R語言sfnetworks包，st_network_join()#基于節(jié)點幾何相等的兩個空間網絡連接
# Mon Jul 26 17:07:15 2021 -
# 字符編碼：UTF-8
# R 版本：R x64 4.1 for window 11
# cgh163email@163.com
# 個人筆記不負責任，拎了個梨????
#.rs.restartR()
require(sfnetworks)
rm(list = ls());gc()
st_network_join()#基于節(jié)點幾何相等的兩個空間網絡連接
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 x 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 x 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)
dev.copy(png, "1.png");dev.off()
image.png
