KSP_GMRES_CGS_REFINE_IFNEEDED#

Do the classical (unmodified) Gram-Schmidt process and one step of iterative refinement if an estimate of the orthogonality of the resulting vectors indicates poor orthogonality.

Note#

This is slower than KSP_GMRES_CGS_REFINE_NEVER because it requires an extra norm computation to estimate the orthogonality but is more stable.

See Also#

KSP: Linear System Solvers, KSPGMRES, KSPGMRESCGSRefinementType, KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESSetOrthogonalization(), KSP, KSPGMRESGetOrthogonalization(), KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSP_GMRES_CGS_REFINE_NEVER, KSP_GMRES_CGS_REFINE_ALWAYS, KSPGMRESModifiedGramSchmidtOrthogonalization()

Level#

advanced

Location#

include/petscksp.h


Index of all KSP routines
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Index of all manual pages