def inv_replace(G, temp):
"""Return the nodes replaced by temporary node
and build a Steiner point.
Arguments:
G -- a graph
temp -- temporary node
"""
neighbor = next(G.neighbors(temp))
u, v = temp
u_v = Segment2D(G.nodes[u]['pos'], G.nodes[v]['pos'])
temp_neighbor = Segment2D(G.nodes[temp]['pos'], G.nodes[neighbor]['pos'])
if temp_neighbor.intersect(u_v):
circle = Circle(G.nodes[temp]['pos'], G.nodes[u]['pos'],
G.nodes[v]['pos'])
points = circle.intersect(temp_neighbor)
steiner_point = next((p for p in points if p != G.node[temp]['pos']))
G.add_node(steiner_point, pos=steiner_point, color=steiner_color)
G.add_path([u, steiner_point, v])
G.add_edge(neighbor, steiner_point)
else:
if G.nodes[neighbor]['pos'].distance(
G.nodes[u]['pos']) > G.nodes[neighbor]['pos'].distance(
G.nodes[v]['pos']):
G.add_path([u, v, neighbor])
else:
G.add_path([v, u, neighbor])
G.remove_node(temp)
