Re: Subset of a shapefile

No, that wasn't quite right. I had to also add a terminating comma to
each string in ROUTES. This line seems to get the right answer, 185
matches:

interstates = str_match_ind_ic(f->ROUTE+",", "I- 5,")

--Dave

On Sat, Apr 6, 2013 at 4:01 PM, Dave Allured - NOAA Affiliate
<dave.allured@noaa.gov> wrote:
> 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
>>
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Received on Sat Apr 6 16:14:50 2013