thredds_download: Download FVCOM outputs from the SAMS thredds server

In edwardlavender/fvcom.tbx: An R Toolbox for the Unstructured Grid Finite Volume Community Ocean Model (FVCOM)

Download FVCOM outputs from the SAMS thredds server

Description

This function is used to download FVCOM outputs from the SAMS thredds server.

Usage

thredds_download(
  file_name,
  pattern = ".nc",
  server_catalog,
  dest_file,
  verbose = TRUE,
  prompt = FALSE,
  ...
)

Arguments

file_name	A character vector of file name(s) which specify the files to be downloaded. These should contain a unique identifier for each file (for example, a date_name, see date_name) but they do not need to match file names precisely.
pattern	A character string containing a regular expression which is matched to identify files (e.g., ".nc").
server_catalog	A character that defines the URL of the catalog.
dest_file	A character that defines the directory in which to save file(s).
verbose	A logical input that defines whether or not to print messages to the console. These can be useful for monitoring progress.
prompt	A logical input that defines whether or not to prompt the user before each download.
...	Additional arguments passed to download.file.

Details

To download files, the function first identifies all files on server_catalog that match pattern. For each inputted file_name, the function identifies the full file name and the necessary URL to download that file from the server (a different URL from the catalog) and then downloads the file. If any files cannot be downloaded, the function will print an error message but continue to attempt to download the next file, until there are no remaining files. Note the following: (a) the function is only designed to query a single catalog at a time (i.e., is not recursive, so it will not identify all files on a thredds server, only the specific files in server_catalog; (b) files are large (usually ~ 700 Mb) and are downloaded in sequence; and (c) the function requires the xml2 and rvest package to be installed.

Value

The function downloads specified files from the SAMS thredds server (https://thredds.sams.ac.uk/thredds/) where WeStCOMS outputs are located.

Author(s)

Edward Lavender

Examples

## Not run: 
# Warning: if you run this code, it may take a long time to download the file
# ... which is nearly 1 Gb in size!
thredds_download(file_name = "20190702",
                      pattern = ".nc",
                      server = paste0("https://thredds.sams.ac.uk/thredds/",
                                      "catalog/scoats-westcoms1/Archive/",
                                      "netcdf_2019/catalog.html"),
                                      dest_file = tempdir(),
                                      verbose = TRUE,
                                      prompt = TRUE)

## End(Not run)

edwardlavender/fvcom.tbx documentation built on Nov. 26, 2022, 10:28 p.m.