Procedure: thm_part_slice2d_subtract Purpose: Helper function for thm_part_slice2d. Subtracts bulk velocity vector from velocity array. Input: vectors: (float) N x 3 array of particle vectors vbulk: (float) bulk velocity 3-vector vel_data: (string) name of tplot variable containing bulk velocity data Output: none, modifies vectors Notes: This shift should NOT be applied when using the geometric method. $LastChangedBy: aaflores $ $LastChangedDate: 2013-12-11 12:41:36 -0800 (Wed, 11 Dec 2013) $ $LastChangedRevision: 13660 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/projects/themis/spacecraft/particles/slices/thm_part_slice2d_subtract.pro $