Actual source code: snes.c
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 available formats include
357: + PETSC_VIEWER_DEFAULT - standard output (default)
358: - PETSC_VIEWER_ASCII_INFO_DETAIL - more verbose output for SNESNASM
360: The user can open an alternative visualization context with
361: PetscViewerASCIIOpen() - output to a specified file.
363: In the debugger you can do "call SNESView(snes,0)" to display the SNES solver. (The same holds for any PETSc object viewer).
365: Level: beginner
367: .seealso: PetscViewerASCIIOpen()
368: @*/
369: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
370: {
371: SNESKSPEW *kctx;
373: KSP ksp;
374: SNESLineSearch linesearch;
375: PetscBool iascii,isstring,isbinary,isdraw;
376: DMSNES dmsnes;
377: #if defined(PETSC_HAVE_SAWS)
378: PetscBool issaws;
379: #endif
383: if (!viewer) {
384: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
385: }
389: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
390: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
391: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
392: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
393: #if defined(PETSC_HAVE_SAWS)
394: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
395: #endif
396: if (iascii) {
397: SNESNormSchedule normschedule;
398: DM dm;
399: PetscErrorCode (*cJ)(SNES,Vec,Mat,Mat,void*);
400: void *ctx;
401: const char *pre = "";
403: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
404: if (!snes->setupcalled) {
405: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
406: }
407: if (snes->ops->view) {
408: PetscViewerASCIIPushTab(viewer);
409: (*snes->ops->view)(snes,viewer);
410: PetscViewerASCIIPopTab(viewer);
411: }
412: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
413: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
414: if (snes->usesksp) {
415: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
416: }
417: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
418: SNESGetNormSchedule(snes, &normschedule);
419: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
420: if (snes->gridsequence) {
421: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
422: }
423: if (snes->ksp_ewconv) {
424: kctx = (SNESKSPEW*)snes->kspconvctx;
425: if (kctx) {
426: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
427: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
428: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
429: }
430: }
431: if (snes->lagpreconditioner == -1) {
432: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
433: } else if (snes->lagpreconditioner > 1) {
434: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
435: }
436: if (snes->lagjacobian == -1) {
437: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
438: } else if (snes->lagjacobian > 1) {
439: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
440: }
441: SNESGetDM(snes,&dm);
442: DMSNESGetJacobian(dm,&cJ,&ctx);
443: if (snes->mf_operator) {
444: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing\n");
445: pre = "Preconditioning ";
446: }
447: if (cJ == SNESComputeJacobianDefault) {
448: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences one column at a time\n",pre);
449: } else if (cJ == SNESComputeJacobianDefaultColor) {
450: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences with coloring\n",pre);
451: /* it slightly breaks data encapsulation for access the DMDA information directly */
452: } else if (cJ == SNESComputeJacobian_DMDA) {
453: MatFDColoring fdcoloring;
454: PetscObjectQuery((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject*)&fdcoloring);
455: if (fdcoloring) {
456: PetscViewerASCIIPrintf(viewer," %sJacobian is built using colored finite differences on a DMDA\n",pre);
457: } else {
458: PetscViewerASCIIPrintf(viewer," %sJacobian is built using a DMDA local Jacobian\n",pre);
459: }
460: } else if (snes->mf) {
461: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing, no explicit Jacobian\n");
462: }
463: } else if (isstring) {
464: const char *type;
465: SNESGetType(snes,&type);
466: PetscViewerStringSPrintf(viewer," SNESType: %-7.7s",type);
467: if (snes->ops->view) {(*snes->ops->view)(snes,viewer);}
468: } else if (isbinary) {
469: PetscInt classid = SNES_FILE_CLASSID;
470: MPI_Comm comm;
471: PetscMPIInt rank;
472: char type[256];
474: PetscObjectGetComm((PetscObject)snes,&comm);
475: MPI_Comm_rank(comm,&rank);
476: if (rank == 0) {
477: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT);
478: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
479: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR);
480: }
481: if (snes->ops->view) {
482: (*snes->ops->view)(snes,viewer);
483: }
484: } else if (isdraw) {
485: PetscDraw draw;
486: char str[36];
487: PetscReal x,y,bottom,h;
489: PetscViewerDrawGetDraw(viewer,0,&draw);
490: PetscDrawGetCurrentPoint(draw,&x,&y);
491: PetscStrncpy(str,"SNES: ",sizeof(str));
492: PetscStrlcat(str,((PetscObject)snes)->type_name,sizeof(str));
493: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
494: bottom = y - h;
495: PetscDrawPushCurrentPoint(draw,x,bottom);
496: if (snes->ops->view) {
497: (*snes->ops->view)(snes,viewer);
498: }
499: #if defined(PETSC_HAVE_SAWS)
500: } else if (issaws) {
501: PetscMPIInt rank;
502: const char *name;
504: PetscObjectGetName((PetscObject)snes,&name);
505: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
506: if (!((PetscObject)snes)->amsmem && rank == 0) {
507: char dir[1024];
509: PetscObjectViewSAWs((PetscObject)snes,viewer);
510: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
511: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
512: if (!snes->conv_hist) {
513: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
514: }
515: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
516: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
517: }
518: #endif
519: }
520: if (snes->linesearch) {
521: SNESGetLineSearch(snes, &linesearch);
522: PetscViewerASCIIPushTab(viewer);
523: SNESLineSearchView(linesearch, viewer);
524: PetscViewerASCIIPopTab(viewer);
525: }
526: if (snes->npc && snes->usesnpc) {
527: PetscViewerASCIIPushTab(viewer);
528: SNESView(snes->npc, viewer);
529: PetscViewerASCIIPopTab(viewer);
530: }
531: PetscViewerASCIIPushTab(viewer);
532: DMGetDMSNES(snes->dm,&dmsnes);
533: DMSNESView(dmsnes, viewer);
534: PetscViewerASCIIPopTab(viewer);
535: if (snes->usesksp) {
536: SNESGetKSP(snes,&ksp);
537: PetscViewerASCIIPushTab(viewer);
538: KSPView(ksp,viewer);
539: PetscViewerASCIIPopTab(viewer);
540: }
541: if (isdraw) {
542: PetscDraw draw;
543: PetscViewerDrawGetDraw(viewer,0,&draw);
544: PetscDrawPopCurrentPoint(draw);
545: }
546: return(0);
547: }
549: /*
550: We retain a list of functions that also take SNES command
551: line options. These are called at the end SNESSetFromOptions()
552: */
553: #define MAXSETFROMOPTIONS 5
554: static PetscInt numberofsetfromoptions;
555: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
557: /*@C
558: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
560: Not Collective
562: Input Parameter:
563: . snescheck - function that checks for options
565: Level: developer
567: .seealso: SNESSetFromOptions()
568: @*/
569: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
570: {
572: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
573: othersetfromoptions[numberofsetfromoptions++] = snescheck;
574: return(0);
575: }
577: PETSC_INTERN PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
579: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
580: {
581: Mat J;
583: MatNullSpace nullsp;
588: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
589: Mat A = snes->jacobian, B = snes->jacobian_pre;
590: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
591: }
593: if (version == 1) {
594: MatCreateSNESMF(snes,&J);
595: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
596: MatSetFromOptions(J);
597: } else if (version == 2) {
598: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
599: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
600: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
601: #else
602: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
603: #endif
604: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
606: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
607: if (snes->jacobian) {
608: MatGetNullSpace(snes->jacobian,&nullsp);
609: if (nullsp) {
610: MatSetNullSpace(J,nullsp);
611: }
612: }
614: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
615: if (hasOperator) {
617: /* This version replaces the user provided Jacobian matrix with a
618: matrix-free version but still employs the user-provided preconditioner matrix. */
619: SNESSetJacobian(snes,J,NULL,NULL,NULL);
620: } else {
621: /* This version replaces both the user-provided Jacobian and the user-
622: provided preconditioner Jacobian with the default matrix free version. */
623: if ((snes->npcside== PC_LEFT) && snes->npc) {
624: if (!snes->jacobian) {SNESSetJacobian(snes,J,NULL,NULL,NULL);}
625: } else {
626: KSP ksp;
627: PC pc;
628: PetscBool match;
630: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,NULL);
631: /* Force no preconditioner */
632: SNESGetKSP(snes,&ksp);
633: KSPGetPC(ksp,&pc);
634: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
635: if (!match) {
636: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
637: PCSetType(pc,PCNONE);
638: }
639: }
640: }
641: MatDestroy(&J);
642: return(0);
643: }
645: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
646: {
647: SNES snes = (SNES)ctx;
649: Vec Xfine,Xfine_named = NULL,Xcoarse;
652: if (PetscLogPrintInfo) {
653: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
654: DMGetRefineLevel(dmfine,&finelevel);
655: DMGetCoarsenLevel(dmfine,&fineclevel);
656: DMGetRefineLevel(dmcoarse,&coarselevel);
657: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
658: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
659: }
660: if (dmfine == snes->dm) Xfine = snes->vec_sol;
661: else {
662: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
663: Xfine = Xfine_named;
664: }
665: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
666: if (Inject) {
667: MatRestrict(Inject,Xfine,Xcoarse);
668: } else {
669: MatRestrict(Restrict,Xfine,Xcoarse);
670: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
671: }
672: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
673: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
674: return(0);
675: }
677: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
678: {
682: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
683: return(0);
684: }
686: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
687: * safely call SNESGetDM() in their residual evaluation routine. */
688: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
689: {
690: SNES snes = (SNES)ctx;
692: Vec X,Xnamed = NULL;
693: DM dmsave;
694: void *ctxsave;
695: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*) = NULL;
698: dmsave = snes->dm;
699: KSPGetDM(ksp,&snes->dm);
700: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
701: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
702: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
703: X = Xnamed;
704: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
705: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
706: if (jac == SNESComputeJacobianDefaultColor) {
707: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,NULL);
708: }
709: }
710: /* Make sure KSP DM has the Jacobian computation routine */
711: {
712: DMSNES sdm;
714: DMGetDMSNES(snes->dm, &sdm);
715: if (!sdm->ops->computejacobian) {
716: DMCopyDMSNES(dmsave, snes->dm);
717: }
718: }
719: /* Compute the operators */
720: SNESComputeJacobian(snes,X,A,B);
721: /* Put the previous context back */
722: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
723: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
724: }
726: if (Xnamed) {DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);}
727: snes->dm = dmsave;
728: return(0);
729: }
731: /*@
732: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
734: Collective
736: Input Parameter:
737: . snes - snes to configure
739: Level: developer
741: .seealso: SNESSetUp()
742: @*/
743: PetscErrorCode SNESSetUpMatrices(SNES snes)
744: {
746: DM dm;
747: DMSNES sdm;
750: SNESGetDM(snes,&dm);
751: DMGetDMSNES(dm,&sdm);
752: if (!snes->jacobian && snes->mf) {
753: Mat J;
754: void *functx;
755: MatCreateSNESMF(snes,&J);
756: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
757: MatSetFromOptions(J);
758: SNESGetFunction(snes,NULL,NULL,&functx);
759: SNESSetJacobian(snes,J,J,NULL,NULL);
760: MatDestroy(&J);
761: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
762: Mat J,B;
763: MatCreateSNESMF(snes,&J);
764: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
765: MatSetFromOptions(J);
766: DMCreateMatrix(snes->dm,&B);
767: /* sdm->computejacobian was already set to reach here */
768: SNESSetJacobian(snes,J,B,NULL,NULL);
769: MatDestroy(&J);
770: MatDestroy(&B);
771: } else if (!snes->jacobian_pre) {
772: PetscDS prob;
773: Mat J, B;
774: PetscBool hasPrec = PETSC_FALSE;
776: J = snes->jacobian;
777: DMGetDS(dm, &prob);
778: if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
779: if (J) {PetscObjectReference((PetscObject) J);}
780: else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
781: DMCreateMatrix(snes->dm, &B);
782: SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
783: MatDestroy(&J);
784: MatDestroy(&B);
785: }
786: {
787: KSP ksp;
788: SNESGetKSP(snes,&ksp);
789: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
790: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
791: }
792: return(0);
793: }
795: /*@C
796: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
798: Collective on SNES
800: Input Parameters:
801: + snes - SNES object you wish to monitor
802: . name - the monitor type one is seeking
803: . help - message indicating what monitoring is done
804: . manual - manual page for the monitor
805: . monitor - the monitor function
806: - 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
808: Level: developer
810: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
811: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
812: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
813: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
814: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
815: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
816: PetscOptionsFList(), PetscOptionsEList()
817: @*/
818: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
819: {
820: PetscErrorCode ierr;
821: PetscViewer viewer;
822: PetscViewerFormat format;
823: PetscBool flg;
826: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
827: if (flg) {
828: PetscViewerAndFormat *vf;
829: PetscViewerAndFormatCreate(viewer,format,&vf);
830: PetscObjectDereference((PetscObject)viewer);
831: if (monitorsetup) {
832: (*monitorsetup)(snes,vf);
833: }
834: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
835: }
836: return(0);
837: }
839: /*@
840: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
842: Collective on SNES
844: Input Parameter:
845: . snes - the SNES context
847: Options Database Keys:
848: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
849: . -snes_stol - convergence tolerance in terms of the norm
850: of the change in the solution between steps
851: . -snes_atol <abstol> - absolute tolerance of residual norm
852: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
853: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
854: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
855: . -snes_max_it <max_it> - maximum number of iterations
856: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
857: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
858: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
859: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
860: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
861: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
862: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
863: . -snes_trtol <trtol> - trust region tolerance
864: . -snes_no_convergence_test - skip convergence test in nonlinear
865: solver; hence iterations will continue until max_it
866: or some other criterion is reached. Saves expense
867: of convergence test
868: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
869: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
870: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
871: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
872: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
873: . -snes_monitor_lg_range - plots residual norm at each iteration
874: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
875: . -snes_fd_color - use finite differences with coloring to compute Jacobian
876: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
877: . -snes_converged_reason - print the reason for convergence/divergence after each solve
878: . -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
879: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one computed via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
880: - -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.
882: Options Database for Eisenstat-Walker method:
883: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
884: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
885: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
886: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
887: . -snes_ksp_ew_gamma <gamma> - Sets gamma
888: . -snes_ksp_ew_alpha <alpha> - Sets alpha
889: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
890: - -snes_ksp_ew_threshold <threshold> - Sets threshold
892: Notes:
893: To see all options, run your program with the -help option or consult the users manual
895: Notes:
896: SNES supports three approaches for computing (approximate) Jacobians: user provided via SNESSetJacobian(), matrix free, and computing explicitly with
897: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
899: Level: beginner
901: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions(), SNES, SNESCreate()
902: @*/
903: PetscErrorCode SNESSetFromOptions(SNES snes)
904: {
905: PetscBool flg,pcset,persist,set;
906: PetscInt i,indx,lag,grids;
907: const char *deft = SNESNEWTONLS;
908: const char *convtests[] = {"default","skip","correct_pressure"};
909: SNESKSPEW *kctx = NULL;
910: char type[256], monfilename[PETSC_MAX_PATH_LEN];
912: PCSide pcside;
913: const char *optionsprefix;
917: SNESRegisterAll();
918: PetscObjectOptionsBegin((PetscObject)snes);
919: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
920: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
921: if (flg) {
922: SNESSetType(snes,type);
923: } else if (!((PetscObject)snes)->type_name) {
924: SNESSetType(snes,deft);
925: }
926: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
927: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
929: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
930: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
931: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
932: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
933: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
934: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
935: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
936: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
937: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
939: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
940: if (flg) {
941: if (lag == -1) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Cannot set the lag to -1 from the command line since the preconditioner must be built as least once, perhaps you mean -2");
942: SNESSetLagPreconditioner(snes,lag);
943: }
944: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple SNES solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
945: if (flg) {
946: SNESSetLagPreconditionerPersists(snes,persist);
947: }
948: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
949: if (flg) {
950: if (lag == -1) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Cannot set the lag to -1 from the command line since the Jacobian must be built as least once, perhaps you mean -2");
951: SNESSetLagJacobian(snes,lag);
952: }
953: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple SNES solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
954: if (flg) {
955: SNESSetLagJacobianPersists(snes,persist);
956: }
958: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
959: if (flg) {
960: SNESSetGridSequence(snes,grids);
961: }
963: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,sizeof(convtests)/sizeof(char*),"default",&indx,&flg);
964: if (flg) {
965: switch (indx) {
966: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
967: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
968: case 2: SNESSetConvergenceTest(snes,SNESConvergedCorrectPressure,NULL,NULL); break;
969: }
970: }
972: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
973: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
975: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
976: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
978: kctx = (SNESKSPEW*)snes->kspconvctx;
980: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
982: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
983: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
984: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
985: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
986: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
987: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
988: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
990: flg = PETSC_FALSE;
991: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
992: if (set && flg) {SNESMonitorCancel(snes);}
994: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
995: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
996: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
998: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
999: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
1000: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
1001: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
1002: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
1003: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
1004: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
1006: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",NULL,monfilename,sizeof(monfilename),&flg);
1007: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
1009: flg = PETSC_FALSE;
1010: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
1011: if (flg) {
1012: PetscViewer ctx;
1014: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
1015: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
1016: }
1018: flg = PETSC_FALSE;
1019: PetscOptionsBool("-snes_converged_reason_view_cancel","Remove all converged reason viewers","SNESConvergedReasonViewCancel",flg,&flg,&set);
1020: if (set && flg) {SNESConvergedReasonViewCancel(snes);}
1022: flg = PETSC_FALSE;
1023: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
1024: if (flg) {
1025: void *functx;
1026: DM dm;
1027: DMSNES sdm;
1028: SNESGetDM(snes,&dm);
1029: DMGetDMSNES(dm,&sdm);
1030: sdm->jacobianctx = NULL;
1031: SNESGetFunction(snes,NULL,NULL,&functx);
1032: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
1033: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
1034: }
1036: flg = PETSC_FALSE;
1037: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
1038: if (flg) {
1039: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
1040: }
1042: flg = PETSC_FALSE;
1043: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1044: if (flg) {
1045: DM dm;
1046: DMSNES sdm;
1047: SNESGetDM(snes,&dm);
1048: DMGetDMSNES(dm,&sdm);
1049: sdm->jacobianctx = NULL;
1050: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,NULL);
1051: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1052: }
1054: flg = PETSC_FALSE;
1055: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1056: if (flg && snes->mf_operator) {
1057: snes->mf_operator = PETSC_TRUE;
1058: snes->mf = PETSC_TRUE;
1059: }
1060: flg = PETSC_FALSE;
1061: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1062: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1063: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,NULL);
1065: flg = PETSC_FALSE;
1066: SNESGetNPCSide(snes,&pcside);
1067: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1068: if (flg) {SNESSetNPCSide(snes,pcside);}
1070: #if defined(PETSC_HAVE_SAWS)
1071: /*
1072: Publish convergence information using SAWs
1073: */
1074: flg = PETSC_FALSE;
1075: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1076: if (flg) {
1077: void *ctx;
1078: SNESMonitorSAWsCreate(snes,&ctx);
1079: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1080: }
1081: #endif
1082: #if defined(PETSC_HAVE_SAWS)
1083: {
1084: PetscBool set;
1085: flg = PETSC_FALSE;
1086: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1087: if (set) {
1088: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1089: }
1090: }
1091: #endif
1093: for (i = 0; i < numberofsetfromoptions; i++) {
1094: (*othersetfromoptions[i])(snes);
1095: }
1097: if (snes->ops->setfromoptions) {
1098: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1099: }
1101: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1102: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1103: PetscOptionsEnd();
1105: if (snes->linesearch) {
1106: SNESGetLineSearch(snes, &snes->linesearch);
1107: SNESLineSearchSetFromOptions(snes->linesearch);
1108: }
1110: if (snes->usesksp) {
1111: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1112: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1113: KSPSetFromOptions(snes->ksp);
1114: }
1116: /* if user has set the SNES NPC type via options database, create it. */
1117: SNESGetOptionsPrefix(snes, &optionsprefix);
1118: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1119: if (pcset && (!snes->npc)) {
1120: SNESGetNPC(snes, &snes->npc);
1121: }
1122: if (snes->npc) {
1123: SNESSetFromOptions(snes->npc);
1124: }
1125: snes->setfromoptionscalled++;
1126: return(0);
1127: }
1129: /*@
1130: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1132: Collective on SNES
1134: Input Parameter:
1135: . snes - the SNES context
1137: Level: beginner
1139: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1140: @*/
1141: PetscErrorCode SNESResetFromOptions(SNES snes)
1142: {
1146: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1147: return(0);
1148: }
1150: /*@C
1151: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1152: the nonlinear solvers.
1154: Logically Collective on SNES
1156: Input Parameters:
1157: + snes - the SNES context
1158: . compute - function to compute the context
1159: - destroy - function to destroy the context
1161: Level: intermediate
1163: Notes:
1164: This function is currently not available from Fortran.
1166: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1167: @*/
1168: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1169: {
1172: snes->ops->usercompute = compute;
1173: snes->ops->userdestroy = destroy;
1174: return(0);
1175: }
1177: /*@
1178: SNESSetApplicationContext - Sets the optional user-defined context for
1179: the nonlinear solvers.
1181: Logically Collective on SNES
1183: Input Parameters:
1184: + snes - the SNES context
1185: - usrP - optional user context
1187: Level: intermediate
1189: Fortran Notes:
1190: To use this from Fortran you must write a Fortran interface definition for this
1191: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1193: .seealso: SNESGetApplicationContext()
1194: @*/
1195: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1196: {
1198: KSP ksp;
1202: SNESGetKSP(snes,&ksp);
1203: KSPSetApplicationContext(ksp,usrP);
1204: snes->user = usrP;
1205: return(0);
1206: }
1208: /*@
1209: SNESGetApplicationContext - Gets the user-defined context for the
1210: nonlinear solvers.
1212: Not Collective
1214: Input Parameter:
1215: . snes - SNES context
1217: Output Parameter:
1218: . usrP - user context
1220: Fortran Notes:
1221: To use this from Fortran you must write a Fortran interface definition for this
1222: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1224: Level: intermediate
1226: .seealso: SNESSetApplicationContext()
1227: @*/
1228: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1229: {
1232: *(void**)usrP = snes->user;
1233: return(0);
1234: }
1236: /*@
1237: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply the Jacobian.
1239: Collective on SNES
1241: Input Parameters:
1242: + snes - SNES context
1243: . mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1244: - mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1246: Options Database:
1247: + -snes_mf - use matrix free for both the mat and pmat operator
1248: . -snes_mf_operator - use matrix free only for the mat operator
1249: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1250: - -snes_fd - compute the Jacobian via finite differences (slow)
1252: Level: intermediate
1254: Notes:
1255: SNES supports three approaches for computing (approximate) Jacobians: user provided via SNESSetJacobian(), matrix free, and computing explicitly with
1256: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
1258: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF(), SNESComputeJacobianDefaultColor()
1259: @*/
1260: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1261: {
1266: snes->mf = mf_operator ? PETSC_TRUE : mf;
1267: snes->mf_operator = mf_operator;
1268: return(0);
1269: }
1271: /*@
1272: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply the Jacobian.
1274: Collective on SNES
1276: Input Parameter:
1277: . snes - SNES context
1279: Output Parameters:
1280: + mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1281: - mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1283: Options Database:
1284: + -snes_mf - use matrix free for both the mat and pmat operator
1285: - -snes_mf_operator - use matrix free only for the mat operator
1287: Level: intermediate
1289: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1290: @*/
1291: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1292: {
1295: if (mf) *mf = snes->mf;
1296: if (mf_operator) *mf_operator = snes->mf_operator;
1297: return(0);
1298: }
1300: /*@
1301: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1302: at this time.
1304: Not Collective
1306: Input Parameter:
1307: . snes - SNES context
1309: Output Parameter:
1310: . iter - iteration number
1312: Notes:
1313: For example, during the computation of iteration 2 this would return 1.
1315: This is useful for using lagged Jacobians (where one does not recompute the
1316: Jacobian at each SNES iteration). For example, the code
1317: .vb
1318: SNESGetIterationNumber(snes,&it);
1319: if (!(it % 2)) {
1320: [compute Jacobian here]
1321: }
1322: .ve
1323: can be used in your ComputeJacobian() function to cause the Jacobian to be
1324: recomputed every second SNES iteration.
1326: After the SNES solve is complete this will return the number of nonlinear iterations used.
1328: Level: intermediate
1330: .seealso: SNESGetLinearSolveIterations()
1331: @*/
1332: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1333: {
1337: *iter = snes->iter;
1338: return(0);
1339: }
1341: /*@
1342: SNESSetIterationNumber - Sets the current iteration number.
1344: Not Collective
1346: Input Parameters:
1347: + snes - SNES context
1348: - iter - iteration number
1350: Level: developer
1352: .seealso: SNESGetLinearSolveIterations()
1353: @*/
1354: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1355: {
1360: PetscObjectSAWsTakeAccess((PetscObject)snes);
1361: snes->iter = iter;
1362: PetscObjectSAWsGrantAccess((PetscObject)snes);
1363: return(0);
1364: }
1366: /*@
1367: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1368: attempted by the nonlinear solver.
1370: Not Collective
1372: Input Parameter:
1373: . snes - SNES context
1375: Output Parameter:
1376: . nfails - number of unsuccessful steps attempted
1378: Notes:
1379: This counter is reset to zero for each successive call to SNESSolve().
1381: Level: intermediate
1383: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1384: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1385: @*/
1386: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1387: {
1391: *nfails = snes->numFailures;
1392: return(0);
1393: }
1395: /*@
1396: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1397: attempted by the nonlinear solver before it gives up.
1399: Not Collective
1401: Input Parameters:
1402: + snes - SNES context
1403: - maxFails - maximum of unsuccessful steps
1405: Level: intermediate
1407: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1408: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1409: @*/
1410: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1411: {
1414: snes->maxFailures = maxFails;
1415: return(0);
1416: }
1418: /*@
1419: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1420: attempted by the nonlinear solver before it gives up.
1422: Not Collective
1424: Input Parameter:
1425: . snes - SNES context
1427: Output Parameter:
1428: . maxFails - maximum of unsuccessful steps
1430: Level: intermediate
1432: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1433: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1435: @*/
1436: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1437: {
1441: *maxFails = snes->maxFailures;
1442: return(0);
1443: }
1445: /*@
1446: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1447: done by SNES.
1449: Not Collective
1451: Input Parameter:
1452: . snes - SNES context
1454: Output Parameter:
1455: . nfuncs - number of evaluations
1457: Level: intermediate
1459: Notes:
1460: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1462: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1463: @*/
1464: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1465: {
1469: *nfuncs = snes->nfuncs;
1470: return(0);
1471: }
1473: /*@
1474: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1475: linear solvers.
1477: Not Collective
1479: Input Parameter:
1480: . snes - SNES context
1482: Output Parameter:
1483: . nfails - number of failed solves
1485: Level: intermediate
1487: Options Database Keys:
1488: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1490: Notes:
1491: This counter is reset to zero for each successive call to SNESSolve().
1493: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1494: @*/
1495: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1496: {
1500: *nfails = snes->numLinearSolveFailures;
1501: return(0);
1502: }
1504: /*@
1505: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1506: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1508: Logically Collective on SNES
1510: Input Parameters:
1511: + snes - SNES context
1512: - maxFails - maximum allowed linear solve failures
1514: Level: intermediate
1516: Options Database Keys:
1517: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1519: Notes:
1520: By default this is 0; that is SNES returns on the first failed linear solve
1522: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1523: @*/
1524: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1525: {
1529: snes->maxLinearSolveFailures = maxFails;
1530: return(0);
1531: }
1533: /*@
1534: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1535: are allowed before SNES terminates
1537: Not Collective
1539: Input Parameter:
1540: . snes - SNES context
1542: Output Parameter:
1543: . maxFails - maximum of unsuccessful solves allowed
1545: Level: intermediate
1547: Notes:
1548: By default this is 1; that is SNES returns on the first failed linear solve
1550: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1551: @*/
1552: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1553: {
1557: *maxFails = snes->maxLinearSolveFailures;
1558: return(0);
1559: }
1561: /*@
1562: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1563: used by the nonlinear solver.
1565: Not Collective
1567: Input Parameter:
1568: . snes - SNES context
1570: Output Parameter:
1571: . lits - number of linear iterations
1573: Notes:
1574: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1576: If the linear solver fails inside the SNESSolve() the iterations for that call to the linear solver are not included. If you wish to count them
1577: then call KSPGetIterationNumber() after the failed solve.
1579: Level: intermediate
1581: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1582: @*/
1583: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1584: {
1588: *lits = snes->linear_its;
1589: return(0);
1590: }
1592: /*@
1593: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1594: are reset every time SNESSolve() is called.
1596: Logically Collective on SNES
1598: Input Parameters:
1599: + snes - SNES context
1600: - reset - whether to reset the counters or not
1602: Notes:
1603: This defaults to PETSC_TRUE
1605: Level: developer
1607: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1608: @*/
1609: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1610: {
1614: snes->counters_reset = reset;
1615: return(0);
1616: }
1618: /*@
1619: SNESSetKSP - Sets a KSP context for the SNES object to use
1621: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1623: Input Parameters:
1624: + snes - the SNES context
1625: - ksp - the KSP context
1627: Notes:
1628: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1629: so this routine is rarely needed.
1631: The KSP object that is already in the SNES object has its reference count
1632: decreased by one.
1634: Level: developer
1636: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1637: @*/
1638: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1639: {
1646: PetscObjectReference((PetscObject)ksp);
1647: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1648: snes->ksp = ksp;
1649: return(0);
1650: }
1652: /* -----------------------------------------------------------*/
1653: /*@
1654: SNESCreate - Creates a nonlinear solver context.
1656: Collective
1658: Input Parameters:
1659: . comm - MPI communicator
1661: Output Parameter:
1662: . outsnes - the new SNES context
1664: Options Database Keys:
1665: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1666: and no preconditioning matrix
1667: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1668: products, and a user-provided preconditioning matrix
1669: as set by SNESSetJacobian()
1670: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1672: Level: beginner
1674: Developer Notes:
1675: SNES always creates a KSP object even though many SNES methods do not use it. This is
1676: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1677: particular method does use KSP and regulates if the information about the KSP is printed
1678: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1679: by help messages about meaningless SNES options.
1681: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1682: be fixed.
1684: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner(), SNESSetLagJacobian()
1686: @*/
1687: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1688: {
1690: SNES snes;
1691: SNESKSPEW *kctx;
1695: *outsnes = NULL;
1696: SNESInitializePackage();
1698: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1700: snes->ops->converged = SNESConvergedDefault;
1701: snes->usesksp = PETSC_TRUE;
1702: snes->tolerancesset = PETSC_FALSE;
1703: snes->max_its = 50;
1704: snes->max_funcs = 10000;
1705: snes->norm = 0.0;
1706: snes->xnorm = 0.0;
1707: snes->ynorm = 0.0;
1708: snes->normschedule = SNES_NORM_ALWAYS;
1709: snes->functype = SNES_FUNCTION_DEFAULT;
1710: #if defined(PETSC_USE_REAL_SINGLE)
1711: snes->rtol = 1.e-5;
1712: #else
1713: snes->rtol = 1.e-8;
1714: #endif
1715: snes->ttol = 0.0;
1716: #if defined(PETSC_USE_REAL_SINGLE)
1717: snes->abstol = 1.e-25;
1718: #else
1719: snes->abstol = 1.e-50;
1720: #endif
1721: #if defined(PETSC_USE_REAL_SINGLE)
1722: snes->stol = 1.e-5;
1723: #else
1724: snes->stol = 1.e-8;
1725: #endif
1726: #if defined(PETSC_USE_REAL_SINGLE)
1727: snes->deltatol = 1.e-6;
1728: #else
1729: snes->deltatol = 1.e-12;
1730: #endif
1731: snes->divtol = 1.e4;
1732: snes->rnorm0 = 0;
1733: snes->nfuncs = 0;
1734: snes->numFailures = 0;
1735: snes->maxFailures = 1;
1736: snes->linear_its = 0;
1737: snes->lagjacobian = 1;
1738: snes->jac_iter = 0;
1739: snes->lagjac_persist = PETSC_FALSE;
1740: snes->lagpreconditioner = 1;
1741: snes->pre_iter = 0;
1742: snes->lagpre_persist = PETSC_FALSE;
1743: snes->numbermonitors = 0;
1744: snes->numberreasonviews = 0;
1745: snes->data = NULL;
1746: snes->setupcalled = PETSC_FALSE;
1747: snes->ksp_ewconv = PETSC_FALSE;
1748: snes->nwork = 0;
1749: snes->work = NULL;
1750: snes->nvwork = 0;
1751: snes->vwork = NULL;
1752: snes->conv_hist_len = 0;
1753: snes->conv_hist_max = 0;
1754: snes->conv_hist = NULL;
1755: snes->conv_hist_its = NULL;
1756: snes->conv_hist_reset = PETSC_TRUE;
1757: snes->counters_reset = PETSC_TRUE;
1758: snes->vec_func_init_set = PETSC_FALSE;
1759: snes->reason = SNES_CONVERGED_ITERATING;
1760: snes->npcside = PC_RIGHT;
1761: snes->setfromoptionscalled = 0;
1763: snes->mf = PETSC_FALSE;
1764: snes->mf_operator = PETSC_FALSE;
1765: snes->mf_version = 1;
1767: snes->numLinearSolveFailures = 0;
1768: snes->maxLinearSolveFailures = 1;
1770: snes->vizerotolerance = 1.e-8;
1771: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1773: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1774: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1776: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1777: PetscNewLog(snes,&kctx);
1779: snes->kspconvctx = (void*)kctx;
1780: kctx->version = 2;
1781: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1782: this was too large for some test cases */
1783: kctx->rtol_last = 0.0;
1784: kctx->rtol_max = .9;
1785: kctx->gamma = 1.0;
1786: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1787: kctx->alpha2 = kctx->alpha;
1788: kctx->threshold = .1;
1789: kctx->lresid_last = 0.0;
1790: kctx->norm_last = 0.0;
1792: *outsnes = snes;
1793: return(0);
1794: }
1796: /*MC
1797: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1799: Synopsis:
1800: #include "petscsnes.h"
1801: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1803: Collective on snes
1805: Input Parameters:
1806: + snes - the SNES context
1807: . x - state at which to evaluate residual
1808: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1810: Output Parameter:
1811: . f - vector to put residual (function value)
1813: Level: intermediate
1815: .seealso: SNESSetFunction(), SNESGetFunction()
1816: M*/
1818: /*@C
1819: SNESSetFunction - Sets the function evaluation routine and function
1820: vector for use by the SNES routines in solving systems of nonlinear
1821: equations.
1823: Logically Collective on SNES
1825: Input Parameters:
1826: + snes - the SNES context
1827: . r - vector to store function values, may be NULL
1828: . f - function evaluation routine; see SNESFunction for calling sequence details
1829: - ctx - [optional] user-defined context for private data for the
1830: function evaluation routine (may be NULL)
1832: Notes:
1833: The Newton-like methods typically solve linear systems of the form
1834: $ f'(x) x = -f(x),
1835: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1837: Level: beginner
1839: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1840: @*/
1841: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1842: {
1844: DM dm;
1848: if (r) {
1851: PetscObjectReference((PetscObject)r);
1852: VecDestroy(&snes->vec_func);
1853: snes->vec_func = r;
1854: }
1855: SNESGetDM(snes,&dm);
1856: DMSNESSetFunction(dm,f,ctx);
1857: if (f == SNESPicardComputeFunction) {
1858: DMSNESSetMFFunction(dm,SNESPicardComputeMFFunction,ctx);
1859: }
1860: return(0);
1861: }
1863: /*@C
1864: SNESSetInitialFunction - Sets the function vector to be used as the
1865: function norm at the initialization of the method. In some
1866: instances, the user has precomputed the function before calling
1867: SNESSolve. This function allows one to avoid a redundant call
1868: to SNESComputeFunction in that case.
1870: Logically Collective on SNES
1872: Input Parameters:
1873: + snes - the SNES context
1874: - f - vector to store function value
1876: Notes:
1877: This should not be modified during the solution procedure.
1879: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1881: Level: developer
1883: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1884: @*/
1885: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1886: {
1888: Vec vec_func;
1894: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1895: snes->vec_func_init_set = PETSC_FALSE;
1896: return(0);
1897: }
1898: SNESGetFunction(snes,&vec_func,NULL,NULL);
1899: VecCopy(f, vec_func);
1901: snes->vec_func_init_set = PETSC_TRUE;
1902: return(0);
1903: }
1905: /*@
1906: SNESSetNormSchedule - Sets the SNESNormSchedule used in convergence and monitoring
1907: of the SNES method.
1909: Logically Collective on SNES
1911: Input Parameters:
1912: + snes - the SNES context
1913: - normschedule - the frequency of norm computation
1915: Options Database Key:
1916: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly>
1918: Notes:
1919: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1920: of the nonlinear function and the taking of its norm at every iteration to
1921: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1922: (SNESNGS) and the like do not require the norm of the function to be computed, and therefore
1923: may either be monitored for convergence or not. As these are often used as nonlinear
1924: preconditioners, monitoring the norm of their error is not a useful enterprise within
1925: their solution.
1927: Level: developer
1929: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1930: @*/
1931: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1932: {
1935: snes->normschedule = normschedule;
1936: return(0);
1937: }
1939: /*@
1940: SNESGetNormSchedule - Gets the SNESNormSchedule used in convergence and monitoring
1941: of the SNES method.
1943: Logically Collective on SNES
1945: Input Parameters:
1946: + snes - the SNES context
1947: - normschedule - the type of the norm used
1949: Level: advanced
1951: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1952: @*/
1953: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1954: {
1957: *normschedule = snes->normschedule;
1958: return(0);
1959: }
1961: /*@
1962: SNESSetFunctionNorm - Sets the last computed residual norm.
1964: Logically Collective on SNES
1966: Input Parameters:
1967: + snes - the SNES context
1969: - normschedule - the frequency of norm computation
1971: Level: developer
1973: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1974: @*/
1975: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1976: {
1979: snes->norm = norm;
1980: return(0);
1981: }
1983: /*@
1984: SNESGetFunctionNorm - Gets the last computed norm of the residual
1986: Not Collective
1988: Input Parameter:
1989: . snes - the SNES context
1991: Output Parameter:
1992: . norm - the last computed residual norm
1994: Level: developer
1996: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1997: @*/
1998: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1999: {
2003: *norm = snes->norm;
2004: return(0);
2005: }
2007: /*@
2008: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
2010: Not Collective
2012: Input Parameter:
2013: . snes - the SNES context
2015: Output Parameter:
2016: . ynorm - the last computed update norm
2018: Level: developer
2020: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
2021: @*/
2022: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2023: {
2027: *ynorm = snes->ynorm;
2028: return(0);
2029: }
2031: /*@
2032: SNESGetSolutionNorm - Gets the last computed norm of the solution
2034: Not Collective
2036: Input Parameter:
2037: . snes - the SNES context
2039: Output Parameter:
2040: . xnorm - the last computed solution norm
2042: Level: developer
2044: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2045: @*/
2046: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2047: {
2051: *xnorm = snes->xnorm;
2052: return(0);
2053: }
2055: /*@C
2056: SNESSetFunctionType - Sets the SNESNormSchedule used in convergence and monitoring
2057: of the SNES method.
2059: Logically Collective on SNES
2061: Input Parameters:
2062: + snes - the SNES context
2063: - normschedule - the frequency of norm computation
2065: Notes:
2066: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2067: of the nonlinear function and the taking of its norm at every iteration to
2068: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2069: (SNESNGS) and the like do not require the norm of the function to be computed, and therefore
2070: may either be monitored for convergence or not. As these are often used as nonlinear
2071: preconditioners, monitoring the norm of their error is not a useful enterprise within
2072: their solution.
2074: Level: developer
2076: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2077: @*/
2078: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2079: {
2082: snes->functype = type;
2083: return(0);
2084: }
2086: /*@C
2087: SNESGetFunctionType - Gets the SNESNormSchedule used in convergence and monitoring
2088: of the SNES method.
2090: Logically Collective on SNES
2092: Input Parameters:
2093: + snes - the SNES context
2094: - normschedule - the type of the norm used
2096: Level: advanced
2098: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2099: @*/
2100: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2101: {
2104: *type = snes->functype;
2105: return(0);
2106: }
2108: /*MC
2109: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2111: Synopsis:
2112: #include <petscsnes.h>
2113: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2115: Collective on snes
2117: Input Parameters:
2118: + X - solution vector
2119: . B - RHS vector
2120: - ctx - optional user-defined Gauss-Seidel context
2122: Output Parameter:
2123: . X - solution vector
2125: Level: intermediate
2127: .seealso: SNESSetNGS(), SNESGetNGS()
2128: M*/
2130: /*@C
2131: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2132: use with composed nonlinear solvers.
2134: Input Parameters:
2135: + snes - the SNES context
2136: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2137: - ctx - [optional] user-defined context for private data for the
2138: smoother evaluation routine (may be NULL)
2140: Notes:
2141: The NGS routines are used by the composed nonlinear solver to generate
2142: a problem appropriate update to the solution, particularly FAS.
2144: Level: intermediate
2146: .seealso: SNESGetFunction(), SNESComputeNGS()
2147: @*/
2148: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2149: {
2151: DM dm;
2155: SNESGetDM(snes,&dm);
2156: DMSNESSetNGS(dm,f,ctx);
2157: return(0);
2158: }
2160: /*
2161: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2162: changed during the KSPSolve()
2163: */
2164: PetscErrorCode SNESPicardComputeMFFunction(SNES snes,Vec x,Vec f,void *ctx)
2165: {
2167: DM dm;
2168: DMSNES sdm;
2171: SNESGetDM(snes,&dm);
2172: DMGetDMSNES(dm,&sdm);
2173: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2174: /* A(x)*x - b(x) */
2175: if (sdm->ops->computepfunction) {
2176: PetscStackPush("SNES Picard user function");
2177: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2178: PetscStackPop;
2179: VecScale(f,-1.0);
2180: if (!snes->picard) {
2181: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2182: MatDuplicate(snes->jacobian_pre,MAT_DO_NOT_COPY_VALUES,&snes->picard);
2183: }
2184: PetscStackPush("SNES Picard user Jacobian");
2185: (*sdm->ops->computepjacobian)(snes,x,snes->picard,snes->picard,sdm->pctx);
2186: PetscStackPop;
2187: MatMultAdd(snes->picard,x,f,f);
2188: } else {
2189: PetscStackPush("SNES Picard user Jacobian");
2190: (*sdm->ops->computepjacobian)(snes,x,snes->picard,snes->picard,sdm->pctx);
2191: PetscStackPop;
2192: MatMult(snes->picard,x,f);
2193: }
2194: return(0);
2195: }
2197: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2198: {
2200: DM dm;
2201: DMSNES sdm;
2204: SNESGetDM(snes,&dm);
2205: DMGetDMSNES(dm,&sdm);
2206: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2207: /* A(x)*x - b(x) */
2208: if (sdm->ops->computepfunction) {
2209: PetscStackPush("SNES Picard user function");
2210: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2211: PetscStackPop;
2212: VecScale(f,-1.0);
2213: PetscStackPush("SNES Picard user Jacobian");
2214: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2215: PetscStackPop;
2216: MatMultAdd(snes->jacobian_pre,x,f,f);
2217: } else {
2218: PetscStackPush("SNES Picard user Jacobian");
2219: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2220: PetscStackPop;
2221: MatMult(snes->jacobian_pre,x,f);
2222: }
2223: return(0);
2224: }
2226: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2227: {
2230: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2231: /* must assembly if matrix-free to get the last SNES solution */
2232: MatAssemblyBegin(J,MAT_FINAL_ASSEMBLY);
2233: MatAssemblyEnd(J,MAT_FINAL_ASSEMBLY);
2234: return(0);
2235: }
2237: /*@C
2238: SNESSetPicard - Use SNES to solve the system A(x) x = bp(x) + b via a Picard type iteration (Picard linearization)
2240: Logically Collective on SNES
2242: Input Parameters:
2243: + snes - the SNES context
2244: . r - vector to store function values, may be NULL
2245: . bp - function evaluation routine, may be NULL
2246: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2247: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2248: . J - function to compute matrix values, see SNESJacobianFunction() for details on its calling sequence
2249: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be NULL)
2251: Notes:
2252: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2253: 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.
2255: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2257: $ Solves the equation A(x) x = bp(x) - b via the defect correction algorithm A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}
2258: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = bp(x^{n}) + b iteration.
2260: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2262: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2263: the direct Picard iteration A(x^n) x^{n+1} = bp(x^n) + b
2265: 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
2266: 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
2267: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2269: When used with -snes_mf_operator this will run matrix-free Newton's method where the matrix-vector product is of the true Jacobian of A(x)x - bp(x) -b.
2271: When used with -snes_fd this will compute the true Jacobian (very slowly one column at at time) and thus represent Newton's method.
2273: When used with -snes_fd_coloring this will compute the Jacobian via coloring and thus represent a faster implementation of Newton's method. But the
2274: the nonzero structure of the Jacobian is, in general larger than that of the Picard matrix A so you must provide in A the needed nonzero structure for the correct
2275: coloring. When using DMDA this may mean creating the matrix A with DMCreateMatrix() using a wider stencil than strictly needed for A or with a DMDA_STENCIL_BOX.
2276: See the commment in src/snes/tutorials/ex15.c.
2278: Level: intermediate
2280: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2281: @*/
2282: PetscErrorCode SNESSetPicard(SNES snes,Vec r,PetscErrorCode (*bp)(SNES,Vec,Vec,void*),Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2283: {
2285: DM dm;
2289: SNESGetDM(snes, &dm);
2290: DMSNESSetPicard(dm,bp,J,ctx);
2291: DMSNESSetMFFunction(dm,SNESPicardComputeMFFunction,ctx);
2292: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2293: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2294: return(0);
2295: }
2297: /*@C
2298: SNESGetPicard - Returns the context for the Picard iteration
2300: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2302: Input Parameter:
2303: . snes - the SNES context
2305: Output Parameters:
2306: + r - the function (or NULL)
2307: . f - the function (or NULL); see SNESFunction for calling sequence details
2308: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2309: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2310: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2311: - ctx - the function context (or NULL)
2313: Level: advanced
2315: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2316: @*/
2317: 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)
2318: {
2320: DM dm;
2324: SNESGetFunction(snes,r,NULL,NULL);
2325: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2326: SNESGetDM(snes,&dm);
2327: DMSNESGetPicard(dm,f,J,ctx);
2328: return(0);
2329: }
2331: /*@C
2332: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2334: Logically Collective on SNES
2336: Input Parameters:
2337: + snes - the SNES context
2338: . func - function evaluation routine
2339: - ctx - [optional] user-defined context for private data for the
2340: function evaluation routine (may be NULL)
2342: Calling sequence of func:
2343: $ func (SNES snes,Vec x,void *ctx);
2345: . f - function vector
2346: - ctx - optional user-defined function context
2348: Level: intermediate
2350: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2351: @*/
2352: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2353: {
2356: if (func) snes->ops->computeinitialguess = func;
2357: if (ctx) snes->initialguessP = ctx;
2358: return(0);
2359: }
2361: /* --------------------------------------------------------------- */
2362: /*@C
2363: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2364: it assumes a zero right hand side.
2366: Logically Collective on SNES
2368: Input Parameter:
2369: . snes - the SNES context
2371: Output Parameter:
2372: . rhs - the right hand side vector or NULL if the right hand side vector is null
2374: Level: intermediate
2376: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2377: @*/
2378: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2379: {
2383: *rhs = snes->vec_rhs;
2384: return(0);
2385: }
2387: /*@
2388: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2390: Collective on SNES
2392: Input Parameters:
2393: + snes - the SNES context
2394: - x - input vector
2396: Output Parameter:
2397: . y - function vector, as set by SNESSetFunction()
2399: Notes:
2400: SNESComputeFunction() is typically used within nonlinear solvers
2401: implementations, so users would not generally call this routine themselves.
2403: Level: developer
2405: .seealso: SNESSetFunction(), SNESGetFunction(), SNESComputeMFFunction()
2406: @*/
2407: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2408: {
2410: DM dm;
2411: DMSNES sdm;
2419: VecValidValues(x,2,PETSC_TRUE);
2421: SNESGetDM(snes,&dm);
2422: DMGetDMSNES(dm,&sdm);
2423: if (sdm->ops->computefunction) {
2424: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2425: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2426: }
2427: VecLockReadPush(x);
2428: PetscStackPush("SNES user function");
2429: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2430: snes->domainerror = PETSC_FALSE;
2431: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2432: PetscStackPop;
2433: VecLockReadPop(x);
2434: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2435: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2436: }
2437: } else if (snes->vec_rhs) {
2438: MatMult(snes->jacobian, x, y);
2439: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2440: if (snes->vec_rhs) {
2441: VecAXPY(y,-1.0,snes->vec_rhs);
2442: }
2443: snes->nfuncs++;
2444: /*
2445: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2446: propagate the value to all processes
2447: */
2448: if (snes->domainerror) {
2449: VecSetInf(y);
2450: }
2451: return(0);
2452: }
2454: /*@
2455: SNESComputeMFFunction - Calls the function that has been set with SNESSetMFFunction().
2457: Collective on SNES
2459: Input Parameters:
2460: + snes - the SNES context
2461: - x - input vector
2463: Output Parameter:
2464: . y - function vector, as set by SNESSetMFFunction()
2466: Notes:
2467: SNESComputeMFFunction() is used within the matrix vector products called by the matrix created with MatCreateSNESMF()
2468: so users would not generally call this routine themselves.
2470: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with SNESSolve()
2471: while SNESComputeFunction() does. As such, this routine cannot be used with MatMFFDSetBase() with a provided F function value even if it applies the
2472: same function as SNESComputeFunction() if a SNESSolve() right hand side vector is use because the two functions difference would include this right hand side function.
2474: Level: developer
2476: .seealso: SNESSetFunction(), SNESGetFunction(), SNESComputeFunction(), MatCreateSNESMF
2477: @*/
2478: PetscErrorCode SNESComputeMFFunction(SNES snes,Vec x,Vec y)
2479: {
2481: DM dm;
2482: DMSNES sdm;
2490: VecValidValues(x,2,PETSC_TRUE);
2492: SNESGetDM(snes,&dm);
2493: DMGetDMSNES(dm,&sdm);
2494: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2495: VecLockReadPush(x);
2496: PetscStackPush("SNES user function");
2497: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2498: snes->domainerror = PETSC_FALSE;
2499: (*sdm->ops->computemffunction)(snes,x,y,sdm->mffunctionctx);
2500: PetscStackPop;
2501: VecLockReadPop(x);
2502: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2503: snes->nfuncs++;
2504: /*
2505: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2506: propagate the value to all processes
2507: */
2508: if (snes->domainerror) {
2509: VecSetInf(y);
2510: }
2511: return(0);
2512: }
2514: /*@
2515: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2517: Collective on SNES
2519: Input Parameters:
2520: + snes - the SNES context
2521: . x - input vector
2522: - b - rhs vector
2524: Output Parameter:
2525: . x - new solution vector
2527: Notes:
2528: SNESComputeNGS() is typically used within composed nonlinear solver
2529: implementations, so most users would not generally call this routine
2530: themselves.
2532: Level: developer
2534: .seealso: SNESSetNGS(), SNESComputeFunction()
2535: @*/
2536: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2537: {
2539: DM dm;
2540: DMSNES sdm;
2548: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2549: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2550: SNESGetDM(snes,&dm);
2551: DMGetDMSNES(dm,&sdm);
2552: if (sdm->ops->computegs) {
2553: if (b) {VecLockReadPush(b);}
2554: PetscStackPush("SNES user NGS");
2555: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2556: PetscStackPop;
2557: if (b) {VecLockReadPop(b);}
2558: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2559: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2560: return(0);
2561: }
2563: PetscErrorCode SNESTestJacobian(SNES snes)
2564: {
2565: Mat A,B,C,D,jacobian;
2566: Vec x = snes->vec_sol,f = snes->vec_func;
2567: PetscErrorCode ierr;
2568: PetscReal nrm,gnorm;
2569: PetscReal threshold = 1.e-5;
2570: MatType mattype;
2571: PetscInt m,n,M,N;
2572: void *functx;
2573: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg,istranspose;
2574: PetscViewer viewer,mviewer;
2575: MPI_Comm comm;
2576: PetscInt tabs;
2577: static PetscBool directionsprinted = PETSC_FALSE;
2578: PetscViewerFormat format;
2581: PetscObjectOptionsBegin((PetscObject)snes);
2582: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2583: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2584: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2585: if (!complete_print) {
2586: PetscOptionsDeprecated("-snes_test_jacobian_display","-snes_test_jacobian_view","3.13",NULL);
2587: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2588: }
2589: /* for compatibility with PETSc 3.9 and older. */
2590: PetscOptionsDeprecated("-snes_test_jacobian_display_threshold","-snes_test_jacobian","3.13","-snes_test_jacobian accepts an optional threshold (since v3.10)");
2591: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2592: PetscOptionsEnd();
2593: if (!test) return(0);
2595: PetscObjectGetComm((PetscObject)snes,&comm);
2596: PetscViewerASCIIGetStdout(comm,&viewer);
2597: PetscViewerASCIIGetTab(viewer, &tabs);
2598: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2599: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2600: if (!complete_print && !directionsprinted) {
2601: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2602: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2603: }
2604: if (!directionsprinted) {
2605: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2606: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2607: directionsprinted = PETSC_TRUE;
2608: }
2609: if (complete_print) {
2610: PetscViewerPushFormat(mviewer,format);
2611: }
2613: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2614: if (!flg) jacobian = snes->jacobian;
2615: else jacobian = snes->jacobian_pre;
2617: if (!x) {
2618: MatCreateVecs(jacobian, &x, NULL);
2619: } else {
2620: PetscObjectReference((PetscObject) x);
2621: }
2622: if (!f) {
2623: VecDuplicate(x, &f);
2624: } else {
2625: PetscObjectReference((PetscObject) f);
2626: }
2627: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2628: SNESComputeFunction(snes,x,f);
2629: VecDestroy(&f);
2630: PetscObjectTypeCompare((PetscObject)snes,SNESKSPTRANSPOSEONLY,&istranspose);
2631: while (jacobian) {
2632: Mat JT = NULL, Jsave = NULL;
2634: if (istranspose) {
2635: MatCreateTranspose(jacobian,&JT);
2636: Jsave = jacobian;
2637: jacobian = JT;
2638: }
2639: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2640: if (flg) {
2641: A = jacobian;
2642: PetscObjectReference((PetscObject)A);
2643: } else {
2644: MatComputeOperator(jacobian,MATAIJ,&A);
2645: }
2647: MatGetType(A,&mattype);
2648: MatGetSize(A,&M,&N);
2649: MatGetLocalSize(A,&m,&n);
2650: MatCreate(PetscObjectComm((PetscObject)A),&B);
2651: MatSetType(B,mattype);
2652: MatSetSizes(B,m,n,M,N);
2653: MatSetBlockSizesFromMats(B,A,A);
2654: MatSetUp(B);
2655: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2657: SNESGetFunction(snes,NULL,NULL,&functx);
2658: SNESComputeJacobianDefault(snes,x,B,B,functx);
2660: MatDuplicate(B,MAT_COPY_VALUES,&D);
2661: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2662: MatNorm(D,NORM_FROBENIUS,&nrm);
2663: MatNorm(A,NORM_FROBENIUS,&gnorm);
2664: MatDestroy(&D);
2665: if (!gnorm) gnorm = 1; /* just in case */
2666: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2668: if (complete_print) {
2669: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2670: MatView(A,mviewer);
2671: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2672: MatView(B,mviewer);
2673: }
2675: if (threshold_print || complete_print) {
2676: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2677: PetscScalar *cvals;
2678: const PetscInt *bcols;
2679: const PetscScalar *bvals;
2681: MatCreate(PetscObjectComm((PetscObject)A),&C);
2682: MatSetType(C,mattype);
2683: MatSetSizes(C,m,n,M,N);
2684: MatSetBlockSizesFromMats(C,A,A);
2685: MatSetUp(C);
2686: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2688: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2689: MatGetOwnershipRange(B,&Istart,&Iend);
2691: for (row = Istart; row < Iend; row++) {
2692: MatGetRow(B,row,&bncols,&bcols,&bvals);
2693: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2694: for (j = 0, cncols = 0; j < bncols; j++) {
2695: if (PetscAbsScalar(bvals[j]) > threshold) {
2696: ccols[cncols] = bcols[j];
2697: cvals[cncols] = bvals[j];
2698: cncols += 1;
2699: }
2700: }
2701: if (cncols) {
2702: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2703: }
2704: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2705: PetscFree2(ccols,cvals);
2706: }
2707: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2708: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2709: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2710: MatView(C,complete_print ? mviewer : viewer);
2711: MatDestroy(&C);
2712: }
2713: MatDestroy(&A);
2714: MatDestroy(&B);
2715: MatDestroy(&JT);
2716: if (Jsave) jacobian = Jsave;
2717: if (jacobian != snes->jacobian_pre) {
2718: jacobian = snes->jacobian_pre;
2719: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2720: }
2721: else jacobian = NULL;
2722: }
2723: VecDestroy(&x);
2724: if (complete_print) {
2725: PetscViewerPopFormat(mviewer);
2726: }
2727: if (mviewer) { PetscViewerDestroy(&mviewer); }
2728: PetscViewerASCIISetTab(viewer,tabs);
2729: return(0);
2730: }
2732: /*@
2733: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2735: Collective on SNES
2737: Input Parameters:
2738: + snes - the SNES context
2739: - x - input vector
2741: Output Parameters:
2742: + A - Jacobian matrix
2743: - B - optional preconditioning matrix
2745: Options Database Keys:
2746: + -snes_lag_preconditioner <lag>
2747: . -snes_lag_jacobian <lag>
2748: . -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.
2749: . -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
2750: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2751: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2752: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2753: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2754: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2755: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2756: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2757: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2758: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2759: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2760: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2762: Notes:
2763: Most users should not need to explicitly call this routine, as it
2764: is used internally within the nonlinear solvers.
2766: Developer Notes:
2767: 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
2768: for with the SNESType of test that has been removed.
2770: Level: developer
2772: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2773: @*/
2774: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2775: {
2777: PetscBool flag;
2778: DM dm;
2779: DMSNES sdm;
2780: KSP ksp;
2786: VecValidValues(X,2,PETSC_TRUE);
2787: SNESGetDM(snes,&dm);
2788: DMGetDMSNES(dm,&sdm);
2790: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2792: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2794: if (snes->lagjacobian == -2) {
2795: snes->lagjacobian = -1;
2797: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2798: } else if (snes->lagjacobian == -1) {
2799: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2800: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2801: if (flag) {
2802: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2803: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2804: }
2805: return(0);
2806: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2807: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2808: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2809: if (flag) {
2810: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2811: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2812: }
2813: return(0);
2814: }
2815: if (snes->npc && snes->npcside== PC_LEFT) {
2816: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2817: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2818: return(0);
2819: }
2821: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2822: VecLockReadPush(X);
2823: PetscStackPush("SNES user Jacobian function");
2824: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2825: PetscStackPop;
2826: VecLockReadPop(X);
2827: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2829: /* attach latest linearization point to the preconditioning matrix */
2830: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2832: /* the next line ensures that snes->ksp exists */
2833: SNESGetKSP(snes,&ksp);
2834: if (snes->lagpreconditioner == -2) {
2835: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2836: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2837: snes->lagpreconditioner = -1;
2838: } else if (snes->lagpreconditioner == -1) {
2839: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2840: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2841: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2842: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2843: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2844: } else {
2845: PetscInfo(snes,"Rebuilding preconditioner\n");
2846: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2847: }
2849: SNESTestJacobian(snes);
2850: /* make sure user returned a correct Jacobian and preconditioner */
2853: {
2854: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2855: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2856: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2857: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2858: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2859: if (flag || flag_draw || flag_contour) {
2860: Mat Bexp_mine = NULL,Bexp,FDexp;
2861: PetscViewer vdraw,vstdout;
2862: PetscBool flg;
2863: if (flag_operator) {
2864: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2865: Bexp = Bexp_mine;
2866: } else {
2867: /* See if the preconditioning matrix can be viewed and added directly */
2868: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2869: if (flg) Bexp = B;
2870: else {
2871: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2872: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2873: Bexp = Bexp_mine;
2874: }
2875: }
2876: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2877: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2878: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2879: if (flag_draw || flag_contour) {
2880: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2881: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2882: } else vdraw = NULL;
2883: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2884: if (flag) {MatView(Bexp,vstdout);}
2885: if (vdraw) {MatView(Bexp,vdraw);}
2886: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2887: if (flag) {MatView(FDexp,vstdout);}
2888: if (vdraw) {MatView(FDexp,vdraw);}
2889: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2890: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2891: if (flag) {MatView(FDexp,vstdout);}
2892: if (vdraw) { /* Always use contour for the difference */
2893: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2894: MatView(FDexp,vdraw);
2895: PetscViewerPopFormat(vdraw);
2896: }
2897: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2898: PetscViewerDestroy(&vdraw);
2899: MatDestroy(&Bexp_mine);
2900: MatDestroy(&FDexp);
2901: }
2902: }
2903: {
2904: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2905: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2906: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2907: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2908: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2909: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2910: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2911: if (flag_threshold) {
2912: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2913: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2914: }
2915: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2916: Mat Bfd;
2917: PetscViewer vdraw,vstdout;
2918: MatColoring coloring;
2919: ISColoring iscoloring;
2920: MatFDColoring matfdcoloring;
2921: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2922: void *funcctx;
2923: PetscReal norm1,norm2,normmax;
2925: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2926: MatColoringCreate(Bfd,&coloring);
2927: MatColoringSetType(coloring,MATCOLORINGSL);
2928: MatColoringSetFromOptions(coloring);
2929: MatColoringApply(coloring,&iscoloring);
2930: MatColoringDestroy(&coloring);
2931: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2932: MatFDColoringSetFromOptions(matfdcoloring);
2933: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2934: ISColoringDestroy(&iscoloring);
2936: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2937: SNESGetFunction(snes,NULL,&func,&funcctx);
2938: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2939: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2940: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2941: MatFDColoringSetFromOptions(matfdcoloring);
2942: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2943: MatFDColoringDestroy(&matfdcoloring);
2945: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2946: if (flag_draw || flag_contour) {
2947: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2948: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2949: } else vdraw = NULL;
2950: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2951: if (flag_display) {MatView(B,vstdout);}
2952: if (vdraw) {MatView(B,vdraw);}
2953: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2954: if (flag_display) {MatView(Bfd,vstdout);}
2955: if (vdraw) {MatView(Bfd,vdraw);}
2956: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2957: MatNorm(Bfd,NORM_1,&norm1);
2958: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2959: MatNorm(Bfd,NORM_MAX,&normmax);
2960: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2961: if (flag_display) {MatView(Bfd,vstdout);}
2962: if (vdraw) { /* Always use contour for the difference */
2963: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2964: MatView(Bfd,vdraw);
2965: PetscViewerPopFormat(vdraw);
2966: }
2967: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2969: if (flag_threshold) {
2970: PetscInt bs,rstart,rend,i;
2971: MatGetBlockSize(B,&bs);
2972: MatGetOwnershipRange(B,&rstart,&rend);
2973: for (i=rstart; i<rend; i++) {
2974: const PetscScalar *ba,*ca;
2975: const PetscInt *bj,*cj;
2976: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2977: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2978: MatGetRow(B,i,&bn,&bj,&ba);
2979: MatGetRow(Bfd,i,&cn,&cj,&ca);
2980: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2981: for (j=0; j<bn; j++) {
2982: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2983: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2984: maxentrycol = bj[j];
2985: maxentry = PetscRealPart(ba[j]);
2986: }
2987: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2988: maxdiffcol = bj[j];
2989: maxdiff = PetscRealPart(ca[j]);
2990: }
2991: if (rdiff > maxrdiff) {
2992: maxrdiffcol = bj[j];
2993: maxrdiff = rdiff;
2994: }
2995: }
2996: if (maxrdiff > 1) {
2997: 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);
2998: for (j=0; j<bn; j++) {
2999: PetscReal rdiff;
3000: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
3001: if (rdiff > 1) {
3002: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
3003: }
3004: }
3005: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
3006: }
3007: MatRestoreRow(B,i,&bn,&bj,&ba);
3008: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
3009: }
3010: }
3011: PetscViewerDestroy(&vdraw);
3012: MatDestroy(&Bfd);
3013: }
3014: }
3015: return(0);
3016: }
3018: /*MC
3019: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
3021: Synopsis:
3022: #include "petscsnes.h"
3023: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
3025: Collective on snes
3027: Input Parameters:
3028: + x - input vector, the Jacobian is to be computed at this value
3029: - ctx - [optional] user-defined Jacobian context
3031: Output Parameters:
3032: + Amat - the matrix that defines the (approximate) Jacobian
3033: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
3035: Level: intermediate
3037: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
3038: M*/
3040: /*@C
3041: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3042: location to store the matrix.
3044: Logically Collective on SNES
3046: Input Parameters:
3047: + snes - the SNES context
3048: . Amat - the matrix that defines the (approximate) Jacobian
3049: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
3050: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
3051: - ctx - [optional] user-defined context for private data for the
3052: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
3054: Notes:
3055: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
3056: each matrix.
3058: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
3059: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
3061: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
3062: must be a MatFDColoring.
3064: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3065: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
3067: Level: beginner
3069: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
3070: SNESSetPicard(), SNESJacobianFunction
3071: @*/
3072: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
3073: {
3075: DM dm;
3083: SNESGetDM(snes,&dm);
3084: DMSNESSetJacobian(dm,J,ctx);
3085: if (Amat) {
3086: PetscObjectReference((PetscObject)Amat);
3087: MatDestroy(&snes->jacobian);
3089: snes->jacobian = Amat;
3090: }
3091: if (Pmat) {
3092: PetscObjectReference((PetscObject)Pmat);
3093: MatDestroy(&snes->jacobian_pre);
3095: snes->jacobian_pre = Pmat;
3096: }
3097: return(0);
3098: }
3100: /*@C
3101: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3102: provided context for evaluating the Jacobian.
3104: Not Collective, but Mat object will be parallel if SNES object is
3106: Input Parameter:
3107: . snes - the nonlinear solver context
3109: Output Parameters:
3110: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
3111: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
3112: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
3113: - ctx - location to stash Jacobian ctx (or NULL)
3115: Level: advanced
3117: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
3118: @*/
3119: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
3120: {
3122: DM dm;
3123: DMSNES sdm;
3127: if (Amat) *Amat = snes->jacobian;
3128: if (Pmat) *Pmat = snes->jacobian_pre;
3129: SNESGetDM(snes,&dm);
3130: DMGetDMSNES(dm,&sdm);
3131: if (J) *J = sdm->ops->computejacobian;
3132: if (ctx) *ctx = sdm->jacobianctx;
3133: return(0);
3134: }
3136: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3137: {
3139: DM dm;
3140: DMSNES sdm;
3143: SNESGetDM(snes,&dm);
3144: DMGetDMSNES(dm,&sdm);
3145: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3146: DM dm;
3147: PetscBool isdense,ismf;
3149: SNESGetDM(snes,&dm);
3150: PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre,&isdense,MATSEQDENSE,MATMPIDENSE,MATDENSE,NULL);
3151: PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre,&ismf,MATMFFD,MATSHELL,NULL);
3152: if (isdense) {
3153: DMSNESSetJacobian(dm,SNESComputeJacobianDefault,NULL);
3154: } else if (!ismf) {
3155: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3156: }
3157: }
3158: return(0);
3159: }
3161: /*@
3162: SNESSetUp - Sets up the internal data structures for the later use
3163: of a nonlinear solver.
3165: Collective on SNES
3167: Input Parameters:
3168: . snes - the SNES context
3170: Notes:
3171: For basic use of the SNES solvers the user need not explicitly call
3172: SNESSetUp(), since these actions will automatically occur during
3173: the call to SNESSolve(). However, if one wishes to control this
3174: phase separately, SNESSetUp() should be called after SNESCreate()
3175: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3177: Level: advanced
3179: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3180: @*/
3181: PetscErrorCode SNESSetUp(SNES snes)
3182: {
3184: DM dm;
3185: DMSNES sdm;
3186: SNESLineSearch linesearch, pclinesearch;
3187: void *lsprectx,*lspostctx;
3188: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3189: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3190: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3191: Vec f,fpc;
3192: void *funcctx;
3193: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3194: void *jacctx,*appctx;
3195: Mat j,jpre;
3199: if (snes->setupcalled) return(0);
3200: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3202: if (!((PetscObject)snes)->type_name) {
3203: SNESSetType(snes,SNESNEWTONLS);
3204: }
3206: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3208: SNESGetDM(snes,&dm);
3209: DMGetDMSNES(dm,&sdm);
3210: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3211: SNESSetDefaultComputeJacobian(snes);
3213: if (!snes->vec_func) {
3214: DMCreateGlobalVector(dm,&snes->vec_func);
3215: }
3217: if (!snes->ksp) {
3218: SNESGetKSP(snes, &snes->ksp);
3219: }
3221: if (snes->linesearch) {
3222: SNESGetLineSearch(snes, &snes->linesearch);
3223: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3224: }
3226: if (snes->npc && (snes->npcside== PC_LEFT)) {
3227: snes->mf = PETSC_TRUE;
3228: snes->mf_operator = PETSC_FALSE;
3229: }
3231: if (snes->npc) {
3232: /* copy the DM over */
3233: SNESGetDM(snes,&dm);
3234: SNESSetDM(snes->npc,dm);
3236: SNESGetFunction(snes,&f,&func,&funcctx);
3237: VecDuplicate(f,&fpc);
3238: SNESSetFunction(snes->npc,fpc,func,funcctx);
3239: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3240: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3241: SNESGetApplicationContext(snes,&appctx);
3242: SNESSetApplicationContext(snes->npc,appctx);
3243: VecDestroy(&fpc);
3245: /* copy the function pointers over */
3246: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3248: /* default to 1 iteration */
3249: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3250: if (snes->npcside==PC_RIGHT) {
3251: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3252: } else {
3253: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3254: }
3255: SNESSetFromOptions(snes->npc);
3257: /* copy the line search context over */
3258: if (snes->linesearch && snes->npc->linesearch) {
3259: SNESGetLineSearch(snes,&linesearch);
3260: SNESGetLineSearch(snes->npc,&pclinesearch);
3261: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3262: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3263: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3264: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3265: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3266: }
3267: }
3268: if (snes->mf) {
3269: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3270: }
3271: if (snes->ops->usercompute && !snes->user) {
3272: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3273: }
3275: snes->jac_iter = 0;
3276: snes->pre_iter = 0;
3278: if (snes->ops->setup) {
3279: (*snes->ops->setup)(snes);
3280: }
3282: SNESSetDefaultComputeJacobian(snes);
3284: if (snes->npc && (snes->npcside== PC_LEFT)) {
3285: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3286: if (snes->linesearch) {
3287: SNESGetLineSearch(snes,&linesearch);
3288: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3289: }
3290: }
3291: }
3292: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3293: snes->setupcalled = PETSC_TRUE;
3294: return(0);
3295: }
3297: /*@
3298: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3300: Collective on SNES
3302: Input Parameter:
3303: . snes - iterative context obtained from SNESCreate()
3305: Level: intermediate
3307: Notes:
3308: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3310: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3311: @*/
3312: PetscErrorCode SNESReset(SNES snes)
3313: {
3318: if (snes->ops->userdestroy && snes->user) {
3319: (*snes->ops->userdestroy)((void**)&snes->user);
3320: snes->user = NULL;
3321: }
3322: if (snes->npc) {
3323: SNESReset(snes->npc);
3324: }
3326: if (snes->ops->reset) {
3327: (*snes->ops->reset)(snes);
3328: }
3329: if (snes->ksp) {
3330: KSPReset(snes->ksp);
3331: }
3333: if (snes->linesearch) {
3334: SNESLineSearchReset(snes->linesearch);
3335: }
3337: VecDestroy(&snes->vec_rhs);
3338: VecDestroy(&snes->vec_sol);
3339: VecDestroy(&snes->vec_sol_update);
3340: VecDestroy(&snes->vec_func);
3341: MatDestroy(&snes->jacobian);
3342: MatDestroy(&snes->jacobian_pre);
3343: MatDestroy(&snes->picard);
3344: VecDestroyVecs(snes->nwork,&snes->work);
3345: VecDestroyVecs(snes->nvwork,&snes->vwork);
3347: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3349: snes->nwork = snes->nvwork = 0;
3350: snes->setupcalled = PETSC_FALSE;
3351: return(0);
3352: }
3354: /*@
3355: SNESConvergedReasonViewCancel - Clears all the reasonview functions for a SNES object.
3357: Collective on SNES
3359: Input Parameter:
3360: . snes - iterative context obtained from SNESCreate()
3362: Level: intermediate
3364: .seealso: SNESCreate(), SNESDestroy(), SNESReset()
3365: @*/
3366: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3367: {
3369: PetscInt i;
3373: for (i=0; i<snes->numberreasonviews; i++) {
3374: if (snes->reasonviewdestroy[i]) {
3375: (*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]);
3376: }
3377: }
3378: snes->numberreasonviews = 0;
3379: return(0);
3380: }
3382: /*@C
3383: SNESDestroy - Destroys the nonlinear solver context that was created
3384: with SNESCreate().
3386: Collective on SNES
3388: Input Parameter:
3389: . snes - the SNES context
3391: Level: beginner
3393: .seealso: SNESCreate(), SNESSolve()
3394: @*/
3395: PetscErrorCode SNESDestroy(SNES *snes)
3396: {
3400: if (!*snes) return(0);
3402: if (--((PetscObject)(*snes))->refct > 0) {*snes = NULL; return(0);}
3404: SNESReset((*snes));
3405: SNESDestroy(&(*snes)->npc);
3407: /* if memory was published with SAWs then destroy it */
3408: PetscObjectSAWsViewOff((PetscObject)*snes);
3409: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3411: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3412: DMDestroy(&(*snes)->dm);
3413: KSPDestroy(&(*snes)->ksp);
3414: SNESLineSearchDestroy(&(*snes)->linesearch);
3416: PetscFree((*snes)->kspconvctx);
3417: if ((*snes)->ops->convergeddestroy) {
3418: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3419: }
3420: if ((*snes)->conv_hist_alloc) {
3421: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3422: }
3423: SNESMonitorCancel((*snes));
3424: SNESConvergedReasonViewCancel((*snes));
3425: PetscHeaderDestroy(snes);
3426: return(0);
3427: }
3429: /* ----------- Routines to set solver parameters ---------- */
3431: /*@
3432: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3434: Logically Collective on SNES
3436: Input Parameters:
3437: + snes - the SNES context
3438: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3439: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3441: Options Database Keys:
3442: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3443: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3444: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3445: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3447: Notes:
3448: The default is 1
3449: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or SNESSetLagPreconditionerPersists() was called
3451: SNESSetLagPreconditionerPersists() allows using the same uniform lagging (for example every second solve) across multiple solves.
3453: Level: intermediate
3455: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetLagPreconditionerPersists(),
3456: SNESSetLagJacobianPersists()
3458: @*/
3459: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3460: {
3463: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3464: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3466: snes->lagpreconditioner = lag;
3467: return(0);
3468: }
3470: /*@
3471: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3473: Logically Collective on SNES
3475: Input Parameters:
3476: + snes - the SNES context
3477: - steps - the number of refinements to do, defaults to 0
3479: Options Database Keys:
3480: . -snes_grid_sequence <steps>
3482: Level: intermediate
3484: Notes:
3485: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3487: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3489: @*/
3490: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3491: {
3495: snes->gridsequence = steps;
3496: return(0);
3497: }
3499: /*@
3500: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3502: Logically Collective on SNES
3504: Input Parameter:
3505: . snes - the SNES context
3507: Output Parameter:
3508: . steps - the number of refinements to do, defaults to 0
3510: Options Database Keys:
3511: . -snes_grid_sequence <steps>
3513: Level: intermediate
3515: Notes:
3516: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3518: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3520: @*/
3521: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3522: {
3525: *steps = snes->gridsequence;
3526: return(0);
3527: }
3529: /*@
3530: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3532: Not Collective
3534: Input Parameter:
3535: . snes - the SNES context
3537: Output Parameter:
3538: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3539: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3541: Options Database Keys:
3542: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3543: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3544: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3545: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3547: Notes:
3548: The default is 1
3549: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3551: Level: intermediate
3553: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
3555: @*/
3556: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3557: {
3560: *lag = snes->lagpreconditioner;
3561: return(0);
3562: }
3564: /*@
3565: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3566: often the preconditioner is rebuilt.
3568: Logically Collective on SNES
3570: Input Parameters:
3571: + snes - the SNES context
3572: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3573: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3575: Options Database Keys:
3576: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3577: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3578: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3579: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3581: Notes:
3582: The default is 1
3583: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3584: 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
3585: at the next Newton step but never again (unless it is reset to another value)
3587: Level: intermediate
3589: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
3591: @*/
3592: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3593: {
3596: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3597: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3599: snes->lagjacobian = lag;
3600: return(0);
3601: }
3603: /*@
3604: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3606: Not Collective
3608: Input Parameter:
3609: . snes - the SNES context
3611: Output Parameter:
3612: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3613: the Jacobian is built etc.
3615: Notes:
3616: The default is 1
3617: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or SNESSetLagJacobianPersists() was called.
3619: Level: intermediate
3621: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
3623: @*/
3624: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3625: {
3628: *lag = snes->lagjacobian;
3629: return(0);
3630: }
3632: /*@
3633: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3635: Logically collective on SNES
3637: Input Parameters:
3638: + snes - the SNES context
3639: - flg - jacobian lagging persists if true
3641: Options Database Keys:
3642: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3643: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3644: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3645: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3647: Notes:
3648: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3649: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3650: timesteps may present huge efficiency gains.
3652: Level: developer
3654: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC(), SNESSetLagJacobianPersists()
3656: @*/
3657: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3658: {
3662: snes->lagjac_persist = flg;
3663: return(0);
3664: }
3666: /*@
3667: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3669: Logically Collective on SNES
3671: Input Parameters:
3672: + snes - the SNES context
3673: - flg - preconditioner lagging persists if true
3675: Options Database Keys:
3676: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3677: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3678: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3679: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3681: Notes:
3682: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3683: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3684: several timesteps may present huge efficiency gains.
3686: Level: developer
3688: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC(), SNESSetLagPreconditioner()
3690: @*/
3691: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3692: {
3696: snes->lagpre_persist = flg;
3697: return(0);
3698: }
3700: /*@
3701: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3703: Logically Collective on SNES
3705: Input Parameters:
3706: + snes - the SNES context
3707: - force - PETSC_TRUE require at least one iteration
3709: Options Database Keys:
3710: . -snes_force_iteration <force> - Sets forcing an iteration
3712: Notes:
3713: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3715: Level: intermediate
3717: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3718: @*/
3719: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3720: {
3723: snes->forceiteration = force;
3724: return(0);
3725: }
3727: /*@
3728: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3730: Logically Collective on SNES
3732: Input Parameters:
3733: . snes - the SNES context
3735: Output Parameter:
3736: . force - PETSC_TRUE requires at least one iteration.
3738: Level: intermediate
3740: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3741: @*/
3742: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3743: {
3746: *force = snes->forceiteration;
3747: return(0);
3748: }
3750: /*@
3751: SNESSetTolerances - Sets various parameters used in convergence tests.
3753: Logically Collective on SNES
3755: Input Parameters:
3756: + snes - the SNES context
3757: . abstol - absolute convergence tolerance
3758: . rtol - relative convergence tolerance
3759: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3760: . maxit - maximum number of iterations
3761: - maxf - maximum number of function evaluations (-1 indicates no limit)
3763: Options Database Keys:
3764: + -snes_atol <abstol> - Sets abstol
3765: . -snes_rtol <rtol> - Sets rtol
3766: . -snes_stol <stol> - Sets stol
3767: . -snes_max_it <maxit> - Sets maxit
3768: - -snes_max_funcs <maxf> - Sets maxf
3770: Notes:
3771: The default maximum number of iterations is 50.
3772: The default maximum number of function evaluations is 1000.
