Hey Mitch Christow,
You’re welcome!
I completely forgot this (ugly) implementation and I also forgot the math behind.
From a first sight of the formulas, there is no period, just the factor variable. And for the first actualL formula the factor range is [0, 1]. Seems the factor fulfills the same role as the alpha parameter in an exponential moving average. If so, the higher the factor, the smoother the indicator.
But I’m not sure how to transformation the factor into period.
Respect to the lookback you mention, are you sure they mean the indicator parameter?
Best
JJD