Example usage for weka.core Instances numClasses

List of usage examples for weka.core Instances numClasses

Introduction

In this page you can find the example usage for weka.core Instances numClasses.

Prototype


publicint numClasses() 

Source Link

Document

Returns the number of class labels.

Usage

From source file:BaggingImprove.java

/**
 * Bagging method./*  w ww.  j  a va2s . com*/
 *
 * @param data the training data to be used for generating the bagged
 * classifier.
 * @throws Exception if the classifier could not be built successfully
 */
public void buildClassifier(Instances data) throws Exception {

    // can classifier handle the data?
    getCapabilities().testWithFail(data);

    // remove instances with missing class
    data = new Instances(data);
    //data.deleteWithMissingClass();

    super.buildClassifier(data);

    if (m_CalcOutOfBag && (m_BagSizePercent != 100)) {
        throw new IllegalArgumentException(
                "Bag size needs to be 100% if " + "out-of-bag error is to be calculated!");
    }
    //+
    System.out.println("Classifier length" + m_Classifiers.length);

    int bagSize = data.numInstances() * m_BagSizePercent / 100;
    //+
    System.out.println("Bag Size " + bagSize);

    Random random = new Random(m_Seed);

    boolean[][] inBag = null;
    if (m_CalcOutOfBag) {
        inBag = new boolean[m_Classifiers.length][];
    }

    //+
    //inisialisasi nama penamaan model
    BufferedWriter writer = new BufferedWriter(new FileWriter("Bootstrap.txt"));

    for (int j = 0; j < m_Classifiers.length; j++) {

        Instances bagData = null;

        // create the in-bag dataset
        if (m_CalcOutOfBag) {
            inBag[j] = new boolean[data.numInstances()];

            //System.out.println("Inbag1 " + inBag[0][1]);
            //bagData = resampleWithWeights(data, random, inBag[j]);
            bagData = data.resampleWithWeights(random, inBag[j]);
            //System.out.println("num after resample " + bagData.numInstances());
            //+
            //                for (int k = 0; k < bagData.numInstances(); k++) {
            //                    System.out.println("Bag Data after resample [calc out bag]" + bagData.instance(k));
            //                }

        } else {
            //+
            System.out.println("Not m_Calc out of bag");
            System.out.println("Please configure code inside!");

            bagData = data.resampleWithWeights(random);
            if (bagSize < data.numInstances()) {
                bagData.randomize(random);
                Instances newBagData = new Instances(bagData, 0, bagSize);
                bagData = newBagData;
            }
        }

        if (m_Classifier instanceof Randomizable) {
            //+
            System.out.println("Randomizable");
            ((Randomizable) m_Classifiers[j]).setSeed(random.nextInt());
        }

        //write bootstrap into file
        writer.write("Bootstrap " + j);
        writer.newLine();
        writer.write(bagData.toString());
        writer.newLine();

        System.out.println("Berhasil menyimpan bootstrap ke file ");

        System.out.println("Bootstrap " + j + 1);
        //            textarea.append("\nBootsrap " + (j + 1));
        //System.out.println("num instance kedua kali "+bagData.numInstances());

        for (int b = 1; b < bagData.numInstances(); b++) {
            System.out.println("" + bagData.instance(b));
            //                textarea.append("\n" + bagData.instance(b));
        }
        //            //+

        // build the classifier
        m_Classifiers[j].buildClassifier(bagData);
        //            //+
        //            
        //            SerializationHelper serialization = new SerializationHelper();
        //            serialization.write("KnnData"+model+".model", m_Classifiers[j]);
        //            System.out.println("Finish write into model");
        //            model++;
    }

    writer.flush();
    writer.close();
    // calc OOB error?
    if (getCalcOutOfBag()) {
        double outOfBagCount = 0.0;
        double errorSum = 0.0;
        boolean numeric = data.classAttribute().isNumeric();

        for (int i = 0; i < data.numInstances(); i++) {
            double vote;
            double[] votes;
            if (numeric) {
                votes = new double[1];
            } else {
                votes = new double[data.numClasses()];
            }

            // determine predictions for instance
            int voteCount = 0;
            for (int j = 0; j < m_Classifiers.length; j++) {
                if (inBag[j][i]) {
                    continue;
                }
                voteCount++;
                // double pred = m_Classifiers[j].classifyInstance(data.instance(i));
                if (numeric) {
                    // votes[0] += pred;
                    votes[0] = m_Classifiers[j].classifyInstance(data.instance(i));
                } else {
                    // votes[(int) pred]++;
                    double[] newProbs = m_Classifiers[j].distributionForInstance(data.instance(i));
                    //-
                    //                        for(double a : newProbs)
                    //                        {
                    //                            System.out.println("Double new probs %.f "+a);
                    //                        }
                    // average the probability estimates
                    for (int k = 0; k < newProbs.length; k++) {
                        votes[k] += newProbs[k];
                    }

                }
            }
            System.out.println("Vote count %d" + voteCount);

            // "vote"
            if (numeric) {
                vote = votes[0];
                if (voteCount > 0) {
                    vote /= voteCount; // average
                }
            } else {
                if (Utils.eq(Utils.sum(votes), 0)) {
                } else {
                    Utils.normalize(votes);

                }
                vote = Utils.maxIndex(votes); // predicted class
                //-
                System.out.println("Vote " + vote);

            }

            // error for instance
            outOfBagCount += data.instance(i).weight();
            if (numeric) {
                errorSum += StrictMath.abs(vote - data.instance(i).classValue()) * data.instance(i).weight();
            } else if (vote != data.instance(i).classValue()) {
                //+
                System.out.println("Vote terakhir" + data.instance(i).classValue());
                errorSum += data.instance(i).weight();
            }
        }

        m_OutOfBagError = errorSum / outOfBagCount;
    } else {
        m_OutOfBagError = 0;
    }
}

From source file:REPTree.java

License:Open Source License

/**
 * Builds classifier./* w ww.jav  a2 s  .com*/
 * 
 * @param data the data to train with
 * @throws Exception if building fails
 */
public void buildClassifier(Instances data) throws Exception {

    // can classifier handle the data?
    getCapabilities().testWithFail(data);

    // remove instances with missing class
    data = new Instances(data);
    data.deleteWithMissingClass();

    Random random = new Random(m_Seed);

    m_zeroR = null;
    if (data.numAttributes() == 1) {
        m_zeroR = new ZeroR();
        m_zeroR.buildClassifier(data);
        return;
    }

    // Randomize and stratify
    data.randomize(random);
    if (data.classAttribute().isNominal()) {
        data.stratify(m_NumFolds);
    }

    // Split data into training and pruning set
    Instances train = null;
    Instances prune = null;
    if (!m_NoPruning) {
        train = data.trainCV(m_NumFolds, 0, random);
        prune = data.testCV(m_NumFolds, 0);
    } else {
        train = data;
    }

    // Create array of sorted indices and weights
    int[][][] sortedIndices = new int[1][train.numAttributes()][0];
    double[][][] weights = new double[1][train.numAttributes()][0];
    double[] vals = new double[train.numInstances()];
    for (int j = 0; j < train.numAttributes(); j++) {
        if (j != train.classIndex()) {
            weights[0][j] = new double[train.numInstances()];
            if (train.attribute(j).isNominal()) {

                // Handling nominal attributes. Putting indices of
                // instances with missing values at the end.
                sortedIndices[0][j] = new int[train.numInstances()];
                int count = 0;
                for (int i = 0; i < train.numInstances(); i++) {
                    Instance inst = train.instance(i);
                    if (!inst.isMissing(j)) {
                        sortedIndices[0][j][count] = i;
                        weights[0][j][count] = inst.weight();
                        count++;
                    }
                }
                for (int i = 0; i < train.numInstances(); i++) {
                    Instance inst = train.instance(i);
                    if (inst.isMissing(j)) {
                        sortedIndices[0][j][count] = i;
                        weights[0][j][count] = inst.weight();
                        count++;
                    }
                }
            } else {

                // Sorted indices are computed for numeric attributes
                for (int i = 0; i < train.numInstances(); i++) {
                    Instance inst = train.instance(i);
                    vals[i] = inst.value(j);
                }
                sortedIndices[0][j] = Utils.sort(vals);
                for (int i = 0; i < train.numInstances(); i++) {
                    weights[0][j][i] = train.instance(sortedIndices[0][j][i]).weight();
                }
            }
        }
    }

    // Compute initial class counts
    double[] classProbs = new double[train.numClasses()];
    double totalWeight = 0, totalSumSquared = 0;
    for (int i = 0; i < train.numInstances(); i++) {
        Instance inst = train.instance(i);
        if (data.classAttribute().isNominal()) {
            classProbs[(int) inst.classValue()] += inst.weight();
            totalWeight += inst.weight();
        } else {
            classProbs[0] += inst.classValue() * inst.weight();
            totalSumSquared += inst.classValue() * inst.classValue() * inst.weight();
            totalWeight += inst.weight();
        }
    }
    m_Tree = new Tree();
    double trainVariance = 0;
    if (data.classAttribute().isNumeric()) {
        trainVariance = m_Tree.singleVariance(classProbs[0], totalSumSquared, totalWeight) / totalWeight;
        classProbs[0] /= totalWeight;
    }

    // Build tree
    m_Tree.buildTree(sortedIndices, weights, train, totalWeight, classProbs, new Instances(train, 0), m_MinNum,
            m_MinVarianceProp * trainVariance, 0, m_MaxDepth);

    // Insert pruning data and perform reduced error pruning
    if (!m_NoPruning) {
        m_Tree.insertHoldOutSet(prune);
        m_Tree.reducedErrorPrune();
        m_Tree.backfitHoldOutSet();
    }
}

From source file:TreeNode.java

License:Common Public License

public double calculateEntropy(Instances instances) {
    if (instances.numClasses() <= 1)
        return 0;
    else {/*from  w  w  w . j av  a2  s  .  com*/
        int numInstances = instances.numInstances();
        int numClasses = instances.numClasses();

        //Count how many in each class
        int[] classCounts = new int[numClasses];
        for (int i = 0; i < numInstances; i++) {
            classCounts[(int) instances.instance(i).classValue()]++;
        }

        //Calculate the entropy
        double entropy = 0;
        double quotient;
        for (int i = 0; i < numClasses; i++) {
            double result;
            if (classCounts[i] == 0) {
                result = 0;
            } else {
                quotient = (double) classCounts[i] / (double) numInstances;
                result = (quotient * Math.log(quotient) / Math.log(numClasses));
                assert (Double.isNaN(result) && result <= 1);
            }

            entropy = entropy - result;
        }
        return entropy;
    }
}

From source file:Pair.java

License:Open Source License

/**
 * Boosting method.//  www  . j a  v a2s . c om
 *
 * @param data the training data to be used for generating the
 * boosted classifier.
 * @exception Exception if the classifier could not be built successfully
 */

public void buildClassifier(Instances data) throws Exception {

    super.buildClassifier(data);

    if (data.checkForStringAttributes()) {
        throw new UnsupportedAttributeTypeException("Cannot handle string attributes!");
    }
    data = new Instances(data);
    data.deleteWithMissingClass();
    if (data.numInstances() == 0) {
        throw new Exception("No train instances without class missing!");
    }
    if (!data.classAttribute().isNumeric()) {
        throw new UnsupportedClassTypeException("TrAdaBoostR2 can only handle a numeric class!");
    }
    if (m_SourceInstances == null) {
        throw new Exception("Source data has not been specified!");
    }

    m_NumClasses = data.numClasses();
    try {
        doCV(data);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

From source file:REPRandomTree.java

License:Open Source License

/**
 * Builds classifier.//from   w w w  .  j a  v a 2s .co  m
 * 
 * @param data the data to train with
 * @throws Exception if building fails
 */
public void buildClassifier(Instances data) throws Exception {

    // can classifier handle the data?
    getCapabilities().testWithFail(data);

    // remove instances with missing class
    data = new Instances(data);
    data.deleteWithMissingClass();

    Random random = new Random(m_Seed);

    m_zeroR = null;
    if (data.numAttributes() == 1) {
        m_zeroR = new ZeroR();
        m_zeroR.buildClassifier(data);
        return;
    }

    // Randomize and stratify
    data.randomize(random);
    if (data.classAttribute().isNominal()) {
        data.stratify(m_NumFolds);
    }

    // Split data into training and pruning set
    Instances train = null;
    Instances prune = null;
    if (!m_NoPruning) {
        train = data.trainCV(m_NumFolds, 0, random);
        prune = data.testCV(m_NumFolds, 0);
    } else {
        train = data;
    }

    // Create array of sorted indices and weights
    int[][][] sortedIndices = new int[1][train.numAttributes()][0];
    double[][][] weights = new double[1][train.numAttributes()][0];
    double[] vals = new double[train.numInstances()];
    for (int j = 0; j < train.numAttributes(); j++) {
        if (j != train.classIndex()) {
            weights[0][j] = new double[train.numInstances()];
            if (train.attribute(j).isNominal()) {

