[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: graphics issues

From: Quentin Spencer
Subject: Re: graphics issues
Date: Mon, 02 Oct 2006 21:51:57 -0500
User-agent: Thunderbird (Windows/20060909)

Joe Koski wrote:
on 9/29/06 11:38 AM, John W. Eaton at address@hidden wrote:

On 29-Sep-2006, Shai Ayal wrote:

| While OpenGL will take care of all the 3D stuff, you still have all
| the "graph" things to take care of -- axes, tics, legends, titles
| etc... All are "trivial" but with many small annoying details (auto
| axes limits and ticks is quite hard IMHO). this is quite a lot of
| work. octplot is under development for more than 2 years (although
| it's not very intensive development) and these things are still far
| from prefect

I agree that these little details, while each may seem like a simple
problem, add up to a major headache, especially given that the code
already exists in other places (gnuplot, plplot, NCAR graphics, etc.).

My preference would be to use some existing code if at all possible,
but I don't know where to find something that is relatively easy to
use and not closely tied to a specific plotting package.


A couple of points. I have the post-processor called smokeview for the NIST
FDS code (see http://fire.nist.gov/fds/ ). It is an OpenGL application and
runs on my Mac (without X11) with 3D displays that I can rotate, change the
viewpoint, etc. without the delays or "inertia" that feel when I'm using
other applications. Whether a graphics language can run natively on many
platforms, including Windows and Macs, should be a major consideration.
Apparently OpenGL has that capability, but I'm no expert, so maybe someone
can comment on that.

Second, the plplot folks have been very active lately, enhancing the
package, so maybe plplot should be reevaluated, especially since there is
already an octave binding included in the plplot distribution. The plplot
folks are adding a wxwidgets driver. Is that tied to X11? The "widgets" in
the name sure sounds like X11 is involved. What is the potential impact of
wxwidgets on octave? I did play with octave/plplot a year or two ago, and
found myself going back to gnuplot. Back then, plplot's main use was for
salvaging the graphics on old legacy codes that had outlived their
commercial graphics interface (remember DISSPLA?). Maybe now it's different.

The soon to be released gnuplot 4.2 also has a wxWidgets terminal. I've tried it and it looks great (anti-aliased fonts and lines). I've been ready to give up hope for gnuplot, but this has convinced me to give it a second chance. wxwidgets is a cross-platform toolkit that supposedly runs natively on each supported platform, so presumably this means X11 is not required to run it on Mac or Windows. I tried plplot once or twice but I finally gave up on it because it found it unstable on Linux.

With the new gnuplot release, it should not be too difficult to add better control over line width, color, etc. It still seems like the shortest path to a working backend to the object-graphics frontend. On the other hand, the real weakness is that gnuplot is a standalone program, rather than a library. The main problem I see with this is that data is transfered via file I/O, rather than simply using on data that is already in memory. The new version helps a little bit because binary data transfer is now supported, but it's still suboptimal for large amounts of data. The other big benefit of the new gnuplot is support for images, so that the image display routines can be displayed as plots with the axes and titles and all.

Anyway, I don't mind dumping gnuplot when something that can replace it supports all of the necessary features, but I agree with John that for now updating the gnuplot interface seems the quickest way to get what people want. I'm happy to be proven wrong by the OpenGL supporters.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]