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

Class XoShiRo256Plus

java.lang.Object

org.apache.commons.rng.core.BaseProvider

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

org.apache.commons.rng.core.source64.XoShiRo256Plus

All Implemented Interfaces:

RandomLongSource, RestorableUniformRandomProvider, UniformRandomProvider

public class XoShiRo256Plus
extends LongProvider

A fast 64-bit generator suitable for double generation. This is slightly faster than the all-purpose generator XoShiRo256StarStar.

This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 256 bits and the period is 2²⁵⁶-1.

Since:

1.3

See Also:

Original source code, xorshiro / xoroshiro generators

Field Summary

Fields

Modifier and Type	Field	Description
protected long	state0	State 0 of the generator.
protected long	state1	State 1 of the generator.
protected long	state2	State 2 of the generator.
protected long	state3	State 3 of the generator.

Constructor Summary

Constructors

Constructor	Description
XoShiRo256Plus(long[] seed)	Creates a new instance.
XoShiRo256Plus(long seed0, long seed1, long seed2, long seed3)	Creates a new instance using a 4 element seed.

Method Summary

Modifier and Type	Method	Description
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
long	next()
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.

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

nextBoolean, nextBytes, nextBytes, nextDouble, nextFloat, nextInt, nextLong

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

checkIndex, checkStateSize, composeStateInternal, fillState, fillState, nextInt, nextLong, restoreState, saveState, splitStateInternal, toString

Methods inherited from class java.lang.Object

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

Field Details

state0

protected long state0

State 0 of the generator.

state1

protected long state1

State 1 of the generator.

state2

protected long state2

State 2 of the generator.

state3

protected long state3

State 3 of the generator.

Constructor Details

XoShiRo256Plus

public XoShiRo256Plus(long[] seed)

Creates a new instance.

Parameters:

seed - Initial seed. If the length is larger than 4, only the first 4 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.

XoShiRo256Plus

public XoShiRo256Plus(long seed0, long seed1, long seed2, long seed3)

Creates a new instance using a 4 element seed. A seed containing all zeros will create a non-functional generator.

Parameters:

seed0 - Initial seed element 0.

seed1 - Initial seed element 1.

seed2 - Initial seed element 2.

seed3 - Initial seed element 3.

Method Details

next

public long next()

Returns:

the next random value.

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)