Using the ordinal scale
In some cases, we may need to map our data to some ordinal values, for example, ["a", "b", "c"] or ["#1f77b4", "#ff7f0e", "#2ca02c"]. So, how can we perform this kind of mapping using D3 scales? This recipe is dedicated to answer this question.
Getting ready
Open your local copy of the following file in your web browser:
https://github.com/NickQiZhu/d3-cookbook-v2/blob/master/src/chapter4/ordinal-scale.html .
How to do it...
This kind of ordinal mapping is quite common in data visualization. For example, you may want to map certain data points through categorization into some textual value or perhaps into RGB color code, which in turn can be used in CSS styling. D3 offers a specialized scale implementation to handle this kind ...
Get Data Visualization with D3 4.x Cookbook - Second Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
