Decode Valhalla Route Shape

Description

For point-to-point routing, Valhalla's API provides a route shapefile in a special ASCII-encoded format. This function takes an encoded string, decodes it, and returns the lat/lon coordinates as a tibble.

Usage

decode(encoded)

Arguments

Details

To map the results, see also valhallr::map_trip().

Value

A tibble containing point locations in lat and lon columns.

Generate Isochrones

Description

An isochrone, also known as a service area, is a polygon that shows the area reachable from a starting point by traveling along a road network for a certain distance or time. This function provides an interface to the Valhalla routing engine's isochrone API. It lets you provide a starting point's latitude and longitude, a distance or time metric, and a vector of distances/times, and if it's successful it returns an sf-class tibble of polygons.

Usage

isochrone(
  from,
  costing = "pedestrian",
  contours = c(5, 10, 15),
  metric = "min",
  min_road_class = "residential",
  minimum_reachability = 500,
  hostname = "localhost",
  port = 8002
)

Arguments

Details

More more information, please see Valhalla's API documentation:

• https://valhalla.readthedocs.io/en/latest/api/isochrone/api-reference/

Value

An sf/tibble object containing isochrone polygons.

Examples

## Not run: 
library(valhallr)
# set up our departure point: the University of Ottawa
from <- test_data("uottawa")

# generate a set of isochrones for travel by bicycle
i <- valhallr::isochrone(from, costing = "bicycle")

# map the isochrones
map_isochrone(i)

## End(Not run)

Generate maps of isochrones

Description

This is a convenience function that takes the output of valhallr::isochrone() and generates either a static or interactive map.

Usage

map_isochrone(isochrone, method = "leaflet")

Arguments

Value

A plot of the isochrones, either a a leaflet object or a ggplot object.

Examples

## Not run: 
library(valhallr)
# set up our departure point: the University of Ottawa
from <- test_data("uottawa")

# generate a set of isochrones for travel by bicycle
i <- valhallr::isochrone(from, costing = "bicycle")

# map the isochrones
map_isochrone(i)

## End(Not run)

Make a Map from a Trip

Description

Make a Map from a Trip

Usage

map_trip(trip, method = "leaflet")

Arguments

Value

A map object, either leaflet or ggplot.

Examples

## Not run: 
  library(valhallr)
  # set up origin and destination data
  from <- test_data("uottawa")
  to <- test_data("cdntirecentre")

  # calculate the trip
  trip <- route(from = from, to = to)

  # show overall trip information
  print_trip(trip, all_details = FALSE)

  # make an interactive map of the trip using the leaflet package
  map_trip(trip, method = "leaflet")

## End(Not run)

Generate Tidy Origin-Destination Data using Valhalla

Description

This function creates a tidy (i.e. long) table of origin-destination trip data using the Valhalla routing engine. For a set of o origins and d destinations, it returns a tibble with (o x d) rows with the travel distance and time between each pair. It can handle several different travel modes and routing options.

This function is a user-friendly wrapper aroundvalhalla::sources_to_targets(), which calls the Valhalla API directly. sources_to_targets() offers finer- grained control over API options, and so this latter function may be more useful for advanced users.

Notable features of od_matrix():

• You can specify human-readable indices with from_id_col and to_id_col. (Valhalla's API only returns zero-indexed integer identifiers.)

• You can specify a batch_size to break computation into several smaller API calls, to prevent your Valhalla instance from running out of memory. This seems especially important for pedestrian routing, where I've sometimes needed to use a batch size as small as 5.

Usage

od_table(
  froms,
  from_id_col,
  tos,
  to_id_col,
  costing = "auto",
  batch_size = 100,
  minimum_reachability = 500,
  verbose = FALSE,
  hostname = "localhost",
  port = 8002
)

Arguments

Value

A tibble showing the trip distances and times from each origin to each named destination.

