[R] file size plot pdf

[Marc Jekel]

Dear R-Fans,

I have been lately working on some plots in R that I save as pdf via the 
pdf() command. I have realized that when I open those files in Adobe and 
then re-save it within Adobe ("save as..."), the size of the pdf files 
decreases rapidly (e.g., from 4mb to 1mb). This can also be observed for 
smaller pdf files (but not as drastically). Does anyone know if Adobe 
somehow compresses pdf files + if it is possible to already do this 
within R (the quality of the pdfs is the same as far as I can judge from 
perceptual inspection).

Thanks for a hint,

Marc