Re: question about country outline

Dear Rick,
Thank you very much for your help. Now I can draw the country outline, but
I've got another question. I want to check whether a point is within the
country. So I use the function gc_inout(lat,lon,mrb_lat,mrb_lon). But there
are points outside the country that show positive results. Does anyone know
why? Thanks in advance for any given help.
Shinn
2010/12/10 Rick Brownrigg <brownrig@ucar.edu>

> Hi Shinn,
>
> The trouble stems from the single call to:
>
> line_data = gsn_add_polyline(wks, map_data, mrb_lon, mrb_lat, lnres)
>
> which will treat all the coordinates in mrb_lot/mrb_lat as a continuous
> line. You want to draw the line segments that make up the countries
> individually, as in shapefile_3.ncl. In particular, you want to replace the
> above call with something like:
>
> segments = f->segments
> geometry = f->geometry
> segsDims = dimsizes(segments)
> geomDims = dimsizes(geometry)
>
> geom_segIndex = f@geom_segIndex
> geom_numSegs = f@geom_numSegs
> segs_xyzIndex = f@segs_xyzIndex
> segs_numPnts = f@segs_numPnts
> numFeatures = geomDims(0)
>
> lines = new(segsDims(0),graphic) ; array to hold polylines
> segNum = 0 ; Counter for adding polylines
> 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, map_data, mrb_lon(startPT:endPT), \
> mrb_lat(startPT:endPT), lnres)
> segNum = segNum + 1
> end do
> end do
>
>
> Check out the discussion at the top of the shapefiles page if the above
> code doesn't make sense. Hope that helps...
> Rick
>
>
>
>
>
> On Dec 9, 2010, at 2:00 AM, shinn wong wrote:
>
> Dear all,
> I've tried to plot the outline boundary of some countries using data
> obtained from DIVA-GIS. The code and the output file can be seen in the
> attachment. However, the output is quite different from that of example 4 in
> the shapefile example page. Does anyone know how can i just plot the outline
> of the country like those in example 4 instead of all the data points? How
> can i get the coordinate of the outline of the country? Many thanks.
> Shinn <aa1.ncl><shapefiles1.000001.png>
> _______________________________________________
> 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 Dec 9 22:50:20 2010