Matching two matrices by sign

    A=[1,1,-3;2,-1,4];
    B=[2,4,-2; 2,-1,-3];

How can I get that the sign of B(2,3) is different than the sign of A(2,3)? i.e. the signs of A and B should be the same. I want to find if I have any observation in B that doesn't match the sign of the respective value in A;

Answer 1

[Azzi Abdelmalek]

sign(B(2,3))==sign(A(2,3))

For the whole matrices

A=[1,1,-3;2,-1,4];
B=[2,4,-2; 2,-1,-3];
[ii,jj]=find(sign(A)==sign(B))

[Cedric]

or

 isOk = all( sign(A(:)) == sign(B(:)) ) ;