[igraph] Query regarding igraph eigen_centrality calculation

[Shivangi Agarwal]

Hi

I am using igraph for calculation of eigen_centrality of human protein protein interaction network, and firstly, I have calculated for example file (small edge file) as

My_Network_Edge_file

v1,v2

1,2

1,3

1,4

2,5

2,3

2,4

3,6

3,4

6,4

4,7

I have calculated degree, pagerank and eigen vector and compared to other softwares as centibin, cytoscape. Degree and pagerank is fine but I am getting different eigen values from igraph and centibin, the values are shown as:

vertex as:

"1" "2" "3" "6" "4" "5" "7"

degree.cent$res(fine)

3 4 4 2 5 1 1

pagerank (fine)

1 2 3 6 4 5 7

0.14446947 0.19732697 0.18885024 0.10253749 0.24104847 0.06336055 0.06240681

Eigen_centrality

1 2 3 6 4 5 7

0.8097211 0.8658518 0.9351728 0.5594204 1.0000000 0.2503007 0.2890803

while eigenvector centrality from centibin was obtained as:

1 2 3 4 5 6 7

0.4187492 0.447773 0.4836268 0.5171524 0.1294436 0.2893056 0.1494986

More, I note that the values obtained from igraph when multiplied by 1.933666 will give exactly same value as by centibin. What may be the reason?.. Please suggest..