Divide an Array equally

gistfile1.rb

class Array

  # Divides the Array into equally sized chunks.
  #
  # @example
  #   list = ["a", "b", "c", "d", "e", "f"]
  #   list.divide(3) # => [["a", "b"], ["c", "d"], ["e", "f"]]
  #
  # @param [Integer] count A recommended number of chunks (sub lists) to create.
  #   The calculated chunk size is rounded up,
  #   so the number of chunks might be less than what you pass here
  # @return [Array<Array>]
  def divide(count)
    each_slice((length / count.to_f).ceil).to_a
  end

end

# A better implementation for this exists in ActiveSupport
# http://rubydoc.info/gems/activesupport/Array#in_groups-instance_method