Sweave, Beamer and ggplot2

Question

There's literally nothing on the internet showing how these work in conjunction with one another. I would really appreciate even the simplest example of a Rnw document that you would run with Sweave() in R.

If you could provide a title, a simple plot, centered on the page, and a page number. Please, lets see how you would do it.

TIA.

Answer 1

Here is an example where I shamelessly copied some R code from Cross-Validated. It can be compiled in many ways, but personally I used

R CMD Sweave 1.Rnw
pdflatex 1.tex

where 1.Rnw actually reads:

\documentclass[a4paper,11pt]{article}

\title{A sample Sweave demo}
\author{Author name}
\date{}

\begin{document}

\SweaveOpts{engine=R,eps=FALSE,pdf=TRUE,strip.white=all}
\SweaveOpts{prefix=TRUE,prefix.string=fig-,include=TRUE}
\setkeys{Gin}{width=0.6\textwidth}

\maketitle

<<echo=false>>=
set.seed(101)
library(ggplot2)
library(ellipse)
@

<<>>=
n <- 1000
x <- rnorm(n, mean=2)
y <- 1.5 + 0.4*x + rnorm(n)
df <- data.frame(x=x, y=y)

# take a bootstrap sample
df <- df[sample(nrow(df), nrow(df), rep=TRUE),]

xc <- with(df, xyTable(x, y))
df2 <- cbind.data.frame(x=xc$x, y=xc$y, n=xc$number)
df.ell <- as.data.frame(with(df, ellipse(cor(x, y), 
                                         scale=c(sd(x),sd(y)), 
                                         centre=c(mean(x),mean(y)))))
p1 <- ggplot(data=df2, aes(x=x, y=y)) + 
  geom_point(aes(size=n), alpha=.6) + 
  stat_smooth(data=df, method="loess", se=FALSE, color="green") + 
  stat_smooth(data=df, method="lm") +
  geom_path(data=df.ell, colour="green", size=1.2)
@

\begin{figure}
  \centering
<<fig=true,echo=false>>=
print(p1)
@
\caption{Here goes the caption.}
\label{fig:p1}
\end{figure}

\end{document}

---

With Beamer, you just have to replace the first line with

\documentclass[t,ucs,12pt,xcolor=dvipsnames]{beamer}

or add whatever customizations you want, replace \maketitle with something like \frame{\titlepage}, and then enclose every code chunks with a \begin{frame}[fragile] ... \end{frame} statement. Compilation goes the same way as aforementioned.

Code chunks can be customized using, e.g.

\DefineVerbatimEnvironment{Sinput}{Verbatim}
{formatcom = {\color{Sinput}},fontsize=\scriptsize} 
\DefineVerbatimEnvironment{Soutput}{Verbatim}
{formatcom = {\color{Soutput}},fontsize=\footnotesize}
\DefineVerbatimEnvironment{Scode}{Verbatim}
{formatcom = {\color{Scode}},fontsize=\small} 

It requires fancyvrb and needs to be somewhere after the \begin{document}. Personally, I hold in an external configuration file, among other stuff,

\definecolor{Sinput}{rgb}{0.75,0.19,0.19}
\definecolor{Soutput}{rgb}{0,0,0}
\definecolor{Scode}{rgb}{0.75,0.19,0.19}

Here is a snapshot: