Drawing nodes

Nodes are similar to points, but we don’t (usually) care explicitly about the x and y values.

  geom_node_<functions>
  geom_node_point()
  geom_node_tile() 

ggraph(luv_graph, layout = "stress") + 
  geom_edge_link() + 
  geom_node_point(aes(colour = factor(members)),
                  show.legend = F)