Example usage for weka.clusterers SimpleKMeans getClusterNominalCounts

Introduction

In this page you can find the example usage for weka.clusterers SimpleKMeans getClusterNominalCounts.

Prototype

public double[][][] getClusterNominalCounts() 

Source Link

Document

Returns for each cluster the weighted frequency counts for the values of each nominal attribute.

Usage

From source file:br.ufrn.ia.core.clustering.EMIaProject.java

License:Open Source License

private void EM_Init(Instances inst) throws Exception {
    int i, j, k;/*w w  w  .  j a  v a2 s . c om*/

    // run k means 10 times and choose best solution
    SimpleKMeans bestK = null;
    double bestSqE = Double.MAX_VALUE;
    for (i = 0; i < 10; i++) {
        SimpleKMeans sk = new SimpleKMeans();
        sk.setSeed(m_rr.nextInt());
        sk.setNumClusters(m_num_clusters);
        sk.setDisplayStdDevs(true);
        sk.buildClusterer(inst);
        if (sk.getSquaredError() < bestSqE) {
            bestSqE = sk.getSquaredError();
            bestK = sk;
        }
    }

    // initialize with best k-means solution
    m_num_clusters = bestK.numberOfClusters();
    m_weights = new double[inst.numInstances()][m_num_clusters];
    m_model = new DiscreteEstimator[m_num_clusters][m_num_attribs];
    m_modelNormal = new double[m_num_clusters][m_num_attribs][3];
    m_priors = new double[m_num_clusters];
    Instances centers = bestK.getClusterCentroids();
    Instances stdD = bestK.getClusterStandardDevs();
    double[][][] nominalCounts = bestK.getClusterNominalCounts();
    double[] clusterSizes = bestK.getClusterSizes();

    for (i = 0; i < m_num_clusters; i++) {
        Instance center = centers.instance(i);
        for (j = 0; j < m_num_attribs; j++) {
            if (inst.attribute(j).isNominal()) {
                m_model[i][j] = new DiscreteEstimator(m_theInstances.attribute(j).numValues(), true);
                for (k = 0; k < inst.attribute(j).numValues(); k++) {
                    m_model[i][j].addValue(k, nominalCounts[i][j][k]);
                }
            } else {
                double minStdD = (m_minStdDevPerAtt != null) ? m_minStdDevPerAtt[j] : m_minStdDev;
                double mean = (center.isMissing(j)) ? inst.meanOrMode(j) : center.value(j);
                m_modelNormal[i][j][0] = mean;
                double stdv = (stdD.instance(i).isMissing(j))
                        ? ((m_maxValues[j] - m_minValues[j]) / (2 * m_num_clusters))
                        : stdD.instance(i).value(j);
                if (stdv < minStdD) {
                    stdv = inst.attributeStats(j).numericStats.stdDev;
                    if (Double.isInfinite(stdv)) {
                        stdv = minStdD;
                    }
                    if (stdv < minStdD) {
                        stdv = minStdD;
                    }
                }
                if (stdv <= 0) {
                    stdv = m_minStdDev;
                }

                m_modelNormal[i][j][1] = stdv;
                m_modelNormal[i][j][2] = 1.0;
            }
        }
    }

    for (j = 0; j < m_num_clusters; j++) {
        // m_priors[j] += 1.0;
        m_priors[j] = clusterSizes[j];
    }
    Utils.normalize(m_priors);
}

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