This is a follow on from the update data graph used as an example in the book D3 Tips and Tricks.
It demonstrates the loading and reverting of data and updating a graph on button presses. It should be taken in context with the text of the book which can be downloaded for free from Leanpub.
Modified http://d3js.org/d3.v3.min.js to a secure url
https://d3js.org/d3.v3.min.js