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#' Reverse geocoding API for OSM elements in \CRANpkg{sf} format
#'
#' @description
#'
#' Generates an address from a latitude and longitude. Latitudes must be
#' between \eqn{\left[-90, 90 \right]} and longitudes between
#' \eqn{\left[-180, 180 \right]}. This function returns the spatial object
#' associated with the query using \CRANpkg{sf}, see [reverse_geo_lite()] for
#' retrieving the data in [`tibble`][tibble::tibble] format.
#'
#' @family reverse
#' @family spatial
#'
#'
#' @inheritParams reverse_geo_lite
#' @inheritParams geo_lite_sf
#'
#' @details
#' See <https://nominatim.org/release-docs/develop/api/Reverse/> for additional
#' parameters to be passed to `custom_query`.
#'
#' @inheritSection reverse_geo_lite About Zooming
#' @inheritSection geo_lite_sf About Geometry Types
#'
#' @return
#'
#' ```{r child = "man/chunks/sfout.Rmd"}
#' ```
#'
#' @export
#'
#' @seealso
#' [reverse_geo_lite()].
#'
#' @examplesIf nominatim_check_access()
#' \donttest{
#' library(ggplot2)
#'
#' # Coliseum coords
#' col_lon <- 12.49309
#' col_lat <- 41.89026
#'
#' # Coliseum as polygon
#' col_sf <- reverse_geo_lite_sf(
#' lat = col_lat,
#' lon = col_lon,
#' points_only = FALSE
#' )
#'
#' dplyr::glimpse(col_sf)
#'
#' if (any(!sf::st_is_empty(col_sf))) {
#' ggplot(col_sf) +
#' geom_sf()
#' }
#'
#' # City of Rome - same coords with zoom 10
#'
#' rome_sf <- reverse_geo_lite_sf(
#' lat = col_lat,
#' lon = col_lon,
#' custom_query = list(zoom = 10),
#' points_only = FALSE
#' )
#'
#' dplyr::glimpse(rome_sf)
#'
#' if (any(!sf::st_is_empty(rome_sf))) {
#' ggplot(rome_sf) +
#' geom_sf()
#' }
#' }
reverse_geo_lite_sf <- function(lat,
long,
address = "address",
full_results = FALSE,
return_coords = TRUE,
verbose = FALSE,
nominatim_server =
"https://nominatim.openstreetmap.org/",
progressbar = TRUE,
custom_query = list(),
points_only = TRUE) {
# Check inputs
if (!is.numeric(lat) || !is.numeric(long)) {
stop("lat and long must be numeric")
}
if (length(lat) != length(long)) {
stop("lat and long should have the same number of elements")
}
# Lat
lat_cap <- pmax(pmin(lat, 90), -90)
if (!identical(lat_cap, lat)) {
message("latitudes have been restricted to [-90, 90]")
}
# Lon
long_cap <- pmax(pmin(long, 180), -180)
if (!all(long_cap == long)) {
message("longitudes have been restricted to [-180, 180]")
}
# Dedupe for query using data frame
init_key <- dplyr::tibble(
lat_key_int = lat, long_key_int = long,
lat_cap_int = lat_cap, long_cap_int = long_cap
)
key <- dplyr::distinct(init_key)
# Set progress bar
ntot <- nrow(key)
# Set progress bar if n > 1
progressbar <- all(progressbar, ntot > 1)
if (progressbar) {
pb <- txtProgressBar(min = 0, max = ntot, width = 50, style = 3)
}
seql <- seq(1, ntot, 1)
all_res <- lapply(seql, function(x) {
if (progressbar) {
setTxtProgressBar(pb, x)
}
rw <- key[x, ]
res_single <- reverse_geo_lite_sf_single(
lat_cap = as.double(rw$lat_cap_int),
long_cap = as.double(rw$long_cap_int),
address = address,
full_results = full_results,
return_coords = return_coords,
verbose = verbose,
custom_query = custom_query,
points_only = points_only,
nominatim_server = nominatim_server
)
res_single <- dplyr::bind_cols(res_single, rw[, c(1, 2)])
res_single
})
if (progressbar) close(pb)
all_res <- dplyr::bind_rows(all_res)
# Handle dupes in sf
if (!identical(nrow(init_key), nrow(all_res))) {
# Join with indexes
tmplt <- sf::st_drop_geometry(all_res)[, c("lat_key_int", "long_key_int")]
tmplt$rindex <- seq_len(nrow(tmplt))
getrows <- dplyr::left_join(init_key, tmplt, by = c(
"lat_key_int",
"long_key_int"
))
# Select rows
all_res <- all_res[as.integer(getrows$rindex), ]
}
# Final cleanup
kpnms <- setdiff(names(all_res), c("lat_key_int", "long_key_int"))
all_res <- all_res[, kpnms]
all_res <- sf_to_tbl(all_res)
all_res
}
#' @noRd
#' @inheritParams reverse_geo_lite_sf
reverse_geo_lite_sf_single <- function(lat_cap,
long_cap,
address = "address",
full_results = TRUE,
return_coords = TRUE,
verbose = TRUE,
nominatim_server =
"https://nominatim.openstreetmap.org/",
custom_query = list(),
points_only = FALSE) {
# First build the api address. If the passed nominatim_server does not end
# with a trailing forward-slash, add one
api <- prepare_api_url(nominatim_server, "reverse?")
# Compose url
url <- paste0(api, "lat=", lat_cap, "&lon=", long_cap, "&format=geojson")
if (!isTRUE(points_only)) url <- paste0(url, "&polygon_geojson=1")
if (isFALSE(full_results)) {
url <- paste0(url, "&addressdetails=0")
} else {
url <- paste0(url, "&addressdetails=1")
}
# Add options
url <- add_custom_query(custom_query, url)
# Download to temp file
json <- tempfile(fileext = ".geojson")
res <- api_call(url, json, isFALSE(verbose))
# Step 2: Read and parse results ----
tbl_query <- dplyr::tibble(lat = lat_cap, lon = long_cap)
if (isFALSE(res)) {
message(url, " not reachable.")
out <- empty_sf(empty_tbl_rev(tbl_query, address))
return(invisible(out))
}
# Empty query
result_init <- jsonlite::fromJSON(json, flatten = TRUE)
if ("error" %in% names(result_init)) {
message(
"No results for query lon=",
long_cap, ", lat=", lat_cap
)
out <- empty_sf(empty_tbl_rev(tbl_query, address))
return(invisible(out))
}
# Prepare output
sfobj <- sf::read_sf(json, stringsAsFactors = FALSE)
# Unnest address
sfobj <- unnest_sf_reverse(sfobj)
# Add lat lon
sf_clean <- dplyr::bind_cols(sfobj, tbl_query)
# Keep names
result_out <- keep_names_rev(sf_clean, address, return_coords, full_results)
# Attach as tibble
result_out <- sf_to_tbl(result_out)
result_out
}
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