KNN_SINGLE - k-Nearest Neighboors classifier for single-label 
  collections
    LABELS_AS=KNN_SINGLE(A, Q, K, LABELS, NORMALIZED_DOCS) 
    classifies the columns of Q with the K-Nearest Neighboors 
    classifier using the pre-classified columns of matrix A 
    with labels LABELS (vector of integers). NORMALIZED_DOCS 
    defines if cosine (1) or euclidean distance (0) similarity 
    measure is to be used. LABELS_AS contains the assigned 
    labels for the columns of Q. 
 
  Copyright 2011 Dimitrios Zeimpekis, Eugenia Maria Kontopoulou, 
                 Efstratios Gallopoulos