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 explict 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) {
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) {
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 Arguments:
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 explictly 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 explictly with
1256: finite differences and coloring using MatFDColoring. It is also possible to use automatic differentiation and the MatFDColoring object.
1258: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF(), SNESComputeJacobianDefaultColor()
1259: @*/
1260: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1261: {
1266: snes->mf = mf_operator ? PETSC_TRUE : mf;
1267: snes->mf_operator = mf_operator;
1268: return(0);
1269: }
1271: /*@
1272: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply the Jacobian.
1274: Collective on SNES
1276: Input Parameter:
1277: . snes - SNES context
1279: Output Parameters:
1280: + mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1281: - mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1283: Options Database:
1284: + -snes_mf - use matrix free for both the mat and pmat operator
1285: - -snes_mf_operator - use matrix free only for the mat operator
1287: Level: intermediate
1289: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1290: @*/
1291: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1292: {
1295: if (mf) *mf = snes->mf;
1296: if (mf_operator) *mf_operator = snes->mf_operator;
1297: return(0);
1298: }
1300: /*@
1301: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1302: at this time.
1304: Not Collective
1306: Input Parameter:
1307: . snes - SNES context
1309: Output Parameter:
1310: . iter - iteration number
1312: Notes:
1313: For example, during the computation of iteration 2 this would return 1.
1315: This is useful for using lagged Jacobians (where one does not recompute the
1316: Jacobian at each SNES iteration). For example, the code
1317: .vb
1318: SNESGetIterationNumber(snes,&it);
1319: if (!(it % 2)) {
1320: [compute Jacobian here]
1321: }
1322: .ve
1323: can be used in your ComputeJacobian() function to cause the Jacobian to be
1324: recomputed every second SNES iteration.
1326: After the SNES solve is complete this will return the number of nonlinear iterations used.
1328: Level: intermediate
1330: .seealso: SNESGetLinearSolveIterations()
1331: @*/
1332: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1333: {
1337: *iter = snes->iter;
1338: return(0);
1339: }
1341: /*@
1342: SNESSetIterationNumber - Sets the current iteration number.
1344: Not Collective
1346: Input Parameter:
1347: + snes - SNES context
1348: - iter - iteration number
1350: Level: developer
1352: .seealso: SNESGetLinearSolveIterations()
1353: @*/
1354: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1355: {
1360: PetscObjectSAWsTakeAccess((PetscObject)snes);
1361: snes->iter = iter;
1362: PetscObjectSAWsGrantAccess((PetscObject)snes);
1363: return(0);
1364: }
1366: /*@
1367: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1368: attempted by the nonlinear solver.
1370: Not Collective
1372: Input Parameter:
1373: . snes - SNES context
1375: Output Parameter:
1376: . nfails - number of unsuccessful steps attempted
1378: Notes:
1379: This counter is reset to zero for each successive call to SNESSolve().
1381: Level: intermediate
1383: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1384: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1385: @*/
1386: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1387: {
1391: *nfails = snes->numFailures;
1392: return(0);
1393: }
1395: /*@
1396: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1397: attempted by the nonlinear solver before it gives up.
1399: Not Collective
1401: Input Parameters:
1402: + snes - SNES context
1403: - maxFails - maximum of unsuccessful steps
1405: Level: intermediate
1407: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1408: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1409: @*/
1410: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1411: {
1414: snes->maxFailures = maxFails;
1415: return(0);
1416: }
1418: /*@
1419: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1420: attempted by the nonlinear solver before it gives up.
1422: Not Collective
1424: Input Parameter:
1425: . snes - SNES context
1427: Output Parameter:
1428: . maxFails - maximum of unsuccessful steps
1430: Level: intermediate
1432: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1433: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1435: @*/
1436: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1437: {
1441: *maxFails = snes->maxFailures;
1442: return(0);
1443: }
1445: /*@
1446: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1447: done by SNES.
1449: Not Collective
1451: Input Parameter:
1452: . snes - SNES context
1454: Output Parameter:
1455: . nfuncs - number of evaluations
1457: Level: intermediate
1459: Notes:
1460: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1462: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1463: @*/
1464: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1465: {
1469: *nfuncs = snes->nfuncs;
1470: return(0);
1471: }
1473: /*@
1474: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1475: linear solvers.
1477: Not Collective
1479: Input Parameter:
1480: . snes - SNES context
1482: Output Parameter:
1483: . nfails - number of failed solves
1485: Level: intermediate
1487: Options Database Keys:
1488: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1490: Notes:
1491: This counter is reset to zero for each successive call to SNESSolve().
1493: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1494: @*/
1495: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1496: {
1500: *nfails = snes->numLinearSolveFailures;
1501: return(0);
1502: }
1504: /*@
1505: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1506: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1508: Logically Collective on SNES
1510: Input Parameters:
1511: + snes - SNES context
1512: - maxFails - maximum allowed linear solve failures
1514: Level: intermediate
1516: Options Database Keys:
1517: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1519: Notes:
1520: By default this is 0; that is SNES returns on the first failed linear solve
1522: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1523: @*/
1524: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1525: {
1529: snes->maxLinearSolveFailures = maxFails;
1530: return(0);
1531: }
1533: /*@
1534: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1535: are allowed before SNES terminates
1537: Not Collective
1539: Input Parameter:
1540: . snes - SNES context
1542: Output Parameter:
1543: . maxFails - maximum of unsuccessful solves allowed
1545: Level: intermediate
1547: Notes:
1548: By default this is 1; that is SNES returns on the first failed linear solve
1550: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1551: @*/
1552: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1553: {
1557: *maxFails = snes->maxLinearSolveFailures;
1558: return(0);
1559: }
1561: /*@
1562: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1563: used by the nonlinear solver.
1565: Not Collective
1567: Input Parameter:
1568: . snes - SNES context
1570: Output Parameter:
1571: . lits - number of linear iterations
1573: Notes:
1574: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1576: If the linear solver fails inside the SNESSolve() the iterations for that call to the linear solver are not included. If you wish to count them
1577: then call KSPGetIterationNumber() after the failed solve.
1579: Level: intermediate
1581: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1582: @*/
1583: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1584: {
1588: *lits = snes->linear_its;
1589: return(0);
1590: }
1592: /*@
1593: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1594: are reset every time SNESSolve() is called.
1596: Logically Collective on SNES
1598: Input Parameter:
1599: + snes - SNES context
1600: - reset - whether to reset the counters or not
1602: Notes:
1603: This defaults to PETSC_TRUE
1605: Level: developer
1607: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1608: @*/
1609: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1610: {
1614: snes->counters_reset = reset;
1615: return(0);
1616: }
1619: /*@
1620: SNESSetKSP - Sets a KSP context for the SNES object to use
1622: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1624: Input Parameters:
1625: + snes - the SNES context
1626: - ksp - the KSP context
1628: Notes:
1629: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1630: so this routine is rarely needed.
1632: The KSP object that is already in the SNES object has its reference count
1633: decreased by one.
1635: Level: developer
1637: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1638: @*/
1639: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1640: {
1647: PetscObjectReference((PetscObject)ksp);
1648: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1649: snes->ksp = ksp;
1650: return(0);
1651: }
1653: /* -----------------------------------------------------------*/
1654: /*@
1655: SNESCreate - Creates a nonlinear solver context.
1657: Collective
1659: Input Parameters:
1660: . comm - MPI communicator
1662: Output Parameter:
1663: . outsnes - the new SNES context
1665: Options Database Keys:
1666: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1667: and no preconditioning matrix
1668: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1669: products, and a user-provided preconditioning matrix
1670: as set by SNESSetJacobian()
1671: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1673: Level: beginner
1675: Developer Notes:
1676: SNES always creates a KSP object even though many SNES methods do not use it. This is
1677: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1678: particular method does use KSP and regulates if the information about the KSP is printed
1679: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1680: by help messages about meaningless SNES options.
1682: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1683: be fixed.
1685: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner(), SNESSetLagJacobian()
1687: @*/
1688: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1689: {
1691: SNES snes;
1692: SNESKSPEW *kctx;
1696: *outsnes = NULL;
1697: SNESInitializePackage();
1699: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1701: snes->ops->converged = SNESConvergedDefault;
1702: snes->usesksp = PETSC_TRUE;
1703: snes->tolerancesset = PETSC_FALSE;
1704: snes->max_its = 50;
1705: snes->max_funcs = 10000;
1706: snes->norm = 0.0;
1707: snes->xnorm = 0.0;
1708: snes->ynorm = 0.0;
1709: snes->normschedule = SNES_NORM_ALWAYS;
1710: snes->functype = SNES_FUNCTION_DEFAULT;
1711: #if defined(PETSC_USE_REAL_SINGLE)
1712: snes->rtol = 1.e-5;
1713: #else
1714: snes->rtol = 1.e-8;
1715: #endif
1716: snes->ttol = 0.0;
1717: #if defined(PETSC_USE_REAL_SINGLE)
1718: snes->abstol = 1.e-25;
1719: #else
1720: snes->abstol = 1.e-50;
1721: #endif
1722: #if defined(PETSC_USE_REAL_SINGLE)
1723: snes->stol = 1.e-5;
1724: #else
1725: snes->stol = 1.e-8;
1726: #endif
1727: #if defined(PETSC_USE_REAL_SINGLE)
1728: snes->deltatol = 1.e-6;
1729: #else
1730: snes->deltatol = 1.e-12;
1731: #endif
1732: snes->divtol = 1.e4;
1733: snes->rnorm0 = 0;
1734: snes->nfuncs = 0;
1735: snes->numFailures = 0;
1736: snes->maxFailures = 1;
1737: snes->linear_its = 0;
1738: snes->lagjacobian = 1;
1739: snes->jac_iter = 0;
1740: snes->lagjac_persist = PETSC_FALSE;
1741: snes->lagpreconditioner = 1;
1742: snes->pre_iter = 0;
1743: snes->lagpre_persist = PETSC_FALSE;
1744: snes->numbermonitors = 0;
1745: snes->numberreasonviews = 0;
1746: snes->data = NULL;
1747: snes->setupcalled = PETSC_FALSE;
1748: snes->ksp_ewconv = PETSC_FALSE;
1749: snes->nwork = 0;
1750: snes->work = NULL;
1751: snes->nvwork = 0;
1752: snes->vwork = NULL;
1753: snes->conv_hist_len = 0;
1754: snes->conv_hist_max = 0;
1755: snes->conv_hist = NULL;
1756: snes->conv_hist_its = NULL;
1757: snes->conv_hist_reset = PETSC_TRUE;
1758: snes->counters_reset = PETSC_TRUE;
1759: snes->vec_func_init_set = PETSC_FALSE;
1760: snes->reason = SNES_CONVERGED_ITERATING;
1761: snes->npcside = PC_RIGHT;
1762: snes->setfromoptionscalled = 0;
1764: snes->mf = PETSC_FALSE;
1765: snes->mf_operator = PETSC_FALSE;
1766: snes->mf_version = 1;
1768: snes->numLinearSolveFailures = 0;
1769: snes->maxLinearSolveFailures = 1;
1771: snes->vizerotolerance = 1.e-8;
1772: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1774: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1775: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1777: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1778: PetscNewLog(snes,&kctx);
1780: snes->kspconvctx = (void*)kctx;
1781: kctx->version = 2;
1782: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1783: this was too large for some test cases */
1784: kctx->rtol_last = 0.0;
1785: kctx->rtol_max = .9;
1786: kctx->gamma = 1.0;
1787: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1788: kctx->alpha2 = kctx->alpha;
1789: kctx->threshold = .1;
1790: kctx->lresid_last = 0.0;
1791: kctx->norm_last = 0.0;
1793: *outsnes = snes;
1794: return(0);
1795: }
1797: /*MC
1798: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1800: Synopsis:
1801: #include "petscsnes.h"
1802: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1804: Collective on snes
1806: Input Parameters:
1807: + snes - the SNES context
1808: . x - state at which to evaluate residual
1809: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1811: Output Parameter:
1812: . f - vector to put residual (function value)
1814: Level: intermediate
1816: .seealso: SNESSetFunction(), SNESGetFunction()
1817: M*/
1819: /*@C
1820: SNESSetFunction - Sets the function evaluation routine and function
1821: vector for use by the SNES routines in solving systems of nonlinear
1822: equations.
