math.rng

Class XorShiftRot256PlusPlus

java.lang.Object

math.rng.AbstractRng64

math.rng.XorShiftRot256PlusPlus

All Implemented Interfaces:

PseudoRandom, PseudoRandomStream, SplittablePseudoRandom

public class XorShiftRot256PlusPlus
extends AbstractRng64

256-bit xoshiro256++ pseudo random generator suggested by David Blackman and Sebastiano Vigna (2019). This implementation is not significantly faster than XorShiftRot256StarStar which has slightly better statistical properties. It is about 40% faster than XorShift64Star despite having a 4 times larger state space.

This generator has a period of 2²⁵⁶ − 1.

This generator is 3-dimensionally equidistributed.

Field Summary

Fields

Modifier and Type	Field and Description
protected long	x0
protected long	x1
protected long	x2
protected long	x3

Fields inherited from class math.rng.AbstractRng64

DOUBLE_NORM, FLOAT_NORM, nextGaussian, unused

Constructor Summary

Constructors

Modifier	Constructor and Description
	XorShiftRot256PlusPlus()
	XorShiftRot256PlusPlus(long seed)
	XorShiftRot256PlusPlus(long[] seed)
protected	XorShiftRot256PlusPlus(long x0, long x1, long x2, long x3)

Method Summary

Modifier and Type	Method and Description
static SplittablePseudoRandom	getDefault()
long	nextLong()
XorShiftRot256PlusPlus	split() Constructs and returns a new SplittablePseudoRandom instance that shares no mutable state with the current instance.

Methods inherited from class math.rng.AbstractRng64

beta, beta, cauchy, cauchy, chiSquare, chiSquare, doubles, doubles, doubles, doubles, exponential, exponential, gamma, gamma, getAlgorithm, getSeed, ints, ints, ints, ints, logNormal, logNormal, longs, longs, longs, longs, next, nextBoolean, nextBytes, nextDouble, nextDouble, nextDoubles, nextFloat, nextFloat, nextGaussian, nextGaussian, nextInt, nextInt, nextInt, nextLong, nextLong, nextLongs, normal, normal, saveSeed, saveSeed, studentT, studentT, weibull, weibull

Methods inherited from class java.lang.Object

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

Methods inherited from interface math.rng.PseudoRandom

getAlgorithm, getSeed, next, nextBoolean, nextBytes, nextDouble, nextDouble, nextDoubles, nextFloat, nextFloat, nextGaussian, nextGaussian, nextInt, nextInt, nextInt, nextLong, nextLong, nextLongs

Methods inherited from interface math.rng.PseudoRandomStream

beta, beta, cauchy, cauchy, chiSquare, chiSquare, doubles, doubles, doubles, doubles, exponential, exponential, gamma, gamma, ints, ints, ints, ints, logNormal, logNormal, longs, longs, longs, longs, normal, normal, studentT, studentT, weibull, weibull

Field Detail

x0

protected long x0

x1

protected long x1

x2

protected long x2

x3

protected long x3

Constructor Detail

XorShiftRot256PlusPlus

public XorShiftRot256PlusPlus()

XorShiftRot256PlusPlus

public XorShiftRot256PlusPlus(long seed)

XorShiftRot256PlusPlus

public XorShiftRot256PlusPlus(long[] seed)

XorShiftRot256PlusPlus

protected XorShiftRot256PlusPlus(long x0,
                                 long x1,
                                 long x2,
                                 long x3)

Method Detail

nextLong

public final long nextLong()

Specified by:

nextLong in interface PseudoRandom

Specified by:

nextLong in class AbstractRng64

split

public XorShiftRot256PlusPlus split()

Description copied from interface: SplittablePseudoRandom

Constructs and returns a new SplittablePseudoRandom instance that shares no mutable state with the current instance. However, with very high probability, the values collectively generated by the two instances have the same statistical properties as if the same quantity of values were generated by a single thread using a single SplittablePseudoRandom instance. Instances of SplittablePseudoRandom are not thread-safe. They are designed to be split, not shared, across threads.

Returns:

a new SplittablePseudoRandom instance that shares no mutable state with the current instance

getDefault

public static SplittablePseudoRandom getDefault()