Thank you for your replies. I think I am misunderstanding something. I have read the shapefile using sf. I would like to combine polygons for Cyprus and Northern Cyprus only within the world shapefile and keep all the other polygons as they are.
world <- sf::st_read(dsn = "~/gadm36_levels_shp", layer = "gadm36_0") Is something like the following correct? I was thinking of generating a group variable which is unique to all the countries except Cyprus and Northern Cyprus. I a probably making this too complicated. world %>% group_by(group) %>% summarise(geometry = sf::st_union(geometry)) %>% ungroup() Thank you again. Best regards, Milu On Fri, Apr 28, 2023 at 8:56 AM Roger Bivand <roger.biv...@nhh.no> wrote: > On Fri, 28 Apr 2023, Michael Sumner wrote: > > > fwiw, a method with geodata/terra > > > > cyp <- geodata::gadm(country = c("CYP", "XNC"), path = tempdir(), > version = > > "3.6") > > > > terra::aggregate(cyp) > > > > and as per > https://github.com/r-spatial/evolution/blob/main/pkgapi_230305_refs.csv. > > > see ?terra::writeVector to write it out > > > > (rgdal is very old and you should abandon it, it will be removed from > > support by the end of this year) > > Thank you! Yes, sp will by default switch to using sf in place of rgdal > for creating "CRS" objects, and under sp::spTransform in June, and all > three retiring packages rgdal, rgeos, and maptools will be gone by October > 2023. An sp release will appear in May with a transition guide. > > It seems that terra does not have an object corresponding to sp's "CRS" or > sf's "crs". As far as I can see, one needs to create an empty > SpatVector/SpatRaster object and assign a CRS, coerce to "Spatial", and > extract its slot. If this makes sense, sp could use terra (and > raster, needed for coercion) rather than sf where workflows did not > otherwise use sf. Very grateful for input here or > https://github.com/r-spatial/evolution/issues. > > Roger > > > > > > > (just as an aside, we can't hit the geodata vector urls directly with > gdal > > as we can with the rasters, as they are in an R specific format) > > > > Cheers, Mike > > > > > > On Fri, Apr 28, 2023 at 10:52 AM Ben Tupper <btup...@bigelow.org> wrote: > > > >> Hi, > >> > >> You might try st_union() from the sf package > >> https://r-spatial.github.io/sf/articles/sf3.html#geometrical-operations > >> > >> > >> > >> On Thu, Apr 27, 2023 at 5:37 PM Miluji Sb <miluj...@gmail.com> wrote: > >> > >>> Dear all, > >>> > >>> I am using the country-level shapefile from GADM. I would like to merge > >>> Cyprus and North Cyprus into one polygon. Is this possible? I am using > >>> rgdal to read the shapefile, subset, and then rewrite it. Any help will > >> be > >>> highly appreciated. > >>> > >>> ## > >>> world <- readOGR("~/gadm36_levels_shp", layer = "gadm36_0") > >>> > >>> Best regards, > >>> > >>> Milu > >>> > >>> [[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 > >> > > > > > > > > -- > Roger Bivand > Emeritus Professor > Department of Economics, Norwegian School of Economics, > Postboks 3490 Ytre Sandviken, 5045 Bergen, Norway. > e-mail: roger.biv...@nhh.no > https://orcid.org/0000-0003-2392-6140 > https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en > _______________________________________________ > 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