mirror of
https://gitlab.com/libeigen/eigen.git
synced 2026-04-10 11:34:33 +08:00
240 lines
8.7 KiB
C++
240 lines
8.7 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
|
|
// for linear algebra. Eigen itself is part of the KDE project.
|
|
//
|
|
// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
|
|
// Copyright (C) 2009 Ricard Marxer <email@ricardmarxer.com>
|
|
//
|
|
// Eigen is free software; you can redistribute it and/or
|
|
// modify it under the terms of the GNU Lesser General Public
|
|
// License as published by the Free Software Foundation; either
|
|
// version 3 of the License, or (at your option) any later version.
|
|
//
|
|
// Alternatively, you can redistribute it and/or
|
|
// modify it under the terms of the GNU General Public License as
|
|
// published by the Free Software Foundation; either version 2 of
|
|
// the License, or (at your option) any later version.
|
|
//
|
|
// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
|
|
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public
|
|
// License and a copy of the GNU General Public License along with
|
|
// Eigen. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
#ifndef EIGEN_REVERSE_H
|
|
#define EIGEN_REVERSE_H
|
|
|
|
#include <iostream>
|
|
using namespace std;
|
|
|
|
/** \array_module \ingroup Array
|
|
*
|
|
* \class Reverse
|
|
*
|
|
* \brief Expression of the reverse of a vector or matrix
|
|
*
|
|
* \param MatrixType the type of the object of which we are taking the reverse
|
|
*
|
|
* This class represents an expression of the reverse of a vector.
|
|
* It is the return type of MatrixBase::reverse() and PartialRedux::reverse()
|
|
* and most of the time this is the only way it is used.
|
|
*
|
|
* \sa MatrixBase::reverse(), PartialRedux::reverse()
|
|
*/
|
|
template<typename MatrixType, int Direction>
|
|
struct ei_traits<Reverse<MatrixType, Direction> >
|
|
{
|
|
typedef typename MatrixType::Scalar Scalar;
|
|
typedef typename ei_nested<MatrixType>::type MatrixTypeNested;
|
|
typedef typename ei_unref<MatrixTypeNested>::type _MatrixTypeNested;
|
|
enum {
|
|
RowsAtCompileTime = MatrixType::RowsAtCompileTime,
|
|
ColsAtCompileTime = MatrixType::ColsAtCompileTime,
|
|
MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
|
|
MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime,
|
|
|
|
// TODO: check how to correctly set the new flags
|
|
Flags = ((int(_MatrixTypeNested::Flags) & HereditaryBits)
|
|
& ~(LowerTriangularBit | UpperTriangularBit))
|
|
| (int(_MatrixTypeNested::Flags)&UpperTriangularBit ? LowerTriangularBit : 0)
|
|
| (int(_MatrixTypeNested::Flags)&LowerTriangularBit ? UpperTriangularBit : 0),
|
|
|
|
// TODO: should add two add costs (due to the -1) or only one, and add the cost of calling .rows() and .cols()
|
|
CoeffReadCost = _MatrixTypeNested::CoeffReadCost
|
|
};
|
|
};
|
|
|
|
template<typename MatrixType, int Direction> class Reverse
|
|
: public MatrixBase<Reverse<MatrixType, Direction> >
|
|
{
|
|
public:
|
|
|
|
EIGEN_GENERIC_PUBLIC_INTERFACE(Reverse)
|
|
|
|
inline Reverse(const MatrixType& matrix) : m_matrix(matrix) { }
|
|
|
|
EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Reverse)
|
|
|
|
inline int rows() const { return m_matrix.rows(); }
|
|
inline int cols() const { return m_matrix.cols(); }
|
|
|
|
inline Scalar& coeffRef(int row, int col)
|
|
{
|
|
return m_matrix.const_cast_derived().coeffRef(((Direction == Vertical) || (Direction == BothDirections)) ? m_matrix.rows() - row - 1 : row,
|
|
((Direction == Horizontal) || (Direction == BothDirections)) ? m_matrix.cols() - col - 1 : col);
|
|
}
|
|
|
|
inline const Scalar coeff(int row, int col) const
|
|
{
|
|
return m_matrix.coeff(((Direction == Vertical) || (Direction == BothDirections)) ? m_matrix.rows() - row - 1 : row,
|
|
((Direction == Horizontal) || (Direction == BothDirections)) ? m_matrix.cols() - col - 1 : col);
|
|
}
|
|
|
|
/* could be removed */
|
|
/*
|
|
inline const Scalar coeff(int index) const
|
|
{
|
|
switch ( Direction )
|
|
{
|
|
case Vertical:
|
|
return m_matrix.coeff( index + m_matrix.rows() - 2 * (index % m_matrix.rows()) - 1 );
|
|
break;
|
|
|
|
case Horizontal:
|
|
return m_matrix.coeff( (index % m_matrix.rows()) + (m_matrix.cols() - 1 - index/m_matrix.rows()) * m_matrix.rows() );
|
|
break;
|
|
|
|
case BothDirections:
|
|
