Deprecating schemeCategory20*

[nicolaskruchten]

schemeCategory10 is appropriate for encoding categorical variables with 10 values or less, and in general it is difficult to make effective visualizations which encode more than 10 categorical values using color. schemeCategory20, schemeCategory20b and schemeCategory20c are deprecated, as using them to visualize categorical data runs the risk of falsely implying non-existent relationships in the data. For example, graphical elements sharing a hue can imply that the data they represent share some value, and the relative lightness of graphical elements can imply an ordinal relationship in the data.

[mbostock]

I would put the deprecation notice in index.js, since that’s the public entry point.

[nicolaskruchten]

Right, sorry, that's what you asked for earlier as well. Done.

[nicolaskruchten]

(bump :)

[mbostock]

Finally getting back to this; sorry for the delay! I’ve moved all the color schemes from this repo to d3-scale-chromatic, and in the process, I’ve removed the deprecated category20* schemes. This will be released in d3-scale@2 (d3@5) in the near future. Thank you for your patience!