Example usage for java.util Random nextDouble

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:com.caseystella.analytics.outlier.streaming.mad.SketchyMovingMADTest.java

@Test
public void testSketchyMovingMAD() throws IOException {
    Random r = new Random(0);
    List<DataPoint> points = new ArrayList<>();
    DescriptiveStatistics stats = new DescriptiveStatistics();
    DescriptiveStatistics medianStats = new DescriptiveStatistics();
    OutlierConfig config = JSONUtil.INSTANCE.load(madConfig, OutlierConfig.class);
    SketchyMovingMAD madAlgo = ((SketchyMovingMAD) config.getSketchyOutlierAlgorithm()).withConfig(config);
    int i = 0;// w ww  . j  av  a  2 s . co  m
    for (i = 0; i < 10000; ++i) {
        double val = r.nextDouble() * 1000 - 10000;
        stats.addValue(val);
        DataPoint dp = (new DataPoint(i, val, null, "foo"));
        madAlgo.analyze(dp);
        points.add(dp);
    }
    for (DataPoint dp : points) {
        medianStats.addValue(Math.abs(dp.getValue() - stats.getPercentile(50)));
    }
    double mad = medianStats.getPercentile(50);
    double median = stats.getPercentile(50);
    {
        double val = getValAtModifiedZScore(3.6, mad, median);
        System.out.println("MODERATE => " + val);
        DataPoint dp = (new DataPoint(i++, val, null, "foo"));
        Severity s = madAlgo.analyze(dp).getSeverity();
        Assert.assertTrue(s == Severity.MODERATE_OUTLIER);
    }
    {
        double val = getValAtModifiedZScore(6, mad, median);
        System.out.println("SEVERE => " + val);
        DataPoint dp = (new DataPoint(i++, val, null, "foo"));
        Severity s = madAlgo.analyze(dp).getSeverity();
        Assert.assertTrue(s == Severity.SEVERE_OUTLIER);
    }

    Assert.assertTrue(madAlgo.getMedianDistributions().get("foo").getAmount() <= 110);
    Assert.assertTrue(madAlgo.getMedianDistributions().get("foo").getChunks().size() <= 12);
}

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From source file:com.google.android.apps.santatracker.presentquest.PlacesIntentService.java

private LatLng randomLatLng(LatLng center, int radius) {
    // Based on http://gis.stackexchange.com/questions/25877/how-to-generate-random-locations-nearby-my-location
    Random random = new Random();
    double radiusInDegrees = radius / 111000f;
    double u = random.nextDouble();
    double v = random.nextDouble();
    double w = radiusInDegrees * Math.sqrt(u);
    double t = 2 * Math.PI * v;
    double x = w * Math.cos(t);
    double y = w * Math.sin(t);
    double new_x = x / Math.cos(center.latitude);
    return new LatLng(y + center.latitude, new_x + center.longitude);
}

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From source file:com.example.geomesa.lambda.LambdaQuickStart.java

@Override
public void run() {
    try {/*from ww w  . jav  a2s .  co  m*/
        // create the schema
        final String sftName = "lambda-quick-start";
        final String sftSchema = "name:String,age:Int,dtg:Date,*geom:Point:srid=4326";
        SimpleFeatureType sft = SimpleFeatureTypes.createType(sftName, sftSchema);

        if (ds.getSchema(sftName) != null) {
            out.println("'" + sftName + "' feature type already exists - quick start will not work correctly");
            out.println("Please delete it and re-run");
            return;
        }

        out.println("Creating feature type '" + sftName + "'");

        ds.createSchema(sft);

        out.println("Feature type created - register the layer '" + sftName
                + "' in geoserver then hit <enter> to continue");
        in.read();

        SimpleFeatureWriter writer = ds.getFeatureWriterAppend(sftName, Transaction.AUTO_COMMIT);

        out.println("Writing features to Kafka... refresh GeoServer layer preview to see changes");

