I read this website : http://lenskit.org/documentation/evaluator/quickstart/ I first tried to run it using the script " $ lenskit eval " and I just created a new groovy file in my hello-lenskit example and run it using the command line but nothing happened. Then I tried to use it in Java program(hello-lenskit.java). I run into some errors.
File dataFile = new File("ml-100k/u.data");
PreferenceDomain domain = new PreferenceDomain(1.0,5.0,1.0);
DataSource data = new CSVDataSource("ml-100k",dataFile,"\t",domain);//give me an error CSVDataSource is not public and can not be accessed from the outside package.
CrossfoldTask cross = new CrossfoldTask();
LenskitConfiguration config1 = new LenskitConfiguration();
config1.bind(ItemScorer.class)
.to(UserMeanItemScorer.class);
AlgorithmInstance alg1 = new AlgorithmInstance("PersMean",config1);
evl.addAlgorithm(alg1);
LenskitConfiguration config2 = new LenskitConfiguration();
config2.bind(ItemScorer.class)
.to(ItemItemScorer.class);
config2.bind(UserVectorNormalizer.class)
.to(BaselineSubtractingUserVectorNormalizer.class);
config2.within(UserVectorNormalizer.class)
.bind(BaselineScorer.class,ItemScorer.class)
.to(ItemMeanRatingItemScorer.class);
AlgorithmInstance alg2 = new AlgorithmInstance("ItemItem",config2);
evl.addAlgorithm(alg2);
evl.addMetric(RMSEPredictMetric.class);
File file = new File("eval-results.csv");
evl.setOutput(file);
What should I do next? How could I generate the overall rating error?
Using the LensKit evaluation commands manually is difficult, undocumented, and not recommended.
The SimpleEvaluator is the best way to get overall accuracy from a LensKit recommender in a Java application.
For further assistance in debugging LensKit runs, I recommend e-mailing the mailing list with exactly the commands you are running and the output or errors you are getting.