Make tiles or get their extents
makeTiles.Rd
Divide a SpatRaster into "tiles". The cells of another SpatRaster (normally with a much lower resolution) or a SpatVector with polygon geometry can be used to define the tiles. You can also provide one or two numbers to indicate the number of rows and columns per tile.
getTileExtents
returns the extents of the (virtual) tiles, while makeTiles
creates files for the tiles and returns their filenames.
Usage
# S4 method for class 'SpatRaster'
makeTiles(x, y, filename="tile_.tif", extend=FALSE,
na.rm=FALSE, buffer=0, overwrite=FALSE, ...)
# S4 method for class 'SpatRaster'
getTileExtents(x, y, extend=FALSE, buffer=0)
Arguments
- x
SpatRaster
- y
SpatRaster or SpatVector defining the zones; or numeric specifying the number of rows and columns for each zone (1 or 2 numbers if the number of rows and columns is not the same)
- filename
character. Output filename template. Filenames will be altered by adding the tile number for each tile
- extend
logical. If
TRUE
, the extent ofy
is expanded to assure that it covers all ofx
- na.rm
logical. If
TRUE
, tiles with only missing values are ignored- buffer
integer. The number of additional rows and columns added to each tile. Can be a single number, or two numbers to specify a separate number of rows and columns. This allows for creating overlapping tiles that can be used for computing spatial context dependent values with e.g.
focal
. The expansion is only insidex
, no rows or columns outside ofx
are added- overwrite
logical. If
TRUE
, existing tiles are overwritten; otherwise they are skipped (without error or warning)- ...
additional arguments for writing files as in
writeRaster
Examples
r <- rast(ncols=100, nrows=100)
values(r) <- 1:ncell(r)
x <- rast(ncols=2, nrows=2)
getTileExtents(r, x)
#> xmin xmax ymin ymax
#> [1,] -1.800000e+02 4.440892e-15 -2.220446e-15 9.000000e+01
#> [2,] 4.440892e-15 1.800000e+02 -2.220446e-15 9.000000e+01
#> [3,] -1.800000e+02 4.440892e-15 -9.000000e+01 -2.220446e-15
#> [4,] 4.440892e-15 1.800000e+02 -9.000000e+01 -2.220446e-15
getTileExtents(r, x, buffer=3)
#> xmin xmax ymin ymax
#> [1,] -190.8 10.8 -5.4 95.4
#> [2,] -10.8 190.8 -5.4 95.4
#> [3,] -190.8 10.8 -95.4 5.4
#> [4,] -10.8 190.8 -95.4 5.4
filename <- paste0(tempfile(), "_.tif")
ff <- makeTiles(r, x, filename)
ff
#> [1] "/var/folders/t_/mmhnh941511_hp2lwh383bp00000gn/T//RtmpS6ajai/file3ba219030f74_1.tif"
#> [2] "/var/folders/t_/mmhnh941511_hp2lwh383bp00000gn/T//RtmpS6ajai/file3ba219030f74_2.tif"
#> [3] "/var/folders/t_/mmhnh941511_hp2lwh383bp00000gn/T//RtmpS6ajai/file3ba219030f74_3.tif"
#> [4] "/var/folders/t_/mmhnh941511_hp2lwh383bp00000gn/T//RtmpS6ajai/file3ba219030f74_4.tif"
vrt(ff)
#> class : SpatRaster
#> dimensions : 100, 100, 1 (nrow, ncol, nlyr)
#> resolution : 3.6, 1.8 (x, y)
#> extent : -180, 180, -90, 90 (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 (EPSG:4326)
#> source : spat_3ba26ba412c4_15266_CjcR62DykkoqBId.vrt
#> name : spat_3ba26ba412c4_15266_CjcR62DykkoqBId
#> min value : 1
#> max value : 10000