On Sat, Sep 12, 2009 at 3:19 AM, Leo Razoumov <slonik...@gmail.com> wrote: > On 9/10/09, Rohit Garg <rpg....@gmail.com> wrote: >> [..snip..] >> But that still begs the question. Why would you want to use GSL's >> linear algebra subset? > > Here are few: > (1) Simplicity of GSL design > (2) No expression templates !! I do not agree with you here, but if you like GSL's approach better here, then good for you.
> (3) support for BLAS with vectorized optimizations (SSE2 and later) I was under the impression that gsl's blas was fairly generic and you had to use ATLAS and the like to get good performance and vectorization. Or are you referring to gsl compiled with auto-vectorization? > (4) total manual control of resources I certainly have less experience than you, and I _demand_ total manual control over my code when I am optimizing it. But since eigen is a purely template library, I think it offers you more choices. BTW, I mostly link with fedora's gsl packages, so our POV may be different. How do you use gsl ( in terms of compiling/compile options/linking etc. ) ? > > I do not want to derogate your project. It could well be very good, > indeed. But my 15+ years of large scale numerical simulations taught > me few lessons. I would pick a simple, clean library with manual > resource management numeric and flat debugging anytime over a "smart" > library like Boost or eigen for that matter. Agreed, overall choice depends on many factors. smartness is one of them. > more crucial. And when you optimize algorithms you want to be very > close to your hardware and have full manual control. In numerics I see > people going from C to asm more often than to C++. How about this for a manual control over optimization http://listengine.tuxfamily.org/lists.tuxfamily.org/eigen/2009/01/msg00234.html The product would have been auto vectorized if the size was a multiple of 2. (3 in this case). Just my 1 cent. :) PS: GSL's non linear algebra subset is great, and I am really thankful to the devs for this. -- Rohit Garg http://rpg-314.blogspot.com/ Senior Undergraduate Department of Physics Indian Institute of Technology Bombay _______________________________________________ Help-gsl mailing list Help-gsl@gnu.org http://lists.gnu.org/mailman/listinfo/help-gsl