[igraph] issue with evcent

[Matthew Galati]

Hi - for this tiny example graph, I am getting an eigenvector/value pair that 
does not seem valid.

> g<-read.graph("xxx",format="edgelist")
> gu<-as.undirected(g)

> print.igraph(gu)
Vertices: 3
Edges: 3
Directed: FALSE
Edges:

[0] 0 -- 1
[1] 0 -- 2
[2] 1 -- 1

> evcent(gu)
$vector
[1] 0.4811943 1.0000000 0.1939366

$value
[1] 2.481194

The eigen pair is suppose to satisfy A.x=lambda.x

But, in the second component, we have 1.48 != 2.48

Note, I checked some other examples where there are no self-loops and they seem 
ok. So, the issue might be related to self-loops.

Any ideas?

Thanks,
Matt