FUNCTION array_cross(l1,l2) Purpose: returns a 2*n array, where n = n_elements(l1)*n_elements(l2) each pair is a combination of l1 and l2 the total list represents all possible pairings of l1 and l2 Written by Patrick Cruce $LastChangedBy: pcruce $ $LastChangedDate: 2009-03-11 11:10:36 -0700 (Wed, 11 Mar 2009) $ $LastChangedRevision: 5255 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/misc/array_cross.pro $