Vertex attributes and labels missing when using sugiyama layout with dummy vertices

Consider the following layered igraph network plotted with sugiyama layout. (As there are dummy vertices, the plotting of vertex labels is not straightforward.)

library(igraph)
nodes <- data.frame(key = c("B", "A", "C", "C1", "C2", "C3", "X", "P", "Y", "M", "N", "O", 
                            "G3", "G2", "G1", "G", "R", "S", "K1", "K2", "K3", "Z", "H", "I"),
                    inter = c(0, 0, 0, 1, 1, 1, 1, 4, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 
                              1, 1, 0, 0),
                    ret = c("F", "F", "F", "F", "F", "F", "F", "F", "F", "F", "T", "F", 
                            "F", "F", "F", "F", "F", "F", "F", "F", "F", "F", "F", "F"))

edges <- data.frame(from = c("A", "C", "C1", "C2", "C3", "X", "M", "N", "O", "G3", "G2", 
                             "G1", "G", "R", "Z", "P", "K1", "K2", "O", "P", "B", "Y", "S", 
                             "X", "B"),
                    to = c("C", "C1", "C2", "C3", "X", "P", "Y", "M", "N", "O", "G3", 
                           "G2", "G1", "G", "R", "K1", "K2", "K3", "H", "I", "C", "P", "G", 
                           "H", "I"))

ig <- graph_from_data_frame(d = edges, directed = TRUE, vertices = nodes)

sug <-layout_with_sugiyama(ig)

origvert <- c(rep(TRUE, vcount(ig)),
              rep(FALSE, nrow(sug$layout.dummy)))
realedge <- as_edgelist(sug$extd_graph)[,2] <= vcount(ig)

plot(sug$extd_graph, vertex.label.cex=0.5,
     edge.arrow.size=0.05,
     edge.color = "black",
     vertex.size=ifelse(origvert, 10, 0),
     vertex.shape=ifelse(origvert, "square", "none"),
     vertex.label=ifelse(origvert, V(ig)$name, ""),
     edge.arrow.mode=ifelse(realedge, 2, 0),
     edge.curved = .1)

In ggraph while creating the same sugiyama layout, the vertex labels along with other vertex attributes are missing when dummy vertices are present.

library("ggraph")
sugig <- create_layout(ig, "sugiyama", use.dummy = TRUE)
head(sugig)
#>     x  y dummy circular .ggraph.index
#> 1 0.5 14 FALSE    FALSE             1
#> 2 1.5 14 FALSE    FALSE             2
#> 3 1.5 13 FALSE    FALSE             3
#> 4 1.5 12 FALSE    FALSE             4
#> 5 1.5 11 FALSE    FALSE             5
#> 6 1.5 10 FALSE    FALSE             6

ggraph(sugig) +
  geom_edge_elbow(strength = 0.75, color = "red", alpha = 0.8, end_cap = circle(4, 'mm'),
                  arrow = arrow(type = "closed", length = unit(2, 'mm'))) +
  geom_node_point(size = 1) +
  # geom_node_label(aes(label = name), size = 5) +
  theme(panel.background = element_blank())

However, the vertex labels and attributes are present when dummy vertices are ignored.

sugig <- create_layout(ig, "sugiyama")
head(sugig)
#>     x  y name inter ret .ggraph.orig_index circular .ggraph.index
#> 1 0.5 14    B     0   F                  1    FALSE             1
#> 2 1.5 14    A     0   F                  2    FALSE             2
#> 3 1.5 13    C     0   F                  3    FALSE             3
#> 4 1.5 12   C1     1   F                  4    FALSE             4
#> 5 1.5 11   C2     1   F                  5    FALSE             5
#> 6 1.5 10   C3     1   F                  6    FALSE             6

ggraph(sugig) +
  geom_edge_elbow(strength = 0.75, color = "red", alpha = 0.8, end_cap = circle(4, 'mm'),
                  arrow = arrow(type = "closed", length = unit(2, 'mm'))) +
  geom_node_point(size = 1) +
  geom_node_label(aes(label = name), size = 5) +
  theme(panel.background = element_blank())

I would assume this is due to the way how the layout is returned from igraph. The names can be added easily though (and I think it is less tricky than with igraph)

library("ggraph")
library("igraph")

nodes <- data.frame(key = c("B", "A", "C", "C1", "C2", "C3", "X", "P", "Y", "M", "N", "O", 
                            "G3", "G2", "G1", "G", "R", "S", "K1", "K2", "K3", "Z", "H", "I"),
                    inter = c(0, 0, 0, 1, 1, 1, 1, 4, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 
                              1, 1, 0, 0),
                    ret = c("F", "F", "F", "F", "F", "F", "F", "F", "F", "F", "T", "F", 
                            "F", "F", "F", "F", "F", "F", "F", "F", "F", "F", "F", "F"))

edges <- data.frame(from = c("A", "C", "C1", "C2", "C3", "X", "M", "N", "O", "G3", "G2", 
                             "G1", "G", "R", "Z", "P", "K1", "K2", "O", "P", "B", "Y", "S", 
                             "X", "B"),
                    to = c("C", "C1", "C2", "C3", "X", "P", "Y", "M", "N", "O", "G3", 
                           "G2", "G1", "G", "R", "K1", "K2", "K3", "H", "I", "C", "P", "G", 
                           "H", "I"))

ig <- graph_from_data_frame(d = edges, directed = TRUE, vertices = nodes)
sugig <- create_layout(ig, "sugiyama", use.dummy = TRUE)

sugig$name <- NA
sugig$name[1:vcount(ig)] <- V(ig)$name

head(sugig)
#>     x  y dummy circular .ggraph.index name
#> 1 0.5 14 FALSE    FALSE             1    B
#> 2 1.5 14 FALSE    FALSE             2    A
#> 3 1.5 13 FALSE    FALSE             3    C
#> 4 1.5 12 FALSE    FALSE             4   C1
#> 5 1.5 11 FALSE    FALSE             5   C2
#> 6 1.5 10 FALSE    FALSE             6   C3
ggraph(sugig) +
  geom_edge_elbow(strength = 0.75, color = "red", alpha = 0.8, end_cap = circle(4, 'mm'),
                  arrow = arrow(type = "closed", length = unit(2, 'mm'))) +
  geom_node_point(size = 1) +
  geom_node_label(aes(label = name), size = 5) +
  theme(panel.background = element_blank())

^{Created on 2022-05-03 by the reprex package (v2.0.1)}

thomasp85 / ggraph

Vertex attributes and labels missing when using sugiyama layout with dummy vertices #307