Function v_dot_u

prefinal.py:131–132

(v, u)

def v_dot_u(v, u):
    return v[0]*u[0] + v[1]*u[1] + v[2]*u[2]
def len_v(v):
    return sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2])