tamg: allow for abritrary number of levels

src/.depends

@@ -110,7 +110,7 @@ multigrid/tree_amg.lo : multigrid/tree_amg.f90 gs/gather_scatter.lo bc/bc_list.l
 multigrid/tree_amg_utils.lo : multigrid/tree_amg_utils.f90 gs/gather_scatter.lo multigrid/tree_amg.lo math/math.lo common/utils.lo config/num_types.lo 
 multigrid/tree_amg_aggregate.lo : multigrid/tree_amg_aggregate.f90 common/log.lo mesh/mesh.lo comm/comm.lo config/num_types.lo common/utils.lo multigrid/tree_amg.lo 
 multigrid/tree_amg_multigrid.lo : multigrid/tree_amg_multigrid.f90 common/log.lo multigrid/tree_amg_smoother.lo multigrid/tree_amg_aggregate.lo multigrid/tree_amg.lo gs/gather_scatter.lo bc/bc_list.lo math/ax.lo sem/space.lo mesh/mesh.lo sem/coef.lo comm/comm.lo math/math.lo common/utils.lo config/num_types.lo 
-multigrid/tree_amg_smoother.lo : multigrid/tree_amg_smoother.f90 gs/gather_scatter.lo bc/bc_list.lo krylov/krylov.lo math/math.lo common/utils.lo config/num_types.lo multigrid/tree_amg_utils.lo multigrid/tree_amg.lo 
+multigrid/tree_amg_smoother.lo : multigrid/tree_amg_smoother.f90 common/log.lo gs/gather_scatter.lo bc/bc_list.lo krylov/krylov.lo math/math.lo common/utils.lo config/num_types.lo multigrid/tree_amg_utils.lo multigrid/tree_amg.lo 
 multigrid/phmg.lo : multigrid/phmg.f90 krylov/krylov.lo math/math.lo sem/interpolation.lo multigrid/tree_amg_multigrid.lo math/ax.lo krylov/bcknd/cpu/pc_jacobi.lo krylov/bcknd/cpu/cheby.lo common/utils.lo bc/dirichlet.lo bc/bc_list.lo bc/bc.lo mesh/mesh.lo sem/coef.lo field/field.lo sem/dofmap.lo sem/space.lo gs/gather_scatter.lo krylov/precon.lo config/num_types.lo 
 common/checkpoint.lo : common/checkpoint.f90 mesh/mesh.lo common/utils.lo field/field.lo device/device.lo sem/space.lo field/field_series.lo config/num_types.lo config/neko_config.lo 
 io/generic_file.lo : io/generic_file.f90 comm/comm.lo common/utils.lo config/num_types.lo 

src/multigrid/tree_amg_multigrid.f90

@@ -92,7 +92,7 @@ subroutine tamg_mg_init(this, ax, Xh, coef, msh, gs_h, nlvls_in, blst, max_iter)
     type(bc_list_t), target, intent(in) :: blst
     integer, intent(in) :: nlvls_in
     integer, intent(in) :: max_iter
-    integer :: nlvls, lvl, n, cheby_degree, env_len, mlvl
+    integer :: nlvls, lvl, n, cheby_degree, env_len, mlvl, target_num_aggs
     integer, allocatable :: agg_nhbr(:,:), asdf(:,:)
     character(len=255) :: env_cheby_degree, env_mlvl
     character(len=LOG_SIZE) :: log_buf
@@ -112,26 +112,27 @@ subroutine tamg_mg_init(this, ax, Xh, coef, msh, gs_h, nlvls_in, blst, max_iter)
     write(log_buf, '(A28,I2,A8)') 'Creating AMG hierarchy with', nlvls, 'levels.'
     call neko_log%message(log_buf)
 
-    if (nlvls .gt. 4) then
-      call neko_error("Can not do more than four levels right now. I recommend two or three.")
-    end if
-
     allocate( this%amg )
     call this%amg%init(ax, Xh, coef, msh, gs_h, nlvls, blst)
 
     !> Create level 1 (neko elements are level 0)
     call aggregate_finest_level(this%amg, Xh%lx, Xh%ly, Xh%lz, msh%nelv)
 
-    if (nlvls .gt. 2) then
-      call print_preagg_info(2,(msh%nelv/8))
-      call aggregate_greedy(this%amg, 2, (msh%nelv/8), msh%facet_neigh, agg_nhbr)
-    end if
-
-    if (nlvls .gt. 3) then
-      call print_preagg_info(3,(this%amg%lvl(2)%nnodes/8))
-      call aggregate_greedy(this%amg, 3, (this%amg%lvl(2)%nnodes/8), agg_nhbr, asdf)
-    end if
+    !> Create the remaining levels
+    allocate( agg_nhbr, SOURCE=msh%facet_neigh )
+    do mlvl = 2, nlvls-1
+      target_num_aggs = this%amg%lvl(mlvl-1)%nnodes / 8
+      call print_preagg_info( mlvl, target_num_aggs)
+      if ( target_num_aggs .lt. 4 ) then
+        call neko_error("TAMG: Too many levels. Not enough DOFs for coarsest grid.")
+      end if
+      call aggregate_greedy( this%amg, mlvl, target_num_aggs, agg_nhbr, asdf)
+      agg_nhbr = asdf
+      deallocate( asdf )
+    end do
+    deallocate( agg_nhbr )
 
+    !> Create the end point
     call aggregate_end(this%amg, nlvls)
 
     this%max_iter = max_iter