/*
* 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.baseline;
import org.grouplens.lenskit.ItemScorer;
import org.grouplens.lenskit.collections.LongUtils;
import org.grouplens.lenskit.vectors.MutableSparseVector;
import org.grouplens.lenskit.vectors.SparseVector;
import org.junit.Test;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.contains;
import static org.hamcrest.Matchers.everyItem;
import static org.junit.Assert.assertThat;
/**
* @author <a href="http://www.grouplens.org">GroupLens Research</a>
*/
public class ConstantItemScorerTest {
@Test
public void testSingleScore() {
ItemScorer pred = new ConstantItemScorer(5);
assertThat(pred.score(5, 10), equalTo(5.0));
}
@Test
public void testScoreSet() {
ItemScorer pred = new ConstantItemScorer(5);
SparseVector v = pred.score(42, LongUtils.packedSet(1, 2, 3, 5, 7));
assertThat(v.keySet(), contains(1L, 2L, 3L, 5L, 7L));
assertThat(v.values(), everyItem(equalTo(5.0)));
}
@Test
public void testScoreVector() {
ItemScorer pred = new ConstantItemScorer(5);
MutableSparseVector v = MutableSparseVector.create(1, 2, 3, 5, 7);
pred.score(42, v);
assertThat(v.keySet(), contains(1L, 2L, 3L, 5L, 7L));
assertThat(v.values(), everyItem(equalTo(5.0)));
}
}