Multidimensional array: how to extract several dimensions at same time?

Hi all,

Imagine there is a 4d array like this:

arrayA = rand(5, 4, 3, 2);

Now I need a new arrayB which contains all elements of dimension 1, 2, 4 and only first elements of dimension 3, such that the new array is:

size(arrayB)
ans = 
     5  4  1  2

how can I do this?

Answer 1

[Stephen23]

arrayA(:,:,1,:)

as explained in the introductory tutorials and documentation:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

https://www.mathworks.com/help/matlab/math/matrix-indexing.html

[Xiaohan Du]

Thank you!