Package net.automatalib.common.util.random

Class RandomUtil

java.lang.Object

net.automatalib.common.util.random.RandomUtil

public final class RandomUtil
extends Object

Method Summary

Modifier and Type	Method	Description
static <T> @Nullable T	choose(Random rand, List<? extends T> list)
static <T> @Nullable T	choose(Random rand, T[] array)
static int[]	distinctIntegers(Random rand, int num, int max)
static int[]	distinctIntegers(Random rand, int num, int min, int max)	Sample a specified number of distinct integers from a specified range.
static <T> List<T>	sample(Random rand, List<? extends T> list, int num)
static <T> List<T>	sampleUnique(Random rand, List<? extends T> list, int num)	Sample a specified number of elements from specified list.

Methods inherited from class java.lang.Object

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

Method Detail

choose

public static <T> @Nullable T choose(Random rand,
                                     T[] array)

choose

public static <T> @Nullable T choose(Random rand,
                                     List<? extends T> list)

distinctIntegers

public static int[] distinctIntegers(Random rand,
                                     int num,
                                     int min,
                                     int max)

Sample a specified number of distinct integers from a specified range.

The implementation is based on Floyd's Algorithm F2. Note that this algorithm ensures equal probability of each integer within in the specified range to appear in the returned array but no equal probability of their order.

Parameters:

rand - the random instance for generating numbers

num - number of integers to sample

min - lower bound (inclusive) of sampled values

max - upper bound (exclusive) of samples values

Returns:

an array of distinct integers sampled from the specified range

distinctIntegers

public static int[] distinctIntegers(Random rand,
                                     int num,
                                     int max)

sample

public static <T> List<T> sample(Random rand,
                                 List<? extends T> list,
                                 int num)

sampleUnique

public static <T> List<T> sampleUnique(Random rand,
                                       List<? extends T> list,
                                       int num)

Sample a specified number of elements from specified list.

The implementation is based on Floyd's Algorithm F2. Note that this algorithm ensures equal probability of each element within in the specified list to appear in the returned list but no equal probability of their order.

Parameters:

rand - the random instance for generating numbers

list - the list to sample elements from

num - number of integers to sample

Returns:

a list of distinct elements sampled from the specified list