Adding abline in Lattice graph

Sundar Dorai-Raj <sdorairaj <at> gmail.com> writes:

Sorry, that was my lack of understanding on how coplot works. 
Try the following:

coplot(lbxglu~lbxgh|eth, data = reg.dat.5,
   panel= function(...) {
     panel.smooth(...)
     abline(h = 126, col = "red")
     abline(v = 6.5, col = "blue")
  },
  xlab="ABC", ylab="FBG")

No, it was not your lack of understanding. Since the original poster 
did not provide sample data (too much work?), you had to provide 
untested code.

Function coplot is standard graphics, not lattice, so panels do not 
work here.

Dieter