diff options
author | Gael Guennebaud <g.gael@free.fr> | 2010-02-24 19:16:10 +0100 |
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committer | Gael Guennebaud <g.gael@free.fr> | 2010-02-24 19:16:10 +0100 |
commit | 7c98c04412322e56b3b6f7e235bc7ebb61ab6b43 (patch) | |
tree | 3c1ecc3f0cc350809388201026a8bc281fc7da45 /Eigen/src/LU/PartialPivLU.h | |
parent | a7e4c0f8250ebcbab8cb26eea0730f12f5e4281d (diff) |
add reconstructedMatrix() to LLT, and LUs
=> they show that some improvements have still to be done
for permutations, tr*tr, trapezoidal matrices
Diffstat (limited to 'Eigen/src/LU/PartialPivLU.h')
-rw-r--r-- | Eigen/src/LU/PartialPivLU.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Eigen/src/LU/PartialPivLU.h b/Eigen/src/LU/PartialPivLU.h index ed2354d78..fcffc2458 100644 --- a/Eigen/src/LU/PartialPivLU.h +++ b/Eigen/src/LU/PartialPivLU.h @@ -165,6 +165,8 @@ template<typename _MatrixType> class PartialPivLU */ typename ei_traits<MatrixType>::Scalar determinant() const; + MatrixType reconstructedMatrix() const; + inline int rows() const { return m_lu.rows(); } inline int cols() const { return m_lu.cols(); } @@ -400,6 +402,24 @@ typename ei_traits<MatrixType>::Scalar PartialPivLU<MatrixType>::determinant() c return Scalar(m_det_p) * m_lu.diagonal().prod(); } +/** \returns the matrix represented by the decomposition, + * i.e., it returns the product: P^{-1} L U. + * This function is provided for debug purpose. */ +template<typename MatrixType> +MatrixType PartialPivLU<MatrixType>::reconstructedMatrix() const +{ + ei_assert(m_isInitialized && "LU is not initialized."); + // LU + MatrixType res = m_lu.template triangularView<UnitLower>().toDenseMatrix() + * m_lu.template triangularView<Upper>(); + + // P^{-1}(LU) + // FIXME implement inplace permutation + res = (m_p.inverse() * res).eval(); + + return res; +} + /***** Implementation of solve() *****************************************************/ template<typename _MatrixType, typename Rhs> |