/*
Creates the default smoother type.
This is SNESNRICHARDSON on each fine level and SNESNEWTONLS on the coarse level.
*/
PetscErrorCode SNESFASCycleCreateSmoother_Private(SNES snes, SNES *smooth)
{
SNES_FAS *fas;
const char *optionsprefix;
char tprefix[128];
PetscErrorCode ierr;
SNES nsmooth;
PetscFunctionBegin;
PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
fas = (SNES_FAS*)snes->data;
ierr = SNESGetOptionsPrefix(fas->fine, &optionsprefix);CHKERRQ(ierr);
/* create the default smoother */
ierr = SNESCreate(PetscObjectComm((PetscObject)snes), &nsmooth);CHKERRQ(ierr);
if (fas->level == 0) {
sprintf(tprefix,"fas_coarse_");
ierr = SNESAppendOptionsPrefix(nsmooth, optionsprefix);CHKERRQ(ierr);
ierr = SNESAppendOptionsPrefix(nsmooth, tprefix);CHKERRQ(ierr);
ierr = SNESSetType(nsmooth, SNESNEWTONLS);CHKERRQ(ierr);
ierr = SNESSetTolerances(nsmooth, nsmooth->abstol, nsmooth->rtol, nsmooth->stol, nsmooth->max_its, nsmooth->max_funcs);CHKERRQ(ierr);
} else {
sprintf(tprefix,"fas_levels_%d_",(int)fas->level);
ierr = SNESAppendOptionsPrefix(nsmooth, optionsprefix);CHKERRQ(ierr);
ierr = SNESAppendOptionsPrefix(nsmooth, tprefix);CHKERRQ(ierr);
ierr = SNESSetType(nsmooth, SNESNRICHARDSON);CHKERRQ(ierr);
ierr = SNESSetTolerances(nsmooth, 0.0, 0.0, 0.0, fas->max_down_it, nsmooth->max_funcs);CHKERRQ(ierr);
}
ierr = PetscObjectIncrementTabLevel((PetscObject)nsmooth, (PetscObject)snes, 1);CHKERRQ(ierr);
ierr = PetscLogObjectParent((PetscObject)snes,(PetscObject)nsmooth);CHKERRQ(ierr);
ierr = PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)nsmooth);CHKERRQ(ierr);
*smooth = nsmooth;
PetscFunctionReturn(0);
}
/*@C
SNESFASSetLevels - Sets the number of levels to use with FAS.
Must be called before any other FAS routine.
Input Parameters:
+ snes - the snes context
. levels - the number of levels
- comms - optional communicators for each level; this is to allow solving the coarser
problems on smaller sets of processors. Use NULL_OBJECT for default in
Fortran.
Level: intermediate
Notes:
If the number of levels is one then the multigrid uses the -fas_levels prefix
for setting the level options rather than the -fas_coarse prefix.
.keywords: FAS, MG, set, levels, multigrid
.seealso: SNESFASGetLevels()
@*/
PetscErrorCode SNESFASSetLevels(SNES snes, PetscInt levels, MPI_Comm * comms)
{
PetscErrorCode ierr;
PetscInt i;
const char *optionsprefix;
char tprefix[128];
SNES_FAS *fas = (SNES_FAS*)snes->data;
SNES prevsnes;
MPI_Comm comm;
PetscFunctionBegin;
ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr);
if (levels == fas->levels) {
if (!comms) PetscFunctionReturn(0);
}
/* user has changed the number of levels; reset */
ierr = SNESReset(snes);CHKERRQ(ierr);
/* destroy any coarser levels if necessary */
if (fas->next) SNESDestroy(&fas->next);CHKERRQ(ierr);
fas->next = NULL;
fas->previous = NULL;
prevsnes = snes;
/* setup the finest level */
ierr = SNESGetOptionsPrefix(snes, &optionsprefix);CHKERRQ(ierr);
for (i = levels - 1; i >= 0; i--) {
if (comms) comm = comms[i];
fas->level = i;
fas->levels = levels;
fas->fine = snes;
fas->next = NULL;
if (i > 0) {
ierr = SNESCreate(comm, &fas->next);CHKERRQ(ierr);
ierr = SNESGetOptionsPrefix(fas->fine, &optionsprefix);CHKERRQ(ierr);
sprintf(tprefix,"fas_levels_%d_cycle_",(int)fas->level);
ierr = SNESAppendOptionsPrefix(fas->next,optionsprefix);CHKERRQ(ierr);
ierr = SNESAppendOptionsPrefix(fas->next,tprefix);CHKERRQ(ierr);
ierr = SNESSetType(fas->next, SNESFAS);CHKERRQ(ierr);
ierr = SNESSetTolerances(fas->next, fas->next->abstol, fas->next->rtol, fas->next->stol, fas->n_cycles, fas->next->max_funcs);CHKERRQ(ierr);
ierr = PetscObjectIncrementTabLevel((PetscObject)fas->next, (PetscObject)snes, levels - i);CHKERRQ(ierr);
((SNES_FAS*)fas->next->data)->previous = prevsnes;
prevsnes = fas->next;
fas = (SNES_FAS*)prevsnes->data;
}
}
PetscFunctionReturn(0);
}
static PetscErrorCode SNESCompositeAddSNES_Composite(SNES snes,SNESType type)
{
SNES_Composite *jac;
SNES_CompositeLink next,ilink;
PetscErrorCode ierr;
PetscInt cnt = 0;
const char *prefix;
char newprefix[20];
DM dm;
PetscFunctionBegin;
ierr = PetscNewLog(snes,&ilink);CHKERRQ(ierr);
ilink->next = 0;
ierr = SNESCreate(PetscObjectComm((PetscObject)snes),&ilink->snes);CHKERRQ(ierr);
ierr = PetscLogObjectParent((PetscObject)snes,(PetscObject)ilink->snes);CHKERRQ(ierr);
ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
ierr = SNESSetDM(ilink->snes,dm);CHKERRQ(ierr);
ierr = SNESSetTolerances(ilink->snes,ilink->snes->abstol,ilink->snes->rtol,ilink->snes->stol,1,ilink->snes->max_funcs);CHKERRQ(ierr);
ierr = PetscObjectCopyFortranFunctionPointers((PetscObject)snes,(PetscObject)ilink->snes);CHKERRQ(ierr);
jac = (SNES_Composite*)snes->data;
next = jac->head;
if (!next) {
jac->head = ilink;
ilink->previous = NULL;
} else {
cnt++;
while (next->next) {
next = next->next;
cnt++;
}
next->next = ilink;
ilink->previous = next;
}
ierr = SNESGetOptionsPrefix(snes,&prefix);CHKERRQ(ierr);
ierr = SNESSetOptionsPrefix(ilink->snes,prefix);CHKERRQ(ierr);
sprintf(newprefix,"sub_%d_",(int)cnt);
ierr = SNESAppendOptionsPrefix(ilink->snes,newprefix);CHKERRQ(ierr);
ierr = PetscObjectIncrementTabLevel((PetscObject)ilink->snes,(PetscObject)snes,1);CHKERRQ(ierr);
ierr = SNESSetType(ilink->snes,type);CHKERRQ(ierr);
ierr = SNESSetNormSchedule(ilink->snes, SNES_NORM_FINAL_ONLY);CHKERRQ(ierr);
ilink->dmp = 1.0;
jac->nsnes++;
PetscFunctionReturn(0);
}
/*@
SNESFASSetContinuation - Sets the FAS cycle to default to exact Newton solves on the upsweep
Logically Collective on SNES
Input Parameters:
+ snes - the multigrid context
- n - the number of smoothing steps
Options Database Key:
. -snes_fas_continuation - sets continuation to true
Level: advanced
Notes: This sets the prefix on the upsweep smoothers to -fas_continuation
.keywords: FAS, MG, smoother, continuation
.seealso: SNESFAS
@*/
PetscErrorCode SNESFASSetContinuation(SNES snes,PetscBool continuation)
{
const char *optionsprefix;
char tprefix[128];
SNES_FAS *fas = (SNES_FAS*)snes->data;
PetscErrorCode ierr = 0;
PetscFunctionBegin;
ierr = SNESGetOptionsPrefix(fas->fine, &optionsprefix);CHKERRQ(ierr);
if (!fas->smoothu) {
ierr = SNESFASCycleCreateSmoother_Private(snes, &fas->smoothu);CHKERRQ(ierr);
}
sprintf(tprefix,"fas_levels_continuation_");
ierr = SNESSetOptionsPrefix(fas->smoothu, optionsprefix);CHKERRQ(ierr);
ierr = SNESAppendOptionsPrefix(fas->smoothu, tprefix);CHKERRQ(ierr);
ierr = SNESSetType(fas->smoothu,SNESNEWTONLS);CHKERRQ(ierr);
ierr = SNESSetTolerances(fas->smoothu,fas->fine->abstol,fas->fine->rtol,fas->fine->stol,50,100);CHKERRQ(ierr);
fas->continuation = continuation;
if (fas->next) {
ierr = SNESFASSetContinuation(fas->next,continuation);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
