(defn cnn1 [D distance]
 (let [initial-prototypes (map first (map shuffle (group-by D (- (ncol D) 1))))
    classify? (fn [one prototypes]
          (let [klass (last 
           (first
            (first
             (sort-by second 
              (map #(vector % (distance one %)) prototypes)))))]
             (if (= (last one) klass) false true)))
    get-prototypes (fn [prototypes]
            (loop [d D result []]
             (if (empty? d)
              (matrix (apply concat 
                       (conj [(apply vector (remove #(= 'none %) result))] prototypes)))
              (recur (rest d)
                  (conj result (if (classify? (first d) prototypes)
                          (first d)
                          'none))))))]
                          
  (loop [cur initial-prototypes prev []]
   (if (= (nrow prev) (nrow cur))
    cur
    (recur (get-prototypes cur) cur)))))       
    
(defn cnn [D distance]
 (let [initial-prototypes (map first (group-by D (- (ncol D) 1)))
    classify? (fn [one prototypes]
          (let [klass (last 
           (first
            (first
             (sort-by second 
              (map #(vector % (distance one %)) prototypes)))))]
             (if (= (last one) klass) false true)))
    get-prototypes (fn [prototypes]
            (loop [d D result []]
             (if (empty? d)
              (matrix (apply concat 
                        (conj [(apply vector (remove #(= 'none %) result))] prototypes)))
              (recur (rest d)
                  (conj result (if (classify? (first d) prototypes)
                          (first d)
                          'none))))))]
                          
  (loop [cur initial-prototypes prev []]
   (if (= (nrow prev) (nrow cur))
    cur
    (recur (get-prototypes cur) cur)))))