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

Introduction

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

Prototype

double probability(int x);

Source Link

Document

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

Usage

From source file:com.github.rinde.rinsim.util.StochasticSuppliersTest.java

@Test
public void testUniform() {
    final RandomGenerator rng = new MersenneTwister(123L);
    final StochasticSupplier<Integer> sup = uniformInt(2, 10);
    final IntegerDistribution id = new UniformIntegerDistribution(2, 10);

    final Multiset<Integer> ms = TreeMultiset.create();
    for (int i = 0; i < 1000; i++) {
        ms.add(sup.get(rng.nextLong()));
    }//from  w w  w .  j  a  v a2s .  c o  m
    final List<Integer> observations = newArrayList();
    final List<Double> expectations = newArrayList();
    for (final Multiset.Entry<Integer> entry : ms.entrySet()) {
        observations.add(entry.getCount());
        expectations.add(id.probability(entry.getElement()));
    }
    assertTrue(chiSquare(expectations, observations, .01));
}

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From source file:org.apache.mahout.math.random.PoissonSamplerTest.java

private static void checkDistribution(Sampler<Double> pd, double alpha) {
    int[] count = new int[(int) Math.max(10, 5 * alpha)];
    for (int i = 0; i < 10000; i++) {
        count[pd.sample().intValue()]++;
    }//from ww w .j a  v a 2  s.  c o  m

    IntegerDistribution ref = new PoissonDistribution(RandomUtils.getRandom().getRandomGenerator(), alpha,
            PoissonDistribution.DEFAULT_EPSILON, PoissonDistribution.DEFAULT_MAX_ITERATIONS);
    for (int i = 0; i < count.length; i++) {
        assertEquals(ref.probability(i), count[i] / 10000.0, 2.0e-2);
    }
}

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

@Override
public Object doWork(Object first, Object second) throws IOException {
    if (null == first) {
        throw new IOException(String.format(Locale.ROOT,
                "Invalid expression %s - null found for the first value", toExpression(constructingFactory)));
    }/*from w  w  w . j  ava  2 s  .  c om*/
    if (null == second) {
        throw new IOException(String.format(Locale.ROOT,
                "Invalid expression %s - null found for the second value", toExpression(constructingFactory)));
    }
    if (!(first instanceof IntegerDistribution)) {
        throw new IOException(String.format(Locale.ROOT,
                "Invalid expression %s - found type %s for the first value, expecting a IntegerDistribution",
                toExpression(constructingFactory), first.getClass().getSimpleName()));
    }
    if (!(second instanceof Number)) {
        throw new IOException(String.format(Locale.ROOT,
                "Invalid expression %s - found type %s for the second value, expecting a Number",
                toExpression(constructingFactory), first.getClass().getSimpleName()));
    }

    IntegerDistribution d = (IntegerDistribution) first;
    Number predictOver = (Number) second;
    return d.probability(predictOver.intValue());
}

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