Mapping Hacks

Automatically Geocode U.S. Addresses #80

Chapter 7, Names and Places

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HACK

HACK

#80

Automatically Geocode U.S. Addresses Hack #80

Use the geocoder.us web services to geocode batches of address

In “Geocode a U.S. Street Address” [Hack #79], you saw how easy it is to geo-

code an individual address. But what about a whole database of addresses?

What about geocoding addresses as people enter them into a web form? You

don’t need to webscrape http://geocoder.us/! There are three different web-

service interfaces. geocoder.us supports XML-RPC and a lightweight REST-

ful interface. There is also an embryonic SOAP interface (for more informa-

tion and a code sample, consult the geocoder.us web site).

A web service is a way for a program to communicate with another program

over the Web. In this case, it is as though you had a magical assistant enter-

ing addresses into the geocoder.us site and returning the resulting coordi-

nates in your program.

Except this assistant is itself a program, and it is optimized to get just the

information that you need and return that information to your program. An

example is “Caffeinated and Unstrung: A Guide to Seattle’s Free Wireless

Coffee Shops” (http://seattle.wifimug.org), created by Kellan Elliot-McCrea.

You can go to the site, select the “Search Nearby” option, enter your

address, and find a spot that provides both coffee and a wireless connec-

tion. At first glance, ...