[petsc-users] nonlinear eigenvalue problem with structured mesh

[Matthew Knepley]

On Mon, Jul 6, 2015 at 7:43 PM, Gideon Simpson <gideon.simpson at gmail.com>
wrote:

> I have a nonlinear eigenvalue problem for a system of equations, of the
> form,
>
> -Delta u + f(u) = E * u,
>
> where E is my nonlinear eigenvalue parameter, and u and f are vector
> valued.
>
> I thus have the following two things to contend with:
>
> 1.  E is a scalar which needs to be distributed across all the processes
> when the right hand side is formed
>
> 2.  I would like to be able to use a da to manage the spatial and
> multicomponent nature of u
>
> Obviously the Vec that my nonlinear solver is going to search for has to
> store both bits of data.  Is there a clever petsc way to handle this, or
> will I need to do all the indexing and broadcasting by hand?
>

My first suggestion would be to investigate SLEPc, which does have some
support for nonlinear
eigenvalue problems. Failing that, E normally comes out of the algorithm as
the result of some
vector algebra which automatically distributes the constant (like VecDot).

  Thanks,

     Matt


> -gideon
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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