problems with KSPComputeEigenvalues

[mafunk at nmsu.edu]

Hi,

i am trying to get some idea on the spectrum of my system. In order to do
that i am calling KSPSetComputeEigenvalues right before calling KSPSetUp.
Right after the call to KSPSolve i call KSPComputeEigenvalues as such:

...


  PetscInt n = -1;
  PetscReal * realpart;
  PetscReal * complexpart;
  PetscInt * neig;

  KSPComputeEigenvalues(m_ksp, n, realpart, complexpart, neig);

...

(I am not sure whether i have to allocate the memory for the arrays,
however, i tried that and it made no difference).

Anyway, the issue is when it enters the KSPComputeEigenvalues call.
The error i get is:

...

[0]PETSC ERROR: --------------------- Error Message
------------------------------------
[0]PETSC ERROR: Nonconforming object sizes!
[0]PETSC ERROR: Not enough room in work space r and c for eigenvalues!

...

What does that mean/how do i debug that? I.e. am i doing something wrong
in terms of usage?


thanks
matt