[R-pkg-devel] [External] compact vignettes

[Mikael Jagan]

> Date: Thu, 24 Jul 2025 02:00:32 +0300
> From: Ivan Krylov<ikrylov using disroot.org>
> 
> В Wed, 23 Jul 2025 20:09:26 +0000
> "Richard M. Heiberger"<rmh using temple.edu> пишет:
> 
>> When I use
>> R_QPDF=/Library/Frameworks/R.framework/Resources/bin/qpdf
>> R_GSCMD=/usr/local/bin/Cellar/ghostscript/10.03.0/bin/gs
>> GS_QUALITY=ebook
>> echo $R_QPDF $R_GSCMD $GS_QUALITY
>> R CMD build --compact-vignettes=both microplot
>>
>> I get 558950 bytes
>>
>> The bytecount for the package went up.
> Unfortunately, this seems to be very dependent on versions of software
> in use, including LaTeX and Ghostscript (and fonts?). I can compress
> your pre-built 372Kb vignette to 96Kb (as does the CRAN machine), but
> when I rebuild the package, I can only get down from 276Kb to 156Kb:
> 
> R -q -s -e '
>   untar("microplot_1.0-47.tar.gz.orig");
>   tools::compactPDF(
>    "microplot/inst/doc",
>    gs_cmd = "gs", gs_quality = "ebook",
>    verbose = TRUE
>   )
> '
> qs_quality="ebook" : use_gs=TRUE, use_qpdf=TRUE
> #{pdf}s = length(paths) = 1
> - microplot/inst/doc/rmhPoster.pdf:    gs: res=0;  + qpdf: res=0;
>      ==> (new=98115)/(old=380862) = 0.257613 =====> using it !!
>    compacted ‘rmhPoster.pdf’ from 372Kb to 96Kb
> 
> 
> LANGUAGE=en R_GSCMD=gs GS_QUALITY=ebook R CMD build \
>   --compact-vignettes=both microplot
> <...>
> * creating vignettes ... OK
> <...>
> * compacting vignettes and other PDF files
>      compacted ‘rmhPoster.pdf’ from 276Kb to 156Kb
> 
> And 'gs --version' says '10.00.0', which shouldn't be that different
> from your '10.03.0'!
> 

I build ghostscript from sources under macOS and upgrade the version
periodically.  I encountered the same issue last year and stayed at
10.02 until they released 10.04, because there was a clear regression
in 10.03.  I was never able to track down a relevant bug report, but
I never looked very hard ...

Mikael

> -- Best regards, Ivan