petsc-3.12.4 2020-02-04
KSPComputeEigenvalues
Computes the extreme eigenvalues for the preconditioned operator. Called after or during KSPSolve().
Synopsis
#include "petscksp.h"
PetscErrorCode KSPComputeEigenvalues(KSP ksp,PetscInt n,PetscReal r[],PetscReal c[],PetscInt *neig)
Not Collective
Input Parameter
| ksp | - iterative context obtained from KSPCreate()
|
| n | - size of arrays r and c. The number of eigenvalues computed (neig) will, in
general, be less than this.
|
Output Parameters
| r | - real part of computed eigenvalues, provided by user with a dimension of at least n
|
| c | - complex part of computed eigenvalues, provided by user with a dimension of at least n
|
| neig | - actual number of eigenvalues computed (will be less than or equal to n)
|
Options Database Keys