Create a spatial network from linestring geometries

Usage

create_from_spatial_lines(
  x,
  directed = TRUE,
  compute_length = FALSE,
  subdivide = FALSE
)

Arguments

x: An object of class sf or sfc with LINESTRING geometries.
directed: Should the constructed network be directed? Defaults to TRUE.
compute_length: Should the geographic length of the edges be stored in a column named length? Uses st_length to compute the length of the edge geometries. If there is already a column named length, it will be overwritten. Please note that the values in this column are not automatically recognized as edge weights. This needs to be specified explicitly when calling a function that uses edge weights. Defaults to FALSE.
subdivide: Should the given linestring geometries be subdivided at locations where an interior point is equal to an interior or boundary point in another feature? This will connect the features at those locations. Defaults to FALSE, meaning that features are only connected at their boundaries.

Value

An object of class sfnetwork.

Details

It is assumed that the given linestring geometries form the edges in the network. Nodes are created at the line boundaries. Shared boundaries between multiple linestrings become the same node.

Note

By default sfnetworks rounds coordinates to 12 decimal places to determine spatial equality. You can influence this behavior by explicitly setting the precision of the linestrings using st_set_precision.

Examples

library(sf, quietly = TRUE)

oldpar = par(no.readonly = TRUE)
par(mar = c(1,1,1,1), mfrow = c(1,2))

net = as_sfnetwork(roxel)
net
#> # A sfnetwork: 987 nodes and 1215 edges
#> #
#> # A directed multigraph with 9 components and spatially explicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 7.522595 ymin: 51.94151 xmax: 7.546705 ymax: 51.96119
#> # Geodetic CRS: WGS 84
#> #
#> # Node data: 987 × 1 (active)
#>              geometry
#>           <POINT [°]>
#> 1 (7.538109 51.95286)
#> 2 (7.537867 51.95282)
#> 3 (7.537815 51.95867)
#> 4 (7.537015 51.95848)
#> 5 (7.533441 51.95578)
#> 6 (7.533415 51.95561)
#> # ℹ 981 more rows
#> #
#> # Edge data: 1,215 × 5
#>    from    to name               type                                   geometry
#>   <int> <int> <chr>              <chr>                          <LINESTRING [°]>
#> 1     1     2 Hagemanns Kämpken  residential (7.538109 51.95286, 7.537867 51.95…
#> 2     3     4 Stiegkamp          residential (7.537815 51.95867, 7.537015 51.95…
#> 3     5     6 Havixbecker Straße residential (7.533441 51.95578, 7.533467 51.95…
#> # ℹ 1,212 more rows

plot(st_geometry(roxel))
plot(net)


par(oldpar)