code: def function(data, maxt=None):
      
      data = np.atleast_1d(data)
      assert len(np.shape(data)) == 1, \
          "The autocorrelation function can only by computed " \
          + "on a 1D time series."
      if maxt is None:
          maxt = len(data)
      result = np.zeros(maxt, dtype=float)
      _acor.function(np.array(data, dtype=float), result)
      return result / result[0]
docs: Calculate the autocorrelation function for a 1D time series.
  
      Parameters
      ----------
      data : numpy.ndarray (N,)
          The time series.
  
      Returns
      -------
      rho : numpy.ndarray (N,)
          An autocorrelation function.