content: /*
   * 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.spark.mllib.clustering;
  
  import com.google.common.collect.Lists;
  
  import org.junit.Assert;
  import org.junit.Test;
  
  import org.apache.spark.SharedSparkSession;
  import org.apache.spark.api.java.JavaRDD;
  import org.apache.spark.mllib.linalg.Vector;
  import org.apache.spark.mllib.linalg.Vectors;
  
  public class JavaBisectingKMeansSuite extends SharedSparkSession {
  
    @Test
    public void twoDimensionalData() {
      JavaRDD<Vector> points = jsc.parallelize(Lists.newArrayList(
        Vectors.dense(4, -1),
        Vectors.dense(4, 1),
        Vectors.sparse(2, new int[]{0}, new double[]{1.0})
      ), 2);
  
      BisectingKMeans bkm = new BisectingKMeans()
        .setK(4)
        .setMaxIterations(2)
        .setSeed(1L);
      BisectingKMeansModel model = bkm.run(points);
      Assert.assertEquals(3, model.k());
      Assert.assertArrayEquals(new double[]{3.0, 0.0}, model.root().center().toArray(), 1e-12);
      for (ClusteringTreeNode child : model.root().children()) {
        double[] center = child.center().toArray();
        if (center[0] > 2) {
          Assert.assertEquals(2, child.size());
          Assert.assertArrayEquals(new double[]{4.0, 0.0}, center, 1e-12);
        } else {
          Assert.assertEquals(1, child.size());
          Assert.assertArrayEquals(new double[]{1.0, 0.0}, center, 1e-12);
        }
      }
    }
  }
  