[R-pkg-devel] .Rd, LaTeX and Unicode

Georgi Boshnakov georg|@bo@hn@kov @end|ng |rom m@nche@ter@@c@uk
Wed Jun 19 11:59:51 CEST 2019

Sorry, I failed to clarify that the link to ltnews.pdf was the point of my message. In some ways it is definitive from the LaTeX team.

My understanding is that option 'mathletters' is not the default in ucs, since it produces math Greek and Hebrew letters also in text mode.

Georgi Boshnakov

-----Original Message-----
From: Serguei Sokol [mailto:serguei.sokol using gmail.com]
Sent: 19 June 2019 09:51
To: Georgi Boshnakov; Martin Maechler; Hugh Parsonage
Cc: r-package-devel using r-project.org
Subject: Re: [R-pkg-devel] .Rd, LaTeX and Unicode

On 18/06/2019 17:10, Georgi Boshnakov wrote:
>
> Since April 2018 'utf8' is the default input encoding in LaTeX, see
> http://anorien.csc.warwick.ac.uk/mirrors/CTAN/macros/latex/doc/ltnews.pdf and they added some symbols in December.
Interesting ... but still not sufficient. I have a fairly recent latex
system:
$latex --version pdfTeX 3.14159265-2.6-1.40.19 (TeX Live 2018/Mageia) but unfortunately utf8 alone (and even including \usepackage[mathletters]{ucs}) cannot compile utf8 math expressions. I have also tried a full scale test on a tex file obtained with$ R CMD Rd2pdf --no-clean pkgname
where I replaced

\usepackage[utf8]{inputenc}

by

\usepackage[mathletters]{ucs}
\usepackage[utf8x]{inputenc}

and it did not compile either. In addition, I had to replace every
occurrence of

\inputencoding{utf8}

by

\inputencoding{utf8x}

after what pdflatex worked like a charm.

Serguei.

>
> -----Original Message-----
> From: R-package-devel [mailto:r-package-devel-bounces using r-project.org] On Behalf Of Martin Maechler
> Sent: 18 June 2019 15:01
> To: serguei.sokol using gmail.com; Hugh Parsonage
> Cc: r-package-devel using r-project.org
> Subject: Re: [R-pkg-devel] .Rd, LaTeX and Unicode
>
>>>>>> Hugh Parsonage
>>>>>>      on Tue, 18 Jun 2019 20:03:41 +1000 writes:
>
>      > utf8x is deprecated
>      > https://tex.stackexchange.com/questions/13067/utf8x-vs-utf8-inputenc#13070
>
> Hmm... interestingly, I've tried quite a few versions of the
> above which started in 2011, but had been updated in April 2016 :
>     https://tex.stackexchange.com/a/203804/7228
> from where it seems that
>
>       	\usepackage[T1]{fontenc}
> 	\usepackage[utf8]{inputenc}
>
> should be sufficient.  Further, note that from
>    https://tex.stackexchange.com/a/238135/7228
> the {ucs} package should no longer be needed since ca. 2013,
> hence your \usepackage[mathletters]{ucs}  would not be needed either.
>
> HOWEVER:  After losing at least half an hour now, trying many
> variants I found that the only version that works correctly for
> me (with a teTeX / TeXlive version of 2018) is the version
> Serguei Sokol proposes (below), including the use of the 'utf8x'
> option *and* the 'ucs' package ...
>
> which is pretty surprising after having read the
>
>      > On Tue, 18 Jun 2019 at 7:52 pm, Serguei Sokol <serguei.sokol using gmail.com>
>      > wrote:
>
>      >> Hi,
>      >>
>      >> I am preparing a package where I would like to use UTF characters in .Rd
>      >> files. When the LaTeX comes to play, I got well known errors e.g.:
>      >> ! Package inputenc Error: Unicode character ∂ (U+2202)
>      >> (inputenc)                not set up for use with LaTeX.
>      >>
>      >> It is coherent with what is said on this page
>      >> https://developer.r-project.org/Encodings_and_R.html :
>      >> "Since LaTeX cannot handle Unicode we would have to convert the encoding
>      >> of latex help files or use Lambda (and tell it they were in UTF-8)."
>
> That whole document has been very important and crucial, written
> by Prof Brian Ripley  who had worked a *LOT* to bring unicode to R,
> -- but it has been written 2004-2005  and indeed, I think it is
> probably fair to say that the above sentence no longer applies
> to current LaTeX engines (including "simple" pdflatex)... though really,
> I'm not the expert here, but I think it's a good point in time
> to reconsider how much UTF8 should be allowed/supported in *.Rd files.
>
> One problem: This is (slightly) the wrong mailing list; this would have
> been a perfect topic for 'R-devel' (discussing about new
> features etc for R) instead....
> ( but we'd rather keep it here for now.)
>
> Martin Maechler
> ETH Zurich and R Core Team
>
>
>
>      >> But LaTeX can support UTF8 as shown with this small example:
>
>   \documentclass{article}
>   \usepackage[mathletters]{ucs}
>   \usepackage[utf8x]{inputenc}
>
>   \begin{document}
>   The vorticity ω is defined as $ω = ∇ × u$.
>   \end{document}
>
>      >> I can compile it with my LaTeX without problem. May be you too?
>      >> So my suggestion would be to place these two lines somewhere in LaTeX
>      >> header generated by R doc system:
>      >> \usepackage[mathletters]{ucs}
>      >> \usepackage[utf8x]{inputenc}
>      >>
>      >> Note "utf8x" and not just "utf8" which is crucial for this example.
>      >> With a hope that it would fix unicode errors from LaTeX.
>      >>
>      >> Best,
>      >> Serguei.
>
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