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




-----Urspr?ngliche Nachricht-----
Von: Duncan Murdoch [mailto:murdoch at stats.uwo.ca] 
Gesendet: Dienstag, 7. April 2009 19:08
An: Mark Heckmann
Cc: r-help at r-project.org
Betreff: Re: [R] change default output size when using Sweave

On 4/7/2009 10:39 AM, Mark Heckmann wrote:
  

I am trying to create a graphic output in Sweave but I do not want it to
    

be
  

standard size. I want the whole graphic to be 80mm of height only, just
    

like
  

the viewport below.

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

How can I make the graphic smaller (80mm of height) without having the
    

white
  

margins at the top and bottom?
    

You can specify height and width as arguments to the code chunk or set 
new defaults with something like

\SweaveOpts{width=5,height=3}

(I think those measurements need to be given in inches; I don't think 
there's a way to use an expression like unit(80,"mm").)

You can also control the size of the plot in the final document with 
LaTeX code like

\usepackage{graphicx}
\setkeys{Gin}{width=3in}

and then the LaTeX rules for handling units would apply, so 80mm is fine 
instead of 3in.

Duncan Murdoch