PCSetDiagonalScale#
Indicates the left scaling to use to apply an additional left and right scaling as needed by certain time-stepping codes.
Synopsis#
#include "petscksp.h"
PetscErrorCode PCSetDiagonalScale(PC pc, Vec s)
Logically Collective
Input Parameters#
pc - the preconditioner context
s - scaling vector
Notes#
The system solved via the Krylov method is, for left and right preconditioning, $$
\begin{align*}
D M A D^{-1} y = D M b \\
D A M D^{-1} z = D b.
\end{align*}
$$
PCDiagonalScaleLeft() scales a vector by \(D\). PCDiagonalScaleRight() scales a vector by \(D^{-1}\).
See Also#
KSP: Linear System Solvers, PCCreate(), PCSetUp(), PCDiagonalScaleLeft(), PCDiagonalScaleRight(), PCGetDiagonalScale()
Level#
intermediate
Location#
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages