KSPSetNormType

Sets the norm that is used for convergence testing.

Synopsis

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

Collective on KSP

Input Parameter

	ksp	- Krylov solver context
	normtype	- one of

  KSP_NO_NORM - 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.

                You must also call KSPSetConvergenceTest(ksp,KSPSkipConverged,PETSC_NULL);

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

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

                of the preconditioned residual

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

                CG, CHEBYCHEV, and RICHARDSON

  KSP_NATURAL_NORM - supported  by cg, cr, and cgs

Options Database Key

-ksp_norm_type <none,preconditioned,unpreconditioned,natural> - Notes: Currently only works with the CG, Richardson, Bi-CG-stab, CR, and CGS methods.

Keywords

KSP, create, context, norms

KSPSetNormType

Synopsis

Input Parameter

Options Database Key

Keywords

See Also