slepc-3.7.1 2016-05-27
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PEPSetWhichEigenpairs

Specifies which portion of the spectrum is to be sought.

Synopsis

#include "slepcpep.h" 
PetscErrorCode PEPSetWhichEigenpairs(PEP pep,PEPWhich which)
Logically Collective on PEP

Input Parameters

pep  - eigensolver context obtained from PEPCreate()
which  - the portion of the spectrum to be sought

Possible values

The parameter 'which' can have one of these values

PEP_LARGEST_MAGNITUDE  - largest eigenvalues in magnitude (default)
PEP_SMALLEST_MAGNITUDE  - smallest eigenvalues in magnitude
PEP_LARGEST_REAL  - largest real parts
PEP_SMALLEST_REAL  - smallest real parts
PEP_LARGEST_IMAGINARY  - largest imaginary parts
PEP_SMALLEST_IMAGINARY  - smallest imaginary parts
PEP_TARGET_MAGNITUDE  - eigenvalues closest to the target (in magnitude)
PEP_TARGET_REAL  - eigenvalues with real part closest to target
PEP_TARGET_IMAGINARY  - eigenvalues with imaginary part closest to target
PEP_WHICH_USER  - user defined ordering set with PEPSetEigenvalueComparison()

Options Database Keys

-pep_largest_magnitude  - Sets largest eigenvalues in magnitude
-pep_smallest_magnitude  - Sets smallest eigenvalues in magnitude
-pep_largest_real  - Sets largest real parts
-pep_smallest_real  - Sets smallest real parts
-pep_largest_imaginary  - Sets largest imaginary parts
-pep_smallest_imaginary  - Sets smallest imaginary parts
-pep_target_magnitude  - Sets eigenvalues closest to target
-pep_target_real  - Sets real parts closest to target
-pep_target_imaginary  - Sets imaginary parts closest to target

Notes

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

The target is a scalar value provided with PEPSetTarget().

The criterion PEP_TARGET_IMAGINARY is available only in case PETSc and SLEPc have been built with complex scalars.

See Also

PEPGetWhichEigenpairs(), PEPSetTarget(), PEPSetEigenvalueComparison(), PEPWhich

Location: src/pep/interface/pepopts.c
Index of all PEP routines
Table of Contents for all manual pages
Index of all manual pages