Re: GSL and ALGLIB

[Brian Gough <bjg@gnu.org>]

At Tue, 13 Apr 2010 14:20:51 +0400,
Sergey Bochkanov wrote:
> What  do  GSL  developers think about using source code from ALGLIB in
> GSL?   
> 
> ALGLIB  is an open source numerical analysis library distributed under
> GPL   2+.  It  uses  automatic  translation  from  specially  designed
> pseudocode  to  provide  same functionality in C++, C#, FreePascal and
> other  programming  languages.  Project  aims  to  be highly portable,
> compiler-  and  OS-independent. It is actively developed (new releases
> each month).
> 
> ALGLIB contains many interesting algorithms which are missing in GSL.
> 
> For example, it includes:
> * limited memory BFGS optimizer
> * improved Levenberg-Marquardt optimizer
> * bound constrained optimizer
> * 2-dimensional   interpolation  (bilinear/bicubic  splines)
> * scattered N-dimensional interpolation/fitting with linearithmic
>   complexity.
> 
> It  should  be easy to write GSL-ish wrapper for ALGLIB. I can help if
> someone  wants to implement it. However it is unclear what is GSL devs
> position  on  using  external libraries. I've read past discussions on
> FLAME and FFTW, but there was no decision.

Hello Sergey

Thanks for your email.  There are two concerns here, licensing and
technical.

Regarding licensing, I think we corresponded about ALGLIB a couple of
years ago and I asked if the underlying converter was free software
(which it was not at that time).  The GPL defines source code as "the
preferred form of the work for making modifications to it" -- which in
this case is the underlying algorithm definitions for the converter,
not the individual routines.  We could only consider using other code
if all the associated software (and documentation) is free.

Whether it makes sense techically to use ALGLIB in GSL, it is
difficult for me to comment without the converter being free software
and available to study.

I do think the principle of converting to different languages from a
common source is a good one and would encourage you to consider
releasing everything under a free software license, whether or not we
might use parts of it.

-- 
best regards

Brian Gough

GNU Scientific Library -
http://www.gnu.org/software/gsl/