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["Garth N. Wells" <gnw20@xxxxxxxxx>]

arizumi@xxxxxxxxxxxx wrote:
> hi,  
> I've been having a problem of calculating sparse matrix-matrix multiplication using uBLASSparseMatrix.  
>
> I declare matrices A and B as following.
>
> Matrix A0;
> uBLASSparseMatrix& A(A0.down_cast<uBLASSparseMatrix>());
> Matrix B0;
> uBLASSparseMatrix& B(B0.down_cast<uBLASSparseMatrix>());
>
> After assigning matrix values, use "prod" from boost to multiply.  but, I don't know where to return.  From compiler error 'ublas_sparse_matrix' is not a member of ‘boost::numeric::ublas’.  even if I use 'matrix' as follows, I don't know how to make this into uBLASSparseMatrix.
>
> boost::numeric::ublas::matrix<double> C;
> C = boost::numeric::ublas::prod(A.mat(), B.mat()); 
>
> My first guess was to declare 
> uBLASSpareseMatrix& C1(C); 
> but this will give a compiler error "‘uBLASSpareseMatrix’ was not declared in this scope"
>
> I would greatly appreciate any helpful suggestion.

Try

    uBLASSpareMatrix A;
    ublas_sparse_matrix& B = A.mat();

B will be a uBLAS object (ublas_sparse_matrix is a DOLFIN typedef for 
the uBLAS matrix which underlies uBLASSpareMatrix).

Garth


> Thank you,
> Nana Arizumi
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