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regarded and expertly designed C++ library projects in the
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— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::random::negative_binomial_distribution
// In header: <boost/random/negative_binomial_distribution.hpp> template<typename IntType = int, typename RealType = double> class negative_binomial_distribution { public: // types typedef IntType result_type; typedef RealType input_type; // member classes/structs/unions class param_type { public: // types typedef negative_binomial_distribution distribution_type; // construct/copy/destruct explicit param_type(IntType = 1, RealType = 0.5); // public member functions IntType k() const; 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 > &, param_type &); friend bool operator==(const param_type &, const param_type &); friend bool operator!=(const param_type &, const param_type &); }; // construct/copy/destruct explicit negative_binomial_distribution(IntType = 1, RealType = 0.5); explicit negative_binomial_distribution(const param_type &); // public member functions template<typename URNG> IntType operator()(URNG &) const; template<typename URNG> IntType operator()(URNG &, const param_type &) const; IntType k() const; RealType p() const; IntType min() const; IntType max() const; param_type param() const; void param(const param_type &); void reset(); // friend functions template<typename CharT, typename Traits> friend std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > &, const negative_binomial_distribution &); template<typename CharT, typename Traits> friend std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > &, negative_binomial_distribution &); friend bool operator==(const negative_binomial_distribution &, const negative_binomial_distribution &); friend bool operator!=(const negative_binomial_distribution &, const negative_binomial_distribution &); };
The negative binomial distribution is an integer valued distribution with two parameters, k
and p
. The distribution produces non-negative values.
The distribution function is .
This implementation uses a gamma-poisson mixture.
negative_binomial_distribution
public
construct/copy/destructexplicit negative_binomial_distribution(IntType k = 1, RealType p = 0.5);
Construct a
object. negative_binomial_distribution
k
and p
are the parameters of the distribution.
Requires: k >=0 && 0 <= p <= 1
explicit negative_binomial_distribution(const param_type & param);
Construct an
object from the parameters. negative_binomial_distribution
negative_binomial_distribution
public member functionstemplate<typename URNG> IntType operator()(URNG & urng) const;
Returns a random variate distributed according to the negative binomial distribution.
template<typename URNG> IntType operator()(URNG & urng, const param_type & param) const;
Returns a random variate distributed according to the negative binomial distribution with parameters specified by param
.
IntType k() const;
Returns the k
parameter of the distribution.
RealType p() const;
Returns the p
parameter of the distribution.
IntType min() const;
Returns the smallest value that the distribution can produce.
IntType max() const;
Returns the largest value that the distribution can produce.
param_type param() const;
Returns the parameters of the distribution.
void param(const param_type & param);
Sets parameters of the distribution.
void reset();
Effects: Subsequent uses of the distribution do not depend on values produced by any engine prior to invoking reset.
negative_binomial_distribution
friend functionstemplate<typename CharT, typename Traits> friend std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > & os, const negative_binomial_distribution & bd);
Writes the parameters of the distribution to a std::ostream
.
template<typename CharT, typename Traits> friend std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > & is, negative_binomial_distribution & bd);
Reads the parameters of the distribution from a std::istream
.
friend bool operator==(const negative_binomial_distribution & lhs, const negative_binomial_distribution & rhs);
Returns true if the two distributions will produce the same sequence of values, given equal generators.
friend bool operator!=(const negative_binomial_distribution & lhs, const negative_binomial_distribution & rhs);
Returns true if the two distributions could produce different sequences of values, given equal generators.