Add min/max delegations

.gitignore

@@ -3,6 +3,7 @@
 .bundle
 .config
 .yardoc
+.idea
 Gemfile.lock
 InstalledFiles
 _yardoc

README.md

@@ -33,6 +33,8 @@ stats.mode #=> 1
 ```ruby
 stats = DescriptiveStatistics.new([1,1,2,3,10])
 stats.range #=> 9
+stats.min #=> 1
+stats.range #=> 10
 stats.percentile_from_value(10) #=> 80
 stats.value_from_percentile(60) #=> 3
 ```

lib/descriptive-statistics.rb

@@ -15,5 +15,5 @@ def initialize(data)
     @data = data
   end
 
-  def_delegators :@data, :length, :inject, :sort, :each, :each_with_object
+  def_delegators :@data, :length, :inject, :sort, :each, :each_with_object, :min, :max
 end

spec/lib/descriptive-statistics/dispersion_spec.rb

@@ -11,6 +11,26 @@
     end
   end
 
+  describe '#min' do
+    it 'delegates to array' do
+      DescriptiveStatistics.new([1,2,6]).min.should == 1
+    end
+
+    it 'returns nil if empty' do
+      DescriptiveStatistics.new([]).min.should be_nil
+    end
+  end
+
+  describe '#max' do
+    it 'delegates to array' do
+      DescriptiveStatistics.new([1,2,6]).max.should == 6
+    end
+
+    it 'returns nil if empty' do
+      DescriptiveStatistics.new([]).max.should be_nil
+    end
+  end
+
   describe '#percentile_from_value' do
     it 'returns the precise percentile of each value' do
       data = [95.1772, 95.1567, 95.1937, 95.1959, 95.1442, 95.061, 95.1591, 95.1195,95.1065, 95.0925, 95.199, 95.1682]