IDL 讀取nc數據代碼

file_ID = NCDF_OPEN(theseFiles[fidx],/NOWRITE)   ;open netCDF file for READ only
    Tag = NCDF_INQUIRE(file_ID)
    timeid = NCDF_VARID(file_ID,'time')             ;initial_time0initial_time0_hours  initial_time0
    NCDF_VARGET, file_ID, timeid, time              ;獲取 時間維變量
    nt = N_ELEMENTS(time)
    ;print,time
    latid = NCDF_VARID(file_ID,'latitude')               ;g0_lat_2
    NCDF_VARGET, file_ID, latid, latitude           ;獲取 時間維變量
    nlat = N_ELEMENTS(latitude)                     ;緯向維長度
    ;print,'dsklfjdsjfkldjsfkljl'+latitude
    lonid = NCDF_VARID(file_ID,'longitude')                ;g0_lon_3
    NCDF_VARGET, file_ID, lonid, longitude           ;獲取 時間維變量
    nlon = N_ELEMENTS(longitude)                     ;徑向維長度

    t2mid = NCDF_VARID(file_ID,'t2m')                ;g0_lon_3
    NCDF_VARGET, file_ID, t2mid, t2m           ;獲取 溫度維變量
    nt2m = N_ELEMENTS(t2m)
    
    ncdf_attget,file_ID,t2mid,'scale_factor',a
    ncdf_attget,file_ID,t2mid,'add_offset',b
    year=STRMID(thesefiles[fidx],0,4)
    month=STRMID(thesefiles[fidx],5,2)
    outtmp=fltarr(480,15,band[fidx]*4)
    outtmp[*,*,*]=t2m[*,*,*]*a+b
    NCDF_CLOSE, file_ID
    print,'  All parameters of file ' + thesefiles[fidx] + ' have been writen out!'
    outfilename = STRCOMPRESS(outfilepath +string(year,FORMAT='(I04)')+'_'+string(month,FORMAT='(I02)'),/remove_all)
    openw,var_lun,outfilename,/get_lun
    writeu,var_lun,outtmp;
    close,var_lun
    free_lun,var_lun

scale_factor','add_offset一定要注意獲取，也要注意最後讀取出來的單位。