R/monitor_noDataPlot.R

In PWFSLSmoke: Utilities for Working with Air Quality Monitoring Data

#' @title Create Blank Plot with "No Data" Message
#'
#' @description
#' Creates a blank plot that indicates there is no data for the monitor of
#' interest.
#'
#' @param ws_monitor \emph{ws_monitor} object
#' @param monitorID id for a specific monitor in the given ws_monitor object
#' @param cex text size of "No data for"; monitor ID is one size smaller
#'
#' @import graphics
#' @export
#' @keywords internal

monitor_noDataPlot <- function(
  ws_monitor,
  monitorID = NULL,
  cex = 2.5
) {

  # Allow single monitor objects to be used without specifying monitorID
  if (is.null(monitorID) && nrow(ws_monitor$meta) == 1) {
    monitorID <- ws_monitor$meta$monitorID[1]
  }

  # Change margins
  opar <- par(mar = c(1, 1, 1, 1))
  on.exit(par(opar))

  # Blank plot
  plot(
    0.5, 0.5,
    xlim = c(0, 1), ylim = c(0, 1),
    axes = FALSE,
    xlab = "", ylab = "",
    col = "transparent"
  )
  box()

  # Text in the middle
  text(0.5, 0.6, "No data for ", cex = cex)

  #NOTE: Might want to set up separate cex argument for this
  text(0.5, 0.4, monitorID, cex = 0.8 * cex)

}