Is there some way to append to a pdf after its device has been closed?

Hello all,

My question has to do with writing to pdf/ps files. Currently, my R program
requires 100+ pdf devices to be open, which is over the limit of 64 devices
that can be open at the same time, causing R to throw an exception. My
problem could be solved if I could append to a pdf file after its initial
device has been closed, but so far I haven't been able to figure out a way
to do that. If one calls pdf(file="myfile"), and "myfile" already exists, it
will be overwritten. Is there any way that I can make the pdf() function
append to the existing file instead? And if not, is there any way to call a
program like pdfmerge ( http://microtronyx.com/pdfmerge/ ) from inside R
code? I know I could simply write to a different pdf file every time I would
otherwise do an append and then merge those files once my R program has
completed, but in my case that would lead to the creation of literally
thousands of pdf files before I merged them all together, and I would like
to avoid that if possible.

Thank you for any help you can give,

Alex

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