matplotlib-users

[Matplotlib-users] Questions about 3D plotting

[anirudh v. <ani...@gm...>]

Hi,

First off, I'd like to congratulate the devs who wrote the 3D plotting
module. Its great and fits a lot of my plotting needs without
resorting to vtk, mayavi etc.

But I've had some issues with 3D plots

1. If i do a
----
import pylab as p
import matplotlib.axes3d as p3
fig=p.figure()
ax = p3.Axes3D(fig)
ax.scatter3D(ravel(x),ravel(y),ravel(z))
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Z')
p.show()
----

then things work well.

But if I do an "from pylab import *",
the plot command does'nt work. Any ideas?

2. In the scatterplot, as well as other 3D plots, I would like to plot
different datasets with different colors. While in plot(), "r." etc
change color, in plot3d etc the option does'nt work.
So, is there a way to use different colors in the same plot.

3. Is there any documentation on the 3D plotting functions. There are
examples at http://scipy.org/Cookbook/Matplotlib/mplot3D, but I
could'nt find any documentation on function calls, options etc.
help(plot3d) just says plot3d(**args) without any other info.

cheers,
anirudh.

Re: [Matplotlib-users] Questions about 3D plotting

[Darren D. <dsd...@gm...>]

On Wednesday 09 July 2008 10:35:55 am anirudh vij wrote:
> Hi,
>
> First off, I'd like to congratulate the devs who wrote the 3D plotting
> module. Its great and fits a lot of my plotting needs without
> resorting to vtk, mayavi etc.
>
> But I've had some issues with 3D plots

I'm sorry to disappoint, but 3D plotting has been unsupported for a long time 
and was recently removed from the mpl codebase.

> 1. If i do a
> ----
> import pylab as p
> import matplotlib.axes3d as p3
> fig=p.figure()
> ax = p3.Axes3D(fig)
> ax.scatter3D(ravel(x),ravel(y),ravel(z))
> ax.set_xlabel('X')
> ax.set_ylabel('Y')
> ax.set_zlabel('Z')
> p.show()
> ----
>
> then things work well.

probably because you have an old version of axes3d.py in your installation 
directory...

> But if I do an "from pylab import *",
> the plot command does'nt work. Any ideas?

... but pylab.py knows that we dropped 3d support so it doesnt try to import 
it anymore. 

Darren

Re: [Matplotlib-users] Questions about 3D plotting

[Darren D. <dsd...@gm...>]

On Wednesday 09 July 2008 11:59:50 am anirudh vij wrote:
> On Wed, Jul 9, 2008 at 4:54 PM, Darren Dale <dsd...@gm...> wrote:
> > On Wednesday 09 July 2008 10:35:55 am anirudh vij wrote:
> >> Hi,
> >>
> >> First off, I'd like to congratulate the devs who wrote the 3D plotting
> >> module. Its great and fits a lot of my plotting needs without
> >> resorting to vtk, mayavi etc.
> >>
> >> But I've had some issues with 3D plots
> >
> > I'm sorry to disappoint, but 3D plotting has been unsupported for a long
> > time and was recently removed from the mpl codebase.
>
> This is horrible. How do I do 3D plots now?
> Mayavi svn crashes when called from python.

We have been warning that 3D plotting was unsupported and needed someone to 
volunteer to maintain it for quite a while now. Nobody answered the call, and 
3d capabilities did not survive the transition to the new transforms in 
mpl-0.98, so it was removed, However...

[...]
> matplotlib version is 0.91.2, straight from ubuntu repos.

3D support should still be present in 0.91.x. I just did a clean install of 
0.91.4 from svn, and this works:

import pylab as p
import matplotlib.axes3d as p3
fig=p.figure()
ax = p3.Axes3D(fig)
p.show()

I haven't used matplotlib's 3d capabilities, so I dont know how you expected 
to work with "from pylab import *" instead of the above. Perhaps you could 
give a short explicit example of what used to work and now does not.

Darren

Re: [Matplotlib-users] Questions about 3D plotting

[anirudh v. <ani...@gm...>]

> We have been warning that 3D plotting was unsupported and needed someone to
> volunteer to maintain it for quite a while now. Nobody answered the call, and
> 3d capabilities did not survive the transition to the new transforms in
> mpl-0.98, so it was removed, However...
>

hmm. Mayavi2 has a mlab module thats under active development. It aims
to do the same stuff that matlab 3D plots do. However, svn currently
crashes for me.

> [...]
>> matplotlib version is 0.91.2, straight from ubuntu repos.
>
> 3D support should still be present in 0.91.x. I just did a clean install of
> 0.91.4 from svn, and this works:
>
> import pylab as p
> import matplotlib.axes3d as p3
> fig=p.figure()
> ax = p3.Axes3D(fig)
> p.show()
>
> I haven't used matplotlib's 3d capabilities, so I dont know how you expected
> to work with "from pylab import *" instead of the above. Perhaps you could
> give a short explicit example of what used to work and now does not.
-----
from pylab import *
import matplotlib.axes3d as p3
fig=figure()
ax= p3.Axes3D(fig)
ax.scatter3D(x,y,z)
show()
-----
this causes an error. x,y,z are valid 1D arrays. They work using the
method you've posted in your mail.

Perhaps a wrapper can be wriitten around mayavi's mlab module. 3D
plotting is too important to leave out of something like matplotlib.
Its perfect for all other things. It would be a pity if one has to
switch to gnuplot or dislin just for 3D.

Re: [Matplotlib-users] Questions about 3D plotting

[Darren D. <dsd...@gm...>]

On Wednesday 09 July 2008 12:40:29 pm anirudh vij wrote:
> > We have been warning that 3D plotting was unsupported and needed someone
> > to volunteer to maintain it for quite a while now. Nobody answered the
> > call, and 3d capabilities did not survive the transition to the new
> > transforms in mpl-0.98, so it was removed, However...
>
> hmm. Mayavi2 has a mlab module thats under active development. It aims
> to do the same stuff that matlab 3D plots do. However, svn currently
> crashes for me.
>
> > [...]
> >
> >> matplotlib version is 0.91.2, straight from ubuntu repos.
> >
> > 3D support should still be present in 0.91.x. I just did a clean install
> > of 0.91.4 from svn, and this works:
> >
> > import pylab as p
> > import matplotlib.axes3d as p3
> > fig=p.figure()
> > ax = p3.Axes3D(fig)
> > p.show()
> >
> > I haven't used matplotlib's 3d capabilities, so I dont know how you
> > expected to work with "from pylab import *" instead of the above. Perhaps
> > you could give a short explicit example of what used to work and now does
> > not.
>
> -----
> from pylab import *
> import matplotlib.axes3d as p3
> fig=figure()
> ax= p3.Axes3D(fig)
> ax.scatter3D(x,y,z)
> show()
> -----
> this causes an error. 

I can't help much if you don't tell me what the error is. I just ran the 
following and I did not observe any error:

from pylab import *
x=rand(100)
y=rand(100)
z=rand(100)
import matplotlib.axes3d as p3
fig=figure()
ax= p3.Axes3D(fig)
ax.scatter3D(x,y,z)
show()

> x,y,z are valid 1D arrays. They work using the 
> method you've posted in your mail.
>
> Perhaps a wrapper can be wriitten around mayavi's mlab module. 3D
> plotting is too important to leave out of something like matplotlib.
> Its perfect for all other things. It would be a pity if one has to
> switch to gnuplot or dislin just for 3D.

It sounds like a good idea to me. Submissions are very welcome.

Darren

Re: [Matplotlib-users] Questions about 3D plotting

[Bryan C. <br...@co...>]

On Wed, 2008-07-09 at 18:40 +0200, anirudh vij wrote:
> > We have been warning that 3D plotting was unsupported and needed someone to
> > volunteer to maintain it for quite a while now. Nobody answered the call, and
> > 3d capabilities did not survive the transition to the new transforms in
> > mpl-0.98, so it was removed, However...
> >
> 
> hmm. Mayavi2 has a mlab module thats under active development. It aims
> to do the same stuff that matlab 3D plots do. However, svn currently
> crashes for me.

An alterative to mpl/mayavi for 3d is Pyx (see
http://pyx.sourceforge.net/examples/3dgraphs/color.html ), although it's
not interactive.

BC