#include "petscksp.h" PetscErrorCode KSPComputeEigenvaluesExplicitly(KSP ksp,PetscInt nmax,PetscReal r,PetscReal c)Collective on KSP
|ksp||- iterative context obtained from KSPCreate()|
|n||- size of arrays r and c|
|r||- real part of computed eigenvalues, provided by user with a dimension at least of n|
|c||- complex part of computed eigenvalues, provided by user with a dimension at least of n|
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.
The preconditoner operator, rhs vector, solution vectors should be set before this routine is called. i.e use KSPSetOperators(),KSPSolve() or KSPSetOperators()