# orginal article : http://blog.jayfields.com/2007/09/ruby-arraychunk.html
 
class Array
 
  # divides an array into a smaller chunks
  # [1,2,3,4].divide_by 2 # => [[1,2],[3,4]]
  def divide_by(number_of_chunks)
    chunks = (1..number_of_chunks).collect { [] }
    self.each_with_index do |item, index|
      chunks[index % number_of_chunks] << item
    end
    chunks
  end
 
  alias / divide_by
 
end