1 files changed, 72 insertions, 0 deletions
diff --git a/Eigen/Core/DiagonalMatrix.h b/Eigen/Core/DiagonalMatrix.h
new file mode 100644
index 000000000..0ae9399e8
--- /dev/null
+++ b/Eigen/Core/DiagonalMatrix.h
@@ -0,0 +1,72 @@
+// 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_DIAGONALMATRIX_H
+#define EIGEN_DIAGONALMATRIX_H
+
+template<typename MatrixType, typename CoeffsVectorType>
+class DiagonalMatrix : NoOperatorEquals,
+  public MatrixBase<typename MatrixType::Scalar,
+                    DiagonalMatrix<MatrixType, CoeffsVectorType> >
+{
+  public:
+    typedef typename MatrixType::Scalar Scalar;
+    typedef typename CoeffsVectorType::Ref CoeffsVecRef;
+    friend class MatrixBase<Scalar, DiagonalMatrix<MatrixType, CoeffsVectorType> >;
+    
+    DiagonalMatrix(const CoeffsVecRef& coeffs) : m_coeffs(coeffs)
+    {
+      assert(CoeffsVectorType::IsVector
+          && _RowsAtCompileTime == _ColsAtCompileTime
+          && _RowsAtCompileTime == CoeffsVectorType::SizeAtCompileTime
+          && coeffs.size() > 0);
+    }
+    
+  private:
+    static const int _RowsAtCompileTime = MatrixType::RowsAtCompileTime,
+                     _ColsAtCompileTime = MatrixType::ColsAtCompileTime;
+
+    const DiagonalMatrix& _ref() const { return *this; }
+    int _rows() const { return m_coeffs.size(); }
+    int _cols() const { return m_coeffs.size(); }
+    
+    Scalar _coeff(int row, int col) const
+    {
+      return row == col ? m_coeffs.coeff(row) : static_cast<Scalar>(0);
+    }
+    
+  protected:
+    CoeffsVecRef m_coeffs;
+};
+
+template<typename Scalar, typename Derived>
+template<typename OtherDerived>
+const DiagonalMatrix<Derived, OtherDerived>
+MatrixBase<Scalar, Derived>::diagonal(const OtherDerived& coeffs)
+{
+  return DiagonalMatrix<Derived, OtherDerived>(coeffs);
+}
+
+#endif // EIGEN_DIAGONALMATRIX_H