Example usage for weka.core Instances resampleWithWeights

Introduction

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

Prototype

public Instances resampleWithWeights(Random random, double[] weights, boolean[] sampled) 

Source Link

Document

Creates a new dataset of the same size as this dataset using random sampling with replacement according to the given weight vector.

Usage

From source file:Bilbo.java

License:Open Source License

/**
 * Returns a training set for a particular iteration.
 * //  ww w . ja v  a2  s.c om
 * @param iteration the number of the iteration for the requested training set.
 * @return the training set for the supplied iteration number
 * @throws Exception if something goes wrong when generating a training set.
 */
@Override
protected synchronized Instances getTrainingSet(Instances p_data, int iteration) throws Exception {
    int bagSize = (int) (p_data.numInstances() * (m_BagSizePercent / 100.0));
    Instances bagData = null;
    Random r = new Random(m_Seed + iteration);

    // create the in-bag dataset
    if (m_CalcOutOfBag && p_data.classIndex() != -1) {
        m_inBag[iteration] = new boolean[p_data.numInstances()];
        bagData = p_data.resampleWithWeights(r, m_inBag[iteration], getRepresentCopiesUsingWeights());
    } else {
        bagData = p_data.resampleWithWeights(r, getRepresentCopiesUsingWeights());
        if (bagSize < p_data.numInstances()) {
            bagData.randomize(r);
            Instances newBagData = new Instances(bagData, 0, bagSize);
            bagData = newBagData;
        }
    }

    return bagData;
}

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