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java.lang.Objectsim.util.distribution.AbstractDistribution
public abstract class AbstractDistribution
Abstract base class for all random distributions. A subclass of this class need to override method nextDouble() and, in rare cases, also nextInt().
Currently all subclasses use a uniform pseudo-random number generation engine and transform its results to the target distribution. Thus, they expect such a uniform engine upon instance construction.
cern.jet.random.engine.MersenneTwister
is recommended as uniform pseudo-random number generation engine, since it is very strong and at the same time quick.
#makeDefaultGenerator()
will conveniently construct and return such a magic thing.
You can also, for example, use cern.jet.random.engine.DRand
, a quicker (but much weaker) uniform random number generation engine.
Of course, you can also use other strong uniform random number generation engines.
Ressources on the Web:
Other useful ressources:
cern.jet.random.engine
,
cern.jet.random.engine.Benchmark
,
cern.jet.random.Benchmark
,
Serialized FormField Summary | |
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protected MersenneTwisterFast |
randomGenerator
|
Constructor Summary | |
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protected |
AbstractDistribution()
Makes this class non instantiable, but still let's others inherit from it. |
Method Summary | |
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double |
apply(double dummy)
Equivalent to nextDouble(). |
int |
apply(int dummy)
Equivalent to nextInt(). |
protected MersenneTwisterFast |
getRandomGenerator()
Returns the used uniform random number generator; |
abstract double |
nextDouble()
Returns a random number from the distribution. |
int |
nextInt()
Returns a random number from the distribution; returns (int) Math.round(nextDouble()). |
protected void |
setRandomGenerator(MersenneTwisterFast randomGenerator)
Sets the uniform random generator internally used. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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protected MersenneTwisterFast randomGenerator
Constructor Detail |
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protected AbstractDistribution()
Method Detail |
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public double apply(double dummy)
public int apply(int dummy)
protected MersenneTwisterFast getRandomGenerator()
public abstract double nextDouble()
public int nextInt()
protected void setRandomGenerator(MersenneTwisterFast randomGenerator)
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