gistfile1.rb

require 'active_support' # Array#sum

def avg(a)
        a.sum.to_f/a.size
end

def groups(a, k)
        result = []
        while (a.size >= k)
                result << a[0..k-1]
                a.shift
        end
        result
end

def moving_average(src, k)
        groups(src, k).map do |win|
                avg(win)
        end
end

# moving_average([1,2,3,4,5,6], 3) => [2.0, 3.0, 4.0, 5.0]