def test_cartesianvector_dist_cubic():
v = CartesianVector(1, -4.5)
d = v.dist_cubic()
assert d == 1 + 4.5
v2 = CartesianVector(1, -3.5)
d = v.dist_cubic(v2)
assert d == 1
def test_cartesianvector_dist_cubic():
v = CartesianVector(1, -4.5)
d = v.dist_cubic()
assert d == 1 + 4.5
v2 = CartesianVector(1, -3.5)
d = v.dist_cubic(v2)
assert d == 1
