lib/disco/recommender.rb in disco-0.1.3 vs lib/disco/recommender.rb in disco-0.2.0

@@ -137,11 +137,11 @@
     def item_norms
       @item_norms ||= norms(@item_factors)
     end
 
     def norms(factors)
-      norms = Numo::DFloat::Math.sqrt((factors * factors).sum(axis: 1))
+      norms = Numo::SFloat::Math.sqrt((factors * factors).sum(axis: 1))
       norms[norms.eq(0)] = 1e-10 # no zeros
       norms
     end
 
     def similar(id, map, factors, norms, count, index)
@@ -169,11 +169,10 @@
           max_score = predictions.delete_at(i)[:score]
           predictions.sort_by! { |pred| -pred[:score] } # already sorted by id
           predictions = predictions.first(count) if count
           # divide by max score to get cosine similarity
           # only need to do for returned records
-          # could alternatively do cosine distance = 1 - cosine similarity
-          # predictions.each { |pred| pred[:score] /= max_score }
+          predictions.each { |pred| pred[:score] /= max_score }
           predictions
         end
       else
         []
       end