Examples

## Not run: 
library(dplyr)
library(valhallr)
# set up our inputs
origins <- bind_rows(test_data("parliament"), test_data("uottawa"), test_data("cntower"))
destinations <- bind_rows(test_data("cdntirecentre"), test_data("parliament"))

# generate a tidy origin-destination table
od <- od_table (froms = origins,
                from_id_col = "name",
                tos = destinations,
                to_id_col = "name",
                costing = "auto",
                batch_size = 100,
                minimum_reachability = 500)

## End(Not run)

Print Trip Summary and Turn-By-Turn Directions

Description

Print Trip Summary and Turn-By-Turn Directions

Usage

print_trip(trip, all_details = FALSE)

Arguments

Value

The input trip object, invisibly.

Examples

## Not run: 
  library(valhallr)
  # set up origin and destination data
  from <- test_data("uottawa")
  to <- test_data("cdntirecentre")

  # calculate the trip
  trip <- route(from = from, to = to)

  # show overall trip information
  print_trip(trip, all_details = FALSE)

  # make an interactive map of the trip using the leaflet package
  map_trip(trip, method = "leaflet")

## End(Not run)

Point-to-Point Routing with Valhalla

Description

This function calls Valhalla's route API to return turn-by-turn directions from one origin to one destination. Several costing methods are supported, and there are parameters that let you give custom options to Valhalla. Please note that this function requires access to a running instance of Valhalla.

Usage

route(
  from = NA,
  to = NA,
  costing = "auto",
  unit = "kilometers",
  from_search_filter = list(max_road_class = "motorway", min_road_class =
    "residential"),
  to_search_filter = list(max_road_class = "motorway", min_road_class = "residential"),
  minimum_reachability = 50,
  costing_options = list(),
  hostname = "localhost",
  port = 8002
)

Arguments

Details

For more details, please check the Valhalla API documentation here:

• https://valhalla.readthedocs.io/en/latest/api/turn-by-turn/api-reference/

Value

A trip object.

Examples

## Not run: 
  library(valhallr)
  # set up origin and destination data
  from <- test_data("uottawa")
  to <- test_data("cdntirecentre")

  # calculate the trip
  trip <- route(from = from, to = to)

  # show overall trip information
  print_trip(trip, all_details = FALSE)

  # make an interactive map of the trip using the leaflet package
  map_trip(trip, method = "leaflet")

## End(Not run)

Source-to-Targets Origin/Destination Matrices with Valhalla

Description

This function creates a tidy (i.e. long) table of origin-destination trip data using the Valhalla routing engine. For a set of o origins and d destinations, it returns a tibble with (o x d) rows with the travel distance and time between each pair. It can handle several different travel modes and routing options. Please note that this function requires access to a running instance of Valhalla.

This function provides fine-grained control over Valhalla's API options.

• For a user-friendly function, see the function valhallr::od_table().

• For details about the API, see Valhalla's documentation here: https://valhalla.readthedocs.io/en/latest/api/matrix/api-reference/

Usage

sources_to_targets(
  froms,
  tos,
  costing = "auto",
  from_search_filter = list(max_road_class = "motorway", min_road_class =
    "residential"),
  to_search_filter = list(max_road_class = "motorway", min_road_class = "residential"),
  minimum_reachability = 50,
  costing_options = list(),
  hostname = "localhost",
  port = 8002
)

Arguments

Value

A tibble showing the trip distances and times from each origin to each destination.

Examples

## Not run: 
# NOTE: Assumes an instance of Valhalla is running on localhost:8002.
library(dplyr)
library(valhallr)
froms <- bind_rows(test_data("parliament"), test_data("uottawa"))
tos <- bind_rows(test_data("cdntirecentre"), test_data("parliament"))
st <- sources_to_targets(froms, tos)

## End(Not run)

Get Lat/Lon Coordinates for Testing

Description

This function gives quick access to lat/lon coordinates for a few points around Ontario for testing and benchmarking purposes.

Usage

test_data(dataset = NA)

Arguments

Value

A tibble with one or more location names, latitudes, and longitudes.