DiagrammeR (version 0.8.1)

get_paths: Get paths from a specified node in a directed graph

Description

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

library(magrittr)

# Create a simple graph
graph <-
  create_graph() %>%
  add_node_df(create_nodes(1:8)) %>%
  add_edge("1", "2") %>% add_edge("1", "3") %>%
  add_edge("3", "4") %>% add_edge("3", "5") %>%
  add_edge("4", "6") %>% add_edge("2", "7") %>%
  add_edge("7", "5") %>% add_edge("4", "8")

# Get a list of all paths outward from node "1"
get_paths(graph, 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"
get_paths(graph, to = "6")
#> [[1]]
#> [1] "4" "6"
#>
#> [[2]]
#> [1] "3" "4" "6"
#>
#> [[3]]
#> [1] "1" "3" "4" "6"

#' # Get a list of all paths from "1" to "5"
get_paths(graph, 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
get_paths(graph, 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"