slepc-3.19.2 2023-09-05
   
EPSSetEigenvalueComparison
Specifies the eigenvalue comparison function when EPSSetWhichEigenpairs() is set to EPS_WHICH_USER. 
Synopsis
#include "slepceps.h" 
PetscErrorCode EPSSetEigenvalueComparison(EPS eps,PetscErrorCode (*func)(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx),void* ctx)
Logically Collective
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
 PetscErrorCode func(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 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(), EPSWhich
Level
advanced
Location
src/eps/interface/epsopts.c
Examples
src/eps/tutorials/ex18.c
Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages