/////////////////////////////////////////////////////////////////////////////// | |
// weighted_sum.hpp | |
// | |
// Copyright 2006 Eric Niebler, Olivier Gygi. Distributed under 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_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_HPP_EAN_28_10_2005 | |
#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_HPP_EAN_28_10_2005 | |
#include <boost/mpl/placeholders.hpp> | |
#include <boost/accumulators/framework/accumulator_base.hpp> | |
#include <boost/accumulators/framework/extractor.hpp> | |
#include <boost/accumulators/numeric/functional.hpp> | |
#include <boost/accumulators/framework/parameters/sample.hpp> | |
#include <boost/accumulators/framework/parameters/weight.hpp> | |
#include <boost/accumulators/framework/accumulators/external_accumulator.hpp> | |
#include <boost/accumulators/framework/depends_on.hpp> | |
#include <boost/accumulators/statistics_fwd.hpp> | |
namespace boost { namespace accumulators | |
{ | |
namespace impl | |
{ | |
/////////////////////////////////////////////////////////////////////////////// | |
// weighted_sum_impl | |
template<typename Sample, typename Weight, typename Tag> | |
struct weighted_sum_impl | |
: accumulator_base | |
{ | |
typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample; | |
// for boost::result_of | |
typedef weighted_sample result_type; | |
template<typename Args> | |
weighted_sum_impl(Args const &args) | |
: weighted_sum_( | |
args[parameter::keyword<Tag>::get() | Sample()] | |
* numeric::one<Weight>::value | |
) | |
{ | |
} | |
template<typename Args> | |
void operator ()(Args const &args) | |
{ | |
// what about overflow? | |
this->weighted_sum_ += args[parameter::keyword<Tag>::get()] * args[weight]; | |
} | |
result_type result(dont_care) const | |
{ | |
return this->weighted_sum_; | |
} | |
private: | |
weighted_sample weighted_sum_; | |
}; | |
} // namespace impl | |
/////////////////////////////////////////////////////////////////////////////// | |
// tag::weighted_sum | |
// | |
namespace tag | |
{ | |
struct weighted_sum | |
: depends_on<> | |
{ | |
/// INTERNAL ONLY | |
/// | |
typedef accumulators::impl::weighted_sum_impl<mpl::_1, mpl::_2, tag::sample> impl; | |
}; | |
template<typename VariateType, typename VariateTag> | |
struct weighted_sum_of_variates | |
: depends_on<> | |
{ | |
/// INTERNAL ONLY | |
/// | |
typedef accumulators::impl::weighted_sum_impl<VariateType, mpl::_2, VariateTag> impl; | |
}; | |
struct abstract_weighted_sum_of_variates | |
: depends_on<> | |
{ | |
}; | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// extract::weighted_sum | |
// | |
namespace extract | |
{ | |
extractor<tag::weighted_sum> const weighted_sum = {}; | |
extractor<tag::abstract_weighted_sum_of_variates> const weighted_sum_of_variates = {}; | |
BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum) | |
BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_of_variates) | |
} | |
using extract::weighted_sum; | |
using extract::weighted_sum_of_variates; | |
template<typename VariateType, typename VariateTag> | |
struct feature_of<tag::weighted_sum_of_variates<VariateType, VariateTag> > | |
: feature_of<tag::abstract_weighted_sum_of_variates> | |
{ | |
}; | |
}} // namespace boost::accumulators | |
#endif |