Example usage for org.apache.commons.math3.random RandomDataGenerator nextExponential

Introduction

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

Prototype

public double nextExponential(double mean) throws NotStrictlyPositiveException 

Source Link

Document

Algorithm Description: Uses the Algorithm SA (Ahrens) from p.

Usage

From source file:gdsc.smlm.model.StandardFluorophoreSequenceModel.java

/**
 * Construct a new flourophore//from w  w  w .  j  a  v  a2s  .  c  o m
 * 
 * @param tAct
 *            Average time for activation
 * @param id
 *            The identifier
 * @param xyz
 *            The [x,y,z] coordinates
 * @param tOn
 *            Average on-state time
 * @param tOff
 *            Average off-state time for the first dark state
 * @param tOff
 *            Average off-state time for the second dark state
 * @param nBlinks
 *            Average number of blinks int the first dark state (used for each burst between second dark states)
 * @param nBlinks2
 *            Average number of blinks into the second dark state
 * @param randomGenerator
 */
public StandardFluorophoreSequenceModel(double tAct, int id, double[] xyz, double tOn, double tOff,
        double tOff2, double nBlinks, double nBlinks2, boolean useGeometricBlinkingDistribution,
        RandomDataGenerator randomGenerator) {
    super(id, xyz);
    init(randomGenerator.nextExponential(tAct), tOn, tOff, tOff2, nBlinks, nBlinks2,
            useGeometricBlinkingDistribution, randomGenerator);
}

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From source file:com.siemens.industrialbenchmark.util.RandomNumberExpectedValueTest.java

@Test
public void testExpectedValues() {

    long seed = 0;
    Random rand = new Random(seed);
    RandomDataGenerator randomData = new RandomDataGenerator();

    double uniformAverage = 0.0;
    double binomialAverage = 0.0;
    double normalAverage = 0.0;
    double exponentialAverage = 0.0;

    for (int i = 0; i < 1e6; i++) {

        // set current seed
        randomData.reSeed(seed);/*from  w  ww  .  j a va2  s.  c  om*/

        // draw random numbers
        double n = randomData.nextGaussian(0, 1);
        double u = randomData.nextUniform(0, 1);
        double b = randomData.nextBinomial(1, 0.5);
        double e = randomData.nextExponential(0.25);

        // average mean random number
        uniformAverage += (1. / (1. + i)) * (u - uniformAverage);
        binomialAverage += (1. / (1. + i)) * (b - binomialAverage);
        normalAverage += (1. / (1. + i)) * (n - normalAverage);
        exponentialAverage += (1. / (1. + i)) * (e - exponentialAverage);

        // draw new seed from global random generator
        seed = rand.nextLong();
    }

    assertEquals(0.5, uniformAverage, 0.001);
    assertEquals(0.5, binomialAverage, 0.001);
    assertEquals(0.0, normalAverage, 0.001);
    assertEquals(0.25, exponentialAverage, 0.001);
}

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From source file:gdsc.smlm.model.StandardFluorophoreSequenceModel.java

private void init(double t, double tOn, double tOff, double tOff2, double nBlinks, double nBlinks2,
        boolean useGeometricBlinkingDistribution, RandomDataGenerator rand) {
    // Model two dark states: short and long. The second tOff and nBlinks is for the long dark state:
    ////w ww.  jav  a 2 s  .c o  m
    // ++-+-+++-+.................+-+--++-+................................+--+++-+
    //
    // + = on
    // - = Short dark state
    // . = Long dark state

    // Note: 1+nBlinks is the number of on-states

    ArrayList<Double> sequence = new ArrayList<Double>();

    // Perform a set number of long blinks
    int nLongBlinks = getBlinks(useGeometricBlinkingDistribution, rand, nBlinks2);
    for (int n = 0; n <= nLongBlinks; n++) {
        // For each burst between long blinks perform a number of short blinks
        int nShortBlinks = getBlinks(useGeometricBlinkingDistribution, rand, nBlinks);

        // Starts on the current time
        sequence.add(t);
        // Stops after the on-time
        t += rand.nextExponential(tOn);
        sequence.add(t);

        // Remaining bursts
        for (int i = 0; i < nShortBlinks; i++) {
            // Next burst starts after the short off-time
            t += rand.nextExponential(tOff);
            sequence.add(t);
            // Stops after the on-time
            t += rand.nextExponential(tOn);
            sequence.add(t);
        }

        // Add the long dark state if there are more bursts.
        t += rand.nextExponential(tOff2);
    }

    // Convert the sequence to the burst sequence array
    double[] burstSequence = new double[sequence.size()];
    int c = 0;
    for (double time : sequence)
        burstSequence[c++] = time;
    setBurstSequence(burstSequence);
}

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