library(plotrix)

twogrp<-c(rnorm(10)+4,rnorm(10)+20)

gap.barplot(twogrp,gap=c(8,16),xlab="Index",ytics=c(3,6,17,20),  ylab="Group values",main="Barplot with gap") gap.barplot(twogrp,gap=c(8,16),xlab="Index",ytics=c(3,6,17,20),  ylab="Group values",horiz=TRUE,main="Horizontal barplot with gap")

http://blog.qiubio.com:8080/archives/2452

参考这里