MatrixFunctions: Clean up StemFunction.h

unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h

@@ -547,7 +547,7 @@ const MatrixFunctionReturnValue<Derived> MatrixBase<Derived>::sin() const
 {
   eigen_assert(rows() == cols());
   typedef typename internal::stem_function<Scalar>::ComplexScalar ComplexScalar;
-  return MatrixFunctionReturnValue<Derived>(derived(), StdStemFunctions<ComplexScalar>::sin);
+  return MatrixFunctionReturnValue<Derived>(derived(), internal::stem_function_sin<ComplexScalar>);
 }
 
 template <typename Derived>
@@ -555,7 +555,7 @@ const MatrixFunctionReturnValue<Derived> MatrixBase<Derived>::cos() const
 {
   eigen_assert(rows() == cols());
   typedef typename internal::stem_function<Scalar>::ComplexScalar ComplexScalar;
-  return MatrixFunctionReturnValue<Derived>(derived(), StdStemFunctions<ComplexScalar>::cos);
+  return MatrixFunctionReturnValue<Derived>(derived(), internal::stem_function_cos<ComplexScalar>);
 }
 
 template <typename Derived>
@@ -563,7 +563,7 @@ const MatrixFunctionReturnValue<Derived> MatrixBase<Derived>::sinh() const
 {
   eigen_assert(rows() == cols());
   typedef typename internal::stem_function<Scalar>::ComplexScalar ComplexScalar;
-  return MatrixFunctionReturnValue<Derived>(derived(), StdStemFunctions<ComplexScalar>::sinh);
+  return MatrixFunctionReturnValue<Derived>(derived(), internal::stem_function_sinh<ComplexScalar>);
 }
 
 template <typename Derived>
@@ -571,7 +571,7 @@ const MatrixFunctionReturnValue<Derived> MatrixBase<Derived>::cosh() const
 {
   eigen_assert(rows() == cols());
   typedef typename internal::stem_function<Scalar>::ComplexScalar ComplexScalar;
-  return MatrixFunctionReturnValue<Derived>(derived(), StdStemFunctions<ComplexScalar>::cosh);
+  return MatrixFunctionReturnValue<Derived>(derived(), internal::stem_function_cosh<ComplexScalar>);
 }
 
 } // end namespace Eigen

unsupported/Eigen/src/MatrixFunctions/StemFunction.h

@@ -12,93 +12,105 @@
 
 namespace Eigen { 
 
-/** \ingroup MatrixFunctions_Module 
+namespace internal {
-  * \brief Stem functions corresponding to standard mathematical functions.
+
-  */
+/** \brief The exponential function (and its derivatives). */
 template <typename Scalar>
-class StdStemFunctions : internal::noncopyable
+Scalar stem_function_exp(Scalar x, int)
 {
-  public:
+  using std::exp;
+  return exp(x);
+}
 
-    /** \brief The exponential function (and its derivatives). */
+/** \brief Cosine (and its derivatives). */
-    static Scalar exp(Scalar x, int)
+template <typename Scalar>
-    {
+Scalar stem_function_cos(Scalar x, int n)
-      return std::exp(x);
+{
-    }
+  using std::cos;
+  using std::sin;
+  Scalar res;
 
-    /** \brief Cosine (and its derivatives). */
+  switch (n % 4) {
-    static Scalar cos(Scalar x, int n)
+  case 0: 
-    {
+    res = std::cos(x);
-      Scalar res;
+    break;
-      switch (n % 4) {
+  case 1:
-      case 0: 
+    res = -std::sin(x);
-	res = std::cos(x);
+    break;
-	break;
+  case 2:
-      case 1:
+    res = -std::cos(x);
-	res = -std::sin(x);
+    break;
-	break;
+  case 3:
-      case 2:
+    res = std::sin(x);
-	res = -std::cos(x);
+    break;
-	break;
+  }
-      case 3:
+  return res;
-	res = std::sin(x);
+}
-	break;
-      }
-      return res;
-    }
 
-    /** \brief Sine (and its derivatives). */
+/** \brief Sine (and its derivatives). */
-    static Scalar sin(Scalar x, int n)
+template <typename Scalar>
-    {
+Scalar stem_function_sin(Scalar x, int n)
-      Scalar res;
+{
-      switch (n % 4) {
+  using std::cos;
-      case 0:
+  using std::sin;
-	res = std::sin(x);
+  Scalar res;
-	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). */
+  switch (n % 4) {
-    static Scalar cosh(Scalar x, int n)
+  case 0:
-    {
+    res = std::sin(x);
-      Scalar res;
+    break;
-      switch (n % 2) {
+  case 1:
-      case 0:
+    res = std::cos(x);
-	res = std::cosh(x);
+    break;
-	break;
+  case 2:
-      case 1:
+    res = -std::sin(x);
-	res = std::sinh(x);
+    break;
-	break;
+  case 3:
-      }
+    res = -std::cos(x);
-      return res;
+    break;
-    }
+  }
+  return res;
+}
+
+/** \brief Hyperbolic cosine (and its derivatives). */
+template <typename Scalar>
+Scalar stem_function_cosh(Scalar x, int n)
+{
+  using std::cosh;
+  using std::sinh;
+  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). */
+/** \brief Hyperbolic sine (and its derivatives). */
-    static Scalar sinh(Scalar x, int n)
+template <typename Scalar>
-    {
+Scalar stem_function_sinh(Scalar x, int n)
-      Scalar res;
+{
-      switch (n % 2) {
+  using std::cosh;
-      case 0:
+  using std::sinh;
-	res = std::sinh(x);
+  Scalar res;
-	break;
+  
-      case 1:
+  switch (n % 2) {
-	res = std::cosh(x);
+  case 0:
-	break;
+    res = std::sinh(x);
-      }
+    break;
-      return res;
+  case 1:
-    }
+    res = std::cosh(x);
+    break;
+  }
+  return res;
+}
 
-}; // end of class StdStemFunctions
+} // end namespace internal
 
 } // end namespace Eigen
 

unsupported/test/matrix_function.cpp

@@ -102,7 +102,7 @@ void testMatrixExponential(const MatrixType& A)
   typedef typename NumTraits<Scalar>::Real RealScalar;
   typedef std::complex<RealScalar> ComplexScalar;
 
-  VERIFY_IS_APPROX(A.exp(), A.matrixFunction(StdStemFunctions<ComplexScalar>::exp));
+  VERIFY_IS_APPROX(A.exp(), A.matrixFunction(internal::stem_function_exp<ComplexScalar>));
 }
 
 template<typename MatrixType>