--- a/src/data.cc
+++ b/src/data.cc
@@ -883,305 +883,6 @@
   DATA_REDUCTION (cumsum);
 }
 
-template <class T>
-static octave_value
-make_diag (const T& v, octave_idx_type k)
-{
-  octave_value retval;
-  dim_vector dv = v.dims ();
-  octave_idx_type nd = dv.length ();
-
-  if (nd > 2)
-    error ("diag: expecting 2-dimensional matrix");
-  else
-    {
-      octave_idx_type nr = dv (0);
-      octave_idx_type nc = dv (1);
-
-      if (nr == 0 || nc == 0)
-	retval = T ();
-      else if (nr != 1 && nc != 1)
-	retval = v.diag (k);
-      else
-	{
-	  octave_idx_type roff = 0;
-	  octave_idx_type coff = 0;
-	  if (k > 0)
-	    {
-	      roff = 0;
-	      coff = k;
-	    }
-	  else if (k < 0)
-	    {
-	      roff = -k;
-	      coff = 0;
-	    }
-
-	  if (nr == 1)
-	    {
-	      octave_idx_type n = nc + std::abs (k);
-	      T m (dim_vector (n, n), T::resize_fill_value ());
-
-	      for (octave_idx_type i = 0; i < nc; i++)
-		m (i+roff, i+coff) = v (0, i);
-	      retval = m;
-	    }
-	  else
-	    {
-	      octave_idx_type n = nr + std::abs (k);
-	      T m (dim_vector (n, n), T::resize_fill_value ());
-	      for (octave_idx_type i = 0; i < nr; i++)
-		m (i+roff, i+coff) = v (i, 0);
-	      retval = m;
-	    }
-	}
-    }
-  
-  return retval;
-}
-
-#if !defined (CXX_NEW_FRIEND_TEMPLATE_DECL)
-static octave_value
-make_diag (const Matrix& v, octave_idx_type k);
-
-static octave_value
-make_diag (const ComplexMatrix& v, octave_idx_type k);
-
-static octave_value
-make_diag (const charMatrix& v, octave_idx_type k);
-
-static octave_value
-make_diag (const boolMatrix& v, octave_idx_type k);
-
-static octave_value
-make_diag (const int8NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const int16NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const int32NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const int64NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const uint8NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const uint16NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const uint32NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const uint64NDArray& v, octave_idx_type k);
-
-static octave_value
-make_diag (const Cell& v, octave_idx_type k);
-#endif
-
-template <class T>
-static octave_value
-make_spdiag (const T& v, octave_idx_type k)
-{
-  octave_value retval;
-  dim_vector dv = v.dims ();
-  octave_idx_type nr = dv (0);
-  octave_idx_type nc = dv (1);
-
-  if (nr == 0 || nc == 0)
-    retval = T ();
-  else if (nr != 1 && nc != 1)
-    retval = v.diag (k);
-  else
-    {
-      octave_idx_type roff = 0;
-      octave_idx_type coff = 0;
-      if (k > 0) 
-	{
-	  roff = 0;
-	  coff = k;
-	} 
-      else if (k < 0) 
-	{
-	  roff = -k;
-	  coff = 0;
-	}
-
-      if (nr == 1) 
-	{
-	  octave_idx_type n = nc + std::abs (k);
-	  octave_idx_type nz = v.nzmax ();
-	  T r (n, n, nz);
-	  for (octave_idx_type i = 0; i < coff+1; i++)
-	    r.xcidx (i) = 0;
-	  for (octave_idx_type j = 0; j < nc; j++)
-	    {
-	      for (octave_idx_type i = v.cidx(j); i < v.cidx(j+1); i++)
-		{
-		  r.xdata (i) = v.data (i);
-		  r.xridx (i) = j + roff;
-		}
-	      r.xcidx (j+coff+1) = v.cidx(j+1);
-	    }
-	  for (octave_idx_type i = nc+coff+1; i < n+1; i++)
-	    r.xcidx (i) = nz;
-	  retval = r;
-	} 
-      else 
-	{
-	  octave_idx_type n = nr + std::abs (k);
-	  octave_idx_type nz = v.nzmax ();
-	  octave_idx_type ii = 0;
-	  octave_idx_type ir = v.ridx(0);
-	  T r (n, n, nz);
-	  for (octave_idx_type i = 0; i < coff+1; i++)
-	    r.xcidx (i) = 0;
-	  for (octave_idx_type i = 0; i < nr; i++)
-	    {
-	      if (ir == i)
-		{
-		  r.xdata (ii) = v.data (ii);
-		  r.xridx (ii++) = ir + roff;
-		  if (ii != nz)
-		    ir = v.ridx (ii);
-		}
-	      r.xcidx (i+coff+1) = ii;
-	    }
-	  for (octave_idx_type i = nr+coff+1; i < n+1; i++)
-	    r.xcidx (i) = nz;
-	  retval = r;
-	}
-    }
-
-  return retval;
-}
-
-#if !defined (CXX_NEW_FRIEND_TEMPLATE_DECL)
-static octave_value
-make_spdiag (const SparseMatrix& v, octave_idx_type k);
-
-static octave_value
-make_spdiag (const SparseComplexMatrix& v, octave_idx_type k);
-
-static octave_value
-make_spdiag (const SparseBoolMatrix& v, octave_idx_type k);
-#endif
-
-static octave_value
-make_diag (const octave_value& a, octave_idx_type k)
-{
-  octave_value retval;
-  std::string result_type = a.class_name ();
-
-  if (result_type == "double")
-    {
-      if (a.is_sparse_type ())
-	{
-	  if (a.is_real_type ())
-	    {
-	      SparseMatrix m = a.sparse_matrix_value ();
-	      if (!error_state)
-		retval = make_spdiag (m, k);
-	    }
-	  else
-	    {
-	      SparseComplexMatrix m = a.sparse_complex_matrix_value ();
-	      if (!error_state)
-		retval = make_spdiag (m, k);
-	    }
-	}
-      else
-	{
-	  if (a.is_real_type ())
-	    {
-	      Matrix m = a.matrix_value ();
-	      if (!error_state)
-		retval = make_diag (m, k);
-	    }
-	  else
-	    {
-	      ComplexMatrix m = a.complex_matrix_value ();
-	      if (!error_state)
-		retval = make_diag (m, k);
-	    }
-	}
-    }
-#if 0
-  else if (result_type == "single")
-    retval = make_diag (a.single_array_value (), k);
-#endif
-  else if (result_type == "char")
-    {
-      charMatrix m = a.char_matrix_value ();
-      if (!error_state)
-	{
-	  retval = make_diag (m, k);
-	  if (a.is_sq_string ())
-	    retval = octave_value (retval.char_array_value (), true, '\'');
-	}
-    }
-  else if (result_type == "logical")
-    {
-      if (a.is_sparse_type ())
-	{
-	  SparseBoolMatrix m = a.sparse_bool_matrix_value ();
-	  if (!error_state)
-	    retval = make_spdiag (m, k);
-	}
-      else
-	{
-	  boolMatrix m = a.bool_matrix_value ();
-	  if (!error_state)
-	    retval = make_diag (m, k);
-	}
-    }
-  else if (result_type == "int8")
-    retval = make_diag (a.int8_array_value (), k);
-  else if (result_type == "int16")
-    retval = make_diag (a.int16_array_value (), k);
-  else if (result_type == "int32")
-    retval = make_diag (a.int32_array_value (), k);
-  else if (result_type == "int64")
-    retval = make_diag (a.int64_array_value (), k);
-  else if (result_type == "uint8")
-    retval = make_diag (a.uint8_array_value (), k);
-  else if (result_type == "uint16")
-    retval = make_diag (a.uint16_array_value (), k);
-  else if (result_type == "uint32")
-    retval = make_diag (a.uint32_array_value (), k);
-  else if (result_type == "uint64")
-    retval = make_diag (a.uint64_array_value (), k);
-  else if (result_type == "cell")
-    retval = make_diag (a.cell_value (), k);
-  else
-    gripe_wrong_type_arg ("diag", a);
-
-  return retval;
-}
-
-static octave_value
-make_diag (const octave_value& arg)
-{
-  return make_diag (arg, 0);
-}
-
-static octave_value
-make_diag (const octave_value& a, const octave_value& b)
-{
-  octave_value retval;
-
-  octave_idx_type k = b.int_value ();
-
-  if (error_state)
-    error ("diag: invalid second argument");      
-  else
-    retval = make_diag (a, k);
-
-  return retval;
-}
-
 DEFUN (diag, args, ,
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} diag (@var{v}, @var{k})\n\
@@ -1211,9 +912,16 @@
   int nargin = args.length ();
 
   if (nargin == 1 && args(0).is_defined ())
-    retval = make_diag (args(0));
+    retval = args(0).diag();
   else if (nargin == 2 && args(0).is_defined () && args(1).is_defined ())
-    retval = make_diag (args(0), args(1));
+    {
+      octave_idx_type k = args(1).int_value ();
+
+      if (error_state)
+	error ("diag: invalid second argument");      
+      else
+	retval = args(0).diag(k);
+    }
   else
     print_usage ();