Re: Lat Lon plot from WRF grib file

Hi,

What's happening is that you have 2D coordinate values for your data,
and hence NCL can't create tickmarks because it can't assume that
your data grid is regularly spaced.

You should be able to get rid of this message by turning off the
tickmarks:

    res@gsnTickMarksOn = False

However, since you are dealing with lat/lon data, did you mean to
overlay this data on a map? If so, then you should call
gsn_csm_contour_map instead of gsn_csm_contour. If you do that, then
you won't have an issue with your tickmarks, and you won't need to
set gsnTickMarksOn to False.

--Mary

On Mar 11, 2010, at 7:09 PM, Estatio Gutierrez wrote:

> Hi,
>
> I want to make a plot from a WRF grib file (obtained from WPP).
>
> I'm trying to change the coordinate system from x/y to lat/lon, but
> I get this error message:
>
> warning:tmXBMinorLengthF is not a valid resource in
> 0_contour.PlotManager at this time
> warning:NhlGetValues:Error retrieving tmXBMinorLengthF
>
> I need to overlay a shapefile which is in lat lon and that is why I
> have to plot the WRF output in lat lon.
>
> I think the problem is that I'm not doing the conversion properly.
>
> Thanks for your help.
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> ;************************************************
> ; MAIN
> ;************************************************
> begin
>
> DATADir = "/home/estatio/ncl_scripts/pbl/"
> FILES = systemfunc (" ls -1 " + DATADir + "WRF* ")
> numFILES = dimsizes(FILES)
>
> do ifil = 0,numFILES-1
>
> a=addfile(FILES(ifil)+".grb","r")
>
> pbl=a->HPBL_GDS3_SFC_10
> lat2d=a->NLAT_GDS3_SFC_10(:,:)
> lon2d=a->ELON_GDS3_SFC_10(:,:)
> pltType = "x11"
>
> wks = gsn_open_wks (pltType,ifil) ; open workstation
> gsn_define_colormap(wks,"BlueDarkRed18") ; choose
> colormap
>
>
>
> res = True ; plot mods desired
> res@gsnMaximize = True ; make ps, eps,
> pdf large
> res@gsnSpreadColors = True ; Use full color map
> ; res@gsnSpreadColorEnd= -2 ; do not use
> gray for contours
> res@cnFillOn = True ; color
> res@cnLinesOn = False
> res@cnLineLabelsOn = False
>
> res@lbLabelAutoStride= True ; let NCL choose
> stride
>
> res@gsnDraw = False ; don't draw
> res@gsnFrame = False
>
> res@tiXAxisString = lon@long_name
> res@tiYAxisString = lat@long_name
> res@sfXArray = lon2d
> res@sfYArray = lat2d
>
> plot = gsn_csm_contour(wks,pbl,res) ; Pacific
>
>
> ; Open the states shapefile and draw the state boundaries...
> f = addfile("/home/estatio/ncl_scripts/nybb_09c_av/
> nybb.shp", "r")
>
> geometry = f->geometry
> segments = f->segments
> segsDims = dimsizes(segments)
> dims = dimsizes(geometry)
>
> ;
> ; We need to reference these inside a nested do loop, so it's
> ; better to read them off the file here once, and use the
> ; local variables inside the do loops.
> ;
> geom_segIndex = f@geom_segIndex
> geom_numSegs = f@geom_numSegs
> segs_xyzIndex = f@segs_xyzIndex
> segs_numPnts = f@segs_numPnts
>
> plres = True
> plres@gsLineColor = "black"
> plres@gsLineThicknessF=1.5
> lines = new(segsDims(0),graphic)
>
> numFeatures = dims(0)
>
> segNum = 0
> latc = f->y
> lonc = f->x
> do i=0, numFeatures-1
> startSegment = geometry(i, geom_segIndex)
> numSegments = geometry(i, geom_numSegs)
> do seg=startSegment, startSegment+numSegments-1
> startPT = segments(seg, segs_xyzIndex)
> endPT = startPT + segments(seg, segs_numPnts) - 1
> lines(segNum) = gsn_add_polyline(wks, plot, lonc
> (startPT:endPT), \
> latc
> (startPT:endPT), plres)
> segNum = segNum + 1
> end do
> end do
>
> draw(plot)
> frame(wks)
>
> delete(wks)
>
> ; cmd = "convert -geometry 1200x1200 -density 1200 -trim " + ifil
> + ".ps " + \
> ; ifil +
> ".png"
> ; system(cmd)
>
>
> end do
>
> end
>
>
>
>
>
>
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Received on Fri Mar 12 08:10:09 2010