Actual source code: snes.c
petsc-master 2019-12-03
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_Setup, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes SNESSolve() to generate an error if the solver has not converged.
18: Logically Collective on SNES
20: Input Parameters:
21: + snes - iterative context obtained from SNESCreate()
22: - flg - PETSC_TRUE indicates you want the error generated
24: Options database keys:
25: . -snes_error_if_not_converged : this takes an optional truth value (0/1/no/yes/true/false)
27: Level: intermediate
29: Notes:
30: Normally PETSc continues if a linear solver fails to converge, you can call SNESGetConvergedReason() after a SNESSolve()
31: to determine if it has converged.
33: .seealso: SNESGetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes,PetscBool flg)
36: {
40: snes->errorifnotconverged = flg;
41: return(0);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Will SNESSolve() generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from SNESCreate()
52: Output Parameter:
53: . flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE
55: Level: intermediate
57: .seealso: SNESSetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes,PetscBool *flag)
60: {
64: *flag = snes->errorifnotconverged;
65: return(0);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
71: Logically Collective on SNES
73: Input Parameters:
74: + snes - the shell SNES
75: - flg - is the residual computed?
77: Level: advanced
79: .seealso: SNESGetAlwaysComputesFinalResidual()
80: @*/
81: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
82: {
85: snes->alwayscomputesfinalresidual = flg;
86: return(0);
87: }
89: /*@
90: SNESGetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
92: Logically Collective on SNES
94: Input Parameter:
95: . snes - the shell SNES
97: Output Parameter:
98: . flg - is the residual computed?
100: Level: advanced
102: .seealso: SNESSetAlwaysComputesFinalResidual()
103: @*/
104: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
105: {
108: *flg = snes->alwayscomputesfinalresidual;
109: return(0);
110: }
112: /*@
113: SNESSetFunctionDomainError - tells SNES that the input vector to your SNESFunction is not
114: in the functions domain. For example, negative pressure.
116: Logically Collective on SNES
118: Input Parameters:
119: . snes - the SNES context
121: Level: advanced
123: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction
124: @*/
125: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
126: {
129: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates input vector is not in the function domain");
130: snes->domainerror = PETSC_TRUE;
131: return(0);
132: }
134: /*@
135: SNESSetJacobianDomainError - tells SNES that computeJacobian does not make sense any more. For example there is a negative element transformation.
137: Logically Collective on SNES
139: Input Parameters:
140: . snes - the SNES context
142: Level: advanced
144: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError()
145: @*/
146: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
147: {
150: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates computeJacobian does not make sense");
151: snes->jacobiandomainerror = PETSC_TRUE;
152: return(0);
153: }
155: /*@
156: SNESSetCheckJacobianDomainError - if or not to check jacobian domain error after each Jacobian evaluation. By default, we check Jacobian domain error
157: in the debug mode, and do not check it in the optimized mode.
159: Logically Collective on SNES
161: Input Parameters:
162: + snes - the SNES context
163: - flg - indicates if or not to check jacobian domain error after each Jacobian evaluation
165: Level: advanced
167: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESGetCheckJacobianDomainError()
168: @*/
169: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
170: {
173: snes->checkjacdomainerror = flg;
174: return(0);
175: }
177: /*@
178: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
180: Logically Collective on SNES
182: Input Parameters:
183: . snes - the SNES context
185: Output Parameters:
186: . flg - PETSC_FALSE indicates that we don't check jacobian domain errors after each Jacobian evaluation
188: Level: advanced
190: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESSetCheckJacobianDomainError()
191: @*/
192: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
193: {
197: *flg = snes->checkjacdomainerror;
198: return(0);
199: }
201: /*@
202: SNESGetFunctionDomainError - Gets the status of the domain error after a call to SNESComputeFunction;
204: Logically Collective on SNES
206: Input Parameters:
207: . snes - the SNES context
209: Output Parameters:
210: . domainerror - Set to PETSC_TRUE if there's a domain error; PETSC_FALSE otherwise.
212: Level: advanced
214: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction()
215: @*/
216: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
217: {
221: *domainerror = snes->domainerror;
222: return(0);
223: }
225: /*@
226: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to SNESComputeJacobian;
228: Logically Collective on SNES
230: Input Parameters:
231: . snes - the SNES context
233: Output Parameters:
234: . domainerror - Set to PETSC_TRUE if there's a jacobian domain error; PETSC_FALSE otherwise.
236: Level: advanced
238: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction(),SNESGetFunctionDomainError()
239: @*/
240: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
241: {
245: *domainerror = snes->jacobiandomainerror;
246: return(0);
247: }
249: /*@C
250: SNESLoad - Loads a SNES that has been stored in binary with SNESView().
252: Collective on PetscViewer
254: Input Parameters:
255: + newdm - the newly loaded SNES, this needs to have been created with SNESCreate() or
256: some related function before a call to SNESLoad().
257: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
259: Level: intermediate
261: Notes:
262: The type is determined by the data in the file, any type set into the SNES before this call is ignored.
264: Notes for advanced users:
265: Most users should not need to know the details of the binary storage
266: format, since SNESLoad() and TSView() completely hide these details.
267: But for anyone who's interested, the standard binary matrix storage
268: format is
269: .vb
270: has not yet been determined
271: .ve
273: .seealso: PetscViewerBinaryOpen(), SNESView(), MatLoad(), VecLoad()
274: @*/
275: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
276: {
278: PetscBool isbinary;
279: PetscInt classid;
280: char type[256];
281: KSP ksp;
282: DM dm;
283: DMSNES dmsnes;
288: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
289: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
291: PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
292: if (classid != SNES_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONG,"Not SNES next in file");
293: PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
294: SNESSetType(snes, type);
295: if (snes->ops->load) {
296: (*snes->ops->load)(snes,viewer);
297: }
298: SNESGetDM(snes,&dm);
299: DMGetDMSNES(dm,&dmsnes);
300: DMSNESLoad(dmsnes,viewer);
301: SNESGetKSP(snes,&ksp);
302: KSPLoad(ksp,viewer);
303: return(0);
304: }
306: #include <petscdraw.h>
307: #if defined(PETSC_HAVE_SAWS)
308: #include <petscviewersaws.h>
309: #endif
311: /*@C
312: SNESViewFromOptions - View from Options
314: Collective on SNES
316: Input Parameters:
317: + A - the application ordering context
318: . obj - Optional object
319: - name - command line option
321: Level: intermediate
322: .seealso: SNES, SNESView, PetscObjectViewFromOptions(), SNESCreate()
323: @*/
324: PetscErrorCode SNESViewFromOptions(SNES A,PetscObject obj,const char name[])
325: {
330: PetscObjectViewFromOptions((PetscObject)A,obj,name);
331: return(0);
332: }
334: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES,Vec,Mat,Mat,void*);
336: /*@C
337: SNESView - Prints the SNES data structure.
339: Collective on SNES
341: Input Parameters:
342: + SNES - the SNES context
343: - viewer - visualization context
345: Options Database Key:
346: . -snes_view - Calls SNESView() at end of SNESSolve()
348: Notes:
349: The available visualization contexts include
350: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
351: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
352: output where only the first processor opens
353: the file. All other processors send their
354: data to the first processor to print.
356: The user can open an alternative visualization context with
357: PetscViewerASCIIOpen() - output to a specified file.
359: Level: beginner
361: .seealso: PetscViewerASCIIOpen()
362: @*/
363: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
364: {
365: SNESKSPEW *kctx;
367: KSP ksp;
368: SNESLineSearch linesearch;
369: PetscBool iascii,isstring,isbinary,isdraw;
370: DMSNES dmsnes;
371: #if defined(PETSC_HAVE_SAWS)
372: PetscBool issaws;
373: #endif
377: if (!viewer) {
378: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
379: }
383: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
384: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
385: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
386: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
387: #if defined(PETSC_HAVE_SAWS)
388: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
389: #endif
390: if (iascii) {
391: SNESNormSchedule normschedule;
392: DM dm;
393: PetscErrorCode (*cJ)(SNES,Vec,Mat,Mat,void*);
394: void *ctx;
395: const char *pre = "";
397: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
398: if (!snes->setupcalled) {
399: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
400: }
401: if (snes->ops->view) {
402: PetscViewerASCIIPushTab(viewer);
403: (*snes->ops->view)(snes,viewer);
404: PetscViewerASCIIPopTab(viewer);
405: }
406: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
407: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
408: if (snes->usesksp) {
409: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
410: }
411: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
412: SNESGetNormSchedule(snes, &normschedule);
413: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
414: if (snes->gridsequence) {
415: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
416: }
417: if (snes->ksp_ewconv) {
418: kctx = (SNESKSPEW*)snes->kspconvctx;
419: if (kctx) {
420: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
421: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
422: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
423: }
424: }
425: if (snes->lagpreconditioner == -1) {
426: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
427: } else if (snes->lagpreconditioner > 1) {
428: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
429: }
430: if (snes->lagjacobian == -1) {
431: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
432: } else if (snes->lagjacobian > 1) {
433: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
434: }
435: SNESGetDM(snes,&dm);
436: DMSNESGetJacobian(dm,&cJ,&ctx);
437: if (snes->mf_operator) {
438: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing\n");
439: pre = "Preconditioning ";
440: }
441: if (cJ == SNESComputeJacobianDefault) {
442: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences one column at a time\n",pre);
443: } else if (cJ == SNESComputeJacobianDefaultColor) {
444: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences with coloring\n",pre);
445: /* it slightly breaks data encapsulation for access the DMDA information directly */
446: } else if (cJ == SNESComputeJacobian_DMDA) {
447: MatFDColoring fdcoloring;
448: PetscObjectQuery((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject*)&fdcoloring);
449: if (fdcoloring) {
450: PetscViewerASCIIPrintf(viewer," %sJacobian is built using colored finite differences on a DMDA\n",pre);
451: } else {
452: PetscViewerASCIIPrintf(viewer," %sJacobian is built using a DMDA local Jacobian\n",pre);
453: }
454: } else if (snes->mf) {
455: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing, no explict Jacobian\n");
456: }
457: } else if (isstring) {
458: const char *type;
459: SNESGetType(snes,&type);
460: PetscViewerStringSPrintf(viewer," SNESType: %-7.7s",type);
461: if (snes->ops->view) {(*snes->ops->view)(snes,viewer);}
462: } else if (isbinary) {
463: PetscInt classid = SNES_FILE_CLASSID;
464: MPI_Comm comm;
465: PetscMPIInt rank;
466: char type[256];
468: PetscObjectGetComm((PetscObject)snes,&comm);
469: MPI_Comm_rank(comm,&rank);
470: if (!rank) {
471: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
472: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
473: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR,PETSC_FALSE);
474: }
475: if (snes->ops->view) {
476: (*snes->ops->view)(snes,viewer);
477: }
478: } else if (isdraw) {
479: PetscDraw draw;
480: char str[36];
481: PetscReal x,y,bottom,h;
483: PetscViewerDrawGetDraw(viewer,0,&draw);
484: PetscDrawGetCurrentPoint(draw,&x,&y);
485: PetscStrncpy(str,"SNES: ",sizeof(str));
486: PetscStrlcat(str,((PetscObject)snes)->type_name,sizeof(str));
487: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
488: bottom = y - h;
489: PetscDrawPushCurrentPoint(draw,x,bottom);
490: if (snes->ops->view) {
491: (*snes->ops->view)(snes,viewer);
492: }
493: #if defined(PETSC_HAVE_SAWS)
494: } else if (issaws) {
495: PetscMPIInt rank;
496: const char *name;
498: PetscObjectGetName((PetscObject)snes,&name);
499: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
500: if (!((PetscObject)snes)->amsmem && !rank) {
501: char dir[1024];
503: PetscObjectViewSAWs((PetscObject)snes,viewer);
504: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
505: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
506: if (!snes->conv_hist) {
507: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
508: }
509: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
510: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
511: }
512: #endif
513: }
514: if (snes->linesearch) {
515: SNESGetLineSearch(snes, &linesearch);
516: PetscViewerASCIIPushTab(viewer);
517: SNESLineSearchView(linesearch, viewer);
518: PetscViewerASCIIPopTab(viewer);
519: }
520: if (snes->npc && snes->usesnpc) {
521: PetscViewerASCIIPushTab(viewer);
522: SNESView(snes->npc, viewer);
523: PetscViewerASCIIPopTab(viewer);
524: }
525: PetscViewerASCIIPushTab(viewer);
526: DMGetDMSNES(snes->dm,&dmsnes);
527: DMSNESView(dmsnes, viewer);
528: PetscViewerASCIIPopTab(viewer);
529: if (snes->usesksp) {
530: SNESGetKSP(snes,&ksp);
531: PetscViewerASCIIPushTab(viewer);
532: KSPView(ksp,viewer);
533: PetscViewerASCIIPopTab(viewer);
534: }
535: if (isdraw) {
536: PetscDraw draw;
537: PetscViewerDrawGetDraw(viewer,0,&draw);
538: PetscDrawPopCurrentPoint(draw);
539: }
540: return(0);
541: }
543: /*
544: We retain a list of functions that also take SNES command
545: line options. These are called at the end SNESSetFromOptions()
546: */
547: #define MAXSETFROMOPTIONS 5
548: static PetscInt numberofsetfromoptions;
549: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
551: /*@C
552: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
554: Not Collective
556: Input Parameter:
557: . snescheck - function that checks for options
559: Level: developer
561: .seealso: SNESSetFromOptions()
562: @*/
563: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
564: {
566: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
567: othersetfromoptions[numberofsetfromoptions++] = snescheck;
568: return(0);
569: }
571: PETSC_INTERN PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
573: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
574: {
575: Mat J;
577: MatNullSpace nullsp;
582: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
583: Mat A = snes->jacobian, B = snes->jacobian_pre;
584: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
585: }
587: if (version == 1) {
588: MatCreateSNESMF(snes,&J);
589: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
590: MatSetFromOptions(J);
591: } else if (version == 2) {
592: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
593: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
594: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
595: #else
596: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
597: #endif
598: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");
600: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
601: if (snes->jacobian) {
602: MatGetNullSpace(snes->jacobian,&nullsp);
603: if (nullsp) {
604: MatSetNullSpace(J,nullsp);
605: }
606: }
608: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
609: if (hasOperator) {
611: /* This version replaces the user provided Jacobian matrix with a
612: matrix-free version but still employs the user-provided preconditioner matrix. */
613: SNESSetJacobian(snes,J,0,0,0);
614: } else {
615: /* This version replaces both the user-provided Jacobian and the user-
616: provided preconditioner Jacobian with the default matrix free version. */
617: if ((snes->npcside== PC_LEFT) && snes->npc) {
618: if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
619: } else {
620: KSP ksp;
621: PC pc;
622: PetscBool match;
624: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
625: /* Force no preconditioner */
626: SNESGetKSP(snes,&ksp);
627: KSPGetPC(ksp,&pc);
628: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
629: if (!match) {
630: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
631: PCSetType(pc,PCNONE);
632: }
633: }
634: }
635: MatDestroy(&J);
636: return(0);
637: }
639: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
640: {
641: SNES snes = (SNES)ctx;
643: Vec Xfine,Xfine_named = NULL,Xcoarse;
646: if (PetscLogPrintInfo) {
647: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
648: DMGetRefineLevel(dmfine,&finelevel);
649: DMGetCoarsenLevel(dmfine,&fineclevel);
650: DMGetRefineLevel(dmcoarse,&coarselevel);
651: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
652: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
653: }
654: if (dmfine == snes->dm) Xfine = snes->vec_sol;
655: else {
656: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
657: Xfine = Xfine_named;
658: }
659: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
660: if (Inject) {
661: MatRestrict(Inject,Xfine,Xcoarse);
662: } else {
663: MatRestrict(Restrict,Xfine,Xcoarse);
664: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
665: }
666: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
667: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
668: return(0);
669: }
671: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
672: {
676: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
677: return(0);
678: }
680: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
681: * safely call SNESGetDM() in their residual evaluation routine. */
682: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
683: {
684: SNES snes = (SNES)ctx;
686: Vec X,Xnamed = NULL;
687: DM dmsave;
688: void *ctxsave;
689: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*) = NULL;
692: dmsave = snes->dm;
693: KSPGetDM(ksp,&snes->dm);
694: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
695: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
696: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
697: X = Xnamed;
698: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
699: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
700: if (jac == SNESComputeJacobianDefaultColor) {
701: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
702: }
703: }
704: /* Make sure KSP DM has the Jacobian computation routine */
705: {
706: DMSNES sdm;
708: DMGetDMSNES(snes->dm, &sdm);
709: if (!sdm->ops->computejacobian) {
710: DMCopyDMSNES(dmsave, snes->dm);
711: }
712: }
713: /* Compute the operators */
714: SNESComputeJacobian(snes,X,A,B);
715: /* Put the previous context back */
716: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
717: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
718: }
720: if (Xnamed) {DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);}
721: snes->dm = dmsave;
722: return(0);
723: }
725: /*@
726: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
728: Collective
730: Input Arguments:
731: . snes - snes to configure
733: Level: developer
735: .seealso: SNESSetUp()
736: @*/
737: PetscErrorCode SNESSetUpMatrices(SNES snes)
738: {
740: DM dm;
741: DMSNES sdm;
744: SNESGetDM(snes,&dm);
745: DMGetDMSNES(dm,&sdm);
746: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
747: else if (!snes->jacobian && snes->mf) {
748: Mat J;
749: void *functx;
750: MatCreateSNESMF(snes,&J);
751: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
752: MatSetFromOptions(J);
753: SNESGetFunction(snes,NULL,NULL,&functx);
754: SNESSetJacobian(snes,J,J,0,0);
755: MatDestroy(&J);
756: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
757: Mat J,B;
758: MatCreateSNESMF(snes,&J);
759: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
760: MatSetFromOptions(J);
761: DMCreateMatrix(snes->dm,&B);
762: /* sdm->computejacobian was already set to reach here */
763: SNESSetJacobian(snes,J,B,NULL,NULL);
764: MatDestroy(&J);
765: MatDestroy(&B);
766: } else if (!snes->jacobian_pre) {
767: PetscErrorCode (*nspconstr)(DM, PetscInt, MatNullSpace *);
768: PetscDS prob;
769: Mat J, B;
770: MatNullSpace nullspace = NULL;
771: PetscBool hasPrec = PETSC_FALSE;
772: PetscInt Nf;
774: J = snes->jacobian;
775: DMGetDS(dm, &prob);
776: if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
777: if (J) {PetscObjectReference((PetscObject) J);}
778: else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
779: DMCreateMatrix(snes->dm, &B);
780: PetscDSGetNumFields(prob, &Nf);
781: DMGetNullSpaceConstructor(snes->dm, Nf, &nspconstr);
782: if (nspconstr) (*nspconstr)(snes->dm, -1, &nullspace);
783: MatSetNullSpace(B, nullspace);
784: MatNullSpaceDestroy(&nullspace);
785: SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
786: MatDestroy(&J);
787: MatDestroy(&B);
788: }
789: {
790: KSP ksp;
791: SNESGetKSP(snes,&ksp);
792: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
793: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
794: }
795: return(0);
796: }
798: /*@C
799: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
801: Collective on SNES
803: Input Parameters:
804: + snes - SNES object you wish to monitor
805: . name - the monitor type one is seeking
806: . help - message indicating what monitoring is done
807: . manual - manual page for the monitor
808: . monitor - the monitor function
809: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the SNES or PetscViewer objects
811: Level: developer
813: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
814: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
815: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
816: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
817: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
818: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
819: PetscOptionsFList(), PetscOptionsEList()
820: @*/
821: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
822: {
823: PetscErrorCode ierr;
824: PetscViewer viewer;
825: PetscViewerFormat format;
826: PetscBool flg;
829: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
830: if (flg) {
831: PetscViewerAndFormat *vf;
832: PetscViewerAndFormatCreate(viewer,format,&vf);
833: PetscObjectDereference((PetscObject)viewer);
834: if (monitorsetup) {
835: (*monitorsetup)(snes,vf);
836: }
837: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
838: }
839: return(0);
840: }
842: /*@
843: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
845: Collective on SNES
847: Input Parameter:
848: . snes - the SNES context
850: Options Database Keys:
851: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
852: . -snes_stol - convergence tolerance in terms of the norm
853: of the change in the solution between steps
854: . -snes_atol <abstol> - absolute tolerance of residual norm
855: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
856: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
857: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
858: . -snes_max_it <max_it> - maximum number of iterations
859: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
860: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
861: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
862: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
863: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
864: . -snes_trtol <trtol> - trust region tolerance
865: . -snes_no_convergence_test - skip convergence test in nonlinear
866: solver; hence iterations will continue until max_it
867: or some other criterion is reached. Saves expense
868: of convergence test
869: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
870: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
871: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
872: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
873: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
874: . -snes_monitor_lg_range - plots residual norm at each iteration
875: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
876: . -snes_fd_color - use finite differences with coloring to compute Jacobian
877: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
878: . -snes_converged_reason - print the reason for convergence/divergence after each solve
879: - -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
881: Options Database for Eisenstat-Walker method:
882: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
883: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
884: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
885: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
886: . -snes_ksp_ew_gamma <gamma> - Sets gamma
887: . -snes_ksp_ew_alpha <alpha> - Sets alpha
888: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
889: - -snes_ksp_ew_threshold <threshold> - Sets threshold
891: Notes:
892: To see all options, run your program with the -help option or consult
893: Users-Manual: ch_snes
895: Level: beginner
897: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions()
898: @*/
899: PetscErrorCode SNESSetFromOptions(SNES snes)
900: {
901: PetscBool flg,pcset,persist,set;
902: PetscInt i,indx,lag,grids;
903: const char *deft = SNESNEWTONLS;
904: const char *convtests[] = {"default","skip"};
905: SNESKSPEW *kctx = NULL;
906: char type[256], monfilename[PETSC_MAX_PATH_LEN];
908: PCSide pcside;
909: const char *optionsprefix;
913: SNESRegisterAll();
914: PetscObjectOptionsBegin((PetscObject)snes);
915: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
916: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
917: if (flg) {
918: SNESSetType(snes,type);
919: } else if (!((PetscObject)snes)->type_name) {
920: SNESSetType(snes,deft);
921: }
922: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
923: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
925: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
926: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
927: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
928: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
929: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
930: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
931: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
932: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
933: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
935: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
936: if (flg) {
937: SNESSetLagPreconditioner(snes,lag);
938: }
939: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
940: if (flg) {
941: SNESSetLagPreconditionerPersists(snes,persist);
942: }
943: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
944: if (flg) {
945: SNESSetLagJacobian(snes,lag);
946: }
947: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
948: if (flg) {
949: SNESSetLagJacobianPersists(snes,persist);
950: }
952: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
953: if (flg) {
954: SNESSetGridSequence(snes,grids);
955: }
957: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
958: if (flg) {
959: switch (indx) {
960: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
961: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
962: }
963: }
965: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
966: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
968: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
969: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
971: kctx = (SNESKSPEW*)snes->kspconvctx;
973: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
975: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
976: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
977: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
978: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
979: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
980: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
981: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
983: flg = PETSC_FALSE;
984: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
985: if (set && flg) {SNESMonitorCancel(snes);}
987: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
988: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
989: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
991: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
992: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
993: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
994: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
995: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
996: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
997: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
999: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
1000: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
1002: flg = PETSC_FALSE;
1003: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
1004: if (flg) {
1005: PetscDrawLG ctx;
1007: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1008: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
1009: }
1010: flg = PETSC_FALSE;
1011: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
1012: if (flg) {
1013: PetscViewer ctx;
1015: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1016: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
1017: }
1019: flg = PETSC_FALSE;
1020: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
1021: if (flg) {
1022: void *functx;
1023: DM dm;
1024: DMSNES sdm;
1025: SNESGetDM(snes,&dm);
1026: DMGetDMSNES(dm,&sdm);
1027: sdm->jacobianctx = NULL;
1028: SNESGetFunction(snes,NULL,NULL,&functx);
1029: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
1030: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
1031: }
1033: flg = PETSC_FALSE;
1034: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
1035: if (flg) {
1036: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
1037: }
1039: flg = PETSC_FALSE;
1040: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1041: if (flg) {
1042: DM dm;
1043: DMSNES sdm;
1044: SNESGetDM(snes,&dm);
1045: DMGetDMSNES(dm,&sdm);
1046: sdm->jacobianctx = NULL;
1047: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
1048: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1049: }
1051: flg = PETSC_FALSE;
1052: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1053: if (flg && snes->mf_operator) {
1054: snes->mf_operator = PETSC_TRUE;
1055: snes->mf = PETSC_TRUE;
1056: }
1057: flg = PETSC_FALSE;
1058: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1059: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1060: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
1062: flg = PETSC_FALSE;
1063: SNESGetNPCSide(snes,&pcside);
1064: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1065: if (flg) {SNESSetNPCSide(snes,pcside);}
1067: #if defined(PETSC_HAVE_SAWS)
1068: /*
1069: Publish convergence information using SAWs
1070: */
1071: flg = PETSC_FALSE;
1072: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1073: if (flg) {
1074: void *ctx;
1075: SNESMonitorSAWsCreate(snes,&ctx);
1076: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1077: }
1078: #endif
1079: #if defined(PETSC_HAVE_SAWS)
1080: {
1081: PetscBool set;
1082: flg = PETSC_FALSE;
1083: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1084: if (set) {
1085: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1086: }
1087: }
1088: #endif
1090: for (i = 0; i < numberofsetfromoptions; i++) {
1091: (*othersetfromoptions[i])(snes);
1092: }
1094: if (snes->ops->setfromoptions) {
1095: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1096: }
1098: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1099: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1100: PetscOptionsEnd();
1102: if (snes->linesearch) {
1103: SNESGetLineSearch(snes, &snes->linesearch);
1104: SNESLineSearchSetFromOptions(snes->linesearch);
1105: }
1107: if (snes->usesksp) {
1108: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1109: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1110: KSPSetFromOptions(snes->ksp);
1111: }
1113: /* if user has set the SNES NPC type via options database, create it. */
1114: SNESGetOptionsPrefix(snes, &optionsprefix);
1115: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1116: if (pcset && (!snes->npc)) {
1117: SNESGetNPC(snes, &snes->npc);
1118: }
1119: if (snes->npc) {
1120: SNESSetFromOptions(snes->npc);
1121: }
1122: snes->setfromoptionscalled++;
1123: return(0);
1124: }
1126: /*@
1127: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1129: Collective on SNES
1131: Input Parameter:
1132: . snes - the SNES context
1134: Level: beginner
1136: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1137: @*/
1138: PetscErrorCode SNESResetFromOptions(SNES snes)
1139: {
1143: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1144: return(0);
1145: }
1147: /*@C
1148: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1149: the nonlinear solvers.
1151: Logically Collective on SNES
1153: Input Parameters:
1154: + snes - the SNES context
1155: . compute - function to compute the context
1156: - destroy - function to destroy the context
1158: Level: intermediate
1160: Notes:
1161: This function is currently not available from Fortran.
1163: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1164: @*/
1165: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1166: {
1169: snes->ops->usercompute = compute;
1170: snes->ops->userdestroy = destroy;
1171: return(0);
1172: }
1174: /*@
1175: SNESSetApplicationContext - Sets the optional user-defined context for
1176: the nonlinear solvers.
1178: Logically Collective on SNES
1180: Input Parameters:
1181: + snes - the SNES context
1182: - usrP - optional user context
1184: Level: intermediate
1186: Fortran Notes:
1187: To use this from Fortran you must write a Fortran interface definition for this
1188: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1190: .seealso: SNESGetApplicationContext()
1191: @*/
1192: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1193: {
1195: KSP ksp;
1199: SNESGetKSP(snes,&ksp);
1200: KSPSetApplicationContext(ksp,usrP);
1201: snes->user = usrP;
1202: return(0);
1203: }
1205: /*@
1206: SNESGetApplicationContext - Gets the user-defined context for the
1207: nonlinear solvers.
1209: Not Collective
1211: Input Parameter:
1212: . snes - SNES context
1214: Output Parameter:
1215: . usrP - user context
1217: Fortran Notes:
1218: To use this from Fortran you must write a Fortran interface definition for this
1219: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1221: Level: intermediate
1223: .seealso: SNESSetApplicationContext()
1224: @*/
1225: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1226: {
1229: *(void**)usrP = snes->user;
1230: return(0);
1231: }
1233: /*@
1234: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply
1235: the Jacobian.
1237: Collective on SNES
1239: Input Parameters:
1240: + snes - SNES context
1241: . mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1242: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1244: Options Database:
1245: + -snes_mf - use matrix free for both the mat and pmat operator
1246: - -snes_mf_operator - use matrix free only for the mat operator
1248: Level: intermediate
1250: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF()
1251: @*/
1252: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1253: {
1258: if (mf && !mf_operator) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"If using mf must also use mf_operator");
1259: snes->mf = mf;
1260: snes->mf_operator = mf_operator;
1261: return(0);
1262: }
1264: /*@
1265: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply
1266: the Jacobian.
1268: Collective on SNES
1270: Input Parameter:
1271: . snes - SNES context
1273: Output Parameters:
1274: + mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1275: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1277: Options Database:
1278: + -snes_mf - use matrix free for both the mat and pmat operator
1279: - -snes_mf_operator - use matrix free only for the mat operator
1281: Level: intermediate
1283: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1284: @*/
1285: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1286: {
1289: if (mf) *mf = snes->mf;
1290: if (mf_operator) *mf_operator = snes->mf_operator;
1291: return(0);
1292: }
1294: /*@
1295: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1296: at this time.
1298: Not Collective
1300: Input Parameter:
1301: . snes - SNES context
1303: Output Parameter:
1304: . iter - iteration number
1306: Notes:
1307: For example, during the computation of iteration 2 this would return 1.
1309: This is useful for using lagged Jacobians (where one does not recompute the
1310: Jacobian at each SNES iteration). For example, the code
1311: .vb
1312: SNESGetIterationNumber(snes,&it);
1313: if (!(it % 2)) {
1314: [compute Jacobian here]
1315: }
1316: .ve
1317: can be used in your ComputeJacobian() function to cause the Jacobian to be
1318: recomputed every second SNES iteration.
1320: After the SNES solve is complete this will return the number of nonlinear iterations used.
1322: Level: intermediate
1324: .seealso: SNESGetLinearSolveIterations()
1325: @*/
1326: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1327: {
1331: *iter = snes->iter;
1332: return(0);
1333: }
1335: /*@
1336: SNESSetIterationNumber - Sets the current iteration number.
1338: Not Collective
1340: Input Parameter:
1341: + snes - SNES context
1342: - iter - iteration number
1344: Level: developer
1346: .seealso: SNESGetLinearSolveIterations()
1347: @*/
1348: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1349: {
1354: PetscObjectSAWsTakeAccess((PetscObject)snes);
1355: snes->iter = iter;
1356: PetscObjectSAWsGrantAccess((PetscObject)snes);
1357: return(0);
1358: }
1360: /*@
1361: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1362: attempted by the nonlinear solver.
1364: Not Collective
1366: Input Parameter:
1367: . snes - SNES context
1369: Output Parameter:
1370: . nfails - number of unsuccessful steps attempted
1372: Notes:
1373: This counter is reset to zero for each successive call to SNESSolve().
1375: Level: intermediate
1377: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1378: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1379: @*/
1380: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1381: {
1385: *nfails = snes->numFailures;
1386: return(0);
1387: }
1389: /*@
1390: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1391: attempted by the nonlinear solver before it gives up.
1393: Not Collective
1395: Input Parameters:
1396: + snes - SNES context
1397: - maxFails - maximum of unsuccessful steps
1399: Level: intermediate
1401: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1402: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1403: @*/
1404: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1405: {
1408: snes->maxFailures = maxFails;
1409: return(0);
1410: }
1412: /*@
1413: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1414: attempted by the nonlinear solver before it gives up.
1416: Not Collective
1418: Input Parameter:
1419: . snes - SNES context
1421: Output Parameter:
1422: . maxFails - maximum of unsuccessful steps
1424: Level: intermediate
1426: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1427: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1429: @*/
1430: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1431: {
1435: *maxFails = snes->maxFailures;
1436: return(0);
1437: }
1439: /*@
1440: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1441: done by SNES.
1443: Not Collective
1445: Input Parameter:
1446: . snes - SNES context
1448: Output Parameter:
1449: . nfuncs - number of evaluations
1451: Level: intermediate
1453: Notes:
1454: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1456: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1457: @*/
1458: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1459: {
1463: *nfuncs = snes->nfuncs;
1464: return(0);
1465: }
1467: /*@
1468: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1469: linear solvers.
1471: Not Collective
1473: Input Parameter:
1474: . snes - SNES context
1476: Output Parameter:
1477: . nfails - number of failed solves
1479: Level: intermediate
1481: Options Database Keys:
1482: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1484: Notes:
1485: This counter is reset to zero for each successive call to SNESSolve().
1487: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1488: @*/
1489: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1490: {
1494: *nfails = snes->numLinearSolveFailures;
1495: return(0);
1496: }
1498: /*@
1499: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1500: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1502: Logically Collective on SNES
1504: Input Parameters:
1505: + snes - SNES context
1506: - maxFails - maximum allowed linear solve failures
1508: Level: intermediate
1510: Options Database Keys:
1511: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1513: Notes:
1514: By default this is 0; that is SNES returns on the first failed linear solve
1516: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1517: @*/
1518: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1519: {
1523: snes->maxLinearSolveFailures = maxFails;
1524: return(0);
1525: }
1527: /*@
1528: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1529: are allowed before SNES terminates
1531: Not Collective
1533: Input Parameter:
1534: . snes - SNES context
1536: Output Parameter:
1537: . maxFails - maximum of unsuccessful solves allowed
1539: Level: intermediate
1541: Notes:
1542: By default this is 1; that is SNES returns on the first failed linear solve
1544: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1545: @*/
1546: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1547: {
1551: *maxFails = snes->maxLinearSolveFailures;
1552: return(0);
1553: }
1555: /*@
1556: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1557: used by the nonlinear solver.
1559: Not Collective
1561: Input Parameter:
1562: . snes - SNES context
1564: Output Parameter:
1565: . lits - number of linear iterations
1567: Notes:
1568: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1570: 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
1571: then call KSPGetIterationNumber() after the failed solve.
1573: Level: intermediate
1575: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1576: @*/
1577: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1578: {
1582: *lits = snes->linear_its;
1583: return(0);
1584: }
1586: /*@
1587: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1588: are reset every time SNESSolve() is called.
1590: Logically Collective on SNES
1592: Input Parameter:
1593: + snes - SNES context
1594: - reset - whether to reset the counters or not
1596: Notes:
1597: This defaults to PETSC_TRUE
1599: Level: developer
1601: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1602: @*/
1603: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1604: {
1608: snes->counters_reset = reset;
1609: return(0);
1610: }
1613: /*@
1614: SNESSetKSP - Sets a KSP context for the SNES object to use
1616: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1618: Input Parameters:
1619: + snes - the SNES context
1620: - ksp - the KSP context
1622: Notes:
1623: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1624: so this routine is rarely needed.
1626: The KSP object that is already in the SNES object has its reference count
1627: decreased by one.
1629: Level: developer
1631: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1632: @*/
1633: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1634: {
1641: PetscObjectReference((PetscObject)ksp);
1642: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1643: snes->ksp = ksp;
1644: return(0);
1645: }
1647: /* -----------------------------------------------------------*/
1648: /*@
1649: SNESCreate - Creates a nonlinear solver context.
1651: Collective
1653: Input Parameters:
1654: . comm - MPI communicator
1656: Output Parameter:
1657: . outsnes - the new SNES context
1659: Options Database Keys:
1660: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1661: and no preconditioning matrix
1662: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1663: products, and a user-provided preconditioning matrix
1664: as set by SNESSetJacobian()
1665: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1667: Level: beginner
1669: Developer Notes:
1670: SNES always creates a KSP object even though many SNES methods do not use it. This is
1671: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1672: particular method does use KSP and regulates if the information about the KSP is printed
1673: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1674: by help messages about meaningless SNES options.
1676: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1677: be fixed.
1679: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1681: @*/
1682: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1683: {
1685: SNES snes;
1686: SNESKSPEW *kctx;
1690: *outsnes = NULL;
1691: SNESInitializePackage();
1693: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1695: snes->ops->converged = SNESConvergedDefault;
1696: snes->usesksp = PETSC_TRUE;
1697: snes->tolerancesset = PETSC_FALSE;
1698: snes->max_its = 50;
1699: snes->max_funcs = 10000;
1700: snes->norm = 0.0;
1701: snes->xnorm = 0.0;
1702: snes->ynorm = 0.0;
1703: snes->normschedule = SNES_NORM_ALWAYS;
1704: snes->functype = SNES_FUNCTION_DEFAULT;
1705: #if defined(PETSC_USE_REAL_SINGLE)
1706: snes->rtol = 1.e-5;
1707: #else
1708: snes->rtol = 1.e-8;
1709: #endif
1710: snes->ttol = 0.0;
1711: #if defined(PETSC_USE_REAL_SINGLE)
1712: snes->abstol = 1.e-25;
1713: #else
1714: snes->abstol = 1.e-50;
1715: #endif
1716: #if defined(PETSC_USE_REAL_SINGLE)
1717: snes->stol = 1.e-5;
1718: #else
1719: snes->stol = 1.e-8;
1720: #endif
1721: #if defined(PETSC_USE_REAL_SINGLE)
1722: snes->deltatol = 1.e-6;
1723: #else
1724: snes->deltatol = 1.e-12;
1725: #endif
1726: snes->divtol = 1.e4;
1727: snes->rnorm0 = 0;
1728: snes->nfuncs = 0;
1729: snes->numFailures = 0;
1730: snes->maxFailures = 1;
1731: snes->linear_its = 0;
1732: snes->lagjacobian = 1;
1733: snes->jac_iter = 0;
1734: snes->lagjac_persist = PETSC_FALSE;
1735: snes->lagpreconditioner = 1;
1736: snes->pre_iter = 0;
1737: snes->lagpre_persist = PETSC_FALSE;
1738: snes->numbermonitors = 0;
1739: snes->data = 0;
1740: snes->setupcalled = PETSC_FALSE;
1741: snes->ksp_ewconv = PETSC_FALSE;
1742: snes->nwork = 0;
1743: snes->work = 0;
1744: snes->nvwork = 0;
1745: snes->vwork = 0;
1746: snes->conv_hist_len = 0;
1747: snes->conv_hist_max = 0;
1748: snes->conv_hist = NULL;
1749: snes->conv_hist_its = NULL;
1750: snes->conv_hist_reset = PETSC_TRUE;
1751: snes->counters_reset = PETSC_TRUE;
1752: snes->vec_func_init_set = PETSC_FALSE;
1753: snes->reason = SNES_CONVERGED_ITERATING;
1754: snes->npcside = PC_RIGHT;
1755: snes->setfromoptionscalled = 0;
1757: snes->mf = PETSC_FALSE;
1758: snes->mf_operator = PETSC_FALSE;
1759: snes->mf_version = 1;
1761: snes->numLinearSolveFailures = 0;
1762: snes->maxLinearSolveFailures = 1;
1764: snes->vizerotolerance = 1.e-8;
1765: #if defined(PETSC_USE_DEBUG)
1766: snes->checkjacdomainerror = PETSC_TRUE;
1767: #else
1768: snes->checkjacdomainerror = PETSC_FALSE;
1769: #endif
1771: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1772: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1774: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1775: PetscNewLog(snes,&kctx);
1777: snes->kspconvctx = (void*)kctx;
1778: kctx->version = 2;
1779: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1780: this was too large for some test cases */
1781: kctx->rtol_last = 0.0;
1782: kctx->rtol_max = .9;
1783: kctx->gamma = 1.0;
1784: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1785: kctx->alpha2 = kctx->alpha;
1786: kctx->threshold = .1;
1787: kctx->lresid_last = 0.0;
1788: kctx->norm_last = 0.0;
1790: *outsnes = snes;
1791: return(0);
1792: }
1794: /*MC
1795: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1797: Synopsis:
1798: #include "petscsnes.h"
1799: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1801: Input Parameters:
1802: + snes - the SNES context
1803: . x - state at which to evaluate residual
1804: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1806: Output Parameter:
1807: . f - vector to put residual (function value)
1809: Level: intermediate
1811: .seealso: SNESSetFunction(), SNESGetFunction()
1812: M*/
1814: /*@C
1815: SNESSetFunction - Sets the function evaluation routine and function
1816: vector for use by the SNES routines in solving systems of nonlinear
1817: equations.
1819: Logically Collective on SNES
1821: Input Parameters:
1822: + snes - the SNES context
1823: . r - vector to store function value
1824: . f - function evaluation routine; see SNESFunction for calling sequence details
1825: - ctx - [optional] user-defined context for private data for the
1826: function evaluation routine (may be NULL)
1828: Notes:
1829: The Newton-like methods typically solve linear systems of the form
1830: $ f'(x) x = -f(x),
1831: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1833: Level: beginner
1835: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1836: @*/
1837: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1838: {
1840: DM dm;
1844: if (r) {
1847: PetscObjectReference((PetscObject)r);
1848: VecDestroy(&snes->vec_func);
1850: snes->vec_func = r;
1851: }
1852: SNESGetDM(snes,&dm);
1853: DMSNESSetFunction(dm,f,ctx);
1854: return(0);
1855: }
1858: /*@C
1859: SNESSetInitialFunction - Sets the function vector to be used as the
1860: function norm at the initialization of the method. In some
1861: instances, the user has precomputed the function before calling
1862: SNESSolve. This function allows one to avoid a redundant call
1863: to SNESComputeFunction in that case.
1865: Logically Collective on SNES
1867: Input Parameters:
1868: + snes - the SNES context
1869: - f - vector to store function value
1871: Notes:
1872: This should not be modified during the solution procedure.
1874: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1876: Level: developer
1878: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1879: @*/
1880: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1881: {
1883: Vec vec_func;
1889: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1890: snes->vec_func_init_set = PETSC_FALSE;
1891: return(0);
1892: }
1893: SNESGetFunction(snes,&vec_func,NULL,NULL);
1894: VecCopy(f, vec_func);
1896: snes->vec_func_init_set = PETSC_TRUE;
1897: return(0);
1898: }
1900: /*@
1901: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1902: of the SNES method.
1904: Logically Collective on SNES
1906: Input Parameters:
1907: + snes - the SNES context
1908: - normschedule - the frequency of norm computation
1910: Options Database Key:
1911: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1913: Notes:
1914: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1915: of the nonlinear function and the taking of its norm at every iteration to
1916: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1917: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1918: may either be monitored for convergence or not. As these are often used as nonlinear
1919: preconditioners, monitoring the norm of their error is not a useful enterprise within
1920: their solution.
1922: Level: developer
1924: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1925: @*/
1926: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1927: {
1930: snes->normschedule = normschedule;
1931: return(0);
1932: }
1935: /*@
1936: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1937: of the SNES method.
1939: Logically Collective on SNES
1941: Input Parameters:
1942: + snes - the SNES context
1943: - normschedule - the type of the norm used
1945: Level: advanced
1947: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1948: @*/
1949: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1950: {
1953: *normschedule = snes->normschedule;
1954: return(0);
1955: }
1958: /*@
1959: SNESSetFunctionNorm - Sets the last computed residual norm.
1961: Logically Collective on SNES
1963: Input Parameters:
1964: + snes - the SNES context
1966: - normschedule - the frequency of norm computation
1968: Level: developer
1970: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1971: @*/
1972: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1973: {
1976: snes->norm = norm;
1977: return(0);
1978: }
1980: /*@
1981: SNESGetFunctionNorm - Gets the last computed norm of the residual
1983: Not Collective
1985: Input Parameter:
1986: . snes - the SNES context
1988: Output Parameter:
1989: . norm - the last computed residual norm
1991: Level: developer
1993: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1994: @*/
1995: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1996: {
2000: *norm = snes->norm;
2001: return(0);
2002: }
2004: /*@
2005: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
2007: Not Collective
2009: Input Parameter:
2010: . snes - the SNES context
2012: Output Parameter:
2013: . ynorm - the last computed update norm
2015: Level: developer
2017: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
2018: @*/
2019: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2020: {
2024: *ynorm = snes->ynorm;
2025: return(0);
2026: }
2028: /*@
2029: SNESGetSolutionNorm - Gets the last computed norm of the solution
2031: Not Collective
2033: Input Parameter:
2034: . snes - the SNES context
2036: Output Parameter:
2037: . xnorm - the last computed solution norm
2039: Level: developer
2041: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2042: @*/
2043: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2044: {
2048: *xnorm = snes->xnorm;
2049: return(0);
2050: }
2052: /*@C
2053: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2054: of the SNES method.
2056: Logically Collective on SNES
2058: Input Parameters:
2059: + snes - the SNES context
2060: - normschedule - the frequency of norm computation
2062: Notes:
2063: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2064: of the nonlinear function and the taking of its norm at every iteration to
2065: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2066: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2067: may either be monitored for convergence or not. As these are often used as nonlinear
2068: preconditioners, monitoring the norm of their error is not a useful enterprise within
2069: their solution.
2071: Level: developer
2073: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2074: @*/
2075: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2076: {
2079: snes->functype = type;
2080: return(0);
2081: }
2084: /*@C
2085: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2086: of the SNES method.
2088: Logically Collective on SNES
2090: Input Parameters:
2091: + snes - the SNES context
2092: - normschedule - the type of the norm used
2094: Level: advanced
2096: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2097: @*/
2098: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2099: {
2102: *type = snes->functype;
2103: return(0);
2104: }
2106: /*MC
2107: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2109: Synopsis:
2110: #include <petscsnes.h>
2111: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2113: + X - solution vector
2114: . B - RHS vector
2115: - ctx - optional user-defined Gauss-Seidel context
2117: Level: intermediate
2119: .seealso: SNESSetNGS(), SNESGetNGS()
2120: M*/
2122: /*@C
2123: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2124: use with composed nonlinear solvers.
2126: Input Parameters:
2127: + snes - the SNES context
2128: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2129: - ctx - [optional] user-defined context for private data for the
2130: smoother evaluation routine (may be NULL)
2132: Notes:
2133: The NGS routines are used by the composed nonlinear solver to generate
2134: a problem appropriate update to the solution, particularly FAS.
2136: Level: intermediate
2138: .seealso: SNESGetFunction(), SNESComputeNGS()
2139: @*/
2140: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2141: {
2143: DM dm;
2147: SNESGetDM(snes,&dm);
2148: DMSNESSetNGS(dm,f,ctx);
2149: return(0);
2150: }
2152: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2153: {
2155: DM dm;
2156: DMSNES sdm;
2159: SNESGetDM(snes,&dm);
2160: DMGetDMSNES(dm,&sdm);
2161: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2162: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2163: /* A(x)*x - b(x) */
2164: PetscStackPush("SNES Picard user function");
2165: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2166: PetscStackPop;
2167: PetscStackPush("SNES Picard user Jacobian");
2168: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2169: PetscStackPop;
2170: VecScale(f,-1.0);
2171: MatMultAdd(snes->jacobian,x,f,f);
2172: return(0);
2173: }
2175: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2176: {
2178: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2179: return(0);
2180: }
2182: /*@C
2183: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2185: Logically Collective on SNES
2187: Input Parameters:
2188: + snes - the SNES context
2189: . r - vector to store function value
2190: . b - function evaluation routine
2191: . Amat - matrix with which A(x) x - b(x) is to be computed
2192: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2193: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2194: - ctx - [optional] user-defined context for private data for the
2195: function evaluation routine (may be NULL)
2197: Notes:
2198: 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
2199: 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.
2201: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2203: $ 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}
2204: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2206: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2208: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2209: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2211: 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
2212: 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
2213: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2215: Level: intermediate
2217: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2218: @*/
2219: 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)
2220: {
2222: DM dm;
2226: SNESGetDM(snes, &dm);
2227: DMSNESSetPicard(dm,b,J,ctx);
2228: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2229: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2230: return(0);
2231: }
2233: /*@C
2234: SNESGetPicard - Returns the context for the Picard iteration
2236: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2238: Input Parameter:
2239: . snes - the SNES context
2241: Output Parameter:
2242: + r - the function (or NULL)
2243: . f - the function (or NULL); see SNESFunction for calling sequence details
2244: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2245: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2246: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2247: - ctx - the function context (or NULL)
2249: Level: advanced
2251: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2252: @*/
2253: 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)
2254: {
2256: DM dm;
2260: SNESGetFunction(snes,r,NULL,NULL);
2261: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2262: SNESGetDM(snes,&dm);
2263: DMSNESGetPicard(dm,f,J,ctx);
2264: return(0);
2265: }
2267: /*@C
2268: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2270: Logically Collective on SNES
2272: Input Parameters:
2273: + snes - the SNES context
2274: . func - function evaluation routine
2275: - ctx - [optional] user-defined context for private data for the
2276: function evaluation routine (may be NULL)
2278: Calling sequence of func:
2279: $ func (SNES snes,Vec x,void *ctx);
2281: . f - function vector
2282: - ctx - optional user-defined function context
2284: Level: intermediate
2286: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2287: @*/
2288: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2289: {
2292: if (func) snes->ops->computeinitialguess = func;
2293: if (ctx) snes->initialguessP = ctx;
2294: return(0);
2295: }
2297: /* --------------------------------------------------------------- */
2298: /*@C
2299: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2300: it assumes a zero right hand side.
2302: Logically Collective on SNES
2304: Input Parameter:
2305: . snes - the SNES context
2307: Output Parameter:
2308: . rhs - the right hand side vector or NULL if the right hand side vector is null
2310: Level: intermediate
2312: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2313: @*/
2314: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2315: {
2319: *rhs = snes->vec_rhs;
2320: return(0);
2321: }
2323: /*@
2324: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2326: Collective on SNES
2328: Input Parameters:
2329: + snes - the SNES context
2330: - x - input vector
2332: Output Parameter:
2333: . y - function vector, as set by SNESSetFunction()
2335: Notes:
2336: SNESComputeFunction() is typically used within nonlinear solvers
2337: implementations, so most users would not generally call this routine
2338: themselves.
2340: Level: developer
2342: .seealso: SNESSetFunction(), SNESGetFunction()
2343: @*/
2344: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2345: {
2347: DM dm;
2348: DMSNES sdm;
2356: VecValidValues(x,2,PETSC_TRUE);
2358: SNESGetDM(snes,&dm);
2359: DMGetDMSNES(dm,&sdm);
2360: if (sdm->ops->computefunction) {
2361: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2362: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2363: }
2364: VecLockReadPush(x);
2365: PetscStackPush("SNES user function");
2366: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2367: snes->domainerror = PETSC_FALSE;
2368: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2369: PetscStackPop;
2370: VecLockReadPop(x);
2371: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2372: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2373: }
2374: } else if (snes->vec_rhs) {
2375: MatMult(snes->jacobian, x, y);
2376: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2377: if (snes->vec_rhs) {
2378: VecAXPY(y,-1.0,snes->vec_rhs);
2379: }
2380: snes->nfuncs++;
2381: /*
2382: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2383: propagate the value to all processes
2384: */
2385: if (snes->domainerror) {
2386: VecSetInf(y);
2387: }
2388: return(0);
2389: }
2391: /*@
2392: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2394: Collective on SNES
2396: Input Parameters:
2397: + snes - the SNES context
2398: . x - input vector
2399: - b - rhs vector
2401: Output Parameter:
2402: . x - new solution vector
2404: Notes:
2405: SNESComputeNGS() is typically used within composed nonlinear solver
2406: implementations, so most users would not generally call this routine
2407: themselves.
2409: Level: developer
2411: .seealso: SNESSetNGS(), SNESComputeFunction()
2412: @*/
2413: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2414: {
2416: DM dm;
2417: DMSNES sdm;
2425: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2426: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2427: SNESGetDM(snes,&dm);
2428: DMGetDMSNES(dm,&sdm);
2429: if (sdm->ops->computegs) {
2430: if (b) {VecLockReadPush(b);}
2431: PetscStackPush("SNES user NGS");
2432: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2433: PetscStackPop;
2434: if (b) {VecLockReadPop(b);}
2435: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2436: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2437: return(0);
2438: }
2440: PetscErrorCode SNESTestJacobian(SNES snes)
2441: {
2442: Mat A,B,C,D,jacobian;
2443: Vec x = snes->vec_sol,f = snes->vec_func;
2444: PetscErrorCode ierr;
2445: PetscReal nrm,gnorm;
2446: PetscReal threshold = 1.e-5;
2447: MatType mattype;
2448: PetscInt m,n,M,N;
2449: void *functx;
2450: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg;
2451: PetscViewer viewer,mviewer;
2452: MPI_Comm comm;
2453: PetscInt tabs;
2454: static PetscBool directionsprinted = PETSC_FALSE;
2455: PetscViewerFormat format;
2458: PetscObjectOptionsBegin((PetscObject)snes);
2459: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2460: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2461: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2462: if (!complete_print) {
2463: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2464: }
2465: /* for compatibility with PETSc 3.9 and older. */
2466: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2467: PetscOptionsEnd();
2468: if (!test) return(0);
2470: PetscObjectGetComm((PetscObject)snes,&comm);
2471: PetscViewerASCIIGetStdout(comm,&viewer);
2472: PetscViewerASCIIGetTab(viewer, &tabs);
2473: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2474: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2475: if (!complete_print && !directionsprinted) {
2476: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2477: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2478: }
2479: if (!directionsprinted) {
2480: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2481: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2482: directionsprinted = PETSC_TRUE;
2483: }
2484: if (complete_print) {
2485: PetscViewerPushFormat(mviewer,format);
2486: }
2488: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2489: if (!flg) jacobian = snes->jacobian;
2490: else jacobian = snes->jacobian_pre;
2492: if (!x) {
2493: MatCreateVecs(jacobian, &x, NULL);
2494: } else {
2495: PetscObjectReference((PetscObject) x);
2496: }
2497: if (!f) {
2498: VecDuplicate(x, &f);
2499: } else {
2500: PetscObjectReference((PetscObject) f);
2501: }
2502: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2503: SNESComputeFunction(snes,x,f);
2504: VecDestroy(&f);
2506: while (jacobian) {
2507: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2508: if (flg) {
2509: A = jacobian;
2510: PetscObjectReference((PetscObject)A);
2511: } else {
2512: MatComputeOperator(jacobian,MATAIJ,&A);
2513: }
2515: MatGetType(A,&mattype);
2516: MatGetSize(A,&M,&N);
2517: MatGetLocalSize(A,&m,&n);
2519: MatCreate(PetscObjectComm((PetscObject)A),&B);
2520: MatSetType(B,mattype);
2521: MatSetSizes(B,m,n,M,N);
2522: MatSetBlockSizesFromMats(B,A,A);
2523: MatSetUp(B);
2524: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2526: SNESGetFunction(snes,NULL,NULL,&functx);
2527: SNESComputeJacobianDefault(snes,x,B,B,functx);
2529: MatDuplicate(B,MAT_COPY_VALUES,&D);
2530: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2531: MatNorm(D,NORM_FROBENIUS,&nrm);
2532: MatNorm(A,NORM_FROBENIUS,&gnorm);
2533: MatDestroy(&D);
2534: if (!gnorm) gnorm = 1; /* just in case */
2535: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2537: if (complete_print) {
2538: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2539: MatView(jacobian,mviewer);
2540: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2541: MatView(B,mviewer);
2542: }
2544: if (threshold_print || complete_print) {
2545: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2546: PetscScalar *cvals;
2547: const PetscInt *bcols;
2548: const PetscScalar *bvals;
2550: MatCreate(PetscObjectComm((PetscObject)A),&C);
2551: MatSetType(C,mattype);
2552: MatSetSizes(C,m,n,M,N);
2553: MatSetBlockSizesFromMats(C,A,A);
2554: MatSetUp(C);
2555: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2557: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2558: MatGetOwnershipRange(B,&Istart,&Iend);
2560: for (row = Istart; row < Iend; row++) {
2561: MatGetRow(B,row,&bncols,&bcols,&bvals);
2562: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2563: for (j = 0, cncols = 0; j < bncols; j++) {
2564: if (PetscAbsScalar(bvals[j]) > threshold) {
2565: ccols[cncols] = bcols[j];
2566: cvals[cncols] = bvals[j];
2567: cncols += 1;
2568: }
2569: }
2570: if (cncols) {
2571: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2572: }
2573: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2574: PetscFree2(ccols,cvals);
2575: }
2576: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2577: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2578: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2579: MatView(C,complete_print ? mviewer : viewer);
2580: MatDestroy(&C);
2581: }
2582: MatDestroy(&A);
2583: MatDestroy(&B);
2585: if (jacobian != snes->jacobian_pre) {
2586: jacobian = snes->jacobian_pre;
2587: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2588: }
2589: else jacobian = NULL;
2590: }
2591: VecDestroy(&x);
2592: if (complete_print) {
2593: PetscViewerPopFormat(mviewer);
2594: }
2595: if (mviewer) { PetscViewerDestroy(&mviewer); }
2596: PetscViewerASCIISetTab(viewer,tabs);
2597: return(0);
2598: }
2600: /*@
2601: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2603: Collective on SNES
2605: Input Parameters:
2606: + snes - the SNES context
2607: - x - input vector
2609: Output Parameters:
2610: + A - Jacobian matrix
2611: - B - optional preconditioning matrix
2613: Options Database Keys:
2614: + -snes_lag_preconditioner <lag>
2615: . -snes_lag_jacobian <lag>
2616: . -snes_test_jacobian - compare the user provided Jacobian with one compute via finite differences to check for errors
2617: . -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
2618: . -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
2619: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2620: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2621: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2622: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2623: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2624: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2625: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2626: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2627: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2628: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2629: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2632: Notes:
2633: Most users should not need to explicitly call this routine, as it
2634: is used internally within the nonlinear solvers.
2636: Developer Notes:
2637: 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
2638: for with the SNESType of test that has been removed.
