[petsc-users] BCs for a EPS solver

[Jeremy Theler]

The usual trick is to set ones in one matrix and zeros in the other
one.


On Mon, 2020-02-17 at 12:35 -0600, Emmanuel Ayala wrote:
> Hi everyone,
> 
> I have an eigenvalue problem where I need to apply BCs to the
> stiffness and mass matrix. 
> 
> Usually, for KSP solver, it is enough to set to zero the rows and
> columns related to the boundary conditions. I used to apply it with
> MatZeroRowsColumns, with a 1s on the diagonal. Then the solver works
> well.
> 
> There is something similar to KSP for EPS solver ? 
> 
> I already used MatZeroRowsColumns (for EPS solver), with a 1s on the
> diagonal, and I got wrong result.
> 
> Kind regards.
> 
> 
> 
>