Example usage for java.lang StrictMath log1p

Introduction

In this page you can find the example usage for java.lang StrictMath log1p.

Prototype

public static native double log1p(double x);

Source Link

Document

Returns the natural logarithm of the sum of the argument and 1.

Usage

From source file:Main.java

public static void main(String[] args) {

    double d1 = 90, d2 = 0.0, d3 = (1.0 / 0.0);

    System.out.println("Logarithm value of double (d1 + 1) with base 10 :" + StrictMath.log1p(d1));

    System.out.println("Logarithm value of double (d2 + 1) with base 10 :" + StrictMath.log1p(d2));

    System.out.println("Logarithm value of double (d3 + 1) with base 10 :" + StrictMath.log1p(d3));
}

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From source file:edu.cornell.med.icb.goby.stats.TTestCalculator.java

@Override
public DifferentialExpressionInfo evaluate(
        final DifferentialExpressionCalculator differentialExpressionCalculator,
        final NormalizationMethod method, final DifferentialExpressionResults results,
        final DifferentialExpressionInfo info, final String... group) {
    final String groupA = group[0];
    final String groupB = group[1];
    final ObjectArraySet<String> samplesA = differentialExpressionCalculator.getSamples(groupA);
    final ObjectArraySet<String> samplesB = differentialExpressionCalculator.getSamples(groupB);
    if (samplesA.size() < 2 || samplesB.size() < 2) {
        return info;
    }//from  ww  w. ja v  a  2  s .c  om

    final int tTestStatIndex = defineStatisticId(results, "t-test", method, group);
    final int tStatisticStatIndex = defineStatisticId(results, "t-statistic", method, group);

    final double[] valuesA = new double[samplesA.size()];
    final double[] valuesB = new double[samplesB.size()];

    int i = 0;
    for (final String sample : samplesA) {
        valuesA[i++] = StrictMath.log1p(differentialExpressionCalculator.getNormalizedExpressionValue(sample,
                method, info.getElementId()));
    }

    i = 0;
    for (final String sample : samplesB) {
        valuesB[i++] = StrictMath.log1p(differentialExpressionCalculator.getNormalizedExpressionValue(sample,
                method, info.getElementId()));
    }

    double pValue = 0;
    double tStatistic = 0;

    try {
        pValue = mathCommonsTTest.homoscedasticTTest(valuesA, valuesB);
        tStatistic = mathCommonsTTest.t(valuesA, valuesB);
    } catch (MathException e) {
        pValue = Double.NaN;
    }

    info.statistics.size(results.getNumberOfStatistics());
    info.statistics.set(tTestStatIndex, pValue);
    info.statistics.set(tStatisticStatIndex, tStatistic);

    return info;
}

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From source file:edu.cornell.med.icb.goby.modes.StatsMode.java

/**
 * Returns the log2 of the sum of the argument plus one.
 *
 * @param x argument./*  ww w . j  a  va  2s .c o m*/
 * @return log2p1(x)=Math.log1p(x)/Math.log(2)
 */
private double log2p1(final double x) {
    return StrictMath.log1p(x) / LOG_2;
}

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From source file:edu.umd.honghongie.RunPersonalizedPageRankBasic.java

private static float sumLogProbs(float a, float b) {
    if (a == Float.NEGATIVE_INFINITY)
        return b;

    if (b == Float.NEGATIVE_INFINITY)
        return a;

    if (a < b) {
        return (float) (b + StrictMath.log1p(StrictMath.exp(a - b)));
    }//w  w  w .  j a v a2 s.  c o m
    return (float) (a + StrictMath.log1p(StrictMath.exp(b - a)));
}

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From source file:RunPageRankSchimmy.java

private static float sumLogProbs(float a, float b) {
    if (a == Float.NEGATIVE_INFINITY)
        return b;

    if (b == Float.NEGATIVE_INFINITY)
        return a;

    if (a < b) {
        return (float) (b + StrictMath.log1p(StrictMath.exp(a - b)));
    }/*from w  w  w .j  ava  2 s.  co m*/

    return (float) (a + StrictMath.log1p(StrictMath.exp(b - a)));
}

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From source file:org.esa.beam.util.math.FastMathPerformance.java

public void testLog1p() {
    System.gc();/*  w  ww  . jav a  2 s. com*/
    double x = 0;
    long time = System.nanoTime();
    for (int i = 0; i < RUNS; i++)
        x += StrictMath.log1p(Math.PI + i/* 1.0 + i/1e9 */);
    long strictMath = System.nanoTime() - time;

    System.gc();
    double y = 0;
    time = System.nanoTime();
    for (int i = 0; i < RUNS; i++)
        y += FastMath.log1p(Math.PI + i/* 1.0 + i/1e9 */);
    long fastTime = System.nanoTime() - time;

    System.gc();
    double z = 0;
    time = System.nanoTime();
    for (int i = 0; i < RUNS; i++)
        z += Math.log1p(Math.PI + i/* 1.0 + i/1e9 */);
    long mathTime = System.nanoTime() - time;

    report("log1p", x + y + z, strictMath, fastTime, mathTime);
}

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