KSPSetUsePreconditionedResidual

Sets a flag so that the two norm of the preconditioned residual is used rather than the true residual, in the default convergence tests.

Synopsis

#include "petscksp.h" 
int KSPSetUsePreconditionedResidual(KSP ksp)
Collective on KSP

Input Parameter

ksp -iterative context obtained from KSPCreate()

Notes

Currently only CG, CHEBYCHEV, and RICHARDSON use this with left preconditioning. All other methods always used the preconditioned residual. With right preconditioning this flag is ignored, since the preconditioned residual and true residual are the same.

Options Database Key

-ksp_preres -Activates KSPSetUsePreconditionedResidual()

Keywords

KSP, set, residual, precondition, flag

Level:advanced
Location:
src/sles/ksp/interface/itfunc.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages