[igraph] Betweenness centralization in python snippet

[Bernie Hogan]

Hi all,

I'm not sure if this has been posted before (I'm filtering a lot of
mail these days), but based on the R recipe I've coded up betweenness
centralization in the python version of igraph. I tested the result
against the most recent Pajek, and its the same to as many digits as
Pajek displays (3 significant digits). Enjoy. Its clearly not robust -
so if you have a graph with less than 3 nodes or all isolates you
might get funny results.

def betweenness_centralization(G):
        vnum = G.vcount()
        denom = ((vnum-1)*(vnum-2))

        temparr = [2*i/denom for i in G.betweenness()]
        result = sum([max(temparr)-i for i in temparr])/(vnum-1)

        return result

G = Graph()
#....
print betweenness_centralization(G)

Take care,
BERNiE
Dr Bernie Hogan
Research Fellow, Oxford Internet Institute
University of Oxford
http://www.oii.ox.ac.uk/people/?id=140