libstdc++
std::poisson_distribution Class Reference

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Public Types

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Friends


Detailed Description

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.


Member Typedef Documentation

The type of the range of the distribution.

Definition at line 3959 of file random.h.


Member Function Documentation

result_type std::poisson_distribution::max ( ) const [inline]

Returns the least upper bound value of the distribution.

Definition at line 4046 of file random.h.

Referenced by operator()(), and std::binomial_distribution::operator()().

double std::poisson_distribution::mean ( ) const [inline]

Returns the distribution parameter mean.

Definition at line 4017 of file random.h.

result_type std::poisson_distribution::min ( ) const [inline]

Returns the greatest lower bound value of the distribution.

Definition at line 4039 of file random.h.

template<typename _UniformRandomNumberGenerator >
result_type std::poisson_distribution::operator() ( _UniformRandomNumberGenerator &  __urng) [inline]

Generating functions.

Definition at line 4054 of file random.h.

References operator()(), and param().

Referenced by operator()().

template<typename _UniformRandomNumberGenerator >
poisson_distribution< _IntType >::result_type std::poisson_distribution::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 1200 of file random.tcc.

References max(), std::log(), and std::abs().

param_type std::poisson_distribution::param ( ) const [inline]

Returns the parameter set of the distribution.

Definition at line 4024 of file random.h.

Referenced by operator()().

void std::poisson_distribution::param ( const param_type __param) [inline]

Sets the parameter set of the distribution.

Parameters:
__paramThe new parameter set of the distribution.

Definition at line 4032 of file random.h.

void std::poisson_distribution::reset ( ) [inline]

Resets the distribution state.

Definition at line 4010 of file random.h.

References std::normal_distribution::reset().


Friends And Related Function Documentation

template<typename _IntType1 , typename _CharT , typename _Traits >
std::basic_ostream<_CharT, _Traits>& operator<< ( std::basic_ostream< _CharT, _Traits > &  ,
const std::poisson_distribution< _IntType1 > &   
) [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.
template<typename _IntType1 >
bool operator== ( const std::poisson_distribution< _IntType1 > &  __d1,
const std::poisson_distribution< _IntType1 > &  __d2 
) [friend]

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

Definition at line 4069 of file random.h.

template<typename _IntType1 , typename _CharT , typename _Traits >
std::basic_istream<_CharT, _Traits>& operator>> ( std::basic_istream< _CharT, _Traits > &  ,
std::poisson_distribution< _IntType1 > &   
) [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: