changeset 712:de2df1214394 feature/selectable_tests

Split testfile for LazyTensors
author Jonatan Werpers <jonatan@werpers.com>
date Sat, 20 Feb 2021 20:59:32 +0100
parents df88aee35bb9
children be648c6d6686
files test/LazyTensors/LazyTensors_test.jl test/LazyTensors/lazy_array_test.jl test/LazyTensors/lazy_tensor_operations_test.jl test/LazyTensors/tensor_mapping_test.jl
diffstat 4 files changed, 583 insertions(+), 580 deletions(-) [+]
line wrap: on
line diff
--- a/test/LazyTensors/LazyTensors_test.jl	Sat Feb 20 20:45:40 2021 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,580 +0,0 @@
-using Test
-using Sbplib.LazyTensors
-using Sbplib.RegionIndices
-
-using Tullio
-
-@testset "LazyTensors" begin
-
-@testset "Generic Mapping methods" begin
-    struct DummyMapping{T,R,D} <: TensorMapping{T,R,D} end
-    LazyTensors.apply(m::DummyMapping{T,R,D}, v, I::Vararg{Any,R}) where {T,R,D} = :apply
-    @test range_dim(DummyMapping{Int,2,3}()) == 2
-    @test domain_dim(DummyMapping{Int,2,3}()) == 3
-    @test apply(DummyMapping{Int,2,3}(), zeros(Int, (0,0,0)),0,0) == :apply
-    @test eltype(DummyMapping{Int,2,3}()) == Int
-    @test eltype(DummyMapping{Float64,2,3}()) == Float64
-end
-
-@testset "Mapping transpose" begin
-    struct DummyMapping{T,R,D} <: TensorMapping{T,R,D} end
-
-    LazyTensors.apply(m::DummyMapping{T,R}, v, I::Vararg{Any,R}) where {T,R} = :apply
-    LazyTensors.apply_transpose(m::DummyMapping{T,R,D}, v, I::Vararg{Any,D}) where {T,R,D} = :apply_transpose
-
-    LazyTensors.range_size(m::DummyMapping) = :range_size
-    LazyTensors.domain_size(m::DummyMapping) = :domain_size
-
-    m = DummyMapping{Float64,2,3}()
-    @test m' isa TensorMapping{Float64, 3,2}
-    @test m'' == m
-    @test apply(m',zeros(Float64,(0,0)), 0, 0, 0) == :apply_transpose
-    @test apply(m'',zeros(Float64,(0,0,0)), 0, 0) == :apply
-    @test apply_transpose(m', zeros(Float64,(0,0,0)), 0, 0) == :apply
-
-    @test range_size(m') == :domain_size
-    @test domain_size(m') == :range_size
-end
-
-@testset "TensorApplication" begin
-    struct SizeDoublingMapping{T,R,D} <: TensorMapping{T,R,D}
-        domain_size::NTuple{D,Int}
-    end
-
-    LazyTensors.apply(m::SizeDoublingMapping{T,R}, v, i::Vararg{Any,R}) where {T,R} = (:apply,v,i)
-    LazyTensors.range_size(m::SizeDoublingMapping) = 2 .* m.domain_size
-    LazyTensors.domain_size(m::SizeDoublingMapping) = m.domain_size
-
-
-    m = SizeDoublingMapping{Int, 1, 1}((3,))
-    v = [0,1,2]
-    @test m*v isa AbstractVector{Int}
-    @test size(m*v) == 2 .*size(v)
-    @test (m*v)[0] == (:apply,v,(0,))
-    @test m*m*v isa AbstractVector{Int}
-    @test (m*m*v)[1] == (:apply,m*v,(1,))
-    @test (m*m*v)[3] == (:apply,m*v,(3,))
-    @test (m*m*v)[6] == (:apply,m*v,(6,))
-    @test_broken BoundsError == (m*m*v)[0]
-    @test_broken BoundsError == (m*m*v)[7]
-    @test_throws MethodError m*m
-
-    m = SizeDoublingMapping{Int, 2, 1}((3,))
-    @test_throws MethodError m*ones(Int,2,2)
-    @test_throws MethodError m*m*v
-
-    m = SizeDoublingMapping{Float64, 2, 2}((3,3))
-    v = ones(3,3)
-    @test size(m*v) == 2 .*size(v)
-    @test (m*v)[1,2] == (:apply,v,(1,2))
-
-    struct ScalingOperator{T,D} <: TensorMapping{T,D,D}
-        λ::T
-        size::NTuple{D,Int}
-    end
-
-    LazyTensors.apply(m::ScalingOperator{T,D}, v, I::Vararg{Any,D}) where {T,D} = m.λ*v[I...]
-    LazyTensors.range_size(m::ScalingOperator) = m.size
-    LazyTensors.domain_size(m::ScalingOperator) = m.size
-
-    m = ScalingOperator{Int,1}(2,(3,))
-    v = [1,2,3]
-    @test m*v isa AbstractVector
-    @test m*v == [2,4,6]
-
-    m = ScalingOperator{Int,2}(2,(2,2))
-    v = [[1 2];[3 4]]
-    @test m*v == [[2 4];[6 8]]
-    @test (m*v)[2,1] == 6
-end
-
-@testset "TensorMapping binary operations" begin
-    struct ScalarMapping{T,R,D} <: TensorMapping{T,R,D}
-        λ::T
-        range_size::NTuple{R,Int}
-        domain_size::NTuple{D,Int}
-    end
-
-    LazyTensors.apply(m::ScalarMapping{T,R}, v, I::Vararg{Any,R}) where {T,R} = m.λ*v[I...]
-    LazyTensors.range_size(m::ScalarMapping) = m.domain_size
-    LazyTensors.domain_size(m::ScalarMapping) = m.range_size
-
-    A = ScalarMapping{Float64,1,1}(2.0, (3,), (3,))
-    B = ScalarMapping{Float64,1,1}(3.0, (3,), (3,))
-
-    v = [1.1,1.2,1.3]
-    for i ∈ eachindex(v)
-        @test ((A+B)*v)[i] == 2*v[i] + 3*v[i]
-    end
-
-    for i ∈ eachindex(v)
-        @test ((A-B)*v)[i] == 2*v[i] - 3*v[i]
-    end
-
-    @test range_size(A+B) == range_size(A) == range_size(B)
-    @test domain_size(A+B) == domain_size(A) == domain_size(B)
-end
-
-@testset "LazyArray" begin
-    @testset "LazyConstantArray" begin
-        @test LazyTensors.LazyConstantArray(3,(3,2)) isa LazyArray{Int,2}
-
-        lca = LazyTensors.LazyConstantArray(3.0,(3,2))
-        @test eltype(lca) == Float64
-        @test ndims(lca) == 2
-        @test size(lca) == (3,2)
-        @test lca[2] == 3.0
-    end
-    struct DummyArray{T,D, T1<:AbstractArray{T,D}} <: LazyArray{T,D}
-        data::T1
-    end
-    Base.size(v::DummyArray) = size(v.data)
-    Base.getindex(v::DummyArray{T,D}, I::Vararg{Int,D}) where {T,D} = v.data[I...]
-
-    # Test lazy operations
-    v1 = [1, 2.3, 4]
-    v2 = [1., 2, 3]
-    s = 3.4
-    r_add_v = v1 .+ v2
-    r_sub_v = v1 .- v2
-    r_times_v = v1 .* v2
-    r_div_v = v1 ./ v2
-    r_add_s = v1 .+ s
-    r_sub_s = v1 .- s
-    r_times_s = v1 .* s
-    r_div_s = v1 ./ s
-    @test isa(v1 +̃ v2, LazyArray)
-    @test isa(v1 -̃ v2, LazyArray)
-    @test isa(v1 *̃ v2, LazyArray)
-    @test isa(v1 /̃ v2, LazyArray)
-    @test isa(v1 +̃ s, LazyArray)
-    @test isa(v1 -̃ s, LazyArray)
-    @test isa(v1 *̃ s, LazyArray)
-    @test isa(v1 /̃ s, LazyArray)
-    @test isa(s +̃ v1, LazyArray)
-    @test isa(s -̃ v1, LazyArray)
-    @test isa(s *̃ v1, LazyArray)
-    @test isa(s /̃ v1, LazyArray)
-    for i ∈ eachindex(v1)
-        @test (v1 +̃ v2)[i] == r_add_v[i]
-        @test (v1 -̃ v2)[i] == r_sub_v[i]
-        @test (v1 *̃ v2)[i] == r_times_v[i]
-        @test (v1 /̃ v2)[i] == r_div_v[i]
-        @test (v1 +̃ s)[i] == r_add_s[i]
-        @test (v1 -̃ s)[i] == r_sub_s[i]
-        @test (v1 *̃ s)[i] == r_times_s[i]
-        @test (v1 /̃ s)[i] == r_div_s[i]
-        @test (s +̃ v1)[i] == r_add_s[i]
-        @test (s -̃ v1)[i] == -r_sub_s[i]
-        @test (s *̃ v1)[i] == r_times_s[i]
-        @test (s /̃ v1)[i] == 1/r_div_s[i]
-    end
-    @test_throws BoundsError (v1 +̃  v2)[4]
-    v2 = [1., 2, 3, 4]
-    # Test that size of arrays is asserted when not specified inbounds
-    # TODO: Replace these errors with SizeMismatch
-    @test_throws DimensionMismatch v1 +̃ v2
-
-    # Test operations on LazyArray
-    v1 = DummyArray([1, 2.3, 4])
-    v2 = [1., 2, 3]
-    @test isa(v1 + v2, LazyArray)
-    @test isa(v2 + v1, LazyArray)
-    @test isa(v1 - v2, LazyArray)
-    @test isa(v2 - v1, LazyArray)
-    for i ∈ eachindex(v2)
-        @test (v1 + v2)[i] == (v2 + v1)[i] == r_add_v[i]
-        @test (v1 - v2)[i] == -(v2 - v1)[i] == r_sub_v[i]
-    end
-    @test_throws BoundsError (v1 + v2)[4]
-    v2 = [1., 2, 3, 4]
-    # Test that size of arrays is asserted when not specified inbounds
-    # TODO: Replace these errors with SizeMismatch
-    @test_throws DimensionMismatch v1 + v2
-end
-
-
-@testset "LazyFunctionArray" begin
-    @test LazyFunctionArray(i->i^2, (3,)) == [1,4,9]
-    @test LazyFunctionArray((i,j)->i*j, (3,2)) == [
-        1 2;
-        2 4;
-        3 6;
-    ]
-
-    @test size(LazyFunctionArray(i->i^2, (3,))) == (3,)
-    @test size(LazyFunctionArray((i,j)->i*j, (3,2))) == (3,2)
-
-    @inferred LazyFunctionArray(i->i^2, (3,))[2]
-
-    @test_throws BoundsError LazyFunctionArray(i->i^2, (3,))[4]
-    @test_throws BoundsError LazyFunctionArray((i,j)->i*j, (3,2))[4,2]
-    @test_throws BoundsError LazyFunctionArray((i,j)->i*j, (3,2))[2,3]
-
-end
-
-@testset "TensorMappingComposition" begin
-    A = rand(2,3)
-    B = rand(3,4)
-
-    Ã = LazyLinearMap(A, (1,), (2,))
-    B̃ = LazyLinearMap(B, (1,), (2,))
-
-    @test Ã∘B̃ isa TensorMappingComposition
-    @test range_size(Ã∘B̃) == (2,)
-    @test domain_size(Ã∘B̃) == (4,)
-    @test_throws SizeMismatch B̃∘Ã
-
-    # @test @inbounds B̃∘Ã # Should not error even though dimensions don't match. (Since ]test runs with forced boundschecking this is currently not testable 2020-10-16)
-
-    v = rand(4)
-    @test Ã∘B̃*v ≈ A*B*v rtol=1e-14
-
-    v = rand(2)
-    @test (Ã∘B̃)'*v ≈ B'*A'*v rtol=1e-14
-end
-
-@testset "LazyLinearMap" begin
-    # Test a standard matrix-vector product
-    # mapping vectors of size 4 to vectors of size 3.
-    A = rand(3,4)
-    Ã = LazyLinearMap(A, (1,), (2,))
-    v = rand(4)
-    w = rand(3)
-
-    @test à isa LazyLinearMap{T,1,1} where T
-    @test à isa TensorMapping{T,1,1} where T
-    @test range_size(Ã) == (3,)
-    @test domain_size(Ã) == (4,)
-
-    @test Ã*ones(4) ≈ A*ones(4) atol=5e-13
-    @test Ã*v ≈ A*v atol=5e-13
-    @test Ã'*w ≈ A'*w
-
-    A = rand(2,3,4)
-    @test_throws DomainError LazyLinearMap(A, (3,1), (2,))
-
-    # Test more exotic mappings
-    B = rand(3,4,2)
-    # Map vectors of size 2 to matrices of size (3,4)
-    B̃ = LazyLinearMap(B, (1,2), (3,))
-    v = rand(2)
-
-    @test range_size(B̃) == (3,4)
-    @test domain_size(B̃) == (2,)
-    @test B̃ isa TensorMapping{T,2,1} where T
-    @test B̃*ones(2) ≈ B[:,:,1] + B[:,:,2] atol=5e-13
-    @test B̃*v ≈ B[:,:,1]*v[1] + B[:,:,2]*v[2] atol=5e-13
-
-    # Map matrices of size (3,2) to vectors of size 4
-    B̃ = LazyLinearMap(B, (2,), (1,3))
-    v = rand(3,2)
-
-    @test range_size(B̃) == (4,)
-    @test domain_size(B̃) == (3,2)
-    @test B̃ isa TensorMapping{T,1,2} where T
-    @test B̃*ones(3,2) ≈ B[1,:,1] + B[2,:,1] + B[3,:,1] +
-                        B[1,:,2] + B[2,:,2] + B[3,:,2] atol=5e-13
-    @test B̃*v ≈ B[1,:,1]*v[1,1] + B[2,:,1]*v[2,1] + B[3,:,1]*v[3,1] +
-                B[1,:,2]v[1,2] + B[2,:,2]*v[2,2] + B[3,:,2]*v[3,2] atol=5e-13
-
-
-    # TODO:
-    # @inferred (B̃*v)[2]
-end
-
-
-@testset "IdentityMapping" begin
-    @test IdentityMapping{Float64}((4,5)) isa IdentityMapping{T,2} where T
-    @test IdentityMapping{Float64}((4,5)) isa TensorMapping{T,2,2} where T
-    @test IdentityMapping{Float64}((4,5)) == IdentityMapping{Float64}(4,5)
-
-    @test IdentityMapping(3,2) isa IdentityMapping{Float64,2}
-
-    for sz ∈ [(4,5),(3,),(5,6,4)]
-        I = IdentityMapping{Float64}(sz)
-        v = rand(sz...)
-        @test I*v == v
-        @test I'*v == v
-
-        @test range_size(I) == sz
-        @test domain_size(I) == sz
-    end
-
-    I = IdentityMapping{Float64}((4,5))
-    v = rand(4,5)
-    @inferred (I*v)[3,2]
-    @inferred (I'*v)[3,2]
-    @inferred range_size(I)
-
-    @inferred range_dim(I)
-    @inferred domain_dim(I)
-
-    Ã = rand(4,2)
-    A = LazyLinearMap(Ã,(1,),(2,))
-    I1 = IdentityMapping{Float64}(2)
-    I2 = IdentityMapping{Float64}(4)
-    @test A∘I1 == A
-    @test I2∘A == A
-    @test I1∘I1 == I1
-    @test_throws SizeMismatch I1∘A
-    @test_throws SizeMismatch A∘I2
-    @test_throws SizeMismatch I1∘I2
-end
-
-@testset "InflatedTensorMapping" begin
-    I(sz...) = IdentityMapping(sz...)
-
-    Ã = rand(4,2)
-    B̃ = rand(4,2,3)
-    C̃ = rand(4,2,3)
-
-    A = LazyLinearMap(Ã,(1,),(2,))
-    B = LazyLinearMap(B̃,(1,2),(3,))
-    C = LazyLinearMap(C̃,(1,),(2,3))
-
-    @testset "Constructors" begin
-        @test InflatedTensorMapping(I(3,2), A, I(4)) isa TensorMapping{Float64, 4, 4}
-        @test InflatedTensorMapping(I(3,2), B, I(4)) isa TensorMapping{Float64, 5, 4}
-        @test InflatedTensorMapping(I(3), C, I(2,3)) isa TensorMapping{Float64, 4, 5}
-        @test InflatedTensorMapping(C, I(2,3)) isa TensorMapping{Float64, 3, 4}
-        @test InflatedTensorMapping(I(3), C) isa TensorMapping{Float64, 2, 3}
-        @test InflatedTensorMapping(I(3), I(2,3)) isa TensorMapping{Float64, 3, 3}
-    end
-
-    @testset "Range and domain size" begin
-        @test range_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,4,4)
-        @test domain_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,2,4)
-
-        @test range_size(InflatedTensorMapping(I(3,2), B, I(4))) == (3,2,4,2,4)
-        @test domain_size(InflatedTensorMapping(I(3,2), B, I(4))) == (3,2,3,4)
-
-        @test range_size(InflatedTensorMapping(I(3), C, I(2,3))) == (3,4,2,3)
-        @test domain_size(InflatedTensorMapping(I(3), C, I(2,3))) == (3,2,3,2,3)
-
-        @inferred range_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,4,4)
-        @inferred domain_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,2,4)
-    end
-
-    @testset "Application" begin
-        # Testing regular application and transposed application with inflation "before", "after" and "before and after".
-        # The inflated tensor mappings are chosen to preserve, reduce and increase the dimension of the result compared to the input.
-        tests = [
-            (
-                InflatedTensorMapping(I(3,2), A, I(4)),
-                (v-> @tullio res[a,b,c,d] := Ã[c,i]*v[a,b,i,d]), # Expected result of apply
-                (v-> @tullio res[a,b,c,d] := Ã[i,c]*v[a,b,i,d]), # Expected result of apply_transpose
-            ),
-            (
-                InflatedTensorMapping(I(3,2), B, I(4)),
-                (v-> @tullio res[a,b,c,d,e] := B̃[c,d,i]*v[a,b,i,e]),
-                (v-> @tullio res[a,b,c,d] := B̃[i,j,c]*v[a,b,i,j,d]),
-            ),
-            (
-                InflatedTensorMapping(I(3,2), C, I(4)),
-                (v-> @tullio res[a,b,c,d] := C̃[c,i,j]*v[a,b,i,j,d]),
-                (v-> @tullio res[a,b,c,d,e] := C̃[i,c,d]*v[a,b,i,e]),
-            ),
-            (
-                InflatedTensorMapping(I(3,2), A),
-                (v-> @tullio res[a,b,c] := Ã[c,i]*v[a,b,i]),
-                (v-> @tullio res[a,b,c] := Ã[i,c]*v[a,b,i]),
-            ),
-            (
-                InflatedTensorMapping(I(3,2), B),
-                (v-> @tullio res[a,b,c,d] := B̃[c,d,i]*v[a,b,i]),
-                (v-> @tullio res[a,b,c] := B̃[i,j,c]*v[a,b,i,j]),
-            ),
-            (
-                InflatedTensorMapping(I(3,2), C),
-                (v-> @tullio res[a,b,c] := C̃[c,i,j]*v[a,b,i,j]),
-                (v-> @tullio res[a,b,c,d] := C̃[i,c,d]*v[a,b,i]),
-            ),
-            (
-                InflatedTensorMapping(A,I(4)),
-                (v-> @tullio res[a,b] := Ã[a,i]*v[i,b]),
-                (v-> @tullio res[a,b] := Ã[i,a]*v[i,b]),
-            ),
-            (
-                InflatedTensorMapping(B,I(4)),
-                (v-> @tullio res[a,b,c] := B̃[a,b,i]*v[i,c]),
-                (v-> @tullio res[a,b] := B̃[i,j,a]*v[i,j,b]),
-            ),
-            (
-                InflatedTensorMapping(C,I(4)),
-                (v-> @tullio res[a,b] := C̃[a,i,j]*v[i,j,b]),
-                (v-> @tullio res[a,b,c] := C̃[i,a,b]*v[i,c]),
-            ),
-        ]
-
-        @testset "apply" begin
-            for i ∈ 1:length(tests)
-                tm = tests[i][1]
-                v = rand(domain_size(tm)...)
-                true_value = tests[i][2](v)
-                @test tm*v ≈ true_value rtol=1e-14
-            end
-        end
-
-        @testset "apply_transpose" begin
-            for i ∈ 1:length(tests)
-                tm = tests[i][1]
-                v = rand(range_size(tm)...)
-                true_value = tests[i][3](v)
-                @test tm'*v ≈ true_value rtol=1e-14
-            end
-        end
-
-        @testset "Inference of application" begin
-            struct ScalingOperator{T,D} <: TensorMapping{T,D,D}
-                λ::T
-                size::NTuple{D,Int}
-            end
-
-            LazyTensors.apply(m::ScalingOperator{T,D}, v, I::Vararg{Any,D}) where {T,D} = m.λ*v[I...]
-            LazyTensors.range_size(m::ScalingOperator) = m.size
-            LazyTensors.domain_size(m::ScalingOperator) = m.size
-
-            tm = InflatedTensorMapping(I(2,3),ScalingOperator(2.0, (3,2)),I(3,4))
-            v = rand(domain_size(tm)...)
-
-            @inferred apply(tm,v,1,2,3,2,2,4)
-            @inferred (tm*v)[1,2,3,2,2,4]
-        end
-    end
-
-    @testset "InflatedTensorMapping of InflatedTensorMapping" begin
-        A = ScalingOperator(2.0,(2,3))
-        itm = InflatedTensorMapping(I(3,2), A, I(4))
-        @test  InflatedTensorMapping(I(4), itm, I(2)) == InflatedTensorMapping(I(4,3,2), A, I(4,2))
-        @test  InflatedTensorMapping(itm, I(2)) == InflatedTensorMapping(I(3,2), A, I(4,2))
-        @test  InflatedTensorMapping(I(4), itm) == InflatedTensorMapping(I(4,3,2), A, I(4))
-
-        @test InflatedTensorMapping(I(2), I(2), I(2)) isa InflatedTensorMapping # The constructor should always return its type.
-    end
-end
-
-@testset "split_index" begin
-    @test LazyTensors.split_index(Val(2),Val(1),Val(2),Val(2),1,2,3,4,5,6) == ((1,2,:,5,6),(3,4))
-    @test LazyTensors.split_index(Val(2),Val(3),Val(2),Val(2),1,2,3,4,5,6) == ((1,2,:,:,:,5,6),(3,4))
-    @test LazyTensors.split_index(Val(3),Val(1),Val(1),Val(2),1,2,3,4,5,6) == ((1,2,3,:,5,6),(4,))
-    @test LazyTensors.split_index(Val(3),Val(2),Val(1),Val(2),1,2,3,4,5,6) == ((1,2,3,:,:,5,6),(4,))
-    @test LazyTensors.split_index(Val(1),Val(1),Val(2),Val(3),1,2,3,4,5,6) == ((1,:,4,5,6),(2,3))
-    @test LazyTensors.split_index(Val(1),Val(2),Val(2),Val(3),1,2,3,4,5,6) == ((1,:,:,4,5,6),(2,3))
-
-    @test LazyTensors.split_index(Val(0),Val(1),Val(3),Val(3),1,2,3,4,5,6) == ((:,4,5,6),(1,2,3))
-    @test LazyTensors.split_index(Val(3),Val(1),Val(3),Val(0),1,2,3,4,5,6) == ((1,2,3,:),(4,5,6))
-
-    @inferred LazyTensors.split_index(Val(2),Val(3),Val(2),Val(2),1,2,3,2,2,4)
-end
-
-@testset "slice_tuple" begin
-    @test LazyTensors.slice_tuple((1,2,3),Val(1), Val(3)) == (1,2,3)
-    @test LazyTensors.slice_tuple((1,2,3,4,5,6),Val(2), Val(5)) == (2,3,4,5)
-    @test LazyTensors.slice_tuple((1,2,3,4,5,6),Val(1), Val(3)) == (1,2,3)
-    @test LazyTensors.slice_tuple((1,2,3,4,5,6),Val(4), Val(6)) == (4,5,6)
-end
-
-@testset "split_tuple" begin
-    @testset "2 parts" begin
-        @test LazyTensors.split_tuple((),Val(0)) == ((),())
-        @test LazyTensors.split_tuple((1,),Val(0)) == ((),(1,))
-        @test LazyTensors.split_tuple((1,),Val(1)) == ((1,),())
-
-        @test LazyTensors.split_tuple((1,2,3,4),Val(0)) == ((),(1,2,3,4))
-        @test LazyTensors.split_tuple((1,2,3,4),Val(1)) == ((1,),(2,3,4))
-        @test LazyTensors.split_tuple((1,2,3,4),Val(2)) == ((1,2),(3,4))
-        @test LazyTensors.split_tuple((1,2,3,4),Val(3)) == ((1,2,3),(4,))
-        @test LazyTensors.split_tuple((1,2,3,4),Val(4)) == ((1,2,3,4),())
-
-        @test LazyTensors.split_tuple((1,2,true,4),Val(3)) == ((1,2,true),(4,))
-
-        @inferred LazyTensors.split_tuple((1,2,3,4),Val(3))
-        @inferred LazyTensors.split_tuple((1,2,true,4),Val(3))
-    end
-
-    @testset "3 parts" begin
-        @test LazyTensors.split_tuple((),Val(0),Val(0)) == ((),(),())
-        @test LazyTensors.split_tuple((1,2,3),Val(1), Val(1)) == ((1,),(2,),(3,))
-        @test LazyTensors.split_tuple((1,true,3),Val(1), Val(1)) == ((1,),(true,),(3,))
-
-        @test LazyTensors.split_tuple((1,2,3,4,5,6),Val(1),Val(2)) == ((1,),(2,3),(4,5,6))
-        @test LazyTensors.split_tuple((1,2,3,4,5,6),Val(3),Val(2)) == ((1,2,3),(4,5),(6,))
-
-        @inferred LazyTensors.split_tuple((1,2,3,4,5,6),Val(3),Val(2))
-        @inferred LazyTensors.split_tuple((1,true,3),Val(1), Val(1))
-    end
-end
-
-@testset "flatten_tuple" begin
-    @test LazyTensors.flatten_tuple((1,)) == (1,)
-    @test LazyTensors.flatten_tuple((1,2,3,4,5,6)) == (1,2,3,4,5,6)
-    @test LazyTensors.flatten_tuple((1,2,(3,4),5,6)) == (1,2,3,4,5,6)
-    @test LazyTensors.flatten_tuple((1,2,(3,(4,5)),6)) == (1,2,3,4,5,6)
-    @test LazyTensors.flatten_tuple(((1,2),(3,4),(5,),6)) == (1,2,3,4,5,6)
-end
-
-
-@testset "LazyOuterProduct" begin
-    struct ScalingOperator{T,D} <: TensorMapping{T,D,D}
-        λ::T
-        size::NTuple{D,Int}
-    end
-
-    LazyTensors.apply(m::ScalingOperator{T,D}, v, I::Vararg{Any,D}) where {T,D} = m.λ*v[I...]
-    LazyTensors.range_size(m::ScalingOperator) = m.size
-    LazyTensors.domain_size(m::ScalingOperator) = m.size
-
-    A = ScalingOperator(2.0, (5,))
-    B = ScalingOperator(3.0, (3,))
-    C = ScalingOperator(5.0, (3,2))
-
-    AB = LazyOuterProduct(A,B)
-    @test AB isa TensorMapping{T,2,2} where T
-    @test range_size(AB) == (5,3)
-    @test domain_size(AB) == (5,3)
-
-    v = rand(range_size(AB)...)
-    @test AB*v == 6*v
-
-    ABC = LazyOuterProduct(A,B,C)
-
-    @test ABC isa TensorMapping{T,4,4} where T
-    @test range_size(ABC) == (5,3,3,2)
-    @test domain_size(ABC) == (5,3,3,2)
-
-    @test A⊗B == AB
-    @test A⊗B⊗C == ABC
-
-    A = rand(3,2)
-    B = rand(2,4,3)
-
-    v₁ = rand(2,4,3)
-    v₂ = rand(4,3,2)
-
-    Ã = LazyLinearMap(A,(1,),(2,))
-    B̃ = LazyLinearMap(B,(1,),(2,3))
-
-    ÃB̃ = LazyOuterProduct(Ã,B̃)
-    @tullio ABv[i,k] := A[i,j]*B[k,l,m]*v₁[j,l,m]
-    @test ÃB̃*v₁ ≈ ABv
-
-    B̃Ã = LazyOuterProduct(B̃,Ã)
-    @tullio BAv[k,i] := A[i,j]*B[k,l,m]*v₂[l,m,j]
-    @test B̃Ã*v₂ ≈ BAv
-
-    @testset "Indentity mapping arguments" begin
-        @test LazyOuterProduct(IdentityMapping(3,2), IdentityMapping(1,2)) == IdentityMapping(3,2,1,2)
-
-        Ã = LazyLinearMap(A,(1,),(2,))
-        @test LazyOuterProduct(IdentityMapping(3,2), Ã) == InflatedTensorMapping(IdentityMapping(3,2),Ã)
-        @test LazyOuterProduct(Ã, IdentityMapping(3,2)) == InflatedTensorMapping(Ã,IdentityMapping(3,2))
-
-        I1 = IdentityMapping(3,2)
-        I2 = IdentityMapping(4)
-        @test I1⊗Ã⊗I2 == InflatedTensorMapping(I1, Ã, I2)
-    end
-
-end
-
-end
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/LazyTensors/lazy_array_test.jl	Sat Feb 20 20:59:32 2021 +0100
@@ -0,0 +1,102 @@
+using Test
+using Sbplib.LazyTensors
+using Sbplib.RegionIndices
+
+
+@testset "LazyArray" begin
+    @testset "LazyConstantArray" begin
+        @test LazyTensors.LazyConstantArray(3,(3,2)) isa LazyArray{Int,2}
+
+        lca = LazyTensors.LazyConstantArray(3.0,(3,2))
+        @test eltype(lca) == Float64
+        @test ndims(lca) == 2
+        @test size(lca) == (3,2)
+        @test lca[2] == 3.0
+    end
+    struct DummyArray{T,D, T1<:AbstractArray{T,D}} <: LazyArray{T,D}
+        data::T1
+    end
+    Base.size(v::DummyArray) = size(v.data)
+    Base.getindex(v::DummyArray{T,D}, I::Vararg{Int,D}) where {T,D} = v.data[I...]
+
+    # Test lazy operations
+    v1 = [1, 2.3, 4]
+    v2 = [1., 2, 3]
+    s = 3.4
+    r_add_v = v1 .+ v2
+    r_sub_v = v1 .- v2
+    r_times_v = v1 .* v2
+    r_div_v = v1 ./ v2
+    r_add_s = v1 .+ s
+    r_sub_s = v1 .- s
+    r_times_s = v1 .* s
+    r_div_s = v1 ./ s
+    @test isa(v1 +̃ v2, LazyArray)
+    @test isa(v1 -̃ v2, LazyArray)
+    @test isa(v1 *̃ v2, LazyArray)
+    @test isa(v1 /̃ v2, LazyArray)
+    @test isa(v1 +̃ s, LazyArray)
+    @test isa(v1 -̃ s, LazyArray)
+    @test isa(v1 *̃ s, LazyArray)
+    @test isa(v1 /̃ s, LazyArray)
+    @test isa(s +̃ v1, LazyArray)
+    @test isa(s -̃ v1, LazyArray)
+    @test isa(s *̃ v1, LazyArray)
+    @test isa(s /̃ v1, LazyArray)
+    for i ∈ eachindex(v1)
+        @test (v1 +̃ v2)[i] == r_add_v[i]
+        @test (v1 -̃ v2)[i] == r_sub_v[i]
+        @test (v1 *̃ v2)[i] == r_times_v[i]
+        @test (v1 /̃ v2)[i] == r_div_v[i]
+        @test (v1 +̃ s)[i] == r_add_s[i]
+        @test (v1 -̃ s)[i] == r_sub_s[i]
+        @test (v1 *̃ s)[i] == r_times_s[i]
+        @test (v1 /̃ s)[i] == r_div_s[i]
+        @test (s +̃ v1)[i] == r_add_s[i]
+        @test (s -̃ v1)[i] == -r_sub_s[i]
+        @test (s *̃ v1)[i] == r_times_s[i]
+        @test (s /̃ v1)[i] == 1/r_div_s[i]
+    end
+    @test_throws BoundsError (v1 +̃  v2)[4]
+    v2 = [1., 2, 3, 4]
+    # Test that size of arrays is asserted when not specified inbounds
+    # TODO: Replace these errors with SizeMismatch
+    @test_throws DimensionMismatch v1 +̃ v2
+
+    # Test operations on LazyArray
+    v1 = DummyArray([1, 2.3, 4])
+    v2 = [1., 2, 3]
+    @test isa(v1 + v2, LazyArray)
+    @test isa(v2 + v1, LazyArray)
+    @test isa(v1 - v2, LazyArray)
+    @test isa(v2 - v1, LazyArray)
+    for i ∈ eachindex(v2)
+        @test (v1 + v2)[i] == (v2 + v1)[i] == r_add_v[i]
+        @test (v1 - v2)[i] == -(v2 - v1)[i] == r_sub_v[i]
+    end
+    @test_throws BoundsError (v1 + v2)[4]
+    v2 = [1., 2, 3, 4]
+    # Test that size of arrays is asserted when not specified inbounds
+    # TODO: Replace these errors with SizeMismatch
+    @test_throws DimensionMismatch v1 + v2
+end
+
+
+@testset "LazyFunctionArray" begin
+    @test LazyFunctionArray(i->i^2, (3,)) == [1,4,9]
+    @test LazyFunctionArray((i,j)->i*j, (3,2)) == [
+        1 2;
+        2 4;
+        3 6;
+    ]
+
+    @test size(LazyFunctionArray(i->i^2, (3,))) == (3,)
+    @test size(LazyFunctionArray((i,j)->i*j, (3,2))) == (3,2)
+
+    @inferred LazyFunctionArray(i->i^2, (3,))[2]
+
+    @test_throws BoundsError LazyFunctionArray(i->i^2, (3,))[4]
+    @test_throws BoundsError LazyFunctionArray((i,j)->i*j, (3,2))[4,2]
+    @test_throws BoundsError LazyFunctionArray((i,j)->i*j, (3,2))[2,3]
+
+end
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/LazyTensors/lazy_tensor_operations_test.jl	Sat Feb 20 20:59:32 2021 +0100
@@ -0,0 +1,469 @@
+using Test
+using Sbplib.LazyTensors
+using Sbplib.RegionIndices
+
+using Tullio
+
+@testset "Mapping transpose" begin
+    struct DummyMapping{T,R,D} <: TensorMapping{T,R,D} end
+
+    LazyTensors.apply(m::DummyMapping{T,R}, v, I::Vararg{Any,R}) where {T,R} = :apply
+    LazyTensors.apply_transpose(m::DummyMapping{T,R,D}, v, I::Vararg{Any,D}) where {T,R,D} = :apply_transpose
+
+    LazyTensors.range_size(m::DummyMapping) = :range_size
+    LazyTensors.domain_size(m::DummyMapping) = :domain_size
+
+    m = DummyMapping{Float64,2,3}()
+    @test m' isa TensorMapping{Float64, 3,2}
+    @test m'' == m
+    @test apply(m',zeros(Float64,(0,0)), 0, 0, 0) == :apply_transpose
+    @test apply(m'',zeros(Float64,(0,0,0)), 0, 0) == :apply
+    @test apply_transpose(m', zeros(Float64,(0,0,0)), 0, 0) == :apply
+
+    @test range_size(m') == :domain_size
+    @test domain_size(m') == :range_size
+end
+
+@testset "TensorApplication" begin
+    struct SizeDoublingMapping{T,R,D} <: TensorMapping{T,R,D}
+        domain_size::NTuple{D,Int}
+    end
+
+    LazyTensors.apply(m::SizeDoublingMapping{T,R}, v, i::Vararg{Any,R}) where {T,R} = (:apply,v,i)
+    LazyTensors.range_size(m::SizeDoublingMapping) = 2 .* m.domain_size
+    LazyTensors.domain_size(m::SizeDoublingMapping) = m.domain_size
+
+
+    m = SizeDoublingMapping{Int, 1, 1}((3,))
+    v = [0,1,2]
+    @test m*v isa AbstractVector{Int}
+    @test size(m*v) == 2 .*size(v)
+    @test (m*v)[0] == (:apply,v,(0,))
+    @test m*m*v isa AbstractVector{Int}
+    @test (m*m*v)[1] == (:apply,m*v,(1,))
+    @test (m*m*v)[3] == (:apply,m*v,(3,))
+    @test (m*m*v)[6] == (:apply,m*v,(6,))
+    @test_broken BoundsError == (m*m*v)[0]
+    @test_broken BoundsError == (m*m*v)[7]
+    @test_throws MethodError m*m
+
+    m = SizeDoublingMapping{Int, 2, 1}((3,))
+    @test_throws MethodError m*ones(Int,2,2)
+    @test_throws MethodError m*m*v
+
+    m = SizeDoublingMapping{Float64, 2, 2}((3,3))
+    v = ones(3,3)
+    @test size(m*v) == 2 .*size(v)
+    @test (m*v)[1,2] == (:apply,v,(1,2))
+
+    struct ScalingOperator{T,D} <: TensorMapping{T,D,D}
+        λ::T
+        size::NTuple{D,Int}
+    end
+
+    LazyTensors.apply(m::ScalingOperator{T,D}, v, I::Vararg{Any,D}) where {T,D} = m.λ*v[I...]
+    LazyTensors.range_size(m::ScalingOperator) = m.size
+    LazyTensors.domain_size(m::ScalingOperator) = m.size
+
+    m = ScalingOperator{Int,1}(2,(3,))
+    v = [1,2,3]
+    @test m*v isa AbstractVector
+    @test m*v == [2,4,6]
+
+    m = ScalingOperator{Int,2}(2,(2,2))
+    v = [[1 2];[3 4]]
+    @test m*v == [[2 4];[6 8]]
+    @test (m*v)[2,1] == 6
+end
+
+@testset "TensorMapping binary operations" begin
+    struct ScalarMapping{T,R,D} <: TensorMapping{T,R,D}
+        λ::T
+        range_size::NTuple{R,Int}
+        domain_size::NTuple{D,Int}
+    end
+
+    LazyTensors.apply(m::ScalarMapping{T,R}, v, I::Vararg{Any,R}) where {T,R} = m.λ*v[I...]
+    LazyTensors.range_size(m::ScalarMapping) = m.domain_size
+    LazyTensors.domain_size(m::ScalarMapping) = m.range_size
+
+    A = ScalarMapping{Float64,1,1}(2.0, (3,), (3,))
+    B = ScalarMapping{Float64,1,1}(3.0, (3,), (3,))
+
+    v = [1.1,1.2,1.3]
+    for i ∈ eachindex(v)
+        @test ((A+B)*v)[i] == 2*v[i] + 3*v[i]
+    end
+
+    for i ∈ eachindex(v)
+        @test ((A-B)*v)[i] == 2*v[i] - 3*v[i]
+    end
+
+    @test range_size(A+B) == range_size(A) == range_size(B)
+    @test domain_size(A+B) == domain_size(A) == domain_size(B)
+end
+
+
+@testset "TensorMappingComposition" begin
+    A = rand(2,3)
+    B = rand(3,4)
+
+    Ã = LazyLinearMap(A, (1,), (2,))
+    B̃ = LazyLinearMap(B, (1,), (2,))
+
+    @test Ã∘B̃ isa TensorMappingComposition
+    @test range_size(Ã∘B̃) == (2,)
+    @test domain_size(Ã∘B̃) == (4,)
+    @test_throws SizeMismatch B̃∘Ã
+
+    # @test @inbounds B̃∘Ã # Should not error even though dimensions don't match. (Since ]test runs with forced boundschecking this is currently not testable 2020-10-16)
+
+    v = rand(4)
+    @test Ã∘B̃*v ≈ A*B*v rtol=1e-14
+
+    v = rand(2)
+    @test (Ã∘B̃)'*v ≈ B'*A'*v rtol=1e-14
+end
+
+@testset "LazyLinearMap" begin
+    # Test a standard matrix-vector product
+    # mapping vectors of size 4 to vectors of size 3.
+    A = rand(3,4)
+    Ã = LazyLinearMap(A, (1,), (2,))
+    v = rand(4)
+    w = rand(3)
+
+    @test à isa LazyLinearMap{T,1,1} where T
+    @test à isa TensorMapping{T,1,1} where T
+    @test range_size(Ã) == (3,)
+    @test domain_size(Ã) == (4,)
+
+    @test Ã*ones(4) ≈ A*ones(4) atol=5e-13
+    @test Ã*v ≈ A*v atol=5e-13
+    @test Ã'*w ≈ A'*w
+
+    A = rand(2,3,4)
+    @test_throws DomainError LazyLinearMap(A, (3,1), (2,))
+
+    # Test more exotic mappings
+    B = rand(3,4,2)
+    # Map vectors of size 2 to matrices of size (3,4)
+    B̃ = LazyLinearMap(B, (1,2), (3,))
+    v = rand(2)
+
+    @test range_size(B̃) == (3,4)
+    @test domain_size(B̃) == (2,)
+    @test B̃ isa TensorMapping{T,2,1} where T
+    @test B̃*ones(2) ≈ B[:,:,1] + B[:,:,2] atol=5e-13
+    @test B̃*v ≈ B[:,:,1]*v[1] + B[:,:,2]*v[2] atol=5e-13
+
+    # Map matrices of size (3,2) to vectors of size 4
+    B̃ = LazyLinearMap(B, (2,), (1,3))
+    v = rand(3,2)
+
+    @test range_size(B̃) == (4,)
+    @test domain_size(B̃) == (3,2)
+    @test B̃ isa TensorMapping{T,1,2} where T
+    @test B̃*ones(3,2) ≈ B[1,:,1] + B[2,:,1] + B[3,:,1] +
+                        B[1,:,2] + B[2,:,2] + B[3,:,2] atol=5e-13
+    @test B̃*v ≈ B[1,:,1]*v[1,1] + B[2,:,1]*v[2,1] + B[3,:,1]*v[3,1] +
+                B[1,:,2]v[1,2] + B[2,:,2]*v[2,2] + B[3,:,2]*v[3,2] atol=5e-13
+
+
+    # TODO:
+    # @inferred (B̃*v)[2]
+end
+
+
+@testset "IdentityMapping" begin
+    @test IdentityMapping{Float64}((4,5)) isa IdentityMapping{T,2} where T
+    @test IdentityMapping{Float64}((4,5)) isa TensorMapping{T,2,2} where T
+    @test IdentityMapping{Float64}((4,5)) == IdentityMapping{Float64}(4,5)
+
+    @test IdentityMapping(3,2) isa IdentityMapping{Float64,2}
+
+    for sz ∈ [(4,5),(3,),(5,6,4)]
+        I = IdentityMapping{Float64}(sz)
+        v = rand(sz...)
+        @test I*v == v
+        @test I'*v == v
+
+        @test range_size(I) == sz
+        @test domain_size(I) == sz
+    end
+
+    I = IdentityMapping{Float64}((4,5))
+    v = rand(4,5)
+    @inferred (I*v)[3,2]
+    @inferred (I'*v)[3,2]
+    @inferred range_size(I)
+
+    @inferred range_dim(I)
+    @inferred domain_dim(I)
+
+    Ã = rand(4,2)
+    A = LazyLinearMap(Ã,(1,),(2,))
+    I1 = IdentityMapping{Float64}(2)
+    I2 = IdentityMapping{Float64}(4)
+    @test A∘I1 == A
+    @test I2∘A == A
+    @test I1∘I1 == I1
+    @test_throws SizeMismatch I1∘A
+    @test_throws SizeMismatch A∘I2
+    @test_throws SizeMismatch I1∘I2
+end
+
+@testset "InflatedTensorMapping" begin
+    I(sz...) = IdentityMapping(sz...)
+
+    Ã = rand(4,2)
+    B̃ = rand(4,2,3)
+    C̃ = rand(4,2,3)
+
+    A = LazyLinearMap(Ã,(1,),(2,))
+    B = LazyLinearMap(B̃,(1,2),(3,))
+    C = LazyLinearMap(C̃,(1,),(2,3))
+
+    @testset "Constructors" begin
+        @test InflatedTensorMapping(I(3,2), A, I(4)) isa TensorMapping{Float64, 4, 4}
+        @test InflatedTensorMapping(I(3,2), B, I(4)) isa TensorMapping{Float64, 5, 4}
+        @test InflatedTensorMapping(I(3), C, I(2,3)) isa TensorMapping{Float64, 4, 5}
+        @test InflatedTensorMapping(C, I(2,3)) isa TensorMapping{Float64, 3, 4}
+        @test InflatedTensorMapping(I(3), C) isa TensorMapping{Float64, 2, 3}
+        @test InflatedTensorMapping(I(3), I(2,3)) isa TensorMapping{Float64, 3, 3}
+    end
+
+    @testset "Range and domain size" begin
+        @test range_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,4,4)
+        @test domain_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,2,4)
+
+        @test range_size(InflatedTensorMapping(I(3,2), B, I(4))) == (3,2,4,2,4)
+        @test domain_size(InflatedTensorMapping(I(3,2), B, I(4))) == (3,2,3,4)
+
+        @test range_size(InflatedTensorMapping(I(3), C, I(2,3))) == (3,4,2,3)
+        @test domain_size(InflatedTensorMapping(I(3), C, I(2,3))) == (3,2,3,2,3)
+
+        @inferred range_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,4,4)
+        @inferred domain_size(InflatedTensorMapping(I(3,2), A, I(4))) == (3,2,2,4)
+    end
+
+    @testset "Application" begin
+        # Testing regular application and transposed application with inflation "before", "after" and "before and after".
+        # The inflated tensor mappings are chosen to preserve, reduce and increase the dimension of the result compared to the input.
+        tests = [
+            (
+                InflatedTensorMapping(I(3,2), A, I(4)),
+                (v-> @tullio res[a,b,c,d] := Ã[c,i]*v[a,b,i,d]), # Expected result of apply
+                (v-> @tullio res[a,b,c,d] := Ã[i,c]*v[a,b,i,d]), # Expected result of apply_transpose
+            ),
+            (
+                InflatedTensorMapping(I(3,2), B, I(4)),
+                (v-> @tullio res[a,b,c,d,e] := B̃[c,d,i]*v[a,b,i,e]),
+                (v-> @tullio res[a,b,c,d] := B̃[i,j,c]*v[a,b,i,j,d]),
+            ),
+            (
+                InflatedTensorMapping(I(3,2), C, I(4)),
+                (v-> @tullio res[a,b,c,d] := C̃[c,i,j]*v[a,b,i,j,d]),
+                (v-> @tullio res[a,b,c,d,e] := C̃[i,c,d]*v[a,b,i,e]),
+            ),
+            (
+                InflatedTensorMapping(I(3,2), A),
+                (v-> @tullio res[a,b,c] := Ã[c,i]*v[a,b,i]),
+                (v-> @tullio res[a,b,c] := Ã[i,c]*v[a,b,i]),
+            ),
+            (
+                InflatedTensorMapping(I(3,2), B),
+                (v-> @tullio res[a,b,c,d] := B̃[c,d,i]*v[a,b,i]),
+                (v-> @tullio res[a,b,c] := B̃[i,j,c]*v[a,b,i,j]),
+            ),
+            (
+                InflatedTensorMapping(I(3,2), C),
+                (v-> @tullio res[a,b,c] := C̃[c,i,j]*v[a,b,i,j]),
+                (v-> @tullio res[a,b,c,d] := C̃[i,c,d]*v[a,b,i]),
+            ),
+            (
+                InflatedTensorMapping(A,I(4)),
+                (v-> @tullio res[a,b] := Ã[a,i]*v[i,b]),
+                (v-> @tullio res[a,b] := Ã[i,a]*v[i,b]),
+            ),
+            (
+                InflatedTensorMapping(B,I(4)),
+                (v-> @tullio res[a,b,c] := B̃[a,b,i]*v[i,c]),
+                (v-> @tullio res[a,b] := B̃[i,j,a]*v[i,j,b]),
+            ),
+            (
+                InflatedTensorMapping(C,I(4)),
+                (v-> @tullio res[a,b] := C̃[a,i,j]*v[i,j,b]),
+                (v-> @tullio res[a,b,c] := C̃[i,a,b]*v[i,c]),
+            ),
+        ]
+
+        @testset "apply" begin
+            for i ∈ 1:length(tests)
+                tm = tests[i][1]
+                v = rand(domain_size(tm)...)
+                true_value = tests[i][2](v)
+                @test tm*v ≈ true_value rtol=1e-14
+            end
+        end
+
+        @testset "apply_transpose" begin
+            for i ∈ 1:length(tests)
+                tm = tests[i][1]
+                v = rand(range_size(tm)...)
+                true_value = tests[i][3](v)
+                @test tm'*v ≈ true_value rtol=1e-14
+            end
+        end
+
+        @testset "Inference of application" begin
+            struct ScalingOperator{T,D} <: TensorMapping{T,D,D}
+                λ::T
+                size::NTuple{D,Int}
+            end
+
+            LazyTensors.apply(m::ScalingOperator{T,D}, v, I::Vararg{Any,D}) where {T,D} = m.λ*v[I...]
+            LazyTensors.range_size(m::ScalingOperator) = m.size
+            LazyTensors.domain_size(m::ScalingOperator) = m.size
+
+            tm = InflatedTensorMapping(I(2,3),ScalingOperator(2.0, (3,2)),I(3,4))
+            v = rand(domain_size(tm)...)
+
+            @inferred apply(tm,v,1,2,3,2,2,4)
+            @inferred (tm*v)[1,2,3,2,2,4]
+        end
+    end
+
+    @testset "InflatedTensorMapping of InflatedTensorMapping" begin
+        A = ScalingOperator(2.0,(2,3))
+        itm = InflatedTensorMapping(I(3,2), A, I(4))
+        @test  InflatedTensorMapping(I(4), itm, I(2)) == InflatedTensorMapping(I(4,3,2), A, I(4,2))
+        @test  InflatedTensorMapping(itm, I(2)) == InflatedTensorMapping(I(3,2), A, I(4,2))
+        @test  InflatedTensorMapping(I(4), itm) == InflatedTensorMapping(I(4,3,2), A, I(4))
+
+        @test InflatedTensorMapping(I(2), I(2), I(2)) isa InflatedTensorMapping # The constructor should always return its type.
