Procedure : tsy_valid_param Purpose: Helper function used by Tsygenanko wrapper routines. Validates model input parameters and interpolates parameters onto position data Input: in_val: tplot variable containing parameter data to be interpolated onto the position data pos_name: the name of the position tplot variable Returns -1L on failure $LastChangedBy: egrimes $ $LastChangedDate: 2014-03-18 08:33:35 -0700 (Tue, 18 Mar 2014) $ $LastChangedRevision: 14571 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/external/IDL_GEOPACK/tsy_valid_param.pro $