atilasaraiva/compgrids.jl

Creates computational grids that can be used with ParallelStencil.jl or PETSc.jl

CompGrids.jl

Creates computational grids and initializes fields on these grids that can be used with ParallelStencil.jl or PETSc.jl

The basic idea is that you specify a backend (ParallelStencil or PETSc), after which the grid can be created. A 2D example using ParallelStencil & ImplicitGlobalGrid:

julia> using CompGrids, MPI, ParallelStencil, ImplicitGlobalGrid, PETSc
julia> @init_backend(ParallelStencil, Threads, true, 2);
julia> grid = RegularRectilinearCollocatedGrid(size=(10,20), extent=(100.0,110), fields=(T=0,P=11.22))
Global grid: 12x22x1 (nprocs: 1, dims: 1x1x1)
RegularRectilinearCollocatedGrid{Float64, 2, Backend{BackendParallelStencil, Float64}}
        Backend: ParallelStencil ( Threads | MPI ) 
       gridtype: Collocated 
         domain: x ∈ [-50.0, 50.0], y ∈ [-55.0, 55.0] 
       topology: (Bounded, Bounded)
     resolution: (10, 20) (global, no halo)
                 (12, 22) (local  + halo)
                 (12, 22) (global + halo)
 grid spacing Δ: (11.11111111111111, 5.7894736842105265)
         fields: (:T, :P)

We can initialize the same grid, but using the PETSc MPI-parallel backend, by changing one line:

julia> @init_backend(PETSc, Threads, true, 2);
julia> grid = RegularRectilinearCollocatedGrid(size=(10,20), extent=(100.0,110), fields=(T=0,P=11.22))
RegularRectilinearCollocatedGrid{Float64, 2, Backend{BackendPETSc, Float64}}
        Backend: PETSc ( Threads | MPI ) 
       gridtype: Collocated 
         domain: x ∈ [-50.0, 50.0], y ∈ [-55.0, 55.0] 
       topology: (Bounded, Bounded)
     resolution: (10, 20) (global, no halo)
                 (10, 20) (local,  no halo)
 grid spacing Δ: (11.11111111111111, 5.7894736842105265)
         fields: (:T, :P) 

The resulting grid is a structure that holds information about the grid (the global grid in case it is run on one core, and the local portion in case it is run in MPI-parallel). If indicated, it also initializes the fields (as a global vector for the PETSc and as 1D/2D/3D arrays for PS), which you can access with grid.fields.T or grid.fields[:T] (for the examples above).

Development

This is work in progress. If you want to get a feel for it, have a look at the test and examples directories.

• The functionality is fairly complete for collocated grids (using PS and PETSc).
• Staggered grid support will be added
• Support for other types of structurally regular grids (e.g., cylindrical, yin-yang?) should be fairly straightforward to add as well, but as we don't use these grids on a daily basis, we would require volunteers to help with this
• Adding interfaces to other types of meshes (finite elements, AMR) could be added as well, but would require external volunteers