With a graph object of class dgr_graph, add one or more edges to the graph using a text string.

add_edges_w_string(graph, edges, rel = NULL, use_labels = FALSE)

Arguments

graph

a graph object of class dgr_graph.

edges

a single-length vector with a character string specifying the edges. For a directed graph, the string object should be formatted as a series of node ID values as [node_ID_1]->[node_ID_2] separated by a one or more space characters. For undirected graphs, -- should replace ->. Line breaks in the vector won't cause an error.

rel

an optional vector specifying the relationship between the connected nodes.

use_labels

an option to use node label values in the edges string to define node connections. Note that this is only possible if all nodes have distinct label values set and none exist as an empty string.

Value

a graph object of class dgr_graph.

Examples

# 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 edges between nodes using # a character string with node # ID values graph_node_id <- graph %>% add_edges_w_string( edges = "1->2 1->3 2->4 2->3") # Show the graph's internal # edge data frame graph_node_id %>% get_edge_df()
#> id from to rel #> 1 1 1 2 <NA> #> 2 2 1 3 <NA> #> 3 3 2 4 <NA> #> 4 4 2 3 <NA>
# Add edges between nodes using # a character string with node # label values and setting # `use_labels = TRUE`; note that # all nodes must have unique # `label` values to use this graph_node_label <- graph %>% add_edges_w_string( edges = "one->two one->three two->four two->three", use_labels = TRUE) # Show the graph's internal # edge data frame (it's the # same as before) graph_node_label %>% get_edge_df()
#> id from to rel #> 1 1 1 2 <NA> #> 2 2 1 3 <NA> #> 3 3 2 4 <NA> #> 4 4 2 3 <NA>