[Numpy-discussion] Instructions on building from source

[Andrew Straw]

Eric Firing wrote:
> Andrew Straw wrote:
>
>   
>> Just for reference, you can find the build dependencies of any Debian
>> source package by looking at its .dsc file. For numpy, that can be found
>> at http://packages.debian.org/sid/python-numpy
>>
>> Currently (version 1.1.0, debian version 1:1.1.0-3), that list is:
>>
>> Build-Depends: cdbs (>= 0.4.43), python-all-dev, python-all-dbg,
>> python-central (>= 0.6), gfortran (>= 4:4.2), libblas-dev [!arm !m68k],
>> liblapack-dev [!arm !m68k], debhelper (>= 5.0.38), patchutils,
>> python-docutils, libfftw3-dev
>>
>> Build-Conflicts: atlas3-base-dev, libatlas-3dnow-dev, libatlas-base-dev,
>> libatlas-headers, libatlas-sse-dev, libatlas-sse2-dev
>>     
>
> Do you know why atlas is not used, and is even listed as a conflict?  I 
> have libatlas-sse2 etc. installed on ubuntu hardy, and I routinely build 
> numpy from source.  Maybe the debian specification is for 
> lowest-common-denominator hardware?

The way it's supposed to work, as far as I understand it, is that atlas
is not required at build time but when installed later automatically
speeds up the blas routines.  (Upon installation of libatlas3gf-sse2,
libblas.so.3gf is pointed to /usr/lib/sse2/atlas/libblas.so.3gf from
libblas.so.3gf => /usr/lib/libblas.so.3gf). I have not verified that any
of this actually happens. So, please take this with a grain of salt.
Especially since my answer differs from Robert's.

-Andrew