return the extent of a spatial object or file (with projection)

Source: R/get_extent.R

helper function used to retrieve the extent of a spatial object or file, and the associated proj4string

get_extent(in_object, proj4string = NULL, abort = FALSE)

# S3 method for default
get_extent(in_object, proj4string = NULL,
  abort = FALSE)

# S3 method for sprawlext
get_extent(in_object, proj4string = NULL,
  abort = FALSE)

# S3 method for Extent
get_extent(in_object, proj4string, abort = FALSE)

# S3 method for matrix
get_extent(in_object, proj4string, abort = FALSE)

# S3 method for character
get_extent(in_object, proj4string = NULL,
  abort = FALSE)

# S3 method for Raster
get_extent(in_object, proj4string = NULL,
  abort = FALSE)

# S3 method for sf
get_extent(in_object, proj4string = NULL, abort = FALSE)

# S3 method for sfc
get_extent(in_object, proj4string = NULL, abort = FALSE)

# S3 method for Spatial
get_extent(in_object, proj4string = NULL,
  abort = FALSE)

# S3 method for Spatial
get_extent(in_object, proj4string = NULL,
  abort = FALSE)

Arguments

in_object

character corresponding to the name of a R object, or a filename (full path)
proj4string

(optional) character proj4string representing the projection of the input extent. It is needed only if in_object does not include a projection (like extent or bbox).
abort

logical if TRUE, the function aborts in case valid a extent can not be retrieved, otherwise, it issues a Warning and returns NA, Default: FALSE

Value

object of class sprawlext

Details

return an object of class sprawlext with two slots:

  • $extent: numeric (4) extent of the object (xmin, ymin, xmax, ymax)

  • $proj4string: character proj4string of the object (if an extent can not be retrieved from in_object)

Examples


library(raster)

in_rast <- system.file("extdata/MODIS_test", "EVIts_test.tif",
  package = "sprawl.data")
get_extent(in_rast)
#> An object of class "sprawlext"
#> Slot "extent":
#>     xmin     ymin     xmax     ymax 
#> 12897004  1685995 12973683  1789545 
#> 
#> Slot "proj4string":
#> [1] "+proj=sinu +lon_0=0 +x_0=0 +y_0=0 +a=6371007.181 +b=6371007.181 +units=m +no_defs"
#> 

in_rast <- raster::raster(in_rast)
get_extent(in_rast)
#> An object of class "sprawlext"
#> Slot "extent":
#>     xmin     ymin     xmax     ymax 
#> 12897004  1685995 12973683  1789545 
#> 
#> Slot "proj4string":
#> [1] "+proj=sinu +lon_0=0 +x_0=0 +y_0=0 +a=6371007.181 +b=6371007.181 +units=m +no_defs"
#> 

in_vect <- system.file("extdata/shapes","lc_polys.shp",
  package = "sprawl.data")
get_extent(in_vect)
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#> 120.17779  15.15353 121.33942  16.09343 
#> 
#> Slot "proj4string":
#> [1] "+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0"
#> 

in_vect <- read_vect(in_vect)
get_extent(in_vect)
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#> 120.17779  15.15353 121.33942  16.09343 
#> 
#> Slot "proj4string":
#> [1] "+proj=longlat +datum=WGS84 +no_defs"
#>