WOLPAWENTROPY calculates the Mutual Information according to  B = wolpaw_entropy(acc,M) B = log2(M) + acc*log2(acc) + (1-acc)*log2((1-acc)/(M-1)) acc Accuracy [0..1] 1 = 100%; N number of classes B mutual information Reference(s):  J.R. Wolpaw, N. Birbaumer, W.J. Heetderks, D.J. McFarland, P. Huntereckham, G. Schalk, E. Donchin, L.A. Quatrano, C-J. Robinson and T.M. Vaughan. Brain-Computer Interface Technology: A Review of the First Inernational Meeting. IEEE Transactions on Rehabilitation Engineering 8(2) (Jun 2000) 164-173.