R/readTau.R

In madrat: May All Data be Reproducible and Transparent (MADRaT) *

#' Read Tau
#'
#' Read-in landuse intensity data (tau) following the methodology published in
#' Dietrich J.P., Schmitz C., Mueller C., Fader M., Lotze-Campen H., Popp A.,
#' Measuring agricultural land-use intensity - A global analysis using a
#' model-assisted approach, Ecological Modelling, Volume 232, 10 May 2012,
#' Pages 109-118, ISSN 0304-3800, 10.1016/j.ecolmodel.2012.03.002.
#'
#' @param subtype Type of Tau data that should be read. Available types are:
#' \itemize{
#' \item \code{paper}: numbers as they are reported in the paper (cellular, crop-specific)
#' \item \code{historical}: historic tau values on iso country level for total tau factor.
#' This numbers were calculated by taking FAO yields and norming it to the 1995 tau values
#' of the paper (faoyields*tau95/mean(faoyields[1995:2005]))
#' }
#' @return Tau data and weights as MAgPIE object in original resolution
#'
#' @author Jan Philipp Dietrich
#' @examples
#' \dontrun{
#' a <- readSource("Tau")
#' }
#' @seealso \code{\link{readSource}}
#' @importFrom magclass read.magpie
readTau <- function(subtype = "paper") {
  files <- c(paper = "tau_data_1995-2000.mz",
             historical = "tau_xref_history_country.mz")
  file <- toolSubtypeSelect(subtype, files)
  x <- read.magpie(file)
  x[x == -999] <- NA
  return(x)
}