Boost C++ Libraries Home Libraries People FAQ More

PrevUpHomeNext

Class template poisson_distribution

boost::random::poisson_distribution

Synopsis

// In header: <boost/random/poisson_distribution.hpp>

template<typename IntType, typename RealType> 
class poisson_distribution {
public:
  // types
  typedef   ;
  typedef  ; 

  // member classes/structs/unions

  class param_type {
  public:
    // types
    typedef poisson_distribution ;

    // construct/copy/destruct
    ( = );

    // public member functions
     () ;

    // friend functions
    template<typename CharT, typename Traits> 
       
      (, param_type &);
    template<typename CharT, typename Traits> 
       
      (, param_type &);
     (param_type &, param_type &);
     (param_type &, param_type &);
  };

  // construct/copy/destruct
  ( = );
  (param_type &);

  // public member functions
  template<typename URNG>  () ;
  template<typename URNG>  (, param_type &) ;
   () ;
   () ;
   () ;
  param_type () ;
   (param_type &);
   ();

  // friend functions
  template<typename CharT, typename Traits> 
     
    (, 
               poisson_distribution &);
  template<typename CharT, typename Traits> 
     
    (, poisson_distribution &);
   (poisson_distribution &, poisson_distribution &);
   (poisson_distribution &, poisson_distribution &);
};

Description

An instantiation of the class template poisson_distribution is a model of random distribution . The poisson distribution has

This implementation is based on the PTRD algorithm described

"The transformed rejection method for generating Poisson random variables", Wolfgang Hormann, Insurance: Mathematics and Economics Volume 12, Issue 1, February 1993, Pages 39-45

poisson_distribution public construct/copy/destruct

  1. ( mean = );

    Constructs a poisson_distribution with the parameter mean.

    Requires: mean > 0

  2. (param_type & param);

    Construct an poisson_distribution object from the parameters.

poisson_distribution public member functions

  1. template<typename URNG>  ( urng) ;

    Returns a random variate distributed according to the poisson distribution.

  2. template<typename URNG> 
       ( urng, param_type & param) ;

    Returns a random variate distributed according to the poisson distribution with parameters specified by param.

  3.  () ;

    Returns the "mean" parameter of the distribution.

  4.  () ;

    Returns the smallest value that the distribution can produce.

  5.  () ;

    Returns the largest value that the distribution can produce.

  6. param_type () ;

    Returns the parameters of the distribution.

  7.  (param_type & param);

    Sets parameters of the distribution.

  8.  ();

    Effects: Subsequent uses of the distribution do not depend on values produced by any engine prior to invoking reset.

poisson_distribution friend functions

  1. template<typename CharT, typename Traits> 
       
      ( os, 
                 poisson_distribution & pd);

    Writes the parameters of the distribution to a std::ostream.

  2. template<typename CharT, typename Traits> 
       
      ( is, 
                 poisson_distribution & pd);

    Reads the parameters of the distribution from a std::istream.

  3.  (poisson_distribution & lhs, 
                    poisson_distribution & rhs);

    Returns true if the two distributions will produce the same sequence of values, given equal generators.

  4.  (poisson_distribution & lhs, 
                    poisson_distribution & rhs);

    Returns true if the two distributions could produce different sequences of values, given equal generators.


PrevUpHomeNext