1824: Logically Collective on SNES
1826: Input Parameters:
1827: + snes - the SNES context
1828: . r - vector to store function value
1829: . f - function evaluation routine; see SNESFunction for calling sequence details
1830: - ctx - [optional] user-defined context for private data for the
1831: function evaluation routine (may be NULL)
1833: Notes:
1834: The Newton-like methods typically solve linear systems of the form
1835: $ f'(x) x = -f(x),
1836: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1838: Level: beginner
1840: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1841: @*/
1842: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1843: {
1845: DM dm;
1849: if (r) {
1852: PetscObjectReference((PetscObject)r);
1853: VecDestroy(&snes->vec_func);
1855: snes->vec_func = r;
1856: }
1857: SNESGetDM(snes,&dm);
1858: DMSNESSetFunction(dm,f,ctx);
1859: return(0);
1860: }
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 covergence 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, initalfinalonly>
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 therfore
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: }
1940: /*@
1941: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1942: of the SNES method.
1944: Logically Collective on SNES
1946: Input Parameters:
1947: + snes - the SNES context
1948: - normschedule - the type of the norm used
1950: Level: advanced
1952: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1953: @*/
1954: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1955: {
1958: *normschedule = snes->normschedule;
1959: return(0);
1960: }
1963: /*@
1964: SNESSetFunctionNorm - Sets the last computed residual norm.
1966: Logically Collective on SNES
1968: Input Parameters:
1969: + snes - the SNES context
1971: - normschedule - the frequency of norm computation
1973: Level: developer
1975: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1976: @*/
1977: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1978: {
1981: snes->norm = norm;
1982: return(0);
1983: }
1985: /*@
1986: SNESGetFunctionNorm - Gets the last computed norm of the residual
1988: Not Collective
1990: Input Parameter:
1991: . snes - the SNES context
1993: Output Parameter:
1994: . norm - the last computed residual norm
1996: Level: developer
1998: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1999: @*/
2000: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2001: {
2005: *norm = snes->norm;
2006: return(0);
2007: }
2009: /*@
2010: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
2012: Not Collective
2014: Input Parameter:
2015: . snes - the SNES context
2017: Output Parameter:
2018: . ynorm - the last computed update norm
2020: Level: developer
2022: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
2023: @*/
2024: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2025: {
2029: *ynorm = snes->ynorm;
2030: return(0);
2031: }
2033: /*@
2034: SNESGetSolutionNorm - Gets the last computed norm of the solution
2036: Not Collective
2038: Input Parameter:
2039: . snes - the SNES context
2041: Output Parameter:
2042: . xnorm - the last computed solution norm
2044: Level: developer
2046: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2047: @*/
2048: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2049: {
2053: *xnorm = snes->xnorm;
2054: return(0);
2055: }
2057: /*@C
2058: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2059: of the SNES method.
2061: Logically Collective on SNES
2063: Input Parameters:
2064: + snes - the SNES context
2065: - normschedule - the frequency of norm computation
2067: Notes:
2068: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2069: of the nonlinear function and the taking of its norm at every iteration to
2070: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2071: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2072: may either be monitored for convergence or not. As these are often used as nonlinear
2073: preconditioners, monitoring the norm of their error is not a useful enterprise within
2074: their solution.
2076: Level: developer
2078: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2079: @*/
2080: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2081: {
2084: snes->functype = type;
2085: return(0);
2086: }
2089: /*@C
2090: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2091: of the SNES method.
2093: Logically Collective on SNES
2095: Input Parameters:
2096: + snes - the SNES context
2097: - normschedule - the type of the norm used
2099: Level: advanced
2101: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2102: @*/
2103: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2104: {
2107: *type = snes->functype;
2108: return(0);
2109: }
2111: /*MC
2112: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2114: Synopsis:
2115: #include <petscsnes.h>
2116: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2118: Collective on snes
2120: Input Parameters:
2121: + X - solution vector
2122: . B - RHS vector
2123: - ctx - optional user-defined Gauss-Seidel context
2125: Output Parameter:
2126: . X - solution vector
2128: Level: intermediate
2130: .seealso: SNESSetNGS(), SNESGetNGS()
2131: M*/
2133: /*@C
2134: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2135: use with composed nonlinear solvers.
2137: Input Parameters:
2138: + snes - the SNES context
2139: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2140: - ctx - [optional] user-defined context for private data for the
2141: smoother evaluation routine (may be NULL)
2143: Notes:
2144: The NGS routines are used by the composed nonlinear solver to generate
2145: a problem appropriate update to the solution, particularly FAS.
2147: Level: intermediate
2149: .seealso: SNESGetFunction(), SNESComputeNGS()
2150: @*/
2151: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2152: {
2154: DM dm;
2158: SNESGetDM(snes,&dm);
2159: DMSNESSetNGS(dm,f,ctx);
2160: return(0);
2161: }
2163: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2164: {
2166: DM dm;
2167: DMSNES sdm;
2170: SNESGetDM(snes,&dm);
2171: DMGetDMSNES(dm,&sdm);
2172: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
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: PetscStackPush("SNES Picard user function");
2176: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2177: PetscStackPop;
2178: PetscStackPush("SNES Picard user Jacobian");
2179: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2180: PetscStackPop;
2181: VecScale(f,-1.0);
2182: MatMultAdd(snes->jacobian,x,f,f);
2183: return(0);
2184: }
2186: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2187: {
2189: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2190: return(0);
2191: }
2193: /*@C
2194: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2196: Logically Collective on SNES
2198: Input Parameters:
2199: + snes - the SNES context
2200: . r - vector to store function value
2201: . b - function evaluation routine
2202: . Amat - matrix with which A(x) x - b(x) is to be computed
2203: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2204: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2205: - ctx - [optional] user-defined context for private data for the
2206: function evaluation routine (may be NULL)
2208: Notes:
2209: We do not recomemend using this routine. It is far better to provide the nonlinear function F() and some approximation to the Jacobian and use
2210: 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.
2212: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2214: $ Solves the equation A(x) x = b(x) via the defect correction algorithm A(x^{n}) (x^{n+1} - x^{n}) = b(x^{n}) - A(x^{n})x^{n}
2215: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2217: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2219: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2220: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2222: 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
2223: 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
2224: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2226: Level: intermediate
2228: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2229: @*/
2230: PetscErrorCode SNESSetPicard(SNES snes,Vec r,PetscErrorCode (*b)(SNES,Vec,Vec,void*),Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2231: {
2233: DM dm;
2237: SNESGetDM(snes, &dm);
2238: DMSNESSetPicard(dm,b,J,ctx);
2239: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2240: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2241: return(0);
2242: }
2244: /*@C
2245: SNESGetPicard - Returns the context for the Picard iteration
2247: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2249: Input Parameter:
2250: . snes - the SNES context
2252: Output Parameter:
2253: + r - the function (or NULL)
2254: . f - the function (or NULL); see SNESFunction for calling sequence details
2255: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2256: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2257: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2258: - ctx - the function context (or NULL)
2260: Level: advanced
2262: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2263: @*/
2264: 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)
2265: {
2267: DM dm;
2271: SNESGetFunction(snes,r,NULL,NULL);
2272: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2273: SNESGetDM(snes,&dm);
2274: DMSNESGetPicard(dm,f,J,ctx);
2275: return(0);
2276: }
2278: /*@C
2279: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2281: Logically Collective on SNES
2283: Input Parameters:
2284: + snes - the SNES context
2285: . func - function evaluation routine
2286: - ctx - [optional] user-defined context for private data for the
2287: function evaluation routine (may be NULL)
2289: Calling sequence of func:
2290: $ func (SNES snes,Vec x,void *ctx);
2292: . f - function vector
2293: - ctx - optional user-defined function context
2295: Level: intermediate
2297: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2298: @*/
2299: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2300: {
2303: if (func) snes->ops->computeinitialguess = func;
2304: if (ctx) snes->initialguessP = ctx;
2305: return(0);
2306: }
2308: /* --------------------------------------------------------------- */
2309: /*@C
2310: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2311: it assumes a zero right hand side.
2313: Logically Collective on SNES
2315: Input Parameter:
2316: . snes - the SNES context
2318: Output Parameter:
2319: . rhs - the right hand side vector or NULL if the right hand side vector is null
2321: Level: intermediate
2323: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2324: @*/
2325: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2326: {
2330: *rhs = snes->vec_rhs;
2331: return(0);
2332: }
2334: /*@
2335: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2337: Collective on SNES
2339: Input Parameters:
2340: + snes - the SNES context
2341: - x - input vector
2343: Output Parameter:
2344: . y - function vector, as set by SNESSetFunction()
2346: Notes:
2347: SNESComputeFunction() is typically used within nonlinear solvers
2348: implementations, so most users would not generally call this routine
2349: themselves.
2351: Level: developer
2353: .seealso: SNESSetFunction(), SNESGetFunction()
2354: @*/
2355: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2356: {
2358: DM dm;
2359: DMSNES sdm;
2367: VecValidValues(x,2,PETSC_TRUE);
2369: SNESGetDM(snes,&dm);
2370: DMGetDMSNES(dm,&sdm);
2371: if (sdm->ops->computefunction) {
2372: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2373: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2374: }
2375: VecLockReadPush(x);
2376: PetscStackPush("SNES user function");
2377: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2378: snes->domainerror = PETSC_FALSE;
2379: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2380: PetscStackPop;
2381: VecLockReadPop(x);
2382: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2383: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2384: }
2385: } else if (snes->vec_rhs) {
2386: MatMult(snes->jacobian, x, y);
2387: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2388: if (snes->vec_rhs) {
2389: VecAXPY(y,-1.0,snes->vec_rhs);
2390: }
2391: snes->nfuncs++;
2392: /*
2393: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2394: propagate the value to all processes
2395: */
2396: if (snes->domainerror) {
2397: VecSetInf(y);
2398: }
2399: return(0);
2400: }
2402: /*@
2403: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2405: Collective on SNES
2407: Input Parameters:
2408: + snes - the SNES context
2409: . x - input vector
2410: - b - rhs vector
2412: Output Parameter:
2413: . x - new solution vector
2415: Notes:
2416: SNESComputeNGS() is typically used within composed nonlinear solver
2417: implementations, so most users would not generally call this routine
2418: themselves.
