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diff --git a/unsupported/Eigen/src/MatrixFunctions/StemFunction.h b/unsupported/Eigen/src/MatrixFunctions/StemFunction.h
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+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2010 Jitse Niesen <jitse@maths.leeds.ac.uk>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef EIGEN_STEM_FUNCTION
+#define EIGEN_STEM_FUNCTION
+
+namespace Eigen { 
+
+/** \ingroup MatrixFunctions_Module 
+  * \brief Stem functions corresponding to standard mathematical functions.
+  */
+template <typename Scalar>
+class StdStemFunctions
+{
+  public:
+
+    /** \brief The exponential function (and its derivatives). */
+    static Scalar exp(Scalar x, int)
+    {
+      return std::exp(x);
+    }
+
+    /** \brief Cosine (and its derivatives). */
+    static Scalar cos(Scalar x, int n)
+    {
+      Scalar res;
+      switch (n % 4) {
+      case 0: 
+	res = std::cos(x);
+	break;
+      case 1:
+	res = -std::sin(x);
+	break;
+      case 2:
+	res = -std::cos(x);
+	break;
+      case 3:
+	res = std::sin(x);
+	break;
+      }
+      return res;
+    }
+
+    /** \brief Sine (and its derivatives). */
+    static Scalar sin(Scalar x, int n)
+    {
+      Scalar res;
+      switch (n % 4) {
+      case 0:
+	res = std::sin(x);
+	break;
+      case 1:
+	res = std::cos(x);
+	break;
+      case 2:
+	res = -std::sin(x);
+	break;
+      case 3:
+	res = -std::cos(x);
+	break;
+      }
+      return res;
+    }
+
+    /** \brief Hyperbolic cosine (and its derivatives). */
+    static Scalar cosh(Scalar x, int n)
+    {
+      Scalar res;
+      switch (n % 2) {
+      case 0:
+	res = std::cosh(x);
+	break;
+      case 1:
+	res = std::sinh(x);
+	break;
+      }
+      return res;
+    }
+	
+    /** \brief Hyperbolic sine (and its derivatives). */
+    static Scalar sinh(Scalar x, int n)
+    {
+      Scalar res;
+      switch (n % 2) {
+      case 0:
+	res = std::sinh(x);
+	break;
+      case 1:
+	res = std::cosh(x);
+	break;
+      }
+      return res;
+    }
+
+}; // end of class StdStemFunctions
+
+} // end namespace Eigen
+
+#endif // EIGEN_STEM_FUNCTION