Squashed 'third_party/eigen/' content from commit 61d72f6

Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h b/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h
new file mode 100644
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+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h
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+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009-2011 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_MATRIX_FUNCTION
+#define EIGEN_MATRIX_FUNCTION
+
+#include "StemFunction.h"
+#include "MatrixFunctionAtomic.h"
+
+
+namespace Eigen { 
+
+/** \ingroup MatrixFunctions_Module
+  * \brief Class for computing matrix functions.
+  * \tparam  MatrixType  type of the argument of the matrix function,
+  *                      expected to be an instantiation of the Matrix class template.
+  * \tparam  AtomicType  type for computing matrix function of atomic blocks.
+  * \tparam  IsComplex   used internally to select correct specialization.
+  *
+  * This class implements the Schur-Parlett algorithm for computing matrix functions. The spectrum of the
+  * matrix is divided in clustered of eigenvalues that lies close together. This class delegates the
+  * computation of the matrix function on every block corresponding to these clusters to an object of type
+  * \p AtomicType and uses these results to compute the matrix function of the whole matrix. The class
+  * \p AtomicType should have a \p compute() member function for computing the matrix function of a block.
+  *
+  * \sa class MatrixFunctionAtomic, class MatrixLogarithmAtomic
+  */
+template <typename MatrixType, 
+	  typename AtomicType,  
+          int IsComplex = NumTraits<typename internal::traits<MatrixType>::Scalar>::IsComplex>
+class MatrixFunction
+{  
+  public:
+
+    /** \brief Constructor. 
+      *
+      * \param[in]  A       argument of matrix function, should be a square matrix.
+      * \param[in]  atomic  class for computing matrix function of atomic blocks.
+      *
+      * The class stores references to \p A and \p atomic, so they should not be
+      * changed (or destroyed) before compute() is called.
+      */
+    MatrixFunction(const MatrixType& A, AtomicType& atomic);
+
+    /** \brief Compute the matrix function.
+      *
+      * \param[out] result  the function \p f applied to \p A, as
+      * specified in the constructor.
+      *
+      * See MatrixBase::matrixFunction() for details on how this computation
+      * is implemented.
+      */
+    template <typename ResultType> 
+    void compute(ResultType &result);    
+};
+
+
+/** \internal \ingroup MatrixFunctions_Module 
+  * \brief Partial specialization of MatrixFunction for real matrices
+  */
+template <typename MatrixType, typename AtomicType>
+class MatrixFunction<MatrixType, AtomicType, 0>
+{  
+  private:
+
+    typedef internal::traits<MatrixType> Traits;
+    typedef typename Traits::Scalar Scalar;
+    static const int Rows = Traits::RowsAtCompileTime;
+    static const int Cols = Traits::ColsAtCompileTime;
+    static const int Options = MatrixType::Options;
+    static const int MaxRows = Traits::MaxRowsAtCompileTime;
+    static const int MaxCols = Traits::MaxColsAtCompileTime;
+
+    typedef std::complex<Scalar> ComplexScalar;
+    typedef Matrix<ComplexScalar, Rows, Cols, Options, MaxRows, MaxCols> ComplexMatrix;
+
+  public:
+
+    /** \brief Constructor. 
+      *
+      * \param[in]  A       argument of matrix function, should be a square matrix.
+      * \param[in]  atomic  class for computing matrix function of atomic blocks.
+      */
+    MatrixFunction(const MatrixType& A, AtomicType& atomic) : m_A(A), m_atomic(atomic) { }
+
+    /** \brief Compute the matrix function.
+      *
+      * \param[out] result  the function \p f applied to \p A, as
+      * specified in the constructor.
+      *
+      * This function converts the real matrix \c A to a complex matrix,
+      * uses MatrixFunction<MatrixType,1> and then converts the result back to
+      * a real matrix.
