Collapsible tree in R

Question

I am motivated by this article regarding Collapsible Tree in R

http://bl.ocks.org/mbostock/4339083

I am trying to reproduce the same example using a toy dataset like this

ID      Car Bus Train   Feedback_Car    Feedback_Bus    Feedback_Train
23433   Yes Yes Yes     Toyota          GreyHound       Amtrak

Which can be represented as a collapsible tree as follows

I am wondering if anybody can help me reproduce that concept (collapsible trees) using this toy dataset above, this example will then give me an idea how different components work, for example formatting the JSON data in R etc...and serve as a starting point. Thanks in advance.

Answer 1

This collapsible tree looks really cool. My approach here is to first, create a graph using igraph. I was hoping there was already a function to convert an igraph to json, however, it looks like that is an issue on github that hasn't been implemented. So, here is a simple function to do that. Then, you can just plug the resulting data into the linked source and you have a collapsible tree.

## Read your data
dat <- read.table(text="ID      Car Bus Train   Feedback_Car    Feedback_Bus    Feedback_Train
23433   Yes Yes Yes     Toyota          GreyHound       Amtrak", header=TRUE)

## Make an edgelist from your data
edges <- rbind(cbind(dat$ID, names(dat)[2:4]),
               cbind(names(dat)[2:4], as.vector(t(dat[5:7]))))

## Convert to a graph data structure
library(igraph)
g <- graph_from_edgelist(edges)

## This is the non-interactive version
plot(g, layout=layout.reingold.tilford(g, root='23433'))

## Recursive function to make a list of nodes to be parsed by toJSON
## call it with 'node' as the root node (here '23433')
f <- function(g, node, size=1000) {
    n <- neighbors(g, node, mode='out')
    if (length(n) == 0) return( list(name=node, size=size) )
    children <- lapply(n$name, function(x) f(g, x, size))
    list(name=node, children=children)
}

## Convert to json
library(jsonlite)
json <- toJSON(f(g, '23433'), auto_unbox = TRUE)

## I made a directory collapsible to store the index.html from the linked
## site, as well as this data
## For completeness, you should be able to run this to see the interactive results,
## But, of course, this is creating files on your box
dir.create('collapsible')
writeLines(json, 'collapsible/data.json')

## Download the index.html
download.file("https://gist.githubusercontent.com/mbostock/4339083/raw/0d003e5ea1686dd6e79562b37f8c7afca287d9a2/index.html", "collapsible/index.html", method='curl')

## Replace with the correct data
txt <- readLines('collapsible/index.html')
txt[grepl("^d3.json", txt)] <- "d3.json('data.json', function(error, flare) {"
writeLines(txt, 'collapsible/index.html')

## Open in broweser
browseURL(paste0('file://', normalizePath('collapsible/index.html')))

The results can also be seen here.