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312 lines
10 KiB
C++
312 lines
10 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) 2008-2009 Gael Guennebaud <g.gael@free.fr>
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// Copyright (C) 2006-2008 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_VECTORBLOCK_H
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#define EIGEN_VECTORBLOCK_H
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/** \class VectorBlock
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*
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* \brief Expression of a fixed-size or dynamic-size sub-vector
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*
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* \param VectorType the type of the object in which we are taking a sub-vector
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* \param Size size of the sub-vector we are taking at compile time (optional)
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* \param _PacketAccess allows to enforce aligned loads and stores if set to ForceAligned.
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* The default is AsRequested. This parameter is internaly used by Eigen
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* in expressions such as \code mat.segment() += other; \endcode and most of
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* the time this is the only way it is used.
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*
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* This class represents an expression of either a fixed-size or dynamic-size sub-vector.
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* It is the return type of MatrixBase::segment(int,int) and MatrixBase::segment<int>(int) and
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* most of the time this is the only way it is used.
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*
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* However, if you want to directly maniputate sub-vector 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 the dynamic case:
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* \include class_VectorBlock.cpp
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* Output: \verbinclude class_VectorBlock.out
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*
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* \note Even though this expression has dynamic size, in the case where \a VectorType
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* has fixed size, this expression inherits a fixed maximal size which means that evaluating
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* it does not cause a dynamic memory allocation.
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*
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* Here is an example illustrating the fixed-size case:
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* \include class_FixedVectorBlock.cpp
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* Output: \verbinclude class_FixedVectorBlock.out
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*
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* \sa class Block, MatrixBase::segment(int,int,int,int), MatrixBase::segment(int,int)
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*/
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template<typename VectorType, int Size, int _PacketAccess>
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struct ei_traits<VectorBlock<VectorType, Size, _PacketAccess> >
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: public ei_traits<Block<VectorType,
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ei_traits<VectorType>::RowsAtCompileTime==1 ? 1 : Size,
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ei_traits<VectorType>::ColsAtCompileTime==1 ? 1 : Size,
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_PacketAccess> >
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{
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};
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template<typename VectorType, int Size, int PacketAccess> class VectorBlock
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: public Block<VectorType,
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ei_traits<VectorType>::RowsAtCompileTime==1 ? 1 : Size,
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ei_traits<VectorType>::ColsAtCompileTime==1 ? 1 : Size,
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PacketAccess>
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{
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typedef Block<VectorType,
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ei_traits<VectorType>::RowsAtCompileTime==1 ? 1 : Size,
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ei_traits<VectorType>::ColsAtCompileTime==1 ? 1 : Size,
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PacketAccess> Base;
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enum {
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IsColVector = ei_traits<VectorType>::ColsAtCompileTime==1
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};
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public:
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using Base::operator=;
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using Base::operator+=;
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using Base::operator-=;
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using Base::operator*=;
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using Base::operator/=;
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/** Dynamic-size constructor
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*/
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inline VectorBlock(const VectorType& vector, int start, int size)
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: Base(vector,
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IsColVector ? start : 0, IsColVector ? 0 : start,
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IsColVector ? size : 1, IsColVector ? 1 : size)
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(VectorBlock);
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}
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/** Fixed-size constructor
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*/
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inline VectorBlock(const VectorType& vector, int start)
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: Base(vector, IsColVector ? start : 0, IsColVector ? 0 : start)
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(VectorBlock);
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}
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};
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/** \returns a dynamic-size expression of a segment (i.e. a vector block) in *this.
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*
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* \only_for_vectors
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*
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* \addexample VectorBlockIntInt \label How to reference a sub-vector (dynamic size)
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*
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* \param start the first coefficient in the segment
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* \param size the number of coefficients in the segment
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*
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* Example: \include MatrixBase_segment_int_int.cpp
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* Output: \verbinclude MatrixBase_segment_int_int.out
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*
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* \note Even though the returned expression has dynamic size, in the case
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* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
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* which means that evaluating it does not cause a dynamic memory allocation.
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*
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* \sa class Block, segment(int)
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*/
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template<typename Derived>
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inline VectorBlock<Derived> MatrixBase<Derived>
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::segment(int start, int size)
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived>(derived(), start, size);
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}
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/** This is the const version of segment(int,int).*/
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template<typename Derived>
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inline const VectorBlock<Derived>
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MatrixBase<Derived>::segment(int start, int size) const
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived>(derived(), start, size);
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}
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/** \returns a dynamic-size expression of the first coefficients of *this.
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*
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* \only_for_vectors
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*
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* \param size the number of coefficients in the block
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*
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* \addexample BlockInt \label How to reference a sub-vector (fixed-size)
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*
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* Example: \include MatrixBase_start_int.cpp
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* Output: \verbinclude MatrixBase_start_int.out
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*
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* \note Even though the returned expression has dynamic size, in the case
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* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
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* which means that evaluating it does not cause a dynamic memory allocation.
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*
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* \sa class Block, block(int,int)
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*/
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template<typename Derived>
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inline VectorBlock<Derived>
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MatrixBase<Derived>::start(int size)
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived>(derived(), 0, size);
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}
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/** This is the const version of start(int).*/
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template<typename Derived>
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inline const VectorBlock<Derived>
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MatrixBase<Derived>::start(int size) const
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived>(derived(), 0, size);
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}
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/** \returns a dynamic-size expression of the last coefficients of *this.
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*
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* \only_for_vectors
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*
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* \param size the number of coefficients in the block
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*
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* \addexample BlockEnd \label How to reference the end of a vector (fixed-size)
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*
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* Example: \include MatrixBase_end_int.cpp
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* Output: \verbinclude MatrixBase_end_int.out
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*
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* \note Even though the returned expression has dynamic size, in the case
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* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
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* which means that evaluating it does not cause a dynamic memory allocation.
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*
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* \sa class Block, block(int,int)
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*/
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template<typename Derived>
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inline VectorBlock<Derived>
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MatrixBase<Derived>::end(int size)
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived>(derived(), this->size() - size, size);
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}
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/** This is the const version of end(int).*/
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template<typename Derived>
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inline const VectorBlock<Derived>
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MatrixBase<Derived>::end(int size) const
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived>(derived(), this->size() - size, size);
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}
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/** \returns a fixed-size expression of a segment (i.e. a vector block) in \c *this
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*
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* \only_for_vectors
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*
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* The template parameter \a Size is the number of coefficients in the block
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*
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* \param start the index of the first element of the sub-vector
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*
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* Example: \include MatrixBase_template_int_segment.cpp
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* Output: \verbinclude MatrixBase_template_int_segment.out
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*
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* \sa class Block
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*/
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template<typename Derived>
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template<int Size>
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inline VectorBlock<Derived,Size>
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MatrixBase<Derived>::segment(int start)
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived,Size>(derived(), start);
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}
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/** This is the const version of segment<int>(int).*/
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template<typename Derived>
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template<int Size>
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inline const VectorBlock<Derived,Size>
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MatrixBase<Derived>::segment(int start) const
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived,Size>(derived(), start);
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}
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/** \returns a fixed-size expression of the first coefficients of *this.
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*
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* \only_for_vectors
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*
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* The template parameter \a Size is the number of coefficients in the block
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*
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* \addexample BlockStart \label How to reference the start of a vector (fixed-size)
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*
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* Example: \include MatrixBase_template_int_start.cpp
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* Output: \verbinclude MatrixBase_template_int_start.out
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*
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* \sa class Block
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*/
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template<typename Derived>
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template<int Size>
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inline VectorBlock<Derived,Size>
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MatrixBase<Derived>::start()
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived,Size>(derived(), 0);
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}
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/** This is the const version of start<int>().*/
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template<typename Derived>
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template<int Size>
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inline const VectorBlock<Derived,Size>
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MatrixBase<Derived>::start() const
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived,Size>(derived(), 0);
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}
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/** \returns a fixed-size expression of the last coefficients of *this.
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*
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* \only_for_vectors
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*
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* The template parameter \a Size is the number of coefficients in the block
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*
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* Example: \include MatrixBase_template_int_end.cpp
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* Output: \verbinclude MatrixBase_template_int_end.out
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*
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* \sa class Block
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*/
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template<typename Derived>
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template<int Size>
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inline VectorBlock<Derived,Size>
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MatrixBase<Derived>::end()
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived, Size>(derived(), size() - Size);
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}
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/** This is the const version of end<int>.*/
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template<typename Derived>
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template<int Size>
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inline const VectorBlock<Derived,Size>
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MatrixBase<Derived>::end() const
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{
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EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
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return VectorBlock<Derived, Size>(derived(), size() - Size);
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}
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#endif // EIGEN_VECTORBLOCK_H
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