slepc-3.23.1 2025-05-01
   
EPSSetInterval
Defines the computational interval for spectrum slicing. 
Synopsis
#include "slepceps.h" 
PetscErrorCode EPSSetInterval(EPS eps,PetscReal inta,PetscReal intb)
Logically Collective
Input Parameters
|  | eps | - eigensolver context | 
|  | inta | - left end of the interval | 
|  | intb | - right end of the interval | 
Options Database Key
|  | -eps_interval <a,b> | - set [a,b] as the interval of interest | 
Notes
Spectrum slicing is a technique employed for computing all eigenvalues of
symmetric eigenproblems in a given interval. This function provides the
interval to be considered. It must be used in combination with EPS_ALL, see
EPSSetWhichEigenpairs().
In the command-line option, two values must be provided. For an open interval,
one can give an infinite, e.g., -eps_interval 1.0,inf or -eps_interval -inf,1.0.
An open interval in the programmatic interface can be specified with
PETSC_MAX_REAL and -PETSC_MAX_REAL.
See Also
 EPSGetInterval(), EPSSetWhichEigenpairs()
Level
intermediate
Location
src/eps/interface/epsbasic.c
Examples
src/eps/tutorials/ex12.c
src/eps/tutorials/ex25.c
Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages