--- a/liboctave/DiagArray2.h
+++ b/liboctave/DiagArray2.h
@@ -3,6 +3,7 @@
 
 Copyright (C) 1996, 1997, 2000, 2002, 2003, 2004, 2005, 2006, 2007
               John W. Eaton
+Copyright (C) 2008 Jaroslav Hajek
 
 This file is part of Octave.
 
@@ -31,8 +32,6 @@
 #include "Array.h"
 #include "lo-error.h"
 
-class idx_vector;
-
 // A two-dimensional array with diagonal elements only.
 //
 // Idea and example code for Proxy class and functions from:
@@ -46,9 +45,13 @@
 // James Kanze                             email: kanze@us-es.sel.de
 // GABI Software, Sarl., 8 rue du Faisan, F-67000 Strasbourg, France
 
+// Array<T> is inherited privately because we abuse the dimensions variable
+// for true dimensions. Therefore, the inherited Array<T> object is not a valid
+// Array<T> object, and should not be publicly accessible.
+
 template <class T>
 class
-DiagArray2 : public Array<T>
+DiagArray2 : private Array<T>
 {
 private:
 
@@ -112,6 +115,8 @@
 
 public:
 
+  typedef T element_type;
+
   DiagArray2 (void) : Array<T> (dim_vector (0, 0)) { }
 
   DiagArray2 (octave_idx_type r, octave_idx_type c) : Array<T> (r < c ? r : c)
@@ -131,7 +136,7 @@
     { this->dimensions = a.dims (); }
 
   template <class U>
-  DiagArray2 (const DiagArray2<U>& a) : Array<T> (a)
+  DiagArray2 (const DiagArray2<U>& a) : Array<T> (a.diag ())
     { this->dimensions = a.dims (); }
 
   ~DiagArray2 (void) { }
@@ -144,6 +149,24 @@
       return *this;
     }
 
+
+  octave_idx_type dim1 (void) const { return Array<T>::dimensions(0); }
+  octave_idx_type dim2 (void) const { return Array<T>::dimensions(1); }
+
+  octave_idx_type rows (void) const { return dim1 (); }
+  octave_idx_type cols (void) const { return dim2 (); }
+  octave_idx_type columns (void) const { return dim2 (); }
+
+  octave_idx_type length (void) const { return Array<T>::length (); }
+  octave_idx_type nelem (void) const { return dim1 () * dim2 (); }
+  octave_idx_type numel (void) const { return nelem (); }
+
+  size_t byte_size (void) const { return length () * sizeof (T); }
+
+  dim_vector dims (void) const { return Array<T>::dimensions; }
+
+  Array<T> diag (octave_idx_type k = 0) const;
+
   Proxy elem (octave_idx_type r, octave_idx_type c)
     {
       return Proxy (this, r, c);
@@ -151,7 +174,7 @@
 
   Proxy checkelem (octave_idx_type r, octave_idx_type c)
     {
-      if (r < 0 || c < 0 || r >= this->dim1 () || c >= this->dim2 ())
+      if (r < 0 || c < 0 || r >= dim1 () || c >= dim2 ())
 	{
 	  (*current_liboctave_error_handler) ("range error in DiagArray2");
 	  return Proxy (0, r, c);
@@ -162,7 +185,7 @@
 
   Proxy operator () (octave_idx_type r, octave_idx_type c)
     {
-      if (r < 0 || c < 0 || r >= this->dim1 () || c >= this->dim2 ())
+      if (r < 0 || c < 0 || r >= dim1 () || c >= dim2 ())
 	{
 	  (*current_liboctave_error_handler) ("range error in DiagArray2");
 	  return Proxy (0, r, c);
@@ -204,6 +227,15 @@
 
   DiagArray2<T> transpose (void) const;
   DiagArray2<T> hermitian (T (*fcn) (const T&) = 0) const;
+
+  const T *data (void) const { return Array<T>::data (); }
+
+  const T *fortran_vec (void) const { return Array<T>::fortran_vec (); }
+
+  T *fortran_vec (void) { return Array<T>::fortran_vec (); }
+
+  void print_info (std::ostream& os, const std::string& prefix) const
+    { Array<T>::print_info (os, prefix); }
 };
 
 #endif