def test_speed():
"""Test calculating wind speed."""
u = np.array([4., 2., 0., 0.])
v = np.array([0., 2., 4., 0.])
speed = get_wind_speed(u, v)
s2 = np.sqrt(2.)
true_speed = np.array([4., 2 * s2, 4., 0.])
assert_array_almost_equal(true_speed, speed, 4)
def test_scalar_speed():
"""Test wind speed with scalars."""
s = get_wind_speed(-3., -4.)
assert_almost_equal(s, 5., 3)
