| \documentclass[11pt,a4paper]{article} |
| |
| %% *** automatically switched by 'make' ( ./Makefile ) --- CARE!! in changing |
| \SweaveOpts{echo=FALSE,eval=FALSE,results=hide} % Exercise mode |
| %\SweaveOpts{echo=TRUE,eval=TRUE,results=verbatim} % Solution mode |
| %% other Sweave options |
| \SweaveOpts{engine=R, keep.source=TRUE, strip.white=true} |
| |
| \newif\ifSolution |
| \Solutiontrue% if solution |
| \Solutionfalse%if exercise |
| % |
| \ifSolution\newcommand{\commentSol}[1]{#1} |
| \else \newcommand{\commentSol}[1]{} |
| \fi |
| \newcommand{\T}[1]{\texttt{#1}} |
| |
| \begin{document} |
| |
| <<preliminaries,echo=FALSE,results=hide>>= |
| options(width = 75, digits = 5, str=list(vec.len=2)) |
| @ |
| |
| We work with the data set \T{airquality} which is part of R.... |
| You can address it simply by \T{airquality}. Use \T{?airquality} to read about the |
| meaning of the variables contained in the dataset. |
| |
| Get a summary of the data, |
| <<s-air-2,echo=TRUE,eval=TRUE>>= |
| summary(airquality) |
| @ |
| |
| \commentSol{The data set contains \Sexpr{nrow(airquality)} observations. The data is |
| complete for all but the first two variables \T{Ozone}, \T{Solar.R}, |
| which contain \Sexpr{sum(is.na(airquality[,1]))} and |
| \Sexpr{sum(is.na(airquality[,2]))} missing values, respectively. |
| } |
| |
| The above works in solution mode, |
| but in exercise mode, the $\backslash$Sexpr results are put out verbatim, |
| unfortunately using $\backslash$\verb|verb{bla bla{| and the left brace |
| \emph{really} messes up the $\backslash$commentSol\verb|{..}| command... |
| |
| \end{document} |
