[pooma-dev] Sparse Engine

[Sergei Mingaleev]

>> But maybe we're again talking about "different" sparsity here... I'd call
>> the unused (what you call zero) elements not participate in calculation,
>> just like with an arbitrary shaped domain. You seem to suggest more like a
>> compressed engine approach?

Yes, we are talking about different sparsity here. I mean just an extension 
of the Sparse Matrix approach - and the requirements for the preformance in 
this case are rather specific - optimization for the matrix-matrix and 
matrix-vector multiplication, in particular. Even log(N) search is too long 
if we have many array-array multiplications - the situation which I have in 
some of my programs. Of course, for different problems one can need different 
types of sparsity and, correspondingly, different Engines. For example, 
sometimes I feel that I really need Arrays with arbitrary shaped domains 
which can be realized as you suggested. 

By the way - sometimes, for some specific problems, we really need some 
additional Engines and some other classes/subroutines, which are not generic 
enough to be included into Pooma - but which could be very useful being 
included into some "contributions" packages - they can include, besides new  
Engines, support for Array/Field visualization, input/output of classes in 
different storage formats, some primitive linear/nonlinear algebra 
subroutines like solving a system of equations, etc. Is it possible to create 
and manage the directory for such contributions on Pooma.CodeSourcery.com? 
I think it would be a good place also for testing new unstable features of 
Pooma or for alternative realizations of some of its classes. 

Cheers,
Sergei.

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Dr. Sergei Mingaleev
Institut fur Theorie der Kondensierten Materie
Universitat Karlsruhe, 76128 Karlsruhe, Germany 
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Phone:  +49-(721)-608-2136   Fax:   +49-(721)-608-7779
E-mail: smino at tkm.physik.uni-karlsruhe.de
Web:    http://www-tkm.physik.uni-karlsruhe.de/~smino/  
        http://wwwrsphysse.anu.edu.au/nonlinear/sfm/
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