node_present {DiagrammeR} | R Documentation |
From a graph object of class dgr_graph
, determine
whether a specified node is present.
node_present(graph, node)
graph |
a graph object of class |
node |
a value that may or may not match a node ID in the graph. |
a logical value.
## Not run: # Before finding out whether a particular node is present, # 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")) # Verify that node with ID 'a' is not in graph node_present(graph, "a") #> FALSE # Is node with ID 'A' in the graph? node_present(graph, "A") #> TRUE # Are all node ID values from the LETTERS vector in the graph? all(sapply(LETTERS, function(x) node_present(graph, x))) #> TRUE ## End(Not run)