cern.jet.random.engine

Class Benchmark

java.lang.Object

cern.jet.random.engine.Benchmark

public class Benchmark
extends java.lang.Object

Benchmarks the performance of the currently provided uniform pseudo-random number generation engines.

All distributions are obtained by using a uniform pseudo-random number generation engine. followed by a transformation to the desired distribution. Therefore, the performance of the uniform engines is crucial.

Comparison of uniform generation engines

Name	Period	Speed [# million uniform random numbers generated/sec] Pentium Pro 200 Mhz, JDK 1.2, NT
MersenneTwister	219937-1 (=106001)	2.5
Ranlux (default luxury level 3)	10171	0.4
Ranmar	1043	1.6
Ranecu	1018	1.5
java.util.Random.nextFloat()	?	2.4

Note: Methods working on the default uniform random generator are synchronized and therefore in current VM's slow (as of June '99). Methods taking as argument a uniform random generator are not synchronized and therefore much quicker. Thus, if you need a lot of random numbers, you should use the unsynchronized approach:

Example usage:

 edu.cornell.lassp.houle.RngPack.RandomElement generator;
 generator = new cern.jet.random.engine.MersenneTwister(new java.util.Date());
 //generator = new edu.cornell.lassp.houle.RngPack.Ranecu(new java.util.Date());
 //generator = new edu.cornell.lassp.houle.RngPack.Ranmar(new java.util.Date());
 //generator = new edu.cornell.lassp.houle.RngPack.Ranlux(new java.util.Date());
 //generator = makeDefaultGenerator();
 for (int i=1000000; --i >=0; ) {
    double uniform = generator.raw();
    ...
 }
 

See Also:

cern.jet.random

Method Summary

Modifier and Type	Method and Description
static void	benchmark(int times) Benchmarks raw() for various uniform generation engines.
static void	main(java.lang.String[] args) Tests various methods of this class.
static void	test(int size, RandomEngine randomEngine) Prints the first size random numbers generated by the given engine.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

benchmark

public static void benchmark(int times)

Benchmarks raw() for various uniform generation engines.

main

public static void main(java.lang.String[] args)

Tests various methods of this class.

test

public static void test(int size,
                        RandomEngine randomEngine)

Prints the first size random numbers generated by the given engine.