Question

Is it possible to plot the following function with R?

$$\lim\limits _{x\to3^{+}}\, f(x)=2$$

$$\lim\limits _{x\to3^{-}}\, f(x)=1$$

Basically, I would like to see a plot with 2 curves. If possible how to make some circle (black or white) at the end of the curves… ?

Thank you

Answer 1

Define a piecewise continuous function:

ff <- function (xx) ifelse(xx<3,xx,xx+1)

Plot the first part of it, reserving enough space to plot the rest:

curve(expr=ff,from=0,to=2.999,xlim=c(0,6),ylim=c(0,7),xlab="",ylab="")

Add the second part:

curve(expr=ff,from=3,to=6,add=TRUE)

Add a little open circle:

points(3,ff(3),pch=21,bg="black")

Result: