rgdal (version 0.5-1)

writeOGR: Write spatial vector data using OGR

Description

The function is an interface with the OGR abstraction library for spatial vector data, allowing data to be written out using supported drivers. The drivers supported will depend on the local installation, and the capabilities of those drivers (many are read-only, only KML where available is write-only). The objects exported are SpatialPointsDataFrame, SpatialLinesDataFrame, or SpatialPolygonsDataFrame objects as defined in the sp package.

Usage

writeOGR(obj, dsn, layer, driver, dataset_options = NULL, layer_options=NULL, verbose = FALSE)

Arguments

obj

a SpatialPointsDataFrame, SpatialLinesDataFrame, or a SpatialPolygonsDataFrame object.

dsn

data source name (interpretation varies by driver --- for some drivers, dsn is a file name, but may also be a folder)

layer

layer name (varies by driver, may be a file name without extension)

driver

a character string equal to one of the driver names returned by ogrDrivers

dataset_options

a character vector of options, which vary by driver, and should be treated as experimental

layer_options

a character vector of options, which vary by driver, and should be treated as experimental

verbose

if TRUE, returns a list of information about the attempted write operation

Value

• if verbose=TRUE, a list of information about the attempted write operation

Details

Working out which combination of dsn, layer, and driver (and option) values give the desired output takes time and care, and is constrained by the ability of drivers to write output; many are read-only. Use of the references given is highly advisable, with searches in the archives of other software using GDAL/OGR.

References

http://www.remotesensing.org/gdal/ogr/index.html, http://www.remotesensing.org/gdal/ogr/ogr_formats.html, http://examples.oreilly.com/webmapping/

See Also

readOGR

Examples

cities <- readOGR(system.file("vectors", package = "rgdal")[1], "cities")
is.na(cities$POPULATION) <- cities$POPULATION == -99
summary(cities$POPULATION)
td <- tempdir()
writeOGR(cities, td, "cities", driver="ESRI Shapefile")
cities2 <- readOGR(td, "cities")
summary(cities2$POPULATION)
all.equal(cities, cities2)
if ("GML" %in% ogrDrivers()$name) {
  airports <- try(readOGR(system.file("vectors/airports.gml", package = "rgdal")[1], "airports"))
  if (class(airports) != "try-error") {
    writeOGR(cities, paste(td, "cities.gml", sep="/"), "cities", driver="GML")
    cities3 <- readOGR(paste(td, "cities.gml", sep="/"), "cities")
    all.equal(cities, cities3)
  }
}
# The GML driver does not support coordinate reference systems
if ("KML" %in% ogrDrivers()$name) {
  data(meuse)
  coordinates(meuse) <- c("x", "y")
  proj4string(meuse) <- CRS("+init=epsg:28992")
  meuse_ll <- spTransform(meuse, CRS("+proj=longlat +datum=WGS84"))
  writeOGR(meuse_ll["zinc"], paste(td, "meuse.kml", sep="/"), "zinc", "KML")
}
list.files(td)
roads <- readOGR(system.file("vectors", package = "rgdal")[1], "kiritimati_primary_roads")
summary(roads)
writeOGR(roads, td, "roads", driver="MapInfo File")
roads2 <- readOGR(paste(td, "roads.tab", sep="/"), "roads")
summary(roads2)
scot_BNG <- readOGR(system.file("vectors", package = "rgdal")[1], "scot_BNG")
summary(scot_BNG)
writeOGR(scot_BNG, td, "scot_BNG", driver="MapInfo File")
list.files(td)
scot_BNG2 <- readOGR(paste(td, "scot_BNG.tab", sep="/"), "scot_BNG")
summary(scot_BNG2)
writeOGR(scot_BNG, td, "scot_BNG", driver="MapInfo File", dataset_options="FORMAT=MIF")
list.files(td)
scot_BNG3 <- readOGR(paste(td, "scot_BNG.mif", sep="/"), "scot_BNG")
summary(scot_BNG3)