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diff --git a/boost/geometry/algorithms/detail/azimuth.hpp b/boost/geometry/algorithms/detail/azimuth.hpp
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+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
+
+// This file was modified by Oracle on 2014.
+// Modifications copyright (c) 2014, Oracle and/or its affiliates.
+
+// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
+
+// Use, modification and distribution is 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)
+
+#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_AZIMUTH_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_AZIMUTH_HPP
+
+#include <boost/geometry/core/cs.hpp>
+#include <boost/geometry/core/access.hpp>
+#include <boost/geometry/core/radian_access.hpp>
+#include <boost/geometry/core/tags.hpp>
+
+#include <boost/geometry/util/math.hpp>
+
+#include <boost/geometry/algorithms/not_implemented.hpp>
+#include <boost/geometry/algorithms/detail/vincenty_inverse.hpp>
+
+namespace boost { namespace geometry
+{
+
+// An azimuth is an angle between a vector/segment from origin to a point of
+// interest and a reference vector. Typically north-based azimuth is used.
+// North direction is used as a reference, angle is measured clockwise
+// (North - 0deg, East - 90deg). For consistency in 2d cartesian CS
+// the reference vector is Y axis, angle is measured clockwise.
+// http://en.wikipedia.org/wiki/Azimuth
+
+#ifndef DOXYGEN_NO_DISPATCH
+namespace detail_dispatch
+{
+
+template <typename ReturnType, typename Tag>
+struct azimuth
+    : not_implemented<Tag>
+{};
+
+template <typename ReturnType>
+struct azimuth<ReturnType, geographic_tag>
+{
+    template <typename P1, typename P2, typename Spheroid>
+    static inline ReturnType apply(P1 const& p1, P2 const& p2, Spheroid const& spheroid)
+    {
+        return geometry::detail::vincenty_inverse<ReturnType>
+                    ( get_as_radian<0>(p1), get_as_radian<1>(p1),
+                      get_as_radian<0>(p2), get_as_radian<1>(p2),
+                      spheroid ).azimuth12();
+    }
+
+    template <typename P1, typename P2>
+    static inline ReturnType apply(P1 const& p1, P2 const& p2)
+    {
+        return apply(p1, p2, srs::spheroid<ReturnType>());
+    }
+};
+
+template <typename ReturnType>
+struct azimuth<ReturnType, spherical_equatorial_tag>
+{
+    template <typename P1, typename P2, typename Sphere>
+    static inline ReturnType apply(P1 const& p1, P2 const& p2, Sphere const& /*unused*/)
+    {
+        // http://williams.best.vwh.net/avform.htm#Crs
+        ReturnType dlon = get_as_radian<0>(p2) - get_as_radian<0>(p1);
+        ReturnType cos_p2lat = cos(get_as_radian<1>(p2));
+
+        // An optimization which should kick in often for Boxes
+        //if ( math::equals(dlon, ReturnType(0)) )
+        //if ( get<0>(p1) == get<0>(p2) )
+        //{
+        //    return - sin(get_as_radian<1>(p1)) * cos_p2lat);
+        //}
+
+        // "An alternative formula, not requiring the pre-computation of d"
+        // In the formula below dlon is used as "d"
+        return atan2(sin(dlon) * cos_p2lat,
+            cos(get_as_radian<1>(p1)) * sin(get_as_radian<1>(p2))
+            - sin(get_as_radian<1>(p1)) * cos_p2lat * cos(dlon));
+    }
+
+    template <typename P1, typename P2>
+    static inline ReturnType apply(P1 const& p1, P2 const& p2)
+    {
+        return apply(p1, p2, 0); // dummy model
+    }
+};
+
+template <typename ReturnType>
+struct azimuth<ReturnType, spherical_polar_tag>
+    : azimuth<ReturnType, spherical_equatorial_tag>
+{};
+
+template <typename ReturnType>
+struct azimuth<ReturnType, cartesian_tag>
+{
+    template <typename P1, typename P2, typename Plane>
+    static inline ReturnType apply(P1 const& p1, P2 const& p2, Plane const& /*unused*/)
+    {
+        ReturnType x = get<0>(p2) - get<0>(p1);
+        ReturnType y = get<1>(p2) - get<1>(p1);
+
+        // NOTE: azimuth 0 is at Y axis, increasing right
+        // as in spherical/geographic where 0 is at North axis
+        return atan2(x, y);
+    }
+
+    template <typename P1, typename P2>
+    static inline ReturnType apply(P1 const& p1, P2 const& p2)
+    {
+        return apply(p1, p2, 0); // dummy model
+    }
+};
+
+} // detail_dispatch
+#endif // DOXYGEN_NO_DISPATCH
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail
+{
+
+/// Calculate azimuth between two points.
+/// The result is in radians.
+template <typename ReturnType, typename Point1, typename Point2>
+inline ReturnType azimuth(Point1 const& p1, Point2 const& p2)
+{
+    return detail_dispatch::azimuth
+            <
+                ReturnType,
+                typename geometry::cs_tag<Point1>::type
+            >::apply(p1, p2);
+}
+
+/// Calculate azimuth between two points.
+/// The result is in radians.
+template <typename ReturnType, typename Point1, typename Point2, typename Model>
+inline ReturnType azimuth(Point1 const& p1, Point2 const& p2, Model const& model)
+{
+    return detail_dispatch::azimuth
+            <
+                ReturnType,
+                typename geometry::cs_tag<Point1>::type
+            >::apply(p1, p2, model);
+}
+
+} // namespace detail
+#endif // DOXYGEN_NO_DETAIL
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_AZIMUTH_HPP