# MATLAB: Sum of matrices and loop

convolution

For example
x = [1 2 3 4 5 6; 7 8 9 10 11 12;13 14 15 16 17 18;1 2 3 4 5 6]
I want sum of [1 2 3 7 8 9] which is = 72 and [4 5 6 10 11 12 15 16 17 18] which is 114 , then [1 2 3 1 1 1 2 4 3] which is 18 and so on

result = conv2(x, ones(3), 'valid');