\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{url}
\begin{document}
<<setup, include=FALSE, cache=FALSE>>=
library(knitr)
opts_chunk$set(cache=TRUE, autodep=TRUE)
options(formatR.arrow=TRUE, width=90)
@
\title{Knitr in SMC}
\author{Author Name}
\maketitle
<<summary>>=
x <- c(2,3,4,5,1,2,3,2,1)
summary(x)
@
<<histogram-plot, fig.width=4, fig.height=4, out.width='.4\\linewidth'>>=
hist(x)
@
Sum of \Sexpr{paste(x, collapse="+")} is \Sexpr{sum(x)}.
\end{document}