Package org.apache.commons.rng.core.source64

Class XoRoShiRo1024PlusPlus

java.lang.Object

org.apache.commons.rng.core.BaseProvider

org.apache.commons.rng.core.source64.LongProvider

org.apache.commons.rng.core.source64.XoRoShiRo1024PlusPlus

All Implemented Interfaces:

RandomLongSource, JumpableUniformRandomProvider, LongJumpableUniformRandomProvider, RestorableUniformRandomProvider, UniformRandomProvider

public class XoRoShiRo1024PlusPlus
extends LongProvider

A large-state all-purpose 64-bit generator.

This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 1024 bits and the period is 2¹⁰²⁴-1.

Note: This can be used as a replacement for XorShift1024Star.

Since:

1.3

See Also:

Original source code, xorshiro / xoroshiro generators

Constructor Summary

Constructors

Modifier	Constructor	Description
	XoRoShiRo1024PlusPlus(long[] seed)	Creates a new instance.
protected	XoRoShiRo1024PlusPlus(XoRoShiRo1024PlusPlus source)	Creates a copy instance.

Method Summary

Modifier and Type	Method	Description
protected XoRoShiRo1024PlusPlus	copy()	Create a copy.
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
UniformRandomProvider	jump()	Creates a copy of the UniformRandomProvider and then advances the state of the current instance.
JumpableUniformRandomProvider	longJump()	Creates a copy of the JumpableUniformRandomProvider and then advances the state of the current instance.
long	next()	Return the next random value.
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.
protected long	transform(long s0, long s15)	Transform the two consecutive 64-bit states of the generator to a 64-bit output.

Methods inherited from class org.apache.commons.rng.core.source64.LongProvider

nextBoolean, nextInt, nextLong, resetCachedState

Methods inherited from class org.apache.commons.rng.core.BaseProvider

checkIndex, checkStateSize, composeStateInternal, extendSeed, extendSeed, fillState, fillState, restoreState, saveState, splitStateInternal, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.rng.JumpableUniformRandomProvider

jumps, jumps

Methods inherited from interface org.apache.commons.rng.LongJumpableUniformRandomProvider

longJumps, longJumps

Methods inherited from interface org.apache.commons.rng.UniformRandomProvider

doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextBytes, nextDouble, nextDouble, nextDouble, nextFloat, nextFloat, nextFloat, nextInt, nextInt, nextInt, nextLong, nextLong, nextLong

Constructor Detail

XoRoShiRo1024PlusPlus

public XoRoShiRo1024PlusPlus(long[] seed)

Creates a new instance.

Parameters:

seed - Initial seed. If the length is larger than 16, only the first 16 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.

XoRoShiRo1024PlusPlus

protected XoRoShiRo1024PlusPlus(XoRoShiRo1024PlusPlus source)

Creates a copy instance.

Parameters:

source - Source to copy.

Method Detail

transform

protected long transform(long s0,
                         long s15)

Transform the two consecutive 64-bit states of the generator to a 64-bit output. The transformation function shall vary with respect to different generators.

Parameters:

s0 - The current state.

s15 - The previous state.

Returns:

the output

copy

protected XoRoShiRo1024PlusPlus copy()

Create a copy.

Returns:

the copy

getStateInternal

protected byte[] getStateInternal()

Creates a snapshot of the RNG state.

Overrides:

getStateInternal in class LongProvider

Returns:

the internal state.

setStateInternal

protected void setStateInternal(byte[] s)

Resets the RNG to the given state.

Overrides:

setStateInternal in class LongProvider

Parameters:

s - State (previously obtained by a call to BaseProvider.getStateInternal()).

See Also:

BaseProvider.checkStateSize(byte[],int)

next

public long next()

Return the next random value.

Specified by:

next in interface RandomLongSource

Returns:

the next random value.

jump

public UniformRandomProvider jump()

Creates a copy of the UniformRandomProvider and then advances the state of the current instance. The copy is returned.

The current state will be advanced in a single operation by the equivalent of a number of sequential calls to a method that updates the state of the provider. The size of the jump is implementation dependent.

Repeat invocations of this method will create a series of generators that are uniformly spaced at intervals of the output sequence. Each generator provides non-overlapping output for the length of the jump for use in parallel computations.

The jump size is the equivalent of 2⁵¹² calls to nextLong(). It can provide up to 2⁵¹² non-overlapping subsequences.

Specified by:

jump in interface JumpableUniformRandomProvider

Returns:

A copy of the current state.

longJump

public JumpableUniformRandomProvider longJump()

Creates a copy of the JumpableUniformRandomProvider and then advances the state of the current instance. The copy is returned.

The current state will be advanced in a single operation by the equivalent of a number of sequential calls to a method that updates the state of the provider. The size of the long jump is implementation dependent.

Repeat invocations of this method will create a series of generators that are uniformly spaced at intervals of the output sequence. Each generator provides non-overlapping output for the length of the long jump for use in parallel computations.

The returned copy may be jumped m / n times before overlap with the current instance where m is the long jump length and n is the jump length of the JumpableUniformRandomProvider.jump() method.

The jump size is the equivalent of 2⁷⁶⁸ calls to nextLong(). It can provide up to 2²⁵⁶ non-overlapping subsequences of length 2⁷⁶⁸; each subsequence can provide up to 2²⁵⁶ non-overlapping subsequences of length 2⁵¹² using the JumpableUniformRandomProvider.jump() method.

Specified by:

longJump in interface LongJumpableUniformRandomProvider

Returns:

A copy of the current state.