[petsc-users] Questions about MatConvert BAIJ to AIJ

[Barry Smith]

  Do you mean that some entries in the matrices are different? That the nonzero structure is different? Something else?

  In general if you are putting the values in with MatSetValuesBlocked() then I would expect the resulting matrices to have the same entries (though once you start solvers such as ILU you will have different convergence results).

  Barry

> On Mar 18, 2015, at 12:12 PM, Chung-Kan Huang <ckhuangf at gmail.com> wrote:
> 
> Hi,
> 
> I created matrix with MATBAIJ and I use  
>     MatConvert(J, MATAIJ, MAT_REUSE_MATRIX, & J);
> to convert it to MATAIJ.
> 
> I ran some tests 
> MATBAIJ: create & use MATBAIJ for later assembly
> MATBAIJ2MATAIJ: create as MATBAIJ then convert to MATAIJ & use MATAIJ for later assembly
> MATAIJ: create & use MATAIJ for later assembly
> 
> and I found following results
> 
> 
> MATBAIJ == MATBAIJ2MATAIJ != MATAIJ
> as I was expected to see
> MATBAIJ != MATBAIJ2MATAIJ == MATAIJ
> 
> Is it a potential of bug or it is what I should actually expect?
> 
> Thanks,
> Kan
> -- 
> Cheers
>