Square function drawing in r plot

Question

I would like to draw a square function in a r plot like this plot (black line) from here:

How can I do this one in R?

Answer 1

You can use a definition of the square wave - use the sign function on a periodic function:

plot(function(x) sign(sin(x)),-10,10,n=1000)

Answer 2

You can use lines to draw any arbitrary pattern by specifying vectors of x and y coordinates.

plot(NA, xlim=c(0,10), ylim=c(-2,2))
lines(rep(0:11,each=2),rep(c(-1,1,1,-1),6))

That's helpful if you have multiple things you want to plot. But, you can also obtain the same result directly in plot.default using the type='s' argument:

plot(rep(0:11,each=2),rep(c(-1,1,1,-1),6), xlim=c(0,10), ylim=c(-2,2), type='s')