sclass RSI extends CandleBasedIndicator<Double> {
  settable int smoothingPeriod;
  settable SmoothedMovingAverage up;
  settable SmoothedMovingAverage down;
  settable double rsi = Double.NaN;
  
  Double value() { ret rsi(); }
  
  void init() {
    up = new SmoothedMovingAverage(this.length());
    down = new SmoothedMovingAverage(this.length());
  }
  
  TickerSequence asTicker(L<TradingCandle> candles) {
    var seq = new TickerSequence("RSI");
    fOr (candle : candles) {
      feed(candle);
      var value = this.get();
      if (not(isNaN(value)))
        seq.addIfPriceChanged(value, candle.endTime().toLong());
    }
    ret seq;
  }
}