From octave-graphics-request at bevo dot che dot wisc dot edu  Fri Feb 25 03:08:06 2000
Subject: Re: gnuplot (Was: Re: New on the list : new plotting tool) 
From: Tim Piessens <Tim dot Piessens at esat dot kuleuven dot ac dot be>
To: Discussion list octave-graphics <octave-graphics at bevo dot che dot wisc dot edu>
Date: Fri, 25 Feb 2000 10:08:04 +0100 (MET)

On Thu, 24 Feb 2000, John W. Eaton wrote:

> On 24-Feb-2000, Teemu Ikonen <tpikonen at pcu dot helsinki dot fi> wrote:
> 
> | A general plotting syntax would solve these problems and allow for a wider
> | set of plotting programs to be used.
> 
> I'm all for this, if by `syntax' you really mean `collection of
> functions' or `api' rather than introducing new commands in the
> parser.  As I've said before, the gplot/gsplot/gset syntax is likely
> to *only* work as an interface to gnuplot because it would be too
> difficult to support using other plotting packages.
> 

Indeed it will be difficult to support other plotting packages, but
data-representation is extremely important in data analysis software. I
think many people will start using octave when data representation is
more sofisticated.
Also other functionality would be handy : the ability to picking points ,
zooming ...
It is indeed difficult and then octave will be dependent of other
libraries as gtk or others. But, referring to your previous mail, I don't
think it is bad design to make your software dependent of a freely
distributed library if you in the other case let the functionality of
your software be dependent of one others free software.

> | Now gnuplot might be great for casual
> | plotting and visualisation, but there are times when one needs to do
> | something a bit more exotic and do it with publication quality.

I don't think pie-charts are that exotic.


> 
> | gnuplot
> | isn't always up to this, as this amusing snippet from gnuplot FAQ
> | 
> | > http://www-ihe.etec.uni-karlsruhe.de/mitarbeiter/vonhagen/gnuplot-faq.html
> | 
> | shows:
> | 
> | ------clippety-clip------
> | 
> | 3.5 How do I change symbol size, line thickness and the like? 
> | 
> | Again, this depends on the terminal type. For PostScript, you can edit the
> | generated PostScript file. An overview of what means what in the
> | PostScript files gnuplot generates can be found at picard.tamu.edu in
> | /pub/gnuplot/ as gs-ps.doc. A general introduction to PostScript can be
> | found at unix.hensa.ac.uk in /pub/misc/ukc.reports/comp.sci/reports/ as
> | 11-92.ps.Z. 
> | 
> | ------cloppety-clop------
> | 
> | I mean, we are living in the year 2000, right? :)
> 
> Dude, I think you have an out-of-date answer to this FAQ, or an old
> version of gnuplot.  With 3.7, you can do
> 
>   set term postscript
>   set output "foo.ps"
>   plot sin(x) w l lw 5, cos(x) w l lw 10
> 
> to set the width of the lines.
> 

That is true and using the postscript terminal one can change the look of
the graphic just the way you want it, maybe we should use that terminal
and redirect it to ghostview to display the results.  

> This may not work from Octave using gplot (I can't remember if I added
> code to handle the linewidth modifier) but it is possible to
> specify the line width in gnuplot without having to edit PostScript.
> 
> jwe
> 

Tim