1 // This file is part of Eigen, a lightweight C++ template library 2 // for linear algebra. 3 // 4 // Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com> 5 // 6 // This Source Code Form is subject to the terms of the Mozilla 7 // Public License v. 2.0. If a copy of the MPL was not distributed 8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. 9 10 #ifndef EIGEN_MISC_KERNEL_H 11 #define EIGEN_MISC_KERNEL_H 12 13 namespace Eigen { 14 15 namespace internal { 16 17 /** \class kernel_retval_base 18 * 19 */ 20 template<typename DecompositionType> 21 struct traits<kernel_retval_base<DecompositionType> > 22 { 23 typedef typename DecompositionType::MatrixType MatrixType; 24 typedef Matrix< 25 typename MatrixType::Scalar, 26 MatrixType::ColsAtCompileTime, // the number of rows in the "kernel matrix" 27 // is the number of cols of the original matrix 28 // so that the product "matrix * kernel = zero" makes sense 29 Dynamic, // we don't know at compile-time the dimension of the kernel 30 MatrixType::Options, 31 MatrixType::MaxColsAtCompileTime, // see explanation for 2nd template parameter 32 MatrixType::MaxColsAtCompileTime // the kernel is a subspace of the domain space, 33 // whose dimension is the number of columns of the original matrix 34 > ReturnType; 35 }; 36 37 template<typename _DecompositionType> struct kernel_retval_base 38 : public ReturnByValue<kernel_retval_base<_DecompositionType> > 39 { 40 typedef _DecompositionType DecompositionType; 41 typedef ReturnByValue<kernel_retval_base> Base; 42 typedef typename Base::Index Index; 43 44 kernel_retval_base(const DecompositionType& dec) 45 : m_dec(dec), 46 m_rank(dec.rank()), 47 m_cols(m_rank==dec.cols() ? 1 : dec.cols() - m_rank) 48 {} 49 50 inline Index rows() const { return m_dec.cols(); } 51 inline Index cols() const { return m_cols; } 52 inline Index rank() const { return m_rank; } 53 inline const DecompositionType& dec() const { return m_dec; } 54 55 template<typename Dest> inline void evalTo(Dest& dst) const 56 { 57 static_cast<const kernel_retval<DecompositionType>*>(this)->evalTo(dst); 58 } 59 60 protected: 61 const DecompositionType& m_dec; 62 Index m_rank, m_cols; 63 }; 64 65 } // end namespace internal 66 67 #define EIGEN_MAKE_KERNEL_HELPERS(DecompositionType) \ 68 typedef typename DecompositionType::MatrixType MatrixType; \ 69 typedef typename MatrixType::Scalar Scalar; \ 70 typedef typename MatrixType::RealScalar RealScalar; \ 71 typedef typename MatrixType::Index Index; \ 72 typedef Eigen::internal::kernel_retval_base<DecompositionType> Base; \ 73 using Base::dec; \ 74 using Base::rank; \ 75 using Base::rows; \ 76 using Base::cols; \ 77 kernel_retval(const DecompositionType& dec) : Base(dec) {} 78 79 } // end namespace Eigen 80 81 #endif // EIGEN_MISC_KERNEL_H 82