Math::GSL::SparseMatrix3pm

    use Math::GSL::SparseMatrix qw/:all/;
    use Math::GSL::Matrix qw/gsl_matrix_alloc/;
    my $sparse = gsl_spmatrix_alloc(100,100);
    my $status = gsl_spmatrix_set($sparse,50,50,42.42);
    my $value  = gsl_spmatrix_get($sparse,50,50);
    # multiply every element by 5
    $status = gsl_spmatrix_scale($sparse, 5);
    # get the number of non-zero elements
    my $nnz = gsl_spmatrix_nnz($sparse);
    # fine min and max values, other than zero elements
    ($status, $min, $max) = gsl_spmatrix_minmax($sparse);
    # set all elements to zero
    $status = gsl_spmatrix_set_zero($sparse);
    my $dense  = gsl_matrix_alloc(100,100);
    # convert a sparse matrix to a dense matrix
    $status = gsl_spmatrix_sp2d($dense, $sparse);
    # convert a dense matrix to a sparse matrix
    $status = gsl_spmatrix_d2sp($sparse, $dense);