Condorcet votes can now properly handle votes expressing equivalency

[rubyvote] / lib / rubyvote / condorcet.rb

diff --git a/lib/rubyvote/condorcet.rb b/lib/rubyvote/condorcet.rb
index e674115a89253359b62f18524280ed2c8f26c744..65c664dd28a57417aa0a90395562289c8de0eed4 100644 (file)
--- a/lib/rubyvote/condorcet.rb
+++ b/lib/rubyvote/condorcet.rb
@@ -51,9 +51,9 @@ class CondorcetVote < ElectionVote
 
   def tally_vote(vote=nil)
 
-    vote.each_with_index do |winner, index|
+    vote.each_with_index do |winners, index|
       if vote.flatten.length < @candidates.length
-        implied_losers = @candidates.select { |c| not vote.include?(c) }
+        implied_losers = @candidates.select { |c| not vote.flatten.include?(c) }
         vote.push(implied_losers)
       end
       if vote.length - 1 == index
@@ -66,18 +66,21 @@ class CondorcetVote < ElectionVote
         place = [place] unless place.class == Array
         place.each do |loser|
           
+          winners = [winners] unless winners.class == Array
+          next if winners.include?(loser)
+          winners.each do |winner|
+            @votes[winner] = Hash.new unless @votes.has_key?(winner)
+            @votes[loser] = Hash.new unless @votes.has_key?(loser)
+
+            if @votes[winner].has_key?(loser)
+              @votes[winner][loser] += 1
+            else
+              @votes[winner][loser] = 1
+            end
 
-          @votes[winner] = Hash.new unless @votes.has_key?(winner)
-          @votes[loser] = Hash.new unless @votes.has_key?(loser)
-
-          if @votes[winner].has_key?(loser)
-            @votes[winner][loser] += 1
-          else
-            @votes[winner][loser] = 1
+            # make sure we have a comparable object
+            @votes[loser][winner] = 0 unless @votes[loser].has_key?( winner )
           end
-
-          # make sure we have a comparable object
-          @votes[loser][winner] = 0 unless @votes[loser].has_key?( winner )
         end
       end
     end
@@ -120,8 +123,8 @@ class CondorcetVote < ElectionVote
 end
 
 class PureCondorcetVote < CondorcetVote
-  def result
-    PureCondorcetResult.new(self)
+  def resultFactory(init)
+    PureCondorcetResult.new(init)
   end
 end
 
@@ -177,6 +180,7 @@ class PureCondorcetResult < CondorcetResult
   end
 
   protected
+
   def condorcet
     votes = @election.votes
     candidates = @election.candidates
@@ -191,11 +195,18 @@ class PureCondorcetResult < CondorcetResult
       victors[winner] << loser
     end
 
-    winners = @election.candidates.find_all do |candidate|
-        victors[candidate].length == @election.candidates.length - 1
+    victory_margin = 1
+    while true
+      winners = @election.candidates.find_all do |candidate|
+        victors[candidate].length == @election.candidates.length - victory_margin
+      end
+      if winners.length > 0
+        @winners = winners
+        return @winners
+      else
+        victory_margin += 1
+      end
     end
-
-    @winners << winners if winners.length == 1
   end
 end