Actual source code: snes.c
petsc-master 2019-08-19
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: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES,Vec,Mat,Mat,void*);
313: /*@C
314: SNESView - Prints the SNES data structure.
316: Collective on SNES
318: Input Parameters:
319: + SNES - the SNES context
320: - viewer - visualization context
322: Options Database Key:
323: . -snes_view - Calls SNESView() at end of SNESSolve()
325: Notes:
326: The available visualization contexts include
327: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
328: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
329: output where only the first processor opens
330: the file. All other processors send their
331: data to the first processor to print.
333: The user can open an alternative visualization context with
334: PetscViewerASCIIOpen() - output to a specified file.
336: Level: beginner
338: .seealso: PetscViewerASCIIOpen()
339: @*/
340: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
341: {
342: SNESKSPEW *kctx;
344: KSP ksp;
345: SNESLineSearch linesearch;
346: PetscBool iascii,isstring,isbinary,isdraw;
347: DMSNES dmsnes;
348: #if defined(PETSC_HAVE_SAWS)
349: PetscBool issaws;
350: #endif
354: if (!viewer) {
355: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
356: }
360: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
361: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
362: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
363: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
364: #if defined(PETSC_HAVE_SAWS)
365: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
366: #endif
367: if (iascii) {
368: SNESNormSchedule normschedule;
369: DM dm;
370: PetscErrorCode (*cJ)(SNES,Vec,Mat,Mat,void*);
371: void *ctx;
372: const char *pre = "";
374: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
375: if (!snes->setupcalled) {
376: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
377: }
378: if (snes->ops->view) {
379: PetscViewerASCIIPushTab(viewer);
380: (*snes->ops->view)(snes,viewer);
381: PetscViewerASCIIPopTab(viewer);
382: }
383: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
384: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
385: if (snes->usesksp) {
386: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
387: }
388: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
389: SNESGetNormSchedule(snes, &normschedule);
390: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
391: if (snes->gridsequence) {
392: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
393: }
394: if (snes->ksp_ewconv) {
395: kctx = (SNESKSPEW*)snes->kspconvctx;
396: if (kctx) {
397: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
398: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
399: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
400: }
401: }
402: if (snes->lagpreconditioner == -1) {
403: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
404: } else if (snes->lagpreconditioner > 1) {
405: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
406: }
407: if (snes->lagjacobian == -1) {
408: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
409: } else if (snes->lagjacobian > 1) {
410: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
411: }
412: SNESGetDM(snes,&dm);
413: DMSNESGetJacobian(dm,&cJ,&ctx);
414: if (snes->mf_operator) {
415: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing\n");
416: pre = "Preconditioning ";
417: }
418: if (cJ == SNESComputeJacobianDefault) {
419: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences one column at a time\n",pre);
420: } else if (cJ == SNESComputeJacobianDefaultColor) {
421: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences with coloring\n",pre);
422: /* it slightly breaks data encapsulation for access the DMDA information directly */
423: } else if (cJ == SNESComputeJacobian_DMDA) {
424: MatFDColoring fdcoloring;
425: PetscObjectQuery((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject*)&fdcoloring);
426: if (fdcoloring) {
427: PetscViewerASCIIPrintf(viewer," %sJacobian is built using colored finite differences on a DMDA\n",pre);
428: } else {
429: PetscViewerASCIIPrintf(viewer," %sJacobian is built using a DMDA local Jacobian\n",pre);
430: }
431: } else if (snes->mf) {
432: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing, no explict Jacobian\n");
433: }
434: } else if (isstring) {
435: const char *type;
436: SNESGetType(snes,&type);
437: PetscViewerStringSPrintf(viewer," SNESType: %-7.7s",type);
438: if (snes->ops->view) {(*snes->ops->view)(snes,viewer);}
439: } else if (isbinary) {
440: PetscInt classid = SNES_FILE_CLASSID;
441: MPI_Comm comm;
442: PetscMPIInt rank;
443: char type[256];
445: PetscObjectGetComm((PetscObject)snes,&comm);
446: MPI_Comm_rank(comm,&rank);
447: if (!rank) {
448: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
449: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
450: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR,PETSC_FALSE);
451: }
452: if (snes->ops->view) {
453: (*snes->ops->view)(snes,viewer);
454: }
455: } else if (isdraw) {
456: PetscDraw draw;
457: char str[36];
458: PetscReal x,y,bottom,h;
460: PetscViewerDrawGetDraw(viewer,0,&draw);
461: PetscDrawGetCurrentPoint(draw,&x,&y);
462: PetscStrncpy(str,"SNES: ",sizeof(str));
463: PetscStrlcat(str,((PetscObject)snes)->type_name,sizeof(str));
464: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
465: bottom = y - h;
466: PetscDrawPushCurrentPoint(draw,x,bottom);
467: if (snes->ops->view) {
468: (*snes->ops->view)(snes,viewer);
469: }
470: #if defined(PETSC_HAVE_SAWS)
471: } else if (issaws) {
472: PetscMPIInt rank;
473: const char *name;
475: PetscObjectGetName((PetscObject)snes,&name);
476: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
477: if (!((PetscObject)snes)->amsmem && !rank) {
478: char dir[1024];
480: PetscObjectViewSAWs((PetscObject)snes,viewer);
481: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
482: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
483: if (!snes->conv_hist) {
484: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
485: }
486: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
487: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
488: }
489: #endif
490: }
491: if (snes->linesearch) {
492: SNESGetLineSearch(snes, &linesearch);
493: PetscViewerASCIIPushTab(viewer);
494: SNESLineSearchView(linesearch, viewer);
495: PetscViewerASCIIPopTab(viewer);
496: }
497: if (snes->npc && snes->usesnpc) {
498: PetscViewerASCIIPushTab(viewer);
499: SNESView(snes->npc, viewer);
500: PetscViewerASCIIPopTab(viewer);
501: }
502: PetscViewerASCIIPushTab(viewer);
503: DMGetDMSNES(snes->dm,&dmsnes);
504: DMSNESView(dmsnes, viewer);
505: PetscViewerASCIIPopTab(viewer);
506: if (snes->usesksp) {
507: SNESGetKSP(snes,&ksp);
508: PetscViewerASCIIPushTab(viewer);
509: KSPView(ksp,viewer);
510: PetscViewerASCIIPopTab(viewer);
511: }
512: if (isdraw) {
513: PetscDraw draw;
514: PetscViewerDrawGetDraw(viewer,0,&draw);
515: PetscDrawPopCurrentPoint(draw);
516: }
517: return(0);
518: }
520: /*
521: We retain a list of functions that also take SNES command
522: line options. These are called at the end SNESSetFromOptions()
523: */
524: #define MAXSETFROMOPTIONS 5
525: static PetscInt numberofsetfromoptions;
526: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
528: /*@C
529: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
531: Not Collective
533: Input Parameter:
534: . snescheck - function that checks for options
536: Level: developer
538: .seealso: SNESSetFromOptions()
539: @*/
540: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
541: {
543: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
544: othersetfromoptions[numberofsetfromoptions++] = snescheck;
545: return(0);
546: }
548: PETSC_INTERN PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
550: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
551: {
552: Mat J;
554: MatNullSpace nullsp;
559: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
560: Mat A = snes->jacobian, B = snes->jacobian_pre;
561: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
562: }
564: if (version == 1) {
565: MatCreateSNESMF(snes,&J);
566: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
567: MatSetFromOptions(J);
568: } else if (version == 2) {
569: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
570: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
571: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
572: #else
573: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
574: #endif
575: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");
577: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
578: if (snes->jacobian) {
579: MatGetNullSpace(snes->jacobian,&nullsp);
580: if (nullsp) {
581: MatSetNullSpace(J,nullsp);
582: }
583: }
585: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
586: if (hasOperator) {
588: /* This version replaces the user provided Jacobian matrix with a
589: matrix-free version but still employs the user-provided preconditioner matrix. */
590: SNESSetJacobian(snes,J,0,0,0);
591: } else {
592: /* This version replaces both the user-provided Jacobian and the user-
593: provided preconditioner Jacobian with the default matrix free version. */
594: if ((snes->npcside== PC_LEFT) && snes->npc) {
595: if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
596: } else {
597: KSP ksp;
598: PC pc;
599: PetscBool match;
601: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
602: /* Force no preconditioner */
603: SNESGetKSP(snes,&ksp);
604: KSPGetPC(ksp,&pc);
605: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
606: if (!match) {
607: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
608: PCSetType(pc,PCNONE);
609: }
610: }
611: }
612: MatDestroy(&J);
613: return(0);
614: }
616: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
617: {
618: SNES snes = (SNES)ctx;
620: Vec Xfine,Xfine_named = NULL,Xcoarse;
623: if (PetscLogPrintInfo) {
624: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
625: DMGetRefineLevel(dmfine,&finelevel);
626: DMGetCoarsenLevel(dmfine,&fineclevel);
627: DMGetRefineLevel(dmcoarse,&coarselevel);
628: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
629: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
630: }
631: if (dmfine == snes->dm) Xfine = snes->vec_sol;
632: else {
633: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
634: Xfine = Xfine_named;
635: }
636: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
637: if (Inject) {
638: MatRestrict(Inject,Xfine,Xcoarse);
639: } else {
640: MatRestrict(Restrict,Xfine,Xcoarse);
641: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
642: }
643: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
644: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
645: return(0);
646: }
648: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
649: {
653: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
654: return(0);
655: }
657: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
658: * safely call SNESGetDM() in their residual evaluation routine. */
659: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
660: {
661: SNES snes = (SNES)ctx;
663: Vec X,Xnamed = NULL;
664: DM dmsave;
665: void *ctxsave;
666: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*) = NULL;
669: dmsave = snes->dm;
670: KSPGetDM(ksp,&snes->dm);
671: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
672: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
673: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
674: X = Xnamed;
675: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
676: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
677: if (jac == SNESComputeJacobianDefaultColor) {
678: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
679: }
680: }
681: /* Make sure KSP DM has the Jacobian computation routine */
682: {
683: DMSNES sdm;
685: DMGetDMSNES(snes->dm, &sdm);
686: if (!sdm->ops->computejacobian) {
687: DMCopyDMSNES(dmsave, snes->dm);
688: }
689: }
690: /* Compute the operators */
691: SNESComputeJacobian(snes,X,A,B);
692: /* Put the previous context back */
693: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
694: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
695: }
697: if (Xnamed) {DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);}
698: snes->dm = dmsave;
699: return(0);
700: }
702: /*@
703: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
705: Collective
707: Input Arguments:
708: . snes - snes to configure
710: Level: developer
712: .seealso: SNESSetUp()
713: @*/
714: PetscErrorCode SNESSetUpMatrices(SNES snes)
715: {
717: DM dm;
718: DMSNES sdm;
721: SNESGetDM(snes,&dm);
722: DMGetDMSNES(dm,&sdm);
723: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
724: else if (!snes->jacobian && snes->mf) {
725: Mat J;
726: void *functx;
727: MatCreateSNESMF(snes,&J);
728: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
729: MatSetFromOptions(J);
730: SNESGetFunction(snes,NULL,NULL,&functx);
731: SNESSetJacobian(snes,J,J,0,0);
732: MatDestroy(&J);
733: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
734: Mat J,B;
735: MatCreateSNESMF(snes,&J);
736: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
737: MatSetFromOptions(J);
738: DMCreateMatrix(snes->dm,&B);
739: /* sdm->computejacobian was already set to reach here */
740: SNESSetJacobian(snes,J,B,NULL,NULL);
741: MatDestroy(&J);
742: MatDestroy(&B);
743: } else if (!snes->jacobian_pre) {
744: PetscErrorCode (*nspconstr)(DM, PetscInt, MatNullSpace *);
745: PetscDS prob;
746: Mat J, B;
747: MatNullSpace nullspace = NULL;
748: PetscBool hasPrec = PETSC_FALSE;
749: PetscInt Nf;
751: J = snes->jacobian;
752: DMGetDS(dm, &prob);
753: if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
754: if (J) {PetscObjectReference((PetscObject) J);}
755: else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
756: DMCreateMatrix(snes->dm, &B);
757: PetscDSGetNumFields(prob, &Nf);
758: DMGetNullSpaceConstructor(snes->dm, Nf, &nspconstr);
759: if (nspconstr) (*nspconstr)(snes->dm, -1, &nullspace);
760: MatSetNullSpace(B, nullspace);
761: MatNullSpaceDestroy(&nullspace);
762: SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
763: MatDestroy(&J);
764: MatDestroy(&B);
765: }
766: {
767: KSP ksp;
768: SNESGetKSP(snes,&ksp);
769: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
770: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
771: }
772: return(0);
773: }
775: /*@C
776: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
778: Collective on SNES
780: Input Parameters:
781: + snes - SNES object you wish to monitor
782: . name - the monitor type one is seeking
783: . help - message indicating what monitoring is done
784: . manual - manual page for the monitor
785: . monitor - the monitor function
786: - 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
788: Level: developer
790: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
791: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
792: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
793: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
794: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
795: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
796: PetscOptionsFList(), PetscOptionsEList()
797: @*/
798: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
799: {
800: PetscErrorCode ierr;
801: PetscViewer viewer;
802: PetscViewerFormat format;
803: PetscBool flg;
806: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
807: if (flg) {
808: PetscViewerAndFormat *vf;
809: PetscViewerAndFormatCreate(viewer,format,&vf);
810: PetscObjectDereference((PetscObject)viewer);
811: if (monitorsetup) {
812: (*monitorsetup)(snes,vf);
813: }
814: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
815: }
816: return(0);
817: }
819: /*@
820: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
822: Collective on SNES
824: Input Parameter:
825: . snes - the SNES context
827: Options Database Keys:
828: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
829: . -snes_stol - convergence tolerance in terms of the norm
830: of the change in the solution between steps
831: . -snes_atol <abstol> - absolute tolerance of residual norm
832: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
833: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
834: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
835: . -snes_max_it <max_it> - maximum number of iterations
836: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
837: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
838: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
839: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
840: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
841: . -snes_trtol <trtol> - trust region tolerance
842: . -snes_no_convergence_test - skip convergence test in nonlinear
843: solver; hence iterations will continue until max_it
844: or some other criterion is reached. Saves expense
845: of convergence test
846: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
847: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
848: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
849: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
850: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
851: . -snes_monitor_lg_range - plots residual norm at each iteration
852: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
853: . -snes_fd_color - use finite differences with coloring to compute Jacobian
854: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
855: . -snes_converged_reason - print the reason for convergence/divergence after each solve
856: - -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
858: Options Database for Eisenstat-Walker method:
859: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
860: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
861: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
862: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
863: . -snes_ksp_ew_gamma <gamma> - Sets gamma
864: . -snes_ksp_ew_alpha <alpha> - Sets alpha
865: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
866: - -snes_ksp_ew_threshold <threshold> - Sets threshold
868: Notes:
869: To see all options, run your program with the -help option or consult
870: Users-Manual: ch_snes
872: Level: beginner
874: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions()
875: @*/
876: PetscErrorCode SNESSetFromOptions(SNES snes)
877: {
878: PetscBool flg,pcset,persist,set;
879: PetscInt i,indx,lag,grids;
880: const char *deft = SNESNEWTONLS;
