create_sankey_colour_string: Create a Javascript colour string appropriate for networkD3...

In MatthewHeun/Recca: R Energy Conversion Chain Analysis

Create a Javascript colour string appropriate for networkD3 Sankey diagrams

Description

This package (Recca) uses networkD3::sankeyNetwork() to create Sankey diagrams in make_sankey(). This function converts a data frame of colors into a correctly formatted javascript string for use with networkD3::sankeyNetwork().

Usage

create_sankey_colour_string(
  colour_df = NULL,
  name_col = "name",
  colour_col = "colour"
)

Arguments

colour_df	A data frame containing name_col and colour_col.
name_col, colour_col	Names of columns in colour_df.

Value

A Javascript string formatted for use as the colourScale argument to networkD3::sankeyNetwork().

Examples

# See https://r-graph-gallery.com/322-custom-colours-in-sankey-diagram.html
# for original examples.
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 entity 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

# Add color to the flows.
links$group <- c("type_a","type_a","type_a","type_b","type_b","type_b")
# Add a 'group' column to each node. Put all nodes in the same group to make them grey.
nodes$group <- c("node_group")

colour_df <- tibble::tribble(~name, ~colour,
                             "type_a", "#69b3a2",
                             "type_b", "steelblue",
                             "node_group", "grey")
colour_string <- create_sankey_colour_string(colour_df)
cat(colour_string)
networkD3::sankeyNetwork(Links = links,
                         Nodes = nodes,
                         Source = "IDsource",
                         Target = "IDtarget",
                         Value = "value",
                         NodeID = "name",
                         colourScale = colour_string,
                         LinkGroup="group",
                         NodeGroup="group")

MatthewHeun/Recca documentation built on Dec. 10, 2024, 10 p.m.