PetscErrorCode EPSSetUp_Lanczos(EPS eps)
{
EPS_LANCZOS *lanczos = (EPS_LANCZOS*)eps->data;
BVOrthogRefineType refine;
PetscReal eta;
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = EPSSetDimensions_Default(eps,eps->nev,&eps->ncv,&eps->mpd);CHKERRQ(ierr);
if (eps->ncv>eps->nev+eps->mpd) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must not be larger than nev+mpd");
if (!eps->max_it) eps->max_it = PetscMax(100,2*eps->n/eps->ncv);
if (!eps->which) { ierr = EPSSetWhichEigenpairs_Default(eps);CHKERRQ(ierr); }
switch (eps->which) {
case EPS_LARGEST_IMAGINARY:
case EPS_SMALLEST_IMAGINARY:
case EPS_TARGET_IMAGINARY:
SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which");
default: ; /* default case to remove warning */
}
if (!eps->extraction) {
ierr = EPSSetExtraction(eps,EPS_RITZ);CHKERRQ(ierr);
} else if (eps->extraction!=EPS_RITZ) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
if (eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not supported in this solver");
ierr = EPSAllocateSolution(eps,1);CHKERRQ(ierr);
ierr = EPS_SetInnerProduct(eps);CHKERRQ(ierr);
if (lanczos->reorthog != EPS_LANCZOS_REORTHOG_FULL) {
ierr = BVGetOrthogonalization(eps->V,NULL,&refine,&eta);CHKERRQ(ierr);
ierr = BVSetOrthogonalization(eps->V,BV_ORTHOG_MGS,refine,eta);CHKERRQ(ierr);
ierr = PetscInfo(eps,"Switching to MGS orthogonalization\n");CHKERRQ(ierr);
}
if (lanczos->reorthog == EPS_LANCZOS_REORTHOG_SELECTIVE) {
ierr = BVDuplicate(eps->V,&lanczos->AV);CHKERRQ(ierr);
}
ierr = DSSetType(eps->ds,DSHEP);CHKERRQ(ierr);
ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr);
ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr);
if (lanczos->reorthog == EPS_LANCZOS_REORTHOG_LOCAL) {
ierr = EPSSetWorkVecs(eps,1);CHKERRQ(ierr);
}
/* dispatch solve method */
if (!eps->ishermitian) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");
if (eps->isgeneralized && eps->ishermitian && !eps->ispositive) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Requested method does not work for indefinite problems");
eps->ops->solve = EPSSolve_Lanczos;
PetscFunctionReturn(0);
}
PetscErrorCode EPSSetUp_KrylovSchur(EPS eps)
{
PetscErrorCode ierr;
EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
enum { EPS_KS_DEFAULT,EPS_KS_SYMM,EPS_KS_SLICE,EPS_KS_INDEF } variant;
PetscFunctionBegin;
/* spectrum slicing requires special treatment of default values */
if (eps->which==EPS_ALL) {
ierr = EPSSetUp_KrylovSchur_Slice(eps);CHKERRQ(ierr);
} else {
ierr = EPSSetDimensions_Default(eps,eps->nev,&eps->ncv,&eps->mpd);CHKERRQ(ierr);
if (eps->ncv>eps->nev+eps->mpd) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must not be larger than nev+mpd");
if (!eps->max_it) eps->max_it = PetscMax(100,2*eps->n/eps->ncv);
if (!eps->which) { ierr = EPSSetWhichEigenpairs_Default(eps);CHKERRQ(ierr); }
}
if (eps->isgeneralized && eps->ishermitian && !eps->ispositive && eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not implemented for indefinite problems");
if (eps->ishermitian && eps->ispositive && (eps->which==EPS_LARGEST_IMAGINARY || eps->which==EPS_SMALLEST_IMAGINARY)) SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which");
if (!eps->extraction) {
ierr = EPSSetExtraction(eps,EPS_RITZ);CHKERRQ(ierr);
} else if (eps->extraction!=EPS_RITZ && eps->extraction!=EPS_HARMONIC)
SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
if (!ctx->keep) ctx->keep = 0.5;
ierr = EPSAllocateSolution(eps,1);CHKERRQ(ierr);
ierr = EPS_SetInnerProduct(eps);CHKERRQ(ierr);
if (eps->arbitrary) {
ierr = EPSSetWorkVecs(eps,2);CHKERRQ(ierr);
} else if (eps->ishermitian && !eps->ispositive){
ierr = EPSSetWorkVecs(eps,1);CHKERRQ(ierr);
}
/* dispatch solve method */
if (eps->ishermitian) {
if (eps->which==EPS_ALL) {
if (eps->isgeneralized && !eps->ispositive) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Spectrum slicing not implemented for indefinite problems");
else variant = EPS_KS_SLICE;
} else if (eps->isgeneralized && !eps->ispositive) {
variant = EPS_KS_INDEF;
} else {
switch (eps->extraction) {
case EPS_RITZ: variant = EPS_KS_SYMM; break;
case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break;
default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
}
}
} else {
switch (eps->extraction) {
case EPS_RITZ: variant = EPS_KS_DEFAULT; break;
case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break;
default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
}
}
switch (variant) {
case EPS_KS_DEFAULT:
eps->ops->solve = EPSSolve_KrylovSchur_Default;
eps->ops->computevectors = EPSComputeVectors_Schur;
ierr = DSSetType(eps->ds,DSNHEP);CHKERRQ(ierr);
ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr);
break;
case EPS_KS_SYMM:
eps->ops->solve = EPSSolve_KrylovSchur_Symm;
eps->ops->computevectors = EPSComputeVectors_Hermitian;
ierr = DSSetType(eps->ds,DSHEP);CHKERRQ(ierr);
ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr);
ierr = DSSetExtraRow(eps->ds,PETSC_TRUE);CHKERRQ(ierr);
ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr);
break;
case EPS_KS_SLICE:
eps->ops->solve = EPSSolve_KrylovSchur_Slice;
eps->ops->computevectors = NULL;
ierr = DSSetType(eps->ds,DSHEP);CHKERRQ(ierr);
ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr);
ierr = DSAllocate(eps->ds,ctx->ncv+1);CHKERRQ(ierr);
break;
case EPS_KS_INDEF:
eps->ops->solve = EPSSolve_KrylovSchur_Indefinite;
eps->ops->computevectors = EPSComputeVectors_Indefinite;
ierr = DSSetType(eps->ds,DSGHIEP);CHKERRQ(ierr);
ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr);
ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr);
break;
default: SETERRQ(PetscObjectComm((PetscObject)eps),1,"Unexpected error");
}
PetscFunctionReturn(0);
}