2640: Level: developer
2642: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2643: @*/
2644: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2645: {
2647: PetscBool flag;
2648: DM dm;
2649: DMSNES sdm;
2650: KSP ksp;
2656: VecValidValues(X,2,PETSC_TRUE);
2657: SNESGetDM(snes,&dm);
2658: DMGetDMSNES(dm,&sdm);
2660: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2662: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2664: if (snes->lagjacobian == -2) {
2665: snes->lagjacobian = -1;
2667: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2668: } else if (snes->lagjacobian == -1) {
2669: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2670: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2671: if (flag) {
2672: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2673: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2674: }
2675: return(0);
2676: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2677: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2678: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2679: if (flag) {
2680: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2681: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2682: }
2683: return(0);
2684: }
2685: if (snes->npc && snes->npcside== PC_LEFT) {
2686: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2687: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2688: return(0);
2689: }
2691: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2692: VecLockReadPush(X);
2693: PetscStackPush("SNES user Jacobian function");
2694: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2695: PetscStackPop;
2696: VecLockReadPop(X);
2697: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2699: /* attach latest linearization point to the preconditioning matrix */
2700: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2702: /* the next line ensures that snes->ksp exists */
2703: SNESGetKSP(snes,&ksp);
2704: if (snes->lagpreconditioner == -2) {
2705: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2706: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2707: snes->lagpreconditioner = -1;
2708: } else if (snes->lagpreconditioner == -1) {
2709: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2710: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2711: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2712: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2713: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2714: } else {
2715: PetscInfo(snes,"Rebuilding preconditioner\n");
2716: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2717: }
2719: SNESTestJacobian(snes);
2720: /* make sure user returned a correct Jacobian and preconditioner */
2723: {
2724: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2725: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2726: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2727: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2728: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2729: if (flag || flag_draw || flag_contour) {
2730: Mat Bexp_mine = NULL,Bexp,FDexp;
2731: PetscViewer vdraw,vstdout;
2732: PetscBool flg;
2733: if (flag_operator) {
2734: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2735: Bexp = Bexp_mine;
2736: } else {
2737: /* See if the preconditioning matrix can be viewed and added directly */
2738: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2739: if (flg) Bexp = B;
2740: else {
2741: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2742: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2743: Bexp = Bexp_mine;
2744: }
2745: }
2746: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2747: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2748: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2749: if (flag_draw || flag_contour) {
2750: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2751: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2752: } else vdraw = NULL;
2753: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2754: if (flag) {MatView(Bexp,vstdout);}
2755: if (vdraw) {MatView(Bexp,vdraw);}
2756: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2757: if (flag) {MatView(FDexp,vstdout);}
2758: if (vdraw) {MatView(FDexp,vdraw);}
2759: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2760: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2761: if (flag) {MatView(FDexp,vstdout);}
2762: if (vdraw) { /* Always use contour for the difference */
2763: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2764: MatView(FDexp,vdraw);
2765: PetscViewerPopFormat(vdraw);
2766: }
2767: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2768: PetscViewerDestroy(&vdraw);
2769: MatDestroy(&Bexp_mine);
2770: MatDestroy(&FDexp);
2771: }
2772: }
2773: {
2774: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2775: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2776: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2777: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2778: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2779: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2780: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2781: if (flag_threshold) {
2782: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2783: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2784: }
2785: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2786: Mat Bfd;
2787: PetscViewer vdraw,vstdout;
2788: MatColoring coloring;
2789: ISColoring iscoloring;
2790: MatFDColoring matfdcoloring;
2791: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2792: void *funcctx;
2793: PetscReal norm1,norm2,normmax;
2795: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2796: MatColoringCreate(Bfd,&coloring);
2797: MatColoringSetType(coloring,MATCOLORINGSL);
2798: MatColoringSetFromOptions(coloring);
2799: MatColoringApply(coloring,&iscoloring);
2800: MatColoringDestroy(&coloring);
2801: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2802: MatFDColoringSetFromOptions(matfdcoloring);
2803: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2804: ISColoringDestroy(&iscoloring);
2806: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2807: SNESGetFunction(snes,NULL,&func,&funcctx);
2808: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2809: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2810: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2811: MatFDColoringSetFromOptions(matfdcoloring);
2812: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2813: MatFDColoringDestroy(&matfdcoloring);
2815: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2816: if (flag_draw || flag_contour) {
2817: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2818: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2819: } else vdraw = NULL;
2820: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2821: if (flag_display) {MatView(B,vstdout);}
2822: if (vdraw) {MatView(B,vdraw);}
2823: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2824: if (flag_display) {MatView(Bfd,vstdout);}
2825: if (vdraw) {MatView(Bfd,vdraw);}
2826: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2827: MatNorm(Bfd,NORM_1,&norm1);
2828: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2829: MatNorm(Bfd,NORM_MAX,&normmax);
2830: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2831: if (flag_display) {MatView(Bfd,vstdout);}
2832: if (vdraw) { /* Always use contour for the difference */
2833: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2834: MatView(Bfd,vdraw);
2835: PetscViewerPopFormat(vdraw);
2836: }
2837: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2839: if (flag_threshold) {
2840: PetscInt bs,rstart,rend,i;
2841: MatGetBlockSize(B,&bs);
2842: MatGetOwnershipRange(B,&rstart,&rend);
2843: for (i=rstart; i<rend; i++) {
2844: const PetscScalar *ba,*ca;
2845: const PetscInt *bj,*cj;
2846: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2847: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2848: MatGetRow(B,i,&bn,&bj,&ba);
2849: MatGetRow(Bfd,i,&cn,&cj,&ca);
2850: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2851: for (j=0; j<bn; j++) {
2852: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2853: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2854: maxentrycol = bj[j];
2855: maxentry = PetscRealPart(ba[j]);
2856: }
2857: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2858: maxdiffcol = bj[j];
2859: maxdiff = PetscRealPart(ca[j]);
2860: }
2861: if (rdiff > maxrdiff) {
2862: maxrdiffcol = bj[j];
2863: maxrdiff = rdiff;
2864: }
2865: }
2866: if (maxrdiff > 1) {
2867: 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);
2868: for (j=0; j<bn; j++) {
2869: PetscReal rdiff;
2870: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2871: if (rdiff > 1) {
2872: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2873: }
2874: }
2875: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2876: }
2877: MatRestoreRow(B,i,&bn,&bj,&ba);
2878: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2879: }
2880: }
2881: PetscViewerDestroy(&vdraw);
2882: MatDestroy(&Bfd);
2883: }
2884: }
2885: return(0);
2886: }
2888: /*MC
2889: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2891: Synopsis:
2892: #include "petscsnes.h"
2893: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2895: + x - input vector
2896: . Amat - the matrix that defines the (approximate) Jacobian
2897: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2898: - ctx - [optional] user-defined Jacobian context
2900: Level: intermediate
2902: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2903: M*/
2905: /*@C
2906: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2907: location to store the matrix.
2909: Logically Collective on SNES
2911: Input Parameters:
2912: + snes - the SNES context
2913: . Amat - the matrix that defines the (approximate) Jacobian
2914: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2915: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2916: - ctx - [optional] user-defined context for private data for the
2917: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2919: Notes:
2920: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2921: each matrix.
2923: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2924: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2926: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2927: must be a MatFDColoring.
2929: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2930: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2932: Level: beginner
2934: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2935: SNESSetPicard(), SNESJacobianFunction
2936: @*/
2937: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2938: {
2940: DM dm;
2948: SNESGetDM(snes,&dm);
2949: DMSNESSetJacobian(dm,J,ctx);
2950: if (Amat) {
2951: PetscObjectReference((PetscObject)Amat);
2952: MatDestroy(&snes->jacobian);
2954: snes->jacobian = Amat;
2955: }
2956: if (Pmat) {
2957: PetscObjectReference((PetscObject)Pmat);
2958: MatDestroy(&snes->jacobian_pre);
2960: snes->jacobian_pre = Pmat;
2961: }
2962: return(0);
2963: }
2965: /*@C
2966: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2967: provided context for evaluating the Jacobian.
2969: Not Collective, but Mat object will be parallel if SNES object is
2971: Input Parameter:
2972: . snes - the nonlinear solver context
2974: Output Parameters:
2975: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2976: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2977: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2978: - ctx - location to stash Jacobian ctx (or NULL)
2980: Level: advanced
2982: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2983: @*/
2984: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2985: {
2987: DM dm;
2988: DMSNES sdm;
2992: if (Amat) *Amat = snes->jacobian;
2993: if (Pmat) *Pmat = snes->jacobian_pre;
2994: SNESGetDM(snes,&dm);
2995: DMGetDMSNES(dm,&sdm);
2996: if (J) *J = sdm->ops->computejacobian;
2997: if (ctx) *ctx = sdm->jacobianctx;
2998: return(0);
2999: }
3001: /*@
3002: SNESSetUp - Sets up the internal data structures for the later use
3003: of a nonlinear solver.
3005: Collective on SNES
3007: Input Parameters:
3008: . snes - the SNES context
3010: Notes:
3011: For basic use of the SNES solvers the user need not explicitly call
3012: SNESSetUp(), since these actions will automatically occur during
3013: the call to SNESSolve(). However, if one wishes to control this
3014: phase separately, SNESSetUp() should be called after SNESCreate()
3015: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3017: Level: advanced
3019: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3020: @*/
3021: PetscErrorCode SNESSetUp(SNES snes)
3022: {
3024: DM dm;
3025: DMSNES sdm;
3026: SNESLineSearch linesearch, pclinesearch;
3027: void *lsprectx,*lspostctx;
3028: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3029: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3030: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3031: Vec f,fpc;
3032: void *funcctx;
3033: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3034: void *jacctx,*appctx;
3035: Mat j,jpre;
3039: if (snes->setupcalled) return(0);
3040: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3042: if (!((PetscObject)snes)->type_name) {
3043: SNESSetType(snes,SNESNEWTONLS);
3044: }
3046: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3048: SNESGetDM(snes,&dm);
3049: DMGetDMSNES(dm,&sdm);
3050: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3051: if (!sdm->ops->computejacobian) {
3052: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3053: }
3054: if (!snes->vec_func) {
3055: DMCreateGlobalVector(dm,&snes->vec_func);
3056: }
3058: if (!snes->ksp) {
3059: SNESGetKSP(snes, &snes->ksp);
3060: }
3062: if (snes->linesearch) {
3063: SNESGetLineSearch(snes, &snes->linesearch);
3064: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3065: }
3067: if (snes->npc && (snes->npcside== PC_LEFT)) {
3068: snes->mf = PETSC_TRUE;
3069: snes->mf_operator = PETSC_FALSE;
3070: }
3072: if (snes->npc) {
3073: /* copy the DM over */
3074: SNESGetDM(snes,&dm);
3075: SNESSetDM(snes->npc,dm);
3077: SNESGetFunction(snes,&f,&func,&funcctx);
3078: VecDuplicate(f,&fpc);
3079: SNESSetFunction(snes->npc,fpc,func,funcctx);
3080: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3081: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3082: SNESGetApplicationContext(snes,&appctx);
3083: SNESSetApplicationContext(snes->npc,appctx);
3084: VecDestroy(&fpc);
3086: /* copy the function pointers over */
3087: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3089: /* default to 1 iteration */
3090: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3091: if (snes->npcside==PC_RIGHT) {
3092: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3093: } else {
3094: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3095: }
3096: SNESSetFromOptions(snes->npc);
3098: /* copy the line search context over */
3099: if (snes->linesearch && snes->npc->linesearch) {
3100: SNESGetLineSearch(snes,&linesearch);
3101: SNESGetLineSearch(snes->npc,&pclinesearch);
3102: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3103: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3104: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3105: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3106: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3107: }
3108: }
3109: if (snes->mf) {
3110: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3111: }
3112: if (snes->ops->usercompute && !snes->user) {
3113: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3114: }
3116: snes->jac_iter = 0;
3117: snes->pre_iter = 0;
3119: if (snes->ops->setup) {
3120: (*snes->ops->setup)(snes);
3121: }
3123: if (snes->npc && (snes->npcside== PC_LEFT)) {
3124: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3125: if (snes->linesearch){
3126: SNESGetLineSearch(snes,&linesearch);
3127: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3128: }
3129: }
3130: }
3131: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3132: snes->setupcalled = PETSC_TRUE;
3133: return(0);
3134: }
3136: /*@
3137: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3139: Collective on SNES
3141: Input Parameter:
3142: . snes - iterative context obtained from SNESCreate()
3144: Level: intermediate
3146: Notes:
3147: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3149: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3150: @*/
3151: PetscErrorCode SNESReset(SNES snes)
3152: {
3157: if (snes->ops->userdestroy && snes->user) {
3158: (*snes->ops->userdestroy)((void**)&snes->user);
3159: snes->user = NULL;
3160: }
3161: if (snes->npc) {
3162: SNESReset(snes->npc);
3163: }
3165: if (snes->ops->reset) {
3166: (*snes->ops->reset)(snes);
3167: }
3168: if (snes->ksp) {
3169: KSPReset(snes->ksp);
3170: }
3172: if (snes->linesearch) {
3173: SNESLineSearchReset(snes->linesearch);
3174: }
3176: VecDestroy(&snes->vec_rhs);
3177: VecDestroy(&snes->vec_sol);
3178: VecDestroy(&snes->vec_sol_update);
3179: VecDestroy(&snes->vec_func);
3180: MatDestroy(&snes->jacobian);
3181: MatDestroy(&snes->jacobian_pre);
3182: VecDestroyVecs(snes->nwork,&snes->work);
3183: VecDestroyVecs(snes->nvwork,&snes->vwork);
3185: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3187: snes->nwork = snes->nvwork = 0;
3188: snes->setupcalled = PETSC_FALSE;
3189: return(0);
3190: }
3192: /*@
3193: SNESDestroy - Destroys the nonlinear solver context that was created
3194: with SNESCreate().
3196: Collective on SNES
3198: Input Parameter:
3199: . snes - the SNES context
3201: Level: beginner
3203: .seealso: SNESCreate(), SNESSolve()
3204: @*/
3205: PetscErrorCode SNESDestroy(SNES *snes)
3206: {
3210: if (!*snes) return(0);
3212: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3214: SNESReset((*snes));
3215: SNESDestroy(&(*snes)->npc);
3217: /* if memory was published with SAWs then destroy it */
3218: PetscObjectSAWsViewOff((PetscObject)*snes);
3219: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3221: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3222: DMDestroy(&(*snes)->dm);
3223: KSPDestroy(&(*snes)->ksp);
3224: SNESLineSearchDestroy(&(*snes)->linesearch);
3226: PetscFree((*snes)->kspconvctx);
3227: if ((*snes)->ops->convergeddestroy) {
3228: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3229: }
3230: if ((*snes)->conv_hist_alloc) {
3231: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3232: }
3233: SNESMonitorCancel((*snes));
3234: PetscHeaderDestroy(snes);
3235: return(0);
3236: }
3238: /* ----------- Routines to set solver parameters ---------- */
3240: /*@
3241: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3243: Logically Collective on SNES
3245: Input Parameters:
3246: + snes - the SNES context
3247: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3248: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3250: Options Database Keys:
3251: . -snes_lag_preconditioner <lag>
3253: Notes:
3254: The default is 1
3255: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3256: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3258: Level: intermediate
3260: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3262: @*/
3263: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3264: {
3267: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3268: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3270: snes->lagpreconditioner = lag;
3271: return(0);
3272: }
3274: /*@
3275: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3277: Logically Collective on SNES
3279: Input Parameters:
3280: + snes - the SNES context
3281: - steps - the number of refinements to do, defaults to 0
3283: Options Database Keys:
3284: . -snes_grid_sequence <steps>
3286: Level: intermediate
3288: Notes:
3289: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3291: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3293: @*/
3294: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3295: {
3299: snes->gridsequence = steps;
3300: return(0);
3301: }
3303: /*@
3304: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3306: Logically Collective on SNES
3308: Input Parameter:
3309: . snes - the SNES context
3311: Output Parameter:
3312: . steps - the number of refinements to do, defaults to 0
3314: Options Database Keys:
3315: . -snes_grid_sequence <steps>
3317: Level: intermediate
3319: Notes:
3320: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3322: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3324: @*/
3325: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3326: {
3329: *steps = snes->gridsequence;
3330: return(0);
3331: }
3333: /*@
3334: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3336: Not Collective
3338: Input Parameter:
3339: . snes - the SNES context
3341: Output Parameter:
3342: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3343: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3345: Options Database Keys:
3346: . -snes_lag_preconditioner <lag>
3348: Notes:
3349: The default is 1
3350: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3352: Level: intermediate
3354: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3356: @*/
3357: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3358: {
3361: *lag = snes->lagpreconditioner;
3362: return(0);
3363: }
3365: /*@
3366: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3367: often the preconditioner is rebuilt.
3369: Logically Collective on SNES
3371: Input Parameters:
3372: + snes - the SNES context
3373: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3374: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3376: Options Database Keys:
3377: . -snes_lag_jacobian <lag>
3379: Notes:
3380: The default is 1
3381: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3382: 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
3383: at the next Newton step but never again (unless it is reset to another value)
3385: Level: intermediate
3387: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3389: @*/
3390: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3391: {
3394: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3395: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3397: snes->lagjacobian = lag;
3398: return(0);
3399: }
3401: /*@
3402: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3404: Not Collective
3406: Input Parameter:
3407: . snes - the SNES context
3409: Output Parameter:
3410: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3411: the Jacobian is built etc.
3413: Options Database Keys:
3414: . -snes_lag_jacobian <lag>
3416: Notes:
3417: The default is 1
3418: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3420: Level: intermediate
3422: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3424: @*/
3425: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3426: {
3429: *lag = snes->lagjacobian;
3430: return(0);
3431: }
3433: /*@
3434: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3436: Logically collective on SNES
3438: Input Parameter:
3439: + snes - the SNES context
3440: - flg - jacobian lagging persists if true
3442: Options Database Keys:
3443: . -snes_lag_jacobian_persists <flg>
3445: Notes:
3446: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3447: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3448: timesteps may present huge efficiency gains.
3450: Level: developer
3452: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3454: @*/
3455: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3456: {
3460: snes->lagjac_persist = flg;
3461: return(0);
3462: }
3464: /*@
3465: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3467: Logically Collective on SNES
3469: Input Parameter:
3470: + snes - the SNES context
3471: - flg - preconditioner lagging persists if true
3473: Options Database Keys:
3474: . -snes_lag_jacobian_persists <flg>
3476: Notes:
3477: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3478: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3479: several timesteps may present huge efficiency gains.
