Add territory outlines and increase resolution

Closes #2

NAMESPACE

@@ -3,3 +3,4 @@
 export(crs_gda2020)
 export(normalise_postcodes)
 export(normalise_state_names)
+export(outline)

NEWS.md

@@ -2,6 +2,9 @@
 
 * Add Primary Health Network (PHN) map data as `phn` dataset.
 * Fixed the `poa_nsw` dataset to avoid strange geometries near the state border.
+* Added geometries for Lord Howe Island, Australian Capital Territory, and
+  Jervis Bay Territory, and a utility function `outline()` for using them.
+* Slightly increase the resolution to 750 m instead of 1 km.
 
 # nswgeo 0.3.3
 

R/data.R

@@ -37,11 +37,43 @@
 #' @describeIn australia State and internal territory boundaries of Australia.
 "states"
 
+#' Outlines of New South Wales and relevant territories.
+#'
+#' Lord Howe Island is administratively part of NSW, but as it is a small
+#' island some 600 km off the coast, it is frequently omitted from maps of NSW.
+#'
+#' The Australian Capital Territory is an enclave within NSW, and Jervis Bay
+#' Territory is a small Australian territory on the coast, surrounded by NSW.
+#' Neither are NSW territory, but they affect the shape of NSW's outline and are
+#' sometimes useful to include in maps alongside NSW due to their locations.
+#'
+#' The geometry for `nsw` has been simplified with a tolerance of 750 m to
+#' reduce the level of detail, whereas the territories maintain their full
+#' resolution.
+#'
+#' @seealso [outline()]
+#' @source
+#'   Australian Bureau of Statistics. "Australian Statistical Geography Standard (ASGS) Edition 3." ABS, Jul2021-Jun2026,
+#'   \url{https://www.abs.gov.au/statistics/standards/australian-statistical-geography-standard-asgs-edition-3/jul2021-jun2026}, accessed 27 September 2022.
+#'
+#'   The original dataset is published under the [Creative Commons Attribution 4.0 International](https://creativecommons.org/licenses/by/4.0/) licence, © Commonwealth of Australia 2021.
+#' @describeIn nsw External state boundary excluding LHI but including ACT and JBT.
+"nsw"
+#' @describeIn nsw Australian Capital Territory boundary.
+"act"
+#' @describeIn nsw Lord Howe Island boundary.
+"lhi"
+#' @describeIn nsw Jervis Bay Territory boundary.
+"jbt"
+
 #' Geospatial data of the New South Wales administrative boundaries.
 #'
-#' Excludes the borders with the ACT and Jervis Bay Territory, and Lord Howe Island.
+#' These include the Unincorporated Far West Region.
+#' `lga_nsw` excludes Jervis Bay Territory and the ACT.
+#' `poa_nsw` includes both territories and some postal areas extend past the
+#' state boundary.
 #'
-#' The geometries have been simplified with a tolerance of 1 km to reduce the
+#' The geometries have been simplified with a tolerance of 750 m to reduce the
 #' level of detail.
 #'
 #' @examples
@@ -62,11 +94,9 @@
 #'   \url{https://www.abs.gov.au/statistics/standards/australian-statistical-geography-standard-asgs-edition-3/jul2021-jun2026}, accessed 27 September 2022.
 #'
 #'   The original dataset is published under the [Creative Commons Attribution 4.0 International](https://creativecommons.org/licenses/by/4.0/) licence, © Commonwealth of Australia 2021.
-#' @describeIn nsw External boundaries of New South Wales as a multipolygon.
-"nsw"
-#' @describeIn nsw Local Government Area boundaries of New South Wales.
+#' @describeIn nsw_admin Local Government Area boundaries of New South Wales.
 "lga_nsw"
-#' @describeIn nsw Postal area boundaries of New South Wales.
+#' @describeIn nsw_admin Postal area boundaries of New South Wales.
 "poa_nsw"
 
 #' Local Health Districts of NSW.

R/utils.R

@@ -65,3 +65,52 @@ normalise_postcodes <- function(codes) {
 crs_gda2020 <- function() {
   sf::st_crs("EPSG:7844")
 }
+
+#' New South Wales outline with or without related territories
+#'
+#' The default outline `nswgeo::nsw` includes Jervis Bay Territory, excludes
+#' Lord Howe Island, and does not have a cut out for the ACT. This utility
+#' allows each of these to be adjusted.
+#'
+#' @seealso [nsw]
+#'
+#' @param lord_howe_island Include Lord Howe Island.
+#' @param act_cutout Cut out the area of the Australian Capital Territory.
+#' @param jervis_bay Cover the area of the Jervis Bay Territory.
+#'
+#' @return A simple features data frame with the requested geometries.
+#' @export
+#'
+#' @examples
+#' library(ggplot2)
+#'
+#' outline(lord_howe_island = TRUE) |> ggplot() + geom_sf()
+outline <- function(lord_howe_island = FALSE, act_cutout = TRUE, jervis_bay = TRUE) {
+  base <- nswgeo::nsw
+
+  if (act_cutout) {
+    base <- sf::st_difference(base, nswgeo::act)
+  }
+
+  if (!jervis_bay) {
+    # Since the default includes JBT and is simplified (reduced resolution), the
+    # shape of JBT needs to be enlarged a bit to avoid leaving odd pieces of
+    # geometry behind when intersecting.
+    crs_working <- sf::st_crs("+proj=eqc +lat_ts=34 units=m")
+    jbt <- nswgeo::jbt |>
+      sf::st_transform(crs_working) |>
+      sf::st_simplify(dTolerance = 750L) |>
+      sf::st_buffer(250L)
+    base <- base |>
+      sf::st_transform(crs_working) |>
+      sf::st_difference(jbt) |>
+      sf::st_transform(sf::st_crs(nswgeo::nsw)) |>
+      sf::st_make_valid()
+  }
+
+  if (lord_howe_island) {
+    sf::st_sf(geometry = rbind(base, nswgeo::lhi), name = c("NSW", "Lord Howe Island"))
+  } else {
+    sf::st_sf(geometry = base, name = "NSW")
+  }
+}

data-raw/ASGS_Ed3.R

@@ -17,7 +17,7 @@ library(nngeo)
 sf_use_s2(FALSE)
 
 # reduce the resolution of the borders to 1km
-tolerance_m <- 1000L
+tolerance_m <- 750L
 
 # list layers available
 st_layers(abs_geopackage)
@@ -27,44 +27,79 @@ lga <- read_sf(abs_geopackage, layer = "LGA_2021_AUST_GDA2020")
 crs_nsw <- sf::st_crs(7844) # GDA2020
 crs_working <- sf::st_crs("+proj=eqc +lat_ts=34 units=m")
 
-# Unincorporated NSW includes Lord Howe Island but also the Unincorporated Far
-# West Region. Remove LHI by culling everything east of 150.
+# NSW administrative boundaries have some quirks to account for:
+#
+#   - Unincorporated Far West Region
+#   - Lord Howe Island
+#   - Australian Capital Territory
+#   - Jervis Bay Territory
+
+# The ABS LGA region of "Unincorporated NSW" includes both Lord Howe Island
+# and the Unincorporated Far West Region. Separate these.
 nsw_hires_ui <- filter(lga, LGA_NAME_2021 == "Unincorporated NSW")
 bb <- st_bbox(nsw_hires_ui)
 bb["xmax"] <- 150
-nsw_hires_ui <- st_intersection(
+ufwr_hires <- st_intersection(
+  st_transform(nsw_hires_ui, crs_working),
+  st_transform(st_as_sfc(bb), crs_working)
+) |> st_transform(crs_nsw)
+bb <- st_bbox(nsw_hires_ui)
+bb["xmin"] <- 158
+lhi_hires <- st_intersection(
   st_transform(nsw_hires_ui, crs_working),
   st_transform(st_as_sfc(bb), crs_working)
-) %>% st_transform(crs_nsw)
+) |> st_transform(crs_nsw)
+lhi <- st_geometry(lhi_hires)
+object.size(lhi)
+usethis::use_data(lhi, overwrite = TRUE)
 
