Example usage for org.apache.mahout.math.jet.random Exponential nextDouble

Introduction

In this page you can find the example usage for org.apache.mahout.math.jet.random Exponential nextDouble.

Prototype

@Override
public double nextDouble() 

Source Link

Document

Returns a random number from the distribution.

Usage

From source file:com.mapr.franz.Traffic.java

License:Apache License

public static void main(String[] args) throws InterruptedException, IOException, ServiceException {
    Options options = parseOptions(args);
    log.warn("Options = {}", options.toString());

    double scale = Math.log(options.ratio) / 2;

    Client client = new Client(Collections.singleton(new PeerInfo(options.host, options.port)));

    History recorder = new History(1, 10, 30).logTicks();

    Random gen = RandomUtils.getRandom();
    ChineseRestaurant topicSampler = new ChineseRestaurant(options.alpha);
    Exponential interval = new Exponential(1, gen);
    double t = 0;
    long t0 = System.nanoTime();
    long messageId = 0;
    while (messageId < options.max) {
        double rate = options.peak * Math.exp(-scale * (Math.cos(2 * Math.PI * t / options.period) + 1));
        double dt = interval.nextDouble() / rate;
        t += dt;// w  w w.jav  a 2  s.  c o  m
        double now = (System.nanoTime() - t0) / 1e9;
        if (t > now + 0.01) {
            double millis = Math.floor((t - now) * 1000);
            double nanos = Math.rint((t - now) * 1e9 - millis * 1e6);
            Thread.sleep((long) millis, (int) nanos);
        }

        String topic = "topic-" + topicSampler.sample();
        String message = "m-" + (++messageId);
        client.sendMessage(topic, message);
        recorder.message(topic);
        log.debug("Sent {} / {}", topic, message);
        if ((messageId % 10000) == 0) {
            log.warn("Sent {} messages", messageId);
        }
    }
}

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From source file:com.mapr.synth.samplers.CommonPointOfCompromise.java

License:Apache License

@Override
public JsonNode sample() {
    ArrayNode r = nodeFactory.arrayNode();

    double t = start;
    double averageInterval = TimeUnit.MILLISECONDS.convert(1, TimeUnit.DAYS) / transactionsPerDay.nextDouble();
    Exponential interval = new Exponential(1 / averageInterval, gen);

    Date date = new Date();
    boolean compromised = false;
    while (t < end) {
        ObjectNode transaction = new ObjectNode(nodeFactory);
        t += interval.nextDouble();
        date.setTime((long) t);
        transaction.set("timestamp", new LongNode((long) (t / 1000)));
        transaction.set("date", new TextNode(df.format(date)));
        Integer merchantId = merchant.sample();
        transaction.set("merchant", new IntNode(merchantId));

        if (merchantId == 0 && t >= compromiseStart && t < compromiseEnd) {
            compromised = true;/*from  ww w .  j a  v a 2s  . co m*/
            transaction.set("compromise", new IntNode(1));
        } else {
            transaction.set("compromise", new IntNode(0));
        }

        if (t > exploitEnd) {
            compromised = false;
        }

        double pFraud;
        if (t >= exploitStart && compromised) {
            pFraud = compromisedFraudRate;
        } else {
            pFraud = uncompromisedFraudRate;
        }

        transaction.set("fraud", new IntNode((gen.nextDouble() < pFraud) ? 1 : 0));

        r.add(transaction);
    }
    return r;
}

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