I must admit, I’ve been extremely lazy about reading Visualizing Data or even updating this blog… but, this post should make up for it.

Earlier this week I skimmed a WSJ blog and article on the Case-Shiller Home Price Index and thought to myself “time for a graph!”

For the uninitiated, Case-Shiller tracks home prices in 20 metro areas. As WSJ states, “[the index has] a base value of 100 in January 2000. So a current index value of 150 translates to a 50% appreciation rate since January 2000 for a typical home located within the metro market.”

This program graphs the history of each city’s home price index. Not satisfied with just a plain-old graph, I added some aesthetic and functional features. The 20-city composite is shown for reference. Moving the mouse over the graph will highlight and display the index for a given point in time. Clicking the mouse will advance to another city.

Oops, your browser does not have a Java Plug-in. Get the latest Java Plug-in here. Or, if you have Java but can’t use the Plug-in, feel free to download the program as an executable jar. Here’s a screen shot of what you’re missing.

The graph’s data comes from a static CSV which I slightly hand-modified from the original XLS spreadsheet.

It’s interesting the number of little things I find missing or bothersome. For example, I’d like to use curveVertex() instead of vertex() for a smoother line curve, but by nature it doesn’t display the first and last data points. Fortunately there are enough data points and few large jumps/drops so the graph does not appear jagged. I could go on…

Taking a break from the book and making something useful has been fun.

The original points are numbered, one through six, but are not listed in any particular order.  Were I to give them an order based on importance, they would be arranged as follows.

1. Are you toxic?
2. Can you learn?  Can you solve problems?
3. Critical thinking.  Can you change?
4. Technical knowledge.

Ok, I cheated; it’s hard to put them in an absolute order.  All are important and relate to each other in some manner.  All software developers — and managers thereof — should read the original!