lenskit eval - run an offline evaluation of recommender behavior and performance.




The eval command runs a LensKit evaluation script to measure the behavior and performance (such as recommendation or prediction accuracy) of one or more recommender algorithms.

Evaluation scripts are written in Groovy, using an embedded domain-specific language for describing LensKit evaluations. This is documented more in the LensKit manual; there is a link in See Also.

The lenskit eval subcommand serves the same purpose as the now-deprecated lenskit-eval command, with slightly different invocation syntax. Use lenskit eval in new scripts and experiments.


Run the target TARGET in the evaluation script. If no targets are specified on the command line, the script is run (which is sufficient for scripts that do not use targets), or the default target specified by the script is run.
Show usage help.
Load evaluation script SCRIPT. The default is eval.groovy.
-j N, –thread-count N
Use up to N threads for parallelizable portions of the evaluation.
-F, –force
Force eval tasks to re-run, even if they detect that their outputs are up-to-date. Not all tasks do up-to-date checking.

This command also takes the standard script environment options.

See Also

Project Information

This command is a part of LensKit, an open source recommender systems toolkit developed by GroupLens Research. Copyright 2010-2014 Regents of the University of Minnesota and 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.