return m_matrix.coeff((m_matrix.rows() * m_matrix.cols()) - index - 1);
|
|
break;
|
|
}
|
|
|
|
}
|
|
|
|
inline Scalar& coeffRef(int index)
|
|
{
|
|
switch ( Direction )
|
|
{
|
|
case Vertical:
|
|
return m_matrix.const_cast_derived().coeffRef( index + m_matrix.rows() - 2 * (index % m_matrix.rows()) - 1 );
|
|
break;
|
|
|
|
case Horizontal:
|
|
return m_matrix.const_cast_derived().coeffRef( (index % m_matrix.rows()) + (m_matrix.cols() - 1 - index/m_matrix.rows()) * m_matrix.rows() );
|
|
break;
|
|
|
|
case BothDirections:
|
|
return m_matrix.const_cast_derived().coeffRef( (m_matrix.rows() * m_matrix.cols()) - index - 1 );
|
|
break;
|
|
}
|
|
}
|
|
*/
|
|
|
|
/* the following is not ready yet */
|
|
/*
|
|
// TODO: We must reverse the packet reading and writing, which is currently not done here, I think
|
|
template<int LoadMode>
|
|
inline const PacketScalar packet(int row, int col) const
|
|
{
|
|
return m_matrix.template packet<LoadMode>(((Direction == Vertical) || (Direction == BothDirections)) ? m_matrix.rows() - row - 1 : row,
|
|
((Direction == Horizontal) || (Direction == BothDirections)) ? m_matrix.cols() - col - 1 : col);
|
|
}
|
|
|
|
template<int LoadMode>
|
|
inline void writePacket(int row, int col, const PacketScalar& x)
|
|
{
|
|
m_matrix.const_cast_derived().template writePacket<LoadMode>(((Direction == Vertical) || (Direction == BothDirections)) ? m_matrix.rows() - row - 1 : row,
|
|
((Direction == Horizontal) || (Direction == BothDirections)) ? m_matrix.cols() - col - 1 : col,
|
|
x);
|
|
}
|
|
|
|
template<int LoadMode>
|
|
inline const PacketScalar packet(int index) const
|
|
{
|
|
switch ( Direction )
|
|
{
|
|
case Vertical:
|
|
return m_matrix.template packet<LoadMode>( index + m_matrix.rows() - 2 * (index % m_matrix.rows()) - 1 );
|
|
break;
|
|
|
|
case Horizontal:
|
|
return m_matrix.template packet<LoadMode>( (index % m_matrix.rows()) + (m_matrix.cols() - 1 - index/m_matrix.rows()) * m_matrix.rows() );
|
|
break;
|
|
|
|
case BothDirections:
|
|
return m_matrix.template packet<LoadMode>( (m_matrix.rows() * m_matrix.cols()) - index - 1 );
|
|
break;
|
|
}
|
|
}
|
|
*/
|
|
|
|
/* could be removed */
|
|
/*
|
|
template<int LoadMode>
|
|
inline void writePacket(int index, const PacketScalar& x)
|
|
{
|
|
switch ( Direction )
|
|
{
|
|
case Vertical:
|
|
return m_matrix.const_cast_derived().template packet<LoadMode>( index + m_matrix.rows() - 2 * (index % m_matrix.rows()) - 1, x );
|
|
break;
|
|
|
|
case Horizontal:
|
|
return m_matrix.const_cast_derived().template packet<LoadMode>( (index % m_matrix.rows()) + (m_matrix.cols() - 1 - index/m_matrix.rows()) * m_matrix.rows(), x );
|
|
break;
|
|
|
|
case BothDirections:
|
|
return m_matrix.const_cast_derived().template packet<LoadMode>( (m_matrix.rows() * m_matrix.cols()) - index - 1, x );
|
|
break;
|
|
}
|
|
}
|
|
*/
|
|
|
|
protected:
|
|
const typename MatrixType::Nested m_matrix;
|
|
};
|
|
|
|
/** \returns an expression of the reverse of *this.
|
|
*
|
|
* Example: \include MatrixBase_reverse.cpp
|
|
* Output: \verbinclude MatrixBase_reverse.out
|
|
*
|
|
*/
|
|
template<typename Derived>
|
|
inline Reverse<Derived, BothDirections>
|
|
MatrixBase<Derived>::reverse()
|
|
{
|
|
return derived();
|
|
}
|
|
|
|
/** This is the const version of reverse(). */
|
|
template<typename Derived>
|
|
inline const Reverse<Derived, BothDirections>
|
|
MatrixBase<Derived>::reverse() const
|
|
{
|
|
return derived();
|
|
}
|
|
|
|
/** This is the "in place" version of reverse: it reverses \c *this.
|
|
*
|
|
* In most cases it is probably better to simply use the reversed expression
|
|
* of a matrix. However, when reversing the matrix data itself is really needed,
|
|
* then this "in-place" version is probably the right choice because it provides
|
|
* the following additional features:
|
|
* - less error prone: doing the same operation with .reverse() requires special care:
|
|
* \code m = m.reverse().eval(); \endcode
|
|
* - no temporary object is created (currently there is one created but could be avoided using swap)
|
|
* - it allows future optimizations (cache friendliness, etc.)
|
|
*
|
|
* \sa reverse() */
|
|
template<typename Derived>
|
|
inline void MatrixBase<Derived>::reverseInPlace()
|
|
{
|
|
derived() = derived().reverse().eval();
|
|
}
|
|
|
|
|
|
#endif // EIGEN_REVERSE_H
|