368: Output Parameter:
3369: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3370: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3372: Options Database Keys:
3373: . -snes_lag_preconditioner <lag>
3375: Notes:
3376: The default is 1
3377: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3379: Level: intermediate
3381: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3383: @*/
3384: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3385: {
3388: *lag = snes->lagpreconditioner;
3389: return(0);
3390: }
3392: /*@
3393: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3394: often the preconditioner is rebuilt.
3396: Logically Collective on SNES
3398: Input Parameters:
3399: + snes - the SNES context
3400: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3401: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3403: Options Database Keys:
3404: . -snes_lag_jacobian <lag>
3406: Notes:
3407: The default is 1
3408: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3409: 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
3410: at the next Newton step but never again (unless it is reset to another value)
3412: Level: intermediate
3414: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3416: @*/
3417: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3418: {
3421: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3422: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3424: snes->lagjacobian = lag;
3425: return(0);
3426: }
3428: /*@
3429: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3431: Not Collective
3433: Input Parameter:
3434: . snes - the SNES context
3436: Output Parameter:
3437: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3438: the Jacobian is built etc.
3440: Options Database Keys:
3441: . -snes_lag_jacobian <lag>
3443: Notes:
3444: The default is 1
3445: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3447: Level: intermediate
3449: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3451: @*/
3452: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3453: {
3456: *lag = snes->lagjacobian;
3457: return(0);
3458: }
3460: /*@
3461: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3463: Logically collective on SNES
3465: Input Parameter:
3466: + snes - the SNES context
3467: - flg - jacobian lagging persists if true
3469: Options Database Keys:
3470: . -snes_lag_jacobian_persists <flg>
3472: Notes:
3473: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3474: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3475: timesteps may present huge efficiency gains.
3477: Level: developer
3479: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3481: @*/
3482: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3483: {
3487: snes->lagjac_persist = flg;
3488: return(0);
3489: }
3491: /*@
3492: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3494: Logically Collective on SNES
3496: Input Parameter:
3497: + snes - the SNES context
3498: - flg - preconditioner lagging persists if true
3500: Options Database Keys:
3501: . -snes_lag_jacobian_persists <flg>
3503: Notes:
3504: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3505: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3506: several timesteps may present huge efficiency gains.
3508: Level: developer
3510: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3512: @*/
3513: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3514: {
3518: snes->lagpre_persist = flg;
3519: return(0);
3520: }
3522: /*@
3523: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3525: Logically Collective on SNES
3527: Input Parameters:
3528: + snes - the SNES context
3529: - force - PETSC_TRUE require at least one iteration
3531: Options Database Keys:
3532: . -snes_force_iteration <force> - Sets forcing an iteration
3534: Notes:
3535: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3537: Level: intermediate
3539: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3540: @*/
3541: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3542: {
3545: snes->forceiteration = force;
3546: return(0);
3547: }
3549: /*@
3550: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3552: Logically Collective on SNES
3554: Input Parameters:
3555: . snes - the SNES context
3557: Output Parameter:
3558: . force - PETSC_TRUE requires at least one iteration.
3560: Level: intermediate
3562: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3563: @*/
3564: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3565: {
3568: *force = snes->forceiteration;
3569: return(0);
3570: }
3572: /*@
3573: SNESSetTolerances - Sets various parameters used in convergence tests.
3575: Logically Collective on SNES
3577: Input Parameters:
3578: + snes - the SNES context
3579: . abstol - absolute convergence tolerance
3580: . rtol - relative convergence tolerance
3581: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3582: . maxit - maximum number of iterations
3583: - maxf - maximum number of function evaluations (-1 indicates no limit)
3585: Options Database Keys:
3586: + -snes_atol <abstol> - Sets abstol
3587: . -snes_rtol <rtol> - Sets rtol
3588: . -snes_stol <stol> - Sets stol
3589: . -snes_max_it <maxit> - Sets maxit
3590: - -snes_max_funcs <maxf> - Sets maxf
3592: Notes:
3593: The default maximum number of iterations is 50.
3594: The default maximum number of function evaluations is 1000.
3596: Level: intermediate
3598: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3599: @*/
3600: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3601: {
3610: if (abstol != PETSC_DEFAULT) {
3611: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3612: snes->abstol = abstol;
3613: }
3614: if (rtol != PETSC_DEFAULT) {
3615: 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);
3616: snes->rtol = rtol;
3617: }
3618: if (stol != PETSC_DEFAULT) {
3619: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3620: snes->stol = stol;
3621: }
3622: if (maxit != PETSC_DEFAULT) {
3623: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3624: snes->max_its = maxit;
3625: }
3626: if (maxf != PETSC_DEFAULT) {
3627: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3628: snes->max_funcs = maxf;
3629: }
3630: snes->tolerancesset = PETSC_TRUE;
3631: return(0);
3632: }
3634: /*@
3635: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3637: Logically Collective on SNES
3639: Input Parameters:
3640: + snes - the SNES context
3641: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3643: Options Database Keys:
3644: . -snes_divergence_tolerance <divtol> - Sets divtol
3646: Notes:
3647: The default divergence tolerance is 1e4.
3649: Level: intermediate
3651: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3652: @*/
3653: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3654: {
3659: if (divtol != PETSC_DEFAULT) {
3660: snes->divtol = divtol;
3661: }
3662: else {
3663: snes->divtol = 1.0e4;
3664: }
3665: return(0);
3666: }
3668: /*@
3669: SNESGetTolerances - Gets various parameters used in convergence tests.
3671: Not Collective
3673: Input Parameters:
3674: + snes - the SNES context
3675: . atol - absolute convergence tolerance
3676: . rtol - relative convergence tolerance
3677: . stol - convergence tolerance in terms of the norm
3678: of the change in the solution between steps
3679: . maxit - maximum number of iterations
3680: - maxf - maximum number of function evaluations
3682: Notes:
3683: The user can specify NULL for any parameter that is not needed.
