mz_isochrone {rmapzen}

Retrieve isochrones

Description

From https://valhalla.readthedocs.io/en/latest/: "An isochrone is a line that connects points of equal travel time about a given location, from the Greek roots of 'iso' for equal and 'chrone' for time. The Mapzen Isochrone service computes areas that are reachable within specified time intervals from a location, and returns the reachable regions as contours of polygons or lines that you can display on a map."

Usage

mz_isochrone(
  locations,
  costing_model,
  contours,
  date_time = NULL,
  polygons = NULL,
  denoise = NULL,
  generalize = NULL,
  id = "my-iso",
  api_key = NULL
)

Arguments

locations

An mz_location, or something that can be coerced to an mz_location, as the departure point for the isochrone. This can be the result of mz_geocode. Despite the argument name, the isochrone service currently can only accept a single location

costing_model

The costing model, see mz_costing

contours

Up to 4 contours, see mz_contours

date_time

The local date and time at the location, and whether it is the departure or arrival time. See mz_date_time

polygons

Whether to return polygons (TRUE) or linestrings (FALSE, default)

denoise

A value between 0 and 1 (default 1) to remove smaller contours. A value of 1 will only return the largest contour for a given time value. A value of 0.5 drops any contours that are less than half the area of the largest contour.

generalize

Tolerance in meters for the Douglas-Peucker generalization.

id

A descriptive identifier, the response will contain the id as an element.

api_key

Your Mapzen API key. The default is to look for the key within the provider information that was set up with 'mz_set_host'.

Value

A mapzen_isochrone_list, which can be converted to sf using as_sf.

See Also

mz_costing

Examples

## Not run: 
mz_isochrone(
    mz_location(lat = 37.87416, lon = -122.2544),
    costing_model = mz_costing$auto(),
    contours = mz_contours(c(10, 20, 30))
)

# departure point can be specified as a geocode result
mz_isochrone(
    mz_geocode("UC Berkeley"),
    costing_model = mz_costing$pedestrian(),
    contours = mz_contours(c(10, 20, 30))
)

## End(Not run)