如何通过指定规则改变边缘的权重？

Posted 2023-02-16

【中文标题】如何通过指定规则改变边缘的权重？

【英文标题】：How to change edges' weight by designated rule?

【发布时间】：2011-04-27 07:02:24

【问题描述】：

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权重：

删除一个节点，比如节点5，很明显，边(4, 5)和(5, 6)会被删除，每条边的权重会变成：

# 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

这个算法怎么写？

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

【问题讨论】：

我不懂重新分配权重的规则

【参考方案1】：

您可以通过 G[u][v]['weight'] 或通过迭代边缘数据来访问边缘权重。所以你可以例如

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)]