Radar Chart

Extending the parallel coordinates visualization to include radar charts could be useful in some instances. I have a data set where the relationships between variables is roughly a ring (like a ring species), and a radar chart would be a more natural fit for this than parallel coordinates (although repeating the first variable as the last would partially resolve this).

In other cases, where the angle of the axes could be adjusted, radar charts may allow one to convey more information than parallel coordinates.

The issue names no files, tests, or entry points; start by locating the existing parallel-coordinates visualization and related visualization tests. Clarify the radar-chart scope, including ring-like data and adjustable axis angles, before implementation; done requires agreed behavior and acceptance criteria.

Written by the indexing model from the issue text.