lib/disco/recommender.rb in disco-0.3.1 vs lib/disco/recommender.rb in disco-0.3.2

@@ -34,10 +34,12 @@
         if validation_set
           check_ratings(validation_set)
         end
       end
 
+      @user_map = {}
+      @item_map = {}
       @rated = Hash.new { |hash, key| hash[key] = {} }
       input = []
       train_set.each do |v|
         # update maps and build matrix in single pass
         u = (@user_map[v[:user_id]] ||= @user_map.size)
@@ -54,9 +56,12 @@
       raise ArgumentError, "Missing item_id" if @item_map.key?(nil)
 
       # TODO improve performance
       unless @implicit
         @min_rating, @max_rating = train_set.minmax_by { |o| o[:rating] }.map { |o| o[:rating] }
+      else
+        @min_rating = nil
+        @max_rating = nil
       end
 
       if @top_items
         @item_count = [0] * @item_map.size
         @item_sum = [0.0] * @item_map.size