diff options
Diffstat (limited to 'eigen/Eigen/src/Eigen2Support/Minor.h')
-rw-r--r-- | eigen/Eigen/src/Eigen2Support/Minor.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/eigen/Eigen/src/Eigen2Support/Minor.h b/eigen/Eigen/src/Eigen2Support/Minor.h new file mode 100644 index 0000000..4cded57 --- /dev/null +++ b/eigen/Eigen/src/Eigen2Support/Minor.h @@ -0,0 +1,117 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2006-2009 Benoit Jacob <jacob.benoit.1@gmail.com> +// +// This Source Code Form is subject to the terms of the Mozilla +// Public License v. 2.0. If a copy of the MPL was not distributed +// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#ifndef EIGEN_MINOR_H +#define EIGEN_MINOR_H + +namespace Eigen { + +/** + * \class Minor + * + * \brief Expression of a minor + * + * \param MatrixType the type of the object in which we are taking a minor + * + * This class represents an expression of a minor. It is the return + * type of MatrixBase::minor() and most of the time this is the only way it + * is used. + * + * \sa MatrixBase::minor() + */ + +namespace internal { +template<typename MatrixType> +struct traits<Minor<MatrixType> > + : traits<MatrixType> +{ + typedef typename nested<MatrixType>::type MatrixTypeNested; + typedef typename remove_reference<MatrixTypeNested>::type _MatrixTypeNested; + typedef typename MatrixType::StorageKind StorageKind; + enum { + RowsAtCompileTime = (MatrixType::RowsAtCompileTime != Dynamic) ? + int(MatrixType::RowsAtCompileTime) - 1 : Dynamic, + ColsAtCompileTime = (MatrixType::ColsAtCompileTime != Dynamic) ? + int(MatrixType::ColsAtCompileTime) - 1 : Dynamic, + MaxRowsAtCompileTime = (MatrixType::MaxRowsAtCompileTime != Dynamic) ? + int(MatrixType::MaxRowsAtCompileTime) - 1 : Dynamic, + MaxColsAtCompileTime = (MatrixType::MaxColsAtCompileTime != Dynamic) ? + int(MatrixType::MaxColsAtCompileTime) - 1 : Dynamic, + Flags = _MatrixTypeNested::Flags & (HereditaryBits | LvalueBit), + CoeffReadCost = _MatrixTypeNested::CoeffReadCost // minor is used typically on tiny matrices, + // where loops are unrolled and the 'if' evaluates at compile time + }; +}; +} + +template<typename MatrixType> class Minor + : public MatrixBase<Minor<MatrixType> > +{ + public: + + typedef MatrixBase<Minor> Base; + EIGEN_DENSE_PUBLIC_INTERFACE(Minor) + + inline Minor(const MatrixType& matrix, + Index row, Index col) + : m_matrix(matrix), m_row(row), m_col(col) + { + eigen_assert(row >= 0 && row < matrix.rows() + && col >= 0 && col < matrix.cols()); + } + + EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Minor) + + inline Index rows() const { return m_matrix.rows() - 1; } + inline Index cols() const { return m_matrix.cols() - 1; } + + inline Scalar& coeffRef(Index row, Index col) + { + return m_matrix.const_cast_derived().coeffRef(row + (row >= m_row), col + (col >= m_col)); + } + + inline const Scalar coeff(Index row, Index col) const + { + return m_matrix.coeff(row + (row >= m_row), col + (col >= m_col)); + } + + protected: + const typename MatrixType::Nested m_matrix; + const Index m_row, m_col; +}; + +/** + * \return an expression of the (\a row, \a col)-minor of *this, + * i.e. an expression constructed from *this by removing the specified + * row and column. + * + * Example: \include MatrixBase_minor.cpp + * Output: \verbinclude MatrixBase_minor.out + * + * \sa class Minor + */ +template<typename Derived> +inline Minor<Derived> +MatrixBase<Derived>::minor(Index row, Index col) +{ + return Minor<Derived>(derived(), row, col); +} + +/** + * This is the const version of minor(). */ +template<typename Derived> +inline const Minor<Derived> +MatrixBase<Derived>::minor(Index row, Index col) const +{ + return Minor<Derived>(derived(), row, col); +} + +} // end namespace Eigen + +#endif // EIGEN_MINOR_H |