DiagrammeR (version 0.8.2)

select_nodes: Select nodes in a graph

Description

Select nodes from a graph object of class dgr_graph.

Usage

select_nodes(graph, node_attr = NULL, search = NULL, set_op = "union", nodes = NULL)

Arguments

graph

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

node_attr

an optional character vector of node attribute values for filtering the node ID values returned.

search

an option to provide a logical expression with a comparison operator (>, <, ==, or !=) followed by a number for numerical filtering, or, a regular expression for filtering the nodes returned through string matching.

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.

nodes

an optional vector of node IDs for filtering list of nodes present in the graph.

Value

a graph object of class dgr_graph.

Examples

## Not run: 
# # Create a simple graph
# nodes <-
#   create_nodes(nodes = c("a", "b", "c", "d"),
#                type = "letter",
#                label = TRUE,
#                value = c(3.5, 2.6, 9.4, 2.7))
# 
# edges <-
#   create_edges(from = c("a", "b", "c"),
#                to = c("d", "c", "a"),
#                rel = "leading_to")
# 
# graph <-
#   create_graph(nodes_df = nodes,
#                edges_df = edges)
# 
# # Select nodes "a" and "c"
# graph <- select_nodes(graph = graph, nodes = c("a", "c"))
# 
# # Verify that a node selection has been made
# get_selection(graph)
# #> $nodes
# #> [1] "a" "c"
# ## End(Not run)