--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/miscellaneous/orderfields.m	Sat Jul 08 03:56:46 2006 +0000
@@ -0,0 +1,96 @@
+## Copyright (C) 2006  Paul Kienzle
+##
+## This file is part of Octave.
+##
+## Octave 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.
+##
+## Octave 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 Octave; see the file COPYING.  If not, write to the Free
+## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+## 02110-1301, USA.
+
+## -*- texinfo -*-
+## @deftypefn {Built-in Function} {[@var{t}, @var{p}] =} orderfields (@var{s1}, @var{s2})
+## Return a struct with fields arranged alphabetically or as specified
+## by @var{s2} and a corresponding permutation vector.
+##
+## Given one struct, arrange field names in @var{s1} alphabetically.
+##
+## Given two structs, arrange field names in @var{s1} as they appear
+## in @var{s2}.  The second argument may also specify the order in
+## a permutation vector or a cell array of strings.
+##
+## @seealso{getfield, rmfield, isfield, isstruct, fieldnames, struct}
+## @end deftypefn
+
+## Author: Paul Kienzle <pkienzle@users.sf.net>
+## Adapted-By: jwe
+
+function [t, p] = orderfields (s1, s2)
+
+  if (nargin == 1 || nargin == 2)
+    if (! isstruct (s1))
+      error ("orderfields: expecting argument to be a struct");
+    endif
+  else
+    print_usage ();
+  endif
+
+  if (nargin == 1)
+    ## One structure: return the fields in alphabetical order.
+    if (isstruct(s1))
+      names = sort (fieldnames (s1));
+    endif
+  elseif (nargin == 2)
+    if (isstruct(s2))
+      ## Two structures: return the fields in the order of s2.
+      names = fieldnames (s2);
+      if (! isequal (sort (fieldnames (s1)), sort (names)))
+	error ("orderfields: s1 and s2 do not have same fields");
+      endif
+    elseif (iscellstr (s2))
+      ## A structure and a list of fields: order by the list of fields.
+      t1 = sort (fieldnames (s1));
+      t2 = sort (s2(:));
+      if (! isequal (t1, t2))
+	error ("orderfields: invalid cell array of field names");
+      endif
+      names = s2;
+    elseif (isvector (s2))
+      ## A structure and a permutation vector: permute the order of s1.
+      names = fieldnames (s1);
+      t1 = sort (s2);
+      t1 = t1(:)';
+      t2 = 1:length (names);
+      if (! isequal (t1, t2))
+	error ("orderfields: invalid permutation vector");
+      endif
+      names = names(s2);
+    endif
+  endif
+
+  ## Find permutation vector which converts the original name order
+  ## into the new name order.  Note: could save a couple of sorts
+  ## in some cases, but performance isn't critical.
+
+  if (nargout == 2)
+    [oldel, oldidx] = sort (fieldnames (s1));
+    [newel, newidx] = sort (names);
+    p = oldidx(newidx);
+  endif
+
+  ## Permute the names in the structure.
+  for i = 1:length (names)
+    el = names(i);
+    t(:).(el) = s1(:).(el);
+  endfor
+
+endfunction