3774: Level: intermediate
3776: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3777: @*/
3778: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3779: {
3788: if (abstol != PETSC_DEFAULT) {
3789: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3790: snes->abstol = abstol;
3791: }
3792: if (rtol != PETSC_DEFAULT) {
3793: 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);
3794: snes->rtol = rtol;
3795: }
3796: if (stol != PETSC_DEFAULT) {
3797: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3798: snes->stol = stol;
3799: }
3800: if (maxit != PETSC_DEFAULT) {
3801: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3802: snes->max_its = maxit;
3803: }
3804: if (maxf != PETSC_DEFAULT) {
3805: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3806: snes->max_funcs = maxf;
3807: }
3808: snes->tolerancesset = PETSC_TRUE;
3809: return(0);
3810: }
3812: /*@
3813: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3815: Logically Collective on SNES
3817: Input Parameters:
3818: + snes - the SNES context
3819: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3821: Options Database Keys:
3822: . -snes_divergence_tolerance <divtol> - Sets divtol
3824: Notes:
3825: The default divergence tolerance is 1e4.
3827: Level: intermediate
3829: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3830: @*/
3831: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3832: {
3837: if (divtol != PETSC_DEFAULT) {
3838: snes->divtol = divtol;
3839: }
3840: else {
3841: snes->divtol = 1.0e4;
3842: }
3843: return(0);
3844: }
3846: /*@
3847: SNESGetTolerances - Gets various parameters used in convergence tests.
3849: Not Collective
3851: Input Parameters:
3852: + snes - the SNES context
3853: . atol - absolute convergence tolerance
3854: . rtol - relative convergence tolerance
3855: . stol - convergence tolerance in terms of the norm
3856: of the change in the solution between steps
3857: . maxit - maximum number of iterations
3858: - maxf - maximum number of function evaluations
3860: Notes:
3861: The user can specify NULL for any parameter that is not needed.
3863: Level: intermediate
3865: .seealso: SNESSetTolerances()
3866: @*/
3867: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3868: {
3871: if (atol) *atol = snes->abstol;
3872: if (rtol) *rtol = snes->rtol;
3873: if (stol) *stol = snes->stol;
3874: if (maxit) *maxit = snes->max_its;
3875: if (maxf) *maxf = snes->max_funcs;
3876: return(0);
3877: }
3879: /*@
3880: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3882: Not Collective
3884: Input Parameters:
3885: + snes - the SNES context
3886: - divtol - divergence tolerance
3888: Level: intermediate
3890: .seealso: SNESSetDivergenceTolerance()
3891: @*/
3892: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3893: {
3896: if (divtol) *divtol = snes->divtol;
3897: return(0);
3898: }
3900: /*@
3901: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3903: Logically Collective on SNES
3905: Input Parameters:
3906: + snes - the SNES context
3907: - tol - tolerance
3909: Options Database Key:
3910: . -snes_trtol <tol> - Sets tol
3912: Level: intermediate
3914: .seealso: SNESSetTolerances()
3915: @*/
3916: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3917: {
3921: snes->deltatol = tol;
3922: return(0);
3923: }
3925: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3927: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3928: {
3929: PetscDrawLG lg;
3930: PetscErrorCode ierr;
3931: PetscReal x,y,per;
3932: PetscViewer v = (PetscViewer)monctx;
3933: static PetscReal prev; /* should be in the context */
3934: PetscDraw draw;
3938: PetscViewerDrawGetDrawLG(v,0,&lg);
3939: if (!n) {PetscDrawLGReset(lg);}
3940: PetscDrawLGGetDraw(lg,&draw);
3941: PetscDrawSetTitle(draw,"Residual norm");
3942: x = (PetscReal)n;
3943: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3944: else y = -15.0;
3945: PetscDrawLGAddPoint(lg,&x,&y);
3946: if (n < 20 || !(n % 5) || snes->reason) {
3947: PetscDrawLGDraw(lg);
3948: PetscDrawLGSave(lg);
3949: }
3951: PetscViewerDrawGetDrawLG(v,1,&lg);
3952: if (!n) {PetscDrawLGReset(lg);}
3953: PetscDrawLGGetDraw(lg,&draw);
3954: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3955: SNESMonitorRange_Private(snes,n,&per);
3956: x = (PetscReal)n;
3957: y = 100.0*per;
3958: PetscDrawLGAddPoint(lg,&x,&y);
3959: if (n < 20 || !(n % 5) || snes->reason) {
3960: PetscDrawLGDraw(lg);
3961: PetscDrawLGSave(lg);
3962: }
3964: PetscViewerDrawGetDrawLG(v,2,&lg);
3965: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3966: PetscDrawLGGetDraw(lg,&draw);
3967: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3968: x = (PetscReal)n;
3969: y = (prev - rnorm)/prev;
3970: PetscDrawLGAddPoint(lg,&x,&y);
3971: if (n < 20 || !(n % 5) || snes->reason) {
3972: PetscDrawLGDraw(lg);
3973: PetscDrawLGSave(lg);
3974: }
3976: PetscViewerDrawGetDrawLG(v,3,&lg);
3977: if (!n) {PetscDrawLGReset(lg);}
3978: PetscDrawLGGetDraw(lg,&draw);
3979: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3980: x = (PetscReal)n;
3981: y = (prev - rnorm)/(prev*per);
3982: if (n > 2) { /*skip initial crazy value */
3983: PetscDrawLGAddPoint(lg,&x,&y);
3984: }
3985: if (n < 20 || !(n % 5) || snes->reason) {
3986: PetscDrawLGDraw(lg);
3987: PetscDrawLGSave(lg);
3988: }
3989: prev = rnorm;
3990: return(0);
3991: }
3993: /*@
3994: SNESMonitor - runs the user provided monitor routines, if they exist
3996: Collective on SNES
3998: Input Parameters:
3999: + snes - nonlinear solver context obtained from SNESCreate()
4000: . iter - iteration number
4001: - rnorm - relative norm of the residual
4003: Notes:
4004: This routine is called by the SNES implementations.
4005: It does not typically need to be called by the user.
4007: Level: developer
4009: .seealso: SNESMonitorSet()
4010: @*/
4011: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
4012: {
4014: PetscInt i,n = snes->numbermonitors;
4017: VecLockReadPush(snes->vec_sol);
4018: for (i=0; i<n; i++) {
4019: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
4020: }
4021: VecLockReadPop(snes->vec_sol);
4022: return(0);
4023: }
4025: /* ------------ Routines to set performance monitoring options ----------- */
4027: /*MC
4028: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
4030: Synopsis:
4031: #include <petscsnes.h>
4032: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
4034: Collective on snes
4036: Input Parameters:
4037: + snes - the SNES context
4038: . its - iteration number
4039: . norm - 2-norm function value (may be estimated)
4040: - mctx - [optional] monitoring context
4042: Level: advanced
4044: .seealso: SNESMonitorSet(), SNESMonitorGet()
4045: M*/
4047: /*@C
4048: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4049: iteration of the nonlinear solver to display the iteration's
4050: progress.
4052: Logically Collective on SNES
4054: Input Parameters:
4055: + snes - the SNES context
4056: . f - the monitor function, see SNESMonitorFunction for the calling sequence
4057: . mctx - [optional] user-defined context for private data for the
4058: monitor routine (use NULL if no context is desired)
4059: - monitordestroy - [optional] routine that frees monitor context
4060: (may be NULL)
4062: Options Database Keys:
4063: + -snes_monitor - sets SNESMonitorDefault()
4064: . -snes_monitor draw::draw_lg - sets line graph monitor,
4065: - -snes_monitor_cancel - cancels all monitors that have
4066: been hardwired into a code by
4067: calls to SNESMonitorSet(), but
4068: does not cancel those set via
4069: the options database.
4071: Notes:
4072: Several different monitoring routines may be set by calling
4073: SNESMonitorSet() multiple times; all will be called in the
4074: order in which they were set.
4076: Fortran Notes:
4077: Only a single monitor function can be set for each SNES object
4079: Level: intermediate
4081: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
4082: @*/
4083: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
4084: {
4085: PetscInt i;
4087: PetscBool identical;
4091: for (i=0; i<snes->numbermonitors;i++) {
4092: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
4093: if (identical) return(0);
4094: }
4095: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
4096: snes->monitor[snes->numbermonitors] = f;
4097: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4098: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
4099: return(0);
4100: }
4102: /*@
4103: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
4105: Logically Collective on SNES
4107: Input Parameters:
4108: . snes - the SNES context
4110: Options Database Key:
4111: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4112: into a code by calls to SNESMonitorSet(), but does not cancel those
4113: set via the options database
4115: Notes:
4116: There is no way to clear one specific monitor from a SNES object.
4118: Level: intermediate
4120: .seealso: SNESMonitorDefault(), SNESMonitorSet()
4121: @*/
4122: PetscErrorCode SNESMonitorCancel(SNES snes)
4123: {
4125: PetscInt i;
4129: for (i=0; i<snes->numbermonitors; i++) {
4130: if (snes->monitordestroy[i]) {
4131: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
4132: }
4133: }
4134: snes->numbermonitors = 0;
4135: return(0);
4136: }
4138: /*MC
4139: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4141: Synopsis:
4142: #include <petscsnes.h>
4143: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
4145: Collective on snes
4147: Input Parameters:
4148: + snes - the SNES context
4149: . it - current iteration (0 is the first and is before any Newton step)
4150: . xnorm - 2-norm of current iterate
4151: . gnorm - 2-norm of current step
4152: . f - 2-norm of function
4153: - cctx - [optional] convergence context
4155: Output Parameter:
4156: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4158: Level: intermediate
4160: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
4161: M*/
4163: /*@C
4164: SNESSetConvergenceTest - Sets the function that is to be used
4165: to test for convergence of the nonlinear iterative solution.
4167: Logically Collective on SNES
4169: Input Parameters:
4170: + snes - the SNES context
4171: . SNESConvergenceTestFunction - routine to test for convergence
4172: . cctx - [optional] context for private data for the convergence routine (may be NULL)
4173: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
4175: Level: advanced
4177: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
4178: @*/
4179: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
4180: {
4185: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4186: if (snes->ops->convergeddestroy) {
4187: (*snes->ops->convergeddestroy)(snes->cnvP);
4188: }
4189: snes->ops->converged = SNESConvergenceTestFunction;
4190: snes->ops->convergeddestroy = destroy;
4191: snes->cnvP = cctx;
4192: return(0);
4193: }
4195: /*@
4196: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4198: Not Collective
4200: Input Parameter:
4201: . snes - the SNES context
4203: Output Parameter:
4204: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4205: manual pages for the individual convergence tests for complete lists
4207: Options Database:
4208: . -snes_converged_reason - prints the reason to standard out
4210: Level: intermediate
4212: Notes:
4213: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4215: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4216: @*/
4217: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4218: {
4222: *reason = snes->reason;
4223: return(0);
4224: }
4226: /*@C
4227: SNESGetConvergedReasonString - Return a human readable string for snes converged reason
4229: Not Collective
4231: Input Parameter:
4232: . snes - the SNES context
4234: Output Parameter:
4235: . strreason - a human readable string that describes SNES converged reason
4237: Level: beginner
4239: .seealso: SNESGetConvergedReason()
4240: @*/
4241: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char** strreason)
4242: {
4246: *strreason = SNESConvergedReasons[snes->reason];
4247: return(0);
4248: }
4250: /*@
4251: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4253: Not Collective
4255: Input Parameters:
4256: + snes - the SNES context
4257: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4258: manual pages for the individual convergence tests for complete lists
4260: Level: intermediate
4262: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4263: @*/
4264: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4265: {
4268: snes->reason = reason;
4269: return(0);
4270: }
4272: /*@
4273: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4275: Logically Collective on SNES
4277: Input Parameters:
4278: + snes - iterative context obtained from SNESCreate()
4279: . a - array to hold history, this array will contain the function norms computed at each step
4280: . its - integer array holds the number of linear iterations for each solve.
4281: . na - size of a and its
4282: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4283: else it continues storing new values for new nonlinear solves after the old ones
4285: Notes:
4286: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4287: default array of length 10000 is allocated.
4289: This routine is useful, e.g., when running a code for purposes
4290: of accurate performance monitoring, when no I/O should be done
4291: during the section of code that is being timed.
4293: Level: intermediate
4295: .seealso: SNESGetConvergenceHistory()
4297: @*/
4298: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4299: {
4306: if (!a) {
4307: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4308: PetscCalloc2(na,&a,na,&its);
4309: snes->conv_hist_alloc = PETSC_TRUE;
4310: }
4311: snes->conv_hist = a;
4312: snes->conv_hist_its = its;
4313: snes->conv_hist_max = na;
4314: snes->conv_hist_len = 0;
4315: snes->conv_hist_reset = reset;
4316: return(0);
4317: }
4319: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4320: #include <engine.h> /* MATLAB include file */
4321: #include <mex.h> /* MATLAB include file */
4323: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4324: {
4325: mxArray *mat;
4326: PetscInt i;
4327: PetscReal *ar;
4330: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4331: ar = (PetscReal*) mxGetData(mat);
4332: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4333: PetscFunctionReturn(mat);
4334: }
4335: #endif
4337: /*@C
4338: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4340: Not Collective
4342: Input Parameter:
4343: . snes - iterative context obtained from SNESCreate()
4345: Output Parameters:
4346: + a - array to hold history
4347: . its - integer array holds the number of linear iterations (or
4348: negative if not converged) for each solve.
4349: - na - size of a and its
4351: Notes:
4352: The calling sequence for this routine in Fortran is
4353: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4355: This routine is useful, e.g., when running a code for purposes
4356: of accurate performance monitoring, when no I/O should be done
4357: during the section of code that is being timed.
4359: Level: intermediate
4361: .seealso: SNESSetConvergenceHistory()
4363: @*/
4364: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4365: {
4368: if (a) *a = snes->conv_hist;
4369: if (its) *its = snes->conv_hist_its;
4370: if (na) *na = snes->conv_hist_len;
4371: return(0);
4372: }
4374: /*@C
4375: SNESSetUpdate - Sets the general-purpose update function called
4376: at the beginning of every iteration of the nonlinear solve. Specifically
4377: it is called just before the Jacobian is "evaluated".
4379: Logically Collective on SNES
4381: Input Parameters:
4382: + snes - The nonlinear solver context
4383: - func - The function
4385: Calling sequence of func:
4386: $ func (SNES snes, PetscInt step);
4388: . step - The current step of the iteration
4390: Level: advanced
4392: Note:
4393: 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()
4394: This is not used by most users.
4396: There are a varity of function hooks one many set that are called at different stages of the nonlinear solution process, see the functions listed below.
4398: .seealso SNESSetJacobian(), SNESSolve(), SNESLineSearchSetPreCheck(), SNESLineSearchSetPostCheck(), SNESNewtonTRSetPreCheck(), SNESNewtonTRSetPostCheck(),
4399: SNESMonitorSet(), SNESSetDivergenceTest()
4400: @*/
4401: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4402: {
4405: snes->ops->update = func;
4406: return(0);
4407: }
4409: /*
4410: SNESScaleStep_Private - Scales a step so that its length is less than the
4411: positive parameter delta.
4413: Input Parameters:
4414: + snes - the SNES context
4415: . y - approximate solution of linear system
4416: . fnorm - 2-norm of current function
4417: - delta - trust region size
4419: Output Parameters:
4420: + gpnorm - predicted function norm at the new point, assuming local
4421: linearization. The value is zero if the step lies within the trust
4422: region, and exceeds zero otherwise.
4423: - ynorm - 2-norm of the step
4425: Note:
4426: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4427: is set to be the maximum allowable step size.
4429: */
4430: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4431: {
4432: PetscReal nrm;
4433: PetscScalar cnorm;
4441: VecNorm(y,NORM_2,&nrm);
4442: if (nrm > *delta) {
4443: nrm = *delta/nrm;
4444: *gpnorm = (1.0 - nrm)*(*fnorm);
4445: cnorm = nrm;
4446: VecScale(y,cnorm);
4447: *ynorm = *delta;
4448: } else {
4449: *gpnorm = 0.0;
4450: *ynorm = nrm;
4451: }
4452: return(0);
4453: }
4455: /*@C
4456: SNESConvergedReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4458: Collective on SNES
4460: Parameter:
4461: + snes - iterative context obtained from SNESCreate()
4462: - viewer - the viewer to display the reason
4464: Options Database Keys:
4465: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4466: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4468: Notes:
4469: To change the format of the output call PetscViewerPushFormat(viewer,format) before this call. Use PETSC_VIEWER_DEFAULT for the default,
4470: use PETSC_VIEWER_FAILED to only display a reason if it fails.
