Semi-join?
On Tue, May 7, 2019 at 1:39 PM Edzer Pebesma <edzer.pebesma at uni-muenster.de> wrote:
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
Hmm... tried this and for some reasons it was not giving me what I wanted. I will investigate. THK
Thanks. THK
-- Edzer Pebesma Institute for Geoinformatics Heisenbergstrasse 2, 48151 Muenster, Germany Phone: +49 251 8333081
_______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo This message is from an external sender. Learn more about why this << matters at https://links.utexas.edu/rtyclf. <<
Timothy H. Keitt Professor of Integrative Biology and Associate Chair for Undergraduate Education http://www.keittlab.org/ [[alternative HTML version deleted]]