The Detrended Ehlers Leading Indicator(DELI) was authored by Jon Ehlers (See “MESA and Trading Market Cycles” by John Ehlers).
Detrended Synthetic Price is a function that is in phase with the dominant cycle of real price data. This one is computed by subtracting a 3 pole Butterworth filter from a 2 Pole Butterworth filter. Ehlers Leading Indicator gives an advanced indication of a cyclic turning point. It is computed by subtracting the simple moving average of the detrended synthetic price from the detrended synthetic price.
According to period lenght, this indicator can be useful to predict turning point in price.
//Detrended Ehlers Leading Indicator
//by AlexF
//period=14
if high>high[1] then
prevhigh=high
endif
if low<low[1] then
prevlow=low
endif
price=(prevhigh+prevlow)/2
if barindex>2 then
alpha=2/(period+1)
else
alpha=.67
endif
alpha2=alpha/2
ema1=(alpha*price)+((1-alpha)*Ema1)
ema2=((alpha2)*price)+((1-alpha2)*Ema2)
dsp=ema1-ema2
temp=(alpha*dsp)+((1-alpha)*temp)
deli=dsp-temp
return deli as "DELI", 0 as "ZERO"