Weka 自动优化参数

import weka.core.*;

import weka.classifiers.*;

import weka.classifiers.meta.*;

import weka.classifiers.trees.*;



import java.io.*;



/**

 * A little example for optimizing J48's confidence parameter with 

 * CVPArameterSelection meta-classifier.

 * The class expects a dataset as first parameter, class attribute is

 * assumed to be the last attribute.

 *

 * @author FracPete (fracpete at waikato dot ac dot nz)

 */

public class CVParam {

   public static void main(String[] args) throws Exception {

      // load data

      BufferedReader reader = new BufferedReader(new FileReader(args[0]));

      Instances data = new Instances(reader);

      reader.close();

      data.setClassIndex(data.numAttributes() - 1);



      // setup classifier

      CVParameterSelection ps = new CVParameterSelection();

      ps.setClassifier(new J48());

      ps.setNumFolds(5);  // using 5-fold CV

      ps.addCVParameter("C 0.1 0.5 5");



      // build and output best options

      ps.buildClassifier(data);

      System.out.println(Utils.joinOptions(ps.getBestClassifierOptions()));

   }

}