| // This file is part of Eigen, a lightweight C++ template library | 
 | // for linear algebra. | 
 | // | 
 | // Copyright (C) 2008-2009 Gael Guennebaud <gael.guennebaud@inria.fr> | 
 | // Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com> | 
 | // | 
 | // 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_FULLPIVOTINGHOUSEHOLDERQR_H | 
 | #define EIGEN_FULLPIVOTINGHOUSEHOLDERQR_H | 
 |  | 
 | #include "./InternalHeaderCheck.h" | 
 |  | 
 | namespace Eigen {  | 
 |  | 
 | namespace internal { | 
 |  | 
 | template<typename MatrixType_> struct traits<FullPivHouseholderQR<MatrixType_> > | 
 |  : traits<MatrixType_> | 
 | { | 
 |   typedef MatrixXpr XprKind; | 
 |   typedef SolverStorage StorageKind; | 
 |   typedef int StorageIndex; | 
 |   enum { Flags = 0 }; | 
 | }; | 
 |  | 
 | template<typename MatrixType> struct FullPivHouseholderQRMatrixQReturnType; | 
 |  | 
 | template<typename MatrixType> | 
 | struct traits<FullPivHouseholderQRMatrixQReturnType<MatrixType> > | 
 | { | 
 |   typedef typename MatrixType::PlainObject ReturnType; | 
 | }; | 
 |  | 
 | } // end namespace internal | 
 |  | 
 | /** \ingroup QR_Module | 
 |   * | 
 |   * \class FullPivHouseholderQR | 
 |   * | 
 |   * \brief Householder rank-revealing QR decomposition of a matrix with full pivoting | 
 |   * | 
 |   * \tparam MatrixType_ the type of the matrix of which we are computing the QR decomposition | 
 |   * | 
 |   * This class performs a rank-revealing QR decomposition of a matrix \b A into matrices \b P, \b P', \b Q and \b R | 
 |   * such that  | 
 |   * \f[ | 
 |   *  \mathbf{P} \, \mathbf{A} \, \mathbf{P}' = \mathbf{Q} \, \mathbf{R} | 
 |   * \f] | 
 |   * by using Householder transformations. Here, \b P and \b P' are permutation matrices, \b Q a unitary matrix  | 
 |   * and \b R an upper triangular matrix. | 
 |   * | 
 |   * This decomposition performs a very prudent full pivoting in order to be rank-revealing and achieve optimal | 
 |   * numerical stability. The trade-off is that it is slower than HouseholderQR and ColPivHouseholderQR. | 
 |   * | 
 |   * This class supports the \link InplaceDecomposition inplace decomposition \endlink mechanism. | 
 |   *  | 
 |   * \sa MatrixBase::fullPivHouseholderQr() | 
 |   */ | 
 | template<typename MatrixType_> class FullPivHouseholderQR | 
 |         : public SolverBase<FullPivHouseholderQR<MatrixType_> > | 
 | { | 
 |   public: | 
 |  | 
 |     typedef MatrixType_ MatrixType; | 
 |     typedef SolverBase<FullPivHouseholderQR> Base; | 
 |     friend class SolverBase<FullPivHouseholderQR>; | 
 |  | 
 |     EIGEN_GENERIC_PUBLIC_INTERFACE(FullPivHouseholderQR) | 
 |     enum { | 
 |       MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime, | 
 |       MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime | 
 |     }; | 
 |     typedef internal::FullPivHouseholderQRMatrixQReturnType<MatrixType> MatrixQReturnType; | 
 |     typedef typename internal::plain_diag_type<MatrixType>::type HCoeffsType; | 
 |     typedef Matrix<StorageIndex, 1, | 
 |                    internal::min_size_prefer_dynamic(ColsAtCompileTime,RowsAtCompileTime), RowMajor, 1, | 
 |                    internal::min_size_prefer_fixed(MaxColsAtCompileTime, MaxRowsAtCompileTime)> IntDiagSizeVectorType; | 
 |     typedef PermutationMatrix<ColsAtCompileTime, MaxColsAtCompileTime> PermutationType; | 
 |     typedef typename internal::plain_row_type<MatrixType>::type RowVectorType; | 
 |     typedef typename internal::plain_col_type<MatrixType>::type ColVectorType; | 
 |     typedef typename MatrixType::PlainObject PlainObject; | 
 |  | 
 |     /** \brief Default Constructor. | 
 |       * | 
 |       * The default constructor is useful in cases in which the user intends to | 
 |       * perform decompositions via FullPivHouseholderQR::compute(const MatrixType&). | 
 |       */ | 
 |     FullPivHouseholderQR() | 
 |       : m_qr(), | 
 |         m_hCoeffs(), | 
 |         m_rows_transpositions(), | 
 |         m_cols_transpositions(), | 
 |         m_cols_permutation(), | 
 |         m_temp(), | 
 |         m_isInitialized(false), | 
 |         m_usePrescribedThreshold(false) {} | 
 |  | 
 |     /** \brief Default Constructor with memory preallocation | 
 |       * | 
 |       * Like the default constructor but with preallocation of the internal data | 
 |       * according to the specified problem \a size. | 
 |       * \sa FullPivHouseholderQR() | 
 |       */ | 
 |     FullPivHouseholderQR(Index rows, Index cols) | 
 |       : m_qr(rows, cols), | 
 |         m_hCoeffs((std::min)(rows,cols)), | 
 |         m_rows_transpositions((std::min)(rows,cols)), | 
 |         m_cols_transpositions((std::min)(rows,cols)), | 
 |         m_cols_permutation(cols), | 
 |         m_temp(cols), | 
 |         m_isInitialized(false), | 
 |         m_usePrescribedThreshold(false) {} | 
 |  | 
 |     /** \brief Constructs a QR factorization from a given matrix | 
 |       * | 
 |       * This constructor computes the QR factorization of the matrix \a matrix by calling | 
 |       * the method compute(). It is a short cut for: | 
 |       *  | 
 |       * \code | 
 |       * FullPivHouseholderQR<MatrixType> qr(matrix.rows(), matrix.cols()); | 
 |       * qr.compute(matrix); | 
 |       * \endcode | 
 |       *  | 
 |       * \sa compute() | 
 |       */ | 
 |     template<typename InputType> | 
 |     explicit FullPivHouseholderQR(const EigenBase<InputType>& matrix) | 
 |       : m_qr(matrix.rows(), matrix.cols()), | 
 |         m_hCoeffs((std::min)(matrix.rows(), matrix.cols())), | 
 |         m_rows_transpositions((std::min)(matrix.rows(), matrix.cols())), | 
 |         m_cols_transpositions((std::min)(matrix.rows(), matrix.cols())), | 
 |         m_cols_permutation(matrix.cols()), | 
 |         m_temp(matrix.cols()), | 
 |         m_isInitialized(false), | 
 |         m_usePrescribedThreshold(false) | 
 |     { | 
 |       compute(matrix.derived()); | 
 |     } | 
 |  | 
 |     /** \brief Constructs a QR factorization from a given matrix | 
 |       * | 
 |       * This overloaded constructor is provided for \link InplaceDecomposition inplace decomposition \endlink when \c MatrixType is a Eigen::Ref. | 
 |       * | 
 |       * \sa FullPivHouseholderQR(const EigenBase&) | 
 |       */ | 
 |     template<typename InputType> | 
 |     explicit FullPivHouseholderQR(EigenBase<InputType>& matrix) | 
 |       : m_qr(matrix.derived()), | 
 |         m_hCoeffs((std::min)(matrix.rows(), matrix.cols())), | 
 |         m_rows_transpositions((std::min)(matrix.rows(), matrix.cols())), | 
 |         m_cols_transpositions((std::min)(matrix.rows(), matrix.cols())), | 
 |         m_cols_permutation(matrix.cols()), | 
 |         m_temp(matrix.cols()), | 
 |         m_isInitialized(false), | 
 |         m_usePrescribedThreshold(false) | 
 |     { | 
 |       computeInPlace(); | 
 |     } | 
 |  | 
 |     #ifdef EIGEN_PARSED_BY_DOXYGEN | 
 |     /** This method finds a solution x to the equation Ax=b, where A is the matrix of which | 
 |       * \c *this is the QR decomposition. | 
 |       * | 
 |       * \param b the right-hand-side of the equation to solve. | 
 |       * | 
 |       * \returns the exact or least-square solution if the rank is greater or equal to the number of columns of A, | 
 |       * and an arbitrary solution otherwise. | 
 |       * | 
 |       * \note_about_checking_solutions | 
 |       * | 
 |       * \note_about_arbitrary_choice_of_solution | 
 |       * | 
 |       * Example: \include FullPivHouseholderQR_solve.cpp | 