3481: Level: developer
3483: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3485: @*/
3486: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3487: {
3491: snes->lagpre_persist = flg;
3492: return(0);
3493: }
3495: /*@
3496: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3498: Logically Collective on SNES
3500: Input Parameters:
3501: + snes - the SNES context
3502: - force - PETSC_TRUE require at least one iteration
3504: Options Database Keys:
3505: . -snes_force_iteration <force> - Sets forcing an iteration
3507: Notes:
3508: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3510: Level: intermediate
3512: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3513: @*/
3514: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3515: {
3518: snes->forceiteration = force;
3519: return(0);
3520: }
3522: /*@
3523: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3525: Logically Collective on SNES
3527: Input Parameters:
3528: . snes - the SNES context
3530: Output Parameter:
3531: . force - PETSC_TRUE requires at least one iteration.
3533: Level: intermediate
3535: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3536: @*/
3537: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3538: {
3541: *force = snes->forceiteration;
3542: return(0);
3543: }
3545: /*@
3546: SNESSetTolerances - Sets various parameters used in convergence tests.
3548: Logically Collective on SNES
3550: Input Parameters:
3551: + snes - the SNES context
3552: . abstol - absolute convergence tolerance
3553: . rtol - relative convergence tolerance
3554: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3555: . maxit - maximum number of iterations
3556: - maxf - maximum number of function evaluations (-1 indicates no limit)
3558: Options Database Keys:
3559: + -snes_atol <abstol> - Sets abstol
3560: . -snes_rtol <rtol> - Sets rtol
3561: . -snes_stol <stol> - Sets stol
3562: . -snes_max_it <maxit> - Sets maxit
3563: - -snes_max_funcs <maxf> - Sets maxf
3565: Notes:
3566: The default maximum number of iterations is 50.
3567: The default maximum number of function evaluations is 1000.
3569: Level: intermediate
3571: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3572: @*/
3573: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3574: {
3583: if (abstol != PETSC_DEFAULT) {
3584: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3585: snes->abstol = abstol;
3586: }
3587: if (rtol != PETSC_DEFAULT) {
3588: 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);
3589: snes->rtol = rtol;
3590: }
3591: if (stol != PETSC_DEFAULT) {
3592: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3593: snes->stol = stol;
3594: }
3595: if (maxit != PETSC_DEFAULT) {
3596: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3597: snes->max_its = maxit;
3598: }
3599: if (maxf != PETSC_DEFAULT) {
3600: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3601: snes->max_funcs = maxf;
3602: }
3603: snes->tolerancesset = PETSC_TRUE;
3604: return(0);
3605: }
3607: /*@
3608: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3610: Logically Collective on SNES
3612: Input Parameters:
3613: + snes - the SNES context
3614: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3616: Options Database Keys:
3617: . -snes_divergence_tolerance <divtol> - Sets divtol
3619: Notes:
3620: The default divergence tolerance is 1e4.
3622: Level: intermediate
3624: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3625: @*/
3626: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3627: {
3632: if (divtol != PETSC_DEFAULT) {
3633: snes->divtol = divtol;
3634: }
3635: else {
3636: snes->divtol = 1.0e4;
3637: }
3638: return(0);
3639: }
3641: /*@
3642: SNESGetTolerances - Gets various parameters used in convergence tests.
3644: Not Collective
3646: Input Parameters:
3647: + snes - the SNES context
3648: . atol - absolute convergence tolerance
3649: . rtol - relative convergence tolerance
3650: . stol - convergence tolerance in terms of the norm
3651: of the change in the solution between steps
3652: . maxit - maximum number of iterations
3653: - maxf - maximum number of function evaluations
3655: Notes:
3656: The user can specify NULL for any parameter that is not needed.
3658: Level: intermediate
3660: .seealso: SNESSetTolerances()
3661: @*/
3662: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3663: {
3666: if (atol) *atol = snes->abstol;
3667: if (rtol) *rtol = snes->rtol;
3668: if (stol) *stol = snes->stol;
3669: if (maxit) *maxit = snes->max_its;
3670: if (maxf) *maxf = snes->max_funcs;
3671: return(0);
3672: }
3674: /*@
3675: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3677: Not Collective
3679: Input Parameters:
3680: + snes - the SNES context
3681: - divtol - divergence tolerance
3683: Level: intermediate
3685: .seealso: SNESSetDivergenceTolerance()
3686: @*/
3687: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3688: {
3691: if (divtol) *divtol = snes->divtol;
3692: return(0);
3693: }
3695: /*@
3696: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3698: Logically Collective on SNES
3700: Input Parameters:
3701: + snes - the SNES context
3702: - tol - tolerance
3704: Options Database Key:
3705: . -snes_trtol <tol> - Sets tol
3707: Level: intermediate
3709: .seealso: SNESSetTolerances()
3710: @*/
3711: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3712: {
3716: snes->deltatol = tol;
3717: return(0);
3718: }
3720: /*
3721: Duplicate the lg monitors for SNES from KSP; for some reason with
3722: dynamic libraries things don't work under Sun4 if we just use
3723: macros instead of functions
3724: */
3725: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3726: {
3731: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3732: return(0);
3733: }
3735: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3736: {
3740: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3741: return(0);
3742: }
3744: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3746: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3747: {
3748: PetscDrawLG lg;
3749: PetscErrorCode ierr;
3750: PetscReal x,y,per;
3751: PetscViewer v = (PetscViewer)monctx;
3752: static PetscReal prev; /* should be in the context */
3753: PetscDraw draw;
3757: PetscViewerDrawGetDrawLG(v,0,&lg);
3758: if (!n) {PetscDrawLGReset(lg);}
3759: PetscDrawLGGetDraw(lg,&draw);
3760: PetscDrawSetTitle(draw,"Residual norm");
3761: x = (PetscReal)n;
3762: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3763: else y = -15.0;
3764: PetscDrawLGAddPoint(lg,&x,&y);
3765: if (n < 20 || !(n % 5) || snes->reason) {
3766: PetscDrawLGDraw(lg);
3767: PetscDrawLGSave(lg);
3768: }
3770: PetscViewerDrawGetDrawLG(v,1,&lg);
3771: if (!n) {PetscDrawLGReset(lg);}
3772: PetscDrawLGGetDraw(lg,&draw);
3773: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3774: SNESMonitorRange_Private(snes,n,&per);
3775: x = (PetscReal)n;
3776: y = 100.0*per;
3777: PetscDrawLGAddPoint(lg,&x,&y);
3778: if (n < 20 || !(n % 5) || snes->reason) {
3779: PetscDrawLGDraw(lg);
3780: PetscDrawLGSave(lg);
3781: }
3783: PetscViewerDrawGetDrawLG(v,2,&lg);
3784: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3785: PetscDrawLGGetDraw(lg,&draw);
3786: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3787: x = (PetscReal)n;
3788: y = (prev - rnorm)/prev;
3789: PetscDrawLGAddPoint(lg,&x,&y);
3790: if (n < 20 || !(n % 5) || snes->reason) {
3791: PetscDrawLGDraw(lg);
3792: PetscDrawLGSave(lg);
3793: }
3795: PetscViewerDrawGetDrawLG(v,3,&lg);
3796: if (!n) {PetscDrawLGReset(lg);}
3797: PetscDrawLGGetDraw(lg,&draw);
3798: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3799: x = (PetscReal)n;
3800: y = (prev - rnorm)/(prev*per);
3801: if (n > 2) { /*skip initial crazy value */
3802: PetscDrawLGAddPoint(lg,&x,&y);
3803: }
3804: if (n < 20 || !(n % 5) || snes->reason) {
3805: PetscDrawLGDraw(lg);
3806: PetscDrawLGSave(lg);
3807: }
3808: prev = rnorm;
3809: return(0);
3810: }
3812: /*@
3813: SNESMonitor - runs the user provided monitor routines, if they exist
3815: Collective on SNES
3817: Input Parameters:
3818: + snes - nonlinear solver context obtained from SNESCreate()
3819: . iter - iteration number
3820: - rnorm - relative norm of the residual
3822: Notes:
3823: This routine is called by the SNES implementations.
3824: It does not typically need to be called by the user.
3826: Level: developer
3828: .seealso: SNESMonitorSet()
3829: @*/
3830: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3831: {
3833: PetscInt i,n = snes->numbermonitors;
3836: VecLockReadPush(snes->vec_sol);
3837: for (i=0; i<n; i++) {
3838: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3839: }
3840: VecLockReadPop(snes->vec_sol);
3841: return(0);
3842: }
3844: /* ------------ Routines to set performance monitoring options ----------- */
3846: /*MC
3847: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3849: Synopsis:
3850: #include <petscsnes.h>
3851: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3853: + snes - the SNES context
3854: . its - iteration number
3855: . norm - 2-norm function value (may be estimated)
3856: - mctx - [optional] monitoring context
3858: Level: advanced
3860: .seealso: SNESMonitorSet(), SNESMonitorGet()
3861: M*/
3863: /*@C
3864: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3865: iteration of the nonlinear solver to display the iteration's
3866: progress.
3868: Logically Collective on SNES
3870: Input Parameters:
3871: + snes - the SNES context
3872: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3873: . mctx - [optional] user-defined context for private data for the
3874: monitor routine (use NULL if no context is desired)
3875: - monitordestroy - [optional] routine that frees monitor context
3876: (may be NULL)
3878: Options Database Keys:
3879: + -snes_monitor - sets SNESMonitorDefault()
3880: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3881: uses SNESMonitorLGCreate()
3882: - -snes_monitor_cancel - cancels all monitors that have
3883: been hardwired into a code by
3884: calls to SNESMonitorSet(), but
3885: does not cancel those set via
3886: the options database.
3888: Notes:
3889: Several different monitoring routines may be set by calling
3890: SNESMonitorSet() multiple times; all will be called in the
3891: order in which they were set.
3893: Fortran Notes:
3894: Only a single monitor function can be set for each SNES object
3896: Level: intermediate
3898: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3899: @*/
3900: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3901: {
3902: PetscInt i;
3904: PetscBool identical;
3908: for (i=0; i<snes->numbermonitors;i++) {
3909: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3910: if (identical) return(0);
3911: }
3912: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3913: snes->monitor[snes->numbermonitors] = f;
3914: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3915: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3916: return(0);
3917: }
3919: /*@
3920: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3922: Logically Collective on SNES
3924: Input Parameters:
3925: . snes - the SNES context
3927: Options Database Key:
3928: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3929: into a code by calls to SNESMonitorSet(), but does not cancel those
3930: set via the options database
3932: Notes:
3933: There is no way to clear one specific monitor from a SNES object.
3935: Level: intermediate
3937: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3938: @*/
3939: PetscErrorCode SNESMonitorCancel(SNES snes)
3940: {
3942: PetscInt i;
3946: for (i=0; i<snes->numbermonitors; i++) {
3947: if (snes->monitordestroy[i]) {
3948: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3949: }
3950: }
3951: snes->numbermonitors = 0;
3952: return(0);
3953: }
3955: /*MC
3956: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3958: Synopsis:
3959: #include <petscsnes.h>
3960: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3962: + snes - the SNES context
3963: . it - current iteration (0 is the first and is before any Newton step)
3964: . cctx - [optional] convergence context
3965: . reason - reason for convergence/divergence
3966: . xnorm - 2-norm of current iterate
3967: . gnorm - 2-norm of current step
3968: - f - 2-norm of function
3970: Level: intermediate
3972: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3973: M*/
3975: /*@C
3976: SNESSetConvergenceTest - Sets the function that is to be used
3977: to test for convergence of the nonlinear iterative solution.
3979: Logically Collective on SNES
3981: Input Parameters:
3982: + snes - the SNES context
3983: . SNESConvergenceTestFunction - routine to test for convergence
3984: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3985: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
3987: Level: advanced
3989: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3990: @*/
3991: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3992: {
3997: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3998: if (snes->ops->convergeddestroy) {
3999: (*snes->ops->convergeddestroy)(snes->cnvP);
4000: }
4001: snes->ops->converged = SNESConvergenceTestFunction;
4002: snes->ops->convergeddestroy = destroy;
4003: snes->cnvP = cctx;
4004: return(0);
4005: }
4007: /*@
4008: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4010: Not Collective
4012: Input Parameter:
4013: . snes - the SNES context
4015: Output Parameter:
4016: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4017: manual pages for the individual convergence tests for complete lists
4019: Options Database:
4020: . -snes_converged_reason - prints the reason to standard out
4022: Level: intermediate
4024: Notes:
4025: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4027: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4028: @*/
4029: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4030: {
4034: *reason = snes->reason;
4035: return(0);
4036: }
4038: /*@
4039: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4041: Not Collective
4043: Input Parameters:
4044: + snes - the SNES context
4045: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4046: manual pages for the individual convergence tests for complete lists
4048: Level: intermediate
4050: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4051: @*/
4052: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4053: {
4056: snes->reason = reason;
4057: return(0);
4058: }
4060: /*@
4061: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4063: Logically Collective on SNES
4065: Input Parameters:
4066: + snes - iterative context obtained from SNESCreate()
4067: . a - array to hold history, this array will contain the function norms computed at each step
4068: . its - integer array holds the number of linear iterations for each solve.
4069: . na - size of a and its
4070: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4071: else it continues storing new values for new nonlinear solves after the old ones
4073: Notes:
4074: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4075: default array of length 10000 is allocated.
4077: This routine is useful, e.g., when running a code for purposes
4078: of accurate performance monitoring, when no I/O should be done
4079: during the section of code that is being timed.
4081: Level: intermediate
4083: .seealso: SNESGetConvergenceHistory()
4085: @*/
4086: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4087: {
4094: if (!a) {
4095: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4096: PetscCalloc2(na,&a,na,&its);
4097: snes->conv_hist_alloc = PETSC_TRUE;
4098: }
4099: snes->conv_hist = a;
4100: snes->conv_hist_its = its;
4101: snes->conv_hist_max = na;
4102: snes->conv_hist_len = 0;
4103: snes->conv_hist_reset = reset;
4104: return(0);
4105: }
4107: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4108: #include <engine.h> /* MATLAB include file */
4109: #include <mex.h> /* MATLAB include file */
4111: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4112: {
4113: mxArray *mat;
4114: PetscInt i;
4115: PetscReal *ar;
4118: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4119: ar = (PetscReal*) mxGetData(mat);
4120: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4121: PetscFunctionReturn(mat);
4122: }
4123: #endif
4125: /*@C
4126: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4128: Not Collective
4130: Input Parameter:
4131: . snes - iterative context obtained from SNESCreate()
4133: Output Parameters:
4134: + a - array to hold history
4135: . its - integer array holds the number of linear iterations (or
4136: negative if not converged) for each solve.
4137: - na - size of a and its
4139: Notes:
4140: The calling sequence for this routine in Fortran is
4141: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4143: This routine is useful, e.g., when running a code for purposes
4144: of accurate performance monitoring, when no I/O should be done
4145: during the section of code that is being timed.
4147: Level: intermediate
4149: .seealso: SNESSetConvergencHistory()
4151: @*/
4152: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4153: {
4156: if (a) *a = snes->conv_hist;
4157: if (its) *its = snes->conv_hist_its;
4158: if (na) *na = snes->conv_hist_len;
4159: return(0);
4160: }
4162: /*@C
4163: SNESSetUpdate - Sets the general-purpose update function called
4164: at the beginning of every iteration of the nonlinear solve. Specifically
4165: it is called just before the Jacobian is "evaluated".
4167: Logically Collective on SNES
4169: Input Parameters:
4170: + snes - The nonlinear solver context
4171: - func - The function
4173: Calling sequence of func:
4174: $ func (SNES snes, PetscInt step);
4176: . step - The current step of the iteration
4178: Level: advanced
4180: 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()
4181: This is not used by most users.
4183: .seealso SNESSetJacobian(), SNESSolve()
4184: @*/
4185: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4186: {
4189: snes->ops->update = func;
4190: return(0);
4191: }
4193: /*
4194: SNESScaleStep_Private - Scales a step so that its length is less than the
4195: positive parameter delta.
4197: Input Parameters:
4198: + snes - the SNES context
4199: . y - approximate solution of linear system
4200: . fnorm - 2-norm of current function
4201: - delta - trust region size
4203: Output Parameters:
4204: + gpnorm - predicted function norm at the new point, assuming local
4205: linearization. The value is zero if the step lies within the trust
4206: region, and exceeds zero otherwise.
4207: - ynorm - 2-norm of the step
4209: Note:
4210: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4211: is set to be the maximum allowable step size.
4213: */
4214: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4215: {
4216: PetscReal nrm;
4217: PetscScalar cnorm;
4225: VecNorm(y,NORM_2,&nrm);
4226: if (nrm > *delta) {
4227: nrm = *delta/nrm;
4228: *gpnorm = (1.0 - nrm)*(*fnorm);
4229: cnorm = nrm;
4230: VecScale(y,cnorm);
4231: *ynorm = *delta;
4232: } else {
4233: *gpnorm = 0.0;
4234: *ynorm = nrm;
4235: }
4236: return(0);
4237: }
4239: /*@
4240: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4242: Collective on SNES
4244: Parameter:
4245: + snes - iterative context obtained from SNESCreate()
4246: - viewer - the viewer to display the reason
4249: Options Database Keys:
4250: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4252: Level: beginner
4254: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4256: @*/
4257: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4258: {
4259: PetscViewerFormat format;
4260: PetscBool isAscii;
4261: PetscErrorCode ierr;
4264: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4265: if (isAscii) {
4266: PetscViewerGetFormat(viewer, &format);
4267: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4268: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4269: DM dm;
4270: Vec u;
4271: PetscDS prob;
4272: PetscInt Nf, f;
4273: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4274: void **exactCtx;
4275: PetscReal error;
4277: SNESGetDM(snes, &dm);
4278: SNESGetSolution(snes, &u);
4279: DMGetDS(dm, &prob);
4280: PetscDSGetNumFields(prob, &Nf);
4281: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4282: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4283: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4284: PetscFree2(exactSol, exactCtx);
4285: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4286: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4287: }
4288: if (snes->reason > 0) {
4289: if (((PetscObject) snes)->prefix) {
4290: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4291: } else {
4292: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4293: }
4294: } else {
4295: if (((PetscObject) snes)->prefix) {
4296: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4297: } else {
4298: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4299: }
4300: }
4301: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4302: }
4303: return(0);
4304: }
4306: /*@C
4307: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4309: Collective on SNES
4311: Input Parameters:
4312: . snes - the SNES object
4314: Level: intermediate
4316: @*/
4317: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4318: {
4319: PetscErrorCode ierr;
4320: PetscViewer viewer;
4321: PetscBool flg;
4322: static PetscBool incall = PETSC_FALSE;
4323: PetscViewerFormat format;
4326: if (incall) return(0);
4327: incall = PETSC_TRUE;
4328: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4329: if (flg) {
4330: PetscViewerPushFormat(viewer,format);
4331: SNESReasonView(snes,viewer);
4332: PetscViewerPopFormat(viewer);
4333: PetscViewerDestroy(&viewer);
4334: }
4335: incall = PETSC_FALSE;
4336: return(0);
4337: }
4339: /*@
4340: SNESSolve - Solves a nonlinear system F(x) = b.
4341: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4343: Collective on SNES
4345: Input Parameters:
4346: + snes - the SNES context
4347: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4348: - x - the solution vector.
4350: Notes:
4351: The user should initialize the vector,x, with the initial guess
4352: for the nonlinear solve prior to calling SNESSolve. In particular,
4353: to employ an initial guess of zero, the user should explicitly set
4354: this vector to zero by calling VecSet().
4356: Level: beginner
4358: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4359: @*/
4360: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4361: {
4362: PetscErrorCode ierr;
4363: PetscBool flg;
4364: PetscInt grid;
4365: Vec xcreated = NULL;
4366: DM dm;
4375: /* High level operations using the nonlinear solver */
4376: {
4377: PetscViewer viewer;
4378: PetscViewerFormat format;
4379: PetscInt num;
4380: PetscBool flg;
4381: static PetscBool incall = PETSC_FALSE;
4383: if (!incall) {
4384: /* Estimate the convergence rate of the discretization */
4385: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4386: if (flg) {
4387: PetscConvEst conv;
4388: DM dm;
4389: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4390: PetscInt Nf;
4392: incall = PETSC_TRUE;
4393: SNESGetDM(snes, &dm);
4394: DMGetNumFields(dm, &Nf);
4395: PetscCalloc1(Nf, &alpha);
4396: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4397: PetscConvEstSetSolver(conv, (PetscObject) snes);
4398: PetscConvEstSetFromOptions(conv);
4399: PetscConvEstSetUp(conv);
4400: PetscConvEstGetConvRate(conv, alpha);
4401: PetscViewerPushFormat(viewer, format);
4402: PetscConvEstRateView(conv, alpha, viewer);
4403: PetscViewerPopFormat(viewer);
4404: PetscViewerDestroy(&viewer);
4405: PetscConvEstDestroy(&conv);
4406: PetscFree(alpha);
4407: incall = PETSC_FALSE;
4408: }
4409: /* Adaptively refine the initial grid */
4410: num = 1;
4411: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4412: if (flg) {
4413: DMAdaptor adaptor;
4415: incall = PETSC_TRUE;
4416: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4417: DMAdaptorSetSolver(adaptor, snes);
4418: DMAdaptorSetSequenceLength(adaptor, num);
4419: DMAdaptorSetFromOptions(adaptor);
4420: DMAdaptorSetUp(adaptor);
4421: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4422: DMAdaptorDestroy(&adaptor);
4423: incall = PETSC_FALSE;
4424: }
4425: /* Use grid sequencing to adapt */
4426: num = 0;
4427: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4428: if (num) {
4429: DMAdaptor adaptor;
4431: incall = PETSC_TRUE;
4432: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4433: DMAdaptorSetSolver(adaptor, snes);
4434: DMAdaptorSetSequenceLength(adaptor, num);
4435: DMAdaptorSetFromOptions(adaptor);
4436: DMAdaptorSetUp(adaptor);
4437: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4438: DMAdaptorDestroy(&adaptor);
4439: incall = PETSC_FALSE;
4440: }
4441: }
4442: }
4443: if (!x) {
4444: SNESGetDM(snes,&dm);
4445: DMCreateGlobalVector(dm,&xcreated);
4446: x = xcreated;
4447: }
4448: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4450: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4451: for (grid=0; grid<snes->gridsequence+1; grid++) {
4453: /* set solution vector */
4454: if (!grid) {PetscObjectReference((PetscObject)x);}
4455: VecDestroy(&snes->vec_sol);
4456: snes->vec_sol = x;
4457: SNESGetDM(snes,&dm);
4459: /* set affine vector if provided */
4460: if (b) { PetscObjectReference((PetscObject)b); }
4461: VecDestroy(&snes->vec_rhs);
4462: snes->vec_rhs = b;
4464: 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");
4465: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4466: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4467: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4468: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4469: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4470: }
4471: DMShellSetGlobalVector(dm,snes->vec_sol);
4472: SNESSetUp(snes);
4474: if (!grid) {
4475: if (snes->ops->computeinitialguess) {
4476: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4477: }
4478: }
4480: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4481: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4483: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4484: (*snes->ops->solve)(snes);
4485: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4486: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4487: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4489: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4490: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4492: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4493: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4494: SNESReasonViewFromOptions(snes);
4496: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4497: if (snes->reason < 0) break;
4498: if (grid < snes->gridsequence) {
4499: DM fine;
4500: Vec xnew;
4501: Mat interp;
4503: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4504: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4505: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4506: DMCreateGlobalVector(fine,&xnew);
4507: MatInterpolate(interp,x,xnew);
4508: DMInterpolate(snes->dm,interp,fine);
4509: MatDestroy(&interp);
4510: x = xnew;
4512: SNESReset(snes);
4513: SNESSetDM(snes,fine);
4514: SNESResetFromOptions(snes);
4515: DMDestroy(&fine);
4516: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4517: }
4518: }
4519: SNESViewFromOptions(snes,NULL,"-snes_view");
4520: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4522: VecDestroy(&xcreated);
4523: PetscObjectSAWsBlock((PetscObject)snes);
4524: return(0);
4525: }
4527: /* --------- Internal routines for SNES Package --------- */
4529: /*@C
4530: SNESSetType - Sets the method for the nonlinear solver.
4532: Collective on SNES
4534: Input Parameters:
4535: + snes - the SNES context
4536: - type - a known method
4538: Options Database Key:
4539: . -snes_type <type> - Sets the method; use -help for a list
4540: of available methods (for instance, newtonls or newtontr)
4542: Notes:
4543: See "petsc/include/petscsnes.h" for available methods (for instance)
4544: + SNESNEWTONLS - Newton's method with line search
4545: (systems of nonlinear equations)
4546: - SNESNEWTONTR - Newton's method with trust region
4547: (systems of nonlinear equations)
4549: Normally, it is best to use the SNESSetFromOptions() command and then
4550: set the SNES solver type from the options database rather than by using
4551: this routine. Using the options database provides the user with
4552: maximum flexibility in evaluating the many nonlinear solvers.
4553: The SNESSetType() routine is provided for those situations where it
4554: is necessary to set the nonlinear solver independently of the command
4555: line or options database. This might be the case, for example, when
4556: the choice of solver changes during the execution of the program,
4557: and the user's application is taking responsibility for choosing the
4558: appropriate method.
4560: Developer Notes:
4561: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4562: the constructor in that list and calls it to create the spexific object.
4564: Level: intermediate
4566: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4568: @*/
4569: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4570: {
4571: PetscErrorCode ierr,(*r)(SNES);
4572: PetscBool match;
4578: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4579: if (match) return(0);
4581: PetscFunctionListFind(SNESList,type,&r);
4582: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4583: /* Destroy the previous private SNES context */
4584: if (snes->ops->destroy) {
4585: (*(snes)->ops->destroy)(snes);
4586: snes->ops->destroy = NULL;
4587: }
4588: /* Reinitialize function pointers in SNESOps structure */
4589: snes->ops->setup = 0;
4590: snes->ops->solve = 0;
4591: snes->ops->view = 0;
4592: snes->ops->setfromoptions = 0;
4593: snes->ops->destroy = 0;
4595: /* It may happen the user has customized the line search before calling SNESSetType */
4596: if (((PetscObject)snes)->type_name) {
4597: SNESLineSearchDestroy(&snes->linesearch);
4598: }
4600: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4601: snes->setupcalled = PETSC_FALSE;
4603: PetscObjectChangeTypeName((PetscObject)snes,type);
4604: (*r)(snes);
4605: return(0);
4606: }
4608: /*@C
4609: SNESGetType - Gets the SNES method type and name (as a string).
4611: Not Collective
4613: Input Parameter:
4614: . snes - nonlinear solver context
4616: Output Parameter:
4617: . type - SNES method (a character string)
4619: Level: intermediate
4621: @*/
4622: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4623: {
4627: *type = ((PetscObject)snes)->type_name;
4628: return(0);
4629: }
4631: /*@
4632: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4634: Logically Collective on SNES
4636: Input Parameters:
4637: + snes - the SNES context obtained from SNESCreate()
4638: - u - the solution vector
4640: Level: beginner
4642: @*/
4643: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4644: {
4645: DM dm;
4651: PetscObjectReference((PetscObject) u);
4652: VecDestroy(&snes->vec_sol);
4654: snes->vec_sol = u;
4656: SNESGetDM(snes, &dm);
4657: DMShellSetGlobalVector(dm, u);
4658: return(0);
4659: }
4661: /*@
4662: SNESGetSolution - Returns the vector where the approximate solution is
4663: stored. This is the fine grid solution when using SNESSetGridSequence().
4665: Not Collective, but Vec is parallel if SNES is parallel
4667: Input Parameter:
4668: . snes - the SNES context
4670: Output Parameter:
4671: . x - the solution
4673: Level: intermediate
4675: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4676: @*/
4677: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4678: {
4682: *x = snes->vec_sol;
4683: return(0);
4684: }
4686: /*@
4687: SNESGetSolutionUpdate - Returns the vector where the solution update is
4688: stored.
4690: Not Collective, but Vec is parallel if SNES is parallel
4692: Input Parameter:
4693: . snes - the SNES context
4695: Output Parameter:
4696: . x - the solution update
4698: Level: advanced
4700: .seealso: SNESGetSolution(), SNESGetFunction()
4701: @*/
4702: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4703: {
4707: *x = snes->vec_sol_update;
4708: return(0);
4709: }
4711: /*@C
4712: SNESGetFunction - Returns the vector where the function is stored.
4714: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4716: Input Parameter:
4717: . snes - the SNES context
4719: Output Parameter:
4720: + r - the vector that is used to store residuals (or NULL if you don't want it)
4721: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4722: - ctx - the function context (or NULL if you don't want it)
4724: Level: advanced
4726: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4728: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4729: @*/
4730: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4731: {
4733: DM dm;
4737: if (r) {
4738: if (!snes->vec_func) {
4739: if (snes->vec_rhs) {
4740: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4741: } else if (snes->vec_sol) {
4742: VecDuplicate(snes->vec_sol,&snes->vec_func);
4743: } else if (snes->dm) {
4744: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4745: }
4746: }
4747: *r = snes->vec_func;
4748: }
4749: SNESGetDM(snes,&dm);
4750: DMSNESGetFunction(dm,f,ctx);
4751: return(0);
4752: }
4754: /*@C
4755: SNESGetNGS - Returns the NGS function and context.
4757: Input Parameter:
4758: . snes - the SNES context
4760: Output Parameter:
4761: + f - the function (or NULL) see SNESNGSFunction for details
4762: - ctx - the function context (or NULL)
4764: Level: advanced
4766: .seealso: SNESSetNGS(), SNESGetFunction()
4767: @*/
4769: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4770: {
4772: DM dm;
4776: SNESGetDM(snes,&dm);
4777: DMSNESGetNGS(dm,f,ctx);
4778: return(0);
4779: }
4781: /*@C
4782: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4783: SNES options in the database.
4785: Logically Collective on SNES
4787: Input Parameter:
4788: + snes - the SNES context
4789: - prefix - the prefix to prepend to all option names
4791: Notes:
4792: A hyphen (-) must NOT be given at the beginning of the prefix name.
4793: The first character of all runtime options is AUTOMATICALLY the hyphen.
4795: Level: advanced
4797: .seealso: SNESSetFromOptions()
4798: @*/
4799: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4800: {
4805: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4806: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4807: if (snes->linesearch) {
4808: SNESGetLineSearch(snes,&snes->linesearch);
4809: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4810: }
4811: KSPSetOptionsPrefix(snes->ksp,prefix);
4812: return(0);
4813: }
4815: /*@C
4816: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4817: SNES options in the database.
4819: Logically Collective on SNES
4821: Input Parameters:
4822: + snes - the SNES context
4823: - prefix - the prefix to prepend to all option names
4825: Notes:
4826: A hyphen (-) must NOT be given at the beginning of the prefix name.
4827: The first character of all runtime options is AUTOMATICALLY the hyphen.
4829: Level: advanced
4831: .seealso: SNESGetOptionsPrefix()
4832: @*/
4833: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4834: {
4839: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4840: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4841: if (snes->linesearch) {
4842: SNESGetLineSearch(snes,&snes->linesearch);
4843: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4844: }
4845: KSPAppendOptionsPrefix(snes->ksp,prefix);
4846: return(0);
4847: }
4849: /*@C
4850: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4851: SNES options in the database.
4853: Not Collective
4855: Input Parameter:
4856: . snes - the SNES context
4858: Output Parameter:
4859: . prefix - pointer to the prefix string used
4861: Notes:
4862: On the fortran side, the user should pass in a string 'prefix' of
4863: sufficient length to hold the prefix.
4865: Level: advanced
4867: .seealso: SNESAppendOptionsPrefix()
4868: @*/
4869: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4870: {
4875: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4876: return(0);
4877: }
4880: /*@C
4881: SNESRegister - Adds a method to the nonlinear solver package.
4883: Not collective
4885: Input Parameters:
4886: + name_solver - name of a new user-defined solver
4887: - routine_create - routine to create method context
4889: Notes:
4890: SNESRegister() may be called multiple times to add several user-defined solvers.
4892: Sample usage:
4893: .vb
4894: SNESRegister("my_solver",MySolverCreate);
4895: .ve
4897: Then, your solver can be chosen with the procedural interface via
4898: $ SNESSetType(snes,"my_solver")
4899: or at runtime via the option
4900: $ -snes_type my_solver
4902: Level: advanced
4904: Note: If your function is not being put into a shared library then use SNESRegister() instead
4906: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4908: Level: advanced
4909: @*/
4910: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4911: {
4915: SNESInitializePackage();
4916: PetscFunctionListAdd(&SNESList,sname,function);
4917: return(0);
4918: }
4920: PetscErrorCode SNESTestLocalMin(SNES snes)
4921: {
4923: PetscInt N,i,j;
4924: Vec u,uh,fh;
4925: PetscScalar value;
4926: PetscReal norm;
4929: SNESGetSolution(snes,&u);
4930: VecDuplicate(u,&uh);
4931: VecDuplicate(u,&fh);
4933: /* currently only works for sequential */
4934: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4935: VecGetSize(u,&N);
4936: for (i=0; i<N; i++) {
4937: VecCopy(u,uh);
4938: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4939: for (j=-10; j<11; j++) {
4940: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4941: VecSetValue(uh,i,value,ADD_VALUES);
4942: SNESComputeFunction(snes,uh,fh);
4943: VecNorm(fh,NORM_2,&norm);
4944: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4945: value = -value;
4946: VecSetValue(uh,i,value,ADD_VALUES);
4947: }
4948: }
4949: VecDestroy(&uh);
4950: VecDestroy(&fh);
4951: return(0);
4952: }
4954: /*@
4955: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4956: computing relative tolerance for linear solvers within an inexact
4957: Newton method.
4959: Logically Collective on SNES
4961: Input Parameters:
4962: + snes - SNES context
4963: - flag - PETSC_TRUE or PETSC_FALSE
4965: Options Database:
4966: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4967: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4968: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4969: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4970: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4971: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4972: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4973: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4975: Notes:
4976: Currently, the default is to use a constant relative tolerance for
4977: the inner linear solvers. Alternatively, one can use the
4978: Eisenstat-Walker method, where the relative convergence tolerance
4979: is reset at each Newton iteration according progress of the nonlinear
4980: solver.
4982: Level: advanced
4984: Reference:
4985: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4986: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4988: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4989: @*/
4990: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
4991: {
4995: snes->ksp_ewconv = flag;
4996: return(0);
4997: }
4999: /*@
5000: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
5001: for computing relative tolerance for linear solvers within an
5002: inexact Newton method.
5004: Not Collective
5006: Input Parameter:
5007: . snes - SNES context
5009: Output Parameter:
5010: . flag - PETSC_TRUE or PETSC_FALSE
5012: Notes:
5013: Currently, the default is to use a constant relative tolerance for
5014: the inner linear solvers. Alternatively, one can use the
5015: Eisenstat-Walker method, where the relative convergence tolerance
5016: is reset at each Newton iteration according progress of the nonlinear
5017: solver.
5019: Level: advanced
5021: Reference:
5022: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5023: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5025: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5026: @*/
5027: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5028: {
5032: *flag = snes->ksp_ewconv;
5033: return(0);
5034: }
5036: /*@
5037: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5038: convergence criteria for the linear solvers within an inexact
5039: Newton method.
5041: Logically Collective on SNES
5043: Input Parameters:
5044: + snes - SNES context
5045: . version - version 1, 2 (default is 2) or 3
5046: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5047: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5048: . gamma - multiplicative factor for version 2 rtol computation
5049: (0 <= gamma2 <= 1)
5050: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5051: . alpha2 - power for safeguard
5052: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5054: Note:
5055: Version 3 was contributed by Luis Chacon, June 2006.
5057: Use PETSC_DEFAULT to retain the default for any of the parameters.
5059: Level: advanced
5061: Reference:
5062: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5063: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5064: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5066: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5067: @*/
5068: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5069: {
5070: SNESKSPEW *kctx;
5074: kctx = (SNESKSPEW*)snes->kspconvctx;
5075: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5084: if (version != PETSC_DEFAULT) kctx->version = version;
5085: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5086: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5087: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5088: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5089: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5090: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5092: 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);
5093: 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);
5094: 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);
5095: 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);
5096: 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);
5097: 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);
5098: return(0);
5099: }
5101: /*@
5102: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5103: convergence criteria for the linear solvers within an inexact
5104: Newton method.
5106: Not Collective
5108: Input Parameters:
5109: snes - SNES context
5111: Output Parameters:
5112: + version - version 1, 2 (default is 2) or 3
5113: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5114: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5115: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5116: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5117: . alpha2 - power for safeguard
5118: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5120: Level: advanced
5122: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5123: @*/
5124: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5125: {
5126: SNESKSPEW *kctx;
5130: kctx = (SNESKSPEW*)snes->kspconvctx;
5131: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5132: if (version) *version = kctx->version;
5133: if (rtol_0) *rtol_0 = kctx->rtol_0;
5134: if (rtol_max) *rtol_max = kctx->rtol_max;
5135: if (gamma) *gamma = kctx->gamma;
5136: if (alpha) *alpha = kctx->alpha;
5137: if (alpha2) *alpha2 = kctx->alpha2;
5138: if (threshold) *threshold = kctx->threshold;
5139: return(0);
5140: }
5142: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5143: {
5145: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5146: PetscReal rtol = PETSC_DEFAULT,stol;
5149: if (!snes->ksp_ewconv) return(0);
5150: if (!snes->iter) {
5151: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5152: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5153: }
5154: else {
5155: if (kctx->version == 1) {
5156: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5157: if (rtol < 0.0) rtol = -rtol;
5158: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5159: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5160: } else if (kctx->version == 2) {
5161: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5162: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5163: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5164: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5165: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5166: /* safeguard: avoid sharp decrease of rtol */
5167: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5168: stol = PetscMax(rtol,stol);
5169: rtol = PetscMin(kctx->rtol_0,stol);
5170: /* safeguard: avoid oversolving */
5171: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5172: stol = PetscMax(rtol,stol);
5173: rtol = PetscMin(kctx->rtol_0,stol);
5174: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5175: }
5176: /* safeguard: avoid rtol greater than one */
5177: rtol = PetscMin(rtol,kctx->rtol_max);
5178: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5179: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5180: return(0);
5181: }
5183: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5184: {
5186: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5187: PCSide pcside;
5188: Vec lres;
5191: if (!snes->ksp_ewconv) return(0);
5192: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5193: kctx->norm_last = snes->norm;
5194: if (kctx->version == 1) {
5195: PC pc;
5196: PetscBool isNone;
5198: KSPGetPC(ksp, &pc);
5199: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5200: KSPGetPCSide(ksp,&pcside);
5201: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5202: /* KSP residual is true linear residual */
5203: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5204: } else {
5205: /* KSP residual is preconditioned residual */
5206: /* compute true linear residual norm */
5207: VecDuplicate(b,&lres);
5208: MatMult(snes->jacobian,x,lres);
5209: VecAYPX(lres,-1.0,b);
5210: VecNorm(lres,NORM_2,&kctx->lresid_last);
5211: VecDestroy(&lres);
5212: }
5213: }
5214: return(0);
5215: }
5217: /*@
5218: SNESGetKSP - Returns the KSP context for a SNES solver.
5220: Not Collective, but if SNES object is parallel, then KSP object is parallel
5222: Input Parameter:
5223: . snes - the SNES context
5225: Output Parameter:
5226: . ksp - the KSP context
5228: Notes:
5229: The user can then directly manipulate the KSP context to set various
5230: options, etc. Likewise, the user can then extract and manipulate the
5231: PC contexts as well.
5233: Level: beginner
5235: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5236: @*/
5237: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5238: {
5245: if (!snes->ksp) {
5246: PetscBool monitor = PETSC_FALSE;
5248: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5249: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5250: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5252: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5253: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5255: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5256: if (monitor) {
5257: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5258: }
5259: monitor = PETSC_FALSE;
5260: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5261: if (monitor) {
5262: PetscObject *objs;
5263: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5264: objs[0] = (PetscObject) snes;
5265: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5266: }
5267: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5268: }
5269: *ksp = snes->ksp;
5270: return(0);
5271: }
5274: #include <petsc/private/dmimpl.h>
5275: /*@
5276: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5278: Logically Collective on SNES
5280: Input Parameters:
5281: + snes - the nonlinear solver context
5282: - dm - the dm, cannot be NULL
5284: Notes:
5285: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5286: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5287: problems using the same function space.
5289: Level: intermediate
5291: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5292: @*/
5293: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5294: {
5296: KSP ksp;
5297: DMSNES sdm;
5302: PetscObjectReference((PetscObject)dm);
5303: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5304: if (snes->dm->dmsnes && !dm->dmsnes) {
5305: DMCopyDMSNES(snes->dm,dm);
5306: DMGetDMSNES(snes->dm,&sdm);
5307: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5308: }
5309: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5310: DMDestroy(&snes->dm);
5311: }
5312: snes->dm = dm;
5313: snes->dmAuto = PETSC_FALSE;
5315: SNESGetKSP(snes,&ksp);
5316: KSPSetDM(ksp,dm);
5317: KSPSetDMActive(ksp,PETSC_FALSE);
5318: if (snes->npc) {
5319: SNESSetDM(snes->npc, snes->dm);
5320: SNESSetNPCSide(snes,snes->npcside);
5321: }
5322: return(0);
5323: }
5325: /*@
5326: SNESGetDM - Gets the DM that may be used by some preconditioners
5328: Not Collective but DM obtained is parallel on SNES
5330: Input Parameter:
5331: . snes - the preconditioner context
5333: Output Parameter:
5334: . dm - the dm
5336: Level: intermediate
5338: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5339: @*/
5340: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5341: {
5346: if (!snes->dm) {
5347: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5348: snes->dmAuto = PETSC_TRUE;
5349: }
5350: *dm = snes->dm;
5351: return(0);
5352: }
5354: /*@
5355: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5357: Collective on SNES
5359: Input Parameters:
5360: + snes - iterative context obtained from SNESCreate()
5361: - pc - the preconditioner object
5363: Notes:
5364: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5365: to configure it using the API).
5367: Level: developer
5369: .seealso: SNESGetNPC(), SNESHasNPC()
5370: @*/
5371: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5372: {
5379: PetscObjectReference((PetscObject) pc);
5380: SNESDestroy(&snes->npc);
5381: snes->npc = pc;
5382: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5383: return(0);
5384: }
5386: /*@
5387: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5389: Not Collective; but any changes to the obtained SNES object must be applied collectively
5391: Input Parameter:
5392: . snes - iterative context obtained from SNESCreate()
5394: Output Parameter:
5395: . pc - preconditioner context
5397: Options Database:
5398: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5400: Notes:
5401: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5403: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5404: SNES during SNESSetUp()
5406: Level: developer
5408: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5409: @*/
5410: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5411: {
5413: const char *optionsprefix;
5418: if (!snes->npc) {
5419: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5420: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5421: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5422: SNESGetOptionsPrefix(snes,&optionsprefix);
5423: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5424: SNESAppendOptionsPrefix(snes->npc,"npc_");
5425: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5426: }
5427: *pc = snes->npc;
5428: return(0);
5429: }
5431: /*@
5432: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5434: Not Collective
5436: Input Parameter:
5437: . snes - iterative context obtained from SNESCreate()
5439: Output Parameter:
5440: . has_npc - whether the SNES has an NPC or not
5442: Level: developer
5444: .seealso: SNESSetNPC(), SNESGetNPC()
5445: @*/
5446: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5447: {
5450: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5451: return(0);
5452: }
5454: /*@
5455: SNESSetNPCSide - Sets the preconditioning side.
5457: Logically Collective on SNES
5459: Input Parameter:
5460: . snes - iterative context obtained from SNESCreate()
5462: Output Parameter:
5463: . side - the preconditioning side, where side is one of
5464: .vb
5465: PC_LEFT - left preconditioning
5466: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5467: .ve
5469: Options Database Keys:
5470: . -snes_pc_side <right,left>
5472: Notes:
5473: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5475: Level: intermediate
5477: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5478: @*/
5479: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5480: {
5484: snes->npcside= side;
5485: return(0);
5486: }
5488: /*@
5489: SNESGetNPCSide - Gets the preconditioning side.
5491: Not Collective
5493: Input Parameter:
5494: . snes - iterative context obtained from SNESCreate()
5496: Output Parameter:
5497: . side - the preconditioning side, where side is one of
5498: .vb
5499: PC_LEFT - left preconditioning
5500: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5501: .ve
5503: Level: intermediate
5505: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5506: @*/
5507: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5508: {
5512: *side = snes->npcside;
5513: return(0);
5514: }
5516: /*@
5517: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5519: Collective on SNES
5521: Input Parameters:
5522: + snes - iterative context obtained from SNESCreate()
5523: - linesearch - the linesearch object
5525: Notes:
5526: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5527: to configure it using the API).
5529: Level: developer
5531: .seealso: SNESGetLineSearch()
5532: @*/
5533: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5534: {
5541: PetscObjectReference((PetscObject) linesearch);
5542: SNESLineSearchDestroy(&snes->linesearch);
5544: snes->linesearch = linesearch;
5546: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5547: return(0);
5548: }
5550: /*@
5551: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5552: or creates a default line search instance associated with the SNES and returns it.
5554: Not Collective
5556: Input Parameter:
5557: . snes - iterative context obtained from SNESCreate()
5559: Output Parameter:
5560: . linesearch - linesearch context
5562: Level: beginner
5564: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5565: @*/
5566: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5567: {
5569: const char *optionsprefix;
5574: if (!snes->linesearch) {
5575: SNESGetOptionsPrefix(snes, &optionsprefix);
5576: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5577: SNESLineSearchSetSNES(snes->linesearch, snes);
5578: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5579: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5580: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5581: }
5582: *linesearch = snes->linesearch;
5583: return(0);
5584: }