[R] pdf with an exact size

[Joerg van den Hoff]

On Fri, Feb 23, 2007 at 04:24:54PM -0200, Alberto Monteiro wrote:
> Is it possible to create a pdf output file with an (as nearly as
> possible) exact size?
> 
> For example, if I want to draw in an A4 paper (210 x 297 mm) a
> square of 100 x 100 mm, how can I do it?
> 
> FWIW, about 6 months ago I learned here how to create an exact
> png image. For example, if I want a 500 x 500 black square in 
> a 1000 x 1000 white png, occupying the center of the png, the 
> procedure is this:
> 
>   png("image.png", width=1000, height=1000, bg="white")
>   par(mar=c(0,0,0,0)) # reset margins
>   plot(0, xlim=c(0, 999), ylim=c(0, 999), col="white")
>   par(usr=c(0, 999, 0, 999))
>   points(c(250, 250, 749, 749, 250), c(250, 749, 749, 250, 250), 
>     type="l", col="black")
>   dev.off()
> 
> However, I don't know how do this with a pdf monstr... oops... file.
> 
> Alberto Monteiro
> 

going via `bitmap' and using the `pdfwrite' type is probably the better
idea since in this case `ghostscript` is used for pdf generation which seems
over all to generate cleaner/better pdf-output in comparsion
to the R internal pdf-device (I believe there was recently some
discussion of this on the list?).

joerg