Thread: [matplotlib-devel] matplotlib 0.63 examples under pylab

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Hey John,

I've added code to ipython to wrap use() to prevent users from switching 
backends interactively, since this will instantly crash things badly.  It's a 
nice example of how python's dynamic nature allows you to tweak a module from 
the outside, without having to poke at its source.  I now see could have done 
this for the show() problem as well, since it's essentially the same logic, so 
I shouldn't really have bothered you with source changes to the backends. 
Well, at least it was done in a generic way and not slapping code all over 
many files...

With this safety in place, I tried running ALL the examples in 0.63 to see how 
we fare.  I compiled some notes along the way, here they are for your (and 
other user's) reference.

I think we're doing pretty good, except that people can always kill themselves 
by running true WX/GTK apps via @run.  IPython is really not made for this, it 
can only handle gracefully show() calls from pure matplotlib scripts, not 
full-blown GUI apps.  But I think we have a very reasonable environment at 
this point for most usage cases.

Cheers,

f

#############################################################################

matplotlib examples under iypthon -pylab
----------------------------------------

I ran all the examples in mpl 0.63 with ipython (CVS from Sept 29/04, post
0.6.4.rc1).  This was done using 'run foo.py', to see how robust this is.
Most examples run fine, and leave ipython usable afterwards.  Those listed
below had some type of problem.

Platform notes: Fedora core 2, python 2.3.3, Numeric 23.5, matplotlib 0.63
compiled only with Numeric (no numarray) support.

// These don't run with LANG==de_DE.UTF-8, but are OK with en_US.UTF-8
run date_demo_convert.py
run date_demo1.py
run date_demo2.py
run date_demo_rrule.py
run finance_demo.py

// these two run but segfault on exit under ipython.  They run OK from a cmd line.
run dynamic_demo_wx.py      # this one runs, segfaults on exit
run dynamic_image_wxagg.py  # this one runs, segfaults on exit

// OK with GTKAgg backend. It needs a use('GTKAgg') call to be safe for other
backends.
run dynamic_image_gtkagg.py #

// these are OK with gtkagg, but they segfault wxagg.  The segfault happens
from a normal command line as well (no ipython).

run system_monitor.py
run dynamic_demo.py

// these block ipython/pylab - any embedded true Wx/gtk stuff will kill 
ipython badly. What should we do here?

run print_stdout.py
run object_picker.py
run embedding_in_gtk2.py
run embedding_in_gtk.py
run embedding_in_tk.py
run embedding_in_wx.py
run embedding_in_wx2.py
run embedding_in_wx3.py
run embedding_in_wx4.py
run mpl_with_glade.py

// other errors (not ipython related)

****run ftface_props.py
---------------------------------------------------------------------------
SystemError                               Traceback (most recent call last)

/home/fperez/code/python/pylab/examples/ftface_props.py
      68 print 'Mult. masters :', font.style_flags & 
FT_FACE_FLAG_MULTIPLE_MASTERS != 0
      69 print 'Glyph names   :', font.style_flags & FT_FACE_FLAG_GLYPH_NAMES 
      != 0
      70
---> 71 font.jdh = 'hi'
      72 print dir(font)

SystemError: error return without exception set
WARNING: Failure executing file: <ftface_props.py>

****run movie_demo.py:
with WX backend it doesn't make the .png frames at all
with WXAgg, it runs fine but fails to make the movie:
...
Saving frame _tmp049.png
Making movie animation.mpg - this make take a while
sh: line 1: mpeg2encode: command not found
convert: Delegate failed (mpeg2encode "%i" "%o").
convert: Delegate failed (mpeg2encode "%i" "%o") [No such file or directory].

Symlinking mpeg2encode to mpeg2enc (the real binary) doesn't help, a different
error comes back.

I got it to work by commenting out the convert call and reverting to the
mencoder one.  Great!

****run vertical_ticklabels.py

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)

/home/fperez/code/python/pylab/examples/vertical_ticklabels.py
       3
       4 plot([1,2,3,4], [1,4,9,16])
       5 xticks([1,2,3,4], ['Frogs', 'Hogs', 'Bogs', 'Slogs'])
----> 6 set(t, 'rotation', 'vertical')
       7 show()

NameError: name 't' is not defined
WARNING: Failure executing file: <vertical_ticklabels.py>