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Add sub/super-diagonal expression (read/write) as a trivial extension of

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DiagonalCoeffs. The current API is simply:
  m.diagonal<1>() => 1st super diagonal
  m.diagonal<-2>() => the 2nd sub diagonal
I'll add a code snippet once we agree on this API.
This commit is contained in:
Gael Guennebaud
2009-02-05 18:37:21 +00:00
parent 9637af5ecf
commit 910b387438
5 changed files with 60 additions and 12 deletions
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51
Eigen/src/Core/DiagonalCoeffs.h
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@@ -39,16 +39,17 @@
*
* \sa MatrixBase::diagonal()
*/
template<typename MatrixType>
struct ei_traits<DiagonalCoeffs<MatrixType> >
template<typename MatrixType, int DiagId>
struct ei_traits<DiagonalCoeffs<MatrixType,DiagId> >
{
typedef typename MatrixType::Scalar Scalar;
typedef typename ei_nested<MatrixType>::type MatrixTypeNested;
typedef typename ei_unref<MatrixTypeNested>::type _MatrixTypeNested;
enum {
AbsDiagId = DiagId<0 ? -DiagId : DiagId,
RowsAtCompileTime = int(MatrixType::SizeAtCompileTime) == Dynamic ? Dynamic
: EIGEN_ENUM_MIN(MatrixType::RowsAtCompileTime,
MatrixType::ColsAtCompileTime),
MatrixType::ColsAtCompileTime) - AbsDiagId,
ColsAtCompileTime = 1,
MaxRowsAtCompileTime = int(MatrixType::MaxSizeAtCompileTime) == Dynamic ? Dynamic
: EIGEN_ENUM_MIN(MatrixType::MaxRowsAtCompileTime,
@@ -59,9 +60,14 @@ struct ei_traits<DiagonalCoeffs<MatrixType> >
};
};
template<typename MatrixType> class DiagonalCoeffs
: public MatrixBase<DiagonalCoeffs<MatrixType> >
template<typename MatrixType, int DiagId> class DiagonalCoeffs
: public MatrixBase<DiagonalCoeffs<MatrixType, DiagId> >
{
enum {
AbsDiagId = DiagId<0 ? -DiagId : DiagId,
OffsetRow = DiagId<0 ? -DiagId : 0,
OffsetCol = DiagId<0 ? 0 : DiagId
};
public:
EIGEN_GENERIC_PUBLIC_INTERFACE(DiagonalCoeffs)
@@ -70,27 +76,27 @@ template<typename MatrixType> class DiagonalCoeffs
EIGEN_INHERIT_ASSIGNMENT_OPERATORS(DiagonalCoeffs)
inline int rows() const { return std::min(m_matrix.rows(), m_matrix.cols()); }
inline int rows() const { return std::min(m_matrix.rows(), m_matrix.cols()) - AbsDiagId; }
inline int cols() const { return 1; }
inline Scalar& coeffRef(int row, int)
{
return m_matrix.const_cast_derived().coeffRef(row, row);
return m_matrix.const_cast_derived().coeffRef(row+OffsetRow, row+OffsetCol);
}
inline const Scalar coeff(int row, int) const
{
return m_matrix.coeff(row, row);
return m_matrix.coeff(row+OffsetRow, row+OffsetCol);
}
inline Scalar& coeffRef(int index)
{
return m_matrix.const_cast_derived().coeffRef(index, index);
return m_matrix.const_cast_derived().coeffRef(index+OffsetRow, index+OffsetCol);
}
inline const Scalar coeff(int index) const
{
return m_matrix.coeff(index, index);
return m_matrix.coeff(index+OffsetRow, index+OffsetCol);
}
protected:
@@ -121,4 +127,29 @@ MatrixBase<Derived>::diagonal() const
return DiagonalCoeffs<Derived>(derived());
}
/** \returns an expression of the \a Id-th sub or super diagonal of the matrix \c *this
*
* \c *this is not required to be square.
*
* The template parameter \a Id represent a super diagonal if \a Id > 0
* and a sub diagonal otherwise. \a Id == 0 is equivalent to the main diagonal.
*
* \sa class DiagonalCoeffs */
template<typename Derived>
template<int Id>
inline DiagonalCoeffs<Derived,Id>
MatrixBase<Derived>::diagonal()
{
return DiagonalCoeffs<Derived,Id>(derived());
}
/** This is the const version of diagonal<int>(). */
template<typename Derived>
template<int Id>
inline const DiagonalCoeffs<Derived,Id>
MatrixBase<Derived>::diagonal() const
{
return DiagonalCoeffs<Derived,Id>(derived());
}
#endif // EIGEN_DIAGONALCOEFFS_H