                // Handling nominal attributes. Putting indices of
                // instances with missing values at the end.
                sortedIndices[0][j] = new int[train.numInstances()];
                int count = 0;
                for (int i = 0; i < train.numInstances(); i++) {
                    Instance inst = train.instance(i);
                    if (!inst.isMissing(j)) {
                        sortedIndices[0][j][count] = i;
                        weights[0][j][count] = inst.weight();
                        count++;
                    }
                }
                for (int i = 0; i < train.numInstances(); i++) {
                    Instance inst = train.instance(i);
                    if (inst.isMissing(j)) {
                        sortedIndices[0][j][count] = i;
                        weights[0][j][count] = inst.weight();
                        count++;
                    }
                }
            } else {

                // Sorted indices are computed for numeric attributes
                for (int i = 0; i < train.numInstances(); i++) {
                    Instance inst = train.instance(i);
                    vals[i] = inst.value(j);
                }
                sortedIndices[0][j] = Utils.sort(vals);
                for (int i = 0; i < train.numInstances(); i++) {
                    weights[0][j][i] = train.instance(sortedIndices[0][j][i]).weight();
                }
            }
        }
    }

    // Compute initial class counts
    double[] classProbs = new double[train.numClasses()];
    double totalWeight = 0, totalSumSquared = 0;
    for (int i = 0; i < train.numInstances(); i++) {
        Instance inst = train.instance(i);
        if (data.classAttribute().isNominal()) {
            classProbs[(int) inst.classValue()] += inst.weight();
            totalWeight += inst.weight();
        } else {
            classProbs[0] += inst.classValue() * inst.weight();
            totalSumSquared += inst.classValue() * inst.classValue() * inst.weight();
            totalWeight += inst.weight();
        }
    }
    m_Tree = new Tree();
    double trainVariance = 0;
    if (data.classAttribute().isNumeric()) {
        trainVariance = m_Tree.singleVariance(classProbs[0], totalSumSquared, totalWeight) / totalWeight;
        classProbs[0] /= totalWeight;
    }

    // Build tree
    m_Tree.buildTree(sortedIndices, weights, train, totalWeight, classProbs, new Instances(train, 0), m_MinNum,
            m_MinVarianceProp * trainVariance, 0, m_MaxDepth, m_FeatureFrac, random);

    // Insert pruning data and perform reduced error pruning
    if (!m_NoPruning) {
        m_Tree.insertHoldOutSet(prune);
        m_Tree.reducedErrorPrune();
        m_Tree.backfitHoldOutSet();
    }
}

From source file:MultiClassClassifier.java

License:Open Source License

/**
 * Builds the classifiers./*from  w ww .  java  2 s. c o m*/
 *
 * @param insts the training data.
 * @throws Exception if a classifier can't be built
 */
public void buildClassifier(Instances insts) throws Exception {

    Instances newInsts;

    // can classifier handle the data?
    getCapabilities().testWithFail(insts);

    // remove instances with missing class
    insts = new Instances(insts);
    insts.deleteWithMissingClass();

    if (m_Classifier == null) {
        throw new Exception("No base classifier has been set!");
    }
    m_ZeroR = new ZeroR();
    m_ZeroR.buildClassifier(insts);

    m_TwoClassDataset = null;

    int numClassifiers = insts.numClasses();
    if (numClassifiers <= 2) {

        m_Classifiers = Classifier.makeCopies(m_Classifier, 1);
        m_Classifiers[0].buildClassifier(insts);

        m_ClassFilters = null;

    } else if (m_Method == METHOD_1_AGAINST_1) {
        // generate fastvector of pairs
        FastVector pairs = new FastVector();
        for (int i = 0; i < insts.numClasses(); i++) {
            for (int j = 0; j < insts.numClasses(); j++) {
                if (j <= i)
                    continue;
                int[] pair = new int[2];
                pair[0] = i;
                pair[1] = j;
                pairs.addElement(pair);
            }
        }

        numClassifiers = pairs.size();
        m_Classifiers = Classifier.makeCopies(m_Classifier, numClassifiers);
        m_ClassFilters = new Filter[numClassifiers];
        m_SumOfWeights = new double[numClassifiers];

