Sum subarrays of a Matrix.
Hi Mathworks community! Could someone give me a hand? I'm having trouble trying to sum parts of the arrays of a matrix. Let's say I have the following matrix A of r rows and c columns (rxc). A = [1,2,3,4,5,6,7,8,9; 10,11,12,13,14,15,16,17,18; 19,20,21,22,23,24,25,26,27] And what I would like to to is to divide each array in n subarrays (n=3) and sum each of those subarrays. In this case, it would be the sum of every three positions. Getting an output suchs as: out = [5,15,24; 33,42,51; 60,69,78]
Kshitij Singh answered .
2025-11-20
transpose(reshape(sum(reshape(A',3,[])),3,[]))
Or
transpose(cell2mat(cellfun(@sum,mat2cell(A',[3,3,3],3),'unif',0)))