[R] change default output size when using Sweave

[Franzini, Gabriele [Nervianoms]]

Hi,
I had a similar problem, and I took the direction of squeezing the
output into a minipage, e.g.:

...
@
\begin{minipage}[c]{0.6\textwidth}
<<fig=TRUE, echo=FALSE>>=
plot(...)
abline(...)
@
\end{minipage}
... 

HTH,
Gabriele Franzini 
ICT Applications Manager 
Nerviano Medical Sciences SRL 
Nerviano Italy 


-----Original Message-----
From: Mark Heckmann [mailto:mark.heckmann at gmx.de] 
Sent: 08 April 2009 10:31
To: 'Duncan Murdoch'
Cc: r-help at r-project.org
Subject: Re: [R] change default output size when using Sweave

Dear Duncan,

Thanks for the reply. This works, but unfortunately I need a different
solution.
My script is supposed to run completely automated and the graphics I
produce vary in size each time I run the script. But I want the graphics
to be fitted to my .pdf output without specifying the height argument
manually each time.
That is why I do not want a fixed height as a code chunk argument.
Actually I do not know if it is possible to have a variable placed in a
code chunk header. I tried the following which does not work:

<<>>=
size <- 3
@

<<fig=TRUE, echo=TRUE, height=size>>=
   pushViewport(viewport(height = unit(80, "mm")))    
   grid.rect()
   grid.text("I want this viewport to be the whole output size")
   popViewport()
@

So still I face the problem to have Sweave generate a .pdf graphic that
is just as big I want it to be.
 
In the Sweave Docu paragraph A.9 I discovered something I use as a
workaround. I produce the .pdf output manually (where I can control the
size) and add each graphic to LaTex manually as well.
 
<<results=tex, echo=FALSE>>=
for (i in 1){
file=paste("myfile", i, ".pdf", sep="")
pdf(file=file, paper="special", width=6, height=3)
   pushViewport(viewport(height = unit(5, "inches")))     
   grid.rect()
   grid.text("I want this viewport to be the whole output size")
   popViewport()dev.off()
cat("\\includegraphics{", file, "}\n\n", sep="") } @

I use parenthesis around the code as it prints out something I do not
want if no parenthesis are used (I use Windows). 

I am not too happy with the solution. I would prefer a more
straightforward approach to define the size of the output graphic. I
wonder if there are some Sweave settings that can be modified. 

In the Sweave manual (A.11) I found the following to customize the par
settings for each figure:

options(SweaveHooks=list(fig=function() par(bg="red", fg="blue")))

I wonder if something similar could be done changing the size of the
default output device (pdf or eps) for each figure like
>pdf.options(height=2) or similar (it seems that this does not work)? 

I suppose this type of graphic customization is quite a common issue
when producing automated customized output/reports using R and Sweave
but I haven't found anything concerning this topic yet.

So I would be really glad if someone knows a solution.

TIA, Mark