Remove whiskers in boxplot made by ggboxplot (of ggpubr package)? - r

Question

Sometimes it is appropriate to show a boxplot without the whiskers.
In geom_boxplot (ggplot2) we can achieve this with coef=0.
Is there a way to achieve this in ggboxplot (ggpubr v0.5.0, current version at the time of writing)?
I note that ggboxplot has much in common with geom_boxplot,
such as the ability to use outlier.shape=NA in each case to suppress
outliers. It seems that there should be an easy way to also suppress the whiskers.

Answer 1

I cannot find a way implemented in ggboxplot directly to do this, which is a bit strange because it passes the ellipsis to a geom_boxplot call, so I am not sure why the coef=0 does not reach there and supresses the whiskers.
As a stopgap, you can modify the ggplot object created by ggboxplot and remove whiskers that way.
The following function shows this:
ggboxplot_whisker_opt <- function(...)
{
opts <- list(...)
# check if user specified a whiskers argument and set options accordingly
if("whisker" %in% names(opts))
{
whisk <- opts$whisker
opts$whisker <- NULL
} else {
whisk <- TRUE
}
pl <- do.call(ggboxplot,opts) # create plot by calling ggboxplot with all user options
if(!whisk)
{
pl_list <- ggplot_build(pl) # get listed version of ggplot object to modify
pl_list$data[[1]]$ymin <- NA # remove the ymin/max that specify the whiskers
pl_list$data[[1]]$ymax <- NA
pl <- ggplot_gtable(pl_list) # convert back to ggplot object
}
# plot the ggplot and return
plot(pl)
}
We can now call that function with whisker=TRUE/FALSE or without it and it produced plots accordingly:
set.seed(123)
x <- rnorm(100)
labels <- round(runif(100,1,2))
df <- data.frame(labels=labels,
value=x)
ggboxplot_whisker_opt(df,"labels","value")
# is the same as
ggboxplot_whisker_opt(df,"labels","value",whisker=TRUE)
ggboxplot_whisker_opt(df,"labels","value",whisker=FALSE)