math.rng

Class XorShift128Plus

java.lang.Object

math.rng.AbstractRng64

math.rng.XorShift128Plus

All Implemented Interfaces:

PseudoRandom, PseudoRandomStream

public class XorShift128Plus
extends AbstractRng64

128-bit xorshift128+ pseudo random generator suggested by Sebastiano Vigna (2017). It is about 40% faster than XorShift64Star despite its larger state size.

This generator has a period of 2¹²⁸ − 1.

At least the two lowest bits of a xorshift* generator satisfy a linear recurrence and will therefore fail linearity tests (MatrixRank and LinearComp in TestU01) which were designed to catch these linear relations. However, low linear complexity of the lowest bits has rarely an effect in practice, and certainly has no impact at all when the generator is only used to generate floating-point numbers.

This generator is 1-dimensionally equidistributed.

Field Summary

Fields inherited from class math.rng.AbstractRng64

DOUBLE_NORM, FLOAT_NORM, nextGaussian, unused

Constructor Summary

Constructors

Constructor and Description
XorShift128Plus()
XorShift128Plus(long seed)
XorShift128Plus(long[] seed)

Method Summary

Modifier and Type	Method and Description
static PseudoRandom	getDefault()
long	nextLong()

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

Constructor Detail

XorShift128Plus

public XorShift128Plus()

XorShift128Plus

public XorShift128Plus(long seed)

XorShift128Plus

public XorShift128Plus(long[] seed)

Method Detail

nextLong

public final long nextLong()

Specified by:

nextLong in interface PseudoRandom

Specified by:

nextLong in class AbstractRng64

getDefault

public static PseudoRandom getDefault()