        // creates and adds SimpleFeatures to the producer every 1/5th of a second

        final int COUNT = 1000;
        final int MIN_X = -180;
        final int MAX_X = 180;
        final int MIN_Y = -90;
        final int MAX_Y = 90;
        final int DX = 2;
        final String[] PEOPLE_NAMES = { "James", "John", "Peter", "Hannah", "Claire", "Gabriel" };
        final long SECONDS_PER_YEAR = 365L * 24L * 60L * 60L;
        ZonedDateTime MIN_DATE = ZonedDateTime.of(2015, 1, 1, 0, 0, 0, 0, ZoneOffset.UTC);
        final Random random = new Random();

        int numUpdates = (MAX_X - MIN_X) / DX;
        for (int j = 0; j < numUpdates; j++) {
            for (int i = 0; i < COUNT; i++) {
                SimpleFeature feature = writer.next();
                feature.setAttribute(0, PEOPLE_NAMES[i % PEOPLE_NAMES.length]); // name
                feature.setAttribute(1, (int) Math.round(random.nextDouble() * 110)); // age
                feature.setAttribute(2, Date.from(MIN_DATE
                        .plusSeconds((int) Math.round(random.nextDouble() * SECONDS_PER_YEAR)).toInstant())); // dtg
                feature.setAttribute(3, "POINT(" + (MIN_X + (DX * j)) + " "
                        + (MIN_Y + ((MAX_Y - MIN_Y) / ((double) COUNT)) * i) + ")"); // geom
                feature.getUserData().put(Hints.PROVIDED_FID, String.format("%04d", i));
                writer.write();
            }
            Thread.sleep(200);
        }

        writer.close();

        out.println("Waiting for expiry and persistence...");

        long total = 0, persisted = 0;
        do {
            long newTotal = (long) ds.stats().getCount(sft, Filter.INCLUDE, true).get();
            long newPersisted = (long) ((AccumuloDataStore) ds.persistence()).stats()
                    .getCount(sft, Filter.INCLUDE, true).get();
            if (newTotal != total || newPersisted != persisted) {
                total = newTotal;
                persisted = newPersisted;
                out.println("Total features: " + total + ", features persisted to Accumulo: " + persisted);
            }
            Thread.sleep(100);
        } while (persisted < COUNT || total > COUNT);
    } catch (Exception e) {
        throw new RuntimeException(e);
    } finally {
        ds.dispose();
    }
}

---

From source file:mase.app.allocation.AllocationProblem.java

private double[][] generateDispersedPoints(Random rand, int num, double distThreshold, double[] min,
        double[] max) {
    double[][] points = new double[num][];
    int filled = 0;
    while (filled < num) {
        // generate random
        double[] candidate = new double[dimensions];
        for (int i = 0; i < candidate.length; i++) {
            candidate[i] = min[i] + rand.nextDouble() * (max[i] - min[i]);
        }/* w  ww  .  j av  a 2  s. co  m*/
        // check if it is not similar to a previous one
        boolean ok = true;
        if (distThreshold > 0) {
            for (int i = 0; i < filled; i++) {
                if (DIST.compute(points[i], candidate) < distThreshold) {
                    ok = false;
                    break;
                }
            }
        }
        // add it
        if (ok) {
            points[filled] = candidate;
            filled++;
        }
    }
    return points;
}

---

From source file:edu.washington.gs.skyline.model.quantification.WeightedRegressionTest.java

public void testWeighted() {
    Random random = new Random((int) new Date().getTime());
    SimpleRegression simpleRegressionWithIntercept = new SimpleRegression(true);
    SimpleRegression simpleRegressionWithoutIntercept = new SimpleRegression(false);
    final int nPoints = 10;
    double[][] xValues = new double[nPoints][];
    double[] yValues = new double[nPoints];
    double[] weights = new double[nPoints];
    for (int i = 0; i < nPoints; i++) {
        int weight = random.nextInt(10) + 1;
        weights[i] = weight;/*from w w  w . ja  v a  2 s  . com*/
        double x = random.nextDouble();
        double y = random.nextDouble();
        xValues[i] = new double[] { x };
        yValues[i] = y;
        for (int w = 0; w < weight; w++) {
            simpleRegressionWithIntercept.addData(x, y);
            simpleRegressionWithoutIntercept.addData(x, y);
        }
    }
    final double epsilon = 1E-12;
    double repeatedIntercept = simpleRegressionWithIntercept.getIntercept();
    double repeatedSlope = simpleRegressionWithIntercept.getSlope();

    double[] weightedRegression = WeightedRegression.weighted(xValues, yValues, weights, true);
    assertEquals(repeatedIntercept, weightedRegression[0], epsilon);
    assertEquals(repeatedSlope, weightedRegression[1], epsilon);
    double[] weightedRegressionWithoutIntercept = WeightedRegression.weighted(xValues, yValues, weights, false);

    double repeatedSlopeWithoutIntercept = simpleRegressionWithoutIntercept.getSlope();
    assertEquals(repeatedSlopeWithoutIntercept, weightedRegressionWithoutIntercept[0], epsilon);

