Get a data frame of spectral indices

This function returns a data frame of spectral indices, from the awesome-spectral-indices repository.

Usage

spectral_indices(
  ...,
  url = spectral_indices_url(),
  download_indices = NULL,
  update_cache = NULL
)

Source

https://github.com/awesome-spectral-indices/awesome-spectral-indices

Arguments

...

These dots are for future extensions and must be empty.

url

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.

download_indices

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.

update_cache

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.

Value

A tibble::tibble with nine columns, containing information about spectral indices.

Examples

spectral_indices()
#> # A tibble: 261 × 9
#>    application_domain bands     contributor   date_of_addition formula long_name
#>    <chr>              <list>    <chr>         <chr>            <chr>   <chr>    
#>  1 vegetation         <chr [2]> https://gith… 2021-11-17       (N - 0… Aerosol …
#>  2 vegetation         <chr [2]> https://gith… 2021-11-17       (N - 0… Aerosol …
#>  3 water              <chr [6]> https://gith… 2022-09-22       (B + G… Augmente…
#>  4 vegetation         <chr [2]> https://gith… 2021-09-20       (1 / G… Anthocya…
#>  5 vegetation         <chr [3]> https://gith… 2022-04-08       N * ((… Anthocya…
#>  6 vegetation         <chr [4]> https://gith… 2021-05-11       (N - (… Atmosphe…
#>  7 vegetation         <chr [4]> https://gith… 2021-05-14       sla * … Adjusted…
#>  8 vegetation         <chr [2]> https://gith… 2022-04-08       (N * (… Advanced…
#>  9 water              <chr [4]> https://gith… 2021-09-18       4.0 * … Automate…
#> 10 water              <chr [5]> https://gith… 2021-09-18       B + 2.… Automate…
#> # ℹ 251 more rows
#> # ℹ 3 more variables: platforms <list>, reference <chr>, short_name <chr>