Modify the layout of a Table-1 filled with data from R

Question

I want to fill automaticly data from R into a table for a TeX-document. Sweave and Knitr are possibilities here. Please feel free to add more. (I know Sweave and Knitr are R package but the focus of my question is the layout - what makes it IMO a TeX-question.)

How can I use data from R in a TeX-table and modify the layout of the table? This question is not about how to produce a beautifull nice table. It is about producing exactly the table I show here.

Sweave or Knitr

This is the example.Rnw file. The table is a example what kind of layout-modifications I want to do. And at the end of the code you see sample-R data. The file can be used via Sweave() or knit().

\documentclass{article}
\usepackage{tabularx}
\begin{document}
\begin{tabularx}{\columnwidth}{XX}
    \hline\hline
    \multicolumn{2}{X}{Should look like this.}\\
    \hline\hline
    \textbf{Gänge}&\\
    \hspace*{5ex}3&15\\
    \hspace*{5ex}4&12\\
    \hspace*{5ex}5&5\\
    \hline
    \textbf{Zylinder}&\\
    \hspace*{5ex}4&11\\
    \hspace*{5ex}6&7\\
    \hspace*{5ex}8&14\\
    \hline\hline
\end{tabularx}
<<>>=
require(xtable)
table(mtcars$gear)

table(mtcars$cyl)
@
\end{document}

Another approach

Another approach I found is this in R.

df <- data.frame(table(mtcars$cyl))
capture.output(
  latex(df, file='')
)

This produces this TeX-code.

 [1] "%latex.default(data.frame(table(mtcars$cyl)), file = \"\")%"                                        
 [2] "\\begin{table}[!tbp]"                                                      
 [3] "\\begin{center}"                                            
 [4] "\\begin{tabular}{llr}"                                                       
 [5] "\\hline\\hline"                                    
 [6] "\\multicolumn{1}{l}{data.frame}&\\multicolumn{1}{c}{Var1}&\\multicolumn{1}{c}{Freq}\\tabularnewline"
 [7] "\\hline"                          
 [8] "1&4&$11$\\tabularnewline"                
 [9] "2&6&$ 7$\\tabularnewline"                                                 
[10] "3&8&$14$\\tabularnewline"                                 
[11] "\\hline"                                         
[12] "\\end{tabular}\\end{center}"            
[13] "\\end{table}"   

When storing that string in an R-object it could be modified then and used for later output. But it sounds like an unefficent workaround and not as a solution. And I am still wouldn't know how to realize my example table witht that approach.

Answer 1

In my eyes it is not a solution but it works.

I puzzeld the pieces of tex-code on the side of R together into a list of strings and than put it out.

This Rnw file

\documentclass{article}
\usepackage{tabularx}
\begin{document}
<<results='asis', echo=FALSE>>=
funcTabCharacteristics <- function (h, t) {
    rc <- c()

    rc <- c(rc, paste('\\textbf{', h, '}&\\tabularnewline', sep=''))
    for (n in names(t)) {
        rc <- c(rc, paste('\\hspace*{5ex}', n, '&', t[n], '\\tabularnewline', sep=''))

    }

    return (rc)
}

# lines of tex-code
tex <- c()
# table head
tex <- c(tex, '\\begin{tabularx}{\\columnwidth}{XX}')
tex <- c(tex, '\\hline\\hline\\multicolumn{2}{X}{My Table-1}\\tabularnewline')
tex <- c(tex, '\\hline\\hline')
# gear
tex <- c(tex, funcTabCharacteristics('Gänge', table(mtcars$gear)))
tex <- c(tex, '\\hline')
# cyl
tex <- c(tex, funcTabCharacteristics('Zylinder', table(mtcars$cyl)))
tex <- c(tex, '\\hline\\hline')
# table foot
tex <- c(tex, '\\end{tabularx}')
# output the texcode
cat(tex, sep='\n')
@
\end{document}

Isn't there a real elegant solution for humans?