1 #include <../src/snes/impls/ngmres/snesngmres.h> /*I "petscsnes.h" I*/ 2 #include <petscblaslapack.h> 3 4 const char *const SNESNGMRESRestartTypes[] = {"NONE","PERIODIC","DIFFERENCE","SNESNGMRESRestartType","SNES_NGMRES_RESTART_",0}; 5 const char *const SNESNGMRESSelectTypes[] = {"NONE","DIFFERENCE","LINESEARCH","SNESNGMRESSelectType","SNES_NGMRES_SELECT_",0}; 6 7 #undef __FUNCT__ 8 #define __FUNCT__ "SNESReset_NGMRES" 9 PetscErrorCode SNESReset_NGMRES(SNES snes) 10 { 11 SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; 12 PetscErrorCode ierr; 13 14 PetscFunctionBegin; 15 ierr = VecDestroyVecs(ngmres->msize,&ngmres->Fdot);CHKERRQ(ierr); 16 ierr = VecDestroyVecs(ngmres->msize,&ngmres->Xdot);CHKERRQ(ierr); 17 ierr = SNESLineSearchDestroy(&ngmres->additive_linesearch);CHKERRQ(ierr); 18 PetscFunctionReturn(0); 19 } 20 21 #undef __FUNCT__ 22 #define __FUNCT__ "SNESDestroy_NGMRES" 23 PetscErrorCode SNESDestroy_NGMRES(SNES snes) 24 { 25 PetscErrorCode ierr; 26 SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data; 27 28 PetscFunctionBegin; 29 ierr = SNESReset_NGMRES(snes);CHKERRQ(ierr); 30 ierr = PetscFree5(ngmres->h,ngmres->beta,ngmres->xi,ngmres->fnorms,ngmres->q);CHKERRQ(ierr); 31 ierr = PetscFree(ngmres->s);CHKERRQ(ierr); 32 ierr = PetscFree(ngmres->xnorms);CHKERRQ(ierr); 33 #if PETSC_USE_COMPLEX 34 ierr = PetscFree(ngmres->rwork);CHKERRQ(ierr); 35 #endif 36 ierr = PetscFree(ngmres->work);CHKERRQ(ierr); 37 ierr = PetscFree(snes->data);CHKERRQ(ierr); 38 PetscFunctionReturn(0); 39 } 40 41 #undef __FUNCT__ 42 #define __FUNCT__ "SNESSetUp_NGMRES" 43 PetscErrorCode SNESSetUp_NGMRES(SNES snes) 44 { 45 SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; 46 const char *optionsprefix; 47 PetscInt msize,hsize; 48 PetscErrorCode ierr; 49 50 PetscFunctionBegin; 51 ierr = SNESDefaultGetWork(snes,5);CHKERRQ(ierr); 52 if (!ngmres->Xdot) {ierr = VecDuplicateVecs(snes->vec_sol,ngmres->msize,&ngmres->Xdot);CHKERRQ(ierr);} 53 if (!ngmres->Fdot) {ierr = VecDuplicateVecs(snes->vec_sol,ngmres->msize,&ngmres->Fdot);CHKERRQ(ierr);} 54 if (!ngmres->setup_called) { 55 msize = ngmres->msize; /* restart size */ 56 hsize = msize * msize; 57 58 /* explicit least squares minimization solve */ 59 ierr = PetscMalloc5(hsize,PetscScalar,&ngmres->h, 60 msize,PetscScalar,&ngmres->beta, 61 msize,PetscScalar,&ngmres->xi, 62 msize,PetscReal, &ngmres->fnorms, 63 hsize,PetscScalar,&ngmres->q);CHKERRQ(ierr); 64 if (ngmres->singlereduction) { 65 ierr = PetscMalloc(msize*sizeof(PetscReal),&ngmres->xnorms);CHKERRQ(ierr); 66 } 67 ngmres->nrhs = 1; 68 ngmres->lda = msize; 69 ngmres->ldb = msize; 70 ierr = PetscMalloc(msize*sizeof(PetscScalar),&ngmres->s);CHKERRQ(ierr); 71 ierr = PetscMemzero(ngmres->h, hsize*sizeof(PetscScalar));CHKERRQ(ierr); 72 ierr = PetscMemzero(ngmres->q, hsize*sizeof(PetscScalar));CHKERRQ(ierr); 73 ierr = PetscMemzero(ngmres->xi, msize*sizeof(PetscScalar));CHKERRQ(ierr); 74 ierr = PetscMemzero(ngmres->beta,msize*sizeof(PetscScalar));CHKERRQ(ierr); 75 ngmres->lwork = 12*msize; 76 #if PETSC_USE_COMPLEX 77 ierr = PetscMalloc(sizeof(PetscReal)*ngmres->lwork,&ngmres->rwork);CHKERRQ(ierr); 