get_edge_attrs {DiagrammeR} | R Documentation |
From a graph object of class
dgr_graph
or an edge data frame, get edge
attribute values for one or more edges.
get_edge_attrs(x, edge_attr, from = NULL, to = NULL)
x |
either a graph object of class
|
edge_attr |
the name of the attribute for which to get values. |
from |
an optional vector of node IDs from which the edge is outgoing for filtering the list of edges. |
to |
an optional vector of node IDs from which the edge is incoming for filtering the list of edges. |
a named vector of edge attribute values for
the attribute given by edge_attr
by edge.
library(magrittr) # Create a simple graph where edges have an edge # attribute named `value` graph <- create_graph() %>% add_n_nodes(4) %>% { edges <- create_edges( from = c(1, 2, 1, 4), to = c(2, 3, 4, 3), rel = "rel") add_edge_df(., edges) } %>% set_edge_attrs( "value", 1.6, 1, 2) %>% set_edge_attrs( "value", 4.3, 1, 4) %>% set_edge_attrs( "value", 2.9, 2, 3) %>% set_edge_attrs( "value", 8.4, 4, 3) # Get the values for the `value` edge attribute graph %>% get_edge_attrs(edge_attr = "value") #> 1 -> 2 2 -> 3 1 -> 4 4 -> 3 #> 1.6 2.9 4.3 8.4 # To only return edge attribute values for specified # edges, use the `from` and `to` arguments graph %>% get_edge_attrs("value", c(1, 2), c(2, 3)) #> 1 -> 2 2 -> 3 #> 1.6 2.9