ellipse() with 3 arguments or circle()?

[shiffman]

Almost all of the objects in the book are drawn with ellipse(). As I am going through I am removing the 4th argument since p5 supports 3 arguments (x, y, diameter) for ellipse(). I could also consider using the new-ish circle() method.

This issue is both a question as well as a reminder to do a global pass over the book for consistency with whatever decision is reached.