KSPGetOperators#

Gets the matrix associated with the linear system and a (possibly) different one used to construct the preconditioner from the KSP context

Synopsis#

#include "petscksp.h" 
PetscErrorCode KSPGetOperators(KSP ksp, Mat *Amat, Mat *Pmat)

Collective

Amat - the matrix that defines the linear system
Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.

If KSPSetOperators() has not been called then the KSP object will attempt to automatically create the matrix Amat and return it

Use KSPGetOperatorsSet() to determine if matrices have been provided. After KSPSolveTranspose() or KSPMatSolveTranspose() with explicit transposition enabled by KSPSetUseExplicitTranspose(), this function returns the explicitly transposed operators until a non-transpose solve restores their parent operators. These explicitly transposed operators are owned by the KSP and may be destroyed by KSPSetUseExplicitTranspose(ksp, PETSC_FALSE), by KSPReset(), or by a non-transpose solve after KSPSetOperators() changes the operators.