Dear r-helpers, I would like to add three fitted lines to this plot. I don't know how to include three panel.abline() to the call to xYplot. I would like the colors of the lines correspond to the color of the dots and CI bars. x <- c(1:4, 1:4, 3:6) y <- c(4:1, 6:3, 5:2) e <- runif(12) - .5 y <- y + e ll <- y - 1 ul <- y + 1 g <- c(rep(1, 4), rep(2, 4), rep(3, 4)) df <- data.frame(x, y, ll, ul, g) xYplot(Cbind(y, ll, ul) ~ x, groups = g, type = 'p', data = df) _____________________________ Professor Michael Kubovy University of Virginia Department of Psychology USPS: P.O.Box 400400 Charlottesville, VA 22904-4400 Parcels: Room 102 Gilmer Hall McCormick Road Charlottesville, VA 22903 Office: B011 +1-434-982-4729 Lab: B019 +1-434-982-4751 Fax: +1-434-982-4766 WWW: http://www.people.virginia.edu/~mk9y/