No, that is a separate task
. The problem I had was in finding the right equations for the fan lines - while 'straight lines' on the chart they were not a 'linear' function wrt weight/index on my chart, but, as I say, I found a reasonable fit having located the origin and various slopes - certainly good enough for the accuracy of the trim wheels!
I am embarrassed/proud (delete as applicable) to say that my aero-eng degree maths module was coming to a close 50 years ago, and despite many wet and windy days at KEF beavering away at the problem in later days I never quite got the hang of Trim=
ƒ(Wt,Index) - if indeed I ever had 'the hang of it'.................
If you can guide me through the process of establishing the formulae I would be interested - PM probably best so as not to bore all here. I have no doubt it will be a 'doh!' moment - as much of the 50 year old times were