EPSSetWhichEigenpairs

Specifies which portion of the spectrum is to be sought.

Synopsis

#include "slepceps.h" 
int 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_ALGEBRAIC - largest (algebraic) eigenvalues
EPS_SMALLEST_ALGEBRAIC - smallest (algebraic) eigenvalues
EPS_LARGEST_REAL - largest real parts
EPS_SMALLEST_REAL - smallest real parts
EPS_LARGEST_IMAGINARY - largest imaginary parts
EPS_SMALLEST_IMAGINARY - smallest imaginary parts
EPS_BOTH_ENDS - eigenvalues from both ends of the spectrum (Hermitian case)

Options Database Keys

-eps_largest_magnitude - Sets largest eigenvalues in magnitude
-eps_smallest_magnitude - Sets smallest eigenvalues in magnitude
-eps_largest_algebraic - Sets largest (algebraic) eigenvalues
-eps_smallest_algebraic - Sets smallest (algebraic) eigenvalues
-eps_largest_real - Sets largest real parts
-eps_smallest_real - Sets smallest real parts
-eps_largest_imaginary - Sets largest imaginary parts
-eps_smallest_imaginary - Sets smallest imaginary parts
-eps_both_ends - Sets both ends

Notes

No all eigensolvers implemented in EPS account for all the possible values stated above. Also, some values make sense only for certain types of problems.

See Also

EPSGetWhichEigenpairs()

Level:intermediate
Index of all EPS routines
Table of Contents for all manual pages
Index of all manual pages