Actual source code: snes.c
petsc-master 2020-07-09
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 application 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,NULL,NULL,NULL);
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,NULL,NULL,NULL);}
619: } else {
620: KSP ksp;
621: PC pc;
622: PetscBool match;
624: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,NULL);
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,NULL);
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,NULL,NULL);
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",NULL,monfilename,sizeof(monfilename),&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,NULL);
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,NULL);
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 = NULL;
1746: snes->setupcalled = PETSC_FALSE;
1747: snes->ksp_ewconv = PETSC_FALSE;
1748: snes->nwork = 0;
1749: snes->work = NULL;
1750: snes->nvwork = 0;
1751: snes->vwork = NULL;
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: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1773: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1774: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1776: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1777: PetscNewLog(snes,&kctx);
1779: snes->kspconvctx = (void*)kctx;
1780: kctx->version = 2;
1781: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1782: this was too large for some test cases */
1783: kctx->rtol_last = 0.0;
1784: kctx->rtol_max = .9;
1785: kctx->gamma = 1.0;
1786: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1787: kctx->alpha2 = kctx->alpha;
1788: kctx->threshold = .1;
1789: kctx->lresid_last = 0.0;
1790: kctx->norm_last = 0.0;
1792: *outsnes = snes;
1793: return(0);
1794: }
1796: /*MC
1797: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1799: Synopsis:
1800: #include "petscsnes.h"
1801: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1803: Collective on snes
1805: Input Parameters:
1806: + snes - the SNES context
1807: . x - state at which to evaluate residual
1808: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1810: Output Parameter:
1811: . f - vector to put residual (function value)
1813: Level: intermediate
1815: .seealso: SNESSetFunction(), SNESGetFunction()
1816: M*/
1818: /*@C
1819: SNESSetFunction - Sets the function evaluation routine and function
1820: vector for use by the SNES routines in solving systems of nonlinear
1821: equations.
1823: Logically Collective on SNES
1825: Input Parameters:
1826: + snes - the SNES context
1827: . r - vector to store function value
1828: . f - function evaluation routine; see SNESFunction for calling sequence details
1829: - ctx - [optional] user-defined context for private data for the
1830: function evaluation routine (may be NULL)
1832: Notes:
1833: The Newton-like methods typically solve linear systems of the form
1834: $ f'(x) x = -f(x),
1835: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1837: Level: beginner
1839: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1840: @*/
1841: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1842: {
1844: DM dm;
1848: if (r) {
1851: PetscObjectReference((PetscObject)r);
1852: VecDestroy(&snes->vec_func);
1854: snes->vec_func = r;
1855: }
1856: SNESGetDM(snes,&dm);
1857: DMSNESSetFunction(dm,f,ctx);
1858: return(0);
1859: }
1862: /*@C
1863: SNESSetInitialFunction - Sets the function vector to be used as the
1864: function norm at the initialization of the method. In some
1865: instances, the user has precomputed the function before calling
1866: SNESSolve. This function allows one to avoid a redundant call
1867: to SNESComputeFunction in that case.
1869: Logically Collective on SNES
1871: Input Parameters:
1872: + snes - the SNES context
1873: - f - vector to store function value
1875: Notes:
1876: This should not be modified during the solution procedure.
1878: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1880: Level: developer
1882: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1883: @*/
1884: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1885: {
1887: Vec vec_func;
1893: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1894: snes->vec_func_init_set = PETSC_FALSE;
1895: return(0);
1896: }
1897: SNESGetFunction(snes,&vec_func,NULL,NULL);
1898: VecCopy(f, vec_func);
1900: snes->vec_func_init_set = PETSC_TRUE;
1901: return(0);
1902: }
1904: /*@
1905: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1906: of the SNES method.
1908: Logically Collective on SNES
1910: Input Parameters:
1911: + snes - the SNES context
1912: - normschedule - the frequency of norm computation
1914: Options Database Key:
1915: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1917: Notes:
1918: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1919: of the nonlinear function and the taking of its norm at every iteration to
1920: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1921: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1922: may either be monitored for convergence or not. As these are often used as nonlinear
1923: preconditioners, monitoring the norm of their error is not a useful enterprise within
1924: their solution.
1926: Level: developer
1928: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1929: @*/
1930: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1931: {
1934: snes->normschedule = normschedule;
1935: return(0);
1936: }
1939: /*@
1940: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1941: of the SNES method.
1943: Logically Collective on SNES
1945: Input Parameters:
1946: + snes - the SNES context
1947: - normschedule - the type of the norm used
1949: Level: advanced
1951: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1952: @*/
1953: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1954: {
1957: *normschedule = snes->normschedule;
1958: return(0);
1959: }
1962: /*@
1963: SNESSetFunctionNorm - Sets the last computed residual norm.
1965: Logically Collective on SNES
1967: Input Parameters:
1968: + snes - the SNES context
1970: - normschedule - the frequency of norm computation
1972: Level: developer
1974: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1975: @*/
1976: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1977: {
1980: snes->norm = norm;
1981: return(0);
1982: }
1984: /*@
1985: SNESGetFunctionNorm - Gets the last computed norm of the residual
1987: Not Collective
1989: Input Parameter:
1990: . snes - the SNES context
1992: Output Parameter:
1993: . norm - the last computed residual norm
1995: Level: developer
1997: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1998: @*/
1999: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2000: {
2004: *norm = snes->norm;
2005: return(0);
2006: }
2008: /*@
2009: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
2011: Not Collective
2013: Input Parameter:
2014: . snes - the SNES context
2016: Output Parameter:
2017: . ynorm - the last computed update norm
2019: Level: developer
2021: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
2022: @*/
2023: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2024: {
2028: *ynorm = snes->ynorm;
2029: return(0);
2030: }
2032: /*@
2033: SNESGetSolutionNorm - Gets the last computed norm of the solution
2035: Not Collective
2037: Input Parameter:
2038: . snes - the SNES context
2040: Output Parameter:
2041: . xnorm - the last computed solution norm
2043: Level: developer
2045: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2046: @*/
2047: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2048: {
2052: *xnorm = snes->xnorm;
2053: return(0);
2054: }
2056: /*@C
2057: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2058: of the SNES method.
2060: Logically Collective on SNES
2062: Input Parameters:
2063: + snes - the SNES context
2064: - normschedule - the frequency of norm computation
2066: Notes:
2067: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2068: of the nonlinear function and the taking of its norm at every iteration to
2069: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2070: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2071: may either be monitored for convergence or not. As these are often used as nonlinear
2072: preconditioners, monitoring the norm of their error is not a useful enterprise within
2073: their solution.
2075: Level: developer
2077: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2078: @*/
2079: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2080: {
2083: snes->functype = type;
2084: return(0);
2085: }
2088: /*@C
2089: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2090: of the SNES method.
2092: Logically Collective on SNES
2094: Input Parameters:
2095: + snes - the SNES context
2096: - normschedule - the type of the norm used
2098: Level: advanced
2100: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2101: @*/
2102: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2103: {
2106: *type = snes->functype;
2107: return(0);
2108: }
2110: /*MC
2111: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2113: Synopsis:
2114: #include <petscsnes.h>
2115: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2117: Collective on snes
2119: Input Parameters:
2120: + X - solution vector
2121: . B - RHS vector
2122: - ctx - optional user-defined Gauss-Seidel context
2124: Output Parameter:
2125: . X - solution vector
2127: Level: intermediate
2129: .seealso: SNESSetNGS(), SNESGetNGS()
2130: M*/
2132: /*@C
2133: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2134: use with composed nonlinear solvers.
2136: Input Parameters:
2137: + snes - the SNES context
2138: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2139: - ctx - [optional] user-defined context for private data for the
2140: smoother evaluation routine (may be NULL)
2142: Notes:
2143: The NGS routines are used by the composed nonlinear solver to generate
2144: a problem appropriate update to the solution, particularly FAS.
2146: Level: intermediate
2148: .seealso: SNESGetFunction(), SNESComputeNGS()
2149: @*/
2150: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2151: {
2153: DM dm;
2157: SNESGetDM(snes,&dm);
2158: DMSNESSetNGS(dm,f,ctx);
2159: return(0);
2160: }
2162: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2163: {
2165: DM dm;
2166: DMSNES sdm;
2169: SNESGetDM(snes,&dm);
2170: DMGetDMSNES(dm,&sdm);
2171: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2172: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2173: /* A(x)*x - b(x) */
2174: PetscStackPush("SNES Picard user function");
2175: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2176: PetscStackPop;
2177: PetscStackPush("SNES Picard user Jacobian");
2178: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2179: PetscStackPop;
2180: VecScale(f,-1.0);
2181: MatMultAdd(snes->jacobian,x,f,f);
2182: return(0);
2183: }
2185: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2186: {
2188: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2189: return(0);
2190: }
2192: /*@C
2193: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2195: Logically Collective on SNES
2197: Input Parameters:
2198: + snes - the SNES context
2199: . r - vector to store function value
2200: . b - function evaluation routine
2201: . Amat - matrix with which A(x) x - b(x) is to be computed
2202: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2203: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2204: - ctx - [optional] user-defined context for private data for the
2205: function evaluation routine (may be NULL)
2207: Notes:
2208: 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
2209: 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.
2211: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2213: $ 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}
2214: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2216: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2218: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2219: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2221: 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
2222: 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
2223: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2225: Level: intermediate
2227: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2228: @*/
2229: 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)
2230: {
2232: DM dm;
2236: SNESGetDM(snes, &dm);
2237: DMSNESSetPicard(dm,b,J,ctx);
2238: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2239: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2240: return(0);
2241: }
2243: /*@C
2244: SNESGetPicard - Returns the context for the Picard iteration
2246: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2248: Input Parameter:
2249: . snes - the SNES context
2251: Output Parameter:
2252: + r - the function (or NULL)
2253: . f - the function (or NULL); see SNESFunction for calling sequence details
2254: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2255: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2256: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2257: - ctx - the function context (or NULL)
2259: Level: advanced
2261: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2262: @*/
2263: 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)
2264: {
2266: DM dm;
2270: SNESGetFunction(snes,r,NULL,NULL);
2271: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2272: SNESGetDM(snes,&dm);
2273: DMSNESGetPicard(dm,f,J,ctx);
2274: return(0);
2275: }
2277: /*@C
2278: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2280: Logically Collective on SNES
2282: Input Parameters:
2283: + snes - the SNES context
2284: . func - function evaluation routine
2285: - ctx - [optional] user-defined context for private data for the
2286: function evaluation routine (may be NULL)
2288: Calling sequence of func:
2289: $ func (SNES snes,Vec x,void *ctx);
2291: . f - function vector
2292: - ctx - optional user-defined function context
2294: Level: intermediate
2296: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2297: @*/
2298: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2299: {
2302: if (func) snes->ops->computeinitialguess = func;
2303: if (ctx) snes->initialguessP = ctx;
2304: return(0);
2305: }
2307: /* --------------------------------------------------------------- */
2308: /*@C
2309: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2310: it assumes a zero right hand side.
