Copy the file-backing of a file-backed Raster* object

Rasters are sometimes file-based, so the normal save and copy and assign mechanisms in R don't work for saving, copying and assigning. This function creates an explicit file copy of the file that is backing the raster, and changes the pointer (i.e., filename(object)) so that it is pointing to the new file.

.prepareFileBackedRaster(obj, repoDir = NULL)

Arguments

obj	The raster object to save to the repository.
repoDir	Character denoting an existing directory in which an artifact will be saved.
...	passed to archivist::saveToRepo

Value

A raster object and its newly located file backing. Note that if this is a legitimate archivist repository, the new location will be a subdirectory called rasters/ of repoDir/. If this is not a repository, the new location will be within repoDir.

Examples

library(raster)
archivist::createLocalRepo(tempdir())
#> Directory /tmp/RtmpzknuyG does exist and contain the backpack.db file. Use force=TRUE to reinitialize.

r <- raster(extent(0,10,0,10), vals = 1:100)

# write to disk manually -- will be in tempdir()
r <- writeRaster(r, file = tempfile())

# copy it to the cache repository
r <- .prepareFileBackedRaster(r, tempdir())

r # now in "rasters" subfolder of tempdir()
#> class       : RasterLayer 
#> dimensions  : 10, 10, 100  (nrow, ncol, ncell)
#> resolution  : 1, 1  (x, y)
#> extent      : 0, 10, 0, 10  (xmin, xmax, ymin, ymax)
#> coord. ref. : NA 
#> data source : /tmp/RtmpzknuyG/rasters/file12bc2c9feff3.grd 
#> names       : layer 
#> values      : 1, 100  (min, max)
#>