plot issues

[Ethan Merritt]

> > Does Octave have a confguration file or configuration menu that the
> > user can find easily?  I suggest to make the production of pdf  
> > output a
> > user-configurable choice.
> > PDF output via (select one)
> >   -->  pdf (let gnuplot choose for you)
> >   -->  pdfcairo
> >   -->  tikz / pdflatex
> >   -->  PostScript / ps2pdf
> 
> 
> Such a configuration capability is not present in Octave's sources.
> 
> However, how do we let gnuplot choose for us (I like this approach) ?

That's what "set term pdf" does.  It chooses either the PDFLib or cairo
based pdf terminal depending one which is installed.  If both are installed
it currently defaults to using PDFLib, but it might make sense to change
that.

There is an unfortunate disconnect between the people who create/name
new terminal drivers and the people who use them.  The developer is
understandably focused on the mechanism being used to create the file.
The user only cares about the output.  We're still at the tail end of
a long back-and-forth about whether the new "driver that creates a pdf
file by using gnuplot to create a lua script, lua to create a tikz
script, and pdflatex to create a pdf file" should be called a 
lua terminal, a tikz terminal, or (new to the mix) a pdf terminal.
There are legitimate points to be made for all three choices:

- "lua" because hypothetically you could use the same terminal and same
output file with other lua scripts to create some other output.
- "tikz" because that is the TeX flavor being created by the existing
script (parallel to the naming of the metapost and pstricks terminals)
- "pdf" because at the end of the day that's probably what you will end
up with.

Context is important also, and it is hard for the program, either Octave
or gnuplot, to know the user's ultimate intent.  If you want a pdf plot
for inclusion in a LaTeX document, then lua/tikz/pdflatex is the way to
go.  But if you have no LaTeX installed, which is common, then this is
probably the worst choice. 

Ugh.

That's why I advocate for providing the user with a configuration option.
You still have to pick a default, but you do so knowing that it may be
the wrong default for many users.