Re: scatter3 is really slow

[David Bateman]

Jaroslav Hajek wrote:
> On Thu, Jul 2, 2009 at 9:25 PM, David Bateman<address@hidden> wrote:
>   
> > Dr. Johannes Zellner wrote:
> >     
> > > hi,
> > >
> > > scatter3 ist really slow here. It's MUCH slower than doing the same
> > > plot in gnuplot.
> > > What's the problem here?
> > >
> > >
> > >
> > >       
> > Blame mathworks for considering that each point in a scatter point is a
> > separate patch object.. Then imagine the for loop that Octave needs to
> > have to send all that mess gnuplot.. I don't think there is much to do
> > here for the gnuplot backend though something might be possible with
> > other backends.
> >
> > D.
> >
> >     
>
> If it is slowing things down this much (and I confirm, scatter takes
> ages for 1000 points), what about making the Matlab compatible
> behavior only optional? I can hardly imagine what it's good for to
> have a separate handle for each point, except maybe scatter plots of
> just several points. Matlab compatibility is generally good, but
> surely not when it renders a function close to unusable.
>
>
>   
The way to get a now matlab compatible behavior is something like

plot3(x,y,z,'r.')

The scatter3 command however allows each point in the scatter to have a 
different color and that is the source of the issue... I don't set a way 
of sending data for a set of points with a seperate color for each point 
to gnuplot..

D.


--
David Bateman                                address@hidden
35 rue Gambetta                              +33 1 46 04 02 18 (Home)
92100 Boulogne-Billancourt FRANCE            +33 6 72 01 06 33 (Mob)