Re: extending pstricks terminal driver

[Ethan M. <merritt@u.washington.edu>]

On Thursday 18 December 2008 11:52:35 Mojca Miklavec wrote:

> > Ugh. That's a problem.  Are you saying that if you have older and
> > newer plots in the same directory, they will conflict with each other?
> 
> The style file should change in some incompatible ways in the near
> future if TikZ terminal would be modified to support ConTeXt. But this
> would change only once.
> 
> I have no idea what plans Peter (the author) has with the terminal,
> but my estimate would be that lifetime of compatible changes should be
> around one or two years for example. Note that gnuplot syntax changes
> as well, so one needs to adapt the scripts as well.

I have plots on my disk going back many years, used for various
publications and presentations.  If it is a *.png or *.ps file, then
it doesn't matter how old it is or how many versions of gnuplot have
come and gone since it was originally created.  But if I save a 
*.tex file, then I will need to run some TeX variant perhaps years
later in order to use it.  It is not acceptable that the associated
style file no longer works.  Note that new and old plot files may
exist in the same directory, so creating a new style file that 
over-writes the old one is a very bad thing.

> If one has a few ancient and a few newer plots in the same folder -
> yes, it might be a problem, but one doesn't update gnuplot on a daily
> basis and usually a new project goes into a new folder.

You obviously arrange your work environment in a very different fashion
than I do.  Plots associated with a multi-year project would indeed 
typically be kept together in a single place.  And I shudder at the 
thought that the results of processing a plot would depend on which
directory I am currently sitting in.

Updating gnuplot is not the issue.  I cannot always re-run gnuplot
itself easily, because the datasets I would run it on are often large
and not typically kept together with the plots and text from the analysis.
The plot itself must continue to be usable, not so much the
original gnuplot script.

> If files of all ages really need to coexist in the same folder, one
> can just as well regenerate the old plots.

Only if the raw data your are plotting are also kept in parallel.
That is not practical for many kinds of data, for reasons ranging
from file size to privacy issues to read-once data sources to
shared external data repositories.

> In short: in my opinion it's much better to create the style in every
> folder. 

I am strictly opposed to that.  If absolutely necessary, we can
(maybe?) include the style as a preamble to each document.  But 
potentially over-writing a *.sty file needed by a different plot
is very bad design.

> Not only because the style file *might* change (usually it 
> should not), but also because one can transfer the files and they will
> still work on any computer without having gnuplot & that particular
> style file installed.

???  You certainly would not have to have gnuplot itself installed
on that other computer.  And as to requiring a compatible style file,
that's always the case for latex documents.

> You can try
>    set term lua createstyle size 10cm,7cm
>    set output 'sin.tex'
>    plot sin(x)
> and it will generate two files: the actual plot and the style file. My
> idea was to "createstyle" by default.

As I tried to explain above, I think the existence of the "createstyle"
option is a design flaw.  Either the style file never changes, in which
case there is no need to keep regenerating it dynamically, or it *does*
change, in which case this option will potentially overwrite a previous
copy of the file that is necessary in its own right.

If we are to keep the "createstyle" option at all, then it needs to 
create a file that has a version number distinguishing it from all
incompatible previous versions.

I should note that this problem is not just hypothetical.
I currently struggle with this issue, in particular for BibTeX style
files.  There is, for example, a style file nar.bst in the standard
TeX repositories originally created to aid submissions to the journal
Nucleic Acids Research.  But the journal itself has changed its
requirements over the years, and so I have multiple copies of
"nar.bst" corresponding to different years of journal submission.
This would have been considerably easier to deal with if the convention
had been to name these files "nar2003.bst", "nar2005.bst", etc. 



-- 
Ethan A Merritt