/*
* 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.transform.truncate;
import org.grouplens.lenskit.transform.threshold.RealThreshold;
import org.grouplens.lenskit.vectors.MutableSparseVector;
import org.grouplens.lenskit.vectors.VectorEntry;
import org.junit.Test;
import static org.hamcrest.Matchers.closeTo;
import static org.hamcrest.Matchers.equalTo;
import static org.junit.Assert.assertThat;
public class ThresholdTruncatorTest {
private static final double EPSILON = 1.0e-6;
@Test
public void testTruncate() {
long[] keys = {1, 2, 3, 4};
double[] values = {1.0, 2.0, 3.0, 4.0};
MutableSparseVector v = MutableSparseVector.wrap(keys, values);
VectorTruncator truncator = new ThresholdTruncator(new RealThreshold(3.5));
truncator.truncate(v);
int numSeen = 0;
for (VectorEntry e : v.view(VectorEntry.State.SET)) {
assertThat(e.getKey(), equalTo(4L));
assertThat(e.getValue(), closeTo(4.0, EPSILON));
numSeen++;
}
assertThat(numSeen, equalTo(1));
}
}