## Copyright (C) 2000 Paul Kienzle
##
## 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

## -*- texinfo -*-
## @deftypefn {Function File} {} setxor(@var{a}, @var{b})
##
## Return the elements exclusive to @var{a} or @var{b}, sorted in ascending
## order. If @var{a} and @var{b} are both column vectors return a column
## vector, otherwise return a row vector.
##
## @end deftypefn
## @seealso{unique, union, intersect, setdiff, ismember}

function c = setxor(a,b)
  if nargin != 2
    usage("setxor(a,b)");
  endif

  ## form a and b into sets
  a = unique(a);
  b = unique(b);

  if isempty(a)
    c = b;
  elseif isempty(b)
    c = a;
  else
    ## reject duplicates
    c = sort([a(:) ; b(:)]);
    n = length(c);
    idx = find(c(1:n-1) == c(2:n));
    if !isempty(idx)
      c([idx, idx+1]) = [];
    endif
    if size(a,1) == 1 ||  size(b,1) == 1
      c = c.';
    endif
  endif
endfunction