def test_calculate_WAW(self):
"""Test that the calculate_WAW method calculates correctly"""
const = 2
A = 0.1767767 * np.ones((4, 4))
params = const * np.ones(4)
waw = StrawberryFieldsGBS.calculate_WAW(params, A)
assert np.allclose(waw, const * A)
def test_calculate_covariance(self):
"""Test that the calculate_covariance method returns the correct covariance matrix for a
fixed example."""
x = np.sqrt(0.5)
A = np.array([[0, x], [x, 0]])
cov = StrawberryFieldsGBS.calculate_covariance(A, 2)
target = np.array(
[
[3.0, 0.0, 0.0, 2.82842712],
[0.0, 3.0, 2.82842712, 0.0],
[0.0, 2.82842712, 3.0, 0.0],
[2.82842712, 0.0, 0.0, 3.0],
]
)
assert np.allclose(cov, target)
def test_calculate_z_inv(self):
"""Test that the _calculate_z_inv returns correctly on a fixed example"""
A = 0.1767767 * np.ones((4, 4))
z_inv = StrawberryFieldsGBS._calculate_z_inv(A)
assert np.allclose(z_inv, 1 / np.sqrt(2))
def test_calculate_n_mean_singular_values_large(self):
"""Test that calculate_n_mean raises a ValueError when not all of the singular values are
less than one"""
A = np.ones((4, 4))
with pytest.raises(ValueError, match="Singular values of matrix A must be less than 1"):
StrawberryFieldsGBS.calculate_n_mean(A)
def test_calculate_n_mean(self):
"""Test that calculate_n_mean computes the mean photon number correctly"""
A = 0.1767767 * np.ones((4, 4))
n_mean = StrawberryFieldsGBS.calculate_n_mean(A)
assert np.allclose(n_mean, 1)