bruce

# http://en.wikipedia.org/wiki/Simple_linear_regression
# Exchange.Calc.Regression.run([{1,1},{2,2},{3,3}])

defrecord Exchange.Calc.Regression.Result, products_avg: nil, x_avg: nil, y_avg: nil, x_sqr_avg: nil do

  def complete?(result) do
    result.products_avg && result.x_avg && result.y_avg && result.x_sqr_avg
  end
end

bruce

  def new
    @image = Image.new
    respond_with @image
  end

bruce

  def exists?(attribs)
    CustomImage.find_by_account_id_and_hash(attribs['account_id'], attribs['id'])
  end

  # Memoize using <tt>defined?</tt>
  def some_method(attribs)
    return @some_method if defined?(@some_method)
    @some_method = exists?(attribs)
  end