2312: Logically Collective on SNES
2314: Input Parameter:
2315: . snes - the SNES context
2317: Output Parameter:
2318: . rhs - the right hand side vector or NULL if the right hand side vector is null
2320: Level: intermediate
2322: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2323: @*/
2324: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2325: {
2329: *rhs = snes->vec_rhs;
2330: return(0);
2331: }
2333: /*@
2334: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2336: Collective on SNES
2338: Input Parameters:
2339: + snes - the SNES context
2340: - x - input vector
2342: Output Parameter:
2343: . y - function vector, as set by SNESSetFunction()
2345: Notes:
2346: SNESComputeFunction() is typically used within nonlinear solvers
2347: implementations, so most users would not generally call this routine
2348: themselves.
2350: Level: developer
2352: .seealso: SNESSetFunction(), SNESGetFunction()
2353: @*/
2354: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2355: {
2357: DM dm;
2358: DMSNES sdm;
2366: VecValidValues(x,2,PETSC_TRUE);
2368: SNESGetDM(snes,&dm);
2369: DMGetDMSNES(dm,&sdm);
2370: if (sdm->ops->computefunction) {
2371: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2372: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2373: }
2374: VecLockReadPush(x);
2375: PetscStackPush("SNES user function");
2376: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2377: snes->domainerror = PETSC_FALSE;
2378: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2379: PetscStackPop;
2380: VecLockReadPop(x);
2381: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2382: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2383: }
2384: } else if (snes->vec_rhs) {
2385: MatMult(snes->jacobian, x, y);
2386: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2387: if (snes->vec_rhs) {
2388: VecAXPY(y,-1.0,snes->vec_rhs);
2389: }
2390: snes->nfuncs++;
2391: /*
2392: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2393: propagate the value to all processes
2394: */
2395: if (snes->domainerror) {
2396: VecSetInf(y);
2397: }
2398: return(0);
2399: }
2401: /*@
2402: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2404: Collective on SNES
2406: Input Parameters:
2407: + snes - the SNES context
2408: . x - input vector
2409: - b - rhs vector
2411: Output Parameter:
2412: . x - new solution vector
2414: Notes:
2415: SNESComputeNGS() is typically used within composed nonlinear solver
2416: implementations, so most users would not generally call this routine
2417: themselves.
2419: Level: developer
2421: .seealso: SNESSetNGS(), SNESComputeFunction()
2422: @*/
2423: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2424: {
2426: DM dm;
2427: DMSNES sdm;
2435: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2436: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2437: SNESGetDM(snes,&dm);
2438: DMGetDMSNES(dm,&sdm);
2439: if (sdm->ops->computegs) {
2440: if (b) {VecLockReadPush(b);}
2441: PetscStackPush("SNES user NGS");
2442: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2443: PetscStackPop;
2444: if (b) {VecLockReadPop(b);}
2445: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2446: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2447: return(0);
2448: }
2450: PetscErrorCode SNESTestJacobian(SNES snes)
2451: {
2452: Mat A,B,C,D,jacobian;
2453: Vec x = snes->vec_sol,f = snes->vec_func;
2454: PetscErrorCode ierr;
2455: PetscReal nrm,gnorm;
2456: PetscReal threshold = 1.e-5;
2457: MatType mattype;
2458: PetscInt m,n,M,N;
2459: void *functx;
2460: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg,istranspose;
2461: PetscViewer viewer,mviewer;
2462: MPI_Comm comm;
2463: PetscInt tabs;
2464: static PetscBool directionsprinted = PETSC_FALSE;
2465: PetscViewerFormat format;
2468: PetscObjectOptionsBegin((PetscObject)snes);
2469: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2470: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2471: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2472: if (!complete_print) {
2473: PetscOptionsDeprecated("-snes_test_jacobian_display","-snes_test_jacobian_view","3.13",NULL);
2474: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2475: }
2476: /* for compatibility with PETSc 3.9 and older. */
2477: PetscOptionsDeprecated("-snes_test_jacobian_display_threshold","-snes_test_jacobian","3.13","-snes_test_jacobian accepts an optional threshold (since v3.10)");
2478: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2479: PetscOptionsEnd();
2480: if (!test) return(0);
2482: PetscObjectGetComm((PetscObject)snes,&comm);
2483: PetscViewerASCIIGetStdout(comm,&viewer);
2484: PetscViewerASCIIGetTab(viewer, &tabs);
2485: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2486: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2487: if (!complete_print && !directionsprinted) {
2488: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2489: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2490: }
2491: if (!directionsprinted) {
2492: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2493: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2494: directionsprinted = PETSC_TRUE;
2495: }
2496: if (complete_print) {
2497: PetscViewerPushFormat(mviewer,format);
2498: }
2500: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2501: if (!flg) jacobian = snes->jacobian;
2502: else jacobian = snes->jacobian_pre;
2504: if (!x) {
2505: MatCreateVecs(jacobian, &x, NULL);
2506: } else {
2507: PetscObjectReference((PetscObject) x);
2508: }
2509: if (!f) {
2510: VecDuplicate(x, &f);
2511: } else {
2512: PetscObjectReference((PetscObject) f);
2513: }
2514: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2515: SNESComputeFunction(snes,x,f);
2516: VecDestroy(&f);
2517: PetscObjectTypeCompare((PetscObject)snes,SNESKSPTRANSPOSEONLY,&istranspose);
2518: while (jacobian) {
2519: Mat JT = NULL, Jsave = NULL;
2521: if (istranspose) {
2522: MatCreateTranspose(jacobian,&JT);
2523: Jsave = jacobian;
2524: jacobian = JT;
2525: }
2526: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2527: if (flg) {
2528: A = jacobian;
2529: PetscObjectReference((PetscObject)A);
2530: } else {
2531: MatComputeOperator(jacobian,MATAIJ,&A);
2532: }
2534: MatGetType(A,&mattype);
2535: MatGetSize(A,&M,&N);
2536: MatGetLocalSize(A,&m,&n);
2537: MatCreate(PetscObjectComm((PetscObject)A),&B);
2538: MatSetType(B,mattype);
2539: MatSetSizes(B,m,n,M,N);
2540: MatSetBlockSizesFromMats(B,A,A);
2541: MatSetUp(B);
2542: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2544: SNESGetFunction(snes,NULL,NULL,&functx);
2545: SNESComputeJacobianDefault(snes,x,B,B,functx);
2547: MatDuplicate(B,MAT_COPY_VALUES,&D);
2548: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2549: MatNorm(D,NORM_FROBENIUS,&nrm);
2550: MatNorm(A,NORM_FROBENIUS,&gnorm);
2551: MatDestroy(&D);
2552: if (!gnorm) gnorm = 1; /* just in case */
2553: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2555: if (complete_print) {
2556: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2557: MatView(A,mviewer);
2558: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2559: MatView(B,mviewer);
2560: }
2562: if (threshold_print || complete_print) {
2563: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2564: PetscScalar *cvals;
2565: const PetscInt *bcols;
2566: const PetscScalar *bvals;
2568: MatCreate(PetscObjectComm((PetscObject)A),&C);
2569: MatSetType(C,mattype);
2570: MatSetSizes(C,m,n,M,N);
2571: MatSetBlockSizesFromMats(C,A,A);
2572: MatSetUp(C);
2573: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2575: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2576: MatGetOwnershipRange(B,&Istart,&Iend);
2578: for (row = Istart; row < Iend; row++) {
2579: MatGetRow(B,row,&bncols,&bcols,&bvals);
2580: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2581: for (j = 0, cncols = 0; j < bncols; j++) {
2582: if (PetscAbsScalar(bvals[j]) > threshold) {
2583: ccols[cncols] = bcols[j];
2584: cvals[cncols] = bvals[j];
2585: cncols += 1;
2586: }
2587: }
2588: if (cncols) {
2589: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2590: }
2591: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2592: PetscFree2(ccols,cvals);
2593: }
2594: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2595: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2596: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2597: MatView(C,complete_print ? mviewer : viewer);
2598: MatDestroy(&C);
2599: }
2600: MatDestroy(&A);
2601: MatDestroy(&B);
2602: MatDestroy(&JT);
2603: if (Jsave) jacobian = Jsave;
2604: if (jacobian != snes->jacobian_pre) {
2605: jacobian = snes->jacobian_pre;
2606: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2607: }
2608: else jacobian = NULL;
2609: }
2610: VecDestroy(&x);
2611: if (complete_print) {
2612: PetscViewerPopFormat(mviewer);
2613: }
2614: if (mviewer) { PetscViewerDestroy(&mviewer); }
2615: PetscViewerASCIISetTab(viewer,tabs);
2616: return(0);
2617: }
2619: /*@
2620: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2622: Collective on SNES
2624: Input Parameters:
2625: + snes - the SNES context
2626: - x - input vector
2628: Output Parameters:
2629: + A - Jacobian matrix
2630: - B - optional preconditioning matrix
2632: Options Database Keys:
2633: + -snes_lag_preconditioner <lag>
2634: . -snes_lag_jacobian <lag>
2635: . -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.
2636: . -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
2637: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2638: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2639: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2640: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2641: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2642: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2643: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2644: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2645: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2646: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2647: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2650: Notes:
2651: Most users should not need to explicitly call this routine, as it
2652: is used internally within the nonlinear solvers.
2654: Developer Notes:
2655: 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
2656: for with the SNESType of test that has been removed.
