wks = gsn_open_wks("pdf","histo_bin_mary")   
  int_radar = ((/-9,-6,-3,0,3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63/))
  num_o = (/0,0,13,160,2339,4632,7374,11044,14245,17172,24537,38696,51255,43006\
                    ,33918,32011,36194,46269,43924,26732,12078,4392,746,62,0/)

  print(dimsizes(int_radar))
  print(dimsizes(num_o))
; Using the bin counts from the previous plot, create
; a bar chart of the already binned data.
;
  levels = int_radar
  nlevels = dimsizes(levels)
; ybinned = plot@NumInBins        ; the binned data
  ybinned = num_o
  x       = (levels(1:)+levels(0:nlevels-2))*0.5  ; the mid point of each range

  xyres                       = True
  xyres@gsnMaximize           = True

  xyres@gsnXYBarChart         = True
  xyres@gsnXYBarChartColors   = "blue"
  xyres@gsnXYBarChartBarWidth = 0.8*(levels(1)-levels(0))  ; 80% of the width

  xyres@trYMinF               = 0.
  xyres@trYMaxF               = max(ybinned)+1 
  xyres@trXMinF               = min(levels)
  xyres@trXMaxF               = max(levels)

  xyres@tmXBMode              = "Explicit"
  xyres@tmXBValues            = levels
  xyres@tmXBLabels            = ""+levels

  xyres@tiMainString          = "Bar chart of already-binned data"
  xyres@tiXAxisString         = "Intervals"
  xyres@tiYAxisString         = "Frequency"

  plot = gsn_csm_xy(wks,x,ybinned,xyres)