```
# make an original plot
plot( 11:20, sample(51:60) )
# add some histograms
subplot( hist(rnorm(100)), 15, 55)
subplot( hist(runif(100),main='',xlab='',ylab=''), 11, 51, hadj=0, vadj=0)
subplot( hist(rexp(100, 1/3)), 20, 60, hadj=1, vadj=1, size=c(0.5,2) )
subplot( hist(rt(100,3)), c(12,16), c(57,59), pars=list(lwd=3,ask=FALSE) )
tmp <- rnorm(25)
qqnorm(tmp)
qqline(tmp)
tmp2 <- subplot( hist(tmp,xlab='',ylab='',main=''),
cnvrt.coords(0.1,0.9,'plt')$usr, vadj=1, hadj=0 )
abline(v=0, col='red') # wrong way to add a reference line to histogram
# right way to add a reference line to histogram
op <- par(no.readonly=TRUE)
par(tmp2)
abline(v=0, col='green')
par(op)
```

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