Capture R output and replacement with LaTeX code

Question

I am trying to grab the output from some R code and replace it with latex code.

If you run this code:

library(stargazer) x <- capture.output(stargazer(mtcars[1:5, 1:3], summary = FALSE, title="The main caption of the table.")) x 

This is the conclusion:

  [1] "" [2] "% Table created by stargazer v.5.1 by Marek Hlavac, Harvard University. E-mail: hlavac at fas.harvard.edu" [3] "% Date and time: Sat, Jun 27, 2015 - 11:36:07" [4] "\\begin{table}[!htbp] \\centering " [5] " \\caption{The main caption of the table.} " [6] " \\label{} " [7] "\\begin{tabular}{@{\\extracolsep{5pt}} cccc} " [8] "\\\\[-1.8ex]\\hline " [9] "\\hline \\\\[-1.8ex] " [10] " & mpg & cyl & disp \\\\ " [11] "\\hline \\\\[-1.8ex] " [12] "Mazda RX4 & $21$ & $6$ & $160$ \\\\ " [13] "Mazda RX4 Wag & $21$ & $6$ & $160$ \\\\ " [14] "Datsun 710 & $22.800$ & $4$ & $108$ \\\\ " [15] "Hornet 4 Drive & $21.400$ & $6$ & $258$ \\\\ " [16] "Hornet Sportabout & $18.700$ & $8$ & $360$ \\\\ " [17] "\\hline \\\\[-1.8ex] " [18] "\\end{tabular} " [19] "\\end{table} " 

I need to replace line 5 with the following:

 " \\caption[short caption]{The main caption of the table.} " 

How can i do this?

Answer 1

Try:

 x <- sub("\\caption{The main caption of the table.}", "\\caption[short caption]{The main caption of the table.}", fixed = TRUE, x) 

Answer 2

This is a bit different than what you meant, but maybe you could just use xtable , which has the caption.width argument, for example:

 print.xtable(xtable(mtcars[1:5, 1:3], caption="The main caption of the table"), caption.width="10cm", caption.placement="top") 

The conclusion will not exactly match what you are going to do, but you can probably bend it for your own purposes if you prefer a more concise code; from ?print.xtable :

The signature will be placed in the "parbox" of the specified width, if caption.width is not NULL, but type = "latex". The default value is NULL.

Here's the conclusion:

 % latex table generated in R 3.1.3 by xtable 1.7-4 package % Tue Jun 30 14:52:06 2015 \begin{table}[ht] \centering \parbox{5cm}{\caption{The main caption of the table}} \begin{tabular}{rrrr} \hline & mpg & cyl & disp \\ \hline Mazda RX4 & 21.00 & 6.00 & 160.00 \\ Mazda RX4 Wag & 21.00 & 6.00 & 160.00 \\ Datsun 710 & 22.80 & 4.00 & 108.00 \\ Hornet 4 Drive & 21.40 & 6.00 & 258.00 \\ Hornet Sportabout & 18.70 & 8.00 & 360.00 \\ \hline \end{tabular} \end{table} 

You will also have to deal with other parameters (e.g. digits ) in order to get the exact formatting of the rest of the table according to what is specified in stargazer , depending on what exactly it formats what you had in mind.