getNMI(A,B)

Compute Normalized Mutual Information (NMI)

call:

NMI = getNMI(A,B)

This function computes the Normalized Mutual Information (NMI) between
2 modular partitions or community structures given in vectors A and B.
NMI is a measure of the similarity between the two graph partitions, and
its interpretation follows that of canonical Mutual Information, i.e.
assuming that I have complete knowledge of partition A, how much knowledge
can I get, from A, about partition B? If A and B are identical, then
NMI = 1, whereas if A and B are independent, NMI --> 0.

INPUT

A : Community partition of graph A *
B : Community partition of graph B *

* A and B are N-length vectors, where each i-th element is the integer
labeling the k-th community to which node i-th was assigned.


OUTPUT

NMI : Normalized Mutual Information



References:
[1] Kuncheva & Hadjitodorov, 2004, IEEE Intern. Conf. on Syst. Man and Cybern.
[2] Alexander-Bloch et al., 2012, NeuroImage