Actual source code: snes.c
petsc-master 2019-10-13
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: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2344: snes->domainerror = PETSC_FALSE;
2345: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2346: PetscStackPop;
2347: VecLockReadPop(x);
2348: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2349: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2350: }
2351: } else if (snes->vec_rhs) {
2352: MatMult(snes->jacobian, x, y);
2353: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2354: if (snes->vec_rhs) {
2355: VecAXPY(y,-1.0,snes->vec_rhs);
2356: }
2357: snes->nfuncs++;
2358: /*
2359: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2360: propagate the value to all processes
2361: */
2362: if (snes->domainerror) {
2363: VecSetInf(y);
2364: }
2365: return(0);
2366: }
2368: /*@
2369: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2371: Collective on SNES
2373: Input Parameters:
2374: + snes - the SNES context
2375: . x - input vector
2376: - b - rhs vector
2378: Output Parameter:
2379: . x - new solution vector
2381: Notes:
2382: SNESComputeNGS() is typically used within composed nonlinear solver
2383: implementations, so most users would not generally call this routine
2384: themselves.
2386: Level: developer
2388: .seealso: SNESSetNGS(), SNESComputeFunction()
2389: @*/
2390: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2391: {
2393: DM dm;
2394: DMSNES sdm;
2402: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2403: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2404: SNESGetDM(snes,&dm);
2405: DMGetDMSNES(dm,&sdm);
2406: if (sdm->ops->computegs) {
2407: if (b) {VecLockReadPush(b);}
2408: PetscStackPush("SNES user NGS");
2409: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2410: PetscStackPop;
2411: if (b) {VecLockReadPop(b);}
2412: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2413: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2414: return(0);
2415: }
2417: PetscErrorCode SNESTestJacobian(SNES snes)
2418: {
2419: Mat A,B,C,D,jacobian;
2420: Vec x = snes->vec_sol,f = snes->vec_func;
2421: PetscErrorCode ierr;
2422: PetscReal nrm,gnorm;
2423: PetscReal threshold = 1.e-5;
2424: MatType mattype;
2425: PetscInt m,n,M,N;
2426: void *functx;
2427: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg;
2428: PetscViewer viewer,mviewer;
2429: MPI_Comm comm;
2430: PetscInt tabs;
2431: static PetscBool directionsprinted = PETSC_FALSE;
2432: PetscViewerFormat format;
2435: PetscObjectOptionsBegin((PetscObject)snes);
2436: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2437: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2438: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2439: if (!complete_print) {
2440: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2441: }
2442: /* for compatibility with PETSc 3.9 and older. */
2443: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2444: PetscOptionsEnd();
2445: if (!test) return(0);
2447: PetscObjectGetComm((PetscObject)snes,&comm);
2448: PetscViewerASCIIGetStdout(comm,&viewer);
2449: PetscViewerASCIIGetTab(viewer, &tabs);
2450: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2451: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2452: if (!complete_print && !directionsprinted) {
2453: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2454: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2455: }
2456: if (!directionsprinted) {
2457: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2458: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2459: directionsprinted = PETSC_TRUE;
2460: }
2461: if (complete_print) {
2462: PetscViewerPushFormat(mviewer,format);
2463: }
2465: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2466: if (!flg) jacobian = snes->jacobian;
2467: else jacobian = snes->jacobian_pre;
2469: if (!x) {
2470: MatCreateVecs(jacobian, &x, NULL);
2471: } else {
2472: PetscObjectReference((PetscObject) x);
2473: }
2474: if (!f) {
2475: VecDuplicate(x, &f);
2476: } else {
2477: PetscObjectReference((PetscObject) f);
2478: }
2479: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2480: SNESComputeFunction(snes,x,f);
2481: VecDestroy(&f);
2483: while (jacobian) {
2484: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2485: if (flg) {
2486: A = jacobian;
2487: PetscObjectReference((PetscObject)A);
2488: } else {
2489: MatComputeOperator(jacobian,MATAIJ,&A);
2490: }
2492: MatGetType(A,&mattype);
2493: MatGetSize(A,&M,&N);
2494: MatGetLocalSize(A,&m,&n);
2496: MatCreate(PetscObjectComm((PetscObject)A),&B);
2497: MatSetType(B,mattype);
2498: MatSetSizes(B,m,n,M,N);
2499: MatSetBlockSizesFromMats(B,A,A);
2500: MatSetUp(B);
2501: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2503: SNESGetFunction(snes,NULL,NULL,&functx);
2504: SNESComputeJacobianDefault(snes,x,B,B,functx);
2506: MatDuplicate(B,MAT_COPY_VALUES,&D);
2507: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2508: MatNorm(D,NORM_FROBENIUS,&nrm);
2509: MatNorm(A,NORM_FROBENIUS,&gnorm);
2510: MatDestroy(&D);
2511: if (!gnorm) gnorm = 1; /* just in case */
2512: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2514: if (complete_print) {
2515: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2516: MatView(jacobian,mviewer);
2517: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2518: MatView(B,mviewer);
2519: }
2521: if (threshold_print || complete_print) {
2522: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2523: PetscScalar *cvals;
2524: const PetscInt *bcols;
2525: const PetscScalar *bvals;
2527: MatCreate(PetscObjectComm((PetscObject)A),&C);
2528: MatSetType(C,mattype);
2529: MatSetSizes(C,m,n,M,N);
2530: MatSetBlockSizesFromMats(C,A,A);
2531: MatSetUp(C);
2532: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2534: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2535: MatGetOwnershipRange(B,&Istart,&Iend);
2537: for (row = Istart; row < Iend; row++) {
2538: MatGetRow(B,row,&bncols,&bcols,&bvals);
2539: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2540: for (j = 0, cncols = 0; j < bncols; j++) {
2541: if (PetscAbsScalar(bvals[j]) > threshold) {
2542: ccols[cncols] = bcols[j];
2543: cvals[cncols] = bvals[j];
2544: cncols += 1;
2545: }
2546: }
2547: if (cncols) {
2548: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2549: }
2550: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2551: PetscFree2(ccols,cvals);
2552: }
2553: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2554: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2555: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2556: MatView(C,complete_print ? mviewer : viewer);
2557: MatDestroy(&C);
2558: }
2559: MatDestroy(&A);
2560: MatDestroy(&B);
2562: if (jacobian != snes->jacobian_pre) {
2563: jacobian = snes->jacobian_pre;
2564: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2565: }
2566: else jacobian = NULL;
2567: }
2568: VecDestroy(&x);
2569: if (complete_print) {
2570: PetscViewerPopFormat(mviewer);
2571: }
2572: if (mviewer) { PetscViewerDestroy(&mviewer); }
2573: PetscViewerASCIISetTab(viewer,tabs);
2574: return(0);
2575: }
2577: /*@
2578: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2580: Collective on SNES
2582: Input Parameters:
2583: + snes - the SNES context
2584: - x - input vector
2586: Output Parameters:
2587: + A - Jacobian matrix
2588: - B - optional preconditioning matrix
2590: Options Database Keys:
2591: + -snes_lag_preconditioner <lag>
2592: . -snes_lag_jacobian <lag>
2593: . -snes_test_jacobian - compare the user provided Jacobian with one compute via finite differences to check for errors
2594: . -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
2595: . -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
2596: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2597: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2598: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2599: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2600: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2601: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2602: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2603: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2604: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2605: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2606: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2609: Notes:
2610: Most users should not need to explicitly call this routine, as it
2611: is used internally within the nonlinear solvers.
2613: Developer Notes:
2614: 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
2615: for with the SNESType of test that has been removed.
2617: Level: developer
2619: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2620: @*/
2621: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2622: {
2624: PetscBool flag;
2625: DM dm;
2626: DMSNES sdm;
2627: KSP ksp;
2633: VecValidValues(X,2,PETSC_TRUE);
2634: SNESGetDM(snes,&dm);
2635: DMGetDMSNES(dm,&sdm);
2637: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2639: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2641: if (snes->lagjacobian == -2) {
2642: snes->lagjacobian = -1;
2644: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2645: } else if (snes->lagjacobian == -1) {
2646: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2647: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2648: if (flag) {
2649: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2650: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2651: }
2652: return(0);
2653: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2654: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2655: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2656: if (flag) {
2657: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2658: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2659: }
2660: return(0);
2661: }
2662: if (snes->npc && snes->npcside== PC_LEFT) {
2663: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2664: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2665: return(0);
2666: }
2668: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2669: VecLockReadPush(X);
2670: PetscStackPush("SNES user Jacobian function");
2671: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2672: PetscStackPop;
2673: VecLockReadPop(X);
2674: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2676: /* attach latest linearization point to the preconditioning matrix */
2677: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2679: /* the next line ensures that snes->ksp exists */
2680: SNESGetKSP(snes,&ksp);
2681: if (snes->lagpreconditioner == -2) {
2682: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2683: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2684: snes->lagpreconditioner = -1;
2685: } else if (snes->lagpreconditioner == -1) {
2686: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2687: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2688: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2689: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2690: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2691: } else {
2692: PetscInfo(snes,"Rebuilding preconditioner\n");
2693: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2694: }
2696: SNESTestJacobian(snes);
2697: /* make sure user returned a correct Jacobian and preconditioner */
2700: {
2701: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2702: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2703: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2704: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2705: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2706: if (flag || flag_draw || flag_contour) {
2707: Mat Bexp_mine = NULL,Bexp,FDexp;
2708: PetscViewer vdraw,vstdout;
2709: PetscBool flg;
2710: if (flag_operator) {
2711: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2712: Bexp = Bexp_mine;
2713: } else {
2714: /* See if the preconditioning matrix can be viewed and added directly */
2715: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2716: if (flg) Bexp = B;
2717: else {
2718: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2719: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2720: Bexp = Bexp_mine;
2721: }
2722: }
2723: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2724: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2725: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2726: if (flag_draw || flag_contour) {
2727: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2728: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2729: } else vdraw = NULL;
2730: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2731: if (flag) {MatView(Bexp,vstdout);}
2732: if (vdraw) {MatView(Bexp,vdraw);}
2733: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2734: if (flag) {MatView(FDexp,vstdout);}
2735: if (vdraw) {MatView(FDexp,vdraw);}
2736: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2737: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2738: if (flag) {MatView(FDexp,vstdout);}
2739: if (vdraw) { /* Always use contour for the difference */
2740: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2741: MatView(FDexp,vdraw);
2742: PetscViewerPopFormat(vdraw);
2743: }
2744: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2745: PetscViewerDestroy(&vdraw);
2746: MatDestroy(&Bexp_mine);
2747: MatDestroy(&FDexp);
2748: }
2749: }
2750: {
2751: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2752: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2753: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2754: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2755: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2756: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2757: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2758: if (flag_threshold) {
2759: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2760: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2761: }
2762: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2763: Mat Bfd;
2764: PetscViewer vdraw,vstdout;
2765: MatColoring coloring;
2766: ISColoring iscoloring;
2767: MatFDColoring matfdcoloring;
2768: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2769: void *funcctx;
2770: PetscReal norm1,norm2,normmax;
2772: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2773: MatColoringCreate(Bfd,&coloring);
2774: MatColoringSetType(coloring,MATCOLORINGSL);
2775: MatColoringSetFromOptions(coloring);
2776: MatColoringApply(coloring,&iscoloring);
2777: MatColoringDestroy(&coloring);
2778: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2779: MatFDColoringSetFromOptions(matfdcoloring);
2780: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2781: ISColoringDestroy(&iscoloring);
2783: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2784: SNESGetFunction(snes,NULL,&func,&funcctx);
2785: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2786: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2787: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2788: MatFDColoringSetFromOptions(matfdcoloring);
2789: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2790: MatFDColoringDestroy(&matfdcoloring);
2792: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2793: if (flag_draw || flag_contour) {
2794: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2795: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2796: } else vdraw = NULL;
2797: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2798: if (flag_display) {MatView(B,vstdout);}
2799: if (vdraw) {MatView(B,vdraw);}
2800: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2801: if (flag_display) {MatView(Bfd,vstdout);}
2802: if (vdraw) {MatView(Bfd,vdraw);}
2803: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2804: MatNorm(Bfd,NORM_1,&norm1);
2805: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2806: MatNorm(Bfd,NORM_MAX,&normmax);
2807: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2808: if (flag_display) {MatView(Bfd,vstdout);}
2809: if (vdraw) { /* Always use contour for the difference */
2810: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2811: MatView(Bfd,vdraw);
2812: PetscViewerPopFormat(vdraw);
2813: }
2814: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2816: if (flag_threshold) {
2817: PetscInt bs,rstart,rend,i;
2818: MatGetBlockSize(B,&bs);
2819: MatGetOwnershipRange(B,&rstart,&rend);
2820: for (i=rstart; i<rend; i++) {
2821: const PetscScalar *ba,*ca;
2822: const PetscInt *bj,*cj;
2823: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2824: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2825: MatGetRow(B,i,&bn,&bj,&ba);
2826: MatGetRow(Bfd,i,&cn,&cj,&ca);
2827: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2828: for (j=0; j<bn; j++) {
2829: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2830: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2831: maxentrycol = bj[j];
2832: maxentry = PetscRealPart(ba[j]);
2833: }
2834: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2835: maxdiffcol = bj[j];
2836: maxdiff = PetscRealPart(ca[j]);
2837: }
2838: if (rdiff > maxrdiff) {
2839: maxrdiffcol = bj[j];
2840: maxrdiff = rdiff;
2841: }
2842: }
2843: if (maxrdiff > 1) {
2844: 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);
2845: for (j=0; j<bn; j++) {
2846: PetscReal rdiff;
2847: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2848: if (rdiff > 1) {
2849: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2850: }
2851: }
2852: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2853: }
2854: MatRestoreRow(B,i,&bn,&bj,&ba);
2855: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2856: }
2857: }
2858: PetscViewerDestroy(&vdraw);
2859: MatDestroy(&Bfd);
2860: }
2861: }
2862: return(0);
2863: }
2865: /*MC
2866: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2868: Synopsis:
2869: #include "petscsnes.h"
2870: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2872: + x - input vector
2873: . Amat - the matrix that defines the (approximate) Jacobian
2874: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2875: - ctx - [optional] user-defined Jacobian context
2877: Level: intermediate
2879: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2880: M*/
2882: /*@C
2883: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2884: location to store the matrix.
2886: Logically Collective on SNES
2888: Input Parameters:
2889: + snes - the SNES context
2890: . Amat - the matrix that defines the (approximate) Jacobian
2891: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2892: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2893: - ctx - [optional] user-defined context for private data for the
2894: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2896: Notes:
2897: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2898: each matrix.
2900: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2901: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2903: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2904: must be a MatFDColoring.
2906: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2907: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2909: Level: beginner
2911: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2912: SNESSetPicard(), SNESJacobianFunction
2913: @*/
2914: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2915: {
2917: DM dm;
2925: SNESGetDM(snes,&dm);
2926: DMSNESSetJacobian(dm,J,ctx);
2927: if (Amat) {
2928: PetscObjectReference((PetscObject)Amat);
2929: MatDestroy(&snes->jacobian);
2931: snes->jacobian = Amat;
2932: }
2933: if (Pmat) {
2934: PetscObjectReference((PetscObject)Pmat);
2935: MatDestroy(&snes->jacobian_pre);
2937: snes->jacobian_pre = Pmat;
2938: }
2939: return(0);
2940: }
2942: /*@C
2943: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2944: provided context for evaluating the Jacobian.
2946: Not Collective, but Mat object will be parallel if SNES object is
2948: Input Parameter:
2949: . snes - the nonlinear solver context
2951: Output Parameters:
2952: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2953: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2954: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2955: - ctx - location to stash Jacobian ctx (or NULL)
2957: Level: advanced
2959: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2960: @*/
2961: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2962: {
2964: DM dm;
2965: DMSNES sdm;
2969: if (Amat) *Amat = snes->jacobian;
2970: if (Pmat) *Pmat = snes->jacobian_pre;
2971: SNESGetDM(snes,&dm);
2972: DMGetDMSNES(dm,&sdm);
2973: if (J) *J = sdm->ops->computejacobian;
2974: if (ctx) *ctx = sdm->jacobianctx;
2975: return(0);
2976: }
2978: /*@
2979: SNESSetUp - Sets up the internal data structures for the later use
2980: of a nonlinear solver.
2982: Collective on SNES
2984: Input Parameters:
2985: . snes - the SNES context
2987: Notes:
2988: For basic use of the SNES solvers the user need not explicitly call
2989: SNESSetUp(), since these actions will automatically occur during
2990: the call to SNESSolve(). However, if one wishes to control this
2991: phase separately, SNESSetUp() should be called after SNESCreate()
2992: and optional routines of the form SNESSetXXX(), but before SNESSolve().
2994: Level: advanced
2996: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
2997: @*/
2998: PetscErrorCode SNESSetUp(SNES snes)
2999: {
3001: DM dm;
3002: DMSNES sdm;
3003: SNESLineSearch linesearch, pclinesearch;
3004: void *lsprectx,*lspostctx;
3005: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3006: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3007: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3008: Vec f,fpc;
3009: void *funcctx;
3010: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3011: void *jacctx,*appctx;
3012: Mat j,jpre;
3016: if (snes->setupcalled) return(0);
3017: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3019: if (!((PetscObject)snes)->type_name) {
3020: SNESSetType(snes,SNESNEWTONLS);
3021: }
3023: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3025: SNESGetDM(snes,&dm);
3026: DMGetDMSNES(dm,&sdm);
3027: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3028: if (!sdm->ops->computejacobian) {
3029: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3030: }
3031: if (!snes->vec_func) {
3032: DMCreateGlobalVector(dm,&snes->vec_func);
3033: }
3035: if (!snes->ksp) {
3036: SNESGetKSP(snes, &snes->ksp);
3037: }
3039: if (snes->linesearch) {
3040: SNESGetLineSearch(snes, &snes->linesearch);
3041: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3042: }
3044: if (snes->npc && (snes->npcside== PC_LEFT)) {
3045: snes->mf = PETSC_TRUE;
3046: snes->mf_operator = PETSC_FALSE;
3047: }
3049: if (snes->npc) {
3050: /* copy the DM over */
3051: SNESGetDM(snes,&dm);
3052: SNESSetDM(snes->npc,dm);
3054: SNESGetFunction(snes,&f,&func,&funcctx);
3055: VecDuplicate(f,&fpc);
3056: SNESSetFunction(snes->npc,fpc,func,funcctx);
3057: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3058: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3059: SNESGetApplicationContext(snes,&appctx);
3060: SNESSetApplicationContext(snes->npc,appctx);
3061: VecDestroy(&fpc);
3063: /* copy the function pointers over */
3064: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3066: /* default to 1 iteration */
3067: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3068: if (snes->npcside==PC_RIGHT) {
3069: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3070: } else {
3071: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3072: }
3073: SNESSetFromOptions(snes->npc);
3075: /* copy the line search context over */
3076: if (snes->linesearch && snes->npc->linesearch) {
3077: SNESGetLineSearch(snes,&linesearch);
3078: SNESGetLineSearch(snes->npc,&pclinesearch);
3079: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3080: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3081: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3082: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3083: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3084: }
3085: }
3086: if (snes->mf) {
3087: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3088: }
3089: if (snes->ops->usercompute && !snes->user) {
3090: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3091: }
3093: snes->jac_iter = 0;
3094: snes->pre_iter = 0;
3096: if (snes->ops->setup) {
3097: (*snes->ops->setup)(snes);
3098: }
3100: if (snes->npc && (snes->npcside== PC_LEFT)) {
3101: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3102: if (snes->linesearch){
3103: SNESGetLineSearch(snes,&linesearch);
3104: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3105: }
3106: }
3107: }
3108: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3109: snes->setupcalled = PETSC_TRUE;
3110: return(0);
3111: }
3113: /*@
3114: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3116: Collective on SNES
3118: Input Parameter:
3119: . snes - iterative context obtained from SNESCreate()
3121: Level: intermediate
3123: Notes:
3124: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3126: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3127: @*/
3128: PetscErrorCode SNESReset(SNES snes)
3129: {
3134: if (snes->ops->userdestroy && snes->user) {
3135: (*snes->ops->userdestroy)((void**)&snes->user);
3136: snes->user = NULL;
3137: }
3138: if (snes->npc) {
3139: SNESReset(snes->npc);
3140: }
3142: if (snes->ops->reset) {
3143: (*snes->ops->reset)(snes);
3144: }
3145: if (snes->ksp) {
3146: KSPReset(snes->ksp);
3147: }
3149: if (snes->linesearch) {
3150: SNESLineSearchReset(snes->linesearch);
3151: }
3153: VecDestroy(&snes->vec_rhs);
3154: VecDestroy(&snes->vec_sol);
3155: VecDestroy(&snes->vec_sol_update);
3156: VecDestroy(&snes->vec_func);
3157: MatDestroy(&snes->jacobian);
3158: MatDestroy(&snes->jacobian_pre);
3159: VecDestroyVecs(snes->nwork,&snes->work);
3160: VecDestroyVecs(snes->nvwork,&snes->vwork);
3162: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3164: snes->nwork = snes->nvwork = 0;
3165: snes->setupcalled = PETSC_FALSE;
3166: return(0);
3167: }
3169: /*@
3170: SNESDestroy - Destroys the nonlinear solver context that was created
3171: with SNESCreate().
3173: Collective on SNES
3175: Input Parameter:
3176: . snes - the SNES context
3178: Level: beginner
3180: .seealso: SNESCreate(), SNESSolve()
3181: @*/
3182: PetscErrorCode SNESDestroy(SNES *snes)
3183: {
3187: if (!*snes) return(0);
3189: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3191: SNESReset((*snes));
3192: SNESDestroy(&(*snes)->npc);
3194: /* if memory was published with SAWs then destroy it */
3195: PetscObjectSAWsViewOff((PetscObject)*snes);
3196: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3198: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3199: DMDestroy(&(*snes)->dm);
3200: KSPDestroy(&(*snes)->ksp);
3201: SNESLineSearchDestroy(&(*snes)->linesearch);
3203: PetscFree((*snes)->kspconvctx);
3204: if ((*snes)->ops->convergeddestroy) {
3205: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3206: }
3207: if ((*snes)->conv_hist_alloc) {
3208: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3209: }
3210: SNESMonitorCancel((*snes));
3211: PetscHeaderDestroy(snes);
3212: return(0);
3213: }
3215: /* ----------- Routines to set solver parameters ---------- */
3217: /*@
3218: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3220: Logically Collective on SNES
3222: Input Parameters:
3223: + snes - the SNES context
3224: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3225: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3227: Options Database Keys:
3228: . -snes_lag_preconditioner <lag>
3230: Notes:
3231: The default is 1
3232: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3233: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3235: Level: intermediate
3237: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3239: @*/
3240: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3241: {
3244: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3245: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3247: snes->lagpreconditioner = lag;
3248: return(0);
3249: }
3251: /*@
3252: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3254: Logically Collective on SNES
3256: Input Parameters:
3257: + snes - the SNES context
3258: - steps - the number of refinements to do, defaults to 0
3260: Options Database Keys:
3261: . -snes_grid_sequence <steps>
3263: Level: intermediate
3265: Notes:
3266: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3268: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3270: @*/
3271: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3272: {
3276: snes->gridsequence = steps;
3277: return(0);
3278: }
3280: /*@
3281: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3283: Logically Collective on SNES
3285: Input Parameter:
3286: . snes - the SNES context
3288: Output Parameter:
3289: . steps - the number of refinements to do, defaults to 0
3291: Options Database Keys:
3292: . -snes_grid_sequence <steps>
3294: Level: intermediate
3296: Notes:
3297: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3299: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3301: @*/
3302: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3303: {
3306: *steps = snes->gridsequence;
3307: return(0);
3308: }
3310: /*@
3311: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3313: Not Collective
3315: Input Parameter:
3316: . snes - the SNES context
3318: Output Parameter:
3319: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3320: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3322: Options Database Keys:
3323: . -snes_lag_preconditioner <lag>
3325: Notes:
3326: The default is 1
3327: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3329: Level: intermediate
3331: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3333: @*/
3334: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3335: {
3338: *lag = snes->lagpreconditioner;
3339: return(0);
3340: }
3342: /*@
3343: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3344: often the preconditioner is rebuilt.
3346: Logically Collective on SNES
3348: Input Parameters:
3349: + snes - the SNES context
3350: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3351: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3353: Options Database Keys:
3354: . -snes_lag_jacobian <lag>
3356: Notes:
3357: The default is 1
3358: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3359: 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
3360: at the next Newton step but never again (unless it is reset to another value)
3362: Level: intermediate
3364: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3366: @*/
3367: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3368: {
3371: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3372: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3374: snes->lagjacobian = lag;
3375: return(0);
3376: }
3378: /*@
3379: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3381: Not Collective
3383: Input Parameter:
3384: . snes - the SNES context
3386: Output Parameter:
3387: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3388: the Jacobian is built etc.
3390: Options Database Keys:
3391: . -snes_lag_jacobian <lag>
3393: Notes:
3394: The default is 1
3395: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3397: Level: intermediate
3399: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3401: @*/
3402: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3403: {
3406: *lag = snes->lagjacobian;
3407: return(0);
3408: }
3410: /*@
3411: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3413: Logically collective on SNES
3415: Input Parameter:
3416: + snes - the SNES context
3417: - flg - jacobian lagging persists if true
3419: Options Database Keys:
3420: . -snes_lag_jacobian_persists <flg>
3422: Notes:
3423: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3424: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3425: timesteps may present huge efficiency gains.
3427: Level: developer
3429: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3431: @*/
3432: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3433: {
3437: snes->lagjac_persist = flg;
3438: return(0);
3439: }
3441: /*@
3442: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3444: Logically Collective on SNES
3446: Input Parameter:
3447: + snes - the SNES context
3448: - flg - preconditioner lagging persists if true
3450: Options Database Keys:
3451: . -snes_lag_jacobian_persists <flg>
3453: Notes:
3454: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3455: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3456: several timesteps may present huge efficiency gains.
3458: Level: developer
3460: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3462: @*/
3463: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3464: {
3468: snes->lagpre_persist = flg;
3469: return(0);
3470: }
3472: /*@
3473: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3475: Logically Collective on SNES
3477: Input Parameters:
3478: + snes - the SNES context
3479: - force - PETSC_TRUE require at least one iteration
3481: Options Database Keys:
3482: . -snes_force_iteration <force> - Sets forcing an iteration
3484: Notes:
3485: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3487: Level: intermediate
3489: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3490: @*/
3491: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3492: {
3495: snes->forceiteration = force;
3496: return(0);
3497: }
3499: /*@
3500: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3502: Logically Collective on SNES
3504: Input Parameters:
3505: . snes - the SNES context
3507: Output Parameter:
3508: . force - PETSC_TRUE requires at least one iteration.
3510: Level: intermediate
3512: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3513: @*/
3514: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3515: {
3518: *force = snes->forceiteration;
3519: return(0);
3520: }
3522: /*@
3523: SNESSetTolerances - Sets various parameters used in convergence tests.
3525: Logically Collective on SNES
3527: Input Parameters:
3528: + snes - the SNES context
3529: . abstol - absolute convergence tolerance
3530: . rtol - relative convergence tolerance
3531: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3532: . maxit - maximum number of iterations
3533: - maxf - maximum number of function evaluations (-1 indicates no limit)
3535: Options Database Keys:
3536: + -snes_atol <abstol> - Sets abstol
3537: . -snes_rtol <rtol> - Sets rtol
3538: . -snes_stol <stol> - Sets stol
3539: . -snes_max_it <maxit> - Sets maxit
3540: - -snes_max_funcs <maxf> - Sets maxf
3542: Notes:
3543: The default maximum number of iterations is 50.
3544: The default maximum number of function evaluations is 1000.
3546: Level: intermediate
3548: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3549: @*/
3550: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3551: {
3560: if (abstol != PETSC_DEFAULT) {
3561: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3562: snes->abstol = abstol;
3563: }
3564: if (rtol != PETSC_DEFAULT) {
3565: 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);
3566: snes->rtol = rtol;
3567: }
3568: if (stol != PETSC_DEFAULT) {
3569: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3570: snes->stol = stol;
3571: }
3572: if (maxit != PETSC_DEFAULT) {
3573: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3574: snes->max_its = maxit;
3575: }
3576: if (maxf != PETSC_DEFAULT) {
3577: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3578: snes->max_funcs = maxf;
3579: }
3580: snes->tolerancesset = PETSC_TRUE;
3581: return(0);
3582: }
3584: /*@
3585: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3587: Logically Collective on SNES
3589: Input Parameters:
3590: + snes - the SNES context
3591: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3593: Options Database Keys:
3594: . -snes_divergence_tolerance <divtol> - Sets divtol
3596: Notes:
3597: The default divergence tolerance is 1e4.
3599: Level: intermediate
3601: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3602: @*/
3603: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3604: {
3609: if (divtol != PETSC_DEFAULT) {
3610: snes->divtol = divtol;
3611: }
3612: else {
3613: snes->divtol = 1.0e4;
3614: }
3615: return(0);
3616: }
3618: /*@
3619: SNESGetTolerances - Gets various parameters used in convergence tests.
3621: Not Collective
3623: Input Parameters:
3624: + snes - the SNES context
3625: . atol - absolute convergence tolerance
3626: . rtol - relative convergence tolerance
3627: . stol - convergence tolerance in terms of the norm
3628: of the change in the solution between steps
3629: . maxit - maximum number of iterations
3630: - maxf - maximum number of function evaluations
3632: Notes:
3633: The user can specify NULL for any parameter that is not needed.
3635: Level: intermediate
3637: .seealso: SNESSetTolerances()
3638: @*/
3639: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3640: {
3643: if (atol) *atol = snes->abstol;
3644: if (rtol) *rtol = snes->rtol;
3645: if (stol) *stol = snes->stol;
3646: if (maxit) *maxit = snes->max_its;
3647: if (maxf) *maxf = snes->max_funcs;
3648: return(0);
3649: }
3651: /*@
3652: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3654: Not Collective
3656: Input Parameters:
3657: + snes - the SNES context
3658: - divtol - divergence tolerance
3660: Level: intermediate
3662: .seealso: SNESSetDivergenceTolerance()
3663: @*/
3664: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3665: {
3668: if (divtol) *divtol = snes->divtol;
3669: return(0);
3670: }
3672: /*@
3673: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3675: Logically Collective on SNES
3677: Input Parameters:
3678: + snes - the SNES context
3679: - tol - tolerance
3681: Options Database Key:
3682: . -snes_trtol <tol> - Sets tol
3684: Level: intermediate
3686: .seealso: SNESSetTolerances()
3687: @*/
3688: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3689: {
3693: snes->deltatol = tol;
3694: return(0);
3695: }
3697: /*
3698: Duplicate the lg monitors for SNES from KSP; for some reason with
3699: dynamic libraries things don't work under Sun4 if we just use
3700: macros instead of functions
3701: */
3702: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3703: {
3708: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3709: return(0);
3710: }
3712: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3713: {
3717: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3718: return(0);
3719: }
3721: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3723: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3724: {
3725: PetscDrawLG lg;
3726: PetscErrorCode ierr;
3727: PetscReal x,y,per;
3728: PetscViewer v = (PetscViewer)monctx;
3729: static PetscReal prev; /* should be in the context */
3730: PetscDraw draw;
3734: PetscViewerDrawGetDrawLG(v,0,&lg);
3735: if (!n) {PetscDrawLGReset(lg);}
3736: PetscDrawLGGetDraw(lg,&draw);
3737: PetscDrawSetTitle(draw,"Residual norm");
3738: x = (PetscReal)n;
3739: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3740: else y = -15.0;
3741: PetscDrawLGAddPoint(lg,&x,&y);
3742: if (n < 20 || !(n % 5) || snes->reason) {
3743: PetscDrawLGDraw(lg);
3744: PetscDrawLGSave(lg);
3745: }
3747: PetscViewerDrawGetDrawLG(v,1,&lg);
3748: if (!n) {PetscDrawLGReset(lg);}
3749: PetscDrawLGGetDraw(lg,&draw);
3750: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3751: SNESMonitorRange_Private(snes,n,&per);
3752: x = (PetscReal)n;
3753: y = 100.0*per;
3754: PetscDrawLGAddPoint(lg,&x,&y);
3755: if (n < 20 || !(n % 5) || snes->reason) {
3756: PetscDrawLGDraw(lg);
3757: PetscDrawLGSave(lg);
3758: }
3760: PetscViewerDrawGetDrawLG(v,2,&lg);
3761: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3762: PetscDrawLGGetDraw(lg,&draw);
3763: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3764: x = (PetscReal)n;
3765: y = (prev - rnorm)/prev;
3766: PetscDrawLGAddPoint(lg,&x,&y);
3767: if (n < 20 || !(n % 5) || snes->reason) {
3768: PetscDrawLGDraw(lg);
3769: PetscDrawLGSave(lg);
3770: }
3772: PetscViewerDrawGetDrawLG(v,3,&lg);
3773: if (!n) {PetscDrawLGReset(lg);}
3774: PetscDrawLGGetDraw(lg,&draw);
3775: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3776: x = (PetscReal)n;
3777: y = (prev - rnorm)/(prev*per);
3778: if (n > 2) { /*skip initial crazy value */
3779: PetscDrawLGAddPoint(lg,&x,&y);
3780: }
3781: if (n < 20 || !(n % 5) || snes->reason) {
3782: PetscDrawLGDraw(lg);
3783: PetscDrawLGSave(lg);
3784: }
3785: prev = rnorm;
3786: return(0);
3787: }
3789: /*@
3790: SNESMonitor - runs the user provided monitor routines, if they exist
3792: Collective on SNES
3794: Input Parameters:
3795: + snes - nonlinear solver context obtained from SNESCreate()
3796: . iter - iteration number
3797: - rnorm - relative norm of the residual
3799: Notes:
3800: This routine is called by the SNES implementations.
3801: It does not typically need to be called by the user.
3803: Level: developer
3805: .seealso: SNESMonitorSet()
3806: @*/
3807: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3808: {
3810: PetscInt i,n = snes->numbermonitors;
3813: VecLockReadPush(snes->vec_sol);
3814: for (i=0; i<n; i++) {
3815: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3816: }
3817: VecLockReadPop(snes->vec_sol);
3818: return(0);
3819: }
3821: /* ------------ Routines to set performance monitoring options ----------- */
3823: /*MC
3824: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3826: Synopsis:
3827: #include <petscsnes.h>
3828: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3830: + snes - the SNES context
3831: . its - iteration number
3832: . norm - 2-norm function value (may be estimated)
3833: - mctx - [optional] monitoring context
3835: Level: advanced
3837: .seealso: SNESMonitorSet(), SNESMonitorGet()
3838: M*/
3840: /*@C
3841: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3842: iteration of the nonlinear solver to display the iteration's
3843: progress.
3845: Logically Collective on SNES
3847: Input Parameters:
3848: + snes - the SNES context
3849: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3850: . mctx - [optional] user-defined context for private data for the
3851: monitor routine (use NULL if no context is desired)
3852: - monitordestroy - [optional] routine that frees monitor context
3853: (may be NULL)
3855: Options Database Keys:
3856: + -snes_monitor - sets SNESMonitorDefault()
3857: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3858: uses SNESMonitorLGCreate()
3859: - -snes_monitor_cancel - cancels all monitors that have
3860: been hardwired into a code by
3861: calls to SNESMonitorSet(), but
3862: does not cancel those set via
3863: the options database.
3865: Notes:
3866: Several different monitoring routines may be set by calling
3867: SNESMonitorSet() multiple times; all will be called in the
3868: order in which they were set.
3870: Fortran Notes:
3871: Only a single monitor function can be set for each SNES object
3873: Level: intermediate
3875: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3876: @*/
3877: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3878: {
3879: PetscInt i;
3881: PetscBool identical;
3885: for (i=0; i<snes->numbermonitors;i++) {
3886: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3887: if (identical) return(0);
3888: }
3889: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3890: snes->monitor[snes->numbermonitors] = f;
3891: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3892: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3893: return(0);
3894: }
3896: /*@
3897: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3899: Logically Collective on SNES
3901: Input Parameters:
3902: . snes - the SNES context
3904: Options Database Key:
3905: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3906: into a code by calls to SNESMonitorSet(), but does not cancel those
3907: set via the options database
3909: Notes:
3910: There is no way to clear one specific monitor from a SNES object.
3912: Level: intermediate
3914: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3915: @*/
3916: PetscErrorCode SNESMonitorCancel(SNES snes)
3917: {
3919: PetscInt i;
3923: for (i=0; i<snes->numbermonitors; i++) {
3924: if (snes->monitordestroy[i]) {
3925: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3926: }
3927: }
3928: snes->numbermonitors = 0;
3929: return(0);
3930: }
3932: /*MC
3933: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3935: Synopsis:
3936: #include <petscsnes.h>
3937: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3939: + snes - the SNES context
3940: . it - current iteration (0 is the first and is before any Newton step)
3941: . cctx - [optional] convergence context
3942: . reason - reason for convergence/divergence
3943: . xnorm - 2-norm of current iterate
3944: . gnorm - 2-norm of current step
3945: - f - 2-norm of function
3947: Level: intermediate
3949: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3950: M*/
3952: /*@C
3953: SNESSetConvergenceTest - Sets the function that is to be used
3954: to test for convergence of the nonlinear iterative solution.
3956: Logically Collective on SNES
3958: Input Parameters:
3959: + snes - the SNES context
3960: . SNESConvergenceTestFunction - routine to test for convergence
3961: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3962: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
3964: Level: advanced
3966: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3967: @*/
3968: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3969: {
3974: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3975: if (snes->ops->convergeddestroy) {
3976: (*snes->ops->convergeddestroy)(snes->cnvP);
3977: }
3978: snes->ops->converged = SNESConvergenceTestFunction;
3979: snes->ops->convergeddestroy = destroy;
3980: snes->cnvP = cctx;
3981: return(0);
3982: }
3984: /*@
3985: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
3987: Not Collective
3989: Input Parameter:
3990: . snes - the SNES context
3992: Output Parameter:
3993: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3994: manual pages for the individual convergence tests for complete lists
3996: Options Database:
3997: . -snes_converged_reason - prints the reason to standard out
3999: Level: intermediate
4001: Notes:
4002: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4004: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4005: @*/
4006: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4007: {
4011: *reason = snes->reason;
4012: return(0);
4013: }
4015: /*@
4016: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4018: Not Collective
4020: Input Parameters:
4021: + snes - the SNES context
4022: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4023: manual pages for the individual convergence tests for complete lists
4025: Level: intermediate
4027: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4028: @*/
4029: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4030: {
4033: snes->reason = reason;
4034: return(0);
4035: }
4037: /*@
4038: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4040: Logically Collective on SNES
4042: Input Parameters:
4043: + snes - iterative context obtained from SNESCreate()
4044: . a - array to hold history, this array will contain the function norms computed at each step
4045: . its - integer array holds the number of linear iterations for each solve.
4046: . na - size of a and its
4047: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4048: else it continues storing new values for new nonlinear solves after the old ones
4050: Notes:
4051: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4052: default array of length 10000 is allocated.
4054: This routine is useful, e.g., when running a code for purposes
4055: of accurate performance monitoring, when no I/O should be done
4056: during the section of code that is being timed.
4058: Level: intermediate
4060: .seealso: SNESGetConvergenceHistory()
4062: @*/
4063: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4064: {
4071: if (!a) {
4072: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4073: PetscCalloc2(na,&a,na,&its);
4074: snes->conv_hist_alloc = PETSC_TRUE;
4075: }
4076: snes->conv_hist = a;
4077: snes->conv_hist_its = its;
4078: snes->conv_hist_max = na;
4079: snes->conv_hist_len = 0;
4080: snes->conv_hist_reset = reset;
4081: return(0);
4082: }
4084: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4085: #include <engine.h> /* MATLAB include file */
4086: #include <mex.h> /* MATLAB include file */
4088: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4089: {
4090: mxArray *mat;
4091: PetscInt i;
4092: PetscReal *ar;
4095: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4096: ar = (PetscReal*) mxGetData(mat);
4097: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4098: PetscFunctionReturn(mat);
4099: }
4100: #endif
4102: /*@C
4103: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4105: Not Collective
4107: Input Parameter:
4108: . snes - iterative context obtained from SNESCreate()
4110: Output Parameters:
4111: + a - array to hold history
4112: . its - integer array holds the number of linear iterations (or
4113: negative if not converged) for each solve.
4114: - na - size of a and its
4116: Notes:
4117: The calling sequence for this routine in Fortran is
4118: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4120: This routine is useful, e.g., when running a code for purposes
4121: of accurate performance monitoring, when no I/O should be done
4122: during the section of code that is being timed.
4124: Level: intermediate
4126: .seealso: SNESSetConvergencHistory()
4128: @*/
4129: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4130: {
4133: if (a) *a = snes->conv_hist;
4134: if (its) *its = snes->conv_hist_its;
4135: if (na) *na = snes->conv_hist_len;
4136: return(0);
4137: }
4139: /*@C
4140: SNESSetUpdate - Sets the general-purpose update function called
4141: at the beginning of every iteration of the nonlinear solve. Specifically
4142: it is called just before the Jacobian is "evaluated".
4144: Logically Collective on SNES
4146: Input Parameters:
4147: + snes - The nonlinear solver context
4148: - func - The function
4150: Calling sequence of func:
4151: $ func (SNES snes, PetscInt step);
4153: . step - The current step of the iteration
4155: Level: advanced
4157: 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()
4158: This is not used by most users.
4160: .seealso SNESSetJacobian(), SNESSolve()
4161: @*/
4162: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4163: {
4166: snes->ops->update = func;
4167: return(0);
4168: }
4170: /*
4171: SNESScaleStep_Private - Scales a step so that its length is less than the
4172: positive parameter delta.
4174: Input Parameters:
4175: + snes - the SNES context
4176: . y - approximate solution of linear system
4177: . fnorm - 2-norm of current function
4178: - delta - trust region size
4180: Output Parameters:
4181: + gpnorm - predicted function norm at the new point, assuming local
4182: linearization. The value is zero if the step lies within the trust
4183: region, and exceeds zero otherwise.
4184: - ynorm - 2-norm of the step
4186: Note:
4187: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4188: is set to be the maximum allowable step size.
4190: */
4191: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4192: {
4193: PetscReal nrm;
4194: PetscScalar cnorm;
4202: VecNorm(y,NORM_2,&nrm);
4203: if (nrm > *delta) {
4204: nrm = *delta/nrm;
4205: *gpnorm = (1.0 - nrm)*(*fnorm);
4206: cnorm = nrm;
4207: VecScale(y,cnorm);
4208: *ynorm = *delta;
4209: } else {
4210: *gpnorm = 0.0;
4211: *ynorm = nrm;
4212: }
4213: return(0);
4214: }
4216: /*@
4217: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4219: Collective on SNES
4221: Parameter:
4222: + snes - iterative context obtained from SNESCreate()
4223: - viewer - the viewer to display the reason
4226: Options Database Keys:
4227: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4229: Level: beginner
4231: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4233: @*/
4234: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4235: {
4236: PetscViewerFormat format;
4237: PetscBool isAscii;
4238: PetscErrorCode ierr;
4241: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4242: if (isAscii) {
4243: PetscViewerGetFormat(viewer, &format);
4244: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4245: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4246: DM dm;
4247: Vec u;
4248: PetscDS prob;
4249: PetscInt Nf, f;
4250: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4251: void **exactCtx;
4252: PetscReal error;
4254: SNESGetDM(snes, &dm);
4255: SNESGetSolution(snes, &u);
4256: DMGetDS(dm, &prob);
4257: PetscDSGetNumFields(prob, &Nf);
4258: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4259: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4260: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4261: PetscFree2(exactSol, exactCtx);
4262: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4263: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4264: }
4265: if (snes->reason > 0) {
4266: if (((PetscObject) snes)->prefix) {
4267: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4268: } else {
4269: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4270: }
4271: } else {
4272: if (((PetscObject) snes)->prefix) {
4273: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4274: } else {
4275: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4276: }
4277: }
4278: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4279: }
4280: return(0);
4281: }
4283: /*@C
4284: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4286: Collective on SNES
4288: Input Parameters:
4289: . snes - the SNES object
4291: Level: intermediate
4293: @*/
4294: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4295: {
4296: PetscErrorCode ierr;
4297: PetscViewer viewer;
4298: PetscBool flg;
4299: static PetscBool incall = PETSC_FALSE;
4300: PetscViewerFormat format;
4303: if (incall) return(0);
4304: incall = PETSC_TRUE;
4305: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4306: if (flg) {
4307: PetscViewerPushFormat(viewer,format);
4308: SNESReasonView(snes,viewer);
4309: PetscViewerPopFormat(viewer);
4310: PetscViewerDestroy(&viewer);
4311: }
4312: incall = PETSC_FALSE;
4313: return(0);
4314: }
4316: /*@
4317: SNESSolve - Solves a nonlinear system F(x) = b.
4318: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4320: Collective on SNES
4322: Input Parameters:
4323: + snes - the SNES context
4324: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4325: - x - the solution vector.
4327: Notes:
4328: The user should initialize the vector,x, with the initial guess
4329: for the nonlinear solve prior to calling SNESSolve. In particular,
4330: to employ an initial guess of zero, the user should explicitly set
4331: this vector to zero by calling VecSet().
4333: Level: beginner
4335: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4336: @*/
4337: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4338: {
4339: PetscErrorCode ierr;
4340: PetscBool flg;
4341: PetscInt grid;
4342: Vec xcreated = NULL;
4343: DM dm;
4352: /* High level operations using the nonlinear solver */
4353: {
4354: PetscViewer viewer;
4355: PetscViewerFormat format;
4356: PetscInt num;
4357: PetscBool flg;
4358: static PetscBool incall = PETSC_FALSE;
4360: if (!incall) {
4361: /* Estimate the convergence rate of the discretization */
4362: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4363: if (flg) {
4364: PetscConvEst conv;
4365: DM dm;
4366: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4367: PetscInt Nf;
4369: incall = PETSC_TRUE;
4370: SNESGetDM(snes, &dm);
4371: DMGetNumFields(dm, &Nf);
4372: PetscCalloc1(Nf, &alpha);
4373: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4374: PetscConvEstSetSolver(conv, snes);
4375: PetscConvEstSetFromOptions(conv);
4376: PetscConvEstSetUp(conv);
4377: PetscConvEstGetConvRate(conv, alpha);
4378: PetscViewerPushFormat(viewer, format);
4379: PetscConvEstRateView(conv, alpha, viewer);
4380: PetscViewerPopFormat(viewer);
4381: PetscViewerDestroy(&viewer);
4382: PetscConvEstDestroy(&conv);
4383: PetscFree(alpha);
4384: incall = PETSC_FALSE;
4385: }
4386: /* Adaptively refine the initial grid */
4387: num = 1;
4388: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4389: if (flg) {
4390: DMAdaptor adaptor;
4392: incall = PETSC_TRUE;
4393: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4394: DMAdaptorSetSolver(adaptor, snes);
4395: DMAdaptorSetSequenceLength(adaptor, num);
4396: DMAdaptorSetFromOptions(adaptor);
4397: DMAdaptorSetUp(adaptor);
4398: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4399: DMAdaptorDestroy(&adaptor);
4400: incall = PETSC_FALSE;
4401: }
4402: /* Use grid sequencing to adapt */
4403: num = 0;
4404: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4405: if (num) {
4406: DMAdaptor adaptor;
4408: incall = PETSC_TRUE;
4409: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4410: DMAdaptorSetSolver(adaptor, snes);
4411: DMAdaptorSetSequenceLength(adaptor, num);
4412: DMAdaptorSetFromOptions(adaptor);
4413: DMAdaptorSetUp(adaptor);
4414: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4415: DMAdaptorDestroy(&adaptor);
4416: incall = PETSC_FALSE;
4417: }
4418: }
4419: }
4420: if (!x) {
4421: SNESGetDM(snes,&dm);
4422: DMCreateGlobalVector(dm,&xcreated);
4423: x = xcreated;
4424: }
4425: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4427: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4428: for (grid=0; grid<snes->gridsequence+1; grid++) {
4430: /* set solution vector */
4431: if (!grid) {PetscObjectReference((PetscObject)x);}
4432: VecDestroy(&snes->vec_sol);
4433: snes->vec_sol = x;
4434: SNESGetDM(snes,&dm);
4436: /* set affine vector if provided */
4437: if (b) { PetscObjectReference((PetscObject)b); }
4438: VecDestroy(&snes->vec_rhs);
4439: snes->vec_rhs = b;
4441: 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");
4442: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4443: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4444: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4445: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4446: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4447: }
4448: DMShellSetGlobalVector(dm,snes->vec_sol);
4449: SNESSetUp(snes);
4451: if (!grid) {
4452: if (snes->ops->computeinitialguess) {
4453: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4454: }
4455: }
4457: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4458: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4460: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4461: (*snes->ops->solve)(snes);
4462: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4463: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4464: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4466: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4467: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4469: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4470: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4471: SNESReasonViewFromOptions(snes);
4473: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4474: if (snes->reason < 0) break;
4475: if (grid < snes->gridsequence) {
4476: DM fine;
4477: Vec xnew;
4478: Mat interp;
4480: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4481: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4482: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4483: DMCreateGlobalVector(fine,&xnew);
4484: MatInterpolate(interp,x,xnew);
4485: DMInterpolate(snes->dm,interp,fine);
4486: MatDestroy(&interp);
4487: x = xnew;
4489: SNESReset(snes);
4490: SNESSetDM(snes,fine);
4491: SNESResetFromOptions(snes);
4492: DMDestroy(&fine);
4493: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4494: }
4495: }
4496: SNESViewFromOptions(snes,NULL,"-snes_view");
4497: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4499: VecDestroy(&xcreated);
4500: PetscObjectSAWsBlock((PetscObject)snes);
4501: return(0);
4502: }
4504: /* --------- Internal routines for SNES Package --------- */
4506: /*@C
4507: SNESSetType - Sets the method for the nonlinear solver.
4509: Collective on SNES
4511: Input Parameters:
4512: + snes - the SNES context
4513: - type - a known method
4515: Options Database Key:
4516: . -snes_type <type> - Sets the method; use -help for a list
4517: of available methods (for instance, newtonls or newtontr)
4519: Notes:
4520: See "petsc/include/petscsnes.h" for available methods (for instance)
4521: + SNESNEWTONLS - Newton's method with line search
4522: (systems of nonlinear equations)
4523: - SNESNEWTONTR - Newton's method with trust region
4524: (systems of nonlinear equations)
4526: Normally, it is best to use the SNESSetFromOptions() command and then
4527: set the SNES solver type from the options database rather than by using
4528: this routine. Using the options database provides the user with
4529: maximum flexibility in evaluating the many nonlinear solvers.
4530: The SNESSetType() routine is provided for those situations where it
4531: is necessary to set the nonlinear solver independently of the command
4532: line or options database. This might be the case, for example, when
4533: the choice of solver changes during the execution of the program,
4534: and the user's application is taking responsibility for choosing the
4535: appropriate method.
4537: Developer Notes:
4538: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4539: the constructor in that list and calls it to create the spexific object.
4541: Level: intermediate
4543: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4545: @*/
4546: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4547: {
4548: PetscErrorCode ierr,(*r)(SNES);
4549: PetscBool match;
4555: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4556: if (match) return(0);
4558: PetscFunctionListFind(SNESList,type,&r);
4559: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4560: /* Destroy the previous private SNES context */
4561: if (snes->ops->destroy) {
4562: (*(snes)->ops->destroy)(snes);
4563: snes->ops->destroy = NULL;
4564: }
4565: /* Reinitialize function pointers in SNESOps structure */
4566: snes->ops->setup = 0;
4567: snes->ops->solve = 0;
4568: snes->ops->view = 0;
4569: snes->ops->setfromoptions = 0;
4570: snes->ops->destroy = 0;
4572: /* It may happen the user has customized the line search before calling SNESSetType */
4573: if (((PetscObject)snes)->type_name) {
4574: SNESLineSearchDestroy(&snes->linesearch);
4575: }
4577: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4578: snes->setupcalled = PETSC_FALSE;
4580: PetscObjectChangeTypeName((PetscObject)snes,type);
4581: (*r)(snes);
4582: return(0);
4583: }
4585: /*@C
4586: SNESGetType - Gets the SNES method type and name (as a string).
4588: Not Collective
4590: Input Parameter:
4591: . snes - nonlinear solver context
4593: Output Parameter:
4594: . type - SNES method (a character string)
4596: Level: intermediate
4598: @*/
4599: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4600: {
4604: *type = ((PetscObject)snes)->type_name;
4605: return(0);
4606: }
4608: /*@
4609: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4611: Logically Collective on SNES
4613: Input Parameters:
4614: + snes - the SNES context obtained from SNESCreate()
4615: - u - the solution vector
4617: Level: beginner
4619: @*/
4620: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4621: {
4622: DM dm;
4628: PetscObjectReference((PetscObject) u);
4629: VecDestroy(&snes->vec_sol);
4631: snes->vec_sol = u;
4633: SNESGetDM(snes, &dm);
4634: DMShellSetGlobalVector(dm, u);
4635: return(0);
4636: }
4638: /*@
4639: SNESGetSolution - Returns the vector where the approximate solution is
4640: stored. This is the fine grid solution when using SNESSetGridSequence().
4642: Not Collective, but Vec is parallel if SNES is parallel
4644: Input Parameter:
4645: . snes - the SNES context
4647: Output Parameter:
4648: . x - the solution
4650: Level: intermediate
4652: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4653: @*/
4654: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4655: {
4659: *x = snes->vec_sol;
4660: return(0);
4661: }
4663: /*@
4664: SNESGetSolutionUpdate - Returns the vector where the solution update is
4665: stored.
4667: Not Collective, but Vec is parallel if SNES is parallel
4669: Input Parameter:
4670: . snes - the SNES context
4672: Output Parameter:
4673: . x - the solution update
4675: Level: advanced
4677: .seealso: SNESGetSolution(), SNESGetFunction()
4678: @*/
4679: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4680: {
4684: *x = snes->vec_sol_update;
4685: return(0);
4686: }
4688: /*@C
4689: SNESGetFunction - Returns the vector where the function is stored.
4691: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4693: Input Parameter:
4694: . snes - the SNES context
4696: Output Parameter:
4697: + r - the vector that is used to store residuals (or NULL if you don't want it)
4698: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4699: - ctx - the function context (or NULL if you don't want it)
4701: Level: advanced
4703: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4705: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4706: @*/
4707: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4708: {
4710: DM dm;
4714: if (r) {
4715: if (!snes->vec_func) {
4716: if (snes->vec_rhs) {
4717: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4718: } else if (snes->vec_sol) {
4719: VecDuplicate(snes->vec_sol,&snes->vec_func);
4720: } else if (snes->dm) {
4721: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4722: }
4723: }
4724: *r = snes->vec_func;
4725: }
4726: SNESGetDM(snes,&dm);
4727: DMSNESGetFunction(dm,f,ctx);
4728: return(0);
4729: }
4731: /*@C
4732: SNESGetNGS - Returns the NGS function and context.
4734: Input Parameter:
4735: . snes - the SNES context
4737: Output Parameter:
4738: + f - the function (or NULL) see SNESNGSFunction for details
4739: - ctx - the function context (or NULL)
4741: Level: advanced
4743: .seealso: SNESSetNGS(), SNESGetFunction()
4744: @*/
4746: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4747: {
4749: DM dm;
4753: SNESGetDM(snes,&dm);
4754: DMSNESGetNGS(dm,f,ctx);
4755: return(0);
4756: }
4758: /*@C
4759: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4760: SNES options in the database.
4762: Logically Collective on SNES
4764: Input Parameter:
4765: + snes - the SNES context
4766: - prefix - the prefix to prepend to all option names
4768: Notes:
4769: A hyphen (-) must NOT be given at the beginning of the prefix name.
4770: The first character of all runtime options is AUTOMATICALLY the hyphen.
4772: Level: advanced
4774: .seealso: SNESSetFromOptions()
4775: @*/
4776: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4777: {
4782: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4783: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4784: if (snes->linesearch) {
4785: SNESGetLineSearch(snes,&snes->linesearch);
4786: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4787: }
4788: KSPSetOptionsPrefix(snes->ksp,prefix);
4789: return(0);
4790: }
4792: /*@C
4793: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4794: SNES options in the database.
4796: Logically Collective on SNES
4798: Input Parameters:
4799: + snes - the SNES context
4800: - prefix - the prefix to prepend to all option names
4802: Notes:
4803: A hyphen (-) must NOT be given at the beginning of the prefix name.
4804: The first character of all runtime options is AUTOMATICALLY the hyphen.
4806: Level: advanced
4808: .seealso: SNESGetOptionsPrefix()
4809: @*/
4810: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4811: {
4816: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4817: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4818: if (snes->linesearch) {
4819: SNESGetLineSearch(snes,&snes->linesearch);
4820: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4821: }
4822: KSPAppendOptionsPrefix(snes->ksp,prefix);
4823: return(0);
4824: }
4826: /*@C
4827: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4828: SNES options in the database.
4830: Not Collective
4832: Input Parameter:
4833: . snes - the SNES context
4835: Output Parameter:
4836: . prefix - pointer to the prefix string used
4838: Notes:
4839: On the fortran side, the user should pass in a string 'prefix' of
4840: sufficient length to hold the prefix.
4842: Level: advanced
4844: .seealso: SNESAppendOptionsPrefix()
4845: @*/
4846: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4847: {
4852: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4853: return(0);
4854: }
4857: /*@C
4858: SNESRegister - Adds a method to the nonlinear solver package.
4860: Not collective
4862: Input Parameters:
4863: + name_solver - name of a new user-defined solver
4864: - routine_create - routine to create method context
4866: Notes:
4867: SNESRegister() may be called multiple times to add several user-defined solvers.
4869: Sample usage:
4870: .vb
4871: SNESRegister("my_solver",MySolverCreate);
4872: .ve
4874: Then, your solver can be chosen with the procedural interface via
4875: $ SNESSetType(snes,"my_solver")
4876: or at runtime via the option
4877: $ -snes_type my_solver
4879: Level: advanced
4881: Note: If your function is not being put into a shared library then use SNESRegister() instead
4883: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4885: Level: advanced
4886: @*/
4887: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4888: {
4892: SNESInitializePackage();
4893: PetscFunctionListAdd(&SNESList,sname,function);
4894: return(0);
4895: }
4897: PetscErrorCode SNESTestLocalMin(SNES snes)
4898: {
4900: PetscInt N,i,j;
4901: Vec u,uh,fh;
4902: PetscScalar value;
4903: PetscReal norm;
4906: SNESGetSolution(snes,&u);
4907: VecDuplicate(u,&uh);
4908: VecDuplicate(u,&fh);
4910: /* currently only works for sequential */
4911: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4912: VecGetSize(u,&N);
4913: for (i=0; i<N; i++) {
4914: VecCopy(u,uh);
4915: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4916: for (j=-10; j<11; j++) {
4917: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4918: VecSetValue(uh,i,value,ADD_VALUES);
4919: SNESComputeFunction(snes,uh,fh);
4920: VecNorm(fh,NORM_2,&norm);
4921: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4922: value = -value;
4923: VecSetValue(uh,i,value,ADD_VALUES);
4924: }
4925: }
4926: VecDestroy(&uh);
4927: VecDestroy(&fh);
4928: return(0);
4929: }
4931: /*@
4932: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4933: computing relative tolerance for linear solvers within an inexact
4934: Newton method.
4936: Logically Collective on SNES
4938: Input Parameters:
4939: + snes - SNES context
4940: - flag - PETSC_TRUE or PETSC_FALSE
4942: Options Database:
4943: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4944: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4945: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4946: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4947: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4948: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4949: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4950: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4952: Notes:
4953: Currently, the default is to use a constant relative tolerance for
4954: the inner linear solvers. Alternatively, one can use the
4955: Eisenstat-Walker method, where the relative convergence tolerance
4956: is reset at each Newton iteration according progress of the nonlinear
4957: solver.
4959: Level: advanced
4961: Reference:
4962: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4963: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4965: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4966: @*/
4967: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
4968: {
4972: snes->ksp_ewconv = flag;
4973: return(0);
4974: }
4976: /*@
4977: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
4978: for computing relative tolerance for linear solvers within an
4979: inexact Newton method.
4981: Not Collective
4983: Input Parameter:
4984: . snes - SNES context
4986: Output Parameter:
4987: . flag - PETSC_TRUE or PETSC_FALSE
4989: Notes:
4990: Currently, the default is to use a constant relative tolerance for
4991: the inner linear solvers. Alternatively, one can use the
4992: Eisenstat-Walker method, where the relative convergence tolerance
4993: is reset at each Newton iteration according progress of the nonlinear
4994: solver.
4996: Level: advanced
4998: Reference:
4999: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5000: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5002: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5003: @*/
5004: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5005: {
5009: *flag = snes->ksp_ewconv;
5010: return(0);
5011: }
5013: /*@
5014: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5015: convergence criteria for the linear solvers within an inexact
5016: Newton method.
5018: Logically Collective on SNES
5020: Input Parameters:
5021: + snes - SNES context
5022: . version - version 1, 2 (default is 2) or 3
5023: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5024: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5025: . gamma - multiplicative factor for version 2 rtol computation
5026: (0 <= gamma2 <= 1)
5027: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5028: . alpha2 - power for safeguard
5029: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5031: Note:
5032: Version 3 was contributed by Luis Chacon, June 2006.
5034: Use PETSC_DEFAULT to retain the default for any of the parameters.
5036: Level: advanced
5038: Reference:
5039: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5040: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5041: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5043: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5044: @*/
5045: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5046: {
5047: SNESKSPEW *kctx;
5051: kctx = (SNESKSPEW*)snes->kspconvctx;
5052: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5061: if (version != PETSC_DEFAULT) kctx->version = version;
5062: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5063: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5064: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5065: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5066: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5067: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5069: 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);
5070: 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);
5071: 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);
5072: 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);
5073: 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);
5074: 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);
5075: return(0);
5076: }
5078: /*@
5079: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5080: convergence criteria for the linear solvers within an inexact
5081: Newton method.
5083: Not Collective
5085: Input Parameters:
5086: snes - SNES context
5088: Output Parameters:
5089: + version - version 1, 2 (default is 2) or 3
5090: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5091: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5092: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5093: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5094: . alpha2 - power for safeguard
5095: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5097: Level: advanced
5099: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5100: @*/
5101: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5102: {
5103: SNESKSPEW *kctx;
5107: kctx = (SNESKSPEW*)snes->kspconvctx;
5108: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5109: if (version) *version = kctx->version;
5110: if (rtol_0) *rtol_0 = kctx->rtol_0;
5111: if (rtol_max) *rtol_max = kctx->rtol_max;
5112: if (gamma) *gamma = kctx->gamma;
5113: if (alpha) *alpha = kctx->alpha;
5114: if (alpha2) *alpha2 = kctx->alpha2;
5115: if (threshold) *threshold = kctx->threshold;
5116: return(0);
5117: }
5119: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5120: {
5122: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5123: PetscReal rtol = PETSC_DEFAULT,stol;
5126: if (!snes->ksp_ewconv) return(0);
5127: if (!snes->iter) {
5128: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5129: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5130: }
5131: else {
5132: if (kctx->version == 1) {
5133: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5134: if (rtol < 0.0) rtol = -rtol;
5135: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5136: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5137: } else if (kctx->version == 2) {
5138: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5139: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5140: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5141: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5142: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5143: /* safeguard: avoid sharp decrease of rtol */
5144: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5145: stol = PetscMax(rtol,stol);
5146: rtol = PetscMin(kctx->rtol_0,stol);
5147: /* safeguard: avoid oversolving */
5148: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5149: stol = PetscMax(rtol,stol);
5150: rtol = PetscMin(kctx->rtol_0,stol);
5151: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5152: }
5153: /* safeguard: avoid rtol greater than one */
5154: rtol = PetscMin(rtol,kctx->rtol_max);
5155: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5156: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5157: return(0);
5158: }
5160: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5161: {
5163: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5164: PCSide pcside;
5165: Vec lres;
5168: if (!snes->ksp_ewconv) return(0);
5169: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5170: kctx->norm_last = snes->norm;
5171: if (kctx->version == 1) {
5172: PC pc;
5173: PetscBool isNone;
5175: KSPGetPC(ksp, &pc);
5176: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5177: KSPGetPCSide(ksp,&pcside);
5178: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5179: /* KSP residual is true linear residual */
5180: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5181: } else {
5182: /* KSP residual is preconditioned residual */
5183: /* compute true linear residual norm */
5184: VecDuplicate(b,&lres);
5185: MatMult(snes->jacobian,x,lres);
5186: VecAYPX(lres,-1.0,b);
5187: VecNorm(lres,NORM_2,&kctx->lresid_last);
5188: VecDestroy(&lres);
5189: }
5190: }
5191: return(0);
5192: }
5194: /*@
5195: SNESGetKSP - Returns the KSP context for a SNES solver.
5197: Not Collective, but if SNES object is parallel, then KSP object is parallel
5199: Input Parameter:
5200: . snes - the SNES context
5202: Output Parameter:
5203: . ksp - the KSP context
5205: Notes:
5206: The user can then directly manipulate the KSP context to set various
5207: options, etc. Likewise, the user can then extract and manipulate the
5208: PC contexts as well.
5210: Level: beginner
5212: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5213: @*/
5214: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5215: {
5222: if (!snes->ksp) {
5223: PetscBool monitor = PETSC_FALSE;
5225: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5226: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5227: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5229: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5230: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5232: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5233: if (monitor) {
5234: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5235: }
5236: monitor = PETSC_FALSE;
5237: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5238: if (monitor) {
5239: PetscObject *objs;
5240: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5241: objs[0] = (PetscObject) snes;
5242: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5243: }
5244: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5245: }
5246: *ksp = snes->ksp;
5247: return(0);
5248: }
5251: #include <petsc/private/dmimpl.h>
5252: /*@
5253: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5255: Logically Collective on SNES
5257: Input Parameters:
5258: + snes - the nonlinear solver context
5259: - dm - the dm, cannot be NULL
5261: Notes:
5262: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5263: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5264: problems using the same function space.
5266: Level: intermediate
5268: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5269: @*/
5270: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5271: {
5273: KSP ksp;
5274: DMSNES sdm;
5279: PetscObjectReference((PetscObject)dm);
5280: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5281: if (snes->dm->dmsnes && !dm->dmsnes) {
5282: DMCopyDMSNES(snes->dm,dm);
5283: DMGetDMSNES(snes->dm,&sdm);
5284: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5285: }
5286: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5287: DMDestroy(&snes->dm);
5288: }
5289: snes->dm = dm;
5290: snes->dmAuto = PETSC_FALSE;
5292: SNESGetKSP(snes,&ksp);
5293: KSPSetDM(ksp,dm);
5294: KSPSetDMActive(ksp,PETSC_FALSE);
5295: if (snes->npc) {
5296: SNESSetDM(snes->npc, snes->dm);
5297: SNESSetNPCSide(snes,snes->npcside);
5298: }
5299: return(0);
5300: }
5302: /*@
5303: SNESGetDM - Gets the DM that may be used by some preconditioners
5305: Not Collective but DM obtained is parallel on SNES
5307: Input Parameter:
5308: . snes - the preconditioner context
5310: Output Parameter:
5311: . dm - the dm
5313: Level: intermediate
5315: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5316: @*/
5317: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5318: {
5323: if (!snes->dm) {
5324: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5325: snes->dmAuto = PETSC_TRUE;
5326: }
5327: *dm = snes->dm;
5328: return(0);
5329: }
5331: /*@
5332: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5334: Collective on SNES
5336: Input Parameters:
5337: + snes - iterative context obtained from SNESCreate()
5338: - pc - the preconditioner object
5340: Notes:
5341: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5342: to configure it using the API).
5344: Level: developer
5346: .seealso: SNESGetNPC(), SNESHasNPC()
5347: @*/
5348: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5349: {
5356: PetscObjectReference((PetscObject) pc);
5357: SNESDestroy(&snes->npc);
5358: snes->npc = pc;
5359: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5360: return(0);
5361: }
5363: /*@
5364: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5366: Not Collective; but any changes to the obtained SNES object must be applied collectively
5368: Input Parameter:
5369: . snes - iterative context obtained from SNESCreate()
5371: Output Parameter:
5372: . pc - preconditioner context
5374: Options Database:
5375: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5377: Notes:
5378: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5380: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5381: SNES during SNESSetUp()
5383: Level: developer
5385: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5386: @*/
5387: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5388: {
5390: const char *optionsprefix;
5395: if (!snes->npc) {
5396: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5397: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5398: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5399: SNESGetOptionsPrefix(snes,&optionsprefix);
5400: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5401: SNESAppendOptionsPrefix(snes->npc,"npc_");
5402: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5403: }
5404: *pc = snes->npc;
5405: return(0);
5406: }
5408: /*@
5409: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5411: Not Collective
5413: Input Parameter:
5414: . snes - iterative context obtained from SNESCreate()
5416: Output Parameter:
5417: . has_npc - whether the SNES has an NPC or not
5419: Level: developer
5421: .seealso: SNESSetNPC(), SNESGetNPC()
5422: @*/
5423: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5424: {
5427: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5428: return(0);
5429: }
5431: /*@
5432: SNESSetNPCSide - Sets the preconditioning side.
5434: Logically Collective on SNES
5436: Input Parameter:
5437: . snes - iterative context obtained from SNESCreate()
5439: Output Parameter:
5440: . side - the preconditioning side, where side is one of
5441: .vb
5442: PC_LEFT - left preconditioning
5443: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5444: .ve
5446: Options Database Keys:
5447: . -snes_pc_side <right,left>
5449: Notes:
5450: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5452: Level: intermediate
5454: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5455: @*/
5456: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5457: {
5461: snes->npcside= side;
5462: return(0);
5463: }
5465: /*@
5466: SNESGetNPCSide - Gets the preconditioning side.
5468: Not Collective
5470: Input Parameter:
5471: . snes - iterative context obtained from SNESCreate()
5473: Output Parameter:
5474: . side - the preconditioning side, where side is one of
5475: .vb
5476: PC_LEFT - left preconditioning
5477: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5478: .ve
5480: Level: intermediate
5482: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5483: @*/
5484: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5485: {
5489: *side = snes->npcside;
5490: return(0);
5491: }
5493: /*@
5494: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5496: Collective on SNES
5498: Input Parameters:
5499: + snes - iterative context obtained from SNESCreate()
5500: - linesearch - the linesearch object
5502: Notes:
5503: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5504: to configure it using the API).
5506: Level: developer
5508: .seealso: SNESGetLineSearch()
5509: @*/
5510: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5511: {
5518: PetscObjectReference((PetscObject) linesearch);
5519: SNESLineSearchDestroy(&snes->linesearch);
5521: snes->linesearch = linesearch;
5523: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5524: return(0);
5525: }
5527: /*@
5528: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5529: or creates a default line search instance associated with the SNES and returns it.
5531: Not Collective
5533: Input Parameter:
5534: . snes - iterative context obtained from SNESCreate()
5536: Output Parameter:
5537: . linesearch - linesearch context
5539: Level: beginner
5541: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5542: @*/
5543: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5544: {
5546: const char *optionsprefix;
5551: if (!snes->linesearch) {
5552: SNESGetOptionsPrefix(snes, &optionsprefix);
5553: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5554: SNESLineSearchSetSNES(snes->linesearch, snes);
5555: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5556: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5557: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5558: }
5559: *linesearch = snes->linesearch;
5560: return(0);
5561: }