在networkx中实现BGLL算法的代码
时间: 2023-04-05 17:01:21 浏览: 98
以下是实现BGLL算法的代码:
```python
import networkx as nx
from networkx.algorithms.community import greedy_modularity_communities
def BGLL_algorithm(G):
# Step 1: Initialize
communities = list(greedy_modularity_communities(G))
num_communities = len(communities)
q = nx.algorithms.community.modularity(G, communities)
# Step 2: Repeat until no improvement
improvement = True
while improvement:
improvement = False
for i in range(num_communities):
for j in range(i+1, num_communities):
# Step 3: Compute delta Q
delta_q = compute_delta_q(G, communities, i, j)
# Step 4: If delta Q is positive, merge the communities
if delta_q > 0:
merge_communities(communities, i, j)
num_communities -= 1
q += delta_q
improvement = True
return list(communities)
def compute_delta_q(G, communities, i, j):
# Compute the change in modularity if communities i and j are merged
delta_q = 0
for node in communities[i]:
for neighbor in G.neighbors(node):
if neighbor in communities[j]:
delta_q += 2 * (G[node][neighbor]['weight'] - compute_expected_weight(G, communities[i], communities[j]))
return delta_q
def compute_expected_weight(G, community1, community2):
# Compute the expected weight between community1 and community2
total_weight = sum(G.degree(node, weight='weight') for node in community1) + sum(G.degree(node, weight='weight') for node in community2)
expected_weight = 0
for node in community1:
expected_weight += sum(G[node][neighbor]['weight'] for neighbor in community2) / total_weight
return expected_weight
def merge_communities(communities, i, j):
# Merge communities i and j
communities[i] |= communities[j]
del communities[j]
```
希望能对你有所帮助!