mirror/eigen
2
0
Fork 0
mirror of https://gitlab.com/libeigen/eigen.git synced 2025-03-01 18:26:24 +08:00
Code Issues Packages Projects Releases Wiki Activity

add a VectorBlock expr as a specialization of Block

Browse Source
This commit is contained in:
Gael Guennebaud 2009-07-05 11:33:55 +02:00
parent eec334c604
commit c6f610093b
8 changed files with 377 additions and 257 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Eigen/Core
View File

@ -164,6 +164,7 @@ namespace Eigen {
#include "src/Core/MapBase.h"
#include "src/Core/Map.h"
#include "src/Core/Block.h"
#include "src/Core/VectorBlock.h"
#include "src/Core/Minor.h"
#include "src/Core/Transpose.h"
#include "src/Core/DiagonalMatrix.h"

243
Eigen/src/Core/Block.h
View File

@ -314,249 +314,6 @@ inline const typename BlockReturnType<Derived>::Type MatrixBase<Derived>
return typename BlockReturnType<Derived>::Type(derived(), startRow, startCol, blockRows, blockCols);
}
/** \returns a dynamic-size expression of a segment (i.e. a vector block) in *this.
*
* \only_for_vectors
*
* \addexample SegmentIntInt \label How to reference a sub-vector (dynamic size)
*
* \param start the first coefficient in the segment
* \param size the number of coefficients in the segment
*
* Example: \include MatrixBase_segment_int_int.cpp
* Output: \verbinclude MatrixBase_segment_int_int.out
*
* \note Even though the returned expression has dynamic size, in the case
* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
* which means that evaluating it does not cause a dynamic memory allocation.
*
* \sa class Block, segment(int)
*/
template<typename Derived>
inline typename BlockReturnType<Derived>::SubVectorType MatrixBase<Derived>
::segment(int start, int size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return typename BlockReturnType<Derived>::SubVectorType(derived(), RowsAtCompileTime == 1 ? 0 : start,
ColsAtCompileTime == 1 ? 0 : start,
RowsAtCompileTime == 1 ? 1 : size,
ColsAtCompileTime == 1 ? 1 : size);
}
/** This is the const version of segment(int,int).*/
template<typename Derived>
inline const typename BlockReturnType<Derived>::SubVectorType
MatrixBase<Derived>::segment(int start, int size) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return typename BlockReturnType<Derived>::SubVectorType(derived(), RowsAtCompileTime == 1 ? 0 : start,
ColsAtCompileTime == 1 ? 0 : start,
RowsAtCompileTime == 1 ? 1 : size,
ColsAtCompileTime == 1 ? 1 : size);
}
/** \returns a dynamic-size expression of the first coefficients of *this.
*
* \only_for_vectors
*
* \param size the number of coefficients in the block
*
* \addexample BlockInt \label How to reference a sub-vector (fixed-size)
*
* Example: \include MatrixBase_start_int.cpp
* Output: \verbinclude MatrixBase_start_int.out
*
* \note Even though the returned expression has dynamic size, in the case
* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
* which means that evaluating it does not cause a dynamic memory allocation.
*
* \sa class Block, block(int,int)
*/
template<typename Derived>
inline typename BlockReturnType<Derived,Dynamic>::SubVectorType
MatrixBase<Derived>::start(int size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived,
RowsAtCompileTime == 1 ? 1 : Dynamic,
ColsAtCompileTime == 1 ? 1 : Dynamic>
(derived(), 0, 0,
RowsAtCompileTime == 1 ? 1 : size,
ColsAtCompileTime == 1 ? 1 : size);
}
/** This is the const version of start(int).*/
template<typename Derived>
inline const typename BlockReturnType<Derived,Dynamic>::SubVectorType
MatrixBase<Derived>::start(int size) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived,
RowsAtCompileTime == 1 ? 1 : Dynamic,
ColsAtCompileTime == 1 ? 1 : Dynamic>
(derived(), 0, 0,
RowsAtCompileTime == 1 ? 1 : size,
ColsAtCompileTime == 1 ? 1 : size);
}
/** \returns a dynamic-size expression of the last coefficients of *this.
*
* \only_for_vectors
*
* \param size the number of coefficients in the block
*
* \addexample BlockEnd \label How to reference the end of a vector (fixed-size)
*
* Example: \include MatrixBase_end_int.cpp
* Output: \verbinclude MatrixBase_end_int.out
*
* \note Even though the returned expression has dynamic size, in the case
* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
* which means that evaluating it does not cause a dynamic memory allocation.
*
* \sa class Block, block(int,int)
*/
template<typename Derived>
inline typename BlockReturnType<Derived,Dynamic>::SubVectorType
MatrixBase<Derived>::end(int size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived,
RowsAtCompileTime == 1 ? 1 : Dynamic,
ColsAtCompileTime == 1 ? 1 : Dynamic>
(derived(),
RowsAtCompileTime == 1 ? 0 : rows() - size,
ColsAtCompileTime == 1 ? 0 : cols() - size,
RowsAtCompileTime == 1 ? 1 : size,
ColsAtCompileTime == 1 ? 1 : size);
}
/** This is the const version of end(int).*/
template<typename Derived>
inline const typename BlockReturnType<Derived,Dynamic>::SubVectorType
MatrixBase<Derived>::end(int size) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived,
RowsAtCompileTime == 1 ? 1 : Dynamic,
ColsAtCompileTime == 1 ? 1 : Dynamic>
(derived(),
RowsAtCompileTime == 1 ? 0 : rows() - size,
ColsAtCompileTime == 1 ? 0 : cols() - size,
RowsAtCompileTime == 1 ? 1 : size,
ColsAtCompileTime == 1 ? 1 : size);
}
/** \returns a fixed-size expression of a segment (i.e. a vector block) in \c *this
*
* \only_for_vectors
*
* The template parameter \a Size is the number of coefficients in the block
*
* \param start the index of the first element of the sub-vector
*
* Example: \include MatrixBase_template_int_segment.cpp
* Output: \verbinclude MatrixBase_template_int_segment.out
*
* \sa class Block
*/
template<typename Derived>
template<int Size>
inline typename BlockReturnType<Derived,Size>::SubVectorType
MatrixBase<Derived>::segment(int start)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived, (RowsAtCompileTime == 1 ? 1 : Size),
(ColsAtCompileTime == 1 ? 1 : Size)>
(derived(), RowsAtCompileTime == 1 ? 0 : start,
ColsAtCompileTime == 1 ? 0 : start);
}
/** This is the const version of segment<int>(int).*/
template<typename Derived>
template<int Size>
inline const typename BlockReturnType<Derived,Size>::SubVectorType
MatrixBase<Derived>::segment(int start) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived, (RowsAtCompileTime == 1 ? 1 : Size),
(ColsAtCompileTime == 1 ? 1 : Size)>
(derived(), RowsAtCompileTime == 1 ? 0 : start,
ColsAtCompileTime == 1 ? 0 : start);
}
/** \returns a fixed-size expression of the first coefficients of *this.
*
* \only_for_vectors
*
* The template parameter \a Size is the number of coefficients in the block
*
* \addexample BlockStart \label How to reference the start of a vector (fixed-size)
*
* Example: \include MatrixBase_template_int_start.cpp
* Output: \verbinclude MatrixBase_template_int_start.out
*
* \sa class Block
*/
template<typename Derived>
template<int Size>
inline typename BlockReturnType<Derived,Size>::SubVectorType
MatrixBase<Derived>::start()
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived, (RowsAtCompileTime == 1 ? 1 : Size),
(ColsAtCompileTime == 1 ? 1 : Size)>(derived(), 0, 0);
}
/** This is the const version of start<int>().*/
template<typename Derived>
template<int Size>
inline const typename BlockReturnType<Derived,Size>::SubVectorType
MatrixBase<Derived>::start() const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived, (RowsAtCompileTime == 1 ? 1 : Size),
(ColsAtCompileTime == 1 ? 1 : Size)>(derived(), 0, 0);
}
/** \returns a fixed-size expression of the last coefficients of *this.
*
* \only_for_vectors
*
* The template parameter \a Size is the number of coefficients in the block
*
* Example: \include MatrixBase_template_int_end.cpp
* Output: \verbinclude MatrixBase_template_int_end.out
*
* \sa class Block
*/
template<typename Derived>
template<int Size>
inline typename BlockReturnType<Derived,Size>::SubVectorType
MatrixBase<Derived>::end()
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived, RowsAtCompileTime == 1 ? 1 : Size,
ColsAtCompileTime == 1 ? 1 : Size>
(derived(),
RowsAtCompileTime == 1 ? 0 : rows() - Size,
ColsAtCompileTime == 1 ? 0 : cols() - Size);
}
/** This is the const version of end<int>.*/
template<typename Derived>
template<int Size>
inline const typename BlockReturnType<Derived,Size>::SubVectorType
MatrixBase<Derived>::end() const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return Block<Derived, RowsAtCompileTime == 1 ? 1 : Size,
ColsAtCompileTime == 1 ? 1 : Size>
(derived(),
RowsAtCompileTime == 1 ? 0 : rows() - Size,
ColsAtCompileTime == 1 ? 0 : cols() - Size);
}
/** \returns a dynamic-size expression of a corner of *this.
*
* \param type the type of corner. Can be \a Eigen::TopLeft, \a Eigen::TopRight,

24
Eigen/src/Core/MatrixBase.h
View File

@ -401,14 +401,14 @@ template<typename Derived> class MatrixBase
const typename BlockReturnType<Derived>::Type
block(int startRow, int startCol, int blockRows, int blockCols) const;
typename BlockReturnType<Derived>::SubVectorType segment(int start, int size);
const typename BlockReturnType<Derived>::SubVectorType segment(int start, int size) const;
VectorBlock<Derived> segment(int start, int size);
const VectorBlock<Derived> segment(int start, int size) const;
typename BlockReturnType<Derived,Dynamic>::SubVectorType start(int size);
const typename BlockReturnType<Derived,Dynamic>::SubVectorType start(int size) const;
VectorBlock<Derived> start(int size);
const VectorBlock<Derived> start(int size) const;
typename BlockReturnType<Derived,Dynamic>::SubVectorType end(int size);
const typename BlockReturnType<Derived,Dynamic>::SubVectorType end(int size) const;
VectorBlock<Derived> end(int size);
const VectorBlock<Derived> end(int size) const;
typename BlockReturnType<Derived>::Type corner(CornerType type, int cRows, int cCols);
const typename BlockReturnType<Derived>::Type corner(CornerType type, int cRows, int cCols) const;
@ -423,14 +423,14 @@ template<typename Derived> class MatrixBase
template<int CRows, int CCols>
const typename BlockReturnType<Derived, CRows, CCols>::Type corner(CornerType type) const;
template<int Size> typename BlockReturnType<Derived,Size>::SubVectorType start(void);
template<int Size> const typename BlockReturnType<Derived,Size>::SubVectorType start() const;
template<int Size> VectorBlock<Derived,Size> start(void);
template<int Size> const VectorBlock<Derived,Size> start() const;
template<int Size> typename BlockReturnType<Derived,Size>::SubVectorType end();
template<int Size> const typename BlockReturnType<Derived,Size>::SubVectorType end() const;
template<int Size> VectorBlock<Derived,Size> end();
template<int Size> const VectorBlock<Derived,Size> end() const;
template<int Size> typename BlockReturnType<Derived,Size>::SubVectorType segment(int start);
template<int Size> const typename BlockReturnType<Derived,Size>::SubVectorType segment(int start) const;
template<int Size> VectorBlock<Derived,Size> segment(int start);
template<int Size> const VectorBlock<Derived,Size> segment(int start) const;
Diagonal<Derived,0> diagonal();
const Diagonal<Derived,0> diagonal() const;