+    end
+end
+
+@testset "split_index" begin
+    @test LazyTensors.split_index(Val(2),Val(1),Val(2),Val(2),1,2,3,4,5,6) == ((1,2,:,5,6),(3,4))
+    @test LazyTensors.split_index(Val(2),Val(3),Val(2),Val(2),1,2,3,4,5,6) == ((1,2,:,:,:,5,6),(3,4))
+    @test LazyTensors.split_index(Val(3),Val(1),Val(1),Val(2),1,2,3,4,5,6) == ((1,2,3,:,5,6),(4,))
+    @test LazyTensors.split_index(Val(3),Val(2),Val(1),Val(2),1,2,3,4,5,6) == ((1,2,3,:,:,5,6),(4,))
+    @test LazyTensors.split_index(Val(1),Val(1),Val(2),Val(3),1,2,3,4,5,6) == ((1,:,4,5,6),(2,3))
+    @test LazyTensors.split_index(Val(1),Val(2),Val(2),Val(3),1,2,3,4,5,6) == ((1,:,:,4,5,6),(2,3))
+
+    @test LazyTensors.split_index(Val(0),Val(1),Val(3),Val(3),1,2,3,4,5,6) == ((:,4,5,6),(1,2,3))
+    @test LazyTensors.split_index(Val(3),Val(1),Val(3),Val(0),1,2,3,4,5,6) == ((1,2,3,:),(4,5,6))
+
+    @inferred LazyTensors.split_index(Val(2),Val(3),Val(2),Val(2),1,2,3,2,2,4)
+end
+
+@testset "slice_tuple" begin
+    @test LazyTensors.slice_tuple((1,2,3),Val(1), Val(3)) == (1,2,3)
+    @test LazyTensors.slice_tuple((1,2,3,4,5,6),Val(2), Val(5)) == (2,3,4,5)
+    @test LazyTensors.slice_tuple((1,2,3,4,5,6),Val(1), Val(3)) == (1,2,3)
+    @test LazyTensors.slice_tuple((1,2,3,4,5,6),Val(4), Val(6)) == (4,5,6)
+end
+
+@testset "split_tuple" begin
+    @testset "2 parts" begin
+        @test LazyTensors.split_tuple((),Val(0)) == ((),())
+        @test LazyTensors.split_tuple((1,),Val(0)) == ((),(1,))
+        @test LazyTensors.split_tuple((1,),Val(1)) == ((1,),())
+
+        @test LazyTensors.split_tuple((1,2,3,4),Val(0)) == ((),(1,2,3,4))
+        @test LazyTensors.split_tuple((1,2,3,4),Val(1)) == ((1,),(2,3,4))
+        @test LazyTensors.split_tuple((1,2,3,4),Val(2)) == ((1,2),(3,4))
+        @test LazyTensors.split_tuple((1,2,3,4),Val(3)) == ((1,2,3),(4,))
+        @test LazyTensors.split_tuple((1,2,3,4),Val(4)) == ((1,2,3,4),())
+
+        @test LazyTensors.split_tuple((1,2,true,4),Val(3)) == ((1,2,true),(4,))
+
+        @inferred LazyTensors.split_tuple((1,2,3,4),Val(3))
+        @inferred LazyTensors.split_tuple((1,2,true,4),Val(3))
+    end
+
+    @testset "3 parts" begin
+        @test LazyTensors.split_tuple((),Val(0),Val(0)) == ((),(),())
+        @test LazyTensors.split_tuple((1,2,3),Val(1), Val(1)) == ((1,),(2,),(3,))
+        @test LazyTensors.split_tuple((1,true,3),Val(1), Val(1)) == ((1,),(true,),(3,))
+
+        @test LazyTensors.split_tuple((1,2,3,4,5,6),Val(1),Val(2)) == ((1,),(2,3),(4,5,6))
+        @test LazyTensors.split_tuple((1,2,3,4,5,6),Val(3),Val(2)) == ((1,2,3),(4,5),(6,))
+
+        @inferred LazyTensors.split_tuple((1,2,3,4,5,6),Val(3),Val(2))
+        @inferred LazyTensors.split_tuple((1,true,3),Val(1), Val(1))
+    end
+end
+
+@testset "flatten_tuple" begin
+    @test LazyTensors.flatten_tuple((1,)) == (1,)
+    @test LazyTensors.flatten_tuple((1,2,3,4,5,6)) == (1,2,3,4,5,6)
+    @test LazyTensors.flatten_tuple((1,2,(3,4),5,6)) == (1,2,3,4,5,6)
+    @test LazyTensors.flatten_tuple((1,2,(3,(4,5)),6)) == (1,2,3,4,5,6)
+    @test LazyTensors.flatten_tuple(((1,2),(3,4),(5,),6)) == (1,2,3,4,5,6)
+end
+
+
+@testset "LazyOuterProduct" begin
+    struct ScalingOperator{T,D} <: TensorMapping{T,D,D}
+        λ::T
+        size::NTuple{D,Int}
+    end
+
+    LazyTensors.apply(m::ScalingOperator{T,D}, v, I::Vararg{Any,D}) where {T,D} = m.λ*v[I...]
+    LazyTensors.range_size(m::ScalingOperator) = m.size
+    LazyTensors.domain_size(m::ScalingOperator) = m.size
+
+    A = ScalingOperator(2.0, (5,))
+    B = ScalingOperator(3.0, (3,))
+    C = ScalingOperator(5.0, (3,2))
+
+    AB = LazyOuterProduct(A,B)
+    @test AB isa TensorMapping{T,2,2} where T
+    @test range_size(AB) == (5,3)
+    @test domain_size(AB) == (5,3)
+
+    v = rand(range_size(AB)...)
+    @test AB*v == 6*v
+
+    ABC = LazyOuterProduct(A,B,C)
+
+    @test ABC isa TensorMapping{T,4,4} where T
+    @test range_size(ABC) == (5,3,3,2)
+    @test domain_size(ABC) == (5,3,3,2)
+
+    @test A⊗B == AB
+    @test A⊗B⊗C == ABC
+
+    A = rand(3,2)
+    B = rand(2,4,3)
+
+    v₁ = rand(2,4,3)
+    v₂ = rand(4,3,2)
+
+    Ã = LazyLinearMap(A,(1,),(2,))
+    B̃ = LazyLinearMap(B,(1,),(2,3))
+
+    ÃB̃ = LazyOuterProduct(Ã,B̃)
+    @tullio ABv[i,k] := A[i,j]*B[k,l,m]*v₁[j,l,m]
+    @test ÃB̃*v₁ ≈ ABv
+
+    B̃Ã = LazyOuterProduct(B̃,Ã)
+    @tullio BAv[k,i] := A[i,j]*B[k,l,m]*v₂[l,m,j]
+    @test B̃Ã*v₂ ≈ BAv
+
+    @testset "Indentity mapping arguments" begin
+        @test LazyOuterProduct(IdentityMapping(3,2), IdentityMapping(1,2)) == IdentityMapping(3,2,1,2)
+
+        Ã = LazyLinearMap(A,(1,),(2,))
+        @test LazyOuterProduct(IdentityMapping(3,2), Ã) == InflatedTensorMapping(IdentityMapping(3,2),Ã)
+        @test LazyOuterProduct(Ã, IdentityMapping(3,2)) == InflatedTensorMapping(Ã,IdentityMapping(3,2))
+
+        I1 = IdentityMapping(3,2)
+        I2 = IdentityMapping(4)
+        @test I1⊗Ã⊗I2 == InflatedTensorMapping(I1, Ã, I2)
+    end
+
+end
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/LazyTensors/tensor_mapping_test.jl	Sat Feb 20 20:59:32 2021 +0100
@@ -0,0 +1,12 @@
+using Test
+using Sbplib.LazyTensors
+
+@testset "Generic Mapping methods" begin
+    struct DummyMapping{T,R,D} <: TensorMapping{T,R,D} end
+    LazyTensors.apply(m::DummyMapping{T,R,D}, v, I::Vararg{Any,R}) where {T,R,D} = :apply
+    @test range_dim(DummyMapping{Int,2,3}()) == 2
+    @test domain_dim(DummyMapping{Int,2,3}()) == 3
+    @test apply(DummyMapping{Int,2,3}(), zeros(Int, (0,0,0)),0,0) == :apply
+    @test eltype(DummyMapping{Int,2,3}()) == Int
+    @test eltype(DummyMapping{Float64,2,3}()) == Float64
+end