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			294 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | // Copyright 2008 Gautam Sewani | ||
|  | // Copyright 2008 John Maddock | ||
|  | // | ||
|  | // Use, modification and distribution are subject to the | ||
|  | // Boost Software License, Version 1.0. | ||
|  | // (See accompanying file LICENSE_1_0.txt | ||
|  | // or copy at http://www.boost.org/LICENSE_1_0.txt) | ||
|  | 
 | ||
|  | #ifndef BOOST_MATH_DISTRIBUTIONS_HYPERGEOMETRIC_HPP | ||
|  | #define BOOST_MATH_DISTRIBUTIONS_HYPERGEOMETRIC_HPP | ||
|  | 
 | ||
|  | #include <boost/math/distributions/detail/common_error_handling.hpp> | ||
|  | #include <boost/math/distributions/complement.hpp> | ||
|  | #include <boost/math/distributions/detail/hypergeometric_pdf.hpp> | ||
|  | #include <boost/math/distributions/detail/hypergeometric_cdf.hpp> | ||
|  | #include <boost/math/distributions/detail/hypergeometric_quantile.hpp> | ||
|  | #include <boost/math/special_functions/fpclassify.hpp> | ||
|  | 
 | ||
|  | 
 | ||
|  | namespace boost { namespace math { | ||
|  | 
 | ||
|  |    template <class RealType = double, class Policy = policies::policy<> > | ||
|  |    class hypergeometric_distribution | ||
|  |    { | ||
|  |    public: | ||
|  |       typedef RealType value_type; | ||
|  |       typedef Policy policy_type; | ||
|  | 
 | ||
|  |       hypergeometric_distribution(unsigned r, unsigned n, unsigned N) // Constructor. | ||
|  |          : m_n(n), m_N(N), m_r(r) | ||
|  |       { | ||
|  |          static const char* function = "boost::math::hypergeometric_distribution<%1%>::hypergeometric_distribution"; | ||
|  |          RealType ret; | ||
|  |          check_params(function, &ret); | ||
|  |       } | ||
|  |       // Accessor functions. | ||
|  |       unsigned total()const | ||
|  |       { | ||
|  |          return m_N; | ||
|  |       } | ||
|  | 
 | ||
|  |       unsigned defective()const | ||
|  |       { | ||
|  |          return m_r; | ||
|  |       } | ||
|  | 
 | ||
|  |       unsigned sample_count()const | ||
|  |       { | ||
|  |          return m_n; | ||
|  |       } | ||
|  | 
 | ||
|  |       bool check_params(const char* function, RealType* result)const | ||
|  |       { | ||
|  |          if(m_r > m_N) | ||
|  |          { | ||
|  |             *result = boost::math::policies::raise_domain_error<RealType>( | ||
|  |                function, "Parameter r out of range: must be <= N but got %1%", static_cast<RealType>(m_r), Policy()); | ||
|  |             return false; | ||
|  |          } | ||
|  |          if(m_n > m_N) | ||
|  |          { | ||
|  |             *result = boost::math::policies::raise_domain_error<RealType>( | ||
|  |                function, "Parameter n out of range: must be <= N but got %1%", static_cast<RealType>(m_n), Policy()); | ||
|  |             return false; | ||
|  |          } | ||
|  |          return true; | ||
|  |       } | ||
|  |       bool check_x(unsigned x, const char* function, RealType* result)const | ||
|  |       { | ||
|  |          if(x < static_cast<unsigned>((std::max)(0, (int)(m_n + m_r) - (int)(m_N)))) | ||
|  |          { | ||
|  |             *result = boost::math::policies::raise_domain_error<RealType>( | ||
|  |                function, "Random variable out of range: must be > 0 and > m + r - N but got %1%", static_cast<RealType>(x), Policy()); | ||
|  |             return false; | ||
|  |          } | ||
|  |          if(x > (std::min)(m_r, m_n)) | ||
|  |          { | ||
|  |             *result = boost::math::policies::raise_domain_error<RealType>( | ||
|  |                function, "Random variable out of range: must be less than both n and r but got %1%", static_cast<RealType>(x), Policy()); | ||
|  |             return false; | ||
|  |          } | ||
|  |          return true; | ||
|  |       } | ||
|  | 
 | ||
|  |    private: | ||
|  |       // Data members: | ||
|  |       unsigned m_n;  // number of items picked | ||
|  |       unsigned m_N; // number of "total" items | ||
|  |       unsigned m_r; // number of "defective" items | ||
|  | 
 | ||
|  |    }; // class hypergeometric_distribution | ||
|  | 
 | ||
|  |    typedef hypergeometric_distribution<double> hypergeometric; | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline const std::pair<unsigned, unsigned> range(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { // Range of permissible values for random variable x. | ||
|  | #ifdef BOOST_MSVC | ||
|  | #  pragma warning(push) | ||
|  | #  pragma warning(disable:4267) | ||
|  | #endif | ||
|  |       unsigned r = dist.defective(); | ||
|  |       unsigned n = dist.sample_count(); | ||
|  |       unsigned N = dist.total(); | ||
|  |       unsigned l = static_cast<unsigned>((std::max)(0, (int)(n + r) - (int)(N))); | ||
|  |       unsigned u = (std::min)(r, n); | ||
|  |       return std::pair<unsigned, unsigned>(l, u); | ||
|  | #ifdef BOOST_MSVC | ||
|  | #  pragma warning(pop) | ||
|  | #endif | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline const std::pair<unsigned, unsigned> support(const hypergeometric_distribution<RealType, Policy>& d) | ||
|  |    {  | ||
|  |       return range(d); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType pdf(const hypergeometric_distribution<RealType, Policy>& dist, const unsigned& x) | ||
|  |    { | ||
|  |       static const char* function = "boost::math::pdf(const hypergeometric_distribution<%1%>&, const %1%&)"; | ||
|  |       RealType result = 0; | ||
|  |       if(!dist.check_params(function, &result)) | ||
|  |          return result; | ||
|  |       if(!dist.check_x(x, function, &result)) | ||
|  |          return result; | ||
|  | 
 | ||
|  |       return boost::math::detail::hypergeometric_pdf<RealType>( | ||
|  |          x, dist.defective(), dist.sample_count(), dist.total(), Policy()); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy, class U> | ||
|  |    inline RealType pdf(const hypergeometric_distribution<RealType, Policy>& dist, const U& x) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING | ||
|  |       static const char* function = "boost::math::pdf(const hypergeometric_distribution<%1%>&, const %1%&)"; | ||
|  |       RealType r = static_cast<RealType>(x); | ||
|  |       unsigned u = itrunc(r, typename policies::normalise<Policy, policies::rounding_error<policies::ignore_error> >::type()); | ||
|  |       if(u != r) | ||
|  |       { | ||
|  |          return boost::math::policies::raise_domain_error<RealType>( | ||
|  |             function, "Random variable out of range: must be an integer but got %1%", r, Policy()); | ||
|  |       } | ||
|  |       return pdf(dist, u); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType cdf(const hypergeometric_distribution<RealType, Policy>& dist, const unsigned& x) | ||
|  |    { | ||
|  |       static const char* function = "boost::math::cdf(const hypergeometric_distribution<%1%>&, const %1%&)"; | ||
|  |       RealType result = 0; | ||
|  |       if(!dist.check_params(function, &result)) | ||
|  |          return result; | ||
|  |       if(!dist.check_x(x, function, &result)) | ||
|  |          return result; | ||
|  | 
 | ||
|  |       return boost::math::detail::hypergeometric_cdf<RealType>( | ||
|  |          x, dist.defective(), dist.sample_count(), dist.total(), false, Policy()); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy, class U> | ||
|  |    inline RealType cdf(const hypergeometric_distribution<RealType, Policy>& dist, const U& x) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING | ||
|  |       static const char* function = "boost::math::cdf(const hypergeometric_distribution<%1%>&, const %1%&)"; | ||
|  |       RealType r = static_cast<RealType>(x); | ||
|  |       unsigned u = itrunc(r, typename policies::normalise<Policy, policies::rounding_error<policies::ignore_error> >::type()); | ||
|  |       if(u != r) | ||
|  |       { | ||
|  |          return boost::math::policies::raise_domain_error<RealType>( | ||
|  |             function, "Random variable out of range: must be an integer but got %1%", r, Policy()); | ||
|  |       } | ||
|  |       return cdf(dist, u); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType cdf(const complemented2_type<hypergeometric_distribution<RealType, Policy>, unsigned>& c) | ||
|  |    { | ||
|  |       static const char* function = "boost::math::cdf(const hypergeometric_distribution<%1%>&, const %1%&)"; | ||
|  |       RealType result = 0; | ||
|  |       if(!c.dist.check_params(function, &result)) | ||
|  |          return result; | ||
|  |       if(!c.dist.check_x(c.param, function, &result)) | ||
|  |          return result; | ||
|  | 
 | ||
|  |       return boost::math::detail::hypergeometric_cdf<RealType>( | ||
|  |          c.param, c.dist.defective(), c.dist.sample_count(), c.dist.total(), true, Policy()); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy, class U> | ||
|  |    inline RealType cdf(const complemented2_type<hypergeometric_distribution<RealType, Policy>, U>& c) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING | ||
|  |       static const char* function = "boost::math::cdf(const hypergeometric_distribution<%1%>&, const %1%&)"; | ||
|  |       RealType r = static_cast<RealType>(c.param); | ||
|  |       unsigned u = itrunc(r, typename policies::normalise<Policy, policies::rounding_error<policies::ignore_error> >::type()); | ||
|  |       if(u != r) | ||
|  |       { | ||
|  |          return boost::math::policies::raise_domain_error<RealType>( | ||
|  |             function, "Random variable out of range: must be an integer but got %1%", r, Policy()); | ||
|  |       } | ||
|  |       return cdf(complement(c.dist, u)); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType quantile(const hypergeometric_distribution<RealType, Policy>& dist, const RealType& p) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING // for ADL of std functions | ||
|  | 
 | ||
|  |          // Checking function argument | ||
|  |          RealType result = 0; | ||
|  |       const char* function = "boost::math::quantile(const hypergeometric_distribution<%1%>&, %1%)"; | ||
|  |       if (false == dist.check_params(function, &result)) return result; | ||
|  |       if(false == detail::check_probability(function, p, &result, Policy())) return result; | ||
|  | 
 | ||
|  |       return static_cast<RealType>(detail::hypergeometric_quantile(p, RealType(1 - p), dist.defective(), dist.sample_count(), dist.total(), Policy())); | ||
|  |    } // quantile | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType quantile(const complemented2_type<hypergeometric_distribution<RealType, Policy>, RealType>& c) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING // for ADL of std functions | ||
|  | 
 | ||
|  |       // Checking function argument | ||
|  |       RealType result = 0; | ||
|  |       const char* function = "quantile(const complemented2_type<hypergeometric_distribution<%1%>, %1%>&)"; | ||
|  |       if (false == c.dist.check_params(function, &result)) return result; | ||
|  |       if(false == detail::check_probability(function, c.param, &result, Policy())) return result; | ||
|  | 
 | ||
|  |       return static_cast<RealType>(detail::hypergeometric_quantile(RealType(1 - c.param), c.param, c.dist.defective(), c.dist.sample_count(), c.dist.total(), Policy())); | ||
|  |    } // quantile | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType mean(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { | ||
|  |       return static_cast<RealType>(dist.defective() * dist.sample_count()) / dist.total(); | ||
|  |    } // RealType mean(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType variance(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { | ||
|  |       RealType r = static_cast<RealType>(dist.defective()); | ||
|  |       RealType n = static_cast<RealType>(dist.sample_count()); | ||
|  |       RealType N = static_cast<RealType>(dist.total()); | ||
|  |       return n * r  * (N - r) * (N - n) / (N * N * (N - 1)); | ||
|  |    } // RealType variance(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType mode(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING | ||
|  |       RealType r = static_cast<RealType>(dist.defective()); | ||
|  |       RealType n = static_cast<RealType>(dist.sample_count()); | ||
|  |       RealType N = static_cast<RealType>(dist.total()); | ||
|  |       return floor((r + 1) * (n + 1) / (N + 2)); | ||
|  |    } | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType skewness(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { | ||
|  |       BOOST_MATH_STD_USING | ||
|  |       RealType r = static_cast<RealType>(dist.defective()); | ||
|  |       RealType n = static_cast<RealType>(dist.sample_count()); | ||
|  |       RealType N = static_cast<RealType>(dist.total()); | ||
|  |       return (N - 2 * r) * sqrt(N - 1) * (N - 2 * n) / (sqrt(n * r * (N - r) * (N - n)) * (N - 2)); | ||
|  |    } // RealType skewness(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType kurtosis_excess(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { | ||
|  |       RealType r = static_cast<RealType>(dist.defective()); | ||
|  |       RealType n = static_cast<RealType>(dist.sample_count()); | ||
|  |       RealType N = static_cast<RealType>(dist.total()); | ||
|  |       RealType t1 = N * N * (N - 1) / (r * (N - 2) * (N - 3) * (N - r)); | ||
|  |       RealType t2 = (N * (N + 1) - 6 * N * (N - r)) / (n * (N - n)) | ||
|  |          + 3 * r * (N - r) * (N + 6) / (N * N) - 6; | ||
|  |       return t1 * t2; | ||
|  |    } // RealType kurtosis_excess(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  | 
 | ||
|  |    template <class RealType, class Policy> | ||
|  |    inline RealType kurtosis(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  |    { | ||
|  |       return kurtosis_excess(dist) + 3; | ||
|  |    } // RealType kurtosis_excess(const hypergeometric_distribution<RealType, Policy>& dist) | ||
|  | }} // namespaces | ||
|  | 
 | ||
|  | // This include must be at the end, *after* the accessors | ||
|  | // for this distribution have been defined, in order to | ||
|  | // keep compilers that support two-phase lookup happy. | ||
|  | #include <boost/math/distributions/detail/derived_accessors.hpp> | ||
|  | 
 | ||
|  | #endif // include guard |