std::tr1::poisson_distribution3
Detailed Description
template<typename _IntType = int, typename _RealType = double> class std::tr1::poisson_distribution< _IntType, _RealType >
The formula for the poisson probability mass function is $ p(i) = ac{mean^i}{i!} e^{-mean} $ where $ mean $ is the parameter of the distribution.
Definition at line 1829 of file random.
Public Types
typedef _RealType input_type
typedef _IntType result_type
Public Member Functions
_RealType mean () const
template<class _UniformRandomNumberGenerator> result_type operator() (_UniformRandomNumberGenerator &__urng)
poisson_distribution (const _RealType &__mean=_RealType(1))
void reset ()
Friends
template<typename _IntType1, typename _RealType1, typename _CharT, typename _Traits> std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const poisson_distribution< _IntType1, _RealType1 > &__x)
template<typename _IntType1, typename _RealType1, typename _CharT, typename _Traits> std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, poisson_distribution< _IntType1, _RealType1 > &__x)
Member Function Documentation
template<typename _IntType = int, typename _RealType = double> _RealType std::tr1::poisson_distribution< _IntType, _RealType >::mean () const [inline]
Gets the distribution parameter mean.
Definition at line 1849 of file random.
template<typename _IntType, typename _RealType> template<class _UniformRandomNumberGenerator> poisson_distribution< _IntType, _RealType >::result_type std::tr1::poisson_distribution< _IntType, _RealType >::operator() (_UniformRandomNumberGenerator & __urng) [inline]
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 906 of file random.tcc.
References std::numeric_limits< _Tp >::epsilon(), and std::numeric_limits< _Tp >::max().