Convert a foreign object to a sfnetwork — as

Convert a given object into an object of class sfnetwork.

Usage

as_sfnetwork(x, ...)

# Default S3 method
as_sfnetwork(x, ...)

# S3 method for class 'sf'
as_sfnetwork(x, ...)

# S3 method for class 'sfc'
as_sfnetwork(x, ...)

# S3 method for class 'dodgr_streetnet'
as_sfnetwork(x, ...)

# S3 method for class 'linnet'
as_sfnetwork(x, ...)

# S3 method for class 'psp'
as_sfnetwork(x, ...)

# S3 method for class 'sfNetwork'
as_sfnetwork(x, ...)

# S3 method for class 'tbl_graph'
as_sfnetwork(x, ...)

Arguments

x: Object to be converted into a sfnetwork.
...: Additional arguments passed on to other functions.

Value

An object of class sfnetwork.

Methods (by class)

as_sfnetwork(default): By default, the provided object is first converted into a tbl_graph using as_tbl_graph. Further conversion into an sfnetwork will work as long as the nodes can be converted to an sf object through st_as_sf. Arguments to st_as_sf can be provided as additional arguments and will be forwarded to st_as_sf through the sfnetwork construction function.
as_sfnetwork(sf): Convert spatial features of class sf directly into a sfnetwork. Supported geometry types are either LINESTRING or POINT. In the first case, the lines become the edges in the network, and nodes are placed at their boundaries. Additional arguments are forwarded to create_from_spatial_lines. In the latter case, the points become the nodes in the network, and are connected by edges according to a specified method. Additional arguments are forwarded to create_from_spatial_points.
as_sfnetwork(sfc): Convert spatial geometries of class sfc directly into a sfnetwork. Supported geometry types are either LINESTRING or POINT. In the first case, the lines become the edges in the network, and nodes are placed at their boundaries. Additional arguments are forwarded to create_from_spatial_lines. In the latter case, the points become the nodes in the network, and are connected by edges according to a specified method. Additional arguments are forwarded to create_from_spatial_points.
as_sfnetwork(dodgr_streetnet): Convert a directed graph of class dodgr_streetnet directly into a sfnetwork. Additional arguments are forwarded to dodgr_to_sfnetwork. This requires the dodgr package to be installed.
as_sfnetwork(linnet): Convert spatial linear networks of class linnet directly into a sfnetwork. Additional arguments are forwarded to create_from_spatial_lines. This requires the spatstat.geom package to be installed.
as_sfnetwork(psp): Convert spatial line segments of class psp directly into a sfnetwork. The lines become the edges in the network, and nodes are placed at their boundary points. Additional arguments are forwarded to create_from_spatial_lines.
as_sfnetwork(sfNetwork): Convert spatial networks of class sfNetwork from the stplanr package directly into a sfnetwork. This will extract the edges as an sf object and re-create the network structure. Additional arguments are forwarded to create_from_spatial_lines.The directness of the original network is preserved unless specified otherwise through the directed argument.
as_sfnetwork(tbl_graph): Convert graph objects of class tbl_graph directly into a sfnetwork. This will work if at least the nodes can be converted to an sf object through st_as_sf. Arguments to st_as_sf can be provided as additional arguments and will be forwarded to st_as_sf through the sfnetwork construction function. The directness of the original graph is preserved unless specified otherwise through the directed argument.

Examples

# From an sf object with LINESTRING geometries.
library(sf, quietly = TRUE)
#> Linking to GEOS 3.10.2, GDAL 3.4.1, PROJ 8.2.1; sf_use_s2() is TRUE

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

as_sfnetwork(roxel)
#> # 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(as_sfnetwork(roxel))


# From an sf object with POINT geometries.
# For more examples see ?create_from_spatial_points.
as_sfnetwork(mozart)
#> # A sfnetwork: 17 nodes and 272 edges
#> #
#> # A bipartite simple graph with 1 component and spatially explicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 4548664 ymin: 2747309 xmax: 4549589 ymax: 2748537
#> # Projected CRS: ETRS89-extended / LAEA Europe
#> #
#> # Node data: 17 × 4 (active)
#>   name                  type     website                        geometry
#>   <chr>                 <chr>    <chr>                       <POINT [m]>
#> 1 Mozartkino            cinema   https://www.mozartki… (4549504 2747309)
#> 2 Haus für Mozart       theatre  NA                    (4549003 2747376)
#> 3 Mozartsteg/Rudolfskai bus_stop NA                    (4549589 2747507)
#> 4 Mozart Denkmal        artwork  NA                    (4549387 2747514)
#> 5 Mozartsteg/Rudolfskai bus_stop NA                    (4549491 2747551)
#> 6 Mozartsteg            bridge   NA                    (4549473 2747624)
#> # ℹ 11 more rows
#> #
#> # Edge data: 272 × 3
#>    from    to                           geometry
#>   <int> <int>                   <LINESTRING [m]>
#> 1     1     2 (4549504 2747309, 4549003 2747376)
#> 2     1     3 (4549504 2747309, 4549589 2747507)
#> 3     1     4 (4549504 2747309, 4549387 2747514)
#> # ℹ 269 more rows

plot(st_geometry(mozart))
plot(as_sfnetwork(mozart))


par(oldpar)

