ggsunburst offers a set of tools to plot adjacency diagrams using ggplot2.

Adjacency diagrams are space-filling variants of node-link diagrams; rather than drawing a link between parent and child in the hierarchy, nodes are drawn as solid areas (either arcs or bars), and their placement relative to adjacent nodes reveals their position in the hierarchy.

• In the icicle layout the root node appears at the top, with child nodes underneath. Because the nodes are space-filling, it reveals an additional dimension that would be difficult to show in a node-link diagram.

• The sunburst layout is equivalent to the "icicle" layout, but in polar coordinates.

• sunburst_data extracts the information from a tree structure, either a string or a file in newick format.

The results can be passed to ggplot().

This package uses some code from the python module ETE, a python Environment for phylogenetic Tree Exploration (http:https://etetoolkit.org/)

ggsunburst depends on ggplot2 and reticulate packages. You will need to install them before using it.

library(devtools)
install_github("didacs/ggsunburst")
library(ggsunburst)

# newick format
nw <- "(((a, b, c), (d, e, f, g)), (f, i, h));"

# extract data
sb <- sunburst_data(nw)
icicle(sb)
sunburst(sb)

# demonstrate use of data with ggplot()
p <- ggplot(sb$rects)

# icicle diagram
p + geom_rect(aes(xmin=xmin, xmax=xmax, ymin=ymin, ymax=ymax), size=1, color="white") + scale_y_reverse()

# sunburst diagram
p + geom_rect(aes(xmin=xmin, xmax=xmax, ymin=ymin, ymax=ymax), size=1, color="white") + coord_polar()