Sometimes, we might wish to add descriptions to a graph, say if we are producing a PDF for a presentation or as a handout with notes. In this recipe, we will learn how to add text descriptions in the margins of a graph, instead of having to add them separately in another program.
We are only using the base graphics functions for this recipe. So, just open up the R prompt and type in the following code. You might wish to save the code as an R script for later use.
Let's plot a random normal distribution and add a little bit of description after the graph:
par(mar=c(12,4,3,2)) plot(rnorm(1000),main="Random Normal Distribution") desc<-expression(paste("The normal distribution has density ", f(x) == frac(1,sqrt(2*pi)*sigma)~ plain(e)^frac(-(x-mu)^2,2*sigma^2))) mtext(desc,side=1,line=4,padj=1,adj=0) mtext(expression(paste("where ", mu, " is the mean of the distribution and ",sigma," the standard deviation.")), side=1,line=7,padj...