Hello, I have just ordered the "ggplot2: Elegant Graphics for Data Analysis (Use R)" but while it arrives :) can anyone please show me how to setup and add a simple legend to a ggplot? This is my use case, I need a legend showing CI "Classic", "Own bootstrap", "R bootstrap": library(ggplot2) e <- 1 p <- 1 x <- 1:S y <- rep(betas[p],S) data <- data.frame(x,y) classiclimits <- aes(x=x,ymax = classic[,e,p,1], ymin=classic[,e,p,2]) ownlimits <- aes(x=x+0.4,ymax = own[,e,p,1], ymin=own[,e,p,2]) rbootlimits <- aes(x=x+0.8,ymax = rboot[,e,p,1], ymin=rboot[,e,p,2]) g1 <- ggplot(data, aes(x, y)) g1 + geom_errorbar(classiclimits, colour = "red") + geom_errorbar(ownlimits, colour = "green") + geom_errorbar(rbootlimits, colour = "blue") + geom_hline(yintercept = betas[p]) + xlab("Simulation") + ylab("beta_1") + opts(title = "CI for error 'normal' and beta_1") + opts(legend.position = c(10,2.5)) Many thanks in advance, Best regards, Giovanni [[alternative HTML version deleted]]