3685: Level: intermediate
3687: .seealso: SNESSetTolerances()
3688: @*/
3689: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3690: {
3693: if (atol) *atol = snes->abstol;
3694: if (rtol) *rtol = snes->rtol;
3695: if (stol) *stol = snes->stol;
3696: if (maxit) *maxit = snes->max_its;
3697: if (maxf) *maxf = snes->max_funcs;
3698: return(0);
3699: }
3701: /*@
3702: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3704: Not Collective
3706: Input Parameters:
3707: + snes - the SNES context
3708: - divtol - divergence tolerance
3710: Level: intermediate
3712: .seealso: SNESSetDivergenceTolerance()
3713: @*/
3714: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3715: {
3718: if (divtol) *divtol = snes->divtol;
3719: return(0);
3720: }
3722: /*@
3723: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3725: Logically Collective on SNES
3727: Input Parameters:
3728: + snes - the SNES context
3729: - tol - tolerance
3731: Options Database Key:
3732: . -snes_trtol <tol> - Sets tol
3734: Level: intermediate
3736: .seealso: SNESSetTolerances()
3737: @*/
3738: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3739: {
3743: snes->deltatol = tol;
3744: return(0);
3745: }
3747: /*
3748: Duplicate the lg monitors for SNES from KSP; for some reason with
3749: dynamic libraries things don't work under Sun4 if we just use
3750: macros instead of functions
3751: */
3752: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3753: {
3758: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3759: return(0);
3760: }
3762: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3763: {
3767: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3768: return(0);
3769: }
3771: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3773: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3774: {
3775: PetscDrawLG lg;
3776: PetscErrorCode ierr;
3777: PetscReal x,y,per;
3778: PetscViewer v = (PetscViewer)monctx;
3779: static PetscReal prev; /* should be in the context */
3780: PetscDraw draw;
3784: PetscViewerDrawGetDrawLG(v,0,&lg);
3785: if (!n) {PetscDrawLGReset(lg);}
3786: PetscDrawLGGetDraw(lg,&draw);
3787: PetscDrawSetTitle(draw,"Residual norm");
3788: x = (PetscReal)n;
3789: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3790: else y = -15.0;
3791: PetscDrawLGAddPoint(lg,&x,&y);
3792: if (n < 20 || !(n % 5) || snes->reason) {
3793: PetscDrawLGDraw(lg);
3794: PetscDrawLGSave(lg);
3795: }
3797: PetscViewerDrawGetDrawLG(v,1,&lg);
3798: if (!n) {PetscDrawLGReset(lg);}
3799: PetscDrawLGGetDraw(lg,&draw);
3800: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3801: SNESMonitorRange_Private(snes,n,&per);
3802: x = (PetscReal)n;
3803: y = 100.0*per;
3804: PetscDrawLGAddPoint(lg,&x,&y);
3805: if (n < 20 || !(n % 5) || snes->reason) {
3806: PetscDrawLGDraw(lg);
3807: PetscDrawLGSave(lg);
3808: }
3810: PetscViewerDrawGetDrawLG(v,2,&lg);
3811: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3812: PetscDrawLGGetDraw(lg,&draw);
3813: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3814: x = (PetscReal)n;
3815: y = (prev - rnorm)/prev;
3816: PetscDrawLGAddPoint(lg,&x,&y);
3817: if (n < 20 || !(n % 5) || snes->reason) {
3818: PetscDrawLGDraw(lg);
3819: PetscDrawLGSave(lg);
3820: }
3822: PetscViewerDrawGetDrawLG(v,3,&lg);
3823: if (!n) {PetscDrawLGReset(lg);}
3824: PetscDrawLGGetDraw(lg,&draw);
3825: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3826: x = (PetscReal)n;
3827: y = (prev - rnorm)/(prev*per);
3828: if (n > 2) { /*skip initial crazy value */
3829: PetscDrawLGAddPoint(lg,&x,&y);
3830: }
3831: if (n < 20 || !(n % 5) || snes->reason) {
3832: PetscDrawLGDraw(lg);
3833: PetscDrawLGSave(lg);
3834: }
3835: prev = rnorm;
3836: return(0);
3837: }
3839: /*@
3840: SNESMonitor - runs the user provided monitor routines, if they exist
3842: Collective on SNES
3844: Input Parameters:
3845: + snes - nonlinear solver context obtained from SNESCreate()
3846: . iter - iteration number
3847: - rnorm - relative norm of the residual
3849: Notes:
3850: This routine is called by the SNES implementations.
3851: It does not typically need to be called by the user.
3853: Level: developer
3855: .seealso: SNESMonitorSet()
3856: @*/
3857: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3858: {
3860: PetscInt i,n = snes->numbermonitors;
3863: VecLockReadPush(snes->vec_sol);
3864: for (i=0; i<n; i++) {
3865: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3866: }
3867: VecLockReadPop(snes->vec_sol);
3868: return(0);
3869: }
3871: /* ------------ Routines to set performance monitoring options ----------- */
3873: /*MC
3874: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3876: Synopsis:
3877: #include <petscsnes.h>
3878: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3880: Collective on snes
3882: Input Parameters:
3883: + snes - the SNES context
3884: . its - iteration number
3885: . norm - 2-norm function value (may be estimated)
3886: - mctx - [optional] monitoring context
3888: Level: advanced
3890: .seealso: SNESMonitorSet(), SNESMonitorGet()
3891: M*/
3893: /*@C
3894: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3895: iteration of the nonlinear solver to display the iteration's
3896: progress.
3898: Logically Collective on SNES
3900: Input Parameters:
3901: + snes - the SNES context
3902: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3903: . mctx - [optional] user-defined context for private data for the
3904: monitor routine (use NULL if no context is desired)
3905: - monitordestroy - [optional] routine that frees monitor context
3906: (may be NULL)
3908: Options Database Keys:
3909: + -snes_monitor - sets SNESMonitorDefault()
3910: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3911: uses SNESMonitorLGCreate()
3912: - -snes_monitor_cancel - cancels all monitors that have
3913: been hardwired into a code by
3914: calls to SNESMonitorSet(), but
3915: does not cancel those set via
3916: the options database.
3918: Notes:
3919: Several different monitoring routines may be set by calling
3920: SNESMonitorSet() multiple times; all will be called in the
3921: order in which they were set.
3923: Fortran Notes:
3924: Only a single monitor function can be set for each SNES object
3926: Level: intermediate
3928: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3929: @*/
3930: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3931: {
3932: PetscInt i;
3934: PetscBool identical;
3938: for (i=0; i<snes->numbermonitors;i++) {
3939: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3940: if (identical) return(0);
3941: }
3942: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3943: snes->monitor[snes->numbermonitors] = f;
3944: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3945: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3946: return(0);
3947: }
3949: /*@
3950: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3952: Logically Collective on SNES
3954: Input Parameters:
3955: . snes - the SNES context
3957: Options Database Key:
3958: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3959: into a code by calls to SNESMonitorSet(), but does not cancel those
3960: set via the options database
3962: Notes:
3963: There is no way to clear one specific monitor from a SNES object.
3965: Level: intermediate
3967: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3968: @*/
3969: PetscErrorCode SNESMonitorCancel(SNES snes)
3970: {
3972: PetscInt i;
3976: for (i=0; i<snes->numbermonitors; i++) {
3977: if (snes->monitordestroy[i]) {
3978: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3979: }
3980: }
3981: snes->numbermonitors = 0;
3982: return(0);
3983: }
3985: /*MC
3986: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3988: Synopsis:
3989: #include <petscsnes.h>
3990: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3992: Collective on snes
3994: Input Parameters:
3995: + snes - the SNES context
3996: . it - current iteration (0 is the first and is before any Newton step)
3997: . xnorm - 2-norm of current iterate
3998: . gnorm - 2-norm of current step
3999: . f - 2-norm of function
4000: - cctx - [optional] convergence context
4002: Output Parameter:
4003: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4005: Level: intermediate
4007: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
4008: M*/
4010: /*@C
4011: SNESSetConvergenceTest - Sets the function that is to be used
4012: to test for convergence of the nonlinear iterative solution.
4014: Logically Collective on SNES
4016: Input Parameters:
4017: + snes - the SNES context
4018: . SNESConvergenceTestFunction - routine to test for convergence
4019: . cctx - [optional] context for private data for the convergence routine (may be NULL)
4020: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
4022: Level: advanced
4024: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
4025: @*/
4026: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
4027: {
4032: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4033: if (snes->ops->convergeddestroy) {
4034: (*snes->ops->convergeddestroy)(snes->cnvP);
4035: }
4036: snes->ops->converged = SNESConvergenceTestFunction;
4037: snes->ops->convergeddestroy = destroy;
4038: snes->cnvP = cctx;
4039: return(0);
4040: }
4042: /*@
4043: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4045: Not Collective
4047: Input Parameter:
4048: . snes - the SNES context
4050: Output Parameter:
4051: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4052: manual pages for the individual convergence tests for complete lists
4054: Options Database:
4055: . -snes_converged_reason - prints the reason to standard out
4057: Level: intermediate
4059: Notes:
4060: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4062: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4063: @*/
4064: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4065: {
4069: *reason = snes->reason;
4070: return(0);
4071: }
4073: /*@
4074: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4076: Not Collective
4078: Input Parameters:
4079: + snes - the SNES context
4080: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4081: manual pages for the individual convergence tests for complete lists
4083: Level: intermediate
4085: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4086: @*/
4087: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4088: {
4091: snes->reason = reason;
4092: return(0);
4093: }
4095: /*@
4096: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4098: Logically Collective on SNES
4100: Input Parameters:
4101: + snes - iterative context obtained from SNESCreate()
4102: . a - array to hold history, this array will contain the function norms computed at each step
4103: . its - integer array holds the number of linear iterations for each solve.
4104: . na - size of a and its
4105: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4106: else it continues storing new values for new nonlinear solves after the old ones
4108: Notes:
4109: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4110: default array of length 10000 is allocated.
4112: This routine is useful, e.g., when running a code for purposes
4113: of accurate performance monitoring, when no I/O should be done
4114: during the section of code that is being timed.
4116: Level: intermediate
4118: .seealso: SNESGetConvergenceHistory()
4120: @*/
4121: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4122: {
4129: if (!a) {
4130: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4131: PetscCalloc2(na,&a,na,&its);
4132: snes->conv_hist_alloc = PETSC_TRUE;
4133: }
4134: snes->conv_hist = a;
4135: snes->conv_hist_its = its;
4136: snes->conv_hist_max = na;
4137: snes->conv_hist_len = 0;
4138: snes->conv_hist_reset = reset;
4139: return(0);
4140: }
4142: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4143: #include <engine.h> /* MATLAB include file */
4144: #include <mex.h> /* MATLAB include file */
4146: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4147: {
4148: mxArray *mat;
4149: PetscInt i;
4150: PetscReal *ar;
4153: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4154: ar = (PetscReal*) mxGetData(mat);
4155: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4156: PetscFunctionReturn(mat);
4157: }
4158: #endif
4160: /*@C
4161: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4163: Not Collective
4165: Input Parameter:
4166: . snes - iterative context obtained from SNESCreate()
4168: Output Parameters:
4169: + a - array to hold history
4170: . its - integer array holds the number of linear iterations (or
4171: negative if not converged) for each solve.
4172: - na - size of a and its
4174: Notes:
4175: The calling sequence for this routine in Fortran is
4176: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4178: This routine is useful, e.g., when running a code for purposes
4179: of accurate performance monitoring, when no I/O should be done
4180: during the section of code that is being timed.
4182: Level: intermediate
4184: .seealso: SNESSetConvergencHistory()
4186: @*/
4187: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4188: {
4191: if (a) *a = snes->conv_hist;
4192: if (its) *its = snes->conv_hist_its;
4193: if (na) *na = snes->conv_hist_len;
4194: return(0);
4195: }
4197: /*@C
4198: SNESSetUpdate - Sets the general-purpose update function called
4199: at the beginning of every iteration of the nonlinear solve. Specifically
4200: it is called just before the Jacobian is "evaluated".
4202: Logically Collective on SNES
4204: Input Parameters:
4205: + snes - The nonlinear solver context
4206: - func - The function
4208: Calling sequence of func:
4209: $ func (SNES snes, PetscInt step);
4211: . step - The current step of the iteration
4213: Level: advanced
4215: 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()
4216: This is not used by most users.
4218: .seealso SNESSetJacobian(), SNESSolve()
4219: @*/
4220: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4221: {
4224: snes->ops->update = func;
4225: return(0);
4226: }
4228: /*
4229: SNESScaleStep_Private - Scales a step so that its length is less than the
4230: positive parameter delta.
