[Pharo-project] Numerical packages

Nicolas Cellier nicolas.cellier.aka.nice at gmail.com
Tue May 31 22:22:51 CEST 2011


I can tell you about Smallapack as author.

First advantage: using a state of the art robust library
LAPACK + BLAS is the core of Matlab/Octave/Scilab/R/etc...
It is robust in terms of API stability, numerical stability, and
number of bugs (try finding known ones).

Second advantage: combine advantages of
- a fast and efficient number crunching library for low level primitives
- and our favourite IDE for higher level code (interpreter debugger
browser etc...)
That's the exact strategy developped by Matlab.
As a bonus, Smalltalk interpreter is faster than Matlab, and don't ask
me about Matlab language design (non) choices ;)
To reach Matlab core preformances, you need an optimized version of
BLAS (ATLAS for example).
I imagine versions of these libraries could exploit multi-core
parallelism (but I did not check status of
http://www.netlib.org/scalapack/).

Good news, I have a working Smallapack in both Dolphin and VW.
Unfortunately, the main drawback is that Squeak/Pharo is not in that list.

First, Smallapack may crash the image in Squeak/Pharo...
I've not found the reasons, but suspect some FFI problems.
Maybe I should try using a plugin rather than FFI. That seems doable
since low level FFI code is generated automatically from Lapack
comments. It's just a matter of changing code generator to generate
slang rather than FFI...

Second drawback is that loading Smallapack in a Squeak/Pharo image
requires some pre-requisite.
This is because LAPACK has the bad property of having functions with
more than 16 arguments.
Squeak/Pharo Compiler cannot handle methods with that many arguments.
I have a Compiler hack ready for handling this case.
I have not automated the process because I'm not so sure that
Gofer/Metacello are good for installing such hack (Compiler overrides
may seem evil).
But I can help any good will.

So, if you're after an off-the-shelf library working out of the box,
Smallapack is not OK.
However, if above goals fit yours, and you're willing to help, I'll be
happy to revive the project and inject a few hours into it.

Nicolas

2011/5/31 Ignacio Vivona <altobarba at gmail.com>:
> Hi all! I'm currently planning on doing some work related to resolving
> partial differential equations (shallow water) in pharo. I'm seeing a couple
> of project for dealing with vectors, matrices and some other math things.
> http://www.squeaksource.com/DHBNumerical.html
> http://www.squeaksource.com/MatrixPlugin.html
> http://www.squeaksource.com/Numerics.html
> http://www.squeaksource.com/Smallapack.html
> Has anyone any experience working with these?
> Also I'm looking at Mathmorphs (does it work in
> pharo?) http://mate.dm.uba.ar/~caniglia/mathMorphs.html and
> DrGEO http://community.ofset.org/index.php/DrGeo for doing the graphical
> interaction.
> If someone knows of some other project related please guide me.
> Thanks in advance,
> Ignacio Vivona



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