2658: Level: developer
2660: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2661: @*/
2662: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2663: {
2665: PetscBool flag;
2666: DM dm;
2667: DMSNES sdm;
2668: KSP ksp;
2674: VecValidValues(X,2,PETSC_TRUE);
2675: SNESGetDM(snes,&dm);
2676: DMGetDMSNES(dm,&sdm);
2678: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2680: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2682: if (snes->lagjacobian == -2) {
2683: snes->lagjacobian = -1;
2685: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2686: } else if (snes->lagjacobian == -1) {
2687: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2688: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2689: if (flag) {
2690: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2691: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2692: }
2693: return(0);
2694: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2695: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2696: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2697: if (flag) {
2698: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2699: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2700: }
2701: return(0);
2702: }
2703: if (snes->npc && snes->npcside== PC_LEFT) {
2704: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2705: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2706: return(0);
2707: }
2709: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2710: VecLockReadPush(X);
2711: PetscStackPush("SNES user Jacobian function");
2712: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2713: PetscStackPop;
2714: VecLockReadPop(X);
2715: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2717: /* attach latest linearization point to the preconditioning matrix */
2718: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2720: /* the next line ensures that snes->ksp exists */
2721: SNESGetKSP(snes,&ksp);
2722: if (snes->lagpreconditioner == -2) {
2723: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2724: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2725: snes->lagpreconditioner = -1;
2726: } else if (snes->lagpreconditioner == -1) {
2727: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2728: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2729: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2730: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2731: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2732: } else {
2733: PetscInfo(snes,"Rebuilding preconditioner\n");
2734: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2735: }
2737: SNESTestJacobian(snes);
2738: /* make sure user returned a correct Jacobian and preconditioner */
2741: {
2742: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2743: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2744: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2745: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2746: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2747: if (flag || flag_draw || flag_contour) {
2748: Mat Bexp_mine = NULL,Bexp,FDexp;
2749: PetscViewer vdraw,vstdout;
2750: PetscBool flg;
2751: if (flag_operator) {
2752: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2753: Bexp = Bexp_mine;
2754: } else {
2755: /* See if the preconditioning matrix can be viewed and added directly */
2756: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2757: if (flg) Bexp = B;
2758: else {
2759: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2760: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2761: Bexp = Bexp_mine;
2762: }
2763: }
2764: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2765: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2766: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2767: if (flag_draw || flag_contour) {
2768: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2769: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2770: } else vdraw = NULL;
2771: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2772: if (flag) {MatView(Bexp,vstdout);}
2773: if (vdraw) {MatView(Bexp,vdraw);}
2774: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2775: if (flag) {MatView(FDexp,vstdout);}
2776: if (vdraw) {MatView(FDexp,vdraw);}
2777: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2778: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2779: if (flag) {MatView(FDexp,vstdout);}
2780: if (vdraw) { /* Always use contour for the difference */
2781: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2782: MatView(FDexp,vdraw);
2783: PetscViewerPopFormat(vdraw);
2784: }
2785: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2786: PetscViewerDestroy(&vdraw);
2787: MatDestroy(&Bexp_mine);
2788: MatDestroy(&FDexp);
2789: }
2790: }
2791: {
2792: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2793: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2794: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2795: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2796: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2797: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2798: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2799: if (flag_threshold) {
2800: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2801: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2802: }
2803: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2804: Mat Bfd;
2805: PetscViewer vdraw,vstdout;
2806: MatColoring coloring;
2807: ISColoring iscoloring;
2808: MatFDColoring matfdcoloring;
2809: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2810: void *funcctx;
2811: PetscReal norm1,norm2,normmax;
2813: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2814: MatColoringCreate(Bfd,&coloring);
2815: MatColoringSetType(coloring,MATCOLORINGSL);
2816: MatColoringSetFromOptions(coloring);
2817: MatColoringApply(coloring,&iscoloring);
2818: MatColoringDestroy(&coloring);
2819: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2820: MatFDColoringSetFromOptions(matfdcoloring);
2821: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2822: ISColoringDestroy(&iscoloring);
2824: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2825: SNESGetFunction(snes,NULL,&func,&funcctx);
2826: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2827: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2828: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2829: MatFDColoringSetFromOptions(matfdcoloring);
2830: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2831: MatFDColoringDestroy(&matfdcoloring);
2833: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2834: if (flag_draw || flag_contour) {
2835: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2836: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2837: } else vdraw = NULL;
2838: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2839: if (flag_display) {MatView(B,vstdout);}
2840: if (vdraw) {MatView(B,vdraw);}
2841: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2842: if (flag_display) {MatView(Bfd,vstdout);}
2843: if (vdraw) {MatView(Bfd,vdraw);}
2844: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2845: MatNorm(Bfd,NORM_1,&norm1);
2846: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2847: MatNorm(Bfd,NORM_MAX,&normmax);
2848: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2849: if (flag_display) {MatView(Bfd,vstdout);}
2850: if (vdraw) { /* Always use contour for the difference */
2851: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2852: MatView(Bfd,vdraw);
2853: PetscViewerPopFormat(vdraw);
2854: }
2855: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2857: if (flag_threshold) {
2858: PetscInt bs,rstart,rend,i;
2859: MatGetBlockSize(B,&bs);
2860: MatGetOwnershipRange(B,&rstart,&rend);
2861: for (i=rstart; i<rend; i++) {
2862: const PetscScalar *ba,*ca;
2863: const PetscInt *bj,*cj;
2864: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2865: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2866: MatGetRow(B,i,&bn,&bj,&ba);
2867: MatGetRow(Bfd,i,&cn,&cj,&ca);
2868: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2869: for (j=0; j<bn; j++) {
2870: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2871: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2872: maxentrycol = bj[j];
2873: maxentry = PetscRealPart(ba[j]);
2874: }
2875: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2876: maxdiffcol = bj[j];
2877: maxdiff = PetscRealPart(ca[j]);
2878: }
2879: if (rdiff > maxrdiff) {
2880: maxrdiffcol = bj[j];
2881: maxrdiff = rdiff;
2882: }
2883: }
2884: if (maxrdiff > 1) {
2885: 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);
2886: for (j=0; j<bn; j++) {
2887: PetscReal rdiff;
2888: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2889: if (rdiff > 1) {
2890: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2891: }
2892: }
2893: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2894: }
2895: MatRestoreRow(B,i,&bn,&bj,&ba);
2896: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2897: }
2898: }
2899: PetscViewerDestroy(&vdraw);
2900: MatDestroy(&Bfd);
2901: }
2902: }
2903: return(0);
2904: }
2906: /*MC
2907: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2909: Synopsis:
2910: #include "petscsnes.h"
2911: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2913: Collective on snes
2915: Input Parameters:
2916: + x - input vector, the Jacobian is to be computed at this value
2917: - ctx - [optional] user-defined Jacobian context
2919: Output Parameters:
2920: + Amat - the matrix that defines the (approximate) Jacobian
2921: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2923: Level: intermediate
2925: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2926: M*/
2928: /*@C
2929: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2930: location to store the matrix.
2932: Logically Collective on SNES
2934: Input Parameters:
2935: + snes - the SNES context
2936: . Amat - the matrix that defines the (approximate) Jacobian
2937: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2938: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2939: - ctx - [optional] user-defined context for private data for the
2940: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2942: Notes:
2943: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2944: each matrix.
2946: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2947: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2949: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2950: must be a MatFDColoring.
2952: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2953: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2955: Level: beginner
2957: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2958: SNESSetPicard(), SNESJacobianFunction
2959: @*/
2960: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2961: {
2963: DM dm;
2971: SNESGetDM(snes,&dm);
2972: DMSNESSetJacobian(dm,J,ctx);
2973: if (Amat) {
2974: PetscObjectReference((PetscObject)Amat);
2975: MatDestroy(&snes->jacobian);
2977: snes->jacobian = Amat;
2978: }
2979: if (Pmat) {
2980: PetscObjectReference((PetscObject)Pmat);
2981: MatDestroy(&snes->jacobian_pre);
2983: snes->jacobian_pre = Pmat;
2984: }
2985: return(0);
2986: }
2988: /*@C
2989: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2990: provided context for evaluating the Jacobian.
2992: Not Collective, but Mat object will be parallel if SNES object is
2994: Input Parameter:
2995: . snes - the nonlinear solver context
2997: Output Parameters:
2998: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2999: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
3000: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
3001: - ctx - location to stash Jacobian ctx (or NULL)
3003: Level: advanced
3005: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
3006: @*/
3007: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
3008: {
3010: DM dm;
3011: DMSNES sdm;
3015: if (Amat) *Amat = snes->jacobian;
3016: if (Pmat) *Pmat = snes->jacobian_pre;
3017: SNESGetDM(snes,&dm);
3018: DMGetDMSNES(dm,&sdm);
3019: if (J) *J = sdm->ops->computejacobian;
3020: if (ctx) *ctx = sdm->jacobianctx;
3021: return(0);
3022: }
3024: /*@
3025: SNESSetUp - Sets up the internal data structures for the later use
3026: of a nonlinear solver.
3028: Collective on SNES
3030: Input Parameters:
3031: . snes - the SNES context
3033: Notes:
3034: For basic use of the SNES solvers the user need not explicitly call
3035: SNESSetUp(), since these actions will automatically occur during
3036: the call to SNESSolve(). However, if one wishes to control this
3037: phase separately, SNESSetUp() should be called after SNESCreate()
3038: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3040: Level: advanced
3042: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3043: @*/
3044: PetscErrorCode SNESSetUp(SNES snes)
3045: {
3047: DM dm;
3048: DMSNES sdm;
3049: SNESLineSearch linesearch, pclinesearch;
3050: void *lsprectx,*lspostctx;
3051: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3052: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3053: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3054: Vec f,fpc;
3055: void *funcctx;
3056: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3057: void *jacctx,*appctx;
3058: Mat j,jpre;
3062: if (snes->setupcalled) return(0);
3063: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3065: if (!((PetscObject)snes)->type_name) {
3066: SNESSetType(snes,SNESNEWTONLS);
3067: }
3069: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3071: SNESGetDM(snes,&dm);
3072: DMGetDMSNES(dm,&sdm);
3073: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3074: if (!sdm->ops->computejacobian) {
3075: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3076: }
3077: if (!snes->vec_func) {
3078: DMCreateGlobalVector(dm,&snes->vec_func);
3079: }
3081: if (!snes->ksp) {
3082: SNESGetKSP(snes, &snes->ksp);
3083: }
3085: if (snes->linesearch) {
3086: SNESGetLineSearch(snes, &snes->linesearch);
3087: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3088: }
3090: if (snes->npc && (snes->npcside== PC_LEFT)) {
3091: snes->mf = PETSC_TRUE;
3092: snes->mf_operator = PETSC_FALSE;
3093: }
3095: if (snes->npc) {
3096: /* copy the DM over */
3097: SNESGetDM(snes,&dm);
3098: SNESSetDM(snes->npc,dm);
3100: SNESGetFunction(snes,&f,&func,&funcctx);
3101: VecDuplicate(f,&fpc);
3102: SNESSetFunction(snes->npc,fpc,func,funcctx);
3103: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3104: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3105: SNESGetApplicationContext(snes,&appctx);
3106: SNESSetApplicationContext(snes->npc,appctx);
3107: VecDestroy(&fpc);
3109: /* copy the function pointers over */
3110: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3112: /* default to 1 iteration */
3113: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3114: if (snes->npcside==PC_RIGHT) {
3115: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3116: } else {
3117: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3118: }
3119: SNESSetFromOptions(snes->npc);
3121: /* copy the line search context over */
3122: if (snes->linesearch && snes->npc->linesearch) {
3123: SNESGetLineSearch(snes,&linesearch);
3124: SNESGetLineSearch(snes->npc,&pclinesearch);
3125: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3126: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3127: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3128: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3129: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3130: }
3131: }
3132: if (snes->mf) {
3133: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3134: }
3135: if (snes->ops->usercompute && !snes->user) {
3136: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3137: }
3139: snes->jac_iter = 0;
3140: snes->pre_iter = 0;
3142: if (snes->ops->setup) {
3143: (*snes->ops->setup)(snes);
3144: }
3146: if (snes->npc && (snes->npcside== PC_LEFT)) {
3147: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3148: if (snes->linesearch){
3149: SNESGetLineSearch(snes,&linesearch);
3150: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3151: }
3152: }
3153: }
3154: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3155: snes->setupcalled = PETSC_TRUE;
3156: return(0);
3157: }
3159: /*@
3160: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3162: Collective on SNES
3164: Input Parameter:
3165: . snes - iterative context obtained from SNESCreate()
3167: Level: intermediate
3169: Notes:
3170: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3172: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3173: @*/
3174: PetscErrorCode SNESReset(SNES snes)
3175: {
3180: if (snes->ops->userdestroy && snes->user) {
3181: (*snes->ops->userdestroy)((void**)&snes->user);
3182: snes->user = NULL;
3183: }
3184: if (snes->npc) {
3185: SNESReset(snes->npc);
3186: }
3188: if (snes->ops->reset) {
3189: (*snes->ops->reset)(snes);
3190: }
3191: if (snes->ksp) {
3192: KSPReset(snes->ksp);
3193: }
3195: if (snes->linesearch) {
3196: SNESLineSearchReset(snes->linesearch);
3197: }
3199: VecDestroy(&snes->vec_rhs);
3200: VecDestroy(&snes->vec_sol);
3201: VecDestroy(&snes->vec_sol_update);
3202: VecDestroy(&snes->vec_func);
3203: MatDestroy(&snes->jacobian);
3204: MatDestroy(&snes->jacobian_pre);
3205: VecDestroyVecs(snes->nwork,&snes->work);
3206: VecDestroyVecs(snes->nvwork,&snes->vwork);
3208: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3210: snes->nwork = snes->nvwork = 0;
3211: snes->setupcalled = PETSC_FALSE;
3212: return(0);
3213: }
3215: /*@
3216: SNESDestroy - Destroys the nonlinear solver context that was created
3217: with SNESCreate().
