code: def array(self):
          
          if not hasattr(self, '_array'): self._array = self.load_data()
          return self._array
docs: Data as a [`numpy.ndarray`][1] in the form
  
              #!python
              [
                  [ x1, x2, x3, ... ],
                  [ y1, y2, y3, ...]
              ]
  
          By default, if unset, this will be set on first access
          by calling `scipy_data_fitting.Data.load_data`.
  
          When loaded from file, the x and y values will be scaled according
          to `scipy_data_fitting.Data.scale`.
  
          [1]: http://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.html