With NumPy I can access a subdimensional array from a multidimensional array without knowing the dimension of the original array:
import numpy as np
a = np.zeros((2, 3, 4)) # A 2-by-3-by-4 array of zeros
a[0] # A 3-by-4 array of zeros
but with Julia I am at a loss. It seems that I must know the dimension of a to do this:
a = zeros(2, 3, 4) # A 2-by-3-by-4 array of zeros
a[1, :, :] # A 3-by-4 array of zeros
What should I do if I don't know the dimension of a?
selectdim gives a view of what you are looking for,
a = zeros(2, 3, 4)
selectdim(a,1,1)
If you want to iterate over each "subdimensional array" in order, you can also use eachslice:
julia> a = reshape(1:24, (2, 3, 4));
julia> eachslice(a, dims = 1) |> first
3×4 view(reshape(::UnitRange{Int64}, 2, 3, 4), 1, :, :) with eltype Int64:
1 7 13 19
3 9 15 21
5 11 17 23
julia> for a2dims in eachslice(a, dims = 1)
@show size(a2dims)
end
size(a2dims) = (3, 4)
size(a2dims) = (3, 4)
