org.uncommons.maths.random
Class XORShiftRNG

java.lang.Object
  java.util.Random
      org.uncommons.maths.random.XORShiftRNG

All Implemented Interfaces:

Serializable, RepeatableRNG

public class XORShiftRNG
extends Random
implements RepeatableRNG

Very fast pseudo random number generator. See this page for a description. This RNG has a period of about 2^160, which is not as long as the MersenneTwisterRNG but it is faster.

NOTE: Because instances of this class require 160-bit seeds, it is not possible to seed this RNG using the Random.setSeed(long) method inherited from Random. Calls to this method will have no effect. Instead the seed must be set by a constructor.

Since:

1.2

Author:

Daniel Dyer

See Also:

Serialized Form

Constructor Summary

XORShiftRNG()
Creates a new RNG and seeds it using the default seeding strategy.

XORShiftRNG(byte[] seed)
Creates an RNG and seeds it with the specified seed data.

XORShiftRNG(SeedGenerator seedGenerator)
Seed the RNG using the provided seed generation strategy.

Method Summary

byte[]	getSeed()
protected int	next(int bits)

Methods inherited from class java.util.Random

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

Methods inherited from class java.lang.Object

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

Constructor Detail

XORShiftRNG

public XORShiftRNG()

Creates a new RNG and seeds it using the default seeding strategy.

XORShiftRNG

public XORShiftRNG(SeedGenerator seedGenerator)
            throws SeedException

Seed the RNG using the provided seed generation strategy.

Parameters:

seedGenerator - The seed generation strategy that will provide the seed value for this RNG.

Throws:

SeedException - If there is a problem generating a seed.

XORShiftRNG

public XORShiftRNG(byte[] seed)

Creates an RNG and seeds it with the specified seed data.

Parameters:

seed - The seed data used to initialise the RNG.

Method Detail

getSeed

public byte[] getSeed()

Specified by:

getSeed in interface RepeatableRNG

Returns:

The seed data used to initialise this pseudo-random number generator.

next

protected int next(int bits)

Overrides:

next in class Random