library(ggplot2) df = data.frame(x = rnorm(1000), y = rnorm(1000), group = sample(letters[1:5], size = 1000, replace = TRUE), stringsAsFactors = FALSE) gbase = ggplot(data = df, aes(x = x, y = y)) g = gbase + geom_point(aes(colour = group)) g2 = g + geom_smooth(se = FALSE) # g + geom_smooth(se = FALSE) + # facet_wrap(~group) # g + geom_smooth(aes(colour = group), se = FALSE) + facet_wrap(~group, ncol = 1) df$outcome = df$y > 0 p = ggplot(data = df, aes(x = x)) p + geom_density(aes(fill = group), alpha = 0.5) p + geom_density(aes(colour = group)) p + geom_line(aes(colour = group), stat = "density") pnew = p + geom_line(aes(colour = outcome), stat= "density") + facet_wrap(~ group, ncol = 1) # pnew %+% df