Willy

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)