Index: boost/accumulators/statistics/sum_kahan.hpp
===================================================================
--- boost/accumulators/statistics/sum_kahan.hpp	(revision 0)
+++ boost/accumulators/statistics/sum_kahan.hpp	(revision 0)
@@ -0,0 +1,91 @@
+///////////////////////////////////////////////////////////////////////////////
+// sum_kahan.hpp
+//
+//  Copyright 2010 Gaetano Mendola. 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_SUM_KAHAN_HPP_EAN_26_07_2010
+#define BOOST_ACCUMULATORS_STATISTICS_SUM_KAHAN_HPP_EAN_26_07_2010
+
+#include <boost/accumulators/framework/accumulator_base.hpp>
+#include <boost/accumulators/framework/parameters/sample.hpp>
+#include <boost/numeric/conversion/cast.hpp>
+
+namespace boost { namespace accumulators
+{
+
+namespace impl
+{
+
+template<typename Sample>
+struct sum_kahan_impl
+  : accumulator_base
+{
+    typedef Sample result_type;
+
+    ////////////////////////////////////////////////////////////////////////////
+    // sum_kahan_impl
+    /**
+        @brief Kahan summation algorithm
+
+        Kahan algorithm reduces the numerical error obtained with standard
+        sequential sum.
+
+    */
+    template<typename Args>
+    sum_kahan_impl(Args const & args)
+      : sum(args[sample | Sample()]),
+        compensation(boost::numeric_cast<Sample>(0.0))
+    {
+    }
+
+    template<typename Args>
+    void operator ()(Args const & args)
+    {
+      const Sample myTmp1 = args[sample] - this->compensation;
+      const Sample myTmp2 = this->sum + myTmp1;
+      this->compensation = (myTmp2 - this->sum) - myTmp1;
+      this->sum = myTmp2;
+    }
+
+    result_type result(dont_care) const
+    {
+      return this->sum;
+    }
+private:
+    Sample sum;
+    Sample compensation;
+};
+
+} // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+// tag::sum_kahan
+namespace tag
+{
+
+    struct sum_kahan
+      : depends_on<>
+    {
+        /// INTERNAL ONLY
+        ///
+        typedef impl::sum_kahan_impl< mpl::_1 > impl;
+    };
+} // namespace tag
+
+///////////////////////////////////////////////////////////////////////////////
+// extract::sum_kahan
+namespace extract
+{
+    extractor<tag::sum_kahan> const sum_kahan = {};
+
+    BOOST_ACCUMULATORS_IGNORE_GLOBAL(sum_kahan)
+} // namespace extract
+
+using extract::sum_kahan;
+
+}} // namespace boost::accumulators
+
+#endif
+
Index: libs/accumulators/test/sum_kahan.cpp
===================================================================
--- libs/accumulators/test/sum_kahan.cpp	(revision 0)
+++ libs/accumulators/test/sum_kahan.cpp	(revision 0)
@@ -0,0 +1,41 @@
+//  (C) Copyright Gaetano Mendola 2010.
+//  Use, modification and distribution are subject to 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)
+
+#include <boost/test/unit_test.hpp>
+#include <boost/accumulators/accumulators.hpp>
+#include <boost/accumulators/statistics/stats.hpp>
+#include <boost/accumulators/statistics/sum_kahan.hpp>
+
+using namespace boost;
+using namespace unit_test;
+using namespace accumulators;
+
+///////////////////////////////////////////////////////////////////////////////
+// test_stat
+//
+void test_stat()
+{
+    accumulator_set<float, stats<tag::sum_kahan> > acc;
+
+    BOOST_CHECK_EQUAL(0.0f, sum_kahan(acc));
+
+    for (size_t i = 0; i < 1e6; ++i) {
+      acc(1e-6f);
+    }
+
+    BOOST_CHECK_EQUAL(1.0f, sum_kahan(acc));
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// init_unit_test_suite
+//
+test_suite* init_unit_test_suite( int argc, char* argv[] )
+{
+    test_suite *test = BOOST_TEST_SUITE("sum kahan test");
+
+    test->add(BOOST_TEST_CASE(&test_stat));
+
+    return test;
+}
Index: libs/accumulators/test/Jamfile.v2
===================================================================
--- libs/accumulators/test/Jamfile.v2	(revision 64372)
+++ libs/accumulators/test/Jamfile.v2	(working copy)
@@ -50,6 +50,7 @@
       [ run rolling_mean.cpp ]
       [ run skewness.cpp ]
       [ run sum.cpp ]
+      [ run sum_kahan.cpp ]
       [ run tail.cpp ]
       [ run tail_mean.cpp ]
       [ run tail_quantile.cpp ]