[petsc-users] Updating the ghost nodes for distributed arrays

[Barry Smith]

On Dec 14, 2010, at 4:15 AM, Mohamad M. Nasr-Azadani wrote:

> Hi guys, 
> 
> Is it possible to update the ghost values from a global to a local vector for distributed arrays when global and local vectors are not from the same DA, but the global vectors are the same?

Yes

> This is the the code that I have, (the only difference between the two DA's is the width. So, I am assuming that any global vector created based on those are going to be the same)

Yes


> 
> G_data is created based on DA_3D, whereas L_data2 is created based on DA_3D2. 
> 
> 
>         Vec G_data, L_data; 
>         Vec G_data2, L_data2; 
>         
> 
> 	ierr = DACreate3d(PCW, DA_NONPERIODIC, DA_STENCIL_STAR, NX, NY, NZ, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE, 1, width, PETSC_NULL, PETSC_NULL, PETSC_NULL, &DA_3D);
> 	ierr = DACreate3d(PCW, DA_NONPERIODIC, DA_STENCIL_STAR, NX, NY, NZ, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE, 1, width+2, PETSC_NULL, PETSC_NULL, PETSC_NULL, &DA_3D2);
> 
> 	ierr = DACreateGlobalVector(DA_3D, &G_data); CHKERRQ(ierr);
> 	ierr = DACreateLocalVector(DA_3D, &L_data); CHKERRQ(ierr);
> 
> 	ierr = DACreateGlobalVector(DA_3D2, &G_data2); CHKERRQ(ierr);
> 	ierr = DACreateLocalVector(DA_3D2, &L_data2); CHKERRQ(ierr);
> 
> /* =====> Is this possible? */
> 	ierr = DAGlobalToLocalBegin(DA_3D2, G_data, INSERT_VALUES, L_data2);CHKERRQ(ierr);
> 	ierr = DAGlobalToLocalEnd(DA_3D2, G_data, INSERT_VALUES, L_data2);CHKERRQ(ierr);
> 
> 
> Thanks, 
> Mohamad
>