A spatial network specific join function which makes a spatial full join on the geometries of the nodes data, based on the st_equals spatial predicate. Edge data are combined using a bind_rows semantic, meaning that data are matched by column name and values are filled with NA if missing in either of the networks. The from and to columns in the edge data are updated such that they match the new node indices of the resulting network.

st_network_join(x, y, ...)

Arguments

x

An object of class sfnetwork.

y

An object of class sfnetwork, or directly convertible to it using as_sfnetwork.

...

Arguments passed on to graph_join.

Value

The joined networks as an object of class sfnetwork.

Examples

library(sf, quietly = TRUE)

node1 = st_point(c(0, 0))
node2 = st_point(c(1, 0))
node3 = st_point(c(1,1))
node4 = st_point(c(0,1))
edge1 = st_sfc(st_linestring(c(node1, node2)))
edge2 = st_sfc(st_linestring(c(node2, node3)))
edge3 = st_sfc(st_linestring(c(node3, node4)))

net1 = as_sfnetwork(c(edge1, edge2))
net2 = as_sfnetwork(c(edge2, edge3))

joined = st_network_join(net1, net2)
joined
#> # A sfnetwork with 4 nodes and 4 edges
#> #
#> # CRS:  NA 
#> #
#> # A directed acyclic multigraph with 1 component with spatially explicit edges
#> #
#> # Node Data:     4 × 1 (active)
#> # Geometry type: POINT
#> # Dimension:     XY
#> # Bounding box:  xmin: 0 ymin: 0 xmax: 1 ymax: 1
#>         x
#>   <POINT>
#> 1   (0 0)
#> 2   (1 0)
#> 3   (1 1)
#> 4   (0 1)
#> #
#> # Edge Data:     4 × 3
#> # Geometry type: LINESTRING
#> # Dimension:     XY
#> # Bounding box:  xmin: 0 ymin: 0 xmax: 1 ymax: 1
#>    from    to            x
#>   <int> <int> <LINESTRING>
#> 1     1     2   (0 0, 1 0)
#> 2     2     3   (1 0, 1 1)
#> 3     2     3   (1 0, 1 1)
#> # … with 1 more row

## Plot results.
oldpar = par(no.readonly = TRUE)
par(mar = c(1,1,1,1), mfrow = c(1,2))
plot(net1, pch = 15, cex = 2, lwd = 4)
plot(net2, col = "red", pch = 18, cex = 2, lty = 3, lwd = 4, add = TRUE)
plot(joined, cex = 2, lwd = 4)

par(oldpar)