Feature request: box-and-whisker plots

[jaanli]

I am not sure whether this is feasible with Mosaic, but it would be very helpful for comparing prices across hospitals. Examples of Mosaic visualizations here:

https://www.payless.health/hospital/lehigh-valley-st-lukes-comparison
https://www.payless.health/hospital/indiana-university
https://www.payless.health/hospital/parkview-health

Box-and-whisker plots would enable easier visual comparison across different procedures, medications, treatments, and insurance products across different regions of the country!

[domoritz]

We'll need to do #163 first so let's close this.

[jheer]

While we don't have a dedicated box plot mark, you can still create a box plot as a set of layered marks. The "athletes" dashboard example already goes half way there by including marks for the average (which you should change to median for a traditional box plot) and IQR (between the 0.25 and 0.75 quantile boundaries). You could similarly add whiskers, e.g., with marks that extend 1.5 * IQR beyond the IQR box or as min/max or another interval, depending on your needs.

[jheer]

I don't think #163 is needed (at least not the CI calculation part), as box plots don't typically involve computed confidence intervals.