Image.h
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00001 // This file is part of Eigen, a lightweight C++ template library
00002 // for linear algebra.
00003 //
00004 // Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
00005 //
00006 // Eigen is free software; you can redistribute it and/or
00007 // modify it under the terms of the GNU Lesser General Public
00008 // License as published by the Free Software Foundation; either
00009 // version 3 of the License, or (at your option) any later version.
00010 //
00011 // Alternatively, you can redistribute it and/or
00012 // modify it under the terms of the GNU General Public License as
00013 // published by the Free Software Foundation; either version 2 of
00014 // the License, or (at your option) any later version.
00015 //
00016 // Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
00017 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
00018 // FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
00019 // GNU General Public License for more details.
00020 //
00021 // You should have received a copy of the GNU Lesser General Public
00022 // License and a copy of the GNU General Public License along with
00023 // Eigen. If not, see <http://www.gnu.org/licenses/>.
00024 
00025 #ifndef EIGEN_MISC_IMAGE_H
00026 #define EIGEN_MISC_IMAGE_H
00027 
00028 namespace Eigen { 
00029 
00030 namespace internal {
00031 
00035 template<typename DecompositionType>
00036 struct traits<image_retval_base<DecompositionType> >
00037 {
00038   typedef typename DecompositionType::MatrixType MatrixType;
00039   typedef Matrix<
00040     typename MatrixType::Scalar,
00041     MatrixType::RowsAtCompileTime, // the image is a subspace of the destination space, whose
00042                                    // dimension is the number of rows of the original matrix
00043     Dynamic,                       // we don't know at compile time the dimension of the image (the rank)
00044     MatrixType::Options,
00045     MatrixType::MaxRowsAtCompileTime, // the image matrix will consist of columns from the original matrix,
00046     MatrixType::MaxColsAtCompileTime  // so it has the same number of rows and at most as many columns.
00047   > ReturnType;
00048 };
00049 
00050 template<typename _DecompositionType> struct image_retval_base
00051  : public ReturnByValue<image_retval_base<_DecompositionType> >
00052 {
00053   typedef _DecompositionType DecompositionType;
00054   typedef typename DecompositionType::MatrixType MatrixType;
00055   typedef ReturnByValue<image_retval_base> Base;
00056   typedef typename Base::Index Index;
00057 
00058   image_retval_base(const DecompositionType& dec, const MatrixType& originalMatrix)
00059     : m_dec(dec), m_rank(dec.rank()),
00060       m_cols(m_rank == 0 ? 1 : m_rank),
00061       m_originalMatrix(originalMatrix)
00062   {}
00063 
00064   inline Index rows() const { return m_dec.rows(); }
00065   inline Index cols() const { return m_cols; }
00066   inline Index rank() const { return m_rank; }
00067   inline const DecompositionType& dec() const { return m_dec; }
00068   inline const MatrixType& originalMatrix() const { return m_originalMatrix; }
00069 
00070   template<typename Dest> inline void evalTo(Dest& dst) const
00071   {
00072     static_cast<const image_retval<DecompositionType>*>(this)->evalTo(dst);
00073   }
00074 
00075   protected:
00076     const DecompositionType& m_dec;
00077     Index m_rank, m_cols;
00078     const MatrixType& m_originalMatrix;
00079 };
00080 
00081 } // end namespace internal
00082 
00083 #define EIGEN_MAKE_IMAGE_HELPERS(DecompositionType) \
00084   typedef typename DecompositionType::MatrixType MatrixType; \
00085   typedef typename MatrixType::Scalar Scalar; \
00086   typedef typename MatrixType::RealScalar RealScalar; \
00087   typedef typename MatrixType::Index Index; \
00088   typedef Eigen::internal::image_retval_base<DecompositionType> Base; \
00089   using Base::dec; \
00090   using Base::originalMatrix; \
00091   using Base::rank; \
00092   using Base::rows; \
00093   using Base::cols; \
00094   image_retval(const DecompositionType& dec, const MatrixType& originalMatrix) \
00095     : Base(dec, originalMatrix) {}
00096 
00097 } // end namespace Eigen
00098 
00099 #endif // EIGEN_MISC_IMAGE_H