R plotting factor with values on y-axis

Question

f <- as.factor(sample( rep(c("a", "b", "c"), 3)))

plot(1:9,f)

gives the values 1.0..3.0 on the y-axis.

How do I get the values of f ("a", "b" and "c") on the y-axis?

Answer 1

f <- as.factor(sample( rep(c("a", "b", "c"), 3)))

R base

plot(1:9, f, yaxt = "n")
axis(2, 1:3, levels(f))

lattice

see fdetsch answer

ggplot2

library(ggplot2)
qplot(seq_along(f), f)