R/depths.R

In r4ecology/rcdo: Tools to manipulate netcdf data

# to do: this potentially should be a list showing depth range and depths separately

#' @title Find depths in a netcdf file
#'
#' @description Find depths available in a netcdf file
#' @param ff This is the file to check.
#' @export


#' @examples
#' 
#' # Get the depths in the sample file
#' ff <- system.file("extdata", "woa18_decav_t01_01.nc", package = "rcdo")
#' nc_depths(ff)
nc_depths <- function(ff) {
  if (!file_valid(ff)) {
    stop(stringr::str_glue("error: {ff} does not exist or is not netcdf"))
  }

  ff_depths <<- system(stringr::str_c("cdo showlevel ", ff), intern = TRUE, ignore.stderr = TRUE) %>%
    stringr::str_split(" ") %>%
    .[[1]]
  ff_depths <- ff_depths[ff_depths != ""]
  ff_depths <- as.numeric(ff_depths)
  if (length(ff_depths) < 2) {
    return("No depth information")
  }


  dplyr::data_frame(Depth = ff_depths) %>%
    dplyr::distinct()
}