Sankey Diagram can be built in
R using the networkD3 package. This post
explains how to customioze the node colors used on the chart.
This page follows the
graph #321
that describes how to make an interactive
Sankey diagram with the
networkD3 library.
Now that you know what kind of input allows to work with this library,
you probably want to control the color of your nodes and connections.
This is a bit tricky since you have to call it in
Javascript, as described in the code below.
The first step is to create a colour links Javascript object.
For each node, attribute a color. Then call this object in the
colourScale argument of networkD3.
# Library
library(networkD3)
library(dplyr)
# Make a connection data frame
links <- data.frame(
source=c("group_A","group_A", "group_B", "group_C", "group_C", "group_E"),
target=c("group_C","group_D", "group_E", "group_F", "group_G", "group_H"),
value=c(2,3, 2, 3, 1, 3)
)
# 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
# prepare color scale: I give one specific color for each node.
my_color <- 'd3.scaleOrdinal() .domain(["group_A", "group_B","group_C", "group_D", "group_E", "group_F", "group_G", "group_H"]) .range(["blue", "blue" , "blue", "red", "red", "yellow", "purple", "purple"])'
# Make the Network. I call my colour scale with the colourScale argument
p <- sankeyNetwork(Links = links, Nodes = nodes, Source = "IDsource", Target = "IDtarget",
Value = "value", NodeID = "name", colourScale=my_color)
p
# save the widget
# library(htmlwidgets)
# saveWidget(p, file=paste0( getwd(), "/HtmlWidget/sankeyColor1.html"))You can color nodes following their attribution to a group.
Usually this information is stored in a column of the
node data frame. You can use this information to create
a JavaScript color attribution object and call it using the
Nodegroup argument.
# Add a 'group' column to the nodes data frame:
nodes$group <- as.factor(c("a","a","a","a","a","b","b","b"))
# Give a color for each group:
my_color <- 'd3.scaleOrdinal() .domain(["a", "b"]) .range(["#69b3a2", "steelblue"])'
# Make the Network
p <- sankeyNetwork(Links = links, Nodes = nodes, Source = "IDsource", Target = "IDtarget",
Value = "value", NodeID = "name",
colourScale=my_color, NodeGroup="group")
p
# save the widget
# library(htmlwidgets)
# saveWidget(p, file=paste0( getwd(), "/HtmlWidget/sankeyColor2.html"))Following the same principle, you can control the color of each flows of your diagram:
# Add a 'group' column to each connection:
links$group <- as.factor(c("type_a","type_a","type_a","type_b","type_b","type_b"))
# Add a 'group' column to each node. Here I decide to put all of them in the same group to make them grey
nodes$group <- as.factor(c("my_unique_group"))
# Give a color for each group:
my_color <- 'd3.scaleOrdinal() .domain(["type_a", "type_b", "my_unique_group"]) .range(["#69b3a2", "steelblue", "grey"])'
# Make the Network
p <- sankeyNetwork(Links = links, Nodes = nodes, Source = "IDsource", Target = "IDtarget",
Value = "value", NodeID = "name",
colourScale=my_color, LinkGroup="group", NodeGroup="group")
p
# save the widget
# library(htmlwidgets)
# saveWidget(p, file=paste0( getwd(), "/HtmlWidget/sankeyColor3.html"))Related chart types
