Actual source code: snes.c
petsc-master 2020-01-26
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_Setup, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes SNESSolve() to generate an error if the solver has not converged.
18: Logically Collective on SNES
20: Input Parameters:
21: + snes - iterative context obtained from SNESCreate()
22: - flg - PETSC_TRUE indicates you want the error generated
24: Options database keys:
25: . -snes_error_if_not_converged : this takes an optional truth value (0/1/no/yes/true/false)
27: Level: intermediate
29: Notes:
30: Normally PETSc continues if a linear solver fails to converge, you can call SNESGetConvergedReason() after a SNESSolve()
31: to determine if it has converged.
33: .seealso: SNESGetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes,PetscBool flg)
36: {
40: snes->errorifnotconverged = flg;
41: return(0);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Will SNESSolve() generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from SNESCreate()
52: Output Parameter:
53: . flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE
55: Level: intermediate
57: .seealso: SNESSetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes,PetscBool *flag)
60: {
64: *flag = snes->errorifnotconverged;
65: return(0);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
71: Logically Collective on SNES
73: Input Parameters:
74: + snes - the shell SNES
75: - flg - is the residual computed?
77: Level: advanced
79: .seealso: SNESGetAlwaysComputesFinalResidual()
80: @*/
81: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
82: {
85: snes->alwayscomputesfinalresidual = flg;
86: return(0);
87: }
89: /*@
90: SNESGetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
92: Logically Collective on SNES
94: Input Parameter:
95: . snes - the shell SNES
97: Output Parameter:
98: . flg - is the residual computed?
100: Level: advanced
102: .seealso: SNESSetAlwaysComputesFinalResidual()
103: @*/
104: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
105: {
108: *flg = snes->alwayscomputesfinalresidual;
109: return(0);
110: }
112: /*@
113: SNESSetFunctionDomainError - tells SNES that the input vector to your SNESFunction is not
114: in the functions domain. For example, negative pressure.
116: Logically Collective on SNES
118: Input Parameters:
119: . snes - the SNES context
121: Level: advanced
123: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction
124: @*/
125: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
126: {
129: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates input vector is not in the function domain");
130: snes->domainerror = PETSC_TRUE;
131: return(0);
132: }
134: /*@
135: SNESSetJacobianDomainError - tells SNES that computeJacobian does not make sense any more. For example there is a negative element transformation.
137: Logically Collective on SNES
139: Input Parameters:
140: . snes - the SNES context
142: Level: advanced
144: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError()
145: @*/
146: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
147: {
150: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates computeJacobian does not make sense");
151: snes->jacobiandomainerror = PETSC_TRUE;
152: return(0);
153: }
155: /*@
156: SNESSetCheckJacobianDomainError - if or not to check jacobian domain error after each Jacobian evaluation. By default, we check Jacobian domain error
157: in the debug mode, and do not check it in the optimized mode.
159: Logically Collective on SNES
161: Input Parameters:
162: + snes - the SNES context
163: - flg - indicates if or not to check jacobian domain error after each Jacobian evaluation
165: Level: advanced
167: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESGetCheckJacobianDomainError()
168: @*/
169: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
170: {
173: snes->checkjacdomainerror = flg;
174: return(0);
175: }
177: /*@
178: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
180: Logically Collective on SNES
182: Input Parameters:
183: . snes - the SNES context
185: Output Parameters:
186: . flg - PETSC_FALSE indicates that we don't check jacobian domain errors after each Jacobian evaluation
188: Level: advanced
190: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESSetCheckJacobianDomainError()
191: @*/
192: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
193: {
197: *flg = snes->checkjacdomainerror;
198: return(0);
199: }
201: /*@
202: SNESGetFunctionDomainError - Gets the status of the domain error after a call to SNESComputeFunction;
204: Logically Collective on SNES
206: Input Parameters:
207: . snes - the SNES context
209: Output Parameters:
210: . domainerror - Set to PETSC_TRUE if there's a domain error; PETSC_FALSE otherwise.
212: Level: advanced
214: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction()
215: @*/
216: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
217: {
221: *domainerror = snes->domainerror;
222: return(0);
223: }
225: /*@
226: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to SNESComputeJacobian;
228: Logically Collective on SNES
230: Input Parameters:
231: . snes - the SNES context
233: Output Parameters:
234: . domainerror - Set to PETSC_TRUE if there's a jacobian domain error; PETSC_FALSE otherwise.
236: Level: advanced
238: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction(),SNESGetFunctionDomainError()
239: @*/
240: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
241: {
245: *domainerror = snes->jacobiandomainerror;
246: return(0);
247: }
249: /*@C
250: SNESLoad - Loads a SNES that has been stored in binary with SNESView().
252: Collective on PetscViewer
254: Input Parameters:
255: + newdm - the newly loaded SNES, this needs to have been created with SNESCreate() or
256: some related function before a call to SNESLoad().
257: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
259: Level: intermediate
261: Notes:
262: The type is determined by the data in the file, any type set into the SNES before this call is ignored.
264: Notes for advanced users:
265: Most users should not need to know the details of the binary storage
266: format, since SNESLoad() and TSView() completely hide these details.
267: But for anyone who's interested, the standard binary matrix storage
268: format is
269: .vb
270: has not yet been determined
271: .ve
273: .seealso: PetscViewerBinaryOpen(), SNESView(), MatLoad(), VecLoad()
274: @*/
275: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
276: {
278: PetscBool isbinary;
279: PetscInt classid;
280: char type[256];
281: KSP ksp;
282: DM dm;
283: DMSNES dmsnes;
288: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
289: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
291: PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
292: if (classid != SNES_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONG,"Not SNES next in file");
293: PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
294: SNESSetType(snes, type);
295: if (snes->ops->load) {
296: (*snes->ops->load)(snes,viewer);
297: }
298: SNESGetDM(snes,&dm);
299: DMGetDMSNES(dm,&dmsnes);
300: DMSNESLoad(dmsnes,viewer);
301: SNESGetKSP(snes,&ksp);
302: KSPLoad(ksp,viewer);
303: return(0);
304: }
306: #include <petscdraw.h>
307: #if defined(PETSC_HAVE_SAWS)
308: #include <petscviewersaws.h>
309: #endif
311: /*@C
312: 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 the users manual
894: Notes:
895: SNES supports three approaches for computing (approximate) Jacobians: user provided via SNESSetJacobian(), matrix free, and computing explictly with
896: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
898: Level: beginner
900: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions(), SNES, SNESCreate()
901: @*/
902: PetscErrorCode SNESSetFromOptions(SNES snes)
903: {
904: PetscBool flg,pcset,persist,set;
905: PetscInt i,indx,lag,grids;
906: const char *deft = SNESNEWTONLS;
907: const char *convtests[] = {"default","skip"};
908: SNESKSPEW *kctx = NULL;
909: char type[256], monfilename[PETSC_MAX_PATH_LEN];
911: PCSide pcside;
912: const char *optionsprefix;
916: SNESRegisterAll();
917: PetscObjectOptionsBegin((PetscObject)snes);
918: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
919: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
920: if (flg) {
921: SNESSetType(snes,type);
922: } else if (!((PetscObject)snes)->type_name) {
923: SNESSetType(snes,deft);
924: }
925: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
926: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
928: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
929: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
930: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
931: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
932: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
933: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
934: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
935: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
936: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
938: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
939: if (flg) {
940: SNESSetLagPreconditioner(snes,lag);
941: }
942: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple SNES solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
943: if (flg) {
944: SNESSetLagPreconditionerPersists(snes,persist);
945: }
946: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
947: if (flg) {
948: SNESSetLagJacobian(snes,lag);
949: }
950: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple SNES solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
951: if (flg) {
952: SNESSetLagJacobianPersists(snes,persist);
953: }
955: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
956: if (flg) {
957: SNESSetGridSequence(snes,grids);
958: }
960: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
961: if (flg) {
962: switch (indx) {
963: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
964: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
965: }
966: }
968: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
969: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
971: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
972: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
974: kctx = (SNESKSPEW*)snes->kspconvctx;
976: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
978: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
979: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
980: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
981: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
982: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
983: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
984: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
986: flg = PETSC_FALSE;
987: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
988: if (set && flg) {SNESMonitorCancel(snes);}
990: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
991: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
992: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
994: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
995: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
996: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
997: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
998: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
999: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
1000: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
1002: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
1003: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
1005: flg = PETSC_FALSE;
1006: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
1007: if (flg) {
1008: PetscDrawLG ctx;
1010: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1011: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
1012: }
1013: flg = PETSC_FALSE;
1014: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
1015: if (flg) {
1016: PetscViewer ctx;
1018: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1019: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
1020: }
1022: flg = PETSC_FALSE;
1023: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
1024: if (flg) {
1025: void *functx;
1026: DM dm;
1027: DMSNES sdm;
1028: SNESGetDM(snes,&dm);
1029: DMGetDMSNES(dm,&sdm);
1030: sdm->jacobianctx = NULL;
1031: SNESGetFunction(snes,NULL,NULL,&functx);
1032: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
1033: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
1034: }
1036: flg = PETSC_FALSE;
1037: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
1038: if (flg) {
1039: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
1040: }
1042: flg = PETSC_FALSE;
1043: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1044: if (flg) {
1045: DM dm;
1046: DMSNES sdm;
1047: SNESGetDM(snes,&dm);
1048: DMGetDMSNES(dm,&sdm);
1049: sdm->jacobianctx = NULL;
1050: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
1051: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1052: }
1054: flg = PETSC_FALSE;
1055: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1056: if (flg && snes->mf_operator) {
1057: snes->mf_operator = PETSC_TRUE;
1058: snes->mf = PETSC_TRUE;
1059: }
1060: flg = PETSC_FALSE;
1061: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1062: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1063: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
1065: flg = PETSC_FALSE;
1066: SNESGetNPCSide(snes,&pcside);
1067: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1068: if (flg) {SNESSetNPCSide(snes,pcside);}
1070: #if defined(PETSC_HAVE_SAWS)
1071: /*
1072: Publish convergence information using SAWs
1073: */
1074: flg = PETSC_FALSE;
1075: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1076: if (flg) {
1077: void *ctx;
1078: SNESMonitorSAWsCreate(snes,&ctx);
1079: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1080: }
1081: #endif
1082: #if defined(PETSC_HAVE_SAWS)
1083: {
1084: PetscBool set;
1085: flg = PETSC_FALSE;
1086: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1087: if (set) {
1088: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1089: }
1090: }
1091: #endif
1093: for (i = 0; i < numberofsetfromoptions; i++) {
1094: (*othersetfromoptions[i])(snes);
1095: }
1097: if (snes->ops->setfromoptions) {
1098: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1099: }
1101: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1102: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1103: PetscOptionsEnd();
1105: if (snes->linesearch) {
1106: SNESGetLineSearch(snes, &snes->linesearch);
1107: SNESLineSearchSetFromOptions(snes->linesearch);
1108: }
1110: if (snes->usesksp) {
1111: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1112: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1113: KSPSetFromOptions(snes->ksp);
1114: }
1116: /* if user has set the SNES NPC type via options database, create it. */
1117: SNESGetOptionsPrefix(snes, &optionsprefix);
1118: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1119: if (pcset && (!snes->npc)) {
1120: SNESGetNPC(snes, &snes->npc);
1121: }
1122: if (snes->npc) {
1123: SNESSetFromOptions(snes->npc);
1124: }
1125: snes->setfromoptionscalled++;
1126: return(0);
1127: }
1129: /*@
1130: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1132: Collective on SNES
1134: Input Parameter:
1135: . snes - the SNES context
1137: Level: beginner
1139: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1140: @*/
1141: PetscErrorCode SNESResetFromOptions(SNES snes)
1142: {
1146: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1147: return(0);
1148: }
1150: /*@C
1151: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1152: the nonlinear solvers.
1154: Logically Collective on SNES
1156: Input Parameters:
1157: + snes - the SNES context
1158: . compute - function to compute the context
1159: - destroy - function to destroy the context
1161: Level: intermediate
1163: Notes:
1164: This function is currently not available from Fortran.
1166: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1167: @*/
1168: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1169: {
1172: snes->ops->usercompute = compute;
1173: snes->ops->userdestroy = destroy;
1174: return(0);
1175: }
1177: /*@
1178: SNESSetApplicationContext - Sets the optional user-defined context for
1179: the nonlinear solvers.
1181: Logically Collective on SNES
1183: Input Parameters:
1184: + snes - the SNES context
1185: - usrP - optional user context
1187: Level: intermediate
1189: Fortran Notes:
1190: To use this from Fortran you must write a Fortran interface definition for this
1191: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1193: .seealso: SNESGetApplicationContext()
1194: @*/
1195: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1196: {
1198: KSP ksp;
1202: SNESGetKSP(snes,&ksp);
1203: KSPSetApplicationContext(ksp,usrP);
1204: snes->user = usrP;
1205: return(0);
1206: }
1208: /*@
1209: SNESGetApplicationContext - Gets the user-defined context for the
1210: nonlinear solvers.
1212: Not Collective
1214: Input Parameter:
1215: . snes - SNES context
1217: Output Parameter:
1218: . usrP - user context
1220: Fortran Notes:
1221: To use this from Fortran you must write a Fortran interface definition for this
1222: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1224: Level: intermediate
1226: .seealso: SNESSetApplicationContext()
1227: @*/
1228: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1229: {
1232: *(void**)usrP = snes->user;
1233: return(0);
1234: }
1236: /*@
1237: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply the Jacobian.
1239: Collective on SNES
1241: Input Parameters:
1242: + snes - SNES context
1243: . mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1244: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1246: Options Database:
1247: + -snes_mf - use matrix free for both the mat and pmat operator
1248: . -snes_mf_operator - use matrix free only for the mat operator
1249: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1250: - -snes_fd - compute the Jacobian via finite differences (slow)
1252: Level: intermediate
1254: Notes:
1255: SNES supports three approaches for computing (approximate) Jacobians: user provided via SNESSetJacobian(), matrix free, and computing explictly with
1256: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
1258: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF(), SNESComputeJacobianDefaultColor()
1259: @*/
1260: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1261: {
1266: if (mf && !mf_operator) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"If using mf must also use mf_operator");
1267: snes->mf = mf;
1268: snes->mf_operator = mf_operator;
1269: return(0);
1270: }
1272: /*@
1273: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply the Jacobian.
1275: Collective on SNES
1277: Input Parameter:
1278: . snes - SNES context
1280: Output Parameters:
1281: + mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1282: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1284: Options Database:
1285: + -snes_mf - use matrix free for both the mat and pmat operator
1286: - -snes_mf_operator - use matrix free only for the mat operator
1288: Level: intermediate
1290: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1291: @*/
1292: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1293: {
1296: if (mf) *mf = snes->mf;
1297: if (mf_operator) *mf_operator = snes->mf_operator;
1298: return(0);
1299: }
1301: /*@
1302: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1303: at this time.
1305: Not Collective
1307: Input Parameter:
1308: . snes - SNES context
1310: Output Parameter:
1311: . iter - iteration number
1313: Notes:
1314: For example, during the computation of iteration 2 this would return 1.
1316: This is useful for using lagged Jacobians (where one does not recompute the
1317: Jacobian at each SNES iteration). For example, the code
1318: .vb
1319: SNESGetIterationNumber(snes,&it);
1320: if (!(it % 2)) {
1321: [compute Jacobian here]
1322: }
1323: .ve
1324: can be used in your ComputeJacobian() function to cause the Jacobian to be
1325: recomputed every second SNES iteration.
1327: After the SNES solve is complete this will return the number of nonlinear iterations used.
1329: Level: intermediate
1331: .seealso: SNESGetLinearSolveIterations()
1332: @*/
1333: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1334: {
1338: *iter = snes->iter;
1339: return(0);
1340: }
1342: /*@
1343: SNESSetIterationNumber - Sets the current iteration number.
1345: Not Collective
1347: Input Parameter:
1348: + snes - SNES context
1349: - iter - iteration number
1351: Level: developer
1353: .seealso: SNESGetLinearSolveIterations()
1354: @*/
1355: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1356: {
1361: PetscObjectSAWsTakeAccess((PetscObject)snes);
1362: snes->iter = iter;
1363: PetscObjectSAWsGrantAccess((PetscObject)snes);
1364: return(0);
1365: }
1367: /*@
1368: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1369: attempted by the nonlinear solver.
1371: Not Collective
1373: Input Parameter:
1374: . snes - SNES context
1376: Output Parameter:
1377: . nfails - number of unsuccessful steps attempted
1379: Notes:
1380: This counter is reset to zero for each successive call to SNESSolve().
1382: Level: intermediate
1384: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1385: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1386: @*/
1387: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1388: {
1392: *nfails = snes->numFailures;
1393: return(0);
1394: }
1396: /*@
1397: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1398: attempted by the nonlinear solver before it gives up.
1400: Not Collective
1402: Input Parameters:
1403: + snes - SNES context
1404: - maxFails - maximum of unsuccessful steps
1406: Level: intermediate
1408: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1409: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1410: @*/
1411: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1412: {
1415: snes->maxFailures = maxFails;
1416: return(0);
1417: }
1419: /*@
1420: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1421: attempted by the nonlinear solver before it gives up.
1423: Not Collective
1425: Input Parameter:
1426: . snes - SNES context
1428: Output Parameter:
1429: . maxFails - maximum of unsuccessful steps
1431: Level: intermediate
1433: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1434: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1436: @*/
1437: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1438: {
1442: *maxFails = snes->maxFailures;
1443: return(0);
1444: }
1446: /*@
1447: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1448: done by SNES.
1450: Not Collective
1452: Input Parameter:
1453: . snes - SNES context
1455: Output Parameter:
1456: . nfuncs - number of evaluations
1458: Level: intermediate
1460: Notes:
1461: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1463: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1464: @*/
1465: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1466: {
1470: *nfuncs = snes->nfuncs;
1471: return(0);
1472: }
1474: /*@
1475: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1476: linear solvers.
1478: Not Collective
1480: Input Parameter:
1481: . snes - SNES context
1483: Output Parameter:
1484: . nfails - number of failed solves
1486: Level: intermediate
1488: Options Database Keys:
1489: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1491: Notes:
1492: This counter is reset to zero for each successive call to SNESSolve().
1494: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1495: @*/
1496: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1497: {
1501: *nfails = snes->numLinearSolveFailures;
1502: return(0);
1503: }
1505: /*@
1506: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1507: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1509: Logically Collective on SNES
1511: Input Parameters:
1512: + snes - SNES context
1513: - maxFails - maximum allowed linear solve failures
1515: Level: intermediate
1517: Options Database Keys:
1518: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1520: Notes:
1521: By default this is 0; that is SNES returns on the first failed linear solve
1523: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1524: @*/
1525: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1526: {
1530: snes->maxLinearSolveFailures = maxFails;
1531: return(0);
1532: }
1534: /*@
1535: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1536: are allowed before SNES terminates
1538: Not Collective
1540: Input Parameter:
1541: . snes - SNES context
1543: Output Parameter:
1544: . maxFails - maximum of unsuccessful solves allowed
1546: Level: intermediate
1548: Notes:
1549: By default this is 1; that is SNES returns on the first failed linear solve
1551: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1552: @*/
1553: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1554: {
1558: *maxFails = snes->maxLinearSolveFailures;
1559: return(0);
1560: }
1562: /*@
1563: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1564: used by the nonlinear solver.
1566: Not Collective
1568: Input Parameter:
1569: . snes - SNES context
1571: Output Parameter:
1572: . lits - number of linear iterations
1574: Notes:
1575: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1577: 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
1578: then call KSPGetIterationNumber() after the failed solve.
1580: Level: intermediate
1582: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1583: @*/
1584: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1585: {
1589: *lits = snes->linear_its;
1590: return(0);
1591: }
1593: /*@
1594: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1595: are reset every time SNESSolve() is called.
1597: Logically Collective on SNES
1599: Input Parameter:
1600: + snes - SNES context
1601: - reset - whether to reset the counters or not
1603: Notes:
1604: This defaults to PETSC_TRUE
1606: Level: developer
1608: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1609: @*/
1610: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1611: {
1615: snes->counters_reset = reset;
1616: return(0);
1617: }
1620: /*@
1621: SNESSetKSP - Sets a KSP context for the SNES object to use
1623: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1625: Input Parameters:
1626: + snes - the SNES context
1627: - ksp - the KSP context
1629: Notes:
1630: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1631: so this routine is rarely needed.
1633: The KSP object that is already in the SNES object has its reference count
1634: decreased by one.
1636: Level: developer
1638: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1639: @*/
1640: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1641: {
1648: PetscObjectReference((PetscObject)ksp);
1649: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1650: snes->ksp = ksp;
1651: return(0);
1652: }
1654: /* -----------------------------------------------------------*/
1655: /*@
1656: SNESCreate - Creates a nonlinear solver context.
1658: Collective
1660: Input Parameters:
1661: . comm - MPI communicator
1663: Output Parameter:
1664: . outsnes - the new SNES context
1666: Options Database Keys:
1667: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1668: and no preconditioning matrix
1669: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1670: products, and a user-provided preconditioning matrix
1671: as set by SNESSetJacobian()
1672: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1674: Level: beginner
1676: Developer Notes:
1677: SNES always creates a KSP object even though many SNES methods do not use it. This is
1678: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1679: particular method does use KSP and regulates if the information about the KSP is printed
1680: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1681: by help messages about meaningless SNES options.
1683: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1684: be fixed.
1686: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1688: @*/
1689: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1690: {
1692: SNES snes;
1693: SNESKSPEW *kctx;
1697: *outsnes = NULL;
1698: SNESInitializePackage();
1700: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1702: snes->ops->converged = SNESConvergedDefault;
1703: snes->usesksp = PETSC_TRUE;
1704: snes->tolerancesset = PETSC_FALSE;
1705: snes->max_its = 50;
1706: snes->max_funcs = 10000;
1707: snes->norm = 0.0;
1708: snes->xnorm = 0.0;
1709: snes->ynorm = 0.0;
1710: snes->normschedule = SNES_NORM_ALWAYS;
1711: snes->functype = SNES_FUNCTION_DEFAULT;
1712: #if defined(PETSC_USE_REAL_SINGLE)
1713: snes->rtol = 1.e-5;
1714: #else
1715: snes->rtol = 1.e-8;
1716: #endif
1717: snes->ttol = 0.0;
1718: #if defined(PETSC_USE_REAL_SINGLE)
1719: snes->abstol = 1.e-25;
1720: #else
1721: snes->abstol = 1.e-50;
1722: #endif
1723: #if defined(PETSC_USE_REAL_SINGLE)
1724: snes->stol = 1.e-5;
1725: #else
1726: snes->stol = 1.e-8;
1727: #endif
1728: #if defined(PETSC_USE_REAL_SINGLE)
1729: snes->deltatol = 1.e-6;
1730: #else
1731: snes->deltatol = 1.e-12;
1732: #endif
1733: snes->divtol = 1.e4;
1734: snes->rnorm0 = 0;
1735: snes->nfuncs = 0;
1736: snes->numFailures = 0;
1737: snes->maxFailures = 1;
1738: snes->linear_its = 0;
1739: snes->lagjacobian = 1;
1740: snes->jac_iter = 0;
1741: snes->lagjac_persist = PETSC_FALSE;
1742: snes->lagpreconditioner = 1;
1743: snes->pre_iter = 0;
1744: snes->lagpre_persist = PETSC_FALSE;
1745: snes->numbermonitors = 0;
1746: snes->data = 0;
1747: snes->setupcalled = PETSC_FALSE;
1748: snes->ksp_ewconv = PETSC_FALSE;
1749: snes->nwork = 0;
1750: snes->work = 0;
1751: snes->nvwork = 0;
1752: snes->vwork = 0;
1753: snes->conv_hist_len = 0;
1754: snes->conv_hist_max = 0;
1755: snes->conv_hist = NULL;
1756: snes->conv_hist_its = NULL;
1757: snes->conv_hist_reset = PETSC_TRUE;
1758: snes->counters_reset = PETSC_TRUE;
1759: snes->vec_func_init_set = PETSC_FALSE;
1760: snes->reason = SNES_CONVERGED_ITERATING;
1761: snes->npcside = PC_RIGHT;
1762: snes->setfromoptionscalled = 0;
1764: snes->mf = PETSC_FALSE;
1765: snes->mf_operator = PETSC_FALSE;
1766: snes->mf_version = 1;
1768: snes->numLinearSolveFailures = 0;
1769: snes->maxLinearSolveFailures = 1;
1771: snes->vizerotolerance = 1.e-8;
1772: #if defined(PETSC_USE_DEBUG)
1773: snes->checkjacdomainerror = PETSC_TRUE;
1774: #else
1775: snes->checkjacdomainerror = PETSC_FALSE;
1776: #endif
1778: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1779: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1781: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1782: PetscNewLog(snes,&kctx);
1784: snes->kspconvctx = (void*)kctx;
1785: kctx->version = 2;
1786: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1787: this was too large for some test cases */
1788: kctx->rtol_last = 0.0;
1789: kctx->rtol_max = .9;
1790: kctx->gamma = 1.0;
1791: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1792: kctx->alpha2 = kctx->alpha;
1793: kctx->threshold = .1;
1794: kctx->lresid_last = 0.0;
1795: kctx->norm_last = 0.0;
1797: *outsnes = snes;
1798: return(0);
1799: }
1801: /*MC
1802: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1804: Synopsis:
1805: #include "petscsnes.h"
1806: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1808: Input Parameters:
1809: + snes - the SNES context
1810: . x - state at which to evaluate residual
1811: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1813: Output Parameter:
1814: . f - vector to put residual (function value)
1816: Level: intermediate
1818: .seealso: SNESSetFunction(), SNESGetFunction()
1819: M*/
1821: /*@C
1822: SNESSetFunction - Sets the function evaluation routine and function
1823: vector for use by the SNES routines in solving systems of nonlinear
1824: equations.
1826: Logically Collective on SNES
1828: Input Parameters:
1829: + snes - the SNES context
1830: . r - vector to store function value
1831: . f - function evaluation routine; see SNESFunction for calling sequence details
1832: - ctx - [optional] user-defined context for private data for the
1833: function evaluation routine (may be NULL)
1835: Notes:
1836: The Newton-like methods typically solve linear systems of the form
1837: $ f'(x) x = -f(x),
1838: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1840: Level: beginner
1842: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1843: @*/
1844: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1845: {
1847: DM dm;
1851: if (r) {
1854: PetscObjectReference((PetscObject)r);
1855: VecDestroy(&snes->vec_func);
1857: snes->vec_func = r;
1858: }
1859: SNESGetDM(snes,&dm);
1860: DMSNESSetFunction(dm,f,ctx);
1861: return(0);
1862: }
1865: /*@C
1866: SNESSetInitialFunction - Sets the function vector to be used as the
1867: function norm at the initialization of the method. In some
1868: instances, the user has precomputed the function before calling
1869: SNESSolve. This function allows one to avoid a redundant call
1870: to SNESComputeFunction in that case.
