lib/qme/map/cv_aggregator.rb in quality-measure-engine-2.5.1 vs lib/qme/map/cv_aggregator.rb in quality-measure-engine-2.5.2

@@ -4,25 +4,30 @@
     class CVAggregator
 
       def self.median(frequencies)
         set_size = frequencies.values.reduce(0, :+)
         offset = set_size.even? ? 1 : 0
-        median_positions = [(set_size / 2), (set_size / 2)+offset]
+        left_position, right_position = [(set_size / 2), (set_size / 2) + offset]
+        current_position = -1 + offset #compensate for integer math flooring
 
-        current_position = 0
         median_left = nil
         median_right = nil
 
         frequencies.keys.sort.each do |value|
-          current_position += frequencies[value]
-          
-          median_left = value if median_left.nil? && current_position >= median_positions[0] 
-          if current_position >= median_positions[1]
-            median_right = value 
+          current_position += (frequencies[value])
+
+          if current_position >= left_position && median_left == nil
+            median_left = value
+            return median_left if set_size.odd?
+          end
+
+          if current_position >= right_position
+            median_right = value
             break
           end
         end
+
         median_left ||= 0
         median_right ||= 0
         (median_left + median_right)/2
       end
 
@@ -35,6 +40,6 @@
       end
 
     end
 
   end
-end
\ No newline at end of file
+end