[RS]Hull Bands V0

//@version=2
study(title='[RS]Hull Bands V0', shorttitle='HB', overlay=true)
length = input(2)
f_hull(_mode, _src, _length)=>
    _base_0 = ema(_src, _length)
    _base_1 = ema(_base_0, _length*2)
    _base_2 = ema(_base_1, _length*3)
    _base_3 = ema(_base_2, _length*4)
    _return = _mode > 0 ? max(high, max(_base_0, max(_base_1, max(_base_2, _base_3)))) : min(low, min(_base_0, min(_base_1, min(_base_2, _base_3))))

top = f_hull(+1, high, length)
bot = f_hull(-1, low, length)
plot(top, color=maroon, linewidth=2)
plot(bot, color=green, linewidth=2)
plot(avg(bot, top), color=black)