Well, I found something more relevant for the formula :
Current ATR = [(Prior ATR x 13) + Current TR] / 14
- Multiply the previous 14-day ATR by 13.
- Add the most recent day's TR value.
- Divide the total by 14
So here is the ATR formula to compute the Daily timeframe to be used in any other timeframe.
period = 14
//True range calculation
d1 = Dhigh(0)-Dlow(0)
d2 = abs(Dhigh(0)-Dclose(1))
d3 = abs(Dlow(0)-Dclose(1))
dailyTR =max(d1,max(d2,d3))
c = exponentialaverage[period](dailyTR)
RETURN c as "Daily Timeframe ATR"
Which return the good result in daily timeframe, same as the embedded ATR of the platform (look at picture attached). But a slightly different one when in inferior timeframe. Don’t know really why for the moment..
Thanks Nicolas, thats great 🙂