PROCEDURE get_fixed_pixel_graph :DESCRIPTION: Generate a tplot variable containing data values for a fixed pixel, with given beam number and range gate number. :PARAMS: vn: name of the tplot variable from which values for a fixed pixel are extracted :KEYWORDS: beam: beam number for a pixel to be extracted range_gate: range gate number for a pixel to be extracted newvn: if a string is set, the new tplot variable is generated with a name given by this keyword :EXAMPLES: get_fixed_pixel_graph, 'sd_hok_vlos_1', beam=3, range_gate=65 :AUTHOR: Tomo Hori (E-mail: horit@stelab.nagoya-u.ac.jp) :HISTORY: 2011/06/22: Created $LastChangedBy: jwl $ $LastChangedDate: 2012-03-16 14:46:35 -0700 (Fri, 16 Mar 2012) $ $LastChangedRevision: 10146 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/projects/erg/ground/radar/superdarn/get_fixed_pixel_graph.pro $