Re: Specify a time for a variable

Hi Ping,
        
        Was browsing the list and think this is a relatively straight froward answer, apologies if I missed something or this doesn't work.

        Your plotting line is just plotting the 0th to 5th time period of data. Essentially this line of code that actually plots has no relation to the variable YYYMM, except for the dimension size.
> plot_p(nt) = gsn_csm_contour_map_ce(pwks,x(nt,:,:),res)

Also your file name and the attributes in the file seem to differ somewhat, the time coordinates in the file seem to fit a 30-minute interval as is the long_name of your variable. The below method will rewrite the time coordinates so that it works. If that is what is actually in the file.

maybe see -> http://www.ncl.ucar.edu/Document/Manuals/Ref_Manual/NclVariables.shtml#CoordinateSubscripts

---------------------------------------------------------------------------------------------------------------

a quick way to possibly make this work if you know you have monthly data from Jan 1970 -> Dec 1999 would be:

time = todouble( ispan(0, 359, 1) ) ; Needs to be double to match up with time_to_plot below.
time@units = "months since 1970-01-01 00:00:00"

x!0 = "time"
x&time = time

YYYY = (/1970,1970,1980,1980,1990,1990/)
MM = (/ 1, 7, 1, 7, 1, 7 /)
tmax = dimsizes(YYYY)

do nt=0,tmax-1
time_to_plot = ut_inv_calendar(YYYY(nt), MM(nt), 01, 00, 00, 00, time@units, 0) ; this could be cd_inv_calendar in recent ncl versions

> res@gsnLeftString = "Monthly Total Precipitation"
> res@gsnRightString = YYYY(nt)+""+sprinti("%0.2i",MM(nt) ) ; didn't test this -> might fail.
> plot_x(nt) = gsn_csm_contour_map_ce(xwks,x({time_to_plot},:,:),res)
> plot_p(nt) = gsn_csm_contour_map_ce(pwks,x({time_to_plot},:,:),res)

end do

Alan.

-------------------------------------
Alan Brammer,
PhD Student

Department of Atmospheric and Environmental Sciences, University at
Albany, SUNY, Albany, NY, 12222

-------------------------------------

On Oct 11, 2012, at 10:10 AM, Ping Yang <pyang@ccny.cuny.edu> wrote:

> Hi NCL,
>
> I have a similar question about how to specify a time for plotting,
> I used
>
> Here is the script content:
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> begin
>
>
> ;Open the merged monthly file for plotting
> fili = "NEUS_Precipitation_HadGEM2-ESv3_30min_monthly1970-1999.nc"
> f = addfile(fili,"r")
> ; x = short2flt(f->precipitation)
> x = f->precipitation
> print("PRICP: min="+min(x)+" max="+max(x))
> printVarSummary(x)
>
> ; you can plot right now
> ;***************************************************
> ; Specify user desired yyyymm to be plotted
> ;***************************************************
> YYYYMM = (/190001,190007,198001,198007,199001,199007/)
> ;***************************************
> ; Replace the input time coordinate with the yyyymm
> ;***************************************
> ; x&time = f->yyyymm
> ;***************************************
> pwks = gsn_open_wks("ps","cru") ; open ps file
> xwks = gsn_open_wks("x11","cru") ; open x11 file
>
> gsn_define_colormap(pwks,"BlAqGrYeOrReVi200")
> gsn_define_colormap(xwks,"BlAqGrYeOrReVi200")
>
> plot_p = new (dimsizes(YYYYMM), graphic) ; create graphical array
> plot_x = new (dimsizes(YYYYMM), graphic) ; create graphical array
>
> res = True ; plot mods desired
> res@gsnDraw = False ; don't draw yet
> res@gsnFrame = False ; don't advance frame yet
>
> res@cnFillOn = True ; color contours
> res@cnLinesOn = False ; turn off contour lines
> res@cnFillMode = "RasterFill" ; Raster Mode
> res@cnInfoLabelOn = False
> res@cnLineLabelsOn = False
>
> res@cnLevelSelectionMode = "ManualLevels" ; set manual contour levels
> res@cnMinLevelValF = 0 ; set min contour level
> res@cnMaxLevelValF = 300 ; set max contour level
> res@cnLevelSpacingF = 10
>
> ;---This resource not needed in NCL V6.1.0
> res@gsnSpreadColors = True ; use full range of color map
>
> res@lbLabelBarOn = False ; turn off individual lb's
>
> res@gsnAddCyclic = False ; regional grid so not cyclic
> res@mpMinLatF = min(x&latitude)
> res@mpMaxLatF = max(x&latitude)
> res@mpMinLonF = min(x&longitude)
> res@mpMaxLonF = max(x&longitude)
>
> ; do nt = 0,dimsizes(YYYYMM)-1
> do nt = 0,5
> print("nt = " + nt)
> res@gsnLeftString = "Monthly Total Precipitation"
> res@gsnRightString = YYYYMM(nt)
> plot_x(nt) = gsn_csm_contour_map_ce(xwks,x(nt,:,:),res)
> plot_p(nt) = gsn_csm_contour_map_ce(pwks,x(nt,:,:),res)
> end do
>
> ;************************************************
> ; create panel plot
> ;************************************************
>
> resP = True ; modify the panel plot
> resP@txString = fili ; plot title
> resP@gsnMaximize = True ; make ps, eps, pdf, ... large
> resP@lbLabelAutoStride = True
> resP@gsnPanelLabelBar = True ; add common label bar
> gsn_panel(xwks,plot_x(0:5),(/3,2/),resP) ; now draw as one plot
> gsn_panel(pwks,plot_p(0:5),(/3,2/),resP) ; now draw as one plot
>
> end
>
> The problem is whatever I change the time
> In this example(I attached the script the data file in this email), I changed it to a wrong time:
> YYYYMM = (/190001,190007,198001,198007,199001,199007/)
>
> I used PrintSummary of the variable here:
> Variable: x
> Type: float
> Total Size: 1641600 bytes
> 410400 values
> Number of Dimensions: 3
> Dimensions and sizes: [time | 360] x [latitude | 30] x [longitude | 38]
> Coordinates:
> time: [ 30..10956]
> latitude: [35.25..49.75]
> longitude: [-83.75..-65.25]
> Number Of Attributes: 5
> long_name : Global, HadGEM2-ESv3 Precipitation (30min, DailyTS, 1970) Vv3
> standard_name : Precipitation
> _FillValue : -9999
> var_desc : Precipitation
> actual_range : ( 0, 400 )
>
> but the script still runs the same. Would you please help me on this?
>
> Ping
>
>
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Thu Oct 11 16:16:18 2012