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122 lines
4.4 KiB
C++
122 lines
4.4 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
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// for linear algebra. Eigen itself is part of the KDE project.
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//
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// Copyright (C) 2006-2008 Benoit Jacob <jacob@math.jussieu.fr>
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//
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// Eigen is free software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the Free Software
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// Foundation; either version 2 or (at your option) any later version.
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//
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// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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// details.
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//
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// You should have received a copy of the GNU General Public License along
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// with Eigen; if not, write to the Free Software Foundation, Inc., 51
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// Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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//
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// As a special exception, if other files instantiate templates or use macros
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// or functions from this file, or you compile this file and link it
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// with other works to produce a work based on this file, this file does not
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// by itself cause the resulting work to be covered by the GNU General Public
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// License. This exception does not invalidate any other reasons why a work
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// based on this file might be covered by the GNU General Public License.
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#ifndef EIGEN_DYNBLOCK_H
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#define EIGEN_DYNBLOCK_H
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/** \class DynBlock
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*
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* \brief Expression of a dynamic-size block
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*
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* \param MatrixType the type of the object in which we are taking a block
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*
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* This class represents an expression of a dynamic-size block. It is the return
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* type of MatrixBase::dynBlock() and most of the time this is the only way it
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* is used.
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*
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* However, if you want to directly maniputate dynamic-size block expressions,
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* for instance if you want to write a function returning such an expression, you
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* will need to use this class.
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*
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* Here is an example illustrating this:
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* \include class_DynBlock.cpp
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* Output: \verbinclude class_DynBlock.out
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*
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* \sa MatrixBase::dynBlock()
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*/
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template<typename MatrixType> class DynBlock
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: public MatrixBase<typename MatrixType::Scalar, DynBlock<MatrixType> >
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{
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public:
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typedef typename MatrixType::Scalar Scalar;
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typedef typename MatrixType::Ref MatRef;
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friend class MatrixBase<Scalar, DynBlock<MatrixType> >;
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DynBlock(const MatRef& matrix,
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int startRow, int startCol,
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int blockRows, int blockCols)
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: m_matrix(matrix), m_startRow(startRow), m_startCol(startCol),
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m_blockRows(blockRows), m_blockCols(blockCols)
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{
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assert(startRow >= 0 && blockRows >= 1 && startRow + blockRows <= matrix.rows()
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&& startCol >= 0 && blockCols >= 1 && startCol + blockCols <= matrix.cols());
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}
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EIGEN_INHERIT_ASSIGNMENT_OPERATORS(DynBlock)
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private:
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static const int
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RowsAtCompileTime = MatrixType::Traits::RowsAtCompileTime == 1 ? 1 : Dynamic,
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ColsAtCompileTime = MatrixType::Traits::ColsAtCompileTime == 1 ? 1 : Dynamic;
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const DynBlock& _ref() const { return *this; }
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int _rows() const { return m_blockRows; }
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int _cols() const { return m_blockCols; }
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Scalar& _coeffRef(int row, int col)
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{
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return m_matrix.coeffRef(row + m_startRow, col + m_startCol);
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}
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Scalar _coeff(int row, int col) const
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{
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return m_matrix.coeff(row + m_startRow, col + m_startCol);
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}
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protected:
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MatRef m_matrix;
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const int m_startRow, m_startCol, m_blockRows, m_blockCols;
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};
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/** \returns a dynamic-size expression of a block in *this.
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*
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* \param startRow the first row in the block
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* \param startCol the first column in the block
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* \param blockRows the number of rows in the block
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* \param blockCols the number of columns in the block
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*
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* Example: \include MatrixBase_dynBlock.cpp
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* Output: \verbinclude MatrixBase_dynBlock.out
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*
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* \sa class DynBlock, block()
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*/
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template<typename Scalar, typename Derived>
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DynBlock<Derived> MatrixBase<Scalar, Derived>
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::dynBlock(int startRow, int startCol, int blockRows, int blockCols)
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{
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return DynBlock<Derived>(ref(), startRow, startCol, blockRows, blockCols);
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}
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/** This is the const version of dynBlock(). */
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template<typename Scalar, typename Derived>
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const DynBlock<Derived> MatrixBase<Scalar, Derived>
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::dynBlock(int startRow, int startCol, int blockRows, int blockCols) const
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{
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return DynBlock<Derived>(ref(), startRow, startCol, blockRows, blockCols);
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}
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#endif // EIGEN_DYNBLOCK_H
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