2420: Level: developer
2422: .seealso: SNESSetNGS(), SNESComputeFunction()
2423: @*/
2424: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2425: {
2427: DM dm;
2428: DMSNES sdm;
2436: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2437: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2438: SNESGetDM(snes,&dm);
2439: DMGetDMSNES(dm,&sdm);
2440: if (sdm->ops->computegs) {
2441: if (b) {VecLockReadPush(b);}
2442: PetscStackPush("SNES user NGS");
2443: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2444: PetscStackPop;
2445: if (b) {VecLockReadPop(b);}
2446: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2447: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2448: return(0);
2449: }
2451: PetscErrorCode SNESTestJacobian(SNES snes)
2452: {
2453: Mat A,B,C,D,jacobian;
2454: Vec x = snes->vec_sol,f = snes->vec_func;
2455: PetscErrorCode ierr;
2456: PetscReal nrm,gnorm;
2457: PetscReal threshold = 1.e-5;
2458: MatType mattype;
2459: PetscInt m,n,M,N;
2460: void *functx;
2461: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg,istranspose;
2462: PetscViewer viewer,mviewer;
2463: MPI_Comm comm;
2464: PetscInt tabs;
2465: static PetscBool directionsprinted = PETSC_FALSE;
2466: PetscViewerFormat format;
2469: PetscObjectOptionsBegin((PetscObject)snes);
2470: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2471: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2472: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2473: if (!complete_print) {
2474: PetscOptionsDeprecated("-snes_test_jacobian_display","-snes_test_jacobian_view","3.13",NULL);
2475: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2476: }
2477: /* for compatibility with PETSc 3.9 and older. */
2478: PetscOptionsDeprecated("-snes_test_jacobian_display_threshold","-snes_test_jacobian","3.13","-snes_test_jacobian accepts an optional threshold (since v3.10)");
2479: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2480: PetscOptionsEnd();
2481: if (!test) return(0);
2483: PetscObjectGetComm((PetscObject)snes,&comm);
2484: PetscViewerASCIIGetStdout(comm,&viewer);
2485: PetscViewerASCIIGetTab(viewer, &tabs);
2486: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2487: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2488: if (!complete_print && !directionsprinted) {
2489: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2490: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2491: }
2492: if (!directionsprinted) {
2493: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2494: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2495: directionsprinted = PETSC_TRUE;
2496: }
2497: if (complete_print) {
2498: PetscViewerPushFormat(mviewer,format);
2499: }
2501: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2502: if (!flg) jacobian = snes->jacobian;
2503: else jacobian = snes->jacobian_pre;
2505: if (!x) {
2506: MatCreateVecs(jacobian, &x, NULL);
2507: } else {
2508: PetscObjectReference((PetscObject) x);
2509: }
2510: if (!f) {
2511: VecDuplicate(x, &f);
2512: } else {
2513: PetscObjectReference((PetscObject) f);
2514: }
2515: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2516: SNESComputeFunction(snes,x,f);
2517: VecDestroy(&f);
2518: PetscObjectTypeCompare((PetscObject)snes,SNESKSPTRANSPOSEONLY,&istranspose);
2519: while (jacobian) {
2520: Mat JT = NULL, Jsave = NULL;
2522: if (istranspose) {
2523: MatCreateTranspose(jacobian,&JT);
2524: Jsave = jacobian;
2525: jacobian = JT;
2526: }
2527: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2528: if (flg) {
2529: A = jacobian;
2530: PetscObjectReference((PetscObject)A);
2531: } else {
2532: MatComputeOperator(jacobian,MATAIJ,&A);
2533: }
2535: MatGetType(A,&mattype);
2536: MatGetSize(A,&M,&N);
2537: MatGetLocalSize(A,&m,&n);
2538: MatCreate(PetscObjectComm((PetscObject)A),&B);
2539: MatSetType(B,mattype);
2540: MatSetSizes(B,m,n,M,N);
2541: MatSetBlockSizesFromMats(B,A,A);
2542: MatSetUp(B);
2543: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2545: SNESGetFunction(snes,NULL,NULL,&functx);
2546: SNESComputeJacobianDefault(snes,x,B,B,functx);
2548: MatDuplicate(B,MAT_COPY_VALUES,&D);
2549: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2550: MatNorm(D,NORM_FROBENIUS,&nrm);
2551: MatNorm(A,NORM_FROBENIUS,&gnorm);
2552: MatDestroy(&D);
2553: if (!gnorm) gnorm = 1; /* just in case */
2554: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2556: if (complete_print) {
2557: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2558: MatView(A,mviewer);
2559: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2560: MatView(B,mviewer);
2561: }
2563: if (threshold_print || complete_print) {
2564: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2565: PetscScalar *cvals;
2566: const PetscInt *bcols;
2567: const PetscScalar *bvals;
2569: MatCreate(PetscObjectComm((PetscObject)A),&C);
2570: MatSetType(C,mattype);
2571: MatSetSizes(C,m,n,M,N);
2572: MatSetBlockSizesFromMats(C,A,A);
2573: MatSetUp(C);
2574: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2576: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2577: MatGetOwnershipRange(B,&Istart,&Iend);
2579: for (row = Istart; row < Iend; row++) {
2580: MatGetRow(B,row,&bncols,&bcols,&bvals);
2581: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2582: for (j = 0, cncols = 0; j < bncols; j++) {
2583: if (PetscAbsScalar(bvals[j]) > threshold) {
2584: ccols[cncols] = bcols[j];
2585: cvals[cncols] = bvals[j];
2586: cncols += 1;
2587: }
2588: }
2589: if (cncols) {
2590: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2591: }
2592: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2593: PetscFree2(ccols,cvals);
2594: }
2595: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2596: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2597: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2598: MatView(C,complete_print ? mviewer : viewer);
2599: MatDestroy(&C);
2600: }
2601: MatDestroy(&A);
2602: MatDestroy(&B);
2603: MatDestroy(&JT);
2604: if (Jsave) jacobian = Jsave;
2605: if (jacobian != snes->jacobian_pre) {
2606: jacobian = snes->jacobian_pre;
2607: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2608: }
2609: else jacobian = NULL;
2610: }
2611: VecDestroy(&x);
2612: if (complete_print) {
2613: PetscViewerPopFormat(mviewer);
2614: }
2615: if (mviewer) { PetscViewerDestroy(&mviewer); }
2616: PetscViewerASCIISetTab(viewer,tabs);
2617: return(0);
2618: }
2620: /*@
2621: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2623: Collective on SNES
2625: Input Parameters:
2626: + snes - the SNES context
2627: - x - input vector
2629: Output Parameters:
2630: + A - Jacobian matrix
2631: - B - optional preconditioning matrix
2633: Options Database Keys:
2634: + -snes_lag_preconditioner <lag>
2635: . -snes_lag_jacobian <lag>
2636: . -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.
2637: . -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
2638: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2639: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2640: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2641: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2642: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2643: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2644: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2645: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2646: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2647: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2648: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2651: Notes:
2652: Most users should not need to explicitly call this routine, as it
2653: is used internally within the nonlinear solvers.
2655: Developer Notes:
2656: 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
2657: for with the SNESType of test that has been removed.
2659: Level: developer
2661: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2662: @*/
2663: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2664: {
2666: PetscBool flag;
2667: DM dm;
2668: DMSNES sdm;
2669: KSP ksp;
2675: VecValidValues(X,2,PETSC_TRUE);
2676: SNESGetDM(snes,&dm);
2677: DMGetDMSNES(dm,&sdm);
2679: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2681: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2683: if (snes->lagjacobian == -2) {
2684: snes->lagjacobian = -1;
2686: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2687: } else if (snes->lagjacobian == -1) {
2688: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2689: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2690: if (flag) {
2691: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2692: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2693: }
2694: return(0);
2695: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2696: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2697: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2698: if (flag) {
2699: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2700: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2701: }
2702: return(0);
2703: }
2704: if (snes->npc && snes->npcside== PC_LEFT) {
2705: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2706: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2707: return(0);
2708: }
2710: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2711: VecLockReadPush(X);
2712: PetscStackPush("SNES user Jacobian function");
2713: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2714: PetscStackPop;
2715: VecLockReadPop(X);
2716: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2718: /* attach latest linearization point to the preconditioning matrix */
2719: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2721: /* the next line ensures that snes->ksp exists */
2722: SNESGetKSP(snes,&ksp);
2723: if (snes->lagpreconditioner == -2) {
2724: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2725: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2726: snes->lagpreconditioner = -1;
2727: } else if (snes->lagpreconditioner == -1) {
2728: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2729: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2730: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2731: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2732: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2733: } else {
2734: PetscInfo(snes,"Rebuilding preconditioner\n");
2735: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2736: }
2738: SNESTestJacobian(snes);
2739: /* make sure user returned a correct Jacobian and preconditioner */
2742: {
2743: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2744: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2745: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2746: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2747: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2748: if (flag || flag_draw || flag_contour) {
2749: Mat Bexp_mine = NULL,Bexp,FDexp;
2750: PetscViewer vdraw,vstdout;
2751: PetscBool flg;
2752: if (flag_operator) {
2753: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2754: Bexp = Bexp_mine;
2755: } else {
2756: /* See if the preconditioning matrix can be viewed and added directly */
2757: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2758: if (flg) Bexp = B;
2759: else {
2760: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2761: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2762: Bexp = Bexp_mine;
2763: }
2764: }
2765: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2766: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2767: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2768: if (flag_draw || flag_contour) {
2769: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2770: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2771: } else vdraw = NULL;
2772: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2773: if (flag) {MatView(Bexp,vstdout);}
2774: if (vdraw) {MatView(Bexp,vdraw);}
2775: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2776: if (flag) {MatView(FDexp,vstdout);}
2777: if (vdraw) {MatView(FDexp,vdraw);}
2778: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2779: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2780: if (flag) {MatView(FDexp,vstdout);}
2781: if (vdraw) { /* Always use contour for the difference */
2782: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2783: MatView(FDexp,vdraw);
2784: PetscViewerPopFormat(vdraw);
2785: }
2786: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2787: PetscViewerDestroy(&vdraw);
2788: MatDestroy(&Bexp_mine);
2789: MatDestroy(&FDexp);
2790: }
2791: }
2792: {
2793: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2794: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2795: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2796: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2797: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2798: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2799: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2800: if (flag_threshold) {
2801: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2802: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2803: }
2804: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2805: Mat Bfd;
2806: PetscViewer vdraw,vstdout;
2807: MatColoring coloring;
2808: ISColoring iscoloring;
2809: MatFDColoring matfdcoloring;
2810: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2811: void *funcctx;
2812: PetscReal norm1,norm2,normmax;
2814: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2815: MatColoringCreate(Bfd,&coloring);
2816: MatColoringSetType(coloring,MATCOLORINGSL);
2817: MatColoringSetFromOptions(coloring);
2818: MatColoringApply(coloring,&iscoloring);
2819: MatColoringDestroy(&coloring);
2820: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2821: MatFDColoringSetFromOptions(matfdcoloring);
2822: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2823: ISColoringDestroy(&iscoloring);
2825: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2826: SNESGetFunction(snes,NULL,&func,&funcctx);
2827: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2828: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2829: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2830: MatFDColoringSetFromOptions(matfdcoloring);
2831: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2832: MatFDColoringDestroy(&matfdcoloring);
2834: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2835: if (flag_draw || flag_contour) {
2836: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2837: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2838: } else vdraw = NULL;
2839: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2840: if (flag_display) {MatView(B,vstdout);}
2841: if (vdraw) {MatView(B,vdraw);}
2842: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2843: if (flag_display) {MatView(Bfd,vstdout);}
2844: if (vdraw) {MatView(Bfd,vdraw);}
2845: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2846: MatNorm(Bfd,NORM_1,&norm1);
2847: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2848: MatNorm(Bfd,NORM_MAX,&normmax);
2849: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2850: if (flag_display) {MatView(Bfd,vstdout);}
2851: if (vdraw) { /* Always use contour for the difference */
2852: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2853: MatView(Bfd,vdraw);
2854: PetscViewerPopFormat(vdraw);
2855: }
2856: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2858: if (flag_threshold) {
2859: PetscInt bs,rstart,rend,i;
2860: MatGetBlockSize(B,&bs);
2861: MatGetOwnershipRange(B,&rstart,&rend);
2862: for (i=rstart; i<rend; i++) {
2863: const PetscScalar *ba,*ca;
2864: const PetscInt *bj,*cj;
2865: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2866: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2867: MatGetRow(B,i,&bn,&bj,&ba);
2868: MatGetRow(Bfd,i,&cn,&cj,&ca);
2869: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2870: for (j=0; j<bn; j++) {
2871: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2872: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2873: maxentrycol = bj[j];
2874: maxentry = PetscRealPart(ba[j]);
2875: }
2876: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2877: maxdiffcol = bj[j];
2878: maxdiff = PetscRealPart(ca[j]);
2879: }
2880: if (rdiff > maxrdiff) {
2881: maxrdiffcol = bj[j];
2882: maxrdiff = rdiff;
2883: }
2884: }
2885: if (maxrdiff > 1) {
2886: 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);
2887: for (j=0; j<bn; j++) {
2888: PetscReal rdiff;
2889: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2890: if (rdiff > 1) {
2891: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2892: }
2893: }
2894: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2895: }
2896: MatRestoreRow(B,i,&bn,&bj,&ba);
2897: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2898: }
2899: }
2900: PetscViewerDestroy(&vdraw);
2901: MatDestroy(&Bfd);
2902: }
2903: }
2904: return(0);
2905: }
2907: /*MC
2908: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2910: Synopsis:
2911: #include "petscsnes.h"
2912: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2914: Collective on snes
2916: Input Parameters:
2917: + x - input vector, the Jacobian is to be computed at this value
2918: - ctx - [optional] user-defined Jacobian context
2920: Output Parameters:
2921: + Amat - the matrix that defines the (approximate) Jacobian
2922: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2924: Level: intermediate
2926: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2927: M*/
2929: /*@C
2930: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2931: location to store the matrix.
2933: Logically Collective on SNES
2935: Input Parameters:
2936: + snes - the SNES context
2937: . Amat - the matrix that defines the (approximate) Jacobian
2938: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2939: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2940: - ctx - [optional] user-defined context for private data for the
2941: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2943: Notes:
2944: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2945: each matrix.
2947: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2948: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2950: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2951: must be a MatFDColoring.
2953: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2954: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2956: Level: beginner
2958: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2959: SNESSetPicard(), SNESJacobianFunction
2960: @*/
2961: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2962: {
2964: DM dm;
2972: SNESGetDM(snes,&dm);
2973: DMSNESSetJacobian(dm,J,ctx);
2974: if (Amat) {
2975: PetscObjectReference((PetscObject)Amat);
2976: MatDestroy(&snes->jacobian);
2978: snes->jacobian = Amat;
2979: }
2980: if (Pmat) {
2981: PetscObjectReference((PetscObject)Pmat);
2982: MatDestroy(&snes->jacobian_pre);
2984: snes->jacobian_pre = Pmat;
2985: }
2986: return(0);
2987: }
2989: /*@C
2990: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2991: provided context for evaluating the Jacobian.
2993: Not Collective, but Mat object will be parallel if SNES object is
2995: Input Parameter:
2996: . snes - the nonlinear solver context
2998: Output Parameters:
2999: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
3000: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
3001: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
3002: - ctx - location to stash Jacobian ctx (or NULL)
3004: Level: advanced
3006: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
3007: @*/
3008: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
3009: {
3011: DM dm;
3012: DMSNES sdm;
3016: if (Amat) *Amat = snes->jacobian;
3017: if (Pmat) *Pmat = snes->jacobian_pre;
3018: SNESGetDM(snes,&dm);
3019: DMGetDMSNES(dm,&sdm);
3020: if (J) *J = sdm->ops->computejacobian;
3021: if (ctx) *ctx = sdm->jacobianctx;
3022: return(0);
3023: }
3025: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3026: {
3028: DM dm;
3029: DMSNES sdm;
3032: SNESGetDM(snes,&dm);
3033: DMGetDMSNES(dm,&sdm);
3034: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3035: DM dm;
3036: PetscBool isdense,ismf;
3038: SNESGetDM(snes,&dm);
3039: PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre,&isdense,MATSEQDENSE,MATMPIDENSE,MATDENSE,NULL);
3040: PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre,&ismf,MATMFFD,MATSHELL,NULL);
3041: if (isdense) {
3042: DMSNESSetJacobian(dm,SNESComputeJacobianDefault,NULL);
3043: } else if (!ismf) {
3044: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3045: }
3046: }
3047: return(0);
3048: }
3050: /*@
3051: SNESSetUp - Sets up the internal data structures for the later use
3052: of a nonlinear solver.
3054: Collective on SNES
3056: Input Parameters:
3057: . snes - the SNES context
3059: Notes:
3060: For basic use of the SNES solvers the user need not explicitly call
3061: SNESSetUp(), since these actions will automatically occur during
3062: the call to SNESSolve(). However, if one wishes to control this
3063: phase separately, SNESSetUp() should be called after SNESCreate()
3064: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3066: Level: advanced
3068: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3069: @*/
3070: PetscErrorCode SNESSetUp(SNES snes)
3071: {
3073: DM dm;
3074: DMSNES sdm;
3075: SNESLineSearch linesearch, pclinesearch;
3076: void *lsprectx,*lspostctx;
3077: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3078: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3079: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3080: Vec f,fpc;
3081: void *funcctx;
3082: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3083: void *jacctx,*appctx;
3084: Mat j,jpre;
3088: if (snes->setupcalled) return(0);
3089: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3091: if (!((PetscObject)snes)->type_name) {
3092: SNESSetType(snes,SNESNEWTONLS);
3093: }
3095: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3097: SNESGetDM(snes,&dm);
3098: DMGetDMSNES(dm,&sdm);
3099: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3100: SNESSetDefaultComputeJacobian(snes);
3102: if (!snes->vec_func) {
3103: DMCreateGlobalVector(dm,&snes->vec_func);
3104: }
3106: if (!snes->ksp) {
3107: SNESGetKSP(snes, &snes->ksp);
3108: }
3110: if (snes->linesearch) {
3111: SNESGetLineSearch(snes, &snes->linesearch);
3112: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3113: }
3115: if (snes->npc && (snes->npcside== PC_LEFT)) {
3116: snes->mf = PETSC_TRUE;
3117: snes->mf_operator = PETSC_FALSE;
3118: }
3120: if (snes->npc) {
3121: /* copy the DM over */
3122: SNESGetDM(snes,&dm);
3123: SNESSetDM(snes->npc,dm);
3125: SNESGetFunction(snes,&f,&func,&funcctx);
3126: VecDuplicate(f,&fpc);
3127: SNESSetFunction(snes->npc,fpc,func,funcctx);
3128: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3129: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3130: SNESGetApplicationContext(snes,&appctx);
3131: SNESSetApplicationContext(snes->npc,appctx);
3132: VecDestroy(&fpc);
3134: /* copy the function pointers over */
3135: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3137: /* default to 1 iteration */
3138: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3139: if (snes->npcside==PC_RIGHT) {
3140: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3141: } else {
3142: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3143: }
3144: SNESSetFromOptions(snes->npc);
3146: /* copy the line search context over */
3147: if (snes->linesearch && snes->npc->linesearch) {
3148: SNESGetLineSearch(snes,&linesearch);
3149: SNESGetLineSearch(snes->npc,&pclinesearch);
3150: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3151: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3152: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3153: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3154: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3155: }
3156: }
3157: if (snes->mf) {
3158: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3159: }
3160: if (snes->ops->usercompute && !snes->user) {
3161: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3162: }
3164: snes->jac_iter = 0;
3165: snes->pre_iter = 0;
3167: if (snes->ops->setup) {
3168: (*snes->ops->setup)(snes);
3169: }
3171: SNESSetDefaultComputeJacobian(snes);
3173: if (snes->npc && (snes->npcside== PC_LEFT)) {
3174: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3175: if (snes->linesearch){
3176: SNESGetLineSearch(snes,&linesearch);
3177: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3178: }
3179: }
3180: }
3181: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3182: snes->setupcalled = PETSC_TRUE;
3183: return(0);
3184: }
3186: /*@
3187: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3189: Collective on SNES
3191: Input Parameter:
3192: . snes - iterative context obtained from SNESCreate()
3194: Level: intermediate
3196: Notes:
3197: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3199: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3200: @*/
3201: PetscErrorCode SNESReset(SNES snes)
3202: {
3207: if (snes->ops->userdestroy && snes->user) {
3208: (*snes->ops->userdestroy)((void**)&snes->user);
3209: snes->user = NULL;
3210: }
3211: if (snes->npc) {
3212: SNESReset(snes->npc);
3213: }
3215: if (snes->ops->reset) {
3216: (*snes->ops->reset)(snes);
3217: }
3218: if (snes->ksp) {
3219: KSPReset(snes->ksp);
3220: }
3222: if (snes->linesearch) {
3223: SNESLineSearchReset(snes->linesearch);
3224: }
3226: VecDestroy(&snes->vec_rhs);
3227: VecDestroy(&snes->vec_sol);
3228: VecDestroy(&snes->vec_sol_update);
3229: VecDestroy(&snes->vec_func);
3230: MatDestroy(&snes->jacobian);
3231: MatDestroy(&snes->jacobian_pre);
3232: VecDestroyVecs(snes->nwork,&snes->work);
3233: VecDestroyVecs(snes->nvwork,&snes->vwork);
3235: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3237: snes->nwork = snes->nvwork = 0;
3238: snes->setupcalled = PETSC_FALSE;
3239: return(0);
3240: }
3242: /*@
3243: SNESConvergedReasonViewCancel - Clears all the reasonview functions for a SNES object.
3245: Collective on SNES
3247: Input Parameter:
3248: . snes - iterative context obtained from SNESCreate()
3250: Level: intermediate
3252: .seealso: SNESCreate(), SNESDestroy(), SNESReset()
3253: @*/
3254: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3255: {
3257: PetscInt i;
3261: for (i=0; i<snes->numberreasonviews; i++) {
3262: if (snes->reasonviewdestroy[i]) {
3263: (*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]);
3264: }
3265: }
3266: snes->numberreasonviews = 0;
3267: return(0);
3268: }
3270: /*@C
3271: SNESDestroy - Destroys the nonlinear solver context that was created
3272: with SNESCreate().
3274: Collective on SNES
3276: Input Parameter:
3277: . snes - the SNES context
3279: Level: beginner
3281: .seealso: SNESCreate(), SNESSolve()
3282: @*/
3283: PetscErrorCode SNESDestroy(SNES *snes)
3284: {
3288: if (!*snes) return(0);
3290: if (--((PetscObject)(*snes))->refct > 0) {*snes = NULL; return(0);}
3292: SNESReset((*snes));
3293: SNESDestroy(&(*snes)->npc);
3295: /* if memory was published with SAWs then destroy it */
3296: PetscObjectSAWsViewOff((PetscObject)*snes);
3297: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3299: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3300: DMDestroy(&(*snes)->dm);
3301: KSPDestroy(&(*snes)->ksp);
3302: SNESLineSearchDestroy(&(*snes)->linesearch);
3304: PetscFree((*snes)->kspconvctx);
3305: if ((*snes)->ops->convergeddestroy) {
3306: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3307: }
3308: if ((*snes)->conv_hist_alloc) {
3309: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3310: }
3311: SNESMonitorCancel((*snes));
3312: SNESConvergedReasonViewCancel((*snes));
3313: PetscHeaderDestroy(snes);
3314: return(0);
3315: }
3317: /* ----------- Routines to set solver parameters ---------- */
3319: /*@
3320: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3322: Logically Collective on SNES
3324: Input Parameters:
3325: + snes - the SNES context
3326: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3327: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3329: Options Database Keys:
3330: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3331: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3332: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3333: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3335: Notes:
3336: The default is 1
3337: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or SNESSetLagPreconditionerPersists() was called
3339: SNESSetLagPreconditionerPersists() allows using the same uniform lagging (for example every second solve) across multiple solves.
3341: Level: intermediate
3343: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetLagPreconditionerPersists(),
3344: SNESSetLagJacobianPersists()
3346: @*/
3347: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3348: {
3351: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3352: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3354: snes->lagpreconditioner = lag;
3355: return(0);
3356: }
3358: /*@
3359: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3361: Logically Collective on SNES
3363: Input Parameters:
3364: + snes - the SNES context
3365: - steps - the number of refinements to do, defaults to 0
3367: Options Database Keys:
3368: . -snes_grid_sequence <steps>
3370: Level: intermediate
3372: Notes:
3373: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3375: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3377: @*/
3378: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3379: {
3383: snes->gridsequence = steps;
3384: return(0);
3385: }
3387: /*@
3388: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3390: Logically Collective on SNES
3392: Input Parameter:
3393: . snes - the SNES context
3395: Output Parameter:
3396: . steps - the number of refinements to do, defaults to 0
3398: Options Database Keys:
3399: . -snes_grid_sequence <steps>
3401: Level: intermediate
3403: Notes:
3404: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3406: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3408: @*/
3409: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3410: {
3413: *steps = snes->gridsequence;
3414: return(0);
3415: }
3417: /*@
3418: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3420: Not Collective
3422: Input Parameter:
3423: . snes - the SNES context
3425: Output Parameter:
3426: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3427: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3429: Options Database Keys:
3430: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3431: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3432: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3433: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3435: Notes:
3436: The default is 1
3437: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3439: Level: intermediate
3441: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
3443: @*/
3444: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3445: {
3448: *lag = snes->lagpreconditioner;
3449: return(0);
3450: }
3452: /*@
3453: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3454: often the preconditioner is rebuilt.
3456: Logically Collective on SNES
3458: Input Parameters:
3459: + snes - the SNES context
3460: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3461: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3463: Options Database Keys:
3464: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3465: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3466: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3467: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3469: Notes:
3470: The default is 1
3471: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3472: 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
3473: at the next Newton step but never again (unless it is reset to another value)
3475: Level: intermediate
3477: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
3479: @*/
3480: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3481: {
3484: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3485: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3487: snes->lagjacobian = lag;
3488: return(0);
3489: }
3491: /*@
3492: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3494: Not Collective
3496: Input Parameter:
3497: . snes - the SNES context
3499: Output Parameter:
3500: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3501: the Jacobian is built etc.
3503: Notes:
3504: The default is 1
3505: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or SNESSetLagJacobianPersists() was called.
3507: Level: intermediate
3509: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
3511: @*/
3512: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3513: {
3516: *lag = snes->lagjacobian;
3517: return(0);
3518: }
3520: /*@
3521: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3523: Logically collective on SNES
3525: Input Parameter:
3526: + snes - the SNES context
3527: - flg - jacobian lagging persists if true
3529: Options Database Keys:
3530: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3531: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3532: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3533: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3536: Notes:
3537: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3538: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3539: timesteps may present huge efficiency gains.
3541: Level: developer
3543: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC(), SNESSetLagJacobianPersists()
3545: @*/
3546: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3547: {
3551: snes->lagjac_persist = flg;
3552: return(0);
3553: }
3555: /*@
3556: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3558: Logically Collective on SNES
3560: Input Parameter:
3561: + snes - the SNES context
3562: - flg - preconditioner lagging persists if true
3564: Options Database Keys:
3565: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3566: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3567: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3568: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3570: Notes:
3571: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3572: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3573: several timesteps may present huge efficiency gains.
3575: Level: developer
3577: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC(), SNESSetLagPreconditioner()
3579: @*/
3580: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3581: {
3585: snes->lagpre_persist = flg;
3586: return(0);
3587: }
3589: /*@
3590: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3592: Logically Collective on SNES
3594: Input Parameters:
3595: + snes - the SNES context
3596: - force - PETSC_TRUE require at least one iteration
3598: Options Database Keys:
3599: . -snes_force_iteration <force> - Sets forcing an iteration
3601: Notes:
3602: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3604: Level: intermediate
3606: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3607: @*/
3608: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3609: {
3612: snes->forceiteration = force;
3613: return(0);
3614: }
3616: /*@
3617: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3619: Logically Collective on SNES
3621: Input Parameters:
3622: . snes - the SNES context
3624: Output Parameter:
3625: . force - PETSC_TRUE requires at least one iteration.
3627: Level: intermediate
3629: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3630: @*/
3631: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3632: {
3635: *force = snes->forceiteration;
3636: return(0);
3637: }
3639: /*@
3640: SNESSetTolerances - Sets various parameters used in convergence tests.
3642: Logically Collective on SNES
3644: Input Parameters:
3645: + snes - the SNES context
3646: . abstol - absolute convergence tolerance
3647: . rtol - relative convergence tolerance
3648: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3649: . maxit - maximum number of iterations
3650: - maxf - maximum number of function evaluations (-1 indicates no limit)
3652: Options Database Keys:
3653: + -snes_atol <abstol> - Sets abstol
3654: . -snes_rtol <rtol> - Sets rtol
3655: . -snes_stol <stol> - Sets stol
3656: . -snes_max_it <maxit> - Sets maxit
3657: - -snes_max_funcs <maxf> - Sets maxf
3659: Notes:
3660: The default maximum number of iterations is 50.
3661: The default maximum number of function evaluations is 1000.
3663: Level: intermediate
3665: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3666: @*/
3667: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3668: {
3677: if (abstol != PETSC_DEFAULT) {
3678: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3679: snes->abstol = abstol;
3680: }
3681: if (rtol != PETSC_DEFAULT) {
3682: 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);
3683: snes->rtol = rtol;
3684: }
3685: if (stol != PETSC_DEFAULT) {
3686: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3687: snes->stol = stol;
3688: }
3689: if (maxit != PETSC_DEFAULT) {
3690: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3691: snes->max_its = maxit;
3692: }
3693: if (maxf != PETSC_DEFAULT) {
3694: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3695: snes->max_funcs = maxf;
3696: }
3697: snes->tolerancesset = PETSC_TRUE;
3698: return(0);
3699: }
3701: /*@
3702: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3704: Logically Collective on SNES
3706: Input Parameters:
3707: + snes - the SNES context
3708: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3710: Options Database Keys:
3711: . -snes_divergence_tolerance <divtol> - Sets divtol
3713: Notes:
3714: The default divergence tolerance is 1e4.
3716: Level: intermediate
3718: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3719: @*/
3720: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3721: {
3726: if (divtol != PETSC_DEFAULT) {
3727: snes->divtol = divtol;
3728: }
3729: else {
3730: snes->divtol = 1.0e4;
3731: }
3732: return(0);
3733: }
3735: /*@
3736: SNESGetTolerances - Gets various parameters used in convergence tests.
3738: Not Collective
3740: Input Parameters:
3741: + snes - the SNES context
3742: . atol - absolute convergence tolerance
3743: . rtol - relative convergence tolerance
3744: . stol - convergence tolerance in terms of the norm
3745: of the change in the solution between steps
3746: . maxit - maximum number of iterations
3747: - maxf - maximum number of function evaluations
3749: Notes:
3750: The user can specify NULL for any parameter that is not needed.
3752: Level: intermediate
3754: .seealso: SNESSetTolerances()
3755: @*/
3756: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3757: {
3760: if (atol) *atol = snes->abstol;
3761: if (rtol) *rtol = snes->rtol;
3762: if (stol) *stol = snes->stol;
3763: if (maxit) *maxit = snes->max_its;
3764: if (maxf) *maxf = snes->max_funcs;
3765: return(0);
3766: }
3768: /*@
3769: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3771: Not Collective
3773: Input Parameters:
3774: + snes - the SNES context
3775: - divtol - divergence tolerance
3777: Level: intermediate
3779: .seealso: SNESSetDivergenceTolerance()
3780: @*/
3781: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3782: {
3785: if (divtol) *divtol = snes->divtol;
3786: return(0);
3787: }
3789: /*@
3790: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3792: Logically Collective on SNES
3794: Input Parameters:
3795: + snes - the SNES context
3796: - tol - tolerance
3798: Options Database Key:
3799: . -snes_trtol <tol> - Sets tol
3801: Level: intermediate
3803: .seealso: SNESSetTolerances()
3804: @*/
3805: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3806: {
3810: snes->deltatol = tol;
3811: return(0);
3812: }
3814: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3816: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3817: {
3818: PetscDrawLG lg;
3819: PetscErrorCode ierr;
3820: PetscReal x,y,per;
3821: PetscViewer v = (PetscViewer)monctx;
3822: static PetscReal prev; /* should be in the context */
3823: PetscDraw draw;
3827: PetscViewerDrawGetDrawLG(v,0,&lg);
3828: if (!n) {PetscDrawLGReset(lg);}
3829: PetscDrawLGGetDraw(lg,&draw);
3830: PetscDrawSetTitle(draw,"Residual norm");
3831: x = (PetscReal)n;
3832: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3833: else y = -15.0;
3834: PetscDrawLGAddPoint(lg,&x,&y);
3835: if (n < 20 || !(n % 5) || snes->reason) {
3836: PetscDrawLGDraw(lg);
3837: PetscDrawLGSave(lg);
3838: }
3840: PetscViewerDrawGetDrawLG(v,1,&lg);
3841: if (!n) {PetscDrawLGReset(lg);}
3842: PetscDrawLGGetDraw(lg,&draw);
3843: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3844: SNESMonitorRange_Private(snes,n,&per);
3845: x = (PetscReal)n;
3846: y = 100.0*per;
3847: PetscDrawLGAddPoint(lg,&x,&y);
3848: if (n < 20 || !(n % 5) || snes->reason) {
3849: PetscDrawLGDraw(lg);
3850: PetscDrawLGSave(lg);
3851: }
3853: PetscViewerDrawGetDrawLG(v,2,&lg);
3854: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3855: PetscDrawLGGetDraw(lg,&draw);
3856: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3857: x = (PetscReal)n;
3858: y = (prev - rnorm)/prev;
3859: PetscDrawLGAddPoint(lg,&x,&y);
3860: if (n < 20 || !(n % 5) || snes->reason) {
3861: PetscDrawLGDraw(lg);
3862: PetscDrawLGSave(lg);
3863: }
3865: PetscViewerDrawGetDrawLG(v,3,&lg);
3866: if (!n) {PetscDrawLGReset(lg);}
3867: PetscDrawLGGetDraw(lg,&draw);
3868: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3869: x = (PetscReal)n;
3870: y = (prev - rnorm)/(prev*per);
3871: if (n > 2) { /*skip initial crazy value */
3872: PetscDrawLGAddPoint(lg,&x,&y);
3873: }
3874: if (n < 20 || !(n % 5) || snes->reason) {
3875: PetscDrawLGDraw(lg);
3876: PetscDrawLGSave(lg);
3877: }
3878: prev = rnorm;
3879: return(0);
3880: }
3882: /*@
3883: SNESMonitor - runs the user provided monitor routines, if they exist
3885: Collective on SNES
3887: Input Parameters:
3888: + snes - nonlinear solver context obtained from SNESCreate()
3889: . iter - iteration number
3890: - rnorm - relative norm of the residual
3892: Notes:
3893: This routine is called by the SNES implementations.
3894: It does not typically need to be called by the user.
3896: Level: developer
3898: .seealso: SNESMonitorSet()
3899: @*/
3900: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3901: {
3903: PetscInt i,n = snes->numbermonitors;
3906: VecLockReadPush(snes->vec_sol);
3907: for (i=0; i<n; i++) {
3908: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3909: }
3910: VecLockReadPop(snes->vec_sol);
3911: return(0);
3912: }
3914: /* ------------ Routines to set performance monitoring options ----------- */
3916: /*MC
3917: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3919: Synopsis:
3920: #include <petscsnes.h>
3921: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3923: Collective on snes
3925: Input Parameters:
3926: + snes - the SNES context
3927: . its - iteration number
3928: . norm - 2-norm function value (may be estimated)
3929: - mctx - [optional] monitoring context
3931: Level: advanced
3933: .seealso: SNESMonitorSet(), SNESMonitorGet()
3934: M*/
3936: /*@C
3937: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3938: iteration of the nonlinear solver to display the iteration's
3939: progress.
3941: Logically Collective on SNES
3943: Input Parameters:
3944: + snes - the SNES context
3945: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3946: . mctx - [optional] user-defined context for private data for the
3947: monitor routine (use NULL if no context is desired)
3948: - monitordestroy - [optional] routine that frees monitor context
3949: (may be NULL)
3951: Options Database Keys:
3952: + -snes_monitor - sets SNESMonitorDefault()
3953: . -snes_monitor draw::draw_lg - sets line graph monitor,
3954: - -snes_monitor_cancel - cancels all monitors that have
3955: been hardwired into a code by
3956: calls to SNESMonitorSet(), but
3957: does not cancel those set via
3958: the options database.
3960: Notes:
3961: Several different monitoring routines may be set by calling
3962: SNESMonitorSet() multiple times; all will be called in the
3963: order in which they were set.
3965: Fortran Notes:
3966: Only a single monitor function can be set for each SNES object
3968: Level: intermediate
3970: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3971: @*/
3972: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3973: {
3974: PetscInt i;
3976: PetscBool identical;
3980: for (i=0; i<snes->numbermonitors;i++) {
3981: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3982: if (identical) return(0);
3983: }
3984: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3985: snes->monitor[snes->numbermonitors] = f;
3986: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3987: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3988: return(0);
3989: }
3991: /*@
3992: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3994: Logically Collective on SNES
3996: Input Parameters:
3997: . snes - the SNES context
3999: Options Database Key:
4000: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4001: into a code by calls to SNESMonitorSet(), but does not cancel those
4002: set via the options database
4004: Notes:
4005: There is no way to clear one specific monitor from a SNES object.
4007: Level: intermediate
4009: .seealso: SNESMonitorDefault(), SNESMonitorSet()
4010: @*/
4011: PetscErrorCode SNESMonitorCancel(SNES snes)
4012: {
4014: PetscInt i;
4018: for (i=0; i<snes->numbermonitors; i++) {
4019: if (snes->monitordestroy[i]) {
4020: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
4021: }
4022: }
4023: snes->numbermonitors = 0;
4024: return(0);
4025: }
4027: /*MC
4028: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4030: Synopsis:
4031: #include <petscsnes.h>
4032: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
4034: Collective on snes
4036: Input Parameters:
4037: + snes - the SNES context
4038: . it - current iteration (0 is the first and is before any Newton step)
4039: . xnorm - 2-norm of current iterate
4040: . gnorm - 2-norm of current step
4041: . f - 2-norm of function
4042: - cctx - [optional] convergence context
4044: Output Parameter:
4045: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4047: Level: intermediate
4049: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
4050: M*/
4052: /*@C
4053: SNESSetConvergenceTest - Sets the function that is to be used
4054: to test for convergence of the nonlinear iterative solution.
4056: Logically Collective on SNES
4058: Input Parameters:
4059: + snes - the SNES context
4060: . SNESConvergenceTestFunction - routine to test for convergence
4061: . cctx - [optional] context for private data for the convergence routine (may be NULL)
4062: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
4064: Level: advanced
4066: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
4067: @*/
4068: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
4069: {
4074: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4075: if (snes->ops->convergeddestroy) {
4076: (*snes->ops->convergeddestroy)(snes->cnvP);
4077: }
4078: snes->ops->converged = SNESConvergenceTestFunction;
4079: snes->ops->convergeddestroy = destroy;
4080: snes->cnvP = cctx;
4081: return(0);
4082: }
4084: /*@
4085: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4087: Not Collective
4089: Input Parameter:
4090: . snes - the SNES context
4092: Output Parameter:
4093: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4094: manual pages for the individual convergence tests for complete lists
4096: Options Database:
4097: . -snes_converged_reason - prints the reason to standard out
4099: Level: intermediate
4101: Notes:
4102: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4104: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4105: @*/
4106: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4107: {
4111: *reason = snes->reason;
4112: return(0);
4113: }
4115: /*@C
4116: SNESGetConvergedReasonString - Return a human readable string for snes converged reason
4118: Not Collective
4120: Input Parameter:
4121: . snes - the SNES context
4123: Output Parameter:
4124: . strreason - a human readable string that describes SNES converged reason
4126: Level: beginner
4128: .seealso: SNESGetConvergedReason()
4129: @*/
4130: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char** strreason)
4131: {
4135: *strreason = SNESConvergedReasons[snes->reason];
4136: return(0);
4137: }
4139: /*@
4140: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4142: Not Collective
4144: Input Parameters:
4145: + snes - the SNES context
4146: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4147: manual pages for the individual convergence tests for complete lists
4149: Level: intermediate
4151: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4152: @*/
4153: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4154: {
4157: snes->reason = reason;
4158: return(0);
4159: }
4161: /*@
4162: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4164: Logically Collective on SNES
4166: Input Parameters:
4167: + snes - iterative context obtained from SNESCreate()
4168: . a - array to hold history, this array will contain the function norms computed at each step
4169: . its - integer array holds the number of linear iterations for each solve.
4170: . na - size of a and its
4171: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4172: else it continues storing new values for new nonlinear solves after the old ones
4174: Notes:
4175: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4176: default array of length 10000 is allocated.
4178: This routine is useful, e.g., when running a code for purposes
4179: of accurate performance monitoring, when no I/O should be done
4180: during the section of code that is being timed.
4182: Level: intermediate
4184: .seealso: SNESGetConvergenceHistory()
4186: @*/
4187: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4188: {
4195: if (!a) {
4196: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4197: PetscCalloc2(na,&a,na,&its);
4198: snes->conv_hist_alloc = PETSC_TRUE;
4199: }
4200: snes->conv_hist = a;
4201: snes->conv_hist_its = its;
4202: snes->conv_hist_max = na;
4203: snes->conv_hist_len = 0;
4204: snes->conv_hist_reset = reset;
4205: return(0);
4206: }
4208: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4209: #include <engine.h> /* MATLAB include file */
4210: #include <mex.h> /* MATLAB include file */
4212: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4213: {
4214: mxArray *mat;
4215: PetscInt i;
4216: PetscReal *ar;
4219: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4220: ar = (PetscReal*) mxGetData(mat);
4221: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4222: PetscFunctionReturn(mat);
4223: }
4224: #endif
4226: /*@C
4227: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4229: Not Collective
4231: Input Parameter:
4232: . snes - iterative context obtained from SNESCreate()
4234: Output Parameters:
4235: + a - array to hold history
4236: . its - integer array holds the number of linear iterations (or
4237: negative if not converged) for each solve.
4238: - na - size of a and its
4240: Notes:
4241: The calling sequence for this routine in Fortran is
4242: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4244: This routine is useful, e.g., when running a code for purposes
4245: of accurate performance monitoring, when no I/O should be done
4246: during the section of code that is being timed.
4248: Level: intermediate
4250: .seealso: SNESSetConvergenceHistory()
4252: @*/
4253: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4254: {
4257: if (a) *a = snes->conv_hist;
4258: if (its) *its = snes->conv_hist_its;
4259: if (na) *na = snes->conv_hist_len;
4260: return(0);
4261: }
4263: /*@C
4264: SNESSetUpdate - Sets the general-purpose update function called
4265: at the beginning of every iteration of the nonlinear solve. Specifically
4266: it is called just before the Jacobian is "evaluated".
4268: Logically Collective on SNES
4270: Input Parameters:
4271: + snes - The nonlinear solver context
4272: - func - The function
4274: Calling sequence of func:
4275: $ func (SNES snes, PetscInt step);
4277: . step - The current step of the iteration
4279: Level: advanced
4281: Note: This is NOT what one uses to update the ghost points before a function evaluation, that should be done at the beginning of your FormFunction()
4282: This is not used by most users.
4284: .seealso SNESSetJacobian(), SNESSolve()
4285: @*/
4286: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4287: {
4290: snes->ops->update = func;
4291: return(0);
4292: }
4294: /*
4295: SNESScaleStep_Private - Scales a step so that its length is less than the
4296: positive parameter delta.
4298: Input Parameters:
4299: + snes - the SNES context
4300: . y - approximate solution of linear system
4301: . fnorm - 2-norm of current function
4302: - delta - trust region size
4304: Output Parameters:
4305: + gpnorm - predicted function norm at the new point, assuming local
4306: linearization. The value is zero if the step lies within the trust
4307: region, and exceeds zero otherwise.
4308: - ynorm - 2-norm of the step
4310: Note:
4311: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4312: is set to be the maximum allowable step size.
4314: */
4315: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4316: {
4317: PetscReal nrm;
4318: PetscScalar cnorm;
4326: VecNorm(y,NORM_2,&nrm);
4327: if (nrm > *delta) {
4328: nrm = *delta/nrm;
4329: *gpnorm = (1.0 - nrm)*(*fnorm);
4330: cnorm = nrm;
4331: VecScale(y,cnorm);
4332: *ynorm = *delta;
4333: } else {
4334: *gpnorm = 0.0;
4335: *ynorm = nrm;
4336: }
4337: return(0);
4338: }
4340: /*@C
4341: SNESConvergedReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4343: Collective on SNES
4345: Parameter:
4346: + snes - iterative context obtained from SNESCreate()
4347: - viewer - the viewer to display the reason
4350: Options Database Keys:
4351: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4352: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4354: Notes:
4355: To change the format of the output call PetscViewerPushFormat(viewer,format) before this call. Use PETSC_VIEWER_DEFAULT for the default,
4356: use PETSC_VIEWER_FAILED to only display a reason if it fails.
4358: Level: beginner
4360: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault(), SNESGetConvergedReason(), SNESConvergedReasonViewFromOptions(),
4361: PetscViewerPushFormat(), PetscViewerPopFormat()
4363: @*/
4364: PetscErrorCode SNESConvergedReasonView(SNES snes,PetscViewer viewer)
4365: {
4366: PetscViewerFormat format;
4367: PetscBool isAscii;
4368: PetscErrorCode ierr;
4371: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4372: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4373: if (isAscii) {
4374: PetscViewerGetFormat(viewer, &format);
4375: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4376: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4377: DM dm;
4378: Vec u;
4379: PetscDS prob;
4380: PetscInt Nf, f;
4381: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4382: void **exactCtx;
4383: PetscReal error;
4385: SNESGetDM(snes, &dm);
4386: SNESGetSolution(snes, &u);
4387: DMGetDS(dm, &prob);
4388: PetscDSGetNumFields(prob, &Nf);
4389: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4390: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4391: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4392: PetscFree2(exactSol, exactCtx);
4393: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4394: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4395: }
4396: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4397: if (((PetscObject) snes)->prefix) {
4398: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4399: } else {
4400: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4401: }
4402: } else if (snes->reason <= 0) {
4403: if (((PetscObject) snes)->prefix) {
4404: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4405: } else {
4406: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4407: }
4408: }
4409: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4410: }
4411: return(0);
4412: }
4414: /*@C
4415: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4416: end of the nonlinear solver to display the conver reason of the nonlinear solver.
4418: Logically Collective on SNES
4420: Input Parameters:
4421: + snes - the SNES context
4422: . f - the snes converged reason view function
4423: . vctx - [optional] user-defined context for private data for the
4424: snes converged reason view routine (use NULL if no context is desired)
4425: - reasonviewdestroy - [optional] routine that frees reasonview context
4426: (may be NULL)
4428: Options Database Keys:
4429: + -snes_converged_reason - sets a default SNESConvergedReasonView()
4430: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have
4431: been hardwired into a code by
4432: calls to SNESConvergedReasonViewSet(), but
4433: does not cancel those set via
4434: the options database.
4436: Notes:
4437: Several different converged reason view routines may be set by calling
4438: SNESConvergedReasonViewSet() multiple times; all will be called in the
4439: order in which they were set.
4441: Level: intermediate
4443: .seealso: SNESConvergedReasonView(), SNESConvergedReasonViewCancel()
4444: @*/
4445: PetscErrorCode SNESConvergedReasonViewSet(SNES snes,PetscErrorCode (*f)(SNES,void*),void *vctx,PetscErrorCode (*reasonviewdestroy)(void**))
4446: {
4447: PetscInt i;
4449: PetscBool identical;
4453: for (i=0; i<snes->numberreasonviews;i++) {
4454: PetscMonitorCompare((PetscErrorCode (*)(void))f,vctx,reasonviewdestroy,(PetscErrorCode (*)(void))snes->reasonview[i],snes->reasonviewcontext[i],snes->reasonviewdestroy[i],&identical);
4455: if (identical) return(0);
4456: }
4457: if (snes->numberreasonviews >= MAXSNESREASONVIEWS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many SNES reasonview set");
4458: snes->reasonview[snes->numberreasonviews] = f;
4459: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4460: snes->reasonviewcontext[snes->numberreasonviews++] = (void*)vctx;
4461: return(0);
4462: }
4464: /*@
4465: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4466: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4468: Collective on SNES
4470: Input Parameters:
4471: . snes - the SNES object
4473: Level: intermediate
4475: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault(), SNESGetConvergedReason(), SNESConvergedReasonView()
4477: @*/
4478: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4479: {
4480: PetscErrorCode ierr;
4481: PetscViewer viewer;
4482: PetscBool flg;
4483: static PetscBool incall = PETSC_FALSE;
4484: PetscViewerFormat format;
4485: PetscInt i;
4488: if (incall) return(0);
4489: incall = PETSC_TRUE;
4491: /* All user-provided viewers are called first, if they exist. */
4492: for (i=0; i<snes->numberreasonviews; i++) {
4493: (*snes->reasonview[i])(snes,snes->reasonviewcontext[i]);
4494: }
4496: /* Call PETSc default routine if users ask for it */
4497: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4498: if (flg) {
4499: PetscViewerPushFormat(viewer,format);
4500: SNESConvergedReasonView(snes,viewer);
4501: PetscViewerPopFormat(viewer);
4502: PetscViewerDestroy(&viewer);
4503: }
4504: incall = PETSC_FALSE;
4505: return(0);
4506: }
4508: /*@
4509: SNESSolve - Solves a nonlinear system F(x) = b.
4510: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4512: Collective on SNES
4514: Input Parameters:
4515: + snes - the SNES context
4516: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4517: - x - the solution vector.
4519: Notes:
4520: The user should initialize the vector,x, with the initial guess
4521: for the nonlinear solve prior to calling SNESSolve. In particular,
4522: to employ an initial guess of zero, the user should explicitly set
4523: this vector to zero by calling VecSet().
