slepc-3.17.2 2022-08-09
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Defines the computational interval for spectrum slicing.


#include "slepceps.h" 
PetscErrorCode EPSSetInterval(EPS eps,PetscReal inta,PetscReal intb)
Logically Collective on eps

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


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()

Location: src/eps/interface/epsbasic.c



Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages