NYT Health's ongoing series on breast cancer afforded another chance to work on a graphic with Hannah Fairfield and Karen Yourish. Having determined mortality rates from 1975 to present using data from the National Cancer Institute, we charted the difference in deaths between black and white women over that period.
After sketching a variety of ideas in code, I put together a prototype with line charts animated in parallel that became the basis of the final piece. Getting the fills between the lines to reflect the appropriate trends was a lot easier once I'd seen this example of difference charts.
Using the same approach to building reusable components outlined in my 2013 NICAR talk made it much easier to work with small multiples – a natural choice for adaptive formatting as they reflow so easily on phones and tablets.
There is also a great tutorial on how to produce these kinds of graphics available on Flowing Data.