PetscErrorCode SNESSolve_FAS(SNES snes)
{
PetscErrorCode ierr;
PetscInt i, maxits;
Vec X, F;
PetscReal fnorm;
SNES_FAS *fas = (SNES_FAS*)snes->data,*ffas;
DM dm;
PetscBool isFine;
PetscFunctionBegin;
ierr = PetscCitationsRegister(SNESCitation,&SNEScite);CHKERRQ(ierr);
maxits = snes->max_its; /* maximum number of iterations */
snes->reason = SNES_CONVERGED_ITERATING;
X = snes->vec_sol;
F = snes->vec_func;
ierr = SNESFASCycleIsFine(snes, &isFine);CHKERRQ(ierr);
/*norm setup */
ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr);
snes->iter = 0;
snes->norm = 0.;
ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr);
if (!snes->vec_func_init_set) {
if (fas->eventresidual) {ierr = PetscLogEventBegin(fas->eventresidual,0,0,0,0);CHKERRQ(ierr);}
ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
if (fas->eventresidual) {ierr = PetscLogEventEnd(fas->eventresidual,0,0,0,0);CHKERRQ(ierr);}
if (snes->domainerror) {
snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
PetscFunctionReturn(0);
}
} else snes->vec_func_init_set = PETSC_FALSE;
ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */
if (PetscIsInfOrNanReal(fnorm)) {
snes->reason = SNES_DIVERGED_FNORM_NAN;
PetscFunctionReturn(0);
}
ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr);
snes->norm = fnorm;
ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr);
ierr = SNESLogConvergenceHistory(snes,fnorm,0);CHKERRQ(ierr);
ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);
/* test convergence */
ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
if (snes->reason) PetscFunctionReturn(0);
if (isFine) {
/* propagate scale-dependent data up the hierarchy */
ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
for (ffas=fas; ffas->next; ffas=(SNES_FAS*)ffas->next->data) {
DM dmcoarse;
ierr = SNESGetDM(ffas->next,&dmcoarse);CHKERRQ(ierr);
ierr = DMRestrict(dm,ffas->restrct,ffas->rscale,ffas->inject,dmcoarse);CHKERRQ(ierr);
dm = dmcoarse;
}
}
for (i = 0; i < maxits; i++) {
/* Call general purpose update function */
if (snes->ops->update) {
ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
}
if (fas->fastype == SNES_FAS_MULTIPLICATIVE) {
ierr = SNESFASCycle_Multiplicative(snes, X);CHKERRQ(ierr);
} else if (fas->fastype == SNES_FAS_ADDITIVE) {
ierr = SNESFASCycle_Additive(snes, X);CHKERRQ(ierr);
} else if (fas->fastype == SNES_FAS_FULL) {
ierr = SNESFASCycle_Full(snes, X);CHKERRQ(ierr);
} else if (fas->fastype ==SNES_FAS_KASKADE) {
ierr = SNESFASCycle_Kaskade(snes, X);CHKERRQ(ierr);
} else {
SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Unsupported FAS type");
}
/* check for FAS cycle divergence */
if (snes->reason != SNES_CONVERGED_ITERATING) PetscFunctionReturn(0);
/* Monitor convergence */
ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr);
snes->iter = i+1;
ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr);
ierr = SNESLogConvergenceHistory(snes,snes->norm,0);CHKERRQ(ierr);
ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
/* Test for convergence */
if (isFine) {
ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,snes->norm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
if (snes->reason) break;
}
}
if (i == maxits) {
ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);CHKERRQ(ierr);
if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
}
PetscFunctionReturn(0);
}
PetscErrorCode SNESSolve_FAS(SNES snes)
{
PetscErrorCode ierr;
PetscInt i, maxits;
Vec X, F;
PetscReal fnorm;
SNES_FAS *fas = (SNES_FAS *)snes->data,*ffas;
DM dm;
PetscBool isFine;
PetscFunctionBegin;
maxits = snes->max_its; /* maximum number of iterations */
snes->reason = SNES_CONVERGED_ITERATING;
X = snes->vec_sol;
F = snes->vec_func;
ierr = SNESFASCycleIsFine(snes, &isFine);CHKERRQ(ierr);
/*norm setup */
ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
snes->iter = 0;
snes->norm = 0.;
ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
if (!snes->vec_func_init_set) {
ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
if (snes->domainerror) {
snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
PetscFunctionReturn(0);
}
} else {
snes->vec_func_init_set = PETSC_FALSE;
}
if (!snes->norm_init_set) {
ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */
if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
} else {
fnorm = snes->norm_init;
snes->norm_init_set = PETSC_FALSE;
}
snes->norm = fnorm;
ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
SNESLogConvHistory(snes,fnorm,0);
ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);
/* set parameter for default relative tolerance convergence test */
snes->ttol = fnorm*snes->rtol;
/* test convergence */
ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
if (snes->reason) PetscFunctionReturn(0);
if (isFine) {
/* propagate scale-dependent data up the hierarchy */
ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
for (ffas=fas; ffas->next; ffas=(SNES_FAS*)ffas->next->data) {
DM dmcoarse;
ierr = SNESGetDM(ffas->next,&dmcoarse);CHKERRQ(ierr);
ierr = DMRestrict(dm,ffas->restrct,ffas->rscale,ffas->inject,dmcoarse);CHKERRQ(ierr);
dm = dmcoarse;
}
}
for (i = 0; i < maxits; i++) {
/* Call general purpose update function */
if (snes->ops->update) {
ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
}
if (fas->fastype == SNES_FAS_MULTIPLICATIVE) {
ierr = SNESFASCycle_Multiplicative(snes, X);CHKERRQ(ierr);
} else {
ierr = SNESFASCycle_Additive(snes, X);CHKERRQ(ierr);
}
/* check for FAS cycle divergence */
if (snes->reason != SNES_CONVERGED_ITERATING) {
PetscFunctionReturn(0);
}
/* Monitor convergence */
ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
snes->iter = i+1;
ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
SNESLogConvHistory(snes,snes->norm,0);
ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
/* Test for convergence */
if (isFine) {
ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,snes->norm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
if (snes->reason) break;
}
}
if (i == maxits) {
ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);CHKERRQ(ierr);
if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
}
PetscFunctionReturn(0);
}
