Base.stack fails if DimArray and non-DimArray mixed

[sethaxen]

Julia v1.9 introduces Base.stack (also available in Compat.jl). This can be used to flatten arrays of arrays via stacking and already works when a DimArray contains all DimArrays:

julia> a = [randn(4) for _ in 1:3, _ in 1:2]
3×2 Matrix{Vector{Float64}}:
 [1.95794, -0.751093, -0.855602, -0.743486]  …  [-1.101, -1.12834, -0.636956, 0.386361]
 [0.388141, -0.13846, -0.837937, -0.630565]     [-0.347909, 0.124861, -0.483844, -0.872112]
 [0.451845, -0.441605, 0.620649, -1.41121]      [-0.0943002, 0.517051, 0.396103, -0.44082]

julia> stack(a)
4×3×2 Array{Float64, 3}:
[:, :, 1] =
  1.95794    0.388141   0.451845
 -0.751093  -0.13846   -0.441605
 -0.855602  -0.837937   0.620649
 -0.743486  -0.630565  -1.41121

[:, :, 2] =
 -1.101     -0.347909  -0.0943002
 -1.12834    0.124861   0.517051
 -0.636956  -0.483844   0.396103
  0.386361  -0.872112  -0.44082

julia> da1 = DimArray(map(x -> DimArray(x, X), a), (Y, Z));

julia> stack(da1)
4×3×2 DimArray{Float64,3} with dimensions: X, Y, Z
[:, :, 1]
  1.95794    0.388141   0.451845
 -0.751093  -0.13846   -0.441605
 -0.855602  -0.837937   0.620649
 -0.743486  -0.630565  -1.41121
[and 1 more slices...]

However, if we have a DimArray of non-dimensional arrays or a non-dimensional array of DimArrays, then instead of falling back to stacking a non-dimensional array, an error is thrown:

julia> da2 = map(x -> DimArray(x, X), a);

julia> stack(da2)
ERROR: MethodError: no method matching similar(::DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, ::Type{Float64}, ::Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Int64, Int64})

Closest candidates are:
  similar(::AbstractDimArray, ::Type{T}) where T
   @ DimensionalData ~/.julia/packages/DimensionalData/09JaV/src/array/array.jl:116
  similar(::AbstractDimArray, ::Type{T}, ::Tuple{}) where T
   @ DimensionalData ~/.julia/packages/DimensionalData/09JaV/src/array/array.jl:156
  similar(::AbstractDimArray, ::Type{T}, ::Tuple{DimensionalData.Dimensions.Dimension, Vararg{DimensionalData.Dimensions.Dimension}}) where T
   @ DimensionalData ~/.julia/packages/DimensionalData/09JaV/src/array/array.jl:154
  ...

Stacktrace:
 [1] similar(::DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, ::Type{Float64}, ::DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, ::Base.OneTo{Int64}, ::Base.OneTo{Int64})
   @ Base ./abstractarray.jl:838
 [2] _typed_stack(::Colon, ::Type{Float64}, ::Type{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, A::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Aax::Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}})
   @ Base ./abstractarray.jl:2791
 [3] _typed_stack(::Colon, ::Type{Float64}, ::Type{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, A::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}})
   @ Base ./abstractarray.jl:2787
 [4] _stack(dims::Function, #unused#::Base.HasShape{2}, iter::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}})
   @ Base ./abstractarray.jl:2777
 [5] _stack(dims::Colon, iter::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}})
   @ Base ./abstractarray.jl:2769
 [6] stack(iter::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}; dims::Function)
   @ Base ./abstractarray.jl:2737
 [7] stack(iter::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}})
   @ Base ./abstractarray.jl:2737
 [8] top-level scope
   @ REPL[16]:1

julia> da3 = DimArray(a, (Y, Z));

julia> stack(da3)
ERROR: MethodError: no method matching similar(::Vector{Float64}, ::Type{Float64}, ::Tuple{Int64, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}})

Closest candidates are:
  similar(::Base.Broadcast.Broadcasted{Base.Broadcast.DefaultArrayStyle{N}}, ::Type{ElType}, ::Any) where {N, ElType}
   @ Base broadcast.jl:212
  similar(::Base.Broadcast.Broadcasted{Base.Broadcast.ArrayConflict}, ::Type{ElType}, ::Any) where ElType
   @ Base broadcast.jl:217
  similar(::AbstractDimStack, ::Any...)
   @ DimensionalData ~/.julia/packages/DimensionalData/09JaV/src/stack/stack.jl:58
  ...

