[cfe-commits] [libcxx] r103722 - in /libcxx/trunk: include/random test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp
Howard Hinnant
hhinnant at apple.com
Thu May 13 10:58:29 PDT 2010
Author: hhinnant
Date: Thu May 13 12:58:28 2010
New Revision: 103722
URL: http://llvm.org/viewvc/llvm-project?rev=103722&view=rev
Log:
partial [rand.dist.pois.gamma]
Modified:
libcxx/trunk/include/random
libcxx/trunk/test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp
Modified: libcxx/trunk/include/random
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/random?rev=103722&r1=103721&r2=103722&view=diff
==============================================================================
--- libcxx/trunk/include/random (original)
+++ libcxx/trunk/include/random Thu May 13 12:58:28 2010
@@ -731,7 +731,62 @@
};
template<class RealType = double>
- class gamma_distribution;
+class gamma_distribution
+{
+public:
+ // types
+ typedef RealType result_type;
+
+ class param_type
+ {
+ public:
+ typedef gamma_distribution distribution_type;
+
+ explicit param_type(result_type alpha = 1, result_type beta = 1);
+
+ result_type alpha() const;
+ result_type beta() const;
+
+ friend bool operator==(const param_type& x, const param_type& y);
+ friend bool operator!=(const param_type& x, const param_type& y);
+ };
+
+ // constructors and reset functions
+ explicit gamma_distribution(result_type alpha = 1, result_type beta = 1);
+ explicit gamma_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 alpha() const;
+ result_type beta() const;
+
+ param_type param() const;
+ void param(const param_type& parm);
+
+ result_type min() const;
+ result_type max() const;
+
+ friend bool operator==(const gamma_distribution& x,
+ const gamma_distribution& y);
+ friend bool operator!=(const gamma_distribution& x,
+ const gamma_distribution& y);
+
+ template <class charT, class traits>
+ friend
+ basic_ostream<charT, traits>&
+ operator<<(basic_ostream<charT, traits>& os,
+ const gamma_distribution& x);
+
+ template <class charT, class traits>
+ friend
+ basic_istream<charT, traits>&
+ operator>>(basic_istream<charT, traits>& is,
+ gamma_distribution& x);
+};
template<class RealType = double>
class weibull_distribution;
@@ -3226,6 +3281,138 @@
return __is;
}
+// gamma_distribution
+
+template<class _RealType = double>
+class gamma_distribution
+{
+public:
+ // types
+ typedef _RealType result_type;
+
+ class param_type
+ {
+ result_type __alpha_;
+ result_type __beta_;
+ public:
+ typedef gamma_distribution distribution_type;
+
+ explicit param_type(result_type __alpha = 1, result_type __beta = 1)
+ : __alpha_(__alpha), __beta_(__beta) {}
+
+ result_type alpha() const {return __alpha_;}
+ result_type beta() const {return __beta_;}
+
+ friend bool operator==(const param_type& __x, const param_type& __y)
+ {return __x.__alpha_ == __y.__alpha_ && __x.__beta_ == __y.__beta_;}
+ friend bool operator!=(const param_type& __x, const param_type& __y)
+ {return !(__x == __y);}
+ };
+
+private:
+ param_type __p_;
+
+public:
+ // constructors and reset functions
+ explicit gamma_distribution(result_type __alpha = 1, result_type __beta = 1)
+ : __p_(param_type(__alpha, __beta)) {}
+ explicit gamma_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 alpha() const {return __p_.alpha();}
+ result_type beta() const {return __p_.beta();}
+
+ 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>::infinity();}
+
+ friend bool operator==(const gamma_distribution& __x,
+ const gamma_distribution& __y)
+ {return __x.__p_ == __y.__p_;}
+ friend bool operator!=(const gamma_distribution& __x,
+ const gamma_distribution& __y)
+ {return !(__x == __y);}
+};
+
+template <class _RealType>
+template<class _URNG>
+_RealType
+gamma_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
+{
+ result_type __a = __p_.alpha();
+ if (__a == 1)
+ return exponential_distribution<result_type>(1/__p_.beta())(__g);
+ else if (__a > 1)
+ {
+ const result_type __b = __a - 1;
+ const result_type __c = 3 * __a - result_type(0.75);
+ uniform_real_distribution<result_type> __gen(0, 1);
+ result_type __x;
+ while (true)
+ {
+ const result_type __u = __gen(__g);
+ const result_type __v = __gen(__g);
+ const result_type __w = __u * (1 - __u);
+ if (__w =! 0)
+ {
+ const result_type __y = _STD::sqrt(__c / __w) *
+ (__u - result_type(0.5));
+ __x = __b + __y;
+ if (__x >= 0)
+ {
+ const result_type __z = 64 * __w * __w * __w * __v * __v;
+ if (__z <= 1 - 2 * __y * __y / __x)
+ break;
+ if (_STD::log(__z) <= 2 * (__b * _STD::log(__x / __b) - __y))
+ break;
+ }
+ }
+ }
+ return __x * __p_.beta();
+ }
+ // else __a < 1
+ return 0; // temp!!!
+}
+
+template <class _CharT, class _Traits, class _RT>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+ const gamma_distribution<_RT>& __x)
+{
+ __save_flags<_CharT, _Traits> _(__os);
+ __os.flags(ios_base::dec | ios_base::left);
+ _CharT __sp = __os.widen(' ');
+ __os.fill(__sp);
+ __os << __x.alpha() << __sp << __x.beta();
+ return __os;
+}
+
+template <class _CharT, class _Traits, class _RT>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+ gamma_distribution<_RT>& __x)
+{
+ typedef gamma_distribution<_RT> _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 __alpha;
+ result_type __beta;
+ __is >> __alpha >> __beta;
+ if (!__is.fail())
+ __x.param(param_type(__alpha, __beta));
+ return __is;
+}
// normal_distribution
template<class _RealType = double>
@@ -3288,7 +3475,7 @@
(!__x._V_hot_ || __x._V_ == __y._V_);}
friend bool operator!=(const normal_distribution& __x,
const normal_distribution& __y)
- {return !(__x == __y);}
+ {return !(__x == __y);}
template <class _CharT, class _Traits, class _RT>
friend
Modified: libcxx/trunk/test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp?rev=103722&r1=103721&r2=103722&view=diff
==============================================================================
--- libcxx/trunk/test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp (original)
+++ libcxx/trunk/test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp Thu May 13 12:58:28 2010
@@ -35,7 +35,7 @@
typedef std::minstd_rand G;
G g;
D d(5, 4);
- const int N = 1000;
+ const int N = 10000;
std::vector<D::result_type> u;
for (int i = 0; i < N; ++i)
u.push_back(d(g));
@@ -48,6 +48,6 @@
D::result_type x_mean = d.mean();
D::result_type x_var = sqr(d.stddev());
assert(std::abs(mean - x_mean) / x_mean < 0.01);
- assert(std::abs(var - x_var) / x_var < 0.01);
+ assert(std::abs(var - x_var) / x_var < 0.02);
}
}
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