[SciPy-user] BLAS and srotgm

Donna Calhoun calhoun@amath.washington....
Tue Sep 11 09:33:44 CDT 2007

Dear SciPy Users :

I just got SciPy installed, finally.  (Many thanks to the user who posted 
a while ago that the "-shared" flag was needed to build _fftpack.so).

But now, when I try to import the blas module, I get the following error :

Python 2.5 (r25:51908, Sep 10 2007, 00:42:23)
[GCC 3.4.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import scipy.linalg.blas
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
   File "/usr/local/Python-2.5-with_tk/lib/python2.5/site-packages/scipy/linalg/__init__.py", 
line 8, in <module>
     from basic import *
   File "/usr/local/Python-2.5-with_tk/lib/python2.5/site-packages/scipy/linalg/basic.py", 
line 227, in <module>
     import decomp
   File "/usr/local/Python-2.5-with_tk/lib/python2.5/site-packages/scipy/linalg/decomp.py", 
line 21, in <module>
     from blas import get_blas_funcs
   File "/usr/local/Python-2.5-with_tk/lib/python2.5/site-packages/scipy/linalg/blas.py", 
line 14, in <module>
     from scipy.linalg import fblas
undefined symbol: srotmg_

I build libblas and liblapack from the latest version of lapack (3.1.1). 
The file srotmg.f is under BLAS/SRC and appears to be in the library :

[calhoun@localhost lapack-3.1.1]# nm libblas.a | grep srotmg
00000000 T srotmg_

(note that libblas.a and liblapack.a are symbolic links to the libraries
blas_LINUX.a and lapack_LINUX.a built by the lapack build/install).

The '00000000' is a bit suspicous, however.

However, fblas.so (under scipy/linalg) has :

[calhoun@localhost linalg]# nm fblas.so | grep srotmg
0016f4a0 d doc_f2py_rout_fblas_srotmg
0005a4b0 t f2py_rout_fblas_srotmg
          U srotmg_

which I guess means 'srotmg' is undefined.  Looking at a build log of 
scipy, the blas/lapack I specified in site.cfg were all found.

So the question is, why can't python find srotmg?

Thank you for any help,


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