Background in edge labels

[thomasp85]

[zouter]

For anyone visiting this page and wanting this functionality now: you can easily extract the edge position data and use the background functionality from geom_label.

graph <- tidygraph::as_tbl_graph(data.frame(from=1:10, to=sample(1:10, 15, T), label=sample(1:10, 20, T)))
ggraph(graph) +
  geom_edge_link() +
  geom_label(aes(x=(xend+x)/2, y = (yend+y)/2, label=label), get_edges()) +
  theme_graph()

You can also use geom_label_repel.

graph <- tidygraph::as_tbl_graph(data.frame(from=1:10, to=sample(1:10, 15, T), label=sample(1:10, 20, T)))
ggraph(graph) +
  geom_edge_link() +
  ggrepel::geom_label_repel(aes(x = (xend+x)/2, y = (yend+y)/2, label=label), get_edges()) +
  theme_graph()

This approach has issues however if the edges are arcs...

[helske]

Bumping up this old issue, any plans to implement this? It would be great to have geom_edge_label() analogous to geom_node_label() so we could have similar kind of background box for the edge labels as for the node labels. This would then make it possible to have figure like the one below without the edge being visible under the label, instead nudging the edge label positions to avoid all the edges:

x <- matrix(1:9, 3, 3)
rownames(x) <- colnames(x) <- c("A", "B", "C")
g <- tidygraph::as_tbl_graph(x)
ggraph(g, "linear") +
    geom_edge_arc(aes(label = weight)) +
    geom_node_point(size = 5) +
    theme_graph()

The solution above using geom_label() works nicely with linear edges, but I can't figure out how to extract the correct positions in case of arcs.