added rake task for generating a CSV of top actives from cohorts

lib/statistics.rb

@@ -162,7 +162,16 @@ SQL
 
   ### % of cohort came back last week
   def retention(n)
-    week_created(n).where("current_sign_in_at > ?", Time.now - 1.week).count.to_f/week_created(n).count
+    users_by_week(n).count.to_f/week_created(n).count
+  end
+
+  def top_active_users(n)
+    ten_percent_lim = (users_by_week(n).count.to_f * 0.3).ceil
+    users_by_week(n).order("sign_in_count DESC").limit(ten_percent_lim).select('email, username, sign_in_count')
+  end
+
+  def users_by_week(n)
+    week_created(n).where("current_sign_in_at > ?", Time.now - 1.week)
   end
 
   protected

lib/tasks/stats.rake

@@ -21,4 +21,20 @@ namespace :stats do
                             :attachments => [{:name => "retention_numbers_#{Time.now.to_s}.csv", :file => string}]})
     emails.each {|e| e.deliver} 
   end
+
+  task :top_actives => :environment do
+
+    require 'fastercsv'
+
+    string = FasterCSV.generate do |csv|
+      (0..32).each do |i|
+        actives = ActiveRecord::Base.connection.select_all(Statistics.new.top_active_users(i).to_sql)
+        actives.each do |a|
+          csv << [i.to_s, a['email'], a['username'], a['sign_in_count']]
+        end
+      end
+    end
+
+    File.open("#{Rails.root}/tmp/top_actives.csv", 'w') {|f| f.write(string) }
+  end
 end