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Coding Standards
boost::random::gamma_distribution
// In header: <boost/random/gamma_distribution.hpp> template<typename RealType = double> class gamma_distribution { public: // types typedef RealType input_type; typedef RealType result_type; // member classes/structs/unions class param_type { public: // types typedef gamma_distribution distribution_type; // public member functions param_type(const RealType & = 1.0, const RealType & = 1.0); RealType alpha() const; RealType beta() const; // friend functions template<typename CharT, typename Traits> std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > &, const param_type &); template<typename CharT, typename Traits> std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > &, param_type &); bool operator==(const param_type &, const param_type &); bool operator!=(const param_type &, const param_type &); }; // public member functions explicit gamma_distribution(const result_type & = 1.0, const result_type & = 1.0); explicit gamma_distribution(const param_type &); RealType alpha() const; RealType beta() const; RealType min() const; RealType max() const; param_type param() const; void param(const param_type &); void reset(); template<typename Engine> result_type operator()(Engine &); template<typename URNG> RealType operator()(URNG &, const param_type &) const; // friend functions template<typename CharT, typename Traits> std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > &, const gamma_distribution &); template<typename CharT, typename Traits> std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > &, gamma_distribution &); bool operator==(const gamma_distribution &, const gamma_distribution &); bool operator!=(const gamma_distribution &, const gamma_distribution &); };
The gamma distribution is a continuous distribution with two parameters alpha and beta. It produces values > 0.
It has .
gamma_distribution
public member functionsexplicit gamma_distribution(const result_type & alpha = 1.0, const result_type & beta = 1.0);
Creates a new gamma_distribution with parameters "alpha" and "beta".
Requires: alpha > 0 && beta > 0
explicit gamma_distribution(const param_type & param);
Constructs a gamma_distribution
from its parameters.
RealType alpha() const;
Returns the "alpha" paramter of the distribution.
RealType beta() const;
Returns the "beta" parameter of the distribution.
RealType min() const;
Returns the smallest value that the distribution can produce.
RealType max() const;
param_type param() const;
Returns the parameters of the distribution.
void param(const param_type & param);
Sets the 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.
template<typename Engine> result_type operator()(Engine & eng);
Returns a random variate distributed according to the gamma distribution.
template<typename URNG> RealType operator()(URNG & urng, const param_type & param) const;
gamma_distribution
friend functionstemplate<typename CharT, typename Traits> std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > & os, const gamma_distribution & gd);
Writes a gamma_distribution
to a std::ostream
.
template<typename CharT, typename Traits> std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > & is, gamma_distribution & gd);
Reads a gamma_distribution
from a std::istream
.
bool operator==(const gamma_distribution & lhs, const gamma_distribution & rhs);
Returns true if the two distributions will produce identical sequences of random variates given equal generators.
bool operator!=(const gamma_distribution & lhs, const gamma_distribution & rhs);
Returns true if the two distributions can produce different sequences of random variates, given equal generators.