# KSPSetComputeSingularValues#

Sets a flag so that the extreme singular values will be calculated via a Lanczos or Arnoldi process as the linear system is solved.

## Synopsis#

#include "petscksp.h"
#include "petscmat.h"
PetscErrorCode KSPSetComputeSingularValues(KSP ksp, PetscBool flg)


Logically Collective

## Input Parameters#

• ksp - iterative context obtained from KSPCreate()

• flg - PETSC_TRUE or PETSC_FALSE

## Options Database Key#

• -ksp_monitor_singular_value - Activates KSPSetComputeSingularValues()

## Notes#

Currently this option is not valid for all iterative methods.

Many users may just want to use the monitoring routine KSPMonitorSingularValue() (which can be set with option -ksp_monitor_singular_value) to print the singular values at each iteration of the linear solve.

KSP: Linear System Solvers, KSPComputeExtremeSingularValues(), KSPMonitorSingularValue(), KSP