KSPGMRESGetOrthogonalization#
Gets the orthogonalization routine used by GMRES and FGMRES.
Synopsis#
#include "petscksp.h"
PetscErrorCode KSPGMRESGetOrthogonalization(KSP ksp, PetscErrorCode (**fcn)(KSP, PetscInt))
Not Collective
Input Parameter#
ksp - iterative context obtained from KSPCreate
Output Parameter#
fcn - orthogonalization function
Calling Sequence of function#
errorcode = PetscErrorCode fcn(KSP ksp,PetscInt it);
it is one minus the number of GMRES iterations since last restart;
i.e. the size of Krylov space minus one
Notes#
Two orthogonalization routines are predefined, including
KSPGMRESModifiedGramSchmidtOrthogonalization()
KSPGMRESClassicalGramSchmidtOrthogonalization() - Default. Use KSPGMRESSetCGSRefinementType() to determine if iterative refinement is used to increase stability.
Options Database Keys#
-ksp_gmres_classicalgramschmidt - Activates KSPGMRESClassicalGramSchmidtOrthogonalization() (default)
-ksp_gmres_modifiedgramschmidt - Activates KSPGMRESModifiedGramSchmidtOrthogonalization()
See Also#
KSPGMRESSetRestart()
, KSPGMRESSetPreAllocateVectors()
, KSPGMRESSetCGSRefinementType()
, KSPGMRESSetOrthogonalization()
,
KSPGMRESModifiedGramSchmidtOrthogonalization()
, KSPGMRESClassicalGramSchmidtOrthogonalization()
, KSPGMRESGetCGSRefinementType()
Level#
intermediate
Location#
Implementations#
KSPGMRESGetOrthogonalization_GMRES in src/ksp/ksp/impls/gmres/gmres.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages