get_file: Downloads a file from a URL if it not already in the cache.

In rstudio/keras: R Interface to 'Keras'

Downloads a file from a URL if it not already in the cache.

Description

By default the file at the url origin is downloaded to the cache_dir ⁠~/.keras⁠, placed in the cache_subdir datasets, and given the filename fname. The final location of a file example.txt would therefore be ⁠~/.keras/datasets/example.txt⁠. Files in .tar, .tar.gz, .tar.bz, and .zip formats can also be extracted.

Passing a hash will verify the file after download. The command line programs shasum and sha256sum can compute the hash.

Usage

get_file(
  fname = NULL,
  origin = NULL,
  ...,
  file_hash = NULL,
  cache_subdir = "datasets",
  hash_algorithm = "auto",
  extract = FALSE,
  archive_format = "auto",
  cache_dir = NULL,
  force_download = FALSE
)

Arguments

fname	Name of the file. If an absolute path, e.g. "/path/to/file.txt" is specified, the file will be saved at that location. If NULL, the name of the file at origin will be used.
origin	Original URL of the file.
...	For forward/backward compatability.
file_hash	The expected hash string of the file after download. The sha256 and md5 hash algorithms are both supported.
cache_subdir	Subdirectory under the Keras cache dir where the file is saved. If an absolute path, e.g. "/path/to/folder" is specified, the file will be saved at that location.
hash_algorithm	Select the hash algorithm to verify the file. options are ⁠"md5'⁠, ⁠"sha256'⁠, and ⁠"auto'⁠. The default 'auto' detects the hash algorithm in use.
extract	TRUE tries extracting the file as an Archive, like tar or zip.
archive_format	Archive format to try for extracting the file. Options are ⁠"auto'⁠, ⁠"tar'⁠, ⁠"zip'⁠, and NULL. "tar" includes tar, tar.gz, and tar.bz files. The default "auto" corresponds to c("tar", "zip"). NULL or an empty list will return no matches found.
cache_dir	Location to store cached files, when NULL it defaults to Sys.getenv("KERAS_HOME", "~/.keras/").
force_download	If TRUE, the file will always be re-downloaded regardless of the cache state.

Value

Path to the downloaded file.

** Warning on malicious downloads **

Downloading something from the Internet carries a risk. NEVER download a file/archive if you do not trust the source. We recommend that you specify the file_hash argument (if the hash of the source file is known) to make sure that the file you are getting is the one you expect.

Examples

path_to_downloaded_file <- get_file(
    origin = "https://storage.googleapis.com/download.tensorflow.org/example_images/flower_photos.tgz",
    extract = TRUE
)

See Also

• https://keras.io/api/utils/python_utils#getfile-function

Other utils:
audio_dataset_from_directory()
clear_session()
config_disable_interactive_logging()
config_disable_traceback_filtering()
config_enable_interactive_logging()
config_enable_traceback_filtering()
config_is_interactive_logging_enabled()
config_is_traceback_filtering_enabled()
get_source_inputs()
image_array_save()
image_dataset_from_directory()
image_from_array()
image_load()
image_smart_resize()
image_to_array()
layer_feature_space()
normalize()
pack_x_y_sample_weight()
pad_sequences()
set_random_seed()
split_dataset()
text_dataset_from_directory()
timeseries_dataset_from_array()
to_categorical()
unpack_x_y_sample_weight()
zip_lists()

rstudio/keras documentation built on April 22, 2024, 11:43 p.m.