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+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2011 Jitse Niesen <jitse@maths.leeds.ac.uk>
+// Copyright (C) 2011 Chen-Pang He <jdh8@ms63.hinet.net>
+//
+// 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_LOGARITHM
+#define EIGEN_MATRIX_LOGARITHM
+
+#ifndef M_PI
+#define M_PI 3.141592653589793238462643383279503L
+#endif
+
+namespace Eigen {
+
+/** \ingroup MatrixFunctions_Module
+ * \class MatrixLogarithmAtomic
+ * \brief Helper class for computing matrix logarithm of atomic matrices.
+ *
+ * \internal
+ * Here, an atomic matrix is a triangular matrix whose diagonal
+ * entries are close to each other.
+ *
+ * \sa class MatrixFunctionAtomic, MatrixBase::log()
+ */
+template <typename MatrixType>
+class MatrixLogarithmAtomic
+{
+public:
+
+ typedef typename MatrixType::Scalar Scalar;
+ // typedef typename MatrixType::Index Index;
+ typedef typename NumTraits<Scalar>::Real RealScalar;
+ // typedef typename internal::stem_function<Scalar>::type StemFunction;
+ // typedef Matrix<Scalar, MatrixType::RowsAtCompileTime, 1> VectorType;
+
+ /** \brief Constructor. */
+ MatrixLogarithmAtomic() { }
+
+ /** \brief Compute matrix logarithm of atomic matrix
+ * \param[in] A argument of matrix logarithm, should be upper triangular and atomic
+ * \returns The logarithm of \p A.
+ */
+ MatrixType compute(const MatrixType& A);
+
+private:
+
+ void compute2x2(const MatrixType& A, MatrixType& result);
+ void computeBig(const MatrixType& A, MatrixType& result);
+ static Scalar atanh(Scalar x);
+ int getPadeDegree(float normTminusI);
+ int getPadeDegree(double normTminusI);
+ int getPadeDegree(long double normTminusI);
+ void computePade(MatrixType& result, const MatrixType& T, int degree);
+ void computePade3(MatrixType& result, const MatrixType& T);
+ void computePade4(MatrixType& result, const MatrixType& T);
+ void computePade5(MatrixType& result, const MatrixType& T);
+ void computePade6(MatrixType& result, const MatrixType& T);
+ void computePade7(MatrixType& result, const MatrixType& T);
+ void computePade8(MatrixType& result, const MatrixType& T);
+ void computePade9(MatrixType& result, const MatrixType& T);
+ void computePade10(MatrixType& result, const MatrixType& T);
+ void computePade11(MatrixType& result, const MatrixType& T);
+
+ static const int minPadeDegree = 3;
+ static const int maxPadeDegree = std::numeric_limits<RealScalar>::digits<= 24? 5: // single precision
+ std::numeric_limits<RealScalar>::digits<= 53? 7: // double precision
+ std::numeric_limits<RealScalar>::digits<= 64? 8: // extended precision
+ std::numeric_limits<RealScalar>::digits<=106? 10: 11; // double-double or quadruple precision
+
+ // Prevent copying
+ MatrixLogarithmAtomic(const MatrixLogarithmAtomic&);
+ MatrixLogarithmAtomic& operator=(const MatrixLogarithmAtomic&);
+};
+
+/** \brief Compute logarithm of triangular matrix with clustered eigenvalues. */
+template <typename MatrixType>
+MatrixType MatrixLogarithmAtomic<MatrixType>::compute(const MatrixType& A)
+{
+ using std::log;
+ MatrixType result(A.rows(), A.rows());
+ if (A.rows() == 1)
+ result(0,0) = log(A(0,0));
+ else if (A.rows() == 2)
+ compute2x2(A, result);
+ else
+ computeBig(A, result);
+ return result;
+}
+
+/** \brief Compute atanh (inverse hyperbolic tangent). */
+template <typename MatrixType>
+typename MatrixType::Scalar MatrixLogarithmAtomic<MatrixType>::atanh(typename MatrixType::Scalar x)
+{
+ using std::abs;
+ using std::sqrt;
+ if (abs(x) > sqrt(NumTraits<Scalar>::epsilon()))
+ return Scalar(0.5) * log((Scalar(1) + x) / (Scalar(1) - x));
+ else
+ return x + x*x*x / Scalar(3);
+}
+
+/** \brief Compute logarithm of 2x2 triangular matrix. */
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::compute2x2(const MatrixType& A, MatrixType& result)
+{
+ using std::abs;
+ using std::ceil;
+ using std::imag;
+ using std::log;
+
+ Scalar logA00 = log(A(0,0));
+ Scalar logA11 = log(A(1,1));
+
+ result(0,0) = logA00;
+ result(1,0) = Scalar(0);
+ result(1,1) = logA11;
+
+ if (A(0,0) == A(1,1)) {
+ result(0,1) = A(0,1) / A(0,0);
+ } else if ((abs(A(0,0)) < 0.5*abs(A(1,1))) || (abs(A(0,0)) > 2*abs(A(1,1)))) {
+ result(0,1) = A(0,1) * (logA11 - logA00) / (A(1,1) - A(0,0));
+ } else {
+ // computation in previous branch is inaccurate if A(1,1) \approx A(0,0)
+ int unwindingNumber = static_cast<int>(ceil((imag(logA11 - logA00) - M_PI) / (2*M_PI)));
+ Scalar z = (A(1,1) - A(0,0)) / (A(1,1) + A(0,0));
+ result(0,1) = A(0,1) * (Scalar(2) * atanh(z) + Scalar(0,2*M_PI*unwindingNumber)) / (A(1,1) - A(0,0));
+ }
+}
+
+/** \brief Compute logarithm of triangular matrices with size > 2.
+ * \details This uses a inverse scale-and-square algorithm. */
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computeBig(const MatrixType& A, MatrixType& result)
+{
+ int numberOfSquareRoots = 0;
+ int numberOfExtraSquareRoots = 0;
+ int degree;
+ MatrixType T = A;
+ const RealScalar maxNormForPade = maxPadeDegree<= 5? 5.3149729967117310e-1: // single precision
+ maxPadeDegree<= 7? 2.6429608311114350e-1: // double precision
+ maxPadeDegree<= 8? 2.32777776523703892094e-1L: // extended precision
+ maxPadeDegree<=10? 1.05026503471351080481093652651105e-1L: // double-double
+ 1.1880960220216759245467951592883642e-1L; // quadruple precision
+
+ while (true) {
+ RealScalar normTminusI = (T - MatrixType::Identity(T.rows(), T.rows())).cwiseAbs().colwise().sum().maxCoeff();
+ if (normTminusI < maxNormForPade) {
+ degree = getPadeDegree(normTminusI);
+ int degree2 = getPadeDegree(normTminusI / RealScalar(2));
+ if ((degree - degree2 <= 1) || (numberOfExtraSquareRoots == 1))
+ break;
+ ++numberOfExtraSquareRoots;
+ }
+ MatrixType sqrtT;
+ MatrixSquareRootTriangular<MatrixType>(T).compute(sqrtT);
+ T = sqrtT;
+ ++numberOfSquareRoots;
+ }
+
+ computePade(result, T, degree);
+ result *= pow(RealScalar(2), numberOfSquareRoots);
+}
+
+/* \brief Get suitable degree for Pade approximation. (specialized for RealScalar = float) */
+template <typename MatrixType>
+int MatrixLogarithmAtomic<MatrixType>::getPadeDegree(float normTminusI)
+{
+ const float maxNormForPade[] = { 2.5111573934555054e-1 /* degree = 3 */ , 4.0535837411880493e-1,
+ 5.3149729967117310e-1 };
+ for (int degree = 3; degree <= maxPadeDegree; ++degree)
+ if (normTminusI <= maxNormForPade[degree - minPadeDegree])
+ return degree;
+ assert(false); // this line should never be reached
+}
+
+/* \brief Get suitable degree for Pade approximation. (specialized for RealScalar = double) */
+template <typename MatrixType>
+int MatrixLogarithmAtomic<MatrixType>::getPadeDegree(double normTminusI)
+{
+ const double maxNormForPade[] = { 1.6206284795015624e-2 /* degree = 3 */ , 5.3873532631381171e-2,
+ 1.1352802267628681e-1, 1.8662860613541288e-1, 2.642960831111435e-1 };
+ for (int degree = 3; degree <= maxPadeDegree; ++degree)
+ if (normTminusI <= maxNormForPade[degree - minPadeDegree])
+ return degree;
+ assert(false); // this line should never be reached
+}
+
+/* \brief Get suitable degree for Pade approximation. (specialized for RealScalar = long double) */
+template <typename MatrixType>
+int MatrixLogarithmAtomic<MatrixType>::getPadeDegree(long double normTminusI)
+{
+#if LDBL_MANT_DIG == 53 // double precision
+ const double maxNormForPade[] = { 1.6206284795015624e-2 /* degree = 3 */ , 5.3873532631381171e-2,
+ 1.1352802267628681e-1, 1.8662860613541288e-1, 2.642960831111435e-1 };
+#elif LDBL_MANT_DIG <= 64 // extended precision
+ const double maxNormForPade[] = { 5.48256690357782863103e-3 /* degree = 3 */, 2.34559162387971167321e-2,
+ 5.84603923897347449857e-2, 1.08486423756725170223e-1, 1.68385767881294446649e-1,
+ 2.32777776523703892094e-1 };
+#elif LDBL_MANT_DIG <= 106 // double-double
+ const double maxNormForPade[] = { 8.58970550342939562202529664318890e-5 /* degree = 3 */,
+ 9.34074328446359654039446552677759e-4, 4.26117194647672175773064114582860e-3,
+ 1.21546224740281848743149666560464e-2, 2.61100544998339436713088248557444e-2,
+ 4.66170074627052749243018566390567e-2, 7.32585144444135027565872014932387e-2,
+ 1.05026503471351080481093652651105e-1 };
+#else // quadruple precision
+ const double maxNormForPade[] = { 4.7419931187193005048501568167858103e-5 /* degree = 3 */,
+ 5.8853168473544560470387769480192666e-4, 2.9216120366601315391789493628113520e-3,
+ 8.8415758124319434347116734705174308e-3, 1.9850836029449446668518049562565291e-2,
+ 3.6688019729653446926585242192447447e-2, 5.9290962294020186998954055264528393e-2,
+ 8.6998436081634343903250580992127677e-2, 1.1880960220216759245467951592883642e-1 };
+#endif
+ for (int degree = 3; degree <= maxPadeDegree; ++degree)
+ if (normTminusI <= maxNormForPade[degree - minPadeDegree])
+ return degree;
+ assert(false); // this line should never be reached
+}
+
+/* \brief Compute Pade approximation to matrix logarithm */
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade(MatrixType& result, const MatrixType& T, int degree)
+{
+ switch (degree) {
+ case 3: computePade3(result, T); break;
+ case 4: computePade4(result, T); break;
+ case 5: computePade5(result, T); break;
+ case 6: computePade6(result, T); break;
+ case 7: computePade7(result, T); break;
+ case 8: computePade8(result, T); break;
+ case 9: computePade9(result, T); break;
+ case 10: computePade10(result, T); break;
+ case 11: computePade11(result, T); break;
+ default: assert(false); // should never happen
+ }
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade3(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 3;
+ const RealScalar nodes[] = { 0.1127016653792583114820734600217600L, 0.5000000000000000000000000000000000L,
+ 0.8872983346207416885179265399782400L };
+ const RealScalar weights[] = { 0.2777777777777777777777777777777778L, 0.4444444444444444444444444444444444L,
+ 0.2777777777777777777777777777777778L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade4(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 4;
+ const RealScalar nodes[] = { 0.0694318442029737123880267555535953L, 0.3300094782075718675986671204483777L,
+ 0.6699905217924281324013328795516223L, 0.9305681557970262876119732444464048L };
+ const RealScalar weights[] = { 0.1739274225687269286865319746109997L, 0.3260725774312730713134680253890003L,
+ 0.3260725774312730713134680253890003L, 0.1739274225687269286865319746109997L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade5(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 5;
+ const RealScalar nodes[] = { 0.0469100770306680036011865608503035L, 0.2307653449471584544818427896498956L,
+ 0.5000000000000000000000000000000000L, 0.7692346550528415455181572103501044L,
+ 0.9530899229693319963988134391496965L };
+ const RealScalar weights[] = { 0.1184634425280945437571320203599587L, 0.2393143352496832340206457574178191L,
+ 0.2844444444444444444444444444444444L, 0.2393143352496832340206457574178191L,
+ 0.1184634425280945437571320203599587L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade6(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 6;
+ const RealScalar nodes[] = { 0.0337652428984239860938492227530027L, 0.1693953067668677431693002024900473L,
+ 0.3806904069584015456847491391596440L, 0.6193095930415984543152508608403560L,
+ 0.8306046932331322568306997975099527L, 0.9662347571015760139061507772469973L };
+ const RealScalar weights[] = { 0.0856622461895851725201480710863665L, 0.1803807865240693037849167569188581L,
+ 0.2339569672863455236949351719947755L, 0.2339569672863455236949351719947755L,
+ 0.1803807865240693037849167569188581L, 0.0856622461895851725201480710863665L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade7(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 7;
+ const RealScalar nodes[] = { 0.0254460438286207377369051579760744L, 0.1292344072003027800680676133596058L,
+ 0.2970774243113014165466967939615193L, 0.5000000000000000000000000000000000L,
+ 0.7029225756886985834533032060384807L, 0.8707655927996972199319323866403942L,
+ 0.9745539561713792622630948420239256L };
+ const RealScalar weights[] = { 0.0647424830844348466353057163395410L, 0.1398526957446383339507338857118898L,
+ 0.1909150252525594724751848877444876L, 0.2089795918367346938775510204081633L,
+ 0.1909150252525594724751848877444876L, 0.1398526957446383339507338857118898L,
+ 0.0647424830844348466353057163395410L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade8(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 8;
+ const RealScalar nodes[] = { 0.0198550717512318841582195657152635L, 0.1016667612931866302042230317620848L,
+ 0.2372337950418355070911304754053768L, 0.4082826787521750975302619288199080L,
+ 0.5917173212478249024697380711800920L, 0.7627662049581644929088695245946232L,
+ 0.8983332387068133697957769682379152L, 0.9801449282487681158417804342847365L };
+ const RealScalar weights[] = { 0.0506142681451881295762656771549811L, 0.1111905172266872352721779972131204L,
+ 0.1568533229389436436689811009933007L, 0.1813418916891809914825752246385978L,
+ 0.1813418916891809914825752246385978L, 0.1568533229389436436689811009933007L,
+ 0.1111905172266872352721779972131204L, 0.0506142681451881295762656771549811L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade9(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 9;
+ const RealScalar nodes[] = { 0.0159198802461869550822118985481636L, 0.0819844463366821028502851059651326L,
+ 0.1933142836497048013456489803292629L, 0.3378732882980955354807309926783317L,
+ 0.5000000000000000000000000000000000L, 0.6621267117019044645192690073216683L,
+ 0.8066857163502951986543510196707371L, 0.9180155536633178971497148940348674L,
+ 0.9840801197538130449177881014518364L };
+ const RealScalar weights[] = { 0.0406371941807872059859460790552618L, 0.0903240803474287020292360156214564L,
+ 0.1303053482014677311593714347093164L, 0.1561735385200014200343152032922218L,
+ 0.1651196775006298815822625346434870L, 0.1561735385200014200343152032922218L,
+ 0.1303053482014677311593714347093164L, 0.0903240803474287020292360156214564L,
+ 0.0406371941807872059859460790552618L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade10(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 10;
+ const RealScalar nodes[] = { 0.0130467357414141399610179939577740L, 0.0674683166555077446339516557882535L,
+ 0.1602952158504877968828363174425632L, 0.2833023029353764046003670284171079L,
+ 0.4255628305091843945575869994351400L, 0.5744371694908156054424130005648600L,
+ 0.7166976970646235953996329715828921L, 0.8397047841495122031171636825574368L,
+ 0.9325316833444922553660483442117465L, 0.9869532642585858600389820060422260L };
+ const RealScalar weights[] = { 0.0333356721543440687967844049466659L, 0.0747256745752902965728881698288487L,
+ 0.1095431812579910219977674671140816L, 0.1346333596549981775456134607847347L,
+ 0.1477621123573764350869464973256692L, 0.1477621123573764350869464973256692L,
+ 0.1346333596549981775456134607847347L, 0.1095431812579910219977674671140816L,
+ 0.0747256745752902965728881698288487L, 0.0333356721543440687967844049466659L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+template <typename MatrixType>
+void MatrixLogarithmAtomic<MatrixType>::computePade11(MatrixType& result, const MatrixType& T)
+{
+ const int degree = 11;
+ const RealScalar nodes[] = { 0.0108856709269715035980309994385713L, 0.0564687001159523504624211153480364L,
+ 0.1349239972129753379532918739844233L, 0.2404519353965940920371371652706952L,
+ 0.3652284220238275138342340072995692L, 0.5000000000000000000000000000000000L,
+ 0.6347715779761724861657659927004308L, 0.7595480646034059079628628347293048L,
+ 0.8650760027870246620467081260155767L, 0.9435312998840476495375788846519636L,
+ 0.9891143290730284964019690005614287L };
+ const RealScalar weights[] = { 0.0278342835580868332413768602212743L, 0.0627901847324523123173471496119701L,
+ 0.0931451054638671257130488207158280L, 0.1165968822959952399592618524215876L,
+ 0.1314022722551233310903444349452546L, 0.1364625433889503153572417641681711L,
+ 0.1314022722551233310903444349452546L, 0.1165968822959952399592618524215876L,
+ 0.0931451054638671257130488207158280L, 0.0627901847324523123173471496119701L,
+ 0.0278342835580868332413768602212743L };
+ assert(degree <= maxPadeDegree);
+ MatrixType TminusI = T - MatrixType::Identity(T.rows(), T.rows());
+ result.setZero(T.rows(), T.rows());
+ for (int k = 0; k < degree; ++k)
+ result += weights[k] * (MatrixType::Identity(T.rows(), T.rows()) + nodes[k] * TminusI)
+ .template triangularView<Upper>().solve(TminusI);
+}
+
+/** \ingroup MatrixFunctions_Module
+ *
+ * \brief Proxy for the matrix logarithm 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::matrixLogarithm() and most of the time this is the
+ * only way it is used.
+ */
+template<typename Derived> class MatrixLogarithmReturnValue
+: public ReturnByValue<MatrixLogarithmReturnValue<Derived> >
+{
+public:
+
+ typedef typename Derived::Scalar Scalar;
+ typedef typename Derived::Index Index;
+
+ /** \brief Constructor.
+ *
+ * \param[in] A %Matrix (expression) forming the argument of the matrix logarithm.
+ */
+ MatrixLogarithmReturnValue(const Derived& A) : m_A(A) { }
+
+ /** \brief Compute the matrix logarithm.
+ *
+ * \param[out] result Logarithm of \p A, where \A is as specified 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 MatrixLogarithmAtomic<DynMatrixType> AtomicType;
+ AtomicType atomic;
+
+ 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;
+
+ MatrixLogarithmReturnValue& operator=(const MatrixLogarithmReturnValue&);
+};
+
+namespace internal {
+ template<typename Derived>
+ struct traits<MatrixLogarithmReturnValue<Derived> >
+ {
+ typedef typename Derived::PlainObject ReturnType;
+ };
+}
+
+
+/********** MatrixBase method **********/
+
+
+template <typename Derived>
+const MatrixLogarithmReturnValue<Derived> MatrixBase<Derived>::log() const
+{
+ eigen_assert(rows() == cols());
+ return MatrixLogarithmReturnValue<Derived>(derived());
+}
+
+} // end namespace Eigen
+
+#endif // EIGEN_MATRIX_LOGARITHM