Change color median line ggplot geom_boxplot()

Question

I would like to change the color of the median line in geom_boxplot(). I have looked and can\'t find a way to do it. I have posted the R code here that I am usi

Answer 1

You can use the details of the plot, to derive the coordinates of where the median line is, and then add colour to it using geom_segment.

library(ggplot2)

p <- ggplot(mtcars, aes(factor(am), mpg)) + geom_boxplot()

dat <- ggplot_build(p)$data[[1]]

p + geom_segment(data=dat, aes(x=xmin, xend=xmax, 
                               y=middle, yend=middle), colour="red", size=2)

Also had to increase the size of the line so that it covers the original black median line