311
Eigen/src/Core/VectorBlock.h Normal file
View File

@ -0,0 +1,311 @@
// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2009 Gael Guennebaud <g.gael@free.fr>
// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.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_VECTORBLOCK_H
#define EIGEN_VECTORBLOCK_H
/** \class VectorBlock
*
* \brief Expression of a fixed-size or dynamic-size sub-vector
*
* \param VectorType the type of the object in which we are taking a sub-vector
* \param Size size of the sub-vector we are taking at compile time (optional)
* \param _PacketAccess allows to enforce aligned loads and stores if set to ForceAligned.
* The default is AsRequested. This parameter is internaly used by Eigen
* in expressions such as \code mat.segment() += other; \endcode and most of
* the time this is the only way it is used.
*
* This class represents an expression of either a fixed-size or dynamic-size sub-vector.
* It is the return type of MatrixBase::segment(int,int) and MatrixBase::segment<int>(int) and
* most of the time this is the only way it is used.
*
* However, if you want to directly maniputate sub-vector expressions,
* for instance if you want to write a function returning such an expression, you
* will need to use this class.
*
* Here is an example illustrating the dynamic case:
* \include class_VectorBlock.cpp
* Output: \verbinclude class_VectorBlock.out
*
* \note Even though this expression has dynamic size, in the case where \a VectorType
* has fixed size, this expression inherits a fixed maximal size which means that evaluating
* it does not cause a dynamic memory allocation.
*
* Here is an example illustrating the fixed-size case:
* \include class_FixedVectorBlock.cpp
* Output: \verbinclude class_FixedVectorBlock.out
*
* \sa class Block, MatrixBase::segment(int,int,int,int), MatrixBase::segment(int,int)
*/
template<typename VectorType, int Size, int _PacketAccess>
struct ei_traits<VectorBlock<VectorType, Size, _PacketAccess> >
: public ei_traits<Block<VectorType,
ei_traits<VectorType>::RowsAtCompileTime==1 ? 1 : Size,
ei_traits<VectorType>::ColsAtCompileTime==1 ? 1 : Size,
_PacketAccess> >
{
};
template<typename VectorType, int Size, int PacketAccess> class VectorBlock
: public Block<VectorType,
ei_traits<VectorType>::RowsAtCompileTime==1 ? 1 : Size,
ei_traits<VectorType>::ColsAtCompileTime==1 ? 1 : Size,
PacketAccess>
{
typedef Block<VectorType,
ei_traits<VectorType>::RowsAtCompileTime==1 ? 1 : Size,
ei_traits<VectorType>::ColsAtCompileTime==1 ? 1 : Size,
PacketAccess> Base;
enum {
IsColVector = ei_traits<VectorType>::ColsAtCompileTime==1
};
public:
using Base::operator=;
using Base::operator+=;
using Base::operator-=;
using Base::operator*=;
using Base::operator/=;
/** Dynamic-size constructor
*/
inline VectorBlock(const VectorType& vector, int start, int size)
: Base(vector,
IsColVector ? start : 0, IsColVector ? 0 : start,
IsColVector ? size : 1, IsColVector ? 1 : size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(VectorBlock);
}
/** Fixed-size constructor
*/
inline VectorBlock(const VectorType& vector, int start)
: Base(vector, IsColVector ? start : 0, IsColVector ? 0 : start)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(VectorBlock);
}
};
/** \returns a dynamic-size expression of a segment (i.e. a vector block) in *this.
*
* \only_for_vectors
*
* \addexample VectorBlockIntInt \label How to reference a sub-vector (dynamic size)
*
* \param start the first coefficient in the segment
* \param size the number of coefficients in the segment
*
* Example: \include MatrixBase_segment_int_int.cpp
* Output: \verbinclude MatrixBase_segment_int_int.out
*
* \note Even though the returned expression has dynamic size, in the case
* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
* which means that evaluating it does not cause a dynamic memory allocation.
*
* \sa class Block, segment(int)
*/
template<typename Derived>
inline VectorBlock<Derived> MatrixBase<Derived>
::segment(int start, int size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived>(derived(), start, size);
}
/** This is the const version of segment(int,int).*/
template<typename Derived>
inline const VectorBlock<Derived>
MatrixBase<Derived>::segment(int start, int size) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived>(derived(), start, size);
}
/** \returns a dynamic-size expression of the first coefficients of *this.
*
* \only_for_vectors
*
* \param size the number of coefficients in the block
*
* \addexample BlockInt \label How to reference a sub-vector (fixed-size)
*
* Example: \include MatrixBase_start_int.cpp
* Output: \verbinclude MatrixBase_start_int.out
*
* \note Even though the returned expression has dynamic size, in the case
* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
* which means that evaluating it does not cause a dynamic memory allocation.
*
* \sa class Block, block(int,int)
*/
template<typename Derived>
inline VectorBlock<Derived>
MatrixBase<Derived>::start(int size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived>(derived(), 0, size);
}
/** This is the const version of start(int).*/
template<typename Derived>
inline const VectorBlock<Derived>
MatrixBase<Derived>::start(int size) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived>(derived(), 0, size);
}
/** \returns a dynamic-size expression of the last coefficients of *this.
*
* \only_for_vectors
*
* \param size the number of coefficients in the block
*
* \addexample BlockEnd \label How to reference the end of a vector (fixed-size)
*
* Example: \include MatrixBase_end_int.cpp
* Output: \verbinclude MatrixBase_end_int.out
*
* \note Even though the returned expression has dynamic size, in the case
* when it is applied to a fixed-size vector, it inherits a fixed maximal size,
* which means that evaluating it does not cause a dynamic memory allocation.
*
* \sa class Block, block(int,int)
*/
template<typename Derived>
inline VectorBlock<Derived>
MatrixBase<Derived>::end(int size)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived>(derived(), this->size() - size, size);
}
/** This is the const version of end(int).*/
template<typename Derived>
inline const VectorBlock<Derived>
MatrixBase<Derived>::end(int size) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived>(derived(), this->size() - size, size);
}
/** \returns a fixed-size expression of a segment (i.e. a vector block) in \c *this
*
* \only_for_vectors
*
* The template parameter \a Size is the number of coefficients in the block
*
* \param start the index of the first element of the sub-vector
*
* Example: \include MatrixBase_template_int_segment.cpp
* Output: \verbinclude MatrixBase_template_int_segment.out
*
* \sa class Block
*/
template<typename Derived>
template<int Size>
inline VectorBlock<Derived,Size>
MatrixBase<Derived>::segment(int start)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived,Size>(derived(), start);
}
/** This is the const version of segment<int>(int).*/
template<typename Derived>
template<int Size>
inline const VectorBlock<Derived,Size>
MatrixBase<Derived>::segment(int start) const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived,Size>(derived(), start);
}
/** \returns a fixed-size expression of the first coefficients of *this.
*
* \only_for_vectors
*
* The template parameter \a Size is the number of coefficients in the block
*
* \addexample BlockStart \label How to reference the start of a vector (fixed-size)
*
* Example: \include MatrixBase_template_int_start.cpp
* Output: \verbinclude MatrixBase_template_int_start.out
*
* \sa class Block
*/
template<typename Derived>
template<int Size>
inline VectorBlock<Derived,Size>
MatrixBase<Derived>::start()
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived,Size>(derived(), 0);
}
/** This is the const version of start<int>().*/
template<typename Derived>
template<int Size>
inline const VectorBlock<Derived,Size>
MatrixBase<Derived>::start() const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived,Size>(derived(), 0);
}
/** \returns a fixed-size expression of the last coefficients of *this.
*
* \only_for_vectors
*
* The template parameter \a Size is the number of coefficients in the block
*
* Example: \include MatrixBase_template_int_end.cpp
* Output: \verbinclude MatrixBase_template_int_end.out
*
* \sa class Block
*/
template<typename Derived>
template<int Size>
inline VectorBlock<Derived,Size>
MatrixBase<Derived>::end()
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived, Size>(derived(), size() - Size);
}
/** This is the const version of end<int>.*/
template<typename Derived>
template<int Size>
inline const VectorBlock<Derived,Size>
MatrixBase<Derived>::end() const
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
return VectorBlock<Derived, Size>(derived(), size() - Size);
}
#endif // EIGEN_VECTORBLOCK_H

