[SciPy-User] Undefined symbols in _flinalg.so

[Norm Wood]

Hi,

I'd run into a problem with determinants last October while trying to
use the kernel density estimation package in (at that time) SciPy 0.7.0
and 0.7.1.  In scipy/linalg/basic.py, the determinant code has the
lines:

   fdet, = get_flinalg_funcs(('det',),(a1,))
   a_det,info = fdet(a1,overwrite_a=overwrite_a)

and the second line was producing a TypeError:
   TypeError:  'NoneType' object is not callable

I never resolved this with SciPy 0.7, but I've managed to dig further
while trying to install 0.8.0.

get_flinalg_funcs() is in sciyp/linalg/flinalg.py. The problem is
occurring when flinalg.py tries to import _flinalg.so.  An ImportError
is raised, causing _flinalg to be set to None, and this in turn causes
get_flinalg_funcs() to return None for fdet.

If I go into my site-packages/scipy/linalg directory, start a python
shell and try to import _flinalg.so, I get:

>>> import _flinalg
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
ImportError: ./_flinalg.so: undefined symbol: ddet_c_

The routine ddet_c() is in scipy/linalg/src/det.f and appears mainly to
be a wrapper which calls LAPACK's dgetrf to compute the LU factorization,
then computes the determinant.


I'd appreciate any suggestions about where to look further to resolve
this.  Running nm on _flinalg.so shows for ddet_c:

            U ddet_c_
   0000bed0 T ddet_c__

indicating ddet_c_ is undefined.  dgetrf_ appears in _flinalg.so, but also has
the symbol type "U" (undefined).  Running ldd on _flinalg.so shows that
it is linked to the liblapack.so and libatlas.so that I just built
(Atlas 3.8.0).  dgetrf_ shows up as a defined symbol (type "T") in
liblapack.so.  

Note that the code for doing determinants in numpy (in
numpy/linalg/linalg.py) also uses dgetrf, but imports it from a
different shared object file, lapack_lite.so, and seems to work fine.


Thanks for any assistance.  I've attached below a summary of my system
and build info.  It's slightly different from that in my earlier message
(newer numpy and scipy).  I've also given a link to that October
thread.

Regards,

Norm


The previous thread:
http://old.nabble.com/scipy.linalg.det-TypeError-td26100345.html

and my current system and build info:

These results are using LAPACK 3.1.1, Atlas 3.8.0, numpy 1.5.0b1, and
SciPy 0.8.0, all built with gcc 3.3.6 and g77.  Python is 2.4..1 built
with gcc 3.3.5.    I'm running Slackware 10.2 with kernel 2.4.31.


Here's partial output from system_info.py:

ATLAS version 3.8.0 built by norm on Tue Aug  3 13:09:42 MDT 2010:
   UNAME    : Linux wombat 2.4.31-1 #1 SMP Wed Dec 7 16:52:41 MST 2005 i686 unknown unknown GNU/Linux
   INSTFLG  : -1 0 -a 1
   ARCHDEFS : -DATL_OS_Linux -DATL_ARCH_P4E -DATL_CPUMHZ=3014 -DATL_SSE3 -DATL_SSE2 -DATL_SSE1 -DATL_GAS_x8632
   F2CDEFS  : -DAdd__ -DF77_INTEGER=int -DStringSunStyle
   CACHEEDGE: 1048576
   F77      : g77, version GNU Fortran (GCC) 3.3.6
   F77FLAGS : -O -fPIC -m32
   SMC      : gcc, version gcc (GCC) 3.3.6
   SMCFLAGS : -fomit-frame-pointer -mfpmath=387 -O2 -falign-loops=4 -fPIC -m32
   SKC      : gcc, version gcc (GCC) 3.3.6
   SKCFLAGS : -fomit-frame-pointer -mfpmath=387 -O2 -falign-loops=4 -fPIC -m32
success!
removing: _configtest.c _configtest.o _configtest
  FOUND:
    libraries = ['lapack', 'ptf77blas', 'ptcblas', 'atlas']
    library_dirs = ['/home/norm/lusr/atlas/lib']
    language = f77
    define_macros = [('ATLAS_INFO', '"\\"3.8.0\\""')]
    include_dirs = ['/home/norm/lusr/atlas/include']

atlas_blas_info:
  libraries f77blas,cblas,atlas not found in /usr/local/lib
  FOUND:
    libraries = ['f77blas', 'cblas', 'atlas']
    library_dirs = ['/home/norm/lusr/atlas/lib']
    language = c
    include_dirs = ['/home/norm/lusr/atlas/include']