boxplot

x1 <- rnorm(20, 1, 2);
x2 <- rnorm(20, 2, 3);
y <- list(x1, x2)
boxplot(y)

boxplot(y, horizontal = TRUE)

boxplot(y, horizontal = TRUE, col=c("red", "green"))

boxplot(y, horizontal = TRUE, col=c("red", "green"), notch=TRUE)

boxplot(y, horizontal = TRUE, col=c("pink", "lightgreen"), notch=TRUE, border = c("darkred", "darkgreen"))