Willy, original
study(title="Willams21EMA13", shorttitle="Willy21MA13") length = input(21, minval=1) upper = highest(length) lower = lowest(length) out = 100 * (close - upper) / (upper - lower) src = out, len = input(13, minval=1, title="Length") out2 = ema(out, len) plot(out, color = green) plot(out2, title="EMA", color=red) band1 = hline(-20) band0 = hline(-80) fill(band1, band0)