SlepcCompareTargetImaginary#

An eigenvalue comparison function used to sort with respect to a target (along the imaginary axis).

Synopsis#

#include "slepcsys.h" 
PetscErrorCode SlepcCompareTargetImaginary(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *result,PetscCtx ctx)

Logically Collective

Input Parameters#

  • ar - real part of the 1st eigenvalue

  • ai - imaginary part of the 1st eigenvalue

  • br - real part of the 2nd eigenvalue

  • bi - imaginary part of the 2nd eigenvalue

  • ctx - user-defined context, contains the target value (a PetscScalar)

Output Parameter#

  • result - result of comparison

Notes#

In complex scalars, the result is 1 if \(\mathrm{Im}(\lambda_1-\tau)<\mathrm{Im}(\lambda_2-\tau)\) where \(\tau\) is the target. In real scalars, the result is always zero because sorting with respect to target is not supported (the target is always real in this case).

See Also#

SlepcEigenvalueComparisonFn, SlepcSCCompare(), SlepcSC

Level#

developer

Location#

src/sys/slepcsc.c

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