Files
JuliaFEM.jl/test/basis/test_kronecker_delta.jl
T
Jukka Aho f67ec02006 test(basis): load JuliaFEM in Kronecker-delta checks
Kronecker tests should exercise exported Lagrange evaluation helpers together with
topology types from the package root.

- Swap fragile src includes for `using JuliaFEM`.
2026-05-09 18:43:32 +03:00

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2.8 KiB
Julia

# Test basis functions at element nodes
# At a node, the corresponding basis function should be 1, all others 0 (Kronecker delta property)
using Test
using StaticArrays, Tensors
using JuliaFEM
@testset "Kronecker Delta Property at Nodes" begin
@testset "Seg2 at nodes" begin
# Node 1: xi = -1
N = get_basis_functions(Seg2(), Lagrange{1}(), Vec{1}((-1.0,)))
@test N[1] ≈ 1.0 atol = 1e-14
@test N[2] ≈ 0.0 atol = 1e-14
# Node 2: xi = 1
N = get_basis_functions(Seg2(), Lagrange{1}(), Vec{1}((1.0,)))
@test N[1] ≈ 0.0 atol = 1e-14
@test N[2] ≈ 1.0 atol = 1e-14
end
@testset "Tri3 at nodes" begin
# Node 1: (0, 0)
N = get_basis_functions(Tri3(), Lagrange{1}(), Vec{2}((0.0, 0.0)))
@test N[1] ≈ 1.0 atol = 1e-14
@test N[2] ≈ 0.0 atol = 1e-14
@test N[3] ≈ 0.0 atol = 1e-14
# Node 2: (1, 0)
N = get_basis_functions(Tri3(), Lagrange{1}(), Vec{2}((1.0, 0.0)))
@test N[1] ≈ 0.0 atol = 1e-14
@test N[2] ≈ 1.0 atol = 1e-14
@test N[3] ≈ 0.0 atol = 1e-14
# Node 3: (0, 1)
N = get_basis_functions(Tri3(), Lagrange{1}(), Vec{2}((0.0, 1.0)))
@test N[1] ≈ 0.0 atol = 1e-14
@test N[2] ≈ 0.0 atol = 1e-14
@test N[3] ≈ 1.0 atol = 1e-14
end
@testset "Quad4 at nodes" begin
# Node 1: (-1, -1)
N = get_basis_functions(Quad4(), Lagrange{1}(), Vec{2}((-1.0, -1.0)))
@test N[1] ≈ 1.0 atol = 1e-14
@test N[2] ≈ 0.0 atol = 1e-14
@test N[3] ≈ 0.0 atol = 1e-14
@test N[4] ≈ 0.0 atol = 1e-14
# Node 3: (1, 1)
N = get_basis_functions(Quad4(), Lagrange{1}(), Vec{2}((1.0, 1.0)))
@test N[1] ≈ 0.0 atol = 1e-14
@test N[2] ≈ 0.0 atol = 1e-14
@test N[3] ≈ 1.0 atol = 1e-14
@test N[4] ≈ 0.0 atol = 1e-14
end
@testset "Tet4 at nodes" begin
# Node 1: (0, 0, 0)
N = get_basis_functions(Tet4(), Lagrange{1}(), Vec{3}((0.0, 0.0, 0.0)))
@test N[1] ≈ 1.0 atol = 1e-14
@test all(N[2:4] .≈ 0.0)
# Node 2: (1, 0, 0)
N = get_basis_functions(Tet4(), Lagrange{1}(), Vec{3}((1.0, 0.0, 0.0)))
@test N[2] ≈ 1.0 atol = 1e-14
@test N[1] ≈ 0.0 atol = 1e-14
@test N[3] ≈ 0.0 atol = 1e-14
@test N[4] ≈ 0.0 atol = 1e-14
end
@testset "Hex8 at nodes" begin
# Node 1: (-1, -1, -1)
N = get_basis_functions(Hex8(), Lagrange{1}(), Vec{3}((-1.0, -1.0, -1.0)))
@test N[1] ≈ 1.0 atol=1e-14
@test all(N[2:8] .≈ 0.0)
# Check interior point for partition of unity
N = get_basis_functions(Hex8(), Lagrange{1}(), Vec{3}((0.5, 0.3, -0.2)))
@test sum(N) ≈ 1.0 atol=1e-14
end
end