On Wed, May 15, 2013 at 9:58 AM, Adrian May <adrian.alexander.may@gmail.com> wrote:

The list indices ati and bti are used only once: to retrieve the (first) item matching the predicate. Might Data.List.find be a better fit?

No, I use them via t1 and t2 to figure out which row to put the squiggle on. The attached picture might put it all in perspective.

D'oh. Didn't see the later references, sorry.

Something to think about is: how would you document "my coordinate system" as you wrote in your comment? Highly visual things like these are challenging to describe even for verbal-thinking types.

Probably sticking the picture in png/pdf format and linking to it in the comments is a good a solution as any.

-- Kim-Ee