libstdc++
std::poisson_distribution< _IntType > Class Template Reference
Numerics » Random Number Generation » Random Number Distributions » Poisson Distributions

#include <random>

Classes

struct  param_type

Public Types

typedef _IntType result_type

Public Member Functions

 poisson_distribution (const param_type &__p)
 poisson_distribution (double __mean)
template<typename _ForwardIterator, typename _UniformRandomNumberGenerator>
void __generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng)
template<typename _ForwardIterator, typename _UniformRandomNumberGenerator>
void __generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng, const param_type &__p)
template<typename _UniformRandomNumberGenerator>
void __generate (result_type *__f, result_type *__t, _UniformRandomNumberGenerator &__urng, const param_type &__p)
result_type max () const
double mean () const
result_type min () const
template<typename _UniformRandomNumberGenerator>
result_type operator() (_UniformRandomNumberGenerator &__urng)
template<typename _UniformRandomNumberGenerator>
result_type operator() (_UniformRandomNumberGenerator &__urng, const param_type &__p)
param_type param () const
void param (const param_type &__param)
void reset ()

Friends

template<typename _IntType1, typename _CharT, typename _Traits>
std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const std::poisson_distribution< _IntType1 > &__x)
bool operator== (const poisson_distribution &__d1, const poisson_distribution &__d2)
template<typename _IntType1, typename _CharT, typename _Traits>
std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, std::poisson_distribution< _IntType1 > &__x)

Detailed Description

template<typename _IntType = int>
class std::poisson_distribution< _IntType >

A discrete Poisson random number distribution.

The formula for the Poisson probability density function is $p(i|\mu) = \frac{\mu^i}{i!} e^{-\mu}$ where $\mu$ is the parameter of the distribution.

Since
C++11

Definition at line 4551 of file random.h.

Member Typedef Documentation

◆ result_type

template<typename _IntType = int>
typedef _IntType std::poisson_distribution< _IntType >::result_type

The type of the range of the distribution.

Definition at line 4558 of file random.h.

Constructor & Destructor Documentation

◆ poisson_distribution() [1/3]

template<typename _IntType = int>
std::poisson_distribution< _IntType >::poisson_distribution ( )
inline

Definition at line 4605 of file random.h.

◆ poisson_distribution() [2/3]

template<typename _IntType = int>
std::poisson_distribution< _IntType >::poisson_distribution ( double __mean)
inlineexplicit

Definition at line 4608 of file random.h.

◆ poisson_distribution() [3/3]

template<typename _IntType = int>
std::poisson_distribution< _IntType >::poisson_distribution ( const param_type & __p)
inlineexplicit

Definition at line 4613 of file random.h.

Member Function Documentation

◆ __generate() [1/3]

template<typename _IntType = int>
template<typename _ForwardIterator, typename _UniformRandomNumberGenerator>
void std::poisson_distribution< _IntType >::__generate ( _ForwardIterator __f,
_ForwardIterator __t,
_UniformRandomNumberGenerator & __urng )
inline

Definition at line 4676 of file random.h.

◆ __generate() [2/3]

template<typename _IntType = int>
template<typename _ForwardIterator, typename _UniformRandomNumberGenerator>
void std::poisson_distribution< _IntType >::__generate ( _ForwardIterator __f,
_ForwardIterator __t,
_UniformRandomNumberGenerator & __urng,
const param_type & __p )
inline

Definition at line 4683 of file random.h.

◆ __generate() [3/3]

template<typename _IntType = int>
template<typename _UniformRandomNumberGenerator>
void std::poisson_distribution< _IntType >::__generate ( result_type * __f,
result_type * __t,
_UniformRandomNumberGenerator & __urng,
const param_type & __p )
inline

Definition at line 4690 of file random.h.

◆ max()

template<typename _IntType = int>
result_type std::poisson_distribution< _IntType >::max ( ) const
inline

Returns the least upper bound value of the distribution.

Definition at line 4657 of file random.h.

◆ mean()

template<typename _IntType = int>
double std::poisson_distribution< _IntType >::mean ( ) const
inline

Returns the distribution parameter mean.

Definition at line 4628 of file random.h.

◆ min()

template<typename _IntType = int>
result_type std::poisson_distribution< _IntType >::min ( ) const
inline

Returns the greatest lower bound value of the distribution.

Definition at line 4650 of file random.h.

◆ operator()() [1/2]

template<typename _IntType = int>
template<typename _UniformRandomNumberGenerator>
result_type std::poisson_distribution< _IntType >::operator() ( _UniformRandomNumberGenerator & __urng)
inline

Generating functions.

Definition at line 4665 of file random.h.

Referenced by operator()().

◆ operator()() [2/2]

template<typename _IntType>
template<typename _UniformRandomNumberGenerator>
poisson_distribution< _IntType >::result_type std::poisson_distribution< _IntType >::operator() ( _UniformRandomNumberGenerator & __urng,
const param_type & __param )

A rejection algorithm when mean >= 12 and a simple method based upon the multiplication of uniform random variates otherwise. NB: The former is available only if _GLIBCXX_USE_C99_MATH_TR1 is defined.

Reference: Devroye, L. Non-Uniform Random Variates Generation. Springer-Verlag, New York, 1986, Ch. X, Sects. 3.3 & 3.4 (+ Errata!).

Definition at line 1311 of file bits/random.tcc.

References std::abs(), std::numeric_limits< _Tp >::epsilon(), std::log(), and std::numeric_limits< _Tp >::max().

◆ param() [1/2]

template<typename _IntType = int>
param_type std::poisson_distribution< _IntType >::param ( ) const
inline

Returns the parameter set of the distribution.

Definition at line 4635 of file random.h.

◆ param() [2/2]

template<typename _IntType = int>
void std::poisson_distribution< _IntType >::param ( const param_type & __param)
inline

Sets the parameter set of the distribution.

Parameters
__paramThe new parameter set of the distribution.

Definition at line 4643 of file random.h.

◆ reset()

template<typename _IntType = int>
void std::poisson_distribution< _IntType >::reset ( )
inline

Resets the distribution state.

Definition at line 4621 of file random.h.

◆ operator<<

template<typename _IntType = int>
template<typename _IntType1, typename _CharT, typename _Traits>
std::basic_ostream< _CharT, _Traits > & operator<< ( std::basic_ostream< _CharT, _Traits > & __os,
const std::poisson_distribution< _IntType1 > & __x )
friend

Inserts a poisson_distribution random number distribution __x into the output stream __os.

Parameters
__osAn output stream.
__xA poisson_distribution random number distribution.
Returns
The output stream with the state of __x inserted or in an error state.

◆ operator==

template<typename _IntType = int>
bool operator== ( const poisson_distribution< _IntType > & __d1,
const poisson_distribution< _IntType > & __d2 )
friend

Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal.

Definition at line 4701 of file random.h.

◆ operator>>

template<typename _IntType = int>
template<typename _IntType1, typename _CharT, typename _Traits>
std::basic_istream< _CharT, _Traits > & operator>> ( std::basic_istream< _CharT, _Traits > & __is,
std::poisson_distribution< _IntType1 > & __x )
friend

Extracts a poisson_distribution random number distribution __x from the input stream __is.

Parameters
__isAn input stream.
__xA poisson_distribution random number generator engine.
Returns
The input stream with __x extracted or in an error state.
The documentation for this class was generated from the following files: