[dune-pdelab] Matrix-Vector / Scalar Products in Parallel

[schauer]

Dear Dune,

I use Dune together with Arpack to solve an eigenvalue problem. I
produce the BCRS-Matrix (of which I want to know the
eigenvectors-/values) with Dune-PDElab and calculate Matrix-Vector
products for the Eigenvalue solver. Serial everything works fine but now
I want to parallelize the code.
When I now parallelize (e.g.without overlap) I build up parts of the
Matrix on every processor and the vector is also distributed where
indices on the boundary of the process are present on more than 1
process. Therefore now the Matrix/Vector-products need communication of
the distributed parts of the vector. 

The IstlSolvers, addressed via the SolverBackends, now also should
calculate Matrix-Vector products and to communicate the right parts. 
Is there now a simple way to directly use the Matrix/Vector- and
Scalarproducts implemented in these solvers ?


And if not I have to find the corresponding parts of the vectors in the
different processes - I suppose that means first finding corresponding
entities on the processes and then also finding the index of the vector,
that corresponds to this entity. How can I do this efficiently ?

Thanks for your answers

Volker


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Volker Schauer (Dipl.Phys)

Institute of Applied Mechanics (Civil Engineering), Chair 1
University of Stuttgart
Pfaffenwaldring 7
D-70569 Stuttgart
GERMANY

Phone ++49 (0)711-68560044
email: schauer at mechbau.uni-stuttgart.de