Execute: Error occurred

Dear ncl users, anyone could help me to fix the problem given below.
Thanks in advance,
Kim
………………………………
 load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
 
  begin
;************************************************
; Read in data
;************************************************
  f     = addfile ("precip.mon.mean.nc","r")
  u = f->precip
  u1 = f->precip
  printVarSummary(u)
; ***********************************************
; create new date array for use on the plot
; ***********************************************
   date  = f->time
   dimDate = dimsizes(date)
   dateF   = new (dimDate,float)
    do n=0,dimDate-1
      yyyy      = date(n)/100
      mon       = date(n)-yyyy*100
      dateF(n) = yyyy + (mon-1)/12
   end do
;*********************************
; plot parameters
;*********************************
  wks          = gsn_open_wks ("x11","xy")
 
  res          = True
  res@gsnFrame = False
 
  res@vpHeightF= 0.4                    ; change aspect ratio of plot
  res@vpWidthF = 0.8
 
  res@trYMinF  = -30.0                   ; min value on y-axis
  res@trYMaxF  =  100.0                   ; max value on y-axis
res@tiYAxisString    = "Precipitation(mm)"    ; y-axis label
  res@tiMainString     = "Average Monthly Rate of Precipitation"
 
  res@gsnYRefLine           = 0.0             ; create a reference line
  polyres                  = True
  polyres@gsLineThicknessF = 3.0
 
  res@gsnAboveYRefLineColor = "red"              ; above ref line fill red
  res@gsnBelowYRefLineColor = "blue"             ; below ref line fill blue
  plot = gsn_csm_xy (wks,dateF,u(:,{20:50},{30:120}),res)
  gsn_polyline(wks,plot,dateF,(/u1/),polyres)
  frame(wks)
  end
*****************
Variable: u
Type: float
Total Size: 15178752 bytes
            3794688 values
Number of Dimensions: 3
Dimensions and sizes:   [time | 366] x [lat | 72] x [lon | 144]
Coordinates:
            time: [101902..113011]
            lat: [88.75..-88.75]
            lon: [1.25..358.75]
Number Of Attributes: 15
  long_name :   Average Monthly Rate of Precipitation
  valid_range : (  0, 100 )
  units :       mm/day
  add_offset :   0
  scale_factor :         1
  actual_range :        (  0, 85.967 )
  missing_value :       -9.96921e+36
  precision :   32767
  least_significant_digit :     2
  var_desc :    Precipitation
  dataset :     GPCP Version 2.1 Combined Precipitation Dataset
  level_desc :  Surface
  statistic :   Mean
  parent_stat : Mean
  _FillValue :  -9.96921e+36
fatal:Assignment type mismatch, right hand side can't be coerced to type of left hand side
fatal:Execute: Error occurred at or near line 22 in file x1.ncl

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Sun Jan 31 06:51:06 2010