Re: How do you change to an ordinate on gsplot?

[Dmitri A. Sergatskov]

Robert A. Macy wrote:

> to do your idea, I tried "long hand" by using...
>
>
> > > x=[(1:400)']*ones(1,70);
> > > xx=vec(x);
> > > y=ordinate(1:70);
> > > yy=vec(y);
> > > zz=vec(values);
> > > mesh(xx,yy,zz);


Robert,

First of all, if you care to provide some examples, try to make them
self-contained. Looking on the code above I have no idea what it
does. What is ordinate there? xx in the above code would be 28000
double vector. If yy only has 70 double values, zz must be 28000x70
matrix (15 Meg). Though it should not be the problem, but it is a killer for
gnuplot. I actually tried it for the kicks, and gnuplot grew to 672M
in size and I killed it after 10 minutes -- it did not finish.
This is on 2.6GHz P4 w/ 1GB of RAM...

Here we come to the real problem -- gnuplot is not a very good 3d plotting
program. One of the problem is its hidden lines removal algorithm.
(Those who have plplot installed -- try 'sombrero(100)' with
gnuplot and with plplot.)
Unfortunately mesh() (and its friends) set hidden removal to "on"
(so one cannot unset it, even if he cares). So I would suggest to
remove it from the mesh() and people who care can do "gset hidden"
(or use some high level wrapper) explicitly.

Sincerely,

Dmitri.



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