add_edge {DiagrammeR} | R Documentation |
With a graph object of class
dgr_graph
, add an edge to nodes within the
graph.
add_edge(graph, from, to, rel = NULL, use_labels = FALSE)
graph |
a graph object of class
|
from |
the outgoing node from which the edge is connected. |
to |
the incoming nodes to which each edge is connected. |
rel |
an optional string specifying the relationship between the connected nodes. |
use_labels |
an option to use node |
a graph object of class dgr_graph
.
# Create a graph with 4 nodes graph <- create_graph() %>% add_node(label = "one") %>% add_node(label = "two") %>% add_node(label = "three") %>% add_node(label = "four") # Add an edge between those nodes and attach a # relationship to the edge graph <- add_edge( graph, from = 1, to = 2, rel = "A") # Use the `edge_info()` function to verify that # the edge has been created edge_info(graph) #> id from to rel #> 1 1 1 2 A # Add another node and edge to the graph graph <- graph %>% add_edge(3, 2, "A") # Verify that the edge has been created by # getting a count of graph edges edge_count(graph) #> [1] 2 # Add edges by specifying node `label` values # and setting `use_labels = TRUE`; note # that all nodes must have unique `label` # values to use this option graph <- graph %>% add_edge( "three", "four", "L", use_labels = TRUE) %>% add_edge( "four", "one", "L", use_labels = TRUE) # Use the `get_edges()` function to verify # that the edges were added get_edges(graph) #> [1] "1->2" "3->2" "3->4" "4->1"