How to add different meshes in JuAFEM?

General Usage
1

I am using the package JuAFEM. I want to join three different meshes and make it into one. Below is the picture attached. Plz help.1

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final
final819Ă—484 4.91 KB

2

If the answer is
mesh= mesh1 + mesh2 + mesh3

I will declare Julia the Queen of Languages.

ps. I just tried adding some meshes with + Didn’t work. Ah well… Julia is still pretty good!

1 Like
3

I don’t think it can work that way. haha
Do you have any suggestions?

4

Not an answer, but a related note that some of us are working on a separate package for meshes in general: https://github.com/JuliaGeometry/Meshes.jl

The plan is to add functionality for mesh composition after we polish some other building blocks.

5

If you translate the coordinates so they align you can use this (adjust tol based on the meshsize):

using Tensors, JuAFEM

function merge_grids(grid1::Grid{dim,CellType}, grid2::Grid{dim,CellType}; tol=0.01) where {N, dim, CellType <: Cell{<:Any, N}}
    cells′ = copy(grid1.cells)
    nodes′ = copy(grid1.nodes)
    nodemap = Dict{Int,Int}()
    next = getnnodes(grid1) + 1
    for (i2, n2) in enumerate(grid2.nodes)
        found = false
        for (i1, n1) in enumerate(grid1.nodes)
            if norm(n1.x - n2.x) < tol
                nodemap[i2] = i1
                found = true
                break
            end
        end
        if !found
            push!(nodes′, n2)
            nodemap[i2] = next
            next += 1
        end
    end
    for c in grid2.cells
        t = ntuple(N) do i
            return nodemap[c.nodes[i]]
        end
        cell′ = CellType(t)
        push!(cells′, cell′)
    end
    return Grid(cells′, nodes′)
end

merge_grids(grid1::G, grid2::G, grids::G...) where G <: Grid =
    merge_grids(merge_grids(grid1, grid2), grids...)

Example:

using JuAFEM, Tensors

# 5-----6
# |     |
# |  2  |
# 3-----4
# |     |
# |  1  |
# 1-----2

coord1 = Vec{2}((0.0, 0.0))
coord4 = Vec{2}((1.0, 1.0))
coord3 = Vec{2}((0.0, 1.0))
coord6 = Vec{2}((1.0, 2.0))

grid1 = generate_grid(Triangle, (3,3), coord1, coord4)
grid2 = generate_grid(Triangle, (3,3), coord3, coord6)


merge_grids(grid1, grid2)
3 Likes
6

Thank you for your reply, but the function file doesnot seem to be working, I run your fuction file and the example and export it to vtk and viewed on paraview but in your example the grids overlap each other. I only intend to join my grids. The co ordinates in my grid are well defined.

grid1 = generate_grid(QuadraticQuadrilateral,(10,10), Vec{2}((0.0,4.5)), Vec{2}((0.5,4.5)), Vec{2}((0.5,5.0)), Vec{2}((0.0,5.0)))

grid2 = generate_grid(QuadraticQuadrilateral,(10,10), Vec{2}((0.0,0.0)), Vec{2}((5.0,0.0)), Vec{2}((0.5,4.5)), Vec{2}((0.0,4.5)))

grid3 = generate_grid(QuadraticQuadrilateral,(10,10), Vec{2}((0.5,4.5)), Vec{2}((5.0,0.0)), Vec{2}((5.0,5.0)), Vec{2}((0.5,5.0)))

7

Sorry, made a mistake in the process of simplifying the implementation, I corrected the code in the previous post and verified it works with your example.

1 Like
8

Thanks a ton from a beginner in Julia programming language, the code works fine.