filename = "/home/smrati/WORK/RS_RO_EXP/LOG_FILE_STATS/averages_atms.csv"

;---Read in file as array of strings so we can parse each line
  lines = asciiread(filename,-1,"string")

 delim = ","

;---Read fields   The "var" suffix is used because "group" is a keyword.
  obs  =           str_get_field(lines,1,delim)
  Obs_cntl  =        tofloat(str_get_field(lines,2,delim))
  RMSE_back_cntl =   str_get_field(lines,4,delim)
  RMSE_anal_cntl  =   str_get_field(lines,6,delim)
  Obs_ro    =        tofloat(str_get_field(lines,7,delim))
  RMSE_back_ro  =      str_get_field(lines,9,delim)
  RMSE_anal_ro  =      str_get_field(lines,11,delim)

  Index =  ispan(0,28,1)*1.
;max_obs = where((tofloat(Obs_cntl)).gt.(tofloat(Obs_ro)),(tofloat(Obs_cntl)),(tofloat(Obs_ro)))
diff_obs = (tofloat(Obs_cntl) - tofloat(Obs_ro))*100/(tofloat(Obs_cntl))
;max_back = where((tofloat(RMSE_back_cntl)).gt.(tofloat(RMSE_back_ro)),(tofloat(RMSE_back_cntl)),(tofloat(RMSE_back_ro)))
diff_back = (tofloat(RMSE_back_cntl) - tofloat(RMSE_back_ro))*100/(tofloat(RMSE_back_cntl))
;max_anal = where((tofloat(RMSE_anal_cntl)).gt.(tofloat(RMSE_anal_ro)),(tofloat(RMSE_anal_cntl)),(tofloat(RMSE_anal_ro)))
diff_anal  = (tofloat(RMSE_anal_cntl) - tofloat(RMSE_anal_ro))*100/(tofloat(RMSE_anal_cntl))
 
;printVarSummary(diff_obs)
;print(diff_obs)
;printVarSummary(diff_anal)
;print("  " + RMSE_anal_cntl+"   "+RMSE_anal_ro)

;---To plot multiple lines, you must put them into a mulidimensional array.

 data      = new((/3,dimsizes(diff_back)/),float)

 data(0,:) =  diff_back
 data(1,:) =  diff_anal
 data(2,:) =  diff_obs

 wks   = gsn_open_wks ("png","avg_back_anal_obs_rms_normaldiff_atms")                 ; send graphics to PNG file

;---Set plotting parameters

 res                   = True                      ; plot mods desired
; res@tiMainString      = "Difference plot"       ; add title

; res@gsnFrame = False                  ; don't advance frame yet      

  res@vpHeightF= 0.4                    ; change aspect ratio of plot
  res@vpWidthF = 0.7                  
  
  res@trYMinF  = min(data)-0.5                   ; min value on y-axis
  res@trYMaxF  = max(data)+0.5                   ; max value on y-axis
  res@trXMinF  = -1.0                   ; min value on y-axis
  res@trXMaxF  = 29.0                   ; max value on y-axis
  res@tmXMajorGrid                = True          ; implement x grid
  res@tmXMajorGridThicknessF      = 0.5           ; 2.0 is default
  res@vpXF     = 0.2                   ; start plot at x ndc coord 
  res@tmXTOn           = False
  res@tmXBOn        = True       ; have tick marks
  res@tmXBMode      = "Explicit" ; label independently
  res@tmXBValues        = Index                       ; location of labels 
  res@tmXBLabelFontHeightF = 0.01
  res@tmXBLabels        = obs                ; labels themselves
  res@tmXBLabelAngleF   = 90.0
  res@tiYAxisString     = "Normalised Difference (%)"
  res@tiXAxisString     = "Observations"
  res@gsnYRefLine           = 0.0
  res@xyMarkLineMode   = "Markers"                ; choose which have markers
  res@xyMarkers         :=  (/16,16,15/)                      ; choose type of marker  
  res@xyMarkerColors    := (/"blue","red","black"/)                    ; Marker color
  res@xyMarkerSizes     := (/0.005,0.007,0.01/)                     ; Marker size (default 0.01)

; add a legend
 res@pmLegendDisplayMode    = "Always"              ; turn on legend
 
 res@pmLegendSide           = "Top"                 ; Change location of 
 res@pmLegendParallelPosF   = .90                   ; move units right
 res@pmLegendOrthogonalPosF = 0.05                  ; more neg = down
 res@xyExplicitLegendLabels = (/"Background","Analysis","OBS"/) 
 res@pmLegendWidthF         = 0.12                  ; Change width and
 res@pmLegendHeightF        = 0.15                  ; height of legend.
 res@lgLabelFontHeightF     = .015                   ; change font height
 res@lgPerimOn              = False                 ; no box around

plot  = gsn_csm_xy(wks,Index,data(1,:),res) ; create plot