[SciPy-user] How do I build scipy using standard BLAS/LAPACK

Pearu Peterson pearu at scipy.org
Mon Nov 22 09:12:58 CST 2004

On Mon, 22 Nov 2004, Nils Wagner wrote:

> Hi all,
> Assuming that libblas.a and liblapack.a are located in /usr/lib
> how do I build scipy from cvs without usage of ATLAS ?
> What are the neccessary steps ? (modify setup.py ?)

Please read 'Linear Algebra libraries' section in


All you need is to specify BLAS and LAPACK environment variables and set 
ATLAS=None. No need to modify setup.py. To see if proper libraries are 
found by scipy setup.py script, study the output of

   python system_info.py lapack_opt blas_opt

Also note that on some systems /usr/lib/lib{blas,lapack}.a
(i) may use ATLAS libraries (e.g. Debian)
(ii) or these BLAS/LAPACK libraries are not complete (e.g. RedHat).

So, in general, using /usr/lib/lib{blas,lapack}.a for Fortran BLAS/LAPACK 
libraries is not always reliable but getting BLAS/LAPACK from netlib and 
building them yourself is.


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