Actual source code: snesngmres.c
petsc-3.14.6 2021-03-30
1: #include <../src/snes/impls/ngmres/snesngmres.h>
2: #include <petscblaslapack.h>
3: #include <petscdm.h>
5: const char *const SNESNGMRESRestartTypes[] = {"NONE","PERIODIC","DIFFERENCE","SNESNGMRESRestartType","SNES_NGMRES_RESTART_",NULL};
6: const char *const SNESNGMRESSelectTypes[] = {"NONE","DIFFERENCE","LINESEARCH","SNESNGMRESSelectType","SNES_NGMRES_SELECT_",NULL};
8: PetscErrorCode SNESReset_NGMRES(SNES snes)
9: {
10: SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data;
14: VecDestroyVecs(ngmres->msize,&ngmres->Fdot);
15: VecDestroyVecs(ngmres->msize,&ngmres->Xdot);
16: SNESLineSearchDestroy(&ngmres->additive_linesearch);
17: return(0);
18: }
20: PetscErrorCode SNESDestroy_NGMRES(SNES snes)
21: {
23: SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data;
26: SNESReset_NGMRES(snes);
27: PetscFree4(ngmres->h,ngmres->beta,ngmres->xi,ngmres->q);
28: PetscFree3(ngmres->xnorms,ngmres->fnorms,ngmres->s);
29: #if defined(PETSC_USE_COMPLEX)
30: PetscFree(ngmres->rwork);
31: #endif
32: PetscFree(ngmres->work);
33: PetscFree(snes->data);
34: return(0);
35: }
37: PetscErrorCode SNESSetUp_NGMRES(SNES snes)
38: {
39: SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data;
40: const char *optionsprefix;
41: PetscInt msize,hsize;
43: DM dm;
46: if (snes->npc && snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_UNPRECONDITIONED) {
47: SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"SNESNGMRES does not support left preconditioning with unpreconditioned function");
48: }
49: if (snes->npcside== PC_LEFT && snes->functype == SNES_FUNCTION_DEFAULT) snes->functype = SNES_FUNCTION_PRECONDITIONED;
50: SNESSetWorkVecs(snes,5);
52: if (!snes->vec_sol) {
53: SNESGetDM(snes,&dm);
54: DMCreateGlobalVector(dm,&snes->vec_sol);
55: }
57: if (!ngmres->Xdot) {VecDuplicateVecs(snes->vec_sol,ngmres->msize,&ngmres->Xdot);}
58: if (!ngmres->Fdot) {VecDuplicateVecs(snes->vec_sol,ngmres->msize,&ngmres->Fdot);}
59: if (!ngmres->setup_called) {
60: msize = ngmres->msize; /* restart size */
61: hsize = msize * msize;
63: /* explicit least squares minimization solve */
64: PetscCalloc4(hsize,&ngmres->h, msize,&ngmres->beta, msize,&ngmres->xi, hsize,&ngmres->q);
65: PetscMalloc3(msize,&ngmres->xnorms,msize,&ngmres->fnorms,msize,&ngmres->s);
66: ngmres->nrhs = 1;
67: ngmres->lda = msize;
68: ngmres->ldb = msize;
69: ngmres->lwork = 12*msize;
70: #if defined(PETSC_USE_COMPLEX)
71: PetscMalloc1(ngmres->lwork,&ngmres->rwork);
72: #endif
73: PetscMalloc1(ngmres->lwork,&ngmres->work);
74: }
76: /* linesearch setup */
77: SNESGetOptionsPrefix(snes,&optionsprefix);
79: if (ngmres->select_type == SNES_NGMRES_SELECT_LINESEARCH) {
80: SNESLineSearchCreate(PetscObjectComm((PetscObject)snes),&ngmres->additive_linesearch);
81: SNESLineSearchSetSNES(ngmres->additive_linesearch,snes);
82: if (!((PetscObject)ngmres->additive_linesearch)->type_name) {
83: SNESLineSearchSetType(ngmres->additive_linesearch,SNESLINESEARCHL2);
84: }
85: SNESLineSearchAppendOptionsPrefix(ngmres->additive_linesearch,"additive_");
86: SNESLineSearchAppendOptionsPrefix(ngmres->additive_linesearch,optionsprefix);
87: SNESLineSearchSetFromOptions(ngmres->additive_linesearch);
88: }
90: ngmres->setup_called = PETSC_TRUE;
91: return(0);
92: }
94: PetscErrorCode SNESSetFromOptions_NGMRES(PetscOptionItems *PetscOptionsObject,SNES snes)
95: {
96: SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data;
98: PetscBool debug = PETSC_FALSE;
101: PetscOptionsHead(PetscOptionsObject,"SNES NGMRES options");
102: PetscOptionsEnum("-snes_ngmres_select_type","Select type","SNESNGMRESSetSelectType",SNESNGMRESSelectTypes,
103: (PetscEnum)ngmres->select_type,(PetscEnum*)&ngmres->select_type,NULL);
104: PetscOptionsEnum("-snes_ngmres_restart_type","Restart type","SNESNGMRESSetRestartType",SNESNGMRESRestartTypes,
105: (PetscEnum)ngmres->restart_type,(PetscEnum*)&ngmres->restart_type,NULL);
106: PetscOptionsBool("-snes_ngmres_candidate", "Use candidate storage", "SNES",ngmres->candidate,&ngmres->candidate,NULL);
107: PetscOptionsBool("-snes_ngmres_approxfunc","Linearly approximate the function", "SNES",ngmres->approxfunc,&ngmres->approxfunc,NULL);
108: PetscOptionsInt("-snes_ngmres_m", "Number of directions", "SNES",ngmres->msize,&ngmres->msize,NULL);
109: PetscOptionsInt("-snes_ngmres_restart", "Iterations before forced restart", "SNES",ngmres->restart_periodic,&ngmres->restart_periodic,NULL);
110: PetscOptionsInt("-snes_ngmres_restart_it", "Tolerance iterations before restart","SNES",ngmres->restart_it,&ngmres->restart_it,NULL);
111: PetscOptionsBool("-snes_ngmres_monitor", "Monitor actions of NGMRES", "SNES",ngmres->monitor ? PETSC_TRUE : PETSC_FALSE,&debug,NULL);
112: if (debug) {
113: ngmres->monitor = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
114: }
115: PetscOptionsReal("-snes_ngmres_gammaA", "Residual selection constant", "SNES",ngmres->gammaA,&ngmres->gammaA,NULL);
116: PetscOptionsReal("-snes_ngmres_gammaC", "Residual restart constant", "SNES",ngmres->gammaC,&ngmres->gammaC,NULL);
117: PetscOptionsReal("-snes_ngmres_epsilonB", "Difference selection constant", "SNES",ngmres->epsilonB,&ngmres->epsilonB,NULL);
118: PetscOptionsReal("-snes_ngmres_deltaB", "Difference residual selection constant", "SNES",ngmres->deltaB,&ngmres->deltaB,NULL);
119: PetscOptionsBool("-snes_ngmres_single_reduction", "Aggregate reductions", "SNES",ngmres->singlereduction,&ngmres->singlereduction,NULL);
120: PetscOptionsBool("-snes_ngmres_restart_fm_rise", "Restart on F_M residual rise", "SNESNGMRESSetRestartFmRise",ngmres->restart_fm_rise,&ngmres->restart_fm_rise,NULL);
121: PetscOptionsTail();
122: if ((ngmres->gammaA > ngmres->gammaC) && (ngmres->gammaC > 2.)) ngmres->gammaC = ngmres->gammaA;
123: return(0);
124: }
126: PetscErrorCode SNESView_NGMRES(SNES snes,PetscViewer viewer)
127: {
128: SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data;
129: PetscBool iascii;
133: PetscObjectTypeCompare((PetscObject) viewer,PETSCVIEWERASCII,&iascii);
134: if (iascii) {
135: PetscViewerASCIIPrintf(viewer," Number of stored past updates: %d\n", ngmres->msize);
136: PetscViewerASCIIPrintf(viewer," Residual selection: gammaA=%1.0e, gammaC=%1.0e\n",ngmres->gammaA,ngmres->gammaC);
137: PetscViewerASCIIPrintf(viewer," Difference restart: epsilonB=%1.0e, deltaB=%1.0e\n",ngmres->epsilonB,ngmres->deltaB);
138: PetscViewerASCIIPrintf(viewer," Restart on F_M residual increase: %s\n",ngmres->restart_fm_rise?"TRUE":"FALSE");
139: }
140: return(0);
141: }
143: PetscErrorCode SNESSolve_NGMRES(SNES snes)
144: {
145: SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data;
146: /* present solution, residual, and preconditioned residual */
147: Vec X,F,B,D,Y;
149: /* candidate linear combination answers */
150: Vec XA,FA,XM,FM;
152: /* coefficients and RHS to the minimization problem */
153: PetscReal fnorm,fMnorm,fAnorm;
154: PetscReal xnorm,xMnorm,xAnorm;
155: PetscReal ynorm,yMnorm,yAnorm;
156: PetscInt k,k_restart,l,ivec,restart_count = 0;
158: /* solution selection data */
159: PetscBool selectRestart;
160: /*
161: These two variables are initialized to prevent compilers/analyzers from producing false warnings about these variables being passed
162: to SNESNGMRESSelect_Private() without being set when SNES_NGMRES_RESTART_DIFFERENCE, the values are not used in the subroutines in that case
163: so the code is correct as written.
164: */
165: PetscReal dnorm = 0.0,dminnorm = 0.0;
166: PetscReal fminnorm;
168: SNESConvergedReason reason;
169: SNESLineSearchReason lssucceed;
170: PetscErrorCode ierr;
173: if (snes->xl || snes->xu || snes->ops->computevariablebounds) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE, "SNES solver %s does not support bounds", ((PetscObject)snes)->type_name);
175: PetscCitationsRegister(SNESCitation,&SNEScite);
176: /* variable initialization */
177: snes->reason = SNES_CONVERGED_ITERATING;
178: X = snes->vec_sol;
179: F = snes->vec_func;
180: B = snes->vec_rhs;
181: XA = snes->vec_sol_update;
182: FA = snes->work[0];
183: D = snes->work[1];
185: /* work for the line search */
186: Y = snes->work[2];
187: XM = snes->work[3];
188: FM = snes->work[4];
190: PetscObjectSAWsTakeAccess((PetscObject)snes);
191: snes->iter = 0;
192: snes->norm = 0.;
193: PetscObjectSAWsGrantAccess((PetscObject)snes);
195: /* initialization */
197: if (snes->npc && snes->npcside== PC_LEFT) {
198: SNESApplyNPC(snes,X,NULL,F);
199: SNESGetConvergedReason(snes->npc,&reason);
200: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
201: snes->reason = SNES_DIVERGED_INNER;
202: return(0);
203: }
204: VecNorm(F,NORM_2,&fnorm);
205: } else {
206: if (!snes->vec_func_init_set) {
207: SNESComputeFunction(snes,X,F);
208: } else snes->vec_func_init_set = PETSC_FALSE;
210: VecNorm(F,NORM_2,&fnorm);
211: SNESCheckFunctionNorm(snes,fnorm);
212: }
213: fminnorm = fnorm;
215: PetscObjectSAWsTakeAccess((PetscObject)snes);
216: snes->norm = fnorm;
217: PetscObjectSAWsGrantAccess((PetscObject)snes);
218: SNESLogConvergenceHistory(snes,fnorm,0);
219: SNESMonitor(snes,0,fnorm);
220: (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);
221: if (snes->reason) return(0);
222: SNESNGMRESUpdateSubspace_Private(snes,0,0,F,fnorm,X);
224: k_restart = 1;
225: l = 1;
226: ivec = 0;
227: for (k=1; k < snes->max_its+1; k++) {
228: /* Computation of x^M */
229: if (snes->npc && snes->npcside== PC_RIGHT) {
230: VecCopy(X,XM);
231: SNESSetInitialFunction(snes->npc,F);
233: PetscLogEventBegin(SNES_NPCSolve,snes->npc,XM,B,0);
234: SNESSolve(snes->npc,B,XM);
235: PetscLogEventEnd(SNES_NPCSolve,snes->npc,XM,B,0);
237: SNESGetConvergedReason(snes->npc,&reason);
238: if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) {
239: snes->reason = SNES_DIVERGED_INNER;
240: return(0);
241: }
242: SNESGetNPCFunction(snes,FM,&fMnorm);
243: } else {
244: /* no preconditioner -- just take gradient descent with line search */
245: VecCopy(F,Y);
246: VecCopy(F,FM);
247: VecCopy(X,XM);
249: fMnorm = fnorm;
251: SNESLineSearchApply(snes->linesearch,XM,FM,&fMnorm,Y);
252: SNESLineSearchGetReason(snes->linesearch,&lssucceed);
253: if (lssucceed) {
254: if (++snes->numFailures >= snes->maxFailures) {
255: snes->reason = SNES_DIVERGED_LINE_SEARCH;
256: return(0);
257: }
258: }
259: }
261: SNESNGMRESFormCombinedSolution_Private(snes,ivec,l,XM,FM,fMnorm,X,XA,FA);
262: /* r = F(x) */
263: if (fminnorm > fMnorm) fminnorm = fMnorm; /* the minimum norm is now of F^M */
265: /* differences for selection and restart */
266: if (ngmres->restart_type == SNES_NGMRES_RESTART_DIFFERENCE || ngmres->select_type == SNES_NGMRES_SELECT_DIFFERENCE) {
