Factorie is a toolkit for developing probabilistic modeling. It is scalable and flexible and allows you to create factor graphs and perform inference. It is written by Andrew Mccallum and his research group at UMass. They previously written Mallet, the java package for text mining. I found that being written in Scala made the code very succinct and clear. You can learn more from its google project page. Prompted by setup questions on the mailing list, I decided to write a quick guide to using Factorie on a mac osx.

Start with cloning the source code:
hg clone https://factorie.googlecode.com/hg/ factorie

Factorie uses maven to manage its build and dependenices. It is an open source package from apache so download it and learn a little how it works.
Compile the code into a jar:
cd factorie
mvn install

This will create a factorie jar file in target/factorie*.jar and install it into your local maven repo. (most likely ~/.m2)

Now that you have factorie jar in your maven repo, clone a sample factorie project:
git clone git@github.com:tc/factorie-example.git

In the factorie-example directory, you’ll notice a pom.xml. Inside the file, you’ll see:

You may have to change the version to match the updated factorie jar version.

This sample project has two files:
src/main/scala/factorie/LDAExample.scala
src/main/scala/factorie/LDAExampleTest.scala

It’s good practice to have a unit test for your code. In this case, the unit test is trivial as it just runs the scala class, but ideally you have some type of assert you want to perform.

Compile and run it using:
mvn test

You should see an output of listed topics:
.....Iteration 20
alpha = 0.7897046248435047 1.083615490115922 1.3493645028398928 0.8200016581775706 1.1115652808961307 1.7646165019929618 2.0397615066201604 1.8106654639049065 1.75947360834168 1.2876416992683335
Topic 0 china science achieved contacts powerful power urbana find faster projects
Topic 1 computing performance list chinese gropp problems smith years today tennessee
Topic 2 service stephen full messages members data twitter contacts services plenty
Topic 3 world erica announcement computer floating components center states couldn fastest
Topic 4 jaguar point ogg year high benchmark speed supercomputers community time
Topic 5 itunes features print mac kessler suggests back challenge tomorrow tuesday
Topic 6 mail facebook google shankland people address big reach ability aol
Topic 7 system news university tianhe top topher national called supercomputing font
Topic 8 apple share supercomputer systems operations machine company based released place
Topic 9 gmail cnet software digg supercomputing social comments technology expected linpack

Be sure to look into src/main/scala/cc/factorie/example directory in the factorie source code for more examples.

If you use an IDE like Eclipse or Intelij IdeaX, type:
mvn eclipse:eclipse
or
mvn idea:idea
to generate the IDE project files.

Additionally, you can just edit using VIM or Emacs and compile using maven.