CODEWITHSUNDEEP
rigraphggraph
flee
flee

Reputation: 1335

ggraph maintain layout after edge removal

I would like to maintain graph layout (vertex position) after removing edges. An example:

library(igraph)
library(ggraph)

# create sample graph
g <- structure(list(from = c(1, 1, 2, 2, 3, 3), 
               to = c(2, 3, 4, 5, 6, 7)), 
          class = "data.frame", row.names = c(NA, 6L))

g <- graph_from_data_frame(g)

# plot with all edges 
ggraph(g, layout = 'tree') + 
  geom_edge_diagonal() +
  geom_node_point(size = 10) +
  theme_void()

enter image description here

Now remove a couple edges and replot

g2 <- delete.edges(g, c(3,5))

ggraph(g2, layout = 'tree') + 
  geom_edge_diagonal() +
  geom_node_point(size = 10) +
  theme_void()

enter image description here

Whereas this is the desired output:

enter image description here

Is there a simple way to maintain vertex positions after edge removal?

Upvotes: 2

Views: 344

Answers (1)

flee
flee

Reputation: 1335

After writing out the question I figured it out, you just need to save the layout from the first graph using igraph::layout_as_tree (or any other layout), which can be used for the second plot:

l <- igraph::layout_as_tree(g)

ggraph(g2, layout = l) + 
  geom_edge_diagonal() +
  geom_node_point(size = 10) +
  theme_void()

enter image description here

Hopefully this saves someone else a bit of time.

Upvotes: 1

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