Hi, after trying to solve an installation problem with scipy, I had to reinstall everything from scratch, and so I now turned back to numpy the installation of which does not work for me (which may in fact explain the pb I had with scipy). To be clear on what I do: - I install blas first, and create a libfblas.a which I copy under /usr/local/lib (using a g77 -fno-second-underscore -O2 -c *.f, ar r libfblas.a *.o, ranlib libfblas.a) - I then define BLAS environment variable accordingly (/usr/local/lib/libfblas.a) - I compile lapack-3.1.0, using "make lapacklib" - I then use a precompiled ATLAS Linux version P4SSE2 (I tried compiling it but it does have the same result) - I copy all ATLAS .a and .h in /usr/local/lib/atlas, and define the ATLAS variable accordingly - I then merge the *.o to have an extended liblapack.a by doing the usual: cd /usr/local/lib/atlas cp liblapack.a liblapack.a_ATLAS mkdir tmp cd tmp ar x ../liblapack.a_ATLAS cp /soft/python/tar/Science_Packages/lapack-3.1.0/lapack_LINUX.a ../liblapack.a ar r ../liblapack.a *.o - I finally get the svn version of numpy, and do the "python setup.py install" (no site.cfg ! but environment variables defined as mentioned above) - I go into ipython, and try: import numpy and I get : exceptions.ImportError Traceback (most recent call last) ................ ---> 40 import linalg ................ ImportError: /usr/local/lib/python2.4/site-packages/numpy/linalg/lapack_lite.so: undefined symbol: ATL_cGetNB I have tried many ways to avoid this problem but does not manage to solve it. Any help is welcome there. (and sorry for those who already saw my numerous posts on scipy forum: I am trying to get to the heart of the pb...) thanks in advance! Eric