计算 networkx 子图中的边数

问题描述

我有以下无向和未加权图，我想衡量聚类算法的质量。对于这个测量，我想要问题的答案：

单个簇的顶点之间有多少条唯一边？

例如：集群 red 有 6 条边，集群 blue 有 4 条边，集群 green 有 4 条边。

这是我用来生成图表的代码：

import networkx as nx

G = nx.Graph(directed=False).to_undirected()

G.add_edges_from([
    ("peter","missy"),("peter","longfellow"),("missy","rhinehardt"),"vivian"),("brandon","zoe"),("longfellow","flash"),"ox"),"heather"),("rhinehardt","zostra"),("ox","jenny"),("vivian","Sarah"),("flash",("zoe","mathilda"),("heather","caitlyn"),("zostra",("Sarah",("caitlyn","jenny")
])

解决方法

绿色集群示例

# Original cluster
cluster = set(["caitlyn","jenny","zostra","ox","flash"])

# Searching for external vertices between two of cluster's vertices 
# Can be more efficient if the inner loop starts from the current position 
# of the outer loop
for u in cluster:
    for v in cluster:
        for between in list(nx.shortest_path(G,u,v)):
            cluster.add(between)

# Create subgraph and count edges
subgraph = G.subgraph(list(cluster))
print(len(subgraph.edges()))

,

您可能还想考虑 networkx 提供的质量度量：Measuring Partitions。它包括覆盖率、模块化和性能。

如果您查看 code，您还会发现 intra_community_edges 和 inter_community_edges 的方法。