Actual source code: snes.c
petsc-master 2019-06-26
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: SNESView - Prints the SNES data structure.
314: Collective on SNES
316: Input Parameters:
317: + SNES - the SNES context
318: - viewer - visualization context
320: Options Database Key:
321: . -snes_view - Calls SNESView() at end of SNESSolve()
323: Notes:
324: The available visualization contexts include
325: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
326: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
327: output where only the first processor opens
328: the file. All other processors send their
329: data to the first processor to print.
331: The user can open an alternative visualization context with
332: PetscViewerASCIIOpen() - output to a specified file.
334: Level: beginner
336: .seealso: PetscViewerASCIIOpen()
337: @*/
338: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
339: {
340: SNESKSPEW *kctx;
342: KSP ksp;
343: SNESLineSearch linesearch;
344: PetscBool iascii,isstring,isbinary,isdraw;
345: DMSNES dmsnes;
346: #if defined(PETSC_HAVE_SAWS)
347: PetscBool issaws;
348: #endif
352: if (!viewer) {
353: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
354: }
358: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
359: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
360: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
361: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
362: #if defined(PETSC_HAVE_SAWS)
363: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
364: #endif
365: if (iascii) {
366: SNESNormSchedule normschedule;
367: DM dm;
368: PetscErrorCode (*cJ)(SNES,Vec,Mat,Mat,void*);
369: void *ctx;
371: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
372: if (!snes->setupcalled) {
373: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
374: }
375: if (snes->ops->view) {
376: PetscViewerASCIIPushTab(viewer);
377: (*snes->ops->view)(snes,viewer);
378: PetscViewerASCIIPopTab(viewer);
379: }
380: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
381: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
382: if (snes->usesksp) {
383: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
384: }
385: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
386: SNESGetNormSchedule(snes, &normschedule);
387: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
388: if (snes->gridsequence) {
389: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
390: }
391: if (snes->ksp_ewconv) {
392: kctx = (SNESKSPEW*)snes->kspconvctx;
393: if (kctx) {
394: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
395: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
396: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
397: }
398: }
399: if (snes->lagpreconditioner == -1) {
400: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
401: } else if (snes->lagpreconditioner > 1) {
402: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
403: }
404: if (snes->lagjacobian == -1) {
405: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
406: } else if (snes->lagjacobian > 1) {
407: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
408: }
409: SNESGetDM(snes,&dm);
410: DMSNESGetJacobian(dm,&cJ,&ctx);
411: if (cJ == SNESComputeJacobianDefault) {
412: PetscViewerASCIIPrintf(viewer," Jacobian is built using finite differences one column at a time\n");
413: } else if (cJ == SNESComputeJacobianDefaultColor) {
414: PetscViewerASCIIPrintf(viewer," Jacobian is built using finite differences with coloring\n");
415: }
416: } else if (isstring) {
417: const char *type;
418: SNESGetType(snes,&type);
419: PetscViewerStringSPrintf(viewer," SNESType: %-7.7s",type);
420: if (snes->ops->view) {(*snes->ops->view)(snes,viewer);}
421: } else if (isbinary) {
422: PetscInt classid = SNES_FILE_CLASSID;
423: MPI_Comm comm;
424: PetscMPIInt rank;
425: char type[256];
427: PetscObjectGetComm((PetscObject)snes,&comm);
428: MPI_Comm_rank(comm,&rank);
429: if (!rank) {
430: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
431: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
432: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR,PETSC_FALSE);
433: }
434: if (snes->ops->view) {
435: (*snes->ops->view)(snes,viewer);
436: }
437: } else if (isdraw) {
438: PetscDraw draw;
439: char str[36];
440: PetscReal x,y,bottom,h;
442: PetscViewerDrawGetDraw(viewer,0,&draw);
443: PetscDrawGetCurrentPoint(draw,&x,&y);
444: PetscStrncpy(str,"SNES: ",sizeof(str));
445: PetscStrlcat(str,((PetscObject)snes)->type_name,sizeof(str));
446: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
447: bottom = y - h;
448: PetscDrawPushCurrentPoint(draw,x,bottom);
449: if (snes->ops->view) {
450: (*snes->ops->view)(snes,viewer);
451: }
452: #if defined(PETSC_HAVE_SAWS)
453: } else if (issaws) {
454: PetscMPIInt rank;
455: const char *name;
457: PetscObjectGetName((PetscObject)snes,&name);
458: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
459: if (!((PetscObject)snes)->amsmem && !rank) {
460: char dir[1024];
462: PetscObjectViewSAWs((PetscObject)snes,viewer);
463: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
464: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
465: if (!snes->conv_hist) {
466: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
467: }
468: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
469: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
470: }
471: #endif
472: }
473: if (snes->linesearch) {
474: SNESGetLineSearch(snes, &linesearch);
475: PetscViewerASCIIPushTab(viewer);
476: SNESLineSearchView(linesearch, viewer);
477: PetscViewerASCIIPopTab(viewer);
478: }
479: if (snes->npc && snes->usesnpc) {
480: PetscViewerASCIIPushTab(viewer);
481: SNESView(snes->npc, viewer);
482: PetscViewerASCIIPopTab(viewer);
483: }
484: PetscViewerASCIIPushTab(viewer);
485: DMGetDMSNES(snes->dm,&dmsnes);
486: DMSNESView(dmsnes, viewer);
487: PetscViewerASCIIPopTab(viewer);
488: if (snes->usesksp) {
489: SNESGetKSP(snes,&ksp);
490: PetscViewerASCIIPushTab(viewer);
491: KSPView(ksp,viewer);
492: PetscViewerASCIIPopTab(viewer);
493: }
494: if (isdraw) {
495: PetscDraw draw;
496: PetscViewerDrawGetDraw(viewer,0,&draw);
497: PetscDrawPopCurrentPoint(draw);
498: }
499: return(0);
500: }
502: /*
503: We retain a list of functions that also take SNES command
504: line options. These are called at the end SNESSetFromOptions()
505: */
506: #define MAXSETFROMOPTIONS 5
507: static PetscInt numberofsetfromoptions;
508: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
510: /*@C
511: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
513: Not Collective
515: Input Parameter:
516: . snescheck - function that checks for options
518: Level: developer
520: .seealso: SNESSetFromOptions()
521: @*/
522: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
523: {
525: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
526: othersetfromoptions[numberofsetfromoptions++] = snescheck;
527: return(0);
528: }
530: PETSC_INTERN PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
532: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
533: {
534: Mat J;
535: KSP ksp;
536: PC pc;
537: PetscBool match;
539: MatNullSpace nullsp;
544: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
545: Mat A = snes->jacobian, B = snes->jacobian_pre;
546: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
547: }
549: if (version == 1) {
550: MatCreateSNESMF(snes,&J);
551: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
552: MatSetFromOptions(J);
553: } else if (version == 2) {
554: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
555: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
556: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
557: #else
558: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
559: #endif
560: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");
562: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
563: if (snes->jacobian) {
564: MatGetNullSpace(snes->jacobian,&nullsp);
565: if (nullsp) {
566: MatSetNullSpace(J,nullsp);
567: }
568: }
570: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
571: if (hasOperator) {
573: /* This version replaces the user provided Jacobian matrix with a
574: matrix-free version but still employs the user-provided preconditioner matrix. */
575: SNESSetJacobian(snes,J,0,0,0);
576: } else {
577: /* This version replaces both the user-provided Jacobian and the user-
578: provided preconditioner Jacobian with the default matrix free version. */
579: if ((snes->npcside== PC_LEFT) && snes->npc) {
580: if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
581: } else {
582: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
583: }
584: /* Force no preconditioner */
585: SNESGetKSP(snes,&ksp);
586: KSPGetPC(ksp,&pc);
587: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
588: if (!match) {
589: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
590: PCSetType(pc,PCNONE);
591: }
592: }
593: MatDestroy(&J);
594: return(0);
595: }
597: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
598: {
599: SNES snes = (SNES)ctx;
601: Vec Xfine,Xfine_named = NULL,Xcoarse;
604: if (PetscLogPrintInfo) {
605: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
606: DMGetRefineLevel(dmfine,&finelevel);
607: DMGetCoarsenLevel(dmfine,&fineclevel);
608: DMGetRefineLevel(dmcoarse,&coarselevel);
609: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
610: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
611: }
612: if (dmfine == snes->dm) Xfine = snes->vec_sol;
613: else {
614: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
615: Xfine = Xfine_named;
616: }
617: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
618: if (Inject) {
619: MatRestrict(Inject,Xfine,Xcoarse);
620: } else {
621: MatRestrict(Restrict,Xfine,Xcoarse);
622: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
623: }
624: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
625: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
626: return(0);
627: }
629: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
630: {
634: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
635: return(0);
636: }
638: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
639: * safely call SNESGetDM() in their residual evaluation routine. */
640: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
641: {
642: SNES snes = (SNES)ctx;
644: Vec X,Xnamed = NULL;
645: DM dmsave;
646: void *ctxsave;
647: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*) = NULL;
650: dmsave = snes->dm;
651: KSPGetDM(ksp,&snes->dm);
652: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
653: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
654: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
655: X = Xnamed;
656: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
657: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
658: if (jac == SNESComputeJacobianDefaultColor) {
659: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
660: }
661: }
662: /* Make sure KSP DM has the Jacobian computation routine */
663: {
664: DMSNES sdm;
666: DMGetDMSNES(snes->dm, &sdm);
667: if (!sdm->ops->computejacobian) {
668: DMCopyDMSNES(dmsave, snes->dm);
669: }
670: }
671: /* Compute the operators */
672: SNESComputeJacobian(snes,X,A,B);
673: /* Put the previous context back */
674: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
675: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
676: }
678: if (Xnamed) {DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);}
679: snes->dm = dmsave;
680: return(0);
681: }
683: /*@
684: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
686: Collective
688: Input Arguments:
689: . snes - snes to configure
691: Level: developer
693: .seealso: SNESSetUp()
694: @*/
695: PetscErrorCode SNESSetUpMatrices(SNES snes)
696: {
698: DM dm;
699: DMSNES sdm;
702: SNESGetDM(snes,&dm);
703: DMGetDMSNES(dm,&sdm);
704: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
705: else if (!snes->jacobian && snes->mf) {
706: Mat J;
707: void *functx;
708: MatCreateSNESMF(snes,&J);
709: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
710: MatSetFromOptions(J);
711: SNESGetFunction(snes,NULL,NULL,&functx);
712: SNESSetJacobian(snes,J,J,0,0);
713: MatDestroy(&J);
714: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
715: Mat J,B;
716: MatCreateSNESMF(snes,&J);
717: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
718: MatSetFromOptions(J);
719: DMCreateMatrix(snes->dm,&B);
720: /* sdm->computejacobian was already set to reach here */
721: SNESSetJacobian(snes,J,B,NULL,NULL);
722: MatDestroy(&J);
723: MatDestroy(&B);
724: } else if (!snes->jacobian_pre) {
725: PetscErrorCode (*nspconstr)(DM, PetscInt, MatNullSpace *);
726: PetscDS prob;
727: Mat J, B;
728: MatNullSpace nullspace = NULL;
729: PetscBool hasPrec = PETSC_FALSE;
730: PetscInt Nf;
732: J = snes->jacobian;
733: DMGetDS(dm, &prob);
734: if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
735: if (J) {PetscObjectReference((PetscObject) J);}
736: else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
737: DMCreateMatrix(snes->dm, &B);
738: PetscDSGetNumFields(prob, &Nf);
739: DMGetNullSpaceConstructor(snes->dm, Nf, &nspconstr);
740: if (nspconstr) (*nspconstr)(snes->dm, -1, &nullspace);
741: MatSetNullSpace(B, nullspace);
742: MatNullSpaceDestroy(&nullspace);
743: SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
744: MatDestroy(&J);
745: MatDestroy(&B);
746: }
747: {
748: KSP ksp;
749: SNESGetKSP(snes,&ksp);
750: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
751: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
752: }
753: return(0);
754: }
756: /*@C
757: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
759: Collective on SNES
761: Input Parameters:
762: + snes - SNES object you wish to monitor
763: . name - the monitor type one is seeking
764: . help - message indicating what monitoring is done
765: . manual - manual page for the monitor
766: . monitor - the monitor function
767: - 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
769: Level: developer
771: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
772: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
773: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
774: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
775: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
776: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
777: PetscOptionsFList(), PetscOptionsEList()
778: @*/
779: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
780: {
781: PetscErrorCode ierr;
782: PetscViewer viewer;
783: PetscViewerFormat format;
784: PetscBool flg;
787: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
788: if (flg) {
789: PetscViewerAndFormat *vf;
790: PetscViewerAndFormatCreate(viewer,format,&vf);
791: PetscObjectDereference((PetscObject)viewer);
792: if (monitorsetup) {
793: (*monitorsetup)(snes,vf);
794: }
795: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
796: }
797: return(0);
798: }
800: /*@
801: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
803: Collective on SNES
805: Input Parameter:
806: . snes - the SNES context
808: Options Database Keys:
809: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
810: . -snes_stol - convergence tolerance in terms of the norm
811: of the change in the solution between steps
812: . -snes_atol <abstol> - absolute tolerance of residual norm
813: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
814: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
815: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
816: . -snes_max_it <max_it> - maximum number of iterations
817: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
818: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
819: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
820: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
821: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
822: . -snes_trtol <trtol> - trust region tolerance
823: . -snes_no_convergence_test - skip convergence test in nonlinear
824: solver; hence iterations will continue until max_it
825: or some other criterion is reached. Saves expense
826: of convergence test
827: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
828: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
829: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
830: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
831: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
832: . -snes_monitor_lg_range - plots residual norm at each iteration
833: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
834: . -snes_fd_color - use finite differences with coloring to compute Jacobian
835: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
836: - -snes_converged_reason - print the reason for convergence/divergence after each solve
838: Options Database for Eisenstat-Walker method:
839: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
840: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
841: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
842: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
843: . -snes_ksp_ew_gamma <gamma> - Sets gamma
844: . -snes_ksp_ew_alpha <alpha> - Sets alpha
845: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
846: - -snes_ksp_ew_threshold <threshold> - Sets threshold
848: Notes:
849: To see all options, run your program with the -help option or consult
850: Users-Manual: ch_snes
852: Level: beginner
854: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions()
855: @*/
856: PetscErrorCode SNESSetFromOptions(SNES snes)
857: {
858: PetscBool flg,pcset,persist,set;
859: PetscInt i,indx,lag,grids;
860: const char *deft = SNESNEWTONLS;
861: const char *convtests[] = {"default","skip"};
862: SNESKSPEW *kctx = NULL;
863: char type[256], monfilename[PETSC_MAX_PATH_LEN];
865: PCSide pcside;
866: const char *optionsprefix;
870: SNESRegisterAll();
871: PetscObjectOptionsBegin((PetscObject)snes);
872: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
873: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
874: if (flg) {
875: SNESSetType(snes,type);
876: } else if (!((PetscObject)snes)->type_name) {
877: SNESSetType(snes,deft);
878: }
879: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
880: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
882: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
883: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
884: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
885: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
886: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
887: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
888: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
889: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
890: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
892: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
893: if (flg) {
894: SNESSetLagPreconditioner(snes,lag);
895: }
896: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
897: if (flg) {
898: SNESSetLagPreconditionerPersists(snes,persist);
899: }
900: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
901: if (flg) {
902: SNESSetLagJacobian(snes,lag);
903: }
904: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
905: if (flg) {
906: SNESSetLagJacobianPersists(snes,persist);
907: }
909: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
910: if (flg) {
911: SNESSetGridSequence(snes,grids);
912: }
914: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
915: if (flg) {
916: switch (indx) {
917: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
918: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
919: }
920: }
922: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
923: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
925: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
926: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
928: kctx = (SNESKSPEW*)snes->kspconvctx;
930: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
932: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
933: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
934: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
935: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
936: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
937: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
938: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
940: flg = PETSC_FALSE;
941: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
942: if (set && flg) {SNESMonitorCancel(snes);}
944: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
945: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
946: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
948: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
949: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
950: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
951: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
952: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
953: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
954: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
956: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
957: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
960: flg = PETSC_FALSE;
961: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
962: if (flg) {
963: PetscDrawLG ctx;
965: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
966: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
967: }
968: flg = PETSC_FALSE;
969: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
970: if (flg) {
971: PetscViewer ctx;
973: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
974: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
975: }
979: flg = PETSC_FALSE;
980: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
981: if (flg) {
982: void *functx;
983: DM dm;
984: DMSNES sdm;
985: SNESGetDM(snes,&dm);
986: DMGetDMSNES(dm,&sdm);
987: sdm->jacobianctx = NULL;
988: SNESGetFunction(snes,NULL,NULL,&functx);
989: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
990: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
991: }
993: flg = PETSC_FALSE;
994: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
995: if (flg) {
996: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
997: }
999: flg = PETSC_FALSE;
1000: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1001: if (flg) {
1002: DM dm;
1003: DMSNES sdm;
1004: SNESGetDM(snes,&dm);
1005: DMGetDMSNES(dm,&sdm);
1006: sdm->jacobianctx = NULL;
1007: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
1008: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1009: }
1011: flg = PETSC_FALSE;
1012: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1013: if (flg && snes->mf_operator) {
1014: snes->mf_operator = PETSC_TRUE;
1015: snes->mf = PETSC_TRUE;
1016: }
1017: flg = PETSC_FALSE;
1018: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1019: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1020: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
1022: flg = PETSC_FALSE;
1023: SNESGetNPCSide(snes,&pcside);
1024: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1025: if (flg) {SNESSetNPCSide(snes,pcside);}
1027: #if defined(PETSC_HAVE_SAWS)
1028: /*
1029: Publish convergence information using SAWs
1030: */
1031: flg = PETSC_FALSE;
1032: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1033: if (flg) {
1034: void *ctx;
1035: SNESMonitorSAWsCreate(snes,&ctx);
1036: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1037: }
1038: #endif
1039: #if defined(PETSC_HAVE_SAWS)
1040: {
1041: PetscBool set;
1042: flg = PETSC_FALSE;
1043: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1044: if (set) {
1045: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1046: }
1047: }
1048: #endif
1050: for (i = 0; i < numberofsetfromoptions; i++) {
1051: (*othersetfromoptions[i])(snes);
1052: }
1054: if (snes->ops->setfromoptions) {
1055: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1056: }
1058: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1059: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1060: PetscOptionsEnd();
1062: if (snes->linesearch) {
1063: SNESGetLineSearch(snes, &snes->linesearch);
1064: SNESLineSearchSetFromOptions(snes->linesearch);
1065: }
1067: if (snes->usesksp) {
1068: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1069: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1070: KSPSetFromOptions(snes->ksp);
1071: }
1073: /* if someone has set the SNES NPC type, create it. */
1074: SNESGetOptionsPrefix(snes, &optionsprefix);
1075: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1076: if (pcset && (!snes->npc)) {
1077: SNESGetNPC(snes, &snes->npc);
1078: }
1079: snes->setfromoptionscalled++;
1080: return(0);
1081: }
1083: /*@
1084: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1086: Collective on SNES
1088: Input Parameter:
1089: . snes - the SNES context
1091: Level: beginner
1093: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1094: @*/
1095: PetscErrorCode SNESResetFromOptions(SNES snes)
1096: {
1100: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1101: return(0);
1102: }
1104: /*@C
1105: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1106: the nonlinear solvers.
1108: Logically Collective on SNES
1110: Input Parameters:
1111: + snes - the SNES context
1112: . compute - function to compute the context
1113: - destroy - function to destroy the context
1115: Level: intermediate
1117: Notes:
1118: This function is currently not available from Fortran.
1120: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1121: @*/
1122: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1123: {
1126: snes->ops->usercompute = compute;
1127: snes->ops->userdestroy = destroy;
1128: return(0);
1129: }
1131: /*@
1132: SNESSetApplicationContext - Sets the optional user-defined context for
1133: the nonlinear solvers.
1135: Logically Collective on SNES
1137: Input Parameters:
1138: + snes - the SNES context
1139: - usrP - optional user context
1141: Level: intermediate
1143: Fortran Notes:
1144: To use this from Fortran you must write a Fortran interface definition for this
1145: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1147: .seealso: SNESGetApplicationContext()
1148: @*/
1149: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1150: {
1152: KSP ksp;
1156: SNESGetKSP(snes,&ksp);
1157: KSPSetApplicationContext(ksp,usrP);
1158: snes->user = usrP;
1159: return(0);
1160: }
1162: /*@
1163: SNESGetApplicationContext - Gets the user-defined context for the
1164: nonlinear solvers.
1166: Not Collective
1168: Input Parameter:
1169: . snes - SNES context
1171: Output Parameter:
1172: . usrP - user context
1174: Fortran Notes:
1175: To use this from Fortran you must write a Fortran interface definition for this
1176: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1178: Level: intermediate
1180: .seealso: SNESSetApplicationContext()
1181: @*/
1182: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1183: {
1186: *(void**)usrP = snes->user;
1187: return(0);
1188: }
1190: /*@
1191: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply
1192: the Jacobian.
1194: Collective on SNES
1196: Input Parameters:
1197: + snes - SNES context
1198: . mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1199: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1201: Options Database:
1202: + -snes_mf - use matrix free for both the mat and pmat operator
1203: - -snes_mf_operator - use matrix free only for the mat operator
1205: Level: intermediate
1207: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF()
1208: @*/
1209: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1210: {
1215: if (mf && !mf_operator) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"If using mf must also use mf_operator");
1216: snes->mf = mf;
1217: snes->mf_operator = mf_operator;
1218: return(0);
1219: }
1221: /*@
1222: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply
1223: the Jacobian.
1225: Collective on SNES
1227: Input Parameter:
1228: . snes - SNES context
1230: Output Parameters:
1231: + mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1232: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1234: Options Database:
1235: + -snes_mf - use matrix free for both the mat and pmat operator
1236: - -snes_mf_operator - use matrix free only for the mat operator
1238: Level: intermediate
1240: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1241: @*/
1242: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1243: {
1246: if (mf) *mf = snes->mf;
1247: if (mf_operator) *mf_operator = snes->mf_operator;
1248: return(0);
1249: }
1251: /*@
1252: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1253: at this time.
1255: Not Collective
1257: Input Parameter:
1258: . snes - SNES context
1260: Output Parameter:
1261: . iter - iteration number
1263: Notes:
1264: For example, during the computation of iteration 2 this would return 1.
1266: This is useful for using lagged Jacobians (where one does not recompute the
1267: Jacobian at each SNES iteration). For example, the code
1268: .vb
1269: SNESGetIterationNumber(snes,&it);
1270: if (!(it % 2)) {
1271: [compute Jacobian here]
1272: }
1273: .ve
1274: can be used in your ComputeJacobian() function to cause the Jacobian to be
1275: recomputed every second SNES iteration.
1277: After the SNES solve is complete this will return the number of nonlinear iterations used.
1279: Level: intermediate
1281: .seealso: SNESGetLinearSolveIterations()
1282: @*/
1283: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1284: {
1288: *iter = snes->iter;
1289: return(0);
1290: }
1292: /*@
1293: SNESSetIterationNumber - Sets the current iteration number.
1295: Not Collective
1297: Input Parameter:
1298: . snes - SNES context
1299: . iter - iteration number
1301: Level: developer
1303: .seealso: SNESGetLinearSolveIterations()
1304: @*/
1305: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1306: {
1311: PetscObjectSAWsTakeAccess((PetscObject)snes);
1312: snes->iter = iter;
1313: PetscObjectSAWsGrantAccess((PetscObject)snes);
1314: return(0);
1315: }
1317: /*@
1318: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1319: attempted by the nonlinear solver.
1321: Not Collective
1323: Input Parameter:
1324: . snes - SNES context
1326: Output Parameter:
1327: . nfails - number of unsuccessful steps attempted
1329: Notes:
1330: This counter is reset to zero for each successive call to SNESSolve().
1332: Level: intermediate
1334: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1335: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1336: @*/
1337: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1338: {
1342: *nfails = snes->numFailures;
1343: return(0);
1344: }
1346: /*@
1347: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1348: attempted by the nonlinear solver before it gives up.
1350: Not Collective
1352: Input Parameters:
1353: + snes - SNES context
1354: - maxFails - maximum of unsuccessful steps
1356: Level: intermediate
1358: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1359: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1360: @*/
1361: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1362: {
1365: snes->maxFailures = maxFails;
1366: return(0);
1367: }
1369: /*@
1370: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1371: attempted by the nonlinear solver before it gives up.
1373: Not Collective
1375: Input Parameter:
1376: . snes - SNES context
1378: Output Parameter:
1379: . maxFails - maximum of unsuccessful steps
1381: Level: intermediate
1383: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1384: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1386: @*/
1387: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1388: {
1392: *maxFails = snes->maxFailures;
1393: return(0);
1394: }
1396: /*@
1397: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1398: done by SNES.
1400: Not Collective
1402: Input Parameter:
1403: . snes - SNES context
1405: Output Parameter:
1406: . nfuncs - number of evaluations
1408: Level: intermediate
1410: Notes:
1411: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1413: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1414: @*/
1415: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1416: {
1420: *nfuncs = snes->nfuncs;
1421: return(0);
1422: }
1424: /*@
1425: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1426: linear solvers.
1428: Not Collective
1430: Input Parameter:
1431: . snes - SNES context
1433: Output Parameter:
1434: . nfails - number of failed solves
1436: Level: intermediate
1438: Options Database Keys:
1439: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1441: Notes:
1442: This counter is reset to zero for each successive call to SNESSolve().
1444: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1445: @*/
1446: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1447: {
1451: *nfails = snes->numLinearSolveFailures;
1452: return(0);
1453: }
1455: /*@
1456: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1457: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1459: Logically Collective on SNES
1461: Input Parameters:
1462: + snes - SNES context
1463: - maxFails - maximum allowed linear solve failures
1465: Level: intermediate
1467: Options Database Keys:
1468: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1470: Notes:
1471: By default this is 0; that is SNES returns on the first failed linear solve
1473: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1474: @*/
1475: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1476: {
1480: snes->maxLinearSolveFailures = maxFails;
1481: return(0);
1482: }
1484: /*@
1485: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1486: are allowed before SNES terminates
1488: Not Collective
1490: Input Parameter:
1491: . snes - SNES context
1493: Output Parameter:
1494: . maxFails - maximum of unsuccessful solves allowed
1496: Level: intermediate
1498: Notes:
1499: By default this is 1; that is SNES returns on the first failed linear solve
1501: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1502: @*/
1503: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1504: {
1508: *maxFails = snes->maxLinearSolveFailures;
1509: return(0);
1510: }
1512: /*@
1513: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1514: used by the nonlinear solver.
1516: Not Collective
1518: Input Parameter:
1519: . snes - SNES context
1521: Output Parameter:
1522: . lits - number of linear iterations
1524: Notes:
1525: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1527: 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
1528: then call KSPGetIterationNumber() after the failed solve.
1530: Level: intermediate
1532: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1533: @*/
1534: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1535: {
1539: *lits = snes->linear_its;
1540: return(0);
1541: }
1543: /*@
1544: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1545: are reset every time SNESSolve() is called.
1547: Logically Collective on SNES
1549: Input Parameter:
1550: + snes - SNES context
1551: - reset - whether to reset the counters or not
1553: Notes:
1554: This defaults to PETSC_TRUE
1556: Level: developer
1558: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1559: @*/
1560: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1561: {
1565: snes->counters_reset = reset;
1566: return(0);
1567: }
1570: /*@
1571: SNESSetKSP - Sets a KSP context for the SNES object to use
1573: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1575: Input Parameters:
1576: + snes - the SNES context
1577: - ksp - the KSP context
1579: Notes:
1580: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1581: so this routine is rarely needed.
1583: The KSP object that is already in the SNES object has its reference count
1584: decreased by one.
1586: Level: developer
1588: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1589: @*/
1590: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1591: {
1598: PetscObjectReference((PetscObject)ksp);
1599: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1600: snes->ksp = ksp;
1601: return(0);
1602: }
1604: /* -----------------------------------------------------------*/
1605: /*@
1606: SNESCreate - Creates a nonlinear solver context.
1608: Collective
1610: Input Parameters:
1611: . comm - MPI communicator
1613: Output Parameter:
1614: . outsnes - the new SNES context
1616: Options Database Keys:
1617: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1618: and no preconditioning matrix
1619: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1620: products, and a user-provided preconditioning matrix
1621: as set by SNESSetJacobian()
1622: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1624: Level: beginner
1626: Developer Notes:
1627: SNES always creates a KSP object even though many SNES methods do not use it. This is
1628: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1629: particular method does use KSP and regulates if the information about the KSP is printed
1630: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1631: by help messages about meaningless SNES options.
1633: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1634: be fixed.