        // generate the classifiers
        for (int i = 0; i < numClassifiers; i++) {
            RemoveWithValues classFilter = new RemoveWithValues();
            classFilter.setAttributeIndex("" + (insts.classIndex() + 1));
            classFilter.setModifyHeader(true);
            classFilter.setInvertSelection(true);
            classFilter.setNominalIndicesArr((int[]) pairs.elementAt(i));
            Instances tempInstances = new Instances(insts, 0);
            tempInstances.setClassIndex(-1);
            classFilter.setInputFormat(tempInstances);
            newInsts = Filter.useFilter(insts, classFilter);
            if (newInsts.numInstances() > 0) {
                newInsts.setClassIndex(insts.classIndex());
                m_Classifiers[i].buildClassifier(newInsts);
                m_ClassFilters[i] = classFilter;
                m_SumOfWeights[i] = newInsts.sumOfWeights();
            } else {
                m_Classifiers[i] = null;
                m_ClassFilters[i] = null;
            }
        }

        // construct a two-class header version of the dataset
        m_TwoClassDataset = new Instances(insts, 0);
        int classIndex = m_TwoClassDataset.classIndex();
        m_TwoClassDataset.setClassIndex(-1);
        m_TwoClassDataset.deleteAttributeAt(classIndex);
        FastVector classLabels = new FastVector();
        classLabels.addElement("class0");
        classLabels.addElement("class1");
        m_TwoClassDataset.insertAttributeAt(new Attribute("class", classLabels), classIndex);
        m_TwoClassDataset.setClassIndex(classIndex);

    } else {
        // use error correcting code style methods
        Code code = null;
        switch (m_Method) {
        case METHOD_ERROR_EXHAUSTIVE:
            code = new ExhaustiveCode(numClassifiers);
            break;
        case METHOD_ERROR_RANDOM:
            code = new RandomCode(numClassifiers, (int) (numClassifiers * m_RandomWidthFactor), insts);
            break;
        case METHOD_1_AGAINST_ALL:
            code = new StandardCode(numClassifiers);
            break;
        default:
            throw new Exception("Unrecognized correction code type");
        }
        numClassifiers = code.size();
        m_Classifiers = Classifier.makeCopies(m_Classifier, numClassifiers);
        m_ClassFilters = new MakeIndicator[numClassifiers];
        for (int i = 0; i < m_Classifiers.length; i++) {
            m_ClassFilters[i] = new MakeIndicator();
            MakeIndicator classFilter = (MakeIndicator) m_ClassFilters[i];
            classFilter.setAttributeIndex("" + (insts.classIndex() + 1));
            classFilter.setValueIndices(code.getIndices(i));
            classFilter.setNumeric(false);
            classFilter.setInputFormat(insts);
            newInsts = Filter.useFilter(insts, m_ClassFilters[i]);
            m_Classifiers[i].buildClassifier(newInsts);
        }
    }
    m_ClassAttribute = insts.classAttribute();
}

From source file:GrowTree.java

public boolean homogeneous(Instances D) {
    distribution = new double[D.numClasses()];
    Enumeration eninst = D.enumerateInstances();
    while (eninst.hasMoreElements()) {
        Instance ele = (Instance) eninst.nextElement();
        distribution[(int) ele.classValue()]++;
    }//from w  ww. ja va 2 s . co  m

    int cnt = 0;
    for (int i = 0; i < D.numClasses(); i++) {
        if (distribution[i] > 0)
            cnt++;
    }
    if (cnt <= 1) // if all instances are of single class
        return true;
    else
        return false;
}

From source file:GrowTree.java

public double imp(Instances data) {
    double localdistribution[] = new double[data.numClasses()];
    Enumeration eninst = data.enumerateInstances();
    while (eninst.hasMoreElements()) {
        Instance ele = (Instance) eninst.nextElement();
        localdistribution[(int) ele.classValue()]++;
    }//from w w w  .j  av  a  2s.  c  o  m

    return imp;
}

From source file:SMO.java

License:Open Source License

/**
 * Method for building the classifier. Implements a one-against-one
 * wrapper for multi-class problems.//from   w ww .  ja v a2 s .c  o  m
 *
 * @param insts the set of training instances
 * @throws Exception if the classifier can't be built successfully
 */
public void buildClassifier(Instances insts) throws Exception {

    if (!m_checksTurnedOff) {
        // can classifier handle the data?
        getCapabilities().testWithFail(insts);

        // remove instances with missing class
        insts = new Instances(insts);
        insts.deleteWithMissingClass();

        /* Removes all the instances with weight equal to 0.
         MUST be done since condition (8) of Keerthi's paper 
         is made with the assertion Ci > 0 (See equation (3a). */
        Instances data = new Instances(insts, insts.numInstances());
        for (int i = 0; i < insts.numInstances(); i++) {
            if (insts.instance(i).weight() > 0)
                data.add(insts.instance(i));
        }
        if (data.numInstances() == 0) {
            throw new Exception("No training instances left after removing " + "instances with weight 0!");
        }
        insts = data;
    }

    if (!m_checksTurnedOff) {
        m_Missing = new ReplaceMissingValues();
        m_Missing.setInputFormat(insts);
        insts = Filter.useFilter(insts, m_Missing);
    } else {
        m_Missing = null;
    }

    if (getCapabilities().handles(Capability.NUMERIC_ATTRIBUTES)) {
        boolean onlyNumeric = true;
        if (!m_checksTurnedOff) {
            for (int i = 0; i < insts.numAttributes(); i++) {
                if (i != insts.classIndex()) {
                    if (!insts.attribute(i).isNumeric()) {
                        onlyNumeric = false;
                        break;
                    }
                }
            }
        }

        if (!onlyNumeric) {
            m_NominalToBinary = new NominalToBinary();
            m_NominalToBinary.setInputFormat(insts);
            insts = Filter.useFilter(insts, m_NominalToBinary);
        } else {
            m_NominalToBinary = null;
        }
    } else {
        m_NominalToBinary = null;
    }

    if (m_filterType == FILTER_STANDARDIZE) {
        m_Filter = new Standardize();
        m_Filter.setInputFormat(insts);
        insts = Filter.useFilter(insts, m_Filter);
    } else if (m_filterType == FILTER_NORMALIZE) {
        m_Filter = new Normalize();
        m_Filter.setInputFormat(insts);
        insts = Filter.useFilter(insts, m_Filter);
    } else {
        m_Filter = null;
    }

    m_classIndex = insts.classIndex();
    m_classAttribute = insts.classAttribute();
    m_KernelIsLinear = (m_kernel instanceof PolyKernel) && (((PolyKernel) m_kernel).getExponent() == 1.0);

    // Generate subsets representing each class
    Instances[] subsets = new Instances[insts.numClasses()];
    for (int i = 0; i < insts.numClasses(); i++) {
        subsets[i] = new Instances(insts, insts.numInstances());
    }
    for (int j = 0; j < insts.numInstances(); j++) {
        Instance inst = insts.instance(j);
        subsets[(int) inst.classValue()].add(inst);
    }
    for (int i = 0; i < insts.numClasses(); i++) {
        subsets[i].compactify();
    }

    // Build the binary classifiers
    Random rand = new Random(m_randomSeed);
    m_classifiers = new BinarySMO[insts.numClasses()][insts.numClasses()];
    for (int i = 0; i < insts.numClasses(); i++) {
        for (int j = i + 1; j < insts.numClasses(); j++) {
            m_classifiers[i][j] = new BinarySMO();
            m_classifiers[i][j].setKernel(Kernel.makeCopy(getKernel()));
            Instances data = new Instances(insts, insts.numInstances());
            for (int k = 0; k < subsets[i].numInstances(); k++) {
                data.add(subsets[i].instance(k));
            }
            for (int k = 0; k < subsets[j].numInstances(); k++) {
                data.add(subsets[j].instance(k));
            }
            data.compactify();
            data.randomize(rand);
            m_classifiers[i][j].buildClassifier(data, i, j, m_fitLogisticModels, m_numFolds, m_randomSeed);
        }
    }
}

From source file:ID3Chi.java

License:Open Source License

private void MakeALeaf(Instances data) {

    data.deleteWithMissing(m_Attribute);

    if (data.numInstances() == 0) {
        SetNullDistribution(data);//from   www .  j  av  a  2  s  . c om
        return;
    }

    m_Distribution = new double[data.numClasses()];
    Enumeration instEnum = data.enumerateInstances();
    while (instEnum.hasMoreElements()) {
        Instance inst = (Instance) instEnum.nextElement();
        m_Distribution[(int) inst.classValue()]++;
    }
    Utils.normalize(m_Distribution);
    m_ClassValue = Utils.maxIndex(m_Distribution);
    m_ClassAttribute = data.classAttribute();

    // set m_Attribute to null to mark this node as a leaf
    m_Attribute = null;
}