petsc-3.5.1 2014-08-06
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KSPMonitorSingularValue

Prints the two norm of the true residual and estimation of the extreme singular values of the preconditioned problem at each iteration.

Synopsis

#include "petscksp.h" 
PetscErrorCode  KSPMonitorSingularValue(KSP ksp,PetscInt n,PetscReal rnorm,void *dummy)
Logically Collective on KSP

Input Parameters

ksp - the iterative context
n - the iteration
rnorm - the two norm of the residual

Options Database Key

-ksp_monitor_singular_value -Activates KSPMonitorSingularValue()

Notes

The CG solver uses the Lanczos technique for eigenvalue computation, while GMRES uses the Arnoldi technique; other iterative methods do not currently compute singular values.

Keywords

KSP, CG, default, monitor, extreme, singular values, Lanczos, Arnoldi

See Also

KSPComputeExtremeSingularValues()

Level:intermediate
Location:
src/ksp/ksp/interface/iterativ.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/snes/examples/tutorials/ex30.c.html