[bug] serious problem retrieving data from table for gnuplot

[bug] serious problem retrieving data from table for gnuplot

[Eric S Fraga]

Hello all,

as I recently updated org, I seem to have run into a bug with ob-gnuplot
(or ob more generally) where data from a table are not interpreted
correctly.  Specifically, if the first column entry in a row is a
negative number, the data file created for use by gnuplot consists of
only - signs, not the actual numbers.

This table, for instance,

#+begin_src org
,#+name: data
|  x |  y |
|----+----|
| -4 | 16 |
| -3 |  9 |
| -2 |  4 |
| -1 |  1 |
|  0 |  0 |
|  1 |  1 |
|  2 |  4 |
|  3 |  9 |
|  4 | 16 |
,#+TBLFM: $2=$1^2
#+end_src

when converted into a file for use by gnuplot for the following script

#+begin_src org
,#+begin_src gnuplot :var d=data :file t.png :results file
  plot d
,#+end_src
#+end_src

looks like this:

,----
| --------------
| --------------
| --------------
| --------------
|  0	 0  
|  1	 1  
|  2	 4  
|  3	 9  
|  4	 16 
`----

I've not yet had a chance to track down why this might be.

Thank you,
eric

-- 
: Eric S Fraga, with org release_9.5.2-298-g1f48d2 in Emacs 29.0.50

Re: [bug] serious problem retrieving data from table for gnuplot

[Eric S Fraga]

By the way, adding an empty column to front of the table fixes the
problem so at least I am not panicking (I have a presentation to give
with the data in a table etc.).  There must be a problem with a regex
looking for dividing lines maybe?

-- 
: Eric S Fraga, with org release_9.5.2-304-g1537bb in Emacs 29.0.50

Re: [bug] serious problem retrieving data from table for gnuplot

[Ihor Radchenko]

Eric S Fraga <e.fraga@ucl.ac.uk> writes:

> Hello all,
>
> as I recently updated org, I seem to have run into a bug with ob-gnuplot
> (or ob more generally) where data from a table are not interpreted
> correctly.  Specifically, if the first column entry in a row is a
> negative number, the data file created for use by gnuplot consists of
> only - signs, not the actual numbers.
> ...
> looks like this:
>
> ,----
> | --------------
> | --------------
> | --------------
> | --------------
> |  0	 0  
> |  1	 1  
> |  2	 4  
> |  3	 9  
> |  4	 16 
> `----

Ouch. Sorry for this. This was introduced by fixing another bug.
Should be fixed on main now.

Best,
Ihor

Re: [bug] serious problem retrieving data from table for gnuplot

[Ihor Radchenko]

Eric S Fraga <e.fraga@ucl.ac.uk> writes:

> By the way, adding an empty column to front of the table fixes the
> problem so at least I am not panicking (I have a presentation to give
> with the data in a table etc.).  There must be a problem with a regex
> looking for dividing lines maybe?

Sorry for causing this issue. The problem was very obscure. It was
related to table conversion during export. When using ox-ascii to export
Org table to Gnuplot-readable text file, ox-ascii sometimes threw an
error because of wrong calculation of cell width. So, I tried to use
ox-org instead. Apparently, ox-org cannot be used in that context (no
idea what went wrong though).

Now, I just put a quick (and incomplete) fix to ox-ascii and reverted
back to the old export approach.

Best,
Ihor

Re: [bug] serious problem retrieving data from table for gnuplot

[Eric S Fraga]

On Friday, 14 Jan 2022 at 22:01, Ihor Radchenko wrote:
> Ouch. Sorry for this. This was introduced by fixing another bug.
> Should be fixed on main now.

Thank you for such a quick response and no worries!  Yes, it seems to
work now.

-- 
: Eric S Fraga, with org release_9.5.2-306-g9623da in Emacs 29.0.50