In doing econometrics i need to check if a spicy numerically determined matrix has full rank.
Is it reliable to just evaluate rank or should one do tricks as rank(A)=rank(A'A) so that one can evaluate det(A'A) and see if it is close to zero. If so, when is the determinant so close to zero that one would consider it to not have full rank?
p.s. I'm new to this forum, sorry if you broke some rules and I really don't know which tag to apply.