petsc-3.9.4 2018-09-11
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 on KSP
Input Parameter
| 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).
Keywords
KSP, create, context, norms
See Also
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