StdRandom

Class StdRandom

Object
  StdRandom

public class StdRandom
extends Object
extends Object

Standard random. This class provides methods for generating random number from various distributions.

For additional documentation, see Section 2.2 of Introduction to Programming in Java: An Interdisciplinary Approach by Robert Sedgewick and Kevin Wayne.

Constructor Summary
`StdRandom()`

Method Summary
`static boolean`	`bernoulli()` Return a boolean, which is true with probability .5, and false otherwise.
`static boolean`	`bernoulli(double p)` Return a boolean, which is true with probability p, and false otherwise.
`static double`	`cauchy()` Return a real number with a Cauchy distribution.
`static int`	`discrete(double[] a)` Return a number from a discrete distribution: i with probability a[i].
`static double`	`exp(double lambda)` Return a real number from an exponential distribution with rate lambda.
`static double`	`gaussian()` Return a real number with a standard Gaussian distribution.
`static double`	`gaussian(double mean, double stddev)` Return a real number from a gaussian distribution with given mean and stddev
`static int`	`geometric(double p)` Return an integer with a geometric distribution with mean 1/p.
`static void`	`main(String[] args)` Unit test.
`static double`	`pareto(double alpha)` Return a real number with a Pareto distribution with parameter alpha.
`static int`	`poisson(double lambda)` Return an integer with a Poisson distribution with mean lambda.
`static void`	`shuffle(double[] a)` Rearrange the elements of a double array in random order.
`static void`	`shuffle(int[] a)` Rearrange the elements of an int array in random order.
`static void`	`shuffle(Object[] a)` Rearrange the elements of an array in random order.
`static double`	`uniform()` Return real number uniformly in [0, 1).
`static double`	`uniform(double a, double b)` Return real number uniformly in [a, b).
`static int`	`uniform(int N)` Return an integer uniformly between 0 and N-1.

Methods inherited from class Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

StdRandom

public StdRandom()

Method Detail

uniform

public static double uniform()

Return real number uniformly in [0, 1).

uniform

public static double uniform(double a,
                             double b)

Return real number uniformly in [a, b).

uniform

public static int uniform(int N)

Return an integer uniformly between 0 and N-1.

bernoulli

public static boolean bernoulli(double p)

Return a boolean, which is true with probability p, and false otherwise.

bernoulli

public static boolean bernoulli()

Return a boolean, which is true with probability .5, and false otherwise.

gaussian

public static double gaussian()

Return a real number with a standard Gaussian distribution.

gaussian

public static double gaussian(double mean,
                              double stddev)

Return a real number from a gaussian distribution with given mean and stddev

geometric

public static int geometric(double p)

Return an integer with a geometric distribution with mean 1/p.

poisson

public static int poisson(double lambda)

Return an integer with a Poisson distribution with mean lambda.

pareto

public static double pareto(double alpha)

Return a real number with a Pareto distribution with parameter alpha.

cauchy

public static double cauchy()

Return a real number with a Cauchy distribution.

discrete

public static int discrete(double[] a)

Return a number from a discrete distribution: i with probability a[i].

exp

public static double exp(double lambda)

Return a real number from an exponential distribution with rate lambda.

shuffle

public static void shuffle(Object[] a)

Rearrange the elements of an array in random order.

shuffle

public static void shuffle(double[] a)

Rearrange the elements of a double array in random order.

shuffle

public static void shuffle(int[] a)

Rearrange the elements of an int array in random order.

main

public static void main(String[] args)

Unit test.