StdRandom (Introduction to Programming in Java

java.lang.Object
- edu.princeton.cs.introcs.StdRandom

```
public final class StdRandom
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.

Author:

Robert Sedgewick, Kevin Wayne

Method Summary

Methods
Modifier and Type	Method and Description
`static boolean`	`bernoulli()` Returns a boolean, which is true with probability .5, and false otherwise.
`static boolean`	`bernoulli(double p)` Returns a boolean, which is true with probability p, and false otherwise.
`static double`	`cauchy()` Returns a real number with a Cauchy distribution.
`static int`	`discrete(double[] a)` Returns a number from a discrete distribution: i with probability a[i].
`static double`	`exp(double lambda)` Returns a real number from an exponential distribution with rate lambda.
`static double`	`gaussian()` Returns a real number with a standard Gaussian distribution.
`static double`	`gaussian(double mean, double stddev)` Returns a real number from a gaussian distribution with given mean and stddev
`static int`	`geometric(double p)` Returns an integer with a geometric distribution with mean 1/p.
`static long`	`getSeed()` Returns the seed of the psedurandom number generator.
`static void`	`main(String[] args)` Unit test.
`static double`	`pareto(double alpha)` Returns 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 double`	`random()` Deprecated. clearer to use `uniform()`
`static void`	`setSeed(long s)` Sets the seed of the psedurandom number generator.
`static void`	`shuffle(double[] a)` Rearrange the elements of a double array in random order.
`static void`	`shuffle(double[] a, int lo, int hi)` Rearrange the elements of the subarray a[lo..hi] in random order.
`static void`	`shuffle(int[] a)` Rearrange the elements of an int array in random order.
`static void`	`shuffle(int[] a, int lo, int hi)` Rearrange the elements of the subarray a[lo..hi] in random order.
`static void`	`shuffle(Object[] a)` Rearrange the elements of an array in random order.
`static void`	`shuffle(Object[] a, int lo, int hi)` Rearrange the elements of the subarray a[lo..hi] in random order.
`static double`	`uniform()` Return real number uniformly in [0, 1).
`static double`	`uniform(double a, double b)` Returns a real number uniformly in [a, b).
`static int`	`uniform(int N)` Returns an integer uniformly between 0 (inclusive) and N (exclusive).
`static int`	`uniform(int a, int b)` Returns an integer uniformly in [a, b).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - setSeed
```
public static void setSeed(long s)
```
    Sets the seed of the psedurandom number generator.
  - getSeed
```
public static long getSeed()
```
    Returns the seed of the psedurandom number generator.
  - uniform
```
public static double uniform()
```
    Return real number uniformly in [0, 1).
  - uniform
```
public static int uniform(int N)
```
    Returns an integer uniformly between 0 (inclusive) and N (exclusive).
    
    Throws:
    
    IllegalArgumentException - if N <= 0
  - random
```
public static double random()
```
    Deprecated. clearer to use uniform()
    
    Returns a real number uniformly in [0, 1).
  - uniform
```
public static int uniform(int a,
          int b)
```
    Returns an integer uniformly in [a, b).
    
    Throws:
    
    IllegalArgumentException - if b <= a
    
    IllegalArgumentException - if b - a >= Integer.MAX_VALUE
  - uniform
```
public static double uniform(double a,
             double b)
```
    Returns a real number uniformly in [a, b).
    
    Throws:
    
    IllegalArgumentException - if b <= a
  - bernoulli
```
public static boolean bernoulli(double p)
```
    Returns a boolean, which is true with probability p, and false otherwise.
    
    Throws:
    
    IllegalArgumentException - if either p < 0.0 or p > 1.0
  - bernoulli
```
public static boolean bernoulli()
```
    Returns a boolean, which is true with probability .5, and false otherwise.
  - gaussian
```
public static double gaussian()
```
    Returns a real number with a standard Gaussian distribution.
  - gaussian
```
public static double gaussian(double mean,
              double stddev)
```
    Returns a real number from a gaussian distribution with given mean and stddev
  - geometric
```
public static int geometric(double p)
```
    Returns an integer with a geometric distribution with mean 1/p.
    
    Throws:
    
    IllegalArgumentException - if either p < 0.0 or p > 1.0
  - poisson
```
public static int poisson(double lambda)
```
    Return an integer with a Poisson distribution with mean lambda.
    
    Throws:
    
    IllegalArgumentException - if lambda <= 0.0
  - pareto
```
public static double pareto(double alpha)
```
    Returns a real number with a Pareto distribution with parameter alpha.
    
    Throws:
    
    IllegalArgumentException - if alpha <= 0.0
  - cauchy
```
public static double cauchy()
```
    Returns a real number with a Cauchy distribution.
  - discrete
```
public static int discrete(double[] a)
```
    Returns a number from a discrete distribution: i with probability a[i]. throws IllegalArgumentException if sum of array entries is not (very nearly) equal to 1.0 throws IllegalArgumentException if a[i] < 0.0 for any index i
  - exp
```
public static double exp(double lambda)
```
    Returns a real number from an exponential distribution with rate lambda.
    
    Throws:
    
    IllegalArgumentException - if lambda <= 0.0
  - 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.
  - shuffle
```
public static void shuffle(Object[] a,
           int lo,
           int hi)
```
    Rearrange the elements of the subarray a[lo..hi] in random order.
  - shuffle
```
public static void shuffle(double[] a,
           int lo,
           int hi)
```
    Rearrange the elements of the subarray a[lo..hi] in random order.
  - shuffle
```
public static void shuffle(int[] a,
           int lo,
           int hi)
```
    Rearrange the elements of the subarray a[lo..hi] in random order.
  - main
```
public static void main(String[] args)
```
    Unit test.

Class StdRandom

Method Summary

Methods inherited from class java.lang.Object

Method Detail

setSeed

getSeed

uniform

uniform

random

uniform

uniform

bernoulli

bernoulli

gaussian

gaussian

geometric

poisson

pareto

cauchy

discrete

exp

shuffle

shuffle

shuffle

shuffle

shuffle

shuffle

main