How to plot horizontal y label

Question

I tried to plot a horizontal y label using the following code:

require(grDevices)

par(mfrow=c(2,1), mar=c(0,3,0,0.5)+0.1, oma=c(3,0,0.5,0)+0.1, 
    mgp=c(2,1,0), cex=tcex)
par(las=1)
#pl-d001
plot(1, type="n", yaxt='n', xaxt='n', xaxs="i", yaxs="i", xlab="xlabel", 
     ylab=expression("axis "*italic(r[infinity])), xlim=c(0, 0.4), ylim=c(0, 1))

But, I only get a normal (vertical) Y label. What is wrong here?

Answer 1

As @rawr said in the comments, your best chance is with mtext:

plot(1, type="n", yaxt='n', xaxt='n', xaxs="i", yaxs="i", 
     xlab="xlabel", ylab="", xlim=c(0, 0.4), ylim=c(0, 1))
mtext(expression("axis "*italic(r[infinity])),side=2,las=1,line=1)

The reason why you can't do that directly from plot is that, internally, plot uses title to draw those labels and title (for some reason) doesn't take las or srt as arguments.