code: def argrelextrema(data, comparator, axis=0, order=1, mode='clip'):
      
      results = _boolrelextrema(data, comparator,
                                axis, order, mode)
      if ~results.any():
          return (np.array([]),) * 2
      else:
          return np.where(results)
docs: Calculate the relative extrema of `data`.
  
      .. versionadded:: 0.11.0
  
      Parameters
      ----------
      data : ndarray
          Array in which to find the relative extrema.
      comparator : callable
          Function to use to compare two data points.
          Should take 2 numbers as arguments.
      axis : int, optional
          Axis over which to select from `data`.  Default is 0.
      order : int, optional
          How many points on each side to use for the comparison
          to consider ``comparator(n, n+x)`` to be True.
      mode : str, optional
          How the edges of the vector are treated.  'wrap' (wrap around) or
          'clip' (treat overflow as the same as the last (or first) element).
          Default is 'clip'.  See `numpy.take`.
  
      Returns
      -------
      extrema : ndarray
          Indices of the extrema, as an array of integers (same format as
          np.argmin, np.argmax).
  
      See also
      --------
      argrelmin, argrelmax