Obtain a list of all possible paths from a given node within a directed graph.
Usage
get_paths(
graph,
from = NULL,
to = NULL,
shortest_path = FALSE,
longest_path = FALSE,
distance = NULL
)Arguments
- graph
A graph object of class
dgr_graph.- from
The node from which all paths will be determined.
- to
The node to which all paths will be determined.
- shortest_path
An option to return paths that are the shortest in the set of all determined paths.
- longest_path
An option to return paths that are the longest in the set of all determined paths.
- distance
A vector of integer values that specify which of the valid paths to return when filtering by distance.
Value
A list of paths, sorted by ascending traversal length, comprising vectors of node IDs in sequence of traversal through the graph.
Examples
# Create a simple graph
graph <-
create_graph() %>%
add_n_nodes(n = 8) %>%
add_edge(from = 1, to = 2) %>%
add_edge(from = 1, to = 3) %>%
add_edge(from = 3, to = 4) %>%
add_edge(from = 3, to = 5) %>%
add_edge(from = 4, to = 6) %>%
add_edge(from = 2, to = 7) %>%
add_edge(from = 7, to = 5) %>%
add_edge(from = 4, to = 8)
# Get a list of all paths outward from node `1`
graph %>%
get_paths(from = 1)
#> [[1]]
#> [1] 1 3 5
#>
#> [[2]]
#> [1] 1 2 7 5
#>
#> [[3]]
#> [1] 1 3 4 6
#>
#> [[4]]
#> [1] 1 3 4 8
#>
# Get a list of all paths leading to node `6`
graph %>%
get_paths(to = 6)
#> [[1]]
#> [1] 1 3 4 6
#>
# Get a list of all paths from `1` to `5`
graph %>%
get_paths(
from = 1,
to = 5)
#> [[1]]
#> [1] 1 3 5
#>
#> [[2]]
#> [1] 1 2 7 5
#>
# Get a list of all paths from `1` up to a distance
# of 2 node traversals
graph %>%
get_paths(
from = 1,
distance = 2)
#> [[1]]
#> [1] 1 3 5
#>
#> [[2]]
#> [1] 1 2 7
#>
#> [[3]]
#> [1] 1 3 4
#>
# Get a list of the shortest paths from `1` to `5`
get_paths(
graph,
from = 1,
to = 5,
shortest_path = TRUE)
#> [[1]]
#> [1] 1 3 5
#>
# Get a list of the longest paths from `1` to `5`
get_paths(
graph,
from = 1,
to = 5,
longest_path = TRUE)
#> [[1]]
#> [1] 1 2 7 5
#>