petsc-3.4.4 2014-03-13

KSPGMRESSetHapTol

Sets tolerance for determining happy breakdown in GMRES, FGMRES and LGMRES.

Synopsis

#include "petscksp.h"  
PetscErrorCode  KSPGMRESSetHapTol(KSP ksp,PetscReal tol)
Logically Collective on KSP

Input Parameters

ksp - the Krylov space context
tol - the tolerance

Options Database

-ksp_gmres_haptol <positive real value> - Note: Happy breakdown is the rare case in GMRES where an 'exact' solution is obtained after a certain number of iterations. If you attempt more iterations after this point unstable things can happen hence very occasionally you may need to set this value to detect this condition

Keywords

KSP, GMRES, tolerance

See Also

KSPSetTolerances()

Level:intermediate
Location:
src/ksp/ksp/impls/gmres/gmres.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages