Random Forest Classifiers as a Web Service in PHP

Recently, I found myself wanting to be able to make real-time, online predictions using a random forest classifier trained in R. Of course, there are many ways to make that happen – I could have used yhat’s ScienceOps product, for example. But, for project-specific reasons, I decided that the best route to go in this case was to get my hands dirty and build my own RESTful API for making predictions using my model.

Apparently, back in 2011, Disney debuted a show called "So Random." Thankfully, it only ran for a single season...

Apparently, back in 2011, Disney debuted a show called “So Random.” Thankfully, it only ran for a single season…

In this post, we’ll walk through all of the code necessary to export a random forest classifier from R and use it to make real-time online predictions in a PHP script.

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Map Addresses for Free with the Census Geocoding API

Looking for a free geocoding solution and frustrated by the lack of options?

Though it’s poorly publicized (and documented), the US Census Bureau maintains a RESTful API for real-time and batch geocoding that’s free, fast, and accurate. It doesn’t even require an API key. Essentially, it’s everything you’d get out of a roll-your-own PostGIS Census/TIGER solution, without the hassle of having to set it up.

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Buildings are related to Geocoding, right?
Image Credit: Diego Delso [CC BY-SA 3.0], via Wikimedia Commons

The only limitation is that the API mainly provides geocoding for residential addresses. Because the Census Bureau’s primary task is, well, conducting the national census, they’re a lot more interested in where people live than where they work. So, if you need to map business addresses, you may have to go elsewhere. But if you’re mapping customers (or students, or volunteers, or mailing list recipients, or whatever), the service is pretty on-point. In my work, I’ve seen about a 90% match rate for customer addresses when submitted to Census. Not too shabby.

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