rotate X axis labels 45 degrees on grouped bar plot R

Question

How can I rotate the X axis labels 45 degrees on a grouped bar plot in R?

I have tried the solution suggested here but got something very messy, the labels seem to h

Answer 1

I had the same problem with a grouped bar plot. I assume that you only want one label below each group. I may be wrong about this, since you don't state it explicitly, but this seems to be the case since your labels are repeated in image. In that case you can use the solution proposed by Stu although you have to apply colMeans to the x variable when you supply it to the text function:

x <- barplot(table(mtcars$cyl), xaxt="n")
labs <- paste(names(table(mtcars$cyl)), "cylinders")
text(cex=1, x=colMeans(x)-.25, y=-1.25, labs, xpd=TRUE, srt=45)