1 /////////////////////////////////////////////////////////////////////////////// 2 // error_of.hpp 3 // 4 // Copyright 2005 Eric Niebler. Distributed under the Boost 5 // Software License, Version 1.0. (See accompanying file 6 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 7 8 #ifndef BOOST_ACCUMULATORS_STATISTICS_ERROR_OF_MEAN_HPP_EAN_27_03_2006 9 #define BOOST_ACCUMULATORS_STATISTICS_ERROR_OF_MEAN_HPP_EAN_27_03_2006 10 11 #include <boost/mpl/placeholders.hpp> 12 #include <boost/accumulators/framework/accumulator_base.hpp> 13 #include <boost/accumulators/framework/extractor.hpp> 14 #include <boost/accumulators/framework/depends_on.hpp> 15 #include <boost/accumulators/statistics_fwd.hpp> 16 #include <boost/accumulators/statistics/error_of.hpp> 17 #include <boost/accumulators/statistics/variance.hpp> 18 #include <boost/accumulators/statistics/count.hpp> 19 20 namespace boost { namespace accumulators 21 { 22 23 namespace impl 24 { 25 /////////////////////////////////////////////////////////////////////////////// 26 // error_of_mean_impl 27 template<typename Sample, typename Variance> 28 struct error_of_mean_impl 29 : accumulator_base 30 { 31 // for boost::result_of 32 typedef typename numeric::functional::fdiv<Sample, std::size_t>::result_type result_type; 33 error_of_mean_implboost::accumulators::impl::error_of_mean_impl34 error_of_mean_impl(dont_care) {} 35 36 template<typename Args> resultboost::accumulators::impl::error_of_mean_impl37 result_type result(Args const &args) const 38 { 39 using namespace std; 40 extractor<Variance> const variance = {}; 41 return sqrt(numeric::fdiv(variance(args), count(args) - 1)); 42 } 43 }; 44 45 } // namespace impl 46 47 /////////////////////////////////////////////////////////////////////////////// 48 // tag::error_of 49 // 50 namespace tag 51 { 52 template<> 53 struct error_of<mean> 54 : depends_on<lazy_variance, count> 55 { 56 /// INTERNAL ONLY 57 /// 58 typedef accumulators::impl::error_of_mean_impl<mpl::_1, lazy_variance> impl; 59 }; 60 61 template<> 62 struct error_of<immediate_mean> 63 : depends_on<variance, count> 64 { 65 /// INTERNAL ONLY 66 /// 67 typedef accumulators::impl::error_of_mean_impl<mpl::_1, variance> impl; 68 }; 69 } 70 71 }} // namespace boost::accumulators 72 73 #endif 74