LCG64ShiftRandom (Jenetics 3.6.0)

java.lang.Object
- java.util.Random
- - org.jenetics.util.Random64
  - - org.jenetics.util.LCG64ShiftRandom

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

LCG64ShiftRandom.ThreadSafe
```
public class LCG64ShiftRandom
extends Random64
```
This class implements a linear congruential PRNG with additional bit-shift transition. The base recursion
$r_{i+1} = (a\cdot r_i + b) \mod 2^{64}$
is followed by a non-linear transformation
$\begin{eqnarray*} t &=& r_i \\ t &=& t \oplus (t >> 17) \\ t &=& t \oplus (t << 31) \\ t &=& t \oplus (t >> 8) \end{eqnarray*}$
which destroys the lattice structure introduced by the recursion. The period of this PRNG is 2⁶⁴, iff b is odd and a mod 4 = 1.
This is an re-implementation of the trng::lcg64_shift PRNG class of the TRNG library created by Heiko Bauke.
Not that the base implementation of the LCG64ShiftRandom class is not thread-safe. If multiple threads requests random numbers from this class, it must be synchronized externally. Alternatively you can use the thread-safe implementations LCG64ShiftRandom.ThreadSafe or LCG64ShiftRandom.ThreadLocal.

Since:

1.1

Version:

2.0

Author:

Franz Wilhelmstötter

See Also:

TRNG, RandomRegistry, Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`LCG64ShiftRandom.Param` Parameter class for the `LCG64ShiftRandom` generator, for the parameters a and b of the LC recursion r_i+1 = a · r_i + b mod 2⁶⁴.
`static class`	`LCG64ShiftRandom.ThreadLocal` This class represents a thread local implementation of the `LCG64ShiftRandom` PRNG.
`static class`	`LCG64ShiftRandom.ThreadSafe` This is a thread safe variation of the this PRNG—by synchronizing the random number generation.

Constructor Summary

Constructors
Constructor and Description
`LCG64ShiftRandom()` Create a new PRNG instance with `LCG64ShiftRandom.Param.DEFAULT` parameter and safe seed.
`LCG64ShiftRandom(LCG64ShiftRandom.Param param)` Create a new PRNG instance with the given parameter and a safe seed
`LCG64ShiftRandom(LCG64ShiftRandom.Param param, long seed)` Create a new PRNG instance with the given parameter and seed.
`LCG64ShiftRandom(long seed)` Create a new PRNG instance with `LCG64ShiftRandom.Param.DEFAULT` parameter and the given seed.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`equals(Object obj)`
`LCG64ShiftRandom.Param`	`getParam()`
`int`	`hashCode()`
`void`	`jump(long step)` Changes the internal state of the PRNG in such a way that the engine jumps s steps ahead.
`void`	`jump2(int s)` Changes the internal state of the PRNG in such a way that the engine jumps 2^s steps ahead.
`double`	`nextDouble(double min, double max)` Returns a pseudorandom, uniformly distributed double value between min (inclusively) and max (exclusively).
`float`	`nextFloat(float min, float max)` Returns a pseudorandom, uniformly distributed double value between min (inclusively) and max (exclusively).
`int`	`nextInt(int min, int max)` Returns a pseudorandom, uniformly distributed int value between min and max (end points included).
`long`	`nextLong()` Force to explicitly override the Random.nextLong() method.
`long`	`nextLong(long n)` Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from the given random number generator's sequence.
`long`	`nextLong(long min, long max)` Returns a pseudorandom, uniformly distributed int value between min and max (end points included).
`void`	`setSeed(long seed)`
`void`	`split(int p, int s)` Changes the internal state of the PRNG in a way that future calls to `nextLong()` will generated the s^th sub-stream of p^th sub-streams.
`String`	`toString()`

Methods inherited from class org.jenetics.util.Random64
next, nextBoolean, nextBytes, nextDouble, nextFloat, nextInt, of

Methods inherited from class java.util.Random
doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextGaussian, nextInt

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - LCG64ShiftRandom
```
public LCG64ShiftRandom(LCG64ShiftRandom.Param param,
                        long seed)
```
    Create a new PRNG instance with the given parameter and seed.
    
    Parameters:
    
    param - the parameter of the PRNG.
    
    seed - the seed of the PRNG.
    
    Throws:
    
    NullPointerException - if the given param is null.
  - LCG64ShiftRandom
```
public LCG64ShiftRandom(LCG64ShiftRandom.Param param)
```
    Create a new PRNG instance with the given parameter and a safe seed
    
    Parameters:
    
    param - the PRNG parameter.
    
    Throws:
    
    NullPointerException - if the given param is null.
  - LCG64ShiftRandom
```
public LCG64ShiftRandom(long seed)
```
    Create a new PRNG instance with LCG64ShiftRandom.Param.DEFAULT parameter and the given seed.
    
    Parameters:
    
    seed - the seed of the PRNG
  - LCG64ShiftRandom
```
public LCG64ShiftRandom()
```
    Create a new PRNG instance with LCG64ShiftRandom.Param.DEFAULT parameter and safe seed.
- Method Detail
  - nextLong
```
public long nextLong()
```
    Description copied from class: Random64
    
    Force to explicitly override the Random.nextLong() method. All other methods of this class are implemented by calling this method.
    
    Specified by:
    
    nextLong in class Random64
  - setSeed
```
public void setSeed(long seed)
```
    Overrides:
    
    setSeed in class Random
  - split
```
public void split(int p,
                  int s)
```
    Changes the internal state of the PRNG in a way that future calls to nextLong() will generated the s^th sub-stream of p^th sub-streams. s must be within the range of [0, p-1). This method is mainly used for parallelization via leap-frogging.
    
    Parameters:
    
    p - the overall number of sub-streams
    
    s - the s^th sub-stream
    
    Throws:
    
    IllegalArgumentException - if p < 1 || s >= p.
  - jump2
```
public void jump2(int s)
```
    Changes the internal state of the PRNG in such a way that the engine jumps 2^s steps ahead.
    
    Parameters:
    
    s - the 2^s steps to jump ahead.
    
    Throws:
    
    IllegalArgumentException - if s < 0.
  - jump
```
public void jump(long step)
```
    Changes the internal state of the PRNG in such a way that the engine jumps s steps ahead.
    
    Parameters:
    
    step - the steps to jump ahead.
    
    Throws:
    
    IllegalArgumentException - if s < 0.
  - getParam
```
public LCG64ShiftRandom.Param getParam()
```
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - nextInt
```
public int nextInt(int min,
                   int max)
```
    Returns a pseudorandom, uniformly distributed int value between min and max (end points included).
    
    Parameters:
    
    min - lower bound for generated integer (inclusively)
    
    max - upper bound for generated integer (inclusively)
    
    Returns:
    
    a random integer greater than or equal to min and less than or equal to max
    
    Throws:
    
    IllegalArgumentException - if min >= max
    
    See Also:
    
    random.nextInt(java.util.Random, int, int)
  - nextLong
```
public long nextLong(long min,
                     long max)
```
    Returns a pseudorandom, uniformly distributed int value between min and max (end points included).
    
    Parameters:
    
    min - lower bound for generated long integer (inclusively)
    
    max - upper bound for generated long integer (inclusively)
    
    Returns:
    
    a random long integer greater than or equal to min and less than or equal to max
    
    Throws:
    
    IllegalArgumentException - if min >= max
    
    See Also:
    
    random.nextLong(java.util.Random, long, long)
  - nextLong
```
public long nextLong(long n)
```
    Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from the given random number generator's sequence.
    
    Parameters:
    
    n - the bound on the random number to be returned. Must be positive.
    
    Returns:
    
    the next pseudorandom, uniformly distributed int value between 0 (inclusive) and n (exclusive) from the given random number generator's sequence
    
    Throws:
    
    IllegalArgumentException - if n is smaller than 1.
    
    See Also:
    
    random.nextLong(java.util.Random, long)
  - nextFloat
```
public float nextFloat(float min,
                       float max)
```
    Returns a pseudorandom, uniformly distributed double value between min (inclusively) and max (exclusively).
    
    Parameters:
    
    min - lower bound for generated float value (inclusively)
    
    max - upper bound for generated float value (exclusively)
    
    Returns:
    
    a random float greater than or equal to min and less than to max
    
    See Also:
    
    random.nextFloat(java.util.Random, float, float)
  - nextDouble
```
public double nextDouble(double min,
                         double max)
```
    Returns a pseudorandom, uniformly distributed double value between min (inclusively) and max (exclusively).
    
    Parameters:
    
    min - lower bound for generated double value (inclusively)
    
    max - upper bound for generated double value (exclusively)
    
    Returns:
    
    a random double greater than or equal to min and less than to max
    
    See Also:
    
    random.nextDouble(java.util.Random, double, double)

Class LCG64ShiftRandom

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class org.jenetics.util.Random64

Methods inherited from class java.util.Random

Methods inherited from class java.lang.Object

Constructor Detail

LCG64ShiftRandom

LCG64ShiftRandom

LCG64ShiftRandom

LCG64ShiftRandom

Method Detail

nextLong

setSeed

split

jump2

jump

getParam

hashCode

equals

toString

nextInt

nextLong

nextLong

nextFloat

nextDouble