881: const char *convtests[] = {"default","skip"};
882: SNESKSPEW *kctx = NULL;
883: char type[256], monfilename[PETSC_MAX_PATH_LEN];
885: PCSide pcside;
886: const char *optionsprefix;
890: SNESRegisterAll();
891: PetscObjectOptionsBegin((PetscObject)snes);
892: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
893: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
894: if (flg) {
895: SNESSetType(snes,type);
896: } else if (!((PetscObject)snes)->type_name) {
897: SNESSetType(snes,deft);
898: }
899: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
900: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
902: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
903: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
904: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
905: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
906: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
907: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
908: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
909: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
910: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
912: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
913: if (flg) {
914: SNESSetLagPreconditioner(snes,lag);
915: }
916: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
917: if (flg) {
918: SNESSetLagPreconditionerPersists(snes,persist);
919: }
920: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
921: if (flg) {
922: SNESSetLagJacobian(snes,lag);
923: }
924: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
925: if (flg) {
926: SNESSetLagJacobianPersists(snes,persist);
927: }
929: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
930: if (flg) {
931: SNESSetGridSequence(snes,grids);
932: }
934: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
935: if (flg) {
936: switch (indx) {
937: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
938: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
939: }
940: }
942: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
943: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
945: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
946: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
948: kctx = (SNESKSPEW*)snes->kspconvctx;
950: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
952: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
953: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
954: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
955: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
956: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
957: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
958: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
960: flg = PETSC_FALSE;
961: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
962: if (set && flg) {SNESMonitorCancel(snes);}
964: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
965: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
966: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
968: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
969: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
970: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
971: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
972: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
973: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
974: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
976: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
977: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
979: flg = PETSC_FALSE;
980: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
981: if (flg) {
982: PetscDrawLG ctx;
984: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
985: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
986: }
987: flg = PETSC_FALSE;
988: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
989: if (flg) {
990: PetscViewer ctx;
992: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
993: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
994: }
996: flg = PETSC_FALSE;
997: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
998: if (flg) {
999: void *functx;
1000: DM dm;
1001: DMSNES sdm;
1002: SNESGetDM(snes,&dm);
1003: DMGetDMSNES(dm,&sdm);
1004: sdm->jacobianctx = NULL;
1005: SNESGetFunction(snes,NULL,NULL,&functx);
1006: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
1007: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
1008: }
1010: flg = PETSC_FALSE;
1011: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
1012: if (flg) {
1013: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
1014: }
1016: flg = PETSC_FALSE;
1017: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1018: if (flg) {
1019: DM dm;
1020: DMSNES sdm;
1021: SNESGetDM(snes,&dm);
1022: DMGetDMSNES(dm,&sdm);
1023: sdm->jacobianctx = NULL;
1024: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
1025: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1026: }
1028: flg = PETSC_FALSE;
1029: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1030: if (flg && snes->mf_operator) {
1031: snes->mf_operator = PETSC_TRUE;
1032: snes->mf = PETSC_TRUE;
1033: }
1034: flg = PETSC_FALSE;
1035: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1036: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1037: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
1039: flg = PETSC_FALSE;
1040: SNESGetNPCSide(snes,&pcside);
1041: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1042: if (flg) {SNESSetNPCSide(snes,pcside);}
1044: #if defined(PETSC_HAVE_SAWS)
1045: /*
1046: Publish convergence information using SAWs
1047: */
1048: flg = PETSC_FALSE;
1049: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1050: if (flg) {
1051: void *ctx;
1052: SNESMonitorSAWsCreate(snes,&ctx);
1053: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1054: }
1055: #endif
1056: #if defined(PETSC_HAVE_SAWS)
1057: {
1058: PetscBool set;
1059: flg = PETSC_FALSE;
1060: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1061: if (set) {
1062: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1063: }
1064: }
1065: #endif
1067: for (i = 0; i < numberofsetfromoptions; i++) {
1068: (*othersetfromoptions[i])(snes);
1069: }
1071: if (snes->ops->setfromoptions) {
1072: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1073: }
1075: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1076: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1077: PetscOptionsEnd();
1079: if (snes->linesearch) {
1080: SNESGetLineSearch(snes, &snes->linesearch);
1081: SNESLineSearchSetFromOptions(snes->linesearch);
1082: }
1084: if (snes->usesksp) {
1085: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1086: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1087: KSPSetFromOptions(snes->ksp);
1088: }
1090: /* if user has set the SNES NPC type via options database, create it. */
1091: SNESGetOptionsPrefix(snes, &optionsprefix);
1092: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1093: if (pcset && (!snes->npc)) {
1094: SNESGetNPC(snes, &snes->npc);
1095: }
1096: if (snes->npc) {
1097: SNESSetFromOptions(snes->npc);
1098: }
1099: snes->setfromoptionscalled++;
1100: return(0);
1101: }
1103: /*@
1104: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1106: Collective on SNES
1108: Input Parameter:
1109: . snes - the SNES context
1111: Level: beginner
1113: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1114: @*/
1115: PetscErrorCode SNESResetFromOptions(SNES snes)
1116: {
1120: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1121: return(0);
1122: }
1124: /*@C
1125: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1126: the nonlinear solvers.
1128: Logically Collective on SNES
1130: Input Parameters:
1131: + snes - the SNES context
1132: . compute - function to compute the context
1133: - destroy - function to destroy the context
1135: Level: intermediate
1137: Notes:
1138: This function is currently not available from Fortran.
1140: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1141: @*/
1142: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1143: {
1146: snes->ops->usercompute = compute;
1147: snes->ops->userdestroy = destroy;
1148: return(0);
1149: }
1151: /*@
1152: SNESSetApplicationContext - Sets the optional user-defined context for
1153: the nonlinear solvers.
1155: Logically Collective on SNES
1157: Input Parameters:
1158: + snes - the SNES context
1159: - usrP - optional user context
1161: Level: intermediate
1163: Fortran Notes:
1164: To use this from Fortran you must write a Fortran interface definition for this
1165: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1167: .seealso: SNESGetApplicationContext()
1168: @*/
1169: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1170: {
1172: KSP ksp;
1176: SNESGetKSP(snes,&ksp);
1177: KSPSetApplicationContext(ksp,usrP);
1178: snes->user = usrP;
1179: return(0);
1180: }
1182: /*@
1183: SNESGetApplicationContext - Gets the user-defined context for the
1184: nonlinear solvers.
1186: Not Collective
1188: Input Parameter:
1189: . snes - SNES context
1191: Output Parameter:
1192: . usrP - user context
1194: Fortran Notes:
1195: To use this from Fortran you must write a Fortran interface definition for this
1196: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1198: Level: intermediate
1200: .seealso: SNESSetApplicationContext()
1201: @*/
1202: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1203: {
1206: *(void**)usrP = snes->user;
1207: return(0);
1208: }
1210: /*@
1211: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply
1212: the Jacobian.
1214: Collective on SNES
1216: Input Parameters:
1217: + snes - SNES context
1218: . mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1219: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1221: Options Database:
1222: + -snes_mf - use matrix free for both the mat and pmat operator
1223: - -snes_mf_operator - use matrix free only for the mat operator
1225: Level: intermediate
1227: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF()
1228: @*/
1229: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1230: {
1235: if (mf && !mf_operator) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"If using mf must also use mf_operator");
1236: snes->mf = mf;
1237: snes->mf_operator = mf_operator;
1238: return(0);
1239: }
1241: /*@
1242: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply
1243: the Jacobian.
1245: Collective on SNES
1247: Input Parameter:
1248: . snes - SNES context
1250: Output Parameters:
1251: + mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1252: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1254: Options Database:
1255: + -snes_mf - use matrix free for both the mat and pmat operator
1256: - -snes_mf_operator - use matrix free only for the mat operator
1258: Level: intermediate
1260: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1261: @*/
1262: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1263: {
1266: if (mf) *mf = snes->mf;
1267: if (mf_operator) *mf_operator = snes->mf_operator;
1268: return(0);
1269: }
1271: /*@
1272: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1273: at this time.
1275: Not Collective
1277: Input Parameter:
1278: . snes - SNES context
1280: Output Parameter:
1281: . iter - iteration number
1283: Notes:
1284: For example, during the computation of iteration 2 this would return 1.
1286: This is useful for using lagged Jacobians (where one does not recompute the
1287: Jacobian at each SNES iteration). For example, the code
1288: .vb
1289: SNESGetIterationNumber(snes,&it);
1290: if (!(it % 2)) {
1291: [compute Jacobian here]
1292: }
1293: .ve
1294: can be used in your ComputeJacobian() function to cause the Jacobian to be
1295: recomputed every second SNES iteration.
1297: After the SNES solve is complete this will return the number of nonlinear iterations used.
1299: Level: intermediate
1301: .seealso: SNESGetLinearSolveIterations()
1302: @*/
1303: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1304: {
1308: *iter = snes->iter;
1309: return(0);
1310: }
1312: /*@
1313: SNESSetIterationNumber - Sets the current iteration number.
1315: Not Collective
1317: Input Parameter:
1318: + snes - SNES context
1319: - iter - iteration number
1321: Level: developer
1323: .seealso: SNESGetLinearSolveIterations()
1324: @*/
1325: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1326: {
1331: PetscObjectSAWsTakeAccess((PetscObject)snes);
1332: snes->iter = iter;
1333: PetscObjectSAWsGrantAccess((PetscObject)snes);
1334: return(0);
1335: }
1337: /*@
1338: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1339: attempted by the nonlinear solver.
1341: Not Collective
1343: Input Parameter:
1344: . snes - SNES context
1346: Output Parameter:
1347: . nfails - number of unsuccessful steps attempted
1349: Notes:
1350: This counter is reset to zero for each successive call to SNESSolve().
1352: Level: intermediate
1354: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1355: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1356: @*/
1357: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1358: {
1362: *nfails = snes->numFailures;
1363: return(0);
1364: }
1366: /*@
1367: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1368: attempted by the nonlinear solver before it gives up.
1370: Not Collective
1372: Input Parameters:
1373: + snes - SNES context
1374: - maxFails - maximum of unsuccessful steps
1376: Level: intermediate
1378: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1379: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1380: @*/
1381: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1382: {
1385: snes->maxFailures = maxFails;
1386: return(0);
1387: }
1389: /*@
1390: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1391: attempted by the nonlinear solver before it gives up.
1393: Not Collective
1395: Input Parameter:
1396: . snes - SNES context
1398: Output Parameter:
1399: . maxFails - maximum of unsuccessful steps
1401: Level: intermediate
1403: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1404: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1406: @*/
1407: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1408: {
1412: *maxFails = snes->maxFailures;
1413: return(0);
1414: }
1416: /*@
1417: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1418: done by SNES.
1420: Not Collective
1422: Input Parameter:
1423: . snes - SNES context
1425: Output Parameter:
1426: . nfuncs - number of evaluations
1428: Level: intermediate
1430: Notes:
1431: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1433: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1434: @*/
1435: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1436: {
1440: *nfuncs = snes->nfuncs;
1441: return(0);
1442: }
1444: /*@
1445: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1446: linear solvers.
1448: Not Collective
1450: Input Parameter:
1451: . snes - SNES context
1453: Output Parameter:
1454: . nfails - number of failed solves
1456: Level: intermediate
1458: Options Database Keys:
1459: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1461: Notes:
1462: This counter is reset to zero for each successive call to SNESSolve().
1464: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1465: @*/
1466: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1467: {
1471: *nfails = snes->numLinearSolveFailures;
1472: return(0);
1473: }
1475: /*@
1476: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1477: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1479: Logically Collective on SNES
1481: Input Parameters:
1482: + snes - SNES context
1483: - maxFails - maximum allowed linear solve failures
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: By default this is 0; that is SNES returns on the first failed linear solve
1493: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1494: @*/
1495: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1496: {
1500: snes->maxLinearSolveFailures = maxFails;
1501: return(0);
1502: }
1504: /*@
1505: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1506: are allowed before SNES terminates
1508: Not Collective
1510: Input Parameter:
1511: . snes - SNES context
1513: Output Parameter:
1514: . maxFails - maximum of unsuccessful solves allowed
1516: Level: intermediate
1518: Notes:
1519: By default this is 1; that is SNES returns on the first failed linear solve
1521: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1522: @*/
1523: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1524: {
1528: *maxFails = snes->maxLinearSolveFailures;
1529: return(0);
1530: }
1532: /*@
1533: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1534: used by the nonlinear solver.
1536: Not Collective
1538: Input Parameter:
1539: . snes - SNES context
1541: Output Parameter:
1542: . lits - number of linear iterations
1544: Notes:
1545: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1547: 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
1548: then call KSPGetIterationNumber() after the failed solve.
1550: Level: intermediate
1552: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1553: @*/
1554: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1555: {
1559: *lits = snes->linear_its;
1560: return(0);
1561: }
1563: /*@
1564: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1565: are reset every time SNESSolve() is called.
1567: Logically Collective on SNES
1569: Input Parameter:
1570: + snes - SNES context
1571: - reset - whether to reset the counters or not
1573: Notes:
1574: This defaults to PETSC_TRUE
1576: Level: developer
1578: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1579: @*/
1580: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1581: {
1585: snes->counters_reset = reset;
1586: return(0);
1587: }
1590: /*@
1591: SNESSetKSP - Sets a KSP context for the SNES object to use
1593: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1595: Input Parameters:
1596: + snes - the SNES context
1597: - ksp - the KSP context
1599: Notes:
1600: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1601: so this routine is rarely needed.
1603: The KSP object that is already in the SNES object has its reference count
1604: decreased by one.
1606: Level: developer
1608: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1609: @*/
1610: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1611: {
1618: PetscObjectReference((PetscObject)ksp);
1619: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1620: snes->ksp = ksp;
1621: return(0);
1622: }
1624: /* -----------------------------------------------------------*/
1625: /*@
1626: SNESCreate - Creates a nonlinear solver context.
