R (networkD3) Sankey Diagram left AND right sinking?

Question

I am trying to produce a Sankey diagram with the help of this page: https://www.r-graph-gallery.com/321-introduction-to-interactive-sankey-diagram-2.html

Now, I modified the data a bit, and was wondering if I can right and left-sink the nodes, i.e. that the top-nodes are always to the left (aligned) and the last nodes always to the right. It appears that networkd3 only has the sinkright option.

Using the following code:

library(networkD3)
library(dplyr)
 
# A connection data frame is a list of flows with intensity for each flow
links <- data.frame(
  source=c("group_A", "group_B", "group_C", "group_C"), 
  target=c("group_D", "group_C", "group_F", "group_G"), 
  value=c(3, 4, 3, 1)
  )
 
# From these flows we need to create a node data frame: it lists every entities involved in the flow
nodes <- data.frame(
  name=c(as.character(links$source), 
  as.character(links$target)) %>% unique()
)
 
# With networkD3, connection must be provided using id, not using real name like in the links dataframe.. So we need to reformat it.
links$IDsource <- match(links$source, nodes$name)-1 
links$IDtarget <- match(links$target, nodes$name)-1
 
# Make the Network
p <- sankeyNetwork(Links = links, Nodes = nodes,
              Source = "IDsource", Target = "IDtarget",
              Value = "value", NodeID = "name",
              fontSize=20)
p

Gives me this output:

Sankey Plot

It looks already promising, but I would like to move group_A to the left side (while keeping the right side aligned). Is this possible?

Answer 1

It appears this seems to be not possible with networkD3 out of the box. However, I found out that plotly offers a x position option, which worked in the end:

fig <- plot_ly(
  type = "sankey",
  arrangement = "snap",
  node = list(
    label = nodes$name,
    x = c(0.1, 0.1, 0.5, 0.7, 0.7, 0.7),
    pad = 10), # 10 Pixel
  link = list(
    source = links$IDsource,
    target = links$IDtarget,
    value = links$value))

fig <- fig %>% layout(title = "Sankey with manually positioned node")

fig