R/filenames_chelsa_trace21k.R

In pastclim: Manipulate Time Series of Climate Reconstructions

#' Generate file names to download the chelsa trace 21k
#'
#' This function creates a vector of paths needed to download the CHELSA
#' trace21k
#' @param dataset the name of the dataset of interest (currently unused)
#' @param bio_var the variable of interest
#' @returns a vector of times, one per band
#'
#' @keywords internal
filenames_chelsa_trace21k <- function(dataset, bio_var) {
  # TODO extract version from the dataset name
  version <- "1.0"

  yr_id <- seq(20, -200, by = -1)

  # based on the variable, get the original var prefix and name for chelsa
  if (grepl("bio", bio_var)) {
    var_prefix <- "bio"

    var_index <- paste0(
      var_prefix,
      sprintf(
        "%02d",
        as.numeric(substr(bio_var, nchar(bio_var) - 1, nchar(bio_var)))
      )
    )
  } else if (grepl("temperature_min", bio_var)) {
    var_prefix <- "tasmin"
    var_index <- paste0(
      var_prefix, "_",
      as.numeric(substr(bio_var, nchar(bio_var) - 1, nchar(bio_var)))
    )
  } else if (grepl("temperature_max", bio_var)) {
    var_prefix <- "tasmax"
    var_index <- paste0(
      var_prefix, "_",
      as.numeric(substr(bio_var, nchar(bio_var) - 1, nchar(bio_var)))
    )
  } else if (grepl("precipitation", bio_var)) {
    var_prefix <- "pr"
    var_index <- paste0(
      var_prefix, "_",
      as.numeric(substr(bio_var, nchar(bio_var) - 1, nchar(bio_var)))
    )
  }
  # create file names for a given variable
  chelsa_trace_root <- "https://os.zhdk.cloud.switch.ch/chelsav1/chelsa_trace"
  file.path(
    chelsa_trace_root, var_prefix,
    paste0(
      "CHELSA_TraCE21k_", var_index, "_", yr_id, "_V",
      version, ".tif"
    )
  )
}