You might remember back in 2015 when Gregor Aisch and Amanda Cox at the New York Times’ published their 3D yield curve graphic. It’s one of the rare examples of a three-dimensional technique used well in data visualization.
I distinctly remember sitting on the bus on my way to work wondering why everyone in my Twitter feed was glowing about this 3D contour map. On my mobile phone, it was a simple stepper with different static views of the data. But when I got to the office and opened it on my desktop, I discovered you could rotate and play around with the visual. And with daily data for 11 different yield curve rates over 26 years, we’re talking about more than 100,00 data points, so it was a really cool way to interact with the data.
Now, seven years later, I was curious about what the data look like now. Inflation was historically high this year and the economy was up and down, so I was curious what the trends look like. Turns out that many of the yield rates are back to Great Recession levels—the one-year rate is 4.77% this week, which, before this fall, we haven’t seen since the summer of 2007.
Now, I’m no Gregor or Amanda, so I wasn’t going to be able to code this up in JavaScript. In fact, getting the data from the Treasury Department website was a bit beyond my skillset, so I asked my colleague Alena Stern to help on that end.
Excel has a lot of bad 3D graph types and I’ve never had a reason to use the 3D contour map, so this was kind of fun. There were three considerations:
- First, Excel couldn’t really handle the 250,000+ observations, so I used an AVERAGEIF formula to condense the data down to quarters.
- Second, changing the colors in the contour map is a bit of a pain. You can’t do it the same as you would with a bar or line chart. First, I created a new blue color palette ramp from the original NYT graph using the Coolors palette tool. Then, I turned on the graph legend and manually changed each of the nine categories to the colors in my color palette.
- Third, I had to play around with the various rotation dimensions to align it the way I wanted. Ideally, I would have made it a bit wider, but that would have required making the entire graph too big.
So, yeah, pretty fun. I’m generally not a fan of 3D graphs, but—certainly in the originally interactive version—this one works pretty well.
If you’d like to play around with the data or the graph, you can grab my Excel file right here.
If you’d like to learn more Excel tricks and tips, check out my YouTube channel.
