constant Diagonal ---> DiagonalBits

introduce ei_is_diagonal to check for it
DiagonalCoeffs ---> Diagonal and allow Index to by Dynamic
-> add MatrixBase::diagonal(int) with unittest and doc

1 files changed, 187 insertions, 0 deletions

diff --git a/Eigen/src/Core/Diagonal.h b/Eigen/src/Core/Diagonal.h
new file mode 100644
index 000000000..90f5c4d89
--- /dev/null
+++ b/Eigen/src/Core/Diagonal.h
@@ -0,0 +1,187 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2007-2009 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_DIAGONAL_H
+#define EIGEN_DIAGONAL_H
+
+/** \class Diagonal
+  *
+  * \brief Expression of a diagonal/subdiagonal/superdiagonal in a matrix
+  *
+  * \param MatrixType the type of the object in which we are taking a sub/main/super diagonal
+  * \param Index the index of the sub/super diagonal. The default is 0 and it means the main diagonal.
+  *              A positive value means a superdiagonal, a negative value means a subdiagonal.
+  *              You can also use Dynamic so the index can be set at runtime.
+  *
+  * The matrix is not required to be square.
+  *
+  * This class represents an expression of the main diagonal, or any sub/super diagonal
+  * of a square matrix. It is the return type of MatrixBase::diagonal() and MatrixBase::diagonal(int) and most of the
+  * time this is the only way it is used.
+  *
+  * \sa MatrixBase::diagonal(), MatrixBase::diagonal(int)
+  */
+template<typename MatrixType, int Index>
+struct ei_traits<Diagonal<MatrixType,Index> >
+{
+  typedef typename MatrixType::Scalar Scalar;
+  typedef typename ei_nested<MatrixType>::type MatrixTypeNested;
+  typedef typename ei_unref<MatrixTypeNested>::type _MatrixTypeNested;
+  enum {
+    AbsIndex = Index<0 ? -Index : Index, // only used if Index != Dynamic
+    RowsAtCompileTime = (int(Index) == Dynamic || int(MatrixType::SizeAtCompileTime) == Dynamic) ? Dynamic
+                      : (EIGEN_ENUM_MIN(MatrixType::RowsAtCompileTime,
+                                        MatrixType::ColsAtCompileTime) - AbsIndex),
+    ColsAtCompileTime = 1,
+    MaxRowsAtCompileTime = int(MatrixType::MaxSizeAtCompileTime) == Dynamic ? Dynamic
+                         : (EIGEN_ENUM_MIN(MatrixType::MaxRowsAtCompileTime,
+                                          MatrixType::MaxColsAtCompileTime) - AbsIndex),
+    MaxColsAtCompileTime = 1,
+    Flags = (unsigned int)_MatrixTypeNested::Flags & (HereditaryBits | LinearAccessBit),
+    CoeffReadCost = _MatrixTypeNested::CoeffReadCost
+  };
+};
+
+template<typename MatrixType, int Index> class Diagonal
+   : public MatrixBase<Diagonal<MatrixType, Index> >
+{
+    // some compilers may fail to optimize std::max etc in case of compile-time constants...
+    EIGEN_STRONG_INLINE int absIndex() const { return m_index.value()>0 ? m_index.value() : -m_index.value(); }
+    EIGEN_STRONG_INLINE int rowOffset() const { return m_index.value()>0 ? 0 : -m_index.value(); }
+    EIGEN_STRONG_INLINE int colOffset() const { return m_index.value()>0 ? m_index.value() : 0; }
+    
+  public:
+
+    EIGEN_GENERIC_PUBLIC_INTERFACE(Diagonal)
+
+    inline Diagonal(const MatrixType& matrix, int index = Index) : m_matrix(matrix), m_index(index) {}
+
+    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Diagonal)
+
+    inline int rows() const{ return m_matrix.diagonalSize() - absIndex(); }
+    inline int cols() const { return 1; }
+
+    inline Scalar& coeffRef(int row, int)
+    {
+      return m_matrix.const_cast_derived().coeffRef(row+rowOffset(), row+colOffset());
+    }
+
+    inline const Scalar coeff(int row, int) const
+    {
+      return m_matrix.coeff(row+rowOffset(), row+colOffset());
+    }
+
+    inline Scalar& coeffRef(int index)
+    {
+      return m_matrix.const_cast_derived().coeffRef(index+rowOffset(), index+colOffset());
+    }
+
+    inline const Scalar coeff(int index) const
+    {
+      return m_matrix.coeff(index+rowOffset(), index+colOffset());
+    }
+
+  protected:
+    const typename MatrixType::Nested m_matrix;
+    const ei_int_if_dynamic<Index> m_index;
+};
+
+/** \returns an expression of the main diagonal of the matrix \c *this
+  *
+  * \c *this is not required to be square.
+  *
+  * Example: \include MatrixBase_diagonal.cpp
+  * Output: \verbinclude MatrixBase_diagonal.out
+  *
+  * \sa class Diagonal */
+template<typename Derived>
+inline Diagonal<Derived, 0>
+MatrixBase<Derived>::diagonal()
+{
+  return Diagonal<Derived, 0>(derived());
+}
+
+/** This is the const version of diagonal(). */
+template<typename Derived>
+inline const Diagonal<Derived, 0>
+MatrixBase<Derived>::diagonal() const
+{
+  return Diagonal<Derived, 0>(derived());
+}
+
+/** \returns an expression of the \a Index-th sub or super diagonal of the matrix \c *this
+  *
+  * \c *this is not required to be square.
+  *
+  * The template parameter \a Index represent a super diagonal if \a Index > 0
+  * and a sub diagonal otherwise. \a Index == 0 is equivalent to the main diagonal.
+  *
+  * Example: \include MatrixBase_diagonal_int.cpp
+  * Output: \verbinclude MatrixBase_diagonal_int.out
+  *
+  * \sa MatrixBase::diagonal(), class Diagonal */
+template<typename Derived>
+inline Diagonal<Derived, Dynamic>
+MatrixBase<Derived>::diagonal(int index)
+{
+  return Diagonal<Derived, Dynamic>(derived(), index);
+}
+
+/** This is the const version of diagonal(int). */
+template<typename Derived>
+inline const Diagonal<Derived, Dynamic>
+MatrixBase<Derived>::diagonal(int index) const
+{
+  return Diagonal<Derived, Dynamic>(derived(), index);
+}
+
+/** \returns an expression of the \a Index-th sub or super diagonal of the matrix \c *this
+  *
+  * \c *this is not required to be square.
+  *
+  * The template parameter \a Index represent a super diagonal if \a Index > 0
+  * and a sub diagonal otherwise. \a Index == 0 is equivalent to the main diagonal.
+  *
+  * Example: \include MatrixBase_diagonal_template_int.cpp
+  * Output: \verbinclude MatrixBase_diagonal_template_int.out
+  *
+  * \sa MatrixBase::diagonal(), class Diagonal */
+template<typename Derived>
+template<int Index>
+inline Diagonal<Derived,Index>
+MatrixBase<Derived>::diagonal()
+{
+  return Diagonal<Derived,Index>(derived());
+}
+
+/** This is the const version of diagonal<int>(). */
+template<typename Derived>
+template<int Index>
+inline const Diagonal<Derived,Index>
+MatrixBase<Derived>::diagonal() const
+{
+  return Diagonal<Derived,Index>(derived());
+}
+
+#endif // EIGEN_DIAGONAL_H