DiagrammeR (version 0.8.1)

create_subgraph: Create a subgraph based on a walk distance from a specified node

Description

Create a subgraph for a neighborhood of nodes connected a specified distance from the selected node.

Usage

create_subgraph(graph, starting_node, distance)

Arguments

graph

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

starting_node

the node from which the subgraph will originate.

distance

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

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", "gray80",
                                    "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 subgraph centered around node "U" and include
# those nodes up to (and including) 2 connections away
subgraph <- create_subgraph(graph = graph,
                            starting_node = "U",
                            distance = 2)

# Render the graph using Graphviz
render_graph(subgraph)

# Render the graph using VivaGraph
render_graph(subgraph, output = "vivagraph")