1872: Logically Collective on SNES
1874: Input Parameters:
1875: + snes - the SNES context
1876: - f - vector to store function value
1878: Notes:
1879: This should not be modified during the solution procedure.
1881: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1883: Level: developer
1885: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1886: @*/
1887: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1888: {
1890: Vec vec_func;
1896: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1897: snes->vec_func_init_set = PETSC_FALSE;
1898: return(0);
1899: }
1900: SNESGetFunction(snes,&vec_func,NULL,NULL);
1901: VecCopy(f, vec_func);
1903: snes->vec_func_init_set = PETSC_TRUE;
1904: return(0);
1905: }
1907: /*@
1908: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1909: of the SNES method.
1911: Logically Collective on SNES
1913: Input Parameters:
1914: + snes - the SNES context
1915: - normschedule - the frequency of norm computation
1917: Options Database Key:
1918: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1920: Notes:
1921: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1922: of the nonlinear function and the taking of its norm at every iteration to
1923: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1924: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1925: may either be monitored for convergence or not. As these are often used as nonlinear
1926: preconditioners, monitoring the norm of their error is not a useful enterprise within
1927: their solution.
1929: Level: developer
1931: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1932: @*/
1933: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1934: {
1937: snes->normschedule = normschedule;
1938: return(0);
1939: }
1942: /*@
1943: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1944: of the SNES method.
1946: Logically Collective on SNES
1948: Input Parameters:
1949: + snes - the SNES context
1950: - normschedule - the type of the norm used
1952: Level: advanced
1954: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1955: @*/
1956: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1957: {
1960: *normschedule = snes->normschedule;
1961: return(0);
1962: }
1965: /*@
1966: SNESSetFunctionNorm - Sets the last computed residual norm.
1968: Logically Collective on SNES
1970: Input Parameters:
1971: + snes - the SNES context
1973: - normschedule - the frequency of norm computation
1975: Level: developer
1977: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1978: @*/
1979: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1980: {
1983: snes->norm = norm;
1984: return(0);
1985: }
1987: /*@
1988: SNESGetFunctionNorm - Gets the last computed norm of the residual
1990: Not Collective
1992: Input Parameter:
1993: . snes - the SNES context
1995: Output Parameter:
1996: . norm - the last computed residual norm
1998: Level: developer
2000: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2001: @*/
2002: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2003: {
2007: *norm = snes->norm;
2008: return(0);
2009: }
2011: /*@
2012: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
2014: Not Collective
2016: Input Parameter:
2017: . snes - the SNES context
2019: Output Parameter:
2020: . ynorm - the last computed update norm
2022: Level: developer
2024: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
2025: @*/
2026: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2027: {
2031: *ynorm = snes->ynorm;
2032: return(0);
2033: }
2035: /*@
2036: SNESGetSolutionNorm - Gets the last computed norm of the solution
2038: Not Collective
2040: Input Parameter:
2041: . snes - the SNES context
2043: Output Parameter:
2044: . xnorm - the last computed solution norm
2046: Level: developer
2048: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2049: @*/
2050: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2051: {
2055: *xnorm = snes->xnorm;
2056: return(0);
2057: }
2059: /*@C
2060: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2061: of the SNES method.
2063: Logically Collective on SNES
2065: Input Parameters:
2066: + snes - the SNES context
2067: - normschedule - the frequency of norm computation
2069: Notes:
2070: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2071: of the nonlinear function and the taking of its norm at every iteration to
2072: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2073: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2074: may either be monitored for convergence or not. As these are often used as nonlinear
2075: preconditioners, monitoring the norm of their error is not a useful enterprise within
2076: their solution.
2078: Level: developer
2080: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2081: @*/
2082: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2083: {
2086: snes->functype = type;
2087: return(0);
2088: }
2091: /*@C
2092: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2093: of the SNES method.
2095: Logically Collective on SNES
2097: Input Parameters:
2098: + snes - the SNES context
2099: - normschedule - the type of the norm used
2101: Level: advanced
2103: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2104: @*/
2105: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2106: {
2109: *type = snes->functype;
2110: return(0);
2111: }
2113: /*MC
2114: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2116: Synopsis:
2117: #include <petscsnes.h>
2118: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2120: + X - solution vector
2121: . B - RHS vector
2122: - ctx - optional user-defined Gauss-Seidel context
2124: Level: intermediate
2126: .seealso: SNESSetNGS(), SNESGetNGS()
2127: M*/
2129: /*@C
2130: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2131: use with composed nonlinear solvers.
2133: Input Parameters:
2134: + snes - the SNES context
2135: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2136: - ctx - [optional] user-defined context for private data for the
2137: smoother evaluation routine (may be NULL)
2139: Notes:
2140: The NGS routines are used by the composed nonlinear solver to generate
2141: a problem appropriate update to the solution, particularly FAS.
2143: Level: intermediate
2145: .seealso: SNESGetFunction(), SNESComputeNGS()
2146: @*/
2147: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2148: {
2150: DM dm;
2154: SNESGetDM(snes,&dm);
2155: DMSNESSetNGS(dm,f,ctx);
2156: return(0);
2157: }
2159: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2160: {
2162: DM dm;
2163: DMSNES sdm;
2166: SNESGetDM(snes,&dm);
2167: DMGetDMSNES(dm,&sdm);
2168: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2169: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2170: /* A(x)*x - b(x) */
2171: PetscStackPush("SNES Picard user function");
2172: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2173: PetscStackPop;
2174: PetscStackPush("SNES Picard user Jacobian");
2175: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2176: PetscStackPop;
2177: VecScale(f,-1.0);
2178: MatMultAdd(snes->jacobian,x,f,f);
2179: return(0);
2180: }
2182: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2183: {
2185: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2186: return(0);
2187: }
2189: /*@C
2190: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2192: Logically Collective on SNES
2194: Input Parameters:
2195: + snes - the SNES context
2196: . r - vector to store function value
2197: . b - function evaluation routine
2198: . Amat - matrix with which A(x) x - b(x) is to be computed
2199: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2200: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2201: - ctx - [optional] user-defined context for private data for the
2202: function evaluation routine (may be NULL)
2204: Notes:
2205: 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
2206: 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.
2208: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2210: $ 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}
2211: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2213: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2215: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2216: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2218: 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
2219: 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
2220: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2222: Level: intermediate
2224: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2225: @*/
2226: 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)
2227: {
2229: DM dm;
2233: SNESGetDM(snes, &dm);
2234: DMSNESSetPicard(dm,b,J,ctx);
2235: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2236: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2237: return(0);
2238: }
2240: /*@C
2241: SNESGetPicard - Returns the context for the Picard iteration
2243: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2245: Input Parameter:
2246: . snes - the SNES context
2248: Output Parameter:
2249: + r - the function (or NULL)
2250: . f - the function (or NULL); see SNESFunction for calling sequence details
2251: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2252: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2253: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2254: - ctx - the function context (or NULL)
2256: Level: advanced
2258: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2259: @*/
2260: 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)
2261: {
2263: DM dm;
2267: SNESGetFunction(snes,r,NULL,NULL);
2268: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2269: SNESGetDM(snes,&dm);
2270: DMSNESGetPicard(dm,f,J,ctx);
2271: return(0);
2272: }
2274: /*@C
2275: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2277: Logically Collective on SNES
2279: Input Parameters:
2280: + snes - the SNES context
2281: . func - function evaluation routine
2282: - ctx - [optional] user-defined context for private data for the
2283: function evaluation routine (may be NULL)
2285: Calling sequence of func:
2286: $ func (SNES snes,Vec x,void *ctx);
2288: . f - function vector
2289: - ctx - optional user-defined function context
2291: Level: intermediate
2293: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2294: @*/
2295: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2296: {
2299: if (func) snes->ops->computeinitialguess = func;
2300: if (ctx) snes->initialguessP = ctx;
2301: return(0);
2302: }
2304: /* --------------------------------------------------------------- */
2305: /*@C
2306: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2307: it assumes a zero right hand side.
2309: Logically Collective on SNES
2311: Input Parameter:
2312: . snes - the SNES context
2314: Output Parameter:
2315: . rhs - the right hand side vector or NULL if the right hand side vector is null
2317: Level: intermediate
2319: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2320: @*/
2321: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2322: {
2326: *rhs = snes->vec_rhs;
2327: return(0);
2328: }
2330: /*@
2331: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2333: Collective on SNES
2335: Input Parameters:
2336: + snes - the SNES context
2337: - x - input vector
2339: Output Parameter:
2340: . y - function vector, as set by SNESSetFunction()
2342: Notes:
2343: SNESComputeFunction() is typically used within nonlinear solvers
2344: implementations, so most users would not generally call this routine
2345: themselves.
2347: Level: developer
2349: .seealso: SNESSetFunction(), SNESGetFunction()
2350: @*/
2351: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2352: {
2354: DM dm;
2355: DMSNES sdm;
2363: VecValidValues(x,2,PETSC_TRUE);
2365: SNESGetDM(snes,&dm);
2366: DMGetDMSNES(dm,&sdm);
2367: if (sdm->ops->computefunction) {
2368: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2369: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2370: }
2371: VecLockReadPush(x);
2372: PetscStackPush("SNES user function");
2373: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2374: snes->domainerror = PETSC_FALSE;
2375: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2376: PetscStackPop;
2377: VecLockReadPop(x);
2378: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2379: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2380: }
2381: } else if (snes->vec_rhs) {
2382: MatMult(snes->jacobian, x, y);
2383: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2384: if (snes->vec_rhs) {
2385: VecAXPY(y,-1.0,snes->vec_rhs);
2386: }
2387: snes->nfuncs++;
2388: /*
2389: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2390: propagate the value to all processes
2391: */
2392: if (snes->domainerror) {
2393: VecSetInf(y);
2394: }
2395: return(0);
2396: }
2398: /*@
2399: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2401: Collective on SNES
2403: Input Parameters:
2404: + snes - the SNES context
2405: . x - input vector
2406: - b - rhs vector
2408: Output Parameter:
2409: . x - new solution vector
2411: Notes:
2412: SNESComputeNGS() is typically used within composed nonlinear solver
2413: implementations, so most users would not generally call this routine
2414: themselves.
2416: Level: developer
2418: .seealso: SNESSetNGS(), SNESComputeFunction()
2419: @*/
2420: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2421: {
2423: DM dm;
2424: DMSNES sdm;
2432: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2433: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2434: SNESGetDM(snes,&dm);
2435: DMGetDMSNES(dm,&sdm);
2436: if (sdm->ops->computegs) {
2437: if (b) {VecLockReadPush(b);}
2438: PetscStackPush("SNES user NGS");
2439: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2440: PetscStackPop;
2441: if (b) {VecLockReadPop(b);}
2442: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2443: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2444: return(0);
2445: }
2447: PetscErrorCode SNESTestJacobian(SNES snes)
2448: {
2449: Mat A,B,C,D,jacobian;
2450: Vec x = snes->vec_sol,f = snes->vec_func;
2451: PetscErrorCode ierr;
2452: PetscReal nrm,gnorm;
2453: PetscReal threshold = 1.e-5;
2454: MatType mattype;
2455: PetscInt m,n,M,N;
2456: void *functx;
2457: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg;
2458: PetscViewer viewer,mviewer;
2459: MPI_Comm comm;
2460: PetscInt tabs;
2461: static PetscBool directionsprinted = PETSC_FALSE;
2462: PetscViewerFormat format;
2465: PetscObjectOptionsBegin((PetscObject)snes);
2466: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2467: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2468: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2469: if (!complete_print) {
2470: PetscOptionsDeprecated("-snes_test_jacobian_display","-snes_test_jacobian_view","3.13",NULL);
2471: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2472: }
2473: /* for compatibility with PETSc 3.9 and older. */
2474: PetscOptionsDeprecated("-snes_test_jacobian_display_threshold","-snes_test_jacobian","3.13","-snes_test_jacobian accepts an optional threshold (since v3.10)");
2475: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2476: PetscOptionsEnd();
2477: if (!test) return(0);
2479: PetscObjectGetComm((PetscObject)snes,&comm);
2480: PetscViewerASCIIGetStdout(comm,&viewer);
2481: PetscViewerASCIIGetTab(viewer, &tabs);
2482: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2483: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2484: if (!complete_print && !directionsprinted) {
2485: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2486: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2487: }
2488: if (!directionsprinted) {
2489: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2490: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2491: directionsprinted = PETSC_TRUE;
2492: }
2493: if (complete_print) {
2494: PetscViewerPushFormat(mviewer,format);
2495: }
2497: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2498: if (!flg) jacobian = snes->jacobian;
2499: else jacobian = snes->jacobian_pre;
2501: if (!x) {
2502: MatCreateVecs(jacobian, &x, NULL);
2503: } else {
2504: PetscObjectReference((PetscObject) x);
2505: }
2506: if (!f) {
2507: VecDuplicate(x, &f);
2508: } else {
2509: PetscObjectReference((PetscObject) f);
2510: }
2511: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2512: SNESComputeFunction(snes,x,f);
2513: VecDestroy(&f);
2515: while (jacobian) {
2516: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2517: if (flg) {
2518: A = jacobian;
2519: PetscObjectReference((PetscObject)A);
2520: } else {
2521: MatComputeOperator(jacobian,MATAIJ,&A);
2522: }
2524: MatGetType(A,&mattype);
2525: MatGetSize(A,&M,&N);
2526: MatGetLocalSize(A,&m,&n);
2528: MatCreate(PetscObjectComm((PetscObject)A),&B);
2529: MatSetType(B,mattype);
2530: MatSetSizes(B,m,n,M,N);
2531: MatSetBlockSizesFromMats(B,A,A);
2532: MatSetUp(B);
2533: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2535: SNESGetFunction(snes,NULL,NULL,&functx);
2536: SNESComputeJacobianDefault(snes,x,B,B,functx);
2538: MatDuplicate(B,MAT_COPY_VALUES,&D);
2539: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2540: MatNorm(D,NORM_FROBENIUS,&nrm);
2541: MatNorm(A,NORM_FROBENIUS,&gnorm);
2542: MatDestroy(&D);
2543: if (!gnorm) gnorm = 1; /* just in case */
2544: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2546: if (complete_print) {
2547: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2548: MatView(jacobian,mviewer);
2549: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2550: MatView(B,mviewer);
2551: }
2553: if (threshold_print || complete_print) {
2554: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2555: PetscScalar *cvals;
2556: const PetscInt *bcols;
2557: const PetscScalar *bvals;
2559: MatCreate(PetscObjectComm((PetscObject)A),&C);
2560: MatSetType(C,mattype);
2561: MatSetSizes(C,m,n,M,N);
2562: MatSetBlockSizesFromMats(C,A,A);
2563: MatSetUp(C);
2564: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2566: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2567: MatGetOwnershipRange(B,&Istart,&Iend);
2569: for (row = Istart; row < Iend; row++) {
2570: MatGetRow(B,row,&bncols,&bcols,&bvals);
2571: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2572: for (j = 0, cncols = 0; j < bncols; j++) {
2573: if (PetscAbsScalar(bvals[j]) > threshold) {
2574: ccols[cncols] = bcols[j];
2575: cvals[cncols] = bvals[j];
2576: cncols += 1;
2577: }
2578: }
2579: if (cncols) {
2580: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2581: }
2582: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2583: PetscFree2(ccols,cvals);
2584: }
2585: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2586: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2587: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2588: MatView(C,complete_print ? mviewer : viewer);
2589: MatDestroy(&C);
2590: }
2591: MatDestroy(&A);
2592: MatDestroy(&B);
2594: if (jacobian != snes->jacobian_pre) {
2595: jacobian = snes->jacobian_pre;
2596: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2597: }
2598: else jacobian = NULL;
2599: }
2600: VecDestroy(&x);
2601: if (complete_print) {
2602: PetscViewerPopFormat(mviewer);
2603: }
2604: if (mviewer) { PetscViewerDestroy(&mviewer); }
2605: PetscViewerASCIISetTab(viewer,tabs);
2606: return(0);
2607: }
2609: /*@
2610: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2612: Collective on SNES
2614: Input Parameters:
2615: + snes - the SNES context
2616: - x - input vector
2618: Output Parameters:
2619: + A - Jacobian matrix
2620: - B - optional preconditioning matrix
2622: Options Database Keys:
2623: + -snes_lag_preconditioner <lag>
2624: . -snes_lag_jacobian <lag>
2625: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one compute via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
2626: . -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2627: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2628: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2629: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2630: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2631: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2632: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2633: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2634: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2635: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2636: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2637: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2640: Notes:
2641: Most users should not need to explicitly call this routine, as it
2642: is used internally within the nonlinear solvers.
