A discrete Poisson random number distribution. More...
A discrete Poisson random number distribution.
The formula for the Poisson probability mass function is where
is the parameter of the distribution.
Definition at line 1864 of file tr1_impl/random.
_RealType std::poisson_distribution< _IntType, _RealType >::mean | ( | ) | const [inline] |
Gets the distribution parameter mean
.
Definition at line 1884 of file tr1_impl/random.
poisson_distribution< _IntType, _RealType >::result_type std::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 936 of file random.tcc.
References std::abs(), std::log(), and std::max().
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
.
__os | An output stream. | |
__x | A poisson_distribution random number distribution. |
__x
inserted or in an error state. 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
.
__is | An input stream. | |
__x | A poisson_distribution random number generator engine. |
__x
extracted or in an error state.