DiagrammeR (version 0.9.2)

get_all_connected_nodes: Get all nodes connected to a specified node

Description

With a single node serving as the starting point get all nodes connected (i.e., reachable with a traversible path) to that node.

Usage

get_all_connected_nodes(graph, node)

Arguments

graph

a graph object of class dgr_graph.

node

a single-length vector containing a node ID value.

Value

a vector of node ID values.

Examples

# NOT RUN {
# This graph, created using `create_random_graph()`
# is almost fully connected but there is an
# isolated node (`8`) with no edges
graph_1 <-
  create_random_graph(
    n = 30, m = 40,
    set_seed = 23)

# There won't be any connected nodes to `8`
# so when specifying this node with
# `get_all_connected_nodes()` we get NA back
graph_1 %>%
  get_all_connected_nodes(node = 8)
#> [1] NA

# Any other node in `graph_1` will provide a vector
# of all the nodes other than `8`
graph_1 %>%
  get_all_connected_nodes(node = 1)
#>  [1]  2  3  4  5  6  7  9 10 11 12 13 14 15 16 17
#> [16] 18 19 20 21 22 23 24 25 26 27 28 29 30

# The following graph has two clusters of nodes
# (i.e., the graph has two connected components)
graph_2 <-
  create_graph() %>%
  add_path(n = 6) %>%
  add_path(n = 4)

# In `graph_2`, node `1` is in the larger of the two
# connected components
graph_2 %>%
  get_all_connected_nodes(node = 1)
#> [1] 2 3 4 5 6

# Also in `graph_2`, node `8` is in the smaller of
# the two connected components
graph_2 %>%
  get_all_connected_nodes(node = 8)
#> [1]  7  9 10
# }