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
21namespace boost { namespace accumulators
22{
23
24namespace 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>
38 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>
47 void operator ()(Args const &args)
48 {
49 // what about overflow?
50 this->weighted_sum_ += args[parameter::keyword<Tag>::get()] * args[weight];
51 }
52
53 result_type result(dont_care) const
54 {
55 return this->weighted_sum_;
56 }
57
58 // make this accumulator serializeable
59 template<class Archive>
60 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//
75namespace 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//
103namespace 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
112using extract::weighted_sum;
113using extract::weighted_sum_of_variates;
114
115template<typename VariateType, typename VariateTag>
116struct 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

source code of include/boost/accumulators/statistics/weighted_sum.hpp