[Numpy-discussion] Blas / lapack / binary installers...

[Matthew Brett]

Hi,

>> We at the NIPY project have run into what seems like a recurring
>> problem; we want to build our code against both numpy and lapack, on
>> windows, linux and OS X.
>>
>> No problem of course if we've done a development install - we already
>> needed to have blas/lapack.
>
> I am not sure I understand: why do you need blas/lapack to build
> projects ? Does NiPY itself uses blas/lapack  ?

Yes it does...

>> Proposal
>> -------------
>> Make the binary installers for windows with the option to put the
>> blas/lapack libraries in some predictable location and adapt the
>> site.cfg file accordingly.
>
> It is possible, but it would make the installers quite big. As Gael
> said, a more general solution would be to use .so (well, dll), put
> them in a known location, so that applications can reuse it. That's
> something which would be great for a lot of reasons, but that's
> difficult to do on windows + distutils.

Yes, I know, hence my suggestion of something more practical in the
short term.  I wonder whether the installer could be:

by default, smallish, with just numpy, with the option of pulling down
the lapack libraries from the web on installation or, possibly
optionally, large, with the lapack libraries installed by default.

I was thinking, that if that were the case, then installing scipy from
source might go from being very nasty (needing a compiled blas /
lapack), to only fairly nasty (needing fortran), making it more
accessible.

Thanks a lot,

Matthew