You can do this with basic R functions: ## create vectors of the longitude and latitude values x <- seq(from = 24, to = 34, by = 0.025) y <- seq(from = -24, to = -14, by = 0.025)
## create a grid of all pairs of coordinates (as a data.frame) xy <- expand.grid(x = x, y = y) ## load the "foreign" package to write to DBF library(foreign) write.dbf(xy, file = "xy.dbf") Note that there's nothing particularly "geographical" about any of this, and using "10km resolution" with longitude / latitude coordinates could only be done with an approximation that was not constant over the area, unless you used an appropriate map projection (i.e. not long/lat). Note that a 0.025 long/lat spacing is more like 2.7 km in this region (and it changes within the region) so you might need to check why you have that number. Also, the coordinates created above are only "WGS84" by virtue of the fact that you state that they are, there's no way to store that metadata in DBF. If you need to explore this further the R-Sig-Geo mailing list is appropriate for spatial functions and formats. Cheers, Mike. On Mon, Dec 10, 2012 at 10:08 PM, Ulrik Bo Pedersen <u...@sund.ku.dk> wrote: > I would like to create a geographical grid to have a sort of a reference grid > for my georeferenced survey data. The grid should be in a xy format, wgs1984 > with a 0.025 degree, alternatively 10km, resolution covering -14 to -24 S and > 24 to -34 E (Zimbabwe). > Additionally I need to be able to export it as a .dbf > > Hope someone can help an R- novice ! > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- Michael Sumner Hobart, Australia e-mail: mdsum...@gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
