Actual source code: snes.c
petsc-3.7.7 2017-09-25
2: #include <petsc/private/snesimpl.h> /*I "petscsnes.h" I*/
3: #include <petscdmshell.h>
4: #include <petscdraw.h>
6: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
7: PetscFunctionList SNESList = NULL;
9: /* Logging support */
10: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
11: PetscLogEvent SNES_Solve, 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: .keywords: SNES, set, initial guess, nonzero
35: .seealso: SNESGetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
36: @*/
37: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes,PetscBool flg)
38: {
42: snes->errorifnotconverged = flg;
43: return(0);
44: }
48: /*@
49: SNESGetErrorIfNotConverged - Will SNESSolve() generate an error if the solver does not converge?
51: Not Collective
53: Input Parameter:
54: . snes - iterative context obtained from SNESCreate()
56: Output Parameter:
57: . flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE
59: Level: intermediate
61: .keywords: SNES, set, initial guess, nonzero
63: .seealso: SNESSetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
64: @*/
65: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes,PetscBool *flag)
66: {
70: *flag = snes->errorifnotconverged;
71: return(0);
72: }
76: /*@
77: SNESSetFunctionDomainError - tells SNES that the input vector to your SNESFunction is not
78: in the functions domain. For example, negative pressure.
80: Logically Collective on SNES
82: Input Parameters:
83: . snes - the SNES context
85: Level: advanced
87: .keywords: SNES, view
89: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction
90: @*/
91: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
92: {
95: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates input vector is not in the function domain");
96: snes->domainerror = PETSC_TRUE;
97: return(0);
98: }
102: /*@
103: SNESGetFunctionDomainError - Gets the status of the domain error after a call to SNESComputeFunction;
105: Logically Collective on SNES
107: Input Parameters:
108: . snes - the SNES context
110: Output Parameters:
111: . domainerror - Set to PETSC_TRUE if there's a domain error; PETSC_FALSE otherwise.
113: Level: advanced
115: .keywords: SNES, view
117: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction()
118: @*/
119: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
120: {
124: *domainerror = snes->domainerror;
125: return(0);
126: }
130: /*@C
131: SNESLoad - Loads a SNES that has been stored in binary with SNESView().
133: Collective on PetscViewer
135: Input Parameters:
136: + newdm - the newly loaded SNES, this needs to have been created with SNESCreate() or
137: some related function before a call to SNESLoad().
138: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
140: Level: intermediate
142: Notes:
143: The type is determined by the data in the file, any type set into the SNES before this call is ignored.
145: Notes for advanced users:
146: Most users should not need to know the details of the binary storage
147: format, since SNESLoad() and TSView() completely hide these details.
148: But for anyone who's interested, the standard binary matrix storage
149: format is
150: .vb
151: has not yet been determined
152: .ve
154: .seealso: PetscViewerBinaryOpen(), SNESView(), MatLoad(), VecLoad()
155: @*/
156: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
157: {
159: PetscBool isbinary;
160: PetscInt classid;
161: char type[256];
162: KSP ksp;
163: DM dm;
164: DMSNES dmsnes;
169: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
170: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
172: PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
173: if (classid != SNES_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONG,"Not SNES next in file");
174: PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
175: SNESSetType(snes, type);
176: if (snes->ops->load) {
177: (*snes->ops->load)(snes,viewer);
178: }
179: SNESGetDM(snes,&dm);
180: DMGetDMSNES(dm,&dmsnes);
181: DMSNESLoad(dmsnes,viewer);
182: SNESGetKSP(snes,&ksp);
183: KSPLoad(ksp,viewer);
184: return(0);
185: }
187: #include <petscdraw.h>
188: #if defined(PETSC_HAVE_SAWS)
189: #include <petscviewersaws.h>
190: #endif
193: /*@C
194: SNESView - Prints the SNES data structure.
196: Collective on SNES
198: Input Parameters:
199: + SNES - the SNES context
200: - viewer - visualization context
202: Options Database Key:
203: . -snes_view - Calls SNESView() at end of SNESSolve()
205: Notes:
206: The available visualization contexts include
207: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
208: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
209: output where only the first processor opens
210: the file. All other processors send their
211: data to the first processor to print.
213: The user can open an alternative visualization context with
214: PetscViewerASCIIOpen() - output to a specified file.
216: Level: beginner
218: .keywords: SNES, view
220: .seealso: PetscViewerASCIIOpen()
221: @*/
222: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
223: {
224: SNESKSPEW *kctx;
226: KSP ksp;
227: SNESLineSearch linesearch;
228: PetscBool iascii,isstring,isbinary,isdraw;
229: DMSNES dmsnes;
230: #if defined(PETSC_HAVE_SAWS)
231: PetscBool issaws;
232: #endif
236: if (!viewer) {
237: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
238: }
242: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
243: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
244: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
245: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
246: #if defined(PETSC_HAVE_SAWS)
247: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
248: #endif
249: if (iascii) {
250: SNESNormSchedule normschedule;
252: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
253: if (!snes->setupcalled) {
254: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
255: }
256: if (snes->ops->view) {
257: PetscViewerASCIIPushTab(viewer);
258: (*snes->ops->view)(snes,viewer);
259: PetscViewerASCIIPopTab(viewer);
260: }
261: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
262: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
263: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
264: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
265: SNESGetNormSchedule(snes, &normschedule);
266: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
267: if (snes->gridsequence) {
268: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
269: }
270: if (snes->ksp_ewconv) {
271: kctx = (SNESKSPEW*)snes->kspconvctx;
272: if (kctx) {
273: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
274: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
275: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
276: }
277: }
278: if (snes->lagpreconditioner == -1) {
279: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
280: } else if (snes->lagpreconditioner > 1) {
281: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
282: }
283: if (snes->lagjacobian == -1) {
284: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
285: } else if (snes->lagjacobian > 1) {
286: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
287: }
288: } else if (isstring) {
289: const char *type;
290: SNESGetType(snes,&type);
291: PetscViewerStringSPrintf(viewer," %-3.3s",type);
292: } else if (isbinary) {
293: PetscInt classid = SNES_FILE_CLASSID;
294: MPI_Comm comm;
295: PetscMPIInt rank;
296: char type[256];
298: PetscObjectGetComm((PetscObject)snes,&comm);
299: MPI_Comm_rank(comm,&rank);
300: if (!rank) {
301: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
302: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
303: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR,PETSC_FALSE);
304: }
305: if (snes->ops->view) {
306: (*snes->ops->view)(snes,viewer);
307: }
308: } else if (isdraw) {
309: PetscDraw draw;
310: char str[36];
311: PetscReal x,y,bottom,h;
313: PetscViewerDrawGetDraw(viewer,0,&draw);
314: PetscDrawGetCurrentPoint(draw,&x,&y);
315: PetscStrcpy(str,"SNES: ");
316: PetscStrcat(str,((PetscObject)snes)->type_name);
317: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
318: bottom = y - h;
319: PetscDrawPushCurrentPoint(draw,x,bottom);
320: if (snes->ops->view) {
321: (*snes->ops->view)(snes,viewer);
322: }
323: #if defined(PETSC_HAVE_SAWS)
324: } else if (issaws) {
325: PetscMPIInt rank;
326: const char *name;
328: PetscObjectGetName((PetscObject)snes,&name);
329: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
330: if (!((PetscObject)snes)->amsmem && !rank) {
331: char dir[1024];
333: PetscObjectViewSAWs((PetscObject)snes,viewer);
334: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
335: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
336: if (!snes->conv_hist) {
337: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
338: }
339: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
340: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
341: }
342: #endif
343: }
344: if (snes->linesearch) {
345: PetscViewerASCIIPushTab(viewer);
346: SNESGetLineSearch(snes, &linesearch);
347: SNESLineSearchView(linesearch, viewer);
348: PetscViewerASCIIPopTab(viewer);
349: }
350: if (snes->pc && snes->usespc) {
351: PetscViewerASCIIPushTab(viewer);
352: SNESView(snes->pc, viewer);
353: PetscViewerASCIIPopTab(viewer);
354: }
355: PetscViewerASCIIPushTab(viewer);
356: DMGetDMSNES(snes->dm,&dmsnes);
357: DMSNESView(dmsnes, viewer);
358: PetscViewerASCIIPopTab(viewer);
359: if (snes->usesksp) {
360: SNESGetKSP(snes,&ksp);
361: PetscViewerASCIIPushTab(viewer);
362: KSPView(ksp,viewer);
363: PetscViewerASCIIPopTab(viewer);
364: }
365: if (isdraw) {
366: PetscDraw draw;
367: PetscViewerDrawGetDraw(viewer,0,&draw);
368: PetscDrawPopCurrentPoint(draw);
369: }
370: return(0);
371: }
373: /*
374: We retain a list of functions that also take SNES command
375: line options. These are called at the end SNESSetFromOptions()
376: */
377: #define MAXSETFROMOPTIONS 5
378: static PetscInt numberofsetfromoptions;
379: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
383: /*@C
384: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
386: Not Collective
388: Input Parameter:
389: . snescheck - function that checks for options
391: Level: developer
393: .seealso: SNESSetFromOptions()
394: @*/
395: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
396: {
398: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
399: othersetfromoptions[numberofsetfromoptions++] = snescheck;
400: return(0);
401: }
403: extern PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
407: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
408: {
409: Mat J;
410: KSP ksp;
411: PC pc;
412: PetscBool match;
414: MatNullSpace nullsp;
419: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
420: Mat A = snes->jacobian, B = snes->jacobian_pre;
421: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
422: }
424: if (version == 1) {
425: MatCreateSNESMF(snes,&J);
426: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
427: MatSetFromOptions(J);
428: } else if (version == 2) {
429: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
430: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128)
431: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
432: #else
433: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
434: #endif
435: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");
437: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
438: if (snes->jacobian) {
439: MatGetNullSpace(snes->jacobian,&nullsp);
440: if (nullsp) {
441: MatSetNullSpace(J,nullsp);
442: }
443: }
445: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
446: if (hasOperator) {
448: /* This version replaces the user provided Jacobian matrix with a
449: matrix-free version but still employs the user-provided preconditioner matrix. */
450: SNESSetJacobian(snes,J,0,0,0);
451: } else {
452: /* This version replaces both the user-provided Jacobian and the user-
453: provided preconditioner Jacobian with the default matrix free version. */
454: if ((snes->pcside == PC_LEFT) && snes->pc) {
455: if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
456: } else {
457: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
458: }
459: /* Force no preconditioner */
460: SNESGetKSP(snes,&ksp);
461: KSPGetPC(ksp,&pc);
462: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
463: if (!match) {
464: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
465: PCSetType(pc,PCNONE);
466: }
467: }
468: MatDestroy(&J);
469: return(0);
470: }
474: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
475: {
476: SNES snes = (SNES)ctx;
478: Vec Xfine,Xfine_named = NULL,Xcoarse;
481: if (PetscLogPrintInfo) {
482: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
483: DMGetRefineLevel(dmfine,&finelevel);
484: DMGetCoarsenLevel(dmfine,&fineclevel);
485: DMGetRefineLevel(dmcoarse,&coarselevel);
486: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
487: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
488: }
489: if (dmfine == snes->dm) Xfine = snes->vec_sol;
490: else {
491: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
492: Xfine = Xfine_named;
493: }
494: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
495: if (Inject) {
496: MatRestrict(Inject,Xfine,Xcoarse);
497: } else {
498: MatRestrict(Restrict,Xfine,Xcoarse);
499: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
500: }
501: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
502: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
503: return(0);
504: }
508: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
509: {
513: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
514: return(0);
515: }
519: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
520: * safely call SNESGetDM() in their residual evaluation routine. */
521: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
522: {
523: SNES snes = (SNES)ctx;
525: Mat Asave = A,Bsave = B;
526: Vec X,Xnamed = NULL;
527: DM dmsave;
528: void *ctxsave;
529: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
532: dmsave = snes->dm;
533: KSPGetDM(ksp,&snes->dm);
534: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
535: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
536: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
537: X = Xnamed;
538: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
539: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
540: if (jac == SNESComputeJacobianDefaultColor) {
541: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
542: }
543: }
544: /* put the previous context back */
546: SNESComputeJacobian(snes,X,A,B);
547: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
548: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
549: }
551: if (A != Asave || B != Bsave) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_SUP,"No support for changing matrices at this time");
552: if (Xnamed) {
553: DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
554: }
555: snes->dm = dmsave;
556: return(0);
557: }
561: /*@
562: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
564: Collective
566: Input Arguments:
567: . snes - snes to configure
569: Level: developer
571: .seealso: SNESSetUp()
572: @*/
573: PetscErrorCode SNESSetUpMatrices(SNES snes)
574: {
576: DM dm;
577: DMSNES sdm;
580: SNESGetDM(snes,&dm);
581: DMGetDMSNES(dm,&sdm);
582: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
583: else if (!snes->jacobian && snes->mf) {
584: Mat J;
585: void *functx;
586: MatCreateSNESMF(snes,&J);
587: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
588: MatSetFromOptions(J);
589: SNESGetFunction(snes,NULL,NULL,&functx);
590: SNESSetJacobian(snes,J,J,0,0);
591: MatDestroy(&J);
592: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
593: Mat J,B;
594: MatCreateSNESMF(snes,&J);
595: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
596: MatSetFromOptions(J);
597: DMCreateMatrix(snes->dm,&B);
598: /* sdm->computejacobian was already set to reach here */
599: SNESSetJacobian(snes,J,B,NULL,NULL);
600: MatDestroy(&J);
601: MatDestroy(&B);
602: } else if (!snes->jacobian_pre) {
603: Mat J,B;
604: J = snes->jacobian;
605: DMCreateMatrix(snes->dm,&B);
606: SNESSetJacobian(snes,J ? J : B,B,NULL,NULL);
607: MatDestroy(&B);
608: }
609: {
610: KSP ksp;
611: SNESGetKSP(snes,&ksp);
612: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
613: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
614: }
615: return(0);
616: }
620: /*@C
621: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
623: Collective on SNES
625: Input Parameters:
626: + snes - SNES object you wish to monitor
627: . name - the monitor type one is seeking
628: . help - message indicating what monitoring is done
629: . manual - manual page for the monitor
630: . monitor - the monitor function
631: - 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
633: Level: developer
635: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
636: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
637: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
638: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
639: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
640: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
641: PetscOptionsFList(), PetscOptionsEList()
642: @*/
643: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
644: {
645: PetscErrorCode ierr;
646: PetscViewer viewer;
647: PetscViewerFormat format;
648: PetscBool flg;
651: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
652: if (flg) {
653: PetscViewerAndFormat *vf;
654: PetscViewerAndFormatCreate(viewer,format,&vf);
655: PetscObjectDereference((PetscObject)viewer);
656: if (monitorsetup) {
657: (*monitorsetup)(snes,vf);
658: }
659: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
660: }
661: return(0);
662: }
666: /*@
667: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
669: Collective on SNES
671: Input Parameter:
672: . snes - the SNES context
674: Options Database Keys:
675: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
676: . -snes_stol - convergence tolerance in terms of the norm
677: of the change in the solution between steps
678: . -snes_atol <abstol> - absolute tolerance of residual norm
679: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
680: . -snes_max_it <max_it> - maximum number of iterations
681: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
682: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
683: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
684: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
685: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
686: . -snes_trtol <trtol> - trust region tolerance
687: . -snes_no_convergence_test - skip convergence test in nonlinear
688: solver; hence iterations will continue until max_it
689: or some other criterion is reached. Saves expense
690: of convergence test
691: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
692: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
693: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
694: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
695: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
696: . -snes_monitor_lg_range - plots residual norm at each iteration
697: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
698: . -snes_fd_color - use finite differences with coloring to compute Jacobian
699: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
700: - -snes_converged_reason - print the reason for convergence/divergence after each solve
702: Options Database for Eisenstat-Walker method:
703: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
704: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
705: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
706: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
707: . -snes_ksp_ew_gamma <gamma> - Sets gamma
708: . -snes_ksp_ew_alpha <alpha> - Sets alpha
709: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
710: - -snes_ksp_ew_threshold <threshold> - Sets threshold
712: Notes:
713: To see all options, run your program with the -help option or consult
714: Users-Manual: ch_snes
716: Level: beginner
718: .keywords: SNES, nonlinear, set, options, database
720: .seealso: SNESSetOptionsPrefix()
721: @*/
722: PetscErrorCode SNESSetFromOptions(SNES snes)
723: {
724: PetscBool flg,pcset,persist,set;
725: PetscInt i,indx,lag,grids;
726: const char *deft = SNESNEWTONLS;
727: const char *convtests[] = {"default","skip"};
728: SNESKSPEW *kctx = NULL;
729: char type[256], monfilename[PETSC_MAX_PATH_LEN];
731: PCSide pcside;
732: const char *optionsprefix;
736: SNESRegisterAll();
737: PetscObjectOptionsBegin((PetscObject)snes);
738: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
739: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
740: if (flg) {
741: SNESSetType(snes,type);
742: } else if (!((PetscObject)snes)->type_name) {
743: SNESSetType(snes,deft);
744: }
745: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
746: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
748: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
749: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
750: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
751: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
752: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
753: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
755: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
756: if (flg) {
757: SNESSetLagPreconditioner(snes,lag);
758: }
759: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
760: if (flg) {
761: SNESSetLagPreconditionerPersists(snes,persist);
762: }
763: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
764: if (flg) {
765: SNESSetLagJacobian(snes,lag);
766: }
767: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
768: if (flg) {
769: SNESSetLagJacobianPersists(snes,persist);
770: }
772: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
773: if (flg) {
774: SNESSetGridSequence(snes,grids);
775: }
777: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
778: if (flg) {
779: switch (indx) {
780: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
781: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
782: }
783: }
785: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
786: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
788: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
789: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
791: kctx = (SNESKSPEW*)snes->kspconvctx;
793: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
795: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
796: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
797: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
798: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
799: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
800: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
801: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
803: flg = PETSC_FALSE;
804: PetscOptionsBool("-snes_check_jacobian","Check each Jacobian with a differenced one","SNESUpdateCheckJacobian",flg,&flg,&set);
805: if (set && flg) {
806: SNESSetUpdate(snes,SNESUpdateCheckJacobian);
807: }
809: flg = PETSC_FALSE;
810: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
811: if (set && flg) {SNESMonitorCancel(snes);}
813: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
814: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
815: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
817: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
818: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
819: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
820: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
821: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
822: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
823: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
825: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
826: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
829: flg = PETSC_FALSE;
830: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
831: if (flg) {
832: PetscDrawLG ctx;
834: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
835: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
836: }
837: flg = PETSC_FALSE;
838: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
839: if (flg) {
840: PetscViewer ctx;
842: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
843: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
844: }
848: flg = PETSC_FALSE;
849: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
850: if (flg) {
851: void *functx;
852: SNESGetFunction(snes,NULL,NULL,&functx);
853: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
854: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
855: }
857: flg = PETSC_FALSE;
858: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
859: if (flg) {
860: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
861: }
863: flg = PETSC_FALSE;
864: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
865: if (flg) {
866: DM dm;
867: DMSNES sdm;
868: SNESGetDM(snes,&dm);
869: DMGetDMSNES(dm,&sdm);
870: sdm->jacobianctx = NULL;
871: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
872: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
873: }
875: flg = PETSC_FALSE;
876: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","MatCreateSNESMF",PETSC_FALSE,&snes->mf_operator,&flg);
877: if (flg && snes->mf_operator) {
878: snes->mf_operator = PETSC_TRUE;
879: snes->mf = PETSC_TRUE;
880: }
881: flg = PETSC_FALSE;
882: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","MatCreateSNESMF",PETSC_FALSE,&snes->mf,&flg);
883: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
884: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
886: flg = PETSC_FALSE;
887: SNESGetNPCSide(snes,&pcside);
888: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
889: if (flg) {SNESSetNPCSide(snes,pcside);}
891: #if defined(PETSC_HAVE_SAWS)
892: /*
893: Publish convergence information using SAWs
894: */
895: flg = PETSC_FALSE;
896: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
897: if (flg) {
898: void *ctx;
899: SNESMonitorSAWsCreate(snes,&ctx);
900: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
901: }
902: #endif
903: #if defined(PETSC_HAVE_SAWS)
904: {
905: PetscBool set;
906: flg = PETSC_FALSE;
907: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
908: if (set) {
909: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
910: }
911: }
912: #endif
914: for (i = 0; i < numberofsetfromoptions; i++) {
915: (*othersetfromoptions[i])(snes);
916: }
918: if (snes->ops->setfromoptions) {
919: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
920: }
922: /* process any options handlers added with PetscObjectAddOptionsHandler() */
923: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
924: PetscOptionsEnd();
926: if (!snes->linesearch) {
927: SNESGetLineSearch(snes, &snes->linesearch);
928: }
929: SNESLineSearchSetFromOptions(snes->linesearch);
931: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
932: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
933: KSPSetFromOptions(snes->ksp);
935: /* if someone has set the SNES NPC type, create it. */
936: SNESGetOptionsPrefix(snes, &optionsprefix);
937: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
938: if (pcset && (!snes->pc)) {
939: SNESGetNPC(snes, &snes->pc);
940: }
941: return(0);
942: }
946: /*@C
947: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
948: the nonlinear solvers.
950: Logically Collective on SNES
952: Input Parameters:
953: + snes - the SNES context
954: . compute - function to compute the context
955: - destroy - function to destroy the context
957: Level: intermediate
959: Notes:
960: This function is currently not available from Fortran.
962: .keywords: SNES, nonlinear, set, application, context
964: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
965: @*/
966: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
967: {
970: snes->ops->usercompute = compute;
971: snes->ops->userdestroy = destroy;
972: return(0);
973: }
977: /*@
978: SNESSetApplicationContext - Sets the optional user-defined context for
979: the nonlinear solvers.
981: Logically Collective on SNES
983: Input Parameters:
984: + snes - the SNES context
985: - usrP - optional user context
987: Level: intermediate
989: Fortran Notes: To use this from Fortran you must write a Fortran interface definition for this
990: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
992: .keywords: SNES, nonlinear, set, application, context
994: .seealso: SNESGetApplicationContext()
995: @*/
996: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
997: {
999: KSP ksp;
1003: SNESGetKSP(snes,&ksp);
1004: KSPSetApplicationContext(ksp,usrP);
1005: snes->user = usrP;
1006: return(0);
1007: }
1011: /*@
1012: SNESGetApplicationContext - Gets the user-defined context for the
1013: nonlinear solvers.
1015: Not Collective
1017: Input Parameter:
1018: . snes - SNES context
1020: Output Parameter:
1021: . usrP - user context
1023: Fortran Notes: To use this from Fortran you must write a Fortran interface definition for this
1024: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1026: Level: intermediate
1028: .keywords: SNES, nonlinear, get, application, context
1030: .seealso: SNESSetApplicationContext()
1031: @*/
1032: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1033: {
1036: *(void**)usrP = snes->user;
1037: return(0);
1038: }
1042: /*@
1043: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1044: at this time.
1046: Not Collective
1048: Input Parameter:
1049: . snes - SNES context
1051: Output Parameter:
1052: . iter - iteration number
1054: Notes:
1055: For example, during the computation of iteration 2 this would return 1.
1057: This is useful for using lagged Jacobians (where one does not recompute the
1058: Jacobian at each SNES iteration). For example, the code
1059: .vb
1060: SNESGetIterationNumber(snes,&it);
1061: if (!(it % 2)) {
1062: [compute Jacobian here]
1063: }
1064: .ve
1065: can be used in your ComputeJacobian() function to cause the Jacobian to be
1066: recomputed every second SNES iteration.
1068: Level: intermediate
1070: .keywords: SNES, nonlinear, get, iteration, number,
1072: .seealso: SNESGetLinearSolveIterations()
1073: @*/
1074: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1075: {
1079: *iter = snes->iter;
1080: return(0);
1081: }
1085: /*@
1086: SNESSetIterationNumber - Sets the current iteration number.
1088: Not Collective
1090: Input Parameter:
1091: . snes - SNES context
1092: . iter - iteration number
1094: Level: developer
1096: .keywords: SNES, nonlinear, set, iteration, number,
1098: .seealso: SNESGetLinearSolveIterations()
1099: @*/
1100: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1101: {
1106: PetscObjectSAWsTakeAccess((PetscObject)snes);
1107: snes->iter = iter;
1108: PetscObjectSAWsGrantAccess((PetscObject)snes);
1109: return(0);
1110: }
1114: /*@
1115: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1116: attempted by the nonlinear solver.
1118: Not Collective
1120: Input Parameter:
1121: . snes - SNES context
1123: Output Parameter:
1124: . nfails - number of unsuccessful steps attempted
1126: Notes:
1127: This counter is reset to zero for each successive call to SNESSolve().
1129: Level: intermediate
1131: .keywords: SNES, nonlinear, get, number, unsuccessful, steps
1133: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1134: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1135: @*/
1136: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1137: {
1141: *nfails = snes->numFailures;
1142: return(0);
1143: }
1147: /*@
1148: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1149: attempted by the nonlinear solver before it gives up.
1151: Not Collective
1153: Input Parameters:
1154: + snes - SNES context
1155: - maxFails - maximum of unsuccessful steps
1157: Level: intermediate
1159: .keywords: SNES, nonlinear, set, maximum, unsuccessful, steps
1161: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1162: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1163: @*/
1164: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1165: {
1168: snes->maxFailures = maxFails;
1169: return(0);
1170: }
1174: /*@
1175: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1176: attempted by the nonlinear solver before it gives up.
1178: Not Collective
1180: Input Parameter:
1181: . snes - SNES context
1183: Output Parameter:
1184: . maxFails - maximum of unsuccessful steps
1186: Level: intermediate
1188: .keywords: SNES, nonlinear, get, maximum, unsuccessful, steps
1190: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1191: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1193: @*/
1194: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1195: {
1199: *maxFails = snes->maxFailures;
1200: return(0);
1201: }
1205: /*@
1206: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1207: done by SNES.
1209: Not Collective
1211: Input Parameter:
1212: . snes - SNES context
1214: Output Parameter:
1215: . nfuncs - number of evaluations
1217: Level: intermediate
1219: Notes: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1221: .keywords: SNES, nonlinear, get, maximum, unsuccessful, steps
1223: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1224: @*/
1225: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1226: {
1230: *nfuncs = snes->nfuncs;
1231: return(0);
1232: }
1236: /*@
1237: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1238: linear solvers.
1240: Not Collective
1242: Input Parameter:
1243: . snes - SNES context
1245: Output Parameter:
1246: . nfails - number of failed solves
1248: Level: intermediate
1250: Options Database Keys:
1251: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1253: Notes:
1254: This counter is reset to zero for each successive call to SNESSolve().
1256: .keywords: SNES, nonlinear, get, number, unsuccessful, steps
1258: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1259: @*/
1260: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1261: {
1265: *nfails = snes->numLinearSolveFailures;
1266: return(0);
1267: }
1271: /*@
1272: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1273: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1275: Logically Collective on SNES
1277: Input Parameters:
1278: + snes - SNES context
1279: - maxFails - maximum allowed linear solve failures
1281: Level: intermediate
1283: Options Database Keys:
1284: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1286: Notes: By default this is 0; that is SNES returns on the first failed linear solve
1288: .keywords: SNES, nonlinear, set, maximum, unsuccessful, steps
1290: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1291: @*/
1292: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1293: {
1297: snes->maxLinearSolveFailures = maxFails;
1298: return(0);
1299: }
1303: /*@
1304: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1305: are allowed before SNES terminates
1307: Not Collective
1309: Input Parameter:
1310: . snes - SNES context
1312: Output Parameter:
1313: . maxFails - maximum of unsuccessful solves allowed
1315: Level: intermediate
1317: Notes: By default this is 1; that is SNES returns on the first failed linear solve
1319: .keywords: SNES, nonlinear, get, maximum, unsuccessful, steps
1321: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1322: @*/
1323: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1324: {
1328: *maxFails = snes->maxLinearSolveFailures;
1329: return(0);
1330: }
1334: /*@
1335: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1336: used by the nonlinear solver.
1338: Not Collective
1340: Input Parameter:
1341: . snes - SNES context
1343: Output Parameter:
1344: . lits - number of linear iterations
1346: Notes:
1347: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1349: 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
1350: then call KSPGetIterationNumber() after the failed solve.
1352: Level: intermediate
1354: .keywords: SNES, nonlinear, get, number, linear, iterations
1356: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1357: @*/
1358: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1359: {
1363: *lits = snes->linear_its;
1364: return(0);
1365: }
1369: /*@
1370: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1371: are reset every time SNESSolve() is called.
1373: Logically Collective on SNES
1375: Input Parameter:
1376: + snes - SNES context
1377: - reset - whether to reset the counters or not
1379: Notes:
1380: This defaults to PETSC_TRUE
1382: Level: developer
1384: .keywords: SNES, nonlinear, set, reset, number, linear, iterations
1386: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1387: @*/
1388: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1389: {
1393: snes->counters_reset = reset;
1394: return(0);
1395: }
1400: /*@
1401: SNESSetKSP - Sets a KSP context for the SNES object to use
1403: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1405: Input Parameters:
1406: + snes - the SNES context
1407: - ksp - the KSP context
1409: Notes:
1410: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1411: so this routine is rarely needed.
1413: The KSP object that is already in the SNES object has its reference count
1414: decreased by one.
1416: Level: developer
1418: .keywords: SNES, nonlinear, get, KSP, context
1420: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1421: @*/
1422: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1423: {
1430: PetscObjectReference((PetscObject)ksp);
1431: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1432: snes->ksp = ksp;
1433: return(0);
1434: }
1436: /* -----------------------------------------------------------*/
1439: /*@
1440: SNESCreate - Creates a nonlinear solver context.
1442: Collective on MPI_Comm
1444: Input Parameters:
1445: . comm - MPI communicator
1447: Output Parameter:
1448: . outsnes - the new SNES context
1450: Options Database Keys:
1451: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1452: and no preconditioning matrix
1453: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1454: products, and a user-provided preconditioning matrix
1455: as set by SNESSetJacobian()
1456: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1458: Level: beginner
1460: .keywords: SNES, nonlinear, create, context
1462: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1464: @*/
1465: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1466: {
1468: SNES snes;
1469: SNESKSPEW *kctx;
1473: *outsnes = NULL;
1474: SNESInitializePackage();
1476: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1478: snes->ops->converged = SNESConvergedDefault;
1479: snes->usesksp = PETSC_TRUE;
1480: snes->tolerancesset = PETSC_FALSE;
1481: snes->max_its = 50;
1482: snes->max_funcs = 10000;
1483: snes->norm = 0.0;
1484: snes->normschedule = SNES_NORM_ALWAYS;
1485: snes->functype = SNES_FUNCTION_DEFAULT;
1486: #if defined(PETSC_USE_REAL_SINGLE)
1487: snes->rtol = 1.e-5;
1488: #else
1489: snes->rtol = 1.e-8;
1490: #endif
1491: snes->ttol = 0.0;
1492: #if defined(PETSC_USE_REAL_SINGLE)
1493: snes->abstol = 1.e-25;
1494: #else
1495: snes->abstol = 1.e-50;
1496: #endif
1497: #if defined(PETSC_USE_REAL_SINGLE)
1498: snes->stol = 1.e-5;
1499: #else
1500: snes->stol = 1.e-8;
1501: #endif
1502: #if defined(PETSC_USE_REAL_SINGLE)
1503: snes->deltatol = 1.e-6;
1504: #else
1505: snes->deltatol = 1.e-12;
1506: #endif
1507: snes->nfuncs = 0;
1508: snes->numFailures = 0;
1509: snes->maxFailures = 1;
1510: snes->linear_its = 0;
1511: snes->lagjacobian = 1;
1512: snes->jac_iter = 0;
1513: snes->lagjac_persist = PETSC_FALSE;
1514: snes->lagpreconditioner = 1;
1515: snes->pre_iter = 0;
1516: snes->lagpre_persist = PETSC_FALSE;
1517: snes->numbermonitors = 0;
1518: snes->data = 0;
1519: snes->setupcalled = PETSC_FALSE;
1520: snes->ksp_ewconv = PETSC_FALSE;
1521: snes->nwork = 0;
1522: snes->work = 0;
1523: snes->nvwork = 0;
1524: snes->vwork = 0;
1525: snes->conv_hist_len = 0;
1526: snes->conv_hist_max = 0;
1527: snes->conv_hist = NULL;
1528: snes->conv_hist_its = NULL;
1529: snes->conv_hist_reset = PETSC_TRUE;
1530: snes->counters_reset = PETSC_TRUE;
1531: snes->vec_func_init_set = PETSC_FALSE;
1532: snes->reason = SNES_CONVERGED_ITERATING;
1533: snes->pcside = PC_RIGHT;
1535: snes->mf = PETSC_FALSE;
1536: snes->mf_operator = PETSC_FALSE;
1537: snes->mf_version = 1;
1539: snes->numLinearSolveFailures = 0;
1540: snes->maxLinearSolveFailures = 1;
1542: snes->vizerotolerance = 1.e-8;
1544: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1545: PetscNewLog(snes,&kctx);
1547: snes->kspconvctx = (void*)kctx;
1548: kctx->version = 2;
1549: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1550: this was too large for some test cases */
1551: kctx->rtol_last = 0.0;
1552: kctx->rtol_max = .9;
1553: kctx->gamma = 1.0;
1554: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1555: kctx->alpha2 = kctx->alpha;
1556: kctx->threshold = .1;
1557: kctx->lresid_last = 0.0;
1558: kctx->norm_last = 0.0;
1560: *outsnes = snes;
1561: return(0);
1562: }
1564: /*MC
1565: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1567: Synopsis:
1568: #include "petscsnes.h"
1569: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1571: Input Parameters:
1572: + snes - the SNES context
1573: . x - state at which to evaluate residual
1574: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1576: Output Parameter:
1577: . f - vector to put residual (function value)
1579: Level: intermediate
1581: .seealso: SNESSetFunction(), SNESGetFunction()
1582: M*/
1586: /*@C
1587: SNESSetFunction - Sets the function evaluation routine and function
1588: vector for use by the SNES routines in solving systems of nonlinear
1589: equations.
1591: Logically Collective on SNES
1593: Input Parameters:
1594: + snes - the SNES context
1595: . r - vector to store function value
1596: . f - function evaluation routine; see SNESFunction for calling sequence details
1597: - ctx - [optional] user-defined context for private data for the
1598: function evaluation routine (may be NULL)
1600: Notes:
1601: The Newton-like methods typically solve linear systems of the form
1602: $ f'(x) x = -f(x),
1603: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1605: Level: beginner
1607: .keywords: SNES, nonlinear, set, function
1609: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1610: @*/
1611: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1612: {
1614: DM dm;
1618: if (r) {
1621: PetscObjectReference((PetscObject)r);
1622: VecDestroy(&snes->vec_func);
1624: snes->vec_func = r;
1625: }
1626: SNESGetDM(snes,&dm);
1627: DMSNESSetFunction(dm,f,ctx);
1628: return(0);
1629: }
1634: /*@C
1635: SNESSetInitialFunction - Sets the function vector to be used as the
1636: function norm at the initialization of the method. In some
1637: instances, the user has precomputed the function before calling
1638: SNESSolve. This function allows one to avoid a redundant call
1639: to SNESComputeFunction in that case.
1641: Logically Collective on SNES
1643: Input Parameters:
1644: + snes - the SNES context
1645: - f - vector to store function value
1647: Notes:
1648: This should not be modified during the solution procedure.
1650: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1652: Level: developer
1654: .keywords: SNES, nonlinear, set, function
1656: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1657: @*/
1658: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1659: {
1661: Vec vec_func;
1667: if (snes->pcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1668: snes->vec_func_init_set = PETSC_FALSE;
1669: return(0);
1670: }
1671: SNESGetFunction(snes,&vec_func,NULL,NULL);
1672: VecCopy(f, vec_func);
1674: snes->vec_func_init_set = PETSC_TRUE;
1675: return(0);
1676: }
1680: /*@
1681: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1682: of the SNES method.
1684: Logically Collective on SNES
1686: Input Parameters:
1687: + snes - the SNES context
1688: - normschedule - the frequency of norm computation
1690: Options Database Key:
1691: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1693: Notes:
1694: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1695: of the nonlinear function and the taking of its norm at every iteration to
1696: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1697: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1698: may either be monitored for convergence or not. As these are often used as nonlinear
1699: preconditioners, monitoring the norm of their error is not a useful enterprise within
1700: their solution.
1702: Level: developer
1704: .keywords: SNES, nonlinear, set, function, norm, type
1706: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1707: @*/
1708: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1709: {
1712: snes->normschedule = normschedule;
1713: return(0);
1714: }
1719: /*@
1720: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1721: of the SNES method.
1723: Logically Collective on SNES
1725: Input Parameters:
1726: + snes - the SNES context
1727: - normschedule - the type of the norm used
1729: Level: advanced
1731: .keywords: SNES, nonlinear, set, function, norm, type
1733: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1734: @*/
1735: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1736: {
1739: *normschedule = snes->normschedule;
1740: return(0);
1741: }
1746: /*@
1747: SNESSetFunctionNorm - Sets the last computed residual norm.
1749: Logically Collective on SNES
1751: Input Parameters:
1752: + snes - the SNES context
1754: - normschedule - the frequency of norm computation
1756: Level: developer
1758: .keywords: SNES, nonlinear, set, function, norm, type
1759: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1760: @*/
1761: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1762: {
1765: snes->norm = norm;
1766: return(0);
1767: }
1771: /*@
1772: SNESGetFunctionNorm - Gets the last computed norm of the residual
1774: Not Collective
1776: Input Parameter:
1777: . snes - the SNES context
1779: Output Parameter:
1780: . norm - the last computed residual norm
1782: Level: developer
1784: .keywords: SNES, nonlinear, set, function, norm, type
1785: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1786: @*/
1787: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1788: {
1792: *norm = snes->norm;
1793: return(0);
1794: }
1798: /*@C
1799: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
1800: of the SNES method.
1802: Logically Collective on SNES
1804: Input Parameters:
1805: + snes - the SNES context
1806: - normschedule - the frequency of norm computation
1808: Notes:
1809: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1810: of the nonlinear function and the taking of its norm at every iteration to
1811: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1812: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1813: may either be monitored for convergence or not. As these are often used as nonlinear
1814: preconditioners, monitoring the norm of their error is not a useful enterprise within
1815: their solution.
1817: Level: developer
1819: .keywords: SNES, nonlinear, set, function, norm, type
1821: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1822: @*/
1823: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
1824: {
1827: snes->functype = type;
1828: return(0);
1829: }
1834: /*@C
1835: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
1836: of the SNES method.
1838: Logically Collective on SNES
1840: Input Parameters:
1841: + snes - the SNES context
1842: - normschedule - the type of the norm used
1844: Level: advanced
1846: .keywords: SNES, nonlinear, set, function, norm, type
1848: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1849: @*/
1850: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
1851: {
1854: *type = snes->functype;
1855: return(0);
1856: }
1858: /*MC
1859: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
1861: Synopsis:
1862: #include <petscsnes.h>
1863: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
1865: + X - solution vector
1866: . B - RHS vector
1867: - ctx - optional user-defined Gauss-Seidel context
1869: Level: intermediate
1871: .seealso: SNESSetNGS(), SNESGetNGS()
1872: M*/
1876: /*@C
1877: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
1878: use with composed nonlinear solvers.
1880: Input Parameters:
1881: + snes - the SNES context
1882: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
1883: - ctx - [optional] user-defined context for private data for the
1884: smoother evaluation routine (may be NULL)
1886: Notes:
1887: The NGS routines are used by the composed nonlinear solver to generate
1888: a problem appropriate update to the solution, particularly FAS.
1890: Level: intermediate
1892: .keywords: SNES, nonlinear, set, Gauss-Seidel
1894: .seealso: SNESGetFunction(), SNESComputeNGS()
1895: @*/
1896: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1897: {
1899: DM dm;
1903: SNESGetDM(snes,&dm);
1904: DMSNESSetNGS(dm,f,ctx);
1905: return(0);
1906: }
1910: PETSC_EXTERN PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
1911: {
1913: DM dm;
1914: DMSNES sdm;
1917: SNESGetDM(snes,&dm);
1918: DMGetDMSNES(dm,&sdm);
1919: /* A(x)*x - b(x) */
1920: if (sdm->ops->computepfunction) {
1921: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
1922: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
1924: if (sdm->ops->computepjacobian) {
1925: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
1926: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard matrix.");
1927: VecScale(f,-1.0);
1928: MatMultAdd(snes->jacobian,x,f,f);
1929: return(0);
1930: }
1934: PETSC_EXTERN PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
1935: {
1937: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
1938: return(0);
1939: }
1943: /*@C
1944: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
1946: Logically Collective on SNES
1948: Input Parameters:
1949: + snes - the SNES context
1950: . r - vector to store function value
1951: . b - function evaluation routine
1952: . Amat - matrix with which A(x) x - b(x) is to be computed
1953: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
1954: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
1955: - ctx - [optional] user-defined context for private data for the
1956: function evaluation routine (may be NULL)
1958: Notes:
1959: 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
1960: 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.
1962: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
1964: $ 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}
1965: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
1967: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
1969: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
1970: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
1972: 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
1973: 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
1974: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
1976: Level: intermediate
1978: .keywords: SNES, nonlinear, set, function
1980: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
1981: @*/
1982: 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)
1983: {
1985: DM dm;
1989: SNESGetDM(snes, &dm);
1990: DMSNESSetPicard(dm,b,J,ctx);
1991: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
1992: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
1993: return(0);
1994: }
1998: /*@C
1999: SNESGetPicard - Returns the context for the Picard iteration
2001: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2003: Input Parameter:
2004: . snes - the SNES context
2006: Output Parameter:
2007: + r - the function (or NULL)
2008: . f - the function (or NULL); see SNESFunction for calling sequence details
2009: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2010: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2011: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2012: - ctx - the function context (or NULL)
2014: Level: advanced
2016: .keywords: SNES, nonlinear, get, function
2018: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2019: @*/
2020: 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)
2021: {
2023: DM dm;
2027: SNESGetFunction(snes,r,NULL,NULL);
2028: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2029: SNESGetDM(snes,&dm);
2030: DMSNESGetPicard(dm,f,J,ctx);
2031: return(0);
2032: }
2036: /*@C
2037: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2039: Logically Collective on SNES
2041: Input Parameters:
2042: + snes - the SNES context
2043: . func - function evaluation routine
2044: - ctx - [optional] user-defined context for private data for the
2045: function evaluation routine (may be NULL)
2047: Calling sequence of func:
2048: $ func (SNES snes,Vec x,void *ctx);
2050: . f - function vector
2051: - ctx - optional user-defined function context
2053: Level: intermediate
2055: .keywords: SNES, nonlinear, set, function
2057: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2058: @*/
2059: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2060: {
2063: if (func) snes->ops->computeinitialguess = func;
2064: if (ctx) snes->initialguessP = ctx;
2065: return(0);
2066: }
2068: /* --------------------------------------------------------------- */
2071: /*@C
2072: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2073: it assumes a zero right hand side.
2075: Logically Collective on SNES
2077: Input Parameter:
2078: . snes - the SNES context
2080: Output Parameter:
2081: . rhs - the right hand side vector or NULL if the right hand side vector is null
2083: Level: intermediate
2085: .keywords: SNES, nonlinear, get, function, right hand side
2087: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2088: @*/
2089: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2090: {
2094: *rhs = snes->vec_rhs;
2095: return(0);
2096: }
2100: /*@
2101: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2103: Collective on SNES
2105: Input Parameters:
2106: + snes - the SNES context
2107: - x - input vector
2109: Output Parameter:
2110: . y - function vector, as set by SNESSetFunction()
2112: Notes:
2113: SNESComputeFunction() is typically used within nonlinear solvers
2114: implementations, so most users would not generally call this routine
2115: themselves.
2117: Level: developer
2119: .keywords: SNES, nonlinear, compute, function
2121: .seealso: SNESSetFunction(), SNESGetFunction()
2122: @*/
2123: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2124: {
2126: DM dm;
2127: DMSNES sdm;
2135: VecValidValues(x,2,PETSC_TRUE);
2137: SNESGetDM(snes,&dm);
2138: DMGetDMSNES(dm,&sdm);
2139: if (sdm->ops->computefunction) {
2140: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2141: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2142: }
2143: VecLockPush(x);
2144: PetscStackPush("SNES user function");
2145: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2146: PetscStackPop;
2147: VecLockPop(x);
2148: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2149: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2150: }
2151: } else if (snes->vec_rhs) {
2152: MatMult(snes->jacobian, x, y);
2153: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2154: if (snes->vec_rhs) {
2155: VecAXPY(y,-1.0,snes->vec_rhs);
2156: }
2157: snes->nfuncs++;
2158: /*
2159: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2160: propagate the value to all processes
2161: */
2162: if (snes->domainerror) {
2163: VecSetInf(y);
2164: }
2165: return(0);
2166: }
2170: /*@
2171: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2173: Collective on SNES
2175: Input Parameters:
2176: + snes - the SNES context
2177: . x - input vector
2178: - b - rhs vector
2180: Output Parameter:
2181: . x - new solution vector
2183: Notes:
2184: SNESComputeNGS() is typically used within composed nonlinear solver
2185: implementations, so most users would not generally call this routine
2186: themselves.
2188: Level: developer
2190: .keywords: SNES, nonlinear, compute, function
2192: .seealso: SNESSetNGS(), SNESComputeFunction()
2193: @*/
2194: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2195: {
2197: DM dm;
2198: DMSNES sdm;
2206: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2207: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2208: SNESGetDM(snes,&dm);
2209: DMGetDMSNES(dm,&sdm);
2210: if (sdm->ops->computegs) {
2211: if (b) {VecLockPush(b);}
2212: PetscStackPush("SNES user NGS");
2213: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2214: PetscStackPop;
2215: if (b) {VecLockPop(b);}
2216: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2217: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2218: return(0);
2219: }
2223: /*@
2224: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2226: Collective on SNES and Mat
2228: Input Parameters:
2229: + snes - the SNES context
2230: - x - input vector
2232: Output Parameters:
2233: + A - Jacobian matrix
2234: - B - optional preconditioning matrix
2236: Options Database Keys:
2237: + -snes_lag_preconditioner <lag>
2238: . -snes_lag_jacobian <lag>
2239: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2240: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2241: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2242: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2243: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2244: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2245: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2246: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2247: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2248: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2249: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2252: Notes:
2253: Most users should not need to explicitly call this routine, as it
2254: is used internally within the nonlinear solvers.
2256: Level: developer
2258: .keywords: SNES, compute, Jacobian, matrix
2260: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2261: @*/
2262: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2263: {
2265: PetscBool flag;
2266: DM dm;
2267: DMSNES sdm;
2268: KSP ksp;
2274: VecValidValues(X,2,PETSC_TRUE);
2275: SNESGetDM(snes,&dm);
2276: DMGetDMSNES(dm,&sdm);
2278: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2280: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2282: if (snes->lagjacobian == -2) {
2283: snes->lagjacobian = -1;
2285: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2286: } else if (snes->lagjacobian == -1) {
2287: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2288: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2289: if (flag) {
2290: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2291: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2292: }
2293: return(0);
2294: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2295: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2296: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2297: if (flag) {
2298: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2299: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2300: }
2301: return(0);
2302: }
2303: if (snes->pc && snes->pcside == PC_LEFT) {
2304: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2305: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2306: return(0);
2307: }
2309: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2310: VecLockPush(X);
2311: PetscStackPush("SNES user Jacobian function");
2312: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2313: PetscStackPop;
2314: VecLockPop(X);
2315: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2317: /* the next line ensures that snes->ksp exists */
2318: SNESGetKSP(snes,&ksp);
2319: if (snes->lagpreconditioner == -2) {
2320: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2321: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2322: snes->lagpreconditioner = -1;
2323: } else if (snes->lagpreconditioner == -1) {
2324: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2325: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2326: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2327: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2328: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2329: } else {
2330: PetscInfo(snes,"Rebuilding preconditioner\n");
2331: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2332: }
2334: /* make sure user returned a correct Jacobian and preconditioner */
2337: {
2338: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2339: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2340: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2341: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2342: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2343: if (flag || flag_draw || flag_contour) {
2344: Mat Bexp_mine = NULL,Bexp,FDexp;
2345: PetscViewer vdraw,vstdout;
2346: PetscBool flg;
2347: if (flag_operator) {
2348: MatComputeExplicitOperator(A,&Bexp_mine);
2349: Bexp = Bexp_mine;
2350: } else {
2351: /* See if the preconditioning matrix can be viewed and added directly */
2352: PetscObjectTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2353: if (flg) Bexp = B;
2354: else {
2355: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2356: MatComputeExplicitOperator(B,&Bexp_mine);
2357: Bexp = Bexp_mine;
2358: }
2359: }
2360: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2361: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2362: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2363: if (flag_draw || flag_contour) {
2364: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2365: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2366: } else vdraw = NULL;
2367: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2368: if (flag) {MatView(Bexp,vstdout);}
2369: if (vdraw) {MatView(Bexp,vdraw);}
2370: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2371: if (flag) {MatView(FDexp,vstdout);}
2372: if (vdraw) {MatView(FDexp,vdraw);}
2373: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2374: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2375: if (flag) {MatView(FDexp,vstdout);}
2376: if (vdraw) { /* Always use contour for the difference */
2377: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2378: MatView(FDexp,vdraw);
2379: PetscViewerPopFormat(vdraw);
2380: }
2381: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2382: PetscViewerDestroy(&vdraw);
2383: MatDestroy(&Bexp_mine);
2384: MatDestroy(&FDexp);
2385: }
2386: }
2387: {
2388: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2389: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2390: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2391: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2392: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2393: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2394: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2395: if (flag_threshold) {
2396: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2397: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2398: }
2399: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2400: Mat Bfd;
2401: PetscViewer vdraw,vstdout;
2402: MatColoring coloring;
2403: ISColoring iscoloring;
2404: MatFDColoring matfdcoloring;
2405: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2406: void *funcctx;
2407: PetscReal norm1,norm2,normmax;
2409: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2410: MatColoringCreate(Bfd,&coloring);
2411: MatColoringSetType(coloring,MATCOLORINGSL);
2412: MatColoringSetFromOptions(coloring);
2413: MatColoringApply(coloring,&iscoloring);
2414: MatColoringDestroy(&coloring);
2415: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2416: MatFDColoringSetFromOptions(matfdcoloring);
2417: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2418: ISColoringDestroy(&iscoloring);
2420: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2421: SNESGetFunction(snes,NULL,&func,&funcctx);
2422: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2423: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2424: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2425: MatFDColoringSetFromOptions(matfdcoloring);
2426: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2427: MatFDColoringDestroy(&matfdcoloring);
2429: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2430: if (flag_draw || flag_contour) {
2431: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2432: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2433: } else vdraw = NULL;
2434: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2435: if (flag_display) {MatView(B,vstdout);}
2436: if (vdraw) {MatView(B,vdraw);}
2437: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2438: if (flag_display) {MatView(Bfd,vstdout);}
2439: if (vdraw) {MatView(Bfd,vdraw);}
2440: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2441: MatNorm(Bfd,NORM_1,&norm1);
2442: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2443: MatNorm(Bfd,NORM_MAX,&normmax);
2444: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2445: if (flag_display) {MatView(Bfd,vstdout);}
2446: if (vdraw) { /* Always use contour for the difference */
2447: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2448: MatView(Bfd,vdraw);
2449: PetscViewerPopFormat(vdraw);
2450: }
2451: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2453: if (flag_threshold) {
2454: PetscInt bs,rstart,rend,i;
2455: MatGetBlockSize(B,&bs);
2456: MatGetOwnershipRange(B,&rstart,&rend);
2457: for (i=rstart; i<rend; i++) {
2458: const PetscScalar *ba,*ca;
2459: const PetscInt *bj,*cj;
2460: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2461: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2462: MatGetRow(B,i,&bn,&bj,&ba);
2463: MatGetRow(Bfd,i,&cn,&cj,&ca);
2464: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2465: for (j=0; j<bn; j++) {
2466: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2467: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2468: maxentrycol = bj[j];
2469: maxentry = PetscRealPart(ba[j]);
2470: }
2471: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2472: maxdiffcol = bj[j];
2473: maxdiff = PetscRealPart(ca[j]);
2474: }
2475: if (rdiff > maxrdiff) {
2476: maxrdiffcol = bj[j];
2477: maxrdiff = rdiff;
2478: }
2479: }
2480: if (maxrdiff > 1) {
2481: 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);
2482: for (j=0; j<bn; j++) {
2483: PetscReal rdiff;
2484: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2485: if (rdiff > 1) {
2486: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2487: }
2488: }
2489: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2490: }
2491: MatRestoreRow(B,i,&bn,&bj,&ba);
2492: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2493: }
2494: }
2495: PetscViewerDestroy(&vdraw);
2496: MatDestroy(&Bfd);
2497: }
2498: }
2499: return(0);
2500: }
2502: /*MC
2503: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2505: Synopsis:
2506: #include "petscsnes.h"
2507: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2509: + x - input vector
2510: . Amat - the matrix that defines the (approximate) Jacobian
2511: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2512: - ctx - [optional] user-defined Jacobian context
2514: Level: intermediate
2516: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2517: M*/
2521: /*@C
2522: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2523: location to store the matrix.
2525: Logically Collective on SNES and Mat
2527: Input Parameters:
2528: + snes - the SNES context
2529: . Amat - the matrix that defines the (approximate) Jacobian
2530: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2531: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2532: - ctx - [optional] user-defined context for private data for the
2533: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2535: Notes:
2536: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2537: each matrix.
2539: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2540: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2542: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2543: must be a MatFDColoring.
2545: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2546: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2548: Level: beginner
2550: .keywords: SNES, nonlinear, set, Jacobian, matrix
2552: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2553: SNESSetPicard(), SNESJacobianFunction
2554: @*/
2555: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2556: {
2558: DM dm;
2566: SNESGetDM(snes,&dm);
2567: DMSNESSetJacobian(dm,J,ctx);
2568: if (Amat) {
2569: PetscObjectReference((PetscObject)Amat);
2570: MatDestroy(&snes->jacobian);
2572: snes->jacobian = Amat;
2573: }
2574: if (Pmat) {
2575: PetscObjectReference((PetscObject)Pmat);
2576: MatDestroy(&snes->jacobian_pre);
2578: snes->jacobian_pre = Pmat;
2579: }
2580: return(0);
2581: }
2585: /*@C
2586: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2587: provided context for evaluating the Jacobian.
2589: Not Collective, but Mat object will be parallel if SNES object is
2591: Input Parameter:
2592: . snes - the nonlinear solver context
2594: Output Parameters:
2595: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2596: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2597: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2598: - ctx - location to stash Jacobian ctx (or NULL)
2600: Level: advanced
2602: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2603: @*/
2604: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2605: {
2607: DM dm;
2608: DMSNES sdm;
2612: if (Amat) *Amat = snes->jacobian;
2613: if (Pmat) *Pmat = snes->jacobian_pre;
2614: SNESGetDM(snes,&dm);
2615: DMGetDMSNES(dm,&sdm);
2616: if (J) *J = sdm->ops->computejacobian;
2617: if (ctx) *ctx = sdm->jacobianctx;
2618: return(0);
2619: }
2623: /*@
2624: SNESSetUp - Sets up the internal data structures for the later use
2625: of a nonlinear solver.
2627: Collective on SNES
2629: Input Parameters:
2630: . snes - the SNES context
2632: Notes:
2633: For basic use of the SNES solvers the user need not explicitly call
2634: SNESSetUp(), since these actions will automatically occur during
2635: the call to SNESSolve(). However, if one wishes to control this
2636: phase separately, SNESSetUp() should be called after SNESCreate()
2637: and optional routines of the form SNESSetXXX(), but before SNESSolve().
2639: Level: advanced
2641: .keywords: SNES, nonlinear, setup
2643: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
2644: @*/
2645: PetscErrorCode SNESSetUp(SNES snes)
2646: {
2648: DM dm;
2649: DMSNES sdm;
2650: SNESLineSearch linesearch, pclinesearch;
2651: void *lsprectx,*lspostctx;
2652: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
2653: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
2654: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2655: Vec f,fpc;
2656: void *funcctx;
2657: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
2658: void *jacctx,*appctx;
2659: Mat j,jpre;
2663: if (snes->setupcalled) return(0);
2665: if (!((PetscObject)snes)->type_name) {
2666: SNESSetType(snes,SNESNEWTONLS);
2667: }
2669: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
2671: SNESGetDM(snes,&dm);
2672: DMGetDMSNES(dm,&sdm);
2673: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
2674: if (!sdm->ops->computejacobian) {
2675: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
2676: }
2677: if (!snes->vec_func) {
2678: DMCreateGlobalVector(dm,&snes->vec_func);
2679: }
2681: if (!snes->ksp) {
2682: SNESGetKSP(snes, &snes->ksp);
2683: }
2685: if (!snes->linesearch) {
2686: SNESGetLineSearch(snes, &snes->linesearch);
2687: }
2688: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
2690: if (snes->pc && (snes->pcside == PC_LEFT)) {
2691: snes->mf = PETSC_TRUE;
2692: snes->mf_operator = PETSC_FALSE;
2693: }
2695: if (snes->pc) {
2696: /* copy the DM over */
2697: SNESGetDM(snes,&dm);
2698: SNESSetDM(snes->pc,dm);
2700: SNESGetFunction(snes,&f,&func,&funcctx);
2701: VecDuplicate(f,&fpc);
2702: SNESSetFunction(snes->pc,fpc,func,funcctx);
2703: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
2704: SNESSetJacobian(snes->pc,j,jpre,jac,jacctx);
2705: SNESGetApplicationContext(snes,&appctx);
2706: SNESSetApplicationContext(snes->pc,appctx);
2707: VecDestroy(&fpc);
2709: /* copy the function pointers over */
2710: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->pc);
2712: /* default to 1 iteration */
2713: SNESSetTolerances(snes->pc,0.0,0.0,0.0,1,snes->pc->max_funcs);
2714: if (snes->pcside==PC_RIGHT) {
2715: SNESSetNormSchedule(snes->pc,SNES_NORM_FINAL_ONLY);
2716: } else {
2717: SNESSetNormSchedule(snes->pc,SNES_NORM_NONE);
2718: }
2719: SNESSetFromOptions(snes->pc);
2721: /* copy the line search context over */
2722: SNESGetLineSearch(snes,&linesearch);
2723: SNESGetLineSearch(snes->pc,&pclinesearch);
2724: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
2725: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
2726: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
2727: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
2728: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
2729: }
2730: if (snes->mf) {
2731: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
2732: }
2733: if (snes->ops->usercompute && !snes->user) {
2734: (*snes->ops->usercompute)(snes,(void**)&snes->user);
2735: }
2737: snes->jac_iter = 0;
2738: snes->pre_iter = 0;
2740: if (snes->ops->setup) {
2741: (*snes->ops->setup)(snes);
2742: }
2744: if (snes->pc && (snes->pcside == PC_LEFT)) {
2745: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
2746: SNESGetLineSearch(snes,&linesearch);
2747: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
2748: }
2749: }
2751: snes->setupcalled = PETSC_TRUE;
2752: return(0);
2753: }
2757: /*@
2758: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
2760: Collective on SNES
2762: Input Parameter:
2763: . snes - iterative context obtained from SNESCreate()
2765: Level: intermediate
2767: Notes: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
2769: .keywords: SNES, destroy
2771: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
2772: @*/
2773: PetscErrorCode SNESReset(SNES snes)
2774: {
2779: if (snes->ops->userdestroy && snes->user) {
2780: (*snes->ops->userdestroy)((void**)&snes->user);
2781: snes->user = NULL;
2782: }
2783: if (snes->pc) {
2784: SNESReset(snes->pc);
2785: }
2787: if (snes->ops->reset) {
2788: (*snes->ops->reset)(snes);
2789: }
2790: if (snes->ksp) {
2791: KSPReset(snes->ksp);
2792: }
2794: if (snes->linesearch) {
2795: SNESLineSearchReset(snes->linesearch);
2796: }
2798: VecDestroy(&snes->vec_rhs);
2799: VecDestroy(&snes->vec_sol);
2800: VecDestroy(&snes->vec_sol_update);
2801: VecDestroy(&snes->vec_func);
2802: MatDestroy(&snes->jacobian);
2803: MatDestroy(&snes->jacobian_pre);
2804: VecDestroyVecs(snes->nwork,&snes->work);
2805: VecDestroyVecs(snes->nvwork,&snes->vwork);
2807: snes->nwork = snes->nvwork = 0;
2808: snes->setupcalled = PETSC_FALSE;
2809: return(0);
2810: }
2814: /*@
2815: SNESDestroy - Destroys the nonlinear solver context that was created
2816: with SNESCreate().
2818: Collective on SNES
2820: Input Parameter:
2821: . snes - the SNES context
2823: Level: beginner
2825: .keywords: SNES, nonlinear, destroy
2827: .seealso: SNESCreate(), SNESSolve()
2828: @*/
2829: PetscErrorCode SNESDestroy(SNES *snes)
2830: {
2834: if (!*snes) return(0);
2836: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
2838: SNESReset((*snes));
2839: SNESDestroy(&(*snes)->pc);
2841: /* if memory was published with SAWs then destroy it */
2842: PetscObjectSAWsViewOff((PetscObject)*snes);
2843: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
2845: DMDestroy(&(*snes)->dm);
2846: KSPDestroy(&(*snes)->ksp);
2847: SNESLineSearchDestroy(&(*snes)->linesearch);
2849: PetscFree((*snes)->kspconvctx);
2850: if ((*snes)->ops->convergeddestroy) {
2851: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
2852: }
2853: if ((*snes)->conv_malloc) {
2854: PetscFree((*snes)->conv_hist);
2855: PetscFree((*snes)->conv_hist_its);
2856: }
2857: SNESMonitorCancel((*snes));
2858: PetscHeaderDestroy(snes);
2859: return(0);
2860: }
2862: /* ----------- Routines to set solver parameters ---------- */
2866: /*@
2867: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
2869: Logically Collective on SNES
2871: Input Parameters:
2872: + snes - the SNES context
2873: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
2874: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
2876: Options Database Keys:
2877: . -snes_lag_preconditioner <lag>
2879: Notes:
2880: The default is 1
2881: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
2882: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
2884: Level: intermediate
2886: .keywords: SNES, nonlinear, set, convergence, tolerances
2888: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
2890: @*/
2891: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
2892: {
2895: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
2896: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
2898: snes->lagpreconditioner = lag;
2899: return(0);
2900: }
2904: /*@
2905: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
2907: Logically Collective on SNES
2909: Input Parameters:
2910: + snes - the SNES context
2911: - steps - the number of refinements to do, defaults to 0
2913: Options Database Keys:
2914: . -snes_grid_sequence <steps>
2916: Level: intermediate
2918: Notes:
2919: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
2921: .keywords: SNES, nonlinear, set, convergence, tolerances
2923: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
2925: @*/
2926: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
2927: {
2931: snes->gridsequence = steps;
2932: return(0);
2933: }
2937: /*@
2938: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
2940: Logically Collective on SNES
2942: Input Parameter:
2943: . snes - the SNES context
2945: Output Parameter:
2946: . steps - the number of refinements to do, defaults to 0
2948: Options Database Keys:
2949: . -snes_grid_sequence <steps>
2951: Level: intermediate
2953: Notes:
2954: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
2956: .keywords: SNES, nonlinear, set, convergence, tolerances
2958: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
2960: @*/
2961: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
2962: {
2965: *steps = snes->gridsequence;
2966: return(0);
2967: }
2971: /*@
2972: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
2974: Not Collective
2976: Input Parameter:
2977: . snes - the SNES context
2979: Output Parameter:
2980: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
2981: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
2983: Options Database Keys:
2984: . -snes_lag_preconditioner <lag>
2986: Notes:
2987: The default is 1
2988: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
2990: Level: intermediate
2992: .keywords: SNES, nonlinear, set, convergence, tolerances
2994: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
2996: @*/
2997: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
2998: {
3001: *lag = snes->lagpreconditioner;
3002: return(0);
3003: }
3007: /*@
3008: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3009: often the preconditioner is rebuilt.
3011: Logically Collective on SNES
3013: Input Parameters:
3014: + snes - the SNES context
3015: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3016: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3018: Options Database Keys:
3019: . -snes_lag_jacobian <lag>
3021: Notes:
3022: The default is 1
3023: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3024: 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
3025: at the next Newton step but never again (unless it is reset to another value)
3027: Level: intermediate
3029: .keywords: SNES, nonlinear, set, convergence, tolerances
3031: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3033: @*/
3034: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3035: {
3038: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3039: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3041: snes->lagjacobian = lag;
3042: return(0);
3043: }
3047: /*@
3048: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3050: Not Collective
3052: Input Parameter:
3053: . snes - the SNES context
3055: Output Parameter:
3056: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3057: the Jacobian is built etc.
3059: Options Database Keys:
3060: . -snes_lag_jacobian <lag>
3062: Notes:
3063: The default is 1
3064: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3066: Level: intermediate
3068: .keywords: SNES, nonlinear, set, convergence, tolerances
3070: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3072: @*/
3073: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3074: {
3077: *lag = snes->lagjacobian;
3078: return(0);
3079: }
3083: /*@
3084: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3086: Logically collective on SNES
3088: Input Parameter:
3089: + snes - the SNES context
3090: - flg - jacobian lagging persists if true
3092: Options Database Keys:
3093: . -snes_lag_jacobian_persists <flg>
3095: Notes: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3096: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3097: timesteps may present huge efficiency gains.
3099: Level: developer
3101: .keywords: SNES, nonlinear, lag
3103: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3105: @*/
3106: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3107: {
3111: snes->lagjac_persist = flg;
3112: return(0);
3113: }
3117: /*@
3118: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3120: Logically Collective on SNES
3122: Input Parameter:
3123: + snes - the SNES context
3124: - flg - preconditioner lagging persists if true
3126: Options Database Keys:
3127: . -snes_lag_jacobian_persists <flg>
3129: Notes: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3130: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3131: several timesteps may present huge efficiency gains.
3133: Level: developer
3135: .keywords: SNES, nonlinear, lag
3137: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3139: @*/
3140: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3141: {
3145: snes->lagpre_persist = flg;
3146: return(0);
3147: }
3151: /*@
3152: SNESSetTolerances - Sets various parameters used in convergence tests.
3154: Logically Collective on SNES
3156: Input Parameters:
3157: + snes - the SNES context
3158: . abstol - absolute convergence tolerance
3159: . rtol - relative convergence tolerance
3160: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3161: . maxit - maximum number of iterations
3162: - maxf - maximum number of function evaluations
3164: Options Database Keys:
3165: + -snes_atol <abstol> - Sets abstol
3166: . -snes_rtol <rtol> - Sets rtol
3167: . -snes_stol <stol> - Sets stol
3168: . -snes_max_it <maxit> - Sets maxit
3169: - -snes_max_funcs <maxf> - Sets maxf
3171: Notes:
3172: The default maximum number of iterations is 50.
3173: The default maximum number of function evaluations is 1000.
3175: Level: intermediate
3177: .keywords: SNES, nonlinear, set, convergence, tolerances
3179: .seealso: SNESSetTrustRegionTolerance()
3180: @*/
3181: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3182: {
3191: if (abstol != PETSC_DEFAULT) {
3192: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3193: snes->abstol = abstol;
3194: }
3195: if (rtol != PETSC_DEFAULT) {
3196: 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);
3197: snes->rtol = rtol;
3198: }
3199: if (stol != PETSC_DEFAULT) {
3200: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3201: snes->stol = stol;
3202: }
3203: if (maxit != PETSC_DEFAULT) {
3204: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3205: snes->max_its = maxit;
3206: }
3207: if (maxf != PETSC_DEFAULT) {
3208: if (maxf < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be non-negative",maxf);
3209: snes->max_funcs = maxf;
3210: }
3211: snes->tolerancesset = PETSC_TRUE;
3212: return(0);
3213: }
3217: /*@
3218: SNESGetTolerances - Gets various parameters used in convergence tests.
3220: Not Collective
3222: Input Parameters:
3223: + snes - the SNES context
3224: . atol - absolute convergence tolerance
3225: . rtol - relative convergence tolerance
3226: . stol - convergence tolerance in terms of the norm
3227: of the change in the solution between steps
3228: . maxit - maximum number of iterations
3229: - maxf - maximum number of function evaluations
3231: Notes:
3232: The user can specify NULL for any parameter that is not needed.
3234: Level: intermediate
3236: .keywords: SNES, nonlinear, get, convergence, tolerances
3238: .seealso: SNESSetTolerances()
3239: @*/
3240: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3241: {
3244: if (atol) *atol = snes->abstol;
3245: if (rtol) *rtol = snes->rtol;
3246: if (stol) *stol = snes->stol;
3247: if (maxit) *maxit = snes->max_its;
3248: if (maxf) *maxf = snes->max_funcs;
3249: return(0);
3250: }
3254: /*@
3255: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3257: Logically Collective on SNES
3259: Input Parameters:
3260: + snes - the SNES context
3261: - tol - tolerance
3263: Options Database Key:
3264: . -snes_trtol <tol> - Sets tol
3266: Level: intermediate
3268: .keywords: SNES, nonlinear, set, trust region, tolerance
3270: .seealso: SNESSetTolerances()
3271: @*/
3272: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3273: {
3277: snes->deltatol = tol;
3278: return(0);
3279: }
3281: /*
3282: Duplicate the lg monitors for SNES from KSP; for some reason with
3283: dynamic libraries things don't work under Sun4 if we just use
3284: macros instead of functions
3285: */
3288: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3289: {
3294: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3295: return(0);
3296: }
3300: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3301: {
3305: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3306: return(0);
3307: }
3309: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3313: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3314: {
3315: PetscDrawLG lg;
3316: PetscErrorCode ierr;
3317: PetscReal x,y,per;
3318: PetscViewer v = (PetscViewer)monctx;
3319: static PetscReal prev; /* should be in the context */
3320: PetscDraw draw;
3324: PetscViewerDrawGetDrawLG(v,0,&lg);
3325: if (!n) {PetscDrawLGReset(lg);}
3326: PetscDrawLGGetDraw(lg,&draw);
3327: PetscDrawSetTitle(draw,"Residual norm");
3328: x = (PetscReal)n;
3329: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3330: else y = -15.0;
3331: PetscDrawLGAddPoint(lg,&x,&y);
3332: if (n < 20 || !(n % 5) || snes->reason) {
3333: PetscDrawLGDraw(lg);
3334: PetscDrawLGSave(lg);
3335: }
3337: PetscViewerDrawGetDrawLG(v,1,&lg);
3338: if (!n) {PetscDrawLGReset(lg);}
3339: PetscDrawLGGetDraw(lg,&draw);
3340: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3341: SNESMonitorRange_Private(snes,n,&per);
3342: x = (PetscReal)n;
3343: y = 100.0*per;
3344: PetscDrawLGAddPoint(lg,&x,&y);
3345: if (n < 20 || !(n % 5) || snes->reason) {
3346: PetscDrawLGDraw(lg);
3347: PetscDrawLGSave(lg);
3348: }
3350: PetscViewerDrawGetDrawLG(v,2,&lg);
3351: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3352: PetscDrawLGGetDraw(lg,&draw);
3353: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3354: x = (PetscReal)n;
3355: y = (prev - rnorm)/prev;
3356: PetscDrawLGAddPoint(lg,&x,&y);
3357: if (n < 20 || !(n % 5) || snes->reason) {
3358: PetscDrawLGDraw(lg);
3359: PetscDrawLGSave(lg);
3360: }
3362: PetscViewerDrawGetDrawLG(v,3,&lg);
3363: if (!n) {PetscDrawLGReset(lg);}
3364: PetscDrawLGGetDraw(lg,&draw);
3365: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3366: x = (PetscReal)n;
3367: y = (prev - rnorm)/(prev*per);
3368: if (n > 2) { /*skip initial crazy value */
3369: PetscDrawLGAddPoint(lg,&x,&y);
3370: }
3371: if (n < 20 || !(n % 5) || snes->reason) {
3372: PetscDrawLGDraw(lg);
3373: PetscDrawLGSave(lg);
3374: }
3375: prev = rnorm;
3376: return(0);
3377: }
3381: /*@
3382: SNESMonitor - runs the user provided monitor routines, if they exist
3384: Collective on SNES
3386: Input Parameters:
3387: + snes - nonlinear solver context obtained from SNESCreate()
3388: . iter - iteration number
3389: - rnorm - relative norm of the residual
3391: Notes:
3392: This routine is called by the SNES implementations.
3393: It does not typically need to be called by the user.
3395: Level: developer
3397: .seealso: SNESMonitorSet()
3398: @*/
3399: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3400: {
3402: PetscInt i,n = snes->numbermonitors;
3405: VecLockPush(snes->vec_sol);
3406: for (i=0; i<n; i++) {
3407: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3408: }
3409: VecLockPop(snes->vec_sol);
3410: return(0);
3411: }
3413: /* ------------ Routines to set performance monitoring options ----------- */
3415: /*MC
3416: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3418: Synopsis:
3419: #include <petscsnes.h>
3420: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3422: + snes - the SNES context
3423: . its - iteration number
3424: . norm - 2-norm function value (may be estimated)
3425: - mctx - [optional] monitoring context
3427: Level: advanced
3429: .seealso: SNESMonitorSet(), SNESMonitorGet()
3430: M*/
3434: /*@C
3435: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3436: iteration of the nonlinear solver to display the iteration's
3437: progress.
3439: Logically Collective on SNES
3441: Input Parameters:
3442: + snes - the SNES context
3443: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3444: . mctx - [optional] user-defined context for private data for the
3445: monitor routine (use NULL if no context is desired)
3446: - monitordestroy - [optional] routine that frees monitor context
3447: (may be NULL)
3449: Options Database Keys:
3450: + -snes_monitor - sets SNESMonitorDefault()
3451: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3452: uses SNESMonitorLGCreate()
3453: - -snes_monitor_cancel - cancels all monitors that have
3454: been hardwired into a code by
3455: calls to SNESMonitorSet(), but
3456: does not cancel those set via
3457: the options database.
3459: Notes:
3460: Several different monitoring routines may be set by calling
3461: SNESMonitorSet() multiple times; all will be called in the
3462: order in which they were set.
3464: Fortran notes: Only a single monitor function can be set for each SNES object
3466: Level: intermediate
3468: .keywords: SNES, nonlinear, set, monitor
3470: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3471: @*/
3472: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3473: {
3474: PetscInt i;
3476: PetscBool identical;
3480: for (i=0; i<snes->numbermonitors;i++) {
3481: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3482: if (identical) return(0);
3483: }
3484: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3485: snes->monitor[snes->numbermonitors] = f;
3486: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3487: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3488: return(0);
3489: }
3493: /*@
3494: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3496: Logically Collective on SNES
3498: Input Parameters:
3499: . snes - the SNES context
3501: Options Database Key:
3502: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3503: into a code by calls to SNESMonitorSet(), but does not cancel those
3504: set via the options database
3506: Notes:
3507: There is no way to clear one specific monitor from a SNES object.
3509: Level: intermediate
3511: .keywords: SNES, nonlinear, set, monitor
3513: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3514: @*/
3515: PetscErrorCode SNESMonitorCancel(SNES snes)
3516: {
3518: PetscInt i;
3522: for (i=0; i<snes->numbermonitors; i++) {
3523: if (snes->monitordestroy[i]) {
3524: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3525: }
3526: }
3527: snes->numbermonitors = 0;
3528: return(0);
3529: }
3531: /*MC
3532: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3534: Synopsis:
3535: #include <petscsnes.h>
3536: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3538: + snes - the SNES context
3539: . it - current iteration (0 is the first and is before any Newton step)
3540: . cctx - [optional] convergence context
3541: . reason - reason for convergence/divergence
3542: . xnorm - 2-norm of current iterate
3543: . gnorm - 2-norm of current step
3544: - f - 2-norm of function
3546: Level: intermediate
3548: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3549: M*/
3553: /*@C
3554: SNESSetConvergenceTest - Sets the function that is to be used
3555: to test for convergence of the nonlinear iterative solution.
3557: Logically Collective on SNES
3559: Input Parameters:
3560: + snes - the SNES context
3561: . SNESConvergenceTestFunction - routine to test for convergence
3562: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3563: - destroy - [optional] destructor for the context (may be NULL; NULL_FUNCTION in Fortran)
3565: Level: advanced
3567: .keywords: SNES, nonlinear, set, convergence, test
3569: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3570: @*/
3571: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3572: {
3577: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3578: if (snes->ops->convergeddestroy) {
3579: (*snes->ops->convergeddestroy)(snes->cnvP);
3580: }
3581: snes->ops->converged = SNESConvergenceTestFunction;
3582: snes->ops->convergeddestroy = destroy;
3583: snes->cnvP = cctx;
3584: return(0);
3585: }
3589: /*@
3590: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
3592: Not Collective
3594: Input Parameter:
3595: . snes - the SNES context
3597: Output Parameter:
3598: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3599: manual pages for the individual convergence tests for complete lists
3601: Level: intermediate
3603: Notes: Can only be called after the call the SNESSolve() is complete.
3605: .keywords: SNES, nonlinear, set, convergence, test
3607: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
3608: @*/
3609: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
3610: {
3614: *reason = snes->reason;
3615: return(0);
3616: }
3620: /*@
3621: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
3623: Not Collective
3625: Input Parameters:
3626: + snes - the SNES context
3627: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
3628: manual pages for the individual convergence tests for complete lists
3630: Level: intermediate
3632: .keywords: SNES, nonlinear, set, convergence, test
3633: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
3634: @*/
3635: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
3636: {
3639: snes->reason = reason;
3640: return(0);
3641: }
3645: /*@
3646: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
3648: Logically Collective on SNES
3650: Input Parameters:
3651: + snes - iterative context obtained from SNESCreate()
3652: . a - array to hold history, this array will contain the function norms computed at each step
3653: . its - integer array holds the number of linear iterations for each solve.
3654: . na - size of a and its
3655: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
3656: else it continues storing new values for new nonlinear solves after the old ones
3658: Notes:
3659: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
3660: default array of length 10000 is allocated.
3662: This routine is useful, e.g., when running a code for purposes
3663: of accurate performance monitoring, when no I/O should be done
3664: during the section of code that is being timed.
3666: Level: intermediate
3668: .keywords: SNES, set, convergence, history
3670: .seealso: SNESGetConvergenceHistory()
3672: @*/
3673: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
3674: {
3681: if (!a) {
3682: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
3683: PetscCalloc1(na,&a);
3684: PetscCalloc1(na,&its);
3686: snes->conv_malloc = PETSC_TRUE;
3687: }
3688: snes->conv_hist = a;
3689: snes->conv_hist_its = its;
3690: snes->conv_hist_max = na;
3691: snes->conv_hist_len = 0;
3692: snes->conv_hist_reset = reset;
3693: return(0);
3694: }
3696: #if defined(PETSC_HAVE_MATLAB_ENGINE)
3697: #include <engine.h> /* MATLAB include file */
3698: #include <mex.h> /* MATLAB include file */
3702: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
3703: {
3704: mxArray *mat;
3705: PetscInt i;
3706: PetscReal *ar;
3709: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
3710: ar = (PetscReal*) mxGetData(mat);
3711: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
3712: PetscFunctionReturn(mat);
3713: }
3714: #endif
3718: /*@C
3719: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
3721: Not Collective
3723: Input Parameter:
3724: . snes - iterative context obtained from SNESCreate()
3726: Output Parameters:
3727: . a - array to hold history
3728: . its - integer array holds the number of linear iterations (or
3729: negative if not converged) for each solve.
3730: - na - size of a and its
3732: Notes:
3733: The calling sequence for this routine in Fortran is
3734: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
3736: This routine is useful, e.g., when running a code for purposes
3737: of accurate performance monitoring, when no I/O should be done
3738: during the section of code that is being timed.
3740: Level: intermediate
3742: .keywords: SNES, get, convergence, history
3744: .seealso: SNESSetConvergencHistory()
3746: @*/
3747: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
3748: {
3751: if (a) *a = snes->conv_hist;
3752: if (its) *its = snes->conv_hist_its;
3753: if (na) *na = snes->conv_hist_len;
3754: return(0);
3755: }
3759: /*@C
3760: SNESSetUpdate - Sets the general-purpose update function called
3761: at the beginning of every iteration of the nonlinear solve. Specifically
3762: it is called just before the Jacobian is "evaluated".
3764: Logically Collective on SNES
3766: Input Parameters:
3767: . snes - The nonlinear solver context
3768: . func - The function
3770: Calling sequence of func:
3771: . func (SNES snes, PetscInt step);
3773: . step - The current step of the iteration
3775: Level: advanced
3777: 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()
3778: This is not used by most users.
3780: .keywords: SNES, update
3782: .seealso SNESSetJacobian(), SNESSolve()
3783: @*/
3784: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
3785: {
3788: snes->ops->update = func;
3789: return(0);
3790: }
3794: /*
3795: SNESScaleStep_Private - Scales a step so that its length is less than the
3796: positive parameter delta.
3798: Input Parameters:
3799: + snes - the SNES context
3800: . y - approximate solution of linear system
3801: . fnorm - 2-norm of current function
3802: - delta - trust region size
3804: Output Parameters:
3805: + gpnorm - predicted function norm at the new point, assuming local
3806: linearization. The value is zero if the step lies within the trust
3807: region, and exceeds zero otherwise.
3808: - ynorm - 2-norm of the step
3810: Note:
3811: For non-trust region methods such as SNESNEWTONLS, the parameter delta
3812: is set to be the maximum allowable step size.
3814: .keywords: SNES, nonlinear, scale, step
3815: */
3816: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
3817: {
3818: PetscReal nrm;
3819: PetscScalar cnorm;
3827: VecNorm(y,NORM_2,&nrm);
3828: if (nrm > *delta) {
3829: nrm = *delta/nrm;
3830: *gpnorm = (1.0 - nrm)*(*fnorm);
3831: cnorm = nrm;
3832: VecScale(y,cnorm);
3833: *ynorm = *delta;
3834: } else {
3835: *gpnorm = 0.0;
3836: *ynorm = nrm;
3837: }
3838: return(0);
3839: }
3843: /*@
3844: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
3846: Collective on SNES
3848: Parameter:
3849: + snes - iterative context obtained from SNESCreate()
3850: - viewer - the viewer to display the reason
3853: Options Database Keys:
3854: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
3856: Level: beginner
3858: .keywords: SNES, solve, linear system
3860: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
3862: @*/
3863: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
3864: {
3866: PetscBool isAscii;
3869: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
3870: if (isAscii) {
3871: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
3872: if (snes->reason > 0) {
3873: if (((PetscObject) snes)->prefix) {
3874: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
3875: } else {
3876: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
3877: }
3878: } else {
3879: if (((PetscObject) snes)->prefix) {
3880: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
3881: } else {
3882: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
3883: }
3884: }
3885: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
3886: }
3887: return(0);
3888: }
3892: /*@C
3893: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
3895: Collective on SNES
3897: Input Parameters:
3898: . snes - the SNES object
3900: Level: intermediate
3902: @*/
3903: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
3904: {
3905: PetscErrorCode ierr;
3906: PetscViewer viewer;
3907: PetscBool flg;
3908: static PetscBool incall = PETSC_FALSE;
3909: PetscViewerFormat format;
3912: if (incall) return(0);
3913: incall = PETSC_TRUE;
3914: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
3915: if (flg) {
3916: PetscViewerPushFormat(viewer,format);
3917: SNESReasonView(snes,viewer);
3918: PetscViewerPopFormat(viewer);
3919: PetscViewerDestroy(&viewer);
3920: }
3921: incall = PETSC_FALSE;
3922: return(0);
3923: }
3927: /*@C
3928: SNESSolve - Solves a nonlinear system F(x) = b.
3929: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
3931: Collective on SNES
3933: Input Parameters:
3934: + snes - the SNES context
3935: . b - the constant part of the equation F(x) = b, or NULL to use zero.
3936: - x - the solution vector.
3938: Notes:
3939: The user should initialize the vector,x, with the initial guess
3940: for the nonlinear solve prior to calling SNESSolve. In particular,
3941: to employ an initial guess of zero, the user should explicitly set
3942: this vector to zero by calling VecSet().
3944: Level: beginner
3946: .keywords: SNES, nonlinear, solve
3948: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
3949: @*/
3950: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
3951: {
3952: PetscErrorCode ierr;
3953: PetscBool flg;
3954: PetscInt grid;
3955: Vec xcreated = NULL;
3956: DM dm;
3965: if (!x) {
3966: SNESGetDM(snes,&dm);
3967: DMCreateGlobalVector(dm,&xcreated);
3968: x = xcreated;
3969: }
3970: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
3972: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
3973: for (grid=0; grid<snes->gridsequence+1; grid++) {
3975: /* set solution vector */
3976: if (!grid) {PetscObjectReference((PetscObject)x);}
3977: VecDestroy(&snes->vec_sol);
3978: snes->vec_sol = x;
3979: SNESGetDM(snes,&dm);
3981: /* set affine vector if provided */
3982: if (b) { PetscObjectReference((PetscObject)b); }
3983: VecDestroy(&snes->vec_rhs);
3984: snes->vec_rhs = b;
3986: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
3987: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
3988: if (!snes->vec_sol_update /* && snes->vec_sol */) {
3989: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
3990: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
3991: }
3992: DMShellSetGlobalVector(dm,snes->vec_sol);
3993: SNESSetUp(snes);
3995: if (!grid) {
3996: if (snes->ops->computeinitialguess) {
3997: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
3998: }
3999: }
4001: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4002: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4004: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4005: (*snes->ops->solve)(snes);
4006: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4007: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4008: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4010: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4011: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4013: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4014: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4015: SNESReasonViewFromOptions(snes);
4017: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4018: if (snes->reason < 0) break;
4019: if (grid < snes->gridsequence) {
4020: DM fine;
4021: Vec xnew;
4022: Mat interp;
4024: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4025: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4026: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4027: DMCreateGlobalVector(fine,&xnew);
4028: MatInterpolate(interp,x,xnew);
4029: DMInterpolate(snes->dm,interp,fine);
4030: MatDestroy(&interp);
4031: x = xnew;
4033: SNESReset(snes);
4034: SNESSetDM(snes,fine);
4035: DMDestroy(&fine);
4036: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4037: }
4038: }
4039: SNESViewFromOptions(snes,NULL,"-snes_view");
4040: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4042: VecDestroy(&xcreated);
4043: PetscObjectSAWsBlock((PetscObject)snes);
4044: return(0);
4045: }
4047: /* --------- Internal routines for SNES Package --------- */
4051: /*@C
4052: SNESSetType - Sets the method for the nonlinear solver.
4054: Collective on SNES
4056: Input Parameters:
4057: + snes - the SNES context
4058: - type - a known method
4060: Options Database Key:
4061: . -snes_type <type> - Sets the method; use -help for a list
4062: of available methods (for instance, newtonls or newtontr)
4064: Notes:
4065: See "petsc/include/petscsnes.h" for available methods (for instance)
4066: + SNESNEWTONLS - Newton's method with line search
4067: (systems of nonlinear equations)
4068: . SNESNEWTONTR - Newton's method with trust region
4069: (systems of nonlinear equations)
4071: Normally, it is best to use the SNESSetFromOptions() command and then
4072: set the SNES solver type from the options database rather than by using
4073: this routine. Using the options database provides the user with
4074: maximum flexibility in evaluating the many nonlinear solvers.
4075: The SNESSetType() routine is provided for those situations where it
4076: is necessary to set the nonlinear solver independently of the command
4077: line or options database. This might be the case, for example, when
4078: the choice of solver changes during the execution of the program,
4079: and the user's application is taking responsibility for choosing the
4080: appropriate method.
4082: Developer Notes: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4083: the constructor in that list and calls it to create the spexific object.
4085: Level: intermediate
4087: .keywords: SNES, set, type
4089: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4091: @*/
4092: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4093: {
4094: PetscErrorCode ierr,(*r)(SNES);
4095: PetscBool match;
4101: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4102: if (match) return(0);
4104: PetscFunctionListFind(SNESList,type,&r);
4105: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4106: /* Destroy the previous private SNES context */
4107: if (snes->ops->destroy) {
4108: (*(snes)->ops->destroy)(snes);
4109: snes->ops->destroy = NULL;
4110: }
4111: /* Reinitialize function pointers in SNESOps structure */
4112: snes->ops->setup = 0;
4113: snes->ops->solve = 0;
4114: snes->ops->view = 0;
4115: snes->ops->setfromoptions = 0;
4116: snes->ops->destroy = 0;
4117: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4118: snes->setupcalled = PETSC_FALSE;
4120: PetscObjectChangeTypeName((PetscObject)snes,type);
4121: (*r)(snes);
4122: return(0);
4123: }
4127: /*@C
4128: SNESGetType - Gets the SNES method type and name (as a string).
4130: Not Collective
4132: Input Parameter:
4133: . snes - nonlinear solver context
4135: Output Parameter:
4136: . type - SNES method (a character string)
4138: Level: intermediate
4140: .keywords: SNES, nonlinear, get, type, name
4141: @*/
4142: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4143: {
4147: *type = ((PetscObject)snes)->type_name;
4148: return(0);
4149: }
4153: /*@
4154: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4156: Logically Collective on SNES and Vec
4158: Input Parameters:
4159: + snes - the SNES context obtained from SNESCreate()
4160: - u - the solution vector
4162: Level: beginner
4164: .keywords: SNES, set, solution
4165: @*/
4166: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4167: {
4168: DM dm;
4174: PetscObjectReference((PetscObject) u);
4175: VecDestroy(&snes->vec_sol);
4177: snes->vec_sol = u;
4179: SNESGetDM(snes, &dm);
4180: DMShellSetGlobalVector(dm, u);
4181: return(0);
4182: }
4186: /*@
4187: SNESGetSolution - Returns the vector where the approximate solution is
4188: stored. This is the fine grid solution when using SNESSetGridSequence().
4190: Not Collective, but Vec is parallel if SNES is parallel
4192: Input Parameter:
4193: . snes - the SNES context
4195: Output Parameter:
4196: . x - the solution
4198: Level: intermediate
4200: .keywords: SNES, nonlinear, get, solution
4202: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4203: @*/
4204: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4205: {
4209: *x = snes->vec_sol;
4210: return(0);
4211: }
4215: /*@
4216: SNESGetSolutionUpdate - Returns the vector where the solution update is
4217: stored.
4219: Not Collective, but Vec is parallel if SNES is parallel
4221: Input Parameter:
4222: . snes - the SNES context
4224: Output Parameter:
4225: . x - the solution update
4227: Level: advanced
4229: .keywords: SNES, nonlinear, get, solution, update
4231: .seealso: SNESGetSolution(), SNESGetFunction()
4232: @*/
4233: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4234: {
4238: *x = snes->vec_sol_update;
4239: return(0);
4240: }
4244: /*@C
4245: SNESGetFunction - Returns the vector where the function is stored.
4247: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4249: Input Parameter:
4250: . snes - the SNES context
4252: Output Parameter:
4253: + r - the vector that is used to store residuals (or NULL if you don't want it)
4254: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4255: - ctx - the function context (or NULL if you don't want it)
4257: Level: advanced
4259: .keywords: SNES, nonlinear, get, function
4261: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4262: @*/
4263: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4264: {
4266: DM dm;
4270: if (r) {
4271: if (!snes->vec_func) {
4272: if (snes->vec_rhs) {
4273: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4274: } else if (snes->vec_sol) {
4275: VecDuplicate(snes->vec_sol,&snes->vec_func);
4276: } else if (snes->dm) {
4277: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4278: }
4279: }
4280: *r = snes->vec_func;
4281: }
4282: SNESGetDM(snes,&dm);
4283: DMSNESGetFunction(dm,f,ctx);
4284: return(0);
4285: }
4287: /*@C
4288: SNESGetNGS - Returns the NGS function and context.
4290: Input Parameter:
4291: . snes - the SNES context
4293: Output Parameter:
4294: + f - the function (or NULL) see SNESNGSFunction for details
4295: - ctx - the function context (or NULL)
4297: Level: advanced
4299: .keywords: SNES, nonlinear, get, function
4301: .seealso: SNESSetNGS(), SNESGetFunction()
4302: @*/
4306: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4307: {
4309: DM dm;
4313: SNESGetDM(snes,&dm);
4314: DMSNESGetNGS(dm,f,ctx);
4315: return(0);
4316: }
4320: /*@C
4321: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4322: SNES options in the database.
4324: Logically Collective on SNES
4326: Input Parameter:
4327: + snes - the SNES context
4328: - prefix - the prefix to prepend to all option names
4330: Notes:
4331: A hyphen (-) must NOT be given at the beginning of the prefix name.
4332: The first character of all runtime options is AUTOMATICALLY the hyphen.
4334: Level: advanced
4336: .keywords: SNES, set, options, prefix, database
4338: .seealso: SNESSetFromOptions()
4339: @*/
4340: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4341: {
4346: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4347: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4348: if (snes->linesearch) {
4349: SNESGetLineSearch(snes,&snes->linesearch);
4350: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4351: }
4352: KSPSetOptionsPrefix(snes->ksp,prefix);
4353: return(0);
4354: }
4358: /*@C
4359: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4360: SNES options in the database.
4362: Logically Collective on SNES
4364: Input Parameters:
4365: + snes - the SNES context
4366: - prefix - the prefix to prepend to all option names
4368: Notes:
4369: A hyphen (-) must NOT be given at the beginning of the prefix name.
4370: The first character of all runtime options is AUTOMATICALLY the hyphen.
4372: Level: advanced
4374: .keywords: SNES, append, options, prefix, database
4376: .seealso: SNESGetOptionsPrefix()
4377: @*/
4378: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4379: {
4384: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4385: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4386: if (snes->linesearch) {
4387: SNESGetLineSearch(snes,&snes->linesearch);
4388: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4389: }
4390: KSPAppendOptionsPrefix(snes->ksp,prefix);
4391: return(0);
4392: }
4396: /*@C
4397: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4398: SNES options in the database.
4400: Not Collective
4402: Input Parameter:
4403: . snes - the SNES context
4405: Output Parameter:
4406: . prefix - pointer to the prefix string used
4408: Notes: On the fortran side, the user should pass in a string 'prefix' of
4409: sufficient length to hold the prefix.
4411: Level: advanced
4413: .keywords: SNES, get, options, prefix, database
4415: .seealso: SNESAppendOptionsPrefix()
4416: @*/
4417: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4418: {
4423: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4424: return(0);
4425: }
4430: /*@C
4431: SNESRegister - Adds a method to the nonlinear solver package.
4433: Not collective
4435: Input Parameters:
4436: + name_solver - name of a new user-defined solver
4437: - routine_create - routine to create method context
4439: Notes:
4440: SNESRegister() may be called multiple times to add several user-defined solvers.
4442: Sample usage:
4443: .vb
4444: SNESRegister("my_solver",MySolverCreate);
4445: .ve
4447: Then, your solver can be chosen with the procedural interface via
4448: $ SNESSetType(snes,"my_solver")
4449: or at runtime via the option
4450: $ -snes_type my_solver
4452: Level: advanced
4454: Note: If your function is not being put into a shared library then use SNESRegister() instead
4456: .keywords: SNES, nonlinear, register
4458: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4460: Level: advanced
4461: @*/
4462: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4463: {
4467: PetscFunctionListAdd(&SNESList,sname,function);
4468: return(0);
4469: }
4473: PetscErrorCode SNESTestLocalMin(SNES snes)
4474: {
4476: PetscInt N,i,j;
4477: Vec u,uh,fh;
4478: PetscScalar value;
4479: PetscReal norm;
4482: SNESGetSolution(snes,&u);
4483: VecDuplicate(u,&uh);
4484: VecDuplicate(u,&fh);
4486: /* currently only works for sequential */
4487: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4488: VecGetSize(u,&N);
4489: for (i=0; i<N; i++) {
4490: VecCopy(u,uh);
4491: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4492: for (j=-10; j<11; j++) {
4493: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4494: VecSetValue(uh,i,value,ADD_VALUES);
4495: SNESComputeFunction(snes,uh,fh);
4496: VecNorm(fh,NORM_2,&norm);
4497: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4498: value = -value;
4499: VecSetValue(uh,i,value,ADD_VALUES);
4500: }
4501: }
4502: VecDestroy(&uh);
4503: VecDestroy(&fh);
4504: return(0);
4505: }
4509: /*@
4510: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4511: computing relative tolerance for linear solvers within an inexact
4512: Newton method.
4514: Logically Collective on SNES
4516: Input Parameters:
4517: + snes - SNES context
4518: - flag - PETSC_TRUE or PETSC_FALSE
4520: Options Database:
4521: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4522: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4523: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4524: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4525: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4526: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4527: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4528: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4530: Notes:
4531: Currently, the default is to use a constant relative tolerance for
4532: the inner linear solvers. Alternatively, one can use the
4533: Eisenstat-Walker method, where the relative convergence tolerance
4534: is reset at each Newton iteration according progress of the nonlinear
4535: solver.
4537: Level: advanced
4539: Reference:
4540: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4541: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4543: .keywords: SNES, KSP, Eisenstat, Walker, convergence, test, inexact, Newton
4545: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4546: @*/
4547: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
4548: {
4552: snes->ksp_ewconv = flag;
4553: return(0);
4554: }
4558: /*@
4559: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
4560: for computing relative tolerance for linear solvers within an
4561: inexact Newton method.
4563: Not Collective
4565: Input Parameter:
4566: . snes - SNES context
4568: Output Parameter:
4569: . flag - PETSC_TRUE or PETSC_FALSE
4571: Notes:
4572: Currently, the default is to use a constant relative tolerance for
4573: the inner linear solvers. Alternatively, one can use the
4574: Eisenstat-Walker method, where the relative convergence tolerance
4575: is reset at each Newton iteration according progress of the nonlinear
4576: solver.
4578: Level: advanced
4580: Reference:
4581: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4582: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4584: .keywords: SNES, KSP, Eisenstat, Walker, convergence, test, inexact, Newton
4586: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4587: @*/
4588: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
4589: {
4593: *flag = snes->ksp_ewconv;
4594: return(0);
4595: }
4599: /*@
4600: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
4601: convergence criteria for the linear solvers within an inexact
4602: Newton method.
4604: Logically Collective on SNES
4606: Input Parameters:
4607: + snes - SNES context
4608: . version - version 1, 2 (default is 2) or 3
4609: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
4610: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
4611: . gamma - multiplicative factor for version 2 rtol computation
4612: (0 <= gamma2 <= 1)
4613: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
4614: . alpha2 - power for safeguard
4615: - threshold - threshold for imposing safeguard (0 < threshold < 1)
4617: Note:
4618: Version 3 was contributed by Luis Chacon, June 2006.
4620: Use PETSC_DEFAULT to retain the default for any of the parameters.
4622: Level: advanced
4624: Reference:
4625: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4626: inexact Newton method", Utah State University Math. Stat. Dept. Res.
4627: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
4629: .keywords: SNES, KSP, Eisenstat, Walker, set, parameters
4631: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
4632: @*/
4633: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
4634: {
4635: SNESKSPEW *kctx;
4639: kctx = (SNESKSPEW*)snes->kspconvctx;
4640: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
4649: if (version != PETSC_DEFAULT) kctx->version = version;
4650: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
4651: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
4652: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
4653: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
4654: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
4655: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
4657: 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);
4658: 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);
4659: 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);
4660: 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);
4661: 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);
4662: 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);
4663: return(0);
4664: }
4668: /*@
4669: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
4670: convergence criteria for the linear solvers within an inexact
4671: Newton method.
4673: Not Collective
4675: Input Parameters:
4676: snes - SNES context
4678: Output Parameters:
4679: + version - version 1, 2 (default is 2) or 3
4680: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
4681: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
4682: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
4683: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
4684: . alpha2 - power for safeguard
4685: - threshold - threshold for imposing safeguard (0 < threshold < 1)
4687: Level: advanced
4689: .keywords: SNES, KSP, Eisenstat, Walker, get, parameters
4691: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
4692: @*/
4693: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
4694: {
4695: SNESKSPEW *kctx;
4699: kctx = (SNESKSPEW*)snes->kspconvctx;
4700: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
4701: if (version) *version = kctx->version;
4702: if (rtol_0) *rtol_0 = kctx->rtol_0;
4703: if (rtol_max) *rtol_max = kctx->rtol_max;
4704: if (gamma) *gamma = kctx->gamma;
4705: if (alpha) *alpha = kctx->alpha;
4706: if (alpha2) *alpha2 = kctx->alpha2;
4707: if (threshold) *threshold = kctx->threshold;
4708: return(0);
4709: }
4713: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
4714: {
4716: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
4717: PetscReal rtol = PETSC_DEFAULT,stol;
4720: if (!snes->ksp_ewconv) return(0);
4721: if (!snes->iter) {
4722: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
4723: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
4724: }
4725: else {
4726: if (kctx->version == 1) {
4727: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
4728: if (rtol < 0.0) rtol = -rtol;
4729: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
4730: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
4731: } else if (kctx->version == 2) {
4732: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
4733: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
4734: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
4735: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
4736: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
4737: /* safeguard: avoid sharp decrease of rtol */
4738: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
4739: stol = PetscMax(rtol,stol);
4740: rtol = PetscMin(kctx->rtol_0,stol);
4741: /* safeguard: avoid oversolving */
4742: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
4743: stol = PetscMax(rtol,stol);
4744: rtol = PetscMin(kctx->rtol_0,stol);
4745: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
4746: }
4747: /* safeguard: avoid rtol greater than one */
4748: rtol = PetscMin(rtol,kctx->rtol_max);
4749: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
4750: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
4751: return(0);
4752: }
4756: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
4757: {
4759: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
4760: PCSide pcside;
4761: Vec lres;
4764: if (!snes->ksp_ewconv) return(0);
4765: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
4766: kctx->norm_last = snes->norm;
4767: if (kctx->version == 1) {
4768: PC pc;
4769: PetscBool isNone;
4771: KSPGetPC(ksp, &pc);
4772: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
4773: KSPGetPCSide(ksp,&pcside);
4774: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
4775: /* KSP residual is true linear residual */
4776: KSPGetResidualNorm(ksp,&kctx->lresid_last);
4777: } else {
4778: /* KSP residual is preconditioned residual */
4779: /* compute true linear residual norm */
4780: VecDuplicate(b,&lres);
4781: MatMult(snes->jacobian,x,lres);
4782: VecAYPX(lres,-1.0,b);
4783: VecNorm(lres,NORM_2,&kctx->lresid_last);
4784: VecDestroy(&lres);
4785: }
4786: }
4787: return(0);
4788: }
4792: /*@
4793: SNESGetKSP - Returns the KSP context for a SNES solver.
4795: Not Collective, but if SNES object is parallel, then KSP object is parallel
4797: Input Parameter:
4798: . snes - the SNES context
4800: Output Parameter:
4801: . ksp - the KSP context
4803: Notes:
4804: The user can then directly manipulate the KSP context to set various
4805: options, etc. Likewise, the user can then extract and manipulate the
4806: PC contexts as well.
4808: Level: beginner
4810: .keywords: SNES, nonlinear, get, KSP, context
4812: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
4813: @*/
4814: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
4815: {
4822: if (!snes->ksp) {
4823: PetscBool monitor = PETSC_FALSE;
4825: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
4826: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
4827: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
4829: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
4830: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
4832: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
4833: if (monitor) {
4834: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
4835: }
4836: monitor = PETSC_FALSE;
4837: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
4838: if (monitor) {
4839: PetscObject *objs;
4840: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
4841: objs[0] = (PetscObject) snes;
4842: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
4843: }
4844: }
4845: *ksp = snes->ksp;
4846: return(0);
4847: }
4850: #include <petsc/private/dmimpl.h>
4853: /*@
4854: SNESSetDM - Sets the DM that may be used by some preconditioners
4856: Logically Collective on SNES
4858: Input Parameters:
4859: + snes - the preconditioner context
4860: - dm - the dm
4862: Level: intermediate
4864: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
4865: @*/
4866: PetscErrorCode SNESSetDM(SNES snes,DM dm)
4867: {
4869: KSP ksp;
4870: DMSNES sdm;
4874: if (dm) {PetscObjectReference((PetscObject)dm);}
4875: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
4876: if (snes->dm->dmsnes && snes->dmAuto && !dm->dmsnes) {
4877: DMCopyDMSNES(snes->dm,dm);
4878: DMGetDMSNES(snes->dm,&sdm);
4879: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
4880: }
4881: DMDestroy(&snes->dm);
4882: }
4883: snes->dm = dm;
4884: snes->dmAuto = PETSC_FALSE;
4886: SNESGetKSP(snes,&ksp);
4887: KSPSetDM(ksp,dm);
4888: KSPSetDMActive(ksp,PETSC_FALSE);
4889: if (snes->pc) {
4890: SNESSetDM(snes->pc, snes->dm);
4891: SNESSetNPCSide(snes,snes->pcside);
4892: }
4893: return(0);
4894: }
4898: /*@
4899: SNESGetDM - Gets the DM that may be used by some preconditioners
4901: Not Collective but DM obtained is parallel on SNES
4903: Input Parameter:
4904: . snes - the preconditioner context
4906: Output Parameter:
4907: . dm - the dm
4909: Level: intermediate
4911: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
4912: @*/
4913: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
4914: {
4919: if (!snes->dm) {
4920: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
4921: snes->dmAuto = PETSC_TRUE;
4922: }
4923: *dm = snes->dm;
4924: return(0);
4925: }
4929: /*@
4930: SNESSetNPC - Sets the nonlinear preconditioner to be used.
4932: Collective on SNES
4934: Input Parameters:
4935: + snes - iterative context obtained from SNESCreate()
4936: - pc - the preconditioner object
4938: Notes:
4939: Use SNESGetNPC() to retrieve the preconditioner context (for example,
4940: to configure it using the API).
4942: Level: developer
4944: .keywords: SNES, set, precondition
4945: .seealso: SNESGetNPC(), SNESHasNPC()
4946: @*/
4947: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
4948: {
4955: PetscObjectReference((PetscObject) pc);
4956: SNESDestroy(&snes->pc);
4957: snes->pc = pc;
4958: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->pc);
4959: return(0);
4960: }
4964: /*@
4965: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
4967: Not Collective
4969: Input Parameter:
4970: . snes - iterative context obtained from SNESCreate()
4972: Output Parameter:
4973: . pc - preconditioner context
4975: Notes: If a SNES was previously set with SNESSetNPC() then that SNES is returned.
4977: Level: developer
4979: .keywords: SNES, get, preconditioner
4980: .seealso: SNESSetNPC(), SNESHasNPC()
4981: @*/
4982: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
4983: {
4985: const char *optionsprefix;
4990: if (!snes->pc) {
4991: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->pc);
4992: PetscObjectIncrementTabLevel((PetscObject)snes->pc,(PetscObject)snes,1);
4993: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->pc);
4994: SNESGetOptionsPrefix(snes,&optionsprefix);
4995: SNESSetOptionsPrefix(snes->pc,optionsprefix);
4996: SNESAppendOptionsPrefix(snes->pc,"npc_");
4997: SNESSetCountersReset(snes->pc,PETSC_FALSE);
4998: }
4999: *pc = snes->pc;
5000: return(0);
5001: }
5005: /*@
5006: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5008: Not Collective
5010: Input Parameter:
5011: . snes - iterative context obtained from SNESCreate()
5013: Output Parameter:
5014: . has_npc - whether the SNES has an NPC or not
5016: Level: developer
5018: .keywords: SNES, has, preconditioner
5019: .seealso: SNESSetNPC(), SNESGetNPC()
5020: @*/
5021: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5022: {
5025: *has_npc = (PetscBool) (snes->pc ? PETSC_TRUE : PETSC_FALSE);
5026: return(0);
5027: }
5031: /*@
5032: SNESSetNPCSide - Sets the preconditioning side.
5034: Logically Collective on SNES
5036: Input Parameter:
5037: . snes - iterative context obtained from SNESCreate()
5039: Output Parameter:
5040: . side - the preconditioning side, where side is one of
5041: .vb
5042: PC_LEFT - left preconditioning
5043: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5044: .ve
5046: Options Database Keys:
5047: . -snes_pc_side <right,left>
5049: Notes: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5051: Level: intermediate
5053: .keywords: SNES, set, right, left, side, preconditioner, flag
5055: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5056: @*/
5057: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5058: {
5062: snes->pcside = side;
5063: return(0);
5064: }
5068: /*@
5069: SNESGetNPCSide - Gets the preconditioning side.
5071: Not Collective
5073: Input Parameter:
5074: . snes - iterative context obtained from SNESCreate()
5076: Output Parameter:
5077: . side - the preconditioning side, where side is one of
5078: .vb
5079: PC_LEFT - left preconditioning
5080: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5081: .ve
5083: Level: intermediate
5085: .keywords: SNES, get, right, left, side, preconditioner, flag
5087: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5088: @*/
5089: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5090: {
5094: *side = snes->pcside;
5095: return(0);
5096: }
5100: /*@
5101: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5103: Collective on SNES
5105: Input Parameters:
5106: + snes - iterative context obtained from SNESCreate()
5107: - linesearch - the linesearch object
5109: Notes:
5110: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5111: to configure it using the API).
5113: Level: developer
5115: .keywords: SNES, set, linesearch
5116: .seealso: SNESGetLineSearch()
5117: @*/
5118: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5119: {
5126: PetscObjectReference((PetscObject) linesearch);
5127: SNESLineSearchDestroy(&snes->linesearch);
5129: snes->linesearch = linesearch;
5131: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5132: return(0);
5133: }
5137: /*@
5138: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5139: or creates a default line search instance associated with the SNES and returns it.
5141: Not Collective
5143: Input Parameter:
5144: . snes - iterative context obtained from SNESCreate()
5146: Output Parameter:
5147: . linesearch - linesearch context
5149: Level: beginner
5151: .keywords: SNES, get, linesearch
5152: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5153: @*/
5154: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5155: {
5157: const char *optionsprefix;
5162: if (!snes->linesearch) {
5163: SNESGetOptionsPrefix(snes, &optionsprefix);
5164: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5165: SNESLineSearchSetSNES(snes->linesearch, snes);
5166: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5167: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5168: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5169: }
5170: *linesearch = snes->linesearch;
5171: return(0);
5172: }
5174: #if defined(PETSC_HAVE_MATLAB_ENGINE)
5175: #include <mex.h>
5177: typedef struct {char *funcname; mxArray *ctx;} SNESMatlabContext;
5181: /*
5182: SNESComputeFunction_Matlab - Calls the function that has been set with SNESSetFunctionMatlab().
5184: Collective on SNES
5186: Input Parameters:
5187: + snes - the SNES context
5188: - x - input vector
5190: Output Parameter:
5191: . y - function vector, as set by SNESSetFunction()
5193: Notes:
5194: SNESComputeFunction() is typically used within nonlinear solvers
5195: implementations, so most users would not generally call this routine
5196: themselves.
5198: Level: developer
5200: .keywords: SNES, nonlinear, compute, function
5202: .seealso: SNESSetFunction(), SNESGetFunction()
5203: */
5204: PetscErrorCode SNESComputeFunction_Matlab(SNES snes,Vec x,Vec y, void *ctx)
5205: {
5206: PetscErrorCode ierr;
5207: SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
5208: int nlhs = 1,nrhs = 5;
5209: mxArray *plhs[1],*prhs[5];
5210: long long int lx = 0,ly = 0,ls = 0;
5219: /* call Matlab function in ctx with arguments x and y */
5221: PetscMemcpy(&ls,&snes,sizeof(snes));
5222: PetscMemcpy(&lx,&x,sizeof(x));
5223: PetscMemcpy(&ly,&y,sizeof(x));
5224: prhs[0] = mxCreateDoubleScalar((double)ls);
5225: prhs[1] = mxCreateDoubleScalar((double)lx);
5226: prhs[2] = mxCreateDoubleScalar((double)ly);
5227: prhs[3] = mxCreateString(sctx->funcname);
5228: prhs[4] = sctx->ctx;
5229: mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESComputeFunctionInternal");
5230: mxGetScalar(plhs[0]);
5231: mxDestroyArray(prhs[0]);
5232: mxDestroyArray(prhs[1]);
5233: mxDestroyArray(prhs[2]);
5234: mxDestroyArray(prhs[3]);
5235: mxDestroyArray(plhs[0]);
5236: return(0);
5237: }
5241: /*
5242: SNESSetFunctionMatlab - Sets the function evaluation routine and function
5243: vector for use by the SNES routines in solving systems of nonlinear
5244: equations from MATLAB. Here the function is a string containing the name of a MATLAB function
5246: Logically Collective on SNES
5248: Input Parameters:
5249: + snes - the SNES context
5250: . r - vector to store function value
5251: - f - function evaluation routine
5253: Notes:
5254: The Newton-like methods typically solve linear systems of the form
5255: $ f'(x) x = -f(x),
5256: where f'(x) denotes the Jacobian matrix and f(x) is the function.
5258: Level: beginner
5260: Developer Note: This bleeds the allocated memory SNESMatlabContext *sctx;
5262: .keywords: SNES, nonlinear, set, function
5264: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
5265: */
5266: PetscErrorCode SNESSetFunctionMatlab(SNES snes,Vec r,const char *f,mxArray *ctx)
5267: {
5268: PetscErrorCode ierr;
5269: SNESMatlabContext *sctx;
5272: /* currently sctx is memory bleed */
5273: PetscNew(&sctx);
5274: PetscStrallocpy(f,&sctx->funcname);
5275: /*
5276: This should work, but it doesn't
5277: sctx->ctx = ctx;
5278: mexMakeArrayPersistent(sctx->ctx);
5279: */
5280: sctx->ctx = mxDuplicateArray(ctx);
5281: SNESSetFunction(snes,r,SNESComputeFunction_Matlab,sctx);
5282: return(0);
5283: }
5287: /*
5288: SNESComputeJacobian_Matlab - Calls the function that has been set with SNESSetJacobianMatlab().
5290: Collective on SNES
5292: Input Parameters:
5293: + snes - the SNES context
5294: . x - input vector
5295: . A, B - the matrices
5296: - ctx - user context
5298: Level: developer
5300: .keywords: SNES, nonlinear, compute, function
5302: .seealso: SNESSetFunction(), SNESGetFunction()
5303: @*/
5304: PetscErrorCode SNESComputeJacobian_Matlab(SNES snes,Vec x,Mat A,Mat B,void *ctx)
5305: {
5306: PetscErrorCode ierr;
5307: SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
5308: int nlhs = 2,nrhs = 6;
5309: mxArray *plhs[2],*prhs[6];
5310: long long int lx = 0,lA = 0,ls = 0, lB = 0;
5316: /* call Matlab function in ctx with arguments x and y */
5318: PetscMemcpy(&ls,&snes,sizeof(snes));
5319: PetscMemcpy(&lx,&x,sizeof(x));
5320: PetscMemcpy(&lA,A,sizeof(x));
5321: PetscMemcpy(&lB,B,sizeof(x));
5322: prhs[0] = mxCreateDoubleScalar((double)ls);
5323: prhs[1] = mxCreateDoubleScalar((double)lx);
5324: prhs[2] = mxCreateDoubleScalar((double)lA);
5325: prhs[3] = mxCreateDoubleScalar((double)lB);
5326: prhs[4] = mxCreateString(sctx->funcname);
5327: prhs[5] = sctx->ctx;
5328: mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESComputeJacobianInternal");
5329: mxGetScalar(plhs[0]);
5330: mxDestroyArray(prhs[0]);
5331: mxDestroyArray(prhs[1]);
5332: mxDestroyArray(prhs[2]);
5333: mxDestroyArray(prhs[3]);
5334: mxDestroyArray(prhs[4]);
5335: mxDestroyArray(plhs[0]);
5336: mxDestroyArray(plhs[1]);
5337: return(0);
5338: }
5342: /*
5343: SNESSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
5344: vector for use by the SNES routines in solving systems of nonlinear
5345: equations from MATLAB. Here the function is a string containing the name of a MATLAB function
5347: Logically Collective on SNES
5349: Input Parameters:
5350: + snes - the SNES context
5351: . A,B - Jacobian matrices
5352: . J - function evaluation routine
5353: - ctx - user context
5355: Level: developer
5357: Developer Note: This bleeds the allocated memory SNESMatlabContext *sctx;
5359: .keywords: SNES, nonlinear, set, function
5361: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction(), J
5362: */
5363: PetscErrorCode SNESSetJacobianMatlab(SNES snes,Mat A,Mat B,const char *J,mxArray *ctx)
5364: {
5365: PetscErrorCode ierr;
5366: SNESMatlabContext *sctx;
5369: /* currently sctx is memory bleed */
5370: PetscNew(&sctx);
5371: PetscStrallocpy(J,&sctx->funcname);
5372: /*
5373: This should work, but it doesn't
5374: sctx->ctx = ctx;
5375: mexMakeArrayPersistent(sctx->ctx);
5376: */
5377: sctx->ctx = mxDuplicateArray(ctx);
5378: SNESSetJacobian(snes,A,B,SNESComputeJacobian_Matlab,sctx);
5379: return(0);
5380: }
5384: /*
5385: SNESMonitor_Matlab - Calls the function that has been set with SNESMonitorSetMatlab().
5387: Collective on SNES
5389: .seealso: SNESSetFunction(), SNESGetFunction()
5390: @*/
5391: PetscErrorCode SNESMonitor_Matlab(SNES snes,PetscInt it, PetscReal fnorm, void *ctx)
5392: {
5393: PetscErrorCode ierr;
5394: SNESMatlabContext *sctx = (SNESMatlabContext*)ctx;
5395: int nlhs = 1,nrhs = 6;
5396: mxArray *plhs[1],*prhs[6];
5397: long long int lx = 0,ls = 0;
5398: Vec x = snes->vec_sol;
5403: PetscMemcpy(&ls,&snes,sizeof(snes));
5404: PetscMemcpy(&lx,&x,sizeof(x));
5405: prhs[0] = mxCreateDoubleScalar((double)ls);
5406: prhs[1] = mxCreateDoubleScalar((double)it);
5407: prhs[2] = mxCreateDoubleScalar((double)fnorm);
5408: prhs[3] = mxCreateDoubleScalar((double)lx);
5409: prhs[4] = mxCreateString(sctx->funcname);
5410: prhs[5] = sctx->ctx;
5411: mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscSNESMonitorInternal");
5412: mxGetScalar(plhs[0]);
5413: mxDestroyArray(prhs[0]);
5414: mxDestroyArray(prhs[1]);
5415: mxDestroyArray(prhs[2]);
5416: mxDestroyArray(prhs[3]);
5417: mxDestroyArray(prhs[4]);
5418: mxDestroyArray(plhs[0]);
5419: return(0);
5420: }
5424: /*
5425: SNESMonitorSetMatlab - Sets the monitor function from MATLAB
5427: Level: developer
5429: Developer Note: This bleeds the allocated memory SNESMatlabContext *sctx;
5431: .keywords: SNES, nonlinear, set, function
5433: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
5434: */
5435: PetscErrorCode SNESMonitorSetMatlab(SNES snes,const char *f,mxArray *ctx)
5436: {
5437: PetscErrorCode ierr;
5438: SNESMatlabContext *sctx;
5441: /* currently sctx is memory bleed */
5442: PetscNew(&sctx);
5443: PetscStrallocpy(f,&sctx->funcname);
5444: /*
5445: This should work, but it doesn't
5446: sctx->ctx = ctx;
5447: mexMakeArrayPersistent(sctx->ctx);
5448: */
5449: sctx->ctx = mxDuplicateArray(ctx);
5450: SNESMonitorSet(snes,SNESMonitor_Matlab,sctx,NULL);
5451: return(0);
5452: }
5454: #endif