Example usage for org.apache.commons.math.stat.descriptive.moment Mean evaluate

Introduction

In this page you can find the example usage for org.apache.commons.math.stat.descriptive.moment Mean evaluate.

Prototype

@Override
public double evaluate(final double[] values, final int begin, final int length) 

Source Link

Document

Returns the arithmetic mean of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Usage

From source file:de.tudarmstadt.ukp.dkpro.tc.weka.evaluation.MekaEvaluationUtils.java

/**
 * Calculates a number of evaluation measures for multi-label classification, without class-wise measures.
 * //from  w  w  w .j  ava2  s.c  o  m
 * @param predictions
 *            predictions by the classifier (ranking)
 * @param goldStandard
 *            gold standard (bipartition)
 * @param t
 *            a threshold to create bipartitions from rankings
 * @return the evaluation statistics
 */
public static HashMap<String, Double> calcMLStats(double predictions[][], int goldStandard[][], double t[]) {
    int N = goldStandard.length;
    int L = goldStandard[0].length;
    int Ypred[][] = ThresholdUtils.threshold(predictions, t);

    HashMap<String, Double> results = new LinkedHashMap<String, Double>();
    Mean mean = new Mean();

    results.put(NUMBER_LABELS, (double) L);
    results.put(NUMBER_EXAMPLES, (double) N);
    results.put(ZERO_ONE_LOSS, Metrics.L_ZeroOne(goldStandard, Ypred));
    results.put(LABEL_CARDINALITY_PRED, MLUtils.labelCardinality(Ypred));
    results.put(LABEL_CARDINALITY_REAL, MLUtils.labelCardinality(goldStandard));
    results.put(AVERAGE_THRESHOLD, mean.evaluate(t, 0, t.length)); // average
    results.put(EMPTY_VECTORS, MLUtils.emptyVectors(Ypred));

    return results;
}

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