petsc-3.14.6 2021-03-30
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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" 
#include "petscmat.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.

See Also

KSPComputeExtremeSingularValues(), KSPMonitorSingularValue(), KSP

Level

advanced

Location

src/ksp/ksp/interface/itfunc.c

Examples

src/ksp/ksp/tutorials/ex56.c.html
src/ksp/ksp/tutorials/ex59.c.html
src/snes/tutorials/ex30.c.html
src/snes/tutorials/ex56.c.html

Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages