DOKK / manpages / debian 12 / libstdc++-11-doc / std::poisson_distribution.3cxx.en
std::poisson_distribution< _IntType >(3cxx) std::poisson_distribution< _IntType >(3cxx)

std::poisson_distribution< _IntType > - A discrete Poisson random number distribution.

#include <random.h>


struct param_type


typedef _IntType result_type


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
Returns the least upper bound value of the distribution. double mean () const
Returns the distribution parameter mean. result_type min () const
Returns the greatest lower bound value of the distribution. template<typename _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng)
Generating functions. template<typename _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng, const param_type &__p)
param_type param () const
Returns the parameter set of the distribution. void param (const param_type &__param)
Sets the parameter set of the distribution. void reset ()
Resets the distribution state.


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)
Inserts a poisson_distribution random number distribution __x into the output stream __os. bool operator== (const poisson_distribution &__d1, const poisson_distribution &__d2)
Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal. template<typename _IntType1 , typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, std::poisson_distribution< _IntType1 > &__x)
Extracts a poisson_distribution random number distribution __x from the input stream __is.

class std::poisson_distribution< _IntType >"A discrete Poisson random number distribution.

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

Definition at line 4421 of file random.h.

The type of the range of the distribution.

Definition at line 4428 of file random.h.

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

Definition at line 4473 of file random.h.

template<typename _IntType = int> std::poisson_distribution< _IntType >::poisson_distribution (double __mean) [inline], [explicit]

Definition at line 4476 of file random.h.

template<typename _IntType = int> std::poisson_distribution< _IntType >::poisson_distribution (const param_type & __p) [inline], [explicit]

Definition at line 4481 of file random.h.

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 4544 of file random.h.

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 4551 of file random.h.

Definition at line 4558 of file random.h.

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 4525 of file random.h.

References std::numeric_limits< _Tp >::max().

Returns the distribution parameter mean.

Definition at line 4496 of file random.h.

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 4518 of file random.h.

Generating functions.

Definition at line 4533 of file random.h.

References std::poisson_distribution< _IntType >::operator()().

Referenced by std::poisson_distribution< _IntType >::operator()().

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 1302 of file bits/random.tcc.

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

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

Returns the parameter set of the distribution.

Definition at line 4503 of file random.h.

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

Sets the parameter set of the distribution.

Parameters

__param The new parameter set of the distribution.

Definition at line 4511 of file random.h.

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

Resets the distribution state.

Definition at line 4489 of file random.h.

References std::normal_distribution< _RealType >::reset().

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

__os An output stream.
__x A poisson_distribution random number distribution.

Returns

The output stream with the state of __x inserted or in an error state.

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

Definition at line 4569 of file random.h.

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

__is An input stream.
__x A poisson_distribution random number generator engine.

Returns

The input stream with __x extracted or in an error state.

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Thu Feb 16 2023 libstdc++