Example usage for org.apache.commons.math3.random RandomGenerator nextFloat

Introduction

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

Prototype

float nextFloat();

Source Link

Document

Returns the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence.

Usage

From source file:com.cloudera.oryx.ml.serving.als.model.LoadTestALSModelFactory.java

private static float[] randomVector(RandomGenerator random) {
    float[] vector = new float[FEATURES];
    for (int i = 0; i < FEATURES; i++) {
        vector[i] = random.nextFloat();
    }/*  w  ww  . ja va 2s  . c om*/
    return vector;
}

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From source file:net.openhft.chronicle.timeseries.Columns.java

public static void generateBrownian(DoubleColumn col, double start, double end, double sd) {
    long length = col.length();
    double sd2 = sd / Math.sqrt(length);
    NormalDistribution nd = new NormalDistribution(0, sd2 * CHUNK_SIZE);
    int trendLength = Math.toIntExact((length - 1) / CHUNK_SIZE + 2);
    BytesStore trend = NativeBytesStore.lazyNativeBytesStoreWithFixedCapacity(trendLength * 8L);
    double x = start;
    RandomGenerator rand = new MersenneTwister();
    for (int i = 0; i < trendLength - 1; i++) {
        float f = rand.nextFloat();
        trend.writeDouble((long) i << 3, x);
        x += nd.inverseCumulativeProbability(f);
    }//from w w  w  . j  a v  a2  s .c o m
    trend.writeDouble((long) (trendLength - 1) << 3, x);
    double diff = end - x;
    double gradient = diff / (trendLength - 1);
    for (int i = 0; i < trendLength; i++) {
        double y = trend.addAndGetDoubleNotAtomic((long) i << 3, i * gradient);
        //            System.out.println(i + ": "+y);
    }
    int procs = Runtime.getRuntime().availableProcessors();
    int chunksPerTask = (trendLength - 1) / procs + 1;
    ForkJoinPool fjp = ForkJoinPool.commonPool();
    List<ForkJoinTask> tasks = new ArrayList<>(procs);
    for (int i = 0; i < procs; i++) {
        int si = i * chunksPerTask;
        int ei = Math.min(trendLength, si + chunksPerTask);
        tasks.add(fjp.submit(() -> {
            NormalDistribution nd2 = new NormalDistribution(0, sd2);
            RandomGenerator rand2 = new MersenneTwister();
            for (int j = si; j < ei; j++) {
                generateBrownian(col, (long) j * CHUNK_SIZE, trend.readDouble((long) j << 3),
                        trend.readDouble((long) (j + 1) << 3), nd2, rand2);
            }
        }));
    }
    for (ForkJoinTask task : tasks) {
        task.join();
    }
    trend.release();
}

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From source file:net.openhft.chronicle.timeseries.Columns.java

private static void generateBrownian(DoubleColumn col, long first, double start, double end,
        NormalDistribution nd, RandomGenerator rand) {
    double x = start;
    int chunkSize = (int) Math.min(col.length() - first, CHUNK_SIZE);
    for (int i = 0; i < chunkSize; i++) {
        col.set(first + i, x);/*from   w w w .  j a v a  2s . co m*/
        double p = rand.nextFloat() + 0.5 / (1 << 24);
        double v = nd.inverseCumulativeProbability(p);
        x += v;
        assert !Double.isInfinite(x);
    }
    double diff = end - x;
    double gradient = diff / chunkSize;
    for (int i = 0; i < chunkSize; i++) {
        col.add(first + i, i * gradient);
    }
}

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From source file:com.github.rinde.rinsim.core.model.rand.RandomModelTest.java

static void testUnmodifiable(RandomGenerator rng) {
    boolean fail = false;
    try {//from  w w w  . j  a  va2 s .  c om
        rng.setSeed(0);
    } catch (final UnsupportedOperationException e) {
        fail = true;
    }
    assertTrue(fail);
    fail = false;
    try {
        rng.setSeed(new int[] { 0 });
    } catch (final UnsupportedOperationException e) {
        fail = true;
    }
    assertTrue(fail);
    fail = false;
    try {
        rng.setSeed(123L);
    } catch (final UnsupportedOperationException e) {
        fail = true;
    }
    assertTrue(fail);
    fail = false;

    rng.nextBoolean();
    rng.nextBytes(new byte[] {});
    rng.nextDouble();
    rng.nextFloat();
    rng.nextGaussian();
    rng.nextInt();
    rng.nextInt(1);
    rng.nextLong();
}

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