(Originally posted on Doug's MATLAB Video Tutorials blog.)

I am blogging a little early this week because of the holiday. What holiday would that be? Square Root Day- 03/03/09. What makes this a particularly special event is that today's video is number 144 (12^2) and I recorded it just minutes ago. Posted at 1:44 local time too! This kind of coincidence can not be ignored! When I first thought of this video, I figured it would take three videos to solve the problem. When I actually sat down to read data from the web and interactively filter it, I was happy to see it could be done so quickly and easily. Basically, the procedure is to read data from Many Eyes, then plot that Census data and filter it for city size. We will use URLREAD and TEXTSCAN to bring the data in and then interactive cell mode and plot to filter and visualize it.