Growing x11 plot window (was: Flickering movies)

[Ben Abbott]

On Jun 25, 2009, at 4:05 PM, Ben Abbott wrote:

> On Thursday, June 25, 2009, at 10:45AM, "Marco Caliari" <marco.caliari at univr.it 
> > wrote:
>> Dear maintainers,
>>
>> I'm not sure I will describe a bug or just a different behavior, so  
>> I'm
>> writing to the maintainers' list.
>> The execution of the following code in Octave 3.0.5
>>
>> x = linspace(-1,1);
>> for i = 1:50
>>  plot(x,i*x.^2)
>>  axis([-1,1,0,50])
>>  pause(0.1)
>> end
>>
>> produces a nice and fluent "movie". In particular, the axis box seems
>> fixed (it is fixed to my eyes), and only the curve inside moves. With
>> 3.2.0, I get a very flickering movie, with the axis box clearly  
>> redrawn
>> at each step. What is strange, moreover, is that if I change
>>
>> pause(0.1)
>>
>> with
>>
>> pause(0.01)
>>
>> the axis box changes its dimensions during the loop and so the  
>> illusion of
>> a movie disappears. I'm using gnuplot 4.2.5.
>
> Marco, I see the same effect.
>
> This "feature" has been present since Gnuplot allowed the x11 window  
> position and size to be set. Gnuplot allows the x11 window position  
> and size to be set for gnuplot 4.2.5 and later.
>
> Unfortunately, I've been unable to demonstrate this behavior using  
> gnuplot scripts (i.e. no Octave). Thus, I'm inclined to conclude the  
> problem is with the plot stream octave send's to gnuplot, but have  
> been unable to debug (isolate) the problem.
>
> Ben

Marco / others

I've taken a fresh look at this and have found a simple gnuplot script  
that demonstrates (for me) the problem of the figure window changing  
its dimension (nearly always resulting in vertical growth). I've  
attached a copy of the script.

The script is very simple

set terminal x11
set multiplot; plot sin(x); unset multiplot;
set multiplot; plot sin(x); unset multiplot;
set multiplot; plot sin(x); unset multiplot;
set multiplot; plot sin(x); unset multiplot;
set multiplot; plot sin(x); unset multiplot;
set multiplot; plot sin(x); unset multiplot;
...

My experience is that the x11 figure window's growth (or change in  
dimension) is related to timing. A sufficiently fast computer may not  
produce the problem.

In any event, if anyone is running gnuplot 4.2.5 or above, I'd  
appreciate it if they'd run this script and report back what happens.  
Just type ...

	gnuplot --persist "debug.gp"

... or run gnuplot and type

	load "debug.gp"

Thanks,
Ben

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