R/getCoords.R

In magclass: Data Class and Tools for Handling Spatial-Temporal Data

#' Get Coordinates
#'
#' Extracts spatial coordinates of a MAgPIE-object
#'
#'
#' @aliases getCoords getCoords<-
#' @param x MAgPIE object
#' @param xlab label of x-dimension
#' @param ylab label of y-dimension
#' @param value coordinates as two column data.frame the data should be set to
#' (first column = x, second column = y).
#' @return coordinates of the MAgPIE-object
#' @author Jan Philipp Dietrich
#' @seealso \code{\link{as.RasterBrick}}, \code{\link{getItems}}, \code{"\linkS4class{magpie}"}
#' @examples
#' a <- maxample("animal")
#' getCoords(a)
#' @export
getCoords <- function(x, xlab = "x", ylab = "y") {
  if (!hasCoords(x, xlab, ylab)) stop("No coordinates found in object!")
  .tmp <- function(x, n) {
    return(as.numeric(sub("p", ".", getItems(x, n, full = TRUE), fixed = TRUE)))
  }
  return(data.frame(x = .tmp(x, xlab), y = .tmp(x, ylab)))
}

#' @describeIn getCoords set coordinates
#' @export
`getCoords<-` <- function(x, xlab = "x", ylab = "y", value) { #nolint
  if (is.null(ncol(value)) || ncol(value) != 2) {
    stop("Coordinates supplied in unsupported format (must be a two column data.frame)")
  }
  if (!is.data.frame(value)) value <- as.data.frame(value)
  if (all(c("x", "y") %in% names(value))) value <- value[c("x", "y")]
  if (ncells(x) != nrow(value)) stop("Number of rows does not match number of cells of the MAgPIE object!")
  getItems(x, xlab, maindim = 1) <- value[[1]]
  getItems(x, ylab, maindim = 1)  <- value[[2]]
  return(x)
}