[R] Help

[Jim Lemon]

Hi Andre,
You can do it manually like this:

testmat<-matrix(rnorm(90),ncol=3)
boxplot(testmat,ylim=c(-3,4))
library(plotrix)
draw.arc(1.5,2,0.5,0,pi,col=1)
draw.arc(2.5,2,0.5,0,pi,col=1)
boxed.labels(c(1.5,2.5),c(3.3,3.3),c("**","***"),border=NA)

Obviously you would have to nudge the arcs and labels around to match
your plot. I don't know of a function that does this automatically.
Also if your aspect ratio is far from 1, the arcs won't be circular.
It is possible to write a function that will use the return values
from boxplot to display rectangular brackets above the boxplots and
then put the asterisks or whatever else you want on the top lines.

Jim


On Sat, Aug 15, 2015 at 5:46 AM, André Luis Neves <andrluis at ualberta.ca> wrote:
> Dear everyone,
>
> Would like to know how to add asterisks and arcs that indicate a subgroup
> comparison above box plots to denote statistical diference.
>
> Thank you.
>
> Andre
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.