NEPSetWhichEigenpairs#

Specifies which portion of the spectrum is to be sought.

Synopsis#

#include "slepcnep.h" 
PetscErrorCode NEPSetWhichEigenpairs(NEP nep,NEPWhich which)

Logically Collective

Input Parameters#

  • nep - the nonlinear eigensolver context

  • which - the portion of the spectrum to be sought, see NEPWhich for possible values

Options Database Keys#

  • -nep_largest_magnitude - sets largest eigenvalues in magnitude

  • -nep_smallest_magnitude - sets smallest eigenvalues in magnitude

  • -nep_largest_real - sets largest real parts

  • -nep_smallest_real - sets smallest real parts

  • -nep_largest_imaginary - sets largest imaginary parts

  • -nep_smallest_imaginary - sets smallest imaginary parts

  • -nep_target_magnitude - sets eigenvalues closest to target

  • -nep_target_real - sets real parts closest to target

  • -nep_target_imaginary - sets imaginary parts closest to target

  • -nep_all - sets all eigenvalues in a region

Notes#

Not all eigensolvers implemented in NEP account for all the possible values of which. Also, some values make sense only for certain types of problems. If SLEPc is compiled for real numbers NEP_LARGEST_IMAGINARY and NEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part for eigenvalue selection.

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

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

NEP_ALL is intended for use in the context of the NEPCISS solver for computing all eigenvalues in a region.

See Also#

NEP: Nonlinear Eigenvalue Problems, NEPGetWhichEigenpairs(), NEPSetTarget(), NEPSetDimensions(), NEPSetEigenvalueComparison(), NEPWhich

Level#

intermediate

Location#

src/nep/interface/nepopts.c

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