dsimcha wrote:
== Quote from Lars T. Kyllingstad ([email protected])'s article
I've just created a new dsource project and uploaded my collection of
numerical routines. You can find it here:
   http://www.dsource.org/projects/scid
Hopefully others will find it useful as well. Most of the code is
written with a "get it to work - NOW" philoshophy, and as such there is
a lot of potential for improvement and polish, not least when it comes
to performance. I am aware of this, so there is really no need to
benchmark it against established scientific libraries quite yet. ;) More
routines will be added as I write them (which is usually when I need
them for work), and the existing ones will be polished whenever I have
time to do so.
Huge thanks to Bill Baxter for letting me use his BLAS and LAPACK bindings!
Requirements:
   DMD 2.037
   BLAS and LAPACK libraries
-Lars

This looks absolutely terrific given that it's a work in progress and all.  I
agree that we shouldn't be too obsessed with performance yet because:

1.  **Make it work**, make it right, make it fast.  We can always optimize it
later provided that there aren't any ridiculously bad design decisions.

A lot of the code is ported from 20-30 year old (i.e. extremely well tested) FORTRAN code, so any performance gains would be a bonus provided by the D language itself, and most likely not in the algorithms.

Also, if you spot any ridiculously bad design decisions, let me know. ;)


2.  At least some of the time people (myself included) would rather a nice API 
and
decent performance than an ugly API (read:  a straight Fortran or C API) and
lightening quick performance.

Yeah, that's what I think too. And, the way it is now, people who for some reason want to use the old-style api can just access the scid.ports functions directly.


We've got the beginnings of a good matrix/numerics lib in your work.  I believe
that my dstats lib would provide just about all the statistical functionality a
good scientific lib would need, and I'm getting close to declaring it
beta-quality.  I'd say based on a quick look at what scipy has that we also need
the following for a credible full-fledged scientific lib:

Machine learning, i.e. classification and clustering.  (I'd probably be 
qualified
to write that and was halfway thinking of breaking ground on it over Christmas
break.  However, I'm not committing to this yet, so if someone else already has 
a
work in progress, let me know.  Also, there's a Java machine learning library
called Weka that I've used before.  It's very complete but the API is painful 
and
it's GPL, so IDK if it'd be worth it to port to D.)

Optimization.  (A few people have tried but IDK if they've actually gotten far 
off
the ground with it.)

Basic image I/O and processing.

Plotting.  I've considered doing this a few times, but I've decided it needs to 
be
put off until D2 is stable and the GUI toolkits for it are reasonably stable.  
One
layer of instability (D2 itself) is workable, but two layers (D2 and the GUI 
libs)
is not.

I agree with all of this. Here's a piece of advice to anyone who wants to try their hand at these and other things: There are a LOT of established and *extremely* well-tested numerical libraries lying around on the internet, and many of them are in the public domain. Instead of spending a lot of time re-inventing the wheel (I've tried it), port some old code and try to improve on it when you get it working. Here are a few starting points:

  http://www.netlib.org/
  http://gams.nist.gov/

And I forgot to say in my original announcement: I welcome contributors with open arms. I have no intention of making this a one-man show. If you want to contribute or participate in some way, let me know.

-Lars

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