;----------------------------------------------------------------------
; minmax_4.ncl
;
; Concepts illustrated:
;   - Using the WhiteBlue color map
;   - Replacing colors in the existing color map with named colors
;   - Changing the contour level spacing
;   - Attaching polymarkers to a contour plot
;   - Calculating the local minima/maxima of your data
;   - Adding text strings at local minima/maxima locations
;   - Drawing a custom legend outside of a map plot
;----------------------------------------------------------------------
;
; These files are loaded by default in NCL V6.2.0 and newer
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"   
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"  

begin
;---Open file and read in Sea Surface Temperature Anomalies
  a   = addfile("/home/peni/skripsi/olr.day.kelvinmjoer.nc","r")
  k = a->kelvin
  t = a->time

;------custom time
   ymdStrt = 20160101                         ; start yyyymmdd
   ymdLast = 20160201                         ; last  

   yrStrt  = ymdStrt/10000
   yrLast  = ymdLast/10000
   


  latS    = -20
  latN    =  20
  lonS    = 60
  lonN    = 180


;***********************************************************
; Read user specified time and create required yyyyddd                    
;***********************************************************
   time    = a->time                          ; all times on file
   ymd     = cd_calendar(time, -2)            ; yyyymmdd
   iStrt   = ind(ymd.eq.ymdStrt)              ; index start
   iLast   = ind(ymd.eq.ymdLast)              ; index last 
   delete(time)
   delete(ymd)

 print(iStrt+" ... "+iLast)

;***********************************************************
; Read user specified time and create required yyyyddd                    
;***********************************************************
   time    = a->time(iStrt:iLast)             ; time:units = "hours since"
   TIME    = cd_calendar(time, 0)             ; type float 
   year    = floattointeger( TIME(:,0) )
   month   = floattointeger( TIME(:,1) )
   day     = floattointeger( TIME(:,2) ) 
   ddd     = day_of_year(year, month, day) 
   yyyyddd = year*1000 + ddd                  ; needed for input

;***********************************************************  



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

  res                      = True

  res@gsnMaximize          = True              ; maximize plot in frame
  res@gsnDraw              = False
  res@gsnFrame             = False

  res@cnFillOn             = True               ; turn on contour fill
  res@cnFillPalette        = "WhiteBlue"        ; set color map
  res@cnLinesOn            = True              ; turn off contour lines
  res@cnLineLabelsOn       = False              ; turn off contour labels
  res@cnLevelSpacingF      = 1.4

  res@tiMainString         = "Anomali OLR Reza"
  res@mpFillDrawOrder      = "PostDraw"         ; Draw map fill last
  
  res@mpMinLatF            = latS         ; zoom in on map
  res@mpMaxLatF            = latN
  res@mpMinLonF            = lonS         ; zoom in on map
  res@mpMaxLonF            = lonN

;---Create plot

;-----reza--------------
  ntBegin   = ind(yyyymmdd.eq.ymdStrt)
  ntEnd     = ind(yyyymmdd.eq.ymdLast) 
	
;-----------------------


  nt = ntBegin,ntEnd ;edit reza
  plot = gsn_csm_contour_map(wks,k(nt,:,:),res)

;
; Called local_min and local_max to get lat/lon locations of local 
; minima and maxima. The lat/lon locations will be returned as
; index values in the X and Y dimensions, "xi" and "yi". 
;
  iimin = local_min(k(nt,:,:),False,0.)
  iimax = local_max(k(nt,:,:),False,0.)


  mkres               = True
  mkres@gsMarkerIndex = 16        ; filled dot
  mkres@gsMarkerSizeF =  8.       ; make dot larger

  mkres@gsMarkerColor = "green"
  dumlow = gsn_add_polymarker(wks,plot,k&lon(iimin@xi),k&lat(iimin@yi),mkres)

  mkres@gsMarkerColor = "red"
  dumhgh = gsn_add_polymarker(wks,plot,k&lon(iimax@xi),k&lat(iimax@yi),mkres)

  draw(plot)   ; Drawing the plot draws the attached markers too

;---Draw a legend at the bottom
  txres               = True
  txres@txJust        = "CenterLeft"
  txres@txFontHeightF = 0.02
  mkres@gsMarkerSizeF = 10.       ; make dot larger

  xpos = 0.15
  ypos = 0.25

  mkres@gsMarkerColor = "green"
  gsn_polymarker_ndc(wks,xpos,ypos,mkres)
  gsn_text_ndc(wks,"  Lokasi minimum lokal",xpos,ypos,txres)

  xpos = 0.55
  ypos = 0.25
  mkres@gsMarkerColor = "red"
  gsn_polymarker_ndc(wks,xpos,ypos,mkres)
  gsn_text_ndc(wks,"  Lokasi maksimum lokal",xpos,ypos,txres)

  frame(wks)
end