EPSSetEigenvalueComparison

Specifies the eigenvalue comparison function when EPSSetWhichEigenpairs() is set to EPS_WHICH_USER.

Synopsis

#include "slepceps.h" 
PetscErrorCode EPSSetEigenvalueComparison(EPS eps,PetscErrorCode (*func)(EPS,PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
Collective on EPS

Input Parameters

eps - eigensolver context obtained from EPSCreate()
func - a pointer to the comparison function
ctx - a context pointer (the last parameter to the comparison function)

Calling Sequence of func

  func(EPS eps,PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx)

eps - eigensolver context obtained from EPSCreate()
ar - real part of the 1st eigenvalue
ai - imaginary part of the 1st eigenvalue
br - real part of the 2nd eigenvalue
bi - imaginary part of the 2nd eigenvalue
res - result of comparison
ctx - optional context, as set by EPSSetEigenvalueComparison()

Note

The returning parameter 'res' can be

negative - if the 1st eigenvalue is preferred to the 2st one
zero - if both eigenvalues are equally preferred
positive - if the 2st eigenvalue is preferred to the 1st one

See Also

EPSSetWhichEigenpairs(), EPSSortEigenvalues(), EPSWhich

Location: src/eps/interface/opts.c
Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages