I am trying to calculate the BIC for the X-Means algorithm as described in the paper by Pelleg and Moore (https://www.cs.cmu.edu/~dpelleg/download/xmeans.pdf).
The paper describes the calculation of the pj variable, which I do not understand completely:
The number of free parameters pj is simply the sum of K-1 class probabilities, M*K centroid coordinates, and one variance estimate.
On another post (X-mean algorithm BIC calculation question), a user described the calculated of pj as simply K-1 + M*K + 1. I am wondering if anyone has any knowledge as to whether this is correct or not?