How to add line for connecting the means of the first quantile and fifth quantile in ggboxplot in R

[Eliarafei]

How to add line for connecting the means of first quantile and fifth quantile in ggboxplot

ggboxplot(testdf, x = "N4_levels", y = "C8",
add =  "jitter",
order = c("0", "0.25", "0.5", "0.75", "1"),   
ylab = "C8 Expres ", xlab = "N4 Expres", bxp.errorbar=TRUE, notch=TRUE)+
        stat_summary(fun=mean, colour="red", shape = 16, size=0.7)

And I was trying to add the following piece of code for adding Line conneting of means of each Quantile, but this is connecting all the means of Quantiles but that's not what I want; the Just first and Fifth Quantile (picture attached).

  stat_summary(fun=mean, colour="red", geom="line", lty="dotdash", lwd =1, aes(group=1)) 

[nirgrahamuk]

Hi!

To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one:

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…