delete_edge {DiagrammeR} | R Documentation |
From a graph object of class
dgr_graph
, delete an existing edge by
specifying either: (1) a pair of node IDs
corresponding to the edge (keeping into
consideration the direction of the edge in
a directed graph), or (2) an edge ID.
delete_edge(graph, from = NULL, to = NULL, id = NULL)
graph |
a graph object of class
|
from |
a node ID from which the edge to be
removed is outgoing. If an edge ID is provided to
|
to |
a node ID to which the edge to be removed
is incoming. If an edge ID is provided to
|
id |
an edge ID of the edge to be removed. |
a graph object of class dgr_graph
.
# Create an empty graph graph <- create_graph() # Add two nodes graph <- add_node(graph) graph <- add_node(graph) # Add an edge graph <- add_edge( graph = graph, from = 1, to = 2) # Delete the edge graph <- delete_edge( graph = graph, from = 1, to = 2) # Get the count of edges in the graph edge_count(graph) #> [1] 0 # Create an undirected graph with # 2 nodes and an edge graph_undirected <- create_graph(directed = FALSE) %>% add_n_nodes(2) %>% add_edge(1, 2) # Delete the edge; order of node ID # values provided in `from` and `to` # don't matter for the undirected case graph_undirected %>% delete_edge(2, 1) %>% edge_count() #> [1] 0 graph_undirected %>% delete_edge(1, 2) %>% edge_count() #> [1] 0 # The undirected graph has a single # edge with ID `1`; it can be # deleted by specifying `id` graph_undirected %>% delete_edge(id = 1) %>% edge_count() #> [1] 0