+      */
+    template <typename ResultType>
+    void compute(ResultType& result) 
+    {
+      ComplexMatrix CA = m_A.template cast<ComplexScalar>();
+      ComplexMatrix Cresult;
+      MatrixFunction<ComplexMatrix, AtomicType> mf(CA, m_atomic);
+      mf.compute(Cresult);
+      result = Cresult.real();
+    }
+
+  private:
+    typename internal::nested<MatrixType>::type m_A; /**< \brief Reference to argument of matrix function. */
+    AtomicType& m_atomic; /**< \brief Class for computing matrix function of atomic blocks. */
+
+    MatrixFunction& operator=(const MatrixFunction&);
+};
+
+      
+/** \internal \ingroup MatrixFunctions_Module 
+  * \brief Partial specialization of MatrixFunction for complex matrices
+  */
+template <typename MatrixType, typename AtomicType>
+class MatrixFunction<MatrixType, AtomicType, 1>
+{
+  private:
+
+    typedef internal::traits<MatrixType> Traits;
+    typedef typename MatrixType::Scalar Scalar;
+    typedef typename MatrixType::Index Index;
+    static const int RowsAtCompileTime = Traits::RowsAtCompileTime;
+    static const int ColsAtCompileTime = Traits::ColsAtCompileTime;
+    static const int Options = MatrixType::Options;
+    typedef typename NumTraits<Scalar>::Real RealScalar;
+    typedef Matrix<Scalar, Traits::RowsAtCompileTime, 1> VectorType;
+    typedef Matrix<Index, Traits::RowsAtCompileTime, 1> IntVectorType;
+    typedef Matrix<Index, Dynamic, 1> DynamicIntVectorType;
+    typedef std::list<Scalar> Cluster;
+    typedef std::list<Cluster> ListOfClusters;
+    typedef Matrix<Scalar, Dynamic, Dynamic, Options, RowsAtCompileTime, ColsAtCompileTime> DynMatrixType;
+
+  public:
+
+    MatrixFunction(const MatrixType& A, AtomicType& atomic);
+    template <typename ResultType> void compute(ResultType& result);
+
+  private:
+
+    void computeSchurDecomposition();
+    void partitionEigenvalues();
+    typename ListOfClusters::iterator findCluster(Scalar key);
+    void computeClusterSize();
+    void computeBlockStart();
+    void constructPermutation();
+    void permuteSchur();
+    void swapEntriesInSchur(Index index);
+    void computeBlockAtomic();
+    Block<MatrixType> block(MatrixType& A, Index i, Index j);
+    void computeOffDiagonal();
+    DynMatrixType solveTriangularSylvester(const DynMatrixType& A, const DynMatrixType& B, const DynMatrixType& C);
+
+    typename internal::nested<MatrixType>::type m_A; /**< \brief Reference to argument of matrix function. */
+    AtomicType& m_atomic; /**< \brief Class for computing matrix function of atomic blocks. */
+    MatrixType m_T; /**< \brief Triangular part of Schur decomposition */
+    MatrixType m_U; /**< \brief Unitary part of Schur decomposition */
+    MatrixType m_fT; /**< \brief %Matrix function applied to #m_T */
+    ListOfClusters m_clusters; /**< \brief Partition of eigenvalues into clusters of ei'vals "close" to each other */
+    DynamicIntVectorType m_eivalToCluster; /**< \brief m_eivalToCluster[i] = j means i-th ei'val is in j-th cluster */
+    DynamicIntVectorType m_clusterSize; /**< \brief Number of eigenvalues in each clusters  */
+    DynamicIntVectorType m_blockStart; /**< \brief Row index at which block corresponding to i-th cluster starts */
+    IntVectorType m_permutation; /**< \brief Permutation which groups ei'vals in the same cluster together */
+
+    /** \brief Maximum distance allowed between eigenvalues to be considered "close".
+      *
+      * This is morally a \c static \c const \c Scalar, but only
+      * integers can be static constant class members in C++. The
+      * separation constant is set to 0.1, a value taken from the
+      * paper by Davies and Higham. */
+    static const RealScalar separation() { return static_cast<RealScalar>(0.1); }
+
+    MatrixFunction& operator=(const MatrixFunction&);
+};
+
+/** \brief Constructor. 
+ *
+ * \param[in]  A       argument of matrix function, should be a square matrix.
+ * \param[in]  atomic  class for computing matrix function of atomic blocks.
+ */
+template <typename MatrixType, typename AtomicType>
+MatrixFunction<MatrixType,AtomicType,1>::MatrixFunction(const MatrixType& A, AtomicType& atomic)
+  : m_A(A), m_atomic(atomic)
+{
+  /* empty body */
+}
+
+/** \brief Compute the matrix function.
+  *
+  * \param[out] result  the function \p f applied to \p A, as
+  * specified in the constructor.
+  */
+template <typename MatrixType, typename AtomicType>
+template <typename ResultType>
+void MatrixFunction<MatrixType,AtomicType,1>::compute(ResultType& result) 
+{
+  computeSchurDecomposition();
+  partitionEigenvalues();
+  computeClusterSize();
+  computeBlockStart();
+  constructPermutation();
+  permuteSchur();
+  computeBlockAtomic();
+  computeOffDiagonal();
+  result = m_U * (m_fT.template triangularView<Upper>() * m_U.adjoint());
+}
+
+/** \brief Store the Schur decomposition of #m_A in #m_T and #m_U */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::computeSchurDecomposition()
+{
+  const ComplexSchur<MatrixType> schurOfA(m_A);  
+  m_T = schurOfA.matrixT();
+  m_U = schurOfA.matrixU();
+}
+
+/** \brief Partition eigenvalues in clusters of ei'vals close to each other
+  * 
+  * This function computes #m_clusters. This is a partition of the
+  * eigenvalues of #m_T in clusters, such that
+  * # Any eigenvalue in a certain cluster is at most separation() away
+  *   from another eigenvalue in the same cluster.
+  * # The distance between two eigenvalues in different clusters is
+  *   more than separation().
+  * The implementation follows Algorithm 4.1 in the paper of Davies
+  * and Higham. 
+  */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::partitionEigenvalues()
+{
+  using std::abs;
+  const Index rows = m_T.rows();
+  VectorType diag = m_T.diagonal(); // contains eigenvalues of A
+
+  for (Index i=0; i<rows; ++i) {
+    // Find set containing diag(i), adding a new set if necessary
+    typename ListOfClusters::iterator qi = findCluster(diag(i));
+    if (qi == m_clusters.end()) {
+      Cluster l;
+      l.push_back(diag(i));
+      m_clusters.push_back(l);
+      qi = m_clusters.end();
+      --qi;
+    }
+
+    // Look for other element to add to the set
+    for (Index j=i+1; j<rows; ++j) {
+      if (abs(diag(j) - diag(i)) <= separation() && std::find(qi->begin(), qi->end(), diag(j)) == qi->end()) {
+        typename ListOfClusters::iterator qj = findCluster(diag(j));
+        if (qj == m_clusters.end()) {
+          qi->push_back(diag(j));
+        } else {
+          qi->insert(qi->end(), qj->begin(), qj->end());
+          m_clusters.erase(qj);
+        }
+      }
+    }
+  }
+}
+
+/** \brief Find cluster in #m_clusters containing some value 
+  * \param[in] key Value to find
+  * \returns Iterator to cluster containing \c key, or
+  * \c m_clusters.end() if no cluster in m_clusters contains \c key.
+  */
+template <typename MatrixType, typename AtomicType>
+typename MatrixFunction<MatrixType,AtomicType,1>::ListOfClusters::iterator MatrixFunction<MatrixType,AtomicType,1>::findCluster(Scalar key)
+{
+  typename Cluster::iterator j;
+  for (typename ListOfClusters::iterator i = m_clusters.begin(); i != m_clusters.end(); ++i) {
+    j = std::find(i->begin(), i->end(), key);
+    if (j != i->end())
+      return i;
+  }
+  return m_clusters.end();
+}
+
+/** \brief Compute #m_clusterSize and #m_eivalToCluster using #m_clusters */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::computeClusterSize()
+{
+  const Index rows = m_T.rows();
+  VectorType diag = m_T.diagonal(); 
+  const Index numClusters = static_cast<Index>(m_clusters.size());
+
+  m_clusterSize.setZero(numClusters);
+  m_eivalToCluster.resize(rows);
+  Index clusterIndex = 0;
+  for (typename ListOfClusters::const_iterator cluster = m_clusters.begin(); cluster != m_clusters.end(); ++cluster) {
+    for (Index i = 0; i < diag.rows(); ++i) {
+      if (std::find(cluster->begin(), cluster->end(), diag(i)) != cluster->end()) {
+        ++m_clusterSize[clusterIndex];
+        m_eivalToCluster[i] = clusterIndex;
+      }
+    }
+    ++clusterIndex;
+  }
+}
+
+/** \brief Compute #m_blockStart using #m_clusterSize */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::computeBlockStart()
+{
+  m_blockStart.resize(m_clusterSize.rows());
+  m_blockStart(0) = 0;
+  for (Index i = 1; i < m_clusterSize.rows(); i++) {
+    m_blockStart(i) = m_blockStart(i-1) + m_clusterSize(i-1);
+  }
+}
+
+/** \brief Compute #m_permutation using #m_eivalToCluster and #m_blockStart */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::constructPermutation()
+{
+  DynamicIntVectorType indexNextEntry = m_blockStart;
+  m_permutation.resize(m_T.rows());
+  for (Index i = 0; i < m_T.rows(); i++) {
+    Index cluster = m_eivalToCluster[i];
+    m_permutation[i] = indexNextEntry[cluster];
+    ++indexNextEntry[cluster];
+  }
+}  
+
+/** \brief Permute Schur decomposition in #m_U and #m_T according to #m_permutation */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::permuteSchur()
+{
+  IntVectorType p = m_permutation;
+  for (Index i = 0; i < p.rows() - 1; i++) {
+    Index j;
+    for (j = i; j < p.rows(); j++) {
+      if (p(j) == i) break;
+    }
+    eigen_assert(p(j) == i);
+    for (Index k = j-1; k >= i; k--) {
+      swapEntriesInSchur(k);
+      std::swap(p.coeffRef(k), p.coeffRef(k+1));
+    }
+  }
+}
+
+/** \brief Swap rows \a index and \a index+1 in Schur decomposition in #m_U and #m_T */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::swapEntriesInSchur(Index index)
+{
+  JacobiRotation<Scalar> rotation;
+  rotation.makeGivens(m_T(index, index+1), m_T(index+1, index+1) - m_T(index, index));
+  m_T.applyOnTheLeft(index, index+1, rotation.adjoint());
+  m_T.applyOnTheRight(index, index+1, rotation);
+  m_U.applyOnTheRight(index, index+1, rotation);
+}  
+
+/** \brief Compute block diagonal part of #m_fT.
+  *
+  * This routine computes the matrix function applied to the block diagonal part of #m_T, with the blocking
+  * given by #m_blockStart. The matrix function of each diagonal block is computed by #m_atomic. The
+  * off-diagonal parts of #m_fT are set to zero.
+  */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::computeBlockAtomic()
+{ 
+  m_fT.resize(m_T.rows(), m_T.cols());
+  m_fT.setZero();
+  for (Index i = 0; i < m_clusterSize.rows(); ++i) {
+    block(m_fT, i, i) = m_atomic.compute(block(m_T, i, i));
+  }
+}
+
+/** \brief Return block of matrix according to blocking given by #m_blockStart */
+template <typename MatrixType, typename AtomicType>
+Block<MatrixType> MatrixFunction<MatrixType,AtomicType,1>::block(MatrixType& A, Index i, Index j)
+{
+  return A.block(m_blockStart(i), m_blockStart(j), m_clusterSize(i), m_clusterSize(j));
+}
+
+/** \brief Compute part of #m_fT above block diagonal.
+  *
+  * This routine assumes that the block diagonal part of #m_fT (which
+  * equals the matrix function applied to #m_T) has already been computed and computes
+  * the part above the block diagonal. The part below the diagonal is
+  * zero, because #m_T is upper triangular.
+  */
+template <typename MatrixType, typename AtomicType>
+void MatrixFunction<MatrixType,AtomicType,1>::computeOffDiagonal()
+{ 
+  for (Index diagIndex = 1; diagIndex < m_clusterSize.rows(); diagIndex++) {
+    for (Index blockIndex = 0; blockIndex < m_clusterSize.rows() - diagIndex; blockIndex++) {
+      // compute (blockIndex, blockIndex+diagIndex) block
+      DynMatrixType A = block(m_T, blockIndex, blockIndex);
+      DynMatrixType B = -block(m_T, blockIndex+diagIndex, blockIndex+diagIndex);
+      DynMatrixType C = block(m_fT, blockIndex, blockIndex) * block(m_T, blockIndex, blockIndex+diagIndex);
+      C -= block(m_T, blockIndex, blockIndex+diagIndex) * block(m_fT, blockIndex+diagIndex, blockIndex+diagIndex);
+      for (Index k = blockIndex + 1; k < blockIndex + diagIndex; k++) {
+	C += block(m_fT, blockIndex, k) * block(m_T, k, blockIndex+diagIndex);
+	C -= block(m_T, blockIndex, k) * block(m_fT, k, blockIndex+diagIndex);
+      }
+      block(m_fT, blockIndex, blockIndex+diagIndex) = solveTriangularSylvester(A, B, C);
+    }
+  }
+}
+
+/** \brief Solve a triangular Sylvester equation AX + XB = C 
+  *
+  * \param[in]  A  the matrix A; should be square and upper triangular
+  * \param[in]  B  the matrix B; should be square and upper triangular
+  * \param[in]  C  the matrix C; should have correct size.
+  *
+  * \returns the solution X.
+  *
+  * If A is m-by-m and B is n-by-n, then both C and X are m-by-n. 
+  * The (i,j)-th component of the Sylvester equation is
+  * \f[ 
+  *     \sum_{k=i}^m A_{ik} X_{kj} + \sum_{k=1}^j X_{ik} B_{kj} = C_{ij}. 
+  * \f]
+  * This can be re-arranged to yield:
+  * \f[ 
+  *     X_{ij} = \frac{1}{A_{ii} + B_{jj}} \Bigl( C_{ij}
+  *     - \sum_{k=i+1}^m A_{ik} X_{kj} - \sum_{k=1}^{j-1} X_{ik} B_{kj} \Bigr).
+  * \f]
+  * It is assumed that A and B are such that the numerator is never
+  * zero (otherwise the Sylvester equation does not have a unique
+  * solution). In that case, these equations can be evaluated in the
+  * order \f$ i=m,\ldots,1 \f$ and \f$ j=1,\ldots,n \f$.
+  */
+template <typename MatrixType, typename AtomicType>
+typename MatrixFunction<MatrixType,AtomicType,1>::DynMatrixType MatrixFunction<MatrixType,AtomicType,1>::solveTriangularSylvester(
+  const DynMatrixType& A, 
+  const DynMatrixType& B, 
+  const DynMatrixType& C)
+{
+  eigen_assert(A.rows() == A.cols());
+  eigen_assert(A.isUpperTriangular());
+  eigen_assert(B.rows() == B.cols());
+  eigen_assert(B.isUpperTriangular());
+  eigen_assert(C.rows() == A.rows());
+  eigen_assert(C.cols() == B.rows());
+
+  Index m = A.rows();
+  Index n = B.rows();
+  DynMatrixType X(m, n);
+
+  for (Index i = m - 1; i >= 0; --i) {
+    for (Index j = 0; j < n; ++j) {
+
+      // Compute AX = \sum_{k=i+1}^m A_{ik} X_{kj}
+      Scalar AX;
+      if (i == m - 1) {
+	AX = 0; 
+      } else {
+	Matrix<Scalar,1,1> AXmatrix = A.row(i).tail(m-1-i) * X.col(j).tail(m-1-i);
+	AX = AXmatrix(0,0);
+      }
+
+      // Compute XB = \sum_{k=1}^{j-1} X_{ik} B_{kj}
+      Scalar XB;
+      if (j == 0) {
+	XB = 0; 
+      } else {
+	Matrix<Scalar,1,1> XBmatrix = X.row(i).head(j) * B.col(j).head(j);
+	XB = XBmatrix(0,0);
+      }
+
+      X(i,j) = (C(i,j) - AX - XB) / (A(i,i) + B(j,j));
+    }
+  }
+  return X;
+}
+
+/** \ingroup MatrixFunctions_Module
+  *
+  * \brief Proxy for the matrix function of some matrix (expression).
+  *
+  * \tparam Derived  Type of the argument to the matrix function.
+  *
+  * This class holds the argument to the matrix function until it is
+  * assigned or evaluated for some other reason (so the argument
+  * should not be changed in the meantime). It is the return type of
+  * matrixBase::matrixFunction() and related functions and most of the
+  * time this is the only way it is used.
+  */
+template<typename Derived> class MatrixFunctionReturnValue
+: public ReturnByValue<MatrixFunctionReturnValue<Derived> >
+{
+  public:
+
+    typedef typename Derived::Scalar Scalar;
+    typedef typename Derived::Index Index;
+    typedef typename internal::stem_function<Scalar>::type StemFunction;
+
+   /** \brief Constructor.
+      *
+      * \param[in] A  %Matrix (expression) forming the argument of the
+      * matrix function.
+      * \param[in] f  Stem function for matrix function under consideration.
+      */
+    MatrixFunctionReturnValue(const Derived& A, StemFunction f) : m_A(A), m_f(f) { }
+
+    /** \brief Compute the matrix function.
+      *
+      * \param[out] result \p f applied to \p A, where \p f and \p A
+      * are as in the constructor.
+      */
+    template <typename ResultType>
+    inline void evalTo(ResultType& result) const
+    {
+      typedef typename Derived::PlainObject PlainObject;
+      typedef internal::traits<PlainObject> Traits;
+      static const int RowsAtCompileTime = Traits::RowsAtCompileTime;
+      static const int ColsAtCompileTime = Traits::ColsAtCompileTime;
+      static const int Options = PlainObject::Options;
+      typedef std::complex<typename NumTraits<Scalar>::Real> ComplexScalar;
+      typedef Matrix<ComplexScalar, Dynamic, Dynamic, Options, RowsAtCompileTime, ColsAtCompileTime> DynMatrixType;
+      typedef MatrixFunctionAtomic<DynMatrixType> AtomicType;
+      AtomicType atomic(m_f);
+
+      const PlainObject Aevaluated = m_A.eval();
+      MatrixFunction<PlainObject, AtomicType> mf(Aevaluated, atomic);
+      mf.compute(result);
+    }
+
+    Index rows() const { return m_A.rows(); }
+    Index cols() const { return m_A.cols(); }
+
+  private:
+    typename internal::nested<Derived>::type m_A;
+    StemFunction *m_f;
+
+    MatrixFunctionReturnValue& operator=(const MatrixFunctionReturnValue&);
+};
+
+namespace internal {
+template<typename Derived>
+struct traits<MatrixFunctionReturnValue<Derived> >
+{
+  typedef typename Derived::PlainObject ReturnType;
+};
+}
+
+
+/********** MatrixBase methods **********/
+
+
+template <typename Derived>
+const MatrixFunctionReturnValue<Derived> MatrixBase<Derived>::matrixFunction(typename internal::stem_function<typename internal::traits<Derived>::Scalar>::type f) const
+{
+  eigen_assert(rows() == cols());
+  return MatrixFunctionReturnValue<Derived>(derived(), f);
+}
+
+template <typename Derived>
+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);
+}
+
+template <typename Derived>
+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);
+}
+
+template <typename Derived>
+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);
+}
+
+template <typename Derived>
+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);
+}
+
+} // end namespace Eigen
+
+#endif // EIGEN_MATRIX_FUNCTION