def get_plotting_vtx(vertex_lst): leftmost, rightmost, top, bottom = Point_2(), Point_2(), Point_2( ), Point_2() CGAL_Convex_hull_2.ch_n_point(vertex_lst, top) # maximal y coordinate. CGAL_Convex_hull_2.ch_e_point(vertex_lst, rightmost) # maximal x coordinate. CGAL_Convex_hull_2.ch_s_point(vertex_lst, bottom) # minimal y coordinates CGAL_Convex_hull_2.ch_w_point(vertex_lst, leftmost) # minimal x coordinate lt, rt = leftmost.x(), rightmost.x() tp, btm = top.y(), bottom.y() draw_pt_list = [] for pair in product([lt, rt], [tp, btm]): draw_pt_list.append(pair) # left_btm_x, left_btm_y= draw_pt_list[1] delta_x = (lt + rt) / 2 - 0 delta_y = (tp + btm) / 2 - 0 ch_height = tp - btm ch_width = rt - lt return ch_height, ch_width, delta_x, delta_y