umontreal.iro.lecuyer.rng
Class RandomPermutation

java.lang.Object
  umontreal.iro.lecuyer.rng.RandomPermutation

public class RandomPermutation
extends Object

Provides methods to randomly shuffle arrays or lists using a random stream.

Constructor Summary

RandomPermutation()

Method Summary

static void	init(byte[] array, int n) Initializes array with the first n positive integers in natural order as array[i - 1] = i, for i = 1,..., n.
static void	init(double[] array, int n) Similar to init(byte[], int).
static void	init(float[] array, int n) Similar to init(byte[], int).
static void	init(int[] array, int n) Similar to init(byte[], int).
static void	init(long[] array, int n) Similar to init(byte[], int).
static void	init(short[] array, int n) Similar to init(byte[], int).
static void	shuffle(boolean[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(boolean[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).
static void	shuffle(byte[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(byte[] array, RandomStream stream) Randomly permutes array using stream.
static void	shuffle(char[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(char[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).
static void	shuffle(double[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(double[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).
static void	shuffle(float[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(float[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).
static void	shuffle(int[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(int[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).
static void	shuffle(List<?> list, int k, RandomStream stream)
static void	shuffle(List<?> list, RandomStream stream)
static void	shuffle(long[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(long[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).
static void	shuffle(Object[] array, int n, int k, RandomStream stream) Partially permutes array as follows using stream: draws the new k elements, array[0] to array[k-1], randomly among the old n elements, array[0] to array[n-1], assuming that k <= n <= array.length.
static void	shuffle(Object[] array, RandomStream stream) Randomly permutes array using stream.
static void	shuffle(short[] array, int n, int k, RandomStream stream) Similar to shuffle(Object[], n, k, RandomStream).
static void	shuffle(short[] array, RandomStream stream) Similar to shuffle(byte[], RandomStream).

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomPermutation

public RandomPermutation()

Method Detail

init

public static void init(byte[] array,
                        int n)

Initializes array with the first n positive integers in natural order as array[i - 1] = i, for i = 1,..., n. The size of array must be at least n.

Parameters:

array - the array to initialize.

n - number of elements initialized.

init

public static void init(short[] array,
                        int n)

Similar to init(byte[], int).

Parameters:

array - the array to initialize.

n - number of elements initialized.

init

public static void init(int[] array,
                        int n)

Similar to init(byte[], int).

Parameters:

array - the array to initialize.

n - number of elements initialized.

init

public static void init(long[] array,
                        int n)

Similar to init(byte[], int).

Parameters:

array - the array to initialize.

n - number of elements initialized.

init

public static void init(float[] array,
                        int n)

Similar to init(byte[], int).

Parameters:

array - the array to initialize.

n - number of elements initialized.

init

public static void init(double[] array,
                        int n)

Similar to init(byte[], int).

Parameters:

array - the array to initialize.

n - number of elements initialized.

shuffle

public static void shuffle(List<?> list,
                           RandomStream stream)

shuffle

public static void shuffle(Object[] array,
                           RandomStream stream)

Randomly permutes array using stream. This method permutes the whole array.

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(byte[] array,
                           RandomStream stream)

Randomly permutes array using stream. This method permutes the whole array.

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(short[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(int[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(long[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(char[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(boolean[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(float[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(double[] array,
                           RandomStream stream)

Similar to shuffle(byte[], RandomStream).

Parameters:

array - the array being shuffled.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(List<?> list,
                           int k,
                           RandomStream stream)

shuffle

public static void shuffle(Object[] array,
                           int n,
                           int k,
                           RandomStream stream)

Partially permutes array as follows using stream: draws the new k elements, array[0] to array[k-1], randomly among the old n elements, array[0] to array[n-1], assuming that k <= n <= array.length. In other words, k elements are selected at random without replacement from the first n array elements and are placed in the first k positions, in random order.

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(byte[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(short[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(int[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(long[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(char[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(boolean[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(float[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.

shuffle

public static void shuffle(double[] array,
                           int n,
                           int k,
                           RandomStream stream)

Similar to shuffle(Object[], n, k, RandomStream).

Parameters:

array - the array being shuffled.

n - selection amongst the first n elements.

k - number of elements selected.

stream - the random stream used to generate random numbers.