Class DotyHumphreySmallFastCounting64

java.lang.Object

org.apache.commons.rng.core.BaseProvider

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

org.apache.commons.rng.core.source64.DotyHumphreySmallFastCounting64

All Implemented Interfaces:

RandomLongSource, RestorableUniformRandomProvider, UniformRandomProvider

public class DotyHumphreySmallFastCounting64
extends LongProvider

Implement the Small, Fast, Counting (SFC) 64-bit generator of Chris Doty-Humphrey. The original source is the PractRand test suite by the same author.

The state size is 256-bits; the period is a minimum of 2⁶⁴ and an average of approximately 2²⁵⁵.

Since:

1.3

See Also:

• PractRand

Field Summary

Fields

Modifier and Type	Field	Description
private long	a	State a.
private long	b	State b.
private long	c	State c.
private long	counter	Counter.
private static final int	SEED_SIZE	Size of the seed.

Constructor Summary

Constructors

Constructor	Description
DotyHumphreySmallFastCounting64(long[] seed)	Creates an instance with the given seed.

Method Summary

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

Methods inherited from class LongProvider

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

Field Details

SEED_SIZE

private static final int SEED_SIZE

Size of the seed.

See Also:

• Constant Field Values

a

private long a

State a.

b

private long b

State b.

c

private long c

State c.

counter

private long counter

Counter.

Constructor Details

DotyHumphreySmallFastCounting64

public DotyHumphreySmallFastCounting64(long[] seed)

Creates an instance with the given seed.

Parameters:

seed - Initial seed. If the length is larger than 3, only the first 3 elements will be used; if smaller, the remaining elements will be automatically set.

Method Details

setSeedInternal

private void setSeedInternal(long[] seed)

Seeds the RNG.

Parameters:

seed - Seed.

next

public final long next()

Return the next random value.

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)