This map uses data() to load the data and so I also use enter(). I didn’t, however, use exit(). Not sure if this is bad form or not really necessary, or could me necessary if I was doing some other kind of data loading….
Anyways if you click on a given city (the circles) the name should be printed to your javascript console. Also the bigger circles are cities in Brazil w/ more than 100,000 people. Looks like there are a lot more big cities in Brazil than I had thought…. 123 according to the population stats w/ Natural Earth’s populated places dataset.
I think I also want the amazon in my next map so I have to get to making that dataset.