MATLAB: Check if all vector elements have same sign

Question

Is there an efficient (and easy) way to check if all elements of a vector have the same sign (not caring about zero values)?

I can think of applying sign(v) and checking if all elements is equal to the first one after having removed all elements where sign(v)==0, but this fells somewhat clumsy. Is there an easier or more efficient way?

Answer 1

true if all non-zero elements of V have the same sign:

~any(diff(sign(V(V~=0))))