\documentclass{article}

\title{A Simple Sweave Example}
\author{Mike Hammond}

\begin{document}

\maketitle

Let's first display a simple statistical comparison and the code that
produces it:

<<>>=
g <- read.table('gender.txt',header=T)
gt <- with(g,tapply(age,gender,mean))
gt
@

\noindent We can display the result of an \texttt R command in the actual
text too. Here is the mean age of female sujects from the
\texttt{gender.txt} dataset: $\Sexpr{round(mean(g$age[g$gender=='f']),3)}$.

Now let's display a nice barplot of the result, without displaying the code
that produces it.

\begin{center}
<<fig=TRUE,echo=FALSE,height=4>>=
barplot(gt,names.arg=c('female','male'),col=rainbow(15),ylab='age')
@
\end{center}

\end{document}