Class MultiplyWithCarry256

java.lang.Object

org.apache.commons.rng.core.BaseProvider

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

org.apache.commons.rng.core.source32.MultiplyWithCarry256

All Implemented Interfaces:

RandomIntSource, RestorableUniformRandomProvider, UniformRandomProvider

public class MultiplyWithCarry256
extends IntProvider

Port from Marsaglia's "Multiply-With-Carry" algorithm.

Implementation is based on the (non-portable!) C code reproduced on that page.

Since:

1.0

See Also:

• Multiply with carry (Wikipedia)

Field Summary

Fields

Modifier and Type	Field	Description
private static final long	A	Multiply.
private int	carry	Carry.
private int	index	Current index in "state" array.
private static final int	Q_SIZE	Length of the state array.
private static final int	SEED_SIZE	Size of the seed.
private final int[]	state	State.

Constructor Summary

Constructors

Constructor	Description
MultiplyWithCarry256(int[] seed)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
int	next()	Return the next random value.
private void	setSeedInternal(int[] seed)	Seeds the RNG.
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.

Methods inherited from class IntProvider

nextBoolean, nextBytes, nextBytes, nextBytesFill, nextDouble, nextInt, nextLong, resetCachedState

Methods inherited from class BaseProvider

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

Methods inherited from class Object

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

Methods inherited from interface UniformRandomProvider

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

Field Details

Q_SIZE

private static final int Q_SIZE

Length of the state array.

See Also:

• Constant Field Values

SEED_SIZE

private static final int SEED_SIZE

Size of the seed.

See Also:

• Constant Field Values

A

private static final long A

Multiply.

See Also:

• Constant Field Values

state

private final int[] state

State.

index

private int index

Current index in "state" array.

carry

private int carry

Carry.

Constructor Details

MultiplyWithCarry256

public MultiplyWithCarry256(int[] seed)

Creates a new instance.

Parameters:

seed - Seed. If the length is larger than 257, only the first 257 elements will be used; if smaller, the remaining elements will be automatically set.

Method Details

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)

setSeedInternal

private void setSeedInternal(int[] seed)

Seeds the RNG.

Parameters:

seed - Seed.

next

public int next()

Return the next random value.

Returns:

the next random value.