I'm confused as how to add text in xyplot. Given the toy example below, I'd like to add the text "A", "B", "C" at the far right of the tips of YA, YB, and YC, respectively. I reformatted my data into a data.frame so it mimics my actual dataset. Any tips are greatly welcome
X = seq(1,100,length.out=5)
YA = 4*X + 10
YB = 2*X-5
YC = 0.5*X + 100
Xs = rep(X,3)
Y = c(YA,YB,YC)
index = as.factor(c(rep(1,5),rep(2,5),rep(3,5)))
Mat = data.frame(index,Xs,Y)
levels(Mat$index)=c("A","B","C")
xyplot(Y~Xs,data=Mat,group=index,col=c("blue","red","black"),type="l")