Re: [igraph] Merge index issue?

[Gabor Csardi]

Gang, 

yes, this is the case, you need to subtract one. E.g. try this:

--------------------------
library(igraph)

g <- graph.full(5) %du% graph.full(5) %du% graph.full(5)
g <- g %u% graph.ring(15)
fc <- fastgreedy.community(g)

memb1 <- community.to.membership(g, fc$merges, which.max(fc$modularity))
memb2 <- community.to.membership(g, fc$merges, which.max(fc$modularity)-1)

modularity(g, memb1$membership)
modularity(g, memb2$membership)
max(fc$modularity)
--------------------------

G.


On Mon, Jun 23, 2008 at 07:50:40PM -0400, Gang Su wrote:
> Dear developers,
>
> I just noticed that if i run the fastgreedy community with a graph of 10  
> nodes,
> it will give 9 merges and 10 modularities.
> therefore, to get the right cut,
> i should assign the step parameter in community.to.membership,
> instead of which.max(modularity)
> should be which.max(modularity-1)?
>
> Thanks!
>
> Gang
>
>
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-- 
Csardi Gabor <address@hidden>    UNIL DGM