Default color used in "networkD3" package

[gtmbini]

We can use the scales package to extract default colors used by ggplot2.
To get the discrete colors used in ggplot2 for 9 levels. The following code can be used
show_col(hue_pal()(9)).

I was wondering similar to the above approach if there is a way to extract the default colors used by the "networkD3" package in R.

[cjyetman]

Most of the functions in networkD3 use D3v4's d3.schemeCategory20 color palette by default. Finding the documentation for that is a bit difficult nowadays because d3.schemeCategory20 has been removed from D3v5+, and it seems they don't like to encourage its use anymore.

The easiest way to get the list as it is is to open a webpage that has D3v4 loaded (e.g. an htmlwidget created by networkD3), open it in a web browser, and use the developer tools to open a JavaScript console and run d3.schemeCategory20, which will give you...

0 "#1f77b4"
1 "#aec7e8"
2 "#ff7f0e"
3 "#ffbb78"
4 "#2ca02c"
5 "#98df8a"
6 "#d62728"
7 "#ff9896"
8 "#9467bd"
9 "#c5b0d5"
10 "#8c564b"
11 "#c49c94"
12 "#e377c2"
13 "#f7b6d2"
14 "#7f7f7f"
15 "#c7c7c7"
16 "#bcbd22"
17 "#dbdb8d"
18 "#17becf"
19 "#9edae5"

If you wanna get closer to the source, you can load/download https://d3js.org/d3.v4.js and search for: "var category20".

[Jwvz001]

Thanks @cjyetman for pointing this out!

@gtmbini if you want to stay closer to the grammar-of-graphics provided by ggplot, you should take a look at ggsankey by David Sjoberg, which I became aware of recently. Nevertheless for awesome Sankey plots network3D is my preference for quick and complex networks. I find myself using ggsankey when I need more control to position the nodes.

Have a look, JW

[gtmbini]

Thank you for your suggestion.