Re: Plotting date on xaxis

[Eric S Fraga <ucecesf@ucl.ac.uk>]

On Mon, 22 Feb 2010 19:31:41 +0100, Johan Ekh <ekh.johan@gmail.com> wrote:
> 
> [1.1  <text/plain; ISO-8859-1 (7bit)>]
> Hi all,
> I try to plot a table looking like this
> 
>      |       Date    |   Kg |
>      |-----------------+--------|
>      | 2010-02-21 | 95.0 |
>      | 2010-02-22 | 93.0 |
>      | 2010-02-23 | 92.0 |
>      | 2010-02-24 | 91.5 |
>      | 2010-02-25 | 91.0 |
>      | 2010-02-29 | 92.0 |
>      |                  |        |
> 
> with the dates on the xaxis using
> 
> #+PLOT: title:"Weight" ind:1 deps:(2) type:2d with:linespo set:"xdata time"
> timefmt:%Y-%m-%d set:"yrange [90:]"
> 
> but no plot is generated. If I remove <set:"xdata time">, the plot is
> generated but without interpreting the dates as dates.
> 
> Can anyone see what I do wrong?
> 
> Thanks in advance,
> 
> Johan
> [1.2  <text/html; ISO-8859-1 (quoted-printable)>]
> 

Johan,

I've played with this a bit and I also cannot get it to work.
However, looking at the gnuplot comint buffer created, there is an
error message that indicates that plotting xdata in time format
requires a using statement to specify directly the columns to plot.  I
have tried, therefore, the following specification on the plot line:

--8<---------------cut here---------------start------------->8---
#+PLOT: title:"Weight" ind:1 deps:(2) type:2d with:linespoints set:"xdata time" set:"timefmt '%Y-%m-%d'" set:"yrange [90:]" ind:1 deps:(2)
|       Date |   Kg |
|------------+------|
| 2010-02-21 | 95.0 |
| 2010-02-22 | 93.0 |
| 2010-02-23 | 92.0 |
| 2010-02-24 | 91.5 |
| 2010-02-25 | 91.0 |
| 2010-02-29 | 92.0 |
--8<---------------cut here---------------end--------------->8---

I had to put quotes around the time format and also (just in case)
spelled out linespoints fully.  However, this still doesn't work
because org-plot/gnuplot generates the following plot command:

,----
| plot '/tmp/org-plot1831zcQ' using 2:xticlabel(1) with linespoints title 'Kg'
`----

Note the strange using parameters!  I am not sure where this is coming
from unfortunately.  Note that if I type this in directly in gnuplot,
with "using 1:2", everything works just fine.

eric