How to increase font size in a plot in R?

Question

I am confused. What is the right way to increase font size of text in the title, labels and other places of a plot?

For example

x <- rnorm(100)
h         


        

Answer 1

Notice that "cex" does change things when the plot is made with text. For example, the plot of an agglomerative hierarchical clustering:

library(cluster)
data(votes.repub)
agn1 <- agnes(votes.repub, metric = "manhattan", stand = TRUE)
plot(agn1, which.plots=2)

will produce a plot with normal sized text:

and plot(agn1, which.plots=2, cex=0.5) will produce this one: