ASM question

Barry Smith bsmith at
Tue May 12 19:55:09 CDT 2009


    Easy as A, B, C

A)   First set the overlap to zero
B)    Second call PCASMSetLocalSubdomains() with the index sets for  
each subdomain on the process (I am assuming you have these and they  
C)    Make a shell matrix with one method MatGetSubMatrices(), pass  
this matrix in as the second matrix to KSPSetOperators()
       have that method give back the created overlapped matrix it  
knows how to do as its method for MatGetSubMatrices()


Note: the index sets you pass into B tells the PCASM the vecscatters  
it needs to make.

On May 12, 2009, at 6:14 PM, Matthew Knepley wrote:

> What is the best way for the user to provide his own submatrices for  
> ASM? We have an RBF code
> that knows about geometry and the best way to create overlapped  
> matrices. This will actually be
> RASM, but I assume that is independent of the way submatrices are  
> created.
>   Matt
> -- 
> What most experimenters take for granted before they begin their  
> experiments is infinitely more interesting than any results to which  
> their experiments lead.
> -- Norbert Wiener

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