(defn find-ranks [data]
  (let [idx-data (map #(vector %1 %2) (range 1 (+ 1 (count data))) (sort data))
    compressed-data (compress (sort data))
    ranks (loop [i 0 idx idx-data result []]
        (if (empty? idx)
         (apply vector (apply concat result))
         (recur 
          (inc i)
          (let [num (first (nth compressed-data i))]
           (drop num idx))
          (conj result (let [nums (first (nth compressed-data i))]
           (repeat nums (/ (apply + (map first (take nums idx))) (* 1.0 nums))))))))]
        ranks))                 

(defn brittleness [testdata data model distance]
  (let [together (if (= (nrow model) 1) model (group-by model (- (ncol data) 1)))]
    (loop [td testdata results (transient [])]
      (if (empty? td)
    (persistent! results)
    (recur 
     (rest td)
     (conj! results 
     (let [together1 (if (= (nrow together) 1)
              (if (not= (last (first td)) (last together)) together [nil]) 
              (filter #(not= 
                (last (first td)) 
                (last (first (if (= (nrow %) 1) [%] %)))) together))
        all-test-nearest (if (= (first together1) nil) 
                  2.5 
                  (first 
                  (sort 
                   (map #(get-nearest-distance 
                   (first td) 
                   (if (= (nrow %) 1) [%] %) distance) together1))))]
      all-test-nearest)))))))