KSPSetNormType

Synopsis

#include "petscksp.h" 
PetscErrorCode  KSPSetNormType(KSP ksp,KSPNormType normtype)

Input Parameter

  KSP_NORM_NONE - skips computing the norm, this should only be used if you are using

                the Krylov method as a smoother with a fixed small number of iterations.

                Implicitly sets KSPSkipConverged as KSP convergence test.

                Supported only by CG, Richardson, Bi-CG-stab, CR, and CGS methods.

  KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm

                of the preconditioned residual

  KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual, supported only by

                CG, CHEBYSHEV, and RICHARDSON, automatically true for right (see KSPSetPCSide()) 

                preconditioning..

  KSP_NORM_NATURAL - supported  by KSPCG, KSPCR, KSPCGNE, KSPCGS

Options Database Key