Package org.apache.commons.rng.sampling

Class UnitSphereSampler

java.lang.Object

org.apache.commons.rng.sampling.UnitSphereSampler

All Implemented Interfaces:

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

public class UnitSphereSampler
extends Object
implements SharedStateObjectSampler<double[]>

Generate vectors isotropically located on the surface of a sphere.

Sampling in 2 or more dimensions uses:

• UniformRandomProvider.nextLong()
• UniformRandomProvider.nextDouble()

Sampling in 1D uses the sign bit from UniformRandomProvider.nextInt() to set the direction of the vector.

Since:

1.1

Constructor Summary

Constructors

Constructor	Description
UnitSphereSampler(int dimension, UniformRandomProvider rng)	Deprecated. Use of(UniformRandomProvider, int).

Method Summary

Modifier and Type	Method	Description
double[]	nextVector()	Deprecated. Use sample().
static UnitSphereSampler	of(UniformRandomProvider rng, int dimension)	Create a unit sphere sampler for the given dimension.
double[]	sample()	Create a sample.
UnitSphereSampler	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 java.lang.Object

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

Constructor Detail

UnitSphereSampler

@Deprecated
public UnitSphereSampler(int dimension,
                         UniformRandomProvider rng)

Deprecated.

Use of(UniformRandomProvider, int).

This instance delegates sampling. Use the factory method of(UniformRandomProvider, int) to create an optimal sampler.

Parameters:

dimension - Space dimension.

rng - Generator for the individual components of the vectors. A shallow copy will be stored in this instance.

Throws:

IllegalArgumentException - If dimension <= 0

Method Detail

sample

public double[] sample()

Description copied from interface: ObjectSampler

Create a sample.

Specified by:

sample in interface ObjectSampler<double[]>

Returns:

a random normalized Cartesian vector.

Since:

1.4

nextVector

@Deprecated
public double[] nextVector()

Deprecated.

Use sample().

Returns:

a random normalized Cartesian vector.

withUniformRandomProvider

public UnitSphereSampler 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

Since:

1.3

of

public static UnitSphereSampler of(UniformRandomProvider rng,
                                   int dimension)

Create a unit sphere sampler for the given dimension.

Parameters:

rng - Generator for the individual components of the vectors. A shallow copy will be stored in the sampler.

dimension - Space dimension.

Returns:

the sampler

Throws:

IllegalArgumentException - If dimension <= 0

Since:

1.4