Since you have a global gaussian grid, use
div = uv2dvG_Wrap(u,v)
printVarSummary(div)
http://www.ncl.ucar.edu/Document/Functions/Contributed/uv2dvG_Wrap.shtml
--- To get a nice symmetric contour range for the divergence, use http://www.ncl.ucar.edu/Document/Functions/Contributed/symMinMaxPlt.shtml symMinMaxPlt (div,20,False,res) ; all levels or symMinMaxPlt (div(nt,{250},:,:),20,False,res) for a specific time (nt=0 means the 1st time) --- Please note: there is a Portuguese manual at http://www.ncl.ucar.edu/Document/Manuals/ Also, a tutorial by Guilherme Martins which has not yet been added to the NCL WWW yet. I wll send offline. Regards On 5/27/13 2:01 PM, Prof. Mônica Senna wrote: > Hi Dennis, > > My data is on global grid at a spectral resolution of T42 (~2.81 X 2.81 > latitude–longitude grid), from CCM3. I want to make a figure like this > below (streamlines with divergence): > > [image: Imagem inline 1] > > > I will start with the script below (that plots streamlines with omega, I > will change omega for divergence...), and I think I should use this > operator uv2dvG, but what will I plot? dv or uvd ( > http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dvG.shtml)? I did > not understand the difference between these two... > > Thanks a lot!! > > Mônica > > -------------------------- > ;================================================; > ; stream_10.ncl > ;================================================; > load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" > load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" > load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl" > load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl" > > ; ================================================; > begin > ;=================================================; > ; open file and read in data > ;=================================================; > f1 = addfile("media12u.nc","r") > u = f1->U(0,10,:,:) ; read in example data [2D only here] > f2 = addfile("media12v.nc","r") > v = f2->V(0,10,:,:) > f3 = addfile("media12o.nc","r") > o = f3->OMEGA(0,10,:,:) > > > ;=================================================; > ; Create plot > > ;=================================================; > ; this data only has an missing_value, so we are > ; copying this to _FillValue for plotting purposes > ; > ;assignFillValue(v,u) > ;assignFillValue(u,v) > > ;---create plot > wks = gsn_open_wks("pdf" ,"stream5") ; open a ps file > gsn_define_colormap(wks,"gui_default") ; choose colormap > > res = True ; plot mods desired > res@mpFillOn = False > > res@cnFillOn = True ; color fill > ;res@cnLevelSpacingF = 3. ; interval spacing > res@cnLinesOn = False ; no contour lines > > res@stLineColor = "white" > res@stLineThicknessF = 2 > > res@gsnSpreadColors = True ; use full colormap > res@gsnSpreadColorStart = -1 > res@gsnSpreadColorEnd = 4 > > res@stArrowLengthF = 0.008 ; default is dynamic > res@stLengthCheckCount = 5 ; default is 35 > res@stArrowStride = 1 > res@stLineStartStride = 1 ; default is 2 > res@stMinArrowSpacingF = 0.03 ; default is 0.0 > > res@stStepSizeF = 0.001 ; default is dynamic > > res@stMinDistanceF = 0.02 ; distance between lines > res@stMinLineSpacingF = 0.009 > > ; because this is ice data, which has a gap in the tropics, we need to > ; explicitly pass the range of the data to plot. Since we are coloring > ; the vectors, this range should also match the MinLatF above, since the > ; range for the colors is chosen over the full data passed, and not the > ; map limits. > > res@mpDataSetName = "Earth..4" ; This new database contains > (inserir delimitações dos estados) > ; divisions for other > countries.(inserir delimitações dos estados) > res@mpDataBaseVersion = "MediumRes" ; Medium resolution database. > (inserir delimitações dos estados) > res@mpOutlineBoundarySets = "allBoundaries" > res@mpOutlineOn = True ; Turn on map outlines > res@mpOutlineSpecifiers =(/"Brazil:states"/) > ;res@mpOutBoundarySets = "National" > > res@mpFillOn = False ; Turn on map fill > res@mpFillBoundarySets = "National" > res@mpFillAreaSpecifiers = (/"Brazil:states"/) ; divisao dos paises > > ;res@cnFillMode = "RasterFill" ; nao interpolar.. > > res@mpGridLineDashPattern = 2 ; lat/lon lines as dashed > res@pmTickMarkDisplayMode = "Always" ; turn on tickmarks > > ;res@tiMainString = "Teste" > ;res@tiMainFontHeightF = 0.020 ; smaller title > > ;res@mpMaxLatF = 15 ; South America limits > > > res@gsnAddCyclic = False ; regional data (Deve > ficar como falso, true altera as cores de cada estado) > res@mpDataBaseVersion = "MediumRes" > > ;res@cnLevelSelectionMode = "ExplicitLevels" > ;res@cnLevels = (/2.,4.,6.,8.,10.,12./) > > res@lbOrientation = "Vertical" > res@pmLabelBarOrthogonalPosF = -0.01 ; move label bar closer > ;res@lbLabelStride = 4 > > > res@mpMaxLatF = 15 > res@mpMinLatF = -60 > res@mpMaxLonF = -33 > res@mpMinLonF = -82 > > > plot = gsn_csm_streamline_contour_map(wks,u,v,o,res) > > end > ------------------------------------------ > > > > > 2013/5/23 Dennis Shea <shea@ucar.edu> > >> You did not say what your data looked like! >> >> printVarSummary(u) >> >> If your data is on a *global* grid, the you can use spherical >> harmonic operators: >> >> http://www.ncl.ucar.edu/**Document/Functions/Built-in/**uv2dvF.shtml<http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dvF.shtml> >> or >> http://www.ncl.ucar.edu/**Document/Functions/Built-in/**uv2dvG.shtml<http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dvG.shtml> >> >> >> ------- >> >> Otherwise, for rectilinear grids: >> >> http://www.ncl.ucar.edu/**Document/Functions/Built-in/**uv2dv_cfd.shtml<http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dv_cfd.shtml> >> >> http://www.ncl.ucar.edu/**Document/Functions/Built-in/**uv2dvr_cfd.shtml<http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dvr_cfd.shtml> >> >> Good luck >> >> >> On 5/23/13 9:37 AM, Prof. Mônica Senna wrote: >> >>> Hi NCL users, >>> >>> I want to make a map of streamlines with divergence (the divergence must >>> be >>> only colors), but I don´t know how. I did one with streamlines and omega >>> (figure below), the appeareance is similar of the map of divergence I want >>> to make. The script will be similar? >>> >>> >>> [image: Imagem inline 1] >>> >>> >>> >>> Thanks a lot for your attention! >>> >>> >>> >>> ______________________________**_________________ >>> ncl-talk mailing list >>> List instructions, subscriber options, unsubscribe: >>> http://mailman.ucar.edu/**mailman/listinfo/ncl-talk<http://mailman.ucar.edu/mailman/listinfo/ncl-talk> >>> >>> > > _______________________________________________ ncl-talk mailing list List instructions, subscriber options, unsubscribe: http://mailman.ucar.edu/mailman/listinfo/ncl-talkReceived on Tue May 28 06:26:16 2013
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