Class XORShiftRNG

java.lang.Object

java.util.Random

org.uncommons.maths.random.XORShiftRNG

All Implemented Interfaces:

Serializable, RandomGenerator, 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

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface RandomGenerator

RandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator

Field Summary

Fields

Modifier and Type	Field	Description
private final ReentrantLock	lock
private final byte[]	seed
private static final int	SEED_SIZE_BYTES
private int	state1
private int	state2
private int	state3
private int	state4
private int	state5

Constructor Summary

Constructors

Constructor	Description
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

Modifier and Type	Method	Description
byte[]	getSeed()
protected int	next(int bits)

Methods inherited from class Random

doubles, doubles, doubles, doubles, from, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong, setSeed

Methods inherited from class Object

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

Methods inherited from interface RandomGenerator

equiDoubles, isDeprecated, nextDouble, nextDouble, nextExponential, nextFloat, nextFloat, nextGaussian, nextInt, nextLong, nextLong

Field Details

SEED_SIZE_BYTES

private static final int SEED_SIZE_BYTES

See Also:

• Constant Field Values

state1

private int state1

state2

private int state2

state3

private int state3

state4

private int state4

state5

private int state5

seed

private final byte[] seed

lock

private final ReentrantLock lock

Constructor Details

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 Details

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