new file mode 100644
--- /dev/null
+++ b/scripts/plot/ancestor.m
@@ -0,0 +1,69 @@
+## Copyright (C) 2007 Michael Goffioul
+##
+## This program 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 of the License, or
+## (at your option) any later version.
+##
+## This program 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 this program; if not, write to the Free Software
+## Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+## 02110-1301  USA
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{parent} =} ancestor (@var{h}, @var{type})
+## @deftypefnx {Function File} {@var{parent} =} ancestor (@var{h}, @var{type}, 'toplevel')
+## Return the first ancestor of handle object @var{h} whose type matches
+## @var{type}, where @var{type} is a character string. If @var{type} is a
+## cell array of strings, return the first parent whose type matches
+## any of the given type strings.
+##
+## If the handle object @var{h} is of type @var{type}, return @var{h}.
+##
+## If @code{"toplevel"} is given as a 3rd argument, return the highest
+## parent in the object hierarchy that matches the condition, instead
+## of the first (nearest) one.
+## @seealso{get, set}
+## @end deftypefn
+
+function p = ancestor (h, type, toplevel)
+
+  if (nargin == 2 || nargin == 3)
+    p = [];
+    if (ischar (type))
+      type = { type };
+    endif
+    if (iscellstr (type))
+      look_first = true;
+      if (nargin == 3)
+        if (ischar (toplevel) && strcmp (toplevel, "toplevel"))
+          look_first = false;
+        else
+          error ("ancestor: third argument must be \"toplevel\"");
+        endif
+      endif
+      while (true)
+        if (isempty (h) || ! ishandle (h))
+          break;
+        endif
+        if (any (strcmpi (get (h, "type"), type)))
+          p = h;
+          if (look_first)
+            break;
+          endif
+        endif
+		h = get (h, "Parent");
+      endwhile
+    else
+      error ("ancestor: second argument must be a string or cell array of strings");
+    endif
+  else
+    print_usage ();
+  endif
+
+endfunction