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124 lines
4.1 KiB
C++
124 lines
4.1 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
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// for linear algebra.
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//
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// Copyright (C) 2006-2009 Benoit Jacob <jacob.benoit.1@gmail.com>
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//
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// Eigen is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 3 of the License, or (at your option) any later version.
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//
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// Alternatively, you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as
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// published by the Free Software Foundation; either version 2 of
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// the License, 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 Lesser General Public License or the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License and a copy of the GNU General Public License along with
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// Eigen. If not, see <http://www.gnu.org/licenses/>.
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#ifndef EIGEN_MINOR_H
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#define EIGEN_MINOR_H
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/** \nonstableyet
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* \class Minor
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*
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* \brief Expression of a minor
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*
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* \param MatrixType the type of the object in which we are taking a minor
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*
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* This class represents an expression of a minor. It is the return
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* type of MatrixBase::minor() 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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* \sa MatrixBase::minor()
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*/
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template<typename MatrixType>
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struct ei_traits<Minor<MatrixType> >
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: ei_traits<MatrixType>
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{
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typedef typename ei_nested<MatrixType>::type MatrixTypeNested;
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typedef typename ei_unref<MatrixTypeNested>::type _MatrixTypeNested;
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enum {
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RowsAtCompileTime = (MatrixType::RowsAtCompileTime != Dynamic) ?
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int(MatrixType::RowsAtCompileTime) - 1 : Dynamic,
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ColsAtCompileTime = (MatrixType::ColsAtCompileTime != Dynamic) ?
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int(MatrixType::ColsAtCompileTime) - 1 : Dynamic,
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MaxRowsAtCompileTime = (MatrixType::MaxRowsAtCompileTime != Dynamic) ?
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int(MatrixType::MaxRowsAtCompileTime) - 1 : Dynamic,
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MaxColsAtCompileTime = (MatrixType::MaxColsAtCompileTime != Dynamic) ?
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int(MatrixType::MaxColsAtCompileTime) - 1 : Dynamic,
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Flags = _MatrixTypeNested::Flags & HereditaryBits,
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CoeffReadCost = _MatrixTypeNested::CoeffReadCost // minor is used typically on tiny matrices,
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// where loops are unrolled and the 'if' evaluates at compile time
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};
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};
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template<typename MatrixType> class Minor
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: public MatrixBase<Minor<MatrixType> >
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{
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public:
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EIGEN_GENERIC_PUBLIC_INTERFACE(Minor)
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inline Minor(const MatrixType& matrix,
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int row, int col)
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: m_matrix(matrix), m_row(row), m_col(col)
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{
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ei_assert(row >= 0 && row < matrix.rows()
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&& col >= 0 && col < matrix.cols());
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}
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EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Minor)
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inline int rows() const { return m_matrix.rows() - 1; }
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inline int cols() const { return m_matrix.cols() - 1; }
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inline Scalar& coeffRef(int row, int col)
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{
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return m_matrix.const_cast_derived().coeffRef(row + (row >= m_row), col + (col >= m_col));
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}
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inline const Scalar coeff(int row, int col) const
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{
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return m_matrix.coeff(row + (row >= m_row), col + (col >= m_col));
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}
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protected:
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const typename MatrixType::Nested m_matrix;
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const int m_row, m_col;
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};
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/** \nonstableyet
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* \return an expression of the (\a row, \a col)-minor of *this,
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* i.e. an expression constructed from *this by removing the specified
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* row and column.
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*
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* Example: \include MatrixBase_minor.cpp
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* Output: \verbinclude MatrixBase_minor.out
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*
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* \sa class Minor
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*/
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template<typename Derived>
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inline Minor<Derived>
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MatrixBase<Derived>::minor(int row, int col)
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{
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return Minor<Derived>(derived(), row, col);
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}
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/** \nonstableyet
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* This is the const version of minor(). */
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template<typename Derived>
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inline const Minor<Derived>
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MatrixBase<Derived>::minor(int row, int col) const
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{
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return Minor<Derived>(derived(), row, col);
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}
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#endif // EIGEN_MINOR_H
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