code: def centralize(data, time=False, units=False):
      
      assert(time is not False or units is not False)
      res = copy.copy(data)
      
      if time is True:
          res = np.array([x - np.mean(x) for x in res])
      
      if units is True:
          res = np.array(res - np.mean(res, axis=0))
      
      return res
docs: Function to subtract the mean across time and/or across units from data
      
      
      Parameters
      ----------  
      data : numpy.ndarray
          1D or 2D array containing time series, 1st index: unit, 2nd index: time
      time : bool
          True: subtract mean across time.
      units : bool
          True: subtract mean across units.
              
      
      Returns
      -------
      numpy.ndarray
          1D or 0D array of centralized signal.