VisualizerTest.java

/**
 * 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.classifier.df.tools;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import org.apache.mahout.classifier.df.DecisionForest;
import org.apache.mahout.classifier.df.builder.DecisionTreeBuilder;
import org.apache.mahout.classifier.df.data.Data;
import org.apache.mahout.classifier.df.data.DataLoader;
import org.apache.mahout.classifier.df.data.Dataset;
import org.apache.mahout.classifier.df.node.CategoricalNode;
import org.apache.mahout.classifier.df.node.Leaf;
import org.apache.mahout.classifier.df.node.Node;
import org.apache.mahout.classifier.df.node.NumericalNode;
import org.apache.mahout.common.MahoutTestCase;
import org.apache.mahout.common.RandomUtils;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

public final class VisualizerTest extends MahoutTestCase {
  
  private static final String[] TRAIN_DATA = {"sunny,85,85,FALSE,no",
    "sunny,80,90,TRUE,no", "overcast,83,86,FALSE,yes",
    "rainy,70,96,FALSE,yes", "rainy,68,80,FALSE,yes", "rainy,65,70,TRUE,no",
    "overcast,64,65,TRUE,yes", "sunny,72,95,FALSE,no",
    "sunny,69,70,FALSE,yes", "rainy,75,80,FALSE,yes", "sunny,75,70,TRUE,yes",
    "overcast,72,90,TRUE,yes", "overcast,81,75,FALSE,yes",
    "rainy,71,91,TRUE,no"};
  
  private static final String[] TEST_DATA = {"rainy,70,96,TRUE,-",
    "overcast,64,65,TRUE,-", "sunny,75,90,TRUE,-",};
  
  private static final String[] ATTR_NAMES = {"outlook", "temperature",
    "humidity", "windy", "play"};
  
  private Random rng;
  private Data data;
  private Data testData;
  
  @Override
  @Before
  public void setUp() throws Exception {
    super.setUp();
    
    rng = RandomUtils.getRandom();
    
    // Dataset
    Dataset dataset = DataLoader.generateDataset("C N N C L", false, TRAIN_DATA);
    
    // Training data
    data = DataLoader.loadData(dataset, TRAIN_DATA);
    
    // Test data
    testData = DataLoader.loadData(dataset, TEST_DATA);
  }
  
  @Test
  public void testTreeVisualize() throws Exception {
    // build tree
    DecisionTreeBuilder builder = new DecisionTreeBuilder();
    builder.setM(data.getDataset().nbAttributes() - 1);
    Node tree = builder.build(rng, data);
    
    assertEquals(TreeVisualizer.toString(tree, data.getDataset(), ATTR_NAMES),
      "\noutlook = rainy\n|   windy = FALSE : yes\n|   windy = TRUE : no\n"
        + "outlook = sunny\n|   humidity < 85 : yes\n|   humidity >= 85 : no\n"
        + "outlook = overcast : yes");
  }
  
  @Test
  public void testPredictTrace() throws Exception {
    // build tree
    DecisionTreeBuilder builder = new DecisionTreeBuilder();
    builder.setM(data.getDataset().nbAttributes() - 1);
    Node tree = builder.build(rng, data);
    
    String[] prediction = TreeVisualizer.predictTrace(tree, testData, ATTR_NAMES);
    Assert.assertArrayEquals(prediction, new String[] {
      "outlook = rainy -> windy = TRUE -> no", "outlook = overcast -> yes",
      "outlook = sunny -> (humidity = 90) >= 85 -> no"});
  }
  
  @Test
  public void testForestVisualize() throws Exception {
    // Tree
    NumericalNode root = new NumericalNode(2, 90, new Leaf(0),
      new CategoricalNode(0, new double[] {0, 1, 2}, new Node[] {
        new NumericalNode(1, 71, new Leaf(0), new Leaf(1)), new Leaf(1),
        new Leaf(0)}));
    List<Node> trees = new ArrayList<Node>();
    trees.add(root);
    
    // Forest
    DecisionForest forest = new DecisionForest(trees);
    assertEquals(ForestVisualizer.toString(forest, data.getDataset(), null),
      "Tree[1]:\n2 < 90 : yes\n2 >= 90\n"
        + "|   0 = rainy\n|   |   1 < 71 : yes\n|   |   1 >= 71 : no\n"
        + "|   0 = sunny : no\n" + "|   0 = overcast : yes\n");
    
    assertEquals(ForestVisualizer.toString(forest, data.getDataset(), ATTR_NAMES),
      "Tree[1]:\nhumidity < 90 : yes\nhumidity >= 90\n"
        + "|   outlook = rainy\n|   |   temperature < 71 : yes\n|   |   temperature >= 71 : no\n"
        + "|   outlook = sunny : no\n" + "|   outlook = overcast : yes\n");
  }
}