plot question when type = "b" and pch is a vector

-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch 
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of toka tokas
Sent: Sunday, October 02, 2005 5:37 AM
To: r-help at stat.math.ethz.ch
Subject: [R] plot question when type = "b" and pch is a vector

Dear R users,

I've been struggling some days with the following
problem: I'm interesting in producing the following plot

x <- seq(0.01, 10, length = 20)

plot(c(0, 10), c(-20, 20), type = "n", xlab = "x", 
        ylab = expression(2 * alpha * log(x)))

pch. <- rep(NA, length(x))
for(i in 1:4){
    pch.[7] <- as.character(i)
    lines(x, 2 * i * log(x), type = "b", pch = pch., lty = 1) }

where all the line segments are connected, except from the 
7th one where I've put the value of alpha -- in other words 
I'd like to produce a line plot where the label appears at 
each line with some white space around it.

thanks in advance,
tokas