[SciPy-dev] the current state and future directions of the sparse solvers

[Robert Kern]

On Mon, Apr 7, 2008 at 10:55 AM, Ondrej Certik <ondrej at certik.cz> wrote:
> Hi,
>
>  these are probably mainly questions to Nathan. :)
>
>  First let me say that the new sparse functionality of scipy is
>  awesome, I really like it, it's just so easy and natural to work with
>  it. Thanks for your work on it.
>
>  Here I have some points:
>
>  1) Why do you want to remove umfpack wrappers from scipy? I suggest to
>  leave wrappers in there (those can be BSD, cannot they?),

That just confuses the issue. If you are going to use the UMFPACK
functionality, you will need UMFPACK and the GPL. Consequently, the
wrappers must be optional; all of scipy must be buildable and usable
without any GPLed code. However, having optional functionality is bad;
in order to depend on it you can't just tell your users "install
scipy" but "install scipy with the UMFPACK wrappers installed". This
makes it especially difficult for things like Linux distributions.
They have to make the choice whether to include the GPL code or not.
If they do, then they can't include a non-GPL-compatible package that
depends on scipy. If they don't, they can't include a package that
needs the UMFPACK wrappers.

I would have spoken against the initial inclusion of the UMFPACK
wrappers if I had been paying attention at the time. I am glad to see
them being removed. However, just moving the wrappers to a scikit
doesn't solve any problem if scipy code is requiring the scikit.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
 -- Umberto Eco