MATLAB: If statements

Question

I have a set of data with 996 columns and 998 rows. Could I construct if statements so that each column returns 0 if all values are positive or all values are negative, and 1 if there is some combination of the two?

Answer 1

A = rand(998,996); % Use your data in place of A
B = not(all(A>0) | all(A<0));