Example usage for java.lang Math random

Introduction

In this page you can find the example usage for java.lang Math random.

Prototype

public static double random()

Source Link

Document

Returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0 .

Usage

From source file:Main.java

public static double cauchy(double u, double s) {
    double res = Math.random();
    double x = Math.tan(Math.PI * (res - 0.5));
    return u + s * x;
}

From source file:Main.java

public static <V> V getRandom(Collection<V> collection) {

    if (collection.isEmpty()) {
        return null;
    }/*from  ww w  . j a  v a 2s . c  om*/

    int randIdx = (int) Math.round(Math.random() * (collection.size() - 1));
    int count = 0;
    Iterator<V> iterator = collection.iterator();
    while (iterator.hasNext()) {
        V current = iterator.next();
        if (count == randIdx) {
            return current;
        }
        count++;
    }

    throw new RuntimeException("Shouldn't happen");
}

From source file:Main.java

public static String toNumberPassword(int length) {
    if (length < 1) {
        return null;
    }//  w  ww  . j  av a  2 s . c o m
    String strChars[] = { "1", "2", "3", "4", "5", "6", "7", "8", "9" };
    StringBuffer strPassword = new StringBuffer();
    int nRand = (int) Math.round(Math.random() * 100D);
    for (int i = 0; i < length; i++) {
        nRand = (int) Math.round(Math.random() * 100D);
        strPassword.append(strChars[nRand % (strChars.length - 1)]);
    }
    return strPassword.toString();
}

From source file:com.cssweb.android.connect.ConnPool.java

public static JSONObject sendReq(String funcname, String funcno, String reqbuf) throws JSONException {
    StringBuffer sb = new StringBuffer();
    sb.append(TradeUtil.getGlobalRequest(funcname, funcno));
    sb.append(reqbuf);/*ww w  . ja v  a2 s  .  c  o m*/
    sb.append("&ram=" + Math.random());
    String sbStr = sb.toString();
    if ("190101".equals(funcno) || "203113".equals(funcno) || "203111".equals(funcno) || "203526".equals(funcno)
            || "203119".equals(funcno) || "202010".equals(funcno) || "202012".equals(funcno)) {
        sbStr = sbStr.replace("isSafe=0", "isSafe=1");
    }
    Log.i("==", sbStr);
    String req = "";
    try {
        req = new String(Base64.encode(sbStr.getBytes("gb2312")));
    } catch (UnsupportedEncodingException e1) {
        e1.printStackTrace();
    }
    req = TradeUtil.getResult(req);

    Log.i(">>>>>url>>>>>>>", getURL() + req);
    return Conn.tradeReq(getURL() + req);
}

From source file:Main.java

/**
 * Gat random item./*from  w  w  w. j a  va  2 s  .co  m*/
 *
 * @param items
 *            the items
 * @return the object
 */
// //////////////////////////////////////////////////////////
public static Object gatRandomItem(final List items) {
    if (items == null || items.size() == 0) {
        return null;
    }
    final int itemIndex = (int) (Math.random() * items.size());
    return items.get(itemIndex);
}

From source file:Main.java

public static double frandom(double a, double b)
// Random real within range [a,b[
{
    return (b - a) * Math.random() + a;
}

From source file:Main.java

public static int irandom(int a, int b)
// Random integer within range {a,...,b}    
{
    return (int) ((b + 1 - a) * Math.random()) + a;
}

From source file:Main.java

/**
 * Method to add a random delay or if none to yield to give any waiting
 * threads a chance. This helps make test threaded code more random to track
 * synchronized issues.//w  ww.j  a  v  a2 s.  co m
 *
 * @param millis
 *            up to the many ms
 * @return actual sleep time
 */
public static final int sleepUpTo(final long millis) {
    try {
        if (millis > 0) {
            int realSleep = (int) Math.floor(Math.random() * (millis + 1));
            if (realSleep > 0) {
                Thread.sleep(realSleep);
                return realSleep;
            } else {
                // Give any waiting threads a go
                Thread.yield();
                return 0;
            }
        }
    } catch (final InterruptedException e) {
        // It's not an error that we were Interrupted!! Don't log the
        // exception !
        return -1;
    }
    return 0;
}

From source file:org.jfree.chart.demo.DefaultXYDatasetDemo2.java

private static XYDataset createDataset() {
    DefaultXYDataset defaultxydataset = new DefaultXYDataset();
    double ad[] = new double[1000];
    double ad1[] = new double[1000];
    for (int i = 0; i < 1000; i++) {
        ad[i] = Math.random() + 1.0D;
        ad1[i] = Math.random() + 1.0D;
    }/*  w  w  w  .jav a 2s  .c  o  m*/

    double ad2[][] = { ad, ad1 };
    defaultxydataset.addSeries("Series 1", ad2);
    return defaultxydataset;
}

From source file:net.estinet.gFeatures.Feature.FusionPlay.GameUtil.WorldUtil.java

public static void initializeGame() {
    FusionGame fg = FusionPlay.currentGame;
    int random = (int) (Math.random() * (fg.getMaps().size()));
    Debug.print("[FusionPlay] World magic number: " + random);
    FusionPlay.currentGame.setFusionMap(fg.getMaps().get(random));
    copyWorld(fg.getMaps().get(random).getFile());
}