2644: Developer Notes:
2645: 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
2646: for with the SNESType of test that has been removed.
2648: Level: developer
2650: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2651: @*/
2652: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2653: {
2655: PetscBool flag;
2656: DM dm;
2657: DMSNES sdm;
2658: KSP ksp;
2664: VecValidValues(X,2,PETSC_TRUE);
2665: SNESGetDM(snes,&dm);
2666: DMGetDMSNES(dm,&sdm);
2668: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2670: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2672: if (snes->lagjacobian == -2) {
2673: snes->lagjacobian = -1;
2675: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2676: } else if (snes->lagjacobian == -1) {
2677: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
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: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2685: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2686: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2687: if (flag) {
2688: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2689: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2690: }
2691: return(0);
2692: }
2693: if (snes->npc && snes->npcside== PC_LEFT) {
2694: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2695: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2696: return(0);
2697: }
2699: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2700: VecLockReadPush(X);
2701: PetscStackPush("SNES user Jacobian function");
2702: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2703: PetscStackPop;
2704: VecLockReadPop(X);
2705: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2707: /* attach latest linearization point to the preconditioning matrix */
2708: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2710: /* the next line ensures that snes->ksp exists */
2711: SNESGetKSP(snes,&ksp);
2712: if (snes->lagpreconditioner == -2) {
2713: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2714: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2715: snes->lagpreconditioner = -1;
2716: } else if (snes->lagpreconditioner == -1) {
2717: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2718: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2719: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2720: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2721: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2722: } else {
2723: PetscInfo(snes,"Rebuilding preconditioner\n");
2724: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2725: }
2727: SNESTestJacobian(snes);
2728: /* make sure user returned a correct Jacobian and preconditioner */
2731: {
2732: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2733: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2734: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2735: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2736: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2737: if (flag || flag_draw || flag_contour) {
2738: Mat Bexp_mine = NULL,Bexp,FDexp;
2739: PetscViewer vdraw,vstdout;
2740: PetscBool flg;
2741: if (flag_operator) {
2742: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2743: Bexp = Bexp_mine;
2744: } else {
2745: /* See if the preconditioning matrix can be viewed and added directly */
2746: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2747: if (flg) Bexp = B;
2748: else {
2749: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2750: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2751: Bexp = Bexp_mine;
2752: }
2753: }
2754: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2755: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2756: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2757: if (flag_draw || flag_contour) {
2758: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2759: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2760: } else vdraw = NULL;
2761: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2762: if (flag) {MatView(Bexp,vstdout);}
2763: if (vdraw) {MatView(Bexp,vdraw);}
2764: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2765: if (flag) {MatView(FDexp,vstdout);}
2766: if (vdraw) {MatView(FDexp,vdraw);}
2767: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2768: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2769: if (flag) {MatView(FDexp,vstdout);}
2770: if (vdraw) { /* Always use contour for the difference */
2771: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2772: MatView(FDexp,vdraw);
2773: PetscViewerPopFormat(vdraw);
2774: }
2775: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2776: PetscViewerDestroy(&vdraw);
2777: MatDestroy(&Bexp_mine);
2778: MatDestroy(&FDexp);
2779: }
2780: }
2781: {
2782: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2783: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2784: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2785: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2786: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2787: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2788: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2789: if (flag_threshold) {
2790: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2791: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2792: }
2793: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2794: Mat Bfd;
2795: PetscViewer vdraw,vstdout;
2796: MatColoring coloring;
2797: ISColoring iscoloring;
2798: MatFDColoring matfdcoloring;
2799: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2800: void *funcctx;
2801: PetscReal norm1,norm2,normmax;
2803: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2804: MatColoringCreate(Bfd,&coloring);
2805: MatColoringSetType(coloring,MATCOLORINGSL);
2806: MatColoringSetFromOptions(coloring);
2807: MatColoringApply(coloring,&iscoloring);
2808: MatColoringDestroy(&coloring);
2809: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2810: MatFDColoringSetFromOptions(matfdcoloring);
2811: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2812: ISColoringDestroy(&iscoloring);
2814: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2815: SNESGetFunction(snes,NULL,&func,&funcctx);
2816: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2817: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2818: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2819: MatFDColoringSetFromOptions(matfdcoloring);
2820: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2821: MatFDColoringDestroy(&matfdcoloring);
2823: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2824: if (flag_draw || flag_contour) {
2825: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2826: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2827: } else vdraw = NULL;
2828: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2829: if (flag_display) {MatView(B,vstdout);}
2830: if (vdraw) {MatView(B,vdraw);}
2831: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2832: if (flag_display) {MatView(Bfd,vstdout);}
2833: if (vdraw) {MatView(Bfd,vdraw);}
2834: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2835: MatNorm(Bfd,NORM_1,&norm1);
2836: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2837: MatNorm(Bfd,NORM_MAX,&normmax);
2838: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2839: if (flag_display) {MatView(Bfd,vstdout);}
2840: if (vdraw) { /* Always use contour for the difference */
2841: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2842: MatView(Bfd,vdraw);
2843: PetscViewerPopFormat(vdraw);
2844: }
2845: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2847: if (flag_threshold) {
2848: PetscInt bs,rstart,rend,i;
2849: MatGetBlockSize(B,&bs);
2850: MatGetOwnershipRange(B,&rstart,&rend);
2851: for (i=rstart; i<rend; i++) {
2852: const PetscScalar *ba,*ca;
2853: const PetscInt *bj,*cj;
2854: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2855: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2856: MatGetRow(B,i,&bn,&bj,&ba);
2857: MatGetRow(Bfd,i,&cn,&cj,&ca);
2858: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2859: for (j=0; j<bn; j++) {
2860: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2861: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2862: maxentrycol = bj[j];
2863: maxentry = PetscRealPart(ba[j]);
2864: }
2865: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2866: maxdiffcol = bj[j];
2867: maxdiff = PetscRealPart(ca[j]);
2868: }
2869: if (rdiff > maxrdiff) {
2870: maxrdiffcol = bj[j];
2871: maxrdiff = rdiff;
2872: }
2873: }
2874: if (maxrdiff > 1) {
2875: 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);
2876: for (j=0; j<bn; j++) {
2877: PetscReal rdiff;
2878: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2879: if (rdiff > 1) {
2880: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2881: }
2882: }
2883: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2884: }
2885: MatRestoreRow(B,i,&bn,&bj,&ba);
2886: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2887: }
2888: }
2889: PetscViewerDestroy(&vdraw);
2890: MatDestroy(&Bfd);
2891: }
2892: }
2893: return(0);
2894: }
2896: /*MC
2897: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2899: Synopsis:
2900: #include "petscsnes.h"
2901: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2903: + x - input vector
2904: . Amat - the matrix that defines the (approximate) Jacobian
2905: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2906: - ctx - [optional] user-defined Jacobian context
2908: Level: intermediate
2910: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2911: M*/
2913: /*@C
2914: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2915: location to store the matrix.
2917: Logically Collective on SNES
2919: Input Parameters:
2920: + snes - the SNES context
2921: . Amat - the matrix that defines the (approximate) Jacobian
2922: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2923: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2924: - ctx - [optional] user-defined context for private data for the
2925: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2927: Notes:
2928: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2929: each matrix.
2931: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2932: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2934: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2935: must be a MatFDColoring.
2937: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2938: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2940: Level: beginner
2942: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2943: SNESSetPicard(), SNESJacobianFunction
2944: @*/
2945: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2946: {
2948: DM dm;
2956: SNESGetDM(snes,&dm);
2957: DMSNESSetJacobian(dm,J,ctx);
2958: if (Amat) {
2959: PetscObjectReference((PetscObject)Amat);
2960: MatDestroy(&snes->jacobian);
2962: snes->jacobian = Amat;
2963: }
2964: if (Pmat) {
2965: PetscObjectReference((PetscObject)Pmat);
2966: MatDestroy(&snes->jacobian_pre);
2968: snes->jacobian_pre = Pmat;
2969: }
2970: return(0);
2971: }
2973: /*@C
2974: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2975: provided context for evaluating the Jacobian.
2977: Not Collective, but Mat object will be parallel if SNES object is
2979: Input Parameter:
2980: . snes - the nonlinear solver context
2982: Output Parameters:
2983: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2984: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2985: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2986: - ctx - location to stash Jacobian ctx (or NULL)
2988: Level: advanced
2990: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2991: @*/
2992: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2993: {
2995: DM dm;
2996: DMSNES sdm;
3000: if (Amat) *Amat = snes->jacobian;
3001: if (Pmat) *Pmat = snes->jacobian_pre;
3002: SNESGetDM(snes,&dm);
3003: DMGetDMSNES(dm,&sdm);
3004: if (J) *J = sdm->ops->computejacobian;
3005: if (ctx) *ctx = sdm->jacobianctx;
3006: return(0);
3007: }
3009: /*@
3010: SNESSetUp - Sets up the internal data structures for the later use
3011: of a nonlinear solver.
