LensKit

LensKit is an implementation of collaborative filtering algorithms and a set of tools for benchmarking them. This readme is about working with the LensKit source code. For more information about LensKit and its documentation, visit the web site or wiki. You can also find information on the wiki about how to use LensKit without downloading the source code. If this is your first time working with LensKit we recommend checking out the Getting Started guide.

LensKit is made available under the GNU Lesser General Public License (LGPL), version 2.1 or later.

Installation and Dependency Management

LensKit is built and deployed with Gradle and publishes its artifacts to Maven Central. To install it to the local Maven repository, making it available to other projects using standard Java-based tools, check out this repository and run ./gradlew install; it is then available to other projects by depending directly on it in your Maven, Gradle, Ivy, or SBT project. The source code can also be checked out and used in most Java IDEs.

Working with the Code

To work with the LensKit code, import the Gradle project into your IDE. Most modern Java IDEs include support for Gradle, including IntelliJ IDEA (used by most LensKit developers), Eclipse, and NetBeans.

No other particular setup is needed.

Modules

LensKit is comprised of several modules. The top-level lenskit module serves as a container to build them and provide common settings and dependencies. The other modules are as follows:

lenskit-api -- the common, public recommender API exposed by LensKit, independent of its actual implementations.
lenskit-test -- infrastructure and helper code for testing.
lenskit-core -- the core support code and configuration facilities for the rest of LensKit. It is the entry point for most of what you want to do with LensKit, providing support for configuring and building recommenders.
lenskit-knn -- k-NN recommenders (user-user and item-item collaborative filtering).
lenskit-svd -- the FunkSVD recommender (and eventually real SVD recommenders).
lenskit-slopeone -- Slope-One recommenders.
lenskit-eval -- the evaluation framework and APIs, along with a command line evaluation runner.
lenskit-groovy -- support for reading LensKit configurations from Groovy files.
lenskit-all -- a metapackage you can depend on to pull in the rest of the LensKit packages.
lenskit-cli -- the LensKit command line interface.
lenskit-gradle -- the Gradle plugin to script the LensKit evaluator
lenskit-integration-tests -- additional integration tests for LensKit.

Running the Tests

After you make changes, it's good to run the unit tests. You can run many of them from your IDE; run all tests in the org.grouplens.lenskit package (and subpackages) across all modules.

To run the full test suite, including data-driven unit tests and integration tests, use Gradle:

$ ./gradlew check

Copyright

LensKit is under the following copyright and license:

Copyright 2010-2016 LensKit Contributors.
Work on LensKit has been funded by the National Science Foundation under grants IIS 05-34939, 08-08692, 08-12148, and 10-17697.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Build System Copyright

To ease reuse, the LensKit build system (all .gradle files and the contents of the buildSrc directory) are licensed under the 3-clause BSD license:

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the University of Minnesota nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Contributing to LensKit

We welcome contribution to LensKit. If you are looking for something to work on, we recommend perusing the open tickets on GitHub or asking on the mailing list.

We prefer to receive code submissions as GitHub pull requests. To do this: