[SciPy-user] Runge-Kutta ODE integrator in SciPy, odepack problems on SciPy Superpack for OSX?

[Zane Selvans]

I'm looking for a Python Runge-Kutta diffeq integrator, and I've found 
conflicting information online as to whether this is included within 
SciPy (the SciPy to Matlab comparison says it's included in Matlab, and 
not in SciPy, but some mailing list commentary says it's part of the 
odepack).

Does anyone know for sure?  I don't actually know a whole lot about how 
numerical ode solvers work (and truthfully, I don't want to learn, which 
is why I'm hoping I can just find an open source solver...)

The reason I'm asking instead of just playing with scipy.integrate.ode 
is for some reason my SciPy installation seems to be having problems 
loading the ode module.  I'm using Chris Fonnesbeck's "SciPy Superpack" 
installation.

I get this:

In [170]: from scipy.integrate import ode
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)

/Users/zane/svn/stress/pySatStress/<ipython console> in <module>()

/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/integrate/__init__.py 
in <module>()
       7 from info import __doc__
       8
----> 9 from quadrature import *
      10 from odepack import *
      11 from quadpack import *

/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/integrate/quadrature.py 
in <module>()
       3            'cumtrapz','newton_cotes','composite']
       4
----> 5 from scipy.special.orthogonal import p_roots
       6 from scipy.special import gammaln
       7 from numpy import sum, ones, add, diff, isinf, isscalar, \

/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/special/__init__.py 
in <module>()
       6 #from special_version import special_version as __version__
       7
----> 8 from basic import *
       9 import specfun
      10 import orthogonal

/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/special/basic.py 
in <module>()
       6
       7 from numpy import *
----> 8 from _cephes import *
       9 import types
      10 import specfun

ImportError: 
dlopen(/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/special/_cephes.so, 
2): Library not loaded: /usr/local/lib/libgfortran.2.dylib
   Referenced from: 
/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/special/_cephes.so
   Reason: image not found

And lo, it turns out I don't have libgfortran.2.dylib on my system.  I 
do have libgfortran.3.dylib though.  If I create a symbolic link from 3 
to 2, and then try the import I get a different error:

ImportError: 
dlopen(/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/special/_cephes.so, 
2): Symbol not found: __gfortran_pow_r4_i4
   Referenced from: 
/Library/Python/2.5/site-packages/scipy-0.7.0.dev3998-py2.5-macosx-10.5-i386.egg/scipy/special/_cephes.so
   Expected in: /usr/local/lib/libgfortran.2.dylib

It turns out there was a libgfortran.2.0.0.dylib included with the 
superpack, but it's for the Mach-0 architecture, not Intel, which is 
what I've got (MacBook Pro).

Any insight appreciated,
Thanks!

Zane

-- 
Zane Selvans
Amateur Human
zane at ideotrope.org
303/815-6866
PGP Key: 55E0815F
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