[petsc-dev] MetSetBlockSize issue

[Barry Smith]

On Apr 25, 2012, at 4:58 PM, Jed Brown wrote:

> On Wed, Apr 25, 2012 at 16:41, Barry Smith <bsmith at mcs.anl.gov> wrote:
>  I admit MatSetVirtualColumnBlockSize() is clunky and would be happy to hear alternatives.
> 
> What about having a separate row and column block size? The BAIJ and MAIJ formats can continue to store data using bs=gcd(rowbs,colbs), but those row and column block sizes indicate that redundancy exists in the data structure, so it can be utilized by appropriate operations.

  Mark told me in a earlier email that the "column block size" isn't really the column block size (except in some cases), since it is not really a column block size I don't want the matrix to list it as the column block size (hence my virtual column block size thing).

  If it is truly a column block size then great, P is given the column block size with MatSetColumnBlockSize() or MatSetBlockSizes(mat,col,row) and PtAP automatically uses that column block size for the resulting matrix block size.

   So Mark I ask you again, in GAMG is it truly a column block size?

   Barry