make Sankey diagram with two-way links R

Question

I have the following data I use to make the Sankey diagram:

list(nodes = structure(list(name = c("1.1.1. Formação Florestal", 
"1.1.2. Formação Savanica", NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, "3.1. Pastagem", NA, NA, NA, "3.2.1. Cultura Anual e Perene", 
NA, "3.3. Mosaico de Agricultura e Pastagem", NA, NA, "4.2. Infraestrutura Urbana", 
"4.5. Outra Área não Vegetada", NA, NA, NA, NA, NA, NA, NA, "5.1 Rio ou Lago ou Oceano"
)), class = "data.frame", row.names = c(NA, -31L)), links = structure(list(
    source = c(0, 0, 0, 1, 1, 1, 1, 1, 1, 12, 12, 12, 12, 12, 
    12, 12, 16, 16, 16, 16, 18, 18, 18, 18, 18, 18, 21, 22, 22, 
    22, 30), target = c(0, 18, 1, 18, 12, 0, 22, 1, 30, 16, 12, 
    18, 0, 22, 1, 30, 12, 16, 1, 18, 1, 18, 22, 30, 12, 0, 1, 
    22, 1, 30, 30), value = c(0.544859347827813, 0.00354385993588971, 
    0.494359662221154, 4.67602736159475, 2.20248911690968, 0.501437742068369, 
    0.00354375594818463, 24.8427814053755, 0.439418727642527, 
    0.0079740332093807, 11.8060486886398, 2.76329829691466, 0.000886029792298199, 
    0.00177186270758855, 3.35504921147758, 0.14263144351167, 
    1.12170804870686, 0.0478454594554582, 0.217079959877658, 
    0.00620223918980076, 1.79754946594068, 9.02868098124075, 
    0.00442981113709027, 0.242743895018645, 0.498770814980772, 
    0.00265782877794886, 0.000885894856554407, 0.379188333632346, 
    0.00265793188317263, 0.00265771537700804, 0.39158027235054
    )), row.names = c(NA, -31L), class = "data.frame"))

My data has the links and nodes to create the diagram. Some links have self-reference (from a Node to itself) and circular reference (from a Node to another and then back to the first). In this case of data I need the nodes to have two directions as in Figure 1 below:

I am trying to make the same chart using the networkD3 package using the following code:

sankeyNetwork(Links = landuse$links, Nodes = landuse$nodes, Source = "source",
              Target = "target", Value = "value", NodeID = "name",
              units = "km²", fontSize = 12, nodeWidth = 30)

It seems to me that the package cannot chart the data formatted in this way. The most I can do by removing the circular nodes and self-references is this result shown in Figure 2:

The diagram above is far from what I want. Is it possible to do the diagram as you would like using this package? There is another package in the R that can make the graph with nodes in both directions and that supports self-reference and circular references as in Figure 1?

Answer 1

The package ggforce can help you in this mission.

library(tidyverse)
library(ggforce)

tidy_landuse <- landuse$links %>% 
  gather_set_data(1:3)

ggplot(tidy_landuse, aes(x, id = id, split = y, value = value)) +
  geom_parallel_sets(alpha = 0.3, axis.width = 0.1) +
  geom_parallel_sets_axes(axis.width = 0.1) +
  geom_parallel_sets_labels(colour = 'white') +
  scale_x_discrete(limits = c("source", "target"), expand = c(0.05, 0.15))

I had to do a little gambiarra for the charts to come out as you needed. For some reason when the tidy_landuse was generated with gather_set_data(1:2), which would be correct, the chart would not go out. So I switched to 1:3 and then hid the third set of parallel bars with the scale_x_discrete(limits = c("source", "target")).

More information about the package can be found in your documentation and in this post.