Class LogNormalSampler

java.lang.Object

org.apache.commons.rng.sampling.distribution.LogNormalSampler

All Implemented Interfaces:

ContinuousSampler, SharedStateContinuousSampler, SharedStateSampler<SharedStateContinuousSampler>

public class LogNormalSampler
extends Object
implements SharedStateContinuousSampler

Sampling from a log-normal distribution.

Since:

1.1

Field Summary

Fields

Modifier and Type	Field	Description
private final NormalizedGaussianSampler	gaussian	Gaussian sampling.
private final double	mu	Mean of the natural logarithm of the distribution values.
private final double	sigma	Standard deviation of the natural logarithm of the distribution values.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	LogNormalSampler(double mu, double sigma, NormalizedGaussianSampler gaussian)
	LogNormalSampler(NormalizedGaussianSampler gaussian, double mu, double sigma)	Create an instance.
private	LogNormalSampler(UniformRandomProvider rng, LogNormalSampler source)

Method Summary

Modifier and Type	Method	Description
static SharedStateContinuousSampler	of(NormalizedGaussianSampler gaussian, double mu, double sigma)	Create a new log-normal distribution sampler.
double	sample()	Creates a double sample.
String	toString()
SharedStateContinuousSampler	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.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface ContinuousSampler

samples, samples

Field Details

mu

private final double mu

Mean of the natural logarithm of the distribution values.

sigma

private final double sigma

Standard deviation of the natural logarithm of the distribution values.

gaussian

private final NormalizedGaussianSampler gaussian

Gaussian sampling.

Constructor Details

LogNormalSampler

public LogNormalSampler(NormalizedGaussianSampler gaussian,
 double mu,
 double sigma)

Create an instance.

Parameters:

gaussian - N(0,1) generator.

mu - Mean of the natural logarithm of the distribution values.

sigma - Standard deviation of the natural logarithm of the distribution values.

Throws:

IllegalArgumentException - if sigma <= 0.

LogNormalSampler

private LogNormalSampler(double mu,
 double sigma,
 NormalizedGaussianSampler gaussian)

Parameters:

mu - Mean of the natural logarithm of the distribution values.

sigma - Standard deviation of the natural logarithm of the distribution values.

gaussian - N(0,1) generator.

LogNormalSampler

private LogNormalSampler(UniformRandomProvider rng,
 LogNormalSampler source)

Parameters:

rng - Generator of uniformly distributed random numbers.

source - Source to copy.

Method Details

sample

public double sample()

Creates a double sample.

Specified by:

sample in interface ContinuousSampler

Returns:

a sample.

toString

public String toString()

Overrides:

toString in class Object

withUniformRandomProvider

public SharedStateContinuousSampler 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.

Note: This function is available if the underlying NormalizedGaussianSampler is a SharedStateSampler. Otherwise a run-time exception is thrown.

Specified by:

withUniformRandomProvider in interface SharedStateSampler<SharedStateContinuousSampler>

Parameters:

rng - Generator of uniformly distributed random numbers.

Returns:

the sampler

Throws:

UnsupportedOperationException - if the underlying sampler is not a SharedStateSampler or does not return a NormalizedGaussianSampler when sharing state.

Since:

1.3

of

public static SharedStateContinuousSampler of(NormalizedGaussianSampler gaussian,
 double mu,
 double sigma)

Create a new log-normal distribution sampler.

Note: The shared-state functionality is available if the NormalizedGaussianSampler is a SharedStateSampler. Otherwise a run-time exception will be thrown when the sampler is used to share state.

Parameters:

gaussian - N(0,1) generator.

mu - Mean of the natural logarithm of the distribution values.

sigma - Standard deviation of the natural logarithm of the distribution values.

Returns:

the sampler

Throws:

IllegalArgumentException - if sigma <= 0.

Since:

1.3

See Also:

• withUniformRandomProvider(UniformRandomProvider)