R help - Mar 2008 - ps or pdf

Hi everyone,

I have been making a fair amount of figures in R recently that I've
been touching up with Illustrator and I've found a difference between
pdf and ps files and I was wondering if someone could enlighten me
about them.

While the figures look the same, the ps version tends to have
truncated strings. The last character of short strings tends to be on
a string of its own, located right beside the rest. This makes it a bit 
awkward to manipulate, especially if scaling is involved. Is there a 
reason for this differences?

There also seems to be somewhat arbitrary grouping of the last column 
cells in heatmaps in ps files.

I used to prefer the ps because they embed more easily in latex
documents (although pdf are not difficult and conversions are trivial
anyhow), but I'm curious if there are other reasons why one format might
be preferred over the other in this context.

This is with R 2.6 on linux, and I've seen this behavior with older R
version also.

Francois

sessionInfo()
R version 2.6.0 (2007-10-03)
x86_64-unknown-linux-gnu

locale:
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=en_US.UTF-8;LC_MONETARY=en_US.UTF-8;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] rcompgen_0.1-15

On Mon, 31 Mar 2008, Francois Pepin wrote:
> Hi everyone,
>
> I have been making a fair amount of figures in R recently that I've
> been touching up with Illustrator and I've found a difference between
> pdf and ps files and I was wondering if someone could enlighten me
> about them.
>
> While the figures look the same, the ps version tends to have
> truncated strings. The last character of short strings tends to be on
> a string of its own, located right beside the rest. This makes it a bit
> awkward to manipulate, especially if scaling is involved. Is there a
> reason for this differences?
Please see the footer of this message.  Neither postscript() nor pdf() 
graphics devices split up strings they are passed (by e.g. text()), so 
this is being done either by the code used to create the plot (and we have 
no idea what that is) or by the viewer.  I suspect the problem is rather 
in the viewer, but without the example we asked for it is impossible to 
know.
> There also seems to be somewhat arbitrary grouping of the last column
> cells in heatmaps in ps files.
Again, we need an example.
> I used to prefer the ps because they embed more easily in latex
> documents (although pdf are not difficult and conversions are trivial
> anyhow), but I'm curious if there are other reasons why one format
might
> be preferred over the other in this context.
The graphics devices are very similar (they share a lot of code).  One 
small difference is that PostScript has an arc primitive, and PDF does 
not.
> This is with R 2.6 on linux, and I've seen this behavior with older R
> version also.
Nothing has changed at that level for a long time -- not even in 
current versions of R (and 2.6.0 is obsolete).
>
> Francois
>
> sessionInfo()
> R version 2.6.0 (2007-10-03)
> x86_64-unknown-linux-gnu
>
> locale:
>
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=en_US.UTF-8;LC_MONETARY=en_US.UTF-8;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> loaded via a namespace (and not attached):
> [1] rcompgen_0.1-15
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

>  The graphics devices are very similar (they share a lot of code).  One
>  small difference is that PostScript has an arc primitive, and PDF does
>  not.
>
Sorry for interjecting, but I have a burning question. It is a bit off
topic, so I apologize in advance.

What is the stance of the R Developers regarding this missing R
primitive in PDF? Because of the missing primitive all circles are
represented as "O" characters. I have run into problems when trying to
import R produced PDF plots into Inkscape for some additional post
processing and beautification. As a workaround I currently use the
Cairo device to export to PDF (and SVG). But this is a bit heavy. It
would be nice to be able to save Inkscape editable PDFs directly from
the plot window.

Some other far more important issues that could occur have been raised
in a past thread:
http://www.nabble.com/pdf%28%29-device-uses-fonts-to-represent-points---data-alteration--td13034770.html
For example the unintentional misrepresentation of data on the plot if
font substitution occurs and the points are shifted from their
original location.

Is this considered a bug or a feature?

Regards,
TL