[Dune] BCRS matrix and matrix operations

[Arne Rekdal]

Hello,

I have this system of equations: (where ' denotes the transpose of the  
matrix)
|	B	-C'	D'	|	v		f
|	C  	0	0	|	p	=	0
|	D	0	0	|	q		g

I have chosen to use BCRS-matrices to represent the matrix blocks B, C  
and D, since these have few non-zero element. This system is  
indefinite, so by applying Schur-complement reduction twice, I achieve  
the following positive definite system

Sq=	r

where S is some product of the matrices B^(-1), C and D. (B is  
diagonal so it is trivial to invert)

My question is, how can this be done with the BCRS matrix in DUNE? My  
problem is that it seems the BCRS-matrix lacks the Matrix-Matrix  
product, and also the transpose operation, so I am not able to  
generate the matrix S.


Thank you!


Best regards
Arne Rekdal