78 #endif 79 ierr = PetscMalloc(sizeof(PetscScalar)*ngmres->lwork,&ngmres->work);CHKERRQ(ierr); 80 } 81 82 /* linesearch setup */ 83 ierr = SNESGetOptionsPrefix(snes,&optionsprefix);CHKERRQ(ierr); 84 85 if (ngmres->select_type == SNES_NGMRES_SELECT_LINESEARCH) { 86 ierr = SNESLineSearchCreate(PetscObjectComm((PetscObject)snes),&ngmres->additive_linesearch);CHKERRQ(ierr); 87 ierr = SNESLineSearchSetSNES(ngmres->additive_linesearch,snes);CHKERRQ(ierr); 88 ierr = SNESLineSearchSetType(ngmres->additive_linesearch,SNESLINESEARCHL2);CHKERRQ(ierr); 89 ierr = SNESLineSearchAppendOptionsPrefix(ngmres->additive_linesearch,"additive_");CHKERRQ(ierr); 90 ierr = SNESLineSearchAppendOptionsPrefix(ngmres->additive_linesearch,optionsprefix);CHKERRQ(ierr); 91 ierr = SNESLineSearchSetFromOptions(ngmres->additive_linesearch);CHKERRQ(ierr); 92 } 93 94 ngmres->setup_called = PETSC_TRUE; 95 PetscFunctionReturn(0); 96 } 97 98 #undef __FUNCT__ 99 #define __FUNCT__ "SNESSetFromOptions_NGMRES" 100 PetscErrorCode SNESSetFromOptions_NGMRES(SNES snes) 101 { 102 SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; 103 PetscErrorCode ierr; 104 PetscBool debug; 105 SNESLineSearch linesearch; 106 107 PetscFunctionBegin; 108 ierr = PetscOptionsHead("SNES NGMRES options");CHKERRQ(ierr); 109 ierr = PetscOptionsEnum("-snes_ngmres_select_type","Select type","SNESNGMRESSetSelectType",SNESNGMRESSelectTypes, 110 (PetscEnum)ngmres->select_type,(PetscEnum*)&ngmres->select_type,NULL);CHKERRQ(ierr); 111 ierr = PetscOptionsEnum("-snes_ngmres_restart_type","Restart type","SNESNGMRESSetRestartType",SNESNGMRESRestartTypes, 112 (PetscEnum)ngmres->restart_type,(PetscEnum*)&ngmres->restart_type,NULL);CHKERRQ(ierr); 113 ierr = PetscOptionsBool("-snes_ngmres_candidate", "Use candidate storage", "SNES",ngmres->candidate,&ngmres->candidate,NULL);CHKERRQ(ierr); 114 ierr = PetscOptionsBool("-snes_ngmres_approxfunc","Linearly approximate the function", "SNES",ngmres->approxfunc,&ngmres->approxfunc,NULL);CHKERRQ(ierr); 115 ierr = PetscOptionsInt("-snes_ngmres_m", "Number of directions", "SNES",ngmres->msize,&ngmres->msize,NULL);CHKERRQ(ierr); 116 ierr = PetscOptionsInt("-snes_ngmres_restart", "Iterations before forced restart", "SNES",ngmres->restart_periodic,&ngmres->restart_periodic,NULL);CHKERRQ(ierr); 117 ierr = PetscOptionsInt("-snes_ngmres_restart_it", "Tolerance iterations before restart","SNES",ngmres->restart_it,&ngmres->restart_it,NULL);CHKERRQ(ierr); 118 ierr = PetscOptionsBool("-snes_ngmres_monitor", "Monitor actions of NGMRES", "SNES",ngmres->monitor ? PETSC_TRUE : PETSC_FALSE,&debug,NULL);CHKERRQ(ierr); 119 if (debug) { 120 ngmres->monitor = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));CHKERRQ(ierr); 121 } 122 ierr = PetscOptionsReal("-snes_ngmres_gammaA", "Residual selection constant", "SNES",ngmres->gammaA,&ngmres->gammaA,NULL);CHKERRQ(ierr); 123 ierr = PetscOptionsReal("-snes_ngmres_gammaC", "Residual restart constant", "SNES",ngmres->gammaC,&ngmres->gammaC,NULL);CHKERRQ(ierr); 124 ierr = PetscOptionsReal("-snes_ngmres_epsilonB", "Difference selection constant", "SNES",ngmres->epsilonB,&ngmres->epsilonB,NULL);CHKERRQ(ierr); 125 ierr = PetscOptionsReal("-snes_ngmres_deltaB", "Difference residual selection constant", "SNES",ngmres->deltaB,&ngmres->deltaB,NULL);CHKERRQ(ierr); 126 ierr = PetscOptionsBool("-snes_ngmres_single_reduction", "Aggregate reductions", "SNES",ngmres->singlereduction,&ngmres->singlereduction,NULL);CHKERRQ(ierr); 127 ierr = PetscOptionsTail();CHKERRQ(ierr); 128 if ((ngmres->gammaA > ngmres->gammaC) && (ngmres->gammaC > 2.)) ngmres->gammaC = ngmres->gammaA; 129 130 /* set the default type of the line search if the user hasn't already. */ 131 if (!snes->linesearch) { 132 ierr = SNESGetSNESLineSearch(snes,&linesearch);CHKERRQ(ierr); 133 ierr = SNESLineSearchSetType(linesearch,SNESLINESEARCHBASIC);CHKERRQ(ierr); 134 } 135 PetscFunctionReturn(0); 136 } 137 138 #undef __FUNCT__ 139 #define __FUNCT__ "SNESView_NGMRES" 140 PetscErrorCode SNESView_NGMRES(SNES snes,PetscViewer viewer) 141 { 142 SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; 143 PetscBool iascii; 144 PetscErrorCode ierr; 145 146 PetscFunctionBegin; 147 ierr = PetscObjectTypeCompare((PetscObject) viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 148 if (iascii) { 149 ierr = PetscViewerASCIIPrintf(viewer," Number of stored past updates: %d\n", ngmres->msize);CHKERRQ(ierr); 150 ierr = PetscViewerASCIIPrintf(viewer," Residual selection: gammaA=%1.0e, gammaC=%1.0e\n",ngmres->gammaA,ngmres->gammaC);CHKERRQ(ierr); 151 ierr = PetscViewerASCIIPrintf(viewer," Difference restart: epsilonB=%1.0e, deltaB=%1.0e\n",ngmres->epsilonB,ngmres->deltaB);CHKERRQ(ierr); 152 } 153 PetscFunctionReturn(0); 154 } 155 156 #undef __FUNCT__ 157 #define __FUNCT__ "SNESSolve_NGMRES" 158 PetscErrorCode SNESSolve_NGMRES(SNES snes) 159 { 160 161 SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; 162 /* present solution, residual, and preconditioned residual */ 163 Vec X,F,B,D,Y; 164 165 /* candidate linear combination answers */ 166 Vec XA,FA,XM,FM,FPC; 167 168 /* coefficients and RHS to the minimization problem */ 169 PetscReal fnorm,fMnorm,fAnorm; 170 PetscInt k,k_restart,l,ivec,restart_count = 0; 171 172 /* solution selection data */ 173 PetscBool selectRestart; 174 PetscReal dnorm,dminnorm = 0.0; 175 PetscReal fminnorm,xnorm,ynorm; 176 177 SNESConvergedReason reason; 178 PetscBool lssucceed; 179 PetscErrorCode ierr; 180 181 PetscFunctionBegin; 182 /* variable initialization */ 183 snes->reason = SNES_CONVERGED_ITERATING; 184 X = snes->vec_sol; 185 F = snes->vec_func; 186 B = snes->vec_rhs; 187 XA = snes->vec_sol_update; 188 FA = snes->work[0]; 189 D = snes->work[1]; 190 191 /* work for the line search */ 192 Y = snes->work[2]; 193 XM = snes->work[3]; 194 FM = snes->work[4]; 195 196 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 197 snes->iter = 0; 198 snes->norm = 0.; 199 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 200 201 /* initialization */ 202 203 /* r = F(x) */ 204 if (!snes->vec_func_init_set) { 205 ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); 206 if (snes->domainerror) { 207 snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; 208 PetscFunctionReturn(0); 209 } 210 } else snes->vec_func_init_set = PETSC_FALSE; 211 212 if (!snes->norm_init_set) { 213 ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); 214 if (PetscIsInfOrNanReal(fnorm)) { 215 snes->reason = SNES_DIVERGED_FNORM_NAN; 216 PetscFunctionReturn(0); 217 } 218 } else { 219 fnorm = snes->norm_init; 220 snes->norm_init_set = PETSC_FALSE; 221 } 222 fminnorm = fnorm; 223 224 /* q_{00} = nu */ 225 SNESNGMRESUpdateSubspace_Private(snes,0,0,F,fnorm,X); 226 227 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 228 snes->norm = fnorm; 229 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 230 ierr = SNESLogConvergenceHistory(snes,fnorm,0);CHKERRQ(ierr); 231 ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); 232 ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 233 if (snes->reason) PetscFunctionReturn(0); 234 235 k_restart = 1; 236 l = 1; 237 for (k=1; k < snes->max_its+1; k++) { 238 /* select which vector of the stored subspace will be updated */ 239 ivec = k_restart % ngmres->msize; /* replace the last used part of the subspace */ 240 241 /* Computation of x^M */ 242 if (snes->pc && snes->pcside == PC_RIGHT) { 243 ierr = VecCopy(X,XM);CHKERRQ(ierr); 244 ierr = SNESSetInitialFunction(snes->pc,F);CHKERRQ(ierr); 245 ierr = SNESSetInitialFunctionNorm(snes->pc,fnorm);CHKERRQ(ierr); 246 247 ierr = PetscLogEventBegin(SNES_NPCSolve,snes->pc,XM,B,0);CHKERRQ(ierr); 248 ierr = SNESSolve(snes->pc,B,XM);CHKERRQ(ierr); 249 ierr = PetscLogEventEnd(SNES_NPCSolve,snes->pc,XM,B,0);CHKERRQ(ierr); 250 251 ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); 252 if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { 253 snes->reason = SNES_DIVERGED_INNER; 254 PetscFunctionReturn(0); 255 } 256 ierr = SNESGetFunction(snes->pc,&FPC,NULL,NULL);CHKERRQ(ierr); 257 ierr = VecCopy(FPC,FM);CHKERRQ(ierr); 258 ierr = SNESGetFunctionNorm(snes->pc,&fMnorm);CHKERRQ(ierr); 259 } else { 260 /* no preconditioner -- just take gradient descent with line search */ 261 ierr = VecCopy(F,Y);CHKERRQ(ierr); 262 ierr = VecCopy(F,FM);CHKERRQ(ierr); 263 ierr = VecCopy(X,XM);CHKERRQ(ierr); 264 265 fMnorm = fnorm; 266 267 ierr = SNESLineSearchApply(snes->linesearch,XM,FM,&fMnorm,Y);CHKERRQ(ierr); 268 ierr = SNESLineSearchGetSuccess(snes->linesearch,&lssucceed);CHKERRQ(ierr); 269 if (!lssucceed) { 270 if (++snes->numFailures >= snes->maxFailures) { 271 snes->reason = SNES_DIVERGED_LINE_SEARCH; 272 PetscFunctionReturn(0); 273 } 274 } 275 } 276 ierr = SNESNGMRESFormCombinedSolution_Private(snes,l,XM,FM,fMnorm,X,XA,FA);CHKERRQ(ierr); 277 /* r = F(x) */ 278 if (fminnorm > fMnorm) fminnorm = fMnorm; /* the minimum norm is now of F^M */ 279 280 /* differences for selection and restart */ 281 if (ngmres->restart_type == SNES_NGMRES_RESTART_DIFFERENCE || ngmres->select_type == SNES_NGMRES_SELECT_DIFFERENCE) { 282 ierr = SNESNGMRESCalculateDifferences_Private(snes,l,X,F,XM,FM,XA,FA,D,&dnorm,&dminnorm,&fAnorm);CHKERRQ(ierr); 283 } else { 284 ierr = VecNorm(FA,NORM_2,&fAnorm);CHKERRQ(ierr); 285 } 286 if (PetscIsInfOrNanReal(fAnorm)) { 287 snes->reason = SNES_DIVERGED_FNORM_NAN; 288 PetscFunctionReturn(0); 289 } 290 291 /* combination (additive) or selection (multiplicative) of the N-GMRES solution */ 292 ierr = SNESNGMRESSelect_Private(snes,k_restart,XM,FM,fMnorm,XA,FA,fAnorm,dnorm,fminnorm,dminnorm,X,F,Y,&fnorm);CHKERRQ(ierr); 293 selectRestart = PETSC_FALSE; 294 if (ngmres->restart_type == SNES_NGMRES_RESTART_DIFFERENCE) { 295 ierr = SNESNGMRESSelectRestart_Private(snes,l,fAnorm,dnorm,fminnorm,dminnorm,&selectRestart);CHKERRQ(ierr); 296 /* if the restart conditions persist for more than restart_it iterations, restart. */ 297 if (selectRestart) restart_count++; 298 else restart_count = 0; 299 } else if (ngmres->restart_type == SNES_NGMRES_RESTART_PERIODIC) { 300 if (k_restart > ngmres->restart_periodic) { 301 if (ngmres->monitor) ierr = PetscViewerASCIIPrintf(ngmres->monitor,"periodic restart after %D iterations\n",k_restart);CHKERRQ(ierr); 302 restart_count = ngmres->restart_it; 303 } 304 } 305 /* restart after restart conditions have persisted for a fixed number of iterations */ 306 if (restart_count >= ngmres->restart_it) { 307 if (ngmres->monitor) { 308 ierr = PetscViewerASCIIPrintf(ngmres->monitor,"Restarted at iteration %d\n",k_restart);CHKERRQ(ierr); 309 } 310 restart_count = 0; 311 k_restart = 1; 312 l = 1; 313 /* q_{00} = nu */ 314 if (ngmres->candidate) { 315 ierr = SNESNGMRESUpdateSubspace_Private(snes,0,0,FM,fMnorm,XM);CHKERRQ(ierr); 316 } else { 317 ierr = SNESNGMRESUpdateSubspace_Private(snes,0,0,F,fMnorm,X);CHKERRQ(ierr); 318 } 319 } else { 320 /* select the current size of the subspace */ 321 if (l < ngmres->msize) l++; 322 k_restart++; 323 /* place the current entry in the list of previous entries */ 324 if (ngmres->candidate) { 325 if (fminnorm > fMnorm) fminnorm = fMnorm; 326 ierr = SNESNGMRESUpdateSubspace_Private(snes,ivec,l,FM,fMnorm,XM);CHKERRQ(ierr); 327 } else { 328 if (fminnorm > fnorm) fminnorm = fnorm; 329 ierr = SNESNGMRESUpdateSubspace_Private(snes,ivec,l,F,fnorm,X);CHKERRQ(ierr); 330 } 331 } 332 333 ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); 334 snes->iter = k; 335 snes->norm = fnorm; 336 ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); 337 ierr = SNESLogConvergenceHistory(snes,snes->norm,snes->iter);CHKERRQ(ierr); 338 ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); 339 ierr = VecNormBegin(Y,NORM_2,&ynorm);CHKERRQ(ierr); 340 ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); 341 ierr = VecNormEnd(Y,NORM_2,&ynorm);CHKERRQ(ierr); 342 ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); 343 ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); 344 if (snes->reason) PetscFunctionReturn(0); 345 } 346 snes->reason = SNES_DIVERGED_MAX_IT; 347 PetscFunctionReturn(0); 348 } 349 350 #undef __FUNCT__ 351 #define __FUNCT__ "SNESNGMRESSetRestartType" 352 /*@ 353 SNESNGMRESSetRestartType - Sets the restart type for SNESNGMRES. 354 355 Logically Collective on SNES 356 357 Input Parameters: 358 + snes - the iterative context 359 - rtype - restart type 360 361 Options Database: 362 + -snes_ngmres_restart_type<difference,periodic,none> - set the restart type 363 - -snes_ngmres_restart[30] - sets the number of iterations before restart for periodic 364 365 Level: intermediate 366 367 SNESNGMRESRestartTypes: 368 + SNES_NGMRES_RESTART_NONE - never restart 369 . SNES_NGMRES_RESTART_DIFFERENCE - restart based upon difference criteria 370 - SNES_NGMRES_RESTART_PERIODIC - restart after a fixed number of iterations 371 372 Notes: 373 The default line search used is the L2 line search and it requires two additional function evaluations. 374 375 .keywords: SNES, SNESNGMRES, restart, type, set SNESLineSearch 376 @*/ 377 PetscErrorCode SNESNGMRESSetRestartType(SNES snes,SNESNGMRESRestartType rtype) 378 { 379 PetscErrorCode ierr; 380 381 PetscFunctionBegin; 382 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 383 ierr = PetscTryMethod(snes,"SNESNGMRESSetRestartType_C",(SNES,SNESNGMRESRestartType),(snes,rtype));CHKERRQ(ierr); 384 PetscFunctionReturn(0); 385 } 386 387 #undef __FUNCT__ 388 #define __FUNCT__ "SNESNGMRESSetSelectType" 389 /*@ 390 SNESNGMRESSetSelectType - Sets the selection type for SNESNGMRES. This determines how the candidate solution and 391 combined solution are used to create the next iterate. 392 393 Logically Collective on SNES 394 395 Input Parameters: 396 + snes - the iterative context 397 - stype - selection type 398 399 Options Database: 400 . -snes_ngmres_select_type<difference,none,linesearch> 401 402 Level: intermediate 403 404 SNESNGMRESSelectTypes: 405 + SNES_NGMRES_SELECT_NONE - choose the combined solution all the time 406 . SNES_NGMRES_SELECT_DIFFERENCE - choose based upon the selection criteria 407 - SNES_NGMRES_SELECT_LINESEARCH - choose based upon line search combination 408 409 Notes: 410 The default line search used is the L2 line search and it requires two additional function evaluations. 411 412 .keywords: SNES, SNESNGMRES, selection, type, set SNESLineSearch 413 @*/ 414 PetscErrorCode SNESNGMRESSetSelectType(SNES snes,SNESNGMRESSelectType stype) 415 { 416 PetscErrorCode ierr; 417 418 PetscFunctionBegin; 419 PetscValidHeaderSpecific(snes,SNES_CLASSID,1); 420 ierr = PetscTryMethod(snes,"SNESNGMRESSetSelectType_C",(SNES,SNESNGMRESSelectType),(snes,stype));CHKERRQ(ierr); 421 PetscFunctionReturn(0); 422 } 423 424 EXTERN_C_BEGIN 425 #undef __FUNCT__ 426 #define __FUNCT__ "SNESNGMRESSetSelectType_NGMRES" 427 PetscErrorCode SNESNGMRESSetSelectType_NGMRES(SNES snes,SNESNGMRESSelectType stype) 428 { 429 SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data; 430 431 PetscFunctionBegin; 432 ngmres->select_type = stype; 433 PetscFunctionReturn(0); 434 } 435 436 #undef __FUNCT__ 437 #define __FUNCT__ "SNESNGMRESSetRestartType_NGMRES" 438 PetscErrorCode SNESNGMRESSetRestartType_NGMRES(SNES snes,SNESNGMRESRestartType rtype) 439 { 440 SNES_NGMRES *ngmres = (SNES_NGMRES*)snes->data; 441 442 PetscFunctionBegin; 443 ngmres->restart_type = rtype; 444 PetscFunctionReturn(0); 445 } 446 EXTERN_C_END 447 448 /*MC 449 SNESNGMRES - The Nonlinear Generalized Minimum Residual method. 450 451 Level: beginner 452 453 Options Database: 454 + -snes_ngmres_select_type<difference,none,linesearch> - choose the select between candidate and combined solution 455 . -snes_ngmres_restart_type<difference,none,periodic> - choose the restart conditions 456 . -snes_ngmres_candidate - Use NGMRES variant which combines candidate solutions instead of actual solutions 457 . -snes_ngmres_m - Number of stored previous solutions and residuals 458 . -snes_ngmres_restart_it - Number of iterations the restart conditions hold before restart 459 . -snes_ngmres_gammaA - Residual tolerance for solution select between the candidate and combination 460 . -snes_ngmres_gammaC - Residual tolerance for restart 461 . -snes_ngmres_epsilonB - Difference tolerance between subsequent solutions triggering restart 462 . -snes_ngmres_deltaB - Difference tolerance between residuals triggering restart 463 . -snes_ngmres_monitor - Prints relevant information about the ngmres iteration 464 . -snes_linesearch_type <basic,basicnonorms,quadratic,critical> - Line search type used for the default smoother 465 - -additive_snes_linesearch_type - linesearch type used to select between the candidate and combined solution with additive select type 466 467 Notes: 468 469 The N-GMRES method combines m previous solutions into a minimum-residual solution by solving a small linearized 470 optimization problem at each iteration. 471 472 References: 473 474 "Krylov Subspace Acceleration of Nonlinear Multigrid with Application to Recirculating Flows", C. W. Oosterlee and T. Washio, 475 SIAM Journal on Scientific Computing, 21(5), 2000. 476 477 .seealso: SNESCreate(), SNES, SNESSetType(), SNESType (for list of available types) 478 M*/ 479 480 EXTERN_C_BEGIN 481 #undef __FUNCT__ 482 #define __FUNCT__ "SNESCreate_NGMRES" 483 PetscErrorCode SNESCreate_NGMRES(SNES snes) 484 { 485 SNES_NGMRES *ngmres; 486 PetscErrorCode ierr; 487 488 PetscFunctionBegin; 489 snes->ops->destroy = SNESDestroy_NGMRES; 490 snes->ops->setup = SNESSetUp_NGMRES; 491 snes->ops->setfromoptions = SNESSetFromOptions_NGMRES; 492 snes->ops->view = SNESView_NGMRES; 493 snes->ops->solve = SNESSolve_NGMRES; 494 snes->ops->reset = SNESReset_NGMRES; 495 496 snes->usespc = PETSC_TRUE; 497 snes->usesksp = PETSC_FALSE; 498 499 ierr = PetscNewLog(snes,SNES_NGMRES,&ngmres);CHKERRQ(ierr); 500 snes->data = (void*) ngmres; 501 ngmres->msize = 30; 502 503 if (!snes->tolerancesset) { 504 snes->max_funcs = 30000; 505 snes->max_its = 10000; 506 } 507 508 ngmres->candidate = PETSC_FALSE; 509 510 ngmres->additive_linesearch = NULL; 511 ngmres->approxfunc = PETSC_FALSE; 512 ngmres->restart_it = 2; 513 ngmres->restart_periodic = 30; 514 ngmres->gammaA = 2.0; 515 ngmres->gammaC = 2.0; 516 ngmres->deltaB = 0.9; 517 ngmres->epsilonB = 0.1; 518 519 ngmres->restart_type = SNES_NGMRES_RESTART_DIFFERENCE; 520 ngmres->select_type = SNES_NGMRES_SELECT_DIFFERENCE; 521 522 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESNGMRESSetSelectType_C","SNESNGMRESSetSelectType_NGMRES",SNESNGMRESSetSelectType_NGMRES);CHKERRQ(ierr); 523 ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESNGMRESSetRestartType_C","SNESNGMRESSetRestartType_NGMRES",SNESNGMRESSetRestartType_NGMRES);CHKERRQ(ierr); 524 PetscFunctionReturn(0); 525 } 526 EXTERN_C_END 527