I vote for wiping out a column in spatial direction as well, for the same reason Gordon mentioned. -- Xiaohui Fan Princeton University Observatory Peyton Hall Princeton, NJ 08544 email : fan@astro.princeton.edu tel : (609) 258-5153 (O) (609) 683-0125 (H) APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 438 in the apo35-general archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-general/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-general@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO