[Dune] readBCRSMatrixFromMatlabFile

[Christian Engwer]

Hi Bernd,

<quote>
BTW: The example contains a routine
void readBCRSMatrixFromMatlabFile(const char *fileName, Matrix& A)
which I think could be interesting for inclusion in
dune/istl/io.hh. It is the reverse to writeMatrixToMatlab.
</quote>

I think you are right, that such a functions would be nice. I had a
look at the code. In the current state it doesn't hold what it
promises, as it only supports 
  BCRSMatrix< FieldMatrix<1,1> >. 
It shouldn't be too difficult to update it to support
  BCRSMatrix< FieldMatrix<n,n> >.
Furthermore the template parameter should not be an arbitrary type
Matrix, but be as strict as possible. In the current implementation,
you wouldn't need any template parameter a all, while in the improved
version you should use a template parameter <int n>.

I still support this new feature, but you should have a look and fix
the afore mentioned minor issues.

Cheers Christian