[Dune] AMG and block matrizes

[Markus Blatt]

On Sun, Jul 13, 2008 at 08:45:42PM +0200, Christian Engwer wrote:
> does anybody have experience in setting up the amg with block
> matrizes?
> 
> I tried to adopt to the amgtest.cc, but I keep getting errors like:
> 
> /home/christi/DuneAll/dune-istl/dune/istl/paamg/aggregates.hh:1235:
> error: cannot convert 'const Dune::FieldMatrix<double, 21, 21>' to
> 'double' in assignment
> 
> It seems that there are certain places where blocksize = 1 is
> assumed. As I don't think that that's the case, I guess that I did a
> mistake and that I got some parameters wrong.
> 

Sorry, but I just can't help it :-)

*Markus takes out his big cristal ball and tries to see something*

Please dear cristal ball, show what template parameters Christian is
using.

*All keeps foggy*

Seems not to work any more...

* Kicks it into the trash *

:-)

Seriously, you are probably using a criterion that is not correctly
setup. Try something like this:

typedef
Dune::Amg::CoarsenCriterion<Dune::Amg::SymmetricCriterion<typename
DG::Matrix,Dune::Amg::RowSum> >
    Criterion;
typedef Dune::SeqILU0<typename DG::Matrix,BVector,BVector> Smoother;
typedef Dune::MatrixAdapter<typename DG::Matrix,BVector,BVector> Operator;
typedef Dune::Amg::AMG<Operator,BVector,Smoother> AMG;

...

Cheers,

Markus