Make statistics work under PostgreSQL.

lib/statistics.rb

@@ -109,7 +109,7 @@ SQL
   def correlation(x_array, y_array)
     sum = 0.0
     x_array.each_index do |i|
-      sum = sum + x_array[i]*y_array[i]
+      sum = sum + x_array[i].to_f * y_array[i].to_f
     end
     x_y_mean = sum/x_array.length.to_f
     x_mean = mean(x_array)
@@ -123,7 +123,7 @@ SQL
 
   def mean(array)
     sum = array.inject(0.0) do |sum, val|
-      sum += val
+      sum += val.to_f
     end
     sum / array.length
   end
@@ -132,7 +132,7 @@ SQL
     variance = lambda do
       m = mean(array)
       sum = 0.0
-      array.each{ |v| sum += (v-m)**2 }
+      array.each{ |v| sum += (v.to_f-m)**2 }
       sum/array.length.to_f
     end.call
 
@@ -146,7 +146,13 @@ SQL
 
   protected
   def where_clause_sql
-    "where users.created_at > FROM_UNIXTIME(#{(Time.now - 1.month).to_i})"
+    if postgres?
+      "WHERE users.created_at > NOW() - '1 month'::INTERVAL"
+    elsif sqlite?
+      raise "#where_clause_sql not yet written for SQLite"
+    else
+      "where users.created_at > FROM_UNIXTIME(#{(Time.now - 1.month).to_i})"
+    end
   end
 
   def week_created(n)

spec/lib/statistics_spec.rb

@@ -3,6 +3,16 @@ require 'lib/statistics'
 
 describe Statistics do
 
+  def result_should_equal( actual )
+    actual.count.should == @result.count
+    @result.each do |expected_hash|
+      actual.find { |actual_hash|
+        actual_hash['id'].to_i == expected_hash['id'].to_i &&
+        actual_hash['count'].to_i == expected_hash['count'].to_i
+      }.should_not be_nil
+    end
+  end
+
   before do
     @time = Time.now
     @stats = Statistics.new#(@time, @time - 1.week)
@@ -16,7 +26,7 @@ describe Statistics do
   describe '#posts_count_sql' do
     it "pulls back an array of post counts and ids" do
       Factory.create(:status_message, :author => bob.person)
-      User.connection.select_all(@stats.posts_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.posts_count_sql)
     end
   end
 
@@ -24,7 +34,7 @@ describe Statistics do
     it "pulls back an array of post counts and ids" do
       sm = Factory.create(:status_message, :author => alice.person)
       bob.comment("sup", :post => sm)
-      User.connection.select_all(@stats.comments_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.comments_count_sql)
     end
   end
 
@@ -32,14 +42,14 @@ describe Statistics do
   describe '#invites_sent_count_sql' do
     it "pulls back an array of invite counts and ids" do
       Invitation.batch_invite(["a@a.com"], :sender => bob, :aspect => bob.aspects.first, :service => 'email')
-      User.connection.select_all(@stats.invites_sent_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.invites_sent_count_sql)
     end
   end
 
   describe '#tags_followed_count_sql' do
     it "pulls back an array of tag following counts and ids" do
       TagFollowing.create!(:user => bob, :tag_id => 1)
-      User.connection.select_all(@stats.tags_followed_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.tags_followed_count_sql)
     end
   end
 
@@ -47,7 +57,7 @@ describe Statistics do
     it "pulls back an array of mentions following counts and ids" do
       post = Factory.create(:status_message, :author => bob.person)
       Mention.create(:post => post, :person => bob.person)
-      User.connection.select_all(@stats.mentions_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.mentions_count_sql)
     end
   end
 
@@ -61,7 +71,7 @@ describe Statistics do
                  {"id" => local_luke.id , "count" => 2 },
                  {"id" => local_leia.id , "count" => 2 }]
 
-      User.connection.select_all(@stats.contacts_sharing_with_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.contacts_sharing_with_count_sql)
     end
   end
 
@@ -69,7 +79,7 @@ describe Statistics do
     it "pulls back an array of sign_in_counts and ids" do
       bob.sign_in_count = 1
       bob.save!
-      User.connection.select_all(@stats.sign_in_count_sql).should =~ @result
+      result_should_equal User.connection.select_all(@stats.sign_in_count_sql)
     end
   end