Re: [Matplotlib-users] segfaults in ipython

[John H. <jdh...@ac...>]

>>>>> "Steve" == Steve Schmerler <el...@gm...> writes:

    Steve> Hi I recently posted something about segfaults I get when
    Steve> plotting. Now here is a little update and I really hope
    Steve> someone has an idea how I can solve this problem.

    Steve> I'm running IPython 0.6.13 on a Debian box, installed the
    Steve> recent mpl 0.83.2 from source, GTKAgg backend.

    Steve> 1)

    Steve> When I start ipython (as normal user) with the -pylab
    Steve> option and then say

    Steve> 	plot([1,2,3])

    Steve> I get

    Steve> In [1]: plot([1,2,3])
    Steve> ---------------------------------------------------------------------------
    Steve> exceptions.SystemError Traceback (most recent call last)


    Steve> SystemError: ../Objects/moduleobject.c:48: bad argument to
    Steve> internal function

You say this is a segfault, but it looks like an exception.  Does this
actually kill the ipython shell?  Is this a full posting of the
traceback?

What happens if you run the following script outside of ipython

    from pylab import plot, show
    plot([1,2,3])
    show()

with 

  > python test.py --verbose-helpful 

Does this create a proper figure window -- please post all output from
the script.


    Steve> 2)

    Steve> However when I change to root

    Steve> 	su <pwd>

    Steve> 	ipython -pylab

    Steve> then plotting works fine!?

Perhaps this has something to do with having permission to connect to
the X11 server?  As a normal user, can you launch graphical apps from
the shell, eg 

 > gedit&


Have you done anything unusual with your system, changed the default
permission bits, done a chroot, etc?  What linux distro are you
running?


    Steve> I have no idea where this moduleobject.c lives or to which
    Steve> application it belongs.

    Steve> 2)

    Steve> If I try the same with the normal python interpreter

    Steve> 	python

    Steve> 	from pylab import *; ion() plot([1,2,3])

    Steve> a plot window pops up but shows no picture (no matter if
    Steve> I'm root or not).


GTKAgg is not expected to work unless you are in a special threaded
environment like ipython with -gthread or -pylab.  Try the same with
the TkAgg backend (edit your rc file) and let me know what happens.

The last thing I'd advise is upgrading your ipython to the latest.

I've never seen this one before so I'm flying by the seat of my pants.


JDH