1636: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1638: @*/
1639: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1640: {
1642: SNES snes;
1643: SNESKSPEW *kctx;
1647: *outsnes = NULL;
1648: SNESInitializePackage();
1650: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1652: snes->ops->converged = SNESConvergedDefault;
1653: snes->usesksp = PETSC_TRUE;
1654: snes->tolerancesset = PETSC_FALSE;
1655: snes->max_its = 50;
1656: snes->max_funcs = 10000;
1657: snes->norm = 0.0;
1658: snes->xnorm = 0.0;
1659: snes->ynorm = 0.0;
1660: snes->normschedule = SNES_NORM_ALWAYS;
1661: snes->functype = SNES_FUNCTION_DEFAULT;
1662: #if defined(PETSC_USE_REAL_SINGLE)
1663: snes->rtol = 1.e-5;
1664: #else
1665: snes->rtol = 1.e-8;
1666: #endif
1667: snes->ttol = 0.0;
1668: #if defined(PETSC_USE_REAL_SINGLE)
1669: snes->abstol = 1.e-25;
1670: #else
1671: snes->abstol = 1.e-50;
1672: #endif
1673: #if defined(PETSC_USE_REAL_SINGLE)
1674: snes->stol = 1.e-5;
1675: #else
1676: snes->stol = 1.e-8;
1677: #endif
1678: #if defined(PETSC_USE_REAL_SINGLE)
1679: snes->deltatol = 1.e-6;
1680: #else
1681: snes->deltatol = 1.e-12;
1682: #endif
1683: snes->divtol = 1.e4;
1684: snes->rnorm0 = 0;
1685: snes->nfuncs = 0;
1686: snes->numFailures = 0;
1687: snes->maxFailures = 1;
1688: snes->linear_its = 0;
1689: snes->lagjacobian = 1;
1690: snes->jac_iter = 0;
1691: snes->lagjac_persist = PETSC_FALSE;
1692: snes->lagpreconditioner = 1;
1693: snes->pre_iter = 0;
1694: snes->lagpre_persist = PETSC_FALSE;
1695: snes->numbermonitors = 0;
1696: snes->data = 0;
1697: snes->setupcalled = PETSC_FALSE;
1698: snes->ksp_ewconv = PETSC_FALSE;
1699: snes->nwork = 0;
1700: snes->work = 0;
1701: snes->nvwork = 0;
1702: snes->vwork = 0;
1703: snes->conv_hist_len = 0;
1704: snes->conv_hist_max = 0;
1705: snes->conv_hist = NULL;
1706: snes->conv_hist_its = NULL;
1707: snes->conv_hist_reset = PETSC_TRUE;
1708: snes->counters_reset = PETSC_TRUE;
1709: snes->vec_func_init_set = PETSC_FALSE;
1710: snes->reason = SNES_CONVERGED_ITERATING;
1711: snes->npcside = PC_RIGHT;
1712: snes->setfromoptionscalled = 0;
1714: snes->mf = PETSC_FALSE;
1715: snes->mf_operator = PETSC_FALSE;
1716: snes->mf_version = 1;
1718: snes->numLinearSolveFailures = 0;
1719: snes->maxLinearSolveFailures = 1;
1721: snes->vizerotolerance = 1.e-8;
1722: #if defined(PETSC_USE_DEBUG)
1723: snes->checkjacdomainerror = PETSC_TRUE;
1724: #else
1725: snes->checkjacdomainerror = PETSC_FALSE;
1726: #endif
1728: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1729: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1731: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1732: PetscNewLog(snes,&kctx);
1734: snes->kspconvctx = (void*)kctx;
1735: kctx->version = 2;
1736: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1737: this was too large for some test cases */
1738: kctx->rtol_last = 0.0;
1739: kctx->rtol_max = .9;
1740: kctx->gamma = 1.0;
1741: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1742: kctx->alpha2 = kctx->alpha;
1743: kctx->threshold = .1;
1744: kctx->lresid_last = 0.0;
1745: kctx->norm_last = 0.0;
1747: *outsnes = snes;
1748: return(0);
1749: }
1751: /*MC
1752: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1754: Synopsis:
1755: #include "petscsnes.h"
1756: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1758: Input Parameters:
1759: + snes - the SNES context
1760: . x - state at which to evaluate residual
1761: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1763: Output Parameter:
1764: . f - vector to put residual (function value)
1766: Level: intermediate
1768: .seealso: SNESSetFunction(), SNESGetFunction()
1769: M*/
1771: /*@C
1772: SNESSetFunction - Sets the function evaluation routine and function
1773: vector for use by the SNES routines in solving systems of nonlinear
1774: equations.
1776: Logically Collective on SNES
1778: Input Parameters:
1779: + snes - the SNES context
1780: . r - vector to store function value
1781: . f - function evaluation routine; see SNESFunction for calling sequence details
1782: - ctx - [optional] user-defined context for private data for the
1783: function evaluation routine (may be NULL)
1785: Notes:
1786: The Newton-like methods typically solve linear systems of the form
1787: $ f'(x) x = -f(x),
1788: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1790: Level: beginner
1792: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1793: @*/
1794: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1795: {
1797: DM dm;
1801: if (r) {
1804: PetscObjectReference((PetscObject)r);
1805: VecDestroy(&snes->vec_func);
1807: snes->vec_func = r;
1808: }
1809: SNESGetDM(snes,&dm);
1810: DMSNESSetFunction(dm,f,ctx);
1811: return(0);
1812: }
1815: /*@C
1816: SNESSetInitialFunction - Sets the function vector to be used as the
1817: function norm at the initialization of the method. In some
1818: instances, the user has precomputed the function before calling
1819: SNESSolve. This function allows one to avoid a redundant call
1820: to SNESComputeFunction in that case.
1822: Logically Collective on SNES
1824: Input Parameters:
1825: + snes - the SNES context
1826: - f - vector to store function value
1828: Notes:
1829: This should not be modified during the solution procedure.
1831: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1833: Level: developer
1835: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1836: @*/
1837: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1838: {
1840: Vec vec_func;
1846: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1847: snes->vec_func_init_set = PETSC_FALSE;
1848: return(0);
1849: }
1850: SNESGetFunction(snes,&vec_func,NULL,NULL);
1851: VecCopy(f, vec_func);
1853: snes->vec_func_init_set = PETSC_TRUE;
1854: return(0);
1855: }
1857: /*@
1858: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1859: of the SNES method.
1861: Logically Collective on SNES
1863: Input Parameters:
1864: + snes - the SNES context
1865: - normschedule - the frequency of norm computation
1867: Options Database Key:
1868: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1870: Notes:
1871: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1872: of the nonlinear function and the taking of its norm at every iteration to
1873: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1874: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1875: may either be monitored for convergence or not. As these are often used as nonlinear
1876: preconditioners, monitoring the norm of their error is not a useful enterprise within
1877: their solution.
1879: Level: developer
1881: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1882: @*/
1883: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1884: {
1887: snes->normschedule = normschedule;
1888: return(0);
1889: }
1892: /*@
1893: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1894: of the SNES method.
1896: Logically Collective on SNES
1898: Input Parameters:
1899: + snes - the SNES context
1900: - normschedule - the type of the norm used
1902: Level: advanced
1904: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1905: @*/
1906: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1907: {
1910: *normschedule = snes->normschedule;
1911: return(0);
1912: }
1915: /*@
1916: SNESSetFunctionNorm - Sets the last computed residual norm.
1918: Logically Collective on SNES
1920: Input Parameters:
1921: + snes - the SNES context
1923: - normschedule - the frequency of norm computation
1925: Level: developer
1927: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1928: @*/
1929: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1930: {
1933: snes->norm = norm;
1934: return(0);
1935: }
1937: /*@
1938: SNESGetFunctionNorm - Gets the last computed norm of the residual
1940: Not Collective
1942: Input Parameter:
1943: . snes - the SNES context
1945: Output Parameter:
1946: . norm - the last computed residual norm
1948: Level: developer
1950: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1951: @*/
1952: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1953: {
1957: *norm = snes->norm;
1958: return(0);
1959: }
1961: /*@
1962: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
1964: Not Collective
1966: Input Parameter:
1967: . snes - the SNES context
1969: Output Parameter:
1970: . ynorm - the last computed update norm
1972: Level: developer
1974: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
1975: @*/
1976: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
1977: {
1981: *ynorm = snes->ynorm;
1982: return(0);
1983: }
1985: /*@
1986: SNESGetSolutionNorm - Gets the last computed norm of the solution
1988: Not Collective
1990: Input Parameter:
1991: . snes - the SNES context
1993: Output Parameter:
1994: . xnorm - the last computed solution norm
1996: Level: developer
1998: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
1999: @*/
2000: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2001: {
2005: *xnorm = snes->xnorm;
2006: return(0);
2007: }
2009: /*@C
2010: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2011: of the SNES method.
2013: Logically Collective on SNES
2015: Input Parameters:
2016: + snes - the SNES context
2017: - normschedule - the frequency of norm computation
2019: Notes:
2020: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2021: of the nonlinear function and the taking of its norm at every iteration to
2022: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2023: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2024: may either be monitored for convergence or not. As these are often used as nonlinear
2025: preconditioners, monitoring the norm of their error is not a useful enterprise within
2026: their solution.
2028: Level: developer
2030: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2031: @*/
2032: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2033: {
2036: snes->functype = type;
2037: return(0);
2038: }
2041: /*@C
2042: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2043: of the SNES method.
2045: Logically Collective on SNES
2047: Input Parameters:
2048: + snes - the SNES context
2049: - normschedule - the type of the norm used
2051: Level: advanced
2053: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2054: @*/
2055: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2056: {
2059: *type = snes->functype;
2060: return(0);
2061: }
2063: /*MC
2064: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2066: Synopsis:
2067: #include <petscsnes.h>
2068: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2070: + X - solution vector
2071: . B - RHS vector
2072: - ctx - optional user-defined Gauss-Seidel context
2074: Level: intermediate
2076: .seealso: SNESSetNGS(), SNESGetNGS()
2077: M*/
2079: /*@C
2080: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2081: use with composed nonlinear solvers.
2083: Input Parameters:
2084: + snes - the SNES context
2085: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2086: - ctx - [optional] user-defined context for private data for the
2087: smoother evaluation routine (may be NULL)
2089: Notes:
2090: The NGS routines are used by the composed nonlinear solver to generate
2091: a problem appropriate update to the solution, particularly FAS.
2093: Level: intermediate
2095: .seealso: SNESGetFunction(), SNESComputeNGS()
2096: @*/
2097: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2098: {
2100: DM dm;
2104: SNESGetDM(snes,&dm);
2105: DMSNESSetNGS(dm,f,ctx);
2106: return(0);
2107: }
2109: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2110: {
2112: DM dm;
2113: DMSNES sdm;
2116: SNESGetDM(snes,&dm);
2117: DMGetDMSNES(dm,&sdm);
2118: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2119: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2120: /* A(x)*x - b(x) */
2121: PetscStackPush("SNES Picard user function");
2122: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2123: PetscStackPop;
2124: PetscStackPush("SNES Picard user Jacobian");
2125: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2126: PetscStackPop;
2127: VecScale(f,-1.0);
2128: MatMultAdd(snes->jacobian,x,f,f);
2129: return(0);
2130: }
2132: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2133: {
2135: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2136: return(0);
2137: }
2139: /*@C
2140: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2142: Logically Collective on SNES
2144: Input Parameters:
2145: + snes - the SNES context
2146: . r - vector to store function value
2147: . b - function evaluation routine
2148: . Amat - matrix with which A(x) x - b(x) is to be computed
2149: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2150: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2151: - ctx - [optional] user-defined context for private data for the
2152: function evaluation routine (may be NULL)
2154: Notes:
2155: 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
2156: 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.
2158: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2160: $ 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}
2161: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2163: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2165: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2166: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2168: 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
2169: 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
2170: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2172: Level: intermediate
2174: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2175: @*/
2176: 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)
2177: {
2179: DM dm;
2183: SNESGetDM(snes, &dm);
2184: DMSNESSetPicard(dm,b,J,ctx);
2185: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2186: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2187: return(0);
2188: }
2190: /*@C
2191: SNESGetPicard - Returns the context for the Picard iteration
2193: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2195: Input Parameter:
2196: . snes - the SNES context
2198: Output Parameter:
2199: + r - the function (or NULL)
2200: . f - the function (or NULL); see SNESFunction for calling sequence details
2201: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2202: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2203: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2204: - ctx - the function context (or NULL)
2206: Level: advanced
2208: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2209: @*/
2210: 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)
2211: {
2213: DM dm;
2217: SNESGetFunction(snes,r,NULL,NULL);
2218: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2219: SNESGetDM(snes,&dm);
2220: DMSNESGetPicard(dm,f,J,ctx);
2221: return(0);
2222: }
2224: /*@C
2225: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2227: Logically Collective on SNES
2229: Input Parameters:
2230: + snes - the SNES context
2231: . func - function evaluation routine
2232: - ctx - [optional] user-defined context for private data for the
2233: function evaluation routine (may be NULL)
2235: Calling sequence of func:
2236: $ func (SNES snes,Vec x,void *ctx);
2238: . f - function vector
2239: - ctx - optional user-defined function context
2241: Level: intermediate
2243: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2244: @*/
2245: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2246: {
2249: if (func) snes->ops->computeinitialguess = func;
2250: if (ctx) snes->initialguessP = ctx;
2251: return(0);
2252: }
2254: /* --------------------------------------------------------------- */
2255: /*@C
2256: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2257: it assumes a zero right hand side.
2259: Logically Collective on SNES
2261: Input Parameter:
2262: . snes - the SNES context
2264: Output Parameter:
2265: . rhs - the right hand side vector or NULL if the right hand side vector is null
2267: Level: intermediate
2269: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2270: @*/
2271: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2272: {
2276: *rhs = snes->vec_rhs;
2277: return(0);
2278: }
2280: /*@
2281: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2283: Collective on SNES
2285: Input Parameters:
2286: + snes - the SNES context
2287: - x - input vector
2289: Output Parameter:
2290: . y - function vector, as set by SNESSetFunction()
2292: Notes:
2293: SNESComputeFunction() is typically used within nonlinear solvers
2294: implementations, so most users would not generally call this routine
2295: themselves.
