[GRASS-user] Checking if a point (X, Y) is inside the, polygons of a shape file using command line. Solution using R

[Rick Reeves]

Hamish:

Good point. For a large dataset such as Corrado's, it would be better to 
use GRASS,
once Corrado surmounts the GRASS learning curve. R is a good alternative 
choice
in that it is simpler to use.

Regards, RR

Hamish wrote:
> Rick Reeves wrote:
>   
>> This is a good task for the R programming environment, which has
>> strong geospatial tools and integrates with GRASS:
>>     
>
> FYI, in GRASS's vector library (available outside of C with e.g.
> SWIG-Python) there a number of x-in-polygon functions found in
> lib/vector/Vlib/poly.c. v.buffer uses such a test to check that its
> centroid is inside the new area, you could trace that back if you
> wanted to see the method in use.
>
> from GRASS modules there is v.select and 'v.distance dmax=0' (?) and
> probably other ways too.
>
>
> many roads,
> Hamish
>
>
>
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