R igraph: how to find the largest community?

问题

I use fastgreedy.community to generate a community object, which contains 15 communities. But how can I extract the largest community among these 15 communities?

Community sizes
1    2    3    4    5    6    7    8    9   10   11   12   13   14 
1862 1708  763  974 2321 1164  649 1046    2    2    2    2    2    2 
15 
2 

In this example, I want to extract the community 5 for further use. Thanks!

回答1:

Assuming that your community object is named community.object, which(membership(community.object) == x) extracts the indices of the vertices in community x. If you want the largest, community, you can set x to which.max(sizes(community.object)). Finally, you can use induced.subgraph to extract that particular community into a separate graph:

> x <- which.max(sizes(community.object))
> subg <- induced.subgraph(graph, which(membership(community.object) == x))

来源：https://stackoverflow.com/questions/15103744/r-igraph-how-to-find-the-largest-community