3013: Collective on SNES
3015: Input Parameters:
3016: . snes - the SNES context
3018: Notes:
3019: For basic use of the SNES solvers the user need not explicitly call
3020: SNESSetUp(), since these actions will automatically occur during
3021: the call to SNESSolve(). However, if one wishes to control this
3022: phase separately, SNESSetUp() should be called after SNESCreate()
3023: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3025: Level: advanced
3027: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3028: @*/
3029: PetscErrorCode SNESSetUp(SNES snes)
3030: {
3032: DM dm;
3033: DMSNES sdm;
3034: SNESLineSearch linesearch, pclinesearch;
3035: void *lsprectx,*lspostctx;
3036: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3037: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3038: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3039: Vec f,fpc;
3040: void *funcctx;
3041: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3042: void *jacctx,*appctx;
3043: Mat j,jpre;
3047: if (snes->setupcalled) return(0);
3048: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3050: if (!((PetscObject)snes)->type_name) {
3051: SNESSetType(snes,SNESNEWTONLS);
3052: }
3054: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3056: SNESGetDM(snes,&dm);
3057: DMGetDMSNES(dm,&sdm);
3058: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3059: if (!sdm->ops->computejacobian) {
3060: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3061: }
3062: if (!snes->vec_func) {
3063: DMCreateGlobalVector(dm,&snes->vec_func);
3064: }
3066: if (!snes->ksp) {
3067: SNESGetKSP(snes, &snes->ksp);
3068: }
3070: if (snes->linesearch) {
3071: SNESGetLineSearch(snes, &snes->linesearch);
3072: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3073: }
3075: if (snes->npc && (snes->npcside== PC_LEFT)) {
3076: snes->mf = PETSC_TRUE;
3077: snes->mf_operator = PETSC_FALSE;
3078: }
3080: if (snes->npc) {
3081: /* copy the DM over */
3082: SNESGetDM(snes,&dm);
3083: SNESSetDM(snes->npc,dm);
3085: SNESGetFunction(snes,&f,&func,&funcctx);
3086: VecDuplicate(f,&fpc);
3087: SNESSetFunction(snes->npc,fpc,func,funcctx);
3088: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3089: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3090: SNESGetApplicationContext(snes,&appctx);
3091: SNESSetApplicationContext(snes->npc,appctx);
3092: VecDestroy(&fpc);
3094: /* copy the function pointers over */
3095: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3097: /* default to 1 iteration */
3098: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3099: if (snes->npcside==PC_RIGHT) {
3100: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3101: } else {
3102: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3103: }
3104: SNESSetFromOptions(snes->npc);
3106: /* copy the line search context over */
3107: if (snes->linesearch && snes->npc->linesearch) {
3108: SNESGetLineSearch(snes,&linesearch);
3109: SNESGetLineSearch(snes->npc,&pclinesearch);
3110: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3111: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3112: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3113: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3114: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3115: }
3116: }
3117: if (snes->mf) {
3118: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3119: }
3120: if (snes->ops->usercompute && !snes->user) {
3121: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3122: }
3124: snes->jac_iter = 0;
3125: snes->pre_iter = 0;
3127: if (snes->ops->setup) {
3128: (*snes->ops->setup)(snes);
3129: }
3131: if (snes->npc && (snes->npcside== PC_LEFT)) {
3132: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3133: if (snes->linesearch){
3134: SNESGetLineSearch(snes,&linesearch);
3135: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3136: }
3137: }
3138: }
3139: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3140: snes->setupcalled = PETSC_TRUE;
3141: return(0);
3142: }
3144: /*@
3145: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3147: Collective on SNES
3149: Input Parameter:
3150: . snes - iterative context obtained from SNESCreate()
3152: Level: intermediate
3154: Notes:
3155: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3157: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3158: @*/
3159: PetscErrorCode SNESReset(SNES snes)
3160: {
3165: if (snes->ops->userdestroy && snes->user) {
3166: (*snes->ops->userdestroy)((void**)&snes->user);
3167: snes->user = NULL;
3168: }
3169: if (snes->npc) {
3170: SNESReset(snes->npc);
3171: }
3173: if (snes->ops->reset) {
3174: (*snes->ops->reset)(snes);
3175: }
3176: if (snes->ksp) {
3177: KSPReset(snes->ksp);
3178: }
3180: if (snes->linesearch) {
3181: SNESLineSearchReset(snes->linesearch);
3182: }
3184: VecDestroy(&snes->vec_rhs);
3185: VecDestroy(&snes->vec_sol);
3186: VecDestroy(&snes->vec_sol_update);
3187: VecDestroy(&snes->vec_func);
3188: MatDestroy(&snes->jacobian);
3189: MatDestroy(&snes->jacobian_pre);
3190: VecDestroyVecs(snes->nwork,&snes->work);
3191: VecDestroyVecs(snes->nvwork,&snes->vwork);
3193: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3195: snes->nwork = snes->nvwork = 0;
3196: snes->setupcalled = PETSC_FALSE;
3197: return(0);
3198: }
3200: /*@
3201: SNESDestroy - Destroys the nonlinear solver context that was created
3202: with SNESCreate().
3204: Collective on SNES
3206: Input Parameter:
3207: . snes - the SNES context
3209: Level: beginner
3211: .seealso: SNESCreate(), SNESSolve()
3212: @*/
3213: PetscErrorCode SNESDestroy(SNES *snes)
3214: {
3218: if (!*snes) return(0);
3220: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3222: SNESReset((*snes));
3223: SNESDestroy(&(*snes)->npc);
3225: /* if memory was published with SAWs then destroy it */
3226: PetscObjectSAWsViewOff((PetscObject)*snes);
3227: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3229: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3230: DMDestroy(&(*snes)->dm);
3231: KSPDestroy(&(*snes)->ksp);
3232: SNESLineSearchDestroy(&(*snes)->linesearch);
3234: PetscFree((*snes)->kspconvctx);
3235: if ((*snes)->ops->convergeddestroy) {
3236: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3237: }
3238: if ((*snes)->conv_hist_alloc) {
3239: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3240: }
3241: SNESMonitorCancel((*snes));
3242: PetscHeaderDestroy(snes);
3243: return(0);
3244: }
3246: /* ----------- Routines to set solver parameters ---------- */
3248: /*@
3249: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3251: Logically Collective on SNES
3253: Input Parameters:
3254: + snes - the SNES context
3255: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3256: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3258: Options Database Keys:
3259: . -snes_lag_preconditioner <lag>
3261: Notes:
3262: The default is 1
3263: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3264: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3266: Level: intermediate
3268: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3270: @*/
3271: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3272: {
3275: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3276: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3278: snes->lagpreconditioner = lag;
3279: return(0);
3280: }
3282: /*@
3283: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3285: Logically Collective on SNES
3287: Input Parameters:
3288: + snes - the SNES context
3289: - steps - the number of refinements to do, defaults to 0
3291: Options Database Keys:
3292: . -snes_grid_sequence <steps>
3294: Level: intermediate
3296: Notes:
3297: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3299: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3301: @*/
3302: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3303: {
3307: snes->gridsequence = steps;
3308: return(0);
3309: }
3311: /*@
3312: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3314: Logically Collective on SNES
3316: Input Parameter:
3317: . snes - the SNES context
3319: Output Parameter:
3320: . steps - the number of refinements to do, defaults to 0
3322: Options Database Keys:
3323: . -snes_grid_sequence <steps>
3325: Level: intermediate
3327: Notes:
3328: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3330: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3332: @*/
3333: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3334: {
3337: *steps = snes->gridsequence;
3338: return(0);
3339: }
3341: /*@
3342: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3344: Not Collective
3346: Input Parameter:
3347: . snes - the SNES context
3349: Output Parameter:
3350: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3351: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3353: Options Database Keys:
3354: . -snes_lag_preconditioner <lag>
3356: Notes:
3357: The default is 1
3358: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3360: Level: intermediate
3362: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3364: @*/
3365: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3366: {
3369: *lag = snes->lagpreconditioner;
3370: return(0);
3371: }
3373: /*@
3374: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3375: often the preconditioner is rebuilt.
3377: Logically Collective on SNES
3379: Input Parameters:
3380: + snes - the SNES context
3381: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3382: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3384: Options Database Keys:
3385: . -snes_lag_jacobian <lag>
3387: Notes:
3388: The default is 1
3389: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3390: 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
3391: at the next Newton step but never again (unless it is reset to another value)
3393: Level: intermediate
3395: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3397: @*/
3398: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3399: {
3402: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3403: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3405: snes->lagjacobian = lag;
3406: return(0);
3407: }
3409: /*@
3410: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3412: Not Collective
3414: Input Parameter:
3415: . snes - the SNES context
3417: Output Parameter:
3418: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3419: the Jacobian is built etc.
3421: Options Database Keys:
3422: . -snes_lag_jacobian <lag>
3424: Notes:
3425: The default is 1
3426: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3428: Level: intermediate
3430: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3432: @*/
3433: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3434: {
3437: *lag = snes->lagjacobian;
3438: return(0);
3439: }
3441: /*@
3442: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3444: Logically collective on SNES
3446: Input Parameter:
3447: + snes - the SNES context
3448: - flg - jacobian lagging persists if true
3450: Options Database Keys:
3451: . -snes_lag_jacobian_persists <flg>
3453: Notes:
3454: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3455: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3456: timesteps may present huge efficiency gains.
3458: Level: developer
3460: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3462: @*/
3463: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3464: {
3468: snes->lagjac_persist = flg;
3469: return(0);
3470: }
3472: /*@
3473: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3475: Logically Collective on SNES
3477: Input Parameter:
3478: + snes - the SNES context
3479: - flg - preconditioner lagging persists if true
3481: Options Database Keys:
3482: . -snes_lag_jacobian_persists <flg>
3484: Notes:
3485: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3486: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3487: several timesteps may present huge efficiency gains.
3489: Level: developer
3491: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3493: @*/
3494: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3495: {
3499: snes->lagpre_persist = flg;
3500: return(0);
3501: }
3503: /*@
3504: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3506: Logically Collective on SNES
3508: Input Parameters:
3509: + snes - the SNES context
3510: - force - PETSC_TRUE require at least one iteration
3512: Options Database Keys:
3513: . -snes_force_iteration <force> - Sets forcing an iteration
3515: Notes:
3516: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3518: Level: intermediate
3520: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3521: @*/
3522: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3523: {
3526: snes->forceiteration = force;
3527: return(0);
3528: }
3530: /*@
3531: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3533: Logically Collective on SNES
3535: Input Parameters:
3536: . snes - the SNES context
3538: Output Parameter:
3539: . force - PETSC_TRUE requires at least one iteration.
3541: Level: intermediate
3543: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3544: @*/
3545: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3546: {
3549: *force = snes->forceiteration;
3550: return(0);
3551: }
3553: /*@
3554: SNESSetTolerances - Sets various parameters used in convergence tests.
3556: Logically Collective on SNES
3558: Input Parameters:
3559: + snes - the SNES context
3560: . abstol - absolute convergence tolerance
3561: . rtol - relative convergence tolerance
3562: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3563: . maxit - maximum number of iterations
3564: - maxf - maximum number of function evaluations (-1 indicates no limit)
3566: Options Database Keys:
3567: + -snes_atol <abstol> - Sets abstol
3568: . -snes_rtol <rtol> - Sets rtol
3569: . -snes_stol <stol> - Sets stol
3570: . -snes_max_it <maxit> - Sets maxit
3571: - -snes_max_funcs <maxf> - Sets maxf
3573: Notes:
3574: The default maximum number of iterations is 50.
3575: The default maximum number of function evaluations is 1000.
3577: Level: intermediate
3579: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3580: @*/
3581: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3582: {
3591: if (abstol != PETSC_DEFAULT) {
3592: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3593: snes->abstol = abstol;
3594: }
3595: if (rtol != PETSC_DEFAULT) {
3596: 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);
3597: snes->rtol = rtol;
3598: }
3599: if (stol != PETSC_DEFAULT) {
3600: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3601: snes->stol = stol;
3602: }
3603: if (maxit != PETSC_DEFAULT) {
3604: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3605: snes->max_its = maxit;
3606: }
3607: if (maxf != PETSC_DEFAULT) {
3608: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3609: snes->max_funcs = maxf;
3610: }
3611: snes->tolerancesset = PETSC_TRUE;
3612: return(0);
3613: }
3615: /*@
3616: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3618: Logically Collective on SNES
3620: Input Parameters:
3621: + snes - the SNES context
3622: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3624: Options Database Keys:
3625: . -snes_divergence_tolerance <divtol> - Sets divtol
3627: Notes:
3628: The default divergence tolerance is 1e4.
3630: Level: intermediate
3632: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3633: @*/
3634: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3635: {
3640: if (divtol != PETSC_DEFAULT) {
3641: snes->divtol = divtol;
3642: }
3643: else {
3644: snes->divtol = 1.0e4;
3645: }
3646: return(0);
3647: }
3649: /*@
3650: SNESGetTolerances - Gets various parameters used in convergence tests.
3652: Not Collective
3654: Input Parameters:
3655: + snes - the SNES context
3656: . atol - absolute convergence tolerance
3657: . rtol - relative convergence tolerance
3658: . stol - convergence tolerance in terms of the norm
3659: of the change in the solution between steps
3660: . maxit - maximum number of iterations
3661: - maxf - maximum number of function evaluations
3663: Notes:
3664: The user can specify NULL for any parameter that is not needed.
3666: Level: intermediate
3668: .seealso: SNESSetTolerances()
3669: @*/
3670: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3671: {
3674: if (atol) *atol = snes->abstol;
3675: if (rtol) *rtol = snes->rtol;
3676: if (stol) *stol = snes->stol;
3677: if (maxit) *maxit = snes->max_its;
3678: if (maxf) *maxf = snes->max_funcs;
3679: return(0);
3680: }
3682: /*@
3683: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3685: Not Collective
3687: Input Parameters:
3688: + snes - the SNES context
3689: - divtol - divergence tolerance
3691: Level: intermediate
3693: .seealso: SNESSetDivergenceTolerance()
3694: @*/
3695: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3696: {
3699: if (divtol) *divtol = snes->divtol;
3700: return(0);
3701: }
3703: /*@
3704: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3706: Logically Collective on SNES
3708: Input Parameters:
3709: + snes - the SNES context
3710: - tol - tolerance
3712: Options Database Key:
3713: . -snes_trtol <tol> - Sets tol
3715: Level: intermediate
3717: .seealso: SNESSetTolerances()
3718: @*/
3719: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3720: {
3724: snes->deltatol = tol;
3725: return(0);
3726: }
3728: /*
3729: Duplicate the lg monitors for SNES from KSP; for some reason with
3730: dynamic libraries things don't work under Sun4 if we just use
3731: macros instead of functions
3732: */
3733: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3734: {
3739: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3740: return(0);
3741: }
3743: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3744: {
3748: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3749: return(0);
3750: }
3752: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3754: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3755: {
3756: PetscDrawLG lg;
3757: PetscErrorCode ierr;
3758: PetscReal x,y,per;
3759: PetscViewer v = (PetscViewer)monctx;
3760: static PetscReal prev; /* should be in the context */
3761: PetscDraw draw;
3765: PetscViewerDrawGetDrawLG(v,0,&lg);
3766: if (!n) {PetscDrawLGReset(lg);}
3767: PetscDrawLGGetDraw(lg,&draw);
3768: PetscDrawSetTitle(draw,"Residual norm");
3769: x = (PetscReal)n;
3770: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3771: else y = -15.0;
3772: PetscDrawLGAddPoint(lg,&x,&y);
3773: if (n < 20 || !(n % 5) || snes->reason) {
3774: PetscDrawLGDraw(lg);
3775: PetscDrawLGSave(lg);
3776: }
3778: PetscViewerDrawGetDrawLG(v,1,&lg);
3779: if (!n) {PetscDrawLGReset(lg);}
3780: PetscDrawLGGetDraw(lg,&draw);
3781: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3782: SNESMonitorRange_Private(snes,n,&per);
3783: x = (PetscReal)n;
3784: y = 100.0*per;
3785: PetscDrawLGAddPoint(lg,&x,&y);
3786: if (n < 20 || !(n % 5) || snes->reason) {
3787: PetscDrawLGDraw(lg);
3788: PetscDrawLGSave(lg);
3789: }
3791: PetscViewerDrawGetDrawLG(v,2,&lg);
3792: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3793: PetscDrawLGGetDraw(lg,&draw);
3794: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3795: x = (PetscReal)n;
3796: y = (prev - rnorm)/prev;
3797: PetscDrawLGAddPoint(lg,&x,&y);
3798: if (n < 20 || !(n % 5) || snes->reason) {
3799: PetscDrawLGDraw(lg);
3800: PetscDrawLGSave(lg);
3801: }
3803: PetscViewerDrawGetDrawLG(v,3,&lg);
3804: if (!n) {PetscDrawLGReset(lg);}
3805: PetscDrawLGGetDraw(lg,&draw);
3806: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3807: x = (PetscReal)n;
3808: y = (prev - rnorm)/(prev*per);
3809: if (n > 2) { /*skip initial crazy value */
3810: PetscDrawLGAddPoint(lg,&x,&y);
3811: }
3812: if (n < 20 || !(n % 5) || snes->reason) {
3813: PetscDrawLGDraw(lg);
3814: PetscDrawLGSave(lg);
3815: }
3816: prev = rnorm;
3817: return(0);
3818: }
3820: /*@
3821: SNESMonitor - runs the user provided monitor routines, if they exist
3823: Collective on SNES
3825: Input Parameters:
3826: + snes - nonlinear solver context obtained from SNESCreate()
3827: . iter - iteration number
3828: - rnorm - relative norm of the residual
3830: Notes:
3831: This routine is called by the SNES implementations.
3832: It does not typically need to be called by the user.
3834: Level: developer
3836: .seealso: SNESMonitorSet()
3837: @*/
3838: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3839: {
3841: PetscInt i,n = snes->numbermonitors;
3844: VecLockReadPush(snes->vec_sol);
3845: for (i=0; i<n; i++) {
3846: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3847: }
3848: VecLockReadPop(snes->vec_sol);
3849: return(0);
3850: }
3852: /* ------------ Routines to set performance monitoring options ----------- */
3854: /*MC
3855: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3857: Synopsis:
3858: #include <petscsnes.h>
3859: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3861: + snes - the SNES context
3862: . its - iteration number
3863: . norm - 2-norm function value (may be estimated)
3864: - mctx - [optional] monitoring context
3866: Level: advanced
3868: .seealso: SNESMonitorSet(), SNESMonitorGet()
3869: M*/
3871: /*@C
3872: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3873: iteration of the nonlinear solver to display the iteration's
3874: progress.
3876: Logically Collective on SNES
3878: Input Parameters:
3879: + snes - the SNES context
3880: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3881: . mctx - [optional] user-defined context for private data for the
3882: monitor routine (use NULL if no context is desired)
3883: - monitordestroy - [optional] routine that frees monitor context
3884: (may be NULL)
3886: Options Database Keys:
3887: + -snes_monitor - sets SNESMonitorDefault()
3888: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3889: uses SNESMonitorLGCreate()
3890: - -snes_monitor_cancel - cancels all monitors that have
3891: been hardwired into a code by
3892: calls to SNESMonitorSet(), but
3893: does not cancel those set via
3894: the options database.
3896: Notes:
3897: Several different monitoring routines may be set by calling
3898: SNESMonitorSet() multiple times; all will be called in the
3899: order in which they were set.
3901: Fortran Notes:
3902: Only a single monitor function can be set for each SNES object
3904: Level: intermediate
3906: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3907: @*/
3908: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3909: {
3910: PetscInt i;
3912: PetscBool identical;
3916: for (i=0; i<snes->numbermonitors;i++) {
3917: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3918: if (identical) return(0);
3919: }
3920: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3921: snes->monitor[snes->numbermonitors] = f;
3922: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3923: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3924: return(0);
3925: }
3927: /*@
3928: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3930: Logically Collective on SNES
3932: Input Parameters:
3933: . snes - the SNES context
3935: Options Database Key:
3936: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3937: into a code by calls to SNESMonitorSet(), but does not cancel those
3938: set via the options database
3940: Notes:
3941: There is no way to clear one specific monitor from a SNES object.
3943: Level: intermediate
3945: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3946: @*/
3947: PetscErrorCode SNESMonitorCancel(SNES snes)
3948: {
3950: PetscInt i;
3954: for (i=0; i<snes->numbermonitors; i++) {
3955: if (snes->monitordestroy[i]) {
3956: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3957: }
3958: }
3959: snes->numbermonitors = 0;
3960: return(0);
3961: }
3963: /*MC
3964: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3966: Synopsis:
3967: #include <petscsnes.h>
3968: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3970: + snes - the SNES context
3971: . it - current iteration (0 is the first and is before any Newton step)
3972: . cctx - [optional] convergence context
3973: . reason - reason for convergence/divergence
3974: . xnorm - 2-norm of current iterate
3975: . gnorm - 2-norm of current step
3976: - f - 2-norm of function
3978: Level: intermediate
3980: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3981: M*/
3983: /*@C
3984: SNESSetConvergenceTest - Sets the function that is to be used
3985: to test for convergence of the nonlinear iterative solution.
3987: Logically Collective on SNES
3989: Input Parameters:
3990: + snes - the SNES context
3991: . SNESConvergenceTestFunction - routine to test for convergence
3992: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3993: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
3995: Level: advanced
3997: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3998: @*/
3999: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
4000: {
4005: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4006: if (snes->ops->convergeddestroy) {
4007: (*snes->ops->convergeddestroy)(snes->cnvP);
4008: }
4009: snes->ops->converged = SNESConvergenceTestFunction;
4010: snes->ops->convergeddestroy = destroy;
4011: snes->cnvP = cctx;
4012: return(0);
4013: }
4015: /*@
4016: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4018: Not Collective
4020: Input Parameter:
4021: . snes - the SNES context
4023: Output Parameter:
4024: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4025: manual pages for the individual convergence tests for complete lists
4027: Options Database:
4028: . -snes_converged_reason - prints the reason to standard out
4030: Level: intermediate
4032: Notes:
4033: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4035: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4036: @*/
4037: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4038: {
4042: *reason = snes->reason;
4043: return(0);
4044: }
4046: /*@
4047: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4049: Not Collective
4051: Input Parameters:
4052: + snes - the SNES context
4053: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4054: manual pages for the individual convergence tests for complete lists
4056: Level: intermediate
4058: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4059: @*/
4060: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4061: {
4064: snes->reason = reason;
4065: return(0);
4066: }
4068: /*@
4069: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4071: Logically Collective on SNES
4073: Input Parameters:
4074: + snes - iterative context obtained from SNESCreate()
4075: . a - array to hold history, this array will contain the function norms computed at each step
4076: . its - integer array holds the number of linear iterations for each solve.
4077: . na - size of a and its
4078: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4079: else it continues storing new values for new nonlinear solves after the old ones
4081: Notes:
4082: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4083: default array of length 10000 is allocated.
4085: This routine is useful, e.g., when running a code for purposes
4086: of accurate performance monitoring, when no I/O should be done
4087: during the section of code that is being timed.
4089: Level: intermediate
4091: .seealso: SNESGetConvergenceHistory()
4093: @*/
4094: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4095: {
4102: if (!a) {
4103: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4104: PetscCalloc2(na,&a,na,&its);
4105: snes->conv_hist_alloc = PETSC_TRUE;
4106: }
4107: snes->conv_hist = a;
4108: snes->conv_hist_its = its;
4109: snes->conv_hist_max = na;
4110: snes->conv_hist_len = 0;
4111: snes->conv_hist_reset = reset;
4112: return(0);
4113: }
4115: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4116: #include <engine.h> /* MATLAB include file */
4117: #include <mex.h> /* MATLAB include file */
4119: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4120: {
4121: mxArray *mat;
4122: PetscInt i;
4123: PetscReal *ar;
4126: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4127: ar = (PetscReal*) mxGetData(mat);
4128: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4129: PetscFunctionReturn(mat);
4130: }
4131: #endif
4133: /*@C
4134: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4136: Not Collective
4138: Input Parameter:
4139: . snes - iterative context obtained from SNESCreate()
4141: Output Parameters:
4142: + a - array to hold history
4143: . its - integer array holds the number of linear iterations (or
4144: negative if not converged) for each solve.
4145: - na - size of a and its
4147: Notes:
4148: The calling sequence for this routine in Fortran is
4149: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4151: This routine is useful, e.g., when running a code for purposes
4152: of accurate performance monitoring, when no I/O should be done
4153: during the section of code that is being timed.
4155: Level: intermediate
4157: .seealso: SNESSetConvergencHistory()
4159: @*/
4160: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4161: {
4164: if (a) *a = snes->conv_hist;
4165: if (its) *its = snes->conv_hist_its;
4166: if (na) *na = snes->conv_hist_len;
4167: return(0);
4168: }
4170: /*@C
4171: SNESSetUpdate - Sets the general-purpose update function called
4172: at the beginning of every iteration of the nonlinear solve. Specifically
4173: it is called just before the Jacobian is "evaluated".
4175: Logically Collective on SNES
4177: Input Parameters:
4178: + snes - The nonlinear solver context
4179: - func - The function
4181: Calling sequence of func:
4182: $ func (SNES snes, PetscInt step);
4184: . step - The current step of the iteration
4186: Level: advanced
4188: 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()
4189: This is not used by most users.
4191: .seealso SNESSetJacobian(), SNESSolve()
4192: @*/
4193: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4194: {
4197: snes->ops->update = func;
4198: return(0);
4199: }
4201: /*
4202: SNESScaleStep_Private - Scales a step so that its length is less than the
4203: positive parameter delta.
4205: Input Parameters:
4206: + snes - the SNES context
4207: . y - approximate solution of linear system
4208: . fnorm - 2-norm of current function
4209: - delta - trust region size
4211: Output Parameters:
4212: + gpnorm - predicted function norm at the new point, assuming local
4213: linearization. The value is zero if the step lies within the trust
4214: region, and exceeds zero otherwise.
4215: - ynorm - 2-norm of the step
4217: Note:
4218: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4219: is set to be the maximum allowable step size.
4221: */
4222: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4223: {
4224: PetscReal nrm;
4225: PetscScalar cnorm;
4233: VecNorm(y,NORM_2,&nrm);
4234: if (nrm > *delta) {
4235: nrm = *delta/nrm;
4236: *gpnorm = (1.0 - nrm)*(*fnorm);
4237: cnorm = nrm;
4238: VecScale(y,cnorm);
4239: *ynorm = *delta;
4240: } else {
4241: *gpnorm = 0.0;
4242: *ynorm = nrm;
4243: }
4244: return(0);
4245: }
4247: /*@
4248: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4250: Collective on SNES
4252: Parameter:
4253: + snes - iterative context obtained from SNESCreate()
4254: - viewer - the viewer to display the reason
4257: Options Database Keys:
4258: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4260: Level: beginner
4262: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4264: @*/
4265: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4266: {
4267: PetscViewerFormat format;
4268: PetscBool isAscii;
4269: PetscErrorCode ierr;
4272: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4273: if (isAscii) {
4274: PetscViewerGetFormat(viewer, &format);
4275: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4276: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4277: DM dm;
4278: Vec u;
4279: PetscDS prob;
4280: PetscInt Nf, f;
4281: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4282: void **exactCtx;
4283: PetscReal error;
4285: SNESGetDM(snes, &dm);
4286: SNESGetSolution(snes, &u);
4287: DMGetDS(dm, &prob);
4288: PetscDSGetNumFields(prob, &Nf);
4289: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4290: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4291: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4292: PetscFree2(exactSol, exactCtx);
4293: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4294: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4295: }
4296: if (snes->reason > 0) {
4297: if (((PetscObject) snes)->prefix) {
4298: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4299: } else {
4300: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4301: }
4302: } else {
4303: if (((PetscObject) snes)->prefix) {
4304: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4305: } else {
4306: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4307: }
4308: }
4309: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4310: }
4311: return(0);
4312: }
4314: /*@C
4315: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4317: Collective on SNES
4319: Input Parameters:
4320: . snes - the SNES object
4322: Level: intermediate
4324: @*/
4325: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4326: {
4327: PetscErrorCode ierr;
4328: PetscViewer viewer;
4329: PetscBool flg;
4330: static PetscBool incall = PETSC_FALSE;
4331: PetscViewerFormat format;
4334: if (incall) return(0);
4335: incall = PETSC_TRUE;
4336: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4337: if (flg) {
4338: PetscViewerPushFormat(viewer,format);
4339: SNESReasonView(snes,viewer);
4340: PetscViewerPopFormat(viewer);
4341: PetscViewerDestroy(&viewer);
4342: }
4343: incall = PETSC_FALSE;
4344: return(0);
4345: }
4347: /*@
4348: SNESSolve - Solves a nonlinear system F(x) = b.
