Example usage for java.util Random nextDouble

List of usage examples for java.util Random nextDouble

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Introduction

In this page you can find the example usage for java.util Random nextDouble.

Prototype

public double nextDouble()

Source Link

Document

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

Usage

From source file:net.lizalab.util.RdRandRandomTest.java

/**
 * Runs the mean test for the specified instance of Random.
 * @param random The RNG instance to test.
 * @param doAssert Flag to indicate whether result should be asserted or simply logged.
 *///  w  ww.j  a v a 2 s.  c  o m
private void meanTest(Random random, boolean doAssert) {
    final String methodName = "meanTest : ";

    ndigits = new int[10];
    // Initialize the array
    for (int i = 0; i < 10; i++) {
        ndigits[i] = 0;
    }
    double x;
    int n;

    SummaryStatistics stats = new SummaryStatistics();

    long start = System.currentTimeMillis();
    // Test the random number generator a whole lot
    for (long i = 0; i < values; i++) {
        // generate a new random number between 0 and 9
        x = random.nextDouble() * 10.0;
        n = (int) x;
        stats.addValue(n);
        // count the digits in the random number
        ndigits[n]++;
    }
    long end = System.currentTimeMillis();

    LOGGER.info("{} Time: {}ms", methodName, end - start);
    LOGGER.info("{} Distribution:", methodName);
    // Print the results
    for (int i = 0; i < 10; i++) {
        LOGGER.info("{} {}: {}", methodName, i, ndigits[i]);
    }
    double sampleMean = stats.getMean();
    double sampleVar = stats.getVariance();
    double meanDiff = (sampleMean - mean) / mean;
    LOGGER.info("{} mean: {}, diff: {}", methodName, sampleMean, meanDiff);
    LOGGER.info("{} sd: {}", methodName, stats.getStandardDeviation());
    LOGGER.info("{} var: {}", methodName, sampleVar);
    // Verify results.
    boolean varResult = sampleVar < var;
    String varMsg = "Random Variance exceeds max expectation!";
    boolean ci99Result = sampleMean >= smLowerRng3SD && sampleMean <= smUpperRng3SD;
    String ci99Msg = "Random 99.7% CI test failed!";
    boolean ci95Result = sampleMean >= smLowerRng2SD && sampleMean <= smUpperRng2SD;
    String ci95Msg = "Random 95% CI test failed!";
    if (doAssert) {
        assertTrue(varMsg, varResult);
        assertTrue(ci99Msg, ci99Result);
        assertTrue(ci95Msg, ci95Result);
    } else {
        if (!varResult) {
            LOGGER.warn("{} {}", methodName, varMsg);
        }
        if (!ci99Result) {
            LOGGER.warn("{} {}", methodName, ci99Msg);
        }
        if (!ci95Result) {
            LOGGER.warn("{} {}", methodName, ci95Msg);
        }
    }
}

From source file:org.gwaspi.gui.qqPlot.java

/**
 * Runs the test.//  w  w w .  j  a va 2s.com
 */
public void run() {

    this.finished = false;

    List<XYSeries> seriesArray = new ArrayList<XYSeries>();

    Random generator = new Random();
    int seriesNb = -1;
    XYSeriesCollection dataSeries = new XYSeriesCollection();
    XYSeries seriesData = new XYSeries("X");
    XYSeries seriesUpper = new XYSeries("Upper bound");
    XYSeries seriesLower = new XYSeries("Lower bound");

    int N = 10000;
    List<Double> rndChiSqrDist1 = org.gwaspi.statistics.Chisquare.getChiSquareDistributionDf1(N, 1.0f);
    Collections.sort(rndChiSqrDist1);
    List<Double> rndChiSqrDist2 = org.gwaspi.statistics.Chisquare.getChiSquareDistributionDf1(N, 1.0f);
    Collections.sort(rndChiSqrDist2);
    for (int i = 0; i < rndChiSqrDist1.size(); i++) {
        double obsVal = rndChiSqrDist1.get(i) + (generator.nextDouble() * 0.00001);
        double expVal = rndChiSqrDist2.get(i);

        // constant chi-square boundaries
        //         double upperVal = expVal*1.05;
        //         double lowerVal = expVal*0.95;
        //         double upperVal = expVal+Math.pow(Math.E,(1.96*Math.sqrt(1/expVal)));
        //         double lowerVal = expVal-Math.pow(Math.E,(1.96*Math.sqrt(1/expVal)));
        double upperVal = expVal + 1.96 * Math.sqrt(0.05 * (1 - 0.05 / N));
        double lowerVal = expVal - 1.96 * Math.sqrt(0.05 * (1 - 0.05 / N));

        seriesData.add(obsVal, expVal);
        seriesLower.add(expVal, lowerVal);
        seriesUpper.add(expVal, upperVal);
    }

    dataSeries.addSeries(seriesData);
    dataSeries.addSeries(seriesLower);
    dataSeries.addSeries(seriesUpper);
    final XYDataset data = dataSeries;

    // create a scatter chart...
    final boolean withLegend = true;
    JFreeChart chart = ChartFactory.createScatterPlot("QQ-plot", "Obs X", "Exp X", data,
            PlotOrientation.VERTICAL, withLegend, false, false);

    final XYPlot plot = chart.getXYPlot();
    XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer(false, true);
    renderer.setSeriesPaint(0, Color.blue);
    renderer.setSeriesPaint(1, Color.gray);
    renderer.setSeriesPaint(2, Color.gray);

    renderer.setBaseShapesVisible(true);
    renderer.setBaseShapesFilled(true);
    renderer.setSeriesShape(0, new Rectangle2D.Double(-1.0, -1.0, 2.0, 2.0));
    renderer.setSeriesShape(1, new Rectangle2D.Double(-2.0, 0.0, 4.0, 0.0));
    renderer.setSeriesShape(2, new Rectangle2D.Double(-2.0, 0.0, 4.0, 0.0));

    plot.setRenderer(renderer);

    try {
        ChartUtilities.saveChartAsPNG(new File(System.getProperty("user.home") + "/Desktop/QQ_plot.png"), chart,
                400, 400);
    } catch (IOException ex) {
        log.error("Problem occurred creating chart", ex);
    }
}

From source file:org.apache.hadoop.hive.serde2.binarysortable.MyTestClass.java

public int randomFill(Random r, ExtraTypeInfo extraTypeInfo) {
    int randField = r.nextInt(MyTestClass.fieldCount);
    int field = 0;

    myBool = (randField == field++) ? null : (r.nextInt(1) == 1);
    myByte = (randField == field++) ? null : Byte.valueOf((byte) r.nextInt());
    myShort = (randField == field++) ? null : Short.valueOf((short) r.nextInt());
    myInt = (randField == field++) ? null : Integer.valueOf(r.nextInt());
    myLong = (randField == field++) ? null : Long.valueOf(r.nextLong());
    myFloat = (randField == field++) ? null : Float.valueOf(r.nextFloat() * 10 - 5);
    myDouble = (randField == field++) ? null : Double.valueOf(r.nextDouble() * 10 - 5);
    myString = (randField == field++) ? null : MyTestPrimitiveClass.getRandString(r);
    myHiveChar = (randField == field++) ? null : MyTestPrimitiveClass.getRandHiveChar(r, extraTypeInfo);
    myHiveVarchar = (randField == field++) ? null : MyTestPrimitiveClass.getRandHiveVarchar(r, extraTypeInfo);
    myBinary = MyTestPrimitiveClass.getRandBinary(r, r.nextInt(1000));
    myDecimal = (randField == field++) ? null : MyTestPrimitiveClass.getRandHiveDecimal(r, extraTypeInfo);
    myDate = (randField == field++) ? null : MyTestPrimitiveClass.getRandDate(r);
    myTimestamp = (randField == field++) ? null : RandomTypeUtil.getRandTimestamp(r);
    myIntervalYearMonth = (randField == field++) ? null : MyTestPrimitiveClass.getRandIntervalYearMonth(r);
    myIntervalDayTime = (randField == field++) ? null : MyTestPrimitiveClass.getRandIntervalDayTime(r);

    myStruct = (randField == field++) ? null : new MyTestInnerStruct(r.nextInt(5) - 2, r.nextInt(5) - 2);
    myList = (randField == field++) ? null : getRandIntegerArray(r);
    return field;
}

From source file:dremel.common.AvroTest.java

@SuppressWarnings(value = "unchecked")
private static Object generateRandomDataRecursive(Schema schema, Random random, int size) {
    switch (schema.getType()) {
    case RECORD://from   w w  w . ja  v  a 2 s  . c o  m
        GenericRecord record = new GenericData.Record(schema);
        boolean isFieldsEmpty = true;
        for (Schema.Field field : schema.getFields()) {
            Object o = generateRandomDataRecursive(field.schema(), random, size);
            if (o != null) {
                record.put(field.name(), o);
                isFieldsEmpty = isFieldsEmpty && o instanceof GenericArray
                        && ((GenericArray<Object>) o).size() == 0;
            }
        }
        return isFieldsEmpty ? null : record;
    case ARRAY:
        int length = size + (random.nextInt(10));
        GenericArray<Object> array = new GenericData.Array<Object>(length <= 0 ? 0 : length, schema);
        Object o;
        for (int i = 0; i < length; i++) {
            o = generateRandomDataRecursive(schema.getElementType(), random, size > 0 ? size - 1 : 0);
            if (o != null)
                array.add(o);
        }
        return array;
    case STRING:
        return generateRandomUtf8(random, 40);
    case INT:
        return random.nextInt();
    case LONG:
        return random.nextLong();
    case FLOAT:
        return random.nextFloat();
    case DOUBLE:
        return random.nextDouble();
    case BOOLEAN:
        return random.nextBoolean();
    default:
        throw new RuntimeException("Unknown type: " + schema);
    }
}

From source file:com.cburch.draw.shapes.Poly.java

private Location getRandomBoundaryPoint(Bounds bds, Random rand) {
    Handle[] hs = handles;//from  w w w . jav  a2 s.c o  m
    double[] ls = lens;
    if (ls == null) {
        ls = new double[hs.length + (closed ? 1 : 0)];
        double total = 0.0;
        for (int i = 0; i < ls.length; i++) {
            int j = (i + 1) % hs.length;
            total += LineUtil.distance(hs[i].getX(), hs[i].getY(), hs[j].getX(), hs[j].getY());
            ls[i] = total;
        }
        lens = ls;
    }
    double pos = ls[ls.length - 1] * rand.nextDouble();
    for (int i = 0; true; i++) {
        if (pos < ls[i]) {
            Handle p = hs[i];
            Handle q = hs[(i + 1) % hs.length];
            double u = Math.random();
            int x = (int) Math.round(p.getX() + u * (q.getX() - p.getX()));
            int y = (int) Math.round(p.getY() + u * (q.getY() - p.getY()));
            return Location.create(x, y);
        }
    }
}

From source file:MetaFramework.Bayesian.java

/**
 * Draws a number from poisson distribution
 *
 * @param l//w  ww  .  j a  v a  2  s.c  om
 * @return
 */
public int poisson(double l) {
    Random random = new Random();
    double limit = Math.exp(-l);
    double prod = random.nextDouble();
    int n = 0;
    for (n = 0; prod >= limit; n++)
        prod *= random.nextDouble();

    return n;
}

From source file:com.adflake.AdFlakeManager.java

public Ration getNextDartedVideoRation(List<Ration> usedVideoRations) {
    Random random = new Random();

    double actualWeight = 0;

    for (Ration ration : _videoRationsList) {
        if (usedVideoRations.contains(ration))
            continue;

        actualWeight += ration.weight;//from  ww  w  .j  a va 2  s  . c  om
    }

    double r = random.nextDouble() * actualWeight;
    double s = 0;

    Log.d(AdFlakeUtil.ADFLAKE,
            "Dart is <" + r + "> of <" + actualWeight + "> and total <" + _totalWeight + ">");

    Iterator<Ration> it = this._videoRationsList.iterator();
    Ration ration = null;
    while (it.hasNext()) {
        ration = it.next();

        if (usedVideoRations.contains(ration))
            continue;

        s += ration.weight;

        if (s >= r) {
            break;
        }
    }

    return ration;
}

From source file:org.apache.hadoop.hbase.client.TestBatchedUpload.java

/**
 * Write data to the htable. While randomly killing/shutting down regionservers.
 * @param table/*from   www .java  2s .c om*/
 * @param numRows
 * @param action -- enum RegionServerAction which defines the type of action.
 * @return number of attempts to complete the batch.
 * @throws IOException
 * @throws InterruptedException 
 */
public int writeData(HTable table, long numRows, RegionServerAction action)
        throws IOException, InterruptedException {
    int attempts = 0;
    int MAX = 10;
    MiniHBaseCluster cluster = TEST_UTIL.getMiniHBaseCluster();
    Random rand = new Random(5234234);
    double killProb = 2.0 / numRows;
    double prob;
    int kills = 0;

    while (attempts < MAX) {
        try {
            attempts++;

            // start batched session
            table.startBatchedLoad();

            // do batched puts
            // with WAL turned off
            for (long i = 0; i < numRows; i++) {
                byte[] rowKey = longToByteArrayKey(i);
                Put put = new Put(rowKey);
                byte[] value = rowKey; // value is the same as the row key
                put.add(FAMILY, QUALIFIER, value);
                put.setWriteToWAL(false);

                prob = rand.nextDouble();
                if (kills < 2 && prob < killProb) { // kill up to 2 rs
                    kills++;
                    // Find the region server for the next put
                    HRegionLocation regLoc = table.getRegionLocation(put.row);
                    int srcRSIdx = cluster.getServerWith(regLoc.getRegionInfo().getRegionName());

                    LOG.debug("Try " + attempts + " written Puts : " + i);
                    if (action == RegionServerAction.KILL_REGIONSERVER) {
                        // abort the region server
                        LOG.info("Killing region server " + srcRSIdx + " before the next put. Got probability "
                                + prob + " < " + killProb);
                        cluster.abortRegionServer(srcRSIdx);

                    } else if (action == RegionServerAction.MOVE_REGION) {

                        // move the region to some other Region Server
                        HRegionServer dstRS = cluster
                                .getRegionServer((srcRSIdx + 1) % cluster.getLiveRegionServerThreads().size());
                        LOG.info("Moving region " + regLoc.getRegionInfo().getRegionName() + "from "
                                + cluster.getRegionServer(srcRSIdx) + " to " + dstRS);
                        moveRegionAndWait(cluster.getRegionServer(srcRSIdx)
                                .getOnlineRegion(regLoc.getRegionInfo().getRegionName()), dstRS);
                    }
                    // keep decreasing the probability of killing the RS
                    killProb = killProb / 2;
                }
                table.put(put);
            }

            LOG.info("Written all puts. Trying to end Batch");
            // complete batched puts
            table.endBatchedLoad();
            return attempts;

        } catch (IOException e) {
            e.printStackTrace();
            LOG.info("Failed try # " + attempts);
        }
    }

    throw new IOException("Failed to do batched puts after " + MAX + " retries.");
}

From source file:hivemall.anomaly.ChangeFinder2DTest.java

@Test
public void testPoissonDist() throws HiveException {
    final int examples = 10000;
    final int dims = 3;
    final PoissonDistribution[] poisson = new PoissonDistribution[] { new PoissonDistribution(10.d),
            new PoissonDistribution(5.d), new PoissonDistribution(20.d) };
    final Random rand = new Random(42);
    final Double[] x = new Double[dims];
    final List<Double> xList = Arrays.asList(x);

    Parameters params = new Parameters();
    params.set(LossFunction.logloss);//from  ww w.j  a v a  2s  . c o m
    params.r1 = 0.01d;
    params.k = 6;
    params.T1 = 10;
    params.T2 = 5;
    PrimitiveObjectInspector oi = PrimitiveObjectInspectorFactory.javaDoubleObjectInspector;
    ListObjectInspector listOI = ObjectInspectorFactory.getStandardListObjectInspector(oi);
    final ChangeFinder2D cf = new ChangeFinder2D(params, listOI);
    final double[] outScores = new double[2];

    println("# time x0 x1 x2 outlier change");
    for (int i = 0; i < examples; i++) {
        double r = rand.nextDouble();
        x[0] = r * poisson[0].sample();
        x[1] = r * poisson[1].sample();
        x[2] = r * poisson[2].sample();

        cf.update(xList, outScores);
        printf("%d %f %f %f %f %f%n", i, x[0], x[1], x[2], outScores[0], outScores[1]);
    }
}