Get or set a coordinate reference system (projection)

Get or set the coordinate reference system (CRS) of a Raster* object.

# S4 method for class 'ANY'
crs(x, asText=FALSE, ...)
# S4 method for class 'Raster'
wkt(obj)
crs(x, ...) <- value

projection(x, asText=TRUE)
projection(x) <- value

Arguments

x

Raster* or Spatial object

obj

Raster*, Spatial, or CRS object

asText

logical. If TRUE, the projection is returned as text. Otherwise a CRS-class object is returned

...

additional arguments. None implemented

value

CRS object or a character string describing a projection and datum in the PROJ.4 format

Value

Raster*, Spatial*, or character object

Note

crs replaces earlier function projection. For compatibility with sp you can use proj4string instead of crs. wkt returns the "well-known-text" representation of the crs.

See also

projectRaster, spTransform

Details

projections are done by with the PROJ library

Examples

r <- raster()
crs(r)
#> Coordinate Reference System:
#> Deprecated Proj.4 representation: +proj=longlat +datum=WGS84 +no_defs 
#> WKT2 2019 representation:
#> GEOGCRS["unknown",
#>     DATUM["World Geodetic System 1984",
#>         ELLIPSOID["WGS 84",6378137,298.257223563,
#>             LENGTHUNIT["metre",1]],
#>         ID["EPSG",6326]],
#>     PRIMEM["Greenwich",0,
#>         ANGLEUNIT["degree",0.0174532925199433],
#>         ID["EPSG",8901]],
#>     CS[ellipsoidal,2],
#>         AXIS["longitude",east,
#>             ORDER[1],
#>             ANGLEUNIT["degree",0.0174532925199433,
#>                 ID["EPSG",9122]]],
#>         AXIS["latitude",north,
#>             ORDER[2],
#>             ANGLEUNIT["degree",0.0174532925199433,
#>                 ID["EPSG",9122]]]] 
crs(r) <- "+proj=lcc +lat_1=48 +lat_2=33 +lon_0=-100 +datum=WGS84"
crs(r)
#> Coordinate Reference System:
#> Deprecated Proj.4 representation:
#>  +proj=lcc +lat_0=0 +lon_0=-100 +lat_1=48 +lat_2=33 +x_0=0 +y_0=0
#> +datum=WGS84 +units=m +no_defs 
#> WKT2 2019 representation:
#> PROJCRS["unknown",
#>     BASEGEOGCRS["unknown",
#>         DATUM["World Geodetic System 1984",
#>             ELLIPSOID["WGS 84",6378137,298.257223563,
#>                 LENGTHUNIT["metre",1]],
#>             ID["EPSG",6326]],
#>         PRIMEM["Greenwich",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8901]]],
#>     CONVERSION["unknown",
#>         METHOD["Lambert Conic Conformal (2SP)",
#>             ID["EPSG",9802]],
#>         PARAMETER["Latitude of false origin",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8821]],
#>         PARAMETER["Longitude of false origin",-100,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8822]],
#>         PARAMETER["Latitude of 1st standard parallel",48,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8823]],
#>         PARAMETER["Latitude of 2nd standard parallel",33,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8824]],
#>         PARAMETER["Easting at false origin",0,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8826]],
#>         PARAMETER["Northing at false origin",0,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8827]]],
#>     CS[Cartesian,2],
#>         AXIS["(E)",east,
#>             ORDER[1],
#>             LENGTHUNIT["metre",1,
#>                 ID["EPSG",9001]]],
#>         AXIS["(N)",north,
#>             ORDER[2],
#>             LENGTHUNIT["metre",1,
#>                 ID["EPSG",9001]]]] 
w <- wkt(r)
w
#> [1] "PROJCRS[\"unknown\",\n    BASEGEOGCRS[\"unknown\",\n        DATUM[\"World Geodetic System 1984\",\n            ELLIPSOID[\"WGS 84\",6378137,298.257223563,\n                LENGTHUNIT[\"metre\",1]],\n            ID[\"EPSG\",6326]],\n        PRIMEM[\"Greenwich\",0,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8901]]],\n    CONVERSION[\"unknown\",\n        METHOD[\"Lambert Conic Conformal (2SP)\",\n            ID[\"EPSG\",9802]],\n        PARAMETER[\"Latitude of false origin\",0,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8821]],\n        PARAMETER[\"Longitude of false origin\",-100,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8822]],\n        PARAMETER[\"Latitude of 1st standard parallel\",48,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8823]],\n        PARAMETER[\"Latitude of 2nd standard parallel\",33,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8824]],\n        PARAMETER[\"Easting at false origin\",0,\n            LENGTHUNIT[\"metre\",1],\n            ID[\"EPSG\",8826]],\n        PARAMETER[\"Northing at false origin\",0,\n            LENGTHUNIT[\"metre\",1],\n            ID[\"EPSG\",8827]]],\n    CS[Cartesian,2],\n        AXIS[\"(E)\",east,\n            ORDER[1],\n            LENGTHUNIT[\"metre\",1,\n                ID[\"EPSG\",9001]]],\n        AXIS[\"(N)\",north,\n            ORDER[2],\n            LENGTHUNIT[\"metre\",1,\n                ID[\"EPSG\",9001]]]]"
cat(w, "\n")
#> PROJCRS["unknown",
#>     BASEGEOGCRS["unknown",
#>         DATUM["World Geodetic System 1984",
#>             ELLIPSOID["WGS 84",6378137,298.257223563,
#>                 LENGTHUNIT["metre",1]],
#>             ID["EPSG",6326]],
#>         PRIMEM["Greenwich",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8901]]],
#>     CONVERSION["unknown",
#>         METHOD["Lambert Conic Conformal (2SP)",
#>             ID["EPSG",9802]],
#>         PARAMETER["Latitude of false origin",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8821]],
#>         PARAMETER["Longitude of false origin",-100,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8822]],
#>         PARAMETER["Latitude of 1st standard parallel",48,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8823]],
#>         PARAMETER["Latitude of 2nd standard parallel",33,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8824]],
#>         PARAMETER["Easting at false origin",0,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8826]],
#>         PARAMETER["Northing at false origin",0,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8827]]],
#>     CS[Cartesian,2],
#>         AXIS["(E)",east,
#>             ORDER[1],
#>             LENGTHUNIT["metre",1,
#>                 ID["EPSG",9001]]],
#>         AXIS["(N)",north,
#>             ORDER[2],
#>             LENGTHUNIT["metre",1,
#>                 ID["EPSG",9001]]]]