Class DirichletSampler
- java.lang.Object
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- org.apache.commons.rng.sampling.distribution.DirichletSampler
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- All Implemented Interfaces:
ObjectSampler<double[]>,SharedStateObjectSampler<double[]>,SharedStateSampler<SharedStateObjectSampler<double[]>>
public abstract class DirichletSampler extends Object implements SharedStateObjectSampler<double[]>
Sampling from a Dirichlet distribution.Sampling uses:
- Since:
- 1.4
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract intgetK()Gets the number of categories.protected abstract doublenextGamma(int category)Create a gamma sample for the given category.static DirichletSamplerof(UniformRandomProvider rng, double... alpha)Creates a new Dirichlet distribution sampler.double[]sample()Create an object sample.static DirichletSamplersymmetric(UniformRandomProvider rng, int k, double alpha)Creates a new symmetric Dirichlet distribution sampler using the same concentration parameter for each category.StringtoString()abstract DirichletSamplerwithUniformRandomProvider(UniformRandomProvider rng)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 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.commons.rng.sampling.ObjectSampler
samples, samples
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Method Detail
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sample
public double[] sample()
Create an object sample.- Specified by:
samplein interfaceObjectSampler<double[]>- Returns:
- a sample.
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getK
protected abstract int getK()
Gets the number of categories.- Returns:
- k
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nextGamma
protected abstract double nextGamma(int category)
Create a gamma sample for the given category.- Parameters:
category- Category.- Returns:
- the sample
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withUniformRandomProvider
public abstract DirichletSampler withUniformRandomProvider(UniformRandomProvider rng)
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:
withUniformRandomProviderin interfaceSharedStateSampler<SharedStateObjectSampler<double[]>>- Parameters:
rng- Generator of uniformly distributed random numbers.- Returns:
- the sampler
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of
public static DirichletSampler of(UniformRandomProvider rng, double... alpha)
Creates a new Dirichlet distribution sampler.- Parameters:
rng- Generator of uniformly distributed random numbers.alpha- Concentration parameters.- Returns:
- the sampler
- Throws:
IllegalArgumentException- if the number of concentration parameters is less than 2; or if any concentration parameter is not strictly positive.
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symmetric
public static DirichletSampler symmetric(UniformRandomProvider rng, int k, double alpha)
Creates a new symmetric Dirichlet distribution sampler using the same concentration parameter for each category.- Parameters:
rng- Generator of uniformly distributed random numbers.k- Number of categories.alpha- Concentration parameter.- Returns:
- the sampler
- Throws:
IllegalArgumentException- if the number of categories is less than 2; or if the concentration parameter is not strictly positive.
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