To add to that, the following link has some methods for that. I was doing the same thing you were doing when I posted for help.
http://r-sig-geo.2731867.n2.nabble.com/Efficient-way-to-obtain-gridded-count-of-overlapping-polygons-td6034590.html Cheers, Lyndon On Mon, Jul 2, 2012 at 8:25 AM, Mathieu Rajerison < mathieu.rajeri...@gmail.com> wrote: > Hi, > > > You could use over( ) function in order to compute the number of different > species. > > You could also use spatstat::marktable > > Some ideas here: > https://stat.ethz.ch/pipermail/r-sig-geo/2011-May/011722.html > > In vegan package, you can find a Simpson and Shannon diversity calculation > function: vegan::diversity > > > 2012/7/2 Barnabas Daru <daruna...@gmail.com> > > > Dear All, > > > > I write to ask if anyone has an R code to calculate species richness per > > quarter degree grid. > > > > > > > > I have a set of polygon shapefiles showing distribution of different > > species within a country. > > > > I would like to first create quarter degree grids over the entire country > > and using the polygon shapefiles, to extract species richness per grid. > > > > > > > > Any help with R code would be highly appreciated. > > > > Barnabas Daru > > > > > > \-/ > > /\ > > /--| > > /---/ Barnabas Daru > > |--/ PhD Student, > > \-/ African Centre for DNA Barcoding, > > /\ University of Johannesburg, > > /--\ PO Box 524, Auckland Park, 2006, > > |---\ South Africa. > > \---\ Lab: +27 11 559 3477 > > \--| Mobile: +277 3818 9583 > > \-/ Website: http://acdb.co.za/index.php?page=mr-barnabas-h-daru > > /\ > > /--\ > > > > # if you can think it, you can do it. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [[alternative HTML version deleted]] > > > > > > _______________________________________________ > > R-sig-Geo mailing list > > R-sig-Geo@r-project.org > > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > > > > > [[alternative HTML version deleted]] > > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > [[alternative HTML version deleted]]
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