Re: [Gnuplot-py-users] Gnuplot Problem

[Leonardo M. <lm...@ud...>]

Hi Dee:

> I was thinking about using gnuplot-py to try to take of a problem I am having with gnuplot itself.  I have a gnuplot script that runs  in a endless 6 second loop (on purpose) that reads a data file that is updated with new data every 4 seconds.  Eventually though, it will abort with the following message:
> 
> 
> gnuplot> plot 'gnuplot.txt' index 0 using 1:2 with points 09,       
>               'gnuplot.txt' index 1 using 1:2 with points 04,
>               'gnuplot.txt' index 2 using 1:2 with points 03,
>               'deviation_upper.txt' thru (( $1 * $2)/(-10.*55.1))**2        with  lines 12,       
>               'deviation_lower.txt' thru ((($1 * $2)/(-10. *55.1))**2)* -1 with  lines 12 ,       
>                U_CPS2 with lines 11 , L_CPS2 with lines 11
>                                                             ^
>          "/emsdat/santee/scripts/gplot/cps.pl", line 25395: no data point found in specified file
> 
> Attached is the script and I would appreciate any suggestions on how to make it work before I dive into Python.  If anyone thinks gnuplot-py can fix the problem I would be most thankful for some help in getting started.

maybe gnuplot, everyonce in a while, trys to read  a data file while it
is being updated ? If the period of data update and data reading from
gnuplot are 6 and 4 seqs, chances are they'll meet at 12, 24, 36 sec. (assuming
they start at the same time)

The advantage I would see on using gnuplot-py is that. within a python
script, you can check for existance/sanity of the data files before
feeding the gnuplot. So, you could, within the loop:

start endless loop:
  * import data files data into python arrays if files exist	
  * check that the data is actually there, check types, value ranges, etc.
  * plot
  * wait some time
  
Hope this helps,
Leo