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, PetscViewerAndFormat *vf)
Logically Collective
Input Parameters#
ksp - the iterative context
n - the iteration
rnorm - the two norm of the residual
vf - The viewer context
Options Database Key#
-ksp_monitor_singular_value - Activates
KSPMonitorSingularValue()
Notes#
The KSPCG
solver uses the Lanczos technique for eigenvalue computation,
while KSPGMRES
uses the Arnoldi technique; other iterative methods do
not currently compute singular values.
This is not called directly by users, rather one calls KSPMonitorSet()
, with this function as an argument, to cause the monitor
to be used during the KSP
solve.
Call KSPMonitorSingularValueCreate()
to create the context needed by this monitor
See Also#
KSP: Linear System Solvers, KSP
, KSPMonitorSet()
, KSPComputeExtremeSingularValues()
, KSPMonitorSingularValueCreate()
Level#
intermediate
Location#
Examples#
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages