Package org.apache.commons.rng.sampling

Class ArraySampler

java.lang.Object

org.apache.commons.rng.sampling.ArraySampler

public final class ArraySampler
extends Object

Utilities for shuffling an array in-place.

Shuffles use the Fisher-Yates algorithm.

Small ranges use batched random integer generation to increase performance.

• Nevin Brackett-Rozinsky, Daniel Lemire, Batched Ranged Random Integer Generation, Software: Practice and Experience (to appear) arXiv:2408.06213M

Since:

1.6

Method Summary

Modifier and Type	Method	Description
static boolean[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, boolean[] array)	Shuffles the entries of the given array.
static boolean[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, boolean[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static byte[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, byte[] array)	Shuffles the entries of the given array.
static byte[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, byte[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static char[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, char[] array)	Shuffles the entries of the given array.
static char[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, char[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static double[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, double[] array)	Shuffles the entries of the given array.
static double[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, double[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static float[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, float[] array)	Shuffles the entries of the given array.
static float[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, float[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static int[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, int[] array)	Shuffles the entries of the given array.
static int[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, int[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static long[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, long[] array)	Shuffles the entries of the given array.
static long[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, long[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static short[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, short[] array)	Shuffles the entries of the given array.
static short[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, short[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).
static <T> T[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, T[] array)	Shuffles the entries of the given array.
static <T> T[]	shuffle(org.apache.commons.rng.UniformRandomProvider rng, T[] array, int from, int to)	Shuffles the entries of the given array in the range [from, to).

Methods inherited from class java.lang.Object

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

Method Detail

shuffle

public static boolean[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                                boolean[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static byte[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                             byte[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static char[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                             char[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static double[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                               double[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static float[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                              float[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static int[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                            int[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static long[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                             long[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static short[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                              short[] array)

Shuffles the entries of the given array.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static <T> T[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                              T[] array)

Shuffles the entries of the given array.

Type Parameters:

T - Type of the items.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

Returns:

a reference to the given array

shuffle

public static boolean[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                                boolean[] array,
                                int from,
                                int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static byte[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                             byte[] array,
                             int from,
                             int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static char[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                             char[] array,
                             int from,
                             int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static double[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                               double[] array,
                               int from,
                               int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static float[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                              float[] array,
                              int from,
                              int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static int[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                            int[] array,
                            int from,
                            int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static long[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                             long[] array,
                             int from,
                             int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static short[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                              short[] array,
                              int from,
                              int to)

Shuffles the entries of the given array in the range [from, to).

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds

shuffle

public static <T> T[] shuffle(org.apache.commons.rng.UniformRandomProvider rng,
                              T[] array,
                              int from,
                              int to)

Shuffles the entries of the given array in the range [from, to).

Type Parameters:

T - Type of the items.

Parameters:

rng - Source of randomness.

array - Array whose entries will be shuffled (in-place).

from - Lower-bound (inclusive) of the sub-range.

to - Upper-bound (exclusive) of the sub-range.

Returns:

a reference to the given array

Throws:

IndexOutOfBoundsException - if the sub-range is out of bounds