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

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

KSP: Linear System Solvers, KSPComputeExtremeSingularValues(), KSPMonitorSingularValue(), KSP, KSPSetComputeRitz()

Level

advanced

Location

src/ksp/ksp/interface/itfunc.c

Examples

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

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Index of all KSP routines
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