code: def hull_moving_average(data, period):
      
      catch_errors.check_for_period_error(data, period)
      hma = wma(
          2 * wma(data, int(period/2)) - wma(data, period), int(np.sqrt(period))
          )
      return hma
docs: Hull Moving Average.
  
      Formula:
      HMA = WMA(2*WMA(n/2) - WMA(n)), sqrt(n)