KSPSetCheckNormIteration#
Sets the first iteration at which the norm of the residual will be computed and used in the convergence test.
Synopsis#
#include "petscksp.h"
PetscErrorCode KSPSetCheckNormIteration(KSP ksp, PetscInt it)
Logically Collective
Input Parameters#
ksp - Krylov solver context
it - use -1 to check at all iterations
Notes#
Currently only works with KSPCG, KSPBCGS and KSPIBCGS
Use KSPSetNormType(ksp,KSP_NORM_NONE) to never check the norm
On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example, -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
See Also#
KSP, KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
Level#
advanced
Location#
src/ksp/ksp/interface/itcreate.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages