[R] help in plotting

[David Winsemius]

"G Ilhamto" <gilhamto at gmail.com> wrote in
news:bebd16360711232355q5e1e68eeke177f7f061829d9c at mail.gmail.com: 

> I want to combine several plots in one graph.
> I did this: plot(a1); plot(a2, add=TRUE); ...plot(a5, add=TRUE)
> The problem is the more plot we put, the more complex the graph.
> Is there any way to label each line; or other way just to make sure I
> know which one which?
> 
Try:
?legend

This is a worked example taken from Seefeld and Kim's monograph:
<http://cran.r-project.org/doc/contrib/Seefeld_StatsRBio.pdf>

plot(x,dgamma(x,shape=2,scale=1), type='l',xlab="x", ylab="f(x)", main="Gamma pdf's")
lines(x,dgamma(x,shape=2,scale=2),lty=2)
lines(x,dgamma(x,shape=2,scale=4),lty=3)
lines(x,dgamma(x,shape=2,scale=8),lty=4)
legend(x=10,y=.3,paste("Scale=",c(1,2,4,8)),lty=1:4)

-- 
David Winsemius