common_group (spanning_l_arr_[i], Y_AXIS);
Real y = spanning_l_arr_[i]->relative_coordinate (common, Y_AXIS)
-relative_coordinate (common,Y_AXIS);
common_group (spanning_l_arr_[i], Y_AXIS);
Real y = spanning_l_arr_[i]->relative_coordinate (common, Y_AXIS)
-relative_coordinate (common,Y_AXIS);