-lga_nsw <- lga %>%
-  filter(STATE_NAME_2021 == "New South Wales", LGA_NAME_2021 != "Unincorporated NSW") %>%
-  rbind(nsw_hires_ui) %>%
-  st_transform(crs_working) %>%
-  st_simplify(dTolerance = tolerance_m) %>%
+# The ABS LGA region of "Unincorp. Other Territories" includes both Norfolk
+# Island and the Jervis Bay Territory, of which we only need the latter.
+aus_hires_ui <- filter(lga, LGA_NAME_2021 == "Unincorp. Other Territories")
+bb <- st_bbox(aus_hires_ui)
+bb["xmax"] <- 153
+jbt_hires <- st_intersection(
+  st_transform(aus_hires_ui, crs_working),
+  st_transform(st_as_sfc(bb), crs_working)
+) |> st_transform(crs_nsw)
+jbt <- st_geometry(jbt_hires)
+object.size(jbt)
+usethis::use_data(jbt, overwrite = TRUE)
+
+lga_nsw <- lga |>
+  filter(STATE_NAME_2021 == "New South Wales", LGA_NAME_2021 != "Unincorporated NSW") |>
+  rbind(ufwr_hires) |>
+  st_transform(crs_working) |>
+  st_simplify(dTolerance = tolerance_m) |>
   st_transform(crs_nsw)
 object.size(lga_nsw)
 usethis::use_data(lga_nsw, overwrite = TRUE)
 
-nsw_hires <- lga %>%
-  filter(STATE_NAME_2021 == "New South Wales", LGA_NAME_2021 != "Unincorporated NSW") %>%
-  rbind(nsw_hires_ui) %>%
-  st_transform(crs_working) %>%
-  st_union() %>%
-  st_remove_holes() %>%
+act_hires <- lga |>
+  filter(STATE_NAME_2021 == "Australian Capital Territory", ! st_is_empty(geom))
+act <- st_geometry(act_hires)
+object.size(act)
+usethis::use_data(act, overwrite = TRUE)
+
+nsw_hires <- lga |>
+  filter(STATE_NAME_2021 == "New South Wales", LGA_NAME_2021 != "Unincorporated NSW") |>
+  rbind(ufwr_hires, jbt_hires) |>
+  st_transform(crs_working) |>
+  st_union() |>
+  st_remove_holes() |>
   st_make_valid()
-nsw <- nsw_hires %>%
-  st_simplify(dTolerance = tolerance_m) %>%
+nsw <- nsw_hires |>
+  st_simplify(dTolerance = tolerance_m) |>
   st_transform(crs_nsw)
 object.size(nsw_hires)
 object.size(nsw)
 usethis::use_data(nsw, overwrite = TRUE)
 
 # sal <- read_sf(abs_geopackage, layer = "SAL_2021_AUST_GDA2020")
-# sal_nsw <- sal %>%
-#   st_transform(crs_working) %>%
-#   filter(STATE_NAME_2021 == "New South Wales") %>%
-#   st_simplify(dTolerance = tolerance_m) %>%
+# sal_nsw <- sal |>
+#   st_transform(crs_working) |>
+#   filter(STATE_NAME_2021 == "New South Wales") |>
+#   st_simplify(dTolerance = tolerance_m) |>
 #   st_transform(crs_nsw)
 # object.size(sal_nsw)
 
@@ -78,10 +113,10 @@ poa_in_nsw <- st_intersects(
   st_buffer(nsw_hires, -100L)) |>
   sapply(function(x) length(x) > 0)
 
-poa_nsw <- poa[poa_in_nsw, ] %>%
-  st_transform(crs_working) %>%
-  st_simplify(dTolerance = tolerance_m, preserveTopology = TRUE) %>%
-  st_transform(crs_nsw) %>%
+poa_nsw <- poa[poa_in_nsw, ] |>
+  st_transform(crs_working) |>
+  st_simplify(dTolerance = tolerance_m, preserveTopology = TRUE) |>
+  st_transform(crs_nsw) |>
   st_make_valid()
 stopifnot(all(!st_is_empty(poa_nsw)))
 stopifnot(all(st_geometry_type(poa_nsw) != "GEOMETRYCOLLECTION"))