[Numpy-discussion] Sparse Matrices in Numpy -- (with eigenvalue algorithms if possible)

[Nathan Bell]

On Mon, Jun 23, 2008 at 10:23 PM, Dan Yamins <dyamins at gmail.com> wrote:

>
> 1) Does your commend imply that the current version of scipy does _not_ have
> an eigensolver? (I installed it but can't find an eigensolver in it ... )

That's correct, SciPy 0.6 does not have a sparse eigensolver.

>
> 2) How would I go about installing the ARPACK and/or LOBPCG routines that do
> exist now?  Or is it too early and they're not quite ready yet?
>

You will need to install the development version of SciPy from SVN:
http://www.scipy.org/Download#head-d0ec9f4cfbf6ed3029a2c409b6d9899586eee0e3
http://www.scipy.org/Installing_SciPy

I can confirm that both solvers work.

> 3) Finally: (and this is slightly off topic) -- I've just installed SciPy
> for the first time.  In the readme.txt for the download it mentioned
> something about having LAPACK and ATLAS installed.  However, on the scipy
> install page (for OSX, http://www.scipy.org/Installing_SciPy/Mac_OS_X), it
> doesn't mention anything about LAPACK and ATLAS -- and the instructions
> there that I followed worked without any need for those packages.    Do I
> need them?  Or are they only necessary for making certain routines faster?
>

I don't know about OSX specifically, but my understanding is that you
can build NumPy and SciPy without those libraries.  Performance in
certain dense linear algebra operations will be slower, but
scipy.sparse will be unchanged.

-- 
Nathan Bell wnbell at gmail.com
http://graphics.cs.uiuc.edu/~wnbell/