1628: Collective
1630: Input Parameters:
1631: . comm - MPI communicator
1633: Output Parameter:
1634: . outsnes - the new SNES context
1636: Options Database Keys:
1637: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1638: and no preconditioning matrix
1639: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1640: products, and a user-provided preconditioning matrix
1641: as set by SNESSetJacobian()
1642: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1644: Level: beginner
1646: Developer Notes:
1647: SNES always creates a KSP object even though many SNES methods do not use it. This is
1648: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1649: particular method does use KSP and regulates if the information about the KSP is printed
1650: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1651: by help messages about meaningless SNES options.
1653: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1654: be fixed.
1656: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1658: @*/
1659: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1660: {
1662: SNES snes;
1663: SNESKSPEW *kctx;
1667: *outsnes = NULL;
1668: SNESInitializePackage();
1670: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1672: snes->ops->converged = SNESConvergedDefault;
1673: snes->usesksp = PETSC_TRUE;
1674: snes->tolerancesset = PETSC_FALSE;
1675: snes->max_its = 50;
1676: snes->max_funcs = 10000;
1677: snes->norm = 0.0;
1678: snes->xnorm = 0.0;
1679: snes->ynorm = 0.0;
1680: snes->normschedule = SNES_NORM_ALWAYS;
1681: snes->functype = SNES_FUNCTION_DEFAULT;
1682: #if defined(PETSC_USE_REAL_SINGLE)
1683: snes->rtol = 1.e-5;
1684: #else
1685: snes->rtol = 1.e-8;
1686: #endif
1687: snes->ttol = 0.0;
1688: #if defined(PETSC_USE_REAL_SINGLE)
1689: snes->abstol = 1.e-25;
1690: #else
1691: snes->abstol = 1.e-50;
1692: #endif
1693: #if defined(PETSC_USE_REAL_SINGLE)
1694: snes->stol = 1.e-5;
1695: #else
1696: snes->stol = 1.e-8;
1697: #endif
1698: #if defined(PETSC_USE_REAL_SINGLE)
1699: snes->deltatol = 1.e-6;
1700: #else
1701: snes->deltatol = 1.e-12;
1702: #endif
1703: snes->divtol = 1.e4;
1704: snes->rnorm0 = 0;
1705: snes->nfuncs = 0;
1706: snes->numFailures = 0;
1707: snes->maxFailures = 1;
1708: snes->linear_its = 0;
1709: snes->lagjacobian = 1;
1710: snes->jac_iter = 0;
1711: snes->lagjac_persist = PETSC_FALSE;
1712: snes->lagpreconditioner = 1;
1713: snes->pre_iter = 0;
1714: snes->lagpre_persist = PETSC_FALSE;
1715: snes->numbermonitors = 0;
1716: snes->data = 0;
1717: snes->setupcalled = PETSC_FALSE;
1718: snes->ksp_ewconv = PETSC_FALSE;
1719: snes->nwork = 0;
1720: snes->work = 0;
1721: snes->nvwork = 0;
1722: snes->vwork = 0;
1723: snes->conv_hist_len = 0;
1724: snes->conv_hist_max = 0;
1725: snes->conv_hist = NULL;
1726: snes->conv_hist_its = NULL;
1727: snes->conv_hist_reset = PETSC_TRUE;
1728: snes->counters_reset = PETSC_TRUE;
1729: snes->vec_func_init_set = PETSC_FALSE;
1730: snes->reason = SNES_CONVERGED_ITERATING;
1731: snes->npcside = PC_RIGHT;
1732: snes->setfromoptionscalled = 0;
1734: snes->mf = PETSC_FALSE;
1735: snes->mf_operator = PETSC_FALSE;
1736: snes->mf_version = 1;
1738: snes->numLinearSolveFailures = 0;
1739: snes->maxLinearSolveFailures = 1;
1741: snes->vizerotolerance = 1.e-8;
1742: #if defined(PETSC_USE_DEBUG)
1743: snes->checkjacdomainerror = PETSC_TRUE;
1744: #else
1745: snes->checkjacdomainerror = PETSC_FALSE;
1746: #endif
1748: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1749: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1751: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1752: PetscNewLog(snes,&kctx);
1754: snes->kspconvctx = (void*)kctx;
1755: kctx->version = 2;
1756: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1757: this was too large for some test cases */
1758: kctx->rtol_last = 0.0;
1759: kctx->rtol_max = .9;
1760: kctx->gamma = 1.0;
1761: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1762: kctx->alpha2 = kctx->alpha;
1763: kctx->threshold = .1;
1764: kctx->lresid_last = 0.0;
1765: kctx->norm_last = 0.0;
1767: *outsnes = snes;
1768: return(0);
1769: }
1771: /*MC
1772: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1774: Synopsis:
1775: #include "petscsnes.h"
1776: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1778: Input Parameters:
1779: + snes - the SNES context
1780: . x - state at which to evaluate residual
1781: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1783: Output Parameter:
1784: . f - vector to put residual (function value)
1786: Level: intermediate
1788: .seealso: SNESSetFunction(), SNESGetFunction()
1789: M*/
1791: /*@C
1792: SNESSetFunction - Sets the function evaluation routine and function
1793: vector for use by the SNES routines in solving systems of nonlinear
1794: equations.
1796: Logically Collective on SNES
1798: Input Parameters:
1799: + snes - the SNES context
1800: . r - vector to store function value
1801: . f - function evaluation routine; see SNESFunction for calling sequence details
1802: - ctx - [optional] user-defined context for private data for the
1803: function evaluation routine (may be NULL)
1805: Notes:
1806: The Newton-like methods typically solve linear systems of the form
1807: $ f'(x) x = -f(x),
1808: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1810: Level: beginner
1812: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1813: @*/
1814: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1815: {
1817: DM dm;
1821: if (r) {
1824: PetscObjectReference((PetscObject)r);
1825: VecDestroy(&snes->vec_func);
1827: snes->vec_func = r;
1828: }
1829: SNESGetDM(snes,&dm);
1830: DMSNESSetFunction(dm,f,ctx);
1831: return(0);
1832: }
1835: /*@C
1836: SNESSetInitialFunction - Sets the function vector to be used as the
1837: function norm at the initialization of the method. In some
1838: instances, the user has precomputed the function before calling
1839: SNESSolve. This function allows one to avoid a redundant call
1840: to SNESComputeFunction in that case.
1842: Logically Collective on SNES
1844: Input Parameters:
1845: + snes - the SNES context
1846: - f - vector to store function value
1848: Notes:
1849: This should not be modified during the solution procedure.
1851: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1853: Level: developer
1855: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1856: @*/
1857: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1858: {
1860: Vec vec_func;
1866: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1867: snes->vec_func_init_set = PETSC_FALSE;
1868: return(0);
1869: }
1870: SNESGetFunction(snes,&vec_func,NULL,NULL);
1871: VecCopy(f, vec_func);
1873: snes->vec_func_init_set = PETSC_TRUE;
1874: return(0);
1875: }
1877: /*@
1878: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1879: of the SNES method.
1881: Logically Collective on SNES
1883: Input Parameters:
1884: + snes - the SNES context
1885: - normschedule - the frequency of norm computation
1887: Options Database Key:
1888: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1890: Notes:
1891: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1892: of the nonlinear function and the taking of its norm at every iteration to
1893: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1894: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1895: may either be monitored for convergence or not. As these are often used as nonlinear
1896: preconditioners, monitoring the norm of their error is not a useful enterprise within
1897: their solution.
1899: Level: developer
1901: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1902: @*/
1903: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1904: {
1907: snes->normschedule = normschedule;
1908: return(0);
1909: }
1912: /*@
1913: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1914: of the SNES method.
1916: Logically Collective on SNES
1918: Input Parameters:
1919: + snes - the SNES context
1920: - normschedule - the type of the norm used
1922: Level: advanced
1924: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1925: @*/
1926: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1927: {
1930: *normschedule = snes->normschedule;
1931: return(0);
1932: }
1935: /*@
1936: SNESSetFunctionNorm - Sets the last computed residual norm.
1938: Logically Collective on SNES
1940: Input Parameters:
1941: + snes - the SNES context
1943: - normschedule - the frequency of norm computation
1945: Level: developer
1947: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1948: @*/
1949: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1950: {
1953: snes->norm = norm;
1954: return(0);
1955: }
1957: /*@
1958: SNESGetFunctionNorm - Gets the last computed norm of the residual
1960: Not Collective
1962: Input Parameter:
1963: . snes - the SNES context
1965: Output Parameter:
1966: . norm - the last computed residual norm
1968: Level: developer
1970: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1971: @*/
1972: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1973: {
1977: *norm = snes->norm;
1978: return(0);
1979: }
1981: /*@
1982: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
1984: Not Collective
1986: Input Parameter:
1987: . snes - the SNES context
1989: Output Parameter:
1990: . ynorm - the last computed update norm
1992: Level: developer
1994: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
1995: @*/
1996: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
1997: {
2001: *ynorm = snes->ynorm;
2002: return(0);
2003: }
2005: /*@
2006: SNESGetSolutionNorm - Gets the last computed norm of the solution
2008: Not Collective
2010: Input Parameter:
2011: . snes - the SNES context
2013: Output Parameter:
2014: . xnorm - the last computed solution norm
2016: Level: developer
2018: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2019: @*/
2020: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2021: {
2025: *xnorm = snes->xnorm;
2026: return(0);
2027: }
2029: /*@C
2030: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2031: of the SNES method.
2033: Logically Collective on SNES
2035: Input Parameters:
2036: + snes - the SNES context
2037: - normschedule - the frequency of norm computation
2039: Notes:
2040: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2041: of the nonlinear function and the taking of its norm at every iteration to
2042: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2043: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2044: may either be monitored for convergence or not. As these are often used as nonlinear
2045: preconditioners, monitoring the norm of their error is not a useful enterprise within
2046: their solution.
2048: Level: developer
2050: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2051: @*/
2052: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2053: {
2056: snes->functype = type;
2057: return(0);
2058: }
2061: /*@C
2062: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2063: of the SNES method.
2065: Logically Collective on SNES
2067: Input Parameters:
2068: + snes - the SNES context
2069: - normschedule - the type of the norm used
2071: Level: advanced
2073: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2074: @*/
2075: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2076: {
2079: *type = snes->functype;
2080: return(0);
2081: }
2083: /*MC
2084: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2086: Synopsis:
2087: #include <petscsnes.h>
2088: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2090: + X - solution vector
2091: . B - RHS vector
2092: - ctx - optional user-defined Gauss-Seidel context
2094: Level: intermediate
2096: .seealso: SNESSetNGS(), SNESGetNGS()
2097: M*/
2099: /*@C
2100: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2101: use with composed nonlinear solvers.
2103: Input Parameters:
2104: + snes - the SNES context
2105: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2106: - ctx - [optional] user-defined context for private data for the
2107: smoother evaluation routine (may be NULL)
2109: Notes:
2110: The NGS routines are used by the composed nonlinear solver to generate
2111: a problem appropriate update to the solution, particularly FAS.
2113: Level: intermediate
2115: .seealso: SNESGetFunction(), SNESComputeNGS()
2116: @*/
2117: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2118: {
2120: DM dm;
2124: SNESGetDM(snes,&dm);
2125: DMSNESSetNGS(dm,f,ctx);
2126: return(0);
2127: }
2129: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2130: {
2132: DM dm;
2133: DMSNES sdm;
2136: SNESGetDM(snes,&dm);
2137: DMGetDMSNES(dm,&sdm);
2138: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2139: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2140: /* A(x)*x - b(x) */
2141: PetscStackPush("SNES Picard user function");
2142: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2143: PetscStackPop;
2144: PetscStackPush("SNES Picard user Jacobian");
2145: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2146: PetscStackPop;
2147: VecScale(f,-1.0);
2148: MatMultAdd(snes->jacobian,x,f,f);
2149: return(0);
2150: }
2152: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2153: {
2155: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2156: return(0);
2157: }
2159: /*@C
2160: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2162: Logically Collective on SNES
2164: Input Parameters:
2165: + snes - the SNES context
2166: . r - vector to store function value
2167: . b - function evaluation routine
2168: . Amat - matrix with which A(x) x - b(x) is to be computed
2169: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2170: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2171: - ctx - [optional] user-defined context for private data for the
2172: function evaluation routine (may be NULL)
2174: Notes:
2175: 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
2176: 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.
2178: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2180: $ 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}
2181: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2183: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2185: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2186: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2188: 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
2189: 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
2190: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2192: Level: intermediate
2194: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2195: @*/
2196: 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)
2197: {
2199: DM dm;
2203: SNESGetDM(snes, &dm);
2204: DMSNESSetPicard(dm,b,J,ctx);
2205: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2206: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2207: return(0);
2208: }
2210: /*@C
2211: SNESGetPicard - Returns the context for the Picard iteration
2213: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2215: Input Parameter:
2216: . snes - the SNES context
2218: Output Parameter:
2219: + r - the function (or NULL)
2220: . f - the function (or NULL); see SNESFunction for calling sequence details
2221: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2222: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2223: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2224: - ctx - the function context (or NULL)
2226: Level: advanced
2228: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2229: @*/
2230: 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)
2231: {
2233: DM dm;
2237: SNESGetFunction(snes,r,NULL,NULL);
2238: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2239: SNESGetDM(snes,&dm);
2240: DMSNESGetPicard(dm,f,J,ctx);
2241: return(0);
2242: }
2244: /*@C
2245: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2247: Logically Collective on SNES
2249: Input Parameters:
2250: + snes - the SNES context
2251: . func - function evaluation routine
2252: - ctx - [optional] user-defined context for private data for the
2253: function evaluation routine (may be NULL)
2255: Calling sequence of func:
2256: $ func (SNES snes,Vec x,void *ctx);
2258: . f - function vector
2259: - ctx - optional user-defined function context
2261: Level: intermediate
2263: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2264: @*/
2265: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2266: {
2269: if (func) snes->ops->computeinitialguess = func;
2270: if (ctx) snes->initialguessP = ctx;
2271: return(0);
2272: }
2274: /* --------------------------------------------------------------- */
2275: /*@C
2276: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2277: it assumes a zero right hand side.
2279: Logically Collective on SNES
2281: Input Parameter:
2282: . snes - the SNES context
2284: Output Parameter:
2285: . rhs - the right hand side vector or NULL if the right hand side vector is null
2287: Level: intermediate
2289: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2290: @*/
2291: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2292: {
2296: *rhs = snes->vec_rhs;
2297: return(0);
2298: }
2300: /*@
2301: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2303: Collective on SNES
2305: Input Parameters:
2306: + snes - the SNES context
2307: - x - input vector
2309: Output Parameter:
2310: . y - function vector, as set by SNESSetFunction()
2312: Notes:
2313: SNESComputeFunction() is typically used within nonlinear solvers
2314: implementations, so most users would not generally call this routine
2315: themselves.
