column map in Mat MPIAdj

[Barry Smith]

    The normal pattern (for example MPIAIJ, MPIBAIJ) is for the  
PetscMap setup
being done in the associated MatXXXSetPreallocation() routine.

    I think the correct fix is
1) change the  ierr =  
MatSetSizes(*A,m,n,PETSC_DETERMINE,n);CHKERRQ(ierr);
in MatCreateMPIAdj to  ierr =  
MatSetSizes(*A,m,PETSC_DECIDE,PETSC_DETERMINE,n);CHKERRQ(ierr);

2) remove the two lines
   if (B->cmap->n  < 0) B->cmap->n = B->cmap->N;
   if (B->cmap->N  < 0) B->cmap->N = B->cmap->n;
from MatCreate_MPIAdj()

3) either add the   ierr = PetscMapSetUp(B->cmap);CHKERRQ(ierr); to
MatCreate_MPIAdj() OR put the PetscMapSetUp() for both rmap and
cmap into MatMPIAdjSetPreallocation() [this would be best cause it  
matches
the pattern of the others]

    Or am I missing something.

    Barry

The business of setting the local column size to the global column  
size came from
long ago and probably makes no sense any more.

On Dec 3, 2008, at 9:36 AM, Lisandro Dalcin wrote:

> Sorry, my comment about PETSC_COMM_SELF was a nonsense :-(
>
> Let me write the rule in C-Python-pseudocode
>
> rank = mat->comm->rank
> size = mat->comm->size
>
> cmap->N = # total_columns
>
> for p in range(size):
>   if p == rank:
>      mat->cmap->n = cmap->N
>   else:
>      mat->cmap->n = 0
>
> # and finally
> PetscMapSetUp(mat->cmap)
>
> That would be fine?
>
>
> On Wed, Dec 3, 2008 at 1:19 PM, Lisandro Dalcin <dalcinl at gmail.com>  
> wrote:
>> Can someone help me to review this routine?
>>
>> MatCreate_MPIAdj(Mat B)
>>
>> I understand that MATMPIADJ is rather special, but the call above  
>> is never made
>>
>> PetscMapSetUp(B->cmap)
>>
>> then It seems that some stuff (ranges) in the column map will be  
>> uninitialized.
>>
>> What values should have the entries in "cmap" for mpiadj matrices?
>> Should the "comm" in "cmap" be MPI_COMM_SELF, then we can call
>> PetscMapSetUp?
>>
>>
>>
>>
>> --
>> Lisandro Dalcín
>> ---------------
>> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
>> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
>> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
>> PTLC - Güemes 3450, (3000) Santa Fe, Argentina
>> Tel/Fax: +54-(0)342-451.1594
>>
>
>
>
> -- 
> Lisandro Dalcín
> ---------------
> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
> PTLC - Güemes 3450, (3000) Santa Fe, Argentina
> Tel/Fax: +54-(0)342-451.1594
>