When I joined Intelliware, we had a reading list. There was a stack of books that we were expected to read. Some of them were really interesting books. The Timeless Way of Building, and Microserfs. But I think my favourite was Tufte’s Visual Display of Quantitative Information. It’s a really interesting book, and although I’d heard of it in before I came to Intelliware, it was only when I got here that I was expected to read it.
One of the chapters in Visual Displayis about erasing lines. It’s actually a fascinating chapter, in that Tufte talks about something that seems boneheadedly simplistic and as he goes through the exercise of erasing lines, you get a good sense for how it really helps.
So, this rambling narrative is leading somewhere, of course. To DevCreek, a great repository of displaying quantitative information. I’ve set up some performance data collection in my application and I’m trying to look at the overall results of some performance profiling. And I want to erase lines. Consider the following picture:
This picture shows some performance numbers. Notice all the almost-vertical lines on the graphs? My data doesn’t really drop to zero at those data points; it’s just that there’s no measure at those moments. I don’t know if this is a limitation of JFreeChart, or if DevCreek is doing something wonky. But from the point of view of conveying quantitative information visually, it really obfuscates the more important performance numbers. I mean, the vertical lines are possibly the most attention grabbing element of the graph. And they’re just noise.
I’m very fond of some of the stuff that’s gone into DevCreek, lately, and I don’t want to sound like I’m criticizing it. But I thought this was an interesting real-life example of a cool concept from Tufte’s book.