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Build a metric_graph directly from an OpenStreetMap query

Source: R/osm.R
metric_graph_from_osm.Rd

Convenience wrapper that fetches OSM data with fetch_osm() and builds a metric_graph from the returned linestrings in one call. longlat = TRUE is set automatically because OSM coordinates are always in WGS84 latitude / longitude. Other graph-construction arguments (tolerance, perform_merges, ...) are forwarded to metric_graph's $new() method without overriding its defaults.

Usage

metric_graph_from_osm(
  bbox,
  key = "highway",
  value = NULL,
  endpoint = "https://overpass-api.de/api/interpreter",
  timeout = 180,
  user_agent = "MetricGraph-R-package",
  cache_path = NULL,
  retries = 2,
  ...
)

Arguments

bbox

A bounding box, passed to osmdata::opq(). May be a length-4 numeric vector c(xmin, ymin, xmax, ymax), an sf::bbox object, or any other form accepted by osmdata::opq().

key

OSM key to filter on, e.g. "highway". Passed to osmdata::add_osm_feature(). Use NULL to skip the feature filter and fetch everything in the bbox.

value

Optional character vector of values for key, e.g. c("motorway", "motorway_link").

endpoint

Overpass endpoint URL, or a character vector of URLs that are tried in order. Defaults to the main overpass-api.de endpoint. Mirror URLs (e.g. https://overpass.kumi.systems/api/interpreter) work too.

timeout

Server-side query timeout in seconds. Forwarded to both osmdata::opq() and the HTTP request.

user_agent

String sent as the User-Agent HTTP header.

cache_path

Optional path. If provided and the file already exists, the download is skipped and the cached response is parsed instead. If provided and the file does not exist, the response is saved there for re-use.

retries

Number of times a request to each endpoint is retried after a transient failure (HTTP 429 or 5xx, or a connection error), with exponential backoff between attempts.

...

Forwarded to metric_graph's $new(). Use this to pass tolerance, perform_merges, check_connected, which_longlat, etc.

Value

A metric_graph object built from the OSM ways.

See also

fetch_osm() for the lower-level fetch + parse step.

Examples

if (FALSE) { # \dontrun{
## Build a freeway graph for a small bbox around San Jose, splitting
## at intersections via the edge_edge tolerance.
g <- metric_graph_from_osm(
  bbox           = c(-122.10, 37.22, -121.80, 37.45),
  value          = c("motorway", "motorway_link"),
  perform_merges = TRUE,
  tolerance      = list(edge_edge = 1e-5)
)
g$plot()
} # }