"Hello world" in R Sweave

hello.Rnw

\documentclass{article}
\begin{document}

<<echo=FALSE,results=tex>>=
cat('\\section{hi}\n')
@


<<echo=FALSE>>=
library(xtable)
@

Hello World

<<fig=TRUE>>=
plot(iris)
@

Here is a regression.

<<>>=
model <- lm(Sepal.Length~Sepal.Width, data=iris)
slope <- model$coefficients['Sepal.Width']
model
@

The slope is \Sexpr{slope}.

Here is a graph.

<<fig=TRUE>>=
plot(model)
@

Here is a table

<<results=tex>>=
xtable(model)
@

\end{document}