[R] Truncated R output in Sweave

[Frank E Harrell Jr]

Romain Francois wrote:
> 
> 
> Frank E Harrell Jr wrote:
>>
>> Dear Colleagues:
>>
>> In producing a book or a handout I sometimes cut out a large part of 
>> the printed output of an R function, substituting ... for that chunk. 
>> Deleting non-essential output saves paper.  It would be nice to have a 
>> capability in Sweave to allow the user to specify a starting and an 
>> ending regular expression that would identify consecutive lines of 
>> output to replace with ..., without showing the extra code required to 
>> do this to the user.  I would want the LaTeX output, other than the 
>> omission, to appear the same as if the section were not omitted.  Does 
>> anyone have an idea of how to do this elegantly?
> 
> Hello,
> 
> You could use the same trick that is sometimes used to embed lattice 
> calls into print calls (see the grid vignette for example)
> 
> \documentclass[a4paper]{article}
> \begin{document}
> <<aa,eval=FALSE,echo=T>>=
> rnorm( 200 )
> <<echo=F>>=
> txt <- capture.output( {
> <<aa>>
>    } )
> if( length(txt) > 10 ){
>    txt <- c( txt[1:10], "..." )
> }
> cat( txt, sep = "\n" )
> @
> \end{document}

Thank you Romain - I did not know of that construct.

> 
>>
>> By the way I just discovered the SweaveListingUtils package by Peter 
>> Ruckdeschel (on CRAN), which produces beautifully printed R code in 
>> Sweave code chunks.  I put some info about it at 
>> http://biostat.mc.vanderbilt.edu/SweaveTemplate which has our Sweave 
>> template for statistical reports.
> You might also be interested by the driver that comes with the highlight 
> package (not yet on cran though, but the r-forge version is stable enough).
> 
>  > install.packages("highlight", repos="http://R-Forge.R-project.org")
>  > require( highlight )
>  > Sweave( file, driver = HighlightWeaveLatex() )

Interesting.  What would be the corresponding batch file command to 
achieve this?  I like to run R CMD Sweave my.Rnw.  And would you mind 
giving a very brief comparison of the two highlighting approaches 
regarding the LaTeX output?

Thanks!
Frank

> *||*
>>
>> Thanks
>> Frank
> 
> 


-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University