conditional statements errors

Dear NCL help,

I am trying to calculate TT index which is showing following errors: In the
below, my script is also shown.

fatal:Conditional statements (if and do while) require SCALAR logical
values, see all and any functions
fatal:Execute: Error occurred at or near line [ where line is: if (TT .lt.
49) ]

;;;========================================
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"

begin

datadir = "/WRF/output/2010062200/"
FILES = systemfunc ("ls -1 " + datadir + "wrfout_d02* " )
numFILES = dimsizes(FILES)

res = True
res@MainTitle = "TT index Variation"

opts = res
opts@cnFillOn = True
pltres = True
mpres = True
        mpres@mpNationalLineThicknessF = 1.5
        mpres@mpNationalLineColor = "black"
        mpres@mpGeophysicalLineColor = "black"
        mpres@mpGeophysicalLineThicknessF = 1.5

do ifil = 0,numFILES-1
   a = addfile(FILES(ifil)+".nc","r")

  times = wrf_user_list_times(a) ; get times in the file
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
day = systemfunc("echo "+times +"|cut -c9-10")
yr = systemfunc("echo "+times +"|cut -c1-4")
mon = systemfunc("date '+%b'|tr [a-z] [A-Z]")
hr = systemfunc("echo "+times +"|cut -c12-13")
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; First get the variables we will need
     tc = wrf_user_getvar(a,"tc",0)
     td = wrf_user_getvar(a,"td",0)
     p = wrf_user_getvar(a,"pressure",0) ; 3D U at mass points
;;;=======================================
   tc_850 = wrf_user_intrp3d(tc,p,"h",850.,0.,False)
   td_850 = wrf_user_intrp3d(td,p,"h",850.,0.,False)
   tc_500 = wrf_user_intrp3d(tc,p,"h",500.,0.,False)

;;;Calculation TT index and condition

    TT = tc_850 + td_850 - 2*tc_500

    if(TT .lt. 49.) then
       TT = 0.
      else
       TT = TT
    end if

   wks = gsn_open_wks("ps","tt_surface_"+day+mon+yr+"_"+hr+"Z")
   contour_tt = wrf_contour(a,wks,TT,opts)
   plot = wrf_map_overlays(a,wks,(/contour_tt/),pltres,mpres)

end do
end
;;;=========================================

Kindly help me to solve this.

Thanking you,

Sahidul

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Received on Tue Jul 20 06:38:33 2010