3219: Collective on SNES
3221: Input Parameter:
3222: . snes - the SNES context
3224: Level: beginner
3226: .seealso: SNESCreate(), SNESSolve()
3227: @*/
3228: PetscErrorCode SNESDestroy(SNES *snes)
3229: {
3233: if (!*snes) return(0);
3235: if (--((PetscObject)(*snes))->refct > 0) {*snes = NULL; return(0);}
3237: SNESReset((*snes));
3238: SNESDestroy(&(*snes)->npc);
3240: /* if memory was published with SAWs then destroy it */
3241: PetscObjectSAWsViewOff((PetscObject)*snes);
3242: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3244: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3245: DMDestroy(&(*snes)->dm);
3246: KSPDestroy(&(*snes)->ksp);
3247: SNESLineSearchDestroy(&(*snes)->linesearch);
3249: PetscFree((*snes)->kspconvctx);
3250: if ((*snes)->ops->convergeddestroy) {
3251: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3252: }
3253: if ((*snes)->conv_hist_alloc) {
3254: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3255: }
3256: SNESMonitorCancel((*snes));
3257: PetscHeaderDestroy(snes);
3258: return(0);
3259: }
3261: /* ----------- Routines to set solver parameters ---------- */
3263: /*@
3264: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3266: Logically Collective on SNES
3268: Input Parameters:
3269: + snes - the SNES context
3270: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3271: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3273: Options Database Keys:
3274: . -snes_lag_preconditioner <lag>
3276: Notes:
3277: The default is 1
3278: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3279: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3281: Level: intermediate
3283: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3285: @*/
3286: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3287: {
3290: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3291: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3293: snes->lagpreconditioner = lag;
3294: return(0);
3295: }
3297: /*@
3298: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3300: Logically Collective on SNES
3302: Input Parameters:
3303: + snes - the SNES context
3304: - steps - the number of refinements to do, defaults to 0
3306: Options Database Keys:
3307: . -snes_grid_sequence <steps>
3309: Level: intermediate
3311: Notes:
3312: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3314: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3316: @*/
3317: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3318: {
3322: snes->gridsequence = steps;
3323: return(0);
3324: }
3326: /*@
3327: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3329: Logically Collective on SNES
3331: Input Parameter:
3332: . snes - the SNES context
3334: Output Parameter:
3335: . steps - the number of refinements to do, defaults to 0
3337: Options Database Keys:
3338: . -snes_grid_sequence <steps>
3340: Level: intermediate
3342: Notes:
3343: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3345: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3347: @*/
3348: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3349: {
3352: *steps = snes->gridsequence;
3353: return(0);
3354: }
3356: /*@
3357: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3359: Not Collective
3361: Input Parameter:
3362: . snes - the SNES context
3364: Output Parameter:
3365: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3366: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3368: Options Database Keys:
3369: . -snes_lag_preconditioner <lag>
3371: Notes:
3372: The default is 1
3373: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3375: Level: intermediate
3377: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3379: @*/
3380: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3381: {
3384: *lag = snes->lagpreconditioner;
3385: return(0);
3386: }
3388: /*@
3389: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3390: often the preconditioner is rebuilt.
3392: Logically Collective on SNES
3394: Input Parameters:
3395: + snes - the SNES context
3396: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3397: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3399: Options Database Keys:
3400: . -snes_lag_jacobian <lag>
3402: Notes:
3403: The default is 1
3404: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3405: 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
3406: at the next Newton step but never again (unless it is reset to another value)
3408: Level: intermediate
3410: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3412: @*/
3413: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3414: {
3417: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3418: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3420: snes->lagjacobian = lag;
3421: return(0);
3422: }
3424: /*@
3425: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3427: Not Collective
3429: Input Parameter:
3430: . snes - the SNES context
3432: Output Parameter:
3433: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3434: the Jacobian is built etc.
3436: Options Database Keys:
3437: . -snes_lag_jacobian <lag>
3439: Notes:
3440: The default is 1
3441: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3443: Level: intermediate
3445: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3447: @*/
3448: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3449: {
3452: *lag = snes->lagjacobian;
3453: return(0);
3454: }
3456: /*@
3457: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3459: Logically collective on SNES
3461: Input Parameter:
3462: + snes - the SNES context
3463: - flg - jacobian lagging persists if true
3465: Options Database Keys:
3466: . -snes_lag_jacobian_persists <flg>
3468: Notes:
3469: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3470: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3471: timesteps may present huge efficiency gains.
3473: Level: developer
3475: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3477: @*/
3478: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3479: {
3483: snes->lagjac_persist = flg;
3484: return(0);
3485: }
3487: /*@
3488: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3490: Logically Collective on SNES
3492: Input Parameter:
3493: + snes - the SNES context
3494: - flg - preconditioner lagging persists if true
3496: Options Database Keys:
3497: . -snes_lag_jacobian_persists <flg>
3499: Notes:
3500: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3501: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3502: several timesteps may present huge efficiency gains.
3504: Level: developer
3506: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3508: @*/
3509: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3510: {
3514: snes->lagpre_persist = flg;
3515: return(0);
3516: }
3518: /*@
3519: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3521: Logically Collective on SNES
3523: Input Parameters:
3524: + snes - the SNES context
3525: - force - PETSC_TRUE require at least one iteration
3527: Options Database Keys:
3528: . -snes_force_iteration <force> - Sets forcing an iteration
3530: Notes:
3531: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3533: Level: intermediate
3535: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3536: @*/
3537: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3538: {
3541: snes->forceiteration = force;
3542: return(0);
3543: }
3545: /*@
3546: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3548: Logically Collective on SNES
3550: Input Parameters:
3551: . snes - the SNES context
3553: Output Parameter:
3554: . force - PETSC_TRUE requires at least one iteration.
3556: Level: intermediate
3558: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3559: @*/
3560: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3561: {
3564: *force = snes->forceiteration;
3565: return(0);
3566: }
3568: /*@
3569: SNESSetTolerances - Sets various parameters used in convergence tests.
3571: Logically Collective on SNES
3573: Input Parameters:
3574: + snes - the SNES context
3575: . abstol - absolute convergence tolerance
3576: . rtol - relative convergence tolerance
3577: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3578: . maxit - maximum number of iterations
3579: - maxf - maximum number of function evaluations (-1 indicates no limit)
3581: Options Database Keys:
3582: + -snes_atol <abstol> - Sets abstol
3583: . -snes_rtol <rtol> - Sets rtol
3584: . -snes_stol <stol> - Sets stol
3585: . -snes_max_it <maxit> - Sets maxit
3586: - -snes_max_funcs <maxf> - Sets maxf
3588: Notes:
3589: The default maximum number of iterations is 50.
3590: The default maximum number of function evaluations is 1000.
3592: Level: intermediate
3594: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3595: @*/
3596: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3597: {
3606: if (abstol != PETSC_DEFAULT) {
3607: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3608: snes->abstol = abstol;
3609: }
3610: if (rtol != PETSC_DEFAULT) {
3611: 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);
3612: snes->rtol = rtol;
3613: }
3614: if (stol != PETSC_DEFAULT) {
3615: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3616: snes->stol = stol;
3617: }
3618: if (maxit != PETSC_DEFAULT) {
3619: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3620: snes->max_its = maxit;
3621: }
3622: if (maxf != PETSC_DEFAULT) {
3623: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3624: snes->max_funcs = maxf;
3625: }
3626: snes->tolerancesset = PETSC_TRUE;
3627: return(0);
3628: }
3630: /*@
3631: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3633: Logically Collective on SNES
3635: Input Parameters:
3636: + snes - the SNES context
3637: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3639: Options Database Keys:
3640: . -snes_divergence_tolerance <divtol> - Sets divtol
3642: Notes:
3643: The default divergence tolerance is 1e4.
3645: Level: intermediate
3647: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3648: @*/
3649: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3650: {
3655: if (divtol != PETSC_DEFAULT) {
3656: snes->divtol = divtol;
3657: }
3658: else {
3659: snes->divtol = 1.0e4;
3660: }
3661: return(0);
3662: }
3664: /*@
3665: SNESGetTolerances - Gets various parameters used in convergence tests.
3667: Not Collective
3669: Input Parameters:
3670: + snes - the SNES context
3671: . atol - absolute convergence tolerance
3672: . rtol - relative convergence tolerance
3673: . stol - convergence tolerance in terms of the norm
3674: of the change in the solution between steps
3675: . maxit - maximum number of iterations
3676: - maxf - maximum number of function evaluations
3678: Notes:
3679: The user can specify NULL for any parameter that is not needed.
