So far Functy has worked only using Cartesian co-ordinates, but I’m currently working on code for the next release to allow functions to be defined using spherical co-ordinates too.
Spherical function plotting is already working as you can see in the screenshot. It seems to produce some nice effects that are quite different from those you generally get using Cartesian functions.
The tricky part seems to be getting the code for both co-ordinate types integrated nicely together, and also sorting out a suitable user interface to allow them both to be added seamlessly.
The reason the code is turning out to be tricky is that I’m trying to develop using object oriented techniques, but using C rather than C++. I know it’s perfectly possible to do this (and do it well; although not necessarily by me!), and so far there hasn’t been much problem. However, I’m now in a situation where inheritance would seem to be the perfect technique to use. Most of the methods needed for the two co-ordinate systems are the same, so in C++ it would make sense to use some virtual interfaces to define them and inherit these from a generic function type. Unfortunately I’m not sure if this is going to work well in C.
It seems like a silly thing to get stuck on and it would be nice to get the spherical functionality into the next build. I’m hoping the best method will become clearer as things progress.