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 (at) 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 43 explicit kernel_retval_base(const DecompositionType& dec) 44 : m_dec(dec), 45 m_rank(dec.rank()), 46 m_cols(m_rank==dec.cols() ? 1 : dec.cols() - m_rank) 47 {} 48 49 inline Index rows() const { return m_dec.cols(); } 50 inline Index cols() const { return m_cols; } 51 inline Index rank() const { return m_rank; } 52 inline const DecompositionType& dec() const { return m_dec; } 53 54 template<typename Dest> inline void evalTo(Dest& dst) const 55 { 56 static_cast<const kernel_retval<DecompositionType>*>(this)->evalTo(dst); 57 } 58 59 protected: 60 const DecompositionType& m_dec; 61 Index m_rank, m_cols; 62 }; 63 64 } // end namespace internal 65 66 #define EIGEN_MAKE_KERNEL_HELPERS(DecompositionType) \ 67 typedef typename DecompositionType::MatrixType MatrixType; \ 68 typedef typename MatrixType::Scalar Scalar; \ 69 typedef typename MatrixType::RealScalar RealScalar; \ 70 typedef Eigen::internal::kernel_retval_base<DecompositionType> Base; \ 71 using Base::dec; \ 72 using Base::rank; \ 73 using Base::rows; \ 74 using Base::cols; \ 75 kernel_retval(const DecompositionType& dec) : Base(dec) {} 76 77 } // end namespace Eigen 78 79 #endif // EIGEN_MISC_KERNEL_H 80