1
Eigen/src/Core/util/ForwardDeclarations.h
View File

@ -39,6 +39,7 @@ template<typename MatrixType> class Minor;
template<typename MatrixType, int BlockRows=Dynamic, int BlockCols=Dynamic, int PacketAccess=AsRequested,
int _DirectAccessStatus = ei_traits<MatrixType>::Flags&DirectAccessBit ? DirectAccessBit
: ei_traits<MatrixType>::Flags&SparseBit> class Block;
template<typename MatrixType, int Size=Dynamic, int PacketAccess=AsRequested> class VectorBlock;
template<typename MatrixType> class Transpose;
template<typename MatrixType> class Conjugate;
template<typename NullaryOp, typename MatrixType> class CwiseNullaryOp;

2
Eigen/src/Core/util/XprHelper.h
View File

@ -237,8 +237,6 @@ struct ei_special_scalar_op_base<Derived,Scalar,OtherScalar,true>
* TODO: could be a good idea to define a big ReturnType struct ??
*/
template<typename ExpressionType, int RowsOrSize=Dynamic, int Cols=Dynamic> struct BlockReturnType {
typedef Block<ExpressionType, (ei_traits<ExpressionType>::RowsAtCompileTime == 1 ? 1 : RowsOrSize),
(ei_traits<ExpressionType>::ColsAtCompileTime == 1 ? 1 : RowsOrSize)> SubVectorType;
typedef Block<ExpressionType, RowsOrSize, Cols> Type;
};

26
doc/examples/class_FixedVectorBlock.cpp Normal file
View File

@ -0,0 +1,26 @@
#include <Eigen/Core>
USING_PART_OF_NAMESPACE_EIGEN
using namespace std;
template<typename Derived>
Eigen::VectorBlock<Derived, 2>
firstTwo(MatrixBase<Derived>& v)
{
return Eigen::VectorBlock<Derived, 2>(v.derived(), 0);
}
template<typename Derived>
const Eigen::VectorBlock<Derived, 2>
firstTwo(const MatrixBase<Derived>& v)
{
return Eigen::VectorBlock<Derived, 2>(v.derived(), 0);
}
int main(int, char**)
{
Matrix<int,1,6> v; v << 1,2,3,4,5,6;
cout << firstTwo(4*v) << endl; // calls the const version
firstTwo(v) *= 2; // calls the non-const version
cout << "Now the vector v is:" << endl << v << endl;
return 0;
}

26
doc/examples/class_VectorBlock.cpp Normal file
View File

@ -0,0 +1,26 @@
#include <Eigen/Core>
USING_PART_OF_NAMESPACE_EIGEN
using namespace std;
template<typename Derived>
Eigen::VectorBlock<Derived>
segmentFromRange(MatrixBase<Derived>& v, int start, int end)
{
return Eigen::VectorBlock<Derived>(v.derived(), start, end-start);
}
template<typename Derived>
const Eigen::VectorBlock<Derived>
segmentFromRange(const MatrixBase<Derived>& v, int start, int end)
{
return Eigen::VectorBlock<Derived>(v.derived(), start, end-start);
}
int main(int, char**)
{
Matrix<int,1,6> v; v << 1,2,3,4,5,6;
cout << segmentFromRange(2*v, 2, 4) << endl; // calls the const version
segmentFromRange(v, 1, 3) *= 5; // calls the non-const version
cout << "Now the vector v is:" << endl << v << endl;
return 0;
}