scatter3 is really slow

[David Bateman]

Jaroslav Hajek wrote:
> On Thu, Jul 2, 2009 at 9:25 PM, David Bateman<dbateman at dbateman.org> 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.


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