4525: Level: beginner
4527: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4528: @*/
4529: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4530: {
4531: PetscErrorCode ierr;
4532: PetscBool flg;
4533: PetscInt grid;
4534: Vec xcreated = NULL;
4535: DM dm;
4544: /* High level operations using the nonlinear solver */
4545: {
4546: PetscViewer viewer;
4547: PetscViewerFormat format;
4548: PetscInt num;
4549: PetscBool flg;
4550: static PetscBool incall = PETSC_FALSE;
4552: if (!incall) {
4553: /* Estimate the convergence rate of the discretization */
4554: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4555: if (flg) {
4556: PetscConvEst conv;
4557: DM dm;
4558: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4559: PetscInt Nf;
4561: incall = PETSC_TRUE;
4562: SNESGetDM(snes, &dm);
4563: DMGetNumFields(dm, &Nf);
4564: PetscCalloc1(Nf, &alpha);
4565: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4566: PetscConvEstSetSolver(conv, (PetscObject) snes);
4567: PetscConvEstSetFromOptions(conv);
4568: PetscConvEstSetUp(conv);
4569: PetscConvEstGetConvRate(conv, alpha);
4570: PetscViewerPushFormat(viewer, format);
4571: PetscConvEstRateView(conv, alpha, viewer);
4572: PetscViewerPopFormat(viewer);
4573: PetscViewerDestroy(&viewer);
4574: PetscConvEstDestroy(&conv);
4575: PetscFree(alpha);
4576: incall = PETSC_FALSE;
4577: }
4578: /* Adaptively refine the initial grid */
4579: num = 1;
4580: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4581: if (flg) {
4582: DMAdaptor adaptor;
4584: incall = PETSC_TRUE;
4585: DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor);
4586: DMAdaptorSetSolver(adaptor, snes);
4587: DMAdaptorSetSequenceLength(adaptor, num);
4588: DMAdaptorSetFromOptions(adaptor);
4589: DMAdaptorSetUp(adaptor);
4590: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4591: DMAdaptorDestroy(&adaptor);
4592: incall = PETSC_FALSE;
4593: }
4594: /* Use grid sequencing to adapt */
4595: num = 0;
4596: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4597: if (num) {
4598: DMAdaptor adaptor;
4600: incall = PETSC_TRUE;
4601: DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor);
4602: DMAdaptorSetSolver(adaptor, snes);
4603: DMAdaptorSetSequenceLength(adaptor, num);
4604: DMAdaptorSetFromOptions(adaptor);
4605: DMAdaptorSetUp(adaptor);
4606: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4607: DMAdaptorDestroy(&adaptor);
4608: incall = PETSC_FALSE;
4609: }
4610: }
4611: }
4612: if (!x) {
4613: SNESGetDM(snes,&dm);
4614: DMCreateGlobalVector(dm,&xcreated);
4615: x = xcreated;
4616: }
4617: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4619: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4620: for (grid=0; grid<snes->gridsequence+1; grid++) {
4622: /* set solution vector */
4623: if (!grid) {PetscObjectReference((PetscObject)x);}
4624: VecDestroy(&snes->vec_sol);
4625: snes->vec_sol = x;
4626: SNESGetDM(snes,&dm);
4628: /* set affine vector if provided */
4629: if (b) { PetscObjectReference((PetscObject)b); }
4630: VecDestroy(&snes->vec_rhs);
4631: snes->vec_rhs = b;
4633: 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");
4634: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4635: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4636: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4637: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4638: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4639: }
4640: DMShellSetGlobalVector(dm,snes->vec_sol);
4641: SNESSetUp(snes);
4643: if (!grid) {
4644: if (snes->ops->computeinitialguess) {
4645: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4646: }
4647: }
4649: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4650: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4652: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4653: (*snes->ops->solve)(snes);
4654: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4655: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4656: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4658: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4659: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4661: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4662: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4663: /* Call converged reason views. This may involve user-provided viewers as well */
4664: SNESConvergedReasonViewFromOptions(snes);
4666: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4667: if (snes->reason < 0) break;
4668: if (grid < snes->gridsequence) {
4669: DM fine;
4670: Vec xnew;
4671: Mat interp;
4673: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4674: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4675: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4676: DMCreateGlobalVector(fine,&xnew);
4677: MatInterpolate(interp,x,xnew);
4678: DMInterpolate(snes->dm,interp,fine);
4679: MatDestroy(&interp);
4680: x = xnew;
4682: SNESReset(snes);
4683: SNESSetDM(snes,fine);
4684: SNESResetFromOptions(snes);
4685: DMDestroy(&fine);
4686: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4687: }
4688: }
4689: SNESViewFromOptions(snes,NULL,"-snes_view");
4690: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4691: DMMonitor(snes->dm);
4693: VecDestroy(&xcreated);
4694: PetscObjectSAWsBlock((PetscObject)snes);
4695: return(0);
4696: }
4698: /* --------- Internal routines for SNES Package --------- */
4700: /*@C
4701: SNESSetType - Sets the method for the nonlinear solver.
4703: Collective on SNES
4705: Input Parameters:
4706: + snes - the SNES context
4707: - type - a known method
4709: Options Database Key:
4710: . -snes_type <type> - Sets the method; use -help for a list
4711: of available methods (for instance, newtonls or newtontr)
4713: Notes:
4714: See "petsc/include/petscsnes.h" for available methods (for instance)
4715: + SNESNEWTONLS - Newton's method with line search
4716: (systems of nonlinear equations)
4717: - SNESNEWTONTR - Newton's method with trust region
4718: (systems of nonlinear equations)
4720: Normally, it is best to use the SNESSetFromOptions() command and then
4721: set the SNES solver type from the options database rather than by using
4722: this routine. Using the options database provides the user with
4723: maximum flexibility in evaluating the many nonlinear solvers.
4724: The SNESSetType() routine is provided for those situations where it
4725: is necessary to set the nonlinear solver independently of the command
4726: line or options database. This might be the case, for example, when
4727: the choice of solver changes during the execution of the program,
4728: and the user's application is taking responsibility for choosing the
4729: appropriate method.
4731: Developer Notes:
4732: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4733: the constructor in that list and calls it to create the spexific object.
4735: Level: intermediate
4737: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4739: @*/
4740: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4741: {
4742: PetscErrorCode ierr,(*r)(SNES);
4743: PetscBool match;
4749: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4750: if (match) return(0);
4752: PetscFunctionListFind(SNESList,type,&r);
4753: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4754: /* Destroy the previous private SNES context */
4755: if (snes->ops->destroy) {
4756: (*(snes)->ops->destroy)(snes);
4757: snes->ops->destroy = NULL;
4758: }
4759: /* Reinitialize function pointers in SNESOps structure */
4760: snes->ops->setup = NULL;
4761: snes->ops->solve = NULL;
4762: snes->ops->view = NULL;
4763: snes->ops->setfromoptions = NULL;
4764: snes->ops->destroy = NULL;
4766: /* It may happen the user has customized the line search before calling SNESSetType */
4767: if (((PetscObject)snes)->type_name) {
4768: SNESLineSearchDestroy(&snes->linesearch);
4769: }
4771: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4772: snes->setupcalled = PETSC_FALSE;
4774: PetscObjectChangeTypeName((PetscObject)snes,type);
4775: (*r)(snes);
4776: return(0);
4777: }
4779: /*@C
4780: SNESGetType - Gets the SNES method type and name (as a string).
4782: Not Collective
4784: Input Parameter:
4785: . snes - nonlinear solver context
4787: Output Parameter:
4788: . type - SNES method (a character string)
4790: Level: intermediate
4792: @*/
4793: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4794: {
4798: *type = ((PetscObject)snes)->type_name;
4799: return(0);
4800: }
4802: /*@
4803: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4805: Logically Collective on SNES
4807: Input Parameters:
4808: + snes - the SNES context obtained from SNESCreate()
4809: - u - the solution vector
4811: Level: beginner
4813: @*/
4814: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4815: {
4816: DM dm;
4822: PetscObjectReference((PetscObject) u);
4823: VecDestroy(&snes->vec_sol);
4825: snes->vec_sol = u;
4827: SNESGetDM(snes, &dm);
4828: DMShellSetGlobalVector(dm, u);
4829: return(0);
4830: }
4832: /*@
4833: SNESGetSolution - Returns the vector where the approximate solution is
4834: stored. This is the fine grid solution when using SNESSetGridSequence().
4836: Not Collective, but Vec is parallel if SNES is parallel
4838: Input Parameter:
4839: . snes - the SNES context
4841: Output Parameter:
4842: . x - the solution
4844: Level: intermediate
4846: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4847: @*/
4848: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4849: {
4853: *x = snes->vec_sol;
4854: return(0);
4855: }
4857: /*@
4858: SNESGetSolutionUpdate - Returns the vector where the solution update is
4859: stored.
4861: Not Collective, but Vec is parallel if SNES is parallel
4863: Input Parameter:
4864: . snes - the SNES context
4866: Output Parameter:
4867: . x - the solution update
4869: Level: advanced
4871: .seealso: SNESGetSolution(), SNESGetFunction()
4872: @*/
4873: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4874: {
4878: *x = snes->vec_sol_update;
4879: return(0);
4880: }
4882: /*@C
4883: SNESGetFunction - Returns the vector where the function is stored.
4885: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4887: Input Parameter:
4888: . snes - the SNES context
4890: Output Parameter:
4891: + r - the vector that is used to store residuals (or NULL if you don't want it)
4892: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4893: - ctx - the function context (or NULL if you don't want it)
4895: Level: advanced
4897: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4899: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4900: @*/
4901: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4902: {
4904: DM dm;
4908: if (r) {
4909: if (!snes->vec_func) {
4910: if (snes->vec_rhs) {
4911: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4912: } else if (snes->vec_sol) {
4913: VecDuplicate(snes->vec_sol,&snes->vec_func);
4914: } else if (snes->dm) {
4915: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4916: }
4917: }
4918: *r = snes->vec_func;
4919: }
4920: SNESGetDM(snes,&dm);
4921: DMSNESGetFunction(dm,f,ctx);
4922: return(0);
4923: }
4925: /*@C
4926: SNESGetNGS - Returns the NGS function and context.
4928: Input Parameter:
4929: . snes - the SNES context
4931: Output Parameter:
4932: + f - the function (or NULL) see SNESNGSFunction for details
4933: - ctx - the function context (or NULL)
4935: Level: advanced
4937: .seealso: SNESSetNGS(), SNESGetFunction()
4938: @*/
4940: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4941: {
4943: DM dm;
4947: SNESGetDM(snes,&dm);
4948: DMSNESGetNGS(dm,f,ctx);
4949: return(0);
4950: }
4952: /*@C
4953: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4954: SNES options in the database.
4956: Logically Collective on SNES
4958: Input Parameter:
4959: + snes - the SNES context
4960: - prefix - the prefix to prepend to all option names
4962: Notes:
4963: A hyphen (-) must NOT be given at the beginning of the prefix name.
4964: The first character of all runtime options is AUTOMATICALLY the hyphen.
4966: Level: advanced
4968: .seealso: SNESSetFromOptions()
4969: @*/
4970: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4971: {
4976: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4977: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4978: if (snes->linesearch) {
4979: SNESGetLineSearch(snes,&snes->linesearch);
4980: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4981: }
4982: KSPSetOptionsPrefix(snes->ksp,prefix);
4983: return(0);
4984: }
4986: /*@C
4987: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4988: SNES options in the database.
4990: Logically Collective on SNES
4992: Input Parameters:
4993: + snes - the SNES context
4994: - prefix - the prefix to prepend to all option names
4996: Notes:
4997: A hyphen (-) must NOT be given at the beginning of the prefix name.
4998: The first character of all runtime options is AUTOMATICALLY the hyphen.
5000: Level: advanced
5002: .seealso: SNESGetOptionsPrefix()
5003: @*/
5004: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
5005: {
5010: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
5011: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
5012: if (snes->linesearch) {
5013: SNESGetLineSearch(snes,&snes->linesearch);
5014: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
5015: }
5016: KSPAppendOptionsPrefix(snes->ksp,prefix);
5017: return(0);
5018: }
5020: /*@C
5021: SNESGetOptionsPrefix - Sets the prefix used for searching for all
5022: SNES options in the database.
5024: Not Collective
5026: Input Parameter:
5027: . snes - the SNES context
5029: Output Parameter:
5030: . prefix - pointer to the prefix string used
5032: Notes:
5033: On the fortran side, the user should pass in a string 'prefix' of
5034: sufficient length to hold the prefix.
5036: Level: advanced
5038: .seealso: SNESAppendOptionsPrefix()
5039: @*/
5040: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
5041: {
5046: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
5047: return(0);
5048: }
5051: /*@C
5052: SNESRegister - Adds a method to the nonlinear solver package.
5054: Not collective
5056: Input Parameters:
5057: + name_solver - name of a new user-defined solver
5058: - routine_create - routine to create method context
5060: Notes:
5061: SNESRegister() may be called multiple times to add several user-defined solvers.
5063: Sample usage:
5064: .vb
5065: SNESRegister("my_solver",MySolverCreate);
5066: .ve
5068: Then, your solver can be chosen with the procedural interface via
5069: $ SNESSetType(snes,"my_solver")
5070: or at runtime via the option
5071: $ -snes_type my_solver
5073: Level: advanced
5075: Note: If your function is not being put into a shared library then use SNESRegister() instead
5077: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
5079: Level: advanced
5080: @*/
5081: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
5082: {
5086: SNESInitializePackage();
5087: PetscFunctionListAdd(&SNESList,sname,function);
5088: return(0);
5089: }
5091: PetscErrorCode SNESTestLocalMin(SNES snes)
5092: {
5094: PetscInt N,i,j;
5095: Vec u,uh,fh;
5096: PetscScalar value;
5097: PetscReal norm;
5100: SNESGetSolution(snes,&u);
5101: VecDuplicate(u,&uh);
5102: VecDuplicate(u,&fh);
5104: /* currently only works for sequential */
5105: PetscPrintf(PetscObjectComm((PetscObject)snes),"Testing FormFunction() for local min\n");
5106: VecGetSize(u,&N);
5107: for (i=0; i<N; i++) {
5108: VecCopy(u,uh);
5109: PetscPrintf(PetscObjectComm((PetscObject)snes),"i = %D\n",i);
5110: for (j=-10; j<11; j++) {
5111: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
5112: VecSetValue(uh,i,value,ADD_VALUES);
5113: SNESComputeFunction(snes,uh,fh);
5114: VecNorm(fh,NORM_2,&norm);
5115: PetscPrintf(PetscObjectComm((PetscObject)snes)," j norm %D %18.16e\n",j,norm);
5116: value = -value;
5117: VecSetValue(uh,i,value,ADD_VALUES);
5118: }
5119: }
5120: VecDestroy(&uh);
5121: VecDestroy(&fh);
5122: return(0);
5123: }
5125: /*@
5126: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
5127: computing relative tolerance for linear solvers within an inexact
5128: Newton method.
5130: Logically Collective on SNES
5132: Input Parameters:
5133: + snes - SNES context
5134: - flag - PETSC_TRUE or PETSC_FALSE
5136: Options Database:
5137: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5138: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5139: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5140: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5141: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5142: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5143: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5144: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5146: Notes:
5147: Currently, the default is to use a constant relative tolerance for
5148: the inner linear solvers. Alternatively, one can use the
5149: Eisenstat-Walker method, where the relative convergence tolerance
5150: is reset at each Newton iteration according progress of the nonlinear
5151: solver.
5153: Level: advanced
5155: Reference:
5156: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5157: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5159: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5160: @*/
5161: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
5162: {
5166: snes->ksp_ewconv = flag;
5167: return(0);
5168: }
5170: /*@
5171: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
5172: for computing relative tolerance for linear solvers within an
5173: inexact Newton method.
5175: Not Collective
5177: Input Parameter:
5178: . snes - SNES context
5180: Output Parameter:
5181: . flag - PETSC_TRUE or PETSC_FALSE
5183: Notes:
5184: Currently, the default is to use a constant relative tolerance for
5185: the inner linear solvers. Alternatively, one can use the
5186: Eisenstat-Walker method, where the relative convergence tolerance
5187: is reset at each Newton iteration according progress of the nonlinear
5188: solver.
5190: Level: advanced
5192: Reference:
5193: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5194: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5196: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5197: @*/
5198: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5199: {
5203: *flag = snes->ksp_ewconv;
5204: return(0);
5205: }
5207: /*@
5208: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5209: convergence criteria for the linear solvers within an inexact
5210: Newton method.
5212: Logically Collective on SNES
5214: Input Parameters:
5215: + snes - SNES context
5216: . version - version 1, 2 (default is 2) or 3
5217: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5218: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5219: . gamma - multiplicative factor for version 2 rtol computation
5220: (0 <= gamma2 <= 1)
5221: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5222: . alpha2 - power for safeguard
5223: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5225: Note:
5226: Version 3 was contributed by Luis Chacon, June 2006.
5228: Use PETSC_DEFAULT to retain the default for any of the parameters.
5230: Level: advanced
5232: Reference:
5233: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5234: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5235: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5237: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5238: @*/
5239: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5240: {
5241: SNESKSPEW *kctx;
5245: kctx = (SNESKSPEW*)snes->kspconvctx;
5246: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5255: if (version != PETSC_DEFAULT) kctx->version = version;
5256: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5257: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5258: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5259: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5260: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5261: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5263: 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);
5264: 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);
5265: 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);
5266: 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);
5267: 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);
5268: 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);
5269: return(0);
5270: }
5272: /*@
5273: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5274: convergence criteria for the linear solvers within an inexact
5275: Newton method.
5277: Not Collective
5279: Input Parameters:
5280: snes - SNES context
5282: Output Parameters:
5283: + version - version 1, 2 (default is 2) or 3
5284: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5285: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5286: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5287: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5288: . alpha2 - power for safeguard
5289: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5291: Level: advanced
5293: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5294: @*/
5295: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5296: {
5297: SNESKSPEW *kctx;
5301: kctx = (SNESKSPEW*)snes->kspconvctx;
5302: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5303: if (version) *version = kctx->version;
5304: if (rtol_0) *rtol_0 = kctx->rtol_0;
5305: if (rtol_max) *rtol_max = kctx->rtol_max;
5306: if (gamma) *gamma = kctx->gamma;
5307: if (alpha) *alpha = kctx->alpha;
5308: if (alpha2) *alpha2 = kctx->alpha2;
5309: if (threshold) *threshold = kctx->threshold;
5310: return(0);
5311: }
5313: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5314: {
5316: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5317: PetscReal rtol = PETSC_DEFAULT,stol;
5320: if (!snes->ksp_ewconv) return(0);
5321: if (!snes->iter) {
5322: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5323: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5324: }
5325: else {
5326: if (kctx->version == 1) {
5327: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5328: if (rtol < 0.0) rtol = -rtol;
5329: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5330: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5331: } else if (kctx->version == 2) {
5332: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5333: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5334: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5335: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5336: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5337: /* safeguard: avoid sharp decrease of rtol */
5338: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5339: stol = PetscMax(rtol,stol);
5340: rtol = PetscMin(kctx->rtol_0,stol);
5341: /* safeguard: avoid oversolving */
5342: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5343: stol = PetscMax(rtol,stol);
5344: rtol = PetscMin(kctx->rtol_0,stol);
5345: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5346: }
5347: /* safeguard: avoid rtol greater than one */
5348: rtol = PetscMin(rtol,kctx->rtol_max);
5349: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5350: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5351: return(0);
5352: }
5354: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5355: {
5357: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5358: PCSide pcside;
5359: Vec lres;
5362: if (!snes->ksp_ewconv) return(0);
5363: KSPGetTolerances(ksp,&kctx->rtol_last,NULL,NULL,NULL);
5364: kctx->norm_last = snes->norm;
5365: if (kctx->version == 1) {
5366: PC pc;
5367: PetscBool isNone;
5369: KSPGetPC(ksp, &pc);
5370: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5371: KSPGetPCSide(ksp,&pcside);
5372: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5373: /* KSP residual is true linear residual */
5374: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5375: } else {
5376: /* KSP residual is preconditioned residual */
5377: /* compute true linear residual norm */
5378: VecDuplicate(b,&lres);
5379: MatMult(snes->jacobian,x,lres);
5380: VecAYPX(lres,-1.0,b);
5381: VecNorm(lres,NORM_2,&kctx->lresid_last);
5382: VecDestroy(&lres);
5383: }
5384: }
5385: return(0);
5386: }
5388: /*@
5389: SNESGetKSP - Returns the KSP context for a SNES solver.
5391: Not Collective, but if SNES object is parallel, then KSP object is parallel
5393: Input Parameter:
5394: . snes - the SNES context
5396: Output Parameter:
5397: . ksp - the KSP context
5399: Notes:
5400: The user can then directly manipulate the KSP context to set various
5401: options, etc. Likewise, the user can then extract and manipulate the
5402: PC contexts as well.
5404: Level: beginner
5406: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5407: @*/
5408: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5409: {
5416: if (!snes->ksp) {
5417: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5418: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5419: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5421: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5422: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5424: KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes);
5425: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5426: }
5427: *ksp = snes->ksp;
5428: return(0);
5429: }
5432: #include <petsc/private/dmimpl.h>
5433: /*@
5434: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5436: Logically Collective on SNES
5438: Input Parameters:
5439: + snes - the nonlinear solver context
5440: - dm - the dm, cannot be NULL
5442: Notes:
5443: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5444: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5445: problems using the same function space.
5447: Level: intermediate
5449: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5450: @*/
5451: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5452: {
5454: KSP ksp;
5455: DMSNES sdm;
5460: PetscObjectReference((PetscObject)dm);
5461: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5462: if (snes->dm->dmsnes && !dm->dmsnes) {
5463: DMCopyDMSNES(snes->dm,dm);
5464: DMGetDMSNES(snes->dm,&sdm);
5465: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5466: }
5467: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5468: DMDestroy(&snes->dm);
5469: }
5470: snes->dm = dm;
5471: snes->dmAuto = PETSC_FALSE;
5473: SNESGetKSP(snes,&ksp);
5474: KSPSetDM(ksp,dm);
5475: KSPSetDMActive(ksp,PETSC_FALSE);
5476: if (snes->npc) {
5477: SNESSetDM(snes->npc, snes->dm);
5478: SNESSetNPCSide(snes,snes->npcside);
5479: }
5480: return(0);
5481: }
5483: /*@
5484: SNESGetDM - Gets the DM that may be used by some preconditioners
5486: Not Collective but DM obtained is parallel on SNES
5488: Input Parameter:
5489: . snes - the preconditioner context
5491: Output Parameter:
5492: . dm - the dm
5494: Level: intermediate
5496: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5497: @*/
5498: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5499: {
5504: if (!snes->dm) {
5505: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5506: snes->dmAuto = PETSC_TRUE;
5507: }
5508: *dm = snes->dm;
5509: return(0);
5510: }
5512: /*@
5513: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5515: Collective on SNES
5517: Input Parameters:
5518: + snes - iterative context obtained from SNESCreate()
5519: - pc - the preconditioner object
5521: Notes:
5522: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5523: to configure it using the API).
5525: Level: developer
5527: .seealso: SNESGetNPC(), SNESHasNPC()
5528: @*/
5529: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5530: {
5537: PetscObjectReference((PetscObject) pc);
5538: SNESDestroy(&snes->npc);
5539: snes->npc = pc;
5540: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5541: return(0);
5542: }
5544: /*@
5545: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5547: Not Collective; but any changes to the obtained SNES object must be applied collectively
5549: Input Parameter:
5550: . snes - iterative context obtained from SNESCreate()
5552: Output Parameter:
5553: . pc - preconditioner context
5555: Options Database:
5556: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5558: Notes:
5559: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5561: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5562: SNES during SNESSetUp()
5564: Level: developer
5566: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5567: @*/
5568: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5569: {
5571: const char *optionsprefix;
5576: if (!snes->npc) {
5577: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5578: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5579: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5580: SNESGetOptionsPrefix(snes,&optionsprefix);
5581: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5582: SNESAppendOptionsPrefix(snes->npc,"npc_");
5583: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5584: }
5585: *pc = snes->npc;
5586: return(0);
5587: }
5589: /*@
5590: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5592: Not Collective
5594: Input Parameter:
5595: . snes - iterative context obtained from SNESCreate()
5597: Output Parameter:
5598: . has_npc - whether the SNES has an NPC or not
5600: Level: developer
5602: .seealso: SNESSetNPC(), SNESGetNPC()
5603: @*/
5604: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5605: {
5608: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5609: return(0);
5610: }
5612: /*@
5613: SNESSetNPCSide - Sets the preconditioning side.
5615: Logically Collective on SNES
5617: Input Parameter:
5618: . snes - iterative context obtained from SNESCreate()
5620: Output Parameter:
5621: . side - the preconditioning side, where side is one of
5622: .vb
5623: PC_LEFT - left preconditioning
5624: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5625: .ve
5627: Options Database Keys:
5628: . -snes_pc_side <right,left>
5630: Notes:
5631: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5633: Level: intermediate
5635: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5636: @*/
5637: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5638: {
5642: snes->npcside= side;
5643: return(0);
5644: }
5646: /*@
5647: SNESGetNPCSide - Gets the preconditioning side.
5649: Not Collective
5651: Input Parameter:
5652: . snes - iterative context obtained from SNESCreate()
5654: Output Parameter:
5655: . side - the preconditioning side, where side is one of
5656: .vb
5657: PC_LEFT - left preconditioning
5658: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5659: .ve
5661: Level: intermediate
5663: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5664: @*/
5665: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5666: {
5670: *side = snes->npcside;
5671: return(0);
5672: }
5674: /*@
5675: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5677: Collective on SNES
5679: Input Parameters:
5680: + snes - iterative context obtained from SNESCreate()
5681: - linesearch - the linesearch object
5683: Notes:
5684: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5685: to configure it using the API).
5687: Level: developer
5689: .seealso: SNESGetLineSearch()
5690: @*/
5691: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5692: {
5699: PetscObjectReference((PetscObject) linesearch);
5700: SNESLineSearchDestroy(&snes->linesearch);
5702: snes->linesearch = linesearch;
5704: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5705: return(0);
5706: }
5708: /*@
5709: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5710: or creates a default line search instance associated with the SNES and returns it.
5712: Not Collective
5714: Input Parameter:
5715: . snes - iterative context obtained from SNESCreate()
5717: Output Parameter:
5718: . linesearch - linesearch context
5720: Level: beginner
5722: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5723: @*/
5724: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5725: {
5727: const char *optionsprefix;
5732: if (!snes->linesearch) {
5733: SNESGetOptionsPrefix(snes, &optionsprefix);
5734: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5735: SNESLineSearchSetSNES(snes->linesearch, snes);
5736: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5737: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5738: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5739: }
5740: *linesearch = snes->linesearch;
5741: return(0);
5742: }