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

Class AbstractWell

java.lang.Object

org.apache.commons.rng.core.BaseProvider

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

org.apache.commons.rng.core.source32.AbstractWell

All Implemented Interfaces:

RandomIntSource, RestorableUniformRandomProvider, UniformRandomProvider

Direct Known Subclasses:

Well1024a, Well19937a, Well44497a, Well512a

public abstract class AbstractWell
extends IntProvider

This abstract class implements the WELL class of pseudo-random number generator from François Panneton, Pierre L'Ecuyer and Makoto Matsumoto.

This generator is described in a paper by François Panneton, Pierre L'Ecuyer and Makoto Matsumoto Improved Long-Period Generators Based on Linear Recurrences Modulo 2 ACM Transactions on Mathematical Software, 32, 1 (2006). The errata for the paper are in wellrng-errata.txt.

Since:

1.0

See Also:

• WELL Random number generator

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static final class	AbstractWell.IndexTable	Inner class used to store the indirection index table which is fixed for a given type of WELL class of pseudo-random number generator.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	BLOCK_SIZE	Block size.
protected int	index	Current index in the bytes pool.
protected final int[]	v	Bytes pool.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractWell(int k, int[] seed)	Creates an instance with the given seed.

Method Summary

Modifier and Type	Method	Description
private static int	calculateBlockCount(int k)	Calculate the number of 32-bits blocks.
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
private void	setSeedInternal(int[] seed)	Initializes the generator with the given seed.
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.

Methods inherited from class org.apache.commons.rng.core.source32.IntProvider

nextBoolean, nextBytes, nextBytes, nextBytesFill, nextDouble, 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.core.source32.RandomIntSource

next

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

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

Field Details

BLOCK_SIZE

private static final int BLOCK_SIZE

Block size.

See Also:

• Constant Field Values

index

protected int index

Current index in the bytes pool.

v

protected final int[] v

Bytes pool.

Constructor Details

AbstractWell

protected AbstractWell(int k,
 int[] seed)

Creates an instance with the given seed.

Parameters:

k - Number of bits in the pool (not necessarily a multiple of 32).

seed - Initial seed.

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)

Initializes the generator with the given seed.

Parameters:

seed - Seed. Cannot be null.

calculateBlockCount

private static int calculateBlockCount(int k)

Calculate the number of 32-bits blocks.

Parameters:

k - Number of bits in the pool (not necessarily a multiple of 32).

Returns:

the number of 32-bits blocks.