Re: [Matplotlib-users] Opensuse RPMs

[Marcel O. <m.o...@iu...>]

Werner Hoch writes:
 > What is Tex output? Do you mean postscript or eps?
 > 
 > >   sh: line 1: 11319 Segmentation fault      gs -dBATCH -dNOPAUSE
 > > -r6000 -sDEVICE=pswrite -sPAPERSIZE=letter
 > > -sOutputFile="/tmp/ef684d47fbac423478eccceef602c8ca.ps"
 > > "/tmp/ef684d47fbac423478eccceef602c8ca"
 > > >"/tmp/ef684d47fbac423478eccceef602c8ca.output"

OK, so I have updated to the latest RPMs and investigated a bit
further.  The gs segfault occurs when setting "usetex=True" AND trying
to save to an eps figure.

Demonstration: take tex_demo.py from the examples collection on the
matplotlib site.  It runs OK.  Now change savefig('tex_demo') to
savefig('tex_demo.eps').  Boom.

Probably a bug with the Suse gs rather than matplotlib, but pretty
annoying anyway because one would like to produce eps rather than
bitmapped figures for publication quality images.

 > Can you please provide some informations about your setup?
 > OS = SuSE 10.2
 > arch = i586

python shell = ipython or even the standard python interpreter

 > backend your trying to use (Agg is default, set it to TkAgg if you like 
 > to use matplotlib interactively)
 > interactive value in matplotlibrc

OK, here is the problem.  With the latest RPM I get

moliver@tlabterm:~/Desktop/examples> ipython -pylab
[Lots of backtrace...]
ImportError: No module named wx

Missing dependency?  In any case, after setting the backend to GTKAgg
in matplotlibrc, everything works.  I believe that's also the default
in the Fedora RPM.

The following tests with GTKAgg backend setting:

 > Minimum Testcode for matplotlib:
 > -------
 > from pylab import *
 > 
 > a = arange(0,10,0.01)
 > plot(a, sin(a))
 > grid()
 > savefig("abc.png")
 > -------
 > Does it work?

Yes.

 > Testcode for postscript:
 > -------
 > from pylab import *
 > 
 > a = arange(0,10,0.01)
 > plot(a, sin(a))
 > grid()
 > savefig("abc.ps")
 > -------
 > Does it work?

Yes.

OK, so boiled the problem with usetex=True down to the following pair
of working vs. nonworking code.  Wierd.

File working.py:
================

#!/usr/bin/env python
from pylab import *
 
rc('text', usetex=True)
a = arange(0,10,0.01)
plot(a, sin(a))
grid()
savefig("abc.ps")

show()

File nonworking.py:
===================

#!/usr/bin/env python
from pylab import *
 
rc('text', usetex=True)
a = arange(0,10,0.01)
plot(a, sin(a)+2)
savefig("abc.ps")

show()

 > After changing the settings for the backend and interactive mode.
 > Does the following code produce a plot when entered into a shell?
 > ---------
 > from pylab import *
 > plot([1,2,3,3,2,3])
 > ---------

As descibed above, changing backend is necessary to do anything...
Did not systematically try all the backends.  Would be nice if the
default was working.

 > Can you provide the version of your Fedora and the Version of the 
 > matplotlib package?
 > It would be much easier to track the differences and fix the package.

http://mirrors.usc.edu/pub/linux/distributions/fedora/extras/6/SRPMS/python-matplotlib-0.87.7-3.fc6.src.rpm

Thanks a lot,
Marcel