Sometimes you will need to add some points to an existing
barplot. You might try par(mfrow = c(1,2)) df <-
data.frame(stolpec1 = 10 * runif(10), stolpec2 = 30 * runif(10))
barplot(df$stolpec1) lines(df$stolpec2/10) #implicitno x = 1:10
points(df$stolpec2/10) but you will get a funky looking
line/points. It’s a bit squeezed. This happens because bars are
not drawn at intervals 1:10, but rather on something else. This
“else” can be seen if you save your barplot object. You will
notice that it’s a matrix object with one column – these are
values that are assumed on x axis. Now you need to feed this to
your lines/points function as a value to x argument and you’re
all set. df.bar <- barplot(df$stolpec1) lines(x = df.bar, y =
df$stolpec2/10) points(x = df.bar, y = df$stolpec2/10) Another
way of plotting this is using plotrix package. The controls are
a bit different and it takes some time getting used to it.
library(plotrix) barp(df$stolpec1, col = "grey70")
lines(df$stolpec2/10) points(df$stolpec2/10)