nl.colorize.multimedialib.math

Class Rand

java.lang.Object

nl.colorize.multimedialib.math.Rand

public final class Rand
extends java.lang.Object

Utility class for working with random numbers. This class uses an instance of Random internally, but adds a number of convenience methods on top of it.

Method Summary

Modifier and Type	Method and Description
static boolean	chance(float f) Generates a random number and compares it to a threshold value.
static boolean	nextBoolean()
static float	nextFloat() Returns a random float between 0 (inclusive) and 1 (exclusive).
static float	nextFloat(float lower, float upper) Returns a random float between lower (inclusive) and upper (exclusive).
static int	nextInt(int upper) Returns an integer between 0 and upper (exclusive).
static int	nextInt(int lower, int upper) Returns a random integer between lower (inclusive) and upper (exclusive).
static <E> E	oneFrom(E[] elements) Returns a random element from an array.
static <E> E	oneFrom(java.util.List<E> elements) Returns a random element from a list.

Methods inherited from class java.lang.Object

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

Method Detail

nextInt

public static int nextInt(int upper)

Returns an integer between 0 and upper (exclusive).

nextInt

public static int nextInt(int lower,
                          int upper)

Returns a random integer between lower (inclusive) and upper (exclusive).

nextFloat

public static float nextFloat()

Returns a random float between 0 (inclusive) and 1 (exclusive).

nextFloat

public static float nextFloat(float lower,
                              float upper)

Returns a random float between lower (inclusive) and upper (exclusive).

nextBoolean

public static boolean nextBoolean()

chance

public static boolean chance(float f)

Generates a random number and compares it to a threshold value. The threshold is a number between 0 and 1. For example, if the argument is 0.7 this method has a 70 percent chance of returning true.

Throws:

java.lang.IllegalArgumentException - if f is outside the range 0..1.

oneFrom

public static <E> E oneFrom(java.util.List<E> elements)

Returns a random element from a list.

Throws:

java.lang.IllegalArgumentException - if the list is empty.

oneFrom

public static <E> E oneFrom(E[] elements)

Returns a random element from an array.

Throws:

java.lang.IllegalArgumentException - if the array is empty.