To change the font size of text elements, use cex (short for character expansion ratio). The default value is 1. To reduce the text size, use a cex value of less than 1; to increase the text size, use a cex value greater than 1.
> x <- seq(0.5, 1.5, 0.25)
> y <- rep(1, length(x))
> plot(x, y, main="Effect of cex on text size")
> text(x, y+0.1, labels=x, cex=x)
To change the size of other plot parameters, use the following:
-
cex.main: Size of main title
-
cex.lab: Size of axis labels (the text describing the axis)
-
cex.axis: Size of axis text (the values that indicate the axis tick labels)
> plot(x, y, main="Effect of cex.main, cex.lab and cex.axis",
+ cex.main=1.25, cex.lab=1.5, cex.axis=0.75)