gistfile1.rb

# Compute an average for <back> elements from the end of the results
def average_value(back, results)
  return results['values'].last['value'] if back.zero?  
  values = results['values'].map { |item| item['value'] }
  values[-back, back].inject {|sum, i| sum + i} / range_of_interest.size.to_f
end