[Getfem-users] gmm++ sparse matrices

[laura cattaneo]

Dear all, 
I want to modify some values stored into a matrix, but I can't do it.

If I try to excute these lines of code: 


      typename gmm::linalg_traits<MAT>::const_sub_row_type
    row = mat_const_row(Mbar,i);
      gmm::linalg_traits< gmm::rsvector<scalar_type> >::const_iterator
    it_nz = vect_const_begin(row);
      gmm::linalg_traits< gmm::rsvector<scalar_type> >::const_iterator
    ite_nz = vect_const_end(row);
      for (; it_nz != ite_nz ; ++it_nz) {
    Mbar(i, it_nz.index()) = (*it_nz)/sum_row; 
    }

the values inside the Mbar matrix don't change and I don't understand why.

Some one can help me??

The MAT type is 

typedef gmm::rsvector<scalar_type> sparse_vector_type;
typedef gmm::row_matrix<sparse_vector_type> sparse_matrix_type;


Thanks

Laura Cattaneo