Re: Subset of a shapefile

Jim,

I took a quick look at the contents of f->ROUTE. Your string search
expression is matching all highway numbers that BEGIN WITH "I- 5", for
example I- 535. If you insert a comma and search for "I- 5,", I think
this will be sufficient to get the indices for only I-5.

--Dave
(Please reply to list only!)

On Fri, Apr 5, 2013 at 6:32 PM, Jim Means <jmeans@ucsd.edu> wrote:
> Hello, I am trying to plot a single interstate highway (I-5) in NCL. I have downloaded a shapefile of interstates and other roads from NOAA (http://www.nws.noaa.gov/geodata/catalog/transportation/html/interst.htm), and by stealing code from one of the NCL examples I'm able to load the shapefile into NCL and plot the road. Unfortunately there are other roads that I don't want to plot that show up also. So far, I've been unable to figure out how to just plot a single road. My code looks like this:
>
> f = addfile("in101503.shp", "r") ; Open shapefile
>
> ;
> ; Read data off shapefile
> ;
> segments = f->segments
> geometry = f->geometry
> segsDims = dimsizes(segments)
> geomDims = dimsizes(geometry)
>
> numFeatures = geomDims(0)
> ;
> ; Read global attributes
> ;
> geom_segIndex = f@geom_segIndex
> geom_numSegs = f@geom_numSegs
> segs_xyzIndex = f@segs_xyzIndex
> segs_numPnts = f@segs_numPnts
> numFeatures = geomDims(0)
>
> interstates = str_match_ind_ic(f->ROUTE, "I- 5")
>
> The last statement gives me the indices that correspond to I-5 in the shapefile. I think I should be able to use this to just plot that single road, but after much experimentation and trying to follow the examples, I haven't been able to do it. Any hints would be greatly appreciated.
>
> Thank you,
>
> Jim Means
>
> _______________________________________________
> 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 Sat Apr 6 16:01:29 2013