.1 is for n-1 item, .2 is for n-2 item. So as an example, P1.2 is the first P1 assigned, the next bar is above so P1.1 and the next one is above too so P1.0 That's for me to remember how many repeated same volume elements have occured in a row. If in my MdMp I come to P1.0 (and there is no acc) I know it's the third one and the Ac scene is set. If I came to P1.1 I know there were only two P1s and then the PP3 scene is set. And so on. It's for remembering how many peaks/troughs of the same nature have occured so that some EE can / can't be encountered forward. The idea to label it this way came from using the PP's board requirements.
I have programmed quite a bit of this stuff (in SierraChart) This is an "ok" starting point, BUT, once you start factoring in Waits (allowable in certain EE's), Lats(which allow/disallow certain EE's), acceleration and fanning (which create "NEW" IDs) and in my experience, getting through the C-band and above EE's, you will probably find your starting point to be too fixed on the "occurred in a row" factor. Unfortunately, I don't have an alternative analog starting point for you. Sometime ago, on a different JH related topic I joked about bit-twiddling. Recently I think it was Sprout that posted something about bit-math. I mention because bit-twiddling/bit-math is the route I took to provide the flexibility needed for more accurately tracking VTP and coding EEs. I mention merely as a heads up... mindmaps are cool, until they are not.
Now that I think about it there is a site... https://www.pearltrees.com/ It is a mindmap that I think COULD handle JH stuff! But since I am a social-media recluse, and pearltrees content (last I checked) was public and could not be made private, it went by the wayside for me. I think since then, they added some paid accounts that have more control.
n-1 is lookback. 0th, 1st, 2nd, 3rd etc. bar index is lookforward. I think the latter bar by bar scheme would make more sense for encompassing all possibilities.
Depends on software implementation. Search on jack hershey Haskell In https://www.elitetrader.com/et/threads/sctlearning-from-scratch.282221/page-2 Workwithus posted an image, @tiddlywinks also posted code for Sierra chart that uses the convention:
Tiny Aha : by following the 5min timeframe, one can deduce at the end of each 5min bar, the sent of the corresponding 30min including it. I'll do my log incorporating it now. It sticks more to real-time datas and makes the log already more "realistic".