Download road emissions data — download

The download_nei() function accesses and downloads road emissions data from the U.S Environmental Protection Agency's (EPA) National Emissions Inventory (NEI).

Usage

download_nei(
  epa_certificate_path = NULL,
  certificate_url = paste0("http://cacerts.digicert.com/",
    "DigiCertGlobalG2TLSRSASHA2562020CA1-1.crt"),
  year = c(2017L, 2020L),
  directory_to_save = NULL,
  acknowledgement = FALSE,
  download = TRUE,
  remove_command = FALSE,
  unzip = TRUE,
  remove_zip = FALSE,
  show_progress = TRUE,
  hash = FALSE,
  max_tries = 20,
  rate_limit = 2
)

Arguments

epa_certificate_path: TO BE DEPRECATED. Certificate path.
certificate_url: TO BE DEPRECATED. Certificate URL.
year: integer(1). Available years of NEI data.
directory_to_save: character(1). Directory to save data.
acknowledgement: logical(1). Must be TRUE to proceed.
download: logical(1). DEPRECATED. Downloads happen automatically.
remove_command: logical(1). Deprecated, ignored.
unzip: logical(1). Unzip zip files (default TRUE).
remove_zip: logical(1). Remove zip files after unzipping (default FALSE).
show_progress: logical(1). Show download progress (default TRUE)
hash: logical(1). Return hash of downloaded files (default FALSE)
max_tries: integer(1). Maximum retry attempts (default 20)
rate_limit: numeric(1). Minimum seconds between requests (default 2)

Value

invisible list with download results; or hash character if hash=TRUE

Note

NEI data does not require authentication.

References

United States Environmental Protection Agency (2024). “Air Emissions Inventories.” https://www.epa.gov/air-emissions-inventories.

Author

Kyle Messier, Insang Song

Examples

if (FALSE) { # \dontrun{
download_nei(
  year = c(2017L, 2020L),
  directory_to_save = tempdir(),
  acknowledgement = TRUE
)
} # }