4232: Input Parameters:
4233: + snes - the SNES context
4234: . y - approximate solution of linear system
4235: . fnorm - 2-norm of current function
4236: - delta - trust region size
4238: Output Parameters:
4239: + gpnorm - predicted function norm at the new point, assuming local
4240: linearization. The value is zero if the step lies within the trust
4241: region, and exceeds zero otherwise.
4242: - ynorm - 2-norm of the step
4244: Note:
4245: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4246: is set to be the maximum allowable step size.
4248: */
4249: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4250: {
4251: PetscReal nrm;
4252: PetscScalar cnorm;
4260: VecNorm(y,NORM_2,&nrm);
4261: if (nrm > *delta) {
4262: nrm = *delta/nrm;
4263: *gpnorm = (1.0 - nrm)*(*fnorm);
4264: cnorm = nrm;
4265: VecScale(y,cnorm);
4266: *ynorm = *delta;
4267: } else {
4268: *gpnorm = 0.0;
4269: *ynorm = nrm;
4270: }
4271: return(0);
4272: }
4274: /*@
4275: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4277: Collective on SNES
4279: Parameter:
4280: + snes - iterative context obtained from SNESCreate()
4281: - viewer - the viewer to display the reason
4284: Options Database Keys:
4285: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4287: Level: beginner
4289: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4291: @*/
4292: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4293: {
4294: PetscViewerFormat format;
4295: PetscBool isAscii;
4296: PetscErrorCode ierr;
4299: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4300: if (isAscii) {
4301: PetscViewerGetFormat(viewer, &format);
4302: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4303: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4304: DM dm;
4305: Vec u;
4306: PetscDS prob;
4307: PetscInt Nf, f;
4308: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4309: void **exactCtx;
4310: PetscReal error;
4312: SNESGetDM(snes, &dm);
4313: SNESGetSolution(snes, &u);
4314: DMGetDS(dm, &prob);
4315: PetscDSGetNumFields(prob, &Nf);
4316: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4317: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4318: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4319: PetscFree2(exactSol, exactCtx);
4320: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4321: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4322: }
4323: if (snes->reason > 0) {
4324: if (((PetscObject) snes)->prefix) {
4325: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4326: } else {
4327: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4328: }
4329: } else {
4330: if (((PetscObject) snes)->prefix) {
4331: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4332: } else {
4333: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4334: }
4335: }
4336: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4337: }
4338: return(0);
4339: }
4341: /*@C
4342: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4344: Collective on SNES
4346: Input Parameters:
4347: . snes - the SNES object
4349: Level: intermediate
4351: @*/
4352: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4353: {
4354: PetscErrorCode ierr;
4355: PetscViewer viewer;
4356: PetscBool flg;
4357: static PetscBool incall = PETSC_FALSE;
4358: PetscViewerFormat format;
4361: if (incall) return(0);
4362: incall = PETSC_TRUE;
4363: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4364: if (flg) {
4365: PetscViewerPushFormat(viewer,format);
4366: SNESReasonView(snes,viewer);
4367: PetscViewerPopFormat(viewer);
4368: PetscViewerDestroy(&viewer);
4369: }
4370: incall = PETSC_FALSE;
4371: return(0);
4372: }
4374: /*@
4375: SNESSolve - Solves a nonlinear system F(x) = b.
4376: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4378: Collective on SNES
4380: Input Parameters:
4381: + snes - the SNES context
4382: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4383: - x - the solution vector.
4385: Notes:
4386: The user should initialize the vector,x, with the initial guess
4387: for the nonlinear solve prior to calling SNESSolve. In particular,
4388: to employ an initial guess of zero, the user should explicitly set
4389: this vector to zero by calling VecSet().
4391: Level: beginner
4393: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4394: @*/
4395: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4396: {
4397: PetscErrorCode ierr;
4398: PetscBool flg;
4399: PetscInt grid;
4400: Vec xcreated = NULL;
4401: DM dm;
4410: /* High level operations using the nonlinear solver */
4411: {
4412: PetscViewer viewer;
4413: PetscViewerFormat format;
4414: PetscInt num;
4415: PetscBool flg;
4416: static PetscBool incall = PETSC_FALSE;
4418: if (!incall) {
4419: /* Estimate the convergence rate of the discretization */
4420: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4421: if (flg) {
4422: PetscConvEst conv;
4423: DM dm;
4424: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4425: PetscInt Nf;
4427: incall = PETSC_TRUE;
4428: SNESGetDM(snes, &dm);
4429: DMGetNumFields(dm, &Nf);
4430: PetscCalloc1(Nf, &alpha);
4431: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4432: PetscConvEstSetSolver(conv, (PetscObject) snes);
4433: PetscConvEstSetFromOptions(conv);
4434: PetscConvEstSetUp(conv);
4435: PetscConvEstGetConvRate(conv, alpha);
4436: PetscViewerPushFormat(viewer, format);
4437: PetscConvEstRateView(conv, alpha, viewer);
4438: PetscViewerPopFormat(viewer);
4439: PetscViewerDestroy(&viewer);
4440: PetscConvEstDestroy(&conv);
4441: PetscFree(alpha);
4442: incall = PETSC_FALSE;
4443: }
4444: /* Adaptively refine the initial grid */
4445: num = 1;
4446: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4447: if (flg) {
4448: DMAdaptor adaptor;
4450: incall = PETSC_TRUE;
4451: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4452: DMAdaptorSetSolver(adaptor, snes);
4453: DMAdaptorSetSequenceLength(adaptor, num);
4454: DMAdaptorSetFromOptions(adaptor);
4455: DMAdaptorSetUp(adaptor);
4456: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4457: DMAdaptorDestroy(&adaptor);
4458: incall = PETSC_FALSE;
4459: }
4460: /* Use grid sequencing to adapt */
4461: num = 0;
4462: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4463: if (num) {
4464: DMAdaptor adaptor;
4466: incall = PETSC_TRUE;
4467: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4468: DMAdaptorSetSolver(adaptor, snes);
4469: DMAdaptorSetSequenceLength(adaptor, num);
4470: DMAdaptorSetFromOptions(adaptor);
4471: DMAdaptorSetUp(adaptor);
4472: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4473: DMAdaptorDestroy(&adaptor);
4474: incall = PETSC_FALSE;
4475: }
4476: }
4477: }
4478: if (!x) {
4479: SNESGetDM(snes,&dm);
4480: DMCreateGlobalVector(dm,&xcreated);
4481: x = xcreated;
4482: }
4483: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4485: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4486: for (grid=0; grid<snes->gridsequence+1; grid++) {
4488: /* set solution vector */
4489: if (!grid) {PetscObjectReference((PetscObject)x);}
4490: VecDestroy(&snes->vec_sol);
4491: snes->vec_sol = x;
4492: SNESGetDM(snes,&dm);
4494: /* set affine vector if provided */
4495: if (b) { PetscObjectReference((PetscObject)b); }
4496: VecDestroy(&snes->vec_rhs);
4497: snes->vec_rhs = b;
4499: if (snes->vec_rhs && (snes->vec_func == snes->vec_rhs)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Right hand side vector cannot be function vector");
4500: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4501: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4502: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4503: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4504: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4505: }
4506: DMShellSetGlobalVector(dm,snes->vec_sol);
4507: SNESSetUp(snes);
4509: if (!grid) {
4510: if (snes->ops->computeinitialguess) {
4511: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4512: }
4513: }
4515: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4516: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4518: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4519: (*snes->ops->solve)(snes);
4520: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4521: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4522: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4524: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4525: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4527: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4528: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4529: SNESReasonViewFromOptions(snes);
4531: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4532: if (snes->reason < 0) break;
4533: if (grid < snes->gridsequence) {
4534: DM fine;
4535: Vec xnew;
4536: Mat interp;
4538: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4539: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4540: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4541: DMCreateGlobalVector(fine,&xnew);
4542: MatInterpolate(interp,x,xnew);
4543: DMInterpolate(snes->dm,interp,fine);
4544: MatDestroy(&interp);
4545: x = xnew;
4547: SNESReset(snes);
4548: SNESSetDM(snes,fine);
4549: SNESResetFromOptions(snes);
4550: DMDestroy(&fine);
4551: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4552: }
4553: }
4554: SNESViewFromOptions(snes,NULL,"-snes_view");
4555: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4556: DMMonitor(snes->dm);
4558: VecDestroy(&xcreated);
4559: PetscObjectSAWsBlock((PetscObject)snes);
4560: return(0);
4561: }
4563: /* --------- Internal routines for SNES Package --------- */
4565: /*@C
4566: SNESSetType - Sets the method for the nonlinear solver.
4568: Collective on SNES
4570: Input Parameters:
4571: + snes - the SNES context
4572: - type - a known method
4574: Options Database Key:
4575: . -snes_type <type> - Sets the method; use -help for a list
4576: of available methods (for instance, newtonls or newtontr)
4578: Notes:
4579: See "petsc/include/petscsnes.h" for available methods (for instance)
4580: + SNESNEWTONLS - Newton's method with line search
4581: (systems of nonlinear equations)
4582: - SNESNEWTONTR - Newton's method with trust region
4583: (systems of nonlinear equations)
4585: Normally, it is best to use the SNESSetFromOptions() command and then
4586: set the SNES solver type from the options database rather than by using
4587: this routine. Using the options database provides the user with
4588: maximum flexibility in evaluating the many nonlinear solvers.
4589: The SNESSetType() routine is provided for those situations where it
4590: is necessary to set the nonlinear solver independently of the command
4591: line or options database. This might be the case, for example, when
4592: the choice of solver changes during the execution of the program,
4593: and the user's Section 1.5 Writing Application Codes with PETSc is taking responsibility for choosing the
4594: appropriate method.
4596: Developer Notes:
4597: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4598: the constructor in that list and calls it to create the spexific object.
4600: Level: intermediate
4602: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4604: @*/
4605: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4606: {
4607: PetscErrorCode ierr,(*r)(SNES);
4608: PetscBool match;
4614: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4615: if (match) return(0);
4617: PetscFunctionListFind(SNESList,type,&r);
4618: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4619: /* Destroy the previous private SNES context */
4620: if (snes->ops->destroy) {
4621: (*(snes)->ops->destroy)(snes);
4622: snes->ops->destroy = NULL;
4623: }
4624: /* Reinitialize function pointers in SNESOps structure */
4625: snes->ops->setup = 0;
4626: snes->ops->solve = 0;
4627: snes->ops->view = 0;
4628: snes->ops->setfromoptions = 0;
4629: snes->ops->destroy = 0;
4631: /* It may happen the user has customized the line search before calling SNESSetType */
4632: if (((PetscObject)snes)->type_name) {
4633: SNESLineSearchDestroy(&snes->linesearch);
4634: }
4636: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4637: snes->setupcalled = PETSC_FALSE;
4639: PetscObjectChangeTypeName((PetscObject)snes,type);
4640: (*r)(snes);
4641: return(0);
4642: }
4644: /*@C
4645: SNESGetType - Gets the SNES method type and name (as a string).
4647: Not Collective
4649: Input Parameter:
4650: . snes - nonlinear solver context
4652: Output Parameter:
4653: . type - SNES method (a character string)
4655: Level: intermediate
4657: @*/
4658: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4659: {
4663: *type = ((PetscObject)snes)->type_name;
4664: return(0);
4665: }
4667: /*@
4668: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4670: Logically Collective on SNES
4672: Input Parameters:
4673: + snes - the SNES context obtained from SNESCreate()
4674: - u - the solution vector
4676: Level: beginner
4678: @*/
4679: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4680: {
4681: DM dm;
4687: PetscObjectReference((PetscObject) u);
4688: VecDestroy(&snes->vec_sol);
4690: snes->vec_sol = u;
4692: SNESGetDM(snes, &dm);
4693: DMShellSetGlobalVector(dm, u);
4694: return(0);
4695: }
4697: /*@
4698: SNESGetSolution - Returns the vector where the approximate solution is
4699: stored. This is the fine grid solution when using SNESSetGridSequence().
