we have a set of patterns arranged as the rows of a matrix, X, then we use an expression similar to the longer expression in
Section 12.2 to obtain a matrix D, whose element D ( I , J ) is the Euclidean distance between the ith pattern vector in X and the jth mean vector in M. Thus, to find the class membership of, say the ith pattern in X, we find the column location in row i of D that yields the smallest value.