267: SNESNGMRESNorms_Private(snes,l,X,F,XM,FM,XA,FA,D,&dnorm,&dminnorm,&xMnorm,NULL,&yMnorm,&xAnorm,&fAnorm,&yAnorm);
268: } else {
269: SNESNGMRESNorms_Private(snes,l,X,F,XM,FM,XA,FA,D,NULL,NULL,&xMnorm,NULL,&yMnorm,&xAnorm,&fAnorm,&yAnorm);
270: }
271: SNESCheckFunctionNorm(snes,fnorm);
273: /* combination (additive) or selection (multiplicative) of the N-GMRES solution */
274: SNESNGMRESSelect_Private(snes,k_restart,XM,FM,xMnorm,fMnorm,yMnorm,XA,FA,xAnorm,fAnorm,yAnorm,dnorm,fminnorm,dminnorm,X,F,Y,&xnorm,&fnorm,&ynorm);
275: selectRestart = PETSC_FALSE;
277: if (ngmres->restart_type == SNES_NGMRES_RESTART_DIFFERENCE) {
278: SNESNGMRESSelectRestart_Private(snes,l,fMnorm,fAnorm,dnorm,fminnorm,dminnorm,&selectRestart);
280: /* if the restart conditions persist for more than restart_it iterations, restart. */
281: if (selectRestart) restart_count++;
282: else restart_count = 0;
283: } else if (ngmres->restart_type == SNES_NGMRES_RESTART_PERIODIC) {
284: if (k_restart > ngmres->restart_periodic) {
285: if (ngmres->monitor) PetscViewerASCIIPrintf(ngmres->monitor,"periodic restart after %D iterations\n",k_restart);
286: restart_count = ngmres->restart_it;
287: }
288: }
290: ivec = k_restart % ngmres->msize; /* replace the last used part of the subspace */
292: /* restart after restart conditions have persisted for a fixed number of iterations */
293: if (restart_count >= ngmres->restart_it) {
294: if (ngmres->monitor) {
295: PetscViewerASCIIPrintf(ngmres->monitor,"Restarted at iteration %d\n",k_restart);
296: }
297: restart_count = 0;
298: k_restart = 1;
299: l = 1;
300: ivec = 0;
301: /* q_{00} = nu */
302: SNESNGMRESUpdateSubspace_Private(snes,0,0,FM,fMnorm,XM);
303: } else {
304: /* select the current size of the subspace */
305: if (l < ngmres->msize) l++;
306: k_restart++;
307: /* place the current entry in the list of previous entries */
308: if (ngmres->candidate) {
309: if (fminnorm > fMnorm) fminnorm = fMnorm;
310: SNESNGMRESUpdateSubspace_Private(snes,ivec,l,FM,fMnorm,XM);
311: } else {
312: if (fminnorm > fnorm) fminnorm = fnorm;
313: SNESNGMRESUpdateSubspace_Private(snes,ivec,l,F,fnorm,X);
314: }
315: }
317: PetscObjectSAWsTakeAccess((PetscObject)snes);
318: snes->iter = k;
319: snes->norm = fnorm;
320: PetscObjectSAWsGrantAccess((PetscObject)snes);
321: SNESLogConvergenceHistory(snes,snes->norm,snes->iter);
322: SNESMonitor(snes,snes->iter,snes->norm);
323: (*snes->ops->converged)(snes,snes->iter,0,0,fnorm,&snes->reason,snes->cnvP);
324: if (snes->reason) return(0);
325: }
326: snes->reason = SNES_DIVERGED_MAX_IT;
327: return(0);
328: }
330: /*@
331: SNESNGMRESSetRestartFmRise - Increase the restart count if the step x_M increases the residual F_M
333: Input Parameters:
334: + snes - the SNES context.
335: - flg - boolean value deciding whether to use the option or not
337: Options Database:
338: + -snes_ngmres_restart_fm_rise - Increase the restart count if the step x_M increases the residual F_M
340: Level: intermediate
342: Notes:
343: If the proposed step x_M increases the residual F_M, it might be trying to get out of a stagnation area.
344: To help the solver do that, reset the Krylov subspace whenever F_M increases.
346: This option must be used with SNES_NGMRES_RESTART_DIFFERENCE
348: The default is FALSE.
349: .seealso: SNES_NGMRES_RESTART_DIFFERENCE
350: @*/
351: PetscErrorCode SNESNGMRESSetRestartFmRise(SNES snes,PetscBool flg)
352: {
353: PetscErrorCode (*f)(SNES,PetscBool);
357: PetscObjectQueryFunction((PetscObject)snes,"SNESNGMRESSetRestartFmRise_C",&f);
358: if (f) {(f)(snes,flg);}
359: return(0);
360: }
362: PetscErrorCode SNESNGMRESSetRestartFmRise_NGMRES(SNES snes,PetscBool flg)
363: {
364: SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data;
367: ngmres->restart_fm_rise = flg;
368: return(0);
369: }
371: PetscErrorCode SNESNGMRESGetRestartFmRise(SNES snes,PetscBool *flg)
372: {
373: PetscErrorCode (*f)(SNES,PetscBool*);
377: PetscObjectQueryFunction((PetscObject)snes,"SNESNGMRESGetRestartFmRise_C",&f);
378: if (f) {(f)(snes,flg);}
379: return(0);
380: }
382: PetscErrorCode SNESNGMRESGetRestartFmRise_NGMRES(SNES snes,PetscBool *flg)
383: {
384: SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data;
387: *flg = ngmres->restart_fm_rise;
388: return(0);
389: }
392: /*@
393: SNESNGMRESSetRestartType - Sets the restart type for SNESNGMRES.
395: Logically Collective on SNES
397: Input Parameters:
398: + snes - the iterative context
399: - rtype - restart type
401: Options Database:
402: + -snes_ngmres_restart_type<difference,periodic,none> - set the restart type
403: - -snes_ngmres_restart[30] - sets the number of iterations before restart for periodic
405: Level: intermediate
407: SNESNGMRESRestartTypes:
408: + SNES_NGMRES_RESTART_NONE - never restart
409: . SNES_NGMRES_RESTART_DIFFERENCE - restart based upon difference criteria
410: - SNES_NGMRES_RESTART_PERIODIC - restart after a fixed number of iterations
412: Notes:
413: The default line search used is the L2 line search and it requires two additional function evaluations.
415: @*/
416: PetscErrorCode SNESNGMRESSetRestartType(SNES snes,SNESNGMRESRestartType rtype)
417: {
422: PetscTryMethod(snes,"SNESNGMRESSetRestartType_C",(SNES,SNESNGMRESRestartType),(snes,rtype));
423: return(0);
424: }
426: /*@
427: SNESNGMRESSetSelectType - Sets the selection type for SNESNGMRES. This determines how the candidate solution and
428: combined solution are used to create the next iterate.
430: Logically Collective on SNES
432: Input Parameters:
433: + snes - the iterative context
434: - stype - selection type
436: Options Database:
437: . -snes_ngmres_select_type<difference,none,linesearch>
439: Level: intermediate
441: SNESNGMRESSelectTypes:
442: + SNES_NGMRES_SELECT_NONE - choose the combined solution all the time
443: . SNES_NGMRES_SELECT_DIFFERENCE - choose based upon the selection criteria
444: - SNES_NGMRES_SELECT_LINESEARCH - choose based upon line search combination
446: Notes:
447: The default line search used is the L2 line search and it requires two additional function evaluations.
449: @*/
450: PetscErrorCode SNESNGMRESSetSelectType(SNES snes,SNESNGMRESSelectType stype)
451: {
456: PetscTryMethod(snes,"SNESNGMRESSetSelectType_C",(SNES,SNESNGMRESSelectType),(snes,stype));
457: return(0);
458: }
460: PetscErrorCode SNESNGMRESSetSelectType_NGMRES(SNES snes,SNESNGMRESSelectType stype)
461: {
462: SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data;
465: ngmres->select_type = stype;
466: return(0);
467: }
469: PetscErrorCode SNESNGMRESSetRestartType_NGMRES(SNES snes,SNESNGMRESRestartType rtype)
470: {
471: SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data;
474: ngmres->restart_type = rtype;
475: return(0);
476: }
478: /*MC
479: SNESNGMRES - The Nonlinear Generalized Minimum Residual method.
