R/set_order.R

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#' Order groups for plotting
#'
#' We determine the subplot as follows: Groups appear in order of appearance in the data, data withing groups as well
#'
#' @param data the data frame with ranges and events
#'
#' @return data with additional numeric column "subplot"
#' @keywords internal
#' @noRd
#' @examples
#' \dontrun{
#' set_order(data.frame(
#'  event = 1:4, start = c("2019-01-01", "2019-01-10"),
#'  end = c("2019-01-01", "2019-01-10"), group = "", stringsAsFactors = F))
#' set_order(data.frame(
#'   event = 1:4, start = c("2019-01-01", "2019-01-10"),
#'   end = c("2019-01-01", "2019-01-10"), group = 1:2, stringsAsFactors = F))
#' set_order(data.frame(
#'   event = 1:3, start = c("2019-01-01", "2019-01-10", "2019-01-01"),
#'   end = c("2019-01-10", "2019-01-20", "2019-01-10"),
#'   group = c(1, 2, 1), stringsAsFactors = F))
#' }
set_order <- function(data) {
    if (!is.factor(data$group)) {
        # set group order to order of appearance using factor levels.
        data$group <- factor(data$group, levels = unique(data$group))
    }
    data <- data[order(data$group),] # bring same groups together
    data$subplot <- as.integer(data$group)

    return(data)
}