Dear Umut,
My "experience" tells me to just plagiarize as much as possible from
getfem itself.
In doing so you might find that a lot of the stiffness matrices are
declared with a type sparse_matrix, which comes from:
typedef getfem::modeling_standard_sparse_matrix sparse_matrix;
and this, in its turn comes from
typedef gmm::col_matrix<modeling_standard_sparse_vector>
modeling_standard_sparse_matrix;
(where they also use: typedef gmm::rsvector<scalar_type>
modeling_standard_sparse_vector;)
So, in my code ALL the global size matrices are "sparse_matrix" type.
It works quite fast, so I don't bother to check whether this is THE
fastest way, but, may be, the other getfemers will comment on this.
Best regards,
Andriy