mllib/clustering/JavaBisectingKMeansSuite.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.mllib.clustering;
0019
0020 import java.util.Arrays;
0021
0022 import org.junit.Assert;
0023 import org.junit.Test;
0024
0025 import org.apache.spark.SharedSparkSession;
0026 import org.apache.spark.api.java.JavaRDD;
0027 import org.apache.spark.mllib.linalg.Vector;
0028 import org.apache.spark.mllib.linalg.Vectors;
0029
0030 public class JavaBisectingKMeansSuite extends SharedSparkSession {
0031
0032   @Test
0033   public void twoDimensionalData() {
0034     JavaRDD<Vector> points = jsc.parallelize(Arrays.asList(
0035       Vectors.dense(4, -1),
0036       Vectors.dense(4, 1),
0037       Vectors.sparse(2, new int[]{0}, new double[]{1.0})
0038     ), 2);
0039
0040     BisectingKMeans bkm = new BisectingKMeans()
0041       .setK(4)
0042       .setMaxIterations(2)
0043       .setSeed(1L);
0044     BisectingKMeansModel model = bkm.run(points);
0045     Assert.assertEquals(3, model.k());
0046     Assert.assertArrayEquals(new double[]{3.0, 0.0}, model.root().center().toArray(), 1e-12);
0047     for (ClusteringTreeNode child : model.root().children()) {
0048       double[] center = child.center().toArray();
0049       if (center[0] > 2) {
0050         Assert.assertEquals(2, child.size());
0051         Assert.assertArrayEquals(new double[]{4.0, 0.0}, center, 1e-12);
0052       } else {
0053         Assert.assertEquals(1, child.size());
0054         Assert.assertArrayEquals(new double[]{1.0, 0.0}, center, 1e-12);
0055       }
0056     }
0057   }
0058 }