maspack.util

Class RandomGenerator

java.lang.Object

maspack.util.RandomGenerator

public class RandomGenerator
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
RandomGenerator()

Method Summary

Modifier and Type	Method and Description
static java.util.Random	get()
static void	main(java.lang.String[] args)
static double	nextDouble()
static double	nextDouble(double min, double max)
static double	nextGaussian() Next random number from a normal (Gaussian) distribution with mean zero and unit standard deviation.
static double	nextGaussian(double mu, double sigma) Generates a random number from a normal (Gaussian) distribution with mean mu and s.d.
static int	nextInt(int n) Generate a random number between 0 and n-1
static int	nextInt(int min, int max) Generate a random number between min and max, inclusive
static int[]	randomSequence(int min, int max, int n) Generates a random non-repeating sequence of n integers in the range min, max (inclusive).
static int[]	randomSubsequence(int n) Generates a random subsequence of the integers 0, ...
static int[]	randomSubsequence(int min, int max) Generates a random subsequence of the integers in the range {@code min, ...
static double[]	randomUnityPartition(int n) Generates a random sequence of n numbers that sum to 1.
static void	set(java.util.Random generator)
static void	setSeed(int seed)

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomGenerator

public RandomGenerator()

Method Detail

get

public static java.util.Random get()

set

public static void set(java.util.Random generator)

setSeed

public static void setSeed(int seed)

nextDouble

public static double nextDouble(double min,
                                double max)

nextDouble

public static double nextDouble()

nextGaussian

public static double nextGaussian()

Next random number from a normal (Gaussian) distribution with mean zero and unit standard deviation.

Returns:

next normal value

nextGaussian

public static double nextGaussian(double mu,
                                  double sigma)

Generates a random number from a normal (Gaussian) distribution with mean mu and s.d. sigma

Parameters:

mu - mean

sigma - standard deviation

Returns:

next normal value

nextInt

public static int nextInt(int min,
                          int max)

Generate a random number between min and max, inclusive

Parameters:

min - minimum value

max - maximum value

Returns:

random number between min and max

nextInt

public static int nextInt(int n)

Generate a random number between 0 and n-1

Parameters:

n - upper limit

Returns:

random number between 0 and n-1

randomSubsequence

public static int[] randomSubsequence(int n)

Generates a random subsequence of the integers 0, ... n-1.

Parameters:

n - size of the subsequence

randomSubsequence

public static int[] randomSubsequence(int min,
                                      int max)

Generates a random subsequence of the integers in the range min, ... max, inclusive.

Parameters:

min - lowest possible integer in the sequence

max - highest possible integer in the sequence

randomSequence

public static int[] randomSequence(int min,
                                   int max,
                                   int n)

Generates a random non-repeating sequence of n integers in the range min, max (inclusive). n must be <= r, where r = max - min + 1.

Note: this method has a complexity of O(r).

Parameters:

min - minimum sequence value

max - maximum sequence value

n - number of sequence values

randomUnityPartition

public static double[] randomUnityPartition(int n)

Generates a random sequence of n numbers that sum to 1.

Parameters:

n - number of sequence values

main

public static void main(java.lang.String[] args)