def test_u_star_1d_nonzero_mean(uvw_and_known_u_star_nonzero_mean):
"""Test friction velocity in 1D with a non-zero-mean time series."""
u, v, w, u_star_true = uvw_and_known_u_star_nonzero_mean
assert_almost_equal(friction_velocity(u, w, perturbation=False),
u_star_true['uw'])
assert_almost_equal(friction_velocity(u, w, v=v, perturbation=False),
u_star_true['uwvw'])
def test_u_star_1d_nonzero_mean(uvw_and_known_u_star_nonzero_mean):
"""Test friction velocity in 1D with a non-zero-mean time series."""
u, v, w, u_star_true = uvw_and_known_u_star_nonzero_mean
assert_almost_equal(friction_velocity(u, w, perturbation=False),
u_star_true['uw'])
assert_almost_equal(friction_velocity(u, w, v=v, perturbation=False),
u_star_true['uwvw'])
def test_u_star_2d_axis_first_nonzero_mean(uvw_and_known_u_star_nonzero_mean):
"""Test friction velocity in 2D with a non-zero-mean time series along the first axis."""
u, v, w, u_star_true = uvw_and_known_u_star_nonzero_mean
u = np.array([u, u, u]).transpose()
v = np.array([v, v, v]).transpose()
w = np.array([w, w, w]).transpose()
assert_almost_equal(friction_velocity(u, w, perturbation=False,
axis=0), u_star_true['uw'])
assert_almost_equal(friction_velocity(u, w, v=v, perturbation=False,
axis=0), u_star_true['uwvw'])
def test_u_star_2d_axis_last_zero_mean(uvw_and_known_u_star_zero_mean):
"""Test friction velocity in 2D with a zero-mean time series along the last axis."""
u, v, w, u_star_true = uvw_and_known_u_star_zero_mean
u = np.array([u, u, u])
v = np.array([v, v, v])
w = np.array([w, w, w])
assert_almost_equal(friction_velocity(u, w, perturbation=False,
axis=-1), u_star_true['uw'])
assert_almost_equal(friction_velocity(u, w, v=v, perturbation=False,
axis=-1), u_star_true['uwvw'])
