R/adaptTradeDataNames.R

In SWS-Methodology/faoswsTrade: FAO Trade Module

#' Standardise TL or ES variable names.
#'
#' Use the same variable names in both datasets.
#'
#' TL and ES data use different variable names for reporters, partners,
#' commodities, values, quantity, and year. This function give these
#' variables the same name in both datasets.
#'
#' @param tradedata TL or ES trade data.
#' @return TL or ES data with common names (TL will also have "qunit").
#' @import data.table
#' @export

adaptTradeDataNames <- function(tradedata) {

  if (missing(tradedata)) stop('"tradedata" should be set.')

  tradedataname <- tolower(lazyeval::expr_text(tradedata))

  if (tradedataname == "tldata")
    old_common_names <- c(
      "tyear", "rep", "prt",
      "flow", "comm", "tvalue",
      "weight", "qty")

  if (tradedataname == "esdata")
    old_common_names <- c(
      "period", "declarant", "partner",
      "flow", "product_nc", "value_1k_euro",
      "qty_ton", "sup_quantity")

  new_common_names <- c("year", "reporter", "partner",
                        "flow", "hs", "value",
                        "weight", "qty")

  stopifnot(length(old_common_names) ==
                      length(new_common_names))

  setnames(tradedata, old_common_names, new_common_names)
}