README.md

ProductArrays

The ProductArrays is a lazy form of

collect(Iterators.product(vectors...))

i.e. it is an AbstractArray in contrast to Iterators.product(vectors...). So is accessible with getindex and gets default Array implementations for free. In particular it can be passed to Base.PermutedDimsArray for lazy permutation and vec() to obtain a lazy Base.ReshapedArray.

Examples:

julia> A = productArray(1:3, (:a,:b))
3×2 ProductArrays.ProductArray{Tuple{UnitRange{Int64}, Tuple{Symbol, Symbol}}, Tuple{Int64, Symbol}, 2}:
 (1, :a)  (1, :b)
 (2, :a)  (2, :b)
 (3, :a)  (3, :b)

julia> vec(A)
6-element reshape(::ProductArrays.ProductArray{Tuple{UnitRange{Int64}, Tuple{Symbol, Symbol}}, Tuple{Int64, Symbol}, 2}, 6) with eltype Tuple{Int64, Symbol}:
 (1, :a)
 (2, :a)
 (3, :a)
 (1, :b)
 (2, :b)
 (3, :b)

julia> sizeof(A) == sizeof(1:3) + sizeof((:a,:b))
true

julia> A == collect(Iterators.product(1:3, (:a,:b)))
true

Related Packages

A list compiled by Alexander Plavin (@aplavin)

Packages focusing on grids/products specifically

• StructuredGrids.jl (the same promise but fails on edge cases)
• LazyGrids.jl (does something else: tuple of grids not grid of tuples)
• RectiGrids.jl (focus on keyed/labeled arrays - fails on the same edge cases as StructuredGrids.jl)

Parts of other packages

• ProductView of SplitApplyCombine.jl
• [WIP] ProductedArrays JuliaArrays/MappedArrays.jl#42