Julia Language for Loops Multidimensional iteration
Example
In Julia, a for loop can contain a comma (,) to specify iterating over multiple dimensions. This acts similarly to nesting a loop within another, but can be more compact. For instance, the below function generates elements of the Cartesian product of two iterables:
function cartesian(xs, ys)
for x in xs, y in ys
produce(x, y)
end
end
Usage:
julia> collect(@task cartesian(1:2, 1:4))
8-element Array{Tuple{Int64,Int64},1}:
(1,1)
(1,2)
(1,3)
(1,4)
(2,1)
(2,2)
(2,3)
(2,4)
However, indexing over arrays of any dimension should be done with eachindex, not with a multidimensional loop (if possible):
s = zero(eltype(A))
for ind in eachindex(A)
s += A[ind]
end
