How to draw a rect() behind a hist() ?

Hi,

I have the following code:

hist(gps$heartpercent, breaks=5)
rect(90, par("usr")[3], 100, par("usr")[4], col = "red")

How do I get the rectangle to appear behind the histogram. Barring that,
how can I make certain bars of the histogram to be a certain color?

Hi Jason,
Does this do what you want?

heartpercent<-sample(0:100,200,TRUE)
library(plotrix)
barp(hist(heartpercent,breaks=5,plot=FALSE)$counts,
  names.arg=c("0-20","21-40","41-60","61-80","81-100"),
  do.first=rect(5,par("usr")[3],par("usr")[2],par("usr")[4],
  col = "red"))

Jim