| /////////////////////////////////////////////////////////////////////////////// |
| // mean.hpp |
| // |
| // Copyright 2005 Eric Niebler. 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_MEAN_HPP_EAN_28_10_2005 |
| #define BOOST_ACCUMULATORS_STATISTICS_MEAN_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/depends_on.hpp> |
| #include <boost/accumulators/statistics_fwd.hpp> |
| #include <boost/accumulators/statistics/count.hpp> |
| #include <boost/accumulators/statistics/sum.hpp> |
| |
| namespace boost { namespace accumulators |
| { |
| |
| namespace impl |
| { |
| /////////////////////////////////////////////////////////////////////////////// |
| // mean_impl |
| // lazy, by default |
| template<typename Sample, typename SumFeature> |
| struct mean_impl |
| : accumulator_base |
| { |
| // for boost::result_of |
| typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type; |
| |
| mean_impl(dont_care) {} |
| |
| template<typename Args> |
| result_type result(Args const &args) const |
| { |
| extractor<SumFeature> sum; |
| return numeric::average(sum(args), count(args)); |
| } |
| }; |
| |
| template<typename Sample, typename Tag> |
| struct immediate_mean_impl |
| : accumulator_base |
| { |
| // for boost::result_of |
| typedef typename numeric::functional::average<Sample, std::size_t>::result_type result_type; |
| |
| template<typename Args> |
| immediate_mean_impl(Args const &args) |
| : mean(numeric::average(args[sample | Sample()], numeric::one<std::size_t>::value)) |
| { |
| } |
| |
| template<typename Args> |
| void operator ()(Args const &args) |
| { |
| std::size_t cnt = count(args); |
| this->mean = numeric::average( |
| (this->mean * (cnt - 1)) + args[parameter::keyword<Tag>::get()] |
| , cnt |
| ); |
| } |
| |
| result_type result(dont_care) const |
| { |
| return this->mean; |
| } |
| |
| private: |
| result_type mean; |
| }; |
| |
| } // namespace impl |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // tag::mean |
| // tag::immediate_mean |
| // tag::mean_of_weights |
| // tag::immediate_mean_of_weights |
| // tag::mean_of_variates |
| // tag::immediate_mean_of_variates |
| // |
| namespace tag |
| { |
| struct mean |
| : depends_on<count, sum> |
| { |
| /// INTERNAL ONLY |
| /// |
| typedef accumulators::impl::mean_impl<mpl::_1, sum> impl; |
| }; |
| struct immediate_mean |
| : depends_on<count> |
| { |
| /// INTERNAL ONLY |
| /// |
| typedef accumulators::impl::immediate_mean_impl<mpl::_1, tag::sample> impl; |
| }; |
| struct mean_of_weights |
| : depends_on<count, sum_of_weights> |
| { |
| typedef mpl::true_ is_weight_accumulator; |
| /// INTERNAL ONLY |
| /// |
| typedef accumulators::impl::mean_impl<mpl::_2, sum_of_weights> impl; |
| }; |
| struct immediate_mean_of_weights |
| : depends_on<count> |
| { |
| typedef mpl::true_ is_weight_accumulator; |
| /// INTERNAL ONLY |
| /// |
| typedef accumulators::impl::immediate_mean_impl<mpl::_2, tag::weight> impl; |
| }; |
| template<typename VariateType, typename VariateTag> |
| struct mean_of_variates |
| : depends_on<count, sum_of_variates<VariateType, VariateTag> > |
| { |
| /// INTERNAL ONLY |
| /// |
| typedef mpl::always<accumulators::impl::mean_impl<VariateType, sum_of_variates<VariateType, VariateTag> > > impl; |
| }; |
| template<typename VariateType, typename VariateTag> |
| struct immediate_mean_of_variates |
| : depends_on<count> |
| { |
| /// INTERNAL ONLY |
| /// |
| typedef mpl::always<accumulators::impl::immediate_mean_impl<VariateType, VariateTag> > impl; |
| }; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // extract::mean |
| // extract::mean_of_weights |
| // extract::mean_of_variates |
| // |
| namespace extract |
| { |
| extractor<tag::mean> const mean = {}; |
| extractor<tag::mean_of_weights> const mean_of_weights = {}; |
| BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(tag, mean_of_variates, (typename)(typename)) |
| |
| BOOST_ACCUMULATORS_IGNORE_GLOBAL(mean) |
| BOOST_ACCUMULATORS_IGNORE_GLOBAL(mean_of_weights) |
| } |
| |
| using extract::mean; |
| using extract::mean_of_weights; |
| using extract::mean_of_variates; |
| |
| // mean(lazy) -> mean |
| template<> |
| struct as_feature<tag::mean(lazy)> |
| { |
| typedef tag::mean type; |
| }; |
| |
| // mean(immediate) -> immediate_mean |
| template<> |
| struct as_feature<tag::mean(immediate)> |
| { |
| typedef tag::immediate_mean type; |
| }; |
| |
| // mean_of_weights(lazy) -> mean_of_weights |
| template<> |
| struct as_feature<tag::mean_of_weights(lazy)> |
| { |
| typedef tag::mean_of_weights type; |
| }; |
| |
| // mean_of_weights(immediate) -> immediate_mean_of_weights |
| template<> |
| struct as_feature<tag::mean_of_weights(immediate)> |
| { |
| typedef tag::immediate_mean_of_weights type; |
| }; |
| |
| // mean_of_variates<VariateType, VariateTag>(lazy) -> mean_of_variates<VariateType, VariateTag> |
| template<typename VariateType, typename VariateTag> |
| struct as_feature<tag::mean_of_variates<VariateType, VariateTag>(lazy)> |
| { |
| typedef tag::mean_of_variates<VariateType, VariateTag> type; |
| }; |
| |
| // mean_of_variates<VariateType, VariateTag>(immediate) -> immediate_mean_of_variates<VariateType, VariateTag> |
| template<typename VariateType, typename VariateTag> |
| struct as_feature<tag::mean_of_variates<VariateType, VariateTag>(immediate)> |
| { |
| typedef tag::immediate_mean_of_variates<VariateType, VariateTag> type; |
| }; |
| |
| // for the purposes of feature-based dependency resolution, |
| // immediate_mean provides the same feature as mean |
| template<> |
| struct feature_of<tag::immediate_mean> |
| : feature_of<tag::mean> |
| { |
| }; |
| |
| // for the purposes of feature-based dependency resolution, |
| // immediate_mean provides the same feature as mean |
| template<> |
| struct feature_of<tag::immediate_mean_of_weights> |
| : feature_of<tag::mean_of_weights> |
| { |
| }; |
| |
| // for the purposes of feature-based dependency resolution, |
| // immediate_mean provides the same feature as mean |
| template<typename VariateType, typename VariateTag> |
| struct feature_of<tag::immediate_mean_of_variates<VariateType, VariateTag> > |
| : feature_of<tag::mean_of_variates<VariateType, VariateTag> > |
| { |
| }; |
| |
| // So that mean can be automatically substituted with |
| // weighted_mean when the weight parameter is non-void. |
| template<> |
| struct as_weighted_feature<tag::mean> |
| { |
| typedef tag::weighted_mean type; |
| }; |
| |
| template<> |
| struct feature_of<tag::weighted_mean> |
| : feature_of<tag::mean> |
| {}; |
| |
| // So that immediate_mean can be automatically substituted with |
| // immediate_weighted_mean when the weight parameter is non-void. |
| template<> |
| struct as_weighted_feature<tag::immediate_mean> |
| { |
| typedef tag::immediate_weighted_mean type; |
| }; |
| |
| template<> |
| struct feature_of<tag::immediate_weighted_mean> |
| : feature_of<tag::immediate_mean> |
| {}; |
| |
| // So that mean_of_weights<> can be automatically substituted with |
| // weighted_mean_of_variates<> when the weight parameter is non-void. |
| template<typename VariateType, typename VariateTag> |
| struct as_weighted_feature<tag::mean_of_variates<VariateType, VariateTag> > |
| { |
| typedef tag::weighted_mean_of_variates<VariateType, VariateTag> type; |
| }; |
| |
| template<typename VariateType, typename VariateTag> |
| struct feature_of<tag::weighted_mean_of_variates<VariateType, VariateTag> > |
| : feature_of<tag::mean_of_variates<VariateType, VariateTag> > |
| { |
| }; |
| |
| // So that immediate_mean_of_weights<> can be automatically substituted with |
| // immediate_weighted_mean_of_variates<> when the weight parameter is non-void. |
| template<typename VariateType, typename VariateTag> |
| struct as_weighted_feature<tag::immediate_mean_of_variates<VariateType, VariateTag> > |
| { |
| typedef tag::immediate_weighted_mean_of_variates<VariateType, VariateTag> type; |
| }; |
| |
| template<typename VariateType, typename VariateTag> |
| struct feature_of<tag::immediate_weighted_mean_of_variates<VariateType, VariateTag> > |
| : feature_of<tag::immediate_mean_of_variates<VariateType, VariateTag> > |
| { |
| }; |
| |
| //////////////////////////////////////////////////////////////////////////// |
| //// droppable_accumulator<mean_impl> |
| //// need to specialize droppable lazy mean to cache the result at the |
| //// point the accumulator is dropped. |
| ///// INTERNAL ONLY |
| ///// |
| //template<typename Sample, typename SumFeature> |
| //struct droppable_accumulator<impl::mean_impl<Sample, SumFeature> > |
| // : droppable_accumulator_base< |
| // with_cached_result<impl::mean_impl<Sample, SumFeature> > |
| // > |
| //{ |
| // template<typename Args> |
| // droppable_accumulator(Args const &args) |
| // : droppable_accumulator::base(args) |
| // { |
| // } |
| //}; |
| |
| }} // namespace boost::accumulators |
| |
| #endif |