[Plplot-devel] plplot image plotting performance with perl/PDL

[Doug H. <dh...@uc...>]

Hi plplot folks:  There has been a conversation on the PDL list recently 
about which plotting package to use by default for PDL.  I've been 
advocating for use of PLplot, but have limited time to spend on interface 
development.

One of the major perceived limitations of PLplot is image plotting speed. 
Apparently PLplot uses an expensive algorithm to contour data.

A nice performance plot showing the problem is attached.

Does any of you know about this?  Is there a way to speed up image 
plotting?

Thanks much,

   Doug Hunt

dh...@uc...
Software Engineer
UCAR - COSMIC, Tel. (303) 497-2611

---------- Forwarded message ----------
Date: Tue, 5 Mar 2013 10:43:10 -0700
From: Craig DeForest <def...@bo...>
To: dh...@uc...
Cc: Craig DeForest <def...@bo...>,
     Karl Glazebrook <kar...@ma...>,
     perldl list <pe...@ja...>
Subject: Re: [Perldl] A common, working plotting package?

Funny you should mention that -- there's a Mac Port of PLplot now, and it 
installed flawlessly when I tried it last night -- which is a huge change 
from my earlier experience.  It is indeed a very nice plotting package - 
the high level plots, in particular, are very nice looking.

Derek has had difficulty using it for image plotting, largely because it 
uses a very expensive algorithm that is best adapted to low resolution 
data (and does a fabulous job in that case) but does not scale well to 
high resolution images.  The difficulty is best summed up in the 
performance plot (apropos to the performance discussion last night).  I 
don't know if there's a better way than the existing high-level contour 
plot method.  As far as point-plotting speed, it's about the same as 
gnuplot.  The plot times are on a 2011 MacBook Pro with stock Ports 
install.




On Mar 5, 2013, at 10:03 AM, Doug Hunt <dh...@uc...> wrote:

> Hi Karl:  I still maintain that PLplot is a good, modern plotting package that runs on all required platforms.  It is well maintained and has a nice build system.  It also has interactive capabilities which I don't know much about.
>
> I have not supported Windows and Mac with PDL::Graphics::PLplot because I don't have the time and access to required machines.
>
> I think others who have time/machines could do this without much effort.
>
> I think PLplot could be brought up to speed with minor enhancements to PDL::Graphics::PLplot, which I don't necessarily have time to do.
>
> Regards,
>
>  Doug
>
> dh...@uc...
> Software Engineer
> UCAR - COSMIC, Tel. (303) 497-2611
>
> On Tue, 5 Mar 2013, Karl Glazebrook wrote:
>
>> If GNUplot can plot a million points or a 4096^2 image with a delay < 1s and no memory disaster then that would be fast enough for me.
>>
>> I wish there was a better solution
>>
>> Karl
>>
>>
>>
>> On 04/03/2013, at 2:04 AM, Henning Glawe wrote:
>>
>>> On Sun, Mar 03, 2013 at 10:04:45PM +1100, Karl Glazebrook wrote:
>>>> I don't know how 'modern' PLplot is. The documentation still talks about Tektronix terminals!
>>>>
>>>> I did some googling, DISLIN seemed the closest but is only semi-frree.
>>>>
>>>> In astronomy people really only use pgplot at the c/f77 level. (At a higher level they use language specific graphics, e.g. IDL, IRAF, Python, sm (!), gnuplot, MMA).
>>>>
>>>> What about other scientific fields? What do people you know use?
>>>
>>> In my field (computational quantum physics/chemistry), computation and
>>> visualization are usually treated separately. Typically, the actual
>>> numerical simulations are very heavy (taking CPU-days or even CPU-weeks on
>>> current HPC-Clusters).
>>> The visualization is performed in a separate step, where different "classes"
>>> of tools are employed:
>>> * Special purpuse tools for molecule/crystal visualization, which show:
>>> - crystal structures
>>> - densities either on cutting planes or as equipotential surfaces
>>> Tools belonging to this class are:
>>> - xcrysden http://www.xcrysden.org/
>>> - v-sim    http://www-drfmc.cea.fr/L_Sim/V_Sim/index.en.html
>>> * General-purpose plotting tools with a focus on 2D-visualization:
>>> - gnuplot  http://gnuplot.sourceforge.net/
>>> - grace    http://plasma-gate.weizmann.ac.il/Grace/
>>> * General-purpose plotting tools with more focus on 3D-visualization:
>>> - OpenDX   http://en.wikipedia.org/wiki/IBM_OpenDX
>>>   (Official website seems to be down)
>>>   Learning curve is quite steep, interface is a bit awkward to use (for
>>>   modern standards)
>>> - paraview http://www.paraview.org/
>>>   Easier to use than OpenDX; very powerful visualization tool, integrated
>>>   python scripting support for
>>>   - sources (data generation)
>>>   - filters (data processing)
>>>   - general-purpose macros
>>>
>>>> Looks dismal. Perhaps the moral is people who put significant effort in to visuals tend to go commercial?
>>>
>>> I don't think so. You can get quite good results out of free
>>> visualization tools, altough sometimes you may have to tweak the settings a
>>> bit. One very good example for this is gnuplot; the default settings have not
>>> changed much in the past 20 years (think backwards compatibility), but with
>>> some modifications in your gnuplot scripts, plots may look a lot more
>>> attractive. This is one of the websites showing how to do this:
>>> http://www.gnuplotting.org
>>>
>>> For paraview, there are some good examples in the image gallery:
>>> http://www.paraview.org/paraview/project/imagegallery.php
>>>
>>>
>>> Maybe we have to go back to the question what _kind_ of visualization support
>>> we need to have available directly within PDL.
>>>
>>> In my opinion, a very simple plotting interface used mainly for
>>> debugging/development is enough.
>>> For anything beyond this, there are really good plotting tools available also
>>> as free software, we just need to be able to export data in a format readable
>>> by them.
>>>
>>> --
>>> c u
>>> henning
>>
>>
>
> _______________________________________________
> Perldl mailing list
> Pe...@ja...
> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
>