spark OneVsRestExample 源码

  • 2022-10-20
  • 浏览 (246)

spark OneVsRestExample 代码

文件路径:/examples/src/main/scala/org/apache/spark/examples/ml/OneVsRestExample.scala

/*
 * 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.ml

// $example on$
import org.apache.spark.ml.classification.{LogisticRegression, OneVsRest}
import org.apache.spark.ml.evaluation.MulticlassClassificationEvaluator
// $example off$
import org.apache.spark.sql.SparkSession

/**
 * An example of Multiclass to Binary Reduction with One Vs Rest,
 * using Logistic Regression as the base classifier.
 * Run with
 * {{{
 * ./bin/run-example ml.OneVsRestExample
 * }}}
 */

object OneVsRestExample {
  def main(args: Array[String]): Unit = {
    val spark = SparkSession
      .builder
      .appName(s"OneVsRestExample")
      .getOrCreate()

    // $example on$
    // load data file.
    val inputData = spark.read.format("libsvm")
      .load("data/mllib/sample_multiclass_classification_data.txt")

    // generate the train/test split.
    val Array(train, test) = inputData.randomSplit(Array(0.8, 0.2))

    // instantiate the base classifier
    val classifier = new LogisticRegression()
      .setMaxIter(10)
      .setTol(1E-6)
      .setFitIntercept(true)

    // instantiate the One Vs Rest Classifier.
    val ovr = new OneVsRest().setClassifier(classifier)

    // train the multiclass model.
    val ovrModel = ovr.fit(train)

    // score the model on test data.
    val predictions = ovrModel.transform(test)

    // obtain evaluator.
    val evaluator = new MulticlassClassificationEvaluator()
      .setMetricName("accuracy")

    // compute the classification error on test data.
    val accuracy = evaluator.evaluate(predictions)
    println(s"Test Error = ${1 - accuracy}")
    // $example off$

    spark.stop()
  }

}
// scalastyle:on println

相关信息

spark 源码目录

相关文章

spark AFTSurvivalRegressionExample 源码

spark ALSExample 源码

spark BinarizerExample 源码

spark BisectingKMeansExample 源码

spark BucketedRandomProjectionLSHExample 源码

spark BucketizerExample 源码

spark ChiSqSelectorExample 源码

spark ChiSquareTestExample 源码

spark CorrelationExample 源码

spark CountVectorizerExample 源码

0  赞