Example usage for org.apache.commons.math.distribution IntegerDistribution inverseCumulativeProbability

Introduction

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

Prototype

int inverseCumulativeProbability(double p) throws MathException;

Source Link

Document

For this distribution, X, this method returns the largest x such that P(X ≤ x) <= p.

Usage

From source file:org.apache.mahout.clustering.lda.TestLDAInference.java

/**
 * Generate random document vector/*from w  ww  .java2  s  .c om*/
 * 
 * @param numWords
 *          int number of words in the vocabulary
 * @param numWords
 *          E[count] for each word
 */
private Vector generateRandomDoc(int numWords, double sparsity) throws MathException {
    Vector v = new DenseVector(numWords);
    IntegerDistribution dist = new PoissonDistributionImpl(sparsity);
    for (int i = 0; i < numWords; i++) {
        // random integer
        v.setQuick(i, dist.inverseCumulativeProbability(random.nextDouble()) + 1);
    }
    return v;
}

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From source file:org.apache.mahout.clustering.lda.TestMapReduce.java

/**
 * Generate random document vector/*from  w w w .  j a v a 2  s . c  o m*/
 * @param numWords int number of words in the vocabulary
 * @param numWords E[count] for each word
 */
private RandomAccessSparseVector generateRandomDoc(int numWords, double sparsity) throws MathException {
    RandomAccessSparseVector v = new RandomAccessSparseVector(numWords, (int) (numWords * sparsity));
    IntegerDistribution dist = new PoissonDistributionImpl(sparsity);
    for (int i = 0; i < numWords; i++) {
        // random integer
        v.set(i, dist.inverseCumulativeProbability(random.nextDouble()) + 1);
    }
    return v;
}

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From source file:org.renjin.Distributions.java

private static double q(IntegerDistribution dist, double p, boolean lowerTail, boolean logP) {
    if (logP) {//from w  w  w  . j a v a2  s  .  c  o m
        p = Math.exp(p);
    }
    double q = 0;
    try {
        q = dist.inverseCumulativeProbability(p);
    } catch (IllegalArgumentException e) {
        return Double.NaN;
    } catch (MathException e) {
        return Double.NaN;
    } catch (MathRuntimeException e) {
        return Double.NaN;
    }
    if (!lowerTail) {
        q = -q;
    }
    return q;
}

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