[Gsll-devel] Common approach to scientific/mathematical/engineering software

[Liam Healy]

I'm changing the subject line here...

On Sat, Jul 4, 2009 at 3:50 PM, A.J. Rossini<blindglobe at gmail.com> wrote:
> On Sat, Jun 27, 2009 at 7:23 PM, Liam Healy<lhealy at common-lisp.net> wrote:
>
>> On another subject, I notice you have been doing a lot of work on Lisp
>> interfaces to other science/engineering/math libraries, like R.  My
>> intent in building GSLL was that it would become part of a collection
>> of systems that would have consistent use and interchange of data
>> between different libraries.  So for example, you would be able to
>> make an object representing an array, call a GSLL function, then pass
>> the resulting array to R.  There are a lot of aspects of this problem,
>> but I'm thinking about array standardization as a start.  Do you have
>> any thoughts on this?
>
> The RCLG package has some stuff in the right direction (Rif wrote it,
> I'm maintaining it).  RCL and CLSR, 2 others, have respectively,
> better lispy interfaces and some better internals (roundtrip and
> better object mapping).  I'd look at Cyrus Harmon's CLSR as a start,
> as much as I'd love to have you contribute to RCLG.

My idea at this point was less to contribute to a specific project
than it was to try to find a common approach to dealing with
e.g. arrays and similar structures.  However, discussions can only go
so far without actual code, so the specific projects are important.
It would take me a long time to crack the R packages to see how they
deal with arrays (I haven't used them) than it would be to describe
what I did with GSLL in this regard and let others who know better
about other packages see what common elements are there.

>
> We ought to be able to seemlessly use R's S4 object systems right out
> of CL, it's just CLOS reinvented poorly (so have to add some bugs to
> get the proper mapping, but sigh, you get the point).

Interesting.  I hadn't heard about S4.  It seems like that might be a
major task to integrate with CLOS.  But, do people really need that?
My goal isn't so much to re-implement another programming language but
to make library functions available in CL.  I realize that it's not
easy to divide something R up like that.

>
> So yes, I've got lots of thoughts on this, but I'm not nearly a good
> enough lisp programmer to make enough progress on what I want to do,
> and I need to get a few working pieces before heading back to
> integration.
>
> And BTW, I am working to see about using GSLL as a feasible backend
> for the lisp-matrix stuff, as you've done a fine job on the overall
> system development and internals, as well as for some of the other
> numerical stuff -- however, it would be great to have a robust and
> consistent front end to many different numerical libraries for testing
> numerical stability and comparability.
>
> All this just to be able to wrap a sensible statistical DSL directly
> on top of CL, keeping all of CL around, so that I can once and for all
> forget about R's annoying syntax burps.
>
> (I do like R, having been responsible for many user-level innovations
> and demonstrations with it, but it truly sucks as a platform for
> statistical computing research; it's great for just "computing
> statistical stuff").
>
> Let me know if there is anything I can do to help out (I don't have
> much time, but it'll help me in the long run).
>
> best,
> -tony

I think not much time is a common problem for all of us.  I will be
essentially without network access starting next week through
mid-August, so I can't do anything until at least then.  But at some
point after that I will write something short on how GSLL deals with
arrays, why I did it that way, and what I would like to see added.
Perhaps that will spur a discussion of these ideas.

In the meantime, Tom Hermann has been thinking about some of these
issues.  I think he is now subscribed to this mailing list, but just
in case I have cc'ed him here.  I don't know what the release state of
his work is, but when he feels comfortable with it he can post it
somewhere for discussion.

Thanks for your feedback.


Liam