create_VRT_from_dir: Create a Virtual Raster (VRT) file from .tif files

In CopernicusDEM: Copernicus Digital Elevation Models

Create a Virtual Raster (VRT) file from .tif files

Description

Create a Virtual Raster (VRT) file from .tif files

Usage

create_VRT_from_dir(
  dir_tifs,
  output_path_VRT,
  file_extension = ".tif",
  verbose = FALSE
)

Arguments

dir_tifs	a valid path to a directory where the .tif files are saved
output_path_VRT	a valid path to a file where the Virtual Raster (VRT) will be saved
file_extension	a character string specifying the image file extension from which the .vrt file will be built
verbose	a boolean. If TRUE then information will be printed out in the console

Value

it doesn't return an object but it saves the output to a file

Examples

## Not run: 

#.........................................................
# create a directory to save the .tif files and a
# Well Known Text (WKT) of a sample Area of Interest (AOI)
#.........................................................

DIR_SAVE = file.path(Sys.getenv('HOME'), 'DIR_SAVE_DEM')
if (!dir.exists(DIR_SAVE)) dir.create(DIR_SAVE)

WKT='POLYGON((61.5234 27.0591, 63.6328 27.0591, 63.6328 28.1495, 61.5234 28.1495, 61.5234 27.0591))'

sf_obj = sf::st_as_sfc(WKT, crs = 4326)
sf_obj = sf::st_make_valid(sf_obj)

#......................
# download 90 meter DEM
#......................

save_matches = CopernicusDEM::aoi_geom_save_tif_matches(sf_or_file = sf_obj,
                                                        dir_save_tifs = DIR_SAVE,
                                                        resolution = 90,
                                                        crs_value = 4326,
                                                        threads = parallel::detectCores(),
                                                        verbose = TRUE)

#........................................
# create a Virtual Raster (VRT) file from
# the 90 meter downloaded .tif files
#........................................

VRT_out = as.character(glue::glue("{DIR_SAVE}.vrt"))

res_vrt = CopernicusDEM::create_VRT_from_dir(dir_tifs = DIR_SAVE,
                                             output_path_VRT = VRT_out,
                                             verbose = TRUE)

#......................................................
# load the saved VRT file as raster (which might
# consist of multiple files, i.e. a mosaic) and plot it
#......................................................

rst = raster::raster(VRT_out)
sp::plot(rst)


## End(Not run)

CopernicusDEM documentation built on Sept. 12, 2024, 6:55 a.m.