This function returns a data frame of spectral indices, from the
awesome-spectral-indices
repository.
spectral_indices(
...,
url = spectral_indices_url(),
download_indices = NULL,
update_cache = NULL
)
A tibble::tibble with nine columns, containing information about spectral indices.
These dots are for future extensions and must be empty.
The URL to download spectral indices from. If the option rsi_url
is set, that value will be used; otherwise, if the environment variable
rsi_url
is set, that value will be used; otherwise, the list at
https://github.com/awesome-spectral-indices/awesome-spectral-indices will
be used.
Logical: should this function download indices? If
NULL
, this function will only download indices if the cache will be
updated. If TRUE
, this function will attempt to download indices no matter
what. If FALSE
, either cached or package indices will be used.
Logical: should cached indices be updated? If NULL
,
cached values will be updated if the cache is older than a day. If TRUE
,
the cache will be updated, if FALSE
it will not.