Combination of rows of two different matrices
Sorry if this is a repeated question but I failed to find an answer myself. I have two matrices: A = [-0.6, -0.2; -60, 2; 6, -20]; B = [-0.4, -0.8; -40, 8; 4, -80]; I want to find all the possible combinations of sum of each row (sum of individual elements of a row) of A with each row of B, i.e., my desired result is (order does not matter): ans = [-1, -1; -40.6, 7.8; 3.4, -80.2; -60.4, 1.2; -100, 10; -56, -78; 5.6, -20.8; -34, -12; 10, -100]; which is a 9 x 2 matrix resulting from 9(=3 x 3 )possible combinations of A and B.
Kshitij Singh answered .
2025-11-20
Feels non-ideal. Any better solution?
>> C=A(:,1)+B(:,1)';
D=A(:,2)+B(:,2)';
reshape([C(:),D(:)],[],2)
ans =
-1.0000 -1.0000
-60.4000 1.2000
5.6000 -20.8000
-40.6000 7.8000
-100.0000 10.0000
-34.0000 -12.0000
3.4000 -80.2000
-56.0000 -78.0000
10.0000 -100.0000
better one
>> m=size(A,1);
ind1=repmat(1:m,1,m);
ind2=repelem(1:m,m);
A(ind1,:)+B(ind2,:)
ans =
-1.0000 -1.0000
-60.4000 1.2000
5.6000 -20.8000
-40.6000 7.8000
-100.0000 10.0000
-34.0000 -12.0000
3.4000 -80.2000
-56.0000 -78.0000
10.0000 -100.0000