/*
* LensKit, an open source recommender systems toolkit.
* Copyright 2010-2014 LensKit Contributors. See CONTRIBUTORS.md.
* 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.
*/
package org.grouplens.lenskit.slopeone;
import org.grouplens.lenskit.ItemScorer;
import org.grouplens.lenskit.RatingPredictor;
import org.grouplens.lenskit.Recommender;
import org.grouplens.lenskit.RecommenderBuildException;
import org.grouplens.lenskit.baseline.BaselineScorer;
import org.grouplens.lenskit.baseline.ItemMeanRatingItemScorer;
import org.grouplens.lenskit.baseline.UserMeanBaseline;
import org.grouplens.lenskit.baseline.UserMeanItemScorer;
import org.grouplens.lenskit.basic.SimpleRatingPredictor;
import org.grouplens.lenskit.basic.TopNItemRecommender;
import org.grouplens.lenskit.core.LenskitConfiguration;
import org.grouplens.lenskit.core.LenskitRecommender;
import org.grouplens.lenskit.core.LenskitRecommenderEngine;
import org.grouplens.lenskit.data.dao.EventCollectionDAO;
import org.grouplens.lenskit.data.dao.EventDAO;
import org.grouplens.lenskit.data.event.Rating;
import org.grouplens.lenskit.data.event.Ratings;
import org.grouplens.lenskit.data.pref.PreferenceDomain;
import org.junit.Before;
import org.junit.Test;
import java.util.ArrayList;
import java.util.List;
import static org.hamcrest.Matchers.*;
import static org.junit.Assert.assertThat;
public class SlopeOneItemRecommenderTest {
private LenskitRecommenderEngine engine;
@SuppressWarnings("deprecation")
@Before
public void setup() throws RecommenderBuildException {
List<Rating> rs = new ArrayList<Rating>();
rs.add(Ratings.make(1, 5, 2));
rs.add(Ratings.make(1, 7, 4));
rs.add(Ratings.make(8, 4, 5));
rs.add(Ratings.make(8, 5, 4));
EventDAO dao = new EventCollectionDAO(rs);
LenskitConfiguration config = new LenskitConfiguration();
config.bind(EventDAO.class).to(dao);
config.bind(ItemScorer.class).to(SlopeOneItemScorer.class);
config.bind(PreferenceDomain.class).to(new PreferenceDomain(1, 5));
// factory.setComponent(UserVectorNormalizer.class, IdentityVectorNormalizer.class);
config.bind(BaselineScorer.class, ItemScorer.class)
.to(UserMeanItemScorer.class);
config.bind(UserMeanBaseline.class, ItemScorer.class)
.to(ItemMeanRatingItemScorer.class);
engine = LenskitRecommenderEngine.build(config);
}
@SuppressWarnings("deprecation")
@Test
public void testSlopeOneRecommenderEngineCreate() {
Recommender rec = engine.createRecommender();
assertThat(rec.getItemScorer(),
instanceOf(SlopeOneItemScorer.class));
RatingPredictor rp = rec.getRatingPredictor();
assertThat(rp, instanceOf(SimpleRatingPredictor.class));
assertThat(((SimpleRatingPredictor) rp).getScorer(),
sameInstance(rec.getItemScorer()));
assertThat(rec.getItemRecommender(),
instanceOf(TopNItemRecommender.class));
}
@Test
public void testConfigSeparation() {
LenskitRecommender rec1 = null;
LenskitRecommender rec2 = null;
rec1 = engine.createRecommender();
rec2 = engine.createRecommender();
assertThat(rec1.getItemScorer(),
not(sameInstance(rec2.getItemScorer())));
assertThat(rec1.get(SlopeOneModel.class),
allOf(not(nullValue()),
sameInstance(rec2.get(SlopeOneModel.class))));
}
}