3681: Level: intermediate
3683: .seealso: SNESSetTolerances()
3684: @*/
3685: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3686: {
3689: if (atol) *atol = snes->abstol;
3690: if (rtol) *rtol = snes->rtol;
3691: if (stol) *stol = snes->stol;
3692: if (maxit) *maxit = snes->max_its;
3693: if (maxf) *maxf = snes->max_funcs;
3694: return(0);
3695: }
3697: /*@
3698: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3700: Not Collective
3702: Input Parameters:
3703: + snes - the SNES context
3704: - divtol - divergence tolerance
3706: Level: intermediate
3708: .seealso: SNESSetDivergenceTolerance()
3709: @*/
3710: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3711: {
3714: if (divtol) *divtol = snes->divtol;
3715: return(0);
3716: }
3718: /*@
3719: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3721: Logically Collective on SNES
3723: Input Parameters:
3724: + snes - the SNES context
3725: - tol - tolerance
3727: Options Database Key:
3728: . -snes_trtol <tol> - Sets tol
3730: Level: intermediate
3732: .seealso: SNESSetTolerances()
3733: @*/
3734: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3735: {
3739: snes->deltatol = tol;
3740: return(0);
3741: }
3743: /*
3744: Duplicate the lg monitors for SNES from KSP; for some reason with
3745: dynamic libraries things don't work under Sun4 if we just use
3746: macros instead of functions
3747: */
3748: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3749: {
3754: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3755: return(0);
3756: }
3758: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3759: {
3763: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3764: return(0);
3765: }
3767: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3769: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3770: {
3771: PetscDrawLG lg;
3772: PetscErrorCode ierr;
3773: PetscReal x,y,per;
3774: PetscViewer v = (PetscViewer)monctx;
3775: static PetscReal prev; /* should be in the context */
3776: PetscDraw draw;
3780: PetscViewerDrawGetDrawLG(v,0,&lg);
3781: if (!n) {PetscDrawLGReset(lg);}
3782: PetscDrawLGGetDraw(lg,&draw);
3783: PetscDrawSetTitle(draw,"Residual norm");
3784: x = (PetscReal)n;
3785: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3786: else y = -15.0;
3787: PetscDrawLGAddPoint(lg,&x,&y);
3788: if (n < 20 || !(n % 5) || snes->reason) {
3789: PetscDrawLGDraw(lg);
3790: PetscDrawLGSave(lg);
3791: }
3793: PetscViewerDrawGetDrawLG(v,1,&lg);
3794: if (!n) {PetscDrawLGReset(lg);}
3795: PetscDrawLGGetDraw(lg,&draw);
3796: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3797: SNESMonitorRange_Private(snes,n,&per);
3798: x = (PetscReal)n;
3799: y = 100.0*per;
3800: PetscDrawLGAddPoint(lg,&x,&y);
3801: if (n < 20 || !(n % 5) || snes->reason) {
3802: PetscDrawLGDraw(lg);
3803: PetscDrawLGSave(lg);
3804: }
3806: PetscViewerDrawGetDrawLG(v,2,&lg);
3807: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3808: PetscDrawLGGetDraw(lg,&draw);
3809: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3810: x = (PetscReal)n;
3811: y = (prev - rnorm)/prev;
3812: PetscDrawLGAddPoint(lg,&x,&y);
3813: if (n < 20 || !(n % 5) || snes->reason) {
3814: PetscDrawLGDraw(lg);
3815: PetscDrawLGSave(lg);
3816: }
3818: PetscViewerDrawGetDrawLG(v,3,&lg);
3819: if (!n) {PetscDrawLGReset(lg);}
3820: PetscDrawLGGetDraw(lg,&draw);
3821: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3822: x = (PetscReal)n;
3823: y = (prev - rnorm)/(prev*per);
3824: if (n > 2) { /*skip initial crazy value */
3825: PetscDrawLGAddPoint(lg,&x,&y);
3826: }
3827: if (n < 20 || !(n % 5) || snes->reason) {
3828: PetscDrawLGDraw(lg);
3829: PetscDrawLGSave(lg);
3830: }
3831: prev = rnorm;
3832: return(0);
3833: }
3835: /*@
3836: SNESMonitor - runs the user provided monitor routines, if they exist
3838: Collective on SNES
3840: Input Parameters:
3841: + snes - nonlinear solver context obtained from SNESCreate()
3842: . iter - iteration number
3843: - rnorm - relative norm of the residual
3845: Notes:
3846: This routine is called by the SNES implementations.
3847: It does not typically need to be called by the user.
3849: Level: developer
3851: .seealso: SNESMonitorSet()
3852: @*/
3853: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3854: {
3856: PetscInt i,n = snes->numbermonitors;
3859: VecLockReadPush(snes->vec_sol);
3860: for (i=0; i<n; i++) {
3861: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3862: }
3863: VecLockReadPop(snes->vec_sol);
3864: return(0);
3865: }
3867: /* ------------ Routines to set performance monitoring options ----------- */
3869: /*MC
3870: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3872: Synopsis:
3873: #include <petscsnes.h>
3874: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3876: Collective on snes
3878: Input Parameters:
3879: + snes - the SNES context
3880: . its - iteration number
3881: . norm - 2-norm function value (may be estimated)
3882: - mctx - [optional] monitoring context
3884: Level: advanced
3886: .seealso: SNESMonitorSet(), SNESMonitorGet()
3887: M*/
3889: /*@C
3890: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3891: iteration of the nonlinear solver to display the iteration's
3892: progress.
3894: Logically Collective on SNES
3896: Input Parameters:
3897: + snes - the SNES context
3898: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3899: . mctx - [optional] user-defined context for private data for the
3900: monitor routine (use NULL if no context is desired)
3901: - monitordestroy - [optional] routine that frees monitor context
3902: (may be NULL)
3904: Options Database Keys:
3905: + -snes_monitor - sets SNESMonitorDefault()
3906: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3907: uses SNESMonitorLGCreate()
3908: - -snes_monitor_cancel - cancels all monitors that have
3909: been hardwired into a code by
3910: calls to SNESMonitorSet(), but
3911: does not cancel those set via
3912: the options database.
3914: Notes:
3915: Several different monitoring routines may be set by calling
3916: SNESMonitorSet() multiple times; all will be called in the
3917: order in which they were set.
3919: Fortran Notes:
3920: Only a single monitor function can be set for each SNES object
3922: Level: intermediate
3924: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3925: @*/
3926: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3927: {
3928: PetscInt i;
3930: PetscBool identical;
3934: for (i=0; i<snes->numbermonitors;i++) {
3935: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3936: if (identical) return(0);
3937: }
3938: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3939: snes->monitor[snes->numbermonitors] = f;
3940: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3941: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3942: return(0);
3943: }
3945: /*@
3946: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3948: Logically Collective on SNES
3950: Input Parameters:
3951: . snes - the SNES context
3953: Options Database Key:
3954: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3955: into a code by calls to SNESMonitorSet(), but does not cancel those
3956: set via the options database
3958: Notes:
3959: There is no way to clear one specific monitor from a SNES object.
3961: Level: intermediate
3963: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3964: @*/
3965: PetscErrorCode SNESMonitorCancel(SNES snes)
3966: {
3968: PetscInt i;
3972: for (i=0; i<snes->numbermonitors; i++) {
3973: if (snes->monitordestroy[i]) {
3974: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3975: }
3976: }
3977: snes->numbermonitors = 0;
3978: return(0);
3979: }
3981: /*MC
3982: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3984: Synopsis:
3985: #include <petscsnes.h>
3986: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3988: Collective on snes
3990: Input Parameters:
3991: + snes - the SNES context
3992: . it - current iteration (0 is the first and is before any Newton step)
3993: . xnorm - 2-norm of current iterate
3994: . gnorm - 2-norm of current step
3995: . f - 2-norm of function
3996: - cctx - [optional] convergence context
3998: Output Parameter:
3999: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4001: Level: intermediate
4003: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
4004: M*/
4006: /*@C
4007: SNESSetConvergenceTest - Sets the function that is to be used
4008: to test for convergence of the nonlinear iterative solution.
4010: Logically Collective on SNES
4012: Input Parameters:
4013: + snes - the SNES context
4014: . SNESConvergenceTestFunction - routine to test for convergence
4015: . cctx - [optional] context for private data for the convergence routine (may be NULL)
4016: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
4018: Level: advanced
4020: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
4021: @*/
4022: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
4023: {
4028: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4029: if (snes->ops->convergeddestroy) {
4030: (*snes->ops->convergeddestroy)(snes->cnvP);
4031: }
4032: snes->ops->converged = SNESConvergenceTestFunction;
4033: snes->ops->convergeddestroy = destroy;
4034: snes->cnvP = cctx;
4035: return(0);
4036: }
4038: /*@
4039: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4041: Not Collective
4043: Input Parameter:
4044: . snes - the SNES context
4046: Output Parameter:
4047: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4048: manual pages for the individual convergence tests for complete lists
4050: Options Database:
4051: . -snes_converged_reason - prints the reason to standard out
4053: Level: intermediate
4055: Notes:
4056: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4058: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4059: @*/
4060: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4061: {
4065: *reason = snes->reason;
4066: return(0);
4067: }
4069: /*@
4070: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4072: Not Collective
4074: Input Parameters:
4075: + snes - the SNES context
4076: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4077: manual pages for the individual convergence tests for complete lists
4079: Level: intermediate
4081: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4082: @*/
4083: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4084: {
4087: snes->reason = reason;
4088: return(0);
4089: }
4091: /*@
4092: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4094: Logically Collective on SNES
4096: Input Parameters:
4097: + snes - iterative context obtained from SNESCreate()
4098: . a - array to hold history, this array will contain the function norms computed at each step
4099: . its - integer array holds the number of linear iterations for each solve.
4100: . na - size of a and its
4101: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4102: else it continues storing new values for new nonlinear solves after the old ones
4104: Notes:
4105: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4106: default array of length 10000 is allocated.
4108: This routine is useful, e.g., when running a code for purposes
4109: of accurate performance monitoring, when no I/O should be done
4110: during the section of code that is being timed.
4112: Level: intermediate
4114: .seealso: SNESGetConvergenceHistory()
4116: @*/
4117: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4118: {
4125: if (!a) {
4126: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4127: PetscCalloc2(na,&a,na,&its);
4128: snes->conv_hist_alloc = PETSC_TRUE;
4129: }
4130: snes->conv_hist = a;
4131: snes->conv_hist_its = its;
4132: snes->conv_hist_max = na;
4133: snes->conv_hist_len = 0;
4134: snes->conv_hist_reset = reset;
4135: return(0);
4136: }
4138: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4139: #include <engine.h> /* MATLAB include file */
4140: #include <mex.h> /* MATLAB include file */
4142: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4143: {
4144: mxArray *mat;
4145: PetscInt i;
4146: PetscReal *ar;
4149: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4150: ar = (PetscReal*) mxGetData(mat);
4151: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4152: PetscFunctionReturn(mat);
4153: }
4154: #endif
4156: /*@C
4157: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4159: Not Collective
4161: Input Parameter:
4162: . snes - iterative context obtained from SNESCreate()
4164: Output Parameters:
4165: + a - array to hold history
4166: . its - integer array holds the number of linear iterations (or
4167: negative if not converged) for each solve.