4701: Not Collective, but Vec is parallel if SNES is parallel
4703: Input Parameter:
4704: . snes - the SNES context
4706: Output Parameter:
4707: . x - the solution
4709: Level: intermediate
4711: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4712: @*/
4713: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4714: {
4718: *x = snes->vec_sol;
4719: return(0);
4720: }
4722: /*@
4723: SNESGetSolutionUpdate - Returns the vector where the solution update is
4724: stored.
4726: Not Collective, but Vec is parallel if SNES is parallel
4728: Input Parameter:
4729: . snes - the SNES context
4731: Output Parameter:
4732: . x - the solution update
4734: Level: advanced
4736: .seealso: SNESGetSolution(), SNESGetFunction()
4737: @*/
4738: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4739: {
4743: *x = snes->vec_sol_update;
4744: return(0);
4745: }
4747: /*@C
4748: SNESGetFunction - Returns the vector where the function is stored.
4750: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4752: Input Parameter:
4753: . snes - the SNES context
4755: Output Parameter:
4756: + r - the vector that is used to store residuals (or NULL if you don't want it)
4757: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4758: - ctx - the function context (or NULL if you don't want it)
4760: Level: advanced
4762: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4764: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4765: @*/
4766: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4767: {
4769: DM dm;
4773: if (r) {
4774: if (!snes->vec_func) {
4775: if (snes->vec_rhs) {
4776: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4777: } else if (snes->vec_sol) {
4778: VecDuplicate(snes->vec_sol,&snes->vec_func);
4779: } else if (snes->dm) {
4780: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4781: }
4782: }
4783: *r = snes->vec_func;
4784: }
4785: SNESGetDM(snes,&dm);
4786: DMSNESGetFunction(dm,f,ctx);
4787: return(0);
4788: }
4790: /*@C
4791: SNESGetNGS - Returns the NGS function and context.
4793: Input Parameter:
4794: . snes - the SNES context
4796: Output Parameter:
4797: + f - the function (or NULL) see SNESNGSFunction for details
4798: - ctx - the function context (or NULL)
4800: Level: advanced
4802: .seealso: SNESSetNGS(), SNESGetFunction()
4803: @*/
4805: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4806: {
4808: DM dm;
4812: SNESGetDM(snes,&dm);
4813: DMSNESGetNGS(dm,f,ctx);
4814: return(0);
4815: }
4817: /*@C
4818: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4819: SNES options in the database.
4821: Logically Collective on SNES
4823: Input Parameter:
4824: + snes - the SNES context
4825: - prefix - the prefix to prepend to all option names
4827: Notes:
4828: A hyphen (-) must NOT be given at the beginning of the prefix name.
4829: The first character of all runtime options is AUTOMATICALLY the hyphen.
4831: Level: advanced
4833: .seealso: SNESSetFromOptions()
4834: @*/
4835: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4836: {
4841: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4842: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4843: if (snes->linesearch) {
4844: SNESGetLineSearch(snes,&snes->linesearch);
4845: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4846: }
4847: KSPSetOptionsPrefix(snes->ksp,prefix);
4848: return(0);
4849: }
4851: /*@C
4852: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4853: SNES options in the database.
4855: Logically Collective on SNES
4857: Input Parameters:
4858: + snes - the SNES context
4859: - prefix - the prefix to prepend to all option names
4861: Notes:
4862: A hyphen (-) must NOT be given at the beginning of the prefix name.
4863: The first character of all runtime options is AUTOMATICALLY the hyphen.
4865: Level: advanced
4867: .seealso: SNESGetOptionsPrefix()
4868: @*/
4869: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4870: {
4875: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4876: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4877: if (snes->linesearch) {
4878: SNESGetLineSearch(snes,&snes->linesearch);
4879: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4880: }
4881: KSPAppendOptionsPrefix(snes->ksp,prefix);
4882: return(0);
4883: }
4885: /*@C
4886: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4887: SNES options in the database.
4889: Not Collective
4891: Input Parameter:
4892: . snes - the SNES context
4894: Output Parameter:
4895: . prefix - pointer to the prefix string used
4897: Notes:
4898: On the fortran side, the user should pass in a string 'prefix' of
4899: sufficient length to hold the prefix.
4901: Level: advanced
4903: .seealso: SNESAppendOptionsPrefix()
4904: @*/
4905: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4906: {
4911: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4912: return(0);
4913: }
4916: /*@C
4917: SNESRegister - Adds a method to the nonlinear solver package.
4919: Not collective
4921: Input Parameters:
4922: + name_solver - name of a new user-defined solver
4923: - routine_create - routine to create method context
4925: Notes:
4926: SNESRegister() may be called multiple times to add several user-defined solvers.
4928: Sample usage:
4929: .vb
4930: SNESRegister("my_solver",MySolverCreate);
4931: .ve
4933: Then, your solver can be chosen with the procedural interface via
4934: $ SNESSetType(snes,"my_solver")
4935: or at runtime via the option
4936: $ -snes_type my_solver
4938: Level: advanced
4940: Note: If your function is not being put into a shared library then use SNESRegister() instead
4942: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4944: Level: advanced
4945: @*/
4946: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4947: {
4951: SNESInitializePackage();
4952: PetscFunctionListAdd(&SNESList,sname,function);
4953: return(0);
4954: }
4956: PetscErrorCode SNESTestLocalMin(SNES snes)
4957: {
4959: PetscInt N,i,j;
4960: Vec u,uh,fh;
4961: PetscScalar value;
4962: PetscReal norm;
4965: SNESGetSolution(snes,&u);
4966: VecDuplicate(u,&uh);
4967: VecDuplicate(u,&fh);
4969: /* currently only works for sequential */
4970: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4971: VecGetSize(u,&N);
4972: for (i=0; i<N; i++) {
4973: VecCopy(u,uh);
4974: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4975: for (j=-10; j<11; j++) {
4976: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4977: VecSetValue(uh,i,value,ADD_VALUES);
4978: SNESComputeFunction(snes,uh,fh);
4979: VecNorm(fh,NORM_2,&norm);
4980: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4981: value = -value;
4982: VecSetValue(uh,i,value,ADD_VALUES);
4983: }
4984: }
4985: VecDestroy(&uh);
4986: VecDestroy(&fh);
4987: return(0);
4988: }
4990: /*@
4991: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4992: computing relative tolerance for linear solvers within an inexact
4993: Newton method.
4995: Logically Collective on SNES
4997: Input Parameters:
4998: + snes - SNES context
4999: - flag - PETSC_TRUE or PETSC_FALSE
5001: Options Database:
5002: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5003: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5004: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5005: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5006: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5007: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5008: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5009: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5011: Notes:
5012: Currently, the default is to use a constant relative tolerance for
5013: the inner linear solvers. Alternatively, one can use the
5014: Eisenstat-Walker method, where the relative convergence tolerance
5015: is reset at each Newton iteration according progress of the nonlinear
5016: solver.
5018: Level: advanced
5020: Reference:
5021: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5022: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5024: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5025: @*/
5026: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
5027: {
5031: snes->ksp_ewconv = flag;
5032: return(0);
5033: }
5035: /*@
5036: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
5037: for computing relative tolerance for linear solvers within an
5038: inexact Newton method.
5040: Not Collective
5042: Input Parameter:
5043: . snes - SNES context
5045: Output Parameter:
5046: . flag - PETSC_TRUE or PETSC_FALSE
5048: Notes:
5049: Currently, the default is to use a constant relative tolerance for
5050: the inner linear solvers. Alternatively, one can use the
5051: Eisenstat-Walker method, where the relative convergence tolerance
5052: is reset at each Newton iteration according progress of the nonlinear
5053: solver.
5055: Level: advanced
5057: Reference:
5058: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5059: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5061: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5062: @*/
5063: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5064: {
5068: *flag = snes->ksp_ewconv;
5069: return(0);
5070: }
5072: /*@
5073: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5074: convergence criteria for the linear solvers within an inexact
5075: Newton method.
5077: Logically Collective on SNES
5079: Input Parameters:
5080: + snes - SNES context
5081: . version - version 1, 2 (default is 2) or 3
5082: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5083: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5084: . gamma - multiplicative factor for version 2 rtol computation
5085: (0 <= gamma2 <= 1)
5086: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5087: . alpha2 - power for safeguard
5088: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5090: Note:
5091: Version 3 was contributed by Luis Chacon, June 2006.
5093: Use PETSC_DEFAULT to retain the default for any of the parameters.
5095: Level: advanced
5097: Reference:
5098: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5099: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5100: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5102: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5103: @*/
5104: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5105: {
5106: SNESKSPEW *kctx;
5110: kctx = (SNESKSPEW*)snes->kspconvctx;
5111: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5120: if (version != PETSC_DEFAULT) kctx->version = version;
5121: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5122: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5123: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5124: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5125: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5126: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5128: 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);
5129: 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);
5130: 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);
5131: 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);
5132: 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);
5133: 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);
5134: return(0);
5135: }
5137: /*@
5138: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5139: convergence criteria for the linear solvers within an inexact
5140: Newton method.
5142: Not Collective
5144: Input Parameters:
5145: snes - SNES context
5147: Output Parameters:
5148: + version - version 1, 2 (default is 2) or 3
5149: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5150: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5151: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5152: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5153: . alpha2 - power for safeguard
5154: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5156: Level: advanced
5158: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5159: @*/
5160: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5161: {
5162: SNESKSPEW *kctx;
5166: kctx = (SNESKSPEW*)snes->kspconvctx;
5167: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5168: if (version) *version = kctx->version;
5169: if (rtol_0) *rtol_0 = kctx->rtol_0;
5170: if (rtol_max) *rtol_max = kctx->rtol_max;
5171: if (gamma) *gamma = kctx->gamma;
5172: if (alpha) *alpha = kctx->alpha;
5173: if (alpha2) *alpha2 = kctx->alpha2;
5174: if (threshold) *threshold = kctx->threshold;
5175: return(0);
5176: }
5178: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5179: {
5181: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5182: PetscReal rtol = PETSC_DEFAULT,stol;
5185: if (!snes->ksp_ewconv) return(0);
5186: if (!snes->iter) {
5187: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5188: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5189: }
5190: else {
5191: if (kctx->version == 1) {
5192: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5193: if (rtol < 0.0) rtol = -rtol;
5194: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5195: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5196: } else if (kctx->version == 2) {
5197: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5198: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5199: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5200: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5201: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5202: /* safeguard: avoid sharp decrease of rtol */
5203: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5204: stol = PetscMax(rtol,stol);
5205: rtol = PetscMin(kctx->rtol_0,stol);
5206: /* safeguard: avoid oversolving */
5207: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5208: stol = PetscMax(rtol,stol);
5209: rtol = PetscMin(kctx->rtol_0,stol);
5210: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5211: }
5212: /* safeguard: avoid rtol greater than one */
5213: rtol = PetscMin(rtol,kctx->rtol_max);
5214: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5215: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5216: return(0);
5217: }
5219: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5220: {
5222: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5223: PCSide pcside;
5224: Vec lres;
5227: if (!snes->ksp_ewconv) return(0);
5228: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5229: kctx->norm_last = snes->norm;
5230: if (kctx->version == 1) {
5231: PC pc;
5232: PetscBool isNone;
5234: KSPGetPC(ksp, &pc);
5235: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5236: KSPGetPCSide(ksp,&pcside);
5237: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5238: /* KSP residual is true linear residual */
5239: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5240: } else {
5241: /* KSP residual is preconditioned residual */
5242: /* compute true linear residual norm */
5243: VecDuplicate(b,&lres);
5244: MatMult(snes->jacobian,x,lres);
5245: VecAYPX(lres,-1.0,b);
5246: VecNorm(lres,NORM_2,&kctx->lresid_last);
5247: VecDestroy(&lres);
5248: }
5249: }
5250: return(0);
5251: }
5253: /*@
5254: SNESGetKSP - Returns the KSP context for a SNES solver.
5256: Not Collective, but if SNES object is parallel, then KSP object is parallel
5258: Input Parameter:
5259: . snes - the SNES context
5261: Output Parameter:
5262: . ksp - the KSP context
5264: Notes:
5265: The user can then directly manipulate the KSP context to set various
5266: options, etc. Likewise, the user can then extract and manipulate the
5267: PC contexts as well.
