R/make_sexy_map.r

In lina2497/Giftmap: Create Decorative Town Maps

#' Download highways data from the Open Streetmaps API for a specified location and plot a map.
#'

#' @return Returns a aesthitically pleasing plot .
#' @param location A character string describing the target, gets passed to osmdata::getbb().
#' @param short_name A character string to be used as a caption.
#' @param monochrome Logical, if TRUE output is black and white.
#' @export
#' @import dplyr ggplot2 osmdata viridis purrr sf
#' @examples
#' make_sexy_map(location="Tuckenhay in England", short_name= "Tuckenhay", monochrome = TRUE)


make_sexy_map<-function(location,short_name,monochrome = FALSE){
  bb<-getbb(location)

print("Downloading Data")
highway_data<-bb%>%
  opq()%>%
  add_osm_feature(key = "highway") %>%
  osmdata_sf()

print("Data Downloaded")

print("Extracting Lines")

osm_lines_list<-highway_data$osm_lines%>%
  split(.$highway)

print("Extracting Polygons")
polygons_list<-highway_data$osm_polygons%>%
  split(.$highway)





plot_osm_lines<-function(osm_line_data,color="#7fc0ff", size=0.4, alpha=0.8){
  geom_sf(data = osm_line_data ,
          inherit.aes = FALSE,
          color = color,
          size = size,
          alpha = alpha)
}


print("Creating Style Table")
style_table<-tibble(tags=names(osm_lines_list),
                    pallete=viridis::viridis(length(osm_lines_list)),
                    size=0.4,
                    alpha=0.8,
                    number_of_lines= map_int(osm_lines_list, nrow))




style_table$size[style_table$tags%in%c("primary","secondary","tertiary","trunk")]<-1.2
style_table$pallete[style_table$tags%in%c("primary","secondary","tertiary","trunk")]<-"lightblue"
style_table$alpha[style_table$tags%in%c("primary","secondary","tertiary","trunk")]<-0.8
style_table$pallete[!(style_table$tags%in%c("primary","secondary","tertiary","trunk"))]<-"#ffbe7f"
style_table$size[!(style_table$tags%in%c("primary","secondary","tertiary","trunk"))]<-0.6
style_table$alpha[!(style_table$tags%in%c("primary","secondary","tertiary","trunk"))]<-0.3
style_table$size[style_table$tags%in%c("track","path","bridleway","footway","cycleway")]<-0.3
style_table$pallete[style_table$tags%in%c("track","path","bridleway","footway","cycleway")]<-"gray48"
style_table$alpha[style_table$tags%in%c("track","path","bridleway","footway","cycleway")]<-0.05





polygon_style_table<-filter(style_table, tags %in% names(polygons_list))

if(monochrome){
  if(nrow(style_table)>0){
  style_table$pallete<-"black"
  }
  if(nrow(polygon_style_table)>0){
  polygon_style_table$pallete<-"black"
  }
}

polygons_list<-polygons_list[names(polygons_list)[names(polygons_list) %in% names(osm_lines_list)]]

print("Generating plot")
p<-ggplot() +
  pmap(
    list(
      osm_line_data = osm_lines_list,
      color = style_table$pallete,
      size = style_table$size,
      alpha = style_table$alpha
    ),
    plot_osm_lines)

q<-p+pmap(
  list(
    osm_line_data = polygons_list,
    color = polygon_style_table$pallete,
    size = polygon_style_table$size,
    alpha = polygon_style_table$alpha
  ),
  plot_osm_lines)


trim_x<-0.001
trim_y <- 0.001


r<-q+
      coord_sf(
        xlim = c(bb[1, 1] + trim_x, bb[1, 2] - trim_x),
        ylim = c(bb[2, 1] + trim_y, bb[2, 2]) - trim_y,
        expand = FALSE
      )


s<-r+theme(axis.text = element_blank(), plot.margin=unit(c(1.1,2.4,1.1,2.4),"cm"),
            panel.grid.major = element_line(colour = ifelse(monochrome,"white","#282828")),
            panel.grid.minor = element_line(colour = ifelse(monochrome,"white","#282828")),
            plot.background = element_rect(fill = ifelse(monochrome,"white","#282828")),
        panel.background = element_rect(fill = ifelse(monochrome,"white","#282828")),
        plot.caption = element_text(hjust = 0.5, color =   ifelse(monochrome,"#282828","white"), size = 18),
        panel.border = element_rect(colour =   ifelse(monochrome,"gray48","white"), fill=NA, size=2),
        axis.ticks = element_blank())

output<-s+labs(caption=paste0(paste(rep("_",nchar(short_name)+4),collapse = ""),"\n",toupper(short_name)))
print("Rendering Final Output... If you've picked a city this may take a while")
print(output)

}