QEPSetWhichEigenpairs

Specifies which portion of the spectrum is to be sought.

Synopsis

#include "slepcqep.h" 
PetscErrorCode QEPSetWhichEigenpairs(QEP qep,QEPWhich which)
Logically Collective on QEP

Input Parameters

qep - eigensolver context obtained from QEPCreate()
which - the portion of the spectrum to be sought

Possible values

The parameter 'which' can have one of these values

QEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
QEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
QEP_LARGEST_REAL - largest real parts
QEP_SMALLEST_REAL - smallest real parts
QEP_LARGEST_IMAGINARY - largest imaginary parts
QEP_SMALLEST_IMAGINARY - smallest imaginary parts
QEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
QEP_TARGET_REAL - eigenvalues with real part closest to target
QEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target

Options Database Keys

-qep_largest_magnitude - Sets largest eigenvalues in magnitude
-qep_smallest_magnitude - Sets smallest eigenvalues in magnitude
-qep_largest_real - Sets largest real parts
-qep_smallest_real - Sets smallest real parts
-qep_largest_imaginary - Sets largest imaginary parts
-qep_smallest_imaginary - Sets smallest imaginary parts
-qep_target_magnitude - Sets eigenvalues closest to target
-qep_target_real - Sets real parts closest to target
-qep_target_imaginary - Sets imaginary parts closest to target

Notes

Not all eigensolvers implemented in QEP account for all the possible values stated above. If SLEPc is compiled for real numbers QEP_LARGEST_IMAGINARY and QEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part for eigenvalue selection.

See Also

QEPGetWhichEigenpairs(), QEPWhich

Location: src/qep/interface/qepopts.c
Index of all QEP routines
Table of Contents for all manual pages
Index of all manual pages