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boost::random::binomial_distribution
// In header: <boost/random/binomial_distribution.hpp> template<typename IntType = int, typename RealType = double> class binomial_distribution { public: // types typedef IntType result_type; typedef RealType input_type; // member classes/structs/unions class param_type { public: // types typedef binomial_distribution distribution_type; // construct/copy/destruct explicit param_type(IntType = 1, RealType = 0.5); // public member functions IntType t() const; RealType p() 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 &); }; // construct/copy/destruct explicit binomial_distribution(IntType = 1, RealType = 0.5); explicit 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 t() 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> std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > &, const binomial_distribution &); template<typename CharT, typename Traits> std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > &, binomial_distribution &); bool operator==(const binomial_distribution &, const binomial_distribution &); bool operator!=(const binomial_distribution &, const binomial_distribution &); };
The binomial distribution is an integer valued distribution with two parameters, t
and p
. The values of the distribution are within the range [0,t].
The distribution function is .
The algorithm used is the BTRD algorithm described in
"The generation of binomial random variates", Wolfgang Hormann, Journal of Statistical Computation and Simulation, Volume 46, Issue 1 & 2 April 1993 , pages 101 - 110
binomial_distribution
public
construct/copy/destructexplicit binomial_distribution(IntType t = 1, RealType p = 0.5);
Construct a
object. binomial_distribution
t
and p
are the parameters of the distribution.
Requires: t >=0 && 0 <= p <= 1
explicit binomial_distribution(const param_type & param);
Construct an
object from the parameters. binomial_distribution
binomial_distribution
public member functionstemplate<typename URNG> IntType operator()(URNG & urng) const;
Returns a random variate distributed according to the binomial distribution.
template<typename URNG> IntType operator()(URNG & urng, const param_type & param) const;
Returns a random variate distributed according to the binomial distribution with parameters specified by param
.
IntType t() const;
Returns the t
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.
binomial_distribution
friend functionstemplate<typename CharT, typename Traits> std::basic_ostream< CharT, Traits > & operator<<(std::basic_ostream< CharT, Traits > & os, const binomial_distribution & bd);
Writes the parameters of the distribution to a std::ostream
.
template<typename CharT, typename Traits> std::basic_istream< CharT, Traits > & operator>>(std::basic_istream< CharT, Traits > & is, binomial_distribution & bd);
Reads the parameters of the distribution from a std::istream
.
bool operator==(const binomial_distribution & lhs, const binomial_distribution & rhs);
Returns true if the two distributions will produce the same sequence of values, given equal generators.
bool operator!=(const binomial_distribution & lhs, const binomial_distribution & rhs);
Returns true if the two distributions could produce different sequences of values, given equal generators.