 |       * Output: \verbinclude FullPivHouseholderQR_solve.out | 
 |       */ | 
 |     template<typename Rhs> | 
 |     inline const Solve<FullPivHouseholderQR, Rhs> | 
 |     solve(const MatrixBase<Rhs>& b) const; | 
 |     #endif | 
 |  | 
 |     /** \returns Expression object representing the matrix Q | 
 |       */ | 
 |     MatrixQReturnType matrixQ(void) const; | 
 |  | 
 |     /** \returns a reference to the matrix where the Householder QR decomposition is stored | 
 |       */ | 
 |     const MatrixType& matrixQR() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return m_qr; | 
 |     } | 
 |  | 
 |     template<typename InputType> | 
 |     FullPivHouseholderQR& compute(const EigenBase<InputType>& matrix); | 
 |  | 
 |     /** \returns a const reference to the column permutation matrix */ | 
 |     const PermutationType& colsPermutation() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return m_cols_permutation; | 
 |     } | 
 |  | 
 |     /** \returns a const reference to the vector of indices representing the rows transpositions */ | 
 |     const IntDiagSizeVectorType& rowsTranspositions() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return m_rows_transpositions; | 
 |     } | 
 |  | 
 |     /** \returns the absolute value of the determinant of the matrix of which | 
 |       * *this is the QR decomposition. It has only linear complexity | 
 |       * (that is, O(n) where n is the dimension of the square matrix) | 
 |       * as the QR decomposition has already been computed. | 
 |       * | 
 |       * \note This is only for square matrices. | 
 |       * | 
 |       * \warning a determinant can be very big or small, so for matrices | 
 |       * of large enough dimension, there is a risk of overflow/underflow. | 
 |       * One way to work around that is to use logAbsDeterminant() instead. | 
 |       * | 
 |       * \sa logAbsDeterminant(), MatrixBase::determinant() | 
 |       */ | 
 |     typename MatrixType::RealScalar absDeterminant() const; | 
 |  | 
 |     /** \returns the natural log of the absolute value of the determinant of the matrix of which | 
 |       * *this is the QR decomposition. It has only linear complexity | 
 |       * (that is, O(n) where n is the dimension of the square matrix) | 
 |       * as the QR decomposition has already been computed. | 
 |       * | 
 |       * \note This is only for square matrices. | 
 |       * | 
 |       * \note This method is useful to work around the risk of overflow/underflow that's inherent | 
 |       * to determinant computation. | 
 |       * | 
 |       * \sa absDeterminant(), MatrixBase::determinant() | 
 |       */ | 
 |     typename MatrixType::RealScalar logAbsDeterminant() const; | 
 |  | 
 |     /** \returns the rank of the matrix of which *this is the QR decomposition. | 
 |       * | 
 |       * \note This method has to determine which pivots should be considered nonzero. | 
 |       *       For that, it uses the threshold value that you can control by calling | 
 |       *       setThreshold(const RealScalar&). | 
 |       */ | 
 |     inline Index rank() const | 
 |     { | 
 |       using std::abs; | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       RealScalar premultiplied_threshold = abs(m_maxpivot) * threshold(); | 
 |       Index result = 0; | 
 |       for(Index i = 0; i < m_nonzero_pivots; ++i) | 
 |         result += (abs(m_qr.coeff(i,i)) > premultiplied_threshold); | 
 |       return result; | 
 |     } | 
 |  | 
 |     /** \returns the dimension of the kernel of the matrix of which *this is the QR decomposition. | 
 |       * | 
 |       * \note This method has to determine which pivots should be considered nonzero. | 
 |       *       For that, it uses the threshold value that you can control by calling | 
 |       *       setThreshold(const RealScalar&). | 
 |       */ | 
 |     inline Index dimensionOfKernel() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return cols() - rank(); | 
 |     } | 
 |  | 
 |     /** \returns true if the matrix of which *this is the QR decomposition represents an injective | 
 |       *          linear map, i.e. has trivial kernel; false otherwise. | 
 |       * | 
 |       * \note This method has to determine which pivots should be considered nonzero. | 
 |       *       For that, it uses the threshold value that you can control by calling | 
 |       *       setThreshold(const RealScalar&). | 
 |       */ | 
 |     inline bool isInjective() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return rank() == cols(); | 
 |     } | 
 |  | 
 |     /** \returns true if the matrix of which *this is the QR decomposition represents a surjective | 
 |       *          linear map; false otherwise. | 
 |       * | 
 |       * \note This method has to determine which pivots should be considered nonzero. | 
 |       *       For that, it uses the threshold value that you can control by calling | 
 |       *       setThreshold(const RealScalar&). | 
 |       */ | 
 |     inline bool isSurjective() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return rank() == rows(); | 
 |     } | 
 |  | 
 |     /** \returns true if the matrix of which *this is the QR decomposition is invertible. | 
 |       * | 
 |       * \note This method has to determine which pivots should be considered nonzero. | 
 |       *       For that, it uses the threshold value that you can control by calling | 
 |       *       setThreshold(const RealScalar&). | 
 |       */ | 
 |     inline bool isInvertible() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return isInjective() && isSurjective(); | 
 |     } | 
 |  | 
 |     /** \returns the inverse of the matrix of which *this is the QR decomposition. | 
 |       * | 
 |       * \note If this matrix is not invertible, the returned matrix has undefined coefficients. | 
 |       *       Use isInvertible() to first determine whether this matrix is invertible. | 
 |       */ | 
 |     inline const Inverse<FullPivHouseholderQR> inverse() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |       return Inverse<FullPivHouseholderQR>(*this); | 
 |     } | 
 |  | 
 |     inline Index rows() const { return m_qr.rows(); } | 
 |     inline Index cols() const { return m_qr.cols(); } | 
 |      | 
 |     /** \returns a const reference to the vector of Householder coefficients used to represent the factor \c Q. | 
 |       *  | 
 |       * For advanced uses only. | 
 |       */ | 
 |     const HCoeffsType& hCoeffs() const { return m_hCoeffs; } | 
 |  | 
 |     /** Allows to prescribe a threshold to be used by certain methods, such as rank(), | 
 |       * who need to determine when pivots are to be considered nonzero. This is not used for the | 
 |       * QR decomposition itself. | 
 |       * | 
 |       * When it needs to get the threshold value, Eigen calls threshold(). By default, this | 
 |       * uses a formula to automatically determine a reasonable threshold. | 
 |       * Once you have called the present method setThreshold(const RealScalar&), | 
 |       * your value is used instead. | 
 |       * | 
 |       * \param threshold The new value to use as the threshold. | 
 |       * | 
 |       * A pivot will be considered nonzero if its absolute value is strictly greater than | 
 |       *  \f$ \vert pivot \vert \leqslant threshold \times \vert maxpivot \vert \f$ | 
 |       * where maxpivot is the biggest pivot. | 
 |       * | 
 |       * If you want to come back to the default behavior, call setThreshold(Default_t) | 
 |       */ | 
 |     FullPivHouseholderQR& setThreshold(const RealScalar& threshold) | 
 |     { | 
 |       m_usePrescribedThreshold = true; | 
 |       m_prescribedThreshold = threshold; | 
 |       return *this; | 
 |     } | 
 |  | 
 |     /** Allows to come back to the default behavior, letting Eigen use its default formula for | 
 |       * determining the threshold. | 
 |       * | 
 |       * You should pass the special object Eigen::Default as parameter here. | 
 |       * \code qr.setThreshold(Eigen::Default); \endcode | 
 |       * | 
 |       * See the documentation of setThreshold(const RealScalar&). | 
 |       */ | 
 |     FullPivHouseholderQR& setThreshold(Default_t) | 
 |     { | 
 |       m_usePrescribedThreshold = false; | 
 |       return *this; | 
 |     } | 
 |  | 
 |     /** Returns the threshold that will be used by certain methods such as rank(). | 
 |       * | 
 |       * See the documentation of setThreshold(const RealScalar&). | 
 |       */ | 
 |     RealScalar threshold() const | 
 |     { | 
 |       eigen_assert(m_isInitialized || m_usePrescribedThreshold); | 
 |       return m_usePrescribedThreshold ? m_prescribedThreshold | 
 |       // this formula comes from experimenting (see "LU precision tuning" thread on the list) | 
 |       // and turns out to be identical to Higham's formula used already in LDLt. | 
 |                                       : NumTraits<Scalar>::epsilon() * RealScalar(m_qr.diagonalSize()); | 
 |     } | 
 |  | 
 |     /** \returns the number of nonzero pivots in the QR decomposition. | 
 |       * Here nonzero is meant in the exact sense, not in a fuzzy sense. | 
 |       * So that notion isn't really intrinsically interesting, but it is | 
 |       * still useful when implementing algorithms. | 
 |       * | 
 |       * \sa rank() | 
 |       */ | 
 |     inline Index nonzeroPivots() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "LU is not initialized."); | 
 |       return m_nonzero_pivots; | 
 |     } | 
 |  | 
 |     /** \returns the absolute value of the biggest pivot, i.e. the biggest | 
 |       *          diagonal coefficient of U. | 
 |       */ | 
 |     RealScalar maxPivot() const { return m_maxpivot; } | 
 |  | 
 |     #ifndef EIGEN_PARSED_BY_DOXYGEN | 
 |     template<typename RhsType, typename DstType> | 
 |     void _solve_impl(const RhsType &rhs, DstType &dst) const; | 
 |  | 
 |     template<bool Conjugate, typename RhsType, typename DstType> | 
 |     void _solve_impl_transposed(const RhsType &rhs, DstType &dst) const; | 
 |     #endif | 
 |  | 
 |   protected: | 
 |  | 
 |     EIGEN_STATIC_ASSERT_NON_INTEGER(Scalar) | 
 |  | 
 |     void computeInPlace(); | 
 |  | 
 |     MatrixType m_qr; | 
 |     HCoeffsType m_hCoeffs; | 
 |     IntDiagSizeVectorType m_rows_transpositions; | 
 |     IntDiagSizeVectorType m_cols_transpositions; | 
 |     PermutationType m_cols_permutation; | 
 |     RowVectorType m_temp; | 
 |     bool m_isInitialized, m_usePrescribedThreshold; | 
 |     RealScalar m_prescribedThreshold, m_maxpivot; | 
 |     Index m_nonzero_pivots; | 
 |     RealScalar m_precision; | 
 |     Index m_det_pq; | 
 | }; | 
 |  | 
 | template<typename MatrixType> | 
 | typename MatrixType::RealScalar FullPivHouseholderQR<MatrixType>::absDeterminant() const | 
 | { | 
 |   using std::abs; | 
 |   eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |   eigen_assert(m_qr.rows() == m_qr.cols() && "You can't take the determinant of a non-square matrix!"); | 
 |   return abs(m_qr.diagonal().prod()); | 
 | } | 
 |  | 
 | template<typename MatrixType> | 
 | typename MatrixType::RealScalar FullPivHouseholderQR<MatrixType>::logAbsDeterminant() const | 
 | { | 
 |   eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |   eigen_assert(m_qr.rows() == m_qr.cols() && "You can't take the determinant of a non-square matrix!"); | 
 |   return m_qr.diagonal().cwiseAbs().array().log().sum(); | 
 | } | 
 |  | 
 | /** Performs the QR factorization of the given matrix \a matrix. The result of | 
 |   * the factorization is stored into \c *this, and a reference to \c *this | 
 |   * is returned. | 
 |   * | 
 |   * \sa class FullPivHouseholderQR, FullPivHouseholderQR(const MatrixType&) | 
 |   */ | 
 | template<typename MatrixType> | 
 | template<typename InputType> | 
 | FullPivHouseholderQR<MatrixType>& FullPivHouseholderQR<MatrixType>::compute(const EigenBase<InputType>& matrix) | 
 | { | 
 |   m_qr = matrix.derived(); | 
 |   computeInPlace(); | 
 |   return *this; | 
 | } | 
 |  | 
 | template<typename MatrixType> | 
 | void FullPivHouseholderQR<MatrixType>::computeInPlace() | 
 | { | 
 |   using std::abs; | 
 |   Index rows = m_qr.rows(); | 
 |   Index cols = m_qr.cols(); | 
 |   Index size = (std::min)(rows,cols); | 
 |  | 
 |    | 
 |   m_hCoeffs.resize(size); | 
 |  | 
 |   m_temp.resize(cols); | 
 |  | 
 |   m_precision = NumTraits<Scalar>::epsilon() * RealScalar(size); | 
 |  | 
 |   m_rows_transpositions.resize(size); | 
 |   m_cols_transpositions.resize(size); | 
 |   Index number_of_transpositions = 0; | 
 |  | 
 |   RealScalar biggest(0); | 
 |  | 
 |   m_nonzero_pivots = size; // the generic case is that in which all pivots are nonzero (invertible case) | 
 |   m_maxpivot = RealScalar(0); | 
 |  | 
 |   for (Index k = 0; k < size; ++k) | 
 |   { | 
 |     Index row_of_biggest_in_corner, col_of_biggest_in_corner; | 
 |     typedef internal::scalar_score_coeff_op<Scalar> Scoring; | 
 |     typedef typename Scoring::result_type Score; | 
 |  | 
 |     Score score = m_qr.bottomRightCorner(rows-k, cols-k) | 
 |                       .unaryExpr(Scoring()) | 
 |                       .maxCoeff(&row_of_biggest_in_corner, &col_of_biggest_in_corner); | 
 |     row_of_biggest_in_corner += k; | 
 |     col_of_biggest_in_corner += k; | 
 |     RealScalar biggest_in_corner = internal::abs_knowing_score<Scalar>()(m_qr(row_of_biggest_in_corner, col_of_biggest_in_corner), score); | 
 |     if(k==0) biggest = biggest_in_corner; | 
 |  | 
 |     // if the corner is negligible, then we have less than full rank, and we can finish early | 
 |     if(internal::isMuchSmallerThan(biggest_in_corner, biggest, m_precision)) | 
 |     { | 
 |       m_nonzero_pivots = k; | 
 |       for(Index i = k; i < size; i++) | 
 |       { | 
 |         m_rows_transpositions.coeffRef(i) = internal::convert_index<StorageIndex>(i); | 
 |         m_cols_transpositions.coeffRef(i) = internal::convert_index<StorageIndex>(i); | 
 |         m_hCoeffs.coeffRef(i) = Scalar(0); | 
 |       } | 
 |       break; | 
 |     } | 
 |  | 
 |     m_rows_transpositions.coeffRef(k) = internal::convert_index<StorageIndex>(row_of_biggest_in_corner); | 
 |     m_cols_transpositions.coeffRef(k) = internal::convert_index<StorageIndex>(col_of_biggest_in_corner); | 
 |     if(k != row_of_biggest_in_corner) { | 
 |       m_qr.row(k).tail(cols-k).swap(m_qr.row(row_of_biggest_in_corner).tail(cols-k)); | 
 |       ++number_of_transpositions; | 
 |     } | 
 |     if(k != col_of_biggest_in_corner) { | 
 |       m_qr.col(k).swap(m_qr.col(col_of_biggest_in_corner)); | 
 |       ++number_of_transpositions; | 
 |     } | 
 |  | 
 |     RealScalar beta; | 
 |     m_qr.col(k).tail(rows-k).makeHouseholderInPlace(m_hCoeffs.coeffRef(k), beta); | 
 |     m_qr.coeffRef(k,k) = beta; | 
 |  | 
 |     // remember the maximum absolute value of diagonal coefficients | 
 |     if(abs(beta) > m_maxpivot) m_maxpivot = abs(beta); | 
 |  | 
 |     m_qr.bottomRightCorner(rows-k, cols-k-1) | 