4168: - na - size of a and its
4170: Notes:
4171: The calling sequence for this routine in Fortran is
4172: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4174: This routine is useful, e.g., when running a code for purposes
4175: of accurate performance monitoring, when no I/O should be done
4176: during the section of code that is being timed.
4178: Level: intermediate
4180: .seealso: SNESSetConvergenceHistory()
4182: @*/
4183: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4184: {
4187: if (a) *a = snes->conv_hist;
4188: if (its) *its = snes->conv_hist_its;
4189: if (na) *na = snes->conv_hist_len;
4190: return(0);
4191: }
4193: /*@C
4194: SNESSetUpdate - Sets the general-purpose update function called
4195: at the beginning of every iteration of the nonlinear solve. Specifically
4196: it is called just before the Jacobian is "evaluated".
4198: Logically Collective on SNES
4200: Input Parameters:
4201: + snes - The nonlinear solver context
4202: - func - The function
4204: Calling sequence of func:
4205: $ func (SNES snes, PetscInt step);
4207: . step - The current step of the iteration
4209: Level: advanced
4211: 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()
4212: This is not used by most users.
4214: .seealso SNESSetJacobian(), SNESSolve()
4215: @*/
4216: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4217: {
4220: snes->ops->update = func;
4221: return(0);
4222: }
4224: /*
4225: SNESScaleStep_Private - Scales a step so that its length is less than the
4226: positive parameter delta.
4228: Input Parameters:
4229: + snes - the SNES context
4230: . y - approximate solution of linear system
4231: . fnorm - 2-norm of current function
4232: - delta - trust region size
4234: Output Parameters:
4235: + gpnorm - predicted function norm at the new point, assuming local
4236: linearization. The value is zero if the step lies within the trust
4237: region, and exceeds zero otherwise.
4238: - ynorm - 2-norm of the step
4240: Note:
4241: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4242: is set to be the maximum allowable step size.
4244: */
4245: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4246: {
4247: PetscReal nrm;
4248: PetscScalar cnorm;
4256: VecNorm(y,NORM_2,&nrm);
4257: if (nrm > *delta) {
4258: nrm = *delta/nrm;
4259: *gpnorm = (1.0 - nrm)*(*fnorm);
4260: cnorm = nrm;
4261: VecScale(y,cnorm);
4262: *ynorm = *delta;
4263: } else {
4264: *gpnorm = 0.0;
4265: *ynorm = nrm;
4266: }
4267: return(0);
4268: }
4270: /*@
4271: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4273: Collective on SNES
4275: Parameter:
4276: + snes - iterative context obtained from SNESCreate()
4277: - viewer - the viewer to display the reason
4280: Options Database Keys:
4281: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4283: Level: beginner
4285: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4287: @*/
4288: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4289: {
4290: PetscViewerFormat format;
4291: PetscBool isAscii;
4292: PetscErrorCode ierr;
4295: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4296: if (isAscii) {
4297: PetscViewerGetFormat(viewer, &format);
4298: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4299: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4300: DM dm;
4301: Vec u;
4302: PetscDS prob;
4303: PetscInt Nf, f;
4304: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4305: void **exactCtx;
4306: PetscReal error;
4308: SNESGetDM(snes, &dm);
4309: SNESGetSolution(snes, &u);
4310: DMGetDS(dm, &prob);
4311: PetscDSGetNumFields(prob, &Nf);
4312: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4313: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4314: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4315: PetscFree2(exactSol, exactCtx);
4316: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4317: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4318: }
4319: if (snes->reason > 0) {
4320: if (((PetscObject) snes)->prefix) {
4321: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4322: } else {
4323: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4324: }
4325: } else {
4326: if (((PetscObject) snes)->prefix) {
4327: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4328: } else {
4329: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4330: }
4331: }
4332: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4333: }
4334: return(0);
4335: }
4337: /*@C
4338: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4340: Collective on SNES
4342: Input Parameters:
4343: . snes - the SNES object
4345: Level: intermediate
4347: @*/
4348: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4349: {
4350: PetscErrorCode ierr;
4351: PetscViewer viewer;
4352: PetscBool flg;
4353: static PetscBool incall = PETSC_FALSE;
4354: PetscViewerFormat format;
4357: if (incall) return(0);
4358: incall = PETSC_TRUE;
4359: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4360: if (flg) {
4361: PetscViewerPushFormat(viewer,format);
4362: SNESReasonView(snes,viewer);
4363: PetscViewerPopFormat(viewer);
4364: PetscViewerDestroy(&viewer);
4365: }
4366: incall = PETSC_FALSE;
4367: return(0);
4368: }
4370: /*@
4371: SNESSolve - Solves a nonlinear system F(x) = b.
4372: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4374: Collective on SNES
4376: Input Parameters:
4377: + snes - the SNES context
4378: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4379: - x - the solution vector.
4381: Notes:
4382: The user should initialize the vector,x, with the initial guess
4383: for the nonlinear solve prior to calling SNESSolve. In particular,
4384: to employ an initial guess of zero, the user should explicitly set
4385: this vector to zero by calling VecSet().
4387: Level: beginner
4389: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4390: @*/
4391: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4392: {
4393: PetscErrorCode ierr;
4394: PetscBool flg;
4395: PetscInt grid;
4396: Vec xcreated = NULL;
4397: DM dm;
4406: /* High level operations using the nonlinear solver */
4407: {
4408: PetscViewer viewer;
4409: PetscViewerFormat format;
4410: PetscInt num;
4411: PetscBool flg;
4412: static PetscBool incall = PETSC_FALSE;
4414: if (!incall) {
4415: /* Estimate the convergence rate of the discretization */
4416: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4417: if (flg) {
4418: PetscConvEst conv;
4419: DM dm;
4420: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4421: PetscInt Nf;
4423: incall = PETSC_TRUE;
4424: SNESGetDM(snes, &dm);
4425: DMGetNumFields(dm, &Nf);
4426: PetscCalloc1(Nf, &alpha);
4427: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4428: PetscConvEstSetSolver(conv, (PetscObject) snes);
4429: PetscConvEstSetFromOptions(conv);
4430: PetscConvEstSetUp(conv);
4431: PetscConvEstGetConvRate(conv, alpha);
4432: PetscViewerPushFormat(viewer, format);
4433: PetscConvEstRateView(conv, alpha, viewer);
4434: PetscViewerPopFormat(viewer);
4435: PetscViewerDestroy(&viewer);
4436: PetscConvEstDestroy(&conv);
4437: PetscFree(alpha);
4438: incall = PETSC_FALSE;
4439: }
4440: /* Adaptively refine the initial grid */
4441: num = 1;
4442: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4443: if (flg) {
4444: DMAdaptor adaptor;
4446: incall = PETSC_TRUE;
4447: DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor);
4448: DMAdaptorSetSolver(adaptor, snes);
4449: DMAdaptorSetSequenceLength(adaptor, num);
4450: DMAdaptorSetFromOptions(adaptor);
4451: DMAdaptorSetUp(adaptor);
4452: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4453: DMAdaptorDestroy(&adaptor);
4454: incall = PETSC_FALSE;
4455: }
4456: /* Use grid sequencing to adapt */
4457: num = 0;
4458: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4459: if (num) {
4460: DMAdaptor adaptor;
4462: incall = PETSC_TRUE;
4463: DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor);
4464: DMAdaptorSetSolver(adaptor, snes);
4465: DMAdaptorSetSequenceLength(adaptor, num);
4466: DMAdaptorSetFromOptions(adaptor);
4467: DMAdaptorSetUp(adaptor);
4468: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4469: DMAdaptorDestroy(&adaptor);
4470: incall = PETSC_FALSE;
4471: }
4472: }
4473: }
4474: if (!x) {
4475: SNESGetDM(snes,&dm);
4476: DMCreateGlobalVector(dm,&xcreated);
4477: x = xcreated;
4478: }
4479: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4481: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4482: for (grid=0; grid<snes->gridsequence+1; grid++) {
4484: /* set solution vector */
4485: if (!grid) {PetscObjectReference((PetscObject)x);}
4486: VecDestroy(&snes->vec_sol);
4487: snes->vec_sol = x;
4488: SNESGetDM(snes,&dm);
4490: /* set affine vector if provided */
4491: if (b) { PetscObjectReference((PetscObject)b); }
4492: VecDestroy(&snes->vec_rhs);
4493: snes->vec_rhs = b;
4495: 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");
4496: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4497: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4498: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4499: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4500: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4501: }
4502: DMShellSetGlobalVector(dm,snes->vec_sol);
4503: SNESSetUp(snes);
4505: if (!grid) {
4506: if (snes->ops->computeinitialguess) {
4507: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4508: }
4509: }
4511: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4512: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4514: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4515: (*snes->ops->solve)(snes);
4516: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4517: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4518: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4520: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4521: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4523: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4524: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4525: SNESReasonViewFromOptions(snes);
4527: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4528: if (snes->reason < 0) break;
4529: if (grid < snes->gridsequence) {
4530: DM fine;
4531: Vec xnew;
4532: Mat interp;
4534: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4535: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4536: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4537: DMCreateGlobalVector(fine,&xnew);
4538: MatInterpolate(interp,x,xnew);
4539: DMInterpolate(snes->dm,interp,fine);
4540: MatDestroy(&interp);
4541: x = xnew;
4543: SNESReset(snes);
4544: SNESSetDM(snes,fine);
4545: SNESResetFromOptions(snes);
4546: DMDestroy(&fine);
4547: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4548: }
4549: }
4550: SNESViewFromOptions(snes,NULL,"-snes_view");
4551: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4552: DMMonitor(snes->dm);
4554: VecDestroy(&xcreated);
4555: PetscObjectSAWsBlock((PetscObject)snes);
4556: return(0);
4557: }
4559: /* --------- Internal routines for SNES Package --------- */
4561: /*@C
4562: SNESSetType - Sets the method for the nonlinear solver.
4564: Collective on SNES
4566: Input Parameters:
4567: + snes - the SNES context
4568: - type - a known method
4570: Options Database Key:
4571: . -snes_type <type> - Sets the method; use -help for a list
4572: of available methods (for instance, newtonls or newtontr)
4574: Notes:
4575: See "petsc/include/petscsnes.h" for available methods (for instance)
4576: + SNESNEWTONLS - Newton's method with line search
4577: (systems of nonlinear equations)
4578: - SNESNEWTONTR - Newton's method with trust region
4579: (systems of nonlinear equations)
4581: Normally, it is best to use the SNESSetFromOptions() command and then
4582: set the SNES solver type from the options database rather than by using
4583: this routine. Using the options database provides the user with
4584: maximum flexibility in evaluating the many nonlinear solvers.
