Added a test city (streets and river centerline) to use for testing rcoins

DESCRIPTION

@@ -21,3 +21,5 @@ Imports:
     dplyr,
     sf,
     sfheaders
+Depends: 
+    R (>= 2.10)

R/data.R

@@ -0,0 +1,6 @@
+#' rcoins test data
+#'
+#' Data extracted from OpenStreetMap for testing the rcoins package.
+#'
+#' @source OpenStreetMap
+"bucharest"

data-raw/bucharest.R

@@ -0,0 +1,107 @@
+library(dplyr)
+library(rlang)
+library(sf)
+library(usethis)
+
+
+get_osm_bb <- function(city_name) {
+  bb <- osmdata::getbb(city_name)
+  bb <- bb |> as.vector()
+  names(bb) <- c("xmin", "ymin", "xmax", "ymax")
+  bb <- st_bbox(bb, crs = 4326)
+  return(bb)
+}
+
+osmdata_as_sf <- function(key, value, bb) {
+  bb |>
+    osmdata::opq() |>
+    osmdata::add_osm_feature(key = key, value = value) |>
+    osmdata::osmdata_sf()
+}
+
+get_osm_streets <- function(bb, crs, highway_values = NULL) {
+  if (is.null(highway_values)) {
+    highway_values <- c("motorway", "trunk", "primary", "secondary", "tertiary")
+  }
+
+  link_values <- sapply(X = highway_values,
+                        FUN = \(x) sprintf("%s_link", x),
+                        USE.NAMES = FALSE)
+
+  streets <- osmdata_as_sf("highway", c(highway_values, link_values), bb)
+
+  # Cast polygons (closed streets) into lines
+  poly_to_lines <- suppressWarnings(
+    streets$osm_polygons |> st_cast("LINESTRING")
+  )
+
+  # Combine all features in one data frame
+  streets_lines <- streets$osm_lines |>
+    bind_rows(poly_to_lines) |>
+    select("highway") |>
+    rename(!!sym("type") := !!sym("highway")) |>
+    st_transform(crs)
+
+  return(streets_lines)
+}
+
+get_osm_river <- function(river_name, bb, crs) {
+  # Get the river centreline
+  river_centerline <- osmdata_as_sf("waterway", "river", bb)
+  river_centerline <- river_centerline$osm_multilines |>
+    filter(.data$name == river_name) |>
+    st_transform(crs) |>
+    st_geometry()
+
+  return(river_centerline)
+}
+
+get_osmdata <- function(city_name, river_name, crs, buffer = NULL) {
+  bb <- get_osm_bb(city_name)
+
+  if (!is.null(buffer)) {
+    bb <- bb |>
+      st_as_sfc() |>
+      st_transform(crs = crs) |>
+      st_buffer(buffer) |>
+      st_transform(crs = 4326) |>
+      st_bbox()
+  }
+
+  streets <- get_osm_streets(bb, crs)
+  river <- get_osm_river(river_name, bb, crs)
+
+  osm_data <- list(
+    bb = bb,
+    river_centerline = river,
+    streets = streets
+  )
+
+  return(osm_data)
+}
+
+
+# Set the parameters
+city_name <- "Bucharest"
+river_name <- "Dâmbovița"
+epsg_code <- 32635
+bbox_buffer <- 2000 # m
+
+# Fetch the data
+bucharest <- get_osmdata(
+  city_name,
+  river_name,
+  crs = epsg_code,
+  buffer = bbox_buffer
+)
+
+# Fix encoding issue in the WKT string of city boundary
+fix_wkt_encoding <- function(x) {
+  wkt <- st_crs(x)$wkt
+  st_crs(x)$wkt <- gsub("°|º", "\\\u00b0", wkt)
+  x
+}
+bucharest <- lapply(bucharest, fix_wkt_encoding)
+
+# Save as package data
+use_data(bucharest, overwrite = TRUE)

environment.yml

@@ -14,3 +14,4 @@ dependencies:
   - r-testthat >=3.0.0
 # Others
   - r-lintr
+  - r-osmdata

tests/testthat/test-data.R

@@ -0,0 +1,7 @@
+test_that("the test data can be loaded", {
+  streets <- bucharest$streets
+  expect_true(length(streets) > 0)
+
+  river <- bucharest$river_centerline
+  expect_true(length(river) > 0)
+})