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 scatterplot chart, while the third dimension is represented using the radius of the bubble (size of the disk). The bubble chart is particularly useful when it's used to facilitate the 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-v2/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, omitting the accessors and peripheral graphic implementation details:

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var _width...