4585: The SNESSetType() routine is provided for those situations where it
4586: is necessary to set the nonlinear solver independently of the command
4587: line or options database. This might be the case, for example, when
4588: the choice of solver changes during the execution of the program,
4589: and the user's application is taking responsibility for choosing the
4590: appropriate method.
4592: Developer Notes:
4593: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4594: the constructor in that list and calls it to create the spexific object.
4596: Level: intermediate
4598: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4600: @*/
4601: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4602: {
4603: PetscErrorCode ierr,(*r)(SNES);
4604: PetscBool match;
4610: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4611: if (match) return(0);
4613: PetscFunctionListFind(SNESList,type,&r);
4614: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4615: /* Destroy the previous private SNES context */
4616: if (snes->ops->destroy) {
4617: (*(snes)->ops->destroy)(snes);
4618: snes->ops->destroy = NULL;
4619: }
4620: /* Reinitialize function pointers in SNESOps structure */
4621: snes->ops->setup = NULL;
4622: snes->ops->solve = NULL;
4623: snes->ops->view = NULL;
4624: snes->ops->setfromoptions = NULL;
4625: snes->ops->destroy = NULL;
4627: /* It may happen the user has customized the line search before calling SNESSetType */
4628: if (((PetscObject)snes)->type_name) {
4629: SNESLineSearchDestroy(&snes->linesearch);
4630: }
4632: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4633: snes->setupcalled = PETSC_FALSE;
4635: PetscObjectChangeTypeName((PetscObject)snes,type);
4636: (*r)(snes);
4637: return(0);
4638: }
4640: /*@C
4641: SNESGetType - Gets the SNES method type and name (as a string).
4643: Not Collective
4645: Input Parameter:
4646: . snes - nonlinear solver context
4648: Output Parameter:
4649: . type - SNES method (a character string)
4651: Level: intermediate
4653: @*/
4654: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4655: {
4659: *type = ((PetscObject)snes)->type_name;
4660: return(0);
4661: }
4663: /*@
4664: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4666: Logically Collective on SNES
4668: Input Parameters:
4669: + snes - the SNES context obtained from SNESCreate()
4670: - u - the solution vector
4672: Level: beginner
4674: @*/
4675: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4676: {
4677: DM dm;
4683: PetscObjectReference((PetscObject) u);
4684: VecDestroy(&snes->vec_sol);
4686: snes->vec_sol = u;
4688: SNESGetDM(snes, &dm);
4689: DMShellSetGlobalVector(dm, u);
4690: return(0);
4691: }
4693: /*@
4694: SNESGetSolution - Returns the vector where the approximate solution is
4695: stored. This is the fine grid solution when using SNESSetGridSequence().
4697: Not Collective, but Vec is parallel if SNES is parallel
4699: Input Parameter:
4700: . snes - the SNES context
4702: Output Parameter:
4703: . x - the solution
4705: Level: intermediate
4707: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4708: @*/
4709: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4710: {
4714: *x = snes->vec_sol;
4715: return(0);
4716: }
4718: /*@
4719: SNESGetSolutionUpdate - Returns the vector where the solution update is
4720: stored.
4722: Not Collective, but Vec is parallel if SNES is parallel
4724: Input Parameter:
4725: . snes - the SNES context
4727: Output Parameter:
4728: . x - the solution update
4730: Level: advanced
4732: .seealso: SNESGetSolution(), SNESGetFunction()
4733: @*/
4734: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4735: {
4739: *x = snes->vec_sol_update;
4740: return(0);
4741: }
4743: /*@C
4744: SNESGetFunction - Returns the vector where the function is stored.
4746: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4748: Input Parameter:
4749: . snes - the SNES context
4751: Output Parameter:
4752: + r - the vector that is used to store residuals (or NULL if you don't want it)
4753: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4754: - ctx - the function context (or NULL if you don't want it)
4756: Level: advanced
4758: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4760: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4761: @*/
4762: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4763: {
4765: DM dm;
4769: if (r) {
4770: if (!snes->vec_func) {
4771: if (snes->vec_rhs) {
4772: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4773: } else if (snes->vec_sol) {
4774: VecDuplicate(snes->vec_sol,&snes->vec_func);
4775: } else if (snes->dm) {
4776: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4777: }
4778: }
4779: *r = snes->vec_func;
4780: }
4781: SNESGetDM(snes,&dm);
4782: DMSNESGetFunction(dm,f,ctx);
4783: return(0);
4784: }
4786: /*@C
4787: SNESGetNGS - Returns the NGS function and context.
4789: Input Parameter:
4790: . snes - the SNES context
4792: Output Parameter:
4793: + f - the function (or NULL) see SNESNGSFunction for details
4794: - ctx - the function context (or NULL)
4796: Level: advanced
4798: .seealso: SNESSetNGS(), SNESGetFunction()
4799: @*/
4801: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4802: {
4804: DM dm;
4808: SNESGetDM(snes,&dm);
4809: DMSNESGetNGS(dm,f,ctx);
4810: return(0);
4811: }
4813: /*@C
4814: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4815: SNES options in the database.
4817: Logically Collective on SNES
4819: Input Parameter:
4820: + snes - the SNES context
4821: - prefix - the prefix to prepend to all option names
4823: Notes:
4824: A hyphen (-) must NOT be given at the beginning of the prefix name.
4825: The first character of all runtime options is AUTOMATICALLY the hyphen.
4827: Level: advanced
4829: .seealso: SNESSetFromOptions()
4830: @*/
4831: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4832: {
4837: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4838: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4839: if (snes->linesearch) {
4840: SNESGetLineSearch(snes,&snes->linesearch);
4841: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4842: }
4843: KSPSetOptionsPrefix(snes->ksp,prefix);
4844: return(0);
4845: }
4847: /*@C
4848: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4849: SNES options in the database.
4851: Logically Collective on SNES
4853: Input Parameters:
4854: + snes - the SNES context
4855: - prefix - the prefix to prepend to all option names
4857: Notes:
4858: A hyphen (-) must NOT be given at the beginning of the prefix name.
4859: The first character of all runtime options is AUTOMATICALLY the hyphen.
4861: Level: advanced
4863: .seealso: SNESGetOptionsPrefix()
4864: @*/
4865: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4866: {
4871: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4872: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4873: if (snes->linesearch) {
4874: SNESGetLineSearch(snes,&snes->linesearch);
4875: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4876: }
4877: KSPAppendOptionsPrefix(snes->ksp,prefix);
4878: return(0);
4879: }
4881: /*@C
4882: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4883: SNES options in the database.
4885: Not Collective
4887: Input Parameter:
4888: . snes - the SNES context
4890: Output Parameter:
4891: . prefix - pointer to the prefix string used
4893: Notes:
4894: On the fortran side, the user should pass in a string 'prefix' of
4895: sufficient length to hold the prefix.
4897: Level: advanced
4899: .seealso: SNESAppendOptionsPrefix()
4900: @*/
4901: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4902: {
4907: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4908: return(0);
4909: }
4912: /*@C
4913: SNESRegister - Adds a method to the nonlinear solver package.
4915: Not collective
4917: Input Parameters:
4918: + name_solver - name of a new user-defined solver
4919: - routine_create - routine to create method context
4921: Notes:
4922: SNESRegister() may be called multiple times to add several user-defined solvers.
4924: Sample usage:
4925: .vb
4926: SNESRegister("my_solver",MySolverCreate);
4927: .ve
4929: Then, your solver can be chosen with the procedural interface via
4930: $ SNESSetType(snes,"my_solver")
4931: or at runtime via the option
4932: $ -snes_type my_solver
4934: Level: advanced
4936: Note: If your function is not being put into a shared library then use SNESRegister() instead
4938: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4940: Level: advanced
4941: @*/
4942: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4943: {
4947: SNESInitializePackage();
4948: PetscFunctionListAdd(&SNESList,sname,function);
4949: return(0);
4950: }
4952: PetscErrorCode SNESTestLocalMin(SNES snes)
4953: {
4955: PetscInt N,i,j;
4956: Vec u,uh,fh;
4957: PetscScalar value;
4958: PetscReal norm;
4961: SNESGetSolution(snes,&u);
4962: VecDuplicate(u,&uh);
4963: VecDuplicate(u,&fh);
4965: /* currently only works for sequential */
4966: PetscPrintf(PetscObjectComm((PetscObject)snes),"Testing FormFunction() for local min\n");
4967: VecGetSize(u,&N);
4968: for (i=0; i<N; i++) {
4969: VecCopy(u,uh);
4970: PetscPrintf(PetscObjectComm((PetscObject)snes),"i = %D\n",i);
4971: for (j=-10; j<11; j++) {
4972: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4973: VecSetValue(uh,i,value,ADD_VALUES);
4974: SNESComputeFunction(snes,uh,fh);
4975: VecNorm(fh,NORM_2,&norm);
4976: PetscPrintf(PetscObjectComm((PetscObject)snes)," j norm %D %18.16e\n",j,norm);
4977: value = -value;
4978: VecSetValue(uh,i,value,ADD_VALUES);
4979: }
4980: }
4981: VecDestroy(&uh);
4982: VecDestroy(&fh);
4983: return(0);
4984: }
4986: /*@
4987: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4988: computing relative tolerance for linear solvers within an inexact
4989: Newton method.
4991: Logically Collective on SNES
4993: Input Parameters:
4994: + snes - SNES context
4995: - flag - PETSC_TRUE or PETSC_FALSE
4997: Options Database:
4998: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4999: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5000: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5001: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5002: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5003: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5004: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5005: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5007: Notes:
5008: Currently, the default is to use a constant relative tolerance for
5009: the inner linear solvers. Alternatively, one can use the
5010: Eisenstat-Walker method, where the relative convergence tolerance
5011: is reset at each Newton iteration according progress of the nonlinear
5012: solver.
5014: Level: advanced
5016: Reference:
5017: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5018: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5020: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5021: @*/
5022: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
5023: {
5027: snes->ksp_ewconv = flag;
5028: return(0);
5029: }
5031: /*@
5032: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
5033: for computing relative tolerance for linear solvers within an
5034: inexact Newton method.
5036: Not Collective
5038: Input Parameter:
5039: . snes - SNES context
5041: Output Parameter:
5042: . flag - PETSC_TRUE or PETSC_FALSE
5044: Notes:
5045: Currently, the default is to use a constant relative tolerance for
5046: the inner linear solvers. Alternatively, one can use the
5047: Eisenstat-Walker method, where the relative convergence tolerance
5048: is reset at each Newton iteration according progress of the nonlinear
5049: solver.
5051: Level: advanced
5053: Reference:
5054: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5055: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5057: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5058: @*/
5059: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5060: {
5064: *flag = snes->ksp_ewconv;
5065: return(0);
5066: }
5068: /*@
5069: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5070: convergence criteria for the linear solvers within an inexact
5071: Newton method.
5073: Logically Collective on SNES
5075: Input Parameters:
5076: + snes - SNES context
5077: . version - version 1, 2 (default is 2) or 3
5078: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5079: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5080: . gamma - multiplicative factor for version 2 rtol computation
5081: (0 <= gamma2 <= 1)
5082: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5083: . alpha2 - power for safeguard
5084: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5086: Note:
5087: Version 3 was contributed by Luis Chacon, June 2006.
5089: Use PETSC_DEFAULT to retain the default for any of the parameters.
5091: Level: advanced
5093: Reference:
5094: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5095: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5096: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5098: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5099: @*/
5100: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5101: {
5102: SNESKSPEW *kctx;
5106: kctx = (SNESKSPEW*)snes->kspconvctx;
5107: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5116: if (version != PETSC_DEFAULT) kctx->version = version;
5117: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5118: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5119: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5120: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5121: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5122: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5124: 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);
5125: 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);
5126: 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);
5127: 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);
5128: 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);
5129: 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);
5130: return(0);
5131: }
5133: /*@
5134: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5135: convergence criteria for the linear solvers within an inexact
5136: Newton method.
5138: Not Collective
5140: Input Parameters:
5141: snes - SNES context
5143: Output Parameters:
5144: + version - version 1, 2 (default is 2) or 3
5145: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5146: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5147: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5148: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5149: . alpha2 - power for safeguard
5150: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5152: Level: advanced
5154: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5155: @*/
5156: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5157: {
5158: SNESKSPEW *kctx;
5162: kctx = (SNESKSPEW*)snes->kspconvctx;
5163: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5164: if (version) *version = kctx->version;
5165: if (rtol_0) *rtol_0 = kctx->rtol_0;
5166: if (rtol_max) *rtol_max = kctx->rtol_max;
5167: if (gamma) *gamma = kctx->gamma;
5168: if (alpha) *alpha = kctx->alpha;
5169: if (alpha2) *alpha2 = kctx->alpha2;
5170: if (threshold) *threshold = kctx->threshold;
5171: return(0);
5172: }
5174: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5175: {
5177: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5178: PetscReal rtol = PETSC_DEFAULT,stol;
5181: if (!snes->ksp_ewconv) return(0);
5182: if (!snes->iter) {
5183: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5184: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5185: }
5186: else {
5187: if (kctx->version == 1) {
5188: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5189: if (rtol < 0.0) rtol = -rtol;
5190: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5191: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5192: } else if (kctx->version == 2) {
5193: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5194: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5195: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5196: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5197: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5198: /* safeguard: avoid sharp decrease of rtol */
5199: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5200: stol = PetscMax(rtol,stol);
5201: rtol = PetscMin(kctx->rtol_0,stol);
5202: /* safeguard: avoid oversolving */
5203: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5204: stol = PetscMax(rtol,stol);
5205: rtol = PetscMin(kctx->rtol_0,stol);
5206: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5207: }
5208: /* safeguard: avoid rtol greater than one */
5209: rtol = PetscMin(rtol,kctx->rtol_max);
5210: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5211: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5212: return(0);
5213: }
5215: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5216: {
5218: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5219: PCSide pcside;
5220: Vec lres;
5223: if (!snes->ksp_ewconv) return(0);
5224: KSPGetTolerances(ksp,&kctx->rtol_last,NULL,NULL,NULL);
5225: kctx->norm_last = snes->norm;
5226: if (kctx->version == 1) {
5227: PC pc;
5228: PetscBool isNone;
5230: KSPGetPC(ksp, &pc);
5231: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5232: KSPGetPCSide(ksp,&pcside);
5233: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5234: /* KSP residual is true linear residual */
5235: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5236: } else {
5237: /* KSP residual is preconditioned residual */
5238: /* compute true linear residual norm */
5239: VecDuplicate(b,&lres);
5240: MatMult(snes->jacobian,x,lres);
5241: VecAYPX(lres,-1.0,b);
5242: VecNorm(lres,NORM_2,&kctx->lresid_last);
5243: VecDestroy(&lres);
5244: }
5245: }
5246: return(0);
5247: }
5249: /*@
5250: SNESGetKSP - Returns the KSP context for a SNES solver.
5252: Not Collective, but if SNES object is parallel, then KSP object is parallel
5254: Input Parameter:
5255: . snes - the SNES context
5257: Output Parameter:
5258: . ksp - the KSP context
5260: Notes:
5261: The user can then directly manipulate the KSP context to set various
5262: options, etc. Likewise, the user can then extract and manipulate the
5263: PC contexts as well.
5265: Level: beginner
5267: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5268: @*/
5269: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5270: {
5277: if (!snes->ksp) {
5278: PetscBool monitor = PETSC_FALSE;
5280: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5281: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5282: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5284: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5285: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5287: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5288: if (monitor) {
5289: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5290: }
5291: monitor = PETSC_FALSE;
5292: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5293: if (monitor) {
5294: PetscObject *objs;
5295: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5296: objs[0] = (PetscObject) snes;
5297: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5298: }
5299: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5300: }
5301: *ksp = snes->ksp;
5302: return(0);
5303: }
5306: #include <petsc/private/dmimpl.h>
5307: /*@
5308: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5310: Logically Collective on SNES
5312: Input Parameters:
5313: + snes - the nonlinear solver context
5314: - dm - the dm, cannot be NULL
5316: Notes:
5317: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5318: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5319: problems using the same function space.
5321: Level: intermediate
5323: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5324: @*/
5325: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5326: {
5328: KSP ksp;
5329: DMSNES sdm;
5334: PetscObjectReference((PetscObject)dm);
5335: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5336: if (snes->dm->dmsnes && !dm->dmsnes) {
5337: DMCopyDMSNES(snes->dm,dm);
5338: DMGetDMSNES(snes->dm,&sdm);
5339: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5340: }
5341: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5342: DMDestroy(&snes->dm);
5343: }
5344: snes->dm = dm;
5345: snes->dmAuto = PETSC_FALSE;
5347: SNESGetKSP(snes,&ksp);
5348: KSPSetDM(ksp,dm);
5349: KSPSetDMActive(ksp,PETSC_FALSE);
5350: if (snes->npc) {
5351: SNESSetDM(snes->npc, snes->dm);
5352: SNESSetNPCSide(snes,snes->npcside);
5353: }
5354: return(0);
5355: }
5357: /*@
5358: SNESGetDM - Gets the DM that may be used by some preconditioners
5360: Not Collective but DM obtained is parallel on SNES
5362: Input Parameter:
5363: . snes - the preconditioner context
5365: Output Parameter:
5366: . dm - the dm
5368: Level: intermediate
5370: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5371: @*/
5372: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5373: {
5378: if (!snes->dm) {
5379: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5380: snes->dmAuto = PETSC_TRUE;
5381: }
5382: *dm = snes->dm;
5383: return(0);
5384: }
5386: /*@
5387: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5389: Collective on SNES
5391: Input Parameters:
5392: + snes - iterative context obtained from SNESCreate()
5393: - pc - the preconditioner object
5395: Notes:
5396: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5397: to configure it using the API).
5399: Level: developer
5401: .seealso: SNESGetNPC(), SNESHasNPC()
5402: @*/
5403: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5404: {
5411: PetscObjectReference((PetscObject) pc);
5412: SNESDestroy(&snes->npc);
5413: snes->npc = pc;
5414: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5415: return(0);
5416: }
5418: /*@
5419: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5421: Not Collective; but any changes to the obtained SNES object must be applied collectively
5423: Input Parameter:
5424: . snes - iterative context obtained from SNESCreate()
5426: Output Parameter:
5427: . pc - preconditioner context
5429: Options Database:
5430: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5432: Notes:
5433: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5435: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5436: SNES during SNESSetUp()
5438: Level: developer
5440: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5441: @*/
5442: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5443: {
5445: const char *optionsprefix;
5450: if (!snes->npc) {
5451: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5452: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5453: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5454: SNESGetOptionsPrefix(snes,&optionsprefix);
5455: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5456: SNESAppendOptionsPrefix(snes->npc,"npc_");
5457: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5458: }
5459: *pc = snes->npc;
5460: return(0);
5461: }
5463: /*@
5464: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5466: Not Collective
5468: Input Parameter:
5469: . snes - iterative context obtained from SNESCreate()
5471: Output Parameter:
5472: . has_npc - whether the SNES has an NPC or not
5474: Level: developer
5476: .seealso: SNESSetNPC(), SNESGetNPC()
5477: @*/
5478: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5479: {
5482: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5483: return(0);
5484: }
5486: /*@
5487: SNESSetNPCSide - Sets the preconditioning side.
5489: Logically Collective on SNES
5491: Input Parameter:
5492: . snes - iterative context obtained from SNESCreate()
5494: Output Parameter:
5495: . side - the preconditioning side, where side is one of
5496: .vb
5497: PC_LEFT - left preconditioning
5498: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5499: .ve
5501: Options Database Keys:
5502: . -snes_pc_side <right,left>
5504: Notes:
5505: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5507: Level: intermediate
5509: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5510: @*/
5511: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5512: {
5516: snes->npcside= side;
5517: return(0);
5518: }
5520: /*@
5521: SNESGetNPCSide - Gets the preconditioning side.
5523: Not Collective
5525: Input Parameter:
5526: . snes - iterative context obtained from SNESCreate()
5528: Output Parameter:
5529: . side - the preconditioning side, where side is one of
5530: .vb
5531: PC_LEFT - left preconditioning
5532: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5533: .ve
5535: Level: intermediate
5537: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5538: @*/
5539: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5540: {
5544: *side = snes->npcside;
5545: return(0);
5546: }
5548: /*@
5549: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5551: Collective on SNES
5553: Input Parameters:
5554: + snes - iterative context obtained from SNESCreate()
5555: - linesearch - the linesearch object
5557: Notes:
5558: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5559: to configure it using the API).
5561: Level: developer
5563: .seealso: SNESGetLineSearch()
5564: @*/
5565: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5566: {
5573: PetscObjectReference((PetscObject) linesearch);
5574: SNESLineSearchDestroy(&snes->linesearch);
5576: snes->linesearch = linesearch;
5578: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5579: return(0);
5580: }
5582: /*@
5583: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5584: or creates a default line search instance associated with the SNES and returns it.
5586: Not Collective
5588: Input Parameter:
5589: . snes - iterative context obtained from SNESCreate()
5591: Output Parameter:
5592: . linesearch - linesearch context
5594: Level: beginner
5596: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5597: @*/
5598: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5599: {
5601: const char *optionsprefix;
5606: if (!snes->linesearch) {
5607: SNESGetOptionsPrefix(snes, &optionsprefix);
5608: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5609: SNESLineSearchSetSNES(snes->linesearch, snes);
5610: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5611: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5612: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5613: }
5614: *linesearch = snes->linesearch;
5615: return(0);
5616: }