KSPOrthogonalizationSet#

Sets the orthogonalization routine used by KSPGMRES and other solvers.

Synopsis#

#include "petscksp.h" 
PetscErrorCode KSPOrthogonalizationSet(KSP ksp, KSPOrthogonalizationFn *orthog)

Logically Collective

Input Parameters#

ksp - the Krylov space solver context
orthog - orthogonalization function; see KSPOrthogonalizationFn for the calling sequence

Options Database Key#

-ksp_orthogonalization (cgs|mgs) - choose between classical (default) or modified Gram-Schmidt for orthogonalization

Notes#

This is used by solvers that explicitly orthogonalize a set of vectors, such as the KSPGMRES variants and KSPIDR; it has no effect on methods such as KSPBCGS that never call it.

Two orthogonalization routines are predefined, KSPOrthogonalizationModifiedGramSchmidt() and the default KSPOrthogonalizationClassicalGramSchmidt().

Use KSPOrthogonalizationSetCGSRefinementType() to determine if iterative refinement is used to increase stability.

Level#

intermediate

Location#

src/ksp/ksp/interface/orthog.c

Examples#

src/ksp/ksp/tutorials/ex5f.F90

Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages