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, ...)
graph |
a graph object of class
|
from |
the outgoing node from which the edge
is connected. There is the option to use a node
|
to |
the incoming nodes to which each edge
is connected. There is the option to use a node
|
rel |
an optional string specifying the relationship between the connected nodes. |
... |
optional edge attributes supplied as vectors. |
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( from = 3, to = 2, rel = "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; note that all nodes must have # unique `label` values to use this option graph <- graph %>% add_edge( from = "three", to = "four", rel = "L") %>% add_edge( from = "four", to = "one", rel = "L") # Use the `get_edges()` function to verify # that the edges were added get_edges(graph) #> [1] "1->2" "3->2" "3->4" "4->1"