Stacktrace:
 [1] similar(::Vector{Float64}, ::Type{Float64}, ::Base.OneTo{Int64}, ::DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, ::DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}})
   @ Base ./abstractarray.jl:838
 [2] _typed_stack(::Colon, ::Type{Float64}, ::Type{Vector{Float64}}, A::DimArray{Vector{Float64}, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Matrix{Vector{Float64}}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Aax::Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}})
   @ Base ./abstractarray.jl:2791
 [3] _typed_stack(::Colon, ::Type{Float64}, ::Type{Vector{Float64}}, A::DimArray{Vector{Float64}, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Matrix{Vector{Float64}}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2787
 [4] _stack(dims::Function, #unused#::Base.HasShape{2}, iter::DimArray{Vector{Float64}, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Matrix{Vector{Float64}}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2777
 [5] _stack(dims::Colon, iter::DimArray{Vector{Float64}, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Matrix{Vector{Float64}}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2769
 [6] stack(iter::DimArray{Vector{Float64}, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Matrix{Vector{Float64}}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}; dims::Function)
   @ Base ./abstractarray.jl:2737
 [7] stack(iter::DimArray{Vector{Float64}, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}, Z{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Matrix{Vector{Float64}}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2737
 [8] top-level scope
   @ REPL[18]:1

The issue seems to be that similar is not defined for a mixture of Int and DimUnitRange. I'm not certain why stack ends up mixing these two, since the similar docstring documents that you can provide integer sizes or axes.

[rafaqz]

Could be a bug in Base? - that it mixes Int and axes. But maybe we just have to handle that.

[sethaxen]

Seems the Ints are what the Base.OneTo axes from the Array get converted to.

I just checked, and OffsetArrays works:

julia> using OffsetArrays

julia> x = OffsetArray([randn(2) for _ in 1:4, _ in 1:3], 0:3, 0:2)
4×3 OffsetArray(::Matrix{Vector{Float64}}, 0:3, 0:2) with eltype Vector{Float64} with indices 0:3×0:2:
 [-1.60527, -0.380328]   [0.583878, -0.910585]   [-0.525119, 1.61862]
 [-0.673478, -0.723257]  [1.00405, -1.54902]     [1.00349, 0.450481]
 [-0.685164, 0.401531]   [-0.646748, -0.995447]  [0.128681, 0.293356]
 [0.243163, -0.243523]   [0.287951, 0.407418]    [-0.0961986, -1.21144]

julia> stack(x)
2×4×3 OffsetArray(::Array{Float64, 3}, 1:2, 0:3, 0:2) with eltype Float64 with indices 1:2×0:3×0:2:
[:, :, 0] =
 -1.60527   -0.673478  -0.685164   0.243163
 -0.380328  -0.723257   0.401531  -0.243523

[:, :, 1] =
  0.583878   1.00405  -0.646748  0.287951
 -0.910585  -1.54902  -0.995447  0.407418

[:, :, 2] =
 -0.525119  1.00349   0.128681  -0.0961986
  1.61862   0.450481  0.293356  -1.21144

julia> x = [OffsetArray(randn(2), 0:1) for _ in 1:4, _ in 1:3]
4×3 Matrix{OffsetVector{Float64, Vector{Float64}}}:
 [-0.607889, -0.603977]  [-0.819231, -1.44292]    [-0.339097, 1.70372]
 [-1.56102, -0.128917]   [0.390498, 0.125584]     [-1.72841, -1.00742]
 [0.0900471, 1.43783]    [-0.369288, -0.0750261]  [2.33101, 0.160303]
 [-0.422105, -0.466955]  [-0.113919, -0.73531]    [0.88667, -1.49588]

julia> stack(x)
2×4×3 OffsetArray(::Array{Float64, 3}, 0:1, 1:4, 1:3) with eltype Float64 with indices 0:1×1:4×1:3:
[:, :, 1] =
 -0.607889  -1.56102   0.0900471  -0.422105
 -0.603977  -0.128917  1.43783    -0.466955

[:, :, 2] =
 -0.819231  0.390498  -0.369288   -0.113919
 -1.44292   0.125584  -0.0750261  -0.73531

[:, :, 3] =
 -0.339097  -1.72841  2.33101    0.88667
  1.70372   -1.00742  0.160303  -1.49588

But this seems to be one of those cases where it works by fundamentally changing how Base works. e.g. if OffsetArrays is in scope, stack now "works" for the examples above, but returns an OffsetArray

julia> using DimensionalData

julia> a = [randn(4) for _ in 1:3, _ in 1:2];

julia> da2 = map(x -> DimArray(x, X), a);

julia> stack(da2)
4×3×2 OffsetArray(::Array{Float64, 3}, 1:4, 1:3, 1:2) with eltype Float64 with indices 1:4×1:3×1:2:
[:, :, 1] =
  0.879905   0.341284  -0.661324
  0.881001   0.811677   0.544223
  0.578309  -1.29874    0.759717
 -1.26487   -0.168756   0.702541

[:, :, 2] =
 -0.606822  -0.801057  -0.857598
 -1.58481   -1.07869    0.591615
 -1.18106    0.462734   0.843158
  0.873367  -0.269853   2.55689

julia> da3 = DimArray(a, (Y, Z));

julia> stack(da3)
4×3×2 OffsetArray(::Array{Float64, 3}, 1:4, 1:3, 1:2) with eltype Float64 with indices 1:4×1:3×1:2:
[:, :, 1] =
  0.879905   0.341284  -0.661324
  0.881001   0.811677   0.544223
  0.578309  -1.29874    0.759717
 -1.26487   -0.168756   0.702541

[:, :, 2] =
 -0.606822  -0.801057  -0.857598
 -1.58481   -1.07869    0.591615
 -1.18106    0.462734   0.843158
  0.873367  -0.269853   2.55689

[rafaqz]

Haha I have a grumpy rant over at OffsetArrays.jl about this.

JuliaArrays/OffsetArrays.jl#306

It's really not Ok that loading OffsetArrays.jl anywhere in the session fixes a bug here with Base Julia behavior.

But in this case it seems OffsetArrays.jl does the right thing and Base doesn't?

[rafaqz]

And we load OffsetArrays.jl in the tests so this bug wont even show up !!!

[sethaxen]

Haha I have a grumpy rant over at OffsetArrays.jl about this.

JuliaArrays/OffsetArrays.jl#306

Yeah I came across this after hours of trying to debug an issue in DimUnitRange while writing it. Turns out OffsetArray's type piracy caused the problem.

I found the function that makes OffsetArrays work:
https://github.com/JuliaArrays/OffsetArrays.jl/blob/add7611dd3b9afc767f9a1a1816de6cec7a70c00/src/OffsetArrays.jl#L320-L329 . All types in this signature are from Base.

We could make this work for us for the most common cases without piracy by defining the methods:

# works for all cases where the DimArray is the wrapper
Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{DimUnitRange,Vararg{Union{DimUnitRange,Integer}}}) where T
# works for all cases where a 1-3-dimensional array is the wrapper.
Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{Integer,DimUnitRange,Vararg{Union{DimUnitRange,Integer}}}) where T
Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{Integer,Integer,DimUnitRange,Vararg{Union{DimUnitRange,Integer}}}) where T
Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{Integer,Integer,Integer,DimUnitRange,Vararg{Union{DimUnitRange,Integer}}}) where T

[mcabbott]

The issue seems to be that similar is not defined for a mixture of Int and DimUnitRange. I'm not certain why stack ends up mixing these two, since the similar docstring documents that you can provide integer sizes or axes.

Notice that stack isn't mixing up the two. _typed_stack at abstractarray.jl:2791 is calling similar with ::DimensionalData.Dimensions.DimUnitRange, ::OneTo, ::OneTo, which are the inner & outer axes.

That falls back to method at abstractarray.jl:838 which allows a mixture, added in JuliaLang/julia#27038.

julia> stack(da2)
ERROR: MethodError: no method matching similar(::DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, ::Type{Float64}, ::Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Int64, Int64})
...
Stacktrace:
 [1] similar(::DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, ::Type{Float64}, ::DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, ::Base.OneTo{Int64}, ::Base.OneTo{Int64})
   @ Base ./abstractarray.jl:838
 [2] _typed_stack(::Colon, ::Type{Float64}, ::Type{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, A::Matrix{DimArray{Float64, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.NoLookup{Base.OneTo{Int64}}}}, Tuple{}, Vector{Float64}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Aax::Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}})
   @ Base ./abstractarray.jl:2791

[rafaqz]

Yeah, seems like a good fix for now. It may also be worth making an issue in base? thanks for clarifying @mcabbott

[sethaxen]

That falls back to method at abstractarray.jl:838 which allows a mixture, added in JuliaLang/julia#27038.

From the comment there:

# but we don't want to require all AbstractArray subtypes to dispatch on Base.OneTo. So instead we
# define this method to convert supported axes to Ints, with the expectation that an offset array
# package will define a method with dims::Tuple{Union{Integer, UnitRange}, Vararg{Union{Integer, UnitRange}}}

Defining a method with this signature would be type piracy. Maybe by UnitRange they mean a type named UnitRange defined in that package? But still, don't the Unions here introduce an ambiguity?

[mcabbott]

That reads as if it's designed for exactly one OffsetArray package.

To allow arbitrary packages to supply weird axes, in any combination, I don't think multiple dispatch can really work. There would need to be some disambiguation mechanism, perhaps peeling them off one-by-one like to_indices does.

To just allow this package & Base, I don't think you should overload similar with a mix of integers and ranges, but rather catch it earlier at OneTo. Something like:

Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{OneTo,DimUnitRange, ...}) =  ...
Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{DimUnitRange, OneTo, ...}) =  ...
Base.similar(A::AbstractArray, ::Type{T}, shape::Tuple{DimUnitRange,DimUnitRange, ...}) = ...

[sethaxen]

Thanks @mcabbott for the input! I opened an issue on Base Julia: JuliaLang/julia#48736

[sethaxen]

Here's another example on v1.9 where stack fails at this method:

julia> da = DimArray(randn(5, 2, 10), (X(1:5), Y(1:2), Z(1:10)))
5×2×10 DimArray{Float64,3} with dimensions: 
  X Sampled{Int64} 1:5 ForwardOrdered Regular Points,
  Y Sampled{Int64} 1:2 ForwardOrdered Regular Points,
  Z Sampled{Int64} 1:10 ForwardOrdered Regular Points
[:, :, 1]
     1          2
 1  -0.102949  -2.11069
 2   1.79828    0.146289
 3  -0.327256  -0.426165
 4  -0.712312   0.524461
 5   0.370998  -1.08046
[and 9 more slices...]

julia> slices = eachslice(da; dims=X)
5-element Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1} with indices DimensionalData.Dimensions.DimUnitRange(Base.OneTo(5), X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}([1, 2, 3, 4, 5])):
 [-0.10294865417938587 0.5698825736323255 … -1.5378023712827968 1.0307246759708226; -2.110688097558331 0.0011790991422298577 … -0.6593841156030812 -0.11688915410161158]
 [1.7982779792641022 0.13907155933046084 … -0.07504633767741557 -0.25039500080737614; 0.14628901474635184 0.9524727566035762 … -0.19643334603411086 -0.009078044117570114]
 [-0.3272564704019956 -0.575908906586761 … -0.050182744578040304 -0.22420385548518917; -0.42616544757027924 0.8776995896758558 … -0.8566502141518096 1.4463988149826326]
 [-0.7123122057852254 0.20799454493477493 … 0.8374795127610608 -1.3053013623918044; 0.5244605108649851 -0.49963337952532505 … -0.2164155911041088 -0.23920201930054835]
 [0.3709978605647305 -2.1742176908724895 … 0.019797323120978306 0.8758089159274857; -1.0804569058541924 -0.44105352240311374 … 0.18673505188968414 -0.6334841199845449]

julia> da_slices = rebuild(da; data=slices, dims=dims(axes(slices)))
5-element DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata},1} with dimensions: 
  X Sampled{Int64} 1:5 ForwardOrdered Regular Points
 1  [-0.102949 0.569883 … -1.5378 1.03072; -2.11069 0.0011791 … -0.659384 -0.116889]
 2  [1.79828 0.139072 … -0.0750463 -0.250395; 0.146289 0.952473 … -0.196433 -0.00907804]
 3  [-0.327256 -0.575909 … -0.0501827 -0.224204; -0.426165 0.8777 … -0.85665 1.4464]
 4  [-0.712312 0.207995 … 0.83748 -1.3053; 0.524461 -0.499633 … -0.216416 -0.239202]
 5  [0.370998 -2.17422 … 0.0197973 0.875809; -1.08046 -0.441054 … 0.186735 -0.633484]

julia> stack(slices)
2×10×5 DimArray{Float64,3} with dimensions: 
  Y Sampled{Int64} 1:2 ForwardOrdered Regular Points,
  Z Sampled{Int64} 1:10 ForwardOrdered Regular Points,
  X Sampled{Int64} 1:5 ForwardOrdered Regular Points
[:, :, 1]
     1         2          3         4          5         …   7        8           9         10
 1  -0.102949  0.569883   0.355713  0.75725   -0.851722     -1.38102  0.0402863  -1.5378     1.03072
 2  -2.11069   0.0011791  1.26613   0.396935   2.40101      -0.42801  0.355688   -0.659384  -0.116889
[and 4 more slices...]

julia> stack(da_slices)
ERROR: MethodError: no method matching similar(::SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, ::Type{Float64}, ::Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}})

Closest candidates are:
  similar(::SubArray, ::Type, ::Tuple{Vararg{Int64, N}} where N)
   @ Base subarray.jl:65
  similar(::Base.Broadcast.Broadcasted{Base.Broadcast.DefaultArrayStyle{N}}, ::Type{ElType}, ::Any) where {N, ElType}
   @ Base broadcast.jl:212
  similar(::Base.Broadcast.Broadcasted{Base.Broadcast.ArrayConflict}, ::Type{ElType}, ::Any) where ElType
   @ Base broadcast.jl:217
  ...

Stacktrace:
 [1] similar(A::DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, T::Type, shape::Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, DimensionalData.Dimensions.DimUnitRange{Int64, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}})
   @ DimensionalData ~/.julia/packages/DimensionalData/bJAtd/src/array/array.jl:132
 [2] similar(::DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, ::Type{Float64}, ::DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, ::DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, ::DimensionalData.Dimensions.DimUnitRange{Int64, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}})
   @ Base ./abstractarray.jl:838
 [3] _typed_stack(::Colon, ::Type{Float64}, ::Type{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, A::DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Aax::Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}})
   @ Base ./abstractarray.jl:2791
 [4] _typed_stack(::Colon, ::Type{Float64}, ::Type{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, A::DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2787
 [5] _stack(dims::Function, #unused#::Base.HasShape{1}, iter::DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2777
 [6] _stack(dims::Colon, iter::DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2769
 [7] stack(iter::DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}; dims::Function)
   @ Base ./abstractarray.jl:2737
 [8] stack(iter::DimArray{DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Slices{DimArray{Float64, 3, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{}, Array{Float64, 3}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, Tuple{Int64, Colon, Colon}, Tuple{DimensionalData.Dimensions.DimUnitRange{Int64, Base.OneTo{Int64}, X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}}, DimArray{Float64, 2, Tuple{Y{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}, Z{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, Tuple{X{DimensionalData.Dimensions.LookupArrays.Sampled{Int64, UnitRange{Int64}, DimensionalData.Dimensions.LookupArrays.ForwardOrdered, DimensionalData.Dimensions.LookupArrays.Regular{Int64}, DimensionalData.Dimensions.LookupArrays.Points, DimensionalData.Dimensions.LookupArrays.NoMetadata}}}, SubArray{Float64, 2, Array{Float64, 3}, Tuple{Int64, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}, true}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata}, 1}, DimensionalData.NoName, DimensionalData.Dimensions.LookupArrays.NoMetadata})
   @ Base ./abstractarray.jl:2737
 [9] top-level scope
   @ REPL[38]:1

In this case, the error is caused by nested DimUnitRanges in the outer DimArray but not the inner:

julia> axes(da_slices[1]) isa Tuple{Vararg{Dimensions.DimUnitRange{Int,Base.OneTo{Int}}}}
true

julia> axes(da_slices) isa Tuple{Vararg{Dimensions.DimUnitRange{Int,<:Dimensions.DimUnitRange{Int}}}}
true

So when we hit this line, the un-nested DimUnitRanges get converted to Base.OneTo, and the rest stay DimUnitRange.

DimensionalData.jl/src/array/array.jl

Line 138 in 8cd137f

data = similar(parent(A), T, map(parent, shape))

Perhaps this should be solved again by a similar method that dispatches on Union{DimUnitRange,Base.OneTo}, but I wonder if this issue of nested DimUnitRanges should be handled elsewhere instead.