Enumerable#avg is an average method for ruby’s enumerable module

Surprisingly, ActiveSupport’s core extensions don’t define a helpful average function in the Enumerable module.


wart:x3 huned$ script/console
Loading development environment (Rails 2.3.4)
>> [1,2,3,4].avg
NoMethodError: undefined method `avg' for [1, 2, 3, 4]:Array
from (irb):1


The absence of an average method is strange given that Enumerable#sum is defined and that it’d be trivially simple to implement. So monkeypatch config/initializers/enumerable.rb thusly:

Now we’re good.

wart:x3 huned$ script/console
Loading development environment (Rails 2.3.4)
>> [1,2,3].avg
=> 2.0
>> [1,2,3,4,5,6].avg
=> 3.5

Note that unlike ActiveSupport’s Enumerable#sum this method doesn’t accept an optional block.