docs: def xcorr(x, y, maxlags):
      """
      Streamlined version of matplotlib's `xcorr`, without the plots.
  
      :param x, y: NumPy arrays to cross-correlate
      :param maxlags: Max number of lags; result will be `2*maxlags+1` in length
      """
      xlen = len(x)
      ylen = len(y)
      assert xlen == ylen
  
      c = np.correlate(x, y, mode=2)
  
      # normalize
      c /= np.sqrt(np.dot(x, x) * np.dot(y, y))
  
      lags = np.arange(-maxlags, maxlags + 1)
      c = c[xlen - 1 - maxlags:xlen + maxlags]
  
      return c