Re: speeding up Babel Gnuplot

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

Hello,

Thierry Banel <tbanelwebmin@free.fr> writes:

> Babel Gnuplot is quite slow on large tables.
> Example: 45 seconds for a 1500 rows table.
>
> Why? Because orgtbl-to-generic is too slow (or too generic). Its
> behavior seems to be quadratic O(size^2). Should we bypass it?

I don't think so.

> Should we try to optimize it?

I did some optimizations in master branch. I go below 1 sec for the 1500
rows table.

> Here is a fix to speed up the rendering to a mere fraction of a second.
>
> #+BEGIN_SRC elisp
> (defun org-babel-gnuplot-table-to-data (table data-file params)
>   "Export TABLE to DATA-FILE in a format readable by gnuplot."
>   (let ((org-babel-gnuplot-timestamp-fmt
>      (or (plist-get params :timefmt) "%Y-%m-%d-%H:%M:%S")))
>     (with-temp-file data-file
>       (mapc (lambda (line)
>           (mapc (lambda (cell)
>               (insert (org-babel-gnuplot-quote-tsv-field cell))
>               (insert "\t"))
>             line)
>           (insert "\n"))
>         table)))
>   data-file)
> #+END_SRC

The comparison is not fair, because the function doesn't handle all the
cases `orgtbl-to-generic' handles.

Regards,

-- 
Nicolas Goaziou