theplu::yat::random::DiscreteUniform Class Reference

Discrete uniform distribution. More...

#include <yat/random/random.h>

Inheritance diagram for theplu::yat::random::DiscreteUniform:

List of all members.

Public Member Functions

DiscreteUniform (unsigned long n=0)

Constructor.

unsigned long operator() (void) const

Get a random number.

unsigned long operator() (unsigned long n) const

Get a random integer in the range $ [0,n-1] $ .

void seed (unsigned long s) const

Set the seed to s.

unsigned long seed_from_devurandom (void)

Set the seed using the /dev/urandom device.

Protected Attributes

RNG * rng_

GSL random gererator.

Detailed Description

Discrete uniform distribution.

Discrete uniform distribution also known as the "equally likely outcomes" distribution. Each outcome, in this case an integer from [0,n-1] , have equal probability to occur.

Distribution function $p(k) = \frac{1}{n+1}$ for $0 \le k < n$
Expectation value: $\frac{n-1}{2}$
Variance: $\frac{1}{12}(n-1)(n+1)$

Constructor & Destructor Documentation

theplu::yat::random::DiscreteUniform::DiscreteUniform ( unsigned long n = 0 ) [explicit]

Constructor.

The generator will generate integers within the range $ [0,n-1] $ . If n is zero, then the whole range of the underlying RNG will be used $ [min,max] $ . Setting n to zero is the preferred way to sample the whole range of the underlying RNG, i.e. not setting
to RNG.max.

Exceptions:

If

n is larger than the maximum number the underlying random number generator can return, then a GSL_error exception is thrown.

Member Function Documentation

unsigned long theplu::yat::random::DiscreteUniform::operator() ( void ) const [virtual]

Get a random number.

The returned integer is either in the range [RNG.min,RNG.max] or [0,n-1] depending on how the random number generator was created.

See also:: DiscreteUniform(const unsigned long n=0)

Implements theplu::yat::random::Discrete.

unsigned long theplu::yat::random::DiscreteUniform::operator() ( unsigned long n ) const

Get a random integer in the range $ [0,n-1] $ .

All integers in the range [0,n-1] are equally likely. This function should be avoided for sampling the whole range of the underlying RNG.

Exceptions:

GSL_error

if n is larger than the range of the underlying generator.

void theplu::yat::random::Discrete::seed ( unsigned long s ) const [inherited]

Set the seed to s.

Set the seed to s in the underlying rng. If s is zero, a default value from the rng's original implementation is used (cf. GSL documentation).

See also:: seed_from_devurandom, RNG::seed_from_devurandom, RNG::seed

unsigned long theplu::yat::random::Discrete::seed_from_devurandom ( void ) [inherited]

Set the seed using the /dev/urandom device.

Returns:: The seed acquired from /dev/urandom.

See also:: seed, RNG::seed_from_devurandom, RNG::seed

The documentation for this class was generated from the following file:

yat/random/random.h


Public Member Functions
	DiscreteUniform (unsigned long n=0)
	Constructor.
unsigned long	operator() (void) const
	Get a random number.
unsigned long	operator() (unsigned long n) const
	Get a random integer in the range .
void	seed (unsigned long s) const
	Set the seed to s.
unsigned long	seed_from_devurandom (void)
	Set the seed using the /dev/urandom device.
Protected Attributes
RNG *	rng_
	GSL random gererator.