4472: Level: beginner
4474: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault(), SNESGetConvergedReason(), SNESConvergedReasonViewFromOptions(),
4475: PetscViewerPushFormat(), PetscViewerPopFormat()
4477: @*/
4478: PetscErrorCode SNESConvergedReasonView(SNES snes,PetscViewer viewer)
4479: {
4480: PetscViewerFormat format;
4481: PetscBool isAscii;
4482: PetscErrorCode ierr;
4485: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4486: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4487: if (isAscii) {
4488: PetscViewerGetFormat(viewer, &format);
4489: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4490: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4491: DM dm;
4492: Vec u;
4493: PetscDS prob;
4494: PetscInt Nf, f;
4495: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4496: void **exactCtx;
4497: PetscReal error;
4499: SNESGetDM(snes, &dm);
4500: SNESGetSolution(snes, &u);
4501: DMGetDS(dm, &prob);
4502: PetscDSGetNumFields(prob, &Nf);
4503: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4504: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4505: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4506: PetscFree2(exactSol, exactCtx);
4507: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4508: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4509: }
4510: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4511: if (((PetscObject) snes)->prefix) {
4512: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4513: } else {
4514: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4515: }
4516: } else if (snes->reason <= 0) {
4517: if (((PetscObject) snes)->prefix) {
4518: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4519: } else {
4520: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4521: }
4522: }
4523: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4524: }
4525: return(0);
4526: }
4528: /*@C
4529: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4530: end of the nonlinear solver to display the conver reason of the nonlinear solver.
4532: Logically Collective on SNES
4534: Input Parameters:
4535: + snes - the SNES context
4536: . f - the snes converged reason view function
4537: . vctx - [optional] user-defined context for private data for the
4538: snes converged reason view routine (use NULL if no context is desired)
4539: - reasonviewdestroy - [optional] routine that frees reasonview context
4540: (may be NULL)
4542: Options Database Keys:
4543: + -snes_converged_reason - sets a default SNESConvergedReasonView()
4544: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have
4545: been hardwired into a code by
4546: calls to SNESConvergedReasonViewSet(), but
4547: does not cancel those set via
4548: the options database.
4550: Notes:
4551: Several different converged reason view routines may be set by calling
4552: SNESConvergedReasonViewSet() multiple times; all will be called in the
4553: order in which they were set.
4555: Level: intermediate
4557: .seealso: SNESConvergedReasonView(), SNESConvergedReasonViewCancel()
4558: @*/
4559: PetscErrorCode SNESConvergedReasonViewSet(SNES snes,PetscErrorCode (*f)(SNES,void*),void *vctx,PetscErrorCode (*reasonviewdestroy)(void**))
4560: {
4561: PetscInt i;
4563: PetscBool identical;
4567: for (i=0; i<snes->numberreasonviews;i++) {
4568: PetscMonitorCompare((PetscErrorCode (*)(void))f,vctx,reasonviewdestroy,(PetscErrorCode (*)(void))snes->reasonview[i],snes->reasonviewcontext[i],snes->reasonviewdestroy[i],&identical);
4569: if (identical) return(0);
4570: }
4571: if (snes->numberreasonviews >= MAXSNESREASONVIEWS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many SNES reasonview set");
4572: snes->reasonview[snes->numberreasonviews] = f;
4573: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4574: snes->reasonviewcontext[snes->numberreasonviews++] = (void*)vctx;
4575: return(0);
4576: }
4578: /*@
4579: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4580: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4582: Collective on SNES
4584: Input Parameters:
4585: . snes - the SNES object
4587: Level: intermediate
4589: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault(), SNESGetConvergedReason(), SNESConvergedReasonView()
4591: @*/
4592: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4593: {
4594: PetscErrorCode ierr;
4595: PetscViewer viewer;
4596: PetscBool flg;
4597: static PetscBool incall = PETSC_FALSE;
4598: PetscViewerFormat format;
4599: PetscInt i;
4602: if (incall) return(0);
4603: incall = PETSC_TRUE;
4605: /* All user-provided viewers are called first, if they exist. */
4606: for (i=0; i<snes->numberreasonviews; i++) {
4607: (*snes->reasonview[i])(snes,snes->reasonviewcontext[i]);
4608: }
4610: /* Call PETSc default routine if users ask for it */
4611: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4612: if (flg) {
4613: PetscViewerPushFormat(viewer,format);
4614: SNESConvergedReasonView(snes,viewer);
4615: PetscViewerPopFormat(viewer);
4616: PetscViewerDestroy(&viewer);
4617: }
4618: incall = PETSC_FALSE;
4619: return(0);
4620: }
4622: /*@
4623: SNESSolve - Solves a nonlinear system F(x) = b.
4624: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4626: Collective on SNES
4628: Input Parameters:
4629: + snes - the SNES context
4630: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4631: - x - the solution vector.
4633: Notes:
4634: The user should initialize the vector,x, with the initial guess
4635: for the nonlinear solve prior to calling SNESSolve(). In particular,
4636: to employ an initial guess of zero, the user should explicitly set
4637: this vector to zero by calling VecSet().
4639: Level: beginner
4641: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution(),
4642: SNESNewtonTRSetPreCheck(), SNESNewtonTRGetPreCheck(), SNESNewtonTRSetPostCheck(), SNESNewtonTRGetPostCheck(),
4643: SNESLineSearchSetPostCheck(), SNESLineSearchGetPostCheck(), SNESLineSearchSetPreCheck(), SNESLineSearchGetPreCheck()
4644: @*/
4645: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4646: {
4647: PetscErrorCode ierr;
4648: PetscBool flg;
4649: PetscInt grid;
4650: Vec xcreated = NULL;
4651: DM dm;
4660: /* High level operations using the nonlinear solver */
4661: {
4662: PetscViewer viewer;
4663: PetscViewerFormat format;
4664: PetscInt num;
4665: PetscBool flg;
4666: static PetscBool incall = PETSC_FALSE;
4668: if (!incall) {
4669: /* Estimate the convergence rate of the discretization */
4670: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4671: if (flg) {
4672: PetscConvEst conv;
4673: DM dm;
4674: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4675: PetscInt Nf;
4677: incall = PETSC_TRUE;
4678: SNESGetDM(snes, &dm);
4679: DMGetNumFields(dm, &Nf);
4680: PetscCalloc1(Nf, &alpha);
4681: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4682: PetscConvEstSetSolver(conv, (PetscObject) snes);
4683: PetscConvEstSetFromOptions(conv);
4684: PetscConvEstSetUp(conv);
4685: PetscConvEstGetConvRate(conv, alpha);
4686: PetscViewerPushFormat(viewer, format);
4687: PetscConvEstRateView(conv, alpha, viewer);
4688: PetscViewerPopFormat(viewer);
4689: PetscViewerDestroy(&viewer);
4690: PetscConvEstDestroy(&conv);
4691: PetscFree(alpha);
4692: incall = PETSC_FALSE;
4693: }
4694: /* Adaptively refine the initial grid */
4695: num = 1;
4696: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4697: if (flg) {
4698: DMAdaptor adaptor;
4700: incall = PETSC_TRUE;
4701: DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor);
4702: DMAdaptorSetSolver(adaptor, snes);
4703: DMAdaptorSetSequenceLength(adaptor, num);
4704: DMAdaptorSetFromOptions(adaptor);
4705: DMAdaptorSetUp(adaptor);
4706: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4707: DMAdaptorDestroy(&adaptor);
4708: incall = PETSC_FALSE;
4709: }
4710: /* Use grid sequencing to adapt */
4711: num = 0;
4712: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4713: if (num) {
4714: DMAdaptor adaptor;
4716: incall = PETSC_TRUE;
4717: DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor);
4718: DMAdaptorSetSolver(adaptor, snes);
4719: DMAdaptorSetSequenceLength(adaptor, num);
4720: DMAdaptorSetFromOptions(adaptor);
4721: DMAdaptorSetUp(adaptor);
4722: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4723: DMAdaptorDestroy(&adaptor);
4724: incall = PETSC_FALSE;
4725: }
4726: }
4727: }
4728: if (!x) {
4729: SNESGetDM(snes,&dm);
4730: DMCreateGlobalVector(dm,&xcreated);
4731: x = xcreated;
4732: }
4733: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4735: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4736: for (grid=0; grid<snes->gridsequence+1; grid++) {
4738: /* set solution vector */
4739: if (!grid) {PetscObjectReference((PetscObject)x);}
4740: VecDestroy(&snes->vec_sol);
4741: snes->vec_sol = x;
4742: SNESGetDM(snes,&dm);
4744: /* set affine vector if provided */
4745: if (b) { PetscObjectReference((PetscObject)b); }
4746: VecDestroy(&snes->vec_rhs);
4747: snes->vec_rhs = b;
4749: 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");
4750: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4751: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4752: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4753: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4754: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4755: }
4756: DMShellSetGlobalVector(dm,snes->vec_sol);
4757: SNESSetUp(snes);
4759: if (!grid) {
4760: if (snes->ops->computeinitialguess) {
4761: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4762: }
4763: }
4765: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4766: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4768: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4769: (*snes->ops->solve)(snes);
4770: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4771: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4772: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4774: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4775: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4777: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4778: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4779: /* Call converged reason views. This may involve user-provided viewers as well */
4780: SNESConvergedReasonViewFromOptions(snes);
4782: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4783: if (snes->reason < 0) break;
4784: if (grid < snes->gridsequence) {
4785: DM fine;
4786: Vec xnew;
4787: Mat interp;
4789: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4790: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4791: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4792: DMCreateGlobalVector(fine,&xnew);
4793: MatInterpolate(interp,x,xnew);
4794: DMInterpolate(snes->dm,interp,fine);
4795: MatDestroy(&interp);
4796: x = xnew;
4798: SNESReset(snes);
4799: SNESSetDM(snes,fine);
4800: SNESResetFromOptions(snes);
4801: DMDestroy(&fine);
4802: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4803: }
4804: }
4805: SNESViewFromOptions(snes,NULL,"-snes_view");
4806: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4807: DMMonitor(snes->dm);
4809: VecDestroy(&xcreated);
4810: PetscObjectSAWsBlock((PetscObject)snes);
4811: return(0);
4812: }
4814: /* --------- Internal routines for SNES Package --------- */
4816: /*@C
4817: SNESSetType - Sets the method for the nonlinear solver.
4819: Collective on SNES
4821: Input Parameters:
4822: + snes - the SNES context
4823: - type - a known method
4825: Options Database Key:
4826: . -snes_type <type> - Sets the method; use -help for a list
4827: of available methods (for instance, newtonls or newtontr)
4829: Notes:
4830: See "petsc/include/petscsnes.h" for available methods (for instance)
4831: + SNESNEWTONLS - Newton's method with line search
4832: (systems of nonlinear equations)
4833: - SNESNEWTONTR - Newton's method with trust region
4834: (systems of nonlinear equations)
4836: Normally, it is best to use the SNESSetFromOptions() command and then
4837: set the SNES solver type from the options database rather than by using
4838: this routine. Using the options database provides the user with
4839: maximum flexibility in evaluating the many nonlinear solvers.
4840: The SNESSetType() routine is provided for those situations where it
4841: is necessary to set the nonlinear solver independently of the command
4842: line or options database. This might be the case, for example, when
4843: the choice of solver changes during the execution of the program,
4844: and the user's application is taking responsibility for choosing the
4845: appropriate method.
4847: Developer Notes:
4848: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4849: the constructor in that list and calls it to create the spexific object.
4851: Level: intermediate
4853: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4855: @*/
4856: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4857: {
4858: PetscErrorCode ierr,(*r)(SNES);
4859: PetscBool match;
4865: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4866: if (match) return(0);
4868: PetscFunctionListFind(SNESList,type,&r);
4869: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4870: /* Destroy the previous private SNES context */
4871: if (snes->ops->destroy) {
4872: (*(snes)->ops->destroy)(snes);
4873: snes->ops->destroy = NULL;
4874: }
4875: /* Reinitialize function pointers in SNESOps structure */
4876: snes->ops->setup = NULL;
4877: snes->ops->solve = NULL;
4878: snes->ops->view = NULL;
4879: snes->ops->setfromoptions = NULL;
4880: snes->ops->destroy = NULL;
4882: /* It may happen the user has customized the line search before calling SNESSetType */
4883: if (((PetscObject)snes)->type_name) {
4884: SNESLineSearchDestroy(&snes->linesearch);
4885: }
4887: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4888: snes->setupcalled = PETSC_FALSE;
4890: PetscObjectChangeTypeName((PetscObject)snes,type);
4891: (*r)(snes);
4892: return(0);
4893: }
4895: /*@C
4896: SNESGetType - Gets the SNES method type and name (as a string).
4898: Not Collective
4900: Input Parameter:
4901: . snes - nonlinear solver context
4903: Output Parameter:
4904: . type - SNES method (a character string)
4906: Level: intermediate
4908: @*/
4909: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4910: {
4914: *type = ((PetscObject)snes)->type_name;
4915: return(0);
4916: }
4918: /*@
4919: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4921: Logically Collective on SNES
4923: Input Parameters:
4924: + snes - the SNES context obtained from SNESCreate()
4925: - u - the solution vector
4927: Level: beginner
4929: @*/
4930: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4931: {
4932: DM dm;
4938: PetscObjectReference((PetscObject) u);
4939: VecDestroy(&snes->vec_sol);
4941: snes->vec_sol = u;
4943: SNESGetDM(snes, &dm);
4944: DMShellSetGlobalVector(dm, u);
4945: return(0);
4946: }
4948: /*@
4949: SNESGetSolution - Returns the vector where the approximate solution is
4950: stored. This is the fine grid solution when using SNESSetGridSequence().
4952: Not Collective, but Vec is parallel if SNES is parallel
4954: Input Parameter:
4955: . snes - the SNES context
4957: Output Parameter:
4958: . x - the solution
4960: Level: intermediate
4962: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4963: @*/
4964: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4965: {
4969: *x = snes->vec_sol;
4970: return(0);
4971: }
4973: /*@
4974: SNESGetSolutionUpdate - Returns the vector where the solution update is
4975: stored.
4977: Not Collective, but Vec is parallel if SNES is parallel
4979: Input Parameter:
4980: . snes - the SNES context
4982: Output Parameter:
4983: . x - the solution update
4985: Level: advanced
4987: .seealso: SNESGetSolution(), SNESGetFunction()
4988: @*/
4989: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4990: {
4994: *x = snes->vec_sol_update;
4995: return(0);
4996: }
4998: /*@C
4999: SNESGetFunction - Returns the vector where the function is stored.
5001: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
5003: Input Parameter:
5004: . snes - the SNES context
5006: Output Parameters:
5007: + r - the vector that is used to store residuals (or NULL if you don't want it)
5008: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
5009: - ctx - the function context (or NULL if you don't want it)
5011: Level: advanced
5013: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
5015: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
5016: @*/
5017: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
5018: {
5020: DM dm;
5024: if (r) {
5025: if (!snes->vec_func) {
5026: if (snes->vec_rhs) {
5027: VecDuplicate(snes->vec_rhs,&snes->vec_func);
5028: } else if (snes->vec_sol) {
5029: VecDuplicate(snes->vec_sol,&snes->vec_func);
5030: } else if (snes->dm) {
5031: DMCreateGlobalVector(snes->dm,&snes->vec_func);
5032: }
5033: }
5034: *r = snes->vec_func;
5035: }
5036: SNESGetDM(snes,&dm);
5037: DMSNESGetFunction(dm,f,ctx);
5038: return(0);
5039: }
5041: /*@C
5042: SNESGetNGS - Returns the NGS function and context.
5044: Input Parameter:
5045: . snes - the SNES context
5047: Output Parameters:
5048: + f - the function (or NULL) see SNESNGSFunction for details
5049: - ctx - the function context (or NULL)
5051: Level: advanced
5053: .seealso: SNESSetNGS(), SNESGetFunction()
5054: @*/
5056: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
5057: {
5059: DM dm;
5063: SNESGetDM(snes,&dm);
5064: DMSNESGetNGS(dm,f,ctx);
5065: return(0);
5066: }
5068: /*@C
5069: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5070: SNES options in the database.
5072: Logically Collective on SNES
5074: Input Parameters:
5075: + snes - the SNES context
5076: - prefix - the prefix to prepend to all option names
5078: Notes:
5079: A hyphen (-) must NOT be given at the beginning of the prefix name.
5080: The first character of all runtime options is AUTOMATICALLY the hyphen.
5082: Level: advanced
5084: .seealso: SNESSetFromOptions()
5085: @*/
5086: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
5087: {
5092: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
5093: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
5094: if (snes->linesearch) {
5095: SNESGetLineSearch(snes,&snes->linesearch);
5096: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
5097: }
5098: KSPSetOptionsPrefix(snes->ksp,prefix);
5099: return(0);
5100: }
5102: /*@C
5103: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5104: SNES options in the database.
5106: Logically Collective on SNES
5108: Input Parameters:
5109: + snes - the SNES context
5110: - prefix - the prefix to prepend to all option names
5112: Notes:
5113: A hyphen (-) must NOT be given at the beginning of the prefix name.
5114: The first character of all runtime options is AUTOMATICALLY the hyphen.
5116: Level: advanced
5118: .seealso: SNESGetOptionsPrefix()
5119: @*/
5120: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
5121: {
5126: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
5127: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
5128: if (snes->linesearch) {
5129: SNESGetLineSearch(snes,&snes->linesearch);
5130: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
5131: }
5132: KSPAppendOptionsPrefix(snes->ksp,prefix);
5133: return(0);
5134: }
5136: /*@C
5137: SNESGetOptionsPrefix - Sets the prefix used for searching for all
5138: SNES options in the database.
5140: Not Collective
5142: Input Parameter:
5143: . snes - the SNES context
5145: Output Parameter:
5146: . prefix - pointer to the prefix string used
5148: Notes:
5149: On the fortran side, the user should pass in a string 'prefix' of
5150: sufficient length to hold the prefix.
5152: Level: advanced
5154: .seealso: SNESAppendOptionsPrefix()
5155: @*/
5156: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
5157: {
5162: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
5163: return(0);
5164: }
5166: /*@C
5167: SNESRegister - Adds a method to the nonlinear solver package.
5169: Not collective
5171: Input Parameters:
5172: + name_solver - name of a new user-defined solver
5173: - routine_create - routine to create method context
5175: Notes:
5176: SNESRegister() may be called multiple times to add several user-defined solvers.
5178: Sample usage:
5179: .vb
5180: SNESRegister("my_solver",MySolverCreate);
5181: .ve
5183: Then, your solver can be chosen with the procedural interface via
5184: $ SNESSetType(snes,"my_solver")
5185: or at runtime via the option
5186: $ -snes_type my_solver
5188: Level: advanced
5190: Note: If your function is not being put into a shared library then use SNESRegister() instead
5192: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
5194: Level: advanced
5195: @*/
5196: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
5197: {
5201: SNESInitializePackage();
5202: PetscFunctionListAdd(&SNESList,sname,function);
5203: return(0);
5204: }
5206: PetscErrorCode SNESTestLocalMin(SNES snes)
5207: {
5209: PetscInt N,i,j;
5210: Vec u,uh,fh;
5211: PetscScalar value;
5212: PetscReal norm;
5215: SNESGetSolution(snes,&u);
5216: VecDuplicate(u,&uh);
5217: VecDuplicate(u,&fh);
5219: /* currently only works for sequential */
5220: PetscPrintf(PetscObjectComm((PetscObject)snes),"Testing FormFunction() for local min\n");
5221: VecGetSize(u,&N);
5222: for (i=0; i<N; i++) {
5223: VecCopy(u,uh);
5224: PetscPrintf(PetscObjectComm((PetscObject)snes),"i = %D\n",i);
5225: for (j=-10; j<11; j++) {
5226: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
5227: VecSetValue(uh,i,value,ADD_VALUES);
5228: SNESComputeFunction(snes,uh,fh);
5229: VecNorm(fh,NORM_2,&norm);
5230: PetscPrintf(PetscObjectComm((PetscObject)snes)," j norm %D %18.16e\n",j,norm);
5231: value = -value;
5232: VecSetValue(uh,i,value,ADD_VALUES);
5233: }
5234: }
5235: VecDestroy(&uh);
5236: VecDestroy(&fh);
5237: return(0);
5238: }
5240: /*@
5241: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
5242: computing relative tolerance for linear solvers within an inexact
5243: Newton method.
5245: Logically Collective on SNES
5247: Input Parameters:
5248: + snes - SNES context
5249: - flag - PETSC_TRUE or PETSC_FALSE
5251: Options Database:
5252: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5253: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5254: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5255: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5256: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5257: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5258: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5259: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5261: Notes:
5262: Currently, the default is to use a constant relative tolerance for
5263: the inner linear solvers. Alternatively, one can use the
5264: Eisenstat-Walker method, where the relative convergence tolerance
5265: is reset at each Newton iteration according progress of the nonlinear
5266: solver.
5268: Level: advanced
5270: Reference:
5271: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5272: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5274: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5275: @*/
5276: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
5277: {
5281: snes->ksp_ewconv = flag;
5282: return(0);
5283: }
5285: /*@
5286: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
5287: for computing relative tolerance for linear solvers within an
5288: inexact Newton method.
5290: Not Collective
5292: Input Parameter:
5293: . snes - SNES context
5295: Output Parameter:
5296: . flag - PETSC_TRUE or PETSC_FALSE
5298: Notes:
5299: Currently, the default is to use a constant relative tolerance for
5300: the inner linear solvers. Alternatively, one can use the
5301: Eisenstat-Walker method, where the relative convergence tolerance
5302: is reset at each Newton iteration according progress of the nonlinear
5303: solver.
5305: Level: advanced
5307: Reference:
5308: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5309: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5311: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5312: @*/
5313: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5314: {
5318: *flag = snes->ksp_ewconv;
5319: return(0);
5320: }
5322: /*@
5323: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5324: convergence criteria for the linear solvers within an inexact
5325: Newton method.
5327: Logically Collective on SNES
5329: Input Parameters:
5330: + snes - SNES context
5331: . version - version 1, 2 (default is 2) or 3
5332: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5333: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5334: . gamma - multiplicative factor for version 2 rtol computation
5335: (0 <= gamma2 <= 1)
5336: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5337: . alpha2 - power for safeguard
5338: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5340: Note:
5341: Version 3 was contributed by Luis Chacon, June 2006.
5343: Use PETSC_DEFAULT to retain the default for any of the parameters.
5345: Level: advanced
5347: Reference:
5348: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5349: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5350: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5352: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5353: @*/
5354: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5355: {
5356: SNESKSPEW *kctx;
5360: kctx = (SNESKSPEW*)snes->kspconvctx;
5361: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5370: if (version != PETSC_DEFAULT) kctx->version = version;
5371: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5372: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5373: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5374: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5375: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5376: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5378: 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);
5379: 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);
5380: 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);
5381: 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);
5382: 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);
5383: 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);
5384: return(0);
5385: }
5387: /*@
5388: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5389: convergence criteria for the linear solvers within an inexact
5390: Newton method.
5392: Not Collective
5394: Input Parameter:
5395: . snes - SNES context
5397: Output Parameters:
5398: + version - version 1, 2 (default is 2) or 3
5399: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5400: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5401: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5402: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5403: . alpha2 - power for safeguard
5404: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5406: Level: advanced
5408: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5409: @*/
5410: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5411: {
5412: SNESKSPEW *kctx;
5416: kctx = (SNESKSPEW*)snes->kspconvctx;
5417: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5418: if (version) *version = kctx->version;
5419: if (rtol_0) *rtol_0 = kctx->rtol_0;
5420: if (rtol_max) *rtol_max = kctx->rtol_max;
5421: if (gamma) *gamma = kctx->gamma;
5422: if (alpha) *alpha = kctx->alpha;
5423: if (alpha2) *alpha2 = kctx->alpha2;
5424: if (threshold) *threshold = kctx->threshold;
5425: return(0);
5426: }
5428: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5429: {
5431: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5432: PetscReal rtol = PETSC_DEFAULT,stol;
5435: if (!snes->ksp_ewconv) return(0);
5436: if (!snes->iter) {
5437: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5438: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5439: }
5440: else {
5441: if (kctx->version == 1) {
5442: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5443: if (rtol < 0.0) rtol = -rtol;
5444: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5445: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5446: } else if (kctx->version == 2) {
5447: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5448: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5449: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5450: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5451: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5452: /* safeguard: avoid sharp decrease of rtol */
5453: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5454: stol = PetscMax(rtol,stol);
5455: rtol = PetscMin(kctx->rtol_0,stol);
5456: /* safeguard: avoid oversolving */
5457: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5458: stol = PetscMax(rtol,stol);
5459: rtol = PetscMin(kctx->rtol_0,stol);
5460: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5461: }
5462: /* safeguard: avoid rtol greater than one */
5463: rtol = PetscMin(rtol,kctx->rtol_max);
5464: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5465: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5466: return(0);
5467: }
5469: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5470: {
5472: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5473: PCSide pcside;
5474: Vec lres;
5477: if (!snes->ksp_ewconv) return(0);
5478: KSPGetTolerances(ksp,&kctx->rtol_last,NULL,NULL,NULL);
5479: kctx->norm_last = snes->norm;
5480: if (kctx->version == 1) {
5481: PC pc;
5482: PetscBool isNone;
5484: KSPGetPC(ksp, &pc);
5485: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5486: KSPGetPCSide(ksp,&pcside);
5487: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5488: /* KSP residual is true linear residual */
5489: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5490: } else {
5491: /* KSP residual is preconditioned residual */
5492: /* compute true linear residual norm */
5493: VecDuplicate(b,&lres);
5494: MatMult(snes->jacobian,x,lres);
5495: VecAYPX(lres,-1.0,b);
5496: VecNorm(lres,NORM_2,&kctx->lresid_last);
5497: VecDestroy(&lres);
5498: }
5499: }
5500: return(0);
5501: }
5503: /*@
5504: SNESGetKSP - Returns the KSP context for a SNES solver.
5506: Not Collective, but if SNES object is parallel, then KSP object is parallel
5508: Input Parameter:
5509: . snes - the SNES context
5511: Output Parameter:
5512: . ksp - the KSP context
5514: Notes:
5515: The user can then directly manipulate the KSP context to set various
5516: options, etc. Likewise, the user can then extract and manipulate the
5517: PC contexts as well.
5519: Level: beginner
5521: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5522: @*/
5523: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5524: {
5531: if (!snes->ksp) {
5532: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5533: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5534: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5536: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5537: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5539: KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes);
5540: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5541: }
5542: *ksp = snes->ksp;
5543: return(0);
5544: }
5546: #include <petsc/private/dmimpl.h>
5547: /*@
5548: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5550: Logically Collective on SNES
5552: Input Parameters:
5553: + snes - the nonlinear solver context
5554: - dm - the dm, cannot be NULL
5556: Notes:
5557: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5558: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5559: problems using the same function space.
5561: Level: intermediate
5563: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5564: @*/
5565: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5566: {
5568: KSP ksp;
5569: DMSNES sdm;
5574: PetscObjectReference((PetscObject)dm);
5575: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5576: if (snes->dm->dmsnes && !dm->dmsnes) {
5577: DMCopyDMSNES(snes->dm,dm);
5578: DMGetDMSNES(snes->dm,&sdm);
5579: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5580: }
5581: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5582: DMDestroy(&snes->dm);
5583: }
5584: snes->dm = dm;
5585: snes->dmAuto = PETSC_FALSE;
5587: SNESGetKSP(snes,&ksp);
5588: KSPSetDM(ksp,dm);
5589: KSPSetDMActive(ksp,PETSC_FALSE);
5590: if (snes->npc) {
5591: SNESSetDM(snes->npc, snes->dm);
5592: SNESSetNPCSide(snes,snes->npcside);
5593: }
5594: return(0);
5595: }
5597: /*@
5598: SNESGetDM - Gets the DM that may be used by some preconditioners
5600: Not Collective but DM obtained is parallel on SNES
5602: Input Parameter:
5603: . snes - the preconditioner context
5605: Output Parameter:
5606: . dm - the dm
5608: Level: intermediate
5610: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5611: @*/
5612: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5613: {
5618: if (!snes->dm) {
5619: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5620: snes->dmAuto = PETSC_TRUE;
5621: }
5622: *dm = snes->dm;
5623: return(0);
5624: }
5626: /*@
5627: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5629: Collective on SNES
5631: Input Parameters:
5632: + snes - iterative context obtained from SNESCreate()
5633: - pc - the preconditioner object
5635: Notes:
5636: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5637: to configure it using the API).
5639: Level: developer
5641: .seealso: SNESGetNPC(), SNESHasNPC()
5642: @*/
5643: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5644: {
5651: PetscObjectReference((PetscObject) pc);
5652: SNESDestroy(&snes->npc);
5653: snes->npc = pc;
5654: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5655: return(0);
5656: }
5658: /*@
5659: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5661: Not Collective; but any changes to the obtained SNES object must be applied collectively
5663: Input Parameter:
5664: . snes - iterative context obtained from SNESCreate()
5666: Output Parameter:
5667: . pc - preconditioner context
5669: Options Database:
5670: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5672: Notes:
5673: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5675: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5676: SNES during SNESSetUp()
5678: Level: developer
5680: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5681: @*/
5682: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5683: {
5685: const char *optionsprefix;
5690: if (!snes->npc) {
5691: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5692: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5693: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5694: SNESGetOptionsPrefix(snes,&optionsprefix);
5695: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5696: SNESAppendOptionsPrefix(snes->npc,"npc_");
5697: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5698: }
5699: *pc = snes->npc;
5700: return(0);
5701: }
5703: /*@
5704: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5706: Not Collective
5708: Input Parameter:
5709: . snes - iterative context obtained from SNESCreate()
5711: Output Parameter:
5712: . has_npc - whether the SNES has an NPC or not
5714: Level: developer
5716: .seealso: SNESSetNPC(), SNESGetNPC()
5717: @*/
5718: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5719: {
5722: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5723: return(0);
5724: }
5726: /*@
5727: SNESSetNPCSide - Sets the preconditioning side.
5729: Logically Collective on SNES
5731: Input Parameter:
5732: . snes - iterative context obtained from SNESCreate()
5734: Output Parameter:
5735: . side - the preconditioning side, where side is one of
5736: .vb
5737: PC_LEFT - left preconditioning
5738: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5739: .ve
5741: Options Database Keys:
5742: . -snes_npc_side <right,left>
5744: Notes:
5745: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5747: Level: intermediate
5749: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5750: @*/
5751: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5752: {
5756: snes->npcside= side;
5757: return(0);
5758: }
5760: /*@
5761: SNESGetNPCSide - Gets the preconditioning side.
5763: Not Collective
5765: Input Parameter:
5766: . snes - iterative context obtained from SNESCreate()
5768: Output Parameter:
5769: . side - the preconditioning side, where side is one of
5770: .vb
5771: PC_LEFT - left preconditioning
5772: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5773: .ve
5775: Level: intermediate
5777: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5778: @*/
5779: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5780: {
5784: *side = snes->npcside;
5785: return(0);
5786: }
5788: /*@
5789: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5791: Collective on SNES
5793: Input Parameters:
5794: + snes - iterative context obtained from SNESCreate()
5795: - linesearch - the linesearch object
5797: Notes:
5798: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5799: to configure it using the API).
5801: Level: developer
5803: .seealso: SNESGetLineSearch()
5804: @*/
5805: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5806: {
5813: PetscObjectReference((PetscObject) linesearch);
5814: SNESLineSearchDestroy(&snes->linesearch);
5816: snes->linesearch = linesearch;
5818: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5819: return(0);
5820: }
5822: /*@
5823: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5824: or creates a default line search instance associated with the SNES and returns it.
5826: Not Collective
5828: Input Parameter:
5829: . snes - iterative context obtained from SNESCreate()
5831: Output Parameter:
5832: . linesearch - linesearch context
5834: Level: beginner
5836: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5837: @*/
5838: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5839: {
5841: const char *optionsprefix;
5846: if (!snes->linesearch) {
5847: SNESGetOptionsPrefix(snes, &optionsprefix);
5848: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5849: SNESLineSearchSetSNES(snes->linesearch, snes);
5850: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5851: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5852: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5853: }
5854: *linesearch = snes->linesearch;
5855: return(0);
5856: }