multiple graphs pdf R

Question

I would like to print multiple graphs in one pdf file. I know there has been a lot on this, but I would like to print different window/graph sizes for each page, i.e. first page a 8.5x11, second page 11x8.5 and so on. I tried this:

pdf(file="Combined_Graphs.pdf",onefile=TRUE,bg="white",width=8.5,height=11)
hist(rnorm(100))
pdf(file="Combined_Graphs.pdf",onefile=TRUE,width=11, height=8.5, bg="white")
hist(rnorm(100,10,2),col="blue")
dev.off()

I must be using onefile=TRUE wrong as it only generates the last graphic before closing. Is there a better way to size the graphic device without having to call the pdf function twice?

Answer 1

What I would do is produce seperate PDF's and them combine them later. I use the PDF toolkit for this. Wrapping this in an R function using a system call through system even makes it scriptable from R. The call to pdftk will look something like:

pdftk *pdf cat output combined.pdf

or in R:

system("pdftk *pdf cat output combined.pdf")  

combine_pdfs = function(path, output_pdf) {
  system(sprintf("pdftk %s/*pdf cat output %s"), path, output_pdf)
}