[Rd] vignettes: problems with PDF compaction

[Uwe Ligges]

On 21.04.2013 19:28, Michael Friendly wrote:
> [Env: OS: Win Xp; R 2.15.2; IDE: eclipse/StatET]
>
> Each time I update my heplots package, I get warnings from R CMD check
> on R-Forge,
>
> * checking sizes of PDF files under ‘inst/doc’ ... WARNING
>    ‘gs+qpdf’ made some significant size reductions:
>       compacted ‘HE-examples.pdf’ from 739Kb to 366Kb
>
> and upon submission to CRAN, a message from maintainers:
>
> On CRAN now: but again there were warnings about significant size
> reductions in PDF compaction, which should really be fixed on your end.
>
> however, I am unable to find what to do to fix this on my end. In my
> package directory,
> I have the vignette sources all under vignettes/, with copies of the
> .pdf and .Rnw
> under inst/doc for historical reasons. [Q: can I now safely delete the
> copies under
> inst/doc ?]
>
> inst/doc/
> HE-examples.pdf
> HE-examples.Rnw
> vignettes/
> HE-examples.pdf
> HE-examples.Rnw
> HE-examples.bib
> fig/
> ...
>
> I have qpdf installed:
>  > Sys.which(Sys.getenv("R_QPDF", "qpdf"))
> qpdf
> "c:\\Rtools\\bin\\qpdf.exe"
>  >
>
> but, if I try to run it on the vignettes/HE-examples.pdf file, nothing
> happens:
>
>  >
> tools::compactPDF("C:/Documents/workspace/heplots/vignettes/HE-examples.pdf")
>
>  >
>
> Since vignettes are re-built from sources and then installed into
> inst/doc, I don't see why
> PDF compaction cannot be run as part of the build process. That is, if
> R CMD check --as-cran detects a problem, shouldn't there be some option for
> R CMD build that would run gs+qpdf to correct it?

Yes, see

R CMD build --help


that tells you

   --compact-vignettes=  try to compact PDF files under inst/doc:
                         "no" (default), "qpdf", "gs", "gs+qpdf", "both"


Best,
Uwe Ligges


>
> The idea of vignettes for R packages is a good thing, but, this problem
> (and others with vignettes) discourages me from using vignettes in
> packages, a bad thing.
>