Second Y axis ylab's location

Question

I want to draw a double Y axis chart, but when I name the right Y axis name, the name can't be drawed on the right, but lay on the left Y axis's label, what should I do?

plot(1:length(S285$LAI),S285$LAI,axes=F,type="o",pch=1,xlim=c(1,length(S285$LAI)),ylim=c(0,6),xlab="",ylab="LAI",cex.lab=1.5)
axis(side=1,kk1,S285$DAY[kk1])
axis(side=2,seq(0,5,1),seq(0,5,1))
par(new=T)
plot(1:length(S285$LAI),S285$WSO,axes=F,type="o",pch=15,xlim=c(1,length(S285$LAI)),ylim=c(0,10000),xlab="",ylab="WSO")
axis(side=1,kk1,S285$DAY[kk1])
axis(side=4,seq(0,10000,1000),seq(0,10000,1000))
mtext("DOY285播种",side=3,line=-3.5,at=15)
legend(x=1,y=6000,legend=c("LAI","产量"),pch=c(1,15),cex=1.1,lty=c(1,1))

if you run this code, the two label "LAI" and "WSO" will get together, how to draw WSO to the right side? thank you all

Answer 1

One option is to use mtext:

op <- par(mar = c(5,4,4,4) + 0.1)
plot(1:10, ylab = "ylabel")
axis(side = 4)
mtext("ylabel 2", side = 4, line = 3, cex = par("cex.lab"))
par(op)

which gives: