DiagrammeR (version 0.8.1)

select_nodes_in_neighborhood: Select nodes based on a walk distance from a specified node

Description

Select those nodes in the neighborhood of nodes connected a specified distance from an initial node.

Usage

select_nodes_in_neighborhood(graph, node, distance, set_op = "union")

Arguments

graph

a graph object of class dgr_graph that is created using create_graph.

node

the node from which the traversal will originate.

distance

the maximum number of steps from the node for inclusion in the subgraph.

set_op

the set operation to perform upon consecutive selections of graph nodes. This can either be as a union (the default), as an intersection, or, as a difference on the previous selection, if it exists.

Value

• a graph object of class dgr_graph.

Examples

# Create a graph, then, create a subgraph of that larger graph
nodes <-
  create_nodes(nodes = LETTERS,
               type = "letter",
               shape = sample(c("circle", "rectangle"),
                              length(LETTERS),
                              replace = TRUE),
               fillcolor = sample(c("aqua", "red",
                                    "pink", "lightgreen",
                                    "azure", "yellow"),
                                  length(LETTERS),
                                  replace = TRUE))

edges <-
  create_edges(from = sample(LETTERS, replace = TRUE),
               to = sample(LETTERS, replace = TRUE),
               rel = "letter_to_letter")

graph <- create_graph(nodes_df = nodes,
                      edges_df = edges,
                      graph_attrs = "layout = neato",
                      node_attrs = c("fontname = Helvetica",
                                     "style = filled"),
                      edge_attrs = c("color = gray20",
                                     "arrowsize = 0.5"))

# Create a selection of nodes centered around node "U" and
# including those nodes a depth of 2 edges away
graph <-
  select_nodes_in_neighborhood(graph = graph,
                               node = "U",
                               distance = 2)