Configure rating scale as class instance variable of MajorityJudgment

mj.rb

@@ -1,8 +1,14 @@
 class MajorityJudgment
 
+  @values = nil
+
   include Comparable
   attr_reader :ratings, :count, :n, :majority
 
+  class << self
+    attr_accessor :values
+  end
+
   def initialize(arg)
     if arg.is_a?(Array)
       @ratings = arg
@@ -22,7 +28,7 @@ class MajorityJudgment
 
   def mj
     s = 0
-    (1..7).to_a.reverse.each do |r|
+    (1..self.class.values.length).to_a.reverse.each do |r|
       s = s + @count[r] if @count[r]
       return r if s >= @majority
     end
@@ -31,7 +37,7 @@ class MajorityJudgment
 
   def proponents(rating = self.mj)
     p = 0
-    (rating+1..7).to_a.reverse.each do |r|
+    (rating+1..self.class.values.length).to_a.reverse.each do |r|
       p = p + @count[r] if @count[r]
     end
     return p