Out of curiosity I implemented the different integration methods Luc had shown as functions and compared their results to the result of the trapezoid integration.
Apart from the spline interpolation Lucs methods work best if the values in abscissa vector X are (nearly, mostly) equidistant.
Worksheet in MC11 format (so Luc can make his own tries with the original data) attached.
Thanks hugely for the help to all of you guys, it's much appreciated - lots of learning tips and useful knowledge for the future.
I understand the maths and engineering behind what I'm trying to do with MathCAD, but have never really been strong in the programming / logic loop mindset. One day I think I'll have it nailed the approach in my mind and then when I come back a few months later to solve a similar problem I've forgotten it again. It's a good thing that this community is here to help!
Most of the time I end up eventually solving my own problems in MathCAD, just not in an elegant or particularly mathematically efficient way.....
Hmm, here a 8388 x 2 matrix is defined, obviously using "Insert-Data-Table".
Looks like this convenient feature which enables to include huge data in the worksheet by copy and paste is not available in MC11!? Can't remember as its too long ago that I used MC11 (and unfortunately missed to register the software for a virtual machine).