<div dir="ltr"><div dir="ltr">It looks like NCL example topo_4 does what you want. Here is my suggestion for debugging. Start with the original code for example topo_4. Change only one thing at a time, moving toward your code version, until you find something that causes the unwanted perimeter lines. Change that back to original. Then continue stepping through all the rest of your changes until you have a reduced set of changes that causes the perimeter lines.</div><div dir="ltr"><br></div><div>In this way, you will reduce the problem to something that is easier to understand.</div><div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Oct 16, 2023 at 9:35 AM lzl lai via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>I have a problem deleting those thin lines in my map (the red arrow pointed area)</div><div>. Could you please help me to remove them? Thanks a lot!</div><div><br></div><div>I use "ETOPO_2022_v1_60s_N90W180_bed.nc" ,for drawing topography,</div><div>and "gadm41_TWN_0.shp" , for drawing coastline in Taiwan</div><div>and also set res@cnMissingValPerimOn = False</div><div><br></div><div>my scrip is below :<br></div><div>========================================</div><div>;---Read data<br>; topo_file = "../topo/ETOPO_2022_v1_60s_N90W180_geoid.nc"<br> topo_file = "../topo/ETOPO_2022_v1_60s_N90W180_bed.nc"<br> f = addfile(topo_file,"r")<br> elev = f->z<br>;<br>; Set all values below -100 to missing, hence removing all<br>; the ocean elevation values. The ocean will be filled in<br>; a light blue (see mpOceanFillColor below).<br>;<br> elev = where(elev.lt.-100.,elev@_FillValue,elev)<br><br></div><div>;;file --- 2<br> shpdir = "/home/lzl/data2/lzl/CWBtrend/topo/TW/"<br> filename ="gadm41_TWN_0.shp"<br></div><div>;----plot-----------------------------------------------------</div><div> wks = gsn_open_wks("pdf","./pic/TW_topo") ; send graphics to PNG file<br> gsn_define_colormap(wks,"WhiteBlueGreenYellowRed")<br></div><div><br> res = True<br> res@gsnMaximize = True ; maximize plot in frame<br><br> res@cnFillOn = True ; turn on contour fill<br> res@cnLinesOn = False ; turn off contour lines<br> res@cnLineLabelsOn = False ; turn off line labels<br> res@cnInfoLabelOn = False ; turn off info label<br> res@lbBoxLinesOn = False ; turn off labelbar box lines<br> res@cnFillMode = "MeshFill" ; for faster draw<br><br> res@cnLevelSelectionMode = "ManualLevels"<br> res@cnMinLevelValF = 100.<br> res@cnMaxLevelValF = 3600.<br> res@cnLevelSpacingF = 200.<br> res@cnMissingValPerimOn = False<br> res@cnMissingValPerimGridBoundOn =False<br> res@gsnAddCyclic = False ; don't add longitude cyclic point</div><div><br></div><div>;---color bar----<br> res@lbAutoManage = False ; we control label bar<br> res@pmLabelBarDisplayMode = "Always" ; turns on label bar<br> res@lbOrientation = "Horizontal" ; ncl default is vertical<br> res@pmLabelBarSide = "Bottom" ; default is right<br> res@lbLabelStride = 1 ; skip every other label<br> res@pmLabelBarWidthF = 0.5 ; default is shorter<br> res@pmLabelBarHeightF = 0.1 ; default is taller<br> res@lbLabelFontHeightF = .018 ; default is HUGE<br> res@lbPerimOn = False ; default has box<br> res@lbBoxLinesOn = True ; turn on labelbar box lines<br> res@lbBoxEndCapStyle = "TriangleBothEnds"<br><br></div><div>;---Zoom in on map<br> res@mpLimitMode = "LatLon"<br> res@mpMinLatF = 21.5<br> res@mpMaxLatF = 25.5<br> res@mpMinLonF = 119.5<br> res@mpMaxLonF = 122.5<br><br> res@mpFillOn = True<br></div><div> res@mpGeophysicalLineColor = "transparent" ; color of cont. outlines</div><div> res@mpOceanFillColor = "transparent"<br> res@mpLandFillColor = "transparent"<br><br> res@mpFillDrawOrder = "PostDraw"<br></div><div> res@mpDataBaseVersion = "MediumRes"</div><div><br> res@mpOutlineOn = False<br> res@pmTickMarkDisplayMode = "Always"<br> res@mpGeophysicalLineThicknessF = 2<br> plot = gsn_csm_contour_map(wks,elev,res)<br><br></div><div> nres = True<br> lnres@gsLineColor = "black"<br> lnres@gsLineThicknessF = 2.0<br> dum = gsn_add_shapefile_polylines(wks,plot,shpdir+filename,lnres)<br></div><div>;---Generate random lat/lon locations and dummy text strings<br> lont = (/121.513,120.684,120.197,120.746,121.613,121.154/)<br> latt = (/25.049,24.12,23.07,22.013,24.05,22.765/)<br> lons = (/121.513,120.684,120.197,120.746,121.613,121.154/)<br> lats = (/25.037,24.145,22.995,22.003,23.975,22.752/)<br> text = (/"Taipei","Taichung","Tainan","Hengchun","Hualian","Taitung"/)<br><br><br>;---Attach some dummy text strings<br> txres = True<br> txres@txFontHeightF = 0.02<br> txres@txJust = "BottomCenter"<br><br> text_id = gsn_add_text(wks,plot,text,lont,latt,txres)<br>;<br> mkres = True<br> mkres@gsMarkerIndex = 16 ; Filled circle<br> mkres@gsMarkerSizeF = 0.01<br><br> locations = gsn_add_polymarker(wks,plot,lons,lats,mkres)<br>;====================================================</div><div> draw(plot) ; This will draw the map and the shapefile outlines.<br> frame(wks)</div></div>
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