[rand.dist.samp.discrete]
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@104103 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/random b/include/random
index 6a3dcce..0ee6633 100644
--- a/include/random
+++ b/include/random
@@ -1410,7 +1410,71 @@
};
template<class IntType = int>
- class discrete_distribution;
+class discrete_distribution
+{
+public:
+ // types
+ typedef IntType result_type;
+
+ class param_type
+ {
+ public:
+ typedef discrete_distribution distribution_type;
+
+ param_type();
+ template<class InputIterator>
+ param_type(InputIterator firstW, InputIterator lastW);
+ param_type(initializer_list<double> wl);
+ template<class UnaryOperation>
+ param_type(size_t nw, double xmin, double xmax, UnaryOperation fw);
+
+ vector<double> probabilities() 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
+ discrete_distribution();
+ template<class InputIterator>
+ discrete_distribution(InputIterator firstW, InputIterator lastW);
+ discrete_distribution(initializer_list<double> wl);
+ template<class UnaryOperation>
+ discrete_distribution(size_t nw, double xmin, double xmax,
+ UnaryOperation fw);
+ explicit discrete_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
+ vector<double> probabilities() const;
+
+ param_type param() const;
+ void param(const param_type& parm);
+
+ result_type min() const;
+ result_type max() const;
+
+ friend bool operator==(const discrete_distribution& x,
+ const discrete_distribution& y);
+ friend bool operator!=(const discrete_distribution& x,
+ const discrete_distribution& y);
+
+ template <class charT, class traits>
+ friend
+ basic_ostream<charT, traits>&
+ operator<<(basic_ostream<charT, traits>& os,
+ const discrete_distribution& x);
+
+ template <class charT, class traits>
+ friend
+ basic_istream<charT, traits>&
+ operator>>(basic_istream<charT, traits>& is,
+ discrete_distribution& x);
+};
template<class RealType = double>
class piecewise_constant_distribution;
@@ -1428,6 +1492,7 @@
#include <cstdint>
#include <limits>
#include <algorithm>
+#include <numeric>
#include <vector>
#include <string>
#include <istream>
@@ -4075,7 +4140,7 @@
result_type s() const {return __p_.s();}
param_type param() const {return __p_;}
- void param(const param_type& __p) {return __p_ = __p;}
+ void param(const param_type& __p) {__p_ = __p;}
result_type min() const {return 0;}
result_type max() const {return numeric_limits<result_type>::infinity();}
@@ -5176,6 +5241,8 @@
return __is;
}
+// student_t_distribution
+
template<class _RealType = double>
class student_t_distribution
{
@@ -5220,7 +5287,7 @@
result_type n() const {return __p_.n();}
param_type param() const {return __p_;}
- void param(const param_type& __p) {return __p_ = __p;}
+ void param(const param_type& __p) {__p_ = __p;}
result_type min() const {return -numeric_limits<result_type>::infinity();}
result_type max() const {return numeric_limits<result_type>::infinity();}
@@ -5270,6 +5337,212 @@
return __is;
}
+// discrete_distribution
+
+template<class _IntType = int>
+class discrete_distribution
+{
+public:
+ // types
+ typedef _IntType result_type;
+
+ class param_type
+ {
+ vector<double> __p_;
+ public:
+ typedef discrete_distribution distribution_type;
+
+ param_type() {}
+ template<class _InputIterator>
+ param_type(_InputIterator __f, _InputIterator __l)
+ : __p_(__f, __l) {__init();}
+ param_type(initializer_list<double> __wl)
+ : __p_(__wl.begin(), __wl.end()) {__init();}
+ template<class _UnaryOperation>
+ param_type(size_t __nw, double __xmin, double __xmax,
+ _UnaryOperation __fw);
+
+ vector<double> probabilities() const;
+
+ friend bool operator==(const param_type& __x, const param_type& __y)
+ {return __x.__p_ == __y.__p_;}
+ friend bool operator!=(const param_type& __x, const param_type& __y)
+ {return !(__x == __y);}
+
+ private:
+ void __init();
+
+ friend class discrete_distribution;
+
+ template <class _CharT, class _Traits, class _IT>
+ friend
+ basic_ostream<_CharT, _Traits>&
+ operator<<(basic_ostream<_CharT, _Traits>& __os,
+ const discrete_distribution<_IT>& __x);
+
+ template <class _CharT, class _Traits, class _IT>
+ friend
+ basic_istream<_CharT, _Traits>&
+ operator>>(basic_istream<_CharT, _Traits>& __is,
+ discrete_distribution<_IT>& __x);
+ };
+
+private:
+ param_type __p_;
+
+public:
+ // constructor and reset functions
+ discrete_distribution() {}
+ template<class _InputIterator>
+ discrete_distribution(_InputIterator __f, _InputIterator __l)
+ : __p_(__f, __l) {}
+ discrete_distribution(initializer_list<double> __wl)
+ : __p_(__wl) {}
+ template<class _UnaryOperation>
+ discrete_distribution(size_t __nw, double __xmin, double __xmax,
+ _UnaryOperation __fw)
+ : __p_(__nw, __xmin, __xmax, __fw) {}
+ explicit discrete_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
+ vector<double> probabilities() const {return __p_.probabilities();}
+
+ 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 __p_.__p_.size();}
+
+ friend bool operator==(const discrete_distribution& __x,
+ const discrete_distribution& __y)
+ {return __x.__p_ == __y.__p_;}
+ friend bool operator!=(const discrete_distribution& __x,
+ const discrete_distribution& __y)
+ {return !(__x == __y);}
+
+ template <class _CharT, class _Traits, class _IT>
+ friend
+ basic_ostream<_CharT, _Traits>&
+ operator<<(basic_ostream<_CharT, _Traits>& __os,
+ const discrete_distribution<_IT>& __x);
+
+ template <class _CharT, class _Traits, class _IT>
+ friend
+ basic_istream<_CharT, _Traits>&
+ operator>>(basic_istream<_CharT, _Traits>& __is,
+ discrete_distribution<_IT>& __x);
+};
+
+template<class _IntType>
+template<class _UnaryOperation>
+discrete_distribution<_IntType>::param_type::param_type(size_t __nw,
+ double __xmin,
+ double __xmax,
+ _UnaryOperation __fw)
+{
+ if (__nw > 1)
+ {
+ __p_.reserve(__nw - 1);
+ double __d = (__xmax - __xmin) / __nw;
+ double __d2 = __d / 2;
+ for (size_t __k = 0; __k < __nw; ++__k)
+ __p_.push_back(__fw(__xmin + __k * __d + __d2));
+ __init();
+ }
+}
+
+template<class _IntType>
+void
+discrete_distribution<_IntType>::param_type::__init()
+{
+ if (!__p_.empty())
+ {
+ if (__p_.size() > 1)
+ {
+ double __s = _STD::accumulate(__p_.begin(), __p_.end(), 0.0);
+ for (_STD::vector<double>::iterator __i = __p_.begin(), __e = __p_.end();
+ __i < __e; ++__i)
+ *__i /= __s;
+ vector<double> __t(__p_.size() - 1);
+ _STD::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
+ swap(__p_, __t);
+ }
+ else
+ {
+ __p_.clear();
+ __p_.shrink_to_fit();
+ }
+ }
+}
+
+template<class _IntType>
+vector<double>
+discrete_distribution<_IntType>::param_type::probabilities() const
+{
+ size_t __n = __p_.size();
+ _STD::vector<double> __p(__n+1);
+ _STD::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
+ if (__n > 0)
+ __p[__n] = 1 - __p_[__n-1];
+ else
+ __p[0] = 1;
+ return __p;
+}
+
+template<class _IntType>
+template<class _URNG>
+_IntType
+discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
+{
+ uniform_real_distribution<double> __gen;
+ return static_cast<_IntType>(
+ _STD::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) -
+ __p.__p_.begin());
+}
+
+template <class _CharT, class _Traits, class _IT>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+ const discrete_distribution<_IT>& __x)
+{
+ __save_flags<_CharT, _Traits> _(__os);
+ __os.flags(ios_base::dec | ios_base::left);
+ _CharT __sp = __os.widen(' ');
+ __os.fill(__sp);
+ size_t __n = __x.__p_.__p_.size();
+ __os << __n;
+ for (size_t __i = 0; __i < __n; ++__i)
+ __os << __sp << __x.__p_.__p_[__i];
+ return __os;
+}
+
+template <class _CharT, class _Traits, class _IT>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+ discrete_distribution<_IT>& __x)
+{
+ typedef discrete_distribution<_IT> _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);
+ size_t __n;
+ __is >> __n;
+ std::vector<double> __p(__n);
+ for (size_t __i = 0; __i < __n; ++__i)
+ __is >> __p[__i];
+ if (!__is.fail())
+ swap(__x.__p_.__p_, __p);
+ return __is;
+}
+
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_RANDOM