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Obtain a sfnetwork object from OpenStreetMap data

Source: R/get-network-graph.R
oe_get_sfnetwork.Rd

This function is a wrapper around oe_get_network() that returns a sfnetwork object. It performs simplification of the highway values and filters by highway types if specified. Minimal network preprocessing tasks i.e. subdivision and smoothing are performed. It also allows for the creation of directed or undirected networks.

Usage

oe_get_sfnetwork(
  place,
  mode = c("cycling", "driving", "walking"),
  ...,
  require_equal = TRUE,
  directed = FALSE,
  highway_filter = NULL,
  quiet = FALSE
)

Arguments

place

Description of the geographical area that should be matched with a .osm.pbf file. Can be either a length-1 character vector, an sf/sfc/bbox object with any CRS, or a numeric vector of coordinates with length 2. In the last case, it is assumed that the EPSG code is 4326 specified as c(LON, LAT), while you can use any CRS with sf/sfc/bbox objects. See Details and Examples in oe_match().

mode

A character string of length one denoting the desired mode of transport. Can be abbreviated. Currently cycling (the default), driving and walking are supported.

...

Additional arguments passed to oe_get_network().

require_equal

logical or character vector. Defaults to TRUE. If TRUE, only pseudo nodes that have incident edges with equal attribute values are removed. Alternatively, a character vector with the names of the attributes to check for equality can be provided. In that case, only those attributes are checked for equality. If FALSE, all pseudo nodes are removed regardless of attribute values. All other attributes are collapsed, separating the values by a comma.

directed

logical, whether to return a directed sfnetwork object (default is FALSE)

highway_filter

Character vector of highway types to keep. Ignored if clean_output is FALSE. Valid values are: "busway", "cycleway", "footway", "living_street", "motorway", "path", "pedestrian", "primary", "residential", "rest_area", "service", "services", "steps", "tertiary", "track", "trunk" and "unclassified".

quiet

Boolean. If FALSE, the function prints informative messages. Starting from sf version 0.9.6, if quiet is equal to FALSE, then vectortranslate operations will display a progress bar.

Value

An sfnetwork object

Details

In particular, the two preprocessing morphers applied to the output returned by oe_get_network() are sfnetworks::to_spatial_subdivision() and sfnetworks::to_spatial_smooth(). Check their help pages for more details. See also the documentation for sfnetworks for more details on the two preprocessing steps: subdividing edges and smoothing pseudo-nodes.

Note that preprocessing is performed on the undirected graph, ignoring road directionality. If directed = TRUE, the function then builds the directed graph by duplicating bidirectional edges with reversed geometries. If the oneway column is missing, a warning is issued and an undirected sfnetwork is returned instead.

See also

oe_get(), oe_get_network(), oe_get_dodgrnetwork()

Examples

# Copy the ITS file to tempdir() to make sure that the examples do not
# require internet connection. You can skip the next 4 lines (and start
# directly with oe_get_keys) when running the examples locally.
its_pbf = file.path(tempdir(), "test_its-example.osm.pbf")
file.copy(
  from = system.file("its-example.osm.pbf", package = "osmextract"),
  to = its_pbf,
  overwrite = TRUE
)
#> [1] TRUE
if (requireNamespace("sfnetworks", quietly = TRUE)) {
  #' # Undirected unfiltered pedestrian network
  walk_sfnet <- oe_get_sfnetwork(
    place = "ITS Leeds",
    mode = "walking",
    download_directory = tempdir(),
    quiet = TRUE
  )
  plot(walk_sfnet)

  #' # Directed unfiltered driving network
  car_sfnet <- oe_get_sfnetwork(
    place = "ITS Leeds",
    mode = "driving",
    directed = TRUE,
    download_directory = tempdir(),
    quiet = TRUE
  )
  plot(car_sfnet)

  #' # Directed filtered driving network
  highway_filter = c(
    "motorway",
    "trunk",
    "primary",
    "secondary",
    "tertiary",
    "unclassified",
    "residential"
  )

  car_sfnet_filtered <- oe_get_sfnetwork(
    place = "ITS Leeds",
    mode = "driving",
    directed = TRUE,
    highway_filter = highway_filter,
    download_directory = tempdir(),
    quiet = TRUE
  )
  plot(car_sfnet_filtered)

  # Smooth pseudo nodes when highway and oneway fields are equal
  car_sfnet_filtered_2 <- oe_get_sfnetwork(
    place = "ITS Leeds",
    mode = "driving",
    directed = TRUE,
    highway_filter = highway_filter,
    require_equal = c("highway", "oneway"),
    download_directory = tempdir(),
    quiet = TRUE
  )
  plot(car_sfnet_filtered_2)
}
#> Warning: to_spatial_subdivision assumes attributes are constant over geometries

#> Warning: to_spatial_subdivision assumes attributes are constant over geometries

#> Warning: to_spatial_subdivision assumes attributes are constant over geometries

#> Warning: to_spatial_subdivision assumes attributes are constant over geometries