NB: Article author here. Interesting idea with Simpson's rule! Perhaps we'll add another method... The other approach is very similar to the LOCF (last observ

NB: Article author here. Interesting idea with Simpson's rule! Perhaps we'll add another method... The other approach is very similar to the LOCF (last observation carried forward) approach, except that it uses the distance to the next sample instead of distance to the previous. I'm sure there are reasons to do the other way, but for most things that use LOCF they record when the value changes so it makes more sense to carry it forward. And it works pretty well as well. These are all also other integral approximation techniques, and which to use probably depends mostly on use case.