[rand.dist.bern.negbin]
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@103916 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/random b/include/random
index 6d17c2c..3298cd3 100644
--- a/include/random
+++ b/include/random
@@ -669,7 +669,62 @@
class geometric_distribution;
template<class IntType = int>
- class negative_binomial_distribution;
+class negative_binomial_distribution
+{
+public:
+ // types
+ typedef IntType result_type;
+
+ class param_type
+ {
+ public:
+ typedef negative_binomial_distribution distribution_type;
+
+ explicit param_type(result_type k = 1, double p = 0.5);
+
+ result_type k() const;
+ double p() const;
+
+ friend bool operator==(const param_type& x, const param_type& y);
+ friend bool operator!=(const param_type& x, const param_type& y);
+ };
+
+ // constructor and reset functions
+ explicit negative_binomial_distribution(result_type k = 1, double p = 0.5);
+ explicit negative_binomial_distribution(const param_type& parm);
+ void reset();
+
+ // generating functions
+ template<class URNG> result_type operator()(URNG& g);
+ template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+ // property functions
+ result_type k() const;
+ double p() const;
+
+ param_type param() const;
+ void param(const param_type& parm);
+
+ result_type min() const;
+ result_type max() const;
+
+ friend bool operator==(const negative_binomial_distribution& x,
+ const negative_binomial_distribution& y);
+ friend bool operator!=(const negative_binomial_distribution& x,
+ const negative_binomial_distribution& y);
+
+ template <class charT, class traits>
+ friend
+ basic_ostream<charT, traits>&
+ operator<<(basic_ostream<charT, traits>& os,
+ const negative_binomial_distribution& x);
+
+ template <class charT, class traits>
+ friend
+ basic_istream<charT, traits>&
+ operator>>(basic_istream<charT, traits>& is,
+ negative_binomial_distribution& x);
+};
template<class IntType = int>
class poisson_distribution
@@ -4098,6 +4153,122 @@
return __is;
}
+// negative_binomial_distribution
+
+template<class _IntType = int>
+class negative_binomial_distribution
+{
+public:
+ // types
+ typedef _IntType result_type;
+
+ class param_type
+ {
+ result_type __k_;
+ double __p_;
+ public:
+ typedef negative_binomial_distribution distribution_type;
+
+ explicit param_type(result_type __k = 1, double __p = 0.5)
+ : __k_(__k), __p_(__p) {}
+
+ result_type k() const {return __k_;}
+ double p() const {return __p_;}
+
+ friend bool operator==(const param_type& __x, const param_type& __y)
+ {return __x.__k_ == __y.__k_ && __x.__p_ == __y.__p_;}
+ friend bool operator!=(const param_type& __x, const param_type& __y)
+ {return !(__x == __y);}
+ };
+
+private:
+ param_type __p_;
+
+public:
+ // constructor and reset functions
+ explicit negative_binomial_distribution(result_type __k = 1, double __p = 0.5)
+ : __p_(__k, __p) {}
+ explicit negative_binomial_distribution(const param_type& __p) : __p_(__p) {}
+ void reset() {}
+
+ // generating functions
+ template<class _URNG> result_type operator()(_URNG& __g)
+ {return (*this)(__g, __p_);}
+ template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
+
+ // property functions
+ result_type k() const {return __p_.k();}
+ double p() const {return __p_.p();}
+
+ param_type param() const {return __p_;}
+ void param(const param_type& __p) {__p_ = __p;}
+
+ result_type min() const {return 0;}
+ result_type max() const {return numeric_limits<result_type>::max();}
+
+ friend bool operator==(const negative_binomial_distribution& __x,
+ const negative_binomial_distribution& __y)
+ {return __x.__p_ == __y.__p_;}
+ friend bool operator!=(const negative_binomial_distribution& __x,
+ const negative_binomial_distribution& __y)
+ {return !(__x == __y);}
+};
+
+template <class _IntType>
+template<class _URNG>
+_IntType
+negative_binomial_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
+{
+ result_type __k = __pr.k();
+ double __p = __pr.p();
+ if (__k <= 21 * __p)
+ {
+ bernoulli_distribution __gen(__p);
+ result_type __f = 0;
+ result_type __s = 0;
+ while (__s < __k)
+ {
+ if (__gen(__urng))
+ ++__s;
+ else
+ ++__f;
+ }
+ return __f;
+ }
+ return poisson_distribution<result_type>(gamma_distribution<double>
+ (__k, (1-__p)/__p)(__urng))(__urng);
+}
+
+template <class _CharT, class _Traits, class _IntType>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+ const negative_binomial_distribution<_IntType>& __x)
+{
+ __save_flags<_CharT, _Traits> _(__os);
+ __os.flags(ios_base::dec | ios_base::left);
+ _CharT __sp = __os.widen(' ');
+ __os.fill(__sp);
+ return __os << __x.k() << __sp << __x.p();
+}
+
+template <class _CharT, class _Traits, class _IntType>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+ negative_binomial_distribution<_IntType>& __x)
+{
+ typedef negative_binomial_distribution<_IntType> _Eng;
+ typedef typename _Eng::result_type result_type;
+ typedef typename _Eng::param_type param_type;
+ __save_flags<_CharT, _Traits> _(__is);
+ __is.flags(ios_base::dec | ios_base::skipws);
+ result_type __k;
+ double __p;
+ __is >> __k >> __p;
+ if (!__is.fail())
+ __x.param(param_type(__k, __p));
+ return __is;
+}
+
// chi_squared_distribution
template<class _RealType = double>