Changed namespace Dune -> namespace Opm.

opm/core/utility/Average.hpp

@@ -0,0 +1,98 @@
+//===========================================================================
+//
+// File: Average.hpp<2>
+//
+// Created: Wed Jul  1 12:25:57 2009
+//
+// Author(s): Atgeirr F Rasmussen <atgeirr@sintef.no>
+//            Bård Skaflestad     <bard.skaflestad@sintef.no>
+//
+// $Date$
+//
+// $Revision$
+//
+//===========================================================================
+
+/*
+  Copyright 2009, 2010 SINTEF ICT, Applied Mathematics.
+  Copyright 2009, 2010 Statoil ASA.
+
+  This file is part of The Open Reservoir Simulator Project (OpenRS).
+
+  OpenRS is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OpenRS is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OpenRS.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef OPENRS_AVERAGE_HEADER
+#define OPENRS_AVERAGE_HEADER
+
+
+#include <boost/static_assert.hpp>
+#include <tr1/type_traits>
+#include <cmath>
+
+namespace Opm {
+    namespace utils {
+
+
+
+	/// Computes the arithmetic average:
+	/// a_A(t_1, t_2) = (t_1 + t_2)/2.
+	template <typename T, typename Tresult>
+	Tresult arithmeticAverage(const T& t1, const T& t2)
+	{
+	    // To avoid some user errors, we disallow taking averages of
+	    // integral values.
+	    BOOST_STATIC_ASSERT(std::tr1::is_integral<T>::value == false);
+	    Tresult retval(t1);
+	    retval += t2;
+	    retval *= 0.5;
+	    return retval;
+	}
+
+
+
+	/// Computes the geometric average:
+	/// a_G(t_1, t_2) = \sqrt{t_1 t_2}.
+	/// Since we use std::sqrt(), this function will only
+	/// compile when T is convertible to and from double.
+	template <typename T>
+	T geometricAverage(const T& t1, const T& t2)
+	{
+	    // To avoid some user errors, we disallow taking averages of
+	    // integral values.
+	    BOOST_STATIC_ASSERT(std::tr1::is_integral<T>::value == false);
+	    return std::sqrt(t1*t2);
+	}
+
+
+
+	/// Computes the harmonic average:
+	/// a_H(t_1, t_2) = \frac{2}{1/t_1 + 1/t_2} = \frac{2 t_1 t_2}{t_1 + t_2}.
+	template <typename T>
+	T harmonicAverage(const T& t1, const T& t2)
+	{
+	    // To avoid some user errors, we disallow taking averages of
+	    // integral values.
+	    BOOST_STATIC_ASSERT(std::tr1::is_integral<T>::value == false);
+	    return (2*t1*t2)/(t1 + t2);
+	}
+
+
+
+    } // namespace utils
+} // namespace Opm
+
+
+
+#endif // OPENRS_AVERAGE_HEADER