vecgcd

Computes the GCD of the elements of the integer vector V.

G = VECGCD(V) is the greatest common divisor of the elements of the integer
vector V. V must be a row or a column vector of integers.We define gcd([]) = 1 and gcd([0 0 ... 0]) = 0.

I believe that this routine is faster than recursively computing GCDs and the algorithm is simple enough to be used for pencil and paper calculations.