Class RejectionInversionZipfSampler
java.lang.Object
org.apache.commons.rng.sampling.distribution.SamplerBase
org.apache.commons.rng.sampling.distribution.RejectionInversionZipfSampler
- All Implemented Interfaces:
DiscreteSampler
,SharedStateDiscreteSampler
,SharedStateSampler<SharedStateDiscreteSampler>
public class RejectionInversionZipfSampler
extends SamplerBase
implements SharedStateDiscreteSampler
Implementation of the Zipf distribution.
Sampling uses UniformRandomProvider.nextDouble()
.
- Since:
- 1.0
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate static final class
Implements the rejection-inversion method for the Zipf distribution. -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final SharedStateDiscreteSampler
The implementation of the sample method. -
Constructor Summary
ConstructorsModifierConstructorDescriptionprivate
Private constructor used by to prevent partially initialized object if the construction of the delegate throws.RejectionInversionZipfSampler
(UniformRandomProvider rng, int numberOfElements, double exponent) This instance delegates sampling. -
Method Summary
Modifier and TypeMethodDescriptionstatic SharedStateDiscreteSampler
of
(UniformRandomProvider rng, int numberOfElements, double exponent) Creates a new Zipf distribution sampler.int
sample()
Rejection inversion sampling method for a discrete, bounded Zipf distribution that is based on the method described in Wolfgang Hörmann and Gerhard Derflinger.toString()
Create a new instance of the sampler with the same underlying state using the given uniform random provider as the source of randomness.Methods inherited from class org.apache.commons.rng.sampling.distribution.SamplerBase
nextDouble, nextInt, nextInt, nextLong
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.apache.commons.rng.sampling.distribution.DiscreteSampler
samples, samples
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Field Details
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delegate
The implementation of the sample method.
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Constructor Details
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RejectionInversionZipfSampler
public RejectionInversionZipfSampler(UniformRandomProvider rng, int numberOfElements, double exponent) This instance delegates sampling. Use the factory methodof(UniformRandomProvider, int, double)
to create an optimal sampler.- Parameters:
rng
- Generator of uniformly distributed random numbers.numberOfElements
- Number of elements.exponent
- Exponent.- Throws:
IllegalArgumentException
- ifnumberOfElements <= 0
orexponent < 0
.
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Method Details
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sample
public int sample()Rejection inversion sampling method for a discrete, bounded Zipf distribution that is based on the method described inWolfgang Hörmann and Gerhard Derflinger. "Rejection-inversion to generate variates from monotone discrete distributions",
ACM Transactions on Modeling and Computer Simulation (TOMACS) 6.3 (1996): 169-184.- Specified by:
sample
in interfaceDiscreteSampler
- Returns:
- a sample.
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toString
- Overrides:
toString
in classSamplerBase
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withUniformRandomProvider
Create a new instance of the sampler with the same underlying state using the given uniform random provider as the source of randomness.- Specified by:
withUniformRandomProvider
in interfaceSharedStateSampler<SharedStateDiscreteSampler>
- Parameters:
rng
- Generator of uniformly distributed random numbers.- Returns:
- the sampler
- Since:
- 1.3
-
of
public static SharedStateDiscreteSampler of(UniformRandomProvider rng, int numberOfElements, double exponent) Creates a new Zipf distribution sampler.Note when
exponent = 0
the Zipf distribution reduces to a discrete uniform distribution over the interval[1, n]
withn
the number of elements.- Parameters:
rng
- Generator of uniformly distributed random numbers.numberOfElements
- Number of elements.exponent
- Exponent.- Returns:
- the sampler
- Throws:
IllegalArgumentException
- ifnumberOfElements <= 0
orexponent < 0
.- Since:
- 1.3
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