#include "petscksp.h" PetscErrorCode PCDiagonalScaleLeft(PC pc,Vec in,Vec out)Logically Collective on PC
| pc | - the preconditioner context | |
| in | - input vector | |
| out | - scaled vector (maybe the same as in) | 
          D M A D^{-1} y = D M b  for left preconditioning or
          D A M D^{-1} z = D b for right preconditioning
PCDiagonalScaleLeft() scales a vector by D. PCDiagonalScaleRight() scales a vector by D^{-1}.
If diagonal scaling is turned off and in is not out then in is copied to out