static PetscErrorCode SNESSetFromOptions_NCG(SNES snes) { SNES_NCG *ncg = (SNES_NCG*)snes->data; PetscErrorCode ierr; PetscBool debug; SNESLineSearch linesearch; SNESNCGType ncgtype=ncg->type; PetscFunctionBegin; ierr = PetscOptionsHead("SNES NCG options");CHKERRQ(ierr); ierr = PetscOptionsBool("-snes_ncg_monitor","Monitor NCG iterations","SNES",ncg->monitor ? PETSC_TRUE : PETSC_FALSE, &debug, NULL);CHKERRQ(ierr); ierr = PetscOptionsEnum("-snes_ncg_type","NCG Beta type used","SNESNCGSetType",SNESNCGTypes,(PetscEnum)ncg->type,(PetscEnum*)&ncgtype,NULL);CHKERRQ(ierr); ierr = SNESNCGSetType(snes, ncgtype);CHKERRQ(ierr); if (debug) { ncg->monitor = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));CHKERRQ(ierr); } ierr = PetscOptionsTail();CHKERRQ(ierr); if (!snes->linesearch) { ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); if (!snes->pc) { ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHCP);CHKERRQ(ierr); } else { ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHL2);CHKERRQ(ierr); } } ierr = SNESLineSearchRegister(SNESLINESEARCHNCGLINEAR, SNESLineSearchCreate_NCGLinear);CHKERRQ(ierr); PetscFunctionReturn(0); }
PetscErrorCode SNESSetFromOptions_Anderson(PetscOptions *PetscOptionsObject,SNES snes) { SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; PetscErrorCode ierr; PetscBool debug; SNESLineSearch linesearch; PetscFunctionBegin; ierr = PetscOptionsHead(PetscOptionsObject,"SNES NGMRES options");CHKERRQ(ierr); ierr = PetscOptionsInt("-snes_anderson_m", "Number of directions","SNES",ngmres->msize,&ngmres->msize,NULL);CHKERRQ(ierr); ierr = PetscOptionsReal("-snes_anderson_beta", "Mixing parameter","SNES",ngmres->andersonBeta,&ngmres->andersonBeta,NULL);CHKERRQ(ierr); ierr = PetscOptionsBool("-snes_anderson_monitor", "Monitor steps of Anderson Mixing","SNES",ngmres->monitor ? PETSC_TRUE : PETSC_FALSE,&debug,NULL);CHKERRQ(ierr); ierr = PetscOptionsInt("-snes_anderson_restart", "Iterations before forced restart", "SNES",ngmres->restart_periodic,&ngmres->restart_periodic,NULL);CHKERRQ(ierr); ierr = PetscOptionsInt("-snes_anderson_restart_it", "Tolerance iterations before restart","SNES",ngmres->restart_it,&ngmres->restart_it,NULL);CHKERRQ(ierr); ierr = PetscOptionsEnum("-snes_anderson_restart_type","Restart type","SNESNGMRESSetRestartType",SNESNGMRESRestartTypes, (PetscEnum)ngmres->restart_type,(PetscEnum*)&ngmres->restart_type,NULL);CHKERRQ(ierr); if (debug) { ngmres->monitor = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));CHKERRQ(ierr); } ierr = PetscOptionsTail();CHKERRQ(ierr); /* set the default type of the line search if the user hasn't already. */ if (!snes->linesearch) { ierr = SNESGetLineSearch(snes,&linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch,SNESLINESEARCHBASIC);CHKERRQ(ierr); } PetscFunctionReturn(0); }
/*MC SNESVINEWTONSSLS - Semi-smooth solver for variational inequalities based on Newton's method Options Database: + -snes_type <vinewtonssls,vinewtonrsls> a semi-smooth solver, a reduced space active set method - -snes_vi_monitor - prints the number of active constraints at each iteration. Level: beginner References: + 1. - T. S. Munson, F. Facchinei, M. C. Ferris, A. Fischer, and C. Kanzow. The semismooth algorithm for large scale complementarity problems. INFORMS Journal on Computing, 13 (2001). - 2. - T. S. Munson, and S. Benson. Flexible Complementarity Solvers for Large Scale Applications, Optimization Methods and Software, 21 (2006). .seealso: SNESVISetVariableBounds(), SNESVISetComputeVariableBounds(), SNESCreate(), SNES, SNESSetType(), SNESVINEWTONRSLS, SNESNEWTONTR, SNESLineSearchSetType(),SNESLineSearchSetPostCheck(), SNESLineSearchSetPreCheck() M*/ PETSC_EXTERN PetscErrorCode SNESCreate_VINEWTONSSLS(SNES snes) { PetscErrorCode ierr; SNES_VINEWTONSSLS *vi; SNESLineSearch linesearch; PetscFunctionBegin; snes->ops->reset = SNESReset_VINEWTONSSLS; snes->ops->setup = SNESSetUp_VINEWTONSSLS; snes->ops->solve = SNESSolve_VINEWTONSSLS; snes->ops->destroy = SNESDestroy_VI; snes->ops->setfromoptions = SNESSetFromOptions_VINEWTONSSLS; snes->ops->view = NULL; snes->usesksp = PETSC_TRUE; snes->usesnpc = PETSC_FALSE; ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);CHKERRQ(ierr); ierr = SNESLineSearchBTSetAlpha(linesearch, 0.0);CHKERRQ(ierr); snes->alwayscomputesfinalresidual = PETSC_FALSE; ierr = PetscNewLog(snes,&vi);CHKERRQ(ierr); snes->data = (void*)vi; ierr = PetscObjectComposeFunction((PetscObject)snes,"SNESVISetVariableBounds_C",SNESVISetVariableBounds_VI);CHKERRQ(ierr); ierr = PetscObjectComposeFunction((PetscObject)snes,"SNESVISetComputeVariableBounds_C",SNESVISetComputeVariableBounds_VI);CHKERRQ(ierr); PetscFunctionReturn(0); }
PetscErrorCode SNESSetUp_VINEWTONRSLS(SNES snes) { PetscErrorCode ierr; SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*) snes->data; PetscInt *indices; PetscInt i,n,rstart,rend; SNESLineSearch linesearch; PetscFunctionBegin; ierr = SNESSetUp_VI(snes);CHKERRQ(ierr); /* Set up previous active index set for the first snes solve vi->IS_inact_prev = 0,1,2,....N */ ierr = VecGetOwnershipRange(snes->vec_sol,&rstart,&rend);CHKERRQ(ierr); ierr = VecGetLocalSize(snes->vec_sol,&n);CHKERRQ(ierr); ierr = PetscMalloc(n*sizeof(PetscInt),&indices);CHKERRQ(ierr); for (i=0;i < n; i++) indices[i] = rstart + i; ierr = ISCreateGeneral(((PetscObject)snes)->comm,n,indices,PETSC_OWN_POINTER,&vi->IS_inact_prev);CHKERRQ(ierr); /* set the line search functions */ if (!snes->linesearch) { ierr = SNESGetSNESLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);CHKERRQ(ierr); } PetscFunctionReturn(0); }
static PetscErrorCode SNESSetFromOptions_QN(SNES snes) { PetscErrorCode ierr; SNES_QN *qn = (SNES_QN*)snes->data; PetscBool monflg = PETSC_FALSE,flg; SNESLineSearch linesearch; SNESQNRestartType rtype = qn->restart_type; SNESQNScaleType stype = qn->scale_type; PetscFunctionBegin; ierr = PetscOptionsHead("SNES QN options");CHKERRQ(ierr); ierr = PetscOptionsInt("-snes_qn_m","Number of past states saved for L-BFGS methods","SNESQN",qn->m,&qn->m,NULL);CHKERRQ(ierr); ierr = PetscOptionsReal("-snes_qn_powell_gamma","Powell angle tolerance", "SNESQN", qn->powell_gamma, &qn->powell_gamma, NULL);CHKERRQ(ierr); ierr = PetscOptionsReal("-snes_qn_powell_downhill","Powell descent tolerance", "SNESQN", qn->powell_downhill, &qn->powell_downhill, NULL);CHKERRQ(ierr); ierr = PetscOptionsBool("-snes_qn_monitor", "Monitor for the QN methods", "SNESQN", monflg, &monflg, NULL);CHKERRQ(ierr); ierr = PetscOptionsBool("-snes_qn_single_reduction", "Aggregate reductions", "SNESQN", qn->singlereduction, &qn->singlereduction, NULL);CHKERRQ(ierr); ierr = PetscOptionsEnum("-snes_qn_scale_type","Scaling type","SNESQNSetScaleType",SNESQNScaleTypes,(PetscEnum)stype,(PetscEnum*)&stype,&flg);CHKERRQ(ierr); if (flg) ierr = SNESQNSetScaleType(snes,stype);CHKERRQ(ierr); ierr = PetscOptionsEnum("-snes_qn_restart_type","Restart type","SNESQNSetRestartType",SNESQNRestartTypes,(PetscEnum)rtype,(PetscEnum*)&rtype,&flg);CHKERRQ(ierr); if (flg) ierr = SNESQNSetRestartType(snes,rtype);CHKERRQ(ierr); ierr = PetscOptionsEnum("-snes_qn_type","Quasi-Newton update type","",SNESQNTypes, (PetscEnum)qn->type,(PetscEnum*)&qn->type,NULL);CHKERRQ(ierr); ierr = PetscOptionsTail();CHKERRQ(ierr); if (!snes->linesearch) { ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHCP);CHKERRQ(ierr); } if (monflg) { qn->monitor = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));CHKERRQ(ierr); } PetscFunctionReturn(0); }
static PetscErrorCode SNESSetFromOptions_NEWTONLS(PetscOptionItems *PetscOptionsObject,SNES snes) { PetscErrorCode ierr; SNESLineSearch linesearch; PetscFunctionBegin; if (!snes->linesearch) { ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);CHKERRQ(ierr); } PetscFunctionReturn(0); }
static PetscErrorCode SNESSetFromOptions_NRichardson(SNES snes) { PetscErrorCode ierr; SNESLineSearch linesearch; PetscFunctionBegin; ierr = PetscOptionsHead("SNES Richardson options");CHKERRQ(ierr); ierr = PetscOptionsTail();CHKERRQ(ierr); if (!snes->linesearch) { ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHL2);CHKERRQ(ierr); } PetscFunctionReturn(0); }
static PetscErrorCode SNESSetFromOptions_NEWTONLS(SNES snes) { PetscErrorCode ierr; SNESLineSearch linesearch; PetscFunctionBegin; ierr = PetscOptionsHead("SNESNEWTONLS options");CHKERRQ(ierr); ierr = PetscOptionsTail();CHKERRQ(ierr); /* set the default line search type */ if (!snes->linesearch) { ierr = SNESGetSNESLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);CHKERRQ(ierr); } PetscFunctionReturn(0); }
PetscErrorCode SNESSetFromOptions_VI(SNES snes) { PetscErrorCode ierr; PetscBool flg; SNESLineSearch linesearch; PetscFunctionBegin; ierr = PetscOptionsHead("SNES VI options");CHKERRQ(ierr); ierr = PetscOptionsBool("-snes_vi_monitor","Monitor all non-active variables","None",PETSC_FALSE,&flg,0);CHKERRQ(ierr); if (flg) { ierr = SNESMonitorSet(snes,SNESMonitorVI,0,0);CHKERRQ(ierr); } if (!snes->linesearch) { ierr = SNESGetSNESLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHBT);CHKERRQ(ierr); ierr = SNESLineSearchBTSetAlpha(linesearch, 0.0);CHKERRQ(ierr); } ierr = PetscOptionsTail();CHKERRQ(ierr); PetscFunctionReturn(0); }
/*MC SNESASPIN - Helper SNES type for Additive-Schwarz Preconditioned Inexact Newton Options Database: + -npc_snes_ - options prefix of the nonlinear subdomain solver (must be of type NASM) . -npc_sub_snes_ - options prefix of the subdomain nonlinear solves . -npc_sub_ksp_ - options prefix of the subdomain Krylov solver - -npc_sub_pc_ - options prefix of the subdomain preconditioner Notes: This routine sets up an instance of NETWONLS with nonlinear left preconditioning. It differs from other similar functionality in SNES as it creates a linear shell matrix that corresponds to the product: \sum_{i=0}^{N_b}J_b({X^b_{converged}})^{-1}J(X + \sum_{i=0}^{N_b}(X^b_{converged} - X^b)) which is the ASPIN preconditioned matrix. Similar solvers may be constructed by having matrix-free differencing of nonlinear solves per linear iteration, but this is far more efficient when subdomain sparse-direct preconditioner factorizations are reused on each application of J_b^{-1}. Level: intermediate .seealso: SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNASM, SNESGetNPC(), SNESGetNPCSide() M*/ PETSC_EXTERN PetscErrorCode SNESCreate_ASPIN(SNES snes) { PetscErrorCode ierr; SNES npc; KSP ksp; PC pc; Mat aspinmat; MPI_Comm comm; Vec F; PetscInt n; SNESLineSearch linesearch; PetscFunctionBegin; /* set up the solver */ ierr = SNESSetType(snes,SNESNEWTONLS);CHKERRQ(ierr); ierr = SNESSetNPCSide(snes,PC_LEFT);CHKERRQ(ierr); ierr = SNESSetFunctionType(snes,SNES_FUNCTION_PRECONDITIONED);CHKERRQ(ierr); ierr = SNESGetNPC(snes,&npc);CHKERRQ(ierr); ierr = SNESSetType(npc,SNESNASM);CHKERRQ(ierr); ierr = SNESNASMSetType(npc,PC_ASM_BASIC);CHKERRQ(ierr); ierr = SNESNASMSetComputeFinalJacobian(npc,PETSC_TRUE);CHKERRQ(ierr); ierr = SNESGetKSP(snes,&ksp);CHKERRQ(ierr); ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr); ierr = PCSetType(pc,PCNONE);CHKERRQ(ierr); ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr); ierr = SNESGetLineSearch(snes,&linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch,SNESLINESEARCHBT);CHKERRQ(ierr); /* set up the shell matrix */ ierr = SNESGetFunction(snes,&F,NULL,NULL);CHKERRQ(ierr); ierr = VecGetLocalSize(F,&n);CHKERRQ(ierr); ierr = MatCreateShell(comm,n,n,PETSC_DECIDE,PETSC_DECIDE,snes,&aspinmat);CHKERRQ(ierr); ierr = MatSetType(aspinmat,MATSHELL);CHKERRQ(ierr); ierr = MatShellSetOperation(aspinmat,MATOP_MULT,(void(*)(void))MatMultASPIN);CHKERRQ(ierr); ierr = SNESSetJacobian(snes,aspinmat,NULL,NULL,NULL);CHKERRQ(ierr); ierr = MatDestroy(&aspinmat);CHKERRQ(ierr); PetscFunctionReturn(0); }
PetscErrorCode SNESSetFromOptions_FAS(PetscOptions *PetscOptionsObject,SNES snes) { SNES_FAS *fas = (SNES_FAS*) snes->data; PetscInt levels = 1; PetscBool flg = PETSC_FALSE, upflg = PETSC_FALSE, downflg = PETSC_FALSE, monflg = PETSC_FALSE, galerkinflg = PETSC_FALSE,continuationflg = PETSC_FALSE; PetscErrorCode ierr; char monfilename[PETSC_MAX_PATH_LEN]; SNESFASType fastype; const char *optionsprefix; SNESLineSearch linesearch; PetscInt m, n_up, n_down; SNES next; PetscBool isFine; PetscFunctionBegin; ierr = SNESFASCycleIsFine(snes, &isFine);CHKERRQ(ierr); ierr = PetscOptionsHead(PetscOptionsObject,"SNESFAS Options-----------------------------------");CHKERRQ(ierr); /* number of levels -- only process most options on the finest level */ if (isFine) { ierr = PetscOptionsInt("-snes_fas_levels", "Number of Levels", "SNESFASSetLevels", levels, &levels, &flg);CHKERRQ(ierr); if (!flg && snes->dm) { ierr = DMGetRefineLevel(snes->dm,&levels);CHKERRQ(ierr); levels++; fas->usedmfornumberoflevels = PETSC_TRUE; } ierr = SNESFASSetLevels(snes, levels, NULL);CHKERRQ(ierr); fastype = fas->fastype; ierr = PetscOptionsEnum("-snes_fas_type","FAS correction type","SNESFASSetType",SNESFASTypes,(PetscEnum)fastype,(PetscEnum*)&fastype,&flg);CHKERRQ(ierr); if (flg) { ierr = SNESFASSetType(snes, fastype);CHKERRQ(ierr); } ierr = SNESGetOptionsPrefix(snes, &optionsprefix);CHKERRQ(ierr); ierr = PetscOptionsInt("-snes_fas_cycles","Number of cycles","SNESFASSetCycles",fas->n_cycles,&m,&flg);CHKERRQ(ierr); if (flg) { ierr = SNESFASSetCycles(snes, m);CHKERRQ(ierr); } ierr = PetscOptionsBool("-snes_fas_continuation","Corrected grid-sequence continuation","SNESFASSetContinuation",fas->continuation,&continuationflg,&flg);CHKERRQ(ierr); if (flg) { ierr = SNESFASSetContinuation(snes,continuationflg);CHKERRQ(ierr); } ierr = PetscOptionsBool("-snes_fas_galerkin", "Form coarse problems with Galerkin","SNESFASSetGalerkin",fas->galerkin,&galerkinflg,&flg);CHKERRQ(ierr); if (flg) { ierr = SNESFASSetGalerkin(snes, galerkinflg);CHKERRQ(ierr); } if (fas->fastype == SNES_FAS_FULL) { ierr = PetscOptionsBool("-snes_fas_full_downsweep","Smooth on the initial upsweep for full FAS cycles","SNESFASFullSetDownSweep",fas->full_downsweep,&fas->full_downsweep,&flg);CHKERRQ(ierr); if (flg) {SNESFASFullSetDownSweep(snes,fas->full_downsweep);CHKERRQ(ierr);} } ierr = PetscOptionsInt("-snes_fas_smoothup","Number of post-smoothing steps","SNESFASSetNumberSmoothUp",fas->max_up_it,&n_up,&upflg);CHKERRQ(ierr); ierr = PetscOptionsInt("-snes_fas_smoothdown","Number of pre-smoothing steps","SNESFASSetNumberSmoothDown",fas->max_down_it,&n_down,&downflg);CHKERRQ(ierr); ierr = PetscOptionsString("-snes_fas_monitor","Monitor FAS progress","SNESFASSetMonitor","stdout",monfilename,PETSC_MAX_PATH_LEN,&monflg);CHKERRQ(ierr); if (monflg) ierr = SNESFASSetMonitor(snes, PETSC_TRUE);CHKERRQ(ierr); flg = PETSC_FALSE; monflg = PETSC_TRUE; ierr = PetscOptionsBool("-snes_fas_log","Log times for each FAS level","SNESFASSetLog",monflg,&monflg,&flg);CHKERRQ(ierr); if (flg) {ierr = SNESFASSetLog(snes,monflg);CHKERRQ(ierr);} } ierr = PetscOptionsTail();CHKERRQ(ierr); /* setup from the determined types if there is no pointwise procedure or smoother defined */ if (upflg) { ierr = SNESFASSetNumberSmoothUp(snes,n_up);CHKERRQ(ierr); } if (downflg) { ierr = SNESFASSetNumberSmoothDown(snes,n_down);CHKERRQ(ierr); } /* set up the default line search for coarse grid corrections */ if (fas->fastype == SNES_FAS_ADDITIVE) { if (!snes->linesearch) { ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch, SNESLINESEARCHL2);CHKERRQ(ierr); } } ierr = SNESFASCycleGetCorrection(snes, &next);CHKERRQ(ierr); /* recursive option setting for the smoothers */ if (next) {ierr = SNESSetFromOptions(next);CHKERRQ(ierr);} PetscFunctionReturn(0); }
int main(int argc,char **argv) { TS ts; /* time integrator */ SNES snes; /* nonlinear solver */ SNESLineSearch linesearch; /* line search */ Vec X; /* solution, residual vectors */ Mat J; /* Jacobian matrix */ PetscInt steps,maxsteps,mx; PetscErrorCode ierr; DM da; PetscReal ftime,dt; struct _User user; /* user-defined work context */ TSConvergedReason reason; PetscInitialize(&argc,&argv,(char*)0,help); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Create distributed array (DMDA) to manage parallel grid and vectors - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = DMDACreate1d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,-11,2,2,NULL,&da);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Extract global vectors from DMDA; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = DMCreateGlobalVector(da,&X);CHKERRQ(ierr); /* Initialize user application context */ ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"Advection-reaction options",""); { user.a[0] = 1; ierr = PetscOptionsReal("-a0","Advection rate 0","",user.a[0],&user.a[0],NULL);CHKERRQ(ierr); user.a[1] = 0; ierr = PetscOptionsReal("-a1","Advection rate 1","",user.a[1],&user.a[1],NULL);CHKERRQ(ierr); user.k[0] = 1e6; ierr = PetscOptionsReal("-k0","Reaction rate 0","",user.k[0],&user.k[0],NULL);CHKERRQ(ierr); user.k[1] = 2*user.k[0]; ierr = PetscOptionsReal("-k1","Reaction rate 1","",user.k[1],&user.k[1],NULL);CHKERRQ(ierr); user.s[0] = 0; ierr = PetscOptionsReal("-s0","Source 0","",user.s[0],&user.s[0],NULL);CHKERRQ(ierr); user.s[1] = 1; ierr = PetscOptionsReal("-s1","Source 1","",user.s[1],&user.s[1],NULL);CHKERRQ(ierr); } ierr = PetscOptionsEnd();CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Create timestepping solver context - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr); ierr = TSSetDM(ts,da);CHKERRQ(ierr); ierr = TSSetType(ts,TSARKIMEX);CHKERRQ(ierr); ierr = TSSetRHSFunction(ts,NULL,FormRHSFunction,&user);CHKERRQ(ierr); ierr = TSSetIFunction(ts,NULL,FormIFunction,&user);CHKERRQ(ierr); ierr = DMCreateMatrix(da,MATAIJ,&J);CHKERRQ(ierr); ierr = TSSetIJacobian(ts,J,J,FormIJacobian,&user);CHKERRQ(ierr); /* A line search in the nonlinear solve can fail due to ill-conditioning unless an absolute tolerance is set. Since * this problem is linear, we deactivate the line search. For a linear problem, it is usually recommended to also use * SNESSetType(snes,SNESKSPONLY). */ ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr); ierr = SNESGetLineSearch(snes,&linesearch);CHKERRQ(ierr); ierr = SNESLineSearchSetType(linesearch,SNESLINESEARCHBASIC);CHKERRQ(ierr); ftime = 1.0; maxsteps = 10000; ierr = TSSetDuration(ts,maxsteps,ftime);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set initial conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = FormInitialSolution(ts,X,&user);CHKERRQ(ierr); ierr = TSSetSolution(ts,X);CHKERRQ(ierr); ierr = VecGetSize(X,&mx);CHKERRQ(ierr); dt = .1 * PetscMax(user.a[0],user.a[1]) / mx; /* Advective CFL, I don't know why it needs so much safety factor. */ ierr = TSSetInitialTimeStep(ts,0.0,dt);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set runtime options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSetFromOptions(ts);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Solve nonlinear system - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSolve(ts,X);CHKERRQ(ierr); ierr = TSGetSolveTime(ts,&ftime);CHKERRQ(ierr); ierr = TSGetTimeStepNumber(ts,&steps);CHKERRQ(ierr); ierr = TSGetConvergedReason(ts,&reason);CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"%s at time %G after %D steps\n",TSConvergedReasons[reason],ftime,steps);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Free work space. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = MatDestroy(&J);CHKERRQ(ierr); ierr = VecDestroy(&X);CHKERRQ(ierr); ierr = TSDestroy(&ts);CHKERRQ(ierr); ierr = DMDestroy(&da);CHKERRQ(ierr); ierr = PetscFinalize(); return 0; }
