reproject the extent of a spatial object

accessory function to convert the extent of a spatial object to a different projection. simple wrapper for the spTransform function on

reproj_extent(ext, out_proj, in_proj = NULL, enlarge = TRUE,
  n_dens = 1000, verbose = TRUE)

Arguments

ext	object of class sprawlext, or any other object or filename from which a sprawlext object can be derived (see get_extent)
out_proj	character proj4string representing the desired projection for the output extent
in_proj	character (optional) proj4string representing the projection of projection (like extent or bbox). the input extent. It is needed only if ext is an object which does not include a
enlarge	logical If TRUE (default), the reprojected bounding box is the one which completely include the original one; if FALSE (faster), it is simply the one obtained by reprojecting the upper-left and the lower-right corners.
n_dens	numeric Densification ratio used in the case enlarge is TRUE. reprojected extent
verbose	logical If FALSE, suppress processing messages, Default: TRUE

Value

An object of class sprawlext representing the reprojected extent

Examples

library(raster)
in_file <- system.file("extdata/MODIS_test", "EVIts_test.tif",
  package = "sprawl.data")
in_rast <- raster::raster(in_file)
in_sprawlext <- get_extent(in_rast)

# Reproject a sprawlext
reproj_extent(in_sprawlext, "+init=epsg:32651")
#> crop_rast --> Reprojecting extent of: in_sprawlext to: +init=epsg:32651
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#>  195742.3 1677398.6  332519.7 1780655.5 
#> 
#> Slot "proj4string":
#> [1] "+proj=utm +zone=51 +datum=WGS84 +units=m +no_defs"
#> 

# Reproject the extent of a file
reproj_extent(in_file, "+init=epsg:32651")
#> crop_rast --> Reprojecting extent of: in_file to: +init=epsg:32651
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#>  195742.3 1677398.6  332519.7 1780655.5 
#> 
#> Slot "proj4string":
#> [1] "+proj=utm +zone=51 +datum=WGS84 +units=m +no_defs"
#> 

# Reproject the extent of a raster
reproj_extent(in_rast, "+init=epsg:32651")
#> crop_rast --> Reprojecting extent of: in_rast to: +init=epsg:32651
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#>  195742.3 1677398.6  332519.7 1780655.5 
#> 
#> Slot "proj4string":
#> [1] "+proj=utm +zone=51 +datum=WGS84 +units=m +no_defs"
#> 

# Reproject an extent or a bounding box (given the input projection)
reproj_extent(raster::extent(in_rast), "+init=epsg:32651", in_proj=in_rast@crs)
#> crop_rast --> Reprojecting extent of: raster::extentin_rast to: +init=epsg:32651
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#>  195742.3 1677398.6  332519.7 1780655.5 
#> 
#> Slot "proj4string":
#> [1] "+proj=utm +zone=51 +datum=WGS84 +units=m +no_defs"
#> 
reproj_extent(sp::bbox(in_rast), "+init=epsg:32651", in_proj=in_rast@crs)
#> crop_rast --> Reprojecting extent of: sp::bboxin_rast to: +init=epsg:32651
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#>  195742.3 1677398.6  332519.7 1780655.5 
#> 
#> Slot "proj4string":
#> [1] "+proj=utm +zone=51 +datum=WGS84 +units=m +no_defs"
#> 

# Reproject without enlarging
reproj_extent(in_sprawlext, "+init=epsg:32651", enlarge = FALSE)
#> crop_rast --> Reprojecting extent of: in_sprawlext to: +init=epsg:32651
#> An object of class "sprawlext"
#> Slot "extent":
#>      xmin      ymin      xmax      ymax 
#>  195742.3 1677398.6  332519.7 1780655.5 
#> 
#> Slot "proj4string":
#> [1] "+proj=utm +zone=51 +datum=WGS84 +units=m +no_defs"
#>