(defn get-criteria [D]
 (let [br (my-best-rest4 D)]
  (loop [br1 br result []]
   (if (empty? br1)
    result
    (recur (rest br1)
        (conj result (rank-vals4 D (first (first br1)) (second (first br1)))))))))
        
(defn select-instances1 [crit inst]
 (loop [c crit result inst]
  (if (or (= result nil) (<= (nrow result) (myutil? (nrow inst) 0.15)))
   result
   (recur (rest c)
       (matrix (filter #(= (nth % (last (first c))) (first (first c))) result))))))
       
(defn select-instances [crit inst]
 (loop [c crit prev inst result inst]
  (if (or (= result nil) (<= (nrow result) (myutil? (nrow inst) 0.15)))
   (if (= result nil) prev result)
   (recur (rest c)
          result
       (matrix (filter #(= (nth % (last (first c))) (first (first c)))
                 (if (= (nrow result) 1) [result] result)))))))       
        
(defn cliff [D]
 (let [crits (get-criteria D)
    insts (group-by D (- (ncol D) 1))]  
  (apply bind-rows (map #(select-instances %1 %2) crits insts))))