MATLAB: How to vectorize this simple for loop

Question

Given a 3D array:

    a = rand(10, 10, 10);

and an integer index array:

    idx = ceil(10 * rand(3, 1000));

is there a way (a clever indexing trick?) to vectorize the following loop:

    b = zeros(1, 1000);
    for i = 1:1000
        b(i) = a(idx(1, i), idx(2, i), idx(3, i));
    end

Thanks!

Answer 1

ii=sub2ind(size(a),idx(:,1),idx(:,2),idx(:,3));
b =a(ii)