DiagrammeR (version 0.9.0)

get_predecessors: Get node IDs for predecessor nodes to the specified node

Description

Provides a vector of node IDs for all nodes that have a connection to the given node.

Usage

get_predecessors(graph, node)

Arguments

graph

a graph object of class dgr_graph.

node

a node ID for the selected node.

Value

a vector of node ID values.

Examples

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

# Create a node data frame (ndf)
ndf <- create_node_df(26)

# Create an edge data frame (edf)
edf <-
  create_edge_df(
    from = sample(1:26, replace = TRUE),
    to = sample(1:26, replace = TRUE))

# From the ndf and edf, create a graph object
graph <-
  create_graph(
    nodes_df = ndf,
    edges_df = edf)

# Get predecessors for node `26` in the graph
get_predecessors(graph, node = 26)
#> [1] 18

# If there are no predecessors, `NA` is returned
get_predecessors(graph, node = 1)
#> [1] NA
# }