R/draw_electoral_divisions_map.R

In HughParsonage/grattanElectionMaps:

#' Draw an electoral map, with insets.
#'
#' @param .polygonal.data Data including the vertices of all polygons, including a \code{fill} variable to colour the polygons.
#' @param year What elections' boundaries should be used?
#' @param scale_fill_manual_args A list of arguments to pass to \code{scale_fill_manual}.
#' @param scale_fill_gradientn_args A list of arguments to pass to \code{scale_fill_gradientn}.
#' @param polygon_outline_colour The outline of polygons.
#' @param city_inset_scale By how much should the cities' insets be scaled by relative to the Australia plot?
#' @param base_size,base_family Passed to \code{theme_map}.
#' @param city_inset_text_size Title size in points.
#' @param legend.title What should the legend title (for \code{fill}) be?
#' @return A printed ggplot object.
#' 
#' @examples
#' library(grattanCharts)
#' library(hutils)
#' library(ggplot2)
#' library(scales)
#' library(data.table)
#' library(magrittr)
#' system.file(package = "grattanElectionMaps",
#'            "examples/wellbeing.csv") %>%
#'  fread %>%
#'  .[, ELECT_DIV := toupper(gsub("[^A-Za-z]", "", Electorate))] %>%
#'  .[aus_division_elect_map_simple_2016, on = "ELECT_DIV"] %T>%
#'  .[, stopifnot(!anyNA(SE), uniqueN(Rank) == 150L)] %>%
#'  setnames("Personal wellbeing index", "fill") %>%
#'  draw_electoral_divisions_map(
#'    scale_fill_gradientn_args = list(colors = gpal(7)),
#'    legend.title = "Well-being",
#'    city_inset_scale = c("PER" = 26,
#'                         "ADL" = 24,
#'                         "MEL" = 18,
#'                         "SYD" = 14,
#'                         "BNE" = 14),
#'    city_inset_text_size = 18, 
#'    base_size = 20)
#' 
#' 
#' 
#' @export
#'

draw_electoral_divisions_map <- function(.polygonal.data,
                                         year = c("2016", "2013", "2010", "2007", "2004"),
                                         scale_fill_manual_args = NULL,
                                         scale_fill_gradientn_args = NULL,
                                         polygon_outline_colour = "black",
                                         city_inset_scale = 13,
                                         base_size = 25,
                                         base_family = "",
                                         city_inset_text_size = 25,
                                         legend.title = NULL){
  
  stopifnot(all(c("lat", "long", "fill", "group") %in% names(.polygonal.data)))
  
  year <- match.arg(year)
  
  entire <-
    ggplot2::ggplot(.polygonal.data) +
    ggplot2::geom_polygon(ggplot2::aes_string(x = "long", y = "lat", fill = "fill", group = "group"),
                          color = polygon_outline_colour) +
    ggplot2::coord_map(xlim = aus_extent$xlim,
                       ylim = aus_extent$ylim) +
    ggthemes::theme_map(base_size = base_size,
                        base_family = base_family)
  
  if (!is.null(scale_fill_manual_args)){
    entire <- entire + do.call(ggplot2::scale_fill_manual, args = scale_fill_manual_args)
  }
  if (!is.null(scale_fill_gradientn_args)){
    entire <- entire + do.call(ggplot2::scale_fill_gradientn, args = scale_fill_gradientn_args)
  }
  
  if (is.null(legend.title)){
    entire <- entire + ggplot2::theme(legend.title = ggplot2::element_blank())
  } else {
    entire <- entire + ggplot2::guides(fill = ggplot2::guide_legend(title = legend.title))
  }
  
  entire <- entire + ggplot2::theme(legend.position = c(0, 1),
                                    legend.justification = c(0, 1),
                                    legend.margin = ggplot2::margin())
  
  if (length(city_inset_scale) == 1L) {
    city_inset_scale <- 
      c("PER" = city_inset_scale,
        "ADL" = city_inset_scale,
        "MEL" = city_inset_scale,
        "SYD" = city_inset_scale,
        "BNE" = city_inset_scale)
  }
  print(entire, newpage = TRUE)
  
  .print_city_plot <- function(...) {
    print_city_plot(...,
                    title.size = city_inset_text_size,
                    base_family = base_family)
  }
  
  .print_city_plot(.polygonal.data, "PER", xpos = 0.100, ypos = 0.450,
                  vfactor = 1, 
                  scale_fill_manual_args = scale_fill_manual_args,
                  scale_fill_gradientn = scale_fill_gradientn_args,
                  city_inset_scale = city_inset_scale["PER"])
  .print_city_plot(.polygonal.data, "ADL", xpos = 0.380, ypos = 0.325,
                  vfactor = 1, 
                  scale_fill_manual_args = scale_fill_manual_args,
                  scale_fill_gradientn = scale_fill_gradientn_args,
                  city_inset_scale = city_inset_scale["ADL"])
  .print_city_plot(.polygonal.data, "MEL", xpos = 0.525, ypos = 0.130,
                  vfactor = 1, 
                  scale_fill_manual_args = scale_fill_manual_args,
                  scale_fill_gradientn = scale_fill_gradientn_args,
                  city_inset_scale = city_inset_scale["MEL"])
  .print_city_plot(.polygonal.data, "SYD", xpos = 0.845, ypos = 0.200,
                  vfactor = 1, 
                  scale_fill_manual_args = scale_fill_manual_args,
                  scale_fill_gradientn = scale_fill_gradientn_args,
                  city_inset_scale = city_inset_scale["SYD"])
  .print_city_plot(.polygonal.data, "BNE", xpos = 0.875, ypos = 0.725,
                  vfactor = 1, 
                  scale_fill_manual_args = scale_fill_manual_args,
                  scale_fill_gradientn = scale_fill_gradientn_args,
                  city_inset_scale = city_inset_scale["BNE"])
}