petsc-3.4.5 2014-06-29

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" 
PetscErrorCode  KSPSetComputeSingularValues(KSP ksp,PetscBool flg)
Logically Collective on KSP

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.

Keywords

KSP, set, compute, singular values

See Also

KSPComputeExtremeSingularValues(), KSPMonitorSingularValue()

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

Examples

src/ksp/ksp/examples/tutorials/ex56.c.html
src/snes/examples/tutorials/ex30.c.html