def test_dual_channel_kraus1():
"""Test dual_channel on a channel represented as Kraus operators (1d list, CP map)."""
kraus_1 = np.array([[1, 0, 1j, 0]])
kraus_2 = np.array([[0, 1, 0, 1j]])
expected_res = [np.array([[1, 0, -1j, 0]]).T, np.array([[0, 1, 0, -1j]]).T]
res = dual_channel([kraus_1, kraus_2])
bool_mat = np.isclose(res, expected_res)
np.testing.assert_equal(np.all(bool_mat), True)
def test_dual_channel_choi_dims():
"""Test dual_channel on a Choi matrix with different input and output dimensions."""
j = np.array([
[1, -1j, 0, 0, 0, 1],
[1j, -1, 0, 0, 0, -1j],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[1, 1j, 0, 0, 0, 1],
])
expected_res = np.array([
[1, 0, 0, 1j, 0, 1],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[-1j, 0, 0, -1, 0, 1j],
[0, 0, 0, 0, 0, 0],
[1, 0, 0, -1j, 0, 1],
])
res = dual_channel(j, [3, 2])
bool_mat = np.isclose(res, expected_res)
np.testing.assert_equal(np.all(bool_mat), True)
def test_dual_channel_invalid_input():
"""Invalid input"""
with np.testing.assert_raises(ValueError):
dual_channel([0])
def test_dual_channel_unspecified_dims():
"""If the size of the Choi matrix is not a perfect square,
the dimensions of the input and output spaces must be specified."""
with np.testing.assert_raises(ValueError):
j = np.arange(36).reshape(6, 6)
dual_channel(j)
def test_dual_channel_not_matrix():
"""If the channel is represented as an array, it must be two-dimensional (a matrix)."""
with np.testing.assert_raises(ValueError):
j = np.array([1, 2, 3, 4])
dual_channel(j)
def test_dual_channel_nonsquare_matrix():
"""If the channel is represented as a Choi matrix, it must be square."""
with np.testing.assert_raises(ValueError):
j = np.array([[1, 2, 3, 4], [4, 3, 2, 1]])
dual_channel(j)
def test_dual_channel_choi_square():
"""Test dual_channel on a 9x9 Choi matrix, inferring dims=[3,3]."""
res = dual_channel(choi(1, 1, 0))
bool_mat = np.isclose(res, choi(1, 0, 1))
np.testing.assert_equal(np.all(bool_mat), True)