001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.math.stat.clustering;
019
020 import static org.junit.Assert.assertEquals;
021 import static org.junit.Assert.assertTrue;
022
023 import java.util.ArrayList;
024 import java.util.List;
025
026 import org.apache.commons.math.TestUtils;
027 import org.junit.Test;
028
029 public class EuclideanIntegerPointTest {
030
031 @Test
032 public void testArrayIsReference() {
033 int[] array = { -3, -2, -1, 0, 1 };
034 assertTrue(array == new EuclideanIntegerPoint(array).getPoint());
035 }
036
037 @Test
038 public void testDistance() {
039 EuclideanIntegerPoint e1 = new EuclideanIntegerPoint(new int[] { -3, -2, -1, 0, 1 });
040 EuclideanIntegerPoint e2 = new EuclideanIntegerPoint(new int[] { 1, 0, -1, 1, 1 });
041 assertEquals(Math.sqrt(21.0), e1.distanceFrom(e2), 1.0e-15);
042 assertEquals(0.0, e1.distanceFrom(e1), 1.0e-15);
043 assertEquals(0.0, e2.distanceFrom(e2), 1.0e-15);
044 }
045
046 @Test
047 public void testCentroid() {
048 List<EuclideanIntegerPoint> list = new ArrayList<EuclideanIntegerPoint>();
049 list.add(new EuclideanIntegerPoint(new int[] { 1, 3 }));
050 list.add(new EuclideanIntegerPoint(new int[] { 2, 2 }));
051 list.add(new EuclideanIntegerPoint(new int[] { 3, 3 }));
052 list.add(new EuclideanIntegerPoint(new int[] { 2, 4 }));
053 EuclideanIntegerPoint c = list.get(0).centroidOf(list);
054 assertEquals(2, c.getPoint()[0]);
055 assertEquals(3, c.getPoint()[1]);
056 }
057
058 @Test
059 public void testSerial() {
060 EuclideanIntegerPoint p = new EuclideanIntegerPoint(new int[] { -3, -2, -1, 0, 1 });
061 assertEquals(p, TestUtils.serializeAndRecover(p));
062 }
063
064 }