geom_boxplot：用第二个矩形替换 IQR 和胡须之间的线

Question

Is there a way in ggplot2::geom_boxplot() to replace the lines between the IQR and the whiskers using a second rectangle? Here is an example of the visual I am trying to achieve:

source: Hydroclimatic Atlas of Southern Québec, https://www.cehq.gouv.qc.ca/atlas-hydroclimatique/Hydraulicite/Qmoy.htm . (click on a river)

I found how to override the quantiles position of geom_stats() using:

environment(ggplot2::StatBoxplot$compute_group)$f

Full explanation of this code can be found here: https://coderedirect.com/questions/468264/override-lower-upper-etc-in-boxplot-while-grouping

It works to draw, for instance, a 95% - 50% - 5% box instead of the classic 75% - 50% - 25% visual, but nothing about how the quantiles are drawn on the graph.

Thanks for your thoughts on this:)

Answer 1

Perhaps you can use geom_crossbar . Here's an example using the iris data:

x = boxplot(Sepal.Length ~ Species, data=iris, plot=FALSE)$stats
x = as.data.frame(t(x))
x$species = unique(iris$Species)
#    V1  V2  V3  V4  V5    species
# 1 4.3 4.8 5.0 5.2 5.8     setosa
# 2 4.9 5.6 5.9 6.3 7.0 versicolor
# 3 5.6 6.2 6.5 6.9 7.9  virginica

ggplot(x, aes(species, V3)) +
  geom_crossbar(aes(ymin=V1,ymax=V5, fill=species), alpha=0.5) +
  geom_crossbar(aes(ymin=V2,ymax=V4, fill=species))