Creating a bubble chart

A bubble chart is a typical visualization capable of displaying three data dimensions. Every data entity with its three data points is visualized as a bubble (or disk) on Cartesian coordinates, with two different variables represented using x axis and y axis, similar to the scatter plot chart. While the third dimension is represented using the radius of the bubble (size of the disk). Bubble chart is particularly useful when used to facilitate understanding of relationships between data entities.

Getting ready

Open your local copy of the following file in your web browser:

https://github.com/NickQiZhu/d3-cookbook/blob/master/src/chapter8/bubble-chart.html

How to do it...

In this recipe we will explore techniques and ways of implementing a typical bubble chart using D3. The following code example shows the important implementation aspects of a bubble chart with accessors and peripheral graphic implementation details omitted.

...
var _width = 600, _height = 300,
  _margins...