RandomEngine (Nuiton Matrix

java.lang.Object
- cern.colt.PersistentObject
- - cern.jet.random.engine.RandomEngine

All Implemented Interfaces:

DoubleFunction, IntFunction, Serializable, Cloneable

Direct Known Subclasses:

DRand, MersenneTwister
```
public abstract class RandomEngine
extends PersistentObject
implements DoubleFunction, IntFunction
```
Abstract base class for uniform pseudo-random number generating engines.
Most probability distributions are obtained by using a uniform pseudo-random number generation engine followed by a transformation to the desired distribution. Thus, subclasses of this class are at the core of computational statistics, simulations, Monte Carlo methods, etc.
Subclasses produce uniformly distributed int's and long's in the closed intervals [Integer.MIN_VALUE,Integer.MAX_VALUE] and [Long.MIN_VALUE,Long.MAX_VALUE], respectively, as well as float's and double's in the open unit intervals (0.0f,1.0f) and (0.0,1.0), respectively.
Subclasses need to override one single method only: nextInt(). All other methods generating different data types or ranges are usually layered upon nextInt(). long's are formed by concatenating two 32 bit int's. float's are formed by dividing the interval [0.0f,1.0f] into 2³² sub intervals, then randomly choosing one subinterval. double's are formed by dividing the interval [0.0,1.0] into 2⁶⁴ sub intervals, then randomly choosing one subinterval.
Note that this implementation is not synchronized.

Version:

1.0, 09/24/99

Author:

wolfgang.hoschek@cern.ch

See Also:
MersenneTwister, Random, Serialized Form

Constructor Summary

Constructors
Modifier Constructor and Description

protected RandomEngine()
Makes this class non instantiable, but still let's others inherit from it.

Constructors
Modifier	Constructor and Description
`protected`	`RandomEngine()` Makes this class non instantiable, but still let's others inherit from it.

Method Summary

Methods
Modifier and Type	Method and Description
`double`	`apply(double dummy)` Equivalent to `raw()`.
`int`	`apply(int dummy)` Equivalent to `nextInt()`.
`static RandomEngine`	`makeDefault()` Constructs and returns a new uniform random number engine seeded with the current time.
`double`	`nextDouble()` Returns a 64 bit uniformly distributed random number in the open unit interval `(0.0,1.0)` (excluding 0.0 and 1.0).
`float`	`nextFloat()` Returns a 32 bit uniformly distributed random number in the open unit interval `(0.0f,1.0f)` (excluding 0.0f and 1.0f).
`abstract int`	`nextInt()` Returns a 32 bit uniformly distributed random number in the closed interval `[Integer.MIN_VALUE,Integer.MAX_VALUE]` (including `Integer.MIN_VALUE` and `Integer.MAX_VALUE`);
`long`	`nextLong()` Returns a 64 bit uniformly distributed random number in the closed interval `[Long.MIN_VALUE,Long.MAX_VALUE]` (including `Long.MIN_VALUE` and `Long.MAX_VALUE`).
`double`	`raw()` Returns a 32 bit uniformly distributed random number in the open unit interval `(0.0,1.0)` (excluding 0.0 and 1.0).

Methods inherited from class cern.colt.PersistentObject
clone

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - RandomEngine
```
protected RandomEngine()
```
    Makes this class non instantiable, but still let's others inherit from it.
- Method Detail
  - apply
```
public double apply(double dummy)
```
    Equivalent to raw(). This has the effect that random engines can now be used as function objects, returning a random number upon function evaluation.
    
    Specified by:
    
    apply in interface DoubleFunction
    
    Parameters:
    dummy - argument passed to the function.
    
    Returns:
    the result of the function.
  - apply
```
public int apply(int dummy)
```
    Equivalent to nextInt(). This has the effect that random engines can now be used as function objects, returning a random number upon function evaluation.
    
    Specified by:
    
    apply in interface IntFunction
    
    Parameters:
    dummy - argument passed to the function.
    
    Returns:
    the result of the function.
  - makeDefault
```
public static RandomEngine makeDefault()
```
    Constructs and returns a new uniform random number engine seeded with the current time. Currently this is MersenneTwister.
  - nextDouble
```
public double nextDouble()
```
    Returns a 64 bit uniformly distributed random number in the open unit interval (0.0,1.0) (excluding 0.0 and 1.0).
  - nextFloat
```
public float nextFloat()
```
    Returns a 32 bit uniformly distributed random number in the open unit interval (0.0f,1.0f) (excluding 0.0f and 1.0f).
  - nextInt
```
public abstract int nextInt()
```
    Returns a 32 bit uniformly distributed random number in the closed interval [Integer.MIN_VALUE,Integer.MAX_VALUE] (including Integer.MIN_VALUE and Integer.MAX_VALUE);
  - nextLong
```
public long nextLong()
```
    Returns a 64 bit uniformly distributed random number in the closed interval [Long.MIN_VALUE,Long.MAX_VALUE] (including Long.MIN_VALUE and Long.MAX_VALUE).
  - raw
```
public double raw()
```
    Returns a 32 bit uniformly distributed random number in the open unit interval (0.0,1.0) (excluding 0.0 and 1.0).

Class RandomEngine

Constructor Summary

Method Summary

Methods inherited from class cern.colt.PersistentObject

Methods inherited from class java.lang.Object

Constructor Detail

RandomEngine

Method Detail

apply

apply

makeDefault

nextDouble

nextFloat

nextInt

nextLong

raw