Re: [pooma-dev] Sparse Engine

[Sergei Mingaleev]

Hello, Jean:

>> John and I are starting to write a sparse engine -- for sparse storage of
>> our material-dependent fields.  
>> ....
>> only demonstrates how to build the engine, not an array or a field.  Could
>> someone please show us how to move forward with this example to building a
>> complete array and field version?

I has written some time ago a simple version of the SparseEngine - 
see it attached.  At the momemnt the Engine works only with 2D 
and 4D arrays, and it cannot be parallelized. 

I don't really like it - it should be completely rewritten - but may 
be, it could be useful for you as an example?

The main file:  SparseEngine.h

All other files are included from the main file:

  SparseEngine2.h - support for 2D Arrays. 
  SparseEngine4.h - support for 4D Arrays.
  SparseOperators.h - some operators.

The program starts with: 

#define SPL_DEBUG_SPARSE
#include "SparseEngine.h"

The Sparse Array can be created as usually:

  Array<2,Sparse>  A(I,J);

I have not tried, but I guess, it should work with Field class, too.

The SparseEngine contains some specific functions, which can 
be accessed as demonstrated in the example below: 

#ifdef SPL_DEBUG_SPARSE
  A.engine().pack();  // compactify the Sparse Array...
  cout << "Sparse Array Filling = " 
       << int(100*(1.0-A.engine().free()/(double)(A.engine().size())))
       << " %" << endl;
#endif

There are predefined constants:

#define SPARSE_TOLERANCE  1e-10
#define SPARSITY_LEVEL  0.5

Before I tried to define these constants in the SparseEngine constructors 
and initialize() functions, but it worked badly - the problem is that
constructors and initializators of Arrays have some restrictive 
assumptions concerning the corresponding functions of Engines. 

Best wishes,
Sergei.

-- 
----  ---  ---  ---  ---  ---  ---  ---  ---  ---  ---
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: address@hidden
Web:    http://www-tkm.physik.uni-karlsruhe.de/~smino/  
        http://wwwrsphysse.anu.edu.au/nonlinear/sfm/
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SparseEngine.h
Description: SparseEngine.h

SparseEngine2.h
Description: SparseEngine2.h

SparseEngine4.h
Description: SparseEngine4.h

SparseOperators.h
Description: SparseOperators.h