[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [igraph] community detection
From: |
Tamas Nepusz |
Subject: |
Re: [igraph] community detection |
Date: |
Wed, 10 Feb 2010 19:19:36 +0000 |
> Then I use igraph_community_to_membership () to create a membership vector
> from a community structure dendrogram. My question is how to fill the
> parameter steps in this function. Right now I use the value corresponding
> largest modularity.
That's what I would do as well. Actually, that's also exactly what the Python
interface does.
> I find that there are several largest modularity values in my case. In other
> words, several steps have the same modularity. They do not have the same
> resulting membership. So, which steps I should choose?
Whichever you want ;) I'd choose either the smallest or the largest. Note that
if you are working with the fast greedy algorithm, the modularity values that
are equal to each other should happen at consecutive numbers of steps due to
how the algorithm works. (I.e. it can be shown that once the modularity started
to decrease after a merge, it will keep on decreasing until it eventually
reaches zero).
--
Tamas