/*
* 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.basic;
import org.grouplens.lenskit.ItemScorer;
import org.grouplens.lenskit.basic.PrecomputedItemScorer;
import org.grouplens.lenskit.vectors.MutableSparseVector;
import org.junit.Test;
import static org.grouplens.lenskit.util.test.ExtraMatchers.notANumber;
import static org.hamcrest.Matchers.closeTo;
import static org.hamcrest.Matchers.equalTo;
import static org.junit.Assert.assertThat;
public class PrecomputedItemScorerTest {
@Test
public void testEmptyScorer() {
ItemScorer scorer = PrecomputedItemScorer.newBuilder().build();
assertThat(scorer.score(42, 1),
notANumber());
}
@Test
public void testAddScore() {
ItemScorer scorer = PrecomputedItemScorer.newBuilder()
.addScore(42, 1, 4)
.build();
assertThat(scorer.score(42, 1),
closeTo(4, 1.0e-5));
assertThat(scorer.score(42, 2), notANumber());
assertThat(scorer.score(39, 1), notANumber());
}
@Test
public void testVectorScore() {
ItemScorer scorer = PrecomputedItemScorer.newBuilder()
.addScore(42, 1, 4)
.build();
MutableSparseVector msv = MutableSparseVector.create(1, 3);
scorer.score(42, msv);
assertThat(msv.containsKey(1), equalTo(true));
assertThat(msv.containsKey(3), equalTo(false));
assertThat(msv.get(1), closeTo(4, 1.0e-5));
}
@Test
public void testAddMultipleScores() {
ItemScorer scorer = PrecomputedItemScorer.newBuilder()
.addScore(42, 3, 4)
.addScore(42, 7, 2)
.build();
MutableSparseVector msv = MutableSparseVector.create(1, 3, 5, 7, 8);
scorer.score(42, msv);
assertThat(msv.keySet().size(), equalTo(2));
assertThat(msv.containsKey(1), equalTo(false));
assertThat(msv.containsKey(3), equalTo(true));
assertThat(msv.containsKey(5), equalTo(false));
assertThat(msv.containsKey(7), equalTo(true));
assertThat(msv.containsKey(8), equalTo(false));
assertThat(msv.get(3), closeTo(4, 1.0e-5));
assertThat(msv.get(7), closeTo(2, 1.0e-5));
scorer.score(5, msv);
assertThat(msv.keySet().isEmpty(), equalTo(true));
}
@Test
public void testAddScoreVector() {
MutableSparseVector uv = MutableSparseVector.create(2, 3, 5);
uv.set(2, 3);
uv.set(3, 4);
uv.set(5, 2);
ItemScorer scorer = PrecomputedItemScorer.newBuilder()
.addUser(3, uv)
.build();
MutableSparseVector output = MutableSparseVector.create(2, 3, 4, 5);
scorer.score(3, output);
assertThat(output, equalTo(uv));
}
}