dodgr (version 0.4.2)

dodgr_streetnet: Extract a street network in sf-format for a given location.

Description

Use the osmdata package to extract the street network for a given location. For routing between a given set of points (passed as pts), the bbox argument may be omitted, in which case a bounding box will be constructed by expanding the range of pts by the relative amount of expand.

Usage

dodgr_streetnet(bbox, pts = NULL, expand = 0.05, quiet = TRUE)

Value

A Simple Features (sf) object with coordinates of all lines in the street network.

Arguments

bbox

Bounding box as vector or matrix of coordinates, or location name. Passed to osmdata::getbb.

pts

List of points presumably containing spatial coordinates

expand

Relative factor by which street network should extend beyond limits defined by pts (only if bbox not given).

quiet

If FALSE, display progress messages

See Also

Other extraction: dodgr_streetnet_sc(), weight_railway(), weight_streetnet()

Examples

if (FALSE) {
streetnet <- dodgr_streetnet ("hampi india", expand = 0)
# convert to form needed for `dodgr` functions:
graph <- weight_streetnet (streetnet)
nrow (graph) # around 5,900 edges
# Alternative ways of extracting street networks by using a small selection
# of graph vertices to define bounding box:
verts <- dodgr_vertices (graph)
verts <- verts [sample (nrow (verts), size = 200), ]
streetnet <- dodgr_streetnet (pts = verts, expand = 0)
graph <- weight_streetnet (streetnet)
nrow (graph)
# This will generally have many more rows because most street networks
# include streets that extend considerably beyond the specified bounding box.

# bbox can also be a polygon:
bb <- osmdata::getbb ("gent belgium") # rectangular bbox
nrow (dodgr_streetnet (bbox = bb)) # around 30,000
bb <- osmdata::getbb ("gent belgium", format_out = "polygon")
nrow (dodgr_streetnet (bbox = bb)) # around 17,000
# The latter has fewer rows because only edges within polygon are returned

# Example with access restrictions
bbox <- c (-122.2935, 47.62663, -122.28, 47.63289)
x <- dodgr_streetnet_sc (bbox)
net <- weight_streetnet (x, keep_cols = "access", turn_penalty = TRUE)
# has many streets with "access" = "private"; these can be removed like this:
net2 <- net [which (!net$access != "private"), ]
# or modified in some other way such as strongly penalizing use of those
# streets:
index <- which (net$access == "private")
net$time_weighted [index] <- net$time_weighted [index] * 100
}