Hi to everyone, Thanks to all of you for the advice on this, which has solved my problem quite nicely now. Based on your suggestions, I figured out the following:
ogr2ogr was broken for me because I had not completely removed a prior custom install of gdal that I had set up for hdf4 support, which required libjpeg. Once removed, I can use ogr2ogr fine from the linux shell. Since I want to select a particular record from the postgis database, and want to keep the object in R without writing it to disk for the time being (which would rule out a system call to ogr2ogr as an option), I am using the RpostgreSQL option together with rgeos::readWKT. I am basing this on the idea that it is not possible to use sql statements in readOGR, and thus can't select an individual geometry from a table (although I see there was some talk about this in 2010: http://r-sig-geo.2731867.n2.nabble.com/passing-SQL-through-readOGR-td3816889.html). library(RPostgreSQL) # CRS drv <- dbDriver("PostgreSQL") con <- dbConnect(drv, dbname = "mydb", user = "me", password = "mypw") sql <- "SELECT ST_AsEWKT(geom) from sa1kgrid where id=9" kmlGeom <- dbGetQuery(con, sql) kmlGeom 1 SRID=97490;MULTIPOLYGON(((570779.01553729 -2401338.07340772,571779.01553729 -2401338.07340772,571779.01553729 -2402338.07340772,570779.01553729 -2402338.07340772,570779.01553729 -2401338.07340772))) # Comes back as data.frame with SRID, which needs to be stripped out for readWKT to work geomStr <- unlist(strsplit(kmlGeom[1, ], ";")) geomPoly <- readWKT(geomStr[-grep("SRID", geomStr)]) That seems to work nicely, so thanks for the solution! Best, Lyndon On Tue, Oct 9, 2012 at 5:21 PM, Edzer Pebesma <edzer.pebe...@uni-muenster.de > wrote: > > > On 10/09/2012 12:04 PM, Barry Rowlingson wrote: > > There must be an R WKT reader somewhere... > > rgeos::readWKT > -- > Edzer Pebesma > Institute for Geoinformatics (ifgi), University of Münster > Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 > 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de > http://www.52north.org/geostatistics e.pebe...@wwu.de > > _______________________________________________ > 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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