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author | Benoit Steiner <benoit.steiner.goog@gmail.com> | 2016-04-29 13:41:26 -0700 |
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committer | Benoit Steiner <benoit.steiner.goog@gmail.com> | 2016-04-29 13:41:26 -0700 |
commit | 07a247dcf4e86f9f741b68e1d8e0897de3eeca57 (patch) | |
tree | d103bd20faa1f103035bac2f21507ecc65f97f68 /Eigen/src/Cholesky/LDLT.h | |
parent | fa5a8f055aebbf4f39fca26e857351103fab4d11 (diff) | |
parent | 0f3c4c8ff4a6635db77195a8919c743f34181cc2 (diff) |
Pulled latest updates from upstream
Diffstat (limited to 'Eigen/src/Cholesky/LDLT.h')
-rw-r--r-- | Eigen/src/Cholesky/LDLT.h | 54 |
1 files changed, 42 insertions, 12 deletions
diff --git a/Eigen/src/Cholesky/LDLT.h b/Eigen/src/Cholesky/LDLT.h index 1d767d5c8..538aff956 100644 --- a/Eigen/src/Cholesky/LDLT.h +++ b/Eigen/src/Cholesky/LDLT.h @@ -13,7 +13,7 @@ #ifndef EIGEN_LDLT_H #define EIGEN_LDLT_H -namespace Eigen { +namespace Eigen { namespace internal { template<typename MatrixType, int UpLo> struct LDLT_Traits; @@ -73,11 +73,11 @@ template<typename _MatrixType, int _UpLo> class LDLT * The default constructor is useful in cases in which the user intends to * perform decompositions via LDLT::compute(const MatrixType&). */ - LDLT() - : m_matrix(), - m_transpositions(), + LDLT() + : m_matrix(), + m_transpositions(), m_sign(internal::ZeroSign), - m_isInitialized(false) + m_isInitialized(false) {} /** \brief Default Constructor with memory preallocation @@ -168,7 +168,7 @@ template<typename _MatrixType, int _UpLo> class LDLT * \note_about_checking_solutions * * More precisely, this method solves \f$ A x = b \f$ using the decomposition \f$ A = P^T L D L^* P \f$ - * by solving the systems \f$ P^T y_1 = b \f$, \f$ L y_2 = y_1 \f$, \f$ D y_3 = y_2 \f$, + * by solving the systems \f$ P^T y_1 = b \f$, \f$ L y_2 = y_1 \f$, \f$ D y_3 = y_2 \f$, * \f$ L^* y_4 = y_3 \f$ and \f$ P x = y_4 \f$ in succession. If the matrix \f$ A \f$ is singular, then * \f$ D \f$ will also be singular (all the other matrices are invertible). In that case, the * least-square solution of \f$ D y_3 = y_2 \f$ is computed. This does not mean that this function @@ -192,6 +192,15 @@ template<typename _MatrixType, int _UpLo> class LDLT template<typename InputType> LDLT& compute(const EigenBase<InputType>& matrix); + /** \returns an estimate of the reciprocal condition number of the matrix of + * which \c *this is the LDLT decomposition. + */ + RealScalar rcond() const + { + eigen_assert(m_isInitialized && "LDLT is not initialized."); + return internal::rcond_estimate_helper(m_l1_norm, *this); + } + template <typename Derived> LDLT& rankUpdate(const MatrixBase<Derived>& w, const RealScalar& alpha=1); @@ -207,6 +216,13 @@ template<typename _MatrixType, int _UpLo> class LDLT MatrixType reconstructedMatrix() const; + /** \returns the adjoint of \c *this, that is, a const reference to the decomposition itself as the underlying matrix is self-adjoint. + * + * This method is provided for compatibility with other matrix decompositions, thus enabling generic code such as: + * \code x = decomposition.adjoint().solve(b) \endcode + */ + const LDLT& adjoint() const { return *this; }; + inline Index rows() const { return m_matrix.rows(); } inline Index cols() const { return m_matrix.cols(); } @@ -220,7 +236,7 @@ template<typename _MatrixType, int _UpLo> class LDLT eigen_assert(m_isInitialized && "LDLT is not initialized."); return Success; } - + #ifndef EIGEN_PARSED_BY_DOXYGEN template<typename RhsType, typename DstType> EIGEN_DEVICE_FUNC @@ -228,7 +244,7 @@ template<typename _MatrixType, int _UpLo> class LDLT #endif protected: - + static void check_template_parameters() { EIGEN_STATIC_ASSERT_NON_INTEGER(Scalar); @@ -241,6 +257,7 @@ template<typename _MatrixType, int _UpLo> class LDLT * is not stored), and the diagonal entries correspond to D. */ MatrixType m_matrix; + RealScalar m_l1_norm; TranspositionType m_transpositions; TmpMatrixType m_temporary; internal::SignMatrix m_sign; @@ -314,7 +331,7 @@ template<> struct ldlt_inplace<Lower> if(rs>0) A21.noalias() -= A20 * temp.head(k); } - + // In some previous versions of Eigen (e.g., 3.2.1), the scaling was omitted if the pivot // was smaller than the cutoff value. However, since LDLT is not rank-revealing // we should only make sure that we do not introduce INF or NaN values. @@ -433,12 +450,25 @@ template<typename InputType> LDLT<MatrixType,_UpLo>& LDLT<MatrixType,_UpLo>::compute(const EigenBase<InputType>& a) { check_template_parameters(); - + eigen_assert(a.rows()==a.cols()); const Index size = a.rows(); m_matrix = a.derived(); + // Compute matrix L1 norm = max abs column sum. + m_l1_norm = RealScalar(0); + // TODO move this code to SelfAdjointView + for (Index col = 0; col < size; ++col) { + RealScalar abs_col_sum; + if (_UpLo == Lower) + abs_col_sum = m_matrix.col(col).tail(size - col).template lpNorm<1>() + m_matrix.row(col).head(col).template lpNorm<1>(); + else + abs_col_sum = m_matrix.col(col).head(col).template lpNorm<1>() + m_matrix.row(col).tail(size - col).template lpNorm<1>(); + if (abs_col_sum > m_l1_norm) + m_l1_norm = abs_col_sum; + } + m_transpositions.resize(size); m_isInitialized = false; m_temporary.resize(size); @@ -466,7 +496,7 @@ LDLT<MatrixType,_UpLo>& LDLT<MatrixType,_UpLo>::rankUpdate(const MatrixBase<Deri eigen_assert(m_matrix.rows()==size); } else - { + { m_matrix.resize(size,size); m_matrix.setZero(); m_transpositions.resize(size); @@ -505,7 +535,7 @@ void LDLT<_MatrixType,_UpLo>::_solve_impl(const RhsType &rhs, DstType &dst) cons // diagonal element is not well justified and leads to numerical issues in some cases. // Moreover, Lapack's xSYTRS routines use 0 for the tolerance. RealScalar tolerance = RealScalar(1) / NumTraits<RealScalar>::highest(); - + for (Index i = 0; i < vecD.size(); ++i) { if(abs(vecD(i)) > tolerance) |