EPSSetWhichEigenpairs

Specifies which portion of the spectrum is to be sought.

Synopsis

#include "slepceps.h" 
PetscErrorCode EPSSetWhichEigenpairs(EPS eps,EPSWhich which)
Collective on EPS

Input Parameter

eps - eigensolver context obtained from EPSCreate()

Output Parameter

which - the portion of the spectrum to be sought

Possible values

The parameter 'which' can have one of these values

EPS_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
EPS_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
EPS_LARGEST_REAL - largest real parts
EPS_SMALLEST_REAL - smallest real parts
EPS_LARGEST_IMAGINARY - largest imaginary parts
EPS_SMALLEST_IMAGINARY - smallest imaginary parts

Options Database Keys

-eps_largest_magnitude - Sets largest eigenvalues in magnitude
-eps_smallest_magnitude - Sets smallest eigenvalues in magnitude
-eps_largest_real - Sets largest real parts
-eps_smallest_real - Sets smallest real parts
-eps_largest_imaginary - Sets largest imaginary parts in magnitude
-eps_smallest_imaginary - Sets smallest imaginary parts in magnitude

Notes

Not all eigensolvers implemented in EPS account for all the possible values stated above. Also, some values make sense only for certain types of problems. If SLEPc is compiled for real numbers EPS_LARGEST_IMAGINARY and EPS_SMALLEST_IMAGINARY use the absolute value of the imaginary part for eigenvalue selection.

See Also

EPSGetWhichEigenpairs(), 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