Actual source code: snes.c
petsc-3.12.5 2020-03-29
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_Setup, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes SNESSolve() to generate an error if the solver has not converged.
18: Logically Collective on SNES
20: Input Parameters:
21: + snes - iterative context obtained from SNESCreate()
22: - flg - PETSC_TRUE indicates you want the error generated
24: Options database keys:
25: . -snes_error_if_not_converged : this takes an optional truth value (0/1/no/yes/true/false)
27: Level: intermediate
29: Notes:
30: Normally PETSc continues if a linear solver fails to converge, you can call SNESGetConvergedReason() after a SNESSolve()
31: to determine if it has converged.
33: .seealso: SNESGetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes,PetscBool flg)
36: {
40: snes->errorifnotconverged = flg;
41: return(0);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Will SNESSolve() generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from SNESCreate()
52: Output Parameter:
53: . flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE
55: Level: intermediate
57: .seealso: SNESSetErrorIfNotConverged(), KSPGetErrorIfNotConverged(), KSPSetErrorIFNotConverged()
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes,PetscBool *flag)
60: {
64: *flag = snes->errorifnotconverged;
65: return(0);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
71: Logically Collective on SNES
73: Input Parameters:
74: + snes - the shell SNES
75: - flg - is the residual computed?
77: Level: advanced
79: .seealso: SNESGetAlwaysComputesFinalResidual()
80: @*/
81: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
82: {
85: snes->alwayscomputesfinalresidual = flg;
86: return(0);
87: }
89: /*@
90: SNESGetAlwaysComputesFinalResidual - does the SNES always compute the residual at the final solution?
92: Logically Collective on SNES
94: Input Parameter:
95: . snes - the shell SNES
97: Output Parameter:
98: . flg - is the residual computed?
100: Level: advanced
102: .seealso: SNESSetAlwaysComputesFinalResidual()
103: @*/
104: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
105: {
108: *flg = snes->alwayscomputesfinalresidual;
109: return(0);
110: }
112: /*@
113: SNESSetFunctionDomainError - tells SNES that the input vector to your SNESFunction is not
114: in the functions domain. For example, negative pressure.
116: Logically Collective on SNES
118: Input Parameters:
119: . snes - the SNES context
121: Level: advanced
123: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction
124: @*/
125: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
126: {
129: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates input vector is not in the function domain");
130: snes->domainerror = PETSC_TRUE;
131: return(0);
132: }
134: /*@
135: SNESSetJacobianDomainError - tells SNES that computeJacobian does not make sense any more. For example there is a negative element transformation.
137: Logically Collective on SNES
139: Input Parameters:
140: . snes - the SNES context
142: Level: advanced
144: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError()
145: @*/
146: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
147: {
150: if (snes->errorifnotconverged) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"User code indicates computeJacobian does not make sense");
151: snes->jacobiandomainerror = PETSC_TRUE;
152: return(0);
153: }
155: /*@
156: SNESSetCheckJacobianDomainError - if or not to check jacobian domain error after each Jacobian evaluation. By default, we check Jacobian domain error
157: in the debug mode, and do not check it in the optimized mode.
159: Logically Collective on SNES
161: Input Parameters:
162: + snes - the SNES context
163: - flg - indicates if or not to check jacobian domain error after each Jacobian evaluation
165: Level: advanced
167: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESGetCheckJacobianDomainError()
168: @*/
169: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
170: {
173: snes->checkjacdomainerror = flg;
174: return(0);
175: }
177: /*@
178: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
180: Logically Collective on SNES
182: Input Parameters:
183: . snes - the SNES context
185: Output Parameters:
186: . flg - PETSC_FALSE indicates that we don't check jacobian domain errors after each Jacobian evaluation
188: Level: advanced
190: .seealso: SNESCreate(), SNESSetFunction(), SNESFunction(), SNESSetFunctionDomainError(), SNESSetCheckJacobianDomainError()
191: @*/
192: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
193: {
197: *flg = snes->checkjacdomainerror;
198: return(0);
199: }
201: /*@
202: SNESGetFunctionDomainError - Gets the status of the domain error after a call to SNESComputeFunction;
204: Logically Collective on SNES
206: Input Parameters:
207: . snes - the SNES context
209: Output Parameters:
210: . domainerror - Set to PETSC_TRUE if there's a domain error; PETSC_FALSE otherwise.
212: Level: advanced
214: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction()
215: @*/
216: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
217: {
221: *domainerror = snes->domainerror;
222: return(0);
223: }
225: /*@
226: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to SNESComputeJacobian;
228: Logically Collective on SNES
230: Input Parameters:
231: . snes - the SNES context
233: Output Parameters:
234: . domainerror - Set to PETSC_TRUE if there's a jacobian domain error; PETSC_FALSE otherwise.
236: Level: advanced
238: .seealso: SNESSetFunctionDomainError(), SNESComputeFunction(),SNESGetFunctionDomainError()
239: @*/
240: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
241: {
245: *domainerror = snes->jacobiandomainerror;
246: return(0);
247: }
249: /*@C
250: SNESLoad - Loads a SNES that has been stored in binary with SNESView().
252: Collective on PetscViewer
254: Input Parameters:
255: + newdm - the newly loaded SNES, this needs to have been created with SNESCreate() or
256: some related function before a call to SNESLoad().
257: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
259: Level: intermediate
261: Notes:
262: The type is determined by the data in the file, any type set into the SNES before this call is ignored.
264: Notes for advanced users:
265: Most users should not need to know the details of the binary storage
266: format, since SNESLoad() and TSView() completely hide these details.
267: But for anyone who's interested, the standard binary matrix storage
268: format is
269: .vb
270: has not yet been determined
271: .ve
273: .seealso: PetscViewerBinaryOpen(), SNESView(), MatLoad(), VecLoad()
274: @*/
275: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
276: {
278: PetscBool isbinary;
279: PetscInt classid;
280: char type[256];
281: KSP ksp;
282: DM dm;
283: DMSNES dmsnes;
288: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
289: if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
291: PetscViewerBinaryRead(viewer,&classid,1,NULL,PETSC_INT);
292: if (classid != SNES_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONG,"Not SNES next in file");
293: PetscViewerBinaryRead(viewer,type,256,NULL,PETSC_CHAR);
294: SNESSetType(snes, type);
295: if (snes->ops->load) {
296: (*snes->ops->load)(snes,viewer);
297: }
298: SNESGetDM(snes,&dm);
299: DMGetDMSNES(dm,&dmsnes);
300: DMSNESLoad(dmsnes,viewer);
301: SNESGetKSP(snes,&ksp);
302: KSPLoad(ksp,viewer);
303: return(0);
304: }
306: #include <petscdraw.h>
307: #if defined(PETSC_HAVE_SAWS)
308: #include <petscviewersaws.h>
309: #endif
311: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES,Vec,Mat,Mat,void*);
313: /*@C
314: SNESView - Prints the SNES data structure.
316: Collective on SNES
318: Input Parameters:
319: + SNES - the SNES context
320: - viewer - visualization context
322: Options Database Key:
323: . -snes_view - Calls SNESView() at end of SNESSolve()
325: Notes:
326: The available visualization contexts include
327: + PETSC_VIEWER_STDOUT_SELF - standard output (default)
328: - PETSC_VIEWER_STDOUT_WORLD - synchronized standard
329: output where only the first processor opens
330: the file. All other processors send their
331: data to the first processor to print.
333: The user can open an alternative visualization context with
334: PetscViewerASCIIOpen() - output to a specified file.
336: Level: beginner
338: .seealso: PetscViewerASCIIOpen()
339: @*/
340: PetscErrorCode SNESView(SNES snes,PetscViewer viewer)
341: {
342: SNESKSPEW *kctx;
344: KSP ksp;
345: SNESLineSearch linesearch;
346: PetscBool iascii,isstring,isbinary,isdraw;
347: DMSNES dmsnes;
348: #if defined(PETSC_HAVE_SAWS)
349: PetscBool issaws;
350: #endif
354: if (!viewer) {
355: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&viewer);
356: }
360: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
361: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
362: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
363: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
364: #if defined(PETSC_HAVE_SAWS)
365: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&issaws);
366: #endif
367: if (iascii) {
368: SNESNormSchedule normschedule;
369: DM dm;
370: PetscErrorCode (*cJ)(SNES,Vec,Mat,Mat,void*);
371: void *ctx;
372: const char *pre = "";
374: PetscObjectPrintClassNamePrefixType((PetscObject)snes,viewer);
375: if (!snes->setupcalled) {
376: PetscViewerASCIIPrintf(viewer," SNES has not been set up so information may be incomplete\n");
377: }
378: if (snes->ops->view) {
379: PetscViewerASCIIPushTab(viewer);
380: (*snes->ops->view)(snes,viewer);
381: PetscViewerASCIIPopTab(viewer);
382: }
383: PetscViewerASCIIPrintf(viewer," maximum iterations=%D, maximum function evaluations=%D\n",snes->max_its,snes->max_funcs);
384: PetscViewerASCIIPrintf(viewer," tolerances: relative=%g, absolute=%g, solution=%g\n",(double)snes->rtol,(double)snes->abstol,(double)snes->stol);
385: if (snes->usesksp) {
386: PetscViewerASCIIPrintf(viewer," total number of linear solver iterations=%D\n",snes->linear_its);
387: }
388: PetscViewerASCIIPrintf(viewer," total number of function evaluations=%D\n",snes->nfuncs);
389: SNESGetNormSchedule(snes, &normschedule);
390: if (normschedule > 0) {PetscViewerASCIIPrintf(viewer," norm schedule %s\n",SNESNormSchedules[normschedule]);}
391: if (snes->gridsequence) {
392: PetscViewerASCIIPrintf(viewer," total number of grid sequence refinements=%D\n",snes->gridsequence);
393: }
394: if (snes->ksp_ewconv) {
395: kctx = (SNESKSPEW*)snes->kspconvctx;
396: if (kctx) {
397: PetscViewerASCIIPrintf(viewer," Eisenstat-Walker computation of KSP relative tolerance (version %D)\n",kctx->version);
398: PetscViewerASCIIPrintf(viewer," rtol_0=%g, rtol_max=%g, threshold=%g\n",(double)kctx->rtol_0,(double)kctx->rtol_max,(double)kctx->threshold);
399: PetscViewerASCIIPrintf(viewer," gamma=%g, alpha=%g, alpha2=%g\n",(double)kctx->gamma,(double)kctx->alpha,(double)kctx->alpha2);
400: }
401: }
402: if (snes->lagpreconditioner == -1) {
403: PetscViewerASCIIPrintf(viewer," Preconditioned is never rebuilt\n");
404: } else if (snes->lagpreconditioner > 1) {
405: PetscViewerASCIIPrintf(viewer," Preconditioned is rebuilt every %D new Jacobians\n",snes->lagpreconditioner);
406: }
407: if (snes->lagjacobian == -1) {
408: PetscViewerASCIIPrintf(viewer," Jacobian is never rebuilt\n");
409: } else if (snes->lagjacobian > 1) {
410: PetscViewerASCIIPrintf(viewer," Jacobian is rebuilt every %D SNES iterations\n",snes->lagjacobian);
411: }
412: SNESGetDM(snes,&dm);
413: DMSNESGetJacobian(dm,&cJ,&ctx);
414: if (snes->mf_operator) {
415: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing\n");
416: pre = "Preconditioning ";
417: }
418: if (cJ == SNESComputeJacobianDefault) {
419: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences one column at a time\n",pre);
420: } else if (cJ == SNESComputeJacobianDefaultColor) {
421: PetscViewerASCIIPrintf(viewer," %sJacobian is built using finite differences with coloring\n",pre);
422: /* it slightly breaks data encapsulation for access the DMDA information directly */
423: } else if (cJ == SNESComputeJacobian_DMDA) {
424: MatFDColoring fdcoloring;
425: PetscObjectQuery((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject*)&fdcoloring);
426: if (fdcoloring) {
427: PetscViewerASCIIPrintf(viewer," %sJacobian is built using colored finite differences on a DMDA\n",pre);
428: } else {
429: PetscViewerASCIIPrintf(viewer," %sJacobian is built using a DMDA local Jacobian\n",pre);
430: }
431: } else if (snes->mf) {
432: PetscViewerASCIIPrintf(viewer," Jacobian is applied matrix-free with differencing, no explict Jacobian\n");
433: }
434: } else if (isstring) {
435: const char *type;
436: SNESGetType(snes,&type);
437: PetscViewerStringSPrintf(viewer," SNESType: %-7.7s",type);
438: if (snes->ops->view) {(*snes->ops->view)(snes,viewer);}
439: } else if (isbinary) {
440: PetscInt classid = SNES_FILE_CLASSID;
441: MPI_Comm comm;
442: PetscMPIInt rank;
443: char type[256];
445: PetscObjectGetComm((PetscObject)snes,&comm);
446: MPI_Comm_rank(comm,&rank);
447: if (!rank) {
448: PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
449: PetscStrncpy(type,((PetscObject)snes)->type_name,sizeof(type));
450: PetscViewerBinaryWrite(viewer,type,sizeof(type),PETSC_CHAR,PETSC_FALSE);
451: }
452: if (snes->ops->view) {
453: (*snes->ops->view)(snes,viewer);
454: }
455: } else if (isdraw) {
456: PetscDraw draw;
457: char str[36];
458: PetscReal x,y,bottom,h;
460: PetscViewerDrawGetDraw(viewer,0,&draw);
461: PetscDrawGetCurrentPoint(draw,&x,&y);
462: PetscStrncpy(str,"SNES: ",sizeof(str));
463: PetscStrlcat(str,((PetscObject)snes)->type_name,sizeof(str));
464: PetscDrawStringBoxed(draw,x,y,PETSC_DRAW_BLUE,PETSC_DRAW_BLACK,str,NULL,&h);
465: bottom = y - h;
466: PetscDrawPushCurrentPoint(draw,x,bottom);
467: if (snes->ops->view) {
468: (*snes->ops->view)(snes,viewer);
469: }
470: #if defined(PETSC_HAVE_SAWS)
471: } else if (issaws) {
472: PetscMPIInt rank;
473: const char *name;
475: PetscObjectGetName((PetscObject)snes,&name);
476: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
477: if (!((PetscObject)snes)->amsmem && !rank) {
478: char dir[1024];
480: PetscObjectViewSAWs((PetscObject)snes,viewer);
481: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/its",name);
482: PetscStackCallSAWs(SAWs_Register,(dir,&snes->iter,1,SAWs_READ,SAWs_INT));
483: if (!snes->conv_hist) {
484: SNESSetConvergenceHistory(snes,NULL,NULL,PETSC_DECIDE,PETSC_TRUE);
485: }
486: PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/conv_hist",name);
487: PetscStackCallSAWs(SAWs_Register,(dir,snes->conv_hist,10,SAWs_READ,SAWs_DOUBLE));
488: }
489: #endif
490: }
491: if (snes->linesearch) {
492: SNESGetLineSearch(snes, &linesearch);
493: PetscViewerASCIIPushTab(viewer);
494: SNESLineSearchView(linesearch, viewer);
495: PetscViewerASCIIPopTab(viewer);
496: }
497: if (snes->npc && snes->usesnpc) {
498: PetscViewerASCIIPushTab(viewer);
499: SNESView(snes->npc, viewer);
500: PetscViewerASCIIPopTab(viewer);
501: }
502: PetscViewerASCIIPushTab(viewer);
503: DMGetDMSNES(snes->dm,&dmsnes);
504: DMSNESView(dmsnes, viewer);
505: PetscViewerASCIIPopTab(viewer);
506: if (snes->usesksp) {
507: SNESGetKSP(snes,&ksp);
508: PetscViewerASCIIPushTab(viewer);
509: KSPView(ksp,viewer);
510: PetscViewerASCIIPopTab(viewer);
511: }
512: if (isdraw) {
513: PetscDraw draw;
514: PetscViewerDrawGetDraw(viewer,0,&draw);
515: PetscDrawPopCurrentPoint(draw);
516: }
517: return(0);
518: }
520: /*
521: We retain a list of functions that also take SNES command
522: line options. These are called at the end SNESSetFromOptions()
523: */
524: #define MAXSETFROMOPTIONS 5
525: static PetscInt numberofsetfromoptions;
526: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
528: /*@C
529: SNESAddOptionsChecker - Adds an additional function to check for SNES options.
531: Not Collective
533: Input Parameter:
534: . snescheck - function that checks for options
536: Level: developer
538: .seealso: SNESSetFromOptions()
539: @*/
540: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
541: {
543: if (numberofsetfromoptions >= MAXSETFROMOPTIONS) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %D allowed", MAXSETFROMOPTIONS);
544: othersetfromoptions[numberofsetfromoptions++] = snescheck;
545: return(0);
546: }
548: PETSC_INTERN PetscErrorCode SNESDefaultMatrixFreeCreate2(SNES,Vec,Mat*);
550: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
551: {
552: Mat J;
554: MatNullSpace nullsp;
559: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
560: Mat A = snes->jacobian, B = snes->jacobian_pre;
561: MatCreateVecs(A ? A : B, NULL,&snes->vec_func);
562: }
564: if (version == 1) {
565: MatCreateSNESMF(snes,&J);
566: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
567: MatSetFromOptions(J);
568: } else if (version == 2) {
569: if (!snes->vec_func) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"SNESSetFunction() must be called first");
570: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
571: SNESDefaultMatrixFreeCreate2(snes,snes->vec_func,&J);
572: #else
573: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "matrix-free operator rutines (version 2)");
574: #endif
575: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator rutines, only version 1 and 2");
577: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
578: if (snes->jacobian) {
579: MatGetNullSpace(snes->jacobian,&nullsp);
580: if (nullsp) {
581: MatSetNullSpace(J,nullsp);
582: }
583: }
585: PetscInfo1(snes,"Setting default matrix-free operator routines (version %D)\n", version);
586: if (hasOperator) {
588: /* This version replaces the user provided Jacobian matrix with a
589: matrix-free version but still employs the user-provided preconditioner matrix. */
590: SNESSetJacobian(snes,J,0,0,0);
591: } else {
592: /* This version replaces both the user-provided Jacobian and the user-
593: provided preconditioner Jacobian with the default matrix free version. */
594: if ((snes->npcside== PC_LEFT) && snes->npc) {
595: if (!snes->jacobian){SNESSetJacobian(snes,J,0,0,0);}
596: } else {
597: KSP ksp;
598: PC pc;
599: PetscBool match;
601: SNESSetJacobian(snes,J,J,MatMFFDComputeJacobian,0);
602: /* Force no preconditioner */
603: SNESGetKSP(snes,&ksp);
604: KSPGetPC(ksp,&pc);
605: PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&match);
606: if (!match) {
607: PetscInfo(snes,"Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n");
608: PCSetType(pc,PCNONE);
609: }
610: }
611: }
612: MatDestroy(&J);
613: return(0);
614: }
616: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine,Mat Restrict,Vec Rscale,Mat Inject,DM dmcoarse,void *ctx)
617: {
618: SNES snes = (SNES)ctx;
620: Vec Xfine,Xfine_named = NULL,Xcoarse;
623: if (PetscLogPrintInfo) {
624: PetscInt finelevel,coarselevel,fineclevel,coarseclevel;
625: DMGetRefineLevel(dmfine,&finelevel);
626: DMGetCoarsenLevel(dmfine,&fineclevel);
627: DMGetRefineLevel(dmcoarse,&coarselevel);
628: DMGetCoarsenLevel(dmcoarse,&coarseclevel);
629: PetscInfo4(dmfine,"Restricting SNES solution vector from level %D-%D to level %D-%D\n",finelevel,fineclevel,coarselevel,coarseclevel);
630: }
631: if (dmfine == snes->dm) Xfine = snes->vec_sol;
632: else {
633: DMGetNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);
634: Xfine = Xfine_named;
635: }
636: DMGetNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
637: if (Inject) {
638: MatRestrict(Inject,Xfine,Xcoarse);
639: } else {
640: MatRestrict(Restrict,Xfine,Xcoarse);
641: VecPointwiseMult(Xcoarse,Xcoarse,Rscale);
642: }
643: DMRestoreNamedGlobalVector(dmcoarse,"SNESVecSol",&Xcoarse);
644: if (Xfine_named) {DMRestoreNamedGlobalVector(dmfine,"SNESVecSol",&Xfine_named);}
645: return(0);
646: }
648: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm,DM dmc,void *ctx)
649: {
653: DMCoarsenHookAdd(dmc,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,ctx);
654: return(0);
655: }
657: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
658: * safely call SNESGetDM() in their residual evaluation routine. */
659: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp,Mat A,Mat B,void *ctx)
660: {
661: SNES snes = (SNES)ctx;
663: Vec X,Xnamed = NULL;
664: DM dmsave;
665: void *ctxsave;
666: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*) = NULL;
669: dmsave = snes->dm;
670: KSPGetDM(ksp,&snes->dm);
671: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
672: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */
673: DMGetNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);
674: X = Xnamed;
675: SNESGetJacobian(snes,NULL,NULL,&jac,&ctxsave);
676: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
677: if (jac == SNESComputeJacobianDefaultColor) {
678: SNESSetJacobian(snes,NULL,NULL,SNESComputeJacobianDefaultColor,0);
679: }
680: }
681: /* Make sure KSP DM has the Jacobian computation routine */
682: {
683: DMSNES sdm;
685: DMGetDMSNES(snes->dm, &sdm);
686: if (!sdm->ops->computejacobian) {
687: DMCopyDMSNES(dmsave, snes->dm);
688: }
689: }
690: /* Compute the operators */
691: SNESComputeJacobian(snes,X,A,B);
692: /* Put the previous context back */
693: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) {
694: SNESSetJacobian(snes,NULL,NULL,jac,ctxsave);
695: }
697: if (Xnamed) {DMRestoreNamedGlobalVector(snes->dm,"SNESVecSol",&Xnamed);}
698: snes->dm = dmsave;
699: return(0);
700: }
702: /*@
703: SNESSetUpMatrices - ensures that matrices are available for SNES, to be called by SNESSetUp_XXX()
705: Collective
707: Input Arguments:
708: . snes - snes to configure
710: Level: developer
712: .seealso: SNESSetUp()
713: @*/
714: PetscErrorCode SNESSetUpMatrices(SNES snes)
715: {
717: DM dm;
718: DMSNES sdm;
721: SNESGetDM(snes,&dm);
722: DMGetDMSNES(dm,&sdm);
723: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_PLIB,"DMSNES not properly configured");
724: else if (!snes->jacobian && snes->mf) {
725: Mat J;
726: void *functx;
727: MatCreateSNESMF(snes,&J);
728: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
729: MatSetFromOptions(J);
730: SNESGetFunction(snes,NULL,NULL,&functx);
731: SNESSetJacobian(snes,J,J,0,0);
732: MatDestroy(&J);
733: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
734: Mat J,B;
735: MatCreateSNESMF(snes,&J);
736: MatMFFDSetOptionsPrefix(J,((PetscObject)snes)->prefix);
737: MatSetFromOptions(J);
738: DMCreateMatrix(snes->dm,&B);
739: /* sdm->computejacobian was already set to reach here */
740: SNESSetJacobian(snes,J,B,NULL,NULL);
741: MatDestroy(&J);
742: MatDestroy(&B);
743: } else if (!snes->jacobian_pre) {
744: PetscErrorCode (*nspconstr)(DM, PetscInt, MatNullSpace *);
745: PetscDS prob;
746: Mat J, B;
747: MatNullSpace nullspace = NULL;
748: PetscBool hasPrec = PETSC_FALSE;
749: PetscInt Nf;
751: J = snes->jacobian;
752: DMGetDS(dm, &prob);
753: if (prob) {PetscDSHasJacobianPreconditioner(prob, &hasPrec);}
754: if (J) {PetscObjectReference((PetscObject) J);}
755: else if (hasPrec) {DMCreateMatrix(snes->dm, &J);}
756: DMCreateMatrix(snes->dm, &B);
757: PetscDSGetNumFields(prob, &Nf);
758: DMGetNullSpaceConstructor(snes->dm, Nf, &nspconstr);
759: if (nspconstr) (*nspconstr)(snes->dm, -1, &nullspace);
760: MatSetNullSpace(B, nullspace);
761: MatNullSpaceDestroy(&nullspace);
762: SNESSetJacobian(snes, J ? J : B, B, NULL, NULL);
763: MatDestroy(&J);
764: MatDestroy(&B);
765: }
766: {
767: KSP ksp;
768: SNESGetKSP(snes,&ksp);
769: KSPSetComputeOperators(ksp,KSPComputeOperators_SNES,snes);
770: DMCoarsenHookAdd(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
771: }
772: return(0);
773: }
775: /*@C
776: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
778: Collective on SNES
780: Input Parameters:
781: + snes - SNES object you wish to monitor
782: . name - the monitor type one is seeking
783: . help - message indicating what monitoring is done
784: . manual - manual page for the monitor
785: . monitor - the monitor function
786: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the SNES or PetscViewer objects
788: Level: developer
790: .seealso: PetscOptionsGetViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
791: PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
792: PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
793: PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
794: PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
795: PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
796: PetscOptionsFList(), PetscOptionsEList()
797: @*/
798: PetscErrorCode SNESMonitorSetFromOptions(SNES snes,const char name[],const char help[], const char manual[],PetscErrorCode (*monitor)(SNES,PetscInt,PetscReal,PetscViewerAndFormat*),PetscErrorCode (*monitorsetup)(SNES,PetscViewerAndFormat*))
799: {
800: PetscErrorCode ierr;
801: PetscViewer viewer;
802: PetscViewerFormat format;
803: PetscBool flg;
806: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,name,&viewer,&format,&flg);
807: if (flg) {
808: PetscViewerAndFormat *vf;
809: PetscViewerAndFormatCreate(viewer,format,&vf);
810: PetscObjectDereference((PetscObject)viewer);
811: if (monitorsetup) {
812: (*monitorsetup)(snes,vf);
813: }
814: SNESMonitorSet(snes,(PetscErrorCode (*)(SNES,PetscInt,PetscReal,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
815: }
816: return(0);
817: }
819: /*@
820: SNESSetFromOptions - Sets various SNES and KSP parameters from user options.
822: Collective on SNES
824: Input Parameter:
825: . snes - the SNES context
827: Options Database Keys:
828: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, SNESType for complete list
829: . -snes_stol - convergence tolerance in terms of the norm
830: of the change in the solution between steps
831: . -snes_atol <abstol> - absolute tolerance of residual norm
832: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
833: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
834: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
835: . -snes_max_it <max_it> - maximum number of iterations
836: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
837: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
838: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
839: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
840: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
841: . -snes_trtol <trtol> - trust region tolerance
842: . -snes_no_convergence_test - skip convergence test in nonlinear
843: solver; hence iterations will continue until max_it
844: or some other criterion is reached. Saves expense
845: of convergence test
846: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
847: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
848: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
849: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
850: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
851: . -snes_monitor_lg_range - plots residual norm at each iteration
852: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
853: . -snes_fd_color - use finite differences with coloring to compute Jacobian
854: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
855: . -snes_converged_reason - print the reason for convergence/divergence after each solve
856: - -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
858: Options Database for Eisenstat-Walker method:
859: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
860: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
861: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
862: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
863: . -snes_ksp_ew_gamma <gamma> - Sets gamma
864: . -snes_ksp_ew_alpha <alpha> - Sets alpha
865: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
866: - -snes_ksp_ew_threshold <threshold> - Sets threshold
868: Notes:
869: To see all options, run your program with the -help option or consult
870: Users-Manual: ch_snes
872: Level: beginner
874: .seealso: SNESSetOptionsPrefix(), SNESResetFromOptions()
875: @*/
876: PetscErrorCode SNESSetFromOptions(SNES snes)
877: {
878: PetscBool flg,pcset,persist,set;
879: PetscInt i,indx,lag,grids;
880: const char *deft = SNESNEWTONLS;
881: const char *convtests[] = {"default","skip"};
882: SNESKSPEW *kctx = NULL;
883: char type[256], monfilename[PETSC_MAX_PATH_LEN];
885: PCSide pcside;
886: const char *optionsprefix;
890: SNESRegisterAll();
891: PetscObjectOptionsBegin((PetscObject)snes);
892: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
893: PetscOptionsFList("-snes_type","Nonlinear solver method","SNESSetType",SNESList,deft,type,256,&flg);
894: if (flg) {
895: SNESSetType(snes,type);
896: } else if (!((PetscObject)snes)->type_name) {
897: SNESSetType(snes,deft);
898: }
899: PetscOptionsReal("-snes_stol","Stop if step length less than","SNESSetTolerances",snes->stol,&snes->stol,NULL);
900: PetscOptionsReal("-snes_atol","Stop if function norm less than","SNESSetTolerances",snes->abstol,&snes->abstol,NULL);
902: PetscOptionsReal("-snes_rtol","Stop if decrease in function norm less than","SNESSetTolerances",snes->rtol,&snes->rtol,NULL);
903: PetscOptionsReal("-snes_divergence_tolerance","Stop if residual norm increases by this factor","SNESSetDivergenceTolerance",snes->divtol,&snes->divtol,NULL);
904: PetscOptionsInt("-snes_max_it","Maximum iterations","SNESSetTolerances",snes->max_its,&snes->max_its,NULL);
905: PetscOptionsInt("-snes_max_funcs","Maximum function evaluations","SNESSetTolerances",snes->max_funcs,&snes->max_funcs,NULL);
906: PetscOptionsInt("-snes_max_fail","Maximum nonlinear step failures","SNESSetMaxNonlinearStepFailures",snes->maxFailures,&snes->maxFailures,NULL);
907: PetscOptionsInt("-snes_max_linear_solve_fail","Maximum failures in linear solves allowed","SNESSetMaxLinearSolveFailures",snes->maxLinearSolveFailures,&snes->maxLinearSolveFailures,NULL);
908: PetscOptionsBool("-snes_error_if_not_converged","Generate error if solver does not converge","SNESSetErrorIfNotConverged",snes->errorifnotconverged,&snes->errorifnotconverged,NULL);
909: PetscOptionsBool("-snes_force_iteration","Force SNESSolve() to take at least one iteration","SNESSetForceIteration",snes->forceiteration,&snes->forceiteration,NULL);
910: PetscOptionsBool("-snes_check_jacobian_domain_error","Check Jacobian domain error after Jacobian evaluation","SNESCheckJacobianDomainError",snes->checkjacdomainerror,&snes->checkjacdomainerror,NULL);
912: PetscOptionsInt("-snes_lag_preconditioner","How often to rebuild preconditioner","SNESSetLagPreconditioner",snes->lagpreconditioner,&lag,&flg);
913: if (flg) {
914: SNESSetLagPreconditioner(snes,lag);
915: }
916: PetscOptionsBool("-snes_lag_preconditioner_persists","Preconditioner lagging through multiple solves","SNESSetLagPreconditionerPersists",snes->lagjac_persist,&persist,&flg);
917: if (flg) {
918: SNESSetLagPreconditionerPersists(snes,persist);
919: }
920: PetscOptionsInt("-snes_lag_jacobian","How often to rebuild Jacobian","SNESSetLagJacobian",snes->lagjacobian,&lag,&flg);
921: if (flg) {
922: SNESSetLagJacobian(snes,lag);
923: }
924: PetscOptionsBool("-snes_lag_jacobian_persists","Jacobian lagging through multiple solves","SNESSetLagJacobianPersists",snes->lagjac_persist,&persist,&flg);
925: if (flg) {
926: SNESSetLagJacobianPersists(snes,persist);
927: }
929: PetscOptionsInt("-snes_grid_sequence","Use grid sequencing to generate initial guess","SNESSetGridSequence",snes->gridsequence,&grids,&flg);
930: if (flg) {
931: SNESSetGridSequence(snes,grids);
932: }
934: PetscOptionsEList("-snes_convergence_test","Convergence test","SNESSetConvergenceTest",convtests,2,"default",&indx,&flg);
935: if (flg) {
936: switch (indx) {
937: case 0: SNESSetConvergenceTest(snes,SNESConvergedDefault,NULL,NULL); break;
938: case 1: SNESSetConvergenceTest(snes,SNESConvergedSkip,NULL,NULL); break;
939: }
940: }
942: PetscOptionsEList("-snes_norm_schedule","SNES Norm schedule","SNESSetNormSchedule",SNESNormSchedules,5,"function",&indx,&flg);
943: if (flg) { SNESSetNormSchedule(snes,(SNESNormSchedule)indx); }
945: PetscOptionsEList("-snes_function_type","SNES Norm schedule","SNESSetFunctionType",SNESFunctionTypes,2,"unpreconditioned",&indx,&flg);
946: if (flg) { SNESSetFunctionType(snes,(SNESFunctionType)indx); }
948: kctx = (SNESKSPEW*)snes->kspconvctx;
950: PetscOptionsBool("-snes_ksp_ew","Use Eisentat-Walker linear system convergence test","SNESKSPSetUseEW",snes->ksp_ewconv,&snes->ksp_ewconv,NULL);
952: PetscOptionsInt("-snes_ksp_ew_version","Version 1, 2 or 3","SNESKSPSetParametersEW",kctx->version,&kctx->version,NULL);
953: PetscOptionsReal("-snes_ksp_ew_rtol0","0 <= rtol0 < 1","SNESKSPSetParametersEW",kctx->rtol_0,&kctx->rtol_0,NULL);
954: PetscOptionsReal("-snes_ksp_ew_rtolmax","0 <= rtolmax < 1","SNESKSPSetParametersEW",kctx->rtol_max,&kctx->rtol_max,NULL);
955: PetscOptionsReal("-snes_ksp_ew_gamma","0 <= gamma <= 1","SNESKSPSetParametersEW",kctx->gamma,&kctx->gamma,NULL);
956: PetscOptionsReal("-snes_ksp_ew_alpha","1 < alpha <= 2","SNESKSPSetParametersEW",kctx->alpha,&kctx->alpha,NULL);
957: PetscOptionsReal("-snes_ksp_ew_alpha2","alpha2","SNESKSPSetParametersEW",kctx->alpha2,&kctx->alpha2,NULL);
958: PetscOptionsReal("-snes_ksp_ew_threshold","0 < threshold < 1","SNESKSPSetParametersEW",kctx->threshold,&kctx->threshold,NULL);
960: flg = PETSC_FALSE;
961: PetscOptionsBool("-snes_monitor_cancel","Remove all monitors","SNESMonitorCancel",flg,&flg,&set);
962: if (set && flg) {SNESMonitorCancel(snes);}
964: SNESMonitorSetFromOptions(snes,"-snes_monitor","Monitor norm of function","SNESMonitorDefault",SNESMonitorDefault,NULL);
965: SNESMonitorSetFromOptions(snes,"-snes_monitor_short","Monitor norm of function with fewer digits","SNESMonitorDefaultShort",SNESMonitorDefaultShort,NULL);
966: SNESMonitorSetFromOptions(snes,"-snes_monitor_range","Monitor range of elements of function","SNESMonitorRange",SNESMonitorRange,NULL);
968: SNESMonitorSetFromOptions(snes,"-snes_monitor_ratio","Monitor ratios of the norm of function for consecutive steps","SNESMonitorRatio",SNESMonitorRatio,SNESMonitorRatioSetUp);
969: SNESMonitorSetFromOptions(snes,"-snes_monitor_field","Monitor norm of function (split into fields)","SNESMonitorDefaultField",SNESMonitorDefaultField,NULL);
970: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution","View solution at each iteration","SNESMonitorSolution",SNESMonitorSolution,NULL);
971: SNESMonitorSetFromOptions(snes,"-snes_monitor_solution_update","View correction at each iteration","SNESMonitorSolutionUpdate",SNESMonitorSolutionUpdate,NULL);
972: SNESMonitorSetFromOptions(snes,"-snes_monitor_residual","View residual at each iteration","SNESMonitorResidual",SNESMonitorResidual,NULL);
973: SNESMonitorSetFromOptions(snes,"-snes_monitor_jacupdate_spectrum","Print the change in the spectrum of the Jacobian","SNESMonitorJacUpdateSpectrum",SNESMonitorJacUpdateSpectrum,NULL);
974: SNESMonitorSetFromOptions(snes,"-snes_monitor_fields","Monitor norm of function per field","SNESMonitorSet",SNESMonitorFields,NULL);
976: PetscOptionsString("-snes_monitor_python","Use Python function","SNESMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
977: if (flg) {PetscPythonMonitorSet((PetscObject)snes,monfilename);}
979: flg = PETSC_FALSE;
980: PetscOptionsBool("-snes_monitor_lg_residualnorm","Plot function norm at each iteration","SNESMonitorLGResidualNorm",flg,&flg,NULL);
981: if (flg) {
982: PetscDrawLG ctx;
984: SNESMonitorLGCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
985: SNESMonitorSet(snes,SNESMonitorLGResidualNorm,ctx,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
986: }
987: flg = PETSC_FALSE;
988: PetscOptionsBool("-snes_monitor_lg_range","Plot function range at each iteration","SNESMonitorLGRange",flg,&flg,NULL);
989: if (flg) {
990: PetscViewer ctx;
992: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300,&ctx);
993: SNESMonitorSet(snes,SNESMonitorLGRange,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
994: }
996: flg = PETSC_FALSE;
997: PetscOptionsBool("-snes_fd","Use finite differences (slow) to compute Jacobian","SNESComputeJacobianDefault",flg,&flg,NULL);
998: if (flg) {
999: void *functx;
1000: DM dm;
1001: DMSNES sdm;
1002: SNESGetDM(snes,&dm);
1003: DMGetDMSNES(dm,&sdm);
1004: sdm->jacobianctx = NULL;
1005: SNESGetFunction(snes,NULL,NULL,&functx);
1006: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefault,functx);
1007: PetscInfo(snes,"Setting default finite difference Jacobian matrix\n");
1008: }
1010: flg = PETSC_FALSE;
1011: PetscOptionsBool("-snes_fd_function","Use finite differences (slow) to compute function from user objective","SNESObjectiveComputeFunctionDefaultFD",flg,&flg,NULL);
1012: if (flg) {
1013: SNESSetFunction(snes,NULL,SNESObjectiveComputeFunctionDefaultFD,NULL);
1014: }
1016: flg = PETSC_FALSE;
1017: PetscOptionsBool("-snes_fd_color","Use finite differences with coloring to compute Jacobian","SNESComputeJacobianDefaultColor",flg,&flg,NULL);
1018: if (flg) {
1019: DM dm;
1020: DMSNES sdm;
1021: SNESGetDM(snes,&dm);
1022: DMGetDMSNES(dm,&sdm);
1023: sdm->jacobianctx = NULL;
1024: SNESSetJacobian(snes,snes->jacobian,snes->jacobian_pre,SNESComputeJacobianDefaultColor,0);
1025: PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");
1026: }
1028: flg = PETSC_FALSE;
1029: PetscOptionsBool("-snes_mf_operator","Use a Matrix-Free Jacobian with user-provided preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf_operator,&flg);
1030: if (flg && snes->mf_operator) {
1031: snes->mf_operator = PETSC_TRUE;
1032: snes->mf = PETSC_TRUE;
1033: }
1034: flg = PETSC_FALSE;
1035: PetscOptionsBool("-snes_mf","Use a Matrix-Free Jacobian with no preconditioner matrix","SNESSetUseMatrixFree",PETSC_FALSE,&snes->mf,&flg);
1036: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1037: PetscOptionsInt("-snes_mf_version","Matrix-Free routines version 1 or 2","None",snes->mf_version,&snes->mf_version,0);
1039: flg = PETSC_FALSE;
1040: SNESGetNPCSide(snes,&pcside);
1041: PetscOptionsEnum("-snes_npc_side","SNES nonlinear preconditioner side","SNESSetNPCSide",PCSides,(PetscEnum)pcside,(PetscEnum*)&pcside,&flg);
1042: if (flg) {SNESSetNPCSide(snes,pcside);}
1044: #if defined(PETSC_HAVE_SAWS)
1045: /*
1046: Publish convergence information using SAWs
1047: */
1048: flg = PETSC_FALSE;
1049: PetscOptionsBool("-snes_monitor_saws","Publish SNES progress using SAWs","SNESMonitorSet",flg,&flg,NULL);
1050: if (flg) {
1051: void *ctx;
1052: SNESMonitorSAWsCreate(snes,&ctx);
1053: SNESMonitorSet(snes,SNESMonitorSAWs,ctx,SNESMonitorSAWsDestroy);
1054: }
1055: #endif
1056: #if defined(PETSC_HAVE_SAWS)
1057: {
1058: PetscBool set;
1059: flg = PETSC_FALSE;
1060: PetscOptionsBool("-snes_saws_block","Block for SAWs at end of SNESSolve","PetscObjectSAWsBlock",((PetscObject)snes)->amspublishblock,&flg,&set);
1061: if (set) {
1062: PetscObjectSAWsSetBlock((PetscObject)snes,flg);
1063: }
1064: }
1065: #endif
1067: for (i = 0; i < numberofsetfromoptions; i++) {
1068: (*othersetfromoptions[i])(snes);
1069: }
1071: if (snes->ops->setfromoptions) {
1072: (*snes->ops->setfromoptions)(PetscOptionsObject,snes);
1073: }
1075: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1076: PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)snes);
1077: PetscOptionsEnd();
1079: if (snes->linesearch) {
1080: SNESGetLineSearch(snes, &snes->linesearch);
1081: SNESLineSearchSetFromOptions(snes->linesearch);
1082: }
1084: if (snes->usesksp) {
1085: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
1086: KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);
1087: KSPSetFromOptions(snes->ksp);
1088: }
1090: /* if user has set the SNES NPC type via options database, create it. */
1091: SNESGetOptionsPrefix(snes, &optionsprefix);
1092: PetscOptionsHasName(((PetscObject)snes)->options,optionsprefix, "-npc_snes_type", &pcset);
1093: if (pcset && (!snes->npc)) {
1094: SNESGetNPC(snes, &snes->npc);
1095: }
1096: if (snes->npc) {
1097: SNESSetFromOptions(snes->npc);
1098: }
1099: snes->setfromoptionscalled++;
1100: return(0);
1101: }
1103: /*@
1104: SNESResetFromOptions - Sets various SNES and KSP parameters from user options ONLY if the SNES was previously set from options
1106: Collective on SNES
1108: Input Parameter:
1109: . snes - the SNES context
1111: Level: beginner
1113: .seealso: SNESSetFromOptions(), SNESSetOptionsPrefix()
1114: @*/
1115: PetscErrorCode SNESResetFromOptions(SNES snes)
1116: {
1120: if (snes->setfromoptionscalled) {SNESSetFromOptions(snes);}
1121: return(0);
1122: }
1124: /*@C
1125: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1126: the nonlinear solvers.
1128: Logically Collective on SNES
1130: Input Parameters:
1131: + snes - the SNES context
1132: . compute - function to compute the context
1133: - destroy - function to destroy the context
1135: Level: intermediate
1137: Notes:
1138: This function is currently not available from Fortran.
1140: .seealso: SNESGetApplicationContext(), SNESSetComputeApplicationContext(), SNESGetApplicationContext()
1141: @*/
1142: PetscErrorCode SNESSetComputeApplicationContext(SNES snes,PetscErrorCode (*compute)(SNES,void**),PetscErrorCode (*destroy)(void**))
1143: {
1146: snes->ops->usercompute = compute;
1147: snes->ops->userdestroy = destroy;
1148: return(0);
1149: }
1151: /*@
1152: SNESSetApplicationContext - Sets the optional user-defined context for
1153: the nonlinear solvers.
1155: Logically Collective on SNES
1157: Input Parameters:
1158: + snes - the SNES context
1159: - usrP - optional user context
1161: Level: intermediate
1163: Fortran Notes:
1164: To use this from Fortran you must write a Fortran interface definition for this
1165: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1167: .seealso: SNESGetApplicationContext()
1168: @*/
1169: PetscErrorCode SNESSetApplicationContext(SNES snes,void *usrP)
1170: {
1172: KSP ksp;
1176: SNESGetKSP(snes,&ksp);
1177: KSPSetApplicationContext(ksp,usrP);
1178: snes->user = usrP;
1179: return(0);
1180: }
1182: /*@
1183: SNESGetApplicationContext - Gets the user-defined context for the
1184: nonlinear solvers.
1186: Not Collective
1188: Input Parameter:
1189: . snes - SNES context
1191: Output Parameter:
1192: . usrP - user context
1194: Fortran Notes:
1195: To use this from Fortran you must write a Fortran interface definition for this
1196: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1198: Level: intermediate
1200: .seealso: SNESSetApplicationContext()
1201: @*/
1202: PetscErrorCode SNESGetApplicationContext(SNES snes,void *usrP)
1203: {
1206: *(void**)usrP = snes->user;
1207: return(0);
1208: }
1210: /*@
1211: SNESSetUseMatrixFree - indicates that SNES should use matrix free finite difference matrix vector products internally to apply
1212: the Jacobian.
1214: Collective on SNES
1216: Input Parameters:
1217: + snes - SNES context
1218: . mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1219: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1221: Options Database:
1222: + -snes_mf - use matrix free for both the mat and pmat operator
1223: - -snes_mf_operator - use matrix free only for the mat operator
1225: Level: intermediate
1227: .seealso: SNESGetUseMatrixFree(), MatCreateSNESMF()
1228: @*/
1229: PetscErrorCode SNESSetUseMatrixFree(SNES snes,PetscBool mf_operator,PetscBool mf)
1230: {
1235: if (mf && !mf_operator) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"If using mf must also use mf_operator");
1236: snes->mf = mf;
1237: snes->mf_operator = mf_operator;
1238: return(0);
1239: }
1241: /*@
1242: SNESGetUseMatrixFree - indicates if the SNES uses matrix free finite difference matrix vector products to apply
1243: the Jacobian.
1245: Collective on SNES
1247: Input Parameter:
1248: . snes - SNES context
1250: Output Parameters:
1251: + mf - use matrix-free for both the Amat and Pmat used by SNESSetJacobian(), both the Amat and Pmat set in SNESSetJacobian() will be ignored
1252: - mf_operator - use matrix-free only for the Amat used by SNESSetJacobian(), this means the user provided Pmat will continue to be used
1254: Options Database:
1255: + -snes_mf - use matrix free for both the mat and pmat operator
1256: - -snes_mf_operator - use matrix free only for the mat operator
1258: Level: intermediate
1260: .seealso: SNESSetUseMatrixFree(), MatCreateSNESMF()
1261: @*/
1262: PetscErrorCode SNESGetUseMatrixFree(SNES snes,PetscBool *mf_operator,PetscBool *mf)
1263: {
1266: if (mf) *mf = snes->mf;
1267: if (mf_operator) *mf_operator = snes->mf_operator;
1268: return(0);
1269: }
1271: /*@
1272: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1273: at this time.
1275: Not Collective
1277: Input Parameter:
1278: . snes - SNES context
1280: Output Parameter:
1281: . iter - iteration number
1283: Notes:
1284: For example, during the computation of iteration 2 this would return 1.
1286: This is useful for using lagged Jacobians (where one does not recompute the
1287: Jacobian at each SNES iteration). For example, the code
1288: .vb
1289: SNESGetIterationNumber(snes,&it);
1290: if (!(it % 2)) {
1291: [compute Jacobian here]
1292: }
1293: .ve
1294: can be used in your ComputeJacobian() function to cause the Jacobian to be
1295: recomputed every second SNES iteration.
1297: After the SNES solve is complete this will return the number of nonlinear iterations used.
1299: Level: intermediate
1301: .seealso: SNESGetLinearSolveIterations()
1302: @*/
1303: PetscErrorCode SNESGetIterationNumber(SNES snes,PetscInt *iter)
1304: {
1308: *iter = snes->iter;
1309: return(0);
1310: }
1312: /*@
1313: SNESSetIterationNumber - Sets the current iteration number.
1315: Not Collective
1317: Input Parameter:
1318: + snes - SNES context
1319: - iter - iteration number
1321: Level: developer
1323: .seealso: SNESGetLinearSolveIterations()
1324: @*/
1325: PetscErrorCode SNESSetIterationNumber(SNES snes,PetscInt iter)
1326: {
1331: PetscObjectSAWsTakeAccess((PetscObject)snes);
1332: snes->iter = iter;
1333: PetscObjectSAWsGrantAccess((PetscObject)snes);
1334: return(0);
1335: }
1337: /*@
1338: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1339: attempted by the nonlinear solver.
1341: Not Collective
1343: Input Parameter:
1344: . snes - SNES context
1346: Output Parameter:
1347: . nfails - number of unsuccessful steps attempted
1349: Notes:
1350: This counter is reset to zero for each successive call to SNESSolve().
1352: Level: intermediate
1354: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1355: SNESSetMaxNonlinearStepFailures(), SNESGetMaxNonlinearStepFailures()
1356: @*/
1357: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes,PetscInt *nfails)
1358: {
1362: *nfails = snes->numFailures;
1363: return(0);
1364: }
1366: /*@
1367: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1368: attempted by the nonlinear solver before it gives up.
1370: Not Collective
1372: Input Parameters:
1373: + snes - SNES context
1374: - maxFails - maximum of unsuccessful steps
1376: Level: intermediate
1378: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1379: SNESGetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1380: @*/
1381: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1382: {
1385: snes->maxFailures = maxFails;
1386: return(0);
1387: }
1389: /*@
1390: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1391: attempted by the nonlinear solver before it gives up.
1393: Not Collective
1395: Input Parameter:
1396: . snes - SNES context
1398: Output Parameter:
1399: . maxFails - maximum of unsuccessful steps
1401: Level: intermediate
1403: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(),
1404: SNESSetMaxNonlinearStepFailures(), SNESGetNonlinearStepFailures()
1406: @*/
1407: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1408: {
1412: *maxFails = snes->maxFailures;
1413: return(0);
1414: }
1416: /*@
1417: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1418: done by SNES.
1420: Not Collective
1422: Input Parameter:
1423: . snes - SNES context
1425: Output Parameter:
1426: . nfuncs - number of evaluations
1428: Level: intermediate
1430: Notes:
1431: Reset every time SNESSolve is called unless SNESSetCountersReset() is used.
1433: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(), SNESGetLinearSolveFailures(), SNESSetCountersReset()
1434: @*/
1435: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1436: {
1440: *nfuncs = snes->nfuncs;
1441: return(0);
1442: }
1444: /*@
1445: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1446: linear solvers.
1448: Not Collective
1450: Input Parameter:
1451: . snes - SNES context
1453: Output Parameter:
1454: . nfails - number of failed solves
1456: Level: intermediate
1458: Options Database Keys:
1459: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1461: Notes:
1462: This counter is reset to zero for each successive call to SNESSolve().
1464: .seealso: SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures()
1465: @*/
1466: PetscErrorCode SNESGetLinearSolveFailures(SNES snes,PetscInt *nfails)
1467: {
1471: *nfails = snes->numLinearSolveFailures;
1472: return(0);
1473: }
1475: /*@
1476: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1477: allowed before SNES returns with a diverged reason of SNES_DIVERGED_LINEAR_SOLVE
1479: Logically Collective on SNES
1481: Input Parameters:
1482: + snes - SNES context
1483: - maxFails - maximum allowed linear solve failures
1485: Level: intermediate
1487: Options Database Keys:
1488: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1490: Notes:
1491: By default this is 0; that is SNES returns on the first failed linear solve
1493: .seealso: SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESGetLinearSolveIterations()
1494: @*/
1495: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1496: {
1500: snes->maxLinearSolveFailures = maxFails;
1501: return(0);
1502: }
1504: /*@
1505: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1506: are allowed before SNES terminates
1508: Not Collective
1510: Input Parameter:
1511: . snes - SNES context
1513: Output Parameter:
1514: . maxFails - maximum of unsuccessful solves allowed
1516: Level: intermediate
1518: Notes:
1519: By default this is 1; that is SNES returns on the first failed linear solve
1521: .seealso: SNESGetLinearSolveFailures(), SNESGetLinearSolveIterations(), SNESSetMaxLinearSolveFailures(),
1522: @*/
1523: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1524: {
1528: *maxFails = snes->maxLinearSolveFailures;
1529: return(0);
1530: }
1532: /*@
1533: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1534: used by the nonlinear solver.
1536: Not Collective
1538: Input Parameter:
1539: . snes - SNES context
1541: Output Parameter:
1542: . lits - number of linear iterations
1544: Notes:
1545: This counter is reset to zero for each successive call to SNESSolve() unless SNESSetCountersReset() is used.
1547: If the linear solver fails inside the SNESSolve() the iterations for that call to the linear solver are not included. If you wish to count them
1548: then call KSPGetIterationNumber() after the failed solve.
1550: Level: intermediate
1552: .seealso: SNESGetIterationNumber(), SNESGetLinearSolveFailures(), SNESGetMaxLinearSolveFailures(), SNESSetCountersReset()
1553: @*/
1554: PetscErrorCode SNESGetLinearSolveIterations(SNES snes,PetscInt *lits)
1555: {
1559: *lits = snes->linear_its;
1560: return(0);
1561: }
1563: /*@
1564: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1565: are reset every time SNESSolve() is called.
1567: Logically Collective on SNES
1569: Input Parameter:
1570: + snes - SNES context
1571: - reset - whether to reset the counters or not
1573: Notes:
1574: This defaults to PETSC_TRUE
1576: Level: developer
1578: .seealso: SNESGetNumberFunctionEvals(), SNESGetLinearSolveIterations(), SNESGetNPC()
1579: @*/
1580: PetscErrorCode SNESSetCountersReset(SNES snes,PetscBool reset)
1581: {
1585: snes->counters_reset = reset;
1586: return(0);
1587: }
1590: /*@
1591: SNESSetKSP - Sets a KSP context for the SNES object to use
1593: Not Collective, but the SNES and KSP objects must live on the same MPI_Comm
1595: Input Parameters:
1596: + snes - the SNES context
1597: - ksp - the KSP context
1599: Notes:
1600: The SNES object already has its KSP object, you can obtain with SNESGetKSP()
1601: so this routine is rarely needed.
1603: The KSP object that is already in the SNES object has its reference count
1604: decreased by one.
1606: Level: developer
1608: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
1609: @*/
1610: PetscErrorCode SNESSetKSP(SNES snes,KSP ksp)
1611: {
1618: PetscObjectReference((PetscObject)ksp);
1619: if (snes->ksp) {PetscObjectDereference((PetscObject)snes->ksp);}
1620: snes->ksp = ksp;
1621: return(0);
1622: }
1624: /* -----------------------------------------------------------*/
1625: /*@
1626: SNESCreate - Creates a nonlinear solver context.
1628: Collective
1630: Input Parameters:
1631: . comm - MPI communicator
1633: Output Parameter:
1634: . outsnes - the new SNES context
1636: Options Database Keys:
1637: + -snes_mf - Activates default matrix-free Jacobian-vector products,
1638: and no preconditioning matrix
1639: . -snes_mf_operator - Activates default matrix-free Jacobian-vector
1640: products, and a user-provided preconditioning matrix
1641: as set by SNESSetJacobian()
1642: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1644: Level: beginner
1646: Developer Notes:
1647: SNES always creates a KSP object even though many SNES methods do not use it. This is
1648: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1649: particular method does use KSP and regulates if the information about the KSP is printed
1650: in SNESView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
1651: by help messages about meaningless SNES options.
1653: SNES always creates the snes->kspconvctx even though it is used by only one type. This should
1654: be fixed.
1656: .seealso: SNESSolve(), SNESDestroy(), SNES, SNESSetLagPreconditioner()
1658: @*/
1659: PetscErrorCode SNESCreate(MPI_Comm comm,SNES *outsnes)
1660: {
1662: SNES snes;
1663: SNESKSPEW *kctx;
1667: *outsnes = NULL;
1668: SNESInitializePackage();
1670: PetscHeaderCreate(snes,SNES_CLASSID,"SNES","Nonlinear solver","SNES",comm,SNESDestroy,SNESView);
1672: snes->ops->converged = SNESConvergedDefault;
1673: snes->usesksp = PETSC_TRUE;
1674: snes->tolerancesset = PETSC_FALSE;
1675: snes->max_its = 50;
1676: snes->max_funcs = 10000;
1677: snes->norm = 0.0;
1678: snes->xnorm = 0.0;
1679: snes->ynorm = 0.0;
1680: snes->normschedule = SNES_NORM_ALWAYS;
1681: snes->functype = SNES_FUNCTION_DEFAULT;
1682: #if defined(PETSC_USE_REAL_SINGLE)
1683: snes->rtol = 1.e-5;
1684: #else
1685: snes->rtol = 1.e-8;
1686: #endif
1687: snes->ttol = 0.0;
1688: #if defined(PETSC_USE_REAL_SINGLE)
1689: snes->abstol = 1.e-25;
1690: #else
1691: snes->abstol = 1.e-50;
1692: #endif
1693: #if defined(PETSC_USE_REAL_SINGLE)
1694: snes->stol = 1.e-5;
1695: #else
1696: snes->stol = 1.e-8;
1697: #endif
1698: #if defined(PETSC_USE_REAL_SINGLE)
1699: snes->deltatol = 1.e-6;
1700: #else
1701: snes->deltatol = 1.e-12;
1702: #endif
1703: snes->divtol = 1.e4;
1704: snes->rnorm0 = 0;
1705: snes->nfuncs = 0;
1706: snes->numFailures = 0;
1707: snes->maxFailures = 1;
1708: snes->linear_its = 0;
1709: snes->lagjacobian = 1;
1710: snes->jac_iter = 0;
1711: snes->lagjac_persist = PETSC_FALSE;
1712: snes->lagpreconditioner = 1;
1713: snes->pre_iter = 0;
1714: snes->lagpre_persist = PETSC_FALSE;
1715: snes->numbermonitors = 0;
1716: snes->data = 0;
1717: snes->setupcalled = PETSC_FALSE;
1718: snes->ksp_ewconv = PETSC_FALSE;
1719: snes->nwork = 0;
1720: snes->work = 0;
1721: snes->nvwork = 0;
1722: snes->vwork = 0;
1723: snes->conv_hist_len = 0;
1724: snes->conv_hist_max = 0;
1725: snes->conv_hist = NULL;
1726: snes->conv_hist_its = NULL;
1727: snes->conv_hist_reset = PETSC_TRUE;
1728: snes->counters_reset = PETSC_TRUE;
1729: snes->vec_func_init_set = PETSC_FALSE;
1730: snes->reason = SNES_CONVERGED_ITERATING;
1731: snes->npcside = PC_RIGHT;
1732: snes->setfromoptionscalled = 0;
1734: snes->mf = PETSC_FALSE;
1735: snes->mf_operator = PETSC_FALSE;
1736: snes->mf_version = 1;
1738: snes->numLinearSolveFailures = 0;
1739: snes->maxLinearSolveFailures = 1;
1741: snes->vizerotolerance = 1.e-8;
1742: #if defined(PETSC_USE_DEBUG)
1743: snes->checkjacdomainerror = PETSC_TRUE;
1744: #else
1745: snes->checkjacdomainerror = PETSC_FALSE;
1746: #endif
1748: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1749: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1751: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1752: PetscNewLog(snes,&kctx);
1754: snes->kspconvctx = (void*)kctx;
1755: kctx->version = 2;
1756: kctx->rtol_0 = .3; /* Eisenstat and Walker suggest rtol_0=.5, but
1757: this was too large for some test cases */
1758: kctx->rtol_last = 0.0;
1759: kctx->rtol_max = .9;
1760: kctx->gamma = 1.0;
1761: kctx->alpha = .5*(1.0 + PetscSqrtReal(5.0));
1762: kctx->alpha2 = kctx->alpha;
1763: kctx->threshold = .1;
1764: kctx->lresid_last = 0.0;
1765: kctx->norm_last = 0.0;
1767: *outsnes = snes;
1768: return(0);
1769: }
1771: /*MC
1772: SNESFunction - Functional form used to convey the nonlinear function to be solved by SNES
1774: Synopsis:
1775: #include "petscsnes.h"
1776: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1778: Collective on snes
1780: Input Parameters:
1781: + snes - the SNES context
1782: . x - state at which to evaluate residual
1783: - ctx - optional user-defined function context, passed in with SNESSetFunction()
1785: Output Parameter:
1786: . f - vector to put residual (function value)
1788: Level: intermediate
1790: .seealso: SNESSetFunction(), SNESGetFunction()
1791: M*/
1793: /*@C
1794: SNESSetFunction - Sets the function evaluation routine and function
1795: vector for use by the SNES routines in solving systems of nonlinear
1796: equations.
1798: Logically Collective on SNES
1800: Input Parameters:
1801: + snes - the SNES context
1802: . r - vector to store function value
1803: . f - function evaluation routine; see SNESFunction for calling sequence details
1804: - ctx - [optional] user-defined context for private data for the
1805: function evaluation routine (may be NULL)
1807: Notes:
1808: The Newton-like methods typically solve linear systems of the form
1809: $ f'(x) x = -f(x),
1810: where f'(x) denotes the Jacobian matrix and f(x) is the function.
1812: Level: beginner
1814: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetPicard(), SNESFunction
1815: @*/
1816: PetscErrorCode SNESSetFunction(SNES snes,Vec r,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
1817: {
1819: DM dm;
1823: if (r) {
1826: PetscObjectReference((PetscObject)r);
1827: VecDestroy(&snes->vec_func);
1829: snes->vec_func = r;
1830: }
1831: SNESGetDM(snes,&dm);
1832: DMSNESSetFunction(dm,f,ctx);
1833: return(0);
1834: }
1837: /*@C
1838: SNESSetInitialFunction - Sets the function vector to be used as the
1839: function norm at the initialization of the method. In some
1840: instances, the user has precomputed the function before calling
1841: SNESSolve. This function allows one to avoid a redundant call
1842: to SNESComputeFunction in that case.
1844: Logically Collective on SNES
1846: Input Parameters:
1847: + snes - the SNES context
1848: - f - vector to store function value
1850: Notes:
1851: This should not be modified during the solution procedure.
1853: This is used extensively in the SNESFAS hierarchy and in nonlinear preconditioning.
1855: Level: developer
1857: .seealso: SNESSetFunction(), SNESComputeFunction(), SNESSetInitialFunctionNorm()
1858: @*/
1859: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1860: {
1862: Vec vec_func;
1868: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1869: snes->vec_func_init_set = PETSC_FALSE;
1870: return(0);
1871: }
1872: SNESGetFunction(snes,&vec_func,NULL,NULL);
1873: VecCopy(f, vec_func);
1875: snes->vec_func_init_set = PETSC_TRUE;
1876: return(0);
1877: }
1879: /*@
1880: SNESSetNormSchedule - Sets the SNESNormSchedule used in covergence and monitoring
1881: of the SNES method.
1883: Logically Collective on SNES
1885: Input Parameters:
1886: + snes - the SNES context
1887: - normschedule - the frequency of norm computation
1889: Options Database Key:
1890: . -snes_norm_schedule <none, always, initialonly, finalonly, initalfinalonly>
1892: Notes:
1893: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
1894: of the nonlinear function and the taking of its norm at every iteration to
1895: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1896: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
1897: may either be monitored for convergence or not. As these are often used as nonlinear
1898: preconditioners, monitoring the norm of their error is not a useful enterprise within
1899: their solution.
1901: Level: developer
1903: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1904: @*/
1905: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1906: {
1909: snes->normschedule = normschedule;
1910: return(0);
1911: }
1914: /*@
1915: SNESGetNormSchedule - Gets the SNESNormSchedule used in covergence and monitoring
1916: of the SNES method.
1918: Logically Collective on SNES
1920: Input Parameters:
1921: + snes - the SNES context
1922: - normschedule - the type of the norm used
1924: Level: advanced
1926: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1927: @*/
1928: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1929: {
1932: *normschedule = snes->normschedule;
1933: return(0);
1934: }
1937: /*@
1938: SNESSetFunctionNorm - Sets the last computed residual norm.
1940: Logically Collective on SNES
1942: Input Parameters:
1943: + snes - the SNES context
1945: - normschedule - the frequency of norm computation
1947: Level: developer
1949: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1950: @*/
1951: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1952: {
1955: snes->norm = norm;
1956: return(0);
1957: }
1959: /*@
1960: SNESGetFunctionNorm - Gets the last computed norm of the residual
1962: Not Collective
1964: Input Parameter:
1965: . snes - the SNES context
1967: Output Parameter:
1968: . norm - the last computed residual norm
1970: Level: developer
1972: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
1973: @*/
1974: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1975: {
1979: *norm = snes->norm;
1980: return(0);
1981: }
1983: /*@
1984: SNESGetUpdateNorm - Gets the last computed norm of the Newton update
1986: Not Collective
1988: Input Parameter:
1989: . snes - the SNES context
1991: Output Parameter:
1992: . ynorm - the last computed update norm
1994: Level: developer
1996: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm()
1997: @*/
1998: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
1999: {
2003: *ynorm = snes->ynorm;
2004: return(0);
2005: }
2007: /*@
2008: SNESGetSolutionNorm - Gets the last computed norm of the solution
2010: Not Collective
2012: Input Parameter:
2013: . snes - the SNES context
2015: Output Parameter:
2016: . xnorm - the last computed solution norm
2018: Level: developer
2020: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), SNESGetFunctionNorm(), SNESGetUpdateNorm()
2021: @*/
2022: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2023: {
2027: *xnorm = snes->xnorm;
2028: return(0);
2029: }
2031: /*@C
2032: SNESSetFunctionType - Sets the SNESNormSchedule used in covergence and monitoring
2033: of the SNES method.
2035: Logically Collective on SNES
2037: Input Parameters:
2038: + snes - the SNES context
2039: - normschedule - the frequency of norm computation
2041: Notes:
2042: Only certain SNES methods support certain SNESNormSchedules. Most require evaluation
2043: of the nonlinear function and the taking of its norm at every iteration to
2044: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2045: (SNESNGS) and the like do not require the norm of the function to be computed, and therfore
2046: may either be monitored for convergence or not. As these are often used as nonlinear
2047: preconditioners, monitoring the norm of their error is not a useful enterprise within
2048: their solution.
2050: Level: developer
2052: .seealso: SNESGetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2053: @*/
2054: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2055: {
2058: snes->functype = type;
2059: return(0);
2060: }
2063: /*@C
2064: SNESGetFunctionType - Gets the SNESNormSchedule used in covergence and monitoring
2065: of the SNES method.
2067: Logically Collective on SNES
2069: Input Parameters:
2070: + snes - the SNES context
2071: - normschedule - the type of the norm used
2073: Level: advanced
2075: .seealso: SNESSetNormSchedule(), SNESComputeFunction(), VecNorm(), SNESSetFunction(), SNESSetInitialFunction(), SNESNormSchedule
2076: @*/
2077: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2078: {
2081: *type = snes->functype;
2082: return(0);
2083: }
2085: /*MC
2086: SNESNGSFunction - function used to convey a Gauss-Seidel sweep on the nonlinear function
2088: Synopsis:
2089: #include <petscsnes.h>
2090: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2092: Collective on snes
2094: Input Parameters:
2095: + X - solution vector
2096: . B - RHS vector
2097: - ctx - optional user-defined Gauss-Seidel context
2099: Output Parameter:
2100: . X - solution vector
2102: Level: intermediate
2104: .seealso: SNESSetNGS(), SNESGetNGS()
2105: M*/
2107: /*@C
2108: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2109: use with composed nonlinear solvers.
2111: Input Parameters:
2112: + snes - the SNES context
2113: . f - function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
2114: - ctx - [optional] user-defined context for private data for the
2115: smoother evaluation routine (may be NULL)
2117: Notes:
2118: The NGS routines are used by the composed nonlinear solver to generate
2119: a problem appropriate update to the solution, particularly FAS.
2121: Level: intermediate
2123: .seealso: SNESGetFunction(), SNESComputeNGS()
2124: @*/
2125: PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)
2126: {
2128: DM dm;
2132: SNESGetDM(snes,&dm);
2133: DMSNESSetNGS(dm,f,ctx);
2134: return(0);
2135: }
2137: PetscErrorCode SNESPicardComputeFunction(SNES snes,Vec x,Vec f,void *ctx)
2138: {
2140: DM dm;
2141: DMSNES sdm;
2144: SNESGetDM(snes,&dm);
2145: DMGetDMSNES(dm,&sdm);
2146: if (!sdm->ops->computepfunction) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard function.");
2147: if (!sdm->ops->computepjacobian) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetPicard() to provide Picard Jacobian.");
2148: /* A(x)*x - b(x) */
2149: PetscStackPush("SNES Picard user function");
2150: (*sdm->ops->computepfunction)(snes,x,f,sdm->pctx);
2151: PetscStackPop;
2152: PetscStackPush("SNES Picard user Jacobian");
2153: (*sdm->ops->computepjacobian)(snes,x,snes->jacobian,snes->jacobian_pre,sdm->pctx);
2154: PetscStackPop;
2155: VecScale(f,-1.0);
2156: MatMultAdd(snes->jacobian,x,f,f);
2157: return(0);
2158: }
2160: PetscErrorCode SNESPicardComputeJacobian(SNES snes,Vec x1,Mat J,Mat B,void *ctx)
2161: {
2163: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2164: return(0);
2165: }
2167: /*@C
2168: SNESSetPicard - Use SNES to solve the semilinear-system A(x) x = b(x) via a Picard type iteration (Picard linearization)
2170: Logically Collective on SNES
2172: Input Parameters:
2173: + snes - the SNES context
2174: . r - vector to store function value
2175: . b - function evaluation routine
2176: . Amat - matrix with which A(x) x - b(x) is to be computed
2177: . Pmat - matrix from which preconditioner is computed (usually the same as Amat)
2178: . J - function to compute matrix value, see SNESJacobianFunction for details on its calling sequence
2179: - ctx - [optional] user-defined context for private data for the
2180: function evaluation routine (may be NULL)
2182: Notes:
2183: 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
2184: 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.
2186: One can call SNESSetPicard() or SNESSetFunction() (and possibly SNESSetJacobian()) but cannot call both
2188: $ 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}
2189: $ Note that when an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = b(x^{n}) iteration.
2191: Run with -snes_mf_operator to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2193: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2194: the direct Picard iteration A(x^n) x^{n+1} = b(x^n)
2196: 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
2197: 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
2198: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2200: Level: intermediate
2202: .seealso: SNESGetFunction(), SNESSetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESGetPicard(), SNESLineSearchPreCheckPicard(), SNESJacobianFunction
2203: @*/
2204: 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)
2205: {
2207: DM dm;
2211: SNESGetDM(snes, &dm);
2212: DMSNESSetPicard(dm,b,J,ctx);
2213: SNESSetFunction(snes,r,SNESPicardComputeFunction,ctx);
2214: SNESSetJacobian(snes,Amat,Pmat,SNESPicardComputeJacobian,ctx);
2215: return(0);
2216: }
2218: /*@C
2219: SNESGetPicard - Returns the context for the Picard iteration
2221: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
2223: Input Parameter:
2224: . snes - the SNES context
2226: Output Parameter:
2227: + r - the function (or NULL)
2228: . f - the function (or NULL); see SNESFunction for calling sequence details
2229: . Amat - the matrix used to defined the operation A(x) x - b(x) (or NULL)
2230: . Pmat - the matrix from which the preconditioner will be constructed (or NULL)
2231: . J - the function for matrix evaluation (or NULL); see SNESJacobianFunction for calling sequence details
2232: - ctx - the function context (or NULL)
2234: Level: advanced
2236: .seealso: SNESSetPicard(), SNESGetFunction(), SNESGetJacobian(), SNESGetDM(), SNESFunction, SNESJacobianFunction
2237: @*/
2238: 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)
2239: {
2241: DM dm;
2245: SNESGetFunction(snes,r,NULL,NULL);
2246: SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
2247: SNESGetDM(snes,&dm);
2248: DMSNESGetPicard(dm,f,J,ctx);
2249: return(0);
2250: }
2252: /*@C
2253: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the problem
2255: Logically Collective on SNES
2257: Input Parameters:
2258: + snes - the SNES context
2259: . func - function evaluation routine
2260: - ctx - [optional] user-defined context for private data for the
2261: function evaluation routine (may be NULL)
2263: Calling sequence of func:
2264: $ func (SNES snes,Vec x,void *ctx);
2266: . f - function vector
2267: - ctx - optional user-defined function context
2269: Level: intermediate
2271: .seealso: SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian()
2272: @*/
2273: PetscErrorCode SNESSetComputeInitialGuess(SNES snes,PetscErrorCode (*func)(SNES,Vec,void*),void *ctx)
2274: {
2277: if (func) snes->ops->computeinitialguess = func;
2278: if (ctx) snes->initialguessP = ctx;
2279: return(0);
2280: }
2282: /* --------------------------------------------------------------- */
2283: /*@C
2284: SNESGetRhs - Gets the vector for solving F(x) = rhs. If rhs is not set
2285: it assumes a zero right hand side.
2287: Logically Collective on SNES
2289: Input Parameter:
2290: . snes - the SNES context
2292: Output Parameter:
2293: . rhs - the right hand side vector or NULL if the right hand side vector is null
2295: Level: intermediate
2297: .seealso: SNESGetSolution(), SNESGetFunction(), SNESComputeFunction(), SNESSetJacobian(), SNESSetFunction()
2298: @*/
2299: PetscErrorCode SNESGetRhs(SNES snes,Vec *rhs)
2300: {
2304: *rhs = snes->vec_rhs;
2305: return(0);
2306: }
2308: /*@
2309: SNESComputeFunction - Calls the function that has been set with SNESSetFunction().
2311: Collective on SNES
2313: Input Parameters:
2314: + snes - the SNES context
2315: - x - input vector
2317: Output Parameter:
2318: . y - function vector, as set by SNESSetFunction()
2320: Notes:
2321: SNESComputeFunction() is typically used within nonlinear solvers
2322: implementations, so most users would not generally call this routine
2323: themselves.
2325: Level: developer
2327: .seealso: SNESSetFunction(), SNESGetFunction()
2328: @*/
2329: PetscErrorCode SNESComputeFunction(SNES snes,Vec x,Vec y)
2330: {
2332: DM dm;
2333: DMSNES sdm;
2341: VecValidValues(x,2,PETSC_TRUE);
2343: SNESGetDM(snes,&dm);
2344: DMGetDMSNES(dm,&sdm);
2345: if (sdm->ops->computefunction) {
2346: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2347: PetscLogEventBegin(SNES_FunctionEval,snes,x,y,0);
2348: }
2349: VecLockReadPush(x);
2350: PetscStackPush("SNES user function");
2351: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2352: snes->domainerror = PETSC_FALSE;
2353: (*sdm->ops->computefunction)(snes,x,y,sdm->functionctx);
2354: PetscStackPop;
2355: VecLockReadPop(x);
2356: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) {
2357: PetscLogEventEnd(SNES_FunctionEval,snes,x,y,0);
2358: }
2359: } else if (snes->vec_rhs) {
2360: MatMult(snes->jacobian, x, y);
2361: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2362: if (snes->vec_rhs) {
2363: VecAXPY(y,-1.0,snes->vec_rhs);
2364: }
2365: snes->nfuncs++;
2366: /*
2367: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2368: propagate the value to all processes
2369: */
2370: if (snes->domainerror) {
2371: VecSetInf(y);
2372: }
2373: return(0);
2374: }
2376: /*@
2377: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with SNESSetNGS().
2379: Collective on SNES
2381: Input Parameters:
2382: + snes - the SNES context
2383: . x - input vector
2384: - b - rhs vector
2386: Output Parameter:
2387: . x - new solution vector
2389: Notes:
2390: SNESComputeNGS() is typically used within composed nonlinear solver
2391: implementations, so most users would not generally call this routine
2392: themselves.
2394: Level: developer
2396: .seealso: SNESSetNGS(), SNESComputeFunction()
2397: @*/
2398: PetscErrorCode SNESComputeNGS(SNES snes,Vec b,Vec x)
2399: {
2401: DM dm;
2402: DMSNES sdm;
2410: if (b) {VecValidValues(b,2,PETSC_TRUE);}
2411: PetscLogEventBegin(SNES_NGSEval,snes,x,b,0);
2412: SNESGetDM(snes,&dm);
2413: DMGetDMSNES(dm,&sdm);
2414: if (sdm->ops->computegs) {
2415: if (b) {VecLockReadPush(b);}
2416: PetscStackPush("SNES user NGS");
2417: (*sdm->ops->computegs)(snes,x,b,sdm->gsctx);
2418: PetscStackPop;
2419: if (b) {VecLockReadPop(b);}
2420: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2421: PetscLogEventEnd(SNES_NGSEval,snes,x,b,0);
2422: return(0);
2423: }
2425: PetscErrorCode SNESTestJacobian(SNES snes)
2426: {
2427: Mat A,B,C,D,jacobian;
2428: Vec x = snes->vec_sol,f = snes->vec_func;
2429: PetscErrorCode ierr;
2430: PetscReal nrm,gnorm;
2431: PetscReal threshold = 1.e-5;
2432: MatType mattype;
2433: PetscInt m,n,M,N;
2434: void *functx;
2435: PetscBool complete_print = PETSC_FALSE,threshold_print = PETSC_FALSE,test = PETSC_FALSE,flg;
2436: PetscViewer viewer,mviewer;
2437: MPI_Comm comm;
2438: PetscInt tabs;
2439: static PetscBool directionsprinted = PETSC_FALSE;
2440: PetscViewerFormat format;
2443: PetscObjectOptionsBegin((PetscObject)snes);
2444: PetscOptionsName("-snes_test_jacobian","Compare hand-coded and finite difference Jacobians","None",&test);
2445: PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold,NULL);
2446: PetscOptionsViewer("-snes_test_jacobian_view","View difference between hand-coded and finite difference Jacobians element entries","None",&mviewer,&format,&complete_print);
2447: if (!complete_print) {
2448: PetscOptionsViewer("-snes_test_jacobian_display","Display difference between hand-coded and finite difference Jacobians","None",&mviewer,&format,&complete_print);
2449: }
2450: /* for compatibility with PETSc 3.9 and older. */
2451: PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print);
2452: PetscOptionsEnd();
2453: if (!test) return(0);
2455: PetscObjectGetComm((PetscObject)snes,&comm);
2456: PetscViewerASCIIGetStdout(comm,&viewer);
2457: PetscViewerASCIIGetTab(viewer, &tabs);
2458: PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel);
2459: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian -------------\n");
2460: if (!complete_print && !directionsprinted) {
2461: PetscViewerASCIIPrintf(viewer," Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n");
2462: PetscViewerASCIIPrintf(viewer," of hand-coded and finite difference Jacobian entries greater than <threshold>.\n");
2463: }
2464: if (!directionsprinted) {
2465: PetscViewerASCIIPrintf(viewer," Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n");
2466: PetscViewerASCIIPrintf(viewer," O(1.e-8), the hand-coded Jacobian is probably correct.\n");
2467: directionsprinted = PETSC_TRUE;
2468: }
2469: if (complete_print) {
2470: PetscViewerPushFormat(mviewer,format);
2471: }
2473: PetscObjectTypeCompare((PetscObject)snes->jacobian,MATMFFD,&flg);
2474: if (!flg) jacobian = snes->jacobian;
2475: else jacobian = snes->jacobian_pre;
2477: if (!x) {
2478: MatCreateVecs(jacobian, &x, NULL);
2479: } else {
2480: PetscObjectReference((PetscObject) x);
2481: }
2482: if (!f) {
2483: VecDuplicate(x, &f);
2484: } else {
2485: PetscObjectReference((PetscObject) f);
2486: }
2487: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2488: SNESComputeFunction(snes,x,f);
2489: VecDestroy(&f);
2491: while (jacobian) {
2492: PetscObjectBaseTypeCompareAny((PetscObject)jacobian,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPISBAIJ,"");
2493: if (flg) {
2494: A = jacobian;
2495: PetscObjectReference((PetscObject)A);
2496: } else {
2497: MatComputeOperator(jacobian,MATAIJ,&A);
2498: }
2500: MatGetType(A,&mattype);
2501: MatGetSize(A,&M,&N);
2502: MatGetLocalSize(A,&m,&n);
2504: MatCreate(PetscObjectComm((PetscObject)A),&B);
2505: MatSetType(B,mattype);
2506: MatSetSizes(B,m,n,M,N);
2507: MatSetBlockSizesFromMats(B,A,A);
2508: MatSetUp(B);
2509: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2511: SNESGetFunction(snes,NULL,NULL,&functx);
2512: SNESComputeJacobianDefault(snes,x,B,B,functx);
2514: MatDuplicate(B,MAT_COPY_VALUES,&D);
2515: MatAYPX(D,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2516: MatNorm(D,NORM_FROBENIUS,&nrm);
2517: MatNorm(A,NORM_FROBENIUS,&gnorm);
2518: MatDestroy(&D);
2519: if (!gnorm) gnorm = 1; /* just in case */
2520: PetscViewerASCIIPrintf(viewer," ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n",(double)(nrm/gnorm),(double)nrm);
2522: if (complete_print) {
2523: PetscViewerASCIIPrintf(viewer," Hand-coded Jacobian ----------\n");
2524: MatView(A,mviewer);
2525: PetscViewerASCIIPrintf(viewer," Finite difference Jacobian ----------\n");
2526: MatView(B,mviewer);
2527: }
2529: if (threshold_print || complete_print) {
2530: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2531: PetscScalar *cvals;
2532: const PetscInt *bcols;
2533: const PetscScalar *bvals;
2535: MatCreate(PetscObjectComm((PetscObject)A),&C);
2536: MatSetType(C,mattype);
2537: MatSetSizes(C,m,n,M,N);
2538: MatSetBlockSizesFromMats(C,A,A);
2539: MatSetUp(C);
2540: MatSetOption(C,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);
2542: MatAYPX(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
2543: MatGetOwnershipRange(B,&Istart,&Iend);
2545: for (row = Istart; row < Iend; row++) {
2546: MatGetRow(B,row,&bncols,&bcols,&bvals);
2547: PetscMalloc2(bncols,&ccols,bncols,&cvals);
2548: for (j = 0, cncols = 0; j < bncols; j++) {
2549: if (PetscAbsScalar(bvals[j]) > threshold) {
2550: ccols[cncols] = bcols[j];
2551: cvals[cncols] = bvals[j];
2552: cncols += 1;
2553: }
2554: }
2555: if (cncols) {
2556: MatSetValues(C,1,&row,cncols,ccols,cvals,INSERT_VALUES);
2557: }
2558: MatRestoreRow(B,row,&bncols,&bcols,&bvals);
2559: PetscFree2(ccols,cvals);
2560: }
2561: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
2562: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
2563: PetscViewerASCIIPrintf(viewer," Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n",(double)threshold);
2564: MatView(C,complete_print ? mviewer : viewer);
2565: MatDestroy(&C);
2566: }
2567: MatDestroy(&A);
2568: MatDestroy(&B);
2570: if (jacobian != snes->jacobian_pre) {
2571: jacobian = snes->jacobian_pre;
2572: PetscViewerASCIIPrintf(viewer," ---------- Testing Jacobian for preconditioner -------------\n");
2573: }
2574: else jacobian = NULL;
2575: }
2576: VecDestroy(&x);
2577: if (complete_print) {
2578: PetscViewerPopFormat(mviewer);
2579: }
2580: if (mviewer) { PetscViewerDestroy(&mviewer); }
2581: PetscViewerASCIISetTab(viewer,tabs);
2582: return(0);
2583: }
2585: /*@
2586: SNESComputeJacobian - Computes the Jacobian matrix that has been set with SNESSetJacobian().
2588: Collective on SNES
2590: Input Parameters:
2591: + snes - the SNES context
2592: - x - input vector
2594: Output Parameters:
2595: + A - Jacobian matrix
2596: - B - optional preconditioning matrix
2598: Options Database Keys:
2599: + -snes_lag_preconditioner <lag>
2600: . -snes_lag_jacobian <lag>
2601: . -snes_test_jacobian - compare the user provided Jacobian with one compute via finite differences to check for errors
2602: . -snes_test_jacobian_display - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2603: . -snes_test_jacobian_display_threshold <numerical value> - display entries in the difference between the user provided Jacobian and finite difference Jacobian that are greater than a certain value to help users detect errors
2604: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2605: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2606: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2607: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2608: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2609: . -snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences
2610: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2611: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2612: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold
2613: . -snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences
2614: - -snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences
2617: Notes:
2618: Most users should not need to explicitly call this routine, as it
2619: is used internally within the nonlinear solvers.
2621: Developer Notes:
2622: This has duplicative ways of checking the accuracy of the user provided Jacobian (see the options above). This is for historical reasons, the routine SNESTestJacobian() use to used
2623: for with the SNESType of test that has been removed.
2625: Level: developer
2627: .seealso: SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()
2628: @*/
2629: PetscErrorCode SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
2630: {
2632: PetscBool flag;
2633: DM dm;
2634: DMSNES sdm;
2635: KSP ksp;
2641: VecValidValues(X,2,PETSC_TRUE);
2642: SNESGetDM(snes,&dm);
2643: DMGetDMSNES(dm,&sdm);
2645: if (!sdm->ops->computejacobian) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_USER,"Must call SNESSetJacobian(), DMSNESSetJacobian(), DMDASNESSetJacobianLocal(), etc");
2647: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2649: if (snes->lagjacobian == -2) {
2650: snes->lagjacobian = -1;
2652: PetscInfo(snes,"Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n");
2653: } else if (snes->lagjacobian == -1) {
2654: PetscInfo(snes,"Reusing Jacobian/preconditioner because lag is -1\n");
2655: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2656: if (flag) {
2657: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2658: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2659: }
2660: return(0);
2661: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2662: PetscInfo2(snes,"Reusing Jacobian/preconditioner because lag is %D and SNES iteration is %D\n",snes->lagjacobian,snes->iter);
2663: PetscObjectTypeCompare((PetscObject)A,MATMFFD,&flag);
2664: if (flag) {
2665: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2666: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2667: }
2668: return(0);
2669: }
2670: if (snes->npc && snes->npcside== PC_LEFT) {
2671: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
2672: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
2673: return(0);
2674: }
2676: PetscLogEventBegin(SNES_JacobianEval,snes,X,A,B);
2677: VecLockReadPush(X);
2678: PetscStackPush("SNES user Jacobian function");
2679: (*sdm->ops->computejacobian)(snes,X,A,B,sdm->jacobianctx);
2680: PetscStackPop;
2681: VecLockReadPop(X);
2682: PetscLogEventEnd(SNES_JacobianEval,snes,X,A,B);
2684: /* attach latest linearization point to the preconditioning matrix */
2685: PetscObjectCompose((PetscObject)B,"__SNES_latest_X",(PetscObject)X);
2687: /* the next line ensures that snes->ksp exists */
2688: SNESGetKSP(snes,&ksp);
2689: if (snes->lagpreconditioner == -2) {
2690: PetscInfo(snes,"Rebuilding preconditioner exactly once since lag is -2\n");
2691: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2692: snes->lagpreconditioner = -1;
2693: } else if (snes->lagpreconditioner == -1) {
2694: PetscInfo(snes,"Reusing preconditioner because lag is -1\n");
2695: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2696: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2697: PetscInfo2(snes,"Reusing preconditioner because lag is %D and SNES iteration is %D\n",snes->lagpreconditioner,snes->iter);
2698: KSPSetReusePreconditioner(snes->ksp,PETSC_TRUE);
2699: } else {
2700: PetscInfo(snes,"Rebuilding preconditioner\n");
2701: KSPSetReusePreconditioner(snes->ksp,PETSC_FALSE);
2702: }
2704: SNESTestJacobian(snes);
2705: /* make sure user returned a correct Jacobian and preconditioner */
2708: {
2709: PetscBool flag = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_operator = PETSC_FALSE;
2710: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit",NULL,NULL,&flag);
2711: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw",NULL,NULL,&flag_draw);
2712: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_explicit_draw_contour",NULL,NULL,&flag_contour);
2713: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject) snes)->options,((PetscObject)snes)->prefix,"-snes_compare_operator",NULL,NULL,&flag_operator);
2714: if (flag || flag_draw || flag_contour) {
2715: Mat Bexp_mine = NULL,Bexp,FDexp;
2716: PetscViewer vdraw,vstdout;
2717: PetscBool flg;
2718: if (flag_operator) {
2719: MatComputeOperator(A,MATAIJ,&Bexp_mine);
2720: Bexp = Bexp_mine;
2721: } else {
2722: /* See if the preconditioning matrix can be viewed and added directly */
2723: PetscObjectBaseTypeCompareAny((PetscObject)B,&flg,MATSEQAIJ,MATMPIAIJ,MATSEQDENSE,MATMPIDENSE,MATSEQBAIJ,MATMPIBAIJ,MATSEQSBAIJ,MATMPIBAIJ,"");
2724: if (flg) Bexp = B;
2725: else {
2726: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2727: MatComputeOperator(B,MATAIJ,&Bexp_mine);
2728: Bexp = Bexp_mine;
2729: }
2730: }
2731: MatConvert(Bexp,MATSAME,MAT_INITIAL_MATRIX,&FDexp);
2732: SNESComputeJacobianDefault(snes,X,FDexp,FDexp,NULL);
2733: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2734: if (flag_draw || flag_contour) {
2735: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Explicit Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2736: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2737: } else vdraw = NULL;
2738: PetscViewerASCIIPrintf(vstdout,"Explicit %s\n",flag_operator ? "Jacobian" : "preconditioning Jacobian");
2739: if (flag) {MatView(Bexp,vstdout);}
2740: if (vdraw) {MatView(Bexp,vdraw);}
2741: PetscViewerASCIIPrintf(vstdout,"Finite difference Jacobian\n");
2742: if (flag) {MatView(FDexp,vstdout);}
2743: if (vdraw) {MatView(FDexp,vdraw);}
2744: MatAYPX(FDexp,-1.0,Bexp,SAME_NONZERO_PATTERN);
2745: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian\n");
2746: if (flag) {MatView(FDexp,vstdout);}
2747: if (vdraw) { /* Always use contour for the difference */
2748: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2749: MatView(FDexp,vdraw);
2750: PetscViewerPopFormat(vdraw);
2751: }
2752: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2753: PetscViewerDestroy(&vdraw);
2754: MatDestroy(&Bexp_mine);
2755: MatDestroy(&FDexp);
2756: }
2757: }
2758: {
2759: PetscBool flag = PETSC_FALSE,flag_display = PETSC_FALSE,flag_draw = PETSC_FALSE,flag_contour = PETSC_FALSE,flag_threshold = PETSC_FALSE;
2760: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON,threshold_rtol = 10*PETSC_SQRT_MACHINE_EPSILON;
2761: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring",NULL,NULL,&flag);
2762: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_display",NULL,NULL,&flag_display);
2763: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw",NULL,NULL,&flag_draw);
2764: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_draw_contour",NULL,NULL,&flag_contour);
2765: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold",NULL,NULL,&flag_threshold);
2766: if (flag_threshold) {
2767: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_rtol",&threshold_rtol,NULL);
2768: PetscOptionsGetReal(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_compare_coloring_threshold_atol",&threshold_atol,NULL);
2769: }
2770: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2771: Mat Bfd;
2772: PetscViewer vdraw,vstdout;
2773: MatColoring coloring;
2774: ISColoring iscoloring;
2775: MatFDColoring matfdcoloring;
2776: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
2777: void *funcctx;
2778: PetscReal norm1,norm2,normmax;
2780: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&Bfd);
2781: MatColoringCreate(Bfd,&coloring);
2782: MatColoringSetType(coloring,MATCOLORINGSL);
2783: MatColoringSetFromOptions(coloring);
2784: MatColoringApply(coloring,&iscoloring);
2785: MatColoringDestroy(&coloring);
2786: MatFDColoringCreate(Bfd,iscoloring,&matfdcoloring);
2787: MatFDColoringSetFromOptions(matfdcoloring);
2788: MatFDColoringSetUp(Bfd,iscoloring,matfdcoloring);
2789: ISColoringDestroy(&iscoloring);
2791: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2792: SNESGetFunction(snes,NULL,&func,&funcctx);
2793: MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))func,funcctx);
2794: PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring,((PetscObject)snes)->prefix);
2795: PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring,"coloring_");
2796: MatFDColoringSetFromOptions(matfdcoloring);
2797: MatFDColoringApply(Bfd,matfdcoloring,X,snes);
2798: MatFDColoringDestroy(&matfdcoloring);
2800: PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes),&vstdout);
2801: if (flag_draw || flag_contour) {
2802: PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes),0,"Colored Jacobians",PETSC_DECIDE,PETSC_DECIDE,300,300,&vdraw);
2803: if (flag_contour) {PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);}
2804: } else vdraw = NULL;
2805: PetscViewerASCIIPrintf(vstdout,"Explicit preconditioning Jacobian\n");
2806: if (flag_display) {MatView(B,vstdout);}
2807: if (vdraw) {MatView(B,vdraw);}
2808: PetscViewerASCIIPrintf(vstdout,"Colored Finite difference Jacobian\n");
2809: if (flag_display) {MatView(Bfd,vstdout);}
2810: if (vdraw) {MatView(Bfd,vdraw);}
2811: MatAYPX(Bfd,-1.0,B,SAME_NONZERO_PATTERN);
2812: MatNorm(Bfd,NORM_1,&norm1);
2813: MatNorm(Bfd,NORM_FROBENIUS,&norm2);
2814: MatNorm(Bfd,NORM_MAX,&normmax);
2815: PetscViewerASCIIPrintf(vstdout,"User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n",(double)norm1,(double)norm2,(double)normmax);
2816: if (flag_display) {MatView(Bfd,vstdout);}
2817: if (vdraw) { /* Always use contour for the difference */
2818: PetscViewerPushFormat(vdraw,PETSC_VIEWER_DRAW_CONTOUR);
2819: MatView(Bfd,vdraw);
2820: PetscViewerPopFormat(vdraw);
2821: }
2822: if (flag_contour) {PetscViewerPopFormat(vdraw);}
2824: if (flag_threshold) {
2825: PetscInt bs,rstart,rend,i;
2826: MatGetBlockSize(B,&bs);
2827: MatGetOwnershipRange(B,&rstart,&rend);
2828: for (i=rstart; i<rend; i++) {
2829: const PetscScalar *ba,*ca;
2830: const PetscInt *bj,*cj;
2831: PetscInt bn,cn,j,maxentrycol = -1,maxdiffcol = -1,maxrdiffcol = -1;
2832: PetscReal maxentry = 0,maxdiff = 0,maxrdiff = 0;
2833: MatGetRow(B,i,&bn,&bj,&ba);
2834: MatGetRow(Bfd,i,&cn,&cj,&ca);
2835: if (bn != cn) SETERRQ(((PetscObject)A)->comm,PETSC_ERR_PLIB,"Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2836: for (j=0; j<bn; j++) {
2837: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2838: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2839: maxentrycol = bj[j];
2840: maxentry = PetscRealPart(ba[j]);
2841: }
2842: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2843: maxdiffcol = bj[j];
2844: maxdiff = PetscRealPart(ca[j]);
2845: }
2846: if (rdiff > maxrdiff) {
2847: maxrdiffcol = bj[j];
2848: maxrdiff = rdiff;
2849: }
2850: }
2851: if (maxrdiff > 1) {
2852: 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);
2853: for (j=0; j<bn; j++) {
2854: PetscReal rdiff;
2855: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol*PetscAbsScalar(ba[j]));
2856: if (rdiff > 1) {
2857: PetscViewerASCIIPrintf(vstdout," (%D,%g:%g)",bj[j],(double)PetscRealPart(ba[j]),(double)PetscRealPart(ca[j]));
2858: }
2859: }
2860: PetscViewerASCIIPrintf(vstdout,"\n",i,maxentry,maxdiff,maxrdiff);
2861: }
2862: MatRestoreRow(B,i,&bn,&bj,&ba);
2863: MatRestoreRow(Bfd,i,&cn,&cj,&ca);
2864: }
2865: }
2866: PetscViewerDestroy(&vdraw);
2867: MatDestroy(&Bfd);
2868: }
2869: }
2870: return(0);
2871: }
2873: /*MC
2874: SNESJacobianFunction - Function used to convey the nonlinear Jacobian of the function to be solved by SNES
2876: Synopsis:
2877: #include "petscsnes.h"
2878: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2880: Collective on snes
2882: Input Parameters:
2883: + x - input vector, the Jacobian is to be computed at this value
2884: - ctx - [optional] user-defined Jacobian context
2886: Output Parameters:
2887: + Amat - the matrix that defines the (approximate) Jacobian
2888: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2890: Level: intermediate
2892: .seealso: SNESSetFunction(), SNESGetFunction(), SNESSetJacobian(), SNESGetJacobian()
2893: M*/
2895: /*@C
2896: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2897: location to store the matrix.
2899: Logically Collective on SNES
2901: Input Parameters:
2902: + snes - the SNES context
2903: . Amat - the matrix that defines the (approximate) Jacobian
2904: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
2905: . J - Jacobian evaluation routine (if NULL then SNES retains any previously set value), see SNESJacobianFunction for details
2906: - ctx - [optional] user-defined context for private data for the
2907: Jacobian evaluation routine (may be NULL) (if NULL then SNES retains any previously set value)
2909: Notes:
2910: If the Amat matrix and Pmat matrix are different you must call MatAssemblyBegin/End() on
2911: each matrix.
2913: If you know the operator Amat has a null space you can use MatSetNullSpace() and MatSetTransposeNullSpace() to supply the null
2914: space to Amat and the KSP solvers will automatically use that null space as needed during the solution process.
2916: If using SNESComputeJacobianDefaultColor() to assemble a Jacobian, the ctx argument
2917: must be a MatFDColoring.
2919: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2920: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term.
2922: Level: beginner
2924: .seealso: KSPSetOperators(), SNESSetFunction(), MatMFFDComputeJacobian(), SNESComputeJacobianDefaultColor(), MatStructure, J,
2925: SNESSetPicard(), SNESJacobianFunction
2926: @*/
2927: PetscErrorCode SNESSetJacobian(SNES snes,Mat Amat,Mat Pmat,PetscErrorCode (*J)(SNES,Vec,Mat,Mat,void*),void *ctx)
2928: {
2930: DM dm;
2938: SNESGetDM(snes,&dm);
2939: DMSNESSetJacobian(dm,J,ctx);
2940: if (Amat) {
2941: PetscObjectReference((PetscObject)Amat);
2942: MatDestroy(&snes->jacobian);
2944: snes->jacobian = Amat;
2945: }
2946: if (Pmat) {
2947: PetscObjectReference((PetscObject)Pmat);
2948: MatDestroy(&snes->jacobian_pre);
2950: snes->jacobian_pre = Pmat;
2951: }
2952: return(0);
2953: }
2955: /*@C
2956: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
2957: provided context for evaluating the Jacobian.
2959: Not Collective, but Mat object will be parallel if SNES object is
2961: Input Parameter:
2962: . snes - the nonlinear solver context
2964: Output Parameters:
2965: + Amat - location to stash (approximate) Jacobian matrix (or NULL)
2966: . Pmat - location to stash matrix used to compute the preconditioner (or NULL)
2967: . J - location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
2968: - ctx - location to stash Jacobian ctx (or NULL)
2970: Level: advanced
2972: .seealso: SNESSetJacobian(), SNESComputeJacobian(), SNESJacobianFunction, SNESGetFunction()
2973: @*/
2974: PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)
2975: {
2977: DM dm;
2978: DMSNES sdm;
2982: if (Amat) *Amat = snes->jacobian;
2983: if (Pmat) *Pmat = snes->jacobian_pre;
2984: SNESGetDM(snes,&dm);
2985: DMGetDMSNES(dm,&sdm);
2986: if (J) *J = sdm->ops->computejacobian;
2987: if (ctx) *ctx = sdm->jacobianctx;
2988: return(0);
2989: }
2991: /*@
2992: SNESSetUp - Sets up the internal data structures for the later use
2993: of a nonlinear solver.
2995: Collective on SNES
2997: Input Parameters:
2998: . snes - the SNES context
3000: Notes:
3001: For basic use of the SNES solvers the user need not explicitly call
3002: SNESSetUp(), since these actions will automatically occur during
3003: the call to SNESSolve(). However, if one wishes to control this
3004: phase separately, SNESSetUp() should be called after SNESCreate()
3005: and optional routines of the form SNESSetXXX(), but before SNESSolve().
3007: Level: advanced
3009: .seealso: SNESCreate(), SNESSolve(), SNESDestroy()
3010: @*/
3011: PetscErrorCode SNESSetUp(SNES snes)
3012: {
3014: DM dm;
3015: DMSNES sdm;
3016: SNESLineSearch linesearch, pclinesearch;
3017: void *lsprectx,*lspostctx;
3018: PetscErrorCode (*precheck)(SNESLineSearch,Vec,Vec,PetscBool*,void*);
3019: PetscErrorCode (*postcheck)(SNESLineSearch,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
3020: PetscErrorCode (*func)(SNES,Vec,Vec,void*);
3021: Vec f,fpc;
3022: void *funcctx;
3023: PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
3024: void *jacctx,*appctx;
3025: Mat j,jpre;
3029: if (snes->setupcalled) return(0);
3030: PetscLogEventBegin(SNES_Setup,snes,0,0,0);
3032: if (!((PetscObject)snes)->type_name) {
3033: SNESSetType(snes,SNESNEWTONLS);
3034: }
3036: SNESGetFunction(snes,&snes->vec_func,NULL,NULL);
3038: SNESGetDM(snes,&dm);
3039: DMGetDMSNES(dm,&sdm);
3040: if (!sdm->ops->computefunction) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"Function never provided to SNES object");
3041: if (!sdm->ops->computejacobian) {
3042: DMSNESSetJacobian(dm,SNESComputeJacobianDefaultColor,NULL);
3043: }
3044: if (!snes->vec_func) {
3045: DMCreateGlobalVector(dm,&snes->vec_func);
3046: }
3048: if (!snes->ksp) {
3049: SNESGetKSP(snes, &snes->ksp);
3050: }
3052: if (snes->linesearch) {
3053: SNESGetLineSearch(snes, &snes->linesearch);
3054: SNESLineSearchSetFunction(snes->linesearch,SNESComputeFunction);
3055: }
3057: if (snes->npc && (snes->npcside== PC_LEFT)) {
3058: snes->mf = PETSC_TRUE;
3059: snes->mf_operator = PETSC_FALSE;
3060: }
3062: if (snes->npc) {
3063: /* copy the DM over */
3064: SNESGetDM(snes,&dm);
3065: SNESSetDM(snes->npc,dm);
3067: SNESGetFunction(snes,&f,&func,&funcctx);
3068: VecDuplicate(f,&fpc);
3069: SNESSetFunction(snes->npc,fpc,func,funcctx);
3070: SNESGetJacobian(snes,&j,&jpre,&jac,&jacctx);
3071: SNESSetJacobian(snes->npc,j,jpre,jac,jacctx);
3072: SNESGetApplicationContext(snes,&appctx);
3073: SNESSetApplicationContext(snes->npc,appctx);
3074: VecDestroy(&fpc);
3076: /* copy the function pointers over */
3077: PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)snes->npc);
3079: /* default to 1 iteration */
3080: SNESSetTolerances(snes->npc,0.0,0.0,0.0,1,snes->npc->max_funcs);
3081: if (snes->npcside==PC_RIGHT) {
3082: SNESSetNormSchedule(snes->npc,SNES_NORM_FINAL_ONLY);
3083: } else {
3084: SNESSetNormSchedule(snes->npc,SNES_NORM_NONE);
3085: }
3086: SNESSetFromOptions(snes->npc);
3088: /* copy the line search context over */
3089: if (snes->linesearch && snes->npc->linesearch) {
3090: SNESGetLineSearch(snes,&linesearch);
3091: SNESGetLineSearch(snes->npc,&pclinesearch);
3092: SNESLineSearchGetPreCheck(linesearch,&precheck,&lsprectx);
3093: SNESLineSearchGetPostCheck(linesearch,&postcheck,&lspostctx);
3094: SNESLineSearchSetPreCheck(pclinesearch,precheck,lsprectx);
3095: SNESLineSearchSetPostCheck(pclinesearch,postcheck,lspostctx);
3096: PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch);
3097: }
3098: }
3099: if (snes->mf) {
3100: SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version);
3101: }
3102: if (snes->ops->usercompute && !snes->user) {
3103: (*snes->ops->usercompute)(snes,(void**)&snes->user);
3104: }
3106: snes->jac_iter = 0;
3107: snes->pre_iter = 0;
3109: if (snes->ops->setup) {
3110: (*snes->ops->setup)(snes);
3111: }
3113: if (snes->npc && (snes->npcside== PC_LEFT)) {
3114: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3115: if (snes->linesearch){
3116: SNESGetLineSearch(snes,&linesearch);
3117: SNESLineSearchSetFunction(linesearch,SNESComputeFunctionDefaultNPC);
3118: }
3119: }
3120: }
3121: PetscLogEventEnd(SNES_Setup,snes,0,0,0);
3122: snes->setupcalled = PETSC_TRUE;
3123: return(0);
3124: }
3126: /*@
3127: SNESReset - Resets a SNES context to the snessetupcalled = 0 state and removes any allocated Vecs and Mats
3129: Collective on SNES
3131: Input Parameter:
3132: . snes - iterative context obtained from SNESCreate()
3134: Level: intermediate
3136: Notes:
3137: Also calls the application context destroy routine set with SNESSetComputeApplicationContext()
3139: .seealso: SNESCreate(), SNESSetUp(), SNESSolve()
3140: @*/
3141: PetscErrorCode SNESReset(SNES snes)
3142: {
3147: if (snes->ops->userdestroy && snes->user) {
3148: (*snes->ops->userdestroy)((void**)&snes->user);
3149: snes->user = NULL;
3150: }
3151: if (snes->npc) {
3152: SNESReset(snes->npc);
3153: }
3155: if (snes->ops->reset) {
3156: (*snes->ops->reset)(snes);
3157: }
3158: if (snes->ksp) {
3159: KSPReset(snes->ksp);
3160: }
3162: if (snes->linesearch) {
3163: SNESLineSearchReset(snes->linesearch);
3164: }
3166: VecDestroy(&snes->vec_rhs);
3167: VecDestroy(&snes->vec_sol);
3168: VecDestroy(&snes->vec_sol_update);
3169: VecDestroy(&snes->vec_func);
3170: MatDestroy(&snes->jacobian);
3171: MatDestroy(&snes->jacobian_pre);
3172: VecDestroyVecs(snes->nwork,&snes->work);
3173: VecDestroyVecs(snes->nvwork,&snes->vwork);
3175: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3177: snes->nwork = snes->nvwork = 0;
3178: snes->setupcalled = PETSC_FALSE;
3179: return(0);
3180: }
3182: /*@
3183: SNESDestroy - Destroys the nonlinear solver context that was created
3184: with SNESCreate().
3186: Collective on SNES
3188: Input Parameter:
3189: . snes - the SNES context
3191: Level: beginner
3193: .seealso: SNESCreate(), SNESSolve()
3194: @*/
3195: PetscErrorCode SNESDestroy(SNES *snes)
3196: {
3200: if (!*snes) return(0);
3202: if (--((PetscObject)(*snes))->refct > 0) {*snes = 0; return(0);}
3204: SNESReset((*snes));
3205: SNESDestroy(&(*snes)->npc);
3207: /* if memory was published with SAWs then destroy it */
3208: PetscObjectSAWsViewOff((PetscObject)*snes);
3209: if ((*snes)->ops->destroy) {(*((*snes))->ops->destroy)((*snes));}
3211: if ((*snes)->dm) {DMCoarsenHookRemove((*snes)->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,*snes);}
3212: DMDestroy(&(*snes)->dm);
3213: KSPDestroy(&(*snes)->ksp);
3214: SNESLineSearchDestroy(&(*snes)->linesearch);
3216: PetscFree((*snes)->kspconvctx);
3217: if ((*snes)->ops->convergeddestroy) {
3218: (*(*snes)->ops->convergeddestroy)((*snes)->cnvP);
3219: }
3220: if ((*snes)->conv_hist_alloc) {
3221: PetscFree2((*snes)->conv_hist,(*snes)->conv_hist_its);
3222: }
3223: SNESMonitorCancel((*snes));
3224: PetscHeaderDestroy(snes);
3225: return(0);
3226: }
3228: /* ----------- Routines to set solver parameters ---------- */
3230: /*@
3231: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3233: Logically Collective on SNES
3235: Input Parameters:
3236: + snes - the SNES context
3237: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3238: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3240: Options Database Keys:
3241: . -snes_lag_preconditioner <lag>
3243: Notes:
3244: The default is 1
3245: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3246: If -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use
3248: Level: intermediate
3250: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()
3252: @*/
3253: PetscErrorCode SNESSetLagPreconditioner(SNES snes,PetscInt lag)
3254: {
3257: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3258: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3260: snes->lagpreconditioner = lag;
3261: return(0);
3262: }
3264: /*@
3265: SNESSetGridSequence - sets the number of steps of grid sequencing that SNES does
3267: Logically Collective on SNES
3269: Input Parameters:
3270: + snes - the SNES context
3271: - steps - the number of refinements to do, defaults to 0
3273: Options Database Keys:
3274: . -snes_grid_sequence <steps>
3276: Level: intermediate
3278: Notes:
3279: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3281: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetGridSequence()
3283: @*/
3284: PetscErrorCode SNESSetGridSequence(SNES snes,PetscInt steps)
3285: {
3289: snes->gridsequence = steps;
3290: return(0);
3291: }
3293: /*@
3294: SNESGetGridSequence - gets the number of steps of grid sequencing that SNES does
3296: Logically Collective on SNES
3298: Input Parameter:
3299: . snes - the SNES context
3301: Output Parameter:
3302: . steps - the number of refinements to do, defaults to 0
3304: Options Database Keys:
3305: . -snes_grid_sequence <steps>
3307: Level: intermediate
3309: Notes:
3310: Use SNESGetSolution() to extract the fine grid solution after grid sequencing.
3312: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESSetGridSequence()
3314: @*/
3315: PetscErrorCode SNESGetGridSequence(SNES snes,PetscInt *steps)
3316: {
3319: *steps = snes->gridsequence;
3320: return(0);
3321: }
3323: /*@
3324: SNESGetLagPreconditioner - Indicates how often the preconditioner is rebuilt
3326: Not Collective
3328: Input Parameter:
3329: . snes - the SNES context
3331: Output Parameter:
3332: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3333: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3335: Options Database Keys:
3336: . -snes_lag_preconditioner <lag>
3338: Notes:
3339: The default is 1
3340: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3342: Level: intermediate
3344: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
3346: @*/
3347: PetscErrorCode SNESGetLagPreconditioner(SNES snes,PetscInt *lag)
3348: {
3351: *lag = snes->lagpreconditioner;
3352: return(0);
3353: }
3355: /*@
3356: SNESSetLagJacobian - Determines when the Jacobian is rebuilt in the nonlinear solve. See SNESSetLagPreconditioner() for determining how
3357: often the preconditioner is rebuilt.
3359: Logically Collective on SNES
3361: Input Parameters:
3362: + snes - the SNES context
3363: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3364: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3366: Options Database Keys:
3367: . -snes_lag_jacobian <lag>
3369: Notes:
3370: The default is 1
3371: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3372: 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
3373: at the next Newton step but never again (unless it is reset to another value)
3375: Level: intermediate
3377: .seealso: SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagPreconditioner(), SNESGetLagJacobian()
3379: @*/
3380: PetscErrorCode SNESSetLagJacobian(SNES snes,PetscInt lag)
3381: {
3384: if (lag < -2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag must be -2, -1, 1 or greater");
3385: if (!lag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Lag cannot be 0");
3387: snes->lagjacobian = lag;
3388: return(0);
3389: }
3391: /*@
3392: SNESGetLagJacobian - Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
3394: Not Collective
3396: Input Parameter:
3397: . snes - the SNES context
3399: Output Parameter:
3400: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3401: the Jacobian is built etc.
3403: Options Database Keys:
3404: . -snes_lag_jacobian <lag>
3406: Notes:
3407: The default is 1
3408: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3410: Level: intermediate
3412: .seealso: SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()
3414: @*/
3415: PetscErrorCode SNESGetLagJacobian(SNES snes,PetscInt *lag)
3416: {
3419: *lag = snes->lagjacobian;
3420: return(0);
3421: }
3423: /*@
3424: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple solves
3426: Logically collective on SNES
3428: Input Parameter:
3429: + snes - the SNES context
3430: - flg - jacobian lagging persists if true
3432: Options Database Keys:
3433: . -snes_lag_jacobian_persists <flg>
3435: Notes:
3436: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3437: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3438: timesteps may present huge efficiency gains.
3440: Level: developer
3442: .seealso: SNESSetLagPreconditionerPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3444: @*/
3445: PetscErrorCode SNESSetLagJacobianPersists(SNES snes,PetscBool flg)
3446: {
3450: snes->lagjac_persist = flg;
3451: return(0);
3452: }
3454: /*@
3455: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple solves
3457: Logically Collective on SNES
3459: Input Parameter:
3460: + snes - the SNES context
3461: - flg - preconditioner lagging persists if true
3463: Options Database Keys:
3464: . -snes_lag_jacobian_persists <flg>
3466: Notes:
3467: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3468: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3469: several timesteps may present huge efficiency gains.
3471: Level: developer
3473: .seealso: SNESSetLagJacobianPersists(), SNESSetLagJacobian(), SNESGetLagJacobian(), SNESGetNPC()
3475: @*/
3476: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes,PetscBool flg)
3477: {
3481: snes->lagpre_persist = flg;
3482: return(0);
3483: }
3485: /*@
3486: SNESSetForceIteration - force SNESSolve() to take at least one iteration regardless of the initial residual norm
3488: Logically Collective on SNES
3490: Input Parameters:
3491: + snes - the SNES context
3492: - force - PETSC_TRUE require at least one iteration
3494: Options Database Keys:
3495: . -snes_force_iteration <force> - Sets forcing an iteration
3497: Notes:
3498: This is used sometimes with TS to prevent TS from detecting a false steady state solution
3500: Level: intermediate
3502: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3503: @*/
3504: PetscErrorCode SNESSetForceIteration(SNES snes,PetscBool force)
3505: {
3508: snes->forceiteration = force;
3509: return(0);
3510: }
3512: /*@
3513: SNESGetForceIteration - Whether or not to force SNESSolve() take at least one iteration regardless of the initial residual norm
3515: Logically Collective on SNES
3517: Input Parameters:
3518: . snes - the SNES context
3520: Output Parameter:
3521: . force - PETSC_TRUE requires at least one iteration.
3523: Level: intermediate
3525: .seealso: SNESSetForceIteration(), SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance()
3526: @*/
3527: PetscErrorCode SNESGetForceIteration(SNES snes,PetscBool *force)
3528: {
3531: *force = snes->forceiteration;
3532: return(0);
3533: }
3535: /*@
3536: SNESSetTolerances - Sets various parameters used in convergence tests.
3538: Logically Collective on SNES
3540: Input Parameters:
3541: + snes - the SNES context
3542: . abstol - absolute convergence tolerance
3543: . rtol - relative convergence tolerance
3544: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3545: . maxit - maximum number of iterations
3546: - maxf - maximum number of function evaluations (-1 indicates no limit)
3548: Options Database Keys:
3549: + -snes_atol <abstol> - Sets abstol
3550: . -snes_rtol <rtol> - Sets rtol
3551: . -snes_stol <stol> - Sets stol
3552: . -snes_max_it <maxit> - Sets maxit
3553: - -snes_max_funcs <maxf> - Sets maxf
3555: Notes:
3556: The default maximum number of iterations is 50.
3557: The default maximum number of function evaluations is 1000.
3559: Level: intermediate
3561: .seealso: SNESSetTrustRegionTolerance(), SNESSetDivergenceTolerance(), SNESSetForceIteration()
3562: @*/
3563: PetscErrorCode SNESSetTolerances(SNES snes,PetscReal abstol,PetscReal rtol,PetscReal stol,PetscInt maxit,PetscInt maxf)
3564: {
3573: if (abstol != PETSC_DEFAULT) {
3574: if (abstol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Absolute tolerance %g must be non-negative",(double)abstol);
3575: snes->abstol = abstol;
3576: }
3577: if (rtol != PETSC_DEFAULT) {
3578: 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);
3579: snes->rtol = rtol;
3580: }
3581: if (stol != PETSC_DEFAULT) {
3582: if (stol < 0.0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Step tolerance %g must be non-negative",(double)stol);
3583: snes->stol = stol;
3584: }
3585: if (maxit != PETSC_DEFAULT) {
3586: if (maxit < 0) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of iterations %D must be non-negative",maxit);
3587: snes->max_its = maxit;
3588: }
3589: if (maxf != PETSC_DEFAULT) {
3590: if (maxf < -1) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_OUTOFRANGE,"Maximum number of function evaluations %D must be -1 or nonnegative",maxf);
3591: snes->max_funcs = maxf;
3592: }
3593: snes->tolerancesset = PETSC_TRUE;
3594: return(0);
3595: }
3597: /*@
3598: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the SNES divergence test.
3600: Logically Collective on SNES
3602: Input Parameters:
3603: + snes - the SNES context
3604: - divtol - the divergence tolerance. Use -1 to deactivate the test.
3606: Options Database Keys:
3607: . -snes_divergence_tolerance <divtol> - Sets divtol
3609: Notes:
3610: The default divergence tolerance is 1e4.
3612: Level: intermediate
3614: .seealso: SNESSetTolerances(), SNESGetDivergenceTolerance
3615: @*/
3616: PetscErrorCode SNESSetDivergenceTolerance(SNES snes,PetscReal divtol)
3617: {
3622: if (divtol != PETSC_DEFAULT) {
3623: snes->divtol = divtol;
3624: }
3625: else {
3626: snes->divtol = 1.0e4;
3627: }
3628: return(0);
3629: }
3631: /*@
3632: SNESGetTolerances - Gets various parameters used in convergence tests.
3634: Not Collective
3636: Input Parameters:
3637: + snes - the SNES context
3638: . atol - absolute convergence tolerance
3639: . rtol - relative convergence tolerance
3640: . stol - convergence tolerance in terms of the norm
3641: of the change in the solution between steps
3642: . maxit - maximum number of iterations
3643: - maxf - maximum number of function evaluations
3645: Notes:
3646: The user can specify NULL for any parameter that is not needed.
3648: Level: intermediate
3650: .seealso: SNESSetTolerances()
3651: @*/
3652: PetscErrorCode SNESGetTolerances(SNES snes,PetscReal *atol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit,PetscInt *maxf)
3653: {
3656: if (atol) *atol = snes->abstol;
3657: if (rtol) *rtol = snes->rtol;
3658: if (stol) *stol = snes->stol;
3659: if (maxit) *maxit = snes->max_its;
3660: if (maxf) *maxf = snes->max_funcs;
3661: return(0);
3662: }
3664: /*@
3665: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3667: Not Collective
3669: Input Parameters:
3670: + snes - the SNES context
3671: - divtol - divergence tolerance
3673: Level: intermediate
3675: .seealso: SNESSetDivergenceTolerance()
3676: @*/
3677: PetscErrorCode SNESGetDivergenceTolerance(SNES snes,PetscReal *divtol)
3678: {
3681: if (divtol) *divtol = snes->divtol;
3682: return(0);
3683: }
3685: /*@
3686: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3688: Logically Collective on SNES
3690: Input Parameters:
3691: + snes - the SNES context
3692: - tol - tolerance
3694: Options Database Key:
3695: . -snes_trtol <tol> - Sets tol
3697: Level: intermediate
3699: .seealso: SNESSetTolerances()
3700: @*/
3701: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes,PetscReal tol)
3702: {
3706: snes->deltatol = tol;
3707: return(0);
3708: }
3710: /*
3711: Duplicate the lg monitors for SNES from KSP; for some reason with
3712: dynamic libraries things don't work under Sun4 if we just use
3713: macros instead of functions
3714: */
3715: PetscErrorCode SNESMonitorLGResidualNorm(SNES snes,PetscInt it,PetscReal norm,void *ctx)
3716: {
3721: KSPMonitorLGResidualNorm((KSP)snes,it,norm,ctx);
3722: return(0);
3723: }
3725: PetscErrorCode SNESMonitorLGCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscDrawLG *lgctx)
3726: {
3730: KSPMonitorLGResidualNormCreate(comm,host,label,x,y,m,n,lgctx);
3731: return(0);
3732: }
3734: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES,PetscInt,PetscReal*);
3736: PetscErrorCode SNESMonitorLGRange(SNES snes,PetscInt n,PetscReal rnorm,void *monctx)
3737: {
3738: PetscDrawLG lg;
3739: PetscErrorCode ierr;
3740: PetscReal x,y,per;
3741: PetscViewer v = (PetscViewer)monctx;
3742: static PetscReal prev; /* should be in the context */
3743: PetscDraw draw;
3747: PetscViewerDrawGetDrawLG(v,0,&lg);
3748: if (!n) {PetscDrawLGReset(lg);}
3749: PetscDrawLGGetDraw(lg,&draw);
3750: PetscDrawSetTitle(draw,"Residual norm");
3751: x = (PetscReal)n;
3752: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3753: else y = -15.0;
3754: PetscDrawLGAddPoint(lg,&x,&y);
3755: if (n < 20 || !(n % 5) || snes->reason) {
3756: PetscDrawLGDraw(lg);
3757: PetscDrawLGSave(lg);
3758: }
3760: PetscViewerDrawGetDrawLG(v,1,&lg);
3761: if (!n) {PetscDrawLGReset(lg);}
3762: PetscDrawLGGetDraw(lg,&draw);
3763: PetscDrawSetTitle(draw,"% elemts > .2*max elemt");
3764: SNESMonitorRange_Private(snes,n,&per);
3765: x = (PetscReal)n;
3766: y = 100.0*per;
3767: PetscDrawLGAddPoint(lg,&x,&y);
3768: if (n < 20 || !(n % 5) || snes->reason) {
3769: PetscDrawLGDraw(lg);
3770: PetscDrawLGSave(lg);
3771: }
3773: PetscViewerDrawGetDrawLG(v,2,&lg);
3774: if (!n) {prev = rnorm;PetscDrawLGReset(lg);}
3775: PetscDrawLGGetDraw(lg,&draw);
3776: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm");
3777: x = (PetscReal)n;
3778: y = (prev - rnorm)/prev;
3779: PetscDrawLGAddPoint(lg,&x,&y);
3780: if (n < 20 || !(n % 5) || snes->reason) {
3781: PetscDrawLGDraw(lg);
3782: PetscDrawLGSave(lg);
3783: }
3785: PetscViewerDrawGetDrawLG(v,3,&lg);
3786: if (!n) {PetscDrawLGReset(lg);}
3787: PetscDrawLGGetDraw(lg,&draw);
3788: PetscDrawSetTitle(draw,"(norm -oldnorm)/oldnorm*(% > .2 max)");
3789: x = (PetscReal)n;
3790: y = (prev - rnorm)/(prev*per);
3791: if (n > 2) { /*skip initial crazy value */
3792: PetscDrawLGAddPoint(lg,&x,&y);
3793: }
3794: if (n < 20 || !(n % 5) || snes->reason) {
3795: PetscDrawLGDraw(lg);
3796: PetscDrawLGSave(lg);
3797: }
3798: prev = rnorm;
3799: return(0);
3800: }
3802: /*@
3803: SNESMonitor - runs the user provided monitor routines, if they exist
3805: Collective on SNES
3807: Input Parameters:
3808: + snes - nonlinear solver context obtained from SNESCreate()
3809: . iter - iteration number
3810: - rnorm - relative norm of the residual
3812: Notes:
3813: This routine is called by the SNES implementations.
3814: It does not typically need to be called by the user.
3816: Level: developer
3818: .seealso: SNESMonitorSet()
3819: @*/
3820: PetscErrorCode SNESMonitor(SNES snes,PetscInt iter,PetscReal rnorm)
3821: {
3823: PetscInt i,n = snes->numbermonitors;
3826: VecLockReadPush(snes->vec_sol);
3827: for (i=0; i<n; i++) {
3828: (*snes->monitor[i])(snes,iter,rnorm,snes->monitorcontext[i]);
3829: }
3830: VecLockReadPop(snes->vec_sol);
3831: return(0);
3832: }
3834: /* ------------ Routines to set performance monitoring options ----------- */
3836: /*MC
3837: SNESMonitorFunction - functional form passed to SNESMonitorSet() to monitor convergence of nonlinear solver
3839: Synopsis:
3840: #include <petscsnes.h>
3841: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3843: Collective on snes
3845: Input Parameters:
3846: + snes - the SNES context
3847: . its - iteration number
3848: . norm - 2-norm function value (may be estimated)
3849: - mctx - [optional] monitoring context
3851: Level: advanced
3853: .seealso: SNESMonitorSet(), SNESMonitorGet()
3854: M*/
3856: /*@C
3857: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3858: iteration of the nonlinear solver to display the iteration's
3859: progress.
3861: Logically Collective on SNES
3863: Input Parameters:
3864: + snes - the SNES context
3865: . f - the monitor function, see SNESMonitorFunction for the calling sequence
3866: . mctx - [optional] user-defined context for private data for the
3867: monitor routine (use NULL if no context is desired)
3868: - monitordestroy - [optional] routine that frees monitor context
3869: (may be NULL)
3871: Options Database Keys:
3872: + -snes_monitor - sets SNESMonitorDefault()
3873: . -snes_monitor_lg_residualnorm - sets line graph monitor,
3874: uses SNESMonitorLGCreate()
3875: - -snes_monitor_cancel - cancels all monitors that have
3876: been hardwired into a code by
3877: calls to SNESMonitorSet(), but
3878: does not cancel those set via
3879: the options database.
3881: Notes:
3882: Several different monitoring routines may be set by calling
3883: SNESMonitorSet() multiple times; all will be called in the
3884: order in which they were set.
3886: Fortran Notes:
3887: Only a single monitor function can be set for each SNES object
3889: Level: intermediate
3891: .seealso: SNESMonitorDefault(), SNESMonitorCancel(), SNESMonitorFunction
3892: @*/
3893: PetscErrorCode SNESMonitorSet(SNES snes,PetscErrorCode (*f)(SNES,PetscInt,PetscReal,void*),void *mctx,PetscErrorCode (*monitordestroy)(void**))
3894: {
3895: PetscInt i;
3897: PetscBool identical;
3901: for (i=0; i<snes->numbermonitors;i++) {
3902: PetscMonitorCompare((PetscErrorCode (*)(void))f,mctx,monitordestroy,(PetscErrorCode (*)(void))snes->monitor[i],snes->monitorcontext[i],snes->monitordestroy[i],&identical);
3903: if (identical) return(0);
3904: }
3905: if (snes->numbermonitors >= MAXSNESMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
3906: snes->monitor[snes->numbermonitors] = f;
3907: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3908: snes->monitorcontext[snes->numbermonitors++] = (void*)mctx;
3909: return(0);
3910: }
3912: /*@
3913: SNESMonitorCancel - Clears all the monitor functions for a SNES object.
3915: Logically Collective on SNES
3917: Input Parameters:
3918: . snes - the SNES context
3920: Options Database Key:
3921: . -snes_monitor_cancel - cancels all monitors that have been hardwired
3922: into a code by calls to SNESMonitorSet(), but does not cancel those
3923: set via the options database
3925: Notes:
3926: There is no way to clear one specific monitor from a SNES object.
3928: Level: intermediate
3930: .seealso: SNESMonitorDefault(), SNESMonitorSet()
3931: @*/
3932: PetscErrorCode SNESMonitorCancel(SNES snes)
3933: {
3935: PetscInt i;
3939: for (i=0; i<snes->numbermonitors; i++) {
3940: if (snes->monitordestroy[i]) {
3941: (*snes->monitordestroy[i])(&snes->monitorcontext[i]);
3942: }
3943: }
3944: snes->numbermonitors = 0;
3945: return(0);
3946: }
3948: /*MC
3949: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
3951: Synopsis:
3952: #include <petscsnes.h>
3953: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
3955: Collective on snes
3957: Input Parameters:
3958: + snes - the SNES context
3959: . it - current iteration (0 is the first and is before any Newton step)
3960: . xnorm - 2-norm of current iterate
3961: . gnorm - 2-norm of current step
3962: . f - 2-norm of function
3963: - cctx - [optional] convergence context
3965: Output Parameter:
3966: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
3968: Level: intermediate
3970: .seealso: SNESSetConvergenceTest(), SNESGetConvergenceTest()
3971: M*/
3973: /*@C
3974: SNESSetConvergenceTest - Sets the function that is to be used
3975: to test for convergence of the nonlinear iterative solution.
3977: Logically Collective on SNES
3979: Input Parameters:
3980: + snes - the SNES context
3981: . SNESConvergenceTestFunction - routine to test for convergence
3982: . cctx - [optional] context for private data for the convergence routine (may be NULL)
3983: - destroy - [optional] destructor for the context (may be NULL; PETSC_NULL_FUNCTION in Fortran)
3985: Level: advanced
3987: .seealso: SNESConvergedDefault(), SNESConvergedSkip(), SNESConvergenceTestFunction
3988: @*/
3989: PetscErrorCode SNESSetConvergenceTest(SNES snes,PetscErrorCode (*SNESConvergenceTestFunction)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void *cctx,PetscErrorCode (*destroy)(void*))
3990: {
3995: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
3996: if (snes->ops->convergeddestroy) {
3997: (*snes->ops->convergeddestroy)(snes->cnvP);
3998: }
3999: snes->ops->converged = SNESConvergenceTestFunction;
4000: snes->ops->convergeddestroy = destroy;
4001: snes->cnvP = cctx;
4002: return(0);
4003: }
4005: /*@
4006: SNESGetConvergedReason - Gets the reason the SNES iteration was stopped.
4008: Not Collective
4010: Input Parameter:
4011: . snes - the SNES context
4013: Output Parameter:
4014: . reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4015: manual pages for the individual convergence tests for complete lists
4017: Options Database:
4018: . -snes_converged_reason - prints the reason to standard out
4020: Level: intermediate
4022: Notes:
4023: Should only be called after the call the SNESSolve() is complete, if it is called earlier it returns the value SNES__CONVERGED_ITERATING.
4025: .seealso: SNESSetConvergenceTest(), SNESSetConvergedReason(), SNESConvergedReason
4026: @*/
4027: PetscErrorCode SNESGetConvergedReason(SNES snes,SNESConvergedReason *reason)
4028: {
4032: *reason = snes->reason;
4033: return(0);
4034: }
4036: /*@
4037: SNESSetConvergedReason - Sets the reason the SNES iteration was stopped.
4039: Not Collective
4041: Input Parameters:
4042: + snes - the SNES context
4043: - reason - negative value indicates diverged, positive value converged, see SNESConvergedReason or the
4044: manual pages for the individual convergence tests for complete lists
4046: Level: intermediate
4048: .seealso: SNESGetConvergedReason(), SNESSetConvergenceTest(), SNESConvergedReason
4049: @*/
4050: PetscErrorCode SNESSetConvergedReason(SNES snes,SNESConvergedReason reason)
4051: {
4054: snes->reason = reason;
4055: return(0);
4056: }
4058: /*@
4059: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4061: Logically Collective on SNES
4063: Input Parameters:
4064: + snes - iterative context obtained from SNESCreate()
4065: . a - array to hold history, this array will contain the function norms computed at each step
4066: . its - integer array holds the number of linear iterations for each solve.
4067: . na - size of a and its
4068: - reset - PETSC_TRUE indicates each new nonlinear solve resets the history counter to zero,
4069: else it continues storing new values for new nonlinear solves after the old ones
4071: Notes:
4072: If 'a' and 'its' are NULL then space is allocated for the history. If 'na' PETSC_DECIDE or PETSC_DEFAULT then a
4073: default array of length 10000 is allocated.
4075: This routine is useful, e.g., when running a code for purposes
4076: of accurate performance monitoring, when no I/O should be done
4077: during the section of code that is being timed.
4079: Level: intermediate
4081: .seealso: SNESGetConvergenceHistory()
4083: @*/
4084: PetscErrorCode SNESSetConvergenceHistory(SNES snes,PetscReal a[],PetscInt its[],PetscInt na,PetscBool reset)
4085: {
4092: if (!a) {
4093: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4094: PetscCalloc2(na,&a,na,&its);
4095: snes->conv_hist_alloc = PETSC_TRUE;
4096: }
4097: snes->conv_hist = a;
4098: snes->conv_hist_its = its;
4099: snes->conv_hist_max = na;
4100: snes->conv_hist_len = 0;
4101: snes->conv_hist_reset = reset;
4102: return(0);
4103: }
4105: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4106: #include <engine.h> /* MATLAB include file */
4107: #include <mex.h> /* MATLAB include file */
4109: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4110: {
4111: mxArray *mat;
4112: PetscInt i;
4113: PetscReal *ar;
4116: mat = mxCreateDoubleMatrix(snes->conv_hist_len,1,mxREAL);
4117: ar = (PetscReal*) mxGetData(mat);
4118: for (i=0; i<snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4119: PetscFunctionReturn(mat);
4120: }
4121: #endif
4123: /*@C
4124: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4126: Not Collective
4128: Input Parameter:
4129: . snes - iterative context obtained from SNESCreate()
4131: Output Parameters:
4132: + a - array to hold history
4133: . its - integer array holds the number of linear iterations (or
4134: negative if not converged) for each solve.
4135: - na - size of a and its
4137: Notes:
4138: The calling sequence for this routine in Fortran is
4139: $ call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4141: This routine is useful, e.g., when running a code for purposes
4142: of accurate performance monitoring, when no I/O should be done
4143: during the section of code that is being timed.
4145: Level: intermediate
4147: .seealso: SNESSetConvergencHistory()
4149: @*/
4150: PetscErrorCode SNESGetConvergenceHistory(SNES snes,PetscReal *a[],PetscInt *its[],PetscInt *na)
4151: {
4154: if (a) *a = snes->conv_hist;
4155: if (its) *its = snes->conv_hist_its;
4156: if (na) *na = snes->conv_hist_len;
4157: return(0);
4158: }
4160: /*@C
4161: SNESSetUpdate - Sets the general-purpose update function called
4162: at the beginning of every iteration of the nonlinear solve. Specifically
4163: it is called just before the Jacobian is "evaluated".
4165: Logically Collective on SNES
4167: Input Parameters:
4168: + snes - The nonlinear solver context
4169: - func - The function
4171: Calling sequence of func:
4172: $ func (SNES snes, PetscInt step);
4174: . step - The current step of the iteration
4176: Level: advanced
4178: 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()
4179: This is not used by most users.
4181: .seealso SNESSetJacobian(), SNESSolve()
4182: @*/
4183: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4184: {
4187: snes->ops->update = func;
4188: return(0);
4189: }
4191: /*
4192: SNESScaleStep_Private - Scales a step so that its length is less than the
4193: positive parameter delta.
4195: Input Parameters:
4196: + snes - the SNES context
4197: . y - approximate solution of linear system
4198: . fnorm - 2-norm of current function
4199: - delta - trust region size
4201: Output Parameters:
4202: + gpnorm - predicted function norm at the new point, assuming local
4203: linearization. The value is zero if the step lies within the trust
4204: region, and exceeds zero otherwise.
4205: - ynorm - 2-norm of the step
4207: Note:
4208: For non-trust region methods such as SNESNEWTONLS, the parameter delta
4209: is set to be the maximum allowable step size.
4211: */
4212: PetscErrorCode SNESScaleStep_Private(SNES snes,Vec y,PetscReal *fnorm,PetscReal *delta,PetscReal *gpnorm,PetscReal *ynorm)
4213: {
4214: PetscReal nrm;
4215: PetscScalar cnorm;
4223: VecNorm(y,NORM_2,&nrm);
4224: if (nrm > *delta) {
4225: nrm = *delta/nrm;
4226: *gpnorm = (1.0 - nrm)*(*fnorm);
4227: cnorm = nrm;
4228: VecScale(y,cnorm);
4229: *ynorm = *delta;
4230: } else {
4231: *gpnorm = 0.0;
4232: *ynorm = nrm;
4233: }
4234: return(0);
4235: }
4237: /*@
4238: SNESReasonView - Displays the reason a SNES solve converged or diverged to a viewer
4240: Collective on SNES
4242: Parameter:
4243: + snes - iterative context obtained from SNESCreate()
4244: - viewer - the viewer to display the reason
4247: Options Database Keys:
4248: . -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4250: Level: beginner
4252: .seealso: SNESCreate(), SNESSetUp(), SNESDestroy(), SNESSetTolerances(), SNESConvergedDefault()
4254: @*/
4255: PetscErrorCode SNESReasonView(SNES snes,PetscViewer viewer)
4256: {
4257: PetscViewerFormat format;
4258: PetscBool isAscii;
4259: PetscErrorCode ierr;
4262: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isAscii);
4263: if (isAscii) {
4264: PetscViewerGetFormat(viewer, &format);
4265: PetscViewerASCIIAddTab(viewer,((PetscObject)snes)->tablevel);
4266: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4267: DM dm;
4268: Vec u;
4269: PetscDS prob;
4270: PetscInt Nf, f;
4271: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4272: void **exactCtx;
4273: PetscReal error;
4275: SNESGetDM(snes, &dm);
4276: SNESGetSolution(snes, &u);
4277: DMGetDS(dm, &prob);
4278: PetscDSGetNumFields(prob, &Nf);
4279: PetscMalloc2(Nf, &exactSol, Nf, &exactCtx);
4280: for (f = 0; f < Nf; ++f) {PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]);}
4281: DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error);
4282: PetscFree2(exactSol, exactCtx);
4283: if (error < 1.0e-11) {PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n");}
4284: else {PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", error);}
4285: }
4286: if (snes->reason > 0) {
4287: if (((PetscObject) snes)->prefix) {
4288: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve converged due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4289: } else {
4290: PetscViewerASCIIPrintf(viewer,"Nonlinear solve converged due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4291: }
4292: } else {
4293: if (((PetscObject) snes)->prefix) {
4294: PetscViewerASCIIPrintf(viewer,"Nonlinear %s solve did not converge due to %s iterations %D\n",((PetscObject) snes)->prefix,SNESConvergedReasons[snes->reason],snes->iter);
4295: } else {
4296: PetscViewerASCIIPrintf(viewer,"Nonlinear solve did not converge due to %s iterations %D\n",SNESConvergedReasons[snes->reason],snes->iter);
4297: }
4298: }
4299: PetscViewerASCIISubtractTab(viewer,((PetscObject)snes)->tablevel);
4300: }
4301: return(0);
4302: }
4304: /*@C
4305: SNESReasonViewFromOptions - Processes command line options to determine if/how a SNESReason is to be viewed.
4307: Collective on SNES
4309: Input Parameters:
4310: . snes - the SNES object
4312: Level: intermediate
4314: @*/
4315: PetscErrorCode SNESReasonViewFromOptions(SNES snes)
4316: {
4317: PetscErrorCode ierr;
4318: PetscViewer viewer;
4319: PetscBool flg;
4320: static PetscBool incall = PETSC_FALSE;
4321: PetscViewerFormat format;
4324: if (incall) return(0);
4325: incall = PETSC_TRUE;
4326: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_converged_reason",&viewer,&format,&flg);
4327: if (flg) {
4328: PetscViewerPushFormat(viewer,format);
4329: SNESReasonView(snes,viewer);
4330: PetscViewerPopFormat(viewer);
4331: PetscViewerDestroy(&viewer);
4332: }
4333: incall = PETSC_FALSE;
4334: return(0);
4335: }
4337: /*@
4338: SNESSolve - Solves a nonlinear system F(x) = b.
4339: Call SNESSolve() after calling SNESCreate() and optional routines of the form SNESSetXXX().
4341: Collective on SNES
4343: Input Parameters:
4344: + snes - the SNES context
4345: . b - the constant part of the equation F(x) = b, or NULL to use zero.
4346: - x - the solution vector.
4348: Notes:
4349: The user should initialize the vector,x, with the initial guess
4350: for the nonlinear solve prior to calling SNESSolve. In particular,
4351: to employ an initial guess of zero, the user should explicitly set
4352: this vector to zero by calling VecSet().
4354: Level: beginner
4356: .seealso: SNESCreate(), SNESDestroy(), SNESSetFunction(), SNESSetJacobian(), SNESSetGridSequence(), SNESGetSolution()
4357: @*/
4358: PetscErrorCode SNESSolve(SNES snes,Vec b,Vec x)
4359: {
4360: PetscErrorCode ierr;
4361: PetscBool flg;
4362: PetscInt grid;
4363: Vec xcreated = NULL;
4364: DM dm;
4373: /* High level operations using the nonlinear solver */
4374: {
4375: PetscViewer viewer;
4376: PetscViewerFormat format;
4377: PetscInt num;
4378: PetscBool flg;
4379: static PetscBool incall = PETSC_FALSE;
4381: if (!incall) {
4382: /* Estimate the convergence rate of the discretization */
4383: PetscOptionsGetViewer(PetscObjectComm((PetscObject) snes),((PetscObject)snes)->options, ((PetscObject) snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg);
4384: if (flg) {
4385: PetscConvEst conv;
4386: DM dm;
4387: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4388: PetscInt Nf;
4390: incall = PETSC_TRUE;
4391: SNESGetDM(snes, &dm);
4392: DMGetNumFields(dm, &Nf);
4393: PetscCalloc1(Nf, &alpha);
4394: PetscConvEstCreate(PetscObjectComm((PetscObject) snes), &conv);
4395: PetscConvEstSetSolver(conv, snes);
4396: PetscConvEstSetFromOptions(conv);
4397: PetscConvEstSetUp(conv);
4398: PetscConvEstGetConvRate(conv, alpha);
4399: PetscViewerPushFormat(viewer, format);
4400: PetscConvEstRateView(conv, alpha, viewer);
4401: PetscViewerPopFormat(viewer);
4402: PetscViewerDestroy(&viewer);
4403: PetscConvEstDestroy(&conv);
4404: PetscFree(alpha);
4405: incall = PETSC_FALSE;
4406: }
4407: /* Adaptively refine the initial grid */
4408: num = 1;
4409: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_initial", &num, &flg);
4410: if (flg) {
4411: DMAdaptor adaptor;
4413: incall = PETSC_TRUE;
4414: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4415: DMAdaptorSetSolver(adaptor, snes);
4416: DMAdaptorSetSequenceLength(adaptor, num);
4417: DMAdaptorSetFromOptions(adaptor);
4418: DMAdaptorSetUp(adaptor);
4419: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x);
4420: DMAdaptorDestroy(&adaptor);
4421: incall = PETSC_FALSE;
4422: }
4423: /* Use grid sequencing to adapt */
4424: num = 0;
4425: PetscOptionsGetInt(NULL, ((PetscObject) snes)->prefix, "-snes_adapt_sequence", &num, NULL);
4426: if (num) {
4427: DMAdaptor adaptor;
4429: incall = PETSC_TRUE;
4430: DMAdaptorCreate(PETSC_COMM_WORLD, &adaptor);
4431: DMAdaptorSetSolver(adaptor, snes);
4432: DMAdaptorSetSequenceLength(adaptor, num);
4433: DMAdaptorSetFromOptions(adaptor);
4434: DMAdaptorSetUp(adaptor);
4435: DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x);
4436: DMAdaptorDestroy(&adaptor);
4437: incall = PETSC_FALSE;
4438: }
4439: }
4440: }
4441: if (!x) {
4442: SNESGetDM(snes,&dm);
4443: DMCreateGlobalVector(dm,&xcreated);
4444: x = xcreated;
4445: }
4446: SNESViewFromOptions(snes,NULL,"-snes_view_pre");
4448: for (grid=0; grid<snes->gridsequence; grid++) {PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));}
4449: for (grid=0; grid<snes->gridsequence+1; grid++) {
4451: /* set solution vector */
4452: if (!grid) {PetscObjectReference((PetscObject)x);}
4453: VecDestroy(&snes->vec_sol);
4454: snes->vec_sol = x;
4455: SNESGetDM(snes,&dm);
4457: /* set affine vector if provided */
4458: if (b) { PetscObjectReference((PetscObject)b); }
4459: VecDestroy(&snes->vec_rhs);
4460: snes->vec_rhs = b;
4462: if (snes->vec_rhs && (snes->vec_func == snes->vec_rhs)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Right hand side vector cannot be function vector");
4463: if (snes->vec_func == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be function vector");
4464: if (snes->vec_rhs == snes->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_IDN,"Solution vector cannot be right hand side vector");
4465: if (!snes->vec_sol_update /* && snes->vec_sol */) {
4466: VecDuplicate(snes->vec_sol,&snes->vec_sol_update);
4467: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->vec_sol_update);
4468: }
4469: DMShellSetGlobalVector(dm,snes->vec_sol);
4470: SNESSetUp(snes);
4472: if (!grid) {
4473: if (snes->ops->computeinitialguess) {
4474: (*snes->ops->computeinitialguess)(snes,snes->vec_sol,snes->initialguessP);
4475: }
4476: }
4478: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4479: if (snes->counters_reset) {snes->nfuncs = 0; snes->linear_its = 0; snes->numFailures = 0;}
4481: PetscLogEventBegin(SNES_Solve,snes,0,0,0);
4482: (*snes->ops->solve)(snes);
4483: PetscLogEventEnd(SNES_Solve,snes,0,0,0);
4484: if (!snes->reason) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
4485: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4487: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4488: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4490: PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes),((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-snes_test_local_min",NULL,NULL,&flg);
4491: if (flg && !PetscPreLoadingOn) { SNESTestLocalMin(snes); }
4492: SNESReasonViewFromOptions(snes);
4494: if (snes->errorifnotconverged && snes->reason < 0) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_NOT_CONVERGED,"SNESSolve has not converged");
4495: if (snes->reason < 0) break;
4496: if (grid < snes->gridsequence) {
4497: DM fine;
4498: Vec xnew;
4499: Mat interp;
4501: DMRefine(snes->dm,PetscObjectComm((PetscObject)snes),&fine);
4502: if (!fine) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_INCOMP,"DMRefine() did not perform any refinement, cannot continue grid sequencing");
4503: DMCreateInterpolation(snes->dm,fine,&interp,NULL);
4504: DMCreateGlobalVector(fine,&xnew);
4505: MatInterpolate(interp,x,xnew);
4506: DMInterpolate(snes->dm,interp,fine);
4507: MatDestroy(&interp);
4508: x = xnew;
4510: SNESReset(snes);
4511: SNESSetDM(snes,fine);
4512: SNESResetFromOptions(snes);
4513: DMDestroy(&fine);
4514: PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes)));
4515: }
4516: }
4517: SNESViewFromOptions(snes,NULL,"-snes_view");
4518: VecViewFromOptions(snes->vec_sol,(PetscObject)snes,"-snes_view_solution");
4520: VecDestroy(&xcreated);
4521: PetscObjectSAWsBlock((PetscObject)snes);
4522: return(0);
4523: }
4525: /* --------- Internal routines for SNES Package --------- */
4527: /*@C
4528: SNESSetType - Sets the method for the nonlinear solver.
4530: Collective on SNES
4532: Input Parameters:
4533: + snes - the SNES context
4534: - type - a known method
4536: Options Database Key:
4537: . -snes_type <type> - Sets the method; use -help for a list
4538: of available methods (for instance, newtonls or newtontr)
4540: Notes:
4541: See "petsc/include/petscsnes.h" for available methods (for instance)
4542: + SNESNEWTONLS - Newton's method with line search
4543: (systems of nonlinear equations)
4544: - SNESNEWTONTR - Newton's method with trust region
4545: (systems of nonlinear equations)
4547: Normally, it is best to use the SNESSetFromOptions() command and then
4548: set the SNES solver type from the options database rather than by using
4549: this routine. Using the options database provides the user with
4550: maximum flexibility in evaluating the many nonlinear solvers.
4551: The SNESSetType() routine is provided for those situations where it
4552: is necessary to set the nonlinear solver independently of the command
4553: line or options database. This might be the case, for example, when
4554: the choice of solver changes during the execution of the program,
4555: and the user's application is taking responsibility for choosing the
4556: appropriate method.
4558: Developer Notes:
4559: SNESRegister() adds a constructor for a new SNESType to SNESList, SNESSetType() locates
4560: the constructor in that list and calls it to create the spexific object.
4562: Level: intermediate
4564: .seealso: SNESType, SNESCreate(), SNESDestroy(), SNESGetType(), SNESSetFromOptions()
4566: @*/
4567: PetscErrorCode SNESSetType(SNES snes,SNESType type)
4568: {
4569: PetscErrorCode ierr,(*r)(SNES);
4570: PetscBool match;
4576: PetscObjectTypeCompare((PetscObject)snes,type,&match);
4577: if (match) return(0);
4579: PetscFunctionListFind(SNESList,type,&r);
4580: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested SNES type %s",type);
4581: /* Destroy the previous private SNES context */
4582: if (snes->ops->destroy) {
4583: (*(snes)->ops->destroy)(snes);
4584: snes->ops->destroy = NULL;
4585: }
4586: /* Reinitialize function pointers in SNESOps structure */
4587: snes->ops->setup = 0;
4588: snes->ops->solve = 0;
4589: snes->ops->view = 0;
4590: snes->ops->setfromoptions = 0;
4591: snes->ops->destroy = 0;
4593: /* It may happen the user has customized the line search before calling SNESSetType */
4594: if (((PetscObject)snes)->type_name) {
4595: SNESLineSearchDestroy(&snes->linesearch);
4596: }
4598: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4599: snes->setupcalled = PETSC_FALSE;
4601: PetscObjectChangeTypeName((PetscObject)snes,type);
4602: (*r)(snes);
4603: return(0);
4604: }
4606: /*@C
4607: SNESGetType - Gets the SNES method type and name (as a string).
4609: Not Collective
4611: Input Parameter:
4612: . snes - nonlinear solver context
4614: Output Parameter:
4615: . type - SNES method (a character string)
4617: Level: intermediate
4619: @*/
4620: PetscErrorCode SNESGetType(SNES snes,SNESType *type)
4621: {
4625: *type = ((PetscObject)snes)->type_name;
4626: return(0);
4627: }
4629: /*@
4630: SNESSetSolution - Sets the solution vector for use by the SNES routines.
4632: Logically Collective on SNES
4634: Input Parameters:
4635: + snes - the SNES context obtained from SNESCreate()
4636: - u - the solution vector
4638: Level: beginner
4640: @*/
4641: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4642: {
4643: DM dm;
4649: PetscObjectReference((PetscObject) u);
4650: VecDestroy(&snes->vec_sol);
4652: snes->vec_sol = u;
4654: SNESGetDM(snes, &dm);
4655: DMShellSetGlobalVector(dm, u);
4656: return(0);
4657: }
4659: /*@
4660: SNESGetSolution - Returns the vector where the approximate solution is
4661: stored. This is the fine grid solution when using SNESSetGridSequence().
4663: Not Collective, but Vec is parallel if SNES is parallel
4665: Input Parameter:
4666: . snes - the SNES context
4668: Output Parameter:
4669: . x - the solution
4671: Level: intermediate
4673: .seealso: SNESGetSolutionUpdate(), SNESGetFunction()
4674: @*/
4675: PetscErrorCode SNESGetSolution(SNES snes,Vec *x)
4676: {
4680: *x = snes->vec_sol;
4681: return(0);
4682: }
4684: /*@
4685: SNESGetSolutionUpdate - Returns the vector where the solution update is
4686: stored.
4688: Not Collective, but Vec is parallel if SNES is parallel
4690: Input Parameter:
4691: . snes - the SNES context
4693: Output Parameter:
4694: . x - the solution update
4696: Level: advanced
4698: .seealso: SNESGetSolution(), SNESGetFunction()
4699: @*/
4700: PetscErrorCode SNESGetSolutionUpdate(SNES snes,Vec *x)
4701: {
4705: *x = snes->vec_sol_update;
4706: return(0);
4707: }
4709: /*@C
4710: SNESGetFunction - Returns the vector where the function is stored.
4712: Not Collective, but Vec is parallel if SNES is parallel. Collective if Vec is requested, but has not been created yet.
4714: Input Parameter:
4715: . snes - the SNES context
4717: Output Parameter:
4718: + r - the vector that is used to store residuals (or NULL if you don't want it)
4719: . f - the function (or NULL if you don't want it); see SNESFunction for calling sequence details
4720: - ctx - the function context (or NULL if you don't want it)
4722: Level: advanced
4724: Notes: The vector r DOES NOT, in general contain the current value of the SNES nonlinear function
4726: .seealso: SNESSetFunction(), SNESGetSolution(), SNESFunction
4727: @*/
4728: PetscErrorCode SNESGetFunction(SNES snes,Vec *r,PetscErrorCode (**f)(SNES,Vec,Vec,void*),void **ctx)
4729: {
4731: DM dm;
4735: if (r) {
4736: if (!snes->vec_func) {
4737: if (snes->vec_rhs) {
4738: VecDuplicate(snes->vec_rhs,&snes->vec_func);
4739: } else if (snes->vec_sol) {
4740: VecDuplicate(snes->vec_sol,&snes->vec_func);
4741: } else if (snes->dm) {
4742: DMCreateGlobalVector(snes->dm,&snes->vec_func);
4743: }
4744: }
4745: *r = snes->vec_func;
4746: }
4747: SNESGetDM(snes,&dm);
4748: DMSNESGetFunction(dm,f,ctx);
4749: return(0);
4750: }
4752: /*@C
4753: SNESGetNGS - Returns the NGS function and context.
4755: Input Parameter:
4756: . snes - the SNES context
4758: Output Parameter:
4759: + f - the function (or NULL) see SNESNGSFunction for details
4760: - ctx - the function context (or NULL)
4762: Level: advanced
4764: .seealso: SNESSetNGS(), SNESGetFunction()
4765: @*/
4767: PetscErrorCode SNESGetNGS (SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void*), void ** ctx)
4768: {
4770: DM dm;
4774: SNESGetDM(snes,&dm);
4775: DMSNESGetNGS(dm,f,ctx);
4776: return(0);
4777: }
4779: /*@C
4780: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4781: SNES options in the database.
4783: Logically Collective on SNES
4785: Input Parameter:
4786: + snes - the SNES context
4787: - prefix - the prefix to prepend to all option names
4789: Notes:
4790: A hyphen (-) must NOT be given at the beginning of the prefix name.
4791: The first character of all runtime options is AUTOMATICALLY the hyphen.
4793: Level: advanced
4795: .seealso: SNESSetFromOptions()
4796: @*/
4797: PetscErrorCode SNESSetOptionsPrefix(SNES snes,const char prefix[])
4798: {
4803: PetscObjectSetOptionsPrefix((PetscObject)snes,prefix);
4804: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4805: if (snes->linesearch) {
4806: SNESGetLineSearch(snes,&snes->linesearch);
4807: PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch,prefix);
4808: }
4809: KSPSetOptionsPrefix(snes->ksp,prefix);
4810: return(0);
4811: }
4813: /*@C
4814: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4815: SNES options in the database.
4817: Logically Collective on SNES
4819: Input Parameters:
4820: + snes - the SNES context
4821: - prefix - the prefix to prepend to all option names
4823: Notes:
4824: A hyphen (-) must NOT be given at the beginning of the prefix name.
4825: The first character of all runtime options is AUTOMATICALLY the hyphen.
4827: Level: advanced
4829: .seealso: SNESGetOptionsPrefix()
4830: @*/
4831: PetscErrorCode SNESAppendOptionsPrefix(SNES snes,const char prefix[])
4832: {
4837: PetscObjectAppendOptionsPrefix((PetscObject)snes,prefix);
4838: if (!snes->ksp) {SNESGetKSP(snes,&snes->ksp);}
4839: if (snes->linesearch) {
4840: SNESGetLineSearch(snes,&snes->linesearch);
4841: PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch,prefix);
4842: }
4843: KSPAppendOptionsPrefix(snes->ksp,prefix);
4844: return(0);
4845: }
4847: /*@C
4848: SNESGetOptionsPrefix - Sets the prefix used for searching for all
4849: SNES options in the database.
4851: Not Collective
4853: Input Parameter:
4854: . snes - the SNES context
4856: Output Parameter:
4857: . prefix - pointer to the prefix string used
4859: Notes:
4860: On the fortran side, the user should pass in a string 'prefix' of
4861: sufficient length to hold the prefix.
4863: Level: advanced
4865: .seealso: SNESAppendOptionsPrefix()
4866: @*/
4867: PetscErrorCode SNESGetOptionsPrefix(SNES snes,const char *prefix[])
4868: {
4873: PetscObjectGetOptionsPrefix((PetscObject)snes,prefix);
4874: return(0);
4875: }
4878: /*@C
4879: SNESRegister - Adds a method to the nonlinear solver package.
4881: Not collective
4883: Input Parameters:
4884: + name_solver - name of a new user-defined solver
4885: - routine_create - routine to create method context
4887: Notes:
4888: SNESRegister() may be called multiple times to add several user-defined solvers.
4890: Sample usage:
4891: .vb
4892: SNESRegister("my_solver",MySolverCreate);
4893: .ve
4895: Then, your solver can be chosen with the procedural interface via
4896: $ SNESSetType(snes,"my_solver")
4897: or at runtime via the option
4898: $ -snes_type my_solver
4900: Level: advanced
4902: Note: If your function is not being put into a shared library then use SNESRegister() instead
4904: .seealso: SNESRegisterAll(), SNESRegisterDestroy()
4906: Level: advanced
4907: @*/
4908: PetscErrorCode SNESRegister(const char sname[],PetscErrorCode (*function)(SNES))
4909: {
4913: SNESInitializePackage();
4914: PetscFunctionListAdd(&SNESList,sname,function);
4915: return(0);
4916: }
4918: PetscErrorCode SNESTestLocalMin(SNES snes)
4919: {
4921: PetscInt N,i,j;
4922: Vec u,uh,fh;
4923: PetscScalar value;
4924: PetscReal norm;
4927: SNESGetSolution(snes,&u);
4928: VecDuplicate(u,&uh);
4929: VecDuplicate(u,&fh);
4931: /* currently only works for sequential */
4932: PetscPrintf(PETSC_COMM_WORLD,"Testing FormFunction() for local min\n");
4933: VecGetSize(u,&N);
4934: for (i=0; i<N; i++) {
4935: VecCopy(u,uh);
4936: PetscPrintf(PETSC_COMM_WORLD,"i = %D\n",i);
4937: for (j=-10; j<11; j++) {
4938: value = PetscSign(j)*PetscExpReal(PetscAbs(j)-10.0);
4939: VecSetValue(uh,i,value,ADD_VALUES);
4940: SNESComputeFunction(snes,uh,fh);
4941: VecNorm(fh,NORM_2,&norm);
4942: PetscPrintf(PETSC_COMM_WORLD," j norm %D %18.16e\n",j,norm);
4943: value = -value;
4944: VecSetValue(uh,i,value,ADD_VALUES);
4945: }
4946: }
4947: VecDestroy(&uh);
4948: VecDestroy(&fh);
4949: return(0);
4950: }
4952: /*@
4953: SNESKSPSetUseEW - Sets SNES use Eisenstat-Walker method for
4954: computing relative tolerance for linear solvers within an inexact
4955: Newton method.
4957: Logically Collective on SNES
4959: Input Parameters:
4960: + snes - SNES context
4961: - flag - PETSC_TRUE or PETSC_FALSE
4963: Options Database:
4964: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
4965: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
4966: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
4967: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
4968: . -snes_ksp_ew_gamma <gamma> - Sets gamma
4969: . -snes_ksp_ew_alpha <alpha> - Sets alpha
4970: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
4971: - -snes_ksp_ew_threshold <threshold> - Sets threshold
4973: Notes:
4974: Currently, the default is to use a constant relative tolerance for
4975: the inner linear solvers. Alternatively, one can use the
4976: Eisenstat-Walker method, where the relative convergence tolerance
4977: is reset at each Newton iteration according progress of the nonlinear
4978: solver.
4980: Level: advanced
4982: Reference:
4983: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
4984: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
4986: .seealso: SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
4987: @*/
4988: PetscErrorCode SNESKSPSetUseEW(SNES snes,PetscBool flag)
4989: {
4993: snes->ksp_ewconv = flag;
4994: return(0);
4995: }
4997: /*@
4998: SNESKSPGetUseEW - Gets if SNES is using Eisenstat-Walker method
4999: for computing relative tolerance for linear solvers within an
5000: inexact Newton method.
5002: Not Collective
5004: Input Parameter:
5005: . snes - SNES context
5007: Output Parameter:
5008: . flag - PETSC_TRUE or PETSC_FALSE
5010: Notes:
5011: Currently, the default is to use a constant relative tolerance for
5012: the inner linear solvers. Alternatively, one can use the
5013: Eisenstat-Walker method, where the relative convergence tolerance
5014: is reset at each Newton iteration according progress of the nonlinear
5015: solver.
5017: Level: advanced
5019: Reference:
5020: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5021: inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5023: .seealso: SNESKSPSetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()
5024: @*/
5025: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5026: {
5030: *flag = snes->ksp_ewconv;
5031: return(0);
5032: }
5034: /*@
5035: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5036: convergence criteria for the linear solvers within an inexact
5037: Newton method.
5039: Logically Collective on SNES
5041: Input Parameters:
5042: + snes - SNES context
5043: . version - version 1, 2 (default is 2) or 3
5044: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5045: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5046: . gamma - multiplicative factor for version 2 rtol computation
5047: (0 <= gamma2 <= 1)
5048: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5049: . alpha2 - power for safeguard
5050: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5052: Note:
5053: Version 3 was contributed by Luis Chacon, June 2006.
5055: Use PETSC_DEFAULT to retain the default for any of the parameters.
5057: Level: advanced
5059: Reference:
5060: S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an
5061: inexact Newton method", Utah State University Math. Stat. Dept. Res.
5062: Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.
5064: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPGetParametersEW()
5065: @*/
5066: PetscErrorCode SNESKSPSetParametersEW(SNES snes,PetscInt version,PetscReal rtol_0,PetscReal rtol_max,PetscReal gamma,PetscReal alpha,PetscReal alpha2,PetscReal threshold)
5067: {
5068: SNESKSPEW *kctx;
5072: kctx = (SNESKSPEW*)snes->kspconvctx;
5073: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5082: if (version != PETSC_DEFAULT) kctx->version = version;
5083: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5084: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5085: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5086: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5087: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5088: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5090: 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);
5091: 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);
5092: 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);
5093: 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);
5094: 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);
5095: 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);
5096: return(0);
5097: }
5099: /*@
5100: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5101: convergence criteria for the linear solvers within an inexact
5102: Newton method.
5104: Not Collective
5106: Input Parameters:
5107: snes - SNES context
5109: Output Parameters:
5110: + version - version 1, 2 (default is 2) or 3
5111: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5112: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5113: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5114: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5115: . alpha2 - power for safeguard
5116: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5118: Level: advanced
5120: .seealso: SNESKSPSetUseEW(), SNESKSPGetUseEW(), SNESKSPSetParametersEW()
5121: @*/
5122: PetscErrorCode SNESKSPGetParametersEW(SNES snes,PetscInt *version,PetscReal *rtol_0,PetscReal *rtol_max,PetscReal *gamma,PetscReal *alpha,PetscReal *alpha2,PetscReal *threshold)
5123: {
5124: SNESKSPEW *kctx;
5128: kctx = (SNESKSPEW*)snes->kspconvctx;
5129: if (!kctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"No Eisenstat-Walker context existing");
5130: if (version) *version = kctx->version;
5131: if (rtol_0) *rtol_0 = kctx->rtol_0;
5132: if (rtol_max) *rtol_max = kctx->rtol_max;
5133: if (gamma) *gamma = kctx->gamma;
5134: if (alpha) *alpha = kctx->alpha;
5135: if (alpha2) *alpha2 = kctx->alpha2;
5136: if (threshold) *threshold = kctx->threshold;
5137: return(0);
5138: }
5140: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5141: {
5143: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5144: PetscReal rtol = PETSC_DEFAULT,stol;
5147: if (!snes->ksp_ewconv) return(0);
5148: if (!snes->iter) {
5149: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5150: VecNorm(snes->vec_func,NORM_2,&kctx->norm_first);
5151: }
5152: else {
5153: if (kctx->version == 1) {
5154: rtol = (snes->norm - kctx->lresid_last)/kctx->norm_last;
5155: if (rtol < 0.0) rtol = -rtol;
5156: stol = PetscPowReal(kctx->rtol_last,kctx->alpha2);
5157: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5158: } else if (kctx->version == 2) {
5159: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5160: stol = kctx->gamma * PetscPowReal(kctx->rtol_last,kctx->alpha);
5161: if (stol > kctx->threshold) rtol = PetscMax(rtol,stol);
5162: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5163: rtol = kctx->gamma * PetscPowReal(snes->norm/kctx->norm_last,kctx->alpha);
5164: /* safeguard: avoid sharp decrease of rtol */
5165: stol = kctx->gamma*PetscPowReal(kctx->rtol_last,kctx->alpha);
5166: stol = PetscMax(rtol,stol);
5167: rtol = PetscMin(kctx->rtol_0,stol);
5168: /* safeguard: avoid oversolving */
5169: stol = kctx->gamma*(kctx->norm_first*snes->rtol)/snes->norm;
5170: stol = PetscMax(rtol,stol);
5171: rtol = PetscMin(kctx->rtol_0,stol);
5172: } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only versions 1, 2 or 3 are supported: %D",kctx->version);
5173: }
5174: /* safeguard: avoid rtol greater than one */
5175: rtol = PetscMin(rtol,kctx->rtol_max);
5176: KSPSetTolerances(ksp,rtol,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
5177: PetscInfo3(snes,"iter %D, Eisenstat-Walker (version %D) KSP rtol=%g\n",snes->iter,kctx->version,(double)rtol);
5178: return(0);
5179: }
5181: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5182: {
5184: SNESKSPEW *kctx = (SNESKSPEW*)snes->kspconvctx;
5185: PCSide pcside;
5186: Vec lres;
5189: if (!snes->ksp_ewconv) return(0);
5190: KSPGetTolerances(ksp,&kctx->rtol_last,0,0,0);
5191: kctx->norm_last = snes->norm;
5192: if (kctx->version == 1) {
5193: PC pc;
5194: PetscBool isNone;
5196: KSPGetPC(ksp, &pc);
5197: PetscObjectTypeCompare((PetscObject) pc, PCNONE, &isNone);
5198: KSPGetPCSide(ksp,&pcside);
5199: if (pcside == PC_RIGHT || isNone) { /* XXX Should we also test KSP_UNPRECONDITIONED_NORM ? */
5200: /* KSP residual is true linear residual */
5201: KSPGetResidualNorm(ksp,&kctx->lresid_last);
5202: } else {
5203: /* KSP residual is preconditioned residual */
5204: /* compute true linear residual norm */
5205: VecDuplicate(b,&lres);
5206: MatMult(snes->jacobian,x,lres);
5207: VecAYPX(lres,-1.0,b);
5208: VecNorm(lres,NORM_2,&kctx->lresid_last);
5209: VecDestroy(&lres);
5210: }
5211: }
5212: return(0);
5213: }
5215: /*@
5216: SNESGetKSP - Returns the KSP context for a SNES solver.
5218: Not Collective, but if SNES object is parallel, then KSP object is parallel
5220: Input Parameter:
5221: . snes - the SNES context
5223: Output Parameter:
5224: . ksp - the KSP context
5226: Notes:
5227: The user can then directly manipulate the KSP context to set various
5228: options, etc. Likewise, the user can then extract and manipulate the
5229: PC contexts as well.
5231: Level: beginner
5233: .seealso: KSPGetPC(), SNESCreate(), KSPCreate(), SNESSetKSP()
5234: @*/
5235: PetscErrorCode SNESGetKSP(SNES snes,KSP *ksp)
5236: {
5243: if (!snes->ksp) {
5244: PetscBool monitor = PETSC_FALSE;
5246: KSPCreate(PetscObjectComm((PetscObject)snes),&snes->ksp);
5247: PetscObjectIncrementTabLevel((PetscObject)snes->ksp,(PetscObject)snes,1);
5248: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->ksp);
5250: KSPSetPreSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPreSolve_SNESEW,snes);
5251: KSPSetPostSolve(snes->ksp,(PetscErrorCode (*)(KSP,Vec,Vec,void*))KSPPostSolve_SNESEW,snes);
5253: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes",&monitor,NULL);
5254: if (monitor) {
5255: KSPMonitorSet(snes->ksp,KSPMonitorSNES,snes,NULL);
5256: }
5257: monitor = PETSC_FALSE;
5258: PetscOptionsGetBool(((PetscObject)snes)->options,((PetscObject)snes)->prefix,"-ksp_monitor_snes_lg",&monitor,NULL);
5259: if (monitor) {
5260: PetscObject *objs;
5261: KSPMonitorSNESLGResidualNormCreate(PetscObjectComm((PetscObject)snes),NULL,NULL,PETSC_DECIDE,PETSC_DECIDE,600,600,&objs);
5262: objs[0] = (PetscObject) snes;
5263: KSPMonitorSet(snes->ksp,(PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*))KSPMonitorSNESLGResidualNorm,objs,(PetscErrorCode (*)(void**))KSPMonitorSNESLGResidualNormDestroy);
5264: }
5265: PetscObjectSetOptions((PetscObject)snes->ksp,((PetscObject)snes)->options);
5266: }
5267: *ksp = snes->ksp;
5268: return(0);
5269: }
5272: #include <petsc/private/dmimpl.h>
5273: /*@
5274: SNESSetDM - Sets the DM that may be used by some nonlinear solvers or their underlying preconditioners
5276: Logically Collective on SNES
5278: Input Parameters:
5279: + snes - the nonlinear solver context
5280: - dm - the dm, cannot be NULL
5282: Notes:
5283: A DM can only be used for solving one problem at a time because information about the problem is stored on the DM,
5284: even when not using interfaces like DMSNESSetFunction(). Use DMClone() to get a distinct DM when solving different
5285: problems using the same function space.
5287: Level: intermediate
5289: .seealso: SNESGetDM(), KSPSetDM(), KSPGetDM()
5290: @*/
5291: PetscErrorCode SNESSetDM(SNES snes,DM dm)
5292: {
5294: KSP ksp;
5295: DMSNES sdm;
5300: PetscObjectReference((PetscObject)dm);
5301: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5302: if (snes->dm->dmsnes && !dm->dmsnes) {
5303: DMCopyDMSNES(snes->dm,dm);
5304: DMGetDMSNES(snes->dm,&sdm);
5305: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5306: }
5307: DMCoarsenHookRemove(snes->dm,DMCoarsenHook_SNESVecSol,DMRestrictHook_SNESVecSol,snes);
5308: DMDestroy(&snes->dm);
5309: }
5310: snes->dm = dm;
5311: snes->dmAuto = PETSC_FALSE;
5313: SNESGetKSP(snes,&ksp);
5314: KSPSetDM(ksp,dm);
5315: KSPSetDMActive(ksp,PETSC_FALSE);
5316: if (snes->npc) {
5317: SNESSetDM(snes->npc, snes->dm);
5318: SNESSetNPCSide(snes,snes->npcside);
5319: }
5320: return(0);
5321: }
5323: /*@
5324: SNESGetDM - Gets the DM that may be used by some preconditioners
5326: Not Collective but DM obtained is parallel on SNES
5328: Input Parameter:
5329: . snes - the preconditioner context
5331: Output Parameter:
5332: . dm - the dm
5334: Level: intermediate
5336: .seealso: SNESSetDM(), KSPSetDM(), KSPGetDM()
5337: @*/
5338: PetscErrorCode SNESGetDM(SNES snes,DM *dm)
5339: {
5344: if (!snes->dm) {
5345: DMShellCreate(PetscObjectComm((PetscObject)snes),&snes->dm);
5346: snes->dmAuto = PETSC_TRUE;
5347: }
5348: *dm = snes->dm;
5349: return(0);
5350: }
5352: /*@
5353: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5355: Collective on SNES
5357: Input Parameters:
5358: + snes - iterative context obtained from SNESCreate()
5359: - pc - the preconditioner object
5361: Notes:
5362: Use SNESGetNPC() to retrieve the preconditioner context (for example,
5363: to configure it using the API).
5365: Level: developer
5367: .seealso: SNESGetNPC(), SNESHasNPC()
5368: @*/
5369: PetscErrorCode SNESSetNPC(SNES snes, SNES pc)
5370: {
5377: PetscObjectReference((PetscObject) pc);
5378: SNESDestroy(&snes->npc);
5379: snes->npc = pc;
5380: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->npc);
5381: return(0);
5382: }
5384: /*@
5385: SNESGetNPC - Creates a nonlinear preconditioning solver (SNES) to be used to precondition the nonlinear solver.
5387: Not Collective; but any changes to the obtained SNES object must be applied collectively
5389: Input Parameter:
5390: . snes - iterative context obtained from SNESCreate()
5392: Output Parameter:
5393: . pc - preconditioner context
5395: Options Database:
5396: . -npc_snes_type <type> - set the type of the SNES to use as the nonlinear preconditioner
5398: Notes:
5399: If a SNES was previously set with SNESSetNPC() then that SNES is returned, otherwise a new SNES object is created.
5401: The (preconditioner) SNES returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5402: SNES during SNESSetUp()
5404: Level: developer
5406: .seealso: SNESSetNPC(), SNESHasNPC(), SNES, SNESCreate()
5407: @*/
5408: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5409: {
5411: const char *optionsprefix;
5416: if (!snes->npc) {
5417: SNESCreate(PetscObjectComm((PetscObject)snes),&snes->npc);
5418: PetscObjectIncrementTabLevel((PetscObject)snes->npc,(PetscObject)snes,1);
5419: PetscLogObjectParent((PetscObject)snes,(PetscObject)snes->npc);
5420: SNESGetOptionsPrefix(snes,&optionsprefix);
5421: SNESSetOptionsPrefix(snes->npc,optionsprefix);
5422: SNESAppendOptionsPrefix(snes->npc,"npc_");
5423: SNESSetCountersReset(snes->npc,PETSC_FALSE);
5424: }
5425: *pc = snes->npc;
5426: return(0);
5427: }
5429: /*@
5430: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5432: Not Collective
5434: Input Parameter:
5435: . snes - iterative context obtained from SNESCreate()
5437: Output Parameter:
5438: . has_npc - whether the SNES has an NPC or not
5440: Level: developer
5442: .seealso: SNESSetNPC(), SNESGetNPC()
5443: @*/
5444: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5445: {
5448: *has_npc = (PetscBool) (snes->npc ? PETSC_TRUE : PETSC_FALSE);
5449: return(0);
5450: }
5452: /*@
5453: SNESSetNPCSide - Sets the preconditioning side.
5455: Logically Collective on SNES
5457: Input Parameter:
5458: . snes - iterative context obtained from SNESCreate()
5460: Output Parameter:
5461: . side - the preconditioning side, where side is one of
5462: .vb
5463: PC_LEFT - left preconditioning
5464: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5465: .ve
5467: Options Database Keys:
5468: . -snes_pc_side <right,left>
5470: Notes:
5471: SNESNRICHARDSON and SNESNCG only support left preconditioning.
5473: Level: intermediate
5475: .seealso: SNESGetNPCSide(), KSPSetPCSide()
5476: @*/
5477: PetscErrorCode SNESSetNPCSide(SNES snes,PCSide side)
5478: {
5482: snes->npcside= side;
5483: return(0);
5484: }
5486: /*@
5487: SNESGetNPCSide - Gets the preconditioning side.
5489: Not Collective
5491: Input Parameter:
5492: . snes - iterative context obtained from SNESCreate()
5494: Output Parameter:
5495: . side - the preconditioning side, where side is one of
5496: .vb
5497: PC_LEFT - left preconditioning
5498: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5499: .ve
5501: Level: intermediate
5503: .seealso: SNESSetNPCSide(), KSPGetPCSide()
5504: @*/
5505: PetscErrorCode SNESGetNPCSide(SNES snes,PCSide *side)
5506: {
5510: *side = snes->npcside;
5511: return(0);
5512: }
5514: /*@
5515: SNESSetLineSearch - Sets the linesearch on the SNES instance.
5517: Collective on SNES
5519: Input Parameters:
5520: + snes - iterative context obtained from SNESCreate()
5521: - linesearch - the linesearch object
5523: Notes:
5524: Use SNESGetLineSearch() to retrieve the preconditioner context (for example,
5525: to configure it using the API).
5527: Level: developer
5529: .seealso: SNESGetLineSearch()
5530: @*/
5531: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5532: {
5539: PetscObjectReference((PetscObject) linesearch);
5540: SNESLineSearchDestroy(&snes->linesearch);
5542: snes->linesearch = linesearch;
5544: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5545: return(0);
5546: }
5548: /*@
5549: SNESGetLineSearch - Returns a pointer to the line search context set with SNESSetLineSearch()
5550: or creates a default line search instance associated with the SNES and returns it.
5552: Not Collective
5554: Input Parameter:
5555: . snes - iterative context obtained from SNESCreate()
5557: Output Parameter:
5558: . linesearch - linesearch context
5560: Level: beginner
5562: .seealso: SNESSetLineSearch(), SNESLineSearchCreate()
5563: @*/
5564: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5565: {
5567: const char *optionsprefix;
5572: if (!snes->linesearch) {
5573: SNESGetOptionsPrefix(snes, &optionsprefix);
5574: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch);
5575: SNESLineSearchSetSNES(snes->linesearch, snes);
5576: SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix);
5577: PetscObjectIncrementTabLevel((PetscObject) snes->linesearch, (PetscObject) snes, 1);
5578: PetscLogObjectParent((PetscObject)snes, (PetscObject)snes->linesearch);
5579: }
5580: *linesearch = snes->linesearch;
5581: return(0);
5582: }