XBT_PUBLIC(xbt_matrix_t) xbt_matrix_double_new_zeros(int lines, int rows);
XBT_PUBLIC(xbt_matrix_t) xbt_matrix_double_new_id(int lines, int rows);
XBT_PUBLIC(xbt_matrix_t) xbt_matrix_double_new_zeros(int lines, int rows);
XBT_PUBLIC(xbt_matrix_t) xbt_matrix_double_new_id(int lines, int rows);