Java Code Examples for org.apache.spark.mllib.tree.RandomForest#trainClassifier()

public static void main(String args[]){

		SparkConf configuration = new SparkConf().setMaster("local[4]").setAppName("Any");
		JavaSparkContext sc = new JavaSparkContext(configuration);

		// Load and parse the data file.
		String input = "data/rf-data.txt";
		JavaRDD<LabeledPoint> data = MLUtils.loadLibSVMFile(sc.sc(), input).toJavaRDD();
		// Split the data into training and test sets (30% held out for testing)
		JavaRDD<LabeledPoint>[] dataSplits = data.randomSplit(new double[]{0.7, 0.3});
		JavaRDD<LabeledPoint> trainingData = dataSplits[0];
		JavaRDD<LabeledPoint> testData = dataSplits[1];

		// Train a RandomForest model.
		Integer numClasses = 2;
		HashMap<Integer, Integer> categoricalFeaturesInfo = new HashMap<Integer, Integer>();//  Empty categoricalFeaturesInfo indicates all features are continuous.
		Integer numTrees = 3; // Use more in practice.
		String featureSubsetStrategy = "auto"; // Let the algorithm choose.
		String impurity = "gini";
		Integer maxDepth = 5;
		Integer maxBins = 32;
		Integer seed = 12345;

		final RandomForestModel rfModel = RandomForest.trainClassifier(trainingData, numClasses,
				categoricalFeaturesInfo, numTrees, featureSubsetStrategy, impurity, maxDepth, maxBins,
				seed);

		// Evaluate model on test instances and compute test error
		JavaPairRDD<Double, Double> label =
				testData.mapToPair(new PairFunction<LabeledPoint, Double, Double>() {
					public Tuple2<Double, Double> call(LabeledPoint p) {
						return new Tuple2<Double, Double>(rfModel.predict(p.features()), p.label());
					}
				});

		Double testError =
				1.0 * label.filter(new Function<Tuple2<Double, Double>, Boolean>() {
					public Boolean call(Tuple2<Double, Double> pl) {
						return !pl._1().equals(pl._2());
					}
				}).count() / testData.count();

		System.out.println("Test Error: " + testError);
		System.out.println("Learned classification forest model:\n" + rfModel.toDebugString());
	}
 

public static void main(String[] args) {
  // $example on$
  SparkConf sparkConf = new SparkConf().setAppName("JavaRandomForestClassificationExample");
  JavaSparkContext jsc = new JavaSparkContext(sparkConf);
  // Load and parse the data file.
  String datapath = "data/mllib/sample_libsvm_data.txt";
  JavaRDD<LabeledPoint> data = MLUtils.loadLibSVMFile(jsc.sc(), datapath).toJavaRDD();
  // Split the data into training and test sets (30% held out for testing)
  JavaRDD<LabeledPoint>[] splits = data.randomSplit(new double[]{0.7, 0.3});
  JavaRDD<LabeledPoint> trainingData = splits[0];
  JavaRDD<LabeledPoint> testData = splits[1];

  // Train a RandomForest model.
  // Empty categoricalFeaturesInfo indicates all features are continuous.
  Integer numClasses = 2;
  HashMap<Integer, Integer> categoricalFeaturesInfo = new HashMap<>();
  Integer numTrees = 3; // Use more in practice.
  String featureSubsetStrategy = "auto"; // Let the algorithm choose.
  String impurity = "gini";
  Integer maxDepth = 5;
  Integer maxBins = 32;
  Integer seed = 12345;

  final RandomForestModel model = RandomForest.trainClassifier(trainingData, numClasses,
    categoricalFeaturesInfo, numTrees, featureSubsetStrategy, impurity, maxDepth, maxBins,
    seed);

  // Evaluate model on test instances and compute test error
  JavaPairRDD<Double, Double> predictionAndLabel =
    testData.mapToPair(new PairFunction<LabeledPoint, Double, Double>() {
      @Override
      public Tuple2<Double, Double> call(LabeledPoint p) {
        return new Tuple2<>(model.predict(p.features()), p.label());
      }
    });
  Double testErr =
    1.0 * predictionAndLabel.filter(new Function<Tuple2<Double, Double>, Boolean>() {
      @Override
      public Boolean call(Tuple2<Double, Double> pl) {
        return !pl._1().equals(pl._2());
      }
    }).count() / testData.count();
  System.out.println("Test Error: " + testErr);
  System.out.println("Learned classification forest model:\n" + model.toDebugString());

  // Save and load model
  model.save(jsc.sc(), "target/tmp/myRandomForestClassificationModel");
  RandomForestModel sameModel = RandomForestModel.load(jsc.sc(),
    "target/tmp/myRandomForestClassificationModel");
  // $example off$

  jsc.stop();
}
 

@Override
public PMML buildModel(JavaSparkContext sparkContext,
                       JavaRDD<String> trainData,
                       List<?> hyperParameters,
                       Path candidatePath) {

  int maxSplitCandidates = (Integer) hyperParameters.get(0);
  int maxDepth = (Integer) hyperParameters.get(1);
  String impurity = (String) hyperParameters.get(2);
  Preconditions.checkArgument(maxSplitCandidates >= 2,
                              "max-split-candidates must be at least 2");
  Preconditions.checkArgument(maxDepth > 0,
                              "max-depth must be at least 1");

  JavaRDD<String[]> parsedRDD = trainData.map(MLFunctions.PARSE_FN);
  CategoricalValueEncodings categoricalValueEncodings =
      new CategoricalValueEncodings(getDistinctValues(parsedRDD));
  JavaRDD<LabeledPoint> trainPointData =
      parseToLabeledPointRDD(parsedRDD, categoricalValueEncodings);

  Map<Integer,Integer> categoryInfo = categoricalValueEncodings.getCategoryCounts();
  categoryInfo.remove(inputSchema.getTargetFeatureIndex()); // Don't specify target count
  // Need to translate indices to predictor indices
  Map<Integer,Integer> categoryInfoByPredictor = new HashMap<>(categoryInfo.size());
  categoryInfo.forEach((k, v) -> categoryInfoByPredictor.put(inputSchema.featureToPredictorIndex(k), v));

  int seed = RandomManager.getRandom().nextInt();

  RandomForestModel model;
  if (inputSchema.isClassification()) {
    int numTargetClasses =
        categoricalValueEncodings.getValueCount(inputSchema.getTargetFeatureIndex());
    model = RandomForest.trainClassifier(trainPointData,
                                         numTargetClasses,
                                         categoryInfoByPredictor,
                                         numTrees,
                                         "auto",
                                         impurity,
                                         maxDepth,
                                         maxSplitCandidates,
                                         seed);
  } else {
    model = RandomForest.trainRegressor(trainPointData,
                                        categoryInfoByPredictor,
                                        numTrees,
                                        "auto",
                                        impurity,
                                        maxDepth,
                                        maxSplitCandidates,
                                        seed);
  }

  List<IntLongHashMap> treeNodeIDCounts = treeNodeExampleCounts(trainPointData, model);
  IntLongHashMap predictorIndexCounts = predictorExampleCounts(trainPointData, model);

  return rdfModelToPMML(model,
                        categoricalValueEncodings,
                        maxDepth,
                        maxSplitCandidates,
                        impurity,
                        treeNodeIDCounts,
                        predictorIndexCounts);
}