boost/accumulators/statistics/rolling_sum.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // rolling_sum.hpp
   3 //
   4 // Copyright 2008 Eric Niebler. 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_ROLLING_SUM_HPP_EAN_26_12_2008
   9 #define BOOST_ACCUMULATORS_STATISTICS_ROLLING_SUM_HPP_EAN_26_12_2008
  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/depends_on.hpp>
  17 #include <boost/accumulators/statistics_fwd.hpp>
  18 #include <boost/accumulators/statistics/rolling_window.hpp>
  19
  20 namespace boost { namespace accumulators
  21 {
  22 namespace impl
  23 {
  24     ///////////////////////////////////////////////////////////////////////////////
  25     // rolling_sum_impl
  26     //    returns the sum of the samples in the rolling window
  27     template<typename Sample>
  28     struct rolling_sum_impl
  29       : accumulator_base
  30     {
  31         typedef Sample result_type;
  32
  33         template<typename Args>
  34         rolling_sum_impl(Args const &args)
  35           : sum_(args[sample | Sample()])
  36         {}
  37
  38         template<typename Args>
  39         void operator ()(Args const &args)
  40         {
  41             if(is_rolling_window_plus1_full(args))
  42             {
  43                 this->sum_ -= rolling_window_plus1(args).front();
  44             }
  45             this->sum_ += args[sample];
  46         }
  47
  48         template<typename Args>
  49         result_type result(Args const & /*args*/) const
  50         {
  51             return this->sum_;
  52         }
  53
  54     private:
  55         Sample sum_;
  56     };
  57 } // namespace impl
  58
  59 ///////////////////////////////////////////////////////////////////////////////
  60 // tag::rolling_sum
  61 //
  62 namespace tag
  63 {
  64     struct rolling_sum
  65       : depends_on< rolling_window_plus1 >
  66     {
  67         /// INTERNAL ONLY
  68         ///
  69         typedef accumulators::impl::rolling_sum_impl< mpl::_1 > impl;
  70
  71         #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
  72         /// tag::rolling_window::window_size named parameter
  73         static boost::parameter::keyword<tag::rolling_window_size> const window_size;
  74         #endif
  75     };
  76 } // namespace tag
  77
  78 ///////////////////////////////////////////////////////////////////////////////
  79 // extract::rolling_sum
  80 //
  81 namespace extract
  82 {
  83     extractor<tag::rolling_sum> const rolling_sum = {};
  84
  85     BOOST_ACCUMULATORS_IGNORE_GLOBAL(rolling_sum)
  86 }
  87
  88 using extract::rolling_sum;
  89 }} // namespace boost::accumulators
  90
  91 #endif