petsc-3.3-p7 2013-05-11

PCGetDiagonalScale

 Indicates if the preconditioner applies an additional left and right scaling as needed by certain time-stepping codes.

Synopsis

#include "petscksp.h" 
PetscErrorCode  PCGetDiagonalScale(PC pc,PetscBool  *flag)
Logically Collective on PC

Input Parameter

pc -the preconditioner context

Output Parameter

flag -PETSC_TRUE if it applies the scaling

Notes: If this returns PETSC_TRUE then the system solved via the Krylov method is 

          D M A D^{-1} y = D M b  for left preconditioning or

          D A M D^{-1} z = D b for right preconditioning

Keywords

PC

See Also

PCCreate(), PCSetUp(), PCDiagonalScaleLeft(), PCDiagonalScaleRight(), PCSetDiagonalScale()

Level:developer
Location:src/ksp/pc/interface/precon.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages