jannisteunissen / octree-mg Goto Github PK

Hi

According to the paper on this code, 2:1 balance is imposed. Could you please whice subroutine implemented the 2:1 balance?

Thanks

Hi

Sorry to bother you again.

I am interested to build a simulation code for incompressible flow based on this library. In the simulation, all variables live in 'leaves', and the ghost cells are necessary for calculation (such as gradient) for interior cells. Since ghost cells do not have all neighboor cells avaiable, they cannot be calculated according the governing equations, but rely on interpolation from neighboor boxes. To interpolate, I tried calling mg_restrict followed by mg_fill_ghost_cells, but the ghost cells are not filled.

I then went back to experiment with the test example "test_refinement.f90". I revised this example so that the set_solution is only done for the interior cells of leaves, and output the i_sol field in Tecplot format. The ghost cells are also zero from what I can see. The revised `set_solution' is attached in the following.

Could you please help? Thank you very much

==================

` subroutine set_solution(mg)
use mpi
type(mg_t), intent(inout) :: mg
integer :: n, id, lvl, nc
real(dp) :: r(NDIM), sol
integer ic, iwrk, i,j,k, irank, ierr
real(dp) x,y,z

do lvl = mg%lowest_lvl, mg%highest_lvl
   nc = mg%box_size_lvl(lvl)
   do n = 1, size(mg%lvls(lvl)%my_leaves)
      id = mg%lvls(lvl)%my_leaves(n)
      do KJI_DO(1, nc)
         r = mg%boxes(id)%r_min + ([IJK] - 0.5_dp) * mg%dr(:, lvl)
         sol = product(sin(2 * pi * n_modes * r))
         mg%boxes(id)%cc(IJK, i_sol) = sol
      end do; CLOSE_DO
   end do
end do

! Set ghost cells for the solution. Because they depend on coarse-grid
! values, first restrict the solution.
call mg_restrict(mg, i_sol)
call mg_fill_ghost_cells(mg, i_sol)

if(mg%my_rank ==0) then
write(,) 'Writing Tecplot file'
open(1, file = 'out.dat', status = 'REPLACE')
write(1,*) 'Variables = x, y, z, u'
close(1)
end if

do irank = 0, mg%n_cpu-1
if(mg%my_rank == irank) then
open(1, file = 'out.dat', position="append", &
status="old", action="write")
do lvl = mg%lowest_lvl, mg%highest_lvl
nc = mg%box_size_lvl(lvl)
do n = 1, size(mg%lvls(lvl)%my_leaves)
id = mg%lvls(lvl)%my_leaves(n)
write(1,) 'zone i = ', nc+2, ' j = ', nc+2, ' k = ',nc+2
do k = 0, nc+1
do j = 0, nc+1
do i = 0, nc+1
x = mg%boxes(id)%r_min(1) + (real(i,8) - 0.5_dp) * mg%boxes(id)%dr(1)
y = mg%boxes(id)%r_min(2) + (real(j,8) - 0.5_dp) * mg%boxes(id)%dr(2)
z = mg%boxes(id)%r_min(3) + (real(k,8) - 0.5_dp) * mg%boxes(id)%dr(3)
write(1,) x, y, z, mg%boxes(id)%cc(i,j,k,i_sol)
end do
end do
end do
end do
end do
close(1)
end if
call MPI_Barrier( MPI_COMM_WORLD,ierr)
end do

end subroutine set_solution`

I suggest adding the topics pde, quadtree, octtree, multigrid, mpi in the About section