Example usage for org.apache.commons.math3.random EmpiricalDistribution probability

Introduction

In this page you can find the example usage for org.apache.commons.math3.random EmpiricalDistribution probability.

Prototype

public double probability(double x0, double x1) 

Source Link

Document

For a random variable X whose values are distributed according to this distribution, this method returns P(x0 < X <= x1) .

Usage

From source file:org.apache.solr.client.solrj.io.eval.HistogramEvaluator.java

@Override
public Object doWork(Object... values) throws IOException {
    if (Arrays.stream(values).anyMatch(item -> null == item)) {
        return null;
    }/*from   w w  w .j  av a2 s.  c om*/

    List<?> sourceValues;
    Integer bins = 10;

    if (values.length >= 1) {
        sourceValues = values[0] instanceof List<?> ? (List<?>) values[0] : Arrays.asList(values[0]);

        if (values.length >= 2) {
            if (values[1] instanceof Number) {
                bins = ((Number) values[1]).intValue();
            } else {
                throw new IOException(String.format(Locale.ROOT,
                        "Invalid expression %s - if second parameter is provided then it must be a valid number but found %s instead",
                        toExpression(constructingFactory), values[1].getClass().getSimpleName()));
            }
        }
    } else {
        throw new IOException(
                String.format(Locale.ROOT, "Invalid expression %s - expecting at least one value but found %d",
                        toExpression(constructingFactory), containedEvaluators.size()));
    }

    EmpiricalDistribution distribution = new EmpiricalDistribution(bins);
    distribution.load(
            ((List<?>) sourceValues).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray());
    ;

    List<Tuple> histogramBins = new ArrayList<>();
    for (SummaryStatistics binSummary : distribution.getBinStats()) {
        Map<String, Number> map = new HashMap<>();
        map.put("max", binSummary.getMax());
        map.put("mean", binSummary.getMean());
        map.put("min", binSummary.getMin());
        map.put("stdev", binSummary.getStandardDeviation());
        map.put("sum", binSummary.getSum());
        map.put("N", binSummary.getN());
        map.put("var", binSummary.getVariance());
        map.put("cumProb", distribution.cumulativeProbability(binSummary.getMean()));
        map.put("prob", distribution.probability(binSummary.getMin(), binSummary.getMax()));
        histogramBins.add(new Tuple(map));
    }

    return histogramBins;
}

---