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+/*
+ * 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.
+ */
+
+// scalastyle:off println
+package org.apache.spark.examples.mllib
+
+import org.apache.spark.{SparkContext, SparkConf}
+// $example on$
+import org.apache.spark.mllib.tree.GradientBoostedTrees
+import org.apache.spark.mllib.tree.configuration.BoostingStrategy
+import org.apache.spark.mllib.tree.model.GradientBoostedTreesModel
+import org.apache.spark.mllib.util.MLUtils
+// $example off$
+
+object GradientBoostingRegressionExample {
+ def main(args: Array[String]): Unit = {
+ val conf = new SparkConf().setAppName("GradientBoostedTreesRegressionExample")
+ val sc = new SparkContext(conf)
+ // $example on$
+ // Load and parse the data file.
+ val data = MLUtils.loadLibSVMFile(sc, "data/mllib/sample_libsvm_data.txt")
+ // Split the data into training and test sets (30% held out for testing)
+ val splits = data.randomSplit(Array(0.7, 0.3))
+ val (trainingData, testData) = (splits(0), splits(1))
+
+ // Train a GradientBoostedTrees model.
+ // The defaultParams for Regression use SquaredError by default.
+ val boostingStrategy = BoostingStrategy.defaultParams("Regression")
+ boostingStrategy.numIterations = 3 // Note: Use more iterations in practice.
+ boostingStrategy.treeStrategy.maxDepth = 5
+ // Empty categoricalFeaturesInfo indicates all features are continuous.
+ boostingStrategy.treeStrategy.categoricalFeaturesInfo = Map[Int, Int]()
+
+ val model = GradientBoostedTrees.train(trainingData, boostingStrategy)
+
+ // Evaluate model on test instances and compute test error
+ val labelsAndPredictions = testData.map { point =>
+ val prediction = model.predict(point.features)
+ (point.label, prediction)
+ }
+ val testMSE = labelsAndPredictions.map{ case(v, p) => math.pow((v - p), 2)}.mean()
+ println("Test Mean Squared Error = " + testMSE)
+ println("Learned regression GBT model:\n" + model.toDebugString)
+
+ // Save and load model
+ model.save(sc, "target/tmp/myGradientBoostingRegressionModel")
+ val sameModel = GradientBoostedTreesModel.load(sc,
+ "target/tmp/myGradientBoostingRegressionModel")
+ // $example off$
+ }
+}
+// scalastyle:on println