2317: Level: developer
2319: .seealso: SNESSetFunction(), SNESGetFunction()
2320: @*/
2321: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2322: {
2324: DM dm;
2325: DMSNES sdm;
2333: VecValidValues(x,2,PETSC_TRUE);
2335: SNESGetDM(snes,&dm);
2336: DMGetDMSNES(dm,&sdm);
2337: if (sdm->ops->computefunction) {
2338: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2339: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2340: }
2341: VecLockReadPush(x);
2342: PetscStackPush("SNES user function");
2343: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2344: PetscStackPop;
2345: VecLockReadPop(x);
2346: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2347: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2348: }
2349: } else if (snes->vec_rhs) {
2350: MatMult(snes->jacobian, x, y);
2351: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2352: if (snes->vec_rhs) {
2353: VecAXPY(y,-1.0,snes->vec_rhs);
2354: }
2355: snes->nfuncs++;
2356: /*
2357: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2358: propagate the value to all processes
2359: */
2360: if (snes->domainerror) {
2361: VecSetInf(y);
2362: }
2363: return(0);
2364: }
2366: /*@
2367: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2369: Collective on SNES
2371: Input Parameters:
2372: + snes - the SNES context
2373: . x - input vector
2374: - b - rhs vector
2376: Output Parameter:
2377: . x - new solution vector
2379: Notes:
2380: SNESComputeNGS() is typically used within composed nonlinear solver
2381: implementations, so most users would not generally call this routine
2382: themselves.
2384: Level: developer
2386: .seealso: SNESSetNGS(), SNESComputeFunction()
2387: @*/
2388: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2389: {
2391: DM dm;
2392: DMSNES sdm;
2400: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2401: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2402: SNESGetDM(snes,&dm);
2403: DMGetDMSNES(dm,&sdm);
2404: if (sdm->ops->computegs) {
2405: if (b) {VecLockReadPush(b);}
2406: PetscStackPush("SNES user NGS");
2407: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2408: PetscStackPop;
2409: if (b) {VecLockReadPop(b);}
2410: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2411: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2412: return(0);
2413: }
2415: PetscErrorCode SNESTestJacobian(SNES snes)
2416: {
2417: Mat A,B,C,D,jacobian;
2418: Vec x = snes->vec_sol,f = snes->vec_func;
2419: PetscErrorCode ierr;
2420: PetscReal nrm,gnorm;
2421: PetscReal threshold = 1.e-5;
2422: MatType mattype;
2423: PetscInt m,n,M,N;
2424: void *functx;
2425: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg;
2426: PetscViewer viewer,mviewer;
2427: MPI_Comm comm;
2428: PetscInt tabs;
2429: static PetscBool directionsprinted = PETSC_FALSE;
2430: PetscViewerFormat format;
2433: PetscObjectOptionsBegin((PetscObject)snes);
2434: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2435: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2436: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2437: if (!complete_print) {
2438: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2439: }
2440: /* for compatibility with PETSc 3.9 and older. */
2441: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2442: PetscOptionsEnd();
2443: if (!test) return(0);
2445: PetscObjectGetComm((PetscObject)snes,&comm);
2446: PetscViewerASCIIGetStdout(comm,&viewer);
2447: PetscViewerASCIIGetTab(viewer, &tabs);
2448: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2449: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2450: if (!complete_print && !directionsprinted) {
2451: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2452: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2453: }
2454: if (!directionsprinted) {
2455: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2456: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2457: directionsprinted = PETSC_TRUE;
2458: }
2459: if (complete_print) {
2460: PetscViewerPushFormat(mviewer,format);
2461: }
2463: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2464: if (!flg) jacobian = snes->jacobian;
2465: else jacobian = snes->jacobian_pre;
2467: if (!x) {
2468: MatCreateVecs(jacobian, &x, NULL);
2469: } else {
2470: PetscObjectReference((PetscObject) x);
2471: }
2472: if (!f) {
2473: VecDuplicate(x, &f);
2474: } else {
2475: PetscObjectReference((PetscObject) f);
2476: }
2477: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2478: SNESComputeFunction(snes,x,f);
2479: VecDestroy(&f);
2481: while (jacobian) {
2482: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2483: if (flg) {
2484: A = jacobian;
2485: PetscObjectReference((PetscObject)A);
2486: } else {
2487: MatComputeOperator(jacobian,MATAIJ,&A);
2488: }
2490: MatGetType(A,&mattype);
2491: MatGetSize(A,&M,&N);
2492: MatGetLocalSize(A,&m,&n);
2494: MatCreate(PetscObjectComm((PetscObject)A),&B);
2495: MatSetType(B,mattype);
2496: MatSetSizes(B,m,n,M,N);
2497: MatSetBlockSizesFromMats(B,A,A);
2498: MatSetUp(B);
2499: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2501: SNESGetFunction(snes,NULL,NULL,&functx);
2502: SNESComputeJacobianDefault(snes,x,B,B,functx);
2504: MatDuplicate(B,MAT_COPY_VALUES,&D);
2505: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2506: MatNorm(D,NORM_FROBENIUS,&nrm);
2507: MatNorm(A,NORM_FROBENIUS,&gnorm);
2508: MatDestroy(&D);
2509: if (!gnorm) gnorm = 1; /* just in case */
2510: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2512: if (complete_print) {
2513: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2514: MatView(jacobian,mviewer);
2515: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2516: MatView(B,mviewer);
2517: }
2519: if (threshold_print || complete_print) {
2520: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2521: PetscScalar *cvals;
2522: const PetscInt *bcols;
2523: const PetscScalar *bvals;
2525: MatCreate(PetscObjectComm((PetscObject)A),&C);
2526: MatSetType(C,mattype);
2527: MatSetSizes(C,m,n,M,N);
2528: MatSetBlockSizesFromMats(C,A,A);
2529: MatSetUp(C);
2530: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2532: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2533: MatGetOwnershipRange(B,&Istart,&Iend);
2535: for (row = Istart; row < Iend; row++) {
2536: MatGetRow(B,row,&bncols,&bcols,&bvals);
2537: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2538: for (j = 0, cncols = 0; j < bncols; j++) {
2539: if (PetscAbsScalar(bvals[j]) > threshold) {
2540: ccols[cncols] = bcols[j];
2541: cvals[cncols] = bvals[j];
2542: cncols += 1;
2543: }
2544: }
2545: if (cncols) {
2546: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2547: }
2548: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2549: PetscFree2(ccols,cvals);
2550: }
2551: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2552: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2553: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2554: MatView(C,complete_print ? mviewer : viewer);
2555: MatDestroy(&C);
2556: }
2557: MatDestroy(&A);
2558: MatDestroy(&B);
2560: if (jacobian != snes->jacobian_pre) {
2561: jacobian = snes->jacobian_pre;
2562: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2563: }
2564: else jacobian = NULL;
2565: }
2566: VecDestroy(&x);
2567: if (complete_print) {
2568: PetscViewerPopFormat(mviewer);
2569: }
2570: if (mviewer) { PetscViewerDestroy(&mviewer); }
2571: PetscViewerASCIISetTab(viewer,tabs);
2572: return(0);
2573: }
2575: /*@
2576: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2578: Collective on SNES
2580: Input Parameters:
2581: + snes - the SNES context
2582: - x - input vector
2584: Output Parameters:
2585: + A - Jacobian matrix
2586: - B - optional preconditioning matrix
2588: Options Database Keys:
2589: + -snes_lag_preconditioner <lag>
2590: . -snes_lag_jacobian <lag>
2591: . -snes_test_jacobian - compare the user provided Jacobian with one compute via finite differences to check for errors
2592: . -snes_test_jacobian_display - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2593: . -snes_test_jacobian_display_threshold <numerical value> - display entries in the difference between the user provided Jacobian and finite difference Jacobian that are greater than a certain value to help users detect errors
2594: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2595: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2596: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2597: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2598: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2599: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2600: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2601: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2602: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2603: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2604: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2607: Notes:
2608: Most users should not need to explicitly call this routine, as it
2609: is used internally within the nonlinear solvers.
2611: Developer Notes:
2612: 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
2613: for with the SNESType of test that has been removed.
2615: Level: developer
2617: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2618: @*/
2619: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2620: {
2622: PetscBool flag;
2623: DM dm;
2624: DMSNES sdm;
2625: KSP ksp;
2631: VecValidValues(X,2,PETSC_TRUE);
2632: SNESGetDM(snes,&dm);
2633: DMGetDMSNES(dm,&sdm);
2635: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2637: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2639: if (snes->lagjacobian == -2) {
2640: snes->lagjacobian = -1;
2642: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2643: } else if (snes->lagjacobian == -1) {
2644: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2645: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2646: if (flag) {
2647: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2648: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2649: }
2650: return(0);
2651: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2652: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2653: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2654: if (flag) {
2655: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2656: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2657: }
2658: return(0);
2659: }
2660: if (snes->npc && snes->npcside== PC_LEFT) {
2661: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2662: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2663: return(0);
2664: }
2666: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2667: VecLockReadPush(X);
2668: PetscStackPush("SNES user Jacobian function");
2669: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2670: PetscStackPop;
2671: VecLockReadPop(X);
2672: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2674: /* the next line ensures that snes->ksp exists */
2675: SNESGetKSP(snes,&ksp);
2676: if (snes->lagpreconditioner == -2) {
2677: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2678: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2679: snes->lagpreconditioner = -1;
2680: } else if (snes->lagpreconditioner == -1) {
2681: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2682: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2683: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2684: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2685: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2686: } else {
2687: PetscInfo(snes,"Rebuilding preconditioner\n");
2688: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2689: }
2691: SNESTestJacobian(snes);
2692: /* make sure user returned a correct Jacobian and preconditioner */
2695: {
2696: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2697: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2698: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2699: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2700: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2701: if (flag || flag_draw || flag_contour) {
2702: Mat Bexp_mine = NULL,Bexp,FDexp;
2703: PetscViewer vdraw,vstdout;
2704: PetscBool flg;
2705: if (flag_operator) {
2706: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2707: Bexp = Bexp_mine;
2708: } else {
2709: /* See if the preconditioning matrix can be viewed and added directly */
2710: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2711: if (flg) Bexp = B;
2712: else {
2713: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2714: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2715: Bexp = Bexp_mine;
2716: }
2717: }
2718: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2719: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2720: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2721: if (flag_draw || flag_contour) {
2722: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2723: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2724: } else vdraw = NULL;
2725: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2726: if (flag) {MatView(Bexp,vstdout);}
2727: if (vdraw) {MatView(Bexp,vdraw);}
2728: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2729: if (flag) {MatView(FDexp,vstdout);}
2730: if (vdraw) {MatView(FDexp,vdraw);}
2731: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2732: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2733: if (flag) {MatView(FDexp,vstdout);}
2734: if (vdraw) { /* Always use contour for the difference */
2735: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2736: MatView(FDexp,vdraw);
2737: PetscViewerPopFormat(vdraw);
2738: }
2739: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2740: PetscViewerDestroy(&vdraw);
2741: MatDestroy(&Bexp_mine);
2742: MatDestroy(&FDexp);
2743: }
2744: }
2745: {
2746: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2747: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2748: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2749: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2750: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2751: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2752: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2753: if (flag_threshold) {
2754: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2755: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2756: }
2757: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2758: Mat Bfd;
2759: PetscViewer vdraw,vstdout;
2760: MatColoring coloring;
2761: ISColoring iscoloring;
2762: MatFDColoring matfdcoloring;
2763: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2764: void *funcctx;
2765: PetscReal norm1,norm2,normmax;
2767: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2768: MatColoringCreate(Bfd,&coloring);
2769: MatColoringSetType(coloring,MATCOLORINGSL);
2770: MatColoringSetFromOptions(coloring);
2771: MatColoringApply(coloring,&iscoloring);
2772: MatColoringDestroy(&coloring);
2773: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2774: MatFDColoringSetFromOptions(matfdcoloring);
2775: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2776: ISColoringDestroy(&iscoloring);
2778: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2779: SNESGetFunction(snes,NULL,&func,&funcctx);
2780: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2781: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2782: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2783: MatFDColoringSetFromOptions(matfdcoloring);
2784: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2785: MatFDColoringDestroy(&matfdcoloring);
2787: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2788: if (flag_draw || flag_contour) {
2789: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2790: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2791: } else vdraw = NULL;
2792: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2793: if (flag_display) {MatView(B,vstdout);}
2794: if (vdraw) {MatView(B,vdraw);}
2795: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2796: if (flag_display) {MatView(Bfd,vstdout);}
2797: if (vdraw) {MatView(Bfd,vdraw);}
2798: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2799: MatNorm(Bfd,NORM_1,&norm1);
2800: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2801: MatNorm(Bfd,NORM_MAX,&normmax);
2802: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2803: if (flag_display) {MatView(Bfd,vstdout);}
2804: if (vdraw) { /* Always use contour for the difference */
2805: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2806: MatView(Bfd,vdraw);
2807: PetscViewerPopFormat(vdraw);
2808: }
2809: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2811: if (flag_threshold) {
2812: PetscInt bs,rstart,rend,i;
2813: MatGetBlockSize(B,&bs);
2814: MatGetOwnershipRange(B,&rstart,&rend);
2815: for (i=rstart; i<rend; i++) {
2816: const PetscScalar *ba,*ca;
2817: const PetscInt *bj,*cj;
2818: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2819: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2820: MatGetRow(B,i,&bn,&bj,&ba);
2821: MatGetRow(Bfd,i,&cn,&cj,&ca);
2822: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2823: for (j=0; j<bn; j++) {
2824: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2825: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2826: maxentrycol = bj[j];
2827: maxentry = PetscRealPart(ba[j]);
2828: }
2829: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2830: maxdiffcol = bj[j];
2831: maxdiff = PetscRealPart(ca[j]);
2832: }
2833: if (rdiff > maxrdiff) {
2834: maxrdiffcol = bj[j];
2835: maxrdiff = rdiff;
2836: }
2837: }
2838: if (maxrdiff > 1) {
2839: 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);
2840: for (j=0; j<bn; j++) {
2841: PetscReal rdiff;
2842: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2843: if (rdiff > 1) {
2844: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2845: }
2846: }
2847: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2848: }
2849: MatRestoreRow(B,i,&bn,&bj,&ba);
2850: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2851: }
2852: }
2853: PetscViewerDestroy(&vdraw);
2854: MatDestroy(&Bfd);
2855: }
2856: }
2857: return(0);
2858: }
2860: /*MC
2861: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2863: Synopsis:
2864: #include "petscsnes.h"
2865: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2867: + x - input vector
2868: . Amat - the matrix that defines the (approximate) Jacobian
2869: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2870: - ctx - [optional] user-defined Jacobian context
2872: Level: intermediate
2874: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2875: M*/
2877: /*@C
2878: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2879: location to store the matrix.
2881: Logically Collective on SNES
2883: Input Parameters:
2884: + snes - the SNES context
2885: . Amat - the matrix that defines the (approximate) Jacobian
2886: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2887: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2888: - ctx - [optional] user-defined context for private data for the
2889: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2891: Notes:
2892: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2893: each matrix.
2895: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2896: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2898: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2899: must be a MatFDColoring.
2901: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2902: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2904: Level: beginner
2906: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2907: SNESSetPicard(), SNESJacobianFunction
2908: @*/
2909: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2910: {
2912: DM dm;
2920: SNESGetDM(snes,&dm);
2921: DMSNESSetJacobian(dm,J,ctx);
2922: if (Amat) {
2923: PetscObjectReference((PetscObject)Amat);
2924: MatDestroy(&snes->jacobian);
2926: snes->jacobian = Amat;
2927: }
2928: if (Pmat) {
2929: PetscObjectReference((PetscObject)Pmat);
2930: MatDestroy(&snes->jacobian_pre);
2932: snes->jacobian_pre = Pmat;
2933: }
2934: return(0);
2935: }
2937: /*@C
2938: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2939: provided context for evaluating the Jacobian.
2941: Not Collective, but Mat object will be parallel if SNES object is
2943: Input Parameter:
2944: . snes - the nonlinear solver context
2946: Output Parameters:
2947: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2948: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2949: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2950: - ctx - location to stash Jacobian ctx (or NULL)
2952: Level: advanced
2954: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2955: @*/
2956: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2957: {
2959: DM dm;
2960: DMSNES sdm;
2964: if (Amat) *Amat = snes->jacobian;
2965: if (Pmat) *Pmat = snes->jacobian_pre;
2966: SNESGetDM(snes,&dm);
2967: DMGetDMSNES(dm,&sdm);
2968: if (J) *J = sdm->ops->computejacobian;
2969: if (ctx) *ctx = sdm->jacobianctx;
2970: return(0);
2971: }
2973: /*@
2974: SNESSetUp - Sets up the internal data structures for the later use
2975: of a nonlinear solver.
2977: Collective on SNES
2979: Input Parameters:
2980: . snes - the SNES context
2982: Notes:
2983: For basic use of the SNES solvers the user need not explicitly call
2984: SNESSetUp(), since these actions will automatically occur during
2985: the call to SNESSolve(). However, if one wishes to control this
2986: phase separately, SNESSetUp() should be called after SNESCreate()
2987: and optional routines of the form SNESSetXXX(), but before SNESSolve().
2989: Level: advanced
2991: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
2992: @*/
2993: PetscErrorCode SNESSetUp(SNES snes)
2994: {
2996: DM dm;
2997: DMSNES sdm;
2998: SNESLineSearch linesearch, pclinesearch;
2999: void *lsprectx,*lspostctx;
3000: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3001: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3002: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3003: Vec f,fpc;
3004: void *funcctx;
3005: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3006: void *jacctx,*appctx;
3007: Mat j,jpre;
3011: if (snes->setupcalled) return(0);
3012: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3014: if (!((PetscObject)snes)->type_name) {
3015: SNESSetType(snes,SNESNEWTONLS);
3016: }
3018: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3020: SNESGetDM(snes,&dm);
3021: DMGetDMSNES(dm,&sdm);
3022: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3023: if (!sdm->ops->computejacobian) {
3024: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3025: }
3026: if (!snes->vec_func) {
3027: DMCreateGlobalVector(dm,&snes->vec_func);
3028: }
3030: if (!snes->ksp) {
3031: SNESGetKSP(snes, &snes->ksp);
3032: }
3034: if (snes->linesearch) {
3035: SNESGetLineSearch(snes, &snes->linesearch);
3036: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3037: }
3039: if (snes->npc && (snes->npcside== PC_LEFT)) {
3040: snes->mf = PETSC_TRUE;
3041: snes->mf_operator = PETSC_FALSE;
3042: }
3044: if (snes->npc) {
3045: /* copy the DM over */
3046: SNESGetDM(snes,&dm);
3047: SNESSetDM(snes->npc,dm);
3049: SNESGetFunction(snes,&f,&func,&funcctx);
3050: VecDuplicate(f,&fpc);
3051: SNESSetFunction(snes->npc,fpc,func,funcctx);
3052: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3053: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3054: SNESGetApplicationContext(snes,&appctx);
3055: SNESSetApplicationContext(snes->npc,appctx);
3056: VecDestroy(&fpc);
3058: /* copy the function pointers over */
3059: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3061: /* default to 1 iteration */
3062: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3063: if (snes->npcside==PC_RIGHT) {
3064: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3065: } else {
3066: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3067: }
3068: SNESSetFromOptions(snes->npc);
3070: /* copy the line search context over */
3071: if (snes->linesearch && snes->npc->linesearch) {
3072: SNESGetLineSearch(snes,&linesearch);
3073: SNESGetLineSearch(snes->npc,&pclinesearch);
3074: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3075: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3076: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3077: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3078: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3079: }
3080: }
3081: if (snes->mf) {
3082: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3083: }
3084: if (snes->ops->usercompute && !snes->user) {
3085: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3086: }
3088: snes->jac_iter = 0;
3089: snes->pre_iter = 0;
3091: if (snes->ops->setup) {
3092: (*snes->ops->setup)(snes);
3093: }
3095: if (snes->npc && (snes->npcside== PC_LEFT)) {
3096: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3097: if (snes->linesearch){
3098: SNESGetLineSearch(snes,&linesearch);
3099: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3100: }
3101: }
3102: }
3103: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3104: snes->setupcalled = PETSC_TRUE;
3105: return(0);
3106: }
3108: /*@
3109: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3111: Collective on SNES
3113: Input Parameter:
3114: . snes - iterative context obtained from SNESCreate()
3116: Level: intermediate
3118: Notes:
3119: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3121: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3122: @*/
3123: PetscErrorCode SNESReset(SNES snes)
3124: {
3129: if (snes->ops->userdestroy && snes->user) {
3130: (*snes->ops->userdestroy)((void**)&snes->user);
3131: snes->user = NULL;
3132: }
3133: if (snes->npc) {
3134: SNESReset(snes->npc);
3135: }
3137: if (snes->ops->reset) {
3138: (*snes->ops->reset)(snes);
3139: }
3140: if (snes->ksp) {
3141: KSPReset(snes->ksp);
3142: }
3144: if (snes->linesearch) {
3145: SNESLineSearchReset(snes->linesearch);
3146: }
3148: VecDestroy(&snes->vec_rhs);
3149: VecDestroy(&snes->vec_sol);
3150: VecDestroy(&snes->vec_sol_update);
3151: VecDestroy(&snes->vec_func);
3152: MatDestroy(&snes->jacobian);
3153: MatDestroy(&snes->jacobian_pre);
3154: VecDestroyVecs(snes->nwork,&snes->work);
3155: VecDestroyVecs(snes->nvwork,&snes->vwork);
3157: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3159: snes->nwork = snes->nvwork = 0;
3160: snes->setupcalled = PETSC_FALSE;
3161: return(0);
3162: }
3164: /*@
3165: SNESDestroy - Destroys the nonlinear solver context that was created
3166: with SNESCreate().
3168: Collective on SNES
3170: Input Parameter:
3171: . snes - the SNES context
3173: Level: beginner
3175: .seealso: SNESCreate(), SNESSolve()
3176: @*/
3177: PetscErrorCode SNESDestroy(SNES *snes)
3178: {
3182: if (!*snes) return(0);
3184: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3186: SNESReset((*snes));
3187: SNESDestroy(&(*snes)->npc);
3189: /* if memory was published with SAWs then destroy it */
3190: PetscObjectSAWsViewOff((PetscObject)*snes);
3191: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3193: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3194: DMDestroy(&(*snes)->dm);
3195: KSPDestroy(&(*snes)->ksp);
3196: SNESLineSearchDestroy(&(*snes)->linesearch);
3198: PetscFree((*snes)->kspconvctx);
3199: if ((*snes)->ops->convergeddestroy) {
3200: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3201: }
3202: if ((*snes)->conv_hist_alloc) {
3203: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3204: }
3205: SNESMonitorCancel((*snes));
3206: PetscHeaderDestroy(snes);
3207: return(0);
3208: }
3210: /* ----------- Routines to set solver parameters ---------- */
3212: /*@
3213: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3215: Logically Collective on SNES
3217: Input Parameters:
3218: + snes - the SNES context
3219: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3220: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3222: Options Database Keys:
3223: . -snes_lag_preconditioner <lag>
3225: Notes:
3226: The default is 1
3227: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3228: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3230: Level: intermediate
3232: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3234: @*/
3235: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3236: {
3239: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3240: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3242: snes->lagpreconditioner = lag;
3243: return(0);
3244: }
3246: /*@
3247: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3249: Logically Collective on SNES
3251: Input Parameters:
3252: + snes - the SNES context
3253: - steps - the number of refinements to do, defaults to 0
3255: Options Database Keys:
3256: . -snes_grid_sequence <steps>
3258: Level: intermediate
3260: Notes:
3261: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3263: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3265: @*/
3266: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3267: {
3271: snes->gridsequence = steps;
3272: return(0);
3273: }
3275: /*@
3276: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3278: Logically Collective on SNES
3280: Input Parameter:
3281: . snes - the SNES context
3283: Output Parameter:
3284: . steps - the number of refinements to do, defaults to 0
3286: Options Database Keys:
3287: . -snes_grid_sequence <steps>
3289: Level: intermediate
3291: Notes:
3292: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3294: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3296: @*/
3297: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3298: {
3301: *steps = snes->gridsequence;
3302: return(0);
3303: }
3305: /*@
3306: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3308: Not Collective
3310: Input Parameter:
3311: . snes - the SNES context
3313: Output Parameter:
3314: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3315: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3317: Options Database Keys:
3318: . -snes_lag_preconditioner <lag>
3320: Notes:
3321: The default is 1
3322: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3324: Level: intermediate
3326: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3328: @*/
3329: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3330: {
3333: *lag = snes->lagpreconditioner;
3334: return(0);
3335: }
3337: /*@
3338: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3339: often the preconditioner is rebuilt.
3341: Logically Collective on SNES
3343: Input Parameters:
3344: + snes - the SNES context
3345: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3346: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3348: Options Database Keys:
3349: . -snes_lag_jacobian <lag>
3351: Notes:
3352: The default is 1
3353: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3354: 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
3355: at the next Newton step but never again (unless it is reset to another value)
3357: Level: intermediate
3359: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3361: @*/
3362: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3363: {
3366: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3367: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3369: snes->lagjacobian = lag;
3370: return(0);
3371: }
3373: /*@
3374: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3376: Not Collective
3378: Input Parameter:
3379: . snes - the SNES context
3381: Output Parameter:
3382: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3383: the Jacobian is built etc.
3385: Options Database Keys:
3386: . -snes_lag_jacobian <lag>
3388: Notes:
3389: The default is 1
3390: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3392: Level: intermediate
3394: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3396: @*/
3397: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3398: {
3401: *lag = snes->lagjacobian;
3402: return(0);
3403: }
3405: /*@
3406: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3408: Logically collective on SNES
3410: Input Parameter:
3411: + snes - the SNES context
3412: - flg - jacobian lagging persists if true
3414: Options Database Keys:
3415: . -snes_lag_jacobian_persists <flg>
3417: Notes:
3418: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3419: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3420: timesteps may present huge efficiency gains.
3422: Level: developer
3424: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3426: @*/
3427: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3428: {
3432: snes->lagjac_persist = flg;
3433: return(0);
3434: }
3436: /*@
3437: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3439: Logically Collective on SNES
3441: Input Parameter:
3442: + snes - the SNES context
3443: - flg - preconditioner lagging persists if true
3445: Options Database Keys:
3446: . -snes_lag_jacobian_persists <flg>
3448: Notes:
3449: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3450: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3451: several timesteps may present huge efficiency gains.
3453: Level: developer
3455: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3457: @*/
3458: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3459: {
3463: snes->lagpre_persist = flg;
3464: return(0);
3465: }
3467: /*@
3468: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3470: Logically Collective on SNES
3472: Input Parameters:
3473: + snes - the SNES context
3474: - force - PETSC_TRUE require at least one iteration
3476: Options Database Keys:
3477: . -snes_force_iteration <force> - Sets forcing an iteration
3479: Notes:
3480: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3482: Level: intermediate
3484: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3485: @*/
3486: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3487: {
3490: snes->forceiteration = force;
3491: return(0);
3492: }
3494: /*@
3495: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3497: Logically Collective on SNES
3499: Input Parameters:
3500: . snes - the SNES context
3502: Output Parameter:
3503: . force - PETSC_TRUE requires at least one iteration.
3505: Level: intermediate
3507: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3508: @*/
3509: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3510: {
3513: *force = snes->forceiteration;
3514: return(0);
3515: }
3517: /*@
3518: SNESSetTolerances - Sets various parameters used in convergence tests.
3520: Logically Collective on SNES
3522: Input Parameters:
3523: + snes - the SNES context
3524: . abstol - absolute convergence tolerance
3525: . rtol - relative convergence tolerance
3526: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3527: . maxit - maximum number of iterations
3528: - maxf - maximum number of function evaluations (-1 indicates no limit)
3530: Options Database Keys:
3531: + -snes_atol <abstol> - Sets abstol
3532: . -snes_rtol <rtol> - Sets rtol
3533: . -snes_stol <stol> - Sets stol
3534: . -snes_max_it <maxit> - Sets maxit
3535: - -snes_max_funcs <maxf> - Sets maxf
3537: Notes:
3538: The default maximum number of iterations is 50.
3539: The default maximum number of function evaluations is 1000.
3541: Level: intermediate
3543: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3544: @*/
3545: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3546: {
3555: if (abstol != PETSC_DEFAULT) {
3556: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3557: snes->abstol = abstol;
3558: }
3559: if (rtol != PETSC_DEFAULT) {
3560: 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);
3561: snes->rtol = rtol;
3562: }
3563: if (stol != PETSC_DEFAULT) {
3564: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3565: snes->stol = stol;
3566: }
3567: if (maxit != PETSC_DEFAULT) {
3568: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3569: snes->max_its = maxit;
3570: }
3571: if (maxf != PETSC_DEFAULT) {
3572: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3573: snes->max_funcs = maxf;
3574: }
3575: snes->tolerancesset = PETSC_TRUE;
3576: return(0);
3577: }
3579: /*@
3580: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3582: Logically Collective on SNES
3584: Input Parameters:
3585: + snes - the SNES context
3586: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3588: Options Database Keys:
3589: . -snes_divergence_tolerance <divtol> - Sets divtol
3591: Notes:
3592: The default divergence tolerance is 1e4.
3594: Level: intermediate
3596: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3597: @*/
3598: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3599: {
3604: if (divtol != PETSC_DEFAULT) {
3605: snes->divtol = divtol;
3606: }
3607: else {
3608: snes->divtol = 1.0e4;
3609: }
3610: return(0);
3611: }
3613: /*@
3614: SNESGetTolerances - Gets various parameters used in convergence tests.
3616: Not Collective
3618: Input Parameters:
3619: + snes - the SNES context
3620: . atol - absolute convergence tolerance
3621: . rtol - relative convergence tolerance
3622: . stol - convergence tolerance in terms of the norm
3623: of the change in the solution between steps
3624: . maxit - maximum number of iterations
3625: - maxf - maximum number of function evaluations
3627: Notes:
3628: The user can specify NULL for any parameter that is not needed.
3630: Level: intermediate
3632: .seealso: SNESSetTolerances()
3633: @*/
3634: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3635: {
3638: if (atol) *atol = snes->abstol;
3639: if (rtol) *rtol = snes->rtol;
3640: if (stol) *stol = snes->stol;
3641: if (maxit) *maxit = snes->max_its;
3642: if (maxf) *maxf = snes->max_funcs;
3643: return(0);
3644: }
3646: /*@
3647: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3649: Not Collective
3651: Input Parameters:
3652: + snes - the SNES context
3653: - divtol - divergence tolerance
3655: Level: intermediate
3657: .seealso: SNESSetDivergenceTolerance()
3658: @*/
3659: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3660: {
3663: if (divtol) *divtol = snes->divtol;
3664: return(0);
3665: }
3667: /*@
3668: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3670: Logically Collective on SNES
3672: Input Parameters:
3673: + snes - the SNES context
3674: - tol - tolerance
3676: Options Database Key:
3677: . -snes_trtol <tol> - Sets tol
3679: Level: intermediate
3681: .seealso: SNESSetTolerances()
3682: @*/
3683: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3684: {
3688: snes->deltatol = tol;
3689: return(0);
3690: }
3692: /*
3693: Duplicate the lg monitors for SNES from KSP; for some reason with
3694: dynamic libraries things don't work under Sun4 if we just use
3695: macros instead of functions
3696: */
3697: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3698: {
3703: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3704: return(0);
3705: }
3707: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3708: {
3712: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3713: return(0);
3714: }
3716: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3718: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3719: {
3720: PetscDrawLG lg;
3721: PetscErrorCode ierr;
3722: PetscReal x,y,per;
3723: PetscViewer v = (PetscViewer)monctx;
3724: static PetscReal prev; /* should be in the context */
3725: PetscDraw draw;
3729: PetscViewerDrawGetDrawLG(v,0,&lg);
3730: if (!n) {PetscDrawLGReset(lg);}
3731: PetscDrawLGGetDraw(lg,&draw);
3732: PetscDrawSetTitle(draw,"Residual norm");
3733: x = (PetscReal)n;
3734: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3735: else y = -15.0;
3736: PetscDrawLGAddPoint(lg,&x,&y);
3737: if (n < 20 || !(n % 5) || snes->reason) {
3738: PetscDrawLGDraw(lg);
3739: PetscDrawLGSave(lg);
3740: }
3742: PetscViewerDrawGetDrawLG(v,1,&lg);
3743: if (!n) {PetscDrawLGReset(lg);}
3744: PetscDrawLGGetDraw(lg,&draw);
3745: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3746: SNESMonitorRange_Private(snes,n,&per);
3747: x = (PetscReal)n;
3748: y = 100.0*per;
3749: PetscDrawLGAddPoint(lg,&x,&y);
3750: if (n < 20 || !(n % 5) || snes->reason) {
3751: PetscDrawLGDraw(lg);
3752: PetscDrawLGSave(lg);
3753: }
3755: PetscViewerDrawGetDrawLG(v,2,&lg);
3756: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3757: PetscDrawLGGetDraw(lg,&draw);
3758: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3759: x = (PetscReal)n;
3760: y = (prev - rnorm)/prev;
3761: PetscDrawLGAddPoint(lg,&x,&y);
3762: if (n < 20 || !(n % 5) || snes->reason) {
3763: PetscDrawLGDraw(lg);
3764: PetscDrawLGSave(lg);
3765: }
3767: PetscViewerDrawGetDrawLG(v,3,&lg);
3768: if (!n) {PetscDrawLGReset(lg);}
3769: PetscDrawLGGetDraw(lg,&draw);
3770: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3771: x = (PetscReal)n;
3772: y = (prev - rnorm)/(prev*per);
3773: if (n > 2) { /*skip initial crazy value */
3774: PetscDrawLGAddPoint(lg,&x,&y);
3775: }
3776: if (n < 20 || !(n % 5) || snes->reason) {
3777: PetscDrawLGDraw(lg);
3778: PetscDrawLGSave(lg);
3779: }
3780: prev = rnorm;
3781: return(0);
3782: }
3784: /*@
3785: SNESMonitor - runs the user provided monitor routines, if they exist
3787: Collective on SNES
3789: Input Parameters:
3790: + snes - nonlinear solver context obtained from SNESCreate()
3791: . iter - iteration number
3792: - rnorm - relative norm of the residual
3794: Notes:
3795: This routine is called by the SNES implementations.
3796: It does not typically need to be called by the user.
3798: Level: developer
3800: .seealso: SNESMonitorSet()
3801: @*/
3802: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3803: {
3805: PetscInt i,n = snes->numbermonitors;
3808: VecLockReadPush(snes->vec_sol);
3809: for (i=0; i<n; i++) {
3810: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3811: }
3812: VecLockReadPop(snes->vec_sol);
3813: return(0);
3814: }
3816: /* ------------ Routines to set performance monitoring options ----------- */
3818: /*MC
3819: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3821: Synopsis:
3822: #include <petscsnes.h>
3823: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3825: + snes - the SNES context
3826: . its - iteration number
3827: . norm - 2-norm function value (may be estimated)
3828: - mctx - [optional] monitoring context
3830: Level: advanced
3832: .seealso: SNESMonitorSet(), SNESMonitorGet()
3833: M*/
3835: /*@C
3836: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3837: iteration of the nonlinear solver to display the iteration's
3838: progress.
3840: Logically Collective on SNES
3842: Input Parameters:
3843: + snes - the SNES context
3844: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3845: . mctx - [optional] user-defined context for private data for the
3846: monitor routine (use NULL if no context is desired)
3847: - monitordestroy - [optional] routine that frees monitor context
3848: (may be NULL)
3850: Options Database Keys:
3851: + -snes_monitor - sets SNESMonitorDefault()
3852: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3853: uses SNESMonitorLGCreate()
3854: - -snes_monitor_cancel - cancels all monitors that have
3855: been hardwired into a code by
3856: calls to SNESMonitorSet(), but
3857: does not cancel those set via
3858: the options database.
3860: Notes:
3861: Several different monitoring routines may be set by calling
3862: SNESMonitorSet() multiple times; all will be called in the
3863: order in which they were set.
3865: Fortran Notes:
3866: Only a single monitor function can be set for each SNES object
3868: Level: intermediate
3870: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3871: @*/
3872: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3873: {
3874: PetscInt i;
3876: PetscBool identical;
3880: for (i=0; i<snes->numbermonitors;i++) {
3881: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3882: if (identical) return(0);
3883: }
3884: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3885: snes->monitor[snes->numbermonitors] = f;
3886: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3887: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3888: return(0);
3889: }
3891: /*@
3892: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3894: Logically Collective on SNES
3896: Input Parameters:
3897: . snes - the SNES context
3899: Options Database Key:
3900: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3901: into a code by calls to SNESMonitorSet(), but does not cancel those
3902: set via the options database
3904: Notes:
3905: There is no way to clear one specific monitor from a SNES object.
3907: Level: intermediate
3909: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3910: @*/
3911: PetscErrorCode SNESMonitorCancel(SNES snes)
3912: {
3914: PetscInt i;
3918: for (i=0; i<snes->numbermonitors; i++) {
3919: if (snes->monitordestroy[i]) {
3920: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3921: }
3922: }
3923: snes->numbermonitors = 0;
3924: return(0);
3925: }
3927: /*MC
3928: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3930: Synopsis:
3931: #include <petscsnes.h>
3932: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3934: + snes - the SNES context
3935: . it - current iteration (0 is the first and is before any Newton step)
3936: . cctx - [optional] convergence context
3937: . reason - reason for convergence/divergence
3938: . xnorm - 2-norm of current iterate
3939: . gnorm - 2-norm of current step
3940: - f - 2-norm of function
3942: Level: intermediate
3944: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3945: M*/
3947: /*@C
3948: SNESSetConvergenceTest - Sets the function that is to be used
3949: to test for convergence of the nonlinear iterative solution.
3951: Logically Collective on SNES
3953: Input Parameters:
3954: + snes - the SNES context
3955: . SNESConvergenceTestFunction - routine to test for convergence
3956: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3957: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
3959: Level: advanced
3961: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3962: @*/
3963: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3964: {
3969: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3970: if (snes->ops->convergeddestroy) {
3971: (*snes->ops->convergeddestroy)(snes->cnvP);
3972: }
3973: snes->ops->converged = SNESConvergenceTestFunction;
3974: snes->ops->convergeddestroy = destroy;
3975: snes->cnvP = cctx;
3976: return(0);
3977: }
3979: /*@
3980: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
3982: Not Collective
3984: Input Parameter:
3985: . snes - the SNES context
3987: Output Parameter:
3988: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3989: manual pages for the individual convergence tests for complete lists
3991: Options Database:
3992: . -snes_converged_reason - prints the reason to standard out
3994: Level: intermediate
3996: Notes:
3997: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
3999: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4000: @*/
4001: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4002: {
4006: *reason = snes->reason;
4007: return(0);
4008: }
4010: /*@
4011: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4013: Not Collective
4015: Input Parameters:
4016: + snes - the SNES context
4017: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4018: manual pages for the individual convergence tests for complete lists
4020: Level: intermediate
4022: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4023: @*/
4024: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4025: {
4028: snes->reason = reason;
4029: return(0);
4030: }
4032: /*@
4033: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4035: Logically Collective on SNES
4037: Input Parameters:
4038: + snes - iterative context obtained from SNESCreate()
4039: . a - array to hold history, this array will contain the function norms computed at each step
4040: . its - integer array holds the number of linear iterations for each solve.
4041: . na - size of a and its
4042: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4043: else it continues storing new values for new nonlinear solves after the old ones
4045: Notes:
4046: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4047: default array of length 10000 is allocated.
4049: This routine is useful, e.g., when running a code for purposes
4050: of accurate performance monitoring, when no I/O should be done
4051: during the section of code that is being timed.
4053: Level: intermediate
4055: .seealso: SNESGetConvergenceHistory()
4057: @*/
4058: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4059: {
4066: if (!a) {
4067: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4068: PetscCalloc2(na,&a,na,&its);
4069: snes->conv_hist_alloc = PETSC_TRUE;
4070: }
4071: snes->conv_hist = a;
4072: snes->conv_hist_its = its;
4073: snes->conv_hist_max = na;
4074: snes->conv_hist_len = 0;
4075: snes->conv_hist_reset = reset;
4076: return(0);
4077: }
4079: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4080: #include <engine.h> /* MATLAB include file */
4081: #include <mex.h> /* MATLAB include file */
4083: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4084: {
4085: mxArray *mat;
4086: PetscInt i;
4087: PetscReal *ar;
4090: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4091: ar = (PetscReal*) mxGetData(mat);
4092: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4093: PetscFunctionReturn(mat);
4094: }
4095: #endif
4097: /*@C
4098: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4100: Not Collective
4102: Input Parameter:
4103: . snes - iterative context obtained from SNESCreate()
4105: Output Parameters:
4106: + a - array to hold history
4107: . its - integer array holds the number of linear iterations (or
4108: negative if not converged) for each solve.
4109: - na - size of a and its
4111: Notes:
4112: The calling sequence for this routine in Fortran is
4113: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4115: This routine is useful, e.g., when running a code for purposes
4116: of accurate performance monitoring, when no I/O should be done
4117: during the section of code that is being timed.
4119: Level: intermediate
4121: .seealso: SNESSetConvergencHistory()
4123: @*/
4124: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4125: {
4128: if (a) *a = snes->conv_hist;
4129: if (its) *its = snes->conv_hist_its;
4130: if (na) *na = snes->conv_hist_len;
4131: return(0);
4132: }
4134: /*@C
4135: SNESSetUpdate - Sets the general-purpose update function called
4136: at the beginning of every iteration of the nonlinear solve. Specifically
4137: it is called just before the Jacobian is "evaluated".
4139: Logically Collective on SNES
4141: Input Parameters:
4142: + snes - The nonlinear solver context
4143: - func - The function
4145: Calling sequence of func:
4146: $ func (SNES snes, PetscInt step);
4148: . step - The current step of the iteration
4150: Level: advanced
4152: 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()
4153: This is not used by most users.
4155: .seealso SNESSetJacobian(), SNESSolve()
4156: @*/
4157: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4158: {
4161: snes->ops->update = func;
4162: return(0);
4163: }
4165: /*
4166: SNESScaleStep_Private - Scales a step so that its length is less than the
4167: positive parameter delta.
4169: Input Parameters:
4170: + snes - the SNES context
4171: . y - approximate solution of linear system
4172: . fnorm - 2-norm of current function
4173: - delta - trust region size
4175: Output Parameters:
4176: + gpnorm - predicted function norm at the new point, assuming local
4177: linearization. The value is zero if the step lies within the trust
4178: region, and exceeds zero otherwise.
4179: - ynorm - 2-norm of the step
4181: Note:
4182: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4183: is set to be the maximum allowable step size.
4185: */
4186: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4187: {
4188: PetscReal nrm;
4189: PetscScalar cnorm;
4197: VecNorm(y,NORM_2,&nrm);
4198: if (nrm > *delta) {
4199: nrm = *delta/nrm;
4200: *gpnorm = (1.0 - nrm)*(*fnorm);
4201: cnorm = nrm;
4202: VecScale(y,cnorm);
4203: *ynorm = *delta;
4204: } else {
4205: *gpnorm = 0.0;
4206: *ynorm = nrm;
4207: }
4208: return(0);
4209: }
4211: /*@
4212: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4214: Collective on SNES
4216: Parameter:
4217: + snes - iterative context obtained from SNESCreate()
4218: - viewer - the viewer to display the reason
4221: Options Database Keys:
4222: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4224: Level: beginner
4226: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4228: @*/
4229: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4230: {
4231: PetscViewerFormat format;
4232: PetscBool isAscii;
4233: PetscErrorCode ierr;
4236: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4237: if (isAscii) {
4238: PetscViewerGetFormat(viewer, &format);
4239: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4240: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4241: DM dm;
4242: Vec u;
4243: PetscDS prob;
4244: PetscInt Nf, f;
4245: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4246: void **exactCtx;
4247: PetscReal error;
4249: SNESGetDM(snes, &dm);
4250: SNESGetSolution(snes, &u);
4251: DMGetDS(dm, &prob);
4252: PetscDSGetNumFields(prob, &Nf);
4253: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4254: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4255: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4256: PetscFree2(exactSol, exactCtx);
4257: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4258: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4259: }
4260: if (snes->reason > 0) {
4261: if (((PetscObject) snes)->prefix) {
4262: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4263: } else {
4264: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4265: }
4266: } else {
4267: if (((PetscObject) snes)->prefix) {
4268: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4269: } else {
4270: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4271: }
4272: }
4273: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4274: }
4275: return(0);
4276: }
4278: /*@C
4279: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4281: Collective on SNES
4283: Input Parameters:
4284: . snes - the SNES object
4286: Level: intermediate
4288: @*/
4289: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4290: {
4291: PetscErrorCode ierr;
4292: PetscViewer viewer;
4293: PetscBool flg;
4294: static PetscBool incall = PETSC_FALSE;
4295: PetscViewerFormat format;
4298: if (incall) return(0);
4299: incall = PETSC_TRUE;
4300: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4301: if (flg) {
4302: PetscViewerPushFormat(viewer,format);
4303: SNESReasonView(snes,viewer);
4304: PetscViewerPopFormat(viewer);
4305: PetscViewerDestroy(&viewer);
4306: }
4307: incall = PETSC_FALSE;
4308: return(0);
4309: }
4311: /*@
4312: SNESSolve - Solves a nonlinear system F(x) = b.
4313: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4315: Collective on SNES
4317: Input Parameters:
4318: + snes - the SNES context
4319: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4320: - x - the solution vector.
4322: Notes:
4323: The user should initialize the vector,x, with the initial guess
4324: for the nonlinear solve prior to calling SNESSolve. In particular,
4325: to employ an initial guess of zero, the user should explicitly set
4326: this vector to zero by calling VecSet().
4328: Level: beginner
4330: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4331: @*/
4332: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4333: {
4334: PetscErrorCode ierr;
4335: PetscBool flg;
4336: PetscInt grid;
4337: Vec xcreated = NULL;
4338: DM dm;
4347: /* High level operations using the nonlinear solver */
4348: {
4349: PetscViewer viewer;
4350: PetscViewerFormat format;
4351: PetscInt num;
4352: PetscBool flg;
4353: static PetscBool incall = PETSC_FALSE;
4355: if (!incall) {
4356: /* Estimate the convergence rate of the discretization */
4357: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4358: if (flg) {
4359: PetscConvEst conv;
4360: DM dm;
4361: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4362: PetscInt Nf;
4364: incall = PETSC_TRUE;
4365: SNESGetDM(snes, &dm);
4366: DMGetNumFields(dm, &Nf);
4367: PetscCalloc1(Nf, &alpha);
4368: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4369: PetscConvEstSetSolver(conv, snes);
4370: PetscConvEstSetFromOptions(conv);
4371: PetscConvEstSetUp(conv);
4372: PetscConvEstGetConvRate(conv, alpha);
4373: PetscViewerPushFormat(viewer, format);
4374: PetscConvEstRateView(conv, alpha, viewer);
4375: PetscViewerPopFormat(viewer);
4376: PetscViewerDestroy(&viewer);
4377: PetscConvEstDestroy(&conv);
4378: PetscFree(alpha);
4379: incall = PETSC_FALSE;
4380: }
4381: /* Adaptively refine the initial grid */
4382: num = 1;
4383: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4384: if (flg) {
4385: DMAdaptor adaptor;
4387: incall = PETSC_TRUE;
4388: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4389: DMAdaptorSetSolver(adaptor, snes);
4390: DMAdaptorSetSequenceLength(adaptor, num);
4391: DMAdaptorSetFromOptions(adaptor);
4392: DMAdaptorSetUp(adaptor);
4393: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4394: DMAdaptorDestroy(&adaptor);
4395: incall = PETSC_FALSE;
4396: }
4397: /* Use grid sequencing to adapt */
4398: num = 0;
4399: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4400: if (num) {
4401: DMAdaptor adaptor;
4403: incall = PETSC_TRUE;
4404: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4405: DMAdaptorSetSolver(adaptor, snes);
4406: DMAdaptorSetSequenceLength(adaptor, num);
4407: DMAdaptorSetFromOptions(adaptor);
4408: DMAdaptorSetUp(adaptor);
4409: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4410: DMAdaptorDestroy(&adaptor);
4411: incall = PETSC_FALSE;
4412: }
4413: }
4414: }
4415: if (!x) {
4416: SNESGetDM(snes,&dm);
4417: DMCreateGlobalVector(dm,&xcreated);
4418: x = xcreated;
4419: }
4420: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4422: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4423: for (grid=0; grid<snes->gridsequence+1; grid++) {
4425: /* set solution vector */
4426: if (!grid) {PetscObjectReference((PetscObject)x);}
4427: VecDestroy(&snes->vec_sol);
4428: snes->vec_sol = x;
4429: SNESGetDM(snes,&dm);
4431: /* set affine vector if provided */
4432: if (b) { PetscObjectReference((PetscObject)b); }
4433: VecDestroy(&snes->vec_rhs);
4434: snes->vec_rhs = b;
4436: 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");
4437: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4438: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4439: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4440: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4441: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4442: }
4443: DMShellSetGlobalVector(dm,snes->vec_sol);
4444: SNESSetUp(snes);
4446: if (!grid) {
4447: if (snes->ops->computeinitialguess) {
4448: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4449: }
4450: }
4452: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4453: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4455: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4456: (*snes->ops->solve)(snes);
4457: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4458: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4459: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4461: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4462: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4464: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4465: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4466: SNESReasonViewFromOptions(snes);
4468: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4469: if (snes->reason < 0) break;
4470: if (grid < snes->gridsequence) {
4471: DM fine;
4472: Vec xnew;
4473: Mat interp;
4475: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4476: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4477: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4478: DMCreateGlobalVector(fine,&xnew);
4479: MatInterpolate(interp,x,xnew);
4480: DMInterpolate(snes->dm,interp,fine);
4481: MatDestroy(&interp);
4482: x = xnew;
4484: SNESReset(snes);
4485: SNESSetDM(snes,fine);
4486: SNESResetFromOptions(snes);
4487: DMDestroy(&fine);
4488: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4489: }
4490: }
4491: SNESViewFromOptions(snes,NULL,"-snes_view");
4492: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4494: VecDestroy(&xcreated);
4495: PetscObjectSAWsBlock((PetscObject)snes);
4496: return(0);
4497: }
4499: /* --------- Internal routines for SNES Package --------- */
4501: /*@C
4502: SNESSetType - Sets the method for the nonlinear solver.
4504: Collective on SNES
4506: Input Parameters:
4507: + snes - the SNES context
4508: - type - a known method
4510: Options Database Key:
4511: . -snes_type <type> - Sets the method; use -help for a list
4512: of available methods (for instance, newtonls or newtontr)
4514: Notes:
4515: See "petsc/include/petscsnes.h" for available methods (for instance)
4516: + SNESNEWTONLS - Newton's method with line search
4517: (systems of nonlinear equations)
4518: - SNESNEWTONTR - Newton's method with trust region
4519: (systems of nonlinear equations)
4521: Normally, it is best to use the SNESSetFromOptions() command and then
4522: set the SNES solver type from the options database rather than by using
4523: this routine. Using the options database provides the user with
4524: maximum flexibility in evaluating the many nonlinear solvers.
4525: The SNESSetType() routine is provided for those situations where it
4526: is necessary to set the nonlinear solver independently of the command
4527: line or options database. This might be the case, for example, when
4528: the choice of solver changes during the execution of the program,
4529: and the user's application is taking responsibility for choosing the
4530: appropriate method.
4532: Developer Notes:
4533: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4534: the constructor in that list and calls it to create the spexific object.
4536: Level: intermediate
4538: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4540: @*/
4541: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4542: {
4543: PetscErrorCode ierr,(*r)(SNES);
4544: PetscBool match;
4550: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4551: if (match) return(0);
4553: PetscFunctionListFind(SNESList,type,&r);
4554: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4555: /* Destroy the previous private SNES context */
4556: if (snes->ops->destroy) {
4557: (*(snes)->ops->destroy)(snes);
4558: snes->ops->destroy = NULL;
4559: }
4560: /* Reinitialize function pointers in SNESOps structure */
4561: snes->ops->setup = 0;
4562: snes->ops->solve = 0;
4563: snes->ops->view = 0;
4564: snes->ops->setfromoptions = 0;
4565: snes->ops->destroy = 0;
4566: SNESLineSearchDestroy(&snes->linesearch);
4567: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4568: snes->setupcalled = PETSC_FALSE;
4570: PetscObjectChangeTypeName((PetscObject)snes,type);
4571: (*r)(snes);
4572: return(0);
4573: }
4575: /*@C
4576: SNESGetType - Gets the SNES method type and name (as a string).
4578: Not Collective
4580: Input Parameter:
4581: . snes - nonlinear solver context
4583: Output Parameter:
4584: . type - SNES method (a character string)
4586: Level: intermediate
4588: @*/
4589: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4590: {
4594: *type = ((PetscObject)snes)->type_name;
4595: return(0);
4596: }
4598: /*@
4599: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4601: Logically Collective on SNES
4603: Input Parameters:
4604: + snes - the SNES context obtained from SNESCreate()
4605: - u - the solution vector
4607: Level: beginner
4609: @*/
4610: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4611: {
4612: DM dm;
4618: PetscObjectReference((PetscObject) u);
4619: VecDestroy(&snes->vec_sol);
4621: snes->vec_sol = u;
4623: SNESGetDM(snes, &dm);
4624: DMShellSetGlobalVector(dm, u);
4625: return(0);
4626: }
4628: /*@
4629: SNESGetSolution - Returns the vector where the approximate solution is
4630: stored. This is the fine grid solution when using SNESSetGridSequence().
4632: Not Collective, but Vec is parallel if SNES is parallel
4634: Input Parameter:
4635: . snes - the SNES context
4637: Output Parameter:
4638: . x - the solution
4640: Level: intermediate
4642: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4643: @*/
4644: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4645: {
4649: *x = snes->vec_sol;
4650: return(0);
4651: }
4653: /*@
4654: SNESGetSolutionUpdate - Returns the vector where the solution update is
4655: stored.
4657: Not Collective, but Vec is parallel if SNES is parallel
4659: Input Parameter:
4660: . snes - the SNES context
4662: Output Parameter:
4663: . x - the solution update
4665: Level: advanced
4667: .seealso: SNESGetSolution(), SNESGetFunction()
4668: @*/
4669: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4670: {
4674: *x = snes->vec_sol_update;
4675: return(0);
4676: }
4678: /*@C
4679: SNESGetFunction - Returns the vector where the function is stored.
4681: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4683: Input Parameter:
4684: . snes - the SNES context
4686: Output Parameter:
4687: + r - the vector that is used to store residuals (or NULL if you don't want it)
4688: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4689: - ctx - the function context (or NULL if you don't want it)
4691: Level: advanced
4693: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4695: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4696: @*/
4697: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4698: {
4700: DM dm;
4704: if (r) {
4705: if (!snes->vec_func) {
4706: if (snes->vec_rhs) {
4707: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4708: } else if (snes->vec_sol) {
4709: VecDuplicate(snes->vec_sol,&snes->vec_func);
4710: } else if (snes->dm) {
4711: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4712: }
4713: }
4714: *r = snes->vec_func;
4715: }
4716: SNESGetDM(snes,&dm);
4717: DMSNESGetFunction(dm,f,ctx);
4718: return(0);
4719: }
4721: /*@C
4722: SNESGetNGS - Returns the NGS function and context.
4724: Input Parameter:
4725: . snes - the SNES context
4727: Output Parameter:
4728: + f - the function (or NULL) see SNESNGSFunction for details
4729: - ctx - the function context (or NULL)
4731: Level: advanced
4733: .seealso: SNESSetNGS(), SNESGetFunction()
4734: @*/
4736: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4737: {
4739: DM dm;
4743: SNESGetDM(snes,&dm);
4744: DMSNESGetNGS(dm,f,ctx);
4745: return(0);
4746: }
4748: /*@C
4749: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4750: SNES options in the database.
4752: Logically Collective on SNES
4754: Input Parameter:
4755: + snes - the SNES context
4756: - prefix - the prefix to prepend to all option names
4758: Notes:
4759: A hyphen (-) must NOT be given at the beginning of the prefix name.
4760: The first character of all runtime options is AUTOMATICALLY the hyphen.
4762: Level: advanced
4764: .seealso: SNESSetFromOptions()
4765: @*/
4766: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4767: {
4772: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4773: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4774: if (snes->linesearch) {
4775: SNESGetLineSearch(snes,&snes->linesearch);
4776: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4777: }
4778: KSPSetOptionsPrefix(snes->ksp,prefix);
4779: return(0);
4780: }
4782: /*@C
4783: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4784: SNES options in the database.
4786: Logically Collective on SNES
4788: Input Parameters:
4789: + snes - the SNES context
4790: - prefix - the prefix to prepend to all option names
4792: Notes:
4793: A hyphen (-) must NOT be given at the beginning of the prefix name.
4794: The first character of all runtime options is AUTOMATICALLY the hyphen.
4796: Level: advanced
4798: .seealso: SNESGetOptionsPrefix()
4799: @*/
4800: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4801: {
4806: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4807: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4808: if (snes->linesearch) {
4809: SNESGetLineSearch(snes,&snes->linesearch);
4810: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4811: }
4812: KSPAppendOptionsPrefix(snes->ksp,prefix);
4813: return(0);
4814: }
4816: /*@C
4817: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4818: SNES options in the database.
