on ubuntu 13.10: "cannot import name _tkagg"

[bueler]

This command works on one of my ubuntu machines but not the other. It is from pism/examples/jako, of course:

+ python pism_regional.py -i gr1km.nc -o jakomask.nc -x 360,382 -y 1135,1176 -b 50
Traceback (most recent call last):
  File "pism_regional.py", line 15, in <module>
    import pylab as plt
  File "/usr/local/lib/python2.7/dist-packages/matplotlib-1.3.1-py2.7-linux-x86_64.egg/pylab.py", line 1, in <module>
    from matplotlib.pylab import *
  File "/usr/local/lib/python2.7/dist-packages/matplotlib-1.3.1-py2.7-linux-x86_64.egg/matplotlib/pylab.py", line 269, in <module>
    from matplotlib.pyplot import *
  File "/usr/local/lib/python2.7/dist-packages/matplotlib-1.3.1-py2.7-linux-x86_64.egg/matplotlib/pyplot.py", line 98, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "/usr/local/lib/python2.7/dist-packages/matplotlib-1.3.1-py2.7-linux-x86_64.egg/matplotlib/backends/__init__.py", line 28, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "/usr/local/lib/python2.7/dist-packages/matplotlib-1.3.1-py2.7-linux-x86_64.egg/matplotlib/backends/backend_tkagg.py", line 11, in <module>
    import matplotlib.backends.tkagg as tkagg
  File "/usr/local/lib/python2.7/dist-packages/matplotlib-1.3.1-py2.7-linux-x86_64.egg/matplotlib/backends/tkagg.py", line 2, in <module>
    from matplotlib.backends import _tkagg
ImportError: cannot import name _tkagg

It may be relevant that I am running python 2.7.5+ and that when I run ipython -pylab I get a message that says

Welcome to pylab, a matplotlib-based Python environment [backend: Qt4Agg].

That is, my Matplotlib does work with the Qt4Agg backend, but the gtkagg backend might not work for me.

Actually I would be happy for regional-tools to have a GUI-free mode (i.e. without needed a functioning gui to run). Or maybe that so defeats the purpose ...

[ckhroulev]

"regional tools" use Tk and Tkinter for the GUI, so it's not that easy to switch to the Qt4Agg backend. :-(

I agree that the "batch" mode should not even try to import GUI-related modules. This is a bug and I will fix it.

[bueler]

I was able to get past this. Apparently the key steps were:

• install debian packages tk and tk-dev
• uninstall and then reinstall matplotlib using pip, i.e. sudo pip uninstall matplotlib and sudo pip install matplotlib

I would not have tried this except I found

http://stackoverflow.com/questions/13110403/matplotlib-backend-missing-modules-with-underscore

[sandwriter]

Thanks, nice solution!