Sets the first iteration at which the norm of the residual will be computed and used in the convergence test.
PetscErrorCode KSPSetCheckNormIteration(KSP ksp,PetscInt it)
Logically Collective on KSP
|ksp ||- Krylov solver context
|it ||- use -1 to check at all iterations
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).
KSP, create, context, norms
KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType()
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages