Package org.apache.commons.rng.core.source32

Class PcgXshRs32

java.lang.Object

org.apache.commons.rng.core.BaseProvider

org.apache.commons.rng.core.source32.IntProvider

org.apache.commons.rng.core.source32.PcgXshRs32

All Implemented Interfaces:

RandomIntSource, RestorableUniformRandomProvider, UniformRandomProvider

public class PcgXshRs32
extends IntProvider

A Permuted Congruential Generator (PCG) that is composed of a 64-bit Linear Congruential Generator (LCG) combined with the XSH-RS (xorshift; random shift) output transformation to create 32-bit output.

State size is 128 bits and the period is 2⁶⁴.

Since:

1.3

See Also:

PCG, A Family of Better Random Number Generators

Constructor Summary

Constructors

Constructor	Description
PcgXshRs32(long[] seed)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
int	next()
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.
protected int	transform(long x)	Transform the 64-bit state of the generator to a 32-bit output.

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 org.apache.commons.rng.core.source32.IntProvider

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

Methods inherited from class java.lang.Object

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

Constructor Detail

PcgXshRs32

public PcgXshRs32(long[] seed)

Creates a new instance.

Parameters:

seed - Initial seed. If the length is larger than 2, only the first 2 elements will be used; if smaller, the remaining elements will be automatically set.

Method Detail

transform

protected int transform(long x)

Transform the 64-bit state of the generator to a 32-bit output. The transformation function shall vary with respect to different generators.

Parameters:

x - State.

Returns:

the output

next

public int next()

Returns:

the next random value.

getStateInternal

protected byte[] getStateInternal()

Creates a snapshot of the RNG state.

Overrides:

getStateInternal in class IntProvider

Returns:

the internal state.

setStateInternal

protected void setStateInternal(byte[] s)

Resets the RNG to the given state.

Overrides:

setStateInternal in class IntProvider

Parameters:

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

See Also:

BaseProvider.checkStateSize(byte[],int)