Re: Combining images and plots

[Ted Harding]

( Re Message From: T.J. Cham )
> 
> Hi,
> 
> Are there any plans/ongoing-projects to integrate images and plots in
> Octave as is possible with Matlab 4+? I guess this may not be that useful
> in general, but it is certainly highly applicable in vision research,
> especially if it's interactive. I don't think it's easily done (or
> possible at all) with gnuplot, but then there was some talk earlier this
> year of supporting other plotting packages in Octave. 
> 
> Thanks.
> Tat Jen
> 
> --
> Tat-Jen Cham
> Speech, Vision and Robotics Group, Department of Engineering,
> Cambridge University, Cambridge CB2 1PZ, UK.
> Tel: +44-(1223)332754, Fax: +44-(1223)332662, email: address@hidden
> 
>
I run octave under Linux and have extensive needs for contouring and
surface plots.
 
Owing to the limitations and defects of gnuplot, I looked around for
alternatives in the "free-software" area. I finally picked plotmtv,
and built some fairly basic m-files to interface octave to plotmtv.
This of course is not "integration within octave", but there's not much
superficial difference between a builtin function and an m-file, except
speed.

I posted a couple of these recently, and plan to post the lot shortly.

Plotmtv is, in a few respects, not ideal (you have to re-run it for every
new plot, so "dynamic plotting" is out - on the other hand you can
accumulate earlier plots and move back and forth between them); but it is
a great improvement on gnuplot for my purposes. One nice feature is that
you can also interactively zoom and pan and rotate using the mouse.

I earlier carried out a similar exercise using the package GLE, which is
also a great improvement on gnuplot (and in a few respects nicer than
plotmtv). However, I was dissatisfied with its approach to contouring, and
didn't much liike it's user interface either. Nonetheless, others might
prefer it.

A while ago, there was some exchange (initiated by Kaj Wiik) about
attaching the PGPLOT library to octave, but I haven't heard that anything
came of it. Something like this is probably the major improvement
that many would like to see come next, rather than put up with gnuplot
(and, by the way, the discussions of gnuplot-3.6-beta on info-gnuplot are
not suggesting that it's an upgrade for octave that's worth spending a lot
of effort on, in my judgement).

Probably there are other programs which might work as well or even better.
Maybe people could be encouraged to try some out, if they look promising?
It's not that difficult to emulate the essentials of the octave plotting
routines for input to other packages than gnuplot.

Ted.                                    (address@hidden)