KSPRichardsonSetSelfScale#

Sets Richardson to automatically determine optimal scaling at each iteration to minimize the 2-norm of the preconditioned residual

Synopsis#

#include "petscksp.h" 
PetscErrorCode KSPRichardsonSetSelfScale(KSP ksp, PetscBool scale)

Logically Collective

Input Parameters#

Options Database Key#

  • -ksp_richardson_self_scale - Use self-scaling

Note#

Requires two extra work vectors. Uses an extra VecAXPY() and VecDotNorm2() per iteration.

Developer Note#

Could also minimize the 2-norm of the true residual with one less work vector

See Also#

KSP: Linear System Solvers, KSPRICHARDSON, KSPRichardsonSetScale()

Level#

intermediate

Location#

src/ksp/ksp/impls/rich/richscale.c

Implementations#

KSPRichardsonSetSelfScale_Richardson in src/ksp/ksp/impls/rich/rich.c

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