Re: goals for 3.1

[Daniel J Sebald]

Shai Ayal wrote:
> On Dec 20, 2007 8:31 PM, John W. Eaton <address@hidden> wrote:
[snip]
> >  11. Graphics:
> >        -- Refactor base_properties
> >        -- Specific types for properties with improved property value
> >           checking
> >        -- Implement the addprops function allow additional properties
> >           to objects
> >        -- add the hggroup object that has no fixed properties for use
> >           by barseries, etc.
> >        -- Add callback DeleteFcn/CreateFcn to objects
> >        -- Allow listener functions to be added to objects
> >        -- Clean separation of backend from property database
> >        -- Implement experimental backend based on OpenGL and GUI
> >           toolkit
>
>
> I would like to add some detail as to the feasibility of this last point:
> I think writing the actual drawing code will be relatively easy and
> can easily be accomplished even by me alone in the 6 month time-frame
> (and I'm sure I'll have help). However today the gnuplot backend does
> a lot more then drawing -- The first thing that comes to mind is
> determining tick marks, but I'm sure that other things will pop-up.

Tick marks is more difficult than one might imagine.  Gnuplot x11 does zooming 
(as conveniently as any other device I've seen).  Gnuplot works on multiple 
platforms.  Hidden line removal.  Perhaps one day hidden surface removal, but 
no promises.

> For each of these things design decisions would have to be taken -- is
> it the backend's responsibility or octave's responsibility. This might
> slow things up a bit (a discussion on the mailing list is always
> slower than frantic coding by a single person). All that being said I
> still think that a 6-9 month milestone is reasonable for this point

As a start, perhaps.  I think that getting a nice interface is the higher 
priority item right away.

John W. Eaton wrote:
> On 20-Dec-2007, Shai Ayal wrote:
>
> | I agree completely. I think it will take more then 3.1 until we have
> | something close to gnuplot in terms of sheer number of output formats
> | and quality.
>
> I don't care too much about all the output formats that gnuplot can
> create.  At least initially it should be sufficient to have PS and
> PS+LaTeX as I think most everything else that is useful today can be
> generated from those using ghostscript and other tools.

If that's the end game, it doesn't seem any more convenient than gnuplot.  By 
working with Octave/gnuplot, people learn that gnuplot can be used in other 
settings.


> Seriously, when is the last time you saw an actual Tektronix, BBN
> Bitgraph, or AED graphics terminal?  Or a real HP pen plotter?

1992?  But it is a decision to keep existing systems alive and not obsolete 
code that someone may have written 15 years ago.

The big output formats are PS+LaTex, PostScript, PNG, GIF (possibly with 
animations), PDF, a few others, and it varies with the user.

Dan