Example usage for weka.classifiers.trees.j48 Distribution Distribution

Introduction

In this page you can find the example usage for weka.classifiers.trees.j48 Distribution Distribution.

Prototype

public Distribution(Distribution toMerge) 

Source Link

Document

Creates distribution with only one bag by merging all bags of given distribution.

Usage

From source file:cs.man.ac.uk.classifiers.GetAUC.java

License:Open Source License

/**
 * Computes the AUC for the supplied stream learner.
 * @return the AUC as a double value./*from ww w.  java 2s.c om*/
 */
private static double validate5x2CVStream() {
    try {
        // Other options
        int runs = 5;
        int folds = 2;
        double AUC_SUM = 0;

        // perform cross-validation
        for (int i = 0; i < runs; i++) {
            // randomize data
            int seed = i + 1;
            Random rand = new Random(seed);
            Instances randData = new Instances(data);
            randData.randomize(rand);

            if (randData.classAttribute().isNominal()) {
                System.out.println("Stratifying...");
                randData.stratify(folds);
            }

            for (int n = 0; n < folds; n++) {
                Instances train = randData.trainCV(folds, n);
                Instances test = randData.testCV(folds, n);

                Distribution testDistribution = new Distribution(test);

                ArffSaver trainSaver = new ArffSaver();
                trainSaver.setInstances(train);
                trainSaver.setFile(new File(trainPath));
                trainSaver.writeBatch();

                ArffSaver testSaver = new ArffSaver();
                testSaver.setInstances(test);

                double[][] dist = testDistribution.matrix();
                int negativeClassSize = (int) dist[0][0];
                int positiveClassSize = (int) dist[0][1];
                double balance = (double) positiveClassSize / (double) negativeClassSize;

                String tempTestPath = testPath.replace(".arff",
                        "_" + positiveClassSize + "_" + negativeClassSize + "_" + balance + "_1.0.arff");// [Test-n-Set-n]_[+]_[-]_[K]_[L];
                testSaver.setFile(new File(tempTestPath));
                testSaver.writeBatch();

                ARFFFile file = new ARFFFile(tempTestPath, CLASS_INDEX, new DebugLogger(false));
                file.createMetaData();

                HoeffdingTreeTester streamClassifier = new HoeffdingTreeTester(trainPath, tempTestPath,
                        CLASS_INDEX, new String[] { "0", "1" }, new DebugLogger(true));

                streamClassifier.train();

                System.in.read();

                //AUC_SUM += streamClassifier.getROCExternalData("",(int)testDistribution.perClass(1),(int)testDistribution.perClass(0));
                streamClassifier.testStatic(homeDirectory + "/FuckSakeTest.txt");

                String[] files = Common.getFilePaths(scratch);
                for (int j = 0; j < files.length; j++)
                    Common.fileDelete(files[j]);
            }
        }

        return AUC_SUM / ((double) runs * (double) folds);
    } catch (Exception e) {
        System.out.println("Exception validating data!");
        e.printStackTrace();
        return 0;
    }
}

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