# From a dodgr_streetnet object.
if (require(dodgr, quietly = TRUE) & require(geodist, quietly = TRUE)) {
  as_sfnetwork(dodgr::weight_streetnet(hampi))
}
#> # A sfnetwork: 3337 nodes and 6813 edges
#> #
#> # A directed simple graph with 3 components and spatially explicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 76.37261 ymin: 15.30104 xmax: 76.49232 ymax: 15.36033
#> # Geodetic CRS: WGS 84
#> #
#> # Node data: 3,337 × 4 (active)
#>   name       component     n            geometry
#>   <chr>          <int> <dbl>         <POINT [°]>
#> 1 339318500          1     0 (76.47491 15.34167)
#> 2 339318502          1     1 (76.47612 15.34173)
#> 3 2398958028         1     2 (76.47621 15.34174)
#> 4 1427116077         1     3 (76.47628 15.34179)
#> 5 7799710916         1     4 (76.47634 15.34184)
#> 6 339318503          1     5  (76.47641 15.3419)
#> # ℹ 3,331 more rows
#> #
#> # Edge data: 6,813 × 12
#>    from    to weight d_weighted  time time_weighted   xfr   yfr   xto   yto
#>   <int> <int>  <dbl>      <dbl> <dbl>         <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1     1     2 130.       144.   39.0          43.3   76.5  15.3  76.5  15.3
#> 2     2     1 130.       144.   39.0          43.3   76.5  15.3  76.5  15.3
#> 3     2     3   8.89       9.88  2.67          2.96  76.5  15.3  76.5  15.3
#> # ℹ 6,810 more rows
#> # ℹ 2 more variables: component <int>, geometry <LINESTRING [°]>

# From a linnet object.
if (require(spatstat.geom, quietly = TRUE)) {
  as_sfnetwork(simplenet)
}
#> spatstat.univar 3.1-1
#> spatstat.geom 3.3-3
#> # A sfnetwork: 10 nodes and 10 edges
#> #
#> # A directed acyclic simple graph with 1 component and spatially explicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 0.1497036 ymin: 0.1608339 xmax: 0.8418658 ymax: 0.9415173
#> # CRS: NA
#> #
#> # Node data: 10 × 1 (active)
#>                    geom
#>                 <POINT>
#> 1  (0.181276 0.8345078)
#> 2 (0.3254689 0.4607012)
#> 3 (0.1497036 0.2119066)
#> 4 (0.5358572 0.8028913)
#> 5 (0.4411403 0.1608339)
#> 6 (0.3795058 0.3206155)
#> # ℹ 4 more rows
#> #
#> # Edge data: 10 × 4
#>    from    to label                                         geom
#>   <int> <int> <chr>                                 <LINESTRING>
#> 1     1     2 segment  (0.181276 0.8345078, 0.3254689 0.4607012)
#> 2     3     2 segment (0.1497036 0.2119066, 0.3254689 0.4607012)
#> 3     2     4 segment (0.3254689 0.4607012, 0.5358572 0.8028913)
#> # ℹ 7 more rows

# From a psp object.
if (require(spatstat.geom, quietly = TRUE)) {
  set.seed(42)
  test_psp = psp(runif(10), runif(10), runif(10), runif(10), window=owin())
  as_sfnetwork(test_psp)
}
#> # A sfnetwork: 20 nodes and 10 edges
#> #
#> # A rooted forest with 10 trees and spatially explicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 0.08243756 ymin: 0.003948339 xmax: 0.9888917 ymax: 0.9782264
#> # CRS: NA
#> #
#> # Node data: 20 × 1 (active)
#>                    geom
#>                 <POINT>
#> 1  (0.914806 0.4577418)
#> 2 (0.9040314 0.7375956)
#> 3 (0.9370754 0.7191123)
#> 4 (0.1387102 0.8110551)
#> 5 (0.2861395 0.9346722)
#> 6 (0.9888917 0.3881083)
#> # ℹ 14 more rows
#> #
#> # Edge data: 10 × 4
#>    from    to label                                         geom
#>   <int> <int> <chr>                                 <LINESTRING>
#> 1     1     2 segment  (0.914806 0.4577418, 0.9040314 0.7375956)
#> 2     3     4 segment (0.9370754 0.7191123, 0.1387102 0.8110551)
#> 3     5     6 segment (0.2861395 0.9346722, 0.9888917 0.3881083)
#> # ℹ 7 more rows

# From a tbl_graph with coordinate columns.
library(tidygraph, quietly = TRUE)
#> 
#> Attaching package: ‘tidygraph’
#> The following object is masked from ‘package:stats’:
#> 
#>     filter

nodes = data.frame(lat = c(7, 7, 8), lon = c(51, 52, 52))
edges = data.frame(from = c(1, 1, 3), to = c(2, 3, 2))
tbl_net = tbl_graph(nodes, edges)
as_sfnetwork(tbl_net, coords = c("lon", "lat"), crs = 4326)
#> → Checking node geometry types ...
#> ✔ All nodes have geometry type POINT
#> ✔ Spatial network structure is valid
#> # A sfnetwork: 3 nodes and 3 edges
#> #
#> # A directed acyclic simple graph with 1 component and spatially implicit edges
#> #
#> # Dimension: XY
#> # Bounding box: xmin: 51 ymin: 7 xmax: 52 ymax: 8
#> # Geodetic CRS: WGS 84
#> #
#> # Node data: 3 × 1 (active)
#>      geometry
#>   <POINT [°]>
#> 1      (51 7)
#> 2      (52 7)
#> 3      (52 8)
#> #
#> # Edge data: 3 × 2
#>    from    to
#>   <int> <int>
#> 1     1     2
#> 2     1     3
#> 3     3     2