Sample of cppRouting with SfNetworks

Sample code to use sfnetworks with cppRouting

First load the functions.

library(wrapr)
#Transform the sfnetworks network, in cppRouting formatsfnet2cppRouting<-modules::use("sfnet2cppRouting.R")
shortest_path<-modules::use("shortest_path.R")
min_distance<-modules::use("min_distance.R")

Then load the network and get the cppRouting one too.

network<-"oldenburg_walking_network.geojson" %.>%
#Read the filesf::st_read(., quiet=TRUE) %.>%
#Only linestringssf::st_cast(., "LINESTRING") %.>%
#Set a column for the weight of the line as the distancedplyr::mutate(., weight=sf::st_length(.)) %.>%
#Get the sfnetworks objectsfnetworks::as_sfnetwork(., directed=FALSE)

Warning in st_cast.sf(., "LINESTRING"): repeating attributes for all
sub-geometries for which they may not be constant

weight<-"weight"cppRouting_graph<-sfnet2cppRouting$sfnet2cppRouting(network, weight)

Set some random nodes to use:

from<- c(1, 2, 3)
to<- c(5, 6, 7)

Shortest Path Matrix:

shortest_path$networks.shortest_path.node2node.cppRouting.matrix(network, cppRouting_graph, from, to)

Simple feature collection with 9 features and 2 fields
Geometry type: GEOMETRY
Dimension: XY
Bounding box: xmin: 8.208518 ymin: 53.13685 xmax: 8.219401 ymax: 53.14239
Geodetic CRS: WGS 84
from to path
1 1 5 MULTILINESTRING ((8.213525 ...
2 1 6 MULTILINESTRING ((8.213525 ...
3 1 7 LINESTRING (8.218106 53.140...
4 2 5 MULTILINESTRING ((8.213525 ...
5 2 6 MULTILINESTRING ((8.213525 ...
6 2 7 MULTILINESTRING ((8.218106 ...
7 3 5 LINESTRING (8.21851 53.1405...
8 3 6 LINESTRING (8.2183 53.14049...
9 3 7 LINESTRING (8.218106 53.140...

Shortest Path Pairs

shortest_path$networks.shortest_path.node2node.cppRouting.pairs(network, cppRouting_graph, from, to)

Simple feature collection with 3 features and 2 fields
Geometry type: GEOMETRY
Dimension: XY
Bounding box: xmin: 8.208733 ymin: 53.13902 xmax: 8.219401 ymax: 53.14239
Geodetic CRS: WGS 84
from to path
1 1 5 MULTILINESTRING ((8.213525 ...
2 2 6 MULTILINESTRING ((8.213525 ...
3 3 7 LINESTRING (8.218106 53.140...

Min Distance Matrix

min_distance$networks.min_distance.node2node.cppRouting.matrix(network, cppRouting_graph, from, to)

 from to distance
1 1 1 1089.56645
2 1 2 1103.61466
3 1 3 1178.87029
4 2 1 1041.89042
5 2 2 1055.93863
6 2 3 1132.26373
7 3 1 73.89156
8 3 2 59.84335
9 3 3 460.52335

Min Distance Paris

min_distance$networks.min_distance.node2node.cppRouting.pairs(network, cppRouting_graph, from, to)

 from to distance
1 1 5 1089.5664
2 2 6 1055.9386
3 3 7 460.5234

Notes

All returns are a dataframe with “from”, “to” columns with the nodes, the last column depends if is distance or shortestpath.

• distance: Use the column distance
• shortestpath: Use the “path” column, is a geom column