Re: color fills with transparency

Hi Rick,
thanks for your reply.

No. I am trying to set the fill between 2 lines to be a transparent colour (in this case red, (/0.80,0.00,0.00,0.30/)

In the past I've had to switch off the line, and to assign the colour to gsnXYFillColors, i.e.

  delete(res@xyLineColors)
  res@gsnXYFillColors = red_trn
  res@xyLineColor = -1 ; We don't want the line, so make it transparent.

So the first call to gsn_csm_xy would have drawn a time-series, and the second a colour fill between 2 time-series. In this case there is a relationship between the time-series and the filled area between the time-series and so the other graph attributes can be the same.

I'll keep plugging' away in the meantime…and let you know if I can work it out.

Many thanks,

On 21/06/2012, at 1:32 AM, brownrig@ucar.edu wrote:

> Hi Mark,
>
> I'm not sure what you are trying to do. If you want the lines in your
> graph to be translucent, try the "gsLineOpacityF"
> resource, which takes a float from 0. (transparent) to 1. (completely
> opaque).
>
> You might also take a look at:
>
> http://ncl.ucar.edu/Applications/rgbacolor.shtml
>
> where the new color resources are described.
>
> Hope that helps...
> Rick
>
> On Wed, 20 Jun 2012 17:55:57 +1000
> <Mark.Collier@csiro.au> wrote:
>> Hi,
>> I have some experience with using transparency with an older
>> unofficial version of NCL, however, I'm having trouble getting this
>> feature to work in the latest version which has this capability.
>>
>> [mac599@dcc Steve]$ ncl -V
>> 6.1.0-beta
>>
>> [mac599@dcc Steve]$ uname -a
>> Linux dcc 2.6.18-274.7.1.el5 #1 SMP Thu Oct 20 16:21:01 EDT 2011
>> x86_64 x86_64 x86_64 GNU/Linux
>>
>> I have put the following files into the incoming ftp area for
>> examination:
>>
>> tas_Amon_CSIRO-Mk3-6-0_historical_r1i1p1_1850-2005_c1850-1899_ANN_YA.nc
>> tas_Amon_CSIRO-Mk3-6-0_historical_r2i1p1_1850-2005_c1850-1899_ANN_YA.nc
>> tas_Amon_CSIRO-Mk3-6-0_rcp45_r1i1p1_2006-2100_chistorical_r1i1p1_1850-1899_ANN_YA.nc
>> tas_Amon_CSIRO-Mk3-6-0_rcp45_r2i1p1_2006-2100_chistorical_r2i1p1_1850-1899_ANN_YA.nc
>> tas_Amon_hadcrut3_glts_r1i1p1_1850-2010_c1850-1899_ANN_YA.nc
>> try.ncl
>>
>> The script is copied below.
>>
>> I assume it is got something to do with gsFillOpacityF - sets
>> opacity for color-filled polygons
>>
>> But I cannot find an example of its implementation or my attempts
>> failed.
>>
>> Thanks for any help,
>> Mark.
>>
>>
>> load "/home/599/mac599/marsland/all_scripts.ncl"
>>
>> begin
>>
>> rad = 4.0*atan(1.0)/180.0
>>
>> nens=2
>>
>> obs="tas_Amon_hadcrut3_glts_r1i1p1_1850-2010_c1850-1899_ANN_YA.nc"
>>
>> histrcp=new(2,string)
>> do ens=1,nens
>>
>> historical="tas_Amon_CSIRO-Mk3-6-0_historical_r"+ens+"i1p1_1850-2005_c1850-1899_ANN_YA.nc"
>>
>> rcp45="tas_Amon_CSIRO-Mk3-6-0_rcp45_r"+ens+"i1p1_2006-2100_chistorical_r"+ens+"i1p1_1850-1899_ANN_YA.nc"
>>
>> histrcp(0)=historical
>> histrcp(1)=rcp45
>>
>> fh_obs=addfile(obs,"r")
>> fh_historical=addfile(historical,"r")
>> fh_rcp45=addfile(rcp45,"r")
>> fh_histrcp = addfiles(histrcp,"r")
>>
>> if(ens.eq.1)then
>> lat = fh_historical->lat
>> clat = doubletofloat(cos(lat*rad))
>> clat!0 = "lat"
>> clat&lat = lat
>>
>> dims_historical=filevardimsizes(fh_historical,"tas")
>> dims_rcp45=filevardimsizes(fh_rcp45,"tas")
>> ntim_historical=dims_historical(0)
>> ntim_rcp45=dims_rcp45(0)
>> histrcpobs_data = new((/2,ntim_historical+ntim_rcp45/),float)
>> histrcp_data = new((/nens,ntim_historical+ntim_rcp45/),float)
>> histrcp_minmax = new((/2,ntim_historical+ntim_rcp45/),float)
>> histrcpobs_data@_FillValue=1e20
>> histrcpobs_data@missing_value=histrcpobs_data@_FillValue
>> histrcpobs_data=0.0
>> histrcpobs_time_year = cd_calendar(fh_histrcp[:]->time,4)
>> end if
>>
>> histrcp_data(nens-1,:)=wgt_areaave(fh_histrcp[:]->tas, clat, 1.0, 0)
>>
>> histrcpobs_data(0,:)=histrcpobs_data(0,:)+wgt_areaave(fh_histrcp[:]->tas,
>> clat, 1.0, 0)
>> end do
>> histrcpobs_data(0,:)=histrcpobs_data(0,:)/nens
>>
>>
>> histrcp_minmax(0,:)=dim_min_n(histrcp_data,0)
>> histrcp_minmax(1,:)=dim_max_n(histrcp_data,0)
>>
>> histrcpobs_data(1,:)=1e20
>> histrcpobs_data(1,0:160)=fh_obs->tas
>>
>> outp="try"
>>
>> wks = gsn_open_wks ("ps",outp)
>> ; wks = gsn_open_wks ("X11",outp)
>>
>> alpha = 0.30 ; 1.0 is fully opaque (?)
>> red_trn = (/0.80,0.00,0.00,alpha/)
>>
>> plots = new(2,graphic)
>>
>> res = True ; plot mods
>> desired
>> res@gsnDraw = False ; don't draw yet
>> res@gsnFrame = False ; don't advance frame yet
>> res@xyLineColors = (/"red","blue","green","black"/) ;
>> change line color
>> res@xyLineThicknesses = (/2.0,2.0,2.0,2.0/) ; make 2nd
>> lines thicker
>> res@xyDashPattern = 0 ; Make curves all solid
>> res@pmLegendDisplayMode = "Always" ; turn on legend
>> res@pmLegendSide = "Top" ; Change location
>> of
>> res@pmLegendParallelPosF = .40 ; move units
>> right
>> res@pmLegendWidthF = 0.12 ; Change width
>> and
>> res@pmLegendHeightF = 0.15 ; height of
>> legend.
>> res@lgLabelFontHeightF = .02 ; change font
>> height
>> res@lgPerimOn = False ; no box around
>>
>> res@tmXBLabelsOn = True
>> ; res@tmXBOn = False
>>
>> res@vpWidthF = 0.95
>>
>> res_lines = True ; polyline mods
>> desired
>> res_lines@gsLineThicknessF = 2. ; line thicker
>> res_lines@gsLineColor = "gray"
>> res_lines@gsLineDashPattern = 1
>>
>> res@gsnLeftString = "(a) Globally averaged surface air temperature
>> anomalies"
>> res@tiYAxisString = "~S~o~N~C"
>> res@tiXAxisString = "Year"
>> res@xyExplicitLegendLabels = (/" historical/rcp45"," observed"/)
>> res@trXMinF = 1850.
>> res@trXMaxF = 2100. ; set x-axis minimum
>> res@trYMinF = -1.
>> res@trYMaxF = 3.
>> res@pmLegendOrthogonalPosF = -0.5 ; more neg = down
>>
>> plots(0) = gsn_csm_xy
>> (wks,histrcpobs_time_year,histrcpobs_data,res) ; create plot
>>
>> res@gsnLeftString = "(b) Globally averaged surface air temperature
>> anomalies"
>> res@tiYAxisString = "~S~o~N~C"
>> res@tiXAxisString = "Year"
>> res@xyExplicitLegendLabels = (/" historical/rcp45"," observed"/)
>> res@trXMinF = 1850.
>> res@trXMaxF = 2100. ; set x-axis minimum
>> res@trYMinF = -1.
>> res@trYMaxF = 3.
>> res@pmLegendOrthogonalPosF = -0.5 ; more neg = down
>> plots(1) = gsn_csm_xy
>> (wks,histrcpobs_time_year,histrcpobs_data,res) ; create plot
>>
>> delete(res@xyLineColors)
>> res@gsnXYFillColors = red_trn
>> res@xyLineColor = -1 ; We don't want
>> the line, so make it transparent.
>>
>> ; res@gsnDraw = True
>>
>> plots1b = gsn_csm_xy (wks,histrcpobs_time_year,histrcp_minmax,res)
>> overlay(plots(1),plots1b)
>>
>> resP = True ; modify the panel
>> plot
>>
>> resP@gsnPanelLeft = 0.05
>>
>> resP@gsnPanelBottom = 0.2 ; shrink panel plot
>> by setting bottom edge of plot
>> resP@gsnPanelTop = 0.9 ; shrink panel plot
>> by setting top edge of plot
>>
>> gsn_panel(wks,plots,(/2,1/),resP) ; now draw as one
>> plot
>>
>> print("Finished "+outp+".")
>>
>> end
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Received on Thu Jun 28 02:39:57 2012