2297: Level: developer
2299: .seealso: SNESSetFunction(), SNESGetFunction()
2300: @*/
2301: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2302: {
2304: DM dm;
2305: DMSNES sdm;
2313: VecValidValues(x,2,PETSC_TRUE);
2315: SNESGetDM(snes,&dm);
2316: DMGetDMSNES(dm,&sdm);
2317: if (sdm->ops->computefunction) {
2318: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2319: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2320: }
2321: VecLockReadPush(x);
2322: PetscStackPush("SNES user function");
2323: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2324: PetscStackPop;
2325: VecLockReadPop(x);
2326: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2327: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2328: }
2329: } else if (snes->vec_rhs) {
2330: MatMult(snes->jacobian, x, y);
2331: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2332: if (snes->vec_rhs) {
2333: VecAXPY(y,-1.0,snes->vec_rhs);
2334: }
2335: snes->nfuncs++;
2336: /*
2337: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2338: propagate the value to all processes
2339: */
2340: if (snes->domainerror) {
2341: VecSetInf(y);
2342: }
2343: return(0);
2344: }
2346: /*@
2347: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2349: Collective on SNES
2351: Input Parameters:
2352: + snes - the SNES context
2353: . x - input vector
2354: - b - rhs vector
2356: Output Parameter:
2357: . x - new solution vector
2359: Notes:
2360: SNESComputeNGS() is typically used within composed nonlinear solver
2361: implementations, so most users would not generally call this routine
2362: themselves.
2364: Level: developer
2366: .seealso: SNESSetNGS(), SNESComputeFunction()
2367: @*/
2368: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2369: {
2371: DM dm;
2372: DMSNES sdm;
2380: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2381: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2382: SNESGetDM(snes,&dm);
2383: DMGetDMSNES(dm,&sdm);
2384: if (sdm->ops->computegs) {
2385: if (b) {VecLockReadPush(b);}
2386: PetscStackPush("SNES user NGS");
2387: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2388: PetscStackPop;
2389: if (b) {VecLockReadPop(b);}
2390: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2391: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2392: return(0);
2393: }
2395: PetscErrorCode SNESTestJacobian(SNES snes)
2396: {
2397: Mat A,B,C,D,jacobian;
2398: Vec x = snes->vec_sol,f = snes->vec_func;
2399: PetscErrorCode ierr;
2400: PetscReal nrm,gnorm;
2401: PetscReal threshold = 1.e-5;
2402: PetscInt m,n,M,N;
2403: void *functx;
2404: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg;
2405: PetscViewer viewer,mviewer;
2406: MPI_Comm comm;
2407: PetscInt tabs;
2408: static PetscBool directionsprinted = PETSC_FALSE;
2409: PetscViewerFormat format;
2412: PetscObjectOptionsBegin((PetscObject)snes);
2413: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2414: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2415: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2416: if (!complete_print) {
2417: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2418: }
2419: /* for compatibility with PETSc 3.9 and older. */
2420: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2421: PetscOptionsEnd();
2422: if (!test) return(0);
2424: PetscObjectGetComm((PetscObject)snes,&comm);
2425: PetscViewerASCIIGetStdout(comm,&viewer);
2426: PetscViewerASCIIGetTab(viewer, &tabs);
2427: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2428: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2429: if (!complete_print && !directionsprinted) {
2430: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2431: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2432: }
2433: if (!directionsprinted) {
2434: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2435: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2436: directionsprinted = PETSC_TRUE;
2437: }
2438: if (complete_print) {
2439: PetscViewerPushFormat(mviewer,format);
2440: }
2442: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2443: if (!flg) jacobian = snes->jacobian;
2444: else jacobian = snes->jacobian_pre;
2446: if (!x) {
2447: MatCreateVecs(jacobian, &x, NULL);
2448: } else {
2449: PetscObjectReference((PetscObject) x);
2450: }
2451: if (!f) {
2452: VecDuplicate(x, &f);
2453: } else {
2454: PetscObjectReference((PetscObject) f);
2455: }
2456: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2457: SNESComputeFunction(snes,x,f);
2458: VecDestroy(&f);
2460: while (jacobian) {
2461: PetscObjectTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2462: if (flg) {
2463: A = jacobian;
2464: PetscObjectReference((PetscObject)A);
2465: } else {
2466: MatComputeOperator(jacobian,MATAIJ,&A);
2467: }
2469: MatCreate(PetscObjectComm((PetscObject)A),&B);
2470: MatGetSize(A,&M,&N);
2471: MatGetLocalSize(A,&m,&n);
2472: MatSetSizes(B,m,n,M,N);
2473: MatSetType(B,((PetscObject)A)->type_name);
2474: MatSetUp(B);
2475: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2477: SNESGetFunction(snes,NULL,NULL,&functx);
2478: SNESComputeJacobianDefault(snes,x,B,B,functx);
2480: MatDuplicate(B,MAT_COPY_VALUES,&D);
2481: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2482: MatNorm(D,NORM_FROBENIUS,&nrm);
2483: MatNorm(A,NORM_FROBENIUS,&gnorm);
2484: MatDestroy(&D);
2485: if (!gnorm) gnorm = 1; /* just in case */
2486: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2488: if (complete_print) {
2489: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2490: MatView(jacobian,mviewer);
2491: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2492: MatView(B,mviewer);
2493: }
2495: if (threshold_print || complete_print) {
2496: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2497: PetscScalar *cvals;
2498: const PetscInt *bcols;
2499: const PetscScalar *bvals;
2501: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2502: MatCreate(PetscObjectComm((PetscObject)A),&C);
2503: MatSetSizes(C,m,n,M,N);
2504: MatSetType(C,((PetscObject)A)->type_name);
2505: MatSetUp(C);
2506: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2507: MatGetOwnershipRange(B,&Istart,&Iend);
2509: for (row = Istart; row < Iend; row++) {
2510: MatGetRow(B,row,&bncols,&bcols,&bvals);
2511: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2512: for (j = 0, cncols = 0; j < bncols; j++) {
2513: if (PetscAbsScalar(bvals[j]) > threshold) {
2514: ccols[cncols] = bcols[j];
2515: cvals[cncols] = bvals[j];
2516: cncols += 1;
2517: }
2518: }
2519: if (cncols) {
2520: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2521: }
2522: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2523: PetscFree2(ccols,cvals);
2524: }
2525: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2526: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2527: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2528: MatView(C,complete_print ? mviewer : viewer);
2529: MatDestroy(&C);
2530: }
2531: MatDestroy(&A);
2532: MatDestroy(&B);
2534: if (jacobian != snes->jacobian_pre) {
2535: jacobian = snes->jacobian_pre;
2536: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2537: }
2538: else jacobian = NULL;
2539: }
2540: VecDestroy(&x);
2541: if (complete_print) {
2542: PetscViewerPopFormat(mviewer);
2543: }
2544: if (mviewer) { PetscViewerDestroy(&mviewer); }
2545: PetscViewerASCIISetTab(viewer,tabs);
2546: return(0);
2547: }
2549: /*@
2550: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2552: Collective on SNES
2554: Input Parameters:
2555: + snes - the SNES context
2556: - x - input vector
2558: Output Parameters:
2559: + A - Jacobian matrix
2560: - B - optional preconditioning matrix
2562: Options Database Keys:
2563: + -snes_lag_preconditioner <lag>
2564: . -snes_lag_jacobian <lag>
2565: . -snes_test_jacobian - compare the user provided Jacobian with one compute via finite differences to check for errors
2566: . -snes_test_jacobian_display - 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
2567: . -snes_test_jacobian_display_threshold <numerical value> - display entries in the difference between the user provided Jacobian and finite difference Jacobian that are greater than a certain value to help users detect errors
2568: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2569: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2570: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2571: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2572: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2573: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2574: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2575: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2576: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2577: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2578: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2581: Notes:
2582: Most users should not need to explicitly call this routine, as it
2583: is used internally within the nonlinear solvers.
2585: Developer Notes:
2586: 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
2587: for with the SNESType of test that has been removed.
2589: Level: developer
2591: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2592: @*/
2593: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2594: {
2596: PetscBool flag;
2597: DM dm;
2598: DMSNES sdm;
2599: KSP ksp;
2605: VecValidValues(X,2,PETSC_TRUE);
2606: SNESGetDM(snes,&dm);
2607: DMGetDMSNES(dm,&sdm);
2609: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2611: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2613: if (snes->lagjacobian == -2) {
2614: snes->lagjacobian = -1;
2616: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2617: } else if (snes->lagjacobian == -1) {
2618: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2619: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2620: if (flag) {
2621: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2622: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2623: }
2624: return(0);
2625: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2626: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2627: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2628: if (flag) {
2629: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2630: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2631: }
2632: return(0);
2633: }
2634: if (snes->npc && snes->npcside== PC_LEFT) {
2635: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2636: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2637: return(0);
2638: }
2640: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2641: VecLockReadPush(X);
2642: PetscStackPush("SNES user Jacobian function");
2643: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2644: PetscStackPop;
2645: VecLockReadPop(X);
2646: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2648: /* the next line ensures that snes->ksp exists */
2649: SNESGetKSP(snes,&ksp);
2650: if (snes->lagpreconditioner == -2) {
2651: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2652: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2653: snes->lagpreconditioner = -1;
2654: } else if (snes->lagpreconditioner == -1) {
2655: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2656: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2657: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2658: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2659: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2660: } else {
2661: PetscInfo(snes,"Rebuilding preconditioner\n");
2662: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2663: }
2665: SNESTestJacobian(snes);
2666: /* make sure user returned a correct Jacobian and preconditioner */
2669: {
2670: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2671: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2672: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2673: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2674: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2675: if (flag || flag_draw || flag_contour) {
2676: Mat Bexp_mine = NULL,Bexp,FDexp;
2677: PetscViewer vdraw,vstdout;
2678: PetscBool flg;
2679: if (flag_operator) {
2680: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2681: Bexp = Bexp_mine;
2682: } else {
2683: /* See if the preconditioning matrix can be viewed and added directly */
2684: PetscObjectTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2685: if (flg) Bexp = B;
2686: else {
2687: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2688: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2689: Bexp = Bexp_mine;
2690: }
2691: }
2692: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2693: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2694: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2695: if (flag_draw || flag_contour) {
2696: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2697: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2698: } else vdraw = NULL;
2699: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2700: if (flag) {MatView(Bexp,vstdout);}
2701: if (vdraw) {MatView(Bexp,vdraw);}
2702: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2703: if (flag) {MatView(FDexp,vstdout);}
2704: if (vdraw) {MatView(FDexp,vdraw);}
2705: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2706: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2707: if (flag) {MatView(FDexp,vstdout);}
2708: if (vdraw) { /* Always use contour for the difference */
2709: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2710: MatView(FDexp,vdraw);
2711: PetscViewerPopFormat(vdraw);
2712: }
2713: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2714: PetscViewerDestroy(&vdraw);
2715: MatDestroy(&Bexp_mine);
2716: MatDestroy(&FDexp);
2717: }
2718: }
2719: {
2720: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2721: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2722: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2723: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2724: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2725: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2726: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2727: if (flag_threshold) {
2728: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2729: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2730: }
2731: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2732: Mat Bfd;
2733: PetscViewer vdraw,vstdout;
2734: MatColoring coloring;
2735: ISColoring iscoloring;
2736: MatFDColoring matfdcoloring;
2737: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2738: void *funcctx;
2739: PetscReal norm1,norm2,normmax;
2741: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2742: MatColoringCreate(Bfd,&coloring);
2743: MatColoringSetType(coloring,MATCOLORINGSL);
2744: MatColoringSetFromOptions(coloring);
2745: MatColoringApply(coloring,&iscoloring);
2746: MatColoringDestroy(&coloring);
2747: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2748: MatFDColoringSetFromOptions(matfdcoloring);
2749: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2750: ISColoringDestroy(&iscoloring);
2752: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2753: SNESGetFunction(snes,NULL,&func,&funcctx);
2754: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2755: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2756: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2757: MatFDColoringSetFromOptions(matfdcoloring);
2758: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2759: MatFDColoringDestroy(&matfdcoloring);
2761: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2762: if (flag_draw || flag_contour) {
2763: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2764: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2765: } else vdraw = NULL;
2766: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2767: if (flag_display) {MatView(B,vstdout);}
2768: if (vdraw) {MatView(B,vdraw);}
2769: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2770: if (flag_display) {MatView(Bfd,vstdout);}
2771: if (vdraw) {MatView(Bfd,vdraw);}
2772: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2773: MatNorm(Bfd,NORM_1,&norm1);
2774: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2775: MatNorm(Bfd,NORM_MAX,&normmax);
2776: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2777: if (flag_display) {MatView(Bfd,vstdout);}
2778: if (vdraw) { /* Always use contour for the difference */
2779: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2780: MatView(Bfd,vdraw);
2781: PetscViewerPopFormat(vdraw);
2782: }
2783: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2785: if (flag_threshold) {
2786: PetscInt bs,rstart,rend,i;
2787: MatGetBlockSize(B,&bs);
2788: MatGetOwnershipRange(B,&rstart,&rend);
2789: for (i=rstart; i<rend; i++) {
2790: const PetscScalar *ba,*ca;
2791: const PetscInt *bj,*cj;
2792: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2793: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2794: MatGetRow(B,i,&bn,&bj,&ba);
2795: MatGetRow(Bfd,i,&cn,&cj,&ca);
2796: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2797: for (j=0; j<bn; j++) {
2798: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2799: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2800: maxentrycol = bj[j];
2801: maxentry = PetscRealPart(ba[j]);
2802: }
2803: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2804: maxdiffcol = bj[j];
2805: maxdiff = PetscRealPart(ca[j]);
2806: }
2807: if (rdiff > maxrdiff) {
2808: maxrdiffcol = bj[j];
2809: maxrdiff = rdiff;
2810: }
2811: }
2812: if (maxrdiff > 1) {
2813: 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);
2814: for (j=0; j<bn; j++) {
2815: PetscReal rdiff;
2816: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2817: if (rdiff > 1) {
2818: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2819: }
2820: }
2821: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2822: }
2823: MatRestoreRow(B,i,&bn,&bj,&ba);
2824: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2825: }
2826: }
2827: PetscViewerDestroy(&vdraw);
2828: MatDestroy(&Bfd);
2829: }
2830: }
2831: return(0);
2832: }
2834: /*MC
2835: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2837: Synopsis:
2838: #include "petscsnes.h"
2839: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2841: + x - input vector
2842: . Amat - the matrix that defines the (approximate) Jacobian
2843: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2844: - ctx - [optional] user-defined Jacobian context
2846: Level: intermediate
2848: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2849: M*/
2851: /*@C
2852: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2853: location to store the matrix.
2855: Logically Collective on SNES
2857: Input Parameters:
2858: + snes - the SNES context
2859: . Amat - the matrix that defines the (approximate) Jacobian
2860: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2861: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2862: - ctx - [optional] user-defined context for private data for the
2863: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2865: Notes:
2866: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2867: each matrix.
