[R] Center labels on a boxplot

[Gabor Grothendieck]

How about something like this suitably fixed up:

 par(mfrow=c(1,3)
 for(i in 1:3)
   boxplot( data.frame( a=myDF1[myDF1[i]==1,4],
                        b=myDF2[myDF2[i]==1,4]),xlab=i,ylim=c(0,25) )