docs: def fano(data, units=False):
      """
      Calculate fano factor (FF) of data. Mean and variance are computed across
      time.
  
  
      Parameters
      ----------   
      data : numpy.ndarray 
          1st axis unit, 2nd axis time.
      units : bool
          Average `FF`.
  
  
      Returns
      -------
      numpy.ndarray
          If units=False, series of unit FFs.
      float
          If units=True, mean FF across units.
  
  
      Examples
      --------
      >>> fano(np.array([[1, 2, 3, 4, 5, 6], [11, 2, 3, 3, 4, 5]]))
      array([ 0.83333333,  1.9047619 ])
  
      >>> fano(np.array([[1, 2, 3, 4, 5, 6], [11, 2, 3, 3, 4, 5]]), units=True)
      1.3690476190476191
  
      """
      mu = mean(data, time=True)
      var = variance(data, time=True)
      ff = var / mu
      
      if units is True:
          return np.mean(ff)
      else:
          return ff