2869: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2870: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2872: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2873: must be a MatFDColoring.
2875: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2876: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2878: Level: beginner
2880: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2881: SNESSetPicard(), SNESJacobianFunction
2882: @*/
2883: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2884: {
2886: DM dm;
2894: SNESGetDM(snes,&dm);
2895: DMSNESSetJacobian(dm,J,ctx);
2896: if (Amat) {
2897: PetscObjectReference((PetscObject)Amat);
2898: MatDestroy(&snes->jacobian);
2900: snes->jacobian = Amat;
2901: }
2902: if (Pmat) {
2903: PetscObjectReference((PetscObject)Pmat);
2904: MatDestroy(&snes->jacobian_pre);
2906: snes->jacobian_pre = Pmat;
2907: }
2908: return(0);
2909: }
2911: /*@C
2912: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2913: provided context for evaluating the Jacobian.
2915: Not Collective, but Mat object will be parallel if SNES object is
2917: Input Parameter:
2918: . snes - the nonlinear solver context
2920: Output Parameters:
2921: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2922: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2923: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2924: - ctx - location to stash Jacobian ctx (or NULL)
2926: Level: advanced
2928: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2929: @*/
2930: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2931: {
2933: DM dm;
2934: DMSNES sdm;
2938: if (Amat) *Amat = snes->jacobian;
2939: if (Pmat) *Pmat = snes->jacobian_pre;
2940: SNESGetDM(snes,&dm);
2941: DMGetDMSNES(dm,&sdm);
2942: if (J) *J = sdm->ops->computejacobian;
2943: if (ctx) *ctx = sdm->jacobianctx;
2944: return(0);
2945: }
2947: /*@
2948: SNESSetUp - Sets up the internal data structures for the later use
2949: of a nonlinear solver.
2951: Collective on SNES
2953: Input Parameters:
2954: . snes - the SNES context
2956: Notes:
2957: For basic use of the SNES solvers the user need not explicitly call
2958: SNESSetUp(), since these actions will automatically occur during
2959: the call to SNESSolve(). However, if one wishes to control this
2960: phase separately, SNESSetUp() should be called after SNESCreate()
2961: and optional routines of the form SNESSetXXX(), but before SNESSolve().
2963: Level: advanced
2965: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
2966: @*/
2967: PetscErrorCode SNESSetUp(SNES snes)
2968: {
2970: DM dm;
2971: DMSNES sdm;
2972: SNESLineSearch linesearch, pclinesearch;
2973: void *lsprectx,*lspostctx;
2974: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
2975: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
2976: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2977: Vec f,fpc;
2978: void *funcctx;
2979: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
2980: void *jacctx,*appctx;
2981: Mat j,jpre;
2985: if (snes->setupcalled) return(0);
2986: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
2988: if (!((PetscObject)snes)->type_name) {
2989: SNESSetType(snes,SNESNEWTONLS);
2990: }
2992: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
2994: SNESGetDM(snes,&dm);
2995: DMGetDMSNES(dm,&sdm);
2996: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
2997: if (!sdm->ops->computejacobian) {
2998: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
2999: }
3000: if (!snes->vec_func) {
3001: DMCreateGlobalVector(dm,&snes->vec_func);
3002: }
3004: if (!snes->ksp) {
3005: SNESGetKSP(snes, &snes->ksp);
3006: }
3008: if (snes->linesearch) {
3009: SNESGetLineSearch(snes, &snes->linesearch);
3010: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3011: }
3013: if (snes->npc && (snes->npcside== PC_LEFT)) {
3014: snes->mf = PETSC_TRUE;
3015: snes->mf_operator = PETSC_FALSE;
3016: }
3018: if (snes->npc) {
3019: /* copy the DM over */
3020: SNESGetDM(snes,&dm);
3021: SNESSetDM(snes->npc,dm);
3023: SNESGetFunction(snes,&f,&func,&funcctx);
3024: VecDuplicate(f,&fpc);
3025: SNESSetFunction(snes->npc,fpc,func,funcctx);
3026: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3027: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3028: SNESGetApplicationContext(snes,&appctx);
3029: SNESSetApplicationContext(snes->npc,appctx);
3030: VecDestroy(&fpc);
3032: /* copy the function pointers over */
3033: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3035: /* default to 1 iteration */
3036: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3037: if (snes->npcside==PC_RIGHT) {
3038: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3039: } else {
3040: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3041: }
3042: SNESSetFromOptions(snes->npc);
3044: /* copy the line search context over */
3045: if (snes->linesearch && snes->npc->linesearch) {
3046: SNESGetLineSearch(snes,&linesearch);
3047: SNESGetLineSearch(snes->npc,&pclinesearch);
3048: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3049: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3050: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3051: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3052: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3053: }
3054: }
3055: if (snes->mf) {
3056: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3057: }
3058: if (snes->ops->usercompute && !snes->user) {
3059: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3060: }
3062: snes->jac_iter = 0;
3063: snes->pre_iter = 0;
3065: if (snes->ops->setup) {
3066: (*snes->ops->setup)(snes);
3067: }
3069: if (snes->npc && (snes->npcside== PC_LEFT)) {
3070: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3071: if (snes->linesearch){
3072: SNESGetLineSearch(snes,&linesearch);
3073: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3074: }
3075: }
3076: }
3077: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3078: snes->setupcalled = PETSC_TRUE;
3079: return(0);
3080: }
3082: /*@
3083: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3085: Collective on SNES
3087: Input Parameter:
3088: . snes - iterative context obtained from SNESCreate()
3090: Level: intermediate
3092: Notes:
3093: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3095: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3096: @*/
3097: PetscErrorCode SNESReset(SNES snes)
3098: {
3103: if (snes->ops->userdestroy && snes->user) {
3104: (*snes->ops->userdestroy)((void**)&snes->user);
3105: snes->user = NULL;
3106: }
3107: if (snes->npc) {
3108: SNESReset(snes->npc);
3109: }
3111: if (snes->ops->reset) {
3112: (*snes->ops->reset)(snes);
3113: }
3114: if (snes->ksp) {
3115: KSPReset(snes->ksp);
3116: }
3118: if (snes->linesearch) {
3119: SNESLineSearchReset(snes->linesearch);
3120: }
3122: VecDestroy(&snes->vec_rhs);
3123: VecDestroy(&snes->vec_sol);
3124: VecDestroy(&snes->vec_sol_update);
3125: VecDestroy(&snes->vec_func);
3126: MatDestroy(&snes->jacobian);
3127: MatDestroy(&snes->jacobian_pre);
3128: VecDestroyVecs(snes->nwork,&snes->work);
3129: VecDestroyVecs(snes->nvwork,&snes->vwork);
3131: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3133: snes->nwork = snes->nvwork = 0;
3134: snes->setupcalled = PETSC_FALSE;
3135: return(0);
3136: }
3138: /*@
3139: SNESDestroy - Destroys the nonlinear solver context that was created
3140: with SNESCreate().
3142: Collective on SNES
3144: Input Parameter:
3145: . snes - the SNES context
3147: Level: beginner
3149: .seealso: SNESCreate(), SNESSolve()
3150: @*/
3151: PetscErrorCode SNESDestroy(SNES *snes)
3152: {
3156: if (!*snes) return(0);
3158: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3160: SNESReset((*snes));
3161: SNESDestroy(&(*snes)->npc);
3163: /* if memory was published with SAWs then destroy it */
3164: PetscObjectSAWsViewOff((PetscObject)*snes);
3165: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3167: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3168: DMDestroy(&(*snes)->dm);
3169: KSPDestroy(&(*snes)->ksp);
3170: SNESLineSearchDestroy(&(*snes)->linesearch);
3172: PetscFree((*snes)->kspconvctx);
3173: if ((*snes)->ops->convergeddestroy) {
3174: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3175: }
3176: if ((*snes)->conv_hist_alloc) {
3177: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3178: }
3179: SNESMonitorCancel((*snes));
3180: PetscHeaderDestroy(snes);
3181: return(0);
3182: }
3184: /* ----------- Routines to set solver parameters ---------- */
3186: /*@
3187: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3189: Logically Collective on SNES
3191: Input Parameters:
3192: + snes - the SNES context
3193: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3194: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3196: Options Database Keys:
3197: . -snes_lag_preconditioner <lag>
3199: Notes:
3200: The default is 1
3201: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3202: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3204: Level: intermediate
3206: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3208: @*/
3209: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3210: {
3213: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3214: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3216: snes->lagpreconditioner = lag;
3217: return(0);
3218: }
3220: /*@
3221: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3223: Logically Collective on SNES
3225: Input Parameters:
3226: + snes - the SNES context
3227: - steps - the number of refinements to do, defaults to 0
3229: Options Database Keys:
3230: . -snes_grid_sequence <steps>
3232: Level: intermediate
3234: Notes:
3235: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3237: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3239: @*/
3240: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3241: {
3245: snes->gridsequence = steps;
3246: return(0);
3247: }
3249: /*@
3250: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3252: Logically Collective on SNES
3254: Input Parameter:
3255: . snes - the SNES context
3257: Output Parameter:
3258: . steps - the number of refinements to do, defaults to 0
3260: Options Database Keys:
3261: . -snes_grid_sequence <steps>
3263: Level: intermediate
3265: Notes:
3266: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3268: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3270: @*/
3271: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3272: {
3275: *steps = snes->gridsequence;
3276: return(0);
3277: }
3279: /*@
3280: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3282: Not Collective
3284: Input Parameter:
3285: . snes - the SNES context
3287: Output Parameter:
3288: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3289: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3291: Options Database Keys:
3292: . -snes_lag_preconditioner <lag>
3294: Notes:
3295: The default is 1
3296: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3298: Level: intermediate
3300: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3302: @*/
3303: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3304: {
3307: *lag = snes->lagpreconditioner;
3308: return(0);
3309: }
3311: /*@
3312: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3313: often the preconditioner is rebuilt.
3315: Logically Collective on SNES
3317: Input Parameters:
3318: + snes - the SNES context
3319: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3320: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3322: Options Database Keys:
3323: . -snes_lag_jacobian <lag>
3325: Notes:
3326: The default is 1
3327: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3328: 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
3329: at the next Newton step but never again (unless it is reset to another value)
3331: Level: intermediate
3333: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3335: @*/
3336: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3337: {
3340: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3341: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3343: snes->lagjacobian = lag;
3344: return(0);
3345: }
3347: /*@
3348: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3350: Not Collective
3352: Input Parameter:
3353: . snes - the SNES context
3355: Output Parameter:
3356: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3357: the Jacobian is built etc.
3359: Options Database Keys:
3360: . -snes_lag_jacobian <lag>
3362: Notes:
3363: The default is 1
3364: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3366: Level: intermediate
3368: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3370: @*/
3371: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3372: {
3375: *lag = snes->lagjacobian;
3376: return(0);
3377: }
3379: /*@
3380: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3382: Logically collective on SNES
3384: Input Parameter:
3385: + snes - the SNES context
3386: - flg - jacobian lagging persists if true
3388: Options Database Keys:
3389: . -snes_lag_jacobian_persists <flg>
3391: Notes:
3392: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3393: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3394: timesteps may present huge efficiency gains.
3396: Level: developer
3398: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3400: @*/
3401: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3402: {
3406: snes->lagjac_persist = flg;
3407: return(0);
3408: }
3410: /*@
3411: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3413: Logically Collective on SNES
3415: Input Parameter:
3416: + snes - the SNES context
3417: - flg - preconditioner lagging persists if true
3419: Options Database Keys:
3420: . -snes_lag_jacobian_persists <flg>
3422: Notes:
3423: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3424: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3425: several timesteps may present huge efficiency gains.
3427: Level: developer
3429: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3431: @*/
3432: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3433: {
3437: snes->lagpre_persist = flg;
3438: return(0);
3439: }
3441: /*@
3442: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3444: Logically Collective on SNES
3446: Input Parameters:
3447: + snes - the SNES context
3448: - force - PETSC_TRUE require at least one iteration
3450: Options Database Keys:
3451: . -snes_force_iteration <force> - Sets forcing an iteration
3453: Notes:
3454: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3456: Level: intermediate
3458: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3459: @*/
3460: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3461: {
3464: snes->forceiteration = force;
3465: return(0);
3466: }
3468: /*@
3469: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3471: Logically Collective on SNES
3473: Input Parameters:
3474: . snes - the SNES context
3476: Output Parameter:
3477: . force - PETSC_TRUE requires at least one iteration.
3479: Level: intermediate
3481: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3482: @*/
3483: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3484: {
3487: *force = snes->forceiteration;
3488: return(0);
3489: }
3491: /*@
3492: SNESSetTolerances - Sets various parameters used in convergence tests.
3494: Logically Collective on SNES
3496: Input Parameters:
3497: + snes - the SNES context
3498: . abstol - absolute convergence tolerance
3499: . rtol - relative convergence tolerance
3500: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3501: . maxit - maximum number of iterations
3502: - maxf - maximum number of function evaluations (-1 indicates no limit)
3504: Options Database Keys:
3505: + -snes_atol <abstol> - Sets abstol
3506: . -snes_rtol <rtol> - Sets rtol
3507: . -snes_stol <stol> - Sets stol
3508: . -snes_max_it <maxit> - Sets maxit
3509: - -snes_max_funcs <maxf> - Sets maxf
3511: Notes:
3512: The default maximum number of iterations is 50.
3513: The default maximum number of function evaluations is 1000.
3515: Level: intermediate
3517: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3518: @*/
3519: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3520: {
3529: if (abstol != PETSC_DEFAULT) {
3530: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3531: snes->abstol = abstol;
3532: }
3533: if (rtol != PETSC_DEFAULT) {
3534: 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);
3535: snes->rtol = rtol;
3536: }
3537: if (stol != PETSC_DEFAULT) {
3538: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3539: snes->stol = stol;
3540: }
3541: if (maxit != PETSC_DEFAULT) {
3542: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3543: snes->max_its = maxit;
3544: }
3545: if (maxf != PETSC_DEFAULT) {
3546: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3547: snes->max_funcs = maxf;
3548: }
3549: snes->tolerancesset = PETSC_TRUE;
3550: return(0);
3551: }
3553: /*@
3554: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3556: Logically Collective on SNES
3558: Input Parameters:
3559: + snes - the SNES context
3560: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3562: Options Database Keys:
3563: + -snes_divergence_tolerance <divtol> - Sets divtol
3565: Notes:
3566: The default divergence tolerance is 1e4.
3568: Level: intermediate
3570: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3571: @*/
3572: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3573: {
3578: if (divtol != PETSC_DEFAULT) {
3579: snes->divtol = divtol;
3580: }
3581: else {
3582: snes->divtol = 1.0e4;
3583: }
3584: return(0);
3585: }
3587: /*@
3588: SNESGetTolerances - Gets various parameters used in convergence tests.
3590: Not Collective
3592: Input Parameters:
3593: + snes - the SNES context
3594: . atol - absolute convergence tolerance
3595: . rtol - relative convergence tolerance
3596: . stol - convergence tolerance in terms of the norm
3597: of the change in the solution between steps
3598: . maxit - maximum number of iterations
3599: - maxf - maximum number of function evaluations
3601: Notes:
3602: The user can specify NULL for any parameter that is not needed.
3604: Level: intermediate
3606: .seealso: SNESSetTolerances()
3607: @*/
3608: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3609: {
3612: if (atol) *atol = snes->abstol;
3613: if (rtol) *rtol = snes->rtol;
3614: if (stol) *stol = snes->stol;
3615: if (maxit) *maxit = snes->max_its;
3616: if (maxf) *maxf = snes->max_funcs;
3617: return(0);
3618: }
3620: /*@
3621: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3623: Not Collective
3625: Input Parameters:
3626: + snes - the SNES context
3627: - divtol - divergence tolerance
3629: Level: intermediate
3631: .seealso: SNESSetDivergenceTolerance()
3632: @*/
3633: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3634: {
3637: if (divtol) *divtol = snes->divtol;
3638: return(0);
3639: }
3641: /*@
3642: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3644: Logically Collective on SNES
3646: Input Parameters:
3647: + snes - the SNES context
3648: - tol - tolerance
3650: Options Database Key:
3651: . -snes_trtol <tol> - Sets tol
3653: Level: intermediate
3655: .seealso: SNESSetTolerances()
3656: @*/
3657: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3658: {
3662: snes->deltatol = tol;
3663: return(0);
3664: }
3666: /*
3667: Duplicate the lg monitors for SNES from KSP; for some reason with
3668: dynamic libraries things don't work under Sun4 if we just use
3669: macros instead of functions
3670: */
3671: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3672: {
3677: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3678: return(0);
3679: }
3681: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3682: {
3686: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3687: return(0);
3688: }
3690: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3692: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3693: {
3694: PetscDrawLG lg;
3695: PetscErrorCode ierr;
3696: PetscReal x,y,per;
3697: PetscViewer v = (PetscViewer)monctx;
3698: static PetscReal prev; /* should be in the context */
3699: PetscDraw draw;
3703: PetscViewerDrawGetDrawLG(v,0,&lg);
3704: if (!n) {PetscDrawLGReset(lg);}
3705: PetscDrawLGGetDraw(lg,&draw);
3706: PetscDrawSetTitle(draw,"Residual norm");
3707: x = (PetscReal)n;
3708: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3709: else y = -15.0;
3710: PetscDrawLGAddPoint(lg,&x,&y);
3711: if (n < 20 || !(n % 5) || snes->reason) {
3712: PetscDrawLGDraw(lg);
3713: PetscDrawLGSave(lg);
3714: }
3716: PetscViewerDrawGetDrawLG(v,1,&lg);
3717: if (!n) {PetscDrawLGReset(lg);}
3718: PetscDrawLGGetDraw(lg,&draw);
3719: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3720: SNESMonitorRange_Private(snes,n,&per);
3721: x = (PetscReal)n;
3722: y = 100.0*per;
3723: PetscDrawLGAddPoint(lg,&x,&y);
3724: if (n < 20 || !(n % 5) || snes->reason) {
3725: PetscDrawLGDraw(lg);
3726: PetscDrawLGSave(lg);
3727: }
3729: PetscViewerDrawGetDrawLG(v,2,&lg);
3730: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3731: PetscDrawLGGetDraw(lg,&draw);
3732: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3733: x = (PetscReal)n;
3734: y = (prev - rnorm)/prev;
3735: PetscDrawLGAddPoint(lg,&x,&y);
3736: if (n < 20 || !(n % 5) || snes->reason) {
3737: PetscDrawLGDraw(lg);
3738: PetscDrawLGSave(lg);
3739: }
3741: PetscViewerDrawGetDrawLG(v,3,&lg);
3742: if (!n) {PetscDrawLGReset(lg);}
3743: PetscDrawLGGetDraw(lg,&draw);
3744: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3745: x = (PetscReal)n;
3746: y = (prev - rnorm)/(prev*per);
3747: if (n > 2) { /*skip initial crazy value */
3748: PetscDrawLGAddPoint(lg,&x,&y);
3749: }
3750: if (n < 20 || !(n % 5) || snes->reason) {
3751: PetscDrawLGDraw(lg);
3752: PetscDrawLGSave(lg);
3753: }
3754: prev = rnorm;
3755: return(0);
3756: }
3758: /*@
3759: SNESMonitor - runs the user provided monitor routines, if they exist
3761: Collective on SNES
3763: Input Parameters:
3764: + snes - nonlinear solver context obtained from SNESCreate()
3765: . iter - iteration number
3766: - rnorm - relative norm of the residual
3768: Notes:
3769: This routine is called by the SNES implementations.
3770: It does not typically need to be called by the user.
3772: Level: developer
3774: .seealso: SNESMonitorSet()
3775: @*/
3776: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3777: {
3779: PetscInt i,n = snes->numbermonitors;
3782: VecLockReadPush(snes->vec_sol);
3783: for (i=0; i<n; i++) {
3784: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3785: }
3786: VecLockReadPop(snes->vec_sol);
3787: return(0);
3788: }
3790: /* ------------ Routines to set performance monitoring options ----------- */
3792: /*MC
3793: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3795: Synopsis:
3796: #include <petscsnes.h>
3797: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3799: + snes - the SNES context
3800: . its - iteration number
3801: . norm - 2-norm function value (may be estimated)
3802: - mctx - [optional] monitoring context
3804: Level: advanced
3806: .seealso: SNESMonitorSet(), SNESMonitorGet()
3807: M*/
3809: /*@C
3810: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3811: iteration of the nonlinear solver to display the iteration's
3812: progress.
3814: Logically Collective on SNES
3816: Input Parameters:
3817: + snes - the SNES context
3818: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3819: . mctx - [optional] user-defined context for private data for the
3820: monitor routine (use NULL if no context is desired)
3821: - monitordestroy - [optional] routine that frees monitor context
3822: (may be NULL)
3824: Options Database Keys:
3825: + -snes_monitor - sets SNESMonitorDefault()
3826: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3827: uses SNESMonitorLGCreate()
3828: - -snes_monitor_cancel - cancels all monitors that have
3829: been hardwired into a code by
3830: calls to SNESMonitorSet(), but
3831: does not cancel those set via
3832: the options database.
3834: Notes:
3835: Several different monitoring routines may be set by calling
3836: SNESMonitorSet() multiple times; all will be called in the
3837: order in which they were set.
3839: Fortran Notes:
3840: Only a single monitor function can be set for each SNES object
3842: Level: intermediate
3844: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3845: @*/
3846: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3847: {
3848: PetscInt i;
3850: PetscBool identical;
3854: for (i=0; i<snes->numbermonitors;i++) {
3855: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3856: if (identical) return(0);
3857: }
3858: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3859: snes->monitor[snes->numbermonitors] = f;
3860: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3861: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3862: return(0);
3863: }
3865: /*@
3866: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3868: Logically Collective on SNES
3870: Input Parameters:
3871: . snes - the SNES context
3873: Options Database Key:
3874: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3875: into a code by calls to SNESMonitorSet(), but does not cancel those
3876: set via the options database
3878: Notes:
3879: There is no way to clear one specific monitor from a SNES object.
3881: Level: intermediate
3883: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3884: @*/
3885: PetscErrorCode SNESMonitorCancel(SNES snes)
3886: {
3888: PetscInt i;
3892: for (i=0; i<snes->numbermonitors; i++) {
3893: if (snes->monitordestroy[i]) {
3894: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3895: }
3896: }
3897: snes->numbermonitors = 0;
3898: return(0);
3899: }
3901: /*MC
3902: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3904: Synopsis:
3905: #include <petscsnes.h>
3906: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3908: + snes - the SNES context
3909: . it - current iteration (0 is the first and is before any Newton step)
3910: . cctx - [optional] convergence context
3911: . reason - reason for convergence/divergence
3912: . xnorm - 2-norm of current iterate
3913: . gnorm - 2-norm of current step
3914: - f - 2-norm of function
3916: Level: intermediate
3918: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3919: M*/
3921: /*@C
3922: SNESSetConvergenceTest - Sets the function that is to be used
3923: to test for convergence of the nonlinear iterative solution.
3925: Logically Collective on SNES
3927: Input Parameters:
3928: + snes - the SNES context
3929: . SNESConvergenceTestFunction - routine to test for convergence
3930: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3931: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
3933: Level: advanced
3935: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3936: @*/
3937: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3938: {
3943: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3944: if (snes->ops->convergeddestroy) {
3945: (*snes->ops->convergeddestroy)(snes->cnvP);
3946: }
3947: snes->ops->converged = SNESConvergenceTestFunction;
3948: snes->ops->convergeddestroy = destroy;
3949: snes->cnvP = cctx;
3950: return(0);
3951: }
3953: /*@
3954: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
3956: Not Collective
3958: Input Parameter:
3959: . snes - the SNES context
3961: Output Parameter:
3962: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3963: manual pages for the individual convergence tests for complete lists
3965: Options Database:
3966: . -snes_converged_reason - prints the reason to standard out
3968: Level: intermediate
3970: Notes:
3971: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
3973: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
3974: @*/
3975: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
3976: {
3980: *reason = snes->reason;
3981: return(0);
3982: }
3984: /*@
3985: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
3987: Not Collective
3989: Input Parameters:
3990: + snes - the SNES context
3991: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3992: manual pages for the individual convergence tests for complete lists
3994: Level: intermediate
3996: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
3997: @*/
3998: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
3999: {
4002: snes->reason = reason;
4003: return(0);
4004: }
4006: /*@
4007: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4009: Logically Collective on SNES
4011: Input Parameters:
4012: + snes - iterative context obtained from SNESCreate()
4013: . a - array to hold history, this array will contain the function norms computed at each step
4014: . its - integer array holds the number of linear iterations for each solve.
4015: . na - size of a and its
4016: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4017: else it continues storing new values for new nonlinear solves after the old ones
4019: Notes:
4020: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4021: default array of length 10000 is allocated.
4023: This routine is useful, e.g., when running a code for purposes
4024: of accurate performance monitoring, when no I/O should be done
4025: during the section of code that is being timed.
4027: Level: intermediate
4029: .seealso: SNESGetConvergenceHistory()
4031: @*/
4032: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4033: {
4040: if (!a) {
4041: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4042: PetscCalloc2(na,&a,na,&its);
4043: snes->conv_hist_alloc = PETSC_TRUE;
4044: }
4045: snes->conv_hist = a;
4046: snes->conv_hist_its = its;
4047: snes->conv_hist_max = na;
4048: snes->conv_hist_len = 0;
4049: snes->conv_hist_reset = reset;
4050: return(0);
4051: }
4053: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4054: #include <engine.h> /* MATLAB include file */
4055: #include <mex.h> /* MATLAB include file */
4057: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4058: {
4059: mxArray *mat;
4060: PetscInt i;
4061: PetscReal *ar;
4064: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4065: ar = (PetscReal*) mxGetData(mat);
4066: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4067: PetscFunctionReturn(mat);
4068: }
4069: #endif
4071: /*@C
4072: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4074: Not Collective
4076: Input Parameter:
4077: . snes - iterative context obtained from SNESCreate()
4079: Output Parameters:
4080: . a - array to hold history
4081: . its - integer array holds the number of linear iterations (or
4082: negative if not converged) for each solve.
4083: - na - size of a and its
4085: Notes:
4086: The calling sequence for this routine in Fortran is
4087: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4089: This routine is useful, e.g., when running a code for purposes
4090: of accurate performance monitoring, when no I/O should be done
4091: during the section of code that is being timed.
4093: Level: intermediate
4095: .seealso: SNESSetConvergencHistory()
4097: @*/
4098: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4099: {
4102: if (a) *a = snes->conv_hist;
4103: if (its) *its = snes->conv_hist_its;
4104: if (na) *na = snes->conv_hist_len;
4105: return(0);
4106: }
4108: /*@C
4109: SNESSetUpdate - Sets the general-purpose update function called
4110: at the beginning of every iteration of the nonlinear solve. Specifically
4111: it is called just before the Jacobian is "evaluated".
4113: Logically Collective on SNES
4115: Input Parameters:
4116: . snes - The nonlinear solver context
4117: . func - The function
4119: Calling sequence of func:
4120: . func (SNES snes, PetscInt step);
4122: . step - The current step of the iteration
4124: Level: advanced
4126: 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()
4127: This is not used by most users.
4129: .seealso SNESSetJacobian(), SNESSolve()
4130: @*/
4131: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4132: {
4135: snes->ops->update = func;
4136: return(0);
4137: }
4139: /*
4140: SNESScaleStep_Private - Scales a step so that its length is less than the
4141: positive parameter delta.
4143: Input Parameters:
4144: + snes - the SNES context
4145: . y - approximate solution of linear system
4146: . fnorm - 2-norm of current function
4147: - delta - trust region size
4149: Output Parameters:
4150: + gpnorm - predicted function norm at the new point, assuming local
4151: linearization. The value is zero if the step lies within the trust
4152: region, and exceeds zero otherwise.
4153: - ynorm - 2-norm of the step
4155: Note:
4156: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4157: is set to be the maximum allowable step size.
4159: */
4160: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4161: {
4162: PetscReal nrm;
4163: PetscScalar cnorm;
4171: VecNorm(y,NORM_2,&nrm);
4172: if (nrm > *delta) {
4173: nrm = *delta/nrm;
4174: *gpnorm = (1.0 - nrm)*(*fnorm);
4175: cnorm = nrm;
4176: VecScale(y,cnorm);
4177: *ynorm = *delta;
4178: } else {
4179: *gpnorm = 0.0;
4180: *ynorm = nrm;
4181: }
4182: return(0);
4183: }
4185: /*@
4186: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4188: Collective on SNES
4190: Parameter:
4191: + snes - iterative context obtained from SNESCreate()
4192: - viewer - the viewer to display the reason
4195: Options Database Keys:
4196: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4198: Level: beginner
4200: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4202: @*/
4203: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4204: {
4205: PetscViewerFormat format;
4206: PetscBool isAscii;
4207: PetscErrorCode ierr;
4210: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4211: if (isAscii) {
4212: PetscViewerGetFormat(viewer, &format);
4213: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4214: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4215: DM dm;
4216: Vec u;
4217: PetscDS prob;
4218: PetscInt Nf, f;
4219: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4220: void **exactCtx;
4221: PetscReal error;
4223: SNESGetDM(snes, &dm);
4224: SNESGetSolution(snes, &u);
4225: DMGetDS(dm, &prob);
4226: PetscDSGetNumFields(prob, &Nf);
4227: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4228: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4229: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4230: PetscFree2(exactSol, exactCtx);
4231: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4232: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4233: }
4234: if (snes->reason > 0) {
4235: if (((PetscObject) snes)->prefix) {
4236: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4237: } else {
4238: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4239: }
4240: } else {
4241: if (((PetscObject) snes)->prefix) {
4242: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4243: } else {
4244: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4245: }
4246: }
4247: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4248: }
4249: return(0);
4250: }
4252: /*@C
4253: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4255: Collective on SNES
4257: Input Parameters:
4258: . snes - the SNES object
4260: Level: intermediate
4262: @*/
4263: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4264: {
4265: PetscErrorCode ierr;
4266: PetscViewer viewer;
4267: PetscBool flg;
4268: static PetscBool incall = PETSC_FALSE;
4269: PetscViewerFormat format;
4272: if (incall) return(0);
4273: incall = PETSC_TRUE;
4274: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4275: if (flg) {
4276: PetscViewerPushFormat(viewer,format);
4277: SNESReasonView(snes,viewer);
4278: PetscViewerPopFormat(viewer);
4279: PetscViewerDestroy(&viewer);
4280: }
4281: incall = PETSC_FALSE;
4282: return(0);
4283: }
4285: /*@
4286: SNESSolve - Solves a nonlinear system F(x) = b.
4287: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4289: Collective on SNES
4291: Input Parameters:
4292: + snes - the SNES context
4293: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4294: - x - the solution vector.
4296: Notes:
4297: The user should initialize the vector,x, with the initial guess
4298: for the nonlinear solve prior to calling SNESSolve. In particular,
4299: to employ an initial guess of zero, the user should explicitly set
4300: this vector to zero by calling VecSet().
4302: Level: beginner
4304: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4305: @*/
4306: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4307: {
4308: PetscErrorCode ierr;
4309: PetscBool flg;
4310: PetscInt grid;
4311: Vec xcreated = NULL;
4312: DM dm;
4321: /* High level operations using the nonlinear solver */
4322: {
4323: PetscViewer viewer;
4324: PetscViewerFormat format;
4325: PetscInt num;
4326: PetscBool flg;
4327: static PetscBool incall = PETSC_FALSE;
4329: if (!incall) {
4330: /* Estimate the convergence rate of the discretization */
4331: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4332: if (flg) {
4333: PetscConvEst conv;
4334: DM dm;
4335: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4336: PetscInt Nf;
4338: incall = PETSC_TRUE;
4339: SNESGetDM(snes, &dm);
4340: DMGetNumFields(dm, &Nf);
4341: PetscCalloc1(Nf, &alpha);
4342: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4343: PetscConvEstSetSolver(conv, snes);
4344: PetscConvEstSetFromOptions(conv);
4345: PetscConvEstSetUp(conv);
4346: PetscConvEstGetConvRate(conv, alpha);
4347: PetscViewerPushFormat(viewer, format);
4348: PetscConvEstRateView(conv, alpha, viewer);
4349: PetscViewerPopFormat(viewer);
4350: PetscViewerDestroy(&viewer);
4351: PetscConvEstDestroy(&conv);
4352: PetscFree(alpha);
4353: incall = PETSC_FALSE;
4354: }
4355: /* Adaptively refine the initial grid */
4356: num = 1;
4357: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4358: if (flg) {
4359: DMAdaptor adaptor;
4361: incall = PETSC_TRUE;
4362: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4363: DMAdaptorSetSolver(adaptor, snes);
4364: DMAdaptorSetSequenceLength(adaptor, num);
4365: DMAdaptorSetFromOptions(adaptor);
4366: DMAdaptorSetUp(adaptor);
4367: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4368: DMAdaptorDestroy(&adaptor);
4369: incall = PETSC_FALSE;
4370: }
4371: /* Use grid sequencing to adapt */
4372: num = 0;
4373: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4374: if (num) {
4375: DMAdaptor adaptor;
4377: incall = PETSC_TRUE;
4378: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4379: DMAdaptorSetSolver(adaptor, snes);
4380: DMAdaptorSetSequenceLength(adaptor, num);
4381: DMAdaptorSetFromOptions(adaptor);
4382: DMAdaptorSetUp(adaptor);
4383: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4384: DMAdaptorDestroy(&adaptor);
4385: incall = PETSC_FALSE;
4386: }
4387: }
4388: }
4389: if (!x) {
4390: SNESGetDM(snes,&dm);
4391: DMCreateGlobalVector(dm,&xcreated);
4392: x = xcreated;
4393: }
4394: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4396: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4397: for (grid=0; grid<snes->gridsequence+1; grid++) {
4399: /* set solution vector */
4400: if (!grid) {PetscObjectReference((PetscObject)x);}
4401: VecDestroy(&snes->vec_sol);
4402: snes->vec_sol = x;
4403: SNESGetDM(snes,&dm);
4405: /* set affine vector if provided */
4406: if (b) { PetscObjectReference((PetscObject)b); }
4407: VecDestroy(&snes->vec_rhs);
4408: snes->vec_rhs = b;
4410: 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");
4411: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4412: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4413: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4414: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4415: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4416: }
4417: DMShellSetGlobalVector(dm,snes->vec_sol);
4418: SNESSetUp(snes);
4420: if (!grid) {
4421: if (snes->ops->computeinitialguess) {
4422: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4423: }
4424: }
4426: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4427: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4429: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4430: (*snes->ops->solve)(snes);
4431: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4432: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4433: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4435: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4436: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4438: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4439: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4440: SNESReasonViewFromOptions(snes);
4442: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4443: if (snes->reason < 0) break;
4444: if (grid < snes->gridsequence) {
4445: DM fine;
4446: Vec xnew;
4447: Mat interp;
4449: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4450: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4451: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4452: DMCreateGlobalVector(fine,&xnew);
4453: MatInterpolate(interp,x,xnew);
4454: DMInterpolate(snes->dm,interp,fine);
4455: MatDestroy(&interp);
4456: x = xnew;
4458: SNESReset(snes);
4459: SNESSetDM(snes,fine);
4460: SNESResetFromOptions(snes);
4461: DMDestroy(&fine);
4462: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4463: }
4464: }
4465: SNESViewFromOptions(snes,NULL,"-snes_view");
4466: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4468: VecDestroy(&xcreated);
4469: PetscObjectSAWsBlock((PetscObject)snes);
4470: return(0);
4471: }
4473: /* --------- Internal routines for SNES Package --------- */
4475: /*@C
4476: SNESSetType - Sets the method for the nonlinear solver.
4478: Collective on SNES
4480: Input Parameters:
4481: + snes - the SNES context
4482: - type - a known method
4484: Options Database Key:
4485: . -snes_type <type> - Sets the method; use -help for a list
4486: of available methods (for instance, newtonls or newtontr)
4488: Notes:
4489: See "petsc/include/petscsnes.h" for available methods (for instance)
4490: + SNESNEWTONLS - Newton's method with line search
4491: (systems of nonlinear equations)
4492: . SNESNEWTONTR - Newton's method with trust region
4493: (systems of nonlinear equations)
4495: Normally, it is best to use the SNESSetFromOptions() command and then
4496: set the SNES solver type from the options database rather than by using
4497: this routine. Using the options database provides the user with
4498: maximum flexibility in evaluating the many nonlinear solvers.
4499: The SNESSetType() routine is provided for those situations where it
4500: is necessary to set the nonlinear solver independently of the command
4501: line or options database. This might be the case, for example, when
4502: the choice of solver changes during the execution of the program,
4503: and the user's application is taking responsibility for choosing the
4504: appropriate method.
4506: Developer Notes:
4507: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4508: the constructor in that list and calls it to create the spexific object.
4510: Level: intermediate
4512: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4514: @*/
4515: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4516: {
4517: PetscErrorCode ierr,(*r)(SNES);
4518: PetscBool match;
4524: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4525: if (match) return(0);
4527: PetscFunctionListFind(SNESList,type,&r);
4528: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4529: /* Destroy the previous private SNES context */
4530: if (snes->ops->destroy) {
4531: (*(snes)->ops->destroy)(snes);
4532: snes->ops->destroy = NULL;
4533: }
4534: /* Reinitialize function pointers in SNESOps structure */
4535: snes->ops->setup = 0;
4536: snes->ops->solve = 0;
4537: snes->ops->view = 0;
4538: snes->ops->setfromoptions = 0;
4539: snes->ops->destroy = 0;
4540: SNESLineSearchDestroy(&snes->linesearch);
4541: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4542: snes->setupcalled = PETSC_FALSE;
4544: PetscObjectChangeTypeName((PetscObject)snes,type);
4545: (*r)(snes);
4546: return(0);
4547: }
4549: /*@C
4550: SNESGetType - Gets the SNES method type and name (as a string).
4552: Not Collective
4554: Input Parameter:
4555: . snes - nonlinear solver context
4557: Output Parameter:
4558: . type - SNES method (a character string)
4560: Level: intermediate
4562: @*/
4563: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4564: {
4568: *type = ((PetscObject)snes)->type_name;
4569: return(0);
4570: }
4572: /*@
4573: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4575: Logically Collective on SNES
4577: Input Parameters:
4578: + snes - the SNES context obtained from SNESCreate()
4579: - u - the solution vector
4581: Level: beginner
4583: @*/
4584: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4585: {
4586: DM dm;
4592: PetscObjectReference((PetscObject) u);
4593: VecDestroy(&snes->vec_sol);
4595: snes->vec_sol = u;
4597: SNESGetDM(snes, &dm);
4598: DMShellSetGlobalVector(dm, u);
4599: return(0);
4600: }
4602: /*@
4603: SNESGetSolution - Returns the vector where the approximate solution is
4604: stored. This is the fine grid solution when using SNESSetGridSequence().
4606: Not Collective, but Vec is parallel if SNES is parallel
4608: Input Parameter:
4609: . snes - the SNES context
4611: Output Parameter:
4612: . x - the solution
4614: Level: intermediate
4616: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4617: @*/
4618: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4619: {
4623: *x = snes->vec_sol;
4624: return(0);
4625: }
4627: /*@
4628: SNESGetSolutionUpdate - Returns the vector where the solution update is
4629: stored.
4631: Not Collective, but Vec is parallel if SNES is parallel
4633: Input Parameter:
4634: . snes - the SNES context
4636: Output Parameter:
4637: . x - the solution update
4639: Level: advanced
4641: .seealso: SNESGetSolution(), SNESGetFunction()
4642: @*/
4643: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4644: {
4648: *x = snes->vec_sol_update;
4649: return(0);
4650: }
4652: /*@C
4653: SNESGetFunction - Returns the vector where the function is stored.
4655: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4657: Input Parameter:
4658: . snes - the SNES context
4660: Output Parameter:
4661: + r - the vector that is used to store residuals (or NULL if you don't want it)
4662: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4663: - ctx - the function context (or NULL if you don't want it)
4665: Level: advanced
4667: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4669: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4670: @*/
4671: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4672: {
4674: DM dm;
4678: if (r) {
4679: if (!snes->vec_func) {
4680: if (snes->vec_rhs) {
4681: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4682: } else if (snes->vec_sol) {
4683: VecDuplicate(snes->vec_sol,&snes->vec_func);
4684: } else if (snes->dm) {
4685: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4686: }
4687: }
4688: *r = snes->vec_func;
4689: }
4690: SNESGetDM(snes,&dm);
4691: DMSNESGetFunction(dm,f,ctx);
4692: return(0);
4693: }
4695: /*@C
4696: SNESGetNGS - Returns the NGS function and context.
4698: Input Parameter:
4699: . snes - the SNES context
4701: Output Parameter:
4702: + f - the function (or NULL) see SNESNGSFunction for details
4703: - ctx - the function context (or NULL)
4705: Level: advanced
4707: .seealso: SNESSetNGS(), SNESGetFunction()
4708: @*/
4710: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4711: {
4713: DM dm;
4717: SNESGetDM(snes,&dm);
4718: DMSNESGetNGS(dm,f,ctx);
4719: return(0);
4720: }
4722: /*@C
4723: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4724: SNES options in the database.
4726: Logically Collective on SNES
4728: Input Parameter:
4729: + snes - the SNES context
4730: - prefix - the prefix to prepend to all option names
4732: Notes:
4733: A hyphen (-) must NOT be given at the beginning of the prefix name.
4734: The first character of all runtime options is AUTOMATICALLY the hyphen.
4736: Level: advanced
4738: .seealso: SNESSetFromOptions()
4739: @*/
4740: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4741: {
4746: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4747: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4748: if (snes->linesearch) {
4749: SNESGetLineSearch(snes,&snes->linesearch);
4750: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4751: }
4752: KSPSetOptionsPrefix(snes->ksp,prefix);
4753: return(0);
4754: }
4756: /*@C
4757: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4758: SNES options in the database.
4760: Logically Collective on SNES
4762: Input Parameters:
4763: + snes - the SNES context
4764: - prefix - the prefix to prepend to all option names
4766: Notes:
4767: A hyphen (-) must NOT be given at the beginning of the prefix name.
4768: The first character of all runtime options is AUTOMATICALLY the hyphen.
4770: Level: advanced
4772: .seealso: SNESGetOptionsPrefix()
4773: @*/
4774: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4775: {
4780: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4781: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4782: if (snes->linesearch) {
4783: SNESGetLineSearch(snes,&snes->linesearch);
4784: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4785: }
4786: KSPAppendOptionsPrefix(snes->ksp,prefix);
4787: return(0);
4788: }
4790: /*@C
4791: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4792: SNES options in the database.
4794: Not Collective
4796: Input Parameter:
4797: . snes - the SNES context
4799: Output Parameter:
4800: . prefix - pointer to the prefix string used
4802: Notes:
4803: On the fortran side, the user should pass in a string 'prefix' of
4804: sufficient length to hold the prefix.
4806: Level: advanced
4808: .seealso: SNESAppendOptionsPrefix()
4809: @*/
4810: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4811: {
4816: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4817: return(0);
4818: }
4821: /*@C
4822: SNESRegister - Adds a method to the nonlinear solver package.
4824: Not collective
4826: Input Parameters:
4827: + name_solver - name of a new user-defined solver
4828: - routine_create - routine to create method context
4830: Notes:
4831: SNESRegister() may be called multiple times to add several user-defined solvers.
4833: Sample usage:
4834: .vb
4835: SNESRegister("my_solver",MySolverCreate);
4836: .ve
4838: Then, your solver can be chosen with the procedural interface via
4839: $ SNESSetType(snes,"my_solver")
4840: or at runtime via the option
4841: $ -snes_type my_solver
4843: Level: advanced
4845: Note: If your function is not being put into a shared library then use SNESRegister() instead
4847: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4849: Level: advanced
4850: @*/
4851: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4852: {
4856: SNESInitializePackage();
4857: PetscFunctionListAdd(&SNESList,sname,function);
4858: return(0);
4859: }
4861: PetscErrorCode SNESTestLocalMin(SNES snes)
4862: {
4864: PetscInt N,i,j;
4865: Vec u,uh,fh;
4866: PetscScalar value;
4867: PetscReal norm;
4870: SNESGetSolution(snes,&u);
4871: VecDuplicate(u,&uh);
4872: VecDuplicate(u,&fh);
4874: /* currently only works for sequential */
4875: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4876: VecGetSize(u,&N);
4877: for (i=0; i<N; i++) {
4878: VecCopy(u,uh);
4879: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4880: for (j=-10; j<11; j++) {
4881: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4882: VecSetValue(uh,i,value,ADD_VALUES);
4883: SNESComputeFunction(snes,uh,fh);
4884: VecNorm(fh,NORM_2,&norm);
4885: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4886: value = -value;
4887: VecSetValue(uh,i,value,ADD_VALUES);
4888: }
4889: }
4890: VecDestroy(&uh);
4891: VecDestroy(&fh);
4892: return(0);
4893: }
4895: /*@
4896: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4897: computing relative tolerance for linear solvers within an inexact
4898: Newton method.
4900: Logically Collective on SNES
4902: Input Parameters:
4903: + snes - SNES context
4904: - flag - PETSC_TRUE or PETSC_FALSE
4906: Options Database:
4907: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4908: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4909: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4910: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4911: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4912: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4913: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4914: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4916: Notes:
4917: Currently, the default is to use a constant relative tolerance for
4918: the inner linear solvers. Alternatively, one can use the
4919: Eisenstat-Walker method, where the relative convergence tolerance
4920: is reset at each Newton iteration according progress of the nonlinear
4921: solver.
4923: Level: advanced
4925: Reference:
4926: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4927: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4929: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4930: @*/
4931: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
4932: {
4936: snes->ksp_ewconv = flag;
4937: return(0);
4938: }
4940: /*@
4941: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
4942: for computing relative tolerance for linear solvers within an
4943: inexact Newton method.
4945: Not Collective
4947: Input Parameter:
4948: . snes - SNES context
4950: Output Parameter:
4951: . flag - PETSC_TRUE or PETSC_FALSE
4953: Notes:
4954: Currently, the default is to use a constant relative tolerance for
4955: the inner linear solvers. Alternatively, one can use the
4956: Eisenstat-Walker method, where the relative convergence tolerance
4957: is reset at each Newton iteration according progress of the nonlinear
4958: solver.
4960: Level: advanced
4962: Reference:
4963: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4964: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4966: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4967: @*/
4968: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
4969: {
4973: *flag = snes->ksp_ewconv;
4974: return(0);
4975: }
4977: /*@
4978: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
4979: convergence criteria for the linear solvers within an inexact
4980: Newton method.
4982: Logically Collective on SNES
4984: Input Parameters:
4985: + snes - SNES context
4986: . version - version 1, 2 (default is 2) or 3
4987: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
4988: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
4989: . gamma - multiplicative factor for version 2 rtol computation
4990: (0 <= gamma2 <= 1)
4991: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
4992: . alpha2 - power for safeguard
4993: - threshold - threshold for imposing safeguard (0 < threshold < 1)
4995: Note:
4996: Version 3 was contributed by Luis Chacon, June 2006.
4998: Use PETSC_DEFAULT to retain the default for any of the parameters.
5000: Level: advanced
5002: Reference:
5003: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5004: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5005: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5007: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5008: @*/
5009: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5010: {
5011: SNESKSPEW *kctx;
5015: kctx = (SNESKSPEW*)snes->kspconvctx;
5016: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5025: if (version != PETSC_DEFAULT) kctx->version = version;
5026: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5027: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5028: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5029: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5030: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5031: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5033: 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);
5034: 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);
5035: 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);
5036: 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);
5037: 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);
5038: 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);
5039: return(0);
5040: }
5042: /*@
5043: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5044: convergence criteria for the linear solvers within an inexact
5045: Newton method.
5047: Not Collective
5049: Input Parameters:
5050: snes - SNES context
5052: Output Parameters:
5053: + version - version 1, 2 (default is 2) or 3
5054: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5055: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5056: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5057: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5058: . alpha2 - power for safeguard
5059: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5061: Level: advanced
5063: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5064: @*/
5065: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5066: {
5067: SNESKSPEW *kctx;
5071: kctx = (SNESKSPEW*)snes->kspconvctx;
5072: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5073: if (version) *version = kctx->version;
5074: if (rtol_0) *rtol_0 = kctx->rtol_0;
5075: if (rtol_max) *rtol_max = kctx->rtol_max;
5076: if (gamma) *gamma = kctx->gamma;
5077: if (alpha) *alpha = kctx->alpha;
5078: if (alpha2) *alpha2 = kctx->alpha2;
5079: if (threshold) *threshold = kctx->threshold;
5080: return(0);
5081: }
5083: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5084: {
5086: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5087: PetscReal rtol = PETSC_DEFAULT,stol;
5090: if (!snes->ksp_ewconv) return(0);
5091: if (!snes->iter) {
5092: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5093: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5094: }
5095: else {
5096: if (kctx->version == 1) {
5097: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5098: if (rtol < 0.0) rtol = -rtol;
5099: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5100: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5101: } else if (kctx->version == 2) {
5102: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5103: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5104: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5105: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5106: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5107: /* safeguard: avoid sharp decrease of rtol */
5108: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5109: stol = PetscMax(rtol,stol);
5110: rtol = PetscMin(kctx->rtol_0,stol);
5111: /* safeguard: avoid oversolving */
5112: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5113: stol = PetscMax(rtol,stol);
5114: rtol = PetscMin(kctx->rtol_0,stol);
5115: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5116: }
5117: /* safeguard: avoid rtol greater than one */
5118: rtol = PetscMin(rtol,kctx->rtol_max);
5119: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5120: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5121: return(0);
5122: }
5124: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5125: {
5127: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5128: PCSide pcside;
5129: Vec lres;
5132: if (!snes->ksp_ewconv) return(0);
5133: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5134: kctx->norm_last = snes->norm;
5135: if (kctx->version == 1) {
5136: PC pc;
5137: PetscBool isNone;
5139: KSPGetPC(ksp, &pc);
5140: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5141: KSPGetPCSide(ksp,&pcside);
5142: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5143: /* KSP residual is true linear residual */
5144: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5145: } else {
5146: /* KSP residual is preconditioned residual */
5147: /* compute true linear residual norm */
5148: VecDuplicate(b,&lres);
5149: MatMult(snes->jacobian,x,lres);
5150: VecAYPX(lres,-1.0,b);
5151: VecNorm(lres,NORM_2,&kctx->lresid_last);
5152: VecDestroy(&lres);
5153: }
5154: }
5155: return(0);
5156: }
5158: /*@
5159: SNESGetKSP - Returns the KSP context for a SNES solver.
5161: Not Collective, but if SNES object is parallel, then KSP object is parallel
5163: Input Parameter:
5164: . snes - the SNES context
5166: Output Parameter:
5167: . ksp - the KSP context
5169: Notes:
5170: The user can then directly manipulate the KSP context to set various
5171: options, etc. Likewise, the user can then extract and manipulate the
5172: PC contexts as well.
5174: Level: beginner
5176: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5177: @*/
5178: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5179: {
5186: if (!snes->ksp) {
5187: PetscBool monitor = PETSC_FALSE;
5189: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5190: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5191: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5193: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5194: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5196: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5197: if (monitor) {
5198: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5199: }
5200: monitor = PETSC_FALSE;
5201: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5202: if (monitor) {
5203: PetscObject *objs;
5204: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5205: objs[0] = (PetscObject) snes;
5206: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5207: }
5208: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5209: }
5210: *ksp = snes->ksp;
5211: return(0);
5212: }
5215: #include <petsc/private/dmimpl.h>
5216: /*@
5217: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5219: Logically Collective on SNES
5221: Input Parameters:
5222: + snes - the nonlinear solver context
5223: - dm - the dm, cannot be NULL
5225: Notes:
5226: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5227: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5228: problems using the same function space.
5230: Level: intermediate
5232: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5233: @*/
5234: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5235: {
5237: KSP ksp;
5238: DMSNES sdm;
5243: PetscObjectReference((PetscObject)dm);
5244: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5245: if (snes->dm->dmsnes && !dm->dmsnes) {
5246: DMCopyDMSNES(snes->dm,dm);
5247: DMGetDMSNES(snes->dm,&sdm);
5248: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5249: }
5250: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5251: DMDestroy(&snes->dm);
5252: }
5253: snes->dm = dm;
5254: snes->dmAuto = PETSC_FALSE;
5256: SNESGetKSP(snes,&ksp);
5257: KSPSetDM(ksp,dm);
5258: KSPSetDMActive(ksp,PETSC_FALSE);
5259: if (snes->npc) {
5260: SNESSetDM(snes->npc, snes->dm);
5261: SNESSetNPCSide(snes,snes->npcside);
5262: }
5263: return(0);
5264: }
5266: /*@
5267: SNESGetDM - Gets the DM that may be used by some preconditioners
5269: Not Collective but DM obtained is parallel on SNES
5271: Input Parameter:
5272: . snes - the preconditioner context
5274: Output Parameter:
5275: . dm - the dm
5277: Level: intermediate
5279: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5280: @*/
5281: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5282: {
5287: if (!snes->dm) {
5288: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5289: snes->dmAuto = PETSC_TRUE;
5290: }
5291: *dm = snes->dm;
5292: return(0);
5293: }
5295: /*@
5296: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5298: Collective on SNES
5300: Input Parameters:
5301: + snes - iterative context obtained from SNESCreate()
5302: - pc - the preconditioner object
5304: Notes:
5305: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5306: to configure it using the API).
5308: Level: developer
5310: .seealso: SNESGetNPC(), SNESHasNPC()
5311: @*/
5312: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5313: {
5320: PetscObjectReference((PetscObject) pc);
5321: SNESDestroy(&snes->npc);
5322: snes->npc = pc;
5323: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5324: return(0);
5325: }
5327: /*@
5328: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5330: Not Collective; but any changes to the obtained SNES object must be applied collectively
5332: Input Parameter:
5333: . snes - iterative context obtained from SNESCreate()
5335: Output Parameter:
5336: . pc - preconditioner context
5338: Notes:
5339: If a SNES was previously set with SNESSetNPC() then that SNES is returned.
5341: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5342: SNES during SNESSetUp()
5344: Level: developer
5346: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5347: @*/
5348: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5349: {
5351: const char *optionsprefix;
5356: if (!snes->npc) {
5357: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5358: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5359: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5360: SNESGetOptionsPrefix(snes,&optionsprefix);
5361: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5362: SNESAppendOptionsPrefix(snes->npc,"npc_");
5363: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5364: }
5365: *pc = snes->npc;
5366: return(0);
5367: }
5369: /*@
5370: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5372: Not Collective
5374: Input Parameter:
5375: . snes - iterative context obtained from SNESCreate()
5377: Output Parameter:
5378: . has_npc - whether the SNES has an NPC or not
5380: Level: developer
5382: .seealso: SNESSetNPC(), SNESGetNPC()
5383: @*/
5384: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5385: {
5388: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5389: return(0);
5390: }
5392: /*@
5393: SNESSetNPCSide - Sets the preconditioning side.
5395: Logically Collective on SNES
5397: Input Parameter:
5398: . snes - iterative context obtained from SNESCreate()
5400: Output Parameter:
5401: . side - the preconditioning side, where side is one of
5402: .vb
5403: PC_LEFT - left preconditioning
5404: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5405: .ve
5407: Options Database Keys:
5408: . -snes_pc_side <right,left>
5410: Notes:
5411: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5413: Level: intermediate
5415: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5416: @*/
5417: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5418: {
5422: snes->npcside= side;
5423: return(0);
5424: }
5426: /*@
5427: SNESGetNPCSide - Gets the preconditioning side.
5429: Not Collective
5431: Input Parameter:
5432: . snes - iterative context obtained from SNESCreate()
5434: Output Parameter:
5435: . side - the preconditioning side, where side is one of
5436: .vb
5437: PC_LEFT - left preconditioning
5438: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5439: .ve
5441: Level: intermediate
5443: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5444: @*/
5445: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5446: {
5450: *side = snes->npcside;
5451: return(0);
5452: }
5454: /*@
5455: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5457: Collective on SNES
5459: Input Parameters:
5460: + snes - iterative context obtained from SNESCreate()
5461: - linesearch - the linesearch object
5463: Notes:
5464: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5465: to configure it using the API).
5467: Level: developer
5469: .seealso: SNESGetLineSearch()
5470: @*/
5471: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5472: {
5479: PetscObjectReference((PetscObject) linesearch);
5480: SNESLineSearchDestroy(&snes->linesearch);
5482: snes->linesearch = linesearch;
5484: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5485: return(0);
5486: }
5488: /*@
5489: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5490: or creates a default line search instance associated with the SNES and returns it.
5492: Not Collective
5494: Input Parameter:
5495: . snes - iterative context obtained from SNESCreate()
5497: Output Parameter:
5498: . linesearch - linesearch context
5500: Level: beginner
5502: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5503: @*/
5504: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5505: {
5507: const char *optionsprefix;
5512: if (!snes->linesearch) {
5513: SNESGetOptionsPrefix(snes, &optionsprefix);
5514: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5515: SNESLineSearchSetSNES(snes->linesearch, snes);
5516: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5517: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5518: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5519: }
5520: *linesearch = snes->linesearch;
5521: return(0);
5522: }