[R-sig-Geo] Semi-join?

[Edzer Pebesma]

On 5/7/19 8:29 PM, Tim Keitt wrote:
> I keep finding things that are trivial in sql are not so in R, so perhaps
> you can help me out.
> 
> What would be the way in the 'sf' package to retain only polygons from one
> coverage that intersect points in another coverage? I think that's a
> semi-join.
> 
> Roughly: 'select a.* from polys a, points b where st_intersects(a.geom,
> b.geom)'

a[b,]

# or

st_join(a, b, left = FALSE) # no left join gives you inner join

> 
> Thanks.
> 
> THK
> 

-- 
Edzer Pebesma
Institute for Geoinformatics
Heisenbergstrasse 2, 48151 Muenster, Germany
Phone: +49 251 8333081

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