DiagrammeR (version 0.9.0)

node_present: Determine whether a specified node is present in an existing graph object

Description

From a graph object of class dgr_graph, determine whether a specified node is present.

Usage

node_present(graph, node)

Arguments

graph

a graph object of class dgr_graph.

node

a value that may or may not match a node ID in the graph.

Value

a logical value.

Examples

# NOT RUN {
# Set a seed
set.seed(24)

# Create a node data frame (ndf)
ndf <-
  create_node_df(
    n = 26,
    label = TRUE,
    type = c(rep("a", 7),
             rep("b", 9),
             rep("c", 8),
             rep("d", 2)))

# Create an edge data frame (edf)
edf <-
  create_edge_df(
    from = sample(1:26, replace = TRUE),
    to = sample(1:26, replace = TRUE),
    rel = c(rep("rel_a", 7),
            rep("rel_b", 9),
            rep("rel_c", 8),
            rep("rel_d", 2)))

# Create a graph using the ndf and edf
graph <-
  create_graph(
    nodes_df = ndf,
    edges_df = edf)

# Verify that node with ID `34` is not in graph
node_present(graph, 34)
#> FALSE

# Is node with ID 5 in the graph?
node_present(graph, 5)
#> TRUE

# Are all node ID values from `1` to `26`
# in the graph?
all(sapply(1:26,
      function(x) node_present(graph, x)))
#> TRUE
# }