How do I change the dimension of an array

General Usage
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1

If I have an array with the size of 33x180x360, how do I change it to the size of 33x360x180?

Thank you.

2

If the order of elements remains unchanged, you may use reshape:

julia> A = [i+j+k for i in 1:4, j in 1:3, k in 1:2]
4×3×2 Array{Int64, 3}:
[:, :, 1] =
 3  4  5
 4  5  6
 5  6  7
 6  7  8

[:, :, 2] =
 4  5  6
 5  6  7
 6  7  8
 7  8  9

julia> reshape(A, 3, 4, 2)
3×4×2 Array{Int64, 3}:
[:, :, 1] =
 3  6  6  6
 4  4  7  7
 5  5  5  8

[:, :, 2] =
 4  7  7  7
 5  5  8  8
 6  6  6  9

On the other hand, if you’re trying to permute the last two axes, you may use permutedims:

julia> permutedims(A, (1, 3, 2))
4×2×3 Array{Int64, 3}:
[:, :, 1] =
 3  4
 4  5
 5  6
 6  7

[:, :, 2] =
 4  5
 5  6
 6  7
 7  8

[:, :, 3] =
 5  6
 6  7
 7  8
 8  9
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3

I think permutedims is what I need. Many thanks!

4

Another suggestion would be to have a good look at Images package eco-system. These packages would be tackling a lot of the stuff you seem to be on and have done some nice work on it.

For example, for the question in the post look at:

julia> using Images

help?> PermutedDimsArray
search: PermutedDimsArray permuteddimsview

  PermutedDimsArray(A, perm) -> B

  Given an AbstractArray A, create a view B such that the dimensions appear to be permuted. Similar
  to permutedims, except that no copying occurs (B shares storage with A).

  See also permutedims, invperm.

  Examples
  ≡≡≡≡≡≡≡≡≡≡

  julia> A = rand(3,5,4);
  
  julia> B = PermutedDimsArray(A, (3,1,2));
  
  julia> size(B)
  (4, 3, 5)
  
  julia> B[3,1,2] == A[1,2,3]
  true
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