MATLAB: How to sample n elements from each column of a matrix

Question

I have this matrix:

A =

1 5 9 13 17

2 6 10 14 18

3 7 11 15 19

4 8 12 16 20

I want to sample n elments with replacement from each column. For instance, if n=2, I would like to get something like:

B =

2 8 10 14 20

4 8 9 15 17

I tried datasample, but it samples entire rows. Is there an efficient way to do this without using a for loop?

Answer 1

B=A(randi(size(A,1),2,size(A,2))+(0:size(A,2)-1)*size(A,1));