PolygonDirectedGraphadd_adj()add_node()adj_matrix()adj_matrix_labels()exterior_cycle()exterior_cycles()from_point_array()from_polygon()insert_node()intersect_graph_with_segment()is_edge_bidirect()min_cycle()next_exterior_node()next_exterior_node_no_backtrack()node()node_exists()polygon_exists()pt_exists()remove_adj()connection_segmentshole_root_nodesnode_countnodesordered_nodesouter_root_nodeskeleton_as_cycle_polygons()skeleton_as_directed_graph()