Fractal Adaptive Moving Average [TradingView]

//
// @author LazyBear
//
study(title = "Fractal Adaptive Moving Average [LazyBear]", shorttitle="FRAMA_LB", overlay=true)
length=input(16, title="Period of Fractal AMA (even #)",minval=4,maxval=60)
w=input(-4.6, title="W", type=float)
src=hl2
n3=(highest(high,length)-lowest(low,length))/length
hd2=highest(high,length/2)
ld2=lowest(low,length/2)
n2=(hd2-ld2)/(length/2)
n1=(nz(hd2[round(length/2)])-nz(ld2[round(length/2)]))/round(length/2)
dimen=(n1>0 and n2>0 and n3>0 ? (log(n1+n2)-log(n3))/log(2) : 0)
alpha=exp(w*(dimen-1))
sc=(alpha<.01 ? .01 : (alpha>1 ? 1 : alpha))
//prev(x) => not na(x[1]) ? x[1] : 0
frama=(cum(1)<=2*length ? src : src*sc+nz(frama[1])*(1-sc))
plot(frama, color=orange, linewidth=2)