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Class template geometric_distribution

boost::random::geometric_distribution

Synopsis

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

template<typename IntType = int, typename RealType = double> 
class geometric_distribution {
public:
  // types
  typedef RealType input_type; 
  typedef IntType  result_type;

  // member classes/structs/unions

  class param_type {
  public:
    // types
    typedef geometric_distribution distribution_type;

    // construct/copy/destruct
    explicit param_type(RealType = 0.5);

    // public member functions
    RealType p() const;

    // friend functions
    template<typename CharT, typename Traits> 
      friend std::basic_ostream< CharT, Traits > & 
      operator<<(std::basic_ostream< CharT, Traits > &, const param_type &);
    template<typename CharT, typename Traits> 
      friend std::basic_istream< CharT, Traits > & 
      operator>>(std::basic_istream< CharT, Traits > &, const param_type &);
    friend bool operator==(const param_type &, const param_type &);
    friend bool operator!=(const param_type &, const param_type &);
  };

  // construct/copy/destruct
  explicit geometric_distribution(const RealType & = 0.5);
  explicit geometric_distribution(const param_type &);

  // public member functions
  RealType p() const;
  IntType min() const;
  IntType max() const;
  param_type param() const;
  void param(const param_type &);
  void reset();
  template<typename Engine> result_type operator()(Engine &) const;
  template<typename Engine> 
    result_type operator()(Engine &, const param_type &) const;

  // friend functions
  template<typename CharT, typename Traits> 
    friend std::basic_ostream< CharT, Traits > & 
    operator<<(std::basic_ostream< CharT, Traits > &, 
               const geometric_distribution &);
  template<typename CharT, typename Traits> 
    friend std::basic_istream< CharT, Traits > & 
    operator>>(std::basic_istream< CharT, Traits > &, 
               const geometric_distribution &);
  friend bool operator==(const geometric_distribution &, 
                         const geometric_distribution &);
  friend bool operator!=(const geometric_distribution &, 
                         const geometric_distribution &);
};

Description

An instantiation of the class template geometric_distribution models a random distribution . The distribution produces positive integers which are the number of bernoulli trials with probability p required to get one that fails.

For the geometric distribution, .

[Warning] Warning

This distribution has been updated to match the C++ standard. Its behavior has changed from the original boost::geometric_distribution. A backwards compatible wrapper is provided in namespace boost.

geometric_distribution public construct/copy/destruct

  1. explicit geometric_distribution(const RealType & p = 0.5);

    Contructs a new geometric_distribution with the paramter p.

    Requires: 0 < p < 1

  2. explicit geometric_distribution(const param_type & param);

    Constructs a new geometric_distribution from its parameters.

geometric_distribution public member functions

  1. RealType p() const;

    Returns: the distribution parameter p

  2. IntType min() const;

    Returns the smallest value that the distribution can produce.

  3. IntType max() const;

    Returns the largest value that the distribution can produce.

  4. param_type param() const;

    Returns the parameters of the distribution.

  5. void param(const param_type & param);

    Sets the parameters of the distribution.

  6. void reset();

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

  7. template<typename Engine> result_type operator()(Engine & eng) const;

    Returns a random variate distributed according to the geometric_distribution.

  8. template<typename Engine> 
      result_type operator()(Engine & eng, const param_type & param) const;

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

geometric_distribution friend functions

  1. template<typename CharT, typename Traits> 
      friend std::basic_ostream< CharT, Traits > & 
      operator<<(std::basic_ostream< CharT, Traits > & os, 
                 const geometric_distribution & gd);

    Writes the distribution to a std::ostream.

  2. template<typename CharT, typename Traits> 
      friend std::basic_istream< CharT, Traits > & 
      operator>>(std::basic_istream< CharT, Traits > & is, 
                 const geometric_distribution & gd);

    Reads the distribution from a std::istream.

  3. friend bool operator==(const geometric_distribution & lhs, 
                           const geometric_distribution & rhs);

    Returns true if the two distributions will produce identical sequences of values given equal generators.

  4. friend bool operator!=(const geometric_distribution & lhs, 
                           const geometric_distribution & rhs);

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


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