spark JavaLBFGSExample 源码

spark JavaLBFGSExample 代码

文件路径：/examples/src/main/java/org/apache/spark/examples/mllib/JavaLBFGSExample.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.spark.examples.mllib;

// $example on$
import java.util.Arrays;

import scala.Tuple2;

import org.apache.spark.api.java.*;
import org.apache.spark.mllib.classification.LogisticRegressionModel;
import org.apache.spark.mllib.evaluation.BinaryClassificationMetrics;
import org.apache.spark.mllib.linalg.Vector;
import org.apache.spark.mllib.linalg.Vectors;
import org.apache.spark.mllib.optimization.*;
import org.apache.spark.mllib.regression.LabeledPoint;
import org.apache.spark.mllib.util.MLUtils;
import org.apache.spark.SparkConf;
import org.apache.spark.SparkContext;
// $example off$

public class JavaLBFGSExample {
  public static void main(String[] args) {
    SparkConf conf = new SparkConf().setAppName("L-BFGS Example");
    SparkContext sc = new SparkContext(conf);

    // $example on$
    String path = "data/mllib/sample_libsvm_data.txt";
    JavaRDD<LabeledPoint> data = MLUtils.loadLibSVMFile(sc, path).toJavaRDD();
    int numFeatures = data.take(1).get(0).features().size();

    // Split initial RDD into two... [60% training data, 40% testing data].
    JavaRDD<LabeledPoint> trainingInit = data.sample(false, 0.6, 11L);
    JavaRDD<LabeledPoint> test = data.subtract(trainingInit);

    // Append 1 into the training data as intercept.
    JavaPairRDD<Object, Vector> training = data.mapToPair(p ->
      new Tuple2<>(p.label(), MLUtils.appendBias(p.features())));
    training.cache();

    // Run training algorithm to build the model.
    int numCorrections = 10;
    double convergenceTol = 1e-4;
    int maxNumIterations = 20;
    double regParam = 0.1;
    Vector initialWeightsWithIntercept = Vectors.dense(new double[numFeatures + 1]);

    Tuple2<Vector, double[]> result = LBFGS.runLBFGS(
      training.rdd(),
      new LogisticGradient(),
      new SquaredL2Updater(),
      numCorrections,
      convergenceTol,
      maxNumIterations,
      regParam,
      initialWeightsWithIntercept);
    Vector weightsWithIntercept = result._1();
    double[] loss = result._2();

    LogisticRegressionModel model = new LogisticRegressionModel(
      Vectors.dense(Arrays.copyOf(weightsWithIntercept.toArray(), weightsWithIntercept.size() - 1)),
      (weightsWithIntercept.toArray())[weightsWithIntercept.size() - 1]);

    // Clear the default threshold.
    model.clearThreshold();

    // Compute raw scores on the test set.
    JavaPairRDD<Object, Object> scoreAndLabels = test.mapToPair(p ->
      new Tuple2<>(model.predict(p.features()), p.label()));

    // Get evaluation metrics.
    BinaryClassificationMetrics metrics =
      new BinaryClassificationMetrics(scoreAndLabels.rdd());
    double auROC = metrics.areaUnderROC();

    System.out.println("Loss of each step in training process");
    for (double l : loss) {
      System.out.println(l);
    }
    System.out.println("Area under ROC = " + auROC);
    // $example off$

    sc.stop();
  }
}

相关信息

spark 源码目录

相关文章

spark JavaALS 源码

spark JavaAssociationRulesExample 源码

spark JavaBinaryClassificationMetricsExample 源码

spark JavaBisectingKMeansExample 源码

spark JavaChiSqSelectorExample 源码

spark JavaCorrelationsExample 源码

spark JavaDecisionTreeClassificationExample 源码

spark JavaDecisionTreeRegressionExample 源码

spark JavaElementwiseProductExample 源码

spark JavaGaussianMixtureExample 源码