Return Well-known Text representation of simple feature geometry or coordinate reference system

# S3 method for class 'crs'
st_as_text(x, ..., projjson = FALSE, pretty = FALSE)

st_as_text(x, ...)

# S3 method for class 'sfg'
st_as_text(x, ...)

# S3 method for class 'sfc'
st_as_text(x, ..., EWKT = FALSE)

Arguments

x: object of class sfg, sfc or crs
...: modifiers; in particular digits can be passed to control the number of digits used
projjson: logical; if TRUE, return projjson form (requires GDAL 3.1 and PROJ 6.2), else return well-known-text form
pretty: logical; if TRUE, print human-readable well-known-text representation of a coordinate reference system
EWKT: logical; if TRUE, print SRID=xxx; before the WKT string if epsg is available

Details

The returned WKT representation of simple feature geometry conforms to the simple features access specification and extensions (known as EWKT, supported by PostGIS and other simple features implementations for addition of a SRID to a WKT string).

Note

To improve conversion performance, the lwgeom package can be used (it must be installed beforehand) and set the Sys.setenv("LWGEOM_WKT" = "true") environment variable. This will also result in faster printing of complex geometries. Note that the representation as WKT is different from the sf package and may cause reproducibility problems. An alternative solution is to use the lwgeom::st_astext() or wk::as_wkt() functions.

Examples

st_as_text(st_point(1:2))
#> [1] "POINT (1 2)"
st_as_text(st_sfc(st_point(c(-90,40)), crs = 4326), EWKT = TRUE)
#> [1] "SRID=4326;POINT (-90 40)"