SciML
Vector of differently sized arrays
julia> size(VectorOfArray([randn(2), randn(4)]))
(2, 2)
This is surprising at least, and runs the risk of subtle bugs if one tries to iterate on the VectorOfArray as if it was a multi-dimensional array.
This is something we need and use in DiffEq for models which dynamically change over time.
Oh I need it too and was pleasantly surprised to see that it worked. The thing is the size method: should it be undefined, or perhaps check that the sizes are all equal at runtime?
Yeah... I don't know. It's something I've never figured out. size is useful in a lot of cases, but when you have a ragged array it's wrong. Maybe it's worth doing a runtime check.
size is useful in a lot of cases
Thought so too but probably it's a code smell for generic code that doesn't assume much about array types. It's only really good for plain old arrays
Yes, is used when doing conversions like Array(x), but there are issues with it we haven't solved.
julia> vec(VectorOfArray([rand(3), rand(5)]))
ERROR: ArgumentError: number of rows of each array must match (got [3, 5])
Stacktrace:
[1] _typed_hcat(#unused#::Type{Float64}, A::Vector{Vector{Float64}})
@ Base ./abstractarray.jl:1518
[2] reduce(#unused#::typeof(hcat), A::Vector{Vector{Float64}})
@ Base ./abstractarray.jl:1572
[3] Array
@ ~/.julia/dev/RecursiveArrayTools/src/vector_of_array.jl:11 [inlined]
[4] convert
@ ./array.jl:532 [inlined]
[5] vec(VA::VectorOfArray{Float64, 2, Vector{Vector{Float64}}})
@ RecursiveArrayTools ~/.julia/dev/RecursiveArrayTools/src/vector_of_array.jl:120
[6] top-level scope
@ REPL[11]:1
This can be triggered e.g. when solving a SteadyStateProblem