}

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From source file:tools.RunSingleTileTest.java

private GetVectorTileRequest createRequest() {
    GetVectorTileRequest request = new GetVectorTileRequest();
    Random rand = new Random();
    TileCode code = new TileCode(5, 16, 8);
    request.setCode(code);//from  w  w  w. j  a  va 2  s .  c  o m
    request.setLayerId(KtunaxaConstant.LAYER_REFERENCE_BASE_SERVER_ID);
    request.setCrs(KtunaxaConstant.MAP_CRS);
    // request.setScale(0.006541332273339661);
    request.setPanOrigin(new Coordinate(-1.2803202237767024E7, 6306054.833527042));
    NamedStyleInfo style = new NamedStyleInfo();
    style.setName("referenceBaseStyleInfo");
    request.setStyleInfo(style);
    request.setScale(0.05233065818671729 + rand.nextDouble() / 1000);
    request.setPaintGeometries(true);
    request.setPaintLabels(false);
    request.setFilter("layer_id = 1 or layer_id = 2 or layer_id = 5 or layer_id = 6 or layer_id = 7 or "
            + "layer_id = 8 or layer_id = 9 or layer_id = 19 or layer_id = 20 or layer_id = 20 or "
            + "layer_id = 22 or layer_id = 22 or layer_id = 24 or layer_id = 25 or layer_id = 26 or "
            + "layer_id = 27 or layer_id = 28 or layer_id = 34 or layer_id = 78 or layer_id = 79 or "
            + "layer_id = 82 or layer_id = 83");
    return request;
}

---

From source file:com.linkedin.pinot.segments.v1.creator.OnHeapDictionariesTest.java

/**
 * Helper method to build a segment with random data as per the schema.
 *
 * @param segmentDirName Name of segment directory
 * @param segmentName Name of segment//from w w  w  .  ja v  a2 s  . c o  m
 * @param schema Schema for segment
 * @return Schema built for the segment
 * @throws Exception
 */
private Schema buildSegment(String segmentDirName, String segmentName, Schema schema) throws Exception {

    SegmentGeneratorConfig config = new SegmentGeneratorConfig(schema);
    config.setOutDir(segmentDirName);
    config.setFormat(FileFormat.AVRO);
    config.setSegmentName(segmentName);

    Random random = new Random(RANDOM_SEED);

    List<GenericRow> rows = new ArrayList<>(NUM_ROWS);

    for (int rowId = 0; rowId < NUM_ROWS; rowId++) {
        HashMap<String, Object> map = new HashMap<>();

        map.put(INT_COLUMN, random.nextInt());
        map.put(LONG_COLUMN, random.nextLong());
        map.put(FLOAT_COLUMN, random.nextFloat());
        map.put(DOUBLE_COLUMN, random.nextDouble());
        map.put(STRING_COLUMN, RandomStringUtils.randomAscii(100));

        GenericRow genericRow = new GenericRow();
        genericRow.init(map);
        rows.add(genericRow);
    }

    SegmentIndexCreationDriverImpl driver = new SegmentIndexCreationDriverImpl();
    driver.init(config, new GenericRowRecordReader(rows, schema));
    driver.build();

    LOGGER.info("Built segment {} at {}", segmentName, segmentDirName);
    return schema;
}

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From source file:org.apache.ctakes.ytex.kernel.FoldGeneratorImpl.java

/**
 * iterate through the labels, split instances into folds
 * /*from  w  w  w  .ja  va 2s . co  m*/
 * @param mapClassToInstanceId
 * @param nFolds
 * @param nMinPerClass
 * @param nSeed
 * @return list with nFolds sets of instance ids corresponding to the folds
 */
private static List<Set<Long>> createFolds(Map<String, List<Long>> mapClassToInstanceId, int nFolds,
        int nMinPerClass, Random r) {
    List<Set<Long>> folds = new ArrayList<Set<Long>>(nFolds);
    Map<String, List<Set<Long>>> mapLabelFolds = new HashMap<String, List<Set<Long>>>();
    for (Map.Entry<String, List<Long>> classToInstanceId : mapClassToInstanceId.entrySet()) {
        List<Long> instanceIds = classToInstanceId.getValue();
        Collections.shuffle(instanceIds, r);
        List<Set<Long>> classFolds = new ArrayList<Set<Long>>(nFolds);
        int blockSize = instanceIds.size() / nFolds;
        for (int i = 0; i < nFolds; i++) {
            Set<Long> foldInstanceIds = new HashSet<Long>(blockSize);
            if (instanceIds.size() <= nMinPerClass) {
                // we don't have minPerClass for the given class
                // just add all of them to each fold
                foldInstanceIds.addAll(instanceIds);
            } else if (blockSize < nMinPerClass) {
                // too few of the given class - just randomly select
                // nMinPerClass
                double fraction = (double) nMinPerClass / (double) instanceIds.size();
                // iterate through the list, start somewhere in the middle
                int instanceIdIndex = (int) (r.nextDouble() * instanceIds.size());
                while (foldInstanceIds.size() < nMinPerClass) {
                    // go back to beginning of list if we hit the end
                    if (instanceIdIndex >= instanceIds.size()) {
                        instanceIdIndex = 0;
                    }
                    // randomly select this line
                    if (r.nextDouble() <= fraction) {
                        long instanceId = instanceIds.get(instanceIdIndex);
                        foldInstanceIds.add(instanceId);
                    }
                    // go to next line
                    instanceIdIndex++;
                }
            } else {
                int nStart = i * blockSize;
                int nEnd = (i == nFolds - 1) ? instanceIds.size() : nStart + blockSize;
                for (int instanceIdIndex = nStart; instanceIdIndex < nEnd; instanceIdIndex++) {
                    foldInstanceIds.add(instanceIds.get(instanceIdIndex));
                }
            }
            classFolds.add(foldInstanceIds);
        }
        mapLabelFolds.put(classToInstanceId.getKey(), classFolds);
    }
    for (int i = 0; i < nFolds; i++) {
        Set<Long> foldInstanceIds = new HashSet<Long>();
        for (List<Set<Long>> labelFold : mapLabelFolds.values()) {
            foldInstanceIds.addAll(labelFold.get(i));
        }
        folds.add(foldInstanceIds);
    }
    return folds;
}

---

From source file:com.pivotal.gemfire.tools.pulse.testbed.PropMockDataUpdater.java

private Client initMemberClient(int count, String host) {

    Client memberClient = new Client();
    Random r = new Random(System.currentTimeMillis());
    memberClient.setName("Name_" + count);
    long processCpuTime = (long) (r.nextDouble() * 100);
    memberClient.setProcessCpuTime(processCpuTime);
    memberClient.setCpuUsage(0);// w ww .  j ava  2s. co m
    memberClient.setGets(Math.abs(r.nextInt(100)));
    memberClient.setHost(host);
    memberClient.setId(String.valueOf(1000 + count));
    memberClient.setPuts(Math.abs(r.nextInt(100)));
    memberClient.setCpus(Math.abs(r.nextInt(20)));
    memberClient.setQueueSize(Math.abs(r.nextInt(100)));
    if ((count % 2) == 0) {
        memberClient.setStatus("up");
    } else {
        memberClient.setStatus("down");
    }
    memberClient.setThreads(Math.abs(r.nextInt(100)));
    memberClient.setUptime(Math.abs(System.currentTimeMillis() - r.nextLong()));

    return memberClient;
}

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From source file:org.apache.hadoop.hbase.stargate.TestScannerResource.java

int insertData(String tableName, String column, double prob) throws IOException {
    Random rng = new Random();
    int count = 0;
    HTable table = new HTable(conf, tableName);
    byte[] k = new byte[3];
    byte[][] famAndQf = KeyValue.parseColumn(Bytes.toBytes(column));
    for (byte b1 = 'a'; b1 < 'z'; b1++) {
        for (byte b2 = 'a'; b2 < 'z'; b2++) {
            for (byte b3 = 'a'; b3 < 'z'; b3++) {
                if (rng.nextDouble() < prob) {
                    k[0] = b1;//from w ww.j av a2s .  c  o m
                    k[1] = b2;
                    k[2] = b3;
                    Put put = new Put(k);
                    if (famAndQf.length > 1 && famAndQf[1] != null) {
                        put.add(famAndQf[0], famAndQf[1], k);
                    } else {
                        put.add(famAndQf[0], null, k);
                    }
                    table.put(put);
                    count++;
                }
            }
        }
    }
    table.flushCommits();
    return count;
}

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