slepc-3.23.1 2025-05-01
   
PEPSetEigenvalueComparison
Specifies the eigenvalue comparison function when PEPSetWhichEigenpairs() is set to PEP_WHICH_USER. 
Synopsis
#include "slepcpep.h" 
PetscErrorCode PEPSetEigenvalueComparison(PEP pep,PetscErrorCode (*comp)(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx),void* ctx)
Logically Collective
Input Parameters
|  | pep | - eigensolver context obtained from PEPCreate() | 
|  | comp | - a pointer to the comparison function | 
|  | ctx | - a context pointer (the last parameter to the comparison function) | 
Calling sequence of comp
 PetscErrorCode comp(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx)
|  | 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 PEPSetEigenvalueComparison() | 
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
 PEPSetWhichEigenpairs(), PEPWhich
Level
advanced
Location
src/pep/interface/pepopts.c
Examples
src/pep/tutorials/nlevp/pdde_stability.c
Index of all PEP routines
Table of Contents for all manual pages
Index of all manual pages