10.4. Example: clustering points on a map

Here’s the situation: your friend Drew wants you to take him out on the town for his birthday. A number of other friends are going to come also, so you need to provide a plan that everyone can follow. Drew has given you a list of places he wants to go. This list is long; it has 70 establishments in it. I included the list in a file called portland-Clubs.txt, which is packaged with the code. The list contains similar establishments in the greater Portland, Oregon, area.

Seventy places in one night! You decide the best strategy is to cluster these places together. You can arrange transportation to the cluster centers and then hit the places on foot. Drew’s list includes addresses, but addresses don’t give you a lot of information about how close two places are. What you need are the latitude and longitude. Then, you can cluster these places together and plan your trip.