Bring back ELO score func, fix ladder view

app/controllers/contests_controller.rb

@@ -41,6 +41,7 @@ class ContestsController < ApplicationController
   def recalc
     raise AccessError unless @contest.can_update? cuser
     @contest.recalculate
+    flash[:notice] = "Contest points recalculated."
     redirect_to_back
   end
 

app/models/contest.rb

@@ -112,6 +112,25 @@ class Contest < ActiveRecord::Base
     end
   end
 
+  def elo_score score1, score2, diff, level = self.modulus_base, weight = self.weight, moduluses = [self.modulus_even, self.modulus_3to1, self.modulus_4to0]
+    points = (score2-score1).abs
+    modulus = moduluses[0].to_f if points <= 1
+    modulus = moduluses[1].to_f if points == 2
+    modulus = moduluses[2].to_f if points >= 3
+
+    if score1 == score2
+      result = 0.5
+    elsif score1 > score2
+      result = 1.0
+    elsif score2 > score1
+      result = 0.0
+    end
+    
+    prob = 1.0/(10**(diff.to_f/weight.to_f)+1.0)
+    total = (level.to_f*modulus*(result-prob)).round
+    return total
+  end
+
   def update_ranks contester, old_rank, new_rank
     if old_rank < new_rank
       Contester.update_all(["score = score -1, trend = ?", Contester::TREND_UP],

app/views/matches/_list.html.erb

@@ -44,7 +44,7 @@
           <% end %>
         <% end %>
       </td>
-      <% if match.contest.contest_type == Contest::TYPE_LADDER and !(max_columns < 4 if (defined? max_columns)) %>
+      <% if match.contest.contest_type == Contest::TYPE_LADDER and (max_columns > 4 if (defined? max_columns)) %>
         <td>
           <% if match.get_friendly(:points) > 0 %>
             <%= icon 'chevron-up' %>