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From: V. <var...@cl...> - 2005-01-16 14:02:41
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Hello,
This is a bit a crazy idea, but I was wondering if it would be possible to
have a povray terminal output for gnuplot, a bit like the latex terminal. I
don't know povray much so I don't know how suited it would be for displaying the
2D elements of a gnuplot output, but it is clearly very powerfull for 3D display.
Why not use povray directly ? First because povray takes longer to learn, but
more important, because quite a few programs already use gnuplot as an output
routine (for instance maxima), adding a povray terminal to gnuplot would
increase the scope of gnuplot, establishing it as a excellent output driver for
scientific programs.
I am aware this is a lot of work, but it would be so convienent.
Regards,
Gaël Varoquaux
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From: Hans-Bernhard B. <br...@ph...> - 2005-01-17 14:29:32
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Ga=C3=ABl Varoquaux wrote: > This is a bit a crazy idea, but I was wondering if it would be possib= le to > have a povray terminal output for gnuplot, a bit like the latex termina= l. I > don't know povray much so I don't know how suited it would be for displ= aying the > 2D elements of a gnuplot output, but it is clearly very powerfull for 3= D display. That issue of 2D vs. 3D is actually a major part of the problem.=20 gnuplot's terminal driver layer is entirely 2D by design. The only case = where 3D data actually survives into an splot's output is 'set term=20 table'. IIRC, filtering that into POVray as, say, a heightfield is=20 quite easy. It'll probably be even easier by way of a 'with image' or=20 pm3d output saved to graylevel image, which POVray already accepts as heightfield input. |
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From: Daniel J S. <dan...@ie...> - 2005-01-17 16:51:32
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Hans-Bernhard Broeker wrote: > Ga=C3=ABl Varoquaux wrote: > >> This is a bit a crazy idea, but I was wondering if it would be=20 >> possible to >> have a povray terminal output for gnuplot, a bit like the latex=20 >> terminal. I >> don't know povray much so I don't know how suited it would be for=20 >> displaying the >> 2D elements of a gnuplot output, but it is clearly very powerfull for=20 >> 3D display. > > > That issue of 2D vs. 3D is actually a major part of the problem.=20 > gnuplot's terminal driver layer is entirely 2D by design. The only=20 > case where 3D data actually survives into an splot's output is 'set=20 > term table'. IIRC, filtering that into POVray as, say, a heightfield=20 > is quite easy. It'll probably be even easier by way of a 'with image'=20 > or pm3d output saved to graylevel image, which POVray already accepts a= s > heightfield input. This probably comes back to the topic of Gnuplot saving so many, often=20 unused, variables per point. A lot of work, yes. Although, it might=20 not be too difficult to create a setup whereby the "width" of=20 multidimensional data is varied depending upon the plot. But again, I'd=20 wait until 2D/3D are made more similar before attempting anything like th= at. Dan |
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From: V. <gae...@en...> - 2005-01-18 18:39:28
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> >That issue of 2D vs. 3D is actually a major part of the problem.=20
> >gnuplot's terminal driver layer is entirely 2D by design. The only=20
> >case where 3D data actually survives into an splot's output is 'set=20
> >term table
> But again, I'd=20
> wait until 2D/3D are made more similar before attempting anything like =
that.
To sum up what I have understood the terminal driver does not
currently take care of the 3D rendering, it is just a 2D output filter.
Well, as you will probably at some point restructure Gnuplot way of
handling 2D/3D by probably creating a suited abstraction layer (every
2D/3D program inventuily runs into that problem), I think you could think
have a close look into a povray output.
I had a small look into povray and I must say it is quite convenient
for scientific plotting. I am amazed at the possibilities. Writing a
terminal driver may actual be more a work of building povray syntax
blocks that would correspond with gnuplot's rendering engine than writing
a conventional terminal driver.
Actually, while writing that I realised that this was probably the ste=
p
where to start to do a povray output in gnuplot (it technically would not
be a terminal driver, as far as I understand how Gnuplot terminal drivers
work) : it would have to do most of its work before gnuplot's rendering
engine.
Well I know nothing of Gnuplot's internals, so I think I am going to
stop my speculations now.
Ga=EBl
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From: Petr M. <mi...@ph...> - 2005-01-19 14:44:58
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> I had a small look into povray and I must say it is quite convenient
> for scientific plotting. I am amazed at the possibilities. Writing a
> terminal driver may actual be more a work of building povray syntax
> blocks that would correspond with gnuplot's rendering engine than writing
> a conventional terminal driver.
>
> Actually, while writing that I realised that this was probably the step
> where to start to do a povray output in gnuplot (it technically would not
> be a terminal driver, as far as I understand how Gnuplot terminal drivers
> work) : it would have to do most of its work before gnuplot's rendering
> engine.
Some question:
- How can povray draw vectors? (I know VRML does not have them.)
- And line thickness is what -- a diameter of a tube, or is it a
"billboard"-like thickness.
- And what about point symbols -- should they be billboard-like characters
or true 3D objects?
Could you draw an expected gnuplot output, e.g. for the "test" page or "plot
1/x", or "splot x*y", by hand, and present it?
---
PM
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From: Harald H. <h.h...@tu...> - 2005-01-19 17:16:12
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On Wed, 19 Jan 2005, Petr Mikulik wrote: > Some question: > - How can povray draw vectors? (I know VRML does not have them.) I think as combination of a cylinder and a cone. > Could you draw an expected gnuplot output, e.g. for the "test" page or "plot > 1/x", or "splot x*y", by hand, and present it? I have an old picture that uses some axes. It shows how coordinate axes could be realized: http://www.harald-harders.de/gnuplot/hindernisabstand1.png (280KB) http://www.harald-harders.de/gnuplot/hindernisabstand1a.jpg (68KB) I also have an example for a graph surface. It is available from http://www.harald-harders.de/gnuplot/funktion3.png (136KB) http://www.harald-harders.de/gnuplot/funktion3.pov (3716KB) http://www.harald-harders.de/gnuplot/funktion3.ini (4KB) May be, this is a little bit more than gnuplot will be able to do (using glass and mirrors). But it was the least work to use this old picture. :-) Harald -- Harald Harders h.h...@tu... http://www.harald-harders.de |
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From: Harald H. <h.h...@tu...> - 2005-01-19 17:17:30
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I have forgotten one thing. > Could you draw an expected gnuplot output, e.g. for the "test" page or "plot > 1/x", or "splot x*y", by hand, and present it? I think it doesn't make sense to export 2d plots to povray. -- Harald Harders h.h...@tu... http://www.harald-harders.de |
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From: V. <gae...@en...> - 2005-01-19 17:51:05
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On Wed, Jan 19, 2005 at 06:18:48PM +0100, Harald Harders wrote: > > Could you draw an expected gnuplot output, e.g. for the "test" page o= r "plot > > 1/x", or "splot x*y", by hand, and present it? I am a bit in a hurry, right now, so here is an splot with pm3D, the povray version and the gnuplot version. www.eleves.ens.fr/home/varoquau/2Dlattice.png www.eleves.ens.fr/home/varoquau/2Dlattice.pov www.eleves.ens.fr/home/varoquau/gnuplot-2Dlattice.png > I think it doesn't make sense to export 2d plots to povray. I think it does, to be able to mix them with 3D plots. Ga=EBl |
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From: Petr M. <mi...@ph...> - 2005-01-25 10:16:40
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> I am a bit in a hurry, right now, so here is an splot with pm3D, the > povray version and the gnuplot version. > > www.eleves.ens.fr/home/varoquau/2Dlattice.png > www.eleves.ens.fr/home/varoquau/2Dlattice.pov > www.eleves.ens.fr/home/varoquau/gnuplot-2Dlattice.png The surface in povray is OK, but what about axes and their labels, and also the colorbox? For exporting only the surface into povray you could use just the "set term table" and an appropriate filter. --- PM |
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From: V. <gae...@en...> - 2005-01-25 10:44:10
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> The surface in povray is OK, but what about axes and their labels, and =
also
> the colorbox?
Yes, I am aware, but I know (because I have seen other people do it)
that such thing are reasonnably easily done in povray.
I am currently overwellmed with other work that is due at the end of the
week. I am planning to work more actively on the use of scientific
plotting with povray afterward. I would greatly enjoy collaborating with
the gnuplot team to get a gnuplot terminal working.
> For exporting only the surface into povray you could use just the "set =
term
> table" and an appropriate filter.
Yes, this is true, and then include it in Povray with a heightfield.
But my goal would be to make povray usable for scientific plotting by
somebody who doesn't know anything about Povray, but only through
standard Gnuplot interface, with a given terminal, and maybe a few
options. For somebody who allready knows Povray it is quite easy to use
it to display plots, eventhough it take a bit of time to put axes and
alike to scale.
Ga=EBl
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From: Harald H. <h.h...@tu...> - 2005-01-26 20:15:54
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On Tue, 25 Jan 2005, Petr Mikulik wrote: > > I am a bit in a hurry, right now, so here is an splot with pm3D, the > > povray version and the gnuplot version. > > > > www.eleves.ens.fr/home/varoquau/2Dlattice.png > > www.eleves.ens.fr/home/varoquau/2Dlattice.pov > > www.eleves.ens.fr/home/varoquau/gnuplot-2Dlattice.png > > The surface in povray is OK, but what about axes and their labels, and also > the colorbox? I have had posted a few links that show possible ways to handle axes. If they are useful is another question. Here once again the links: http://www.harald-harders.de/gnuplot/hindernisabstand1.png (280KB) http://www.harald-harders.de/gnuplot/hindernisabstand1a.jpg (68KB) http://www.harald-harders.de/gnuplot/funktion3.png (136KB) http://www.harald-harders.de/gnuplot/funktion3.pov (3716KB) http://www.harald-harders.de/gnuplot/funktion3.ini (4KB) -- Harald Harders h.h...@tu... http://www.harald-harders.de |
