Example usage for org.apache.commons.math3.distribution IntegerDistribution sample

Introduction

In this page you can find the example usage for org.apache.commons.math3.distribution IntegerDistribution sample.

Prototype

int[] sample(int sampleSize);

Source Link

Document

Generate a random sample from the distribution.

Usage

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

@Override
public Object doWork(Object... objects) throws IOException {
    if (objects.length < 1) {
        throw new IOException(String.format(Locale.ROOT,
                "Invalid expression %s - null found for the first value", toExpression(constructingFactory)));
    }//from  www .ja v a 2  s. c  om

    Object first = objects[0];

    if (!(first instanceof RealDistribution) && !(first instanceof IntegerDistribution)
            && !(first instanceof MarkovChainEvaluator.MarkovChain)) {
        throw new IOException(String.format(Locale.ROOT,
                "Invalid expression %s - found type %s for the first value, expecting a Markov Chain, Real or Integer Distribution",
                toExpression(constructingFactory), first.getClass().getSimpleName()));
    }

    Object second = null;
    if (objects.length > 1) {
        second = objects[1];
    }

    if (first instanceof MarkovChainEvaluator.MarkovChain) {
        MarkovChainEvaluator.MarkovChain markovChain = (MarkovChainEvaluator.MarkovChain) first;
        if (second != null) {
            return Arrays.stream(markovChain.sample(((Number) second).intValue())).mapToObj(item -> item)
                    .collect(Collectors.toList());
        } else {
            return markovChain.sample();
        }
    } else if (first instanceof RealDistribution) {
        RealDistribution realDistribution = (RealDistribution) first;
        if (second != null) {
            return Arrays.stream(realDistribution.sample(((Number) second).intValue())).mapToObj(item -> item)
                    .collect(Collectors.toList());
        } else {
            return realDistribution.sample();
        }
    } else {
        IntegerDistribution integerDistribution = (IntegerDistribution) first;
        if (second != null) {
            return Arrays.stream(integerDistribution.sample(((Number) second).intValue()))
                    .mapToObj(item -> item).collect(Collectors.toList());
        } else {
            return integerDistribution.sample();
        }
    }
}

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