def test_even_validation(self):
"""Test that the graph_embed decomposition raises exception if not even number of rows"""
A = np.random.rand(5, 5) + 1j * np.random.rand(5, 5)
A += A.T
with pytest.raises(ValueError,
match="must have an even number of rows/columns"):
williamson(A)
def test_pure_state(self, create_cov, hbar, tol):
"""Test pure state"""
n = 3
O = omega(n)
cov, _ = create_cov(np.zeros([n]))
Db, S = williamson(cov)
nbar = np.diag(Db) / hbar - 0.5
# check decomposition is correct
assert np.allclose(S @ Db @ S.T, cov, atol=tol, rtol=0)
# check nbar = 0
assert np.allclose(nbar, 0, atol=tol, rtol=0)
# check S is symplectic
assert np.allclose(S @ O @ S.T, O, atol=tol, rtol=0)
def test_mixed_state(self, create_cov, hbar, tol):
"""Test mixed state"""
n = 3
O = omega(n)
nbar_in = np.abs(np.random.rand(n))
cov, _ = create_cov(nbar_in)
Db, S = williamson(cov)
nbar = np.diag(Db) / hbar - 0.5
# check decomposition is correct
assert np.allclose(S @ Db @ S.T, cov, atol=tol, rtol=0)
# check nbar
assert np.allclose(sorted(nbar[:n]), sorted(nbar_in), atol=tol, rtol=0)
# check S is symplectic
assert np.allclose(S @ O @ S.T, O, atol=tol, rtol=0)
def test_symmetric_validation(self):
"""Test that the graph_embed decomposition raises exception if not symmetric"""
A = np.random.rand(5, 5) + 1j * np.random.rand(5, 5)
with pytest.raises(ValueError, match="matrix is not symmetric"):
williamson(A)
def test_vacuum_state(self, tol):
"""Test vacuum state"""
V = np.identity(4)
Db, S = williamson(V)
assert np.allclose(Db, np.identity(4), atol=tol, rtol=0)
assert np.allclose(S, np.identity(4), atol=tol, rtol=0)
def test_positive_definite_validation(self):
"""Test that the graph_embed decomposition raises exception if not positive definite"""
A = np.diag([-2, 0.1, 2, 3])
with pytest.raises(ValueError,
match="matrix is not positive definite"):
williamson(A)