What are some good letters for variables when dealing with systems of ODEs?

Question

I have x for x-position. I can't exactly use it for the (x,y,z) position. And on top of that, I have the state vector which consists of position and attitude of a quadrotor. What are some good letter choices for representing these? Papers seem to enjoy using $\zeta$, but I cannot draw this on the whiteboard.

Answer 1

When I was an undergraduate, one lecturer's notation was explained to me as "zeta, squiggle and super-squiggle" - whatever he called the symbols, we could tell which was which.

The examiners' reports for the "STEP" tests now used as entrance tests by Cambridge University amongst others, regularly report that candidates make mistakes "because they can't read their own writing"

I had a mathematical friend at school who managed to make the letters "n" and "x" indistinguishable - at least to me - in his formulae (can you imagine ... )

The point about notation is simply that it should be clear and readily identifiable. There are conventional usages, of course, but if they are inconvenient or problematic, the names of variables don't matter so long as they are consistent.

I have a book (can't quite just remember which), which notes that there are more mathematical ideas than letters of the various alphabets used to represent them. Therefore - implicit suggestion - it is impossible to avoid all potential ambiguities.