Added boost header

test/external/boost/accumulators/statistics/weighted_sum_kahan.hpp

@@ -0,0 +1,138 @@
+///////////////////////////////////////////////////////////////////////////////
+// weighted_sum_kahan.hpp
+//
+//  Copyright 2011 Simon West. 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_KAHAN_HPP_EAN_11_05_2011
+#define BOOST_ACCUMULATORS_STATISTICS_WEIGHTED_SUM_KAHAN_HPP_EAN_11_05_2011
+
+#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>
+#include <boost/accumulators/statistics/weighted_sum.hpp>
+#include <boost/numeric/conversion/cast.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+#if _MSC_VER > 1400
+# pragma float_control(push)
+# pragma float_control(precise, on)
+#endif
+
+    ///////////////////////////////////////////////////////////////////////////////
+    // weighted_sum_kahan_impl
+    template<typename Sample, typename Weight, typename Tag>
+    struct weighted_sum_kahan_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_kahan_impl(Args const &args)
+          : weighted_sum_(
+                args[parameter::keyword<Tag>::get() | Sample()] * numeric::one<Weight>::value),
+                compensation(boost::numeric_cast<weighted_sample>(0.0))
+        {
+        }
+
+        template<typename Args>
+        void 
+#if BOOST_ACCUMULATORS_GCC_VERSION > 40305
+        __attribute__((optimize("no-associative-math")))
+#endif
+        operator ()(Args const &args)
+        {
+            const weighted_sample myTmp1 = args[parameter::keyword<Tag>::get()] * args[weight] - this->compensation;
+            const weighted_sample myTmp2 = this->weighted_sum_ + myTmp1;
+            this->compensation = (myTmp2 - this->weighted_sum_) - myTmp1;
+            this->weighted_sum_ = myTmp2;
+
+        }
+
+        result_type result(dont_care) const
+        {
+            return this->weighted_sum_;
+        }
+
+    private:
+        weighted_sample weighted_sum_;
+        weighted_sample compensation;
+    };
+
+#if _MSC_VER > 1400
+# pragma float_control(pop)
+#endif
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::weighted_sum_kahan
+// tag::weighted_sum_of_variates_kahan
+//
+namespace tag
+{
+    struct weighted_sum_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_sum_kahan_impl<mpl::_1, mpl::_2, tag::sample> impl;
+    };
+
+    template<typename VariateType, typename VariateTag>
+    struct weighted_sum_of_variates_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef accumulators::impl::weighted_sum_kahan_impl<VariateType, mpl::_2, VariateTag> impl;
+    };
+
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::weighted_sum_kahan
+// extract::weighted_sum_of_variates_kahan
+//
+namespace extract
+{
+    extractor<tag::weighted_sum_kahan> const weighted_sum_kahan = {};
+    extractor<tag::abstract_weighted_sum_of_variates> const weighted_sum_of_variates_kahan = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_kahan)
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(weighted_sum_of_variates_kahan)
+}
+
+using extract::weighted_sum_kahan;
+using extract::weighted_sum_of_variates_kahan;
+
+// weighted_sum(kahan) -> weighted_sum_kahan
+template<>
+struct as_feature<tag::weighted_sum(kahan)>
+{
+    typedef tag::weighted_sum_kahan type;
+};
+
+template<typename VariateType, typename VariateTag>
+struct feature_of<tag::weighted_sum_of_variates_kahan<VariateType, VariateTag> >
+  : feature_of<tag::abstract_weighted_sum_of_variates>
+{
+};
+
+}} // namespace boost::accumulators
+
+#endif