Class UnitBallSampler

java.lang.Object

org.apache.commons.rng.sampling.shape.UnitBallSampler

All Implemented Interfaces:

ObjectSampler<double[]>, SharedStateObjectSampler<double[]>, SharedStateSampler<SharedStateObjectSampler<double[]>>

public abstract class UnitBallSampler
extends Object
implements SharedStateObjectSampler<double[]>

Generate coordinates uniformly distributed within the unit n-ball.

Sampling uses:

• UniformRandomProvider.nextLong()
• UniformRandomProvider.nextDouble() (only for dimensions above 2)

Since:

1.4

Constructor Summary

Constructors

Constructor	Description
UnitBallSampler()	Create an instance.

Method Summary

Modifier and Type	Method	Description
static UnitBallSampler	of(UniformRandomProvider rng, int dimension)	Create a unit n-ball sampler for the given dimension.
abstract double[]	sample()	Create an object sample.
abstract UnitBallSampler	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, toString, wait, wait, wait

Methods inherited from interface ObjectSampler

samples, samples

Constructor Details

UnitBallSampler

public UnitBallSampler()

Create an instance.

Method Details

sample

public abstract double[] sample()

Description copied from interface: ObjectSampler

Create an object sample.

Specified by:

sample in interface ObjectSampler<double[]>

Returns:

a random Cartesian coordinate within the unit n-ball.

withUniformRandomProvider

public abstract UnitBallSampler 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:

withUniformRandomProvider in interface SharedStateSampler<SharedStateObjectSampler<double[]>>

Parameters:

rng - Generator of uniformly distributed random numbers.

Returns:

the sampler

of

public static UnitBallSampler of(UniformRandomProvider rng,
 int dimension)

Create a unit n-ball sampler for the given dimension. Sampled points are uniformly distributed within the unit n-ball.

Sampling is supported in dimensions of 1 or above.

Parameters:

rng - Source of randomness.

dimension - Space dimension.

Returns:

the sampler

Throws:

IllegalArgumentException - If dimension <= 0