trusty (3) std::poisson_distribution.3cxx.gz

NAME

       std::poisson_distribution< _IntType, _RealType > -

SYNOPSIS

   Public Types
       typedef _RealType input_type
       typedef _IntType result_type

   Public Member Functions
       _RealType mean () const
       template<class _UniformRandomNumberGenerator > poisson_distribution< _IntType,
           _RealType >::result_type operator() (_UniformRandomNumberGenerator &__urng)"
       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)"

Detailed Description

   template<typename _IntType = int, typename _RealType = double>class std::poisson_distribution< _IntType,
       _RealType >
       A discrete Poisson random number distribution.

       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 1864 of file tr1_impl/random.

Member Function Documentation

   template<typename _IntType = int, typename _RealType = double> _RealType std::poisson_distribution< _IntType,
       _RealType >::mean () const [inline]
       Gets the distribution parameter mean.

       Definition at line 1884 of file tr1_impl/random.

   template<typename _IntType = int, typename _RealType = double> template<class _UniformRandomNumberGenerator >
       poisson_distribution<_IntType, _RealType>::result_type std::poisson_distribution< _IntType, _RealType
       >::operator() (_UniformRandomNumberGenerator &__urng)
       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 936 of file random.tcc.

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

Friends And Related Function Documentation

   template<typename _IntType = int, typename _RealType = double> 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)
       [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.

   template<typename _IntType = int, typename _RealType = double> 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)
       [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.

Author

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libstdc++                                        Thu Mar 2std::poisson_distribution< _IntType, _RealType >(3cxx)