I've used Processing for some remedial sketches, and was hoping to get into animation. I found Ani, which appears quite simple and useful. However, when I begin to dive into the more complicated sketches, I get lost. 

Essentially, I want to create a sketch with multiple rows of elements that animate along one axis. So, let's say there's two rows, of two elements*, I'd like these elements to be on the canvas side-by-side, and to move to a random x position on click while retaining their y position.

I found this thread which recommended I look at the  "Ani_in_Classes" sketch, but I'm afraid it's over my head. For instance I'm getting confused by what's controlling the radius, and why this appears (to me) to be an essential part of the sketch.

Any help is really appreciated in this matter. Thanks!

*More specifically, I'd like to load text or images, and have them move along one axis, and maybe within a range along the other. Ideally they'd return to their initial position after a period of time, but if I could get the basics done that would be fantastic.