5269: Level: beginner
5271: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5272: @*/
5273: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5274: {
5281: if (!snes->ksp) {
5282: PetscBool monitor = PETSC_FALSE;
5284: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5285: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5286: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5288: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5289: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5291: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5292: if (monitor) {
5293: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5294: }
5295: monitor = PETSC_FALSE;
5296: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5297: if (monitor) {
5298: PetscObject *objs;
5299: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5300: objs[0] = (PetscObject) snes;
5301: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5302: }
5303: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5304: }
5305: *ksp = snes->ksp;
5306: return(0);
5307: }
5310: #include <petsc/private/dmimpl.h>
5311: /*@
5312: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5314: Logically Collective on SNES
5316: Input Parameters:
5317: + snes - the nonlinear solver context
5318: - dm - the dm, cannot be NULL
5320: Notes:
5321: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5322: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5323: problems using the same function space.
5325: Level: intermediate
5327: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5328: @*/
5329: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5330: {
5332: KSP ksp;
5333: DMSNES sdm;
5338: PetscObjectReference((PetscObject)dm);
5339: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5340: if (snes->dm->dmsnes && !dm->dmsnes) {
5341: DMCopyDMSNES(snes->dm,dm);
5342: DMGetDMSNES(snes->dm,&sdm);
5343: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5344: }
5345: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5346: DMDestroy(&snes->dm);
5347: }
5348: snes->dm = dm;
5349: snes->dmAuto = PETSC_FALSE;
5351: SNESGetKSP(snes,&ksp);
5352: KSPSetDM(ksp,dm);
5353: KSPSetDMActive(ksp,PETSC_FALSE);
5354: if (snes->npc) {
5355: SNESSetDM(snes->npc, snes->dm);
5356: SNESSetNPCSide(snes,snes->npcside);
5357: }
5358: return(0);
5359: }
5361: /*@
5362: SNESGetDM - Gets the DM that may be used by some preconditioners
5364: Not Collective but DM obtained is parallel on SNES
5366: Input Parameter:
5367: . snes - the preconditioner context
5369: Output Parameter:
5370: . dm - the dm
5372: Level: intermediate
5374: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5375: @*/
5376: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5377: {
5382: if (!snes->dm) {
5383: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5384: snes->dmAuto = PETSC_TRUE;
5385: }
5386: *dm = snes->dm;
5387: return(0);
5388: }
5390: /*@
5391: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5393: Collective on SNES
5395: Input Parameters:
5396: + snes - iterative context obtained from SNESCreate()
5397: - pc - the preconditioner object
5399: Notes:
5400: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5401: to configure it using the API).
5403: Level: developer
5405: .seealso: SNESGetNPC(), SNESHasNPC()
5406: @*/
5407: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5408: {
5415: PetscObjectReference((PetscObject) pc);
5416: SNESDestroy(&snes->npc);
5417: snes->npc = pc;
5418: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5419: return(0);
5420: }
5422: /*@
5423: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5425: Not Collective; but any changes to the obtained SNES object must be applied collectively
5427: Input Parameter:
5428: . snes - iterative context obtained from SNESCreate()
5430: Output Parameter:
5431: . pc - preconditioner context
5433: Options Database:
5434: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5436: Notes:
5437: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5439: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5440: SNES during SNESSetUp()
5442: Level: developer
5444: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5445: @*/
5446: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5447: {
5449: const char *optionsprefix;
5454: if (!snes->npc) {
5455: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5456: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5457: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5458: SNESGetOptionsPrefix(snes,&optionsprefix);
5459: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5460: SNESAppendOptionsPrefix(snes->npc,"npc_");
5461: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5462: }
5463: *pc = snes->npc;
5464: return(0);
5465: }
5467: /*@
5468: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5470: Not Collective
5472: Input Parameter:
5473: . snes - iterative context obtained from SNESCreate()
5475: Output Parameter:
5476: . has_npc - whether the SNES has an NPC or not
5478: Level: developer
5480: .seealso: SNESSetNPC(), SNESGetNPC()
5481: @*/
5482: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5483: {
5486: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5487: return(0);
5488: }
5490: /*@
5491: SNESSetNPCSide - Sets the preconditioning side.
5493: Logically Collective on SNES
5495: Input Parameter:
5496: . snes - iterative context obtained from SNESCreate()
5498: Output Parameter:
5499: . side - the preconditioning side, where side is one of
5500: .vb
5501: PC_LEFT - left preconditioning
5502: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5503: .ve
5505: Options Database Keys:
5506: . -snes_pc_side <right,left>
5508: Notes:
5509: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5511: Level: intermediate
5513: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5514: @*/
5515: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5516: {
5520: snes->npcside= side;
5521: return(0);
5522: }
5524: /*@
5525: SNESGetNPCSide - Gets the preconditioning side.
5527: Not Collective
5529: Input Parameter:
5530: . snes - iterative context obtained from SNESCreate()
5532: Output Parameter:
5533: . side - the preconditioning side, where side is one of
5534: .vb
5535: PC_LEFT - left preconditioning
5536: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5537: .ve
5539: Level: intermediate
5541: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5542: @*/
5543: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5544: {
5548: *side = snes->npcside;
5549: return(0);
5550: }
5552: /*@
5553: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5555: Collective on SNES
5557: Input Parameters:
5558: + snes - iterative context obtained from SNESCreate()
5559: - linesearch - the linesearch object
5561: Notes:
5562: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5563: to configure it using the API).
5565: Level: developer
5567: .seealso: SNESGetLineSearch()
5568: @*/
5569: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5570: {
5577: PetscObjectReference((PetscObject) linesearch);
5578: SNESLineSearchDestroy(&snes->linesearch);
5580: snes->linesearch = linesearch;
5582: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5583: return(0);
5584: }
5586: /*@
5587: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5588: or creates a default line search instance associated with the SNES and returns it.
5590: Not Collective
5592: Input Parameter:
5593: . snes - iterative context obtained from SNESCreate()
5595: Output Parameter:
5596: . linesearch - linesearch context
5598: Level: beginner
5600: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5601: @*/
5602: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5603: {
5605: const char *optionsprefix;
5610: if (!snes->linesearch) {
5611: SNESGetOptionsPrefix(snes, &optionsprefix);
5612: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5613: SNESLineSearchSetSNES(snes->linesearch, snes);
5614: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5615: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5616: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5617: }
5618: *linesearch = snes->linesearch;
5619: return(0);
5620: }