geojson_sf {geojsonsf} | R Documentation |
Geojson to sf
Description
Converts GeoJSON to an 'sf' object
Usage
geojson_sf(
geojson,
expand_geometries = FALSE,
input = NULL,
wkt = NULL,
crs = NULL,
proj4string = NULL,
buffer_size = 1024
)
Arguments
geojson |
string or vector of GeoJSON, or a URL or file pointing to a geojson file |
expand_geometries |
logical indicating whether to unnest GEOMETRYCOLLECTION rows. see details |
input |
user input for coordinate reference system object |
wkt |
well-known text for coordinate reference system object |
crs |
deprecated. coordinate reference system. See Details |
proj4string |
deprecated. proj4string. See Details |
buffer_size |
size of buffer used when reading a file from disk. Defaults 1024 |
Details
specifying expand_geometries = TRUE
will expand individual GEOMETRYCOLLECTION
geometries to their own row in the resulting 'sf' object. If the geometries are part
of a Feature
(i.e., with properties), the properties will be repeated on each row.
The GEOMETRYCOLLECTION
information is not kept when using expand_geometries = TRUE
. Therefore,
it is not possible to reconstruct the GEOMETRYCOLLECTION
after unnesting it.
Geojson specification RFC7946 https://tools.ietf.org/html/rfc7946#page-12 says all CRS should be the World Geodetic System 1984 (WGS 84) [WGS84] datum, with longitude and latitude units of decimal degrees. This is equivalent to the coordinate reference system identified by the Open Geospatial Consortium (OGC) URN urn:ogc:def:crs:OGC::CRS84
geojson_sfc
and geojson_sf
automatically set the CRS to WGS 84.
The fields input
and wkt
let you to overwrite the defaults.
Examples
## character string of GeoJSON
## load 'sf' for print methods
# library(sf)
geojson <- '{ "type" : "Point", "coordinates" : [0, 0] }'
geojson_sf(geojson)
## Not run:
## GeoJSON at a url
myurl <- "http://eric.clst.org/assets/wiki/uploads/Stuff/gz_2010_us_050_00_500k.json"
sf <- geojson_sf(myurl)
## End(Not run)