y.util
Class YRandom

java.lang.Object
  java.util.Random
      y.util.YRandom

All Implemented Interfaces:

Serializable

public class YRandom
extends Random

Generates pseudo-random numbers and the such.

See Also:

Serialized Form

Constructor Summary

YRandom()
Creates a new instance of this class.

YRandom(long seed)
Creates a new instance of this class with a given initial random seed.

Method Summary

boolean[]	getBoolArray(int n, int trueCount) Returns an array of n randomly chosen boolean values of which trueCount of them are true.
int[]	getIntArray(int bucketCount, int ballCount) Returns an int array of length bucketCount for which the values of all fields are non-negative and sum up to ballCount.
int[]	getUniqueArray(int n, int min, int max) Returns an array of n unique random integers that lie within the range min (inclusive) and max (exclusive).
double	nextDouble(double minValue, double maxValue) Returns a double with a random value between minValue (inclusive) and maxValue (exclusive).
int	nextInt(int n) Returns a pseudo-random, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
int	nextInt(int minValue, int maxValue) Returns an int with a random value between minValue (inclusive) and maxValue (exclusive).
void	permutate(Object[] a) Permutes the positions of the elements within the given array.

Methods inherited from class java.util.Random

next, nextBoolean, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextLong, setSeed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

YRandom

public YRandom()

Creates a new instance of this class.

YRandom

public YRandom(long seed)

Creates a new instance of this class with a given initial random seed.

Method Detail

nextInt

public int nextInt(int n)

Returns a pseudo-random, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.

Overrides:

nextInt in class Random

getUniqueArray

public int[] getUniqueArray(int n,
                            int min,
                            int max)

Returns an array of n unique random integers that lie within the range min (inclusive) and max (exclusive). If max - min < n then null is returned.

getBoolArray

public boolean[] getBoolArray(int n,
                              int trueCount)

Returns an array of n randomly chosen boolean values of which trueCount of them are true. If the requested numbers of true values is bigger than the number of requested boolean values, an Exception is raised.

getIntArray

public int[] getIntArray(int bucketCount,
                         int ballCount)

Returns an int array of length bucketCount for which the values of all fields are non-negative and sum up to ballCount. The values are put in the array randomly.

nextDouble

public double nextDouble(double minValue,
                         double maxValue)

Returns a double with a random value between minValue (inclusive) and maxValue (exclusive).

Precondition:

maxValue > minValue

nextInt

public int nextInt(int minValue,
                   int maxValue)

Returns an int with a random value between minValue (inclusive) and maxValue (exclusive).

Precondition:

maxValue > minValue

permutate

public void permutate(Object[] a)

Permutes the positions of the elements within the given array.