petsc-3.5.4 2015-05-23

PCEisenstatNoDiagonalScaling

Causes the Eisenstat preconditioner not to do additional diagonal preconditioning. For matrices with a constant along the diagonal, this may save a small amount of work.

Synopsis

#include "petscpc.h" 
PetscErrorCode  PCEisenstatNoDiagonalScaling(PC pc)

Logically Collective on PC

Input Parameter

pc -the preconditioner context

Options Database Key

-pc_eisenstat_no_diagonal_scaling -Activates PCEisenstatNoDiagonalScaling()

Note

If you use the KPSSetDiagonalScaling() or -ksp_diagonal_scale option then you will likley want to use this routine since it will save you some unneeded flops.

Keywords