/////////////////////////////////////////////////////////////////////////////// | |
// 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 |