A spatial network specific join function which makes a spatial full join on
the geometries of the nodes data. 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.
Arguments
- x
An object of class
sfnetwork.- y
An object of class
sfnetwork, or directly convertible to it usingas_sfnetwork.- ...
Arguments passed on to
graph_join.
Value
The joined networks as an object of class sfnetwork.
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 networks 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))
# Create two networks.
n1 = st_point(c(0, 0))
n2 = st_point(c(1, 0))
n3 = st_point(c(1,1))
n4 = st_point(c(0,1))
e1 = st_sfc(st_linestring(c(n1, n2)))
e2 = st_sfc(st_linestring(c(n2, n3)))
e3 = st_sfc(st_linestring(c(n3, n4)))
neta = as_sfnetwork(c(e1, e2))
netb = as_sfnetwork(c(e2, e3))
# Join the networks based on spatial equality of nodes.
net = st_network_join(neta, netb)
net
#> # A sfnetwork: 4 nodes and 4 edges
#> #
#> # A directed acyclic multigraph with 1 component and spatially explicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 0 ymin: 0 xmax: 1 ymax: 1
#> # CRS: NA
#> #
#> # Node data: 4 × 1 (active)
#> x
#> <POINT>
#> 1 (0 0)
#> 2 (1 0)
#> 3 (1 1)
#> 4 (0 1)
#> #
#> # Edge data: 4 × 3
#> 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)
#> # ℹ 1 more row
# Plot.
plot(neta, pch = 15, cex = 2, lwd = 4)
plot(netb, col = "orange", pch = 18, cex = 2, lty = 3, lwd = 4, add = TRUE)
plot(net, cex = 2, lwd = 4)
par(oldpar)