hits does not normalize y (hub) values
The graph_tool.centrality.hits algorithm returns normalized x values but not normalized y values. According to J. Kleinberg, “Authoritative sources in a hyperlinked environment”: We maintain the invariant that the weights of each type are normalized so their squares sum to 1.
Example:
> gt.__version__
'2.2.36 (commit e3865108, Thu Jan 8 17:03:44 2015 +0100)'
> eig, x, y = gt.hits(g, max_iter=30)
> print x.get_array()
[ 0.00000000e+00 6.17918851e-01 7.42199570e-01 1.81367287e-07
1.24280718e-01 2.27750729e-01]
> print y.get_array()
[ 1.58786915e+00 8.66480290e-01 4.18388784e-07 1.36011842e+00
4.18388784e-07 1.36011842e+00]
> xsum = sum(x.get_array()**2)
> print xsum
1.0
> ysum = sum(y.get_array()**2)
> print ysum
6.9719607684
Thanks.