[R] vertex labels in igraph from adjacency matrix

[Gabor Csardi]

On Wed, Mar 05, 2008 at 02:27:21AM -0500, Charilaos Skiadas wrote:
[...]
> 
> Btw, you will likely want to take the betweenness call out, and call  
> it once and store the result, instead of calling it twice (well,  
> assuming the graph is largish). Or even better, use which.max:
> 
> which.max(betweenness(graph = my.graph, v=V(my.graph), directed =  
> FALSE))

This is almost good, but there is a catch, in igraph vertices are 
numbered from zero. So if you want an igraph vertex id, then you 
need to subtract one from this, i.e.:

maxb <- which.max(betweennness(my.graph, directed=FALSE))-1

You can double check it:

betweenness(my.graph, maxb, directed=FALSE)

Gabor

PS. there is also an igraph mailing list, see the igraph homepage
at igraph.sf.net

> Haris Skiadas
> Department of Mathematics and Computer Science
> Hanover College
> 
[...]

-- 
Csardi Gabor <csardi at rmki.kfki.hu>    UNIL DGM