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author | emsr <emsr@138bc75d-0d04-0410-961f-82ee72b054a4> | 2013-11-21 12:27:02 +0000 |
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committer | emsr <emsr@138bc75d-0d04-0410-961f-82ee72b054a4> | 2013-11-21 12:27:02 +0000 |
commit | 94612be7a540d99c1996776706c2d3c45f5f8e62 (patch) | |
tree | 87279389735f7bac55d97f4929c8b474962aa641 /libstdc++-v3/include/ext/random | |
parent | dbf51ba1248a78c1a74cde573b0ad16ca5946517 (diff) | |
download | gcc-94612be7a540d99c1996776706c2d3c45f5f8e62.tar.gz |
2013-11-21 Edward Smith-Rowland <3dw4rd@verizon.net>
Implement __gnu_cxx::hypergeometric_distribution.
* include/ext/random: Add hypergeometric_distribution.
* include/ext/random.tcc: Add hypergeometric_distribution.
* testsuite/util/testsuite_random.h (hypergeometric_pdf): New pdf
for the hypergeometric discreet distribution;
(lbincoef): New supporting function for binomial coefficients.
* testsuite/ext/random/hypergeometric_distribution/operators/
serialize.cc: New.
* testsuite/ext/random/hypergeometric_distribution/operators/
equal.cc: New.
* testsuite/ext/random/hypergeometric_distribution/operators/
inequal.cc: New.
* testsuite/ext/random/hypergeometric_distribution/operators/
values.cc: New.
* testsuite/ext/random/hypergeometric_distribution/cons/parms.cc: New.
* testsuite/ext/random/hypergeometric_distribution/cons/default.cc: New.
* testsuite/ext/random/hypergeometric_distribution/requirements/
explicit_instantiation/1.cc: New.
* testsuite/ext/random/hypergeometric_distribution/requirements/
typedefs.cc: New.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@205212 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libstdc++-v3/include/ext/random')
-rw-r--r-- | libstdc++-v3/include/ext/random | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/libstdc++-v3/include/ext/random b/libstdc++-v3/include/ext/random index 347ebed449c..c82430e0746 100644 --- a/libstdc++-v3/include/ext/random +++ b/libstdc++-v3/include/ext/random @@ -2845,6 +2845,267 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION const __gnu_cxx::von_mises_distribution<_RealType>& __d2) { return !(__d1 == __d2); } + + /** + * @brief A discrete hypergeometric random number distribution. + * + * The hypergeometric distribution is a discrete probability distribution + * that describes the probability of @p k successes in @p n draws @a without + * replacement from a finite population of size @p N containing exactly @p K + * successes. + * + * The formula for the hypergeometric probability density function is + * @f[ + * p(k|N,K,n) = \frac{\binom{K}{k} \binom{N-K}{n-k}}{\binom{N}{n}} + * @f] + * where @f$N@f$ is the total population of the distribution, + * @f$K@f$ is the total population of the distribution. + * + * <table border=1 cellpadding=10 cellspacing=0> + * <caption align=top>Distribution Statistics</caption> + * <tr><td>Mean</td><td>@f$ n\frac{K}{N} @f$</td></tr> + * <tr><td>Variance</td><td>@f$ n\frac{K}{N}\frac{N-K}{N}\frac{N-n}{N-1} + * @f$</td></tr> + * <tr><td>Range</td><td>@f$[max(0, n+K-N), min(K, n)]@f$</td></tr> + * </table> + */ + template<typename _UIntType = unsigned int> + class hypergeometric_distribution + { + static_assert(std::is_unsigned<_UIntType>::value, "template argument " + "substituting _UIntType not an unsigned integral type"); + + public: + /** The type of the range of the distribution. */ + typedef _UIntType result_type; + + /** Parameter type. */ + struct param_type + { + typedef hypergeometric_distribution<_UIntType> distribution_type; + friend class hypergeometric_distribution<_UIntType>; + + explicit + param_type(result_type __N = 10, result_type __K = 5, + result_type __n = 1) + : _M_N{__N}, _M_K{__K}, _M_n{__n} + { + _GLIBCXX_DEBUG_ASSERT(_M_N >= _M_K); + _GLIBCXX_DEBUG_ASSERT(_M_N >= _M_n); + } + + result_type + total_size() const + { return _M_N; } + + result_type + successful_size() const + { return _M_K; } + + result_type + unsuccessful_size() const + { return _M_N - _M_K; } + + result_type + total_draws() const + { return _M_n; } + + friend bool + operator==(const param_type& __p1, const param_type& __p2) + { return (__p1._M_N == __p2._M_N) + && (__p1._M_K == __p2._M_K) + && (__p1._M_n == __p2._M_n); } + + private: + + result_type _M_N; + result_type _M_K; + result_type _M_n; + }; + + // constructors and member function + explicit + hypergeometric_distribution(result_type __N = 10, result_type __K = 5, + result_type __n = 1) + : _M_param{__N, __K, __n} + { } + + explicit + hypergeometric_distribution(const param_type& __p) + : _M_param{__p} + { } + + /** + * @brief Resets the distribution state. + */ + void + reset() + { } + + /** + * @brief Returns the distribution parameter @p N, + * the total number of items. + */ + result_type + total_size() const + { return this->_M_param.total_size(); } + + /** + * @brief Returns the distribution parameter @p K, + * the total number of successful items. + */ + result_type + successful_size() const + { return this->_M_param.successful_size(); } + + /** + * @brief Returns the total number of unsuccessful items @f$ N - K @f$. + */ + result_type + unsuccessful_size() const + { return this->_M_param.unsuccessful_size(); } + + /** + * @brief Returns the distribution parameter @p n, + * the total number of draws. + */ + result_type + total_draws() const + { return this->_M_param.total_draws(); } + + /** + * @brief Returns the parameter set of the distribution. + */ + param_type + param() const + { return this->_M_param; } + + /** + * @brief Sets the parameter set of the distribution. + * @param __param The new parameter set of the distribution. + */ + void + param(const param_type& __param) + { this->_M_param = __param; } + + /** + * @brief Returns the greatest lower bound value of the distribution. + */ + result_type + min() const + { + using _IntType = typename std::make_signed<result_type>::type; + return static_cast<result_type>(std::max(static_cast<_IntType>(0), + static_cast<_IntType>(this->total_draws() + - this->unsuccessful_size()))); + } + + /** + * @brief Returns the least upper bound value of the distribution. + */ + result_type + max() const + { return std::min(this->successful_size(), this->total_draws()); } + + /** + * @brief Generating functions. + */ + template<typename _UniformRandomNumberGenerator> + result_type + operator()(_UniformRandomNumberGenerator& __urng) + { return this->operator()(__urng, this->_M_param); } + + template<typename _UniformRandomNumberGenerator> + result_type + operator()(_UniformRandomNumberGenerator& __urng, + const param_type& __p); + + template<typename _ForwardIterator, + typename _UniformRandomNumberGenerator> + void + __generate(_ForwardIterator __f, _ForwardIterator __t, + _UniformRandomNumberGenerator& __urng) + { this->__generate(__f, __t, __urng, this->_M_param); } + + template<typename _ForwardIterator, + typename _UniformRandomNumberGenerator> + void + __generate(_ForwardIterator __f, _ForwardIterator __t, + _UniformRandomNumberGenerator& __urng, + const param_type& __p) + { this->__generate_impl(__f, __t, __urng, __p); } + + template<typename _UniformRandomNumberGenerator> + void + __generate(result_type* __f, result_type* __t, + _UniformRandomNumberGenerator& __urng, + const param_type& __p) + { this->__generate_impl(__f, __t, __urng, __p); } + + /** + * @brief Return true if two hypergeometric distributions have the same + * parameters and the sequences that would be generated + * are equal. + */ + friend bool + operator==(const hypergeometric_distribution& __d1, + const hypergeometric_distribution& __d2) + { return __d1._M_param == __d2._M_param; } + + /** + * @brief Inserts a %hypergeometric_distribution random number + * distribution @p __x into the output stream @p __os. + * + * @param __os An output stream. + * @param __x A %hypergeometric_distribution random number + * distribution. + * + * @returns The output stream with the state of @p __x inserted or in + * an error state. + */ + template<typename _UIntType1, typename _CharT, typename _Traits> + friend std::basic_ostream<_CharT, _Traits>& + operator<<(std::basic_ostream<_CharT, _Traits>& __os, + const __gnu_cxx::hypergeometric_distribution<_UIntType1>& + __x); + + /** + * @brief Extracts a %hypergeometric_distribution random number + * distribution @p __x from the input stream @p __is. + * + * @param __is An input stream. + * @param __x A %hypergeometric_distribution random number generator + * distribution. + * + * @returns The input stream with @p __x extracted or in an error + * state. + */ + template<typename _UIntType1, typename _CharT, typename _Traits> + friend std::basic_istream<_CharT, _Traits>& + operator>>(std::basic_istream<_CharT, _Traits>& __is, + __gnu_cxx::hypergeometric_distribution<_UIntType1>& __x); + + private: + + template<typename _ForwardIterator, + typename _UniformRandomNumberGenerator> + void + __generate_impl(_ForwardIterator __f, _ForwardIterator __t, + _UniformRandomNumberGenerator& __urng, + const param_type& __p); + + param_type _M_param; + }; + + /** + * @brief Return true if two hypergeometric distributions are different. + */ + template<typename _UIntType> + inline bool + operator!=(const __gnu_cxx::hypergeometric_distribution<_UIntType>& __d1, + const __gnu_cxx::hypergeometric_distribution<_UIntType>& __d2) + { return !(__d1 == __d2); } + _GLIBCXX_END_NAMESPACE_VERSION } // namespace __gnu_cxx |