Iterated Function System

There is a type of fractal called an iterated function system (IFS) that applies a 'function' to your 'system' then applies the function again and again to the output (iterates). I tried this for trochoids and below is one of the creations. In this case the system is the sequence of circles comprising the trochoid (a circle being 2 numbers, radius and frequency). The function is a list of simple functions. The simple functions...well, I'll show how it works sometime, it's difficult to explain.

As I was hoping, the trochoids are somewhat fractalish in being self similar. I couldn't find my favorite example though; it looked just like a (slightly bulged) Sierpinski Triangle. I should be able to remake it sometime....