Finally finished. Question: I see I can inspect the canvas element and even edit the code. How do I run it with my edits (without pushing it to a server?)
Thanks for the easy-to-follow instructions. I could quickly come up with an updated, less-likely-to-bore version ( http://bl.ocks.org/mdengler/a36fac5f10098bb94846 ), and included a version of your instructions and link to your comment.