#include "slepcpep.h" PetscErrorCode PEPCheckDefiniteQEP(PEP pep,PetscReal *xi,PetscReal *mu,PetscInt *definite,PetscInt *hyperbolic)Collective
pep | - eigensolver context |
xi | - first computed parameter | |
mu | - second computed parameter | |
definite | - flag indicating that the problem is definite | |
hyperbolic | - flag indicating that the problem is hyperbolic |
On output, the flag 'definite' may have the values -1 (meaning that the QEP is not definite), 1 (if the problem is definite), or 0 if the algorithm was not able to determine whether the problem is definite or not.
If definite=1, the output flag 'hyperbolic' informs in a similar way about whether the problem is hyperbolic or not.
If definite=1, the computed values xi and mu satisfy Q(xi)<0 and Q(mu)>0, as obtained via the method proposed in [Niendorf and Voss, LAA 2010]. Furthermore, if hyperbolic=1 then only xi is computed.