Mahout playground buffer

mahout.clj

;; :dependencies [[org.apache.mahout/mahout-core "0.5"]]
;; :dev-dependencies [[slamhound "1.2.0"]]
(ns mia.mahout
  (:import
    (java.io File)
    (org.apache.mahout.cf.taste.eval RecommenderBuilder)
    (org.apache.mahout.cf.taste.impl.eval
      AverageAbsoluteDifferenceRecommenderEvaluator
      GenericRecommenderIRStatsEvaluator)
    (org.apache.mahout.cf.taste.impl.model.file FileDataModel)
    (org.apache.mahout.cf.taste.impl.neighborhood
      NearestNUserNeighborhood)
    (org.apache.mahout.cf.taste.impl.recommender
      GenericUserBasedRecommender)
    (org.apache.mahout.cf.taste.impl.similarity
      PearsonCorrelationSimilarity)))

(def model (FileDataModel. (File. "intro.csv")))

(def builder
     (reify RecommenderBuilder
       (buildRecommender [_ model]
                         (let [similarity (PearsonCorrelationSimilarity. model)
                               neighborhood (NearestNUserNeighborhood. 2 similarity model)] 
                           (GenericUserBasedRecommender. model neighborhood similarity)))))
; Listing 2.2
(doseq [recommendation (.recommend (.buildRecommender builder model) 1 1)]
  (println (str recommendation)))

; Listing 2.3
(def evaluator (AverageAbsoluteDifferenceRecommenderEvaluator.))
(.evaluate evaluator builder nil model 0.7 1.0)

; Listing 2.4.1
(def evaluator (GenericRecommenderIRStatsEvaluator.))
(def stats (.evaluate evaluator builder nil model nil 2 GenericRecommenderIRStatsEvaluator/CHOOSE_THRESHOLD 1.0)) 
(println (.getPrecision stats))
(println (.getRecall stats))