Parallel Colt 0.7.2

cern.jet.random.tfloat.engine
Class FloatRandomEngine

java.lang.Object
  extended by cern.colt.PersistentObject
      extended by cern.jet.random.tfloat.engine.FloatRandomEngine
All Implemented Interfaces:
FloatFunction, IntFunction, Serializable, Cloneable
Direct Known Subclasses:
FloatMersenneTwister, FRand

public abstract class FloatRandomEngine
extends PersistentObject
implements FloatFunction, 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 float'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. float'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:
FloatMersenneTwister, MersenneTwister64, Random, Serialized Form

Field Summary
 
Fields inherited from class cern.colt.PersistentObject
serialVersionUID
 
Method Summary
 float apply(float dummy)
          Equivalent to raw().
 int apply(int dummy)
          Equivalent to nextInt().
static FloatRandomEngine makeDefault()
          Constructs and returns a new uniform random number engine seeded with the current time.
 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).
 float 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, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

apply

public float apply(float 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 FloatFunction
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 FloatRandomEngine makeDefault()
Constructs and returns a new uniform random number engine seeded with the current time. Currently this is FloatMersenneTwister.


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 float raw()
Returns a 32 bit uniformly distributed random number in the open unit interval (0.0,1.0) (excluding 0.0 and 1.0).


Parallel Colt 0.7.2

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