NAME:read_grads PURPOSE:reading grads file (except "data type station" or "grib") from the grads control file even if there is multiple data files. CATEGORY:reading function CALLING SEQUENCE: res=read_grads(var, date1 [, date2], FILENAME = filename) INPUTS: var: the variable name date1: date of the beginning (yyyymmdd if TIMESTEP is not activate) date2: last date. Optionnal, if not scpecified date2=date1 KEYWORD PARAMETERS: FILENAME: the grads control file name: 'xxxx.ctl' GLAMBOUNDARY (via computegrid.pro):a 2 elements vector, {lon1,lon2], giving the longitute boundaries that should be used to visualize the data. lon2 > lon1 lon2 - lon1 eq 360 key_shift will be automatically defined according to GLAMBOUNDARY. /TIMESTEP: to specify that the dates are time steps instead of true calendar. IODIRECTORY;a string giving the name of iodirectory (see isafile.pro for all possibilities). default value is common variable iodir