Add edges in the same direction of one or more edges available as an edge selection in a graph object of class dgr_graph. New graph edges have the same edge definitions as those in the selection except with new edge ID values. There is also the option to assign a common rel grouping to the newly created edges. Upon addition of the edges, the edge selection will be retained for further selection or traversal operations.

Selections of edges can be performed using the following select_... functions: select_edges(), select_last_edge(), or select_edges_by_node_id(). Selections of edges can also be performed using the following traversal functions: trav_out_edge(), trav_in_edge(), or trav_both_edge().

add_forward_edges_ws(graph, rel = NULL)

Arguments

graph

a graph object of class dgr_graph.

rel

an optional string to apply a rel attribute to all newly created edges.

Value

a graph object of class dgr_graph.

Examples

# Create an empty graph, add 2 nodes to it, # and create the edge `1->2` graph <- create_graph() %>% add_n_nodes( n = 2, type = "type_a", label = c("a_1", "a_2")) %>% add_edge( from = 1, to = 2, rel = "a") # Get the graph's edges graph %>% get_edge_ids()
#> [1] 1
# Select the edge and create 2 additional edges # with the same definition (`1->2`) but with # different `rel` values (`b` and `c`) graph <- graph %>% select_edges() %>% add_forward_edges_ws(rel = "b") %>% add_forward_edges_ws(rel = "c") %>% clear_selection() # Get the graph's edge data frame graph %>% get_edge_df()
#> id from to rel #> 1 1 1 2 a #> 2 2 1 2 b #> 3 3 1 2 c