code: def half_mag_amplitude_ratio2(self, mag, avg):
          
  
          # For lower (fainter) magnitude than average.
          index = np.where(mag > avg)
          fainter_mag = mag[index]
  
          lower_sum = np.sum((fainter_mag - avg) ** 2) / len(fainter_mag)
  
          # For higher (brighter) magnitude than average.
          index = np.where(mag <= avg)
          brighter_mag = mag[index]
  
          higher_sum = np.sum((avg - brighter_mag) ** 2) / len(brighter_mag)
  
          # Return ratio.
          return np.sqrt(lower_sum / higher_sum)
docs: Return ratio of amplitude of higher and lower magnitudes.
  
  
          A ratio of amplitude of higher and lower magnitudes than average,
          considering weights. This ratio, by definition, should be higher
          for EB than for others.
  
          Parameters
          ----------
          mag : array_like
              An array of magnitudes.
          avg : float
              An average value of magnitudes.
  
          Returns
          -------
          hl_ratio : float
              Ratio of amplitude of higher and lower magnitudes than average.