PetscErrorCode SNESSetUp_NASM(SNES snes)
{
SNES_NASM *nasm = (SNES_NASM*)snes->data;
PetscErrorCode ierr;
DM dm,subdm;
DM *subdms;
PetscInt i;
const char *optionsprefix;
Vec F;
PetscMPIInt size;
KSP ksp;
PC pc;
PetscFunctionBegin;
if (!nasm->subsnes) {
ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
if (dm) {
nasm->usesdm = PETSC_TRUE;
ierr = DMCreateDomainDecomposition(dm,&nasm->n,NULL,NULL,NULL,&subdms);CHKERRQ(ierr);
if (!subdms) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"DM has no default decomposition defined. Set subsolves manually with SNESNASMSetSubdomains().");
ierr = DMCreateDomainDecompositionScatters(dm,nasm->n,subdms,&nasm->iscatter,&nasm->oscatter,&nasm->gscatter);CHKERRQ(ierr);
ierr = SNESGetOptionsPrefix(snes, &optionsprefix);CHKERRQ(ierr);
ierr = PetscMalloc(nasm->n*sizeof(SNES),&nasm->subsnes);CHKERRQ(ierr);
for (i=0; i<nasm->n; i++) {
ierr = SNESCreate(PETSC_COMM_SELF,&nasm->subsnes[i]);CHKERRQ(ierr);
ierr = SNESAppendOptionsPrefix(nasm->subsnes[i],optionsprefix);CHKERRQ(ierr);
ierr = SNESAppendOptionsPrefix(nasm->subsnes[i],"sub_");CHKERRQ(ierr);
ierr = SNESSetDM(nasm->subsnes[i],subdms[i]);CHKERRQ(ierr);
ierr = MPI_Comm_size(PetscObjectComm((PetscObject)nasm->subsnes[i]),&size);CHKERRQ(ierr);
if (size == 1) {
ierr = SNESGetKSP(nasm->subsnes[i],&ksp);CHKERRQ(ierr);
ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
ierr = KSPSetType(ksp,KSPPREONLY);CHKERRQ(ierr);
ierr = PCSetType(pc,PCLU);CHKERRQ(ierr);
}
ierr = SNESSetFromOptions(nasm->subsnes[i]);CHKERRQ(ierr);
ierr = DMDestroy(&subdms[i]);CHKERRQ(ierr);
}
ierr = PetscFree(subdms);CHKERRQ(ierr);
} else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Cannot construct local problems automatically without a DM!");
} else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Must set subproblems manually if there is no DM!");
/* allocate the global vectors */
if (!nasm->x) {
ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->x);CHKERRQ(ierr);
ierr = PetscMemzero(nasm->x,nasm->n*sizeof(Vec));CHKERRQ(ierr);
}
if (!nasm->xl) {
ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->xl);CHKERRQ(ierr);
ierr = PetscMemzero(nasm->xl,nasm->n*sizeof(Vec));CHKERRQ(ierr);
}
if (!nasm->y) {
ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->y);CHKERRQ(ierr);
ierr = PetscMemzero(nasm->y,nasm->n*sizeof(Vec));CHKERRQ(ierr);
}
if (!nasm->b) {
ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->b);CHKERRQ(ierr);
ierr = PetscMemzero(nasm->b,nasm->n*sizeof(Vec));CHKERRQ(ierr);
}
for (i=0; i<nasm->n; i++) {
ierr = SNESGetFunction(nasm->subsnes[i],&F,NULL,NULL);CHKERRQ(ierr);
if (!nasm->x[i]) {ierr = VecDuplicate(F,&nasm->x[i]);CHKERRQ(ierr);}
if (!nasm->y[i]) {ierr = VecDuplicate(F,&nasm->y[i]);CHKERRQ(ierr);}
if (!nasm->b[i]) {ierr = VecDuplicate(F,&nasm->b[i]);CHKERRQ(ierr);}
if (!nasm->xl[i]) {
ierr = SNESGetDM(nasm->subsnes[i],&subdm);CHKERRQ(ierr);
ierr = DMCreateLocalVector(subdm,&nasm->xl[i]);CHKERRQ(ierr);
}
ierr = DMGlobalToLocalHookAdd(subdm,DMGlobalToLocalSubDomainDirichletHook_Private,NULL,nasm->xl[i]);CHKERRQ(ierr);
}
if (nasm->finaljacobian) {
ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
if (nasm->fjtype == 2) {
ierr = VecDuplicate(snes->vec_sol,&nasm->xinit);CHKERRQ(ierr);
}
for (i=0; i<nasm->n;i++) {
ierr = SNESSetUpMatrices(nasm->subsnes[i]);CHKERRQ(ierr);
}
}
PetscFunctionReturn(0);
}
