如何通过指定规则改变边缘的重量?

时间:2010-10-19 04:35:01

标签: python algorithm networkx edge-list

我有一个加权图:

F=nx.path_graph(10)
G=nx.Graph()
for (u, v) in F.edges():
    G.add_edge(u,v,weight=1)

获取节点列表:

[(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9)]

我想通过这条规则改变每条边的重量:

删除一个节点,例如节点5,边缘(4, 5)(5, 6)将被删除,每条边的权重将转为:

{# these edges are nearby the deleted edge (4, 5) and (5, 6)

(3,4):'weight'=1.1,

(6,7):'weight'=1.1,

 #these edges are nearby the edges above mentioned

(2,3):'weight'=1.2,

(7,8):'weight'=1.2,

 #these edges are nearby the edges above mentioned

(1,2):'weight'=1.3,

(8,9):'weight'=1.3,

 # this edge is nearby (1,2)

(0,1):'weight'=1.4}

如何编写此算法?

path_graph只是一个例子。我需要一个适合任何图表类型的程序。此外,程序需要是可迭代的,这意味着我每次都可以从原始图中删除一个节点。

1 个答案:

答案 0 :(得分:29)

您可以将边权重作为G [u] [v] ['weight']或通过迭代边数据来访问。所以你可以这样。

In [1]: import networkx as nx

In [2]: G=nx.DiGraph()

In [3]: G.add_edge(1,2,weight=10)

In [4]: G.add_edge(2,3,weight=20)

In [5]: G[2][3]['weight']
Out[5]: 20

In [6]: G[2][3]['weight']=200

In [7]: G[2][3]['weight']
Out[7]: 200

In [8]: G.edges(data=True)
Out[8]: [(1, 2, {'weight': 10}), (2, 3, {'weight': 200})]

In [9]: for u,v,d in G.edges(data=True):
   ...:     d['weight']+=7
   ...:     
   ...:     

In [10]: G.edges(data=True)
Out[10]: [(1, 2, {'weight': 17}), (2, 3, {'weight': 207})]