The way it looks is easy.
The code eventually looked like this. Discerning eyes may note differences between the one at Daily Coding and here. I made the constructor a little more useful, taking in the interval and callback. I also renamed it, because heaven forbid I actually keep the term Timer.
(In the above code, the slide.elements refer to a getElementById item, and util.addClass and util.removeClass functions add and remove classes, and maxWidth and importantMax are defined elsewhere.)
Anyway, what happens in the above is that the line chart is masked off by the CSS. Once the animateChart method is called, the mask’s width grows and grows until the full line chart is revealed. The timer is used to call an update method on whatever numbers will be updated. By pointing object.tick to the function object you want to run, and setting the interval, it will run as often as you like. The version I used (such a fan of setTimeout I am) wasn’t producing the desired results, so thank you, Daily Coding, for the much-needed help.
(It’s not that daily!)