 |         .applyHouseholderOnTheLeft(m_qr.col(k).tail(rows-k-1), m_hCoeffs.coeffRef(k), &m_temp.coeffRef(k+1)); | 
 |   } | 
 |  | 
 |   m_cols_permutation.setIdentity(cols); | 
 |   for(Index k = 0; k < size; ++k) | 
 |     m_cols_permutation.applyTranspositionOnTheRight(k, m_cols_transpositions.coeff(k)); | 
 |  | 
 |   m_det_pq = (number_of_transpositions%2) ? -1 : 1; | 
 |   m_isInitialized = true; | 
 | } | 
 |  | 
 | #ifndef EIGEN_PARSED_BY_DOXYGEN | 
 | template<typename MatrixType_> | 
 | template<typename RhsType, typename DstType> | 
 | void FullPivHouseholderQR<MatrixType_>::_solve_impl(const RhsType &rhs, DstType &dst) const | 
 | { | 
 |   const Index l_rank = rank(); | 
 |  | 
 |   // FIXME introduce nonzeroPivots() and use it here. and more generally, | 
 |   // make the same improvements in this dec as in FullPivLU. | 
 |   if(l_rank==0) | 
 |   { | 
 |     dst.setZero(); | 
 |     return; | 
 |   } | 
 |  | 
 |   typename RhsType::PlainObject c(rhs); | 
 |  | 
 |   Matrix<typename RhsType::Scalar,1,RhsType::ColsAtCompileTime> temp(rhs.cols()); | 
 |   for (Index k = 0; k < l_rank; ++k) | 
 |   { | 
 |     Index remainingSize = rows()-k; | 
 |     c.row(k).swap(c.row(m_rows_transpositions.coeff(k))); | 
 |     c.bottomRightCorner(remainingSize, rhs.cols()) | 
 |       .applyHouseholderOnTheLeft(m_qr.col(k).tail(remainingSize-1), | 
 |                                m_hCoeffs.coeff(k), &temp.coeffRef(0)); | 
 |   } | 
 |  | 
 |   m_qr.topLeftCorner(l_rank, l_rank) | 
 |       .template triangularView<Upper>() | 
 |       .solveInPlace(c.topRows(l_rank)); | 
 |  | 
 |   for(Index i = 0; i < l_rank; ++i) dst.row(m_cols_permutation.indices().coeff(i)) = c.row(i); | 
 |   for(Index i = l_rank; i < cols(); ++i) dst.row(m_cols_permutation.indices().coeff(i)).setZero(); | 
 | } | 
 |  | 
 | template<typename MatrixType_> | 
 | template<bool Conjugate, typename RhsType, typename DstType> | 
 | void FullPivHouseholderQR<MatrixType_>::_solve_impl_transposed(const RhsType &rhs, DstType &dst) const | 
 | { | 
 |   const Index l_rank = rank(); | 
 |  | 
 |   if(l_rank == 0) | 
 |   { | 
 |     dst.setZero(); | 
 |     return; | 
 |   } | 
 |  | 
 |   typename RhsType::PlainObject c(m_cols_permutation.transpose()*rhs); | 
 |  | 
 |   m_qr.topLeftCorner(l_rank, l_rank) | 
 |          .template triangularView<Upper>() | 
 |          .transpose().template conjugateIf<Conjugate>() | 
 |          .solveInPlace(c.topRows(l_rank)); | 
 |  | 
 |   dst.topRows(l_rank) = c.topRows(l_rank); | 
 |   dst.bottomRows(rows()-l_rank).setZero(); | 
 |  | 
 |   Matrix<Scalar, 1, DstType::ColsAtCompileTime> temp(dst.cols()); | 
 |   const Index size = (std::min)(rows(), cols()); | 
 |   for (Index k = size-1; k >= 0; --k) | 
 |   { | 
 |     Index remainingSize = rows()-k; | 
 |  | 
 |     dst.bottomRightCorner(remainingSize, dst.cols()) | 
 |        .applyHouseholderOnTheLeft(m_qr.col(k).tail(remainingSize-1).template conjugateIf<!Conjugate>(), | 
 |                                   m_hCoeffs.template conjugateIf<Conjugate>().coeff(k), &temp.coeffRef(0)); | 
 |  | 
 |     dst.row(k).swap(dst.row(m_rows_transpositions.coeff(k))); | 
 |   } | 
 | } | 
 | #endif | 
 |  | 
 | namespace internal { | 
 |    | 
 | template<typename DstXprType, typename MatrixType> | 
 | struct Assignment<DstXprType, Inverse<FullPivHouseholderQR<MatrixType> >, internal::assign_op<typename DstXprType::Scalar,typename FullPivHouseholderQR<MatrixType>::Scalar>, Dense2Dense> | 
 | { | 
 |   typedef FullPivHouseholderQR<MatrixType> QrType; | 
 |   typedef Inverse<QrType> SrcXprType; | 
 |   static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<typename DstXprType::Scalar,typename QrType::Scalar> &) | 
 |   {     | 
 |     dst = src.nestedExpression().solve(MatrixType::Identity(src.rows(), src.cols())); | 
 |   } | 
 | }; | 
 |  | 
 | /** \ingroup QR_Module | 
 |   * | 
 |   * \brief Expression type for return value of FullPivHouseholderQR::matrixQ() | 
 |   * | 
 |   * \tparam MatrixType type of underlying dense matrix | 
 |   */ | 
 | template<typename MatrixType> struct FullPivHouseholderQRMatrixQReturnType | 
 |   : public ReturnByValue<FullPivHouseholderQRMatrixQReturnType<MatrixType> > | 
 | { | 
 | public: | 
 |   typedef typename FullPivHouseholderQR<MatrixType>::IntDiagSizeVectorType IntDiagSizeVectorType; | 
 |   typedef typename internal::plain_diag_type<MatrixType>::type HCoeffsType; | 
 |   typedef Matrix<typename MatrixType::Scalar, 1, MatrixType::RowsAtCompileTime, RowMajor, 1, | 
 |                  MatrixType::MaxRowsAtCompileTime> WorkVectorType; | 
 |  | 
 |   FullPivHouseholderQRMatrixQReturnType(const MatrixType&       qr, | 
 |                                         const HCoeffsType&      hCoeffs, | 
 |                                         const IntDiagSizeVectorType& rowsTranspositions) | 
 |     : m_qr(qr), | 
 |       m_hCoeffs(hCoeffs), | 
 |       m_rowsTranspositions(rowsTranspositions) | 
 |   {} | 
 |  | 
 |   template <typename ResultType> | 
 |   void evalTo(ResultType& result) const | 
 |   { | 
 |     const Index rows = m_qr.rows(); | 
 |     WorkVectorType workspace(rows); | 
 |     evalTo(result, workspace); | 
 |   } | 
 |  | 
 |   template <typename ResultType> | 
 |   void evalTo(ResultType& result, WorkVectorType& workspace) const | 
 |   { | 
 |     using numext::conj; | 
 |     // compute the product H'_0 H'_1 ... H'_n-1, | 
 |     // where H_k is the k-th Householder transformation I - h_k v_k v_k' | 
 |     // and v_k is the k-th Householder vector [1,m_qr(k+1,k), m_qr(k+2,k), ...] | 
 |     const Index rows = m_qr.rows(); | 
 |     const Index cols = m_qr.cols(); | 
 |     const Index size = (std::min)(rows, cols); | 
 |     workspace.resize(rows); | 
 |     result.setIdentity(rows, rows); | 
 |     for (Index k = size-1; k >= 0; k--) | 
 |     { | 
 |       result.block(k, k, rows-k, rows-k) | 
 |             .applyHouseholderOnTheLeft(m_qr.col(k).tail(rows-k-1), conj(m_hCoeffs.coeff(k)), &workspace.coeffRef(k)); | 
 |       result.row(k).swap(result.row(m_rowsTranspositions.coeff(k))); | 
 |     } | 
 |   } | 
 |  | 
 |   Index rows() const { return m_qr.rows(); } | 
 |   Index cols() const { return m_qr.rows(); } | 
 |  | 
 | protected: | 
 |   typename MatrixType::Nested m_qr; | 
 |   typename HCoeffsType::Nested m_hCoeffs; | 
 |   typename IntDiagSizeVectorType::Nested m_rowsTranspositions; | 
 | }; | 
 |  | 
 | // template<typename MatrixType> | 
 | // struct evaluator<FullPivHouseholderQRMatrixQReturnType<MatrixType> > | 
 | //  : public evaluator<ReturnByValue<FullPivHouseholderQRMatrixQReturnType<MatrixType> > > | 
 | // {}; | 
 |  | 
 | } // end namespace internal | 
 |  | 
 | template<typename MatrixType> | 
 | inline typename FullPivHouseholderQR<MatrixType>::MatrixQReturnType FullPivHouseholderQR<MatrixType>::matrixQ() const | 
 | { | 
 |   eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized."); | 
 |   return MatrixQReturnType(m_qr, m_hCoeffs, m_rows_transpositions); | 
 | } | 
 |  | 
 | /** \return the full-pivoting Householder QR decomposition of \c *this. | 
 |   * | 
 |   * \sa class FullPivHouseholderQR | 
 |   */ | 
 | template<typename Derived> | 
 | const FullPivHouseholderQR<typename MatrixBase<Derived>::PlainObject> | 
 | MatrixBase<Derived>::fullPivHouseholderQr() const | 
 | { | 
 |   return FullPivHouseholderQR<PlainObject>(eval()); | 
 | } | 
 |  | 
 | } // end namespace Eigen | 
 |  | 
 | #endif // EIGEN_FULLPIVOTINGHOUSEHOLDERQR_H |