/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.cf.taste.impl.recommender;
import org.apache.mahout.cf.taste.impl.TasteTestCase;
import org.apache.mahout.cf.taste.recommender.IDRescorer;
import org.junit.Test;
/** <p>Tests {@link NullRescorer}.</p> */
public final class NullRescorerTest extends TasteTestCase {
@Test
public void testItemRescorer() throws Exception {
IDRescorer rescorer = NullRescorer.getItemInstance();
assertNotNull(rescorer);
assertEquals(1.0, rescorer.rescore(1L, 1.0), EPSILON);
assertEquals(1.0, rescorer.rescore(0L, 1.0), EPSILON);
assertEquals(0.0, rescorer.rescore(1L, 0.0), EPSILON);
assertTrue(Double.isNaN(rescorer.rescore(1L, Double.NaN)));
}
@Test
public void testUserRescorer() throws Exception {
IDRescorer rescorer = NullRescorer.getUserInstance();
assertNotNull(rescorer);
assertEquals(1.0, rescorer.rescore(1L, 1.0), EPSILON);
assertEquals(1.0, rescorer.rescore(0L, 1.0), EPSILON);
assertEquals(0.0, rescorer.rescore(1L, 0.0), EPSILON);
assertTrue(Double.isNaN(rescorer.rescore(1L, Double.NaN)));
}
}