481: Level: beginner
483: Options Database:
484: + -snes_ngmres_select_type<difference,none,linesearch> - choose the select between candidate and combined solution
485: . -snes_ngmres_restart_type<difference,none,periodic> - choose the restart conditions
486: . -snes_ngmres_candidate - Use NGMRES variant which combines candidate solutions instead of actual solutions
487: . -snes_ngmres_m - Number of stored previous solutions and residuals
488: . -snes_ngmres_restart_it - Number of iterations the restart conditions hold before restart
489: . -snes_ngmres_gammaA - Residual tolerance for solution select between the candidate and combination
490: . -snes_ngmres_gammaC - Residual tolerance for restart
491: . -snes_ngmres_epsilonB - Difference tolerance between subsequent solutions triggering restart
492: . -snes_ngmres_deltaB - Difference tolerance between residuals triggering restart
493: . -snes_ngmres_restart_fm_rise - Restart on residual rise from x_M step
494: . -snes_ngmres_monitor - Prints relevant information about the ngmres iteration
495: . -snes_linesearch_type <basic,l2,cp> - Line search type used for the default smoother
496: - -additive_snes_linesearch_type - linesearch type used to select between the candidate and combined solution with additive select type
498: Notes:
500: The N-GMRES method combines m previous solutions into a minimum-residual solution by solving a small linearized
501: optimization problem at each iteration.
503: Very similar to the SNESANDERSON algorithm.
505: References:
506: + 1. - C. W. Oosterlee and T. Washio, "Krylov Subspace Acceleration of Nonlinear Multigrid with Application to Recirculating Flows",
507: SIAM Journal on Scientific Computing, 21(5), 2000.
508: - 2. - Peter R. Brune, Matthew G. Knepley, Barry F. Smith, and Xuemin Tu, "Composing Scalable Nonlinear Algebraic Solvers",
509: SIAM Review, 57(4), 2015
512: .seealso: SNESCreate(), SNES, SNESSetType(), SNESType (for list of available types)
513: M*/
515: PETSC_EXTERN PetscErrorCode SNESCreate_NGMRES(SNES snes)
516: {
517: SNES_NGMRES *ngmres;
519: SNESLineSearch linesearch;
522: snes->ops->destroy = SNESDestroy_NGMRES;
523: snes->ops->setup = SNESSetUp_NGMRES;
524: snes->ops->setfromoptions = SNESSetFromOptions_NGMRES;
525: snes->ops->view = SNESView_NGMRES;
526: snes->ops->solve = SNESSolve_NGMRES;
527: snes->ops->reset = SNESReset_NGMRES;
529: snes->usesnpc = PETSC_TRUE;
530: snes->usesksp = PETSC_FALSE;
531: snes->npcside = PC_RIGHT;
533: snes->alwayscomputesfinalresidual = PETSC_TRUE;
535: PetscNewLog(snes,&ngmres);
536: snes->data = (void*) ngmres;
537: ngmres->msize = 30;
539: if (!snes->tolerancesset) {
540: snes->max_funcs = 30000;
541: snes->max_its = 10000;
542: }
544: ngmres->candidate = PETSC_FALSE;
546: SNESGetLineSearch(snes,&linesearch);
547: if (!((PetscObject)linesearch)->type_name) {
548: SNESLineSearchSetType(linesearch,SNESLINESEARCHBASIC);
549: }
551: ngmres->additive_linesearch = NULL;
552: ngmres->approxfunc = PETSC_FALSE;
553: ngmres->restart_it = 2;
554: ngmres->restart_periodic = 30;
555: ngmres->gammaA = 2.0;
556: ngmres->gammaC = 2.0;
557: ngmres->deltaB = 0.9;
558: ngmres->epsilonB = 0.1;
559: ngmres->restart_fm_rise = PETSC_FALSE;
561: ngmres->restart_type = SNES_NGMRES_RESTART_DIFFERENCE;
562: ngmres->select_type = SNES_NGMRES_SELECT_DIFFERENCE;
564: PetscObjectComposeFunction((PetscObject)snes,"SNESNGMRESSetSelectType_C",SNESNGMRESSetSelectType_NGMRES);
565: PetscObjectComposeFunction((PetscObject)snes,"SNESNGMRESSetRestartType_C",SNESNGMRESSetRestartType_NGMRES);
566: PetscObjectComposeFunction((PetscObject)snes,"SNESNGMRESSetRestartFmRise_C",SNESNGMRESSetRestartFmRise_NGMRES);
567: PetscObjectComposeFunction((PetscObject)snes,"SNESNGMRESGetRestartFmRise_C",SNESNGMRESGetRestartFmRise_NGMRES);
568: return(0);
569: }