[petsc-users] Problem Using EPSGetEigenpair

[Eda Oktay via petsc-users]

Hello,

I am trying to test EPSGetEigenpair function on ex11 in EPS.

First, I executed ex11 and get 0.097887 as eigenvalue (k).

Then under the code

ierr = PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues:
%D\n",nev);CHKERRQ(ierr);

I added the following code:

  ierr = EPSGetEigenpair(eps,0,&kr,NULL,NULL,NULL);
  ierr = PetscPrintf(PETSC_COMM_WORLD," Requested eigenvalue:
%D\n",kr);CHKERRQ(ierr);

After execution, I expected to find 0.097887 but the requested eigenvalue
was found as -876957631.

Why EPSGetEigenpair couldn't give 0.097887, isn't  0.097887 the eigenvalue
that EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL) calculated?

Best regards,

Eda