users: remove score confidence intervals from /users index.

These were originally used to find uploaders with high-scoring uploads
for promotion purposes. The weekly reports generated by Reportbooru are
better suited for this.

Also clean up some unused and redundant code.

app/logical/reports/user_promotions.rb

@@ -1,72 +1,10 @@
-require 'statistics2'
-
 module Reports
   class UserPromotions
-    class User
-      attr_reader :user
-      delegate :name, :post_upload_count, :level_string, :level, :created_at, :upload_limit, :max_upload_limit, :to => :user
-
-      def initialize(user)
-        @user = user
-      end
-
-      def confidence_interval_for(n)
-        Reports::UserPromotions.confidence_interval_for(user, n)
-      end
-
-      def deletion_confidence_interval
-        Reports::UserPromotions.deletion_confidence_interval_for(user)
-      end
-
-      def negative_score_confidence_interval
-        Reports::UserPromotions.negative_score_confidence_interval_for(user)
-      end
-
-      def median_score
-        ActiveRecord::Base.select_value_sql("select percentile_cont(0.50) within group (order by score) from posts where created_at >= ? and uploader_id = ?", ::Reports::UserPromotions.min_time, user.id).to_i
-      end
-
-      def quartile_score
-        ActiveRecord::Base.select_value_sql("select percentile_cont(0.25) within group (order by score) from posts where created_at >= ? and uploader_id = ?", ::Reports::UserPromotions.min_time, user.id).to_i
-      end
-    end
-
-    def self.confidence_interval_for(user, n)
-      up_votes = Post.where("created_at >= ?", min_time).where(:is_deleted => false, :uploader_id => user.id).where("score >= ?", n).count
-      total_votes = Post.where("created_at >= ?", min_time).where(:uploader_id => user.id).count
-      ci_lower_bound(up_votes, total_votes)
-    end
-
     def self.deletion_confidence_interval_for(user, days = nil)
       date = (days || 60).days.ago
       deletions = Post.where("created_at >= ?", date).where(:uploader_id => user.id, :is_deleted => true).count
       total = Post.where("created_at >= ?", date).where(:uploader_id => user.id).count
-      ci_lower_bound(deletions, total)
-    end
-
-    def self.negative_score_confidence_interval_for(user, days = nil)
-      date = (days || 60).days.ago
-      hits = Post.where("created_at >= ? and score < 0", date).where(:uploader_id => user.id).count
-      total = Post.where("created_at >= ?", date).where(:uploader_id => user.id).count
-      ci_lower_bound(hits, total)
-    end
-
-    def self.ci_lower_bound(pos, n, confidence = 0.95)
-      if n == 0
-        return 0
-      end
-
-      z = Statistics2.pnormaldist(1 - (1 - confidence) / 2)
-      phat = 1.0 * pos / n
-      100 * (phat + z * z / (2 * n) - z * Math.sqrt((phat * (1 - phat) + z * z / (4 * n)) / n)) / (1 + z * z / n)
-    end
-
-    def self.min_time
-      30.days.ago
-    end
-
-    def users
-      ::User.where("users.bit_prefs & ? = 0 and users.post_upload_count >= 250", ::User.flag_value_for("can_upload_free")).order("created_at desc").map {|x| Reports::UserPromotions::User.new(x)}
+      DanbooruMath.ci_lower_bound(deletions, total)
     end
   end
 end

app/views/users/index.html.erb

@@ -9,10 +9,6 @@
           <th>Name</th>
           <th>Posts</th>
           <th>Deleted</th>
-          <% if CurrentUser.is_moderator? %>
-            <th><abbr title="3+ Score Binomial Confidence Interval">5+ SBCI</abbr></th>
-            <th><abbr title="6+ Score Binomial Confidence Interval">10+ SBCI</abbr></th>
-          <% end %>
           <th>Notes</th>
           <th>Edits</th>
           <th>Level</th>
@@ -35,10 +31,6 @@
             </td>
             <td><%= link_to user.posts.count, posts_path(:tags => "user:#{user.name}") %></td>
             <td><%= user.posts.deleted.count %></td>
-            <% if CurrentUser.is_moderator? %>
-              <td><%= number_to_percentage Reports::UserPromotions.confidence_interval_for(user, 3), :precision => 0 %></td>
-              <td><%= number_to_percentage Reports::UserPromotions.confidence_interval_for(user, 6), :precision => 0 %></td>
-            <% end %>
             <td><%= link_to user.note_versions.count, note_versions_path(:search => {:updater_id => user.id}) %></td>
             <td><%= link_to user.post_update_count, post_versions_path(:search => {:updater_id => user.id}) %></td>
             <td><%= user.level_string %></td>