turtle donchian channel tradingview

//@version=4
study("Turtle Donchian Channel", overlay=true)
long = 20, short = 10
upper = highest(high[1], long)
lower = lowest(low[1], short)
long_signal = high >= upper
short_signal = low <= lower
plot(upper, color=color.purple, linewidth=2, transp=20)
plot(lower, color=color.yellow, linewidth=2, transp=20)
plotshape(long_signal, style=shape.triangleup, location=location.abovebar, color=color.green)
plotshape(short_signal, style=shape.triangledown, location=location.belowbar, color=color.red)