如何使用igraph在最短路径上获取顶点？

Question

我正在使用igraph生成顶点对之间最短路径距离的矩阵，但我无法弄清楚如何返回顶点。到目前为止，我有：

path_length_matrix = ig_graph.shortest_paths_dijkstra(None,None,"distance", "ALL")

我正在寻找一个返回路径矩阵的函数，比如距离矩阵，但我在igraph documentation中看不到任何显示如何获取路径的内容。

Answer 1

你需要的功能是get_shortest_paths我相信。见http://packages.python.org/python-igraph/igraph.GraphBase-class.html#get_shortest_paths

您需要为每个源顶点单独调用它，并且它将为每对节点仅提供单个（任意）最短路径。如果您需要所有最短路径，请参阅get_all_shortest_paths：http://packages.python.org/python-igraph/igraph.GraphBase-class.html#get_all_shortest_paths

Answer 2

我这样做

from igraph import *
g = Graph([(0,1), (0,2), (2,3), (3,4), (4,2), (2,5), (5,0), (6,3), (5,6)])
g.vs["name"] = ["Alice", "Bob", "Claire", "Dennis", "Esther", "Frank", "George"]
#You could create Vertexes like g.add_vertex(name="Bill") 
path=g.get_shortest_paths("Alice",to="Frank",mode=OUT,output='vpath')
for n in path[0]:
    print("{}".format(g.vs[n]['name']))

希望这可以帮助

Answer 3

这是找到加权有向图（DAG）的最短路径的方法。所以这就是我想到的：

import igraph
from igraph import *
g = Graph(directed=True)
g.add_vertices(3)
g.vs["name"]=["GO:1234567","GO:6789056","GO:5674321"]
g.es["weight"]=1
g['GO:1234567','GO:6789056']=1
g['GO:6789056','GO:5674321']=5
weight=g.es["weight"]
print weight
print g.degree(mode="in") 
print g.shortest_paths_dijkstra(source="GO:1234567", target="GO:5674321", 
    weights=weight, mode=OUT)