Support for Radar Plots

[aishfenton]

Useful and currently missing.
https://en.wikipedia.org/wiki/Radar_chart

[g3o2]

This issue may be related to #408

[domoritz]

Let's track this as #408. We need support for polar coordinates for any of these chart types.

[kanitw]

Note that Radar chart has a lot of problems, some of which are already noted in the Wikipedia article.
So I don't think we would prioritize supporting it.

We need support for polar coordinates for any of these chart types.

That's not true. Vega supports arc as a native mark, so pie and arc do not need a special polar coordinate. However, to support the radar chart, a new coordinate must be supported. So if you think this is important, please file a feature request for polar coordinate in Vega.