Okay, it might be the early morning hour---when I read it a second time it made sense.
-roger Prof Brian Ripley wrote: > No, it means what it actually says. > > If you include R's PDF in another application, the latter will usually > compress *if you asked the application for compressed PDF*. > > On Thu, 2 Mar 2006, Hin-Tak Leung wrote: > >> Roger D. Peng wrote: >>> The following paragraph from ?pdf struck me as a bit odd: >>> >>> 'pdf' writes uncompressed PDF. It is primarily intended for >>> producing PDF graphics for inclusion in other documents, and >>> PDF-includers such as 'pdftex' are usually able to handle >>> compression. >>> >>> Should that be "...and PDF-includers such as 'pdftex' are usually >>> _un_able to >>> handle compression" ? >> >> Hmm, I think the documentation is correct but incomplete - pdftex *can* >> handle compression, but compression is not implemented in R's pdf >> output device. So it should say: >> >> "... PDF-includers such as 'pdftex' are usually able to handle >> compression, but R's pdf device does not utilise that feature of pdf." >> >> (I have checked a pdf generated by R, and it doesn't compress, and I was >> using pdflatex this morning to include a compressed pdf, so both >> parts are correct). >> >> There is a caveat: the PDF specs (and the postscript language standard) >> actually defines a few stream compression schemes - LZW and deflate >> are two I know of from the top of my head, I think there are more. >> But LZW used to be tangled up with the Unisys patent until recently >> when the patent expired, so most open-source softwares won't do >> it. deflate is implemented in zlib and ghostscript-written pdf >> usually have stream compression on. i.e. For some purposes such >> as getting smaller pdf's, it may be better to output from R >> postscript and use ghostscript to do ps2pdf rather than doing >> it directly from R, and to be pedantic, pdftex can only handle >> deflate encoded compression, AFAIK, for the reason I outlined above, >> but it is sufficient for most purposes, since most tools cannot >> generate LZW-compressed pdf's. >> >> HTL >> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> > -- Roger D. Peng | http://www.biostat.jhsph.edu/~rpeng/ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
