get_predecessors {DiagrammeR} | R Documentation |
Provides a vector of node IDs for all nodes that have a connection to the given node.
get_predecessors(graph, node)
graph |
a graph object of class |
node |
a node ID for the selected node. |
a vector of node ID values.
## Not run: # Before getting node ID values for predecessors of # a specified node, create a simple graph nodes <- create_nodes(nodes = LETTERS, label = TRUE, type = c(rep("a_to_g", 7), rep("h_to_p", 9), rep("q_to_x", 8), rep("y_and_z",2))) edges <- create_edges(from = sample(LETTERS, replace = TRUE), to = sample(LETTERS, replace = TRUE), label = "edge", rel = "letter_to_letter") graph <- create_graph(nodes_df = nodes, edges_df = edges, graph_attrs = "layout = neato", node_attrs = c("fontname = Helvetica", "shape = circle")) # Get predecessors for node "Z" in the graph get_predecessors(graph, node = "Z") #> [1] "A" "R" "R" # If there are no predecessors, NA is returned get_predecessors(graph, node = "A") #> [1] NA ## End(Not run)