4820: Not Collective
4822: Input Parameter:
4823: . snes - the SNES context
4825: Output Parameter:
4826: . prefix - pointer to the prefix string used
4828: Notes:
4829: On the fortran side, the user should pass in a string 'prefix' of
4830: sufficient length to hold the prefix.
4832: Level: advanced
4834: .seealso: SNESAppendOptionsPrefix()
4835: @*/
4836: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4837: {
4842: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4843: return(0);
4844: }
4847: /*@C
4848: SNESRegister - Adds a method to the nonlinear solver package.
4850: Not collective
4852: Input Parameters:
4853: + name_solver - name of a new user-defined solver
4854: - routine_create - routine to create method context
4856: Notes:
4857: SNESRegister() may be called multiple times to add several user-defined solvers.
4859: Sample usage:
4860: .vb
4861: SNESRegister("my_solver",MySolverCreate);
4862: .ve
4864: Then, your solver can be chosen with the procedural interface via
4865: $ SNESSetType(snes,"my_solver")
4866: or at runtime via the option
4867: $ -snes_type my_solver
4869: Level: advanced
4871: Note: If your function is not being put into a shared library then use SNESRegister() instead
4873: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4875: Level: advanced
4876: @*/
4877: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4878: {
4882: SNESInitializePackage();
4883: PetscFunctionListAdd(&SNESList,sname,function);
4884: return(0);
4885: }
4887: PetscErrorCode SNESTestLocalMin(SNES snes)
4888: {
4890: PetscInt N,i,j;
4891: Vec u,uh,fh;
4892: PetscScalar value;
4893: PetscReal norm;
4896: SNESGetSolution(snes,&u);
4897: VecDuplicate(u,&uh);
4898: VecDuplicate(u,&fh);
4900: /* currently only works for sequential */
4901: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4902: VecGetSize(u,&N);
4903: for (i=0; i<N; i++) {
4904: VecCopy(u,uh);
4905: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4906: for (j=-10; j<11; j++) {
4907: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4908: VecSetValue(uh,i,value,ADD_VALUES);
4909: SNESComputeFunction(snes,uh,fh);
4910: VecNorm(fh,NORM_2,&norm);
4911: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4912: value = -value;
4913: VecSetValue(uh,i,value,ADD_VALUES);
4914: }
4915: }
4916: VecDestroy(&uh);
4917: VecDestroy(&fh);
4918: return(0);
4919: }
4921: /*@
4922: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4923: computing relative tolerance for linear solvers within an inexact
4924: Newton method.
4926: Logically Collective on SNES
4928: Input Parameters:
4929: + snes - SNES context
4930: - flag - PETSC_TRUE or PETSC_FALSE
4932: Options Database:
4933: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4934: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4935: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4936: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4937: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4938: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4939: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4940: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4942: Notes:
4943: Currently, the default is to use a constant relative tolerance for
4944: the inner linear solvers. Alternatively, one can use the
4945: Eisenstat-Walker method, where the relative convergence tolerance
4946: is reset at each Newton iteration according progress of the nonlinear
4947: solver.
4949: Level: advanced
4951: Reference:
4952: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4953: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4955: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4956: @*/
4957: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
4958: {
4962: snes->ksp_ewconv = flag;
4963: return(0);
4964: }
4966: /*@
4967: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
4968: for computing relative tolerance for linear solvers within an
4969: inexact Newton method.
4971: Not Collective
4973: Input Parameter:
4974: . snes - SNES context
4976: Output Parameter:
4977: . flag - PETSC_TRUE or PETSC_FALSE
4979: Notes:
4980: Currently, the default is to use a constant relative tolerance for
4981: the inner linear solvers. Alternatively, one can use the
4982: Eisenstat-Walker method, where the relative convergence tolerance
4983: is reset at each Newton iteration according progress of the nonlinear
4984: solver.
4986: Level: advanced
4988: Reference:
4989: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4990: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4992: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4993: @*/
4994: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
4995: {
4999: *flag = snes->ksp_ewconv;
5000: return(0);
5001: }
5003: /*@
5004: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5005: convergence criteria for the linear solvers within an inexact
5006: Newton method.
5008: Logically Collective on SNES
5010: Input Parameters:
5011: + snes - SNES context
5012: . version - version 1, 2 (default is 2) or 3
5013: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5014: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5015: . gamma - multiplicative factor for version 2 rtol computation
5016: (0 <= gamma2 <= 1)
5017: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5018: . alpha2 - power for safeguard
5019: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5021: Note:
5022: Version 3 was contributed by Luis Chacon, June 2006.
5024: Use PETSC_DEFAULT to retain the default for any of the parameters.
5026: Level: advanced
5028: Reference:
5029: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5030: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5031: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5033: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5034: @*/
5035: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5036: {
5037: SNESKSPEW *kctx;
5041: kctx = (SNESKSPEW*)snes->kspconvctx;
5042: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5051: if (version != PETSC_DEFAULT) kctx->version = version;
5052: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5053: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5054: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5055: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5056: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5057: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5059: 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);
5060: 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);
5061: 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);
5062: 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);
5063: 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);
5064: 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);
5065: return(0);
5066: }
5068: /*@
5069: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5070: convergence criteria for the linear solvers within an inexact
5071: Newton method.
5073: Not Collective
5075: Input Parameters:
5076: snes - SNES context
5078: Output Parameters:
5079: + version - version 1, 2 (default is 2) or 3
5080: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5081: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5082: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5083: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5084: . alpha2 - power for safeguard
5085: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5087: Level: advanced
5089: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5090: @*/
5091: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5092: {
5093: SNESKSPEW *kctx;
5097: kctx = (SNESKSPEW*)snes->kspconvctx;
5098: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5099: if (version) *version = kctx->version;
5100: if (rtol_0) *rtol_0 = kctx->rtol_0;
5101: if (rtol_max) *rtol_max = kctx->rtol_max;
5102: if (gamma) *gamma = kctx->gamma;
5103: if (alpha) *alpha = kctx->alpha;
5104: if (alpha2) *alpha2 = kctx->alpha2;
5105: if (threshold) *threshold = kctx->threshold;
5106: return(0);
5107: }
5109: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5110: {
5112: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5113: PetscReal rtol = PETSC_DEFAULT,stol;
5116: if (!snes->ksp_ewconv) return(0);
5117: if (!snes->iter) {
5118: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5119: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5120: }
5121: else {
5122: if (kctx->version == 1) {
5123: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5124: if (rtol < 0.0) rtol = -rtol;
5125: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5126: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5127: } else if (kctx->version == 2) {
5128: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5129: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5130: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5131: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5132: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5133: /* safeguard: avoid sharp decrease of rtol */
5134: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5135: stol = PetscMax(rtol,stol);
5136: rtol = PetscMin(kctx->rtol_0,stol);
5137: /* safeguard: avoid oversolving */
5138: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5139: stol = PetscMax(rtol,stol);
5140: rtol = PetscMin(kctx->rtol_0,stol);
5141: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5142: }
5143: /* safeguard: avoid rtol greater than one */
5144: rtol = PetscMin(rtol,kctx->rtol_max);
5145: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5146: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5147: return(0);
5148: }
5150: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5151: {
5153: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5154: PCSide pcside;
5155: Vec lres;
5158: if (!snes->ksp_ewconv) return(0);
5159: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5160: kctx->norm_last = snes->norm;
5161: if (kctx->version == 1) {
5162: PC pc;
5163: PetscBool isNone;
5165: KSPGetPC(ksp, &pc);
5166: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5167: KSPGetPCSide(ksp,&pcside);
5168: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5169: /* KSP residual is true linear residual */
5170: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5171: } else {
5172: /* KSP residual is preconditioned residual */
5173: /* compute true linear residual norm */
5174: VecDuplicate(b,&lres);
5175: MatMult(snes->jacobian,x,lres);
5176: VecAYPX(lres,-1.0,b);
5177: VecNorm(lres,NORM_2,&kctx->lresid_last);
5178: VecDestroy(&lres);
5179: }
5180: }
5181: return(0);
5182: }
5184: /*@
5185: SNESGetKSP - Returns the KSP context for a SNES solver.
5187: Not Collective, but if SNES object is parallel, then KSP object is parallel
5189: Input Parameter:
5190: . snes - the SNES context
5192: Output Parameter:
5193: . ksp - the KSP context
5195: Notes:
5196: The user can then directly manipulate the KSP context to set various
5197: options, etc. Likewise, the user can then extract and manipulate the
5198: PC contexts as well.
5200: Level: beginner
5202: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5203: @*/
5204: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5205: {
5212: if (!snes->ksp) {
5213: PetscBool monitor = PETSC_FALSE;
5215: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5216: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5217: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5219: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5220: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5222: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5223: if (monitor) {
5224: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5225: }
5226: monitor = PETSC_FALSE;
5227: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5228: if (monitor) {
5229: PetscObject *objs;
5230: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5231: objs[0] = (PetscObject) snes;
5232: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5233: }
5234: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5235: }
5236: *ksp = snes->ksp;
5237: return(0);
5238: }
5241: #include <petsc/private/dmimpl.h>
5242: /*@
5243: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5245: Logically Collective on SNES
5247: Input Parameters:
5248: + snes - the nonlinear solver context
5249: - dm - the dm, cannot be NULL
5251: Notes:
5252: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5253: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5254: problems using the same function space.
5256: Level: intermediate
5258: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5259: @*/
5260: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5261: {
5263: KSP ksp;
5264: DMSNES sdm;
5269: PetscObjectReference((PetscObject)dm);
5270: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5271: if (snes->dm->dmsnes && !dm->dmsnes) {
5272: DMCopyDMSNES(snes->dm,dm);
5273: DMGetDMSNES(snes->dm,&sdm);
5274: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5275: }
5276: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5277: DMDestroy(&snes->dm);
5278: }
5279: snes->dm = dm;
5280: snes->dmAuto = PETSC_FALSE;
5282: SNESGetKSP(snes,&ksp);
5283: KSPSetDM(ksp,dm);
5284: KSPSetDMActive(ksp,PETSC_FALSE);
5285: if (snes->npc) {
5286: SNESSetDM(snes->npc, snes->dm);
5287: SNESSetNPCSide(snes,snes->npcside);
5288: }
5289: return(0);
5290: }
5292: /*@
5293: SNESGetDM - Gets the DM that may be used by some preconditioners
5295: Not Collective but DM obtained is parallel on SNES
5297: Input Parameter:
5298: . snes - the preconditioner context
5300: Output Parameter:
5301: . dm - the dm
5303: Level: intermediate
5305: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5306: @*/
5307: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5308: {
5313: if (!snes->dm) {
5314: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5315: snes->dmAuto = PETSC_TRUE;
5316: }
5317: *dm = snes->dm;
5318: return(0);
5319: }
5321: /*@
5322: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5324: Collective on SNES
5326: Input Parameters:
5327: + snes - iterative context obtained from SNESCreate()
5328: - pc - the preconditioner object
5330: Notes:
5331: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5332: to configure it using the API).
5334: Level: developer
5336: .seealso: SNESGetNPC(), SNESHasNPC()
5337: @*/
5338: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5339: {
5346: PetscObjectReference((PetscObject) pc);
5347: SNESDestroy(&snes->npc);
5348: snes->npc = pc;
5349: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5350: return(0);
5351: }
5353: /*@
5354: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5356: Not Collective; but any changes to the obtained SNES object must be applied collectively
5358: Input Parameter:
5359: . snes - iterative context obtained from SNESCreate()
5361: Output Parameter:
5362: . pc - preconditioner context
5364: Options Database:
5365: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5367: Notes:
5368: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5370: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5371: SNES during SNESSetUp()
5373: Level: developer
5375: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5376: @*/
5377: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5378: {
5380: const char *optionsprefix;
5385: if (!snes->npc) {
5386: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5387: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5388: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5389: SNESGetOptionsPrefix(snes,&optionsprefix);
5390: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5391: SNESAppendOptionsPrefix(snes->npc,"npc_");
5392: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5393: }
5394: *pc = snes->npc;
5395: return(0);
5396: }
5398: /*@
5399: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5401: Not Collective
5403: Input Parameter:
5404: . snes - iterative context obtained from SNESCreate()
5406: Output Parameter:
5407: . has_npc - whether the SNES has an NPC or not
5409: Level: developer
5411: .seealso: SNESSetNPC(), SNESGetNPC()
5412: @*/
5413: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5414: {
5417: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5418: return(0);
5419: }
5421: /*@
5422: SNESSetNPCSide - Sets the preconditioning side.
5424: Logically Collective on SNES
5426: Input Parameter:
5427: . snes - iterative context obtained from SNESCreate()
5429: Output Parameter:
5430: . side - the preconditioning side, where side is one of
5431: .vb
5432: PC_LEFT - left preconditioning
5433: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5434: .ve
5436: Options Database Keys:
5437: . -snes_pc_side <right,left>
5439: Notes:
5440: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5442: Level: intermediate
5444: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5445: @*/
5446: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5447: {
5451: snes->npcside= side;
5452: return(0);
5453: }
5455: /*@
5456: SNESGetNPCSide - Gets the preconditioning side.
5458: Not Collective
5460: Input Parameter:
5461: . snes - iterative context obtained from SNESCreate()
5463: Output Parameter:
5464: . side - the preconditioning side, where side is one of
5465: .vb
5466: PC_LEFT - left preconditioning
5467: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5468: .ve
5470: Level: intermediate
5472: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5473: @*/
5474: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5475: {
5479: *side = snes->npcside;
5480: return(0);
5481: }
5483: /*@
5484: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5486: Collective on SNES
5488: Input Parameters:
5489: + snes - iterative context obtained from SNESCreate()
5490: - linesearch - the linesearch object
5492: Notes:
5493: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5494: to configure it using the API).
5496: Level: developer
5498: .seealso: SNESGetLineSearch()
5499: @*/
5500: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5501: {
5508: PetscObjectReference((PetscObject) linesearch);
5509: SNESLineSearchDestroy(&snes->linesearch);
5511: snes->linesearch = linesearch;
5513: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5514: return(0);
5515: }
5517: /*@
5518: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5519: or creates a default line search instance associated with the SNES and returns it.
5521: Not Collective
5523: Input Parameter:
5524: . snes - iterative context obtained from SNESCreate()
5526: Output Parameter:
5527: . linesearch - linesearch context
5529: Level: beginner
5531: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5532: @*/
5533: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5534: {
5536: const char *optionsprefix;
5541: if (!snes->linesearch) {
5542: SNESGetOptionsPrefix(snes, &optionsprefix);
5543: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5544: SNESLineSearchSetSNES(snes->linesearch, snes);
5545: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5546: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5547: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5548: }
5549: *linesearch = snes->linesearch;
5550: return(0);
5551: }