static PetscErrorCode oursneslinesearchpostcheck(SNESLineSearch linesearch, Vec X, Vec Y, Vec W, PetscBool * changed_Y, PetscBool * changed_W, void * ctx) { PetscErrorCode ierr = 0; (*(void (PETSC_STDCALL *)(SNESLineSearch*,Vec*,Vec*,Vec*,PetscBool*,PetscBool*,void*,PetscErrorCode*)) (((PetscObject)linesearch)->fortran_func_pointers[2]))(&linesearch,&X,&Y,&W,changed_Y,changed_W,ctx,&ierr);CHKERRQ(ierr); return 0; } EXTERN_C_BEGIN void PETSC_STDCALL sneslinesearchsettype_(SNESLineSearch *linesearch,CHAR type PETSC_MIXED_LEN(len),PetscErrorCode *ierr PETSC_END_LEN(len)) { char *t; FIXCHAR(type,len,t); *ierr = SNESLineSearchSetType(*linesearch,t); FREECHAR(type,t); } void PETSC_STDCALL sneslinesearchsetprecheck_(SNESLineSearch *linesearch, void (PETSC_STDCALL *func)(SNESLineSearch*,Vec*,Vec*,PetscBool*,PetscErrorCode*), void *ctx, PetscErrorCode *ierr) { PetscObjectAllocateFortranPointers(*linesearch,3); ((PetscObject)*linesearch)->fortran_func_pointers[1] = (PetscVoidFunction)func; *ierr = SNESLineSearchSetPreCheck(*linesearch,oursneslinesearchprecheck,ctx); } void PETSC_STDCALL sneslinesearchsetpostcheck_(SNESLineSearch *linesearch,
void VentilationProblem::SolveFromPressureWithSnes() { assert( !mFluxGivenAtInflow ); // It's not a direct solve if (mTerminalInteractionMatrix == NULL) { SetupIterativeSolver(); } SNES snes; SNESCreate(PETSC_COMM_SELF, &snes); // Set the residual creation function (direct solve flux->pressure followed by pressure matching) SNESSetFunction(snes, mTerminalPressureChangeVector /*residual*/ , &ComputeSnesResidual, this); // The approximate Jacobian has been precomputed so we are going to wing it SNESSetJacobian(snes, mTerminalInteractionMatrix, mTerminalInteractionMatrix, /*&ComputeSnesJacobian*/ NULL, this); #if (PETSC_VERSION_MAJOR == 3) //PETSc 3.x SNESSetLagJacobian(snes, -1 /*Never rebuild Jacobian*/); #else SNESSetType(snes, SNESLS); #endif #if (PETSC_VERSION_MAJOR == 3 && PETSC_VERSION_MINOR >= 4) //PETSc 3.4 or later SNESSetType(snes, SNESNEWTONLS); #else SNESSetType(snes, SNESLS); #endif // Set the relative tolerance on the residual // Also set the absolute tolerance - useful for when the solver is started from the correct answer SNESSetTolerances(snes, 1.0e-16/*abs_tol*/, 1e-15/*r_tol*/, PETSC_DEFAULT/*step_tol*/, PETSC_DEFAULT, PETSC_DEFAULT); #if (PETSC_VERSION_MAJOR == 3 && PETSC_VERSION_MINOR == 3) //PETSc 3.3 SNESLineSearch linesearch; SNESGetSNESLineSearch(snes, &linesearch); SNESLineSearchSetType(linesearch, "bt"); //Use backtracking search as default #elif (PETSC_VERSION_MAJOR == 3 && PETSC_VERSION_MINOR >= 4) //PETSc 3.4 or later SNESLineSearch linesearch; SNESGetLineSearch(snes, &linesearch); SNESLineSearchSetType(linesearch, "bt"); //Use backtracking search as default #endif SNESSetFromOptions(snes); #if (PETSC_VERSION_MAJOR == 3 && PETSC_VERSION_MINOR >= 5) // Seems to want the preconditioner to be explicitly set to none now // Copied this from the similar PETSc example at: // http://www.mcs.anl.gov/petsc/petsc-current/src/snes/examples/tutorials/ex1.c // Which got it to work... KSP ksp; SNESGetKSP(snes,&ksp); PC pc; KSPGetPC(ksp,&pc); PCSetType(pc,PCNONE); #endif #if (PETSC_VERSION_MAJOR == 2 && PETSC_VERSION_MINOR == 2) //PETSc 2.2 SNESSolve(snes, mTerminalFluxChangeVector); #else SNESSolve(snes, PETSC_NULL, mTerminalFluxChangeVector); #endif ///\todo #2300 If used with time-stepping we should maintain a permanent SNES object SNESDestroy(PETSC_DESTROY_PARAM(snes)); }