KSPSetDM#

Sets the DM that may be used by some preconditioners and that may be used to construct the linear system

Synopsis#

#include "petscksp.h" 
PetscErrorCode KSPSetDM(KSP ksp, DM dm)

Logically Collective

Input Parameters#

ksp - the KSP
dm - the DM, cannot be NULL to remove a previously set DM

Notes#

If this is used then the KSP will attempt to use the DM to create the matrix and use the routine set with DMKSPSetComputeOperators(). Use KSPSetDMActive(ksp,PETSC_FALSE) to instead use the matrix you’ve provided with KSPSetOperators().

A DM can only be used for solving one problem at a time because information about the problem is stored on the DM, even when not using interfaces like DMKSPSetComputeOperators(). Use DMClone() to get a distinct DM when solving different problems using the same function space.