Function File: infogain_seq (seq_x, seq_y)

Gives the information gain ratio (also known as the `uncertainty coefficient') of the sequence x conditional on y: I(X|Y) = I(X;Y)/H(X)

                   X=[1, 1, 2, 1, 1];
                   Y=[2, 2, 1, 1, 2];
                   infogain_seq(X,Y)