[R] change default output size when using Sweave

[Duncan Murdoch]

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