Hello, I am trying to print the lm coefficients using grid graphs (code below), and am getting all the coefficients on top of each other. My aim is to put them as legend, showing both coefficients and mean values separated by colors as shown in xyplot. testData <- data.frame(f1 = factor(rep(LETTERS[1:5], each = 20)), f2 = factor(rep(letters[6:7], 50)), x1 = rnorm(100, mean = 2, sd = 1), x2 = rnorm(100, mean = 10, sd = 4), x3 = rnorm(100, mean = 4, sd = 3), y = (1:50) + rnorm(50, sd = 3) + rep(c(-2, 2), 50)) grid.newpage() grps <- factor(testData[, "f2"]) xyplot( y ~ x1|f1, groups=grps, panel=function(x, y, ...) { panel.superpose(x, y, ...) }, panel.groups = function(x, y, ...) { fit.lm <- lm(y~x) coef.fit <- round(coef(fit.lm)[-1], 2) avg.y <- round(mean(y), 2) panel.abline(fit.lm) panel.xyplot(x, y, ...) ## Add lm coefficients: grid.text(x= unit(0.1, "npc"), y= unit(seq(0.1, length= length(levels(grps)), by =0.1), "npc"), label = paste(expression(beta), "=", coef.fit) ), ## Add mean values: (note that "mu" is not shown as symbol) grid.text(x= unit(0.1, "npc"), y= unit(seq(0.9, length= length(levels(grps)), by =-0.1), "npc"), label = paste(expression(mu), "=", avg.y) ), }, ## Key key = simpleKey(levels(grps), columns = 2, space = "bottom", points = TRUE, lines = TRUE ), ## grid.legend() data= testData ) Thanks. -NJ ____________________________________________________________________________________ Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.