This function crops an input raster layer (.tif) given a bounding box (xmin, ymin, xmax, ymax coordinates, or a spatial object from which to extract a bounding box) or to the boundary of a polygon vector layer (cutline source). The cropping is performed directly on disk, i.e. the input layer does not need to be loaded into R. The output is always written to disk, and can be optionally loaded into R as a SpatRaster (terra package) object (using read = TRUE).
Usage
crop_to_extent(
raster_layer,
vector_layer = NULL,
bounding_box = NULL,
out_dir,
file_name,
compression = "low",
bigtiff = TRUE,
read = TRUE,
quiet = TRUE
)Arguments
- raster_layer
character. Full path to the input raster .tif layer.
- vector_layer
character. Full path to a vector layer that is used as a cutline data source (similar to a mask operation).
- bounding_box
numeric vector of the coordinates of the corners of a bounding box (xmin, ymin, xmax, ymax), SpatRaster, SpatVector, or other spatial object.
- out_dir
character. The directory where the output will be stored.
- file_name
character. Name of the cropped output raster .tif file.
- compression
character. Compression of the written output file. Compression levels can be defined as "none", "low", or "high". Default is "low".
- bigtiff
logical. Define whether the output file is expected to be a BIGTIFF (file size larger than 4 GB). If FALSE and size > 4GB no file will be written. Default is TRUE.
- read
logical. If TRUE, the cropped raster .tif layer gets read into R. If FALSE, the layer is only stored on disk. Default is TRUE.
- quiet
logical. If FALSE, the standard output will be printed. Default is TRUE.
Value
The function returns always a .tif raster file written to disk. Optionally, a SpatRaster (terra object) can be loaded into R with read = TRUE.
Examples
# Download test data into the temporary R folder
# or define a different directory
my_directory <- tempdir()
download_test_data(my_directory)
# Define full path to the input raster .tif layer ans vector layer
spi_raster <- paste0(my_directory, "/hydrography90m_test_data",
"/spi_1264942.tif")
basin_vector <- paste0(my_directory, "/hydrography90m_test_data",
"/basin_59.gpkg")
# Crop the Stream Power Index to the basin
spi_basin <- crop_to_extent(raster_layer = spi_raster,
vector_layer = basin_vector,
out_dir = my_directory,
file_name = "spi_basin_cropped.tif",
read = TRUE)