vignettes: problems with PDF compaction

But this doesn't do anything, not even changing the timestamp on the
file, because the file size doesn't change enough.

Either you changed it or not, there is no "not enough".

I meant that the code in tools::compact compares the sizes of the old
and new files and only replaces the old file if the change in size is 
"sufficient":

  if (new/old < 0.9 && new < old - 10000) {
                 file.copy(tf, p, overwrite = TRUE)
             }

At any rate, with R_GSCMD now fixed (Thx: Henrik), tools::compactPDF,
with gs_quality="ebook",
still does not reduce the size of my HE-examples.pdf file.

I tried the same on my Ubuntu system (R 2.15.2 also), and there I get

 > tools::compactPDF("HE-examples.pdf", gs_quality="ebook")
   compacted 'HE-examples.pdf' from 739Kb to 366Kb

So, I can now copy the compacted file back to my development tree
on Windows; however, as I understand things, vignettes are re-built
by R CMD build and --compact-vignettes=gs+qpdf has no effect.
So my Ubuntu-compacted file will be overwritten.

It's somewhat maddening to have to spend so much time to save ~373Kb
in order to avoid a CRAN warning.

Michael Friendly     Email: friendly AT yorku DOT ca
Professor, Psychology Dept. & Chair, Quantitative Methods
York University      Voice: 416 736-2100 x66249 Fax: 416 736-5814
4700 Keele Street    Web:   http://www.datavis.ca
Toronto, ONT  M3J 1P3 CANADA