Hi,
I am using DA. For e.g.
DM da_u
call
DMDACreate3d(MPI_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,size_x,size_y,&
size_z,1,PETSC_DECIDE,PETSC_DECIDE,1,stencil_width,lx,PETSC_NULL_INTEGER,PETSC_NULL_INTEGER,da_u,ierr)
call DMCreateGlobalVector(da_u,u_global,ierr)
call DMCreateLocalVector(da_u,u_local,ierr)
To update the ghost values, I use:
call DMLocalToLocalBegin(da_u,u_local,INSERT_VALUES,u_local,ierr)
call DMLocalToLocalEnd(da_u,u_local,INSERT_VALUES,u_local,ierr)
It seems that I don't need to use global vector at all.
So what's the difference between local and global vector?
When will I need to use?:
call DMGlobalToLocalBegin(da_u,u_global,INSERT_VALUES,u_local,ierr)
call DMGlobalToLocalEnd(da_u,u_global,INSERT_VALUES,u_local,ierr)
--
Thank you
Yours sincerely,
TAY wee-beng
