Plot the outlines of Auckland's local board areas

local_board_ploygons.R

# #30DayMapChallenge 2021 - Day 3 - Polygons
# Displaying the local board ares of Auckland
# -- David Friggens, November 2021

library(magrittr)
library(dplyr)
library(tidyr)
library(stringr)
library(purrr)
library(sf)
library(rmapshaper)
library(ggplot2)
library(patchwork)

# from https://datafinder.stats.govt.nz
talb_full <- read_sf("territorial-authority-local-board-2021-clipped-generalised.gpkg")

# My initial thought was to plot all TAs, but 67 was just too much
lb_med <- 
  talb_full %>% 
  filter(TALB2021_V1_00 %>% str_detect("^076")) %>% 
  arrange(TALB2021_V1_00_NAME) %>% 
  ms_simplify(keep = 0.4, keep_shapes = FALSE)

PLOT_FONT <- "BellTopo Sans" # from https://www.sarahbellmaps.com/belltopo-sans-font-by-sarah-bell/
BG_COLOUR <- "#252a32"
TEXT_COLOUR <- "#dddddd"
TITLE_COLOUR <- "white"

# facet_wrap won't allow free scales with sf so I needed to
# plot each area separately and then join them with patchwork::wrap_plots

gg_lb <- 
  lb_med %>% 
  select(code = TALB2021_V1_00,
         name = TALB2021_V1_00_NAME,
         land_area = LAND_AREA_SQ_KM) %>% 
  mutate(name = name %>% str_replace("Local Board Area", "")) %>% 
  nest(lb = c("name", "land_area", "geom")) %>% 
  mutate(lb_plot =
           lb %>% 
           map(~ ggplot(.x) +
                 geom_sf(fill = "3B454A",
                         size = 0.1,
                         color = "#b2b2b277") +
                 coord_sf(datum = NA) +
                 labs(title = .x$name) +
                 theme(plot.title = element_text(size = 14, family = PLOT_FONT, colour = TEXT_COLOUR, hjust = 0.5))
               )
  ) %>% 
  pull(lb_plot) %>% 
  wrap_plots(ncol = 11) +
  plot_annotation(title = "Auckland Local Board Areas",
                  subtitle = "#30DayMapChallenge 2021 - Day 3 - Polygons",
                  caption = "David Friggens @dakvid, Data: Stats NZ",
                  theme = theme(plot.title = element_text(size = 72, family = PLOT_FONT, colour = TITLE_COLOUR),
                                plot.subtitle = element_text(size = 32, family = PLOT_FONT, colour = TEXT_COLOUR),
                                plot.caption = element_text(size = 32, family = PLOT_FONT, colour = TEXT_COLOUR))) &
  theme(plot.background = element_rect(fill = BG_COLOUR, colour = BG_COLOUR),
        panel.background = element_rect(fill = BG_COLOUR, colour = BG_COLOUR))
gg_lb
ggsave(plot = gg_lb,
       path = ".", filename = "Day_03_auckland_local_boards.png", device = "png",
       width = 30, height = 9, dpi = 72)