/**
* 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.neighborhood;
import org.apache.mahout.cf.taste.impl.TasteTestCase;
import org.apache.mahout.cf.taste.impl.model.GenericDataModel;
import org.apache.mahout.cf.taste.model.DataModel;
import org.apache.mahout.cf.taste.model.User;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
/**
* <p>Tests {@link NearestNUserNeighborhood}.</p>
*/
public final class NearestNNeighborhoodTest extends TasteTestCase {
public void testNeighborhood() throws Exception {
List<User> users = getMockUsers();
DataModel dataModel = new GenericDataModel(users);
Collection<User> neighborhood =
new NearestNUserNeighborhood(1, new DummySimilarity(), dataModel).getUserNeighborhood("test1");
assertNotNull(neighborhood);
assertEquals(1, neighborhood.size());
assertTrue(neighborhood.contains(users.get(1)));
Collection<User> neighborhood2 =
new NearestNUserNeighborhood(2, new DummySimilarity(), dataModel).getUserNeighborhood("test2");
assertNotNull(neighborhood2);
assertEquals(2, neighborhood2.size());
assertTrue(neighborhood2.contains(users.get(0)));
assertTrue(neighborhood2.contains(users.get(2)));
Collection<User> neighborhood3 =
new NearestNUserNeighborhood(4, new DummySimilarity(), dataModel).getUserNeighborhood("test4");
assertNotNull(neighborhood3);
assertEquals(3, neighborhood3.size());
assertTrue(neighborhood3.contains(users.get(0)));
assertTrue(neighborhood3.contains(users.get(1)));
assertTrue(neighborhood3.contains(users.get(2)));
}
public void testRefresh() throws Exception {
// Make sure this doesn't throw an exception
DataModel dataModel = new GenericDataModel(Collections.singletonList(getUser("test1", 0.1)));
new NearestNUserNeighborhood(1, new DummySimilarity(), dataModel).refresh(null);
}
}