/////////////////////////////////////////////////////////////////////////////// // weighted_moment.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_MOMENT_HPP_EAN_15_11_2005 #define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_MOMENT_HPP_EAN_15_11_2005 #include <boost/config/no_tr1/cmath.hpp> #include <boost/mpl/int.hpp> #include <boost/mpl/assert.hpp> #include <boost/mpl/placeholders.hpp> #include <boost/preprocessor/arithmetic/inc.hpp> #include <boost/preprocessor/repetition/repeat_from_to.hpp> #include <boost/preprocessor/repetition/enum_trailing_params.hpp> #include <boost/preprocessor/repetition/enum_trailing_binary_params.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/depends_on.hpp> #include <boost/accumulators/statistics_fwd.hpp> #include <boost/accumulators/statistics/count.hpp> #include <boost/accumulators/statistics/moment.hpp> // for pow() #include <boost/accumulators/statistics/sum.hpp> namespace boost { namespace accumulators { namespace impl { /////////////////////////////////////////////////////////////////////////////// // weighted_moment_impl template<typename N, typename Sample, typename Weight> struct weighted_moment_impl : accumulator_base // TODO: also depends_on sum of powers { BOOST_MPL_ASSERT_RELATION(N::value, >, 0); typedef typename numeric::functional::multiplies<Sample, Weight>::result_type weighted_sample; // for boost::result_of typedef typename numeric::functional::fdiv<weighted_sample, Weight>::result_type result_type; template<typename Args> weighted_moment_impl(Args const &args) : sum(args[sample | Sample()] * numeric::one<Weight>::value) { } template<typename Args> void operator ()(Args const &args) { this->sum += args[weight] * numeric::pow(args[sample], N()); } template<typename Args> result_type result(Args const &args) const { return numeric::fdiv(this->sum, sum_of_weights(args)); } // make this accumulator serializeable template<class Archive> void serialize(Archive & ar, const unsigned int file_version) { ar & sum; } private: weighted_sample sum; }; } // namespace impl /////////////////////////////////////////////////////////////////////////////// // tag::weighted_moment // namespace tag { template<int N> struct weighted_moment : depends_on<count, sum_of_weights> { /// INTERNAL ONLY /// typedef accumulators::impl::weighted_moment_impl<mpl::int_<N>, mpl::_1, mpl::_2> impl; }; } /////////////////////////////////////////////////////////////////////////////// // extract::weighted_moment // namespace extract { BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, weighted_moment, (int)) } using extract::weighted_moment; }} // namespace boost::accumulators #endif