Re: Real-time plots under X11/Exceed

[Ethan M. <merritt@u.washington.edu>]

On Thursday 28 October 2004 08:46 am, pa...@mi... wrote:
> 
> In effect I see that gnuplot_x11 takes al large amount of CPU resurces 
> (no matter if the gnuplot is iconified or not).

Please explain your configuration in more detail.
Is gnuplot_x11 running on the same PC?  Or is it running on another
machine and displaying on a separate X-server (the PC + Exceed)?

Also, please tell us exactly what version of gnuplot you are running.
If you built from the CVS source, please look in the ChangeLog to
see what was the most recent date of bug-fixes.

> Worst, when X11 is displayed on a PC through an emulator Exceed, Exceed
> runs out of memory (or so it says) no matter how it is configured.

There have been at least 2 memory leaks fixed in gnuplot_x11
since the release of version 4.0  (one that also affected 4.0, one
that did not). Neither was terribly serious for a typical X11 configuration
on a single unix/linux machine, but I could imagine that the effect on a
more complicated setup would be larger.  So it is at least possible
that switching to very recent CVS versions of gnuplot_x11 would fix
one of your problems.

> Questions are
>   1) What is the best way to use gnuplot for real-time visualization
>   (are there any buffering options reducing resouces needed for redraw)

If "real-time" means event-driven - there is no good way that I know of.
If "real-time" means repeated refresh - it's pretty easy:

	load 'setup.gnu'	    # prepare the plot description
	load 'loop.gnu'      # loop forever

where loop.gnu contains
	replot
	pause 1		# wait 1 second before looping
	reread

On my machine this 1 second loop and repeat consumes less than
0.5% of the CPU even for a reasonably complicated 3D surface.

>   2) How to iconify gnuplot windows (other through -noraise option)
>    so when window is inconified gnuplot does not eat X11 resources.

That is an interesting question. You will definitely need the -noraise
option (or "set term x11 noraise"). But also the gnuplot_x11 program
itself should check to see if it is currently iconfied, and skip at least 
some of its processing if so. I will have a look at what is possible.
I'm not sure there is much to be gained, however.  If things are working
properly it shouldn't be consuming substantial resources in any case.


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195