[SciPy-user] Ubuntu Libraries

[David Cournapeau]

jah wrote:
> Hi,
>
> I was hoping someone could clarify the ubuntu packages and what is
> actually needed by scipy.
>
> 1) I keep seeing posts about g77 not being required anymore and
> gfortran preferred.  What is the "official" statement?  In
> INSTALL.txt, only g77 is mentioned for Ubuntu packages via: 
> """Debian/Ubuntu packages (g77): atlas3-base atlas3-base-dev""".  The
> only reference to gfortran is with Mac OS X.  Also, in "Optional
> Packages" debian packages 'gcc g++ g77' are recommened.

It depends on the version. g77 and gfortran are not ABI compatible: you
can't mix them in your binary, including shared libraries. So the advice
was and still is to use the compiler of your distribution's ABI. Ubuntu
8.04 transitionned from g77 to gfortran ABI (both ABI were available in
e.g. atlas: atlas3-base-dev for g77 ABI vs libatlas-sse2-dev for
gfortran ABI).

>
> 2) The install notes also say that a complete version of LAPACK is
> required for scipy.  All the ubuntu descriptions say that only a
> subset of routines from LAPACK are included with ATLAS.  For example,
> http://packages.ubuntu.com/hardy/libatlas-sse2-dev.  Is this a problem?

Ubuntu (and debian) do include the full lapack into atlas: you have
nothing to do with them on Ubuntu.

>
> 3) It looks like there are two packages:  atlas3-sse2 and
> libatlas-sse2-dev.  Are both required?  It seems that they refer to
> different versions of ATLAS.
>
>  http://packages.ubuntu.com/hardy/atlas3-sse2
>  http://packages.ubuntu.com/hardy/libatlas-sse2-dev
>
> On reading http://www.scipy.org/Installing_SciPy/Linux, it seems like
> I only should need libatlas-sse2-dev.  Correct?

Yep, if you use gfortran. You should install libatlas-sse2-dev if you
build everything (numpy and scipy) with gfortran.

David