1 /////////////////////////////////////////////////////////////////////////////// 2 // weighted_sum.hpp 3 // 4 // Copyright 2006 Eric Niebler, Olivier Gygi. 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_WEIGHTED_SUM_HPP_EAN_28_10_2005 9 #define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_HPP_EAN_28_10_2005 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/numeric/functional.hpp> 15 #include <boost/accumulators/framework/parameters/sample.hpp> 16 #include <boost/accumulators/framework/parameters/weight.hpp> 17 #include <boost/accumulators/framework/accumulators/external_accumulator.hpp> 18 #include <boost/accumulators/framework/depends_on.hpp> 19 #include <boost/accumulators/statistics_fwd.hpp> 20 21 namespace boost { namespace accumulators 22 { 23 24 namespace impl 25 { 26 /////////////////////////////////////////////////////////////////////////////// 27 // weighted_sum_impl 28 template<typename Sample, typename Weight, typename Tag> 29 struct weighted_sum_impl 30 : accumulator_base 31 { 32 typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample; 33 34 // for boost::result_of 35 typedef weighted_sample result_type; 36 37 template<typename Args> weighted_sum_implboost::accumulators::impl::weighted_sum_impl38 weighted_sum_impl(Args const &args) 39 : weighted_sum_( 40 args[parameter::keyword<Tag>::get() | Sample()] 41 * numeric::one<Weight>::value 42 ) 43 { 44 } 45 46 template<typename Args> operator ()boost::accumulators::impl::weighted_sum_impl47 void operator ()(Args const &args) 48 { 49 // what about overflow? 50 this->weighted_sum_ += args[parameter::keyword<Tag>::get()] * args[weight]; 51 } 52 resultboost::accumulators::impl::weighted_sum_impl53 result_type result(dont_care) const 54 { 55 return this->weighted_sum_; 56 } 57 58 // make this accumulator serializeable 59 template<class Archive> serializeboost::accumulators::impl::weighted_sum_impl60 void serialize(Archive & ar, const unsigned int file_version) 61 { 62 ar & weighted_sum_; 63 } 64 65 private: 66 67 weighted_sample weighted_sum_; 68 }; 69 70 } // namespace impl 71 72 /////////////////////////////////////////////////////////////////////////////// 73 // tag::weighted_sum 74 // 75 namespace tag 76 { 77 struct weighted_sum 78 : depends_on<> 79 { 80 /// INTERNAL ONLY 81 /// 82 typedef accumulators::impl::weighted_sum_impl<mpl::_1, mpl::_2, tag::sample> impl; 83 }; 84 85 template<typename VariateType, typename VariateTag> 86 struct weighted_sum_of_variates 87 : depends_on<> 88 { 89 /// INTERNAL ONLY 90 /// 91 typedef accumulators::impl::weighted_sum_impl<VariateType, mpl::_2, VariateTag> impl; 92 }; 93 94 struct abstract_weighted_sum_of_variates 95 : depends_on<> 96 { 97 }; 98 } 99 100 /////////////////////////////////////////////////////////////////////////////// 101 // extract::weighted_sum 102 // 103 namespace extract 104 { 105 extractor<tag::weighted_sum> const weighted_sum = {}; 106 extractor<tag::abstract_weighted_sum_of_variates> const weighted_sum_of_variates = {}; 107 108 BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum) 109 BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_of_variates) 110 } 111 112 using extract::weighted_sum; 113 using extract::weighted_sum_of_variates; 114 115 template<typename VariateType, typename VariateTag> 116 struct feature_of<tag::weighted_sum_of_variates<VariateType, VariateTag> > 117 : feature_of<tag::abstract_weighted_sum_of_variates> 118 { 119 }; 120 121 }} // namespace boost::accumulators 122 123 #endif 124