eigen/Eigen/Core/Column.h
Benoit Jacob dad245af56 - eigen2 now fully enforces constness! found a way to achieve that
with minimal code duplication. There now are only two (2)
  const_cast remaining in the whole source code.
- eigen2 now fully allows copying a row-vector into a column-vector.
  added a unit-test for that.
- split unit tests, improve docs, various improvements.
2007-12-25 17:20:58 +00:00

112 lines
3.6 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) 2006-2007 Benoit Jacob <jacob@math.jussieu.fr>
//
// Eigen is free software; 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 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 General Public License for more
// details.
//
// You should have received a copy of the GNU General Public License along
// with Eigen; if not, write to the Free Software Foundation, Inc., 51
// Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. This exception does not invalidate any other reasons why a work
// based on this file might be covered by the GNU General Public License.
#ifndef EIGEN_COLUMN_H
#define EIGEN_COLUMN_H
/** \class Column
*
* \brief Expression of a column
*
* \param MatrixType the type of the object in which we are taking a column
*
* This class represents an expression of a column. It is the return
* type of MatrixBase::col() and most of the time this is the only way it
* is used.
*
* However, if you want to directly maniputate column 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 this:
* \include class_Column.cpp
* Output: \verbinclude class_Column.out
*
* \sa MatrixBase::col()
*/
template<typename MatrixType> class Column
: public MatrixBase<typename MatrixType::Scalar, Column<MatrixType> >
{
public:
typedef typename MatrixType::Scalar Scalar;
typedef typename MatrixType::Ref MatRef;
friend class MatrixBase<Scalar, Column<MatrixType> >;
Column(const MatRef& matrix, int col)
: m_matrix(matrix), m_col(col)
{
assert(col >= 0 && col < matrix.cols());
}
Column(const Column& other)
: m_matrix(other.m_matrix), m_col(other.m_col) {}
EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Column)
private:
static const int _RowsAtCompileTime = MatrixType::RowsAtCompileTime,
_ColsAtCompileTime = 1;
const Column& _ref() const { return *this; }
int _rows() const { return m_matrix.rows(); }
int _cols() const { return 1; }
Scalar& _coeffRef(int row, int)
{
return m_matrix.coeffRef(row, m_col);
}
Scalar _coeff(int row, int) const
{
return m_matrix.coeff(row, m_col);
}
protected:
MatRef m_matrix;
const int m_col;
};
/** \returns an expression of the \a i-th column of *this. Note that the numbering starts at 0.
*
* Example: \include MatrixBase_column.cpp
* Output: \verbinclude MatrixBase_column.out
*
* \sa row(), class Column */
template<typename Scalar, typename Derived>
Column<Derived>
MatrixBase<Scalar, Derived>::col(int i)
{
return Column<Derived>(ref(), i);
}
/** This is the const version of col(). */
template<typename Scalar, typename Derived>
const Column<Derived>
MatrixBase<Scalar, Derived>::col(int i) const
{
return Column<Derived>(ref(), i);
}
#endif // EIGEN_COLUMN_H