KSPComputeEigenvaluesExplicitly
Computes all of the eigenvalues of the preconditioned operator using LAPACK.
Synopsis
int KSPComputeEigenvaluesExplicitly(KSP ksp,int nmax,double *r,double *c)
Collective on
KSP
Input Parameter
ksp | - iterative context obtained from KSPCreate()
|
n | - size of arrays r and c
|
Output Parameters
r | - real part of computed eigenvalues
|
c | - complex part of computed eigenvalues
|
Notes
This approach is very slow but will generally provide accurate
eigenvalueestimates. This routine explicitly forms a dense matrix
representingthe preconditioned operator, and thus will run only for relatively
smallproblems, say n < 500.
Many users may just want to use the monitoring
routineKSPSingularValueMonitor() (which can be set with option -ksp_singmonitor)
to print the singular values at each iteration of the linear solve.
Keywords
KSP, compute, eigenvalues, explicitly
See Also
KSPComputeEigenvalues(), KSPSingularValueMonitor(), KSPComputeExtremeSingularValues()
Location: src/ksp/interface/eige.c
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