RSI Ensemble

// This sample indicator colors each candle according to how 3 RSIs (14, 9, 5) signal "overbought"
// for it. A candle will be gray if none of the RSIs are current overbought. A candle will be yellow if only
// one of them is overbought. A candle will be orange if 2 RSIs signal "overbought", and it will be
// red if all 3 of RSIs are in agreement that the stock is overbought. 
// 
// This indicator also provides a signal named "Surely Overbought", which emerges
// any time all 3 RSIs are signaling Overbought. It also provides a signal named
// "Probably Overbought", which emerges when 2 of 3 RSIs are in agreement that it's overbought.
// These signals can be used in scanning, backtesting and such, while the actual
// candle color can't.

describe_indicator('RSI Ensemble');

const OVERBOUGHT_LEVEL = 80;

const COLOR_BY_SCORE = {
    0: 'gray',
    1: 'yellow',
    2: 'orange',
    3: 'red'
};

const scoreOfRSI = length => for_every(
    rsi(close, length),
    rsiValue => rsiValue > OVERBOUGHT_LEVEL ? 1 : 0
);

const summaryScores = add(
    scoreOfRSI(14),
    scoreOfRSI(9),
    scoreOfRSI(5)
);

color_candles(for_every(summaryScores, score => COLOR_BY_SCORE[score]));

register_signal(summaryScores.map(value => value === 3), 'Surely Overbought');
register_signal(summaryScores.map(value => value === 2), 'Probably Overbought');