ROCCHIO_SINGLE - Rocchio classifier for single-label collections
    LABELS_AS=KNN_SINGLE(A, CLUSTERS, BETA, GAMMA, Q, LABELS, 
    NORMALIZED_DOCS) classifies the columns of Q with the 
    Rocchio classifier using the pre-classified columns of 
    matrix A with labels LABELS (vector of integers). 
    BETA and GAMMA define the weight of positive and negative 
    examples in the formation of each class centroid. 
    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