[SciPy-dev] Introductions, sparse matrix support

[Ed Schofield]

Hi all,

First of all, let me congratulate Travis, Robert, Pearu, and the other 
core developers for their great work on SciPy and SciPy Core.  I'd like 
to introduce myself and express my interest to get involved.

I'm the author of a toolkit for maximum entropy modelling (with the 
misleading Sourceforge project name 'textmodeller') that uses SciPy and 
PySparse.  I've been reading the scipy-dev list for about a year with 
interest.  Now I'd like to get involved in SciPy development, starting 
with improving the sparse matrix module and, when that's in shape, 
contributing my maxent module to SciPy (if you want it!)

I've made small contributions to PySparse in the past and briefly 
discussed the idea of merging PySparse into SciPy with Roman Geus by 
email.  His comment in April was:

"So far I  have not had contacts to the scipy people, and admittedly I 
have never even installed scipy. When creating pysparse (some years ago 
now) I liked the idea of smaller well-definied packages more, than a big 
collection dependent packages. "

I broadly agree with this philosophy, and it has served PySparse 
development well until now, but in this case I think that there's value 
to the community in having a well-integrated core of matrix 
functionality (sparse and dense) and one set of prerequisites and 
interfaces rather than several.

Jonathan mentioned that he'd collect some stats on how pysparse and 
scipy.sparse stack up.  If we're cherry-picking among different sparse 
matrix implementations, here's a qualitative assessment: PySparse has 
several advantages, including a mature and apparently well-written code 
base, a simple interface, some good documentation, even a good set of 
unit tests.  These were the reasons I adopted it for my maximum entropy 
module 1-2 years ago.  It has some momentum too as a project, with a 
small but steady number of patches flowing in since Roman stopped active 
development a couple of years ago.

I'd be happy to work with Jonathan, Dan, and Robert on sparse matrix 
support in SciPy, integrating PySparse code with Travis and Robert's 
UMFPACK wrapper.  Perhaps we could even find support among other 
PySparse developers.  PySparse currently depends on Numeric, and will 
need porting to SciPy Core eventually...