4349: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4351: Collective on SNES
4353: Input Parameters:
4354: + snes - the SNES context
4355: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4356: - x - the solution vector.
4358: Notes:
4359: The user should initialize the vector,x, with the initial guess
4360: for the nonlinear solve prior to calling SNESSolve. In particular,
4361: to employ an initial guess of zero, the user should explicitly set
4362: this vector to zero by calling VecSet().
4364: Level: beginner
4366: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4367: @*/
4368: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4369: {
4370: PetscErrorCode ierr;
4371: PetscBool flg;
4372: PetscInt grid;
4373: Vec xcreated = NULL;
4374: DM dm;
4383: /* High level operations using the nonlinear solver */
4384: {
4385: PetscViewer viewer;
4386: PetscViewerFormat format;
4387: PetscInt num;
4388: PetscBool flg;
4389: static PetscBool incall = PETSC_FALSE;
4391: if (!incall) {
4392: /* Estimate the convergence rate of the discretization */
4393: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4394: if (flg) {
4395: PetscConvEst conv;
4396: DM dm;
4397: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4398: PetscInt Nf;
4400: incall = PETSC_TRUE;
4401: SNESGetDM(snes, &dm);
4402: DMGetNumFields(dm, &Nf);
4403: PetscCalloc1(Nf, &alpha);
4404: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4405: PetscConvEstSetSolver(conv, (PetscObject) snes);
4406: PetscConvEstSetFromOptions(conv);
4407: PetscConvEstSetUp(conv);
4408: PetscConvEstGetConvRate(conv, alpha);
4409: PetscViewerPushFormat(viewer, format);
4410: PetscConvEstRateView(conv, alpha, viewer);
4411: PetscViewerPopFormat(viewer);
4412: PetscViewerDestroy(&viewer);
4413: PetscConvEstDestroy(&conv);
4414: PetscFree(alpha);
4415: incall = PETSC_FALSE;
4416: }
4417: /* Adaptively refine the initial grid */
4418: num = 1;
4419: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4420: if (flg) {
4421: DMAdaptor adaptor;
4423: incall = PETSC_TRUE;
4424: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4425: DMAdaptorSetSolver(adaptor, snes);
4426: DMAdaptorSetSequenceLength(adaptor, num);
4427: DMAdaptorSetFromOptions(adaptor);
4428: DMAdaptorSetUp(adaptor);
4429: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4430: DMAdaptorDestroy(&adaptor);
4431: incall = PETSC_FALSE;
4432: }
4433: /* Use grid sequencing to adapt */
4434: num = 0;
4435: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4436: if (num) {
4437: DMAdaptor adaptor;
4439: incall = PETSC_TRUE;
4440: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4441: DMAdaptorSetSolver(adaptor, snes);
4442: DMAdaptorSetSequenceLength(adaptor, num);
4443: DMAdaptorSetFromOptions(adaptor);
4444: DMAdaptorSetUp(adaptor);
4445: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4446: DMAdaptorDestroy(&adaptor);
4447: incall = PETSC_FALSE;
4448: }
4449: }
4450: }
4451: if (!x) {
4452: SNESGetDM(snes,&dm);
4453: DMCreateGlobalVector(dm,&xcreated);
4454: x = xcreated;
4455: }
4456: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4458: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4459: for (grid=0; grid<snes->gridsequence+1; grid++) {
4461: /* set solution vector */
4462: if (!grid) {PetscObjectReference((PetscObject)x);}
4463: VecDestroy(&snes->vec_sol);
4464: snes->vec_sol = x;
4465: SNESGetDM(snes,&dm);
4467: /* set affine vector if provided */
4468: if (b) { PetscObjectReference((PetscObject)b); }
4469: VecDestroy(&snes->vec_rhs);
4470: snes->vec_rhs = b;
4472: 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");
4473: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4474: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4475: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4476: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4477: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4478: }
4479: DMShellSetGlobalVector(dm,snes->vec_sol);
4480: SNESSetUp(snes);
4482: if (!grid) {
4483: if (snes->ops->computeinitialguess) {
4484: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4485: }
4486: }
4488: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4489: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4491: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4492: (*snes->ops->solve)(snes);
4493: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4494: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4495: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4497: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4498: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4500: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4501: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4502: SNESReasonViewFromOptions(snes);
4504: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4505: if (snes->reason < 0) break;
4506: if (grid < snes->gridsequence) {
4507: DM fine;
4508: Vec xnew;
4509: Mat interp;
4511: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4512: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4513: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4514: DMCreateGlobalVector(fine,&xnew);
4515: MatInterpolate(interp,x,xnew);
4516: DMInterpolate(snes->dm,interp,fine);
4517: MatDestroy(&interp);
4518: x = xnew;
4520: SNESReset(snes);
4521: SNESSetDM(snes,fine);
4522: SNESResetFromOptions(snes);
4523: DMDestroy(&fine);
4524: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4525: }
4526: }
4527: SNESViewFromOptions(snes,NULL,"-snes_view");
4528: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4529: DMMonitor(snes->dm);
4531: VecDestroy(&xcreated);
4532: PetscObjectSAWsBlock((PetscObject)snes);
4533: return(0);
4534: }
4536: /* --------- Internal routines for SNES Package --------- */
4538: /*@C
4539: SNESSetType - Sets the method for the nonlinear solver.
4541: Collective on SNES
4543: Input Parameters:
4544: + snes - the SNES context
4545: - type - a known method
4547: Options Database Key:
4548: . -snes_type <type> - Sets the method; use -help for a list
4549: of available methods (for instance, newtonls or newtontr)
4551: Notes:
4552: See "petsc/include/petscsnes.h" for available methods (for instance)
4553: + SNESNEWTONLS - Newton's method with line search
4554: (systems of nonlinear equations)
4555: - SNESNEWTONTR - Newton's method with trust region
4556: (systems of nonlinear equations)
4558: Normally, it is best to use the SNESSetFromOptions() command and then
4559: set the SNES solver type from the options database rather than by using
4560: this routine. Using the options database provides the user with
4561: maximum flexibility in evaluating the many nonlinear solvers.
4562: The SNESSetType() routine is provided for those situations where it
4563: is necessary to set the nonlinear solver independently of the command
4564: line or options database. This might be the case, for example, when
4565: the choice of solver changes during the execution of the program,
4566: and the user's application is taking responsibility for choosing the
4567: appropriate method.
4569: Developer Notes:
4570: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4571: the constructor in that list and calls it to create the spexific object.
4573: Level: intermediate
4575: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4577: @*/
4578: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4579: {
4580: PetscErrorCode ierr,(*r)(SNES);
4581: PetscBool match;
4587: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4588: if (match) return(0);
4590: PetscFunctionListFind(SNESList,type,&r);
4591: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4592: /* Destroy the previous private SNES context */
4593: if (snes->ops->destroy) {
4594: (*(snes)->ops->destroy)(snes);
4595: snes->ops->destroy = NULL;
4596: }
4597: /* Reinitialize function pointers in SNESOps structure */
4598: snes->ops->setup = 0;
4599: snes->ops->solve = 0;
4600: snes->ops->view = 0;
4601: snes->ops->setfromoptions = 0;
4602: snes->ops->destroy = 0;
4604: /* It may happen the user has customized the line search before calling SNESSetType */
4605: if (((PetscObject)snes)->type_name) {
4606: SNESLineSearchDestroy(&snes->linesearch);
4607: }
4609: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4610: snes->setupcalled = PETSC_FALSE;
4612: PetscObjectChangeTypeName((PetscObject)snes,type);
4613: (*r)(snes);
4614: return(0);
4615: }
4617: /*@C
4618: SNESGetType - Gets the SNES method type and name (as a string).
4620: Not Collective
4622: Input Parameter:
4623: . snes - nonlinear solver context
4625: Output Parameter:
4626: . type - SNES method (a character string)
4628: Level: intermediate
4630: @*/
4631: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4632: {
4636: *type = ((PetscObject)snes)->type_name;
4637: return(0);
4638: }
4640: /*@
4641: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4643: Logically Collective on SNES
4645: Input Parameters:
4646: + snes - the SNES context obtained from SNESCreate()
4647: - u - the solution vector
4649: Level: beginner
4651: @*/
4652: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4653: {
4654: DM dm;
4660: PetscObjectReference((PetscObject) u);
4661: VecDestroy(&snes->vec_sol);
4663: snes->vec_sol = u;
4665: SNESGetDM(snes, &dm);
4666: DMShellSetGlobalVector(dm, u);
4667: return(0);
4668: }
4670: /*@
4671: SNESGetSolution - Returns the vector where the approximate solution is
4672: stored. This is the fine grid solution when using SNESSetGridSequence().
4674: Not Collective, but Vec is parallel if SNES is parallel
4676: Input Parameter:
4677: . snes - the SNES context
4679: Output Parameter:
4680: . x - the solution
4682: Level: intermediate
4684: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4685: @*/
4686: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4687: {
4691: *x = snes->vec_sol;
4692: return(0);
4693: }
4695: /*@
4696: SNESGetSolutionUpdate - Returns the vector where the solution update is
4697: stored.
4699: Not Collective, but Vec is parallel if SNES is parallel
4701: Input Parameter:
4702: . snes - the SNES context
4704: Output Parameter:
4705: . x - the solution update
4707: Level: advanced
4709: .seealso: SNESGetSolution(), SNESGetFunction()
4710: @*/
4711: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4712: {
4716: *x = snes->vec_sol_update;
4717: return(0);
4718: }
4720: /*@C
4721: SNESGetFunction - Returns the vector where the function is stored.
4723: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4725: Input Parameter:
4726: . snes - the SNES context
4728: Output Parameter:
4729: + r - the vector that is used to store residuals (or NULL if you don't want it)
4730: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4731: - ctx - the function context (or NULL if you don't want it)
4733: Level: advanced
4735: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4737: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4738: @*/
4739: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4740: {
4742: DM dm;
4746: if (r) {
4747: if (!snes->vec_func) {
4748: if (snes->vec_rhs) {
4749: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4750: } else if (snes->vec_sol) {
4751: VecDuplicate(snes->vec_sol,&snes->vec_func);
4752: } else if (snes->dm) {
4753: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4754: }
4755: }
4756: *r = snes->vec_func;
4757: }
4758: SNESGetDM(snes,&dm);
4759: DMSNESGetFunction(dm,f,ctx);
4760: return(0);
4761: }
4763: /*@C
4764: SNESGetNGS - Returns the NGS function and context.
4766: Input Parameter:
4767: . snes - the SNES context
4769: Output Parameter:
4770: + f - the function (or NULL) see SNESNGSFunction for details
4771: - ctx - the function context (or NULL)
4773: Level: advanced
4775: .seealso: SNESSetNGS(), SNESGetFunction()
4776: @*/
4778: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4779: {
4781: DM dm;
4785: SNESGetDM(snes,&dm);
4786: DMSNESGetNGS(dm,f,ctx);
4787: return(0);
4788: }
4790: /*@C
4791: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4792: SNES options in the database.
4794: Logically Collective on SNES
4796: Input Parameter:
4797: + snes - the SNES context
4798: - prefix - the prefix to prepend to all option names
4800: Notes:
4801: A hyphen (-) must NOT be given at the beginning of the prefix name.
4802: The first character of all runtime options is AUTOMATICALLY the hyphen.
4804: Level: advanced
4806: .seealso: SNESSetFromOptions()
4807: @*/
4808: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4809: {
4814: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4815: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4816: if (snes->linesearch) {
4817: SNESGetLineSearch(snes,&snes->linesearch);
4818: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4819: }
4820: KSPSetOptionsPrefix(snes->ksp,prefix);
4821: return(0);
4822: }
4824: /*@C
4825: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4826: SNES options in the database.
4828: Logically Collective on SNES
4830: Input Parameters:
4831: + snes - the SNES context
4832: - prefix - the prefix to prepend to all option names
4834: Notes:
4835: A hyphen (-) must NOT be given at the beginning of the prefix name.
4836: The first character of all runtime options is AUTOMATICALLY the hyphen.
4838: Level: advanced
4840: .seealso: SNESGetOptionsPrefix()
4841: @*/
4842: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4843: {
4848: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4849: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4850: if (snes->linesearch) {
4851: SNESGetLineSearch(snes,&snes->linesearch);
4852: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4853: }
4854: KSPAppendOptionsPrefix(snes->ksp,prefix);
4855: return(0);
4856: }
4858: /*@C
4859: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4860: SNES options in the database.
4862: Not Collective
4864: Input Parameter:
4865: . snes - the SNES context
4867: Output Parameter:
4868: . prefix - pointer to the prefix string used
4870: Notes:
4871: On the fortran side, the user should pass in a string 'prefix' of
4872: sufficient length to hold the prefix.
4874: Level: advanced
4876: .seealso: SNESAppendOptionsPrefix()
4877: @*/
4878: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4879: {
4884: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4885: return(0);
4886: }
4889: /*@C
4890: SNESRegister - Adds a method to the nonlinear solver package.
4892: Not collective
4894: Input Parameters:
4895: + name_solver - name of a new user-defined solver
4896: - routine_create - routine to create method context
4898: Notes:
4899: SNESRegister() may be called multiple times to add several user-defined solvers.
4901: Sample usage:
4902: .vb
4903: SNESRegister("my_solver",MySolverCreate);
4904: .ve
4906: Then, your solver can be chosen with the procedural interface via
4907: $ SNESSetType(snes,"my_solver")
4908: or at runtime via the option
4909: $ -snes_type my_solver
4911: Level: advanced
4913: Note: If your function is not being put into a shared library then use SNESRegister() instead
4915: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4917: Level: advanced
4918: @*/
4919: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4920: {
4924: SNESInitializePackage();
4925: PetscFunctionListAdd(&SNESList,sname,function);
4926: return(0);
4927: }
4929: PetscErrorCode SNESTestLocalMin(SNES snes)
4930: {
4932: PetscInt N,i,j;
4933: Vec u,uh,fh;
4934: PetscScalar value;
4935: PetscReal norm;
4938: SNESGetSolution(snes,&u);
4939: VecDuplicate(u,&uh);
4940: VecDuplicate(u,&fh);
4942: /* currently only works for sequential */
4943: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4944: VecGetSize(u,&N);
4945: for (i=0; i<N; i++) {
4946: VecCopy(u,uh);
4947: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4948: for (j=-10; j<11; j++) {
4949: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4950: VecSetValue(uh,i,value,ADD_VALUES);
4951: SNESComputeFunction(snes,uh,fh);
4952: VecNorm(fh,NORM_2,&norm);
4953: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4954: value = -value;
4955: VecSetValue(uh,i,value,ADD_VALUES);
4956: }
4957: }
4958: VecDestroy(&uh);
4959: VecDestroy(&fh);
4960: return(0);
4961: }
4963: /*@
4964: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4965: computing relative tolerance for linear solvers within an inexact
4966: Newton method.
4968: Logically Collective on SNES
4970: Input Parameters:
4971: + snes - SNES context
4972: - flag - PETSC_TRUE or PETSC_FALSE
4974: Options Database:
4975: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4976: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4977: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4978: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4979: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4980: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4981: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4982: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4984: Notes:
4985: Currently, the default is to use a constant relative tolerance for
4986: the inner linear solvers. Alternatively, one can use the
4987: Eisenstat-Walker method, where the relative convergence tolerance
4988: is reset at each Newton iteration according progress of the nonlinear
4989: solver.
4991: Level: advanced
4993: Reference:
4994: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4995: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4997: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4998: @*/
4999: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
5000: {
5004: snes->ksp_ewconv = flag;
5005: return(0);
5006: }
5008: /*@
5009: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
5010: for computing relative tolerance for linear solvers within an
5011: inexact Newton method.
5013: Not Collective
5015: Input Parameter:
5016: . snes - SNES context
5018: Output Parameter:
5019: . flag - PETSC_TRUE or PETSC_FALSE
5021: Notes:
5022: Currently, the default is to use a constant relative tolerance for
5023: the inner linear solvers. Alternatively, one can use the
5024: Eisenstat-Walker method, where the relative convergence tolerance
5025: is reset at each Newton iteration according progress of the nonlinear
5026: solver.
5028: Level: advanced
5030: Reference:
5031: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5032: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5034: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5035: @*/
5036: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5037: {
5041: *flag = snes->ksp_ewconv;
5042: return(0);
5043: }
5045: /*@
5046: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5047: convergence criteria for the linear solvers within an inexact
5048: Newton method.
5050: Logically Collective on SNES
5052: Input Parameters:
5053: + snes - SNES context
5054: . version - version 1, 2 (default is 2) or 3
5055: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5056: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5057: . gamma - multiplicative factor for version 2 rtol computation
5058: (0 <= gamma2 <= 1)
5059: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5060: . alpha2 - power for safeguard
5061: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5063: Note:
5064: Version 3 was contributed by Luis Chacon, June 2006.
5066: Use PETSC_DEFAULT to retain the default for any of the parameters.
5068: Level: advanced
5070: Reference:
5071: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5072: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5073: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5075: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5076: @*/
5077: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5078: {
5079: SNESKSPEW *kctx;
5083: kctx = (SNESKSPEW*)snes->kspconvctx;
5084: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5093: if (version != PETSC_DEFAULT) kctx->version = version;
5094: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5095: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5096: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5097: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5098: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5099: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5101: 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);
5102: 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);
5103: 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);
5104: 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);
5105: 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);
5106: 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);
5107: return(0);
5108: }
5110: /*@
5111: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5112: convergence criteria for the linear solvers within an inexact
5113: Newton method.
5115: Not Collective
5117: Input Parameters:
5118: snes - SNES context
5120: Output Parameters:
5121: + version - version 1, 2 (default is 2) or 3
5122: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5123: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5124: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5125: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5126: . alpha2 - power for safeguard
5127: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5129: Level: advanced
5131: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5132: @*/
5133: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5134: {
5135: SNESKSPEW *kctx;
5139: kctx = (SNESKSPEW*)snes->kspconvctx;
5140: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5141: if (version) *version = kctx->version;
5142: if (rtol_0) *rtol_0 = kctx->rtol_0;
5143: if (rtol_max) *rtol_max = kctx->rtol_max;
5144: if (gamma) *gamma = kctx->gamma;
5145: if (alpha) *alpha = kctx->alpha;
5146: if (alpha2) *alpha2 = kctx->alpha2;
5147: if (threshold) *threshold = kctx->threshold;
5148: return(0);
5149: }
5151: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5152: {
5154: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5155: PetscReal rtol = PETSC_DEFAULT,stol;
5158: if (!snes->ksp_ewconv) return(0);
5159: if (!snes->iter) {
5160: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5161: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5162: }
5163: else {
5164: if (kctx->version == 1) {
5165: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5166: if (rtol < 0.0) rtol = -rtol;
5167: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5168: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5169: } else if (kctx->version == 2) {
5170: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5171: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5172: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5173: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5174: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5175: /* safeguard: avoid sharp decrease of rtol */
5176: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5177: stol = PetscMax(rtol,stol);
5178: rtol = PetscMin(kctx->rtol_0,stol);
5179: /* safeguard: avoid oversolving */
5180: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5181: stol = PetscMax(rtol,stol);
5182: rtol = PetscMin(kctx->rtol_0,stol);
5183: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5184: }
5185: /* safeguard: avoid rtol greater than one */
5186: rtol = PetscMin(rtol,kctx->rtol_max);
5187: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5188: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5189: return(0);
5190: }
5192: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5193: {
5195: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5196: PCSide pcside;
5197: Vec lres;
5200: if (!snes->ksp_ewconv) return(0);
5201: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5202: kctx->norm_last = snes->norm;
5203: if (kctx->version == 1) {
5204: PC pc;
5205: PetscBool isNone;
5207: KSPGetPC(ksp, &pc);
5208: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5209: KSPGetPCSide(ksp,&pcside);
5210: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5211: /* KSP residual is true linear residual */
5212: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5213: } else {
5214: /* KSP residual is preconditioned residual */
5215: /* compute true linear residual norm */
5216: VecDuplicate(b,&lres);
5217: MatMult(snes->jacobian,x,lres);
5218: VecAYPX(lres,-1.0,b);
5219: VecNorm(lres,NORM_2,&kctx->lresid_last);
5220: VecDestroy(&lres);
5221: }
5222: }
5223: return(0);
5224: }
5226: /*@
5227: SNESGetKSP - Returns the KSP context for a SNES solver.
5229: Not Collective, but if SNES object is parallel, then KSP object is parallel
5231: Input Parameter:
5232: . snes - the SNES context
5234: Output Parameter:
5235: . ksp - the KSP context
5237: Notes:
5238: The user can then directly manipulate the KSP context to set various
5239: options, etc. Likewise, the user can then extract and manipulate the
5240: PC contexts as well.
5242: Level: beginner
5244: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5245: @*/
5246: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5247: {
5254: if (!snes->ksp) {
5255: PetscBool monitor = PETSC_FALSE;
5257: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5258: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5259: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5261: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5262: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5264: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5265: if (monitor) {
5266: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5267: }
5268: monitor = PETSC_FALSE;
5269: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5270: if (monitor) {
5271: PetscObject *objs;
5272: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5273: objs[0] = (PetscObject) snes;
5274: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5275: }
5276: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5277: }
5278: *ksp = snes->ksp;
5279: return(0);
5280: }
5283: #include <petsc/private/dmimpl.h>
5284: /*@
5285: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5287: Logically Collective on SNES
5289: Input Parameters:
5290: + snes - the nonlinear solver context
5291: - dm - the dm, cannot be NULL
5293: Notes:
5294: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5295: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5296: problems using the same function space.
5298: Level: intermediate
5300: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5301: @*/
5302: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5303: {
5305: KSP ksp;
5306: DMSNES sdm;
5311: PetscObjectReference((PetscObject)dm);
5312: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5313: if (snes->dm->dmsnes && !dm->dmsnes) {
5314: DMCopyDMSNES(snes->dm,dm);
5315: DMGetDMSNES(snes->dm,&sdm);
5316: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5317: }
5318: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5319: DMDestroy(&snes->dm);
5320: }
5321: snes->dm = dm;
5322: snes->dmAuto = PETSC_FALSE;
5324: SNESGetKSP(snes,&ksp);
5325: KSPSetDM(ksp,dm);
5326: KSPSetDMActive(ksp,PETSC_FALSE);
5327: if (snes->npc) {
5328: SNESSetDM(snes->npc, snes->dm);
5329: SNESSetNPCSide(snes,snes->npcside);
5330: }
5331: return(0);
5332: }
5334: /*@
5335: SNESGetDM - Gets the DM that may be used by some preconditioners
5337: Not Collective but DM obtained is parallel on SNES
5339: Input Parameter:
5340: . snes - the preconditioner context
5342: Output Parameter:
5343: . dm - the dm
5345: Level: intermediate
5347: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5348: @*/
5349: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5350: {
5355: if (!snes->dm) {
5356: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5357: snes->dmAuto = PETSC_TRUE;
5358: }
5359: *dm = snes->dm;
5360: return(0);
5361: }
5363: /*@
5364: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5366: Collective on SNES
5368: Input Parameters:
5369: + snes - iterative context obtained from SNESCreate()
5370: - pc - the preconditioner object
5372: Notes:
5373: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5374: to configure it using the API).
5376: Level: developer
5378: .seealso: SNESGetNPC(), SNESHasNPC()
5379: @*/
5380: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5381: {
5388: PetscObjectReference((PetscObject) pc);
5389: SNESDestroy(&snes->npc);
5390: snes->npc = pc;
5391: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5392: return(0);
5393: }
5395: /*@
5396: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5398: Not Collective; but any changes to the obtained SNES object must be applied collectively
5400: Input Parameter:
5401: . snes - iterative context obtained from SNESCreate()
5403: Output Parameter:
5404: . pc - preconditioner context
5406: Options Database:
5407: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5409: Notes:
5410: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5412: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5413: SNES during SNESSetUp()
5415: Level: developer
5417: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5418: @*/
5419: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5420: {
5422: const char *optionsprefix;
5427: if (!snes->npc) {
5428: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5429: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5430: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5431: SNESGetOptionsPrefix(snes,&optionsprefix);
5432: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5433: SNESAppendOptionsPrefix(snes->npc,"npc_");
5434: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5435: }
5436: *pc = snes->npc;
5437: return(0);
5438: }
5440: /*@
5441: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5443: Not Collective
5445: Input Parameter:
5446: . snes - iterative context obtained from SNESCreate()
5448: Output Parameter:
5449: . has_npc - whether the SNES has an NPC or not
5451: Level: developer
5453: .seealso: SNESSetNPC(), SNESGetNPC()
5454: @*/
5455: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5456: {
5459: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5460: return(0);
5461: }
5463: /*@
5464: SNESSetNPCSide - Sets the preconditioning side.
5466: Logically Collective on SNES
5468: Input Parameter:
5469: . snes - iterative context obtained from SNESCreate()
5471: Output Parameter:
5472: . side - the preconditioning side, where side is one of
5473: .vb
5474: PC_LEFT - left preconditioning
5475: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5476: .ve
5478: Options Database Keys:
5479: . -snes_pc_side <right,left>
5481: Notes:
5482: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5484: Level: intermediate
5486: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5487: @*/
5488: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5489: {
5493: snes->npcside= side;
5494: return(0);
5495: }
5497: /*@
5498: SNESGetNPCSide - Gets the preconditioning side.
5500: Not Collective
5502: Input Parameter:
5503: . snes - iterative context obtained from SNESCreate()
5505: Output Parameter:
5506: . side - the preconditioning side, where side is one of
5507: .vb
5508: PC_LEFT - left preconditioning
5509: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5510: .ve
5512: Level: intermediate
5514: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5515: @*/
5516: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5517: {
5521: *side = snes->npcside;
5522: return(0);
5523: }
5525: /*@
5526: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5528: Collective on SNES
5530: Input Parameters:
5531: + snes - iterative context obtained from SNESCreate()
5532: - linesearch - the linesearch object
5534: Notes:
5535: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5536: to configure it using the API).
5538: Level: developer
5540: .seealso: SNESGetLineSearch()
5541: @*/
5542: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5543: {
5550: PetscObjectReference((PetscObject) linesearch);
5551: SNESLineSearchDestroy(&snes->linesearch);
5553: snes->linesearch = linesearch;
5555: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5556: return(0);
5557: }
5559: /*@
5560: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5561: or creates a default line search instance associated with the SNES and returns it.
5563: Not Collective
5565: Input Parameter:
5566: . snes - iterative context obtained from SNESCreate()
5568: Output Parameter:
5569: . linesearch - linesearch context
5571: Level: beginner
5573: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5574: @*/
5575: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5576: {
5578: const char *optionsprefix;
5583: if (!snes->linesearch) {
5584: SNESGetOptionsPrefix(snes, &optionsprefix);
5585: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5586: SNESLineSearchSetSNES(snes->linesearch, snes);
5587: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5588